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Journal of Manufacturing and Materials Processing
Number of Followers: 0  Open Access journalISSN (Online) 2504-4494 Published by MDPI  [255 journals]
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- JMMP, Vol. 7, Pages 51: Linear Friction Welding of Abrasion Resistant CPM
15V Tool Steel to an Alloyed Carbon Shovel-Tooth Steel
Authors: Oscar A. Zambrano, Javad Gholipour, Priti Wanjara, Jiaren (Jimmy) Jiang
First page: 51
Abstract: Alloyed carbon steels used in ground engaging tools (GETs), such as shovel-teeth, can withstand high working loads, but their wear resistance is inadequate for abrasive operations in the mining industry. Different approaches to engineer protective surfaces on GETs for improving wear resistance have been developed over the years, but the effectiveness of the applied abrasive resistance layer has been limited by the maximum thickness that can be realized reliably. Considering wear requirements for GETs to reach end-of-life without requiring unscheduled maintenance for after-failure repairs, a minimum thickness of 25 mm has been postulated for the abrasive resistance surface layer, which is roughly four times greater than the thickness of overlays currently manufacturable by weld deposition technologies. Thus, in this study, a novel approach for conceiving thick abrasive surface protection layers—that are unlimited in thickness—on GETs is presented. The method involves applying solid-state linear friction welding and was demonstrated to be feasible for joining abrasive-resistant CPM 15V tool steel to an alloyed carbon steel (extracted from a shovel-tooth). After welding, the integrity of the joints was examined microscopically using optical and scanning electron microscopy to understand the microstructural characteristics, as well as through microhardness and tensile testing to evaluate the performance. A high frequency welding condition was identified that provided integral bonding (i.e., without voids and cracking) at the interface between the CPM 15V tool steel and alloyed carbon shovel-tooth steel. In the as-welded condition, the measured hardness profiles across the joints showed minor softening of both base materials in the heat-affected zone just adjacent to the weld center; this was attributed to over aging of the tempered martensite structures of CPM 15V tool steel and alloyed carbon shovel-tooth steel. The maximum tensile strength of the joint (553 MPa) provides evidence for the viability of linear friction welding technology for joining protective surface materials on GETs.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-02-21
DOI: 10.3390/jmmp7020051
Issue No: Vol. 7, No. 2 (2023)
- JMMP, Vol. 7, Pages 52: Influence of ECAP Parameters on the Structural,
Electrochemical and Mechanical Behavior of ZK30: A Combination of
Experimental and Machine Learning Approaches
Authors: Mahmoud Shaban, Abdulrahman I. Alateyah, Mohammed F. Alsharekh, Majed O. Alawad, Amal BaQais, Mokhtar Kamel, Fahad Nasser Alsunaydih, Waleed H. El-Garaihy, Hanadi G. Salem
First page: 52
Abstract: Several physics-based models have been utilized in material design for the simulation and prediction of material properties. In this study, several machine-learning (ML) approaches were used to construct a prediction model to analyze the influence of equal-channel angular pressing (ECAP) parameters on the microstructural, corrosion and mechanical behavior of the biodegradable magnesium alloy ZK30. The ML approaches employed were linear regression, the Gaussian process, and support vector regression. For the optimization of the alloy’s performance, experiments were conducted on ZK30 billets using different ECAP routes, channel angles, and number of passes. The adopted ML model is an adequate predictive model which agreed with the experimental results. ECAP die angles had an insignificant effect on grain refinement, compared to the route type. ECAP via four passes of route Bc (rotating the sample 90° on its longitudinal axis after each pass in the same direction) was the most effective condition producing homogenous ultrafine grain distribution of 1.92 µm. Processing via 4-Bc and 90° die angle produced the highest hardness (97-HV) coupled with the highest tensile strength (344 MPa). The optimum corrosion rate of 0.140 mils penetration per year (mpy) and the optimum corrosion resistance of 1101 Ω·cm2 resulted from processing through 1-pass using the 120°-die. Grain refinement resulted in reducing the corrosion rates and increased corrosion resistance, which agreed with the ML findings.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-02-22
DOI: 10.3390/jmmp7020052
Issue No: Vol. 7, No. 2 (2023)
- JMMP, Vol. 7, Pages 53: Manufacturing Method for Large Cylindrical Worm
Gear Set of ISO Type I on Universal CNC Machine Tools
Authors: Kazumasa Kawasaki, Isamu Tsuji
First page: 53
Abstract: Large cylindrical worm gear set of ISO type I are manufactured using endmill tools on universal CNC machine tools. This manufacturing method requires neither special gear-generating machines nor special tools. The tooth flank forms of ISO type I cylindrical worm gears are involute helicoids as a standard. The targeted theoretical tooth flanks of the worm and the mating worm wheel are determined based on a tooth contact analysis (TCA) of such worm gear set. The cutting conditions of the worm are determined after the offset distance between the worm axis, and the central axis of the endmill tool is calculated. Afterward, the worm is manufactured by controlling only two axes on machine tools using a swarf milling method by use of the side of the endmill tool under the determined conditions. Meanwhile, the targeted theoretical tooth flanks of the mating worm wheel are modeled in 3-dimensional computer-aided design software, and the worm wheel is manufactured by a swarf milling method in a computer-aided manufacturing process. The comparison of experimental and analytical tooth contact patterns indicates almost no difference between the two tooth contact patterns.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-02-24
DOI: 10.3390/jmmp7020053
Issue No: Vol. 7, No. 2 (2023)
- JMMP, Vol. 7, Pages 54: Investigation of the Formability of Cryogenic
Rolled AA6061 and Its Improvement Using Artificial Aging Treatment
Authors: Abbas Sadeghi, Ernst Kozeschnik, Farid R. Biglari
First page: 54
Abstract: Cryogenic rolling is one of the essential severe plastic deformation processes to manufacture high-strength aluminum sheets with excellent formability limits. The present work characterizes the formability of AA6061 for cryogenic rolling before and after artificial aging. Nakajima method based on ISO standard is used to measure formability. Samples are aged in the range of 100 °C to 150 °C. Artificial aging at 150 °C is found to be the optimum temperature for achieving a good combination of strength and formability. Over the course of artificial aging, strength improved up to 40%, where the original value of 250 MPa for cryo-rolled condition increased to 350 MPa after 50 h of aging at 150 °C, and the formability of the cryo-rolled sample improved especially for multi-axial forming condition.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-02-27
DOI: 10.3390/jmmp7020054
Issue No: Vol. 7, No. 2 (2023)
- JMMP, Vol. 7, Pages 55: Effect of the Sintering Conditions on the Neck
Growth during the Powder Bed Fusion with Electron Beam (PBF-EB) Process
Authors: Giovanni Rizza, Manuela Galati, Paolo Antonioni, Luca Iuliano
First page: 55
Abstract: A distinctive characteristic of the powder bed fusion with electron beam (PBF-EB) process is the sintering of the powder particles. For certain metallic materials, this is crucial for the success of the subsequent step, the melting, and, generally, the whole process. Despite the sintering mechanisms that occur during the PBF-EB process being similar to well-known powder metallurgy, the neck growth rates are significantly different. Therefore, specific analyses are needed to understand the influence of the PBF-EB process conditions on neck growth and neck growth rate. Additionally, some aspects, such as the rigid body motion of the particles during the sintering process, are still challenging to analyze. This work systematically investigated the effects of different particle diameters and particle diameter ratios. Additionally, the impact of the rigid body motion of the particles in the sintering was analyzed. This work demonstrated that the sintering results significantly depended on the EB-PBF process conditions.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-03-01
DOI: 10.3390/jmmp7020055
Issue No: Vol. 7, No. 2 (2023)
- JMMP, Vol. 7, Pages 56: Real-Time In-Process Evaluation of Spatter Area
and Depth of Aluminium Surface in a Pulsed Laser Ablation Process Using
Received Radio Frequency Power from Plasma Plumes
Authors: Mahdieh Samimi, Hassan Hosseinlaghab, Patrick J. McNally
First page: 56
Abstract: During the pulsed laser ablation of metals, as well as other materials, the development of a plasma plume close to the ablated surface leads to the emission of radio frequency energy. In this paper, we describe a process for analysing the received radio frequency power (RFP) for an aluminium (Al) surface ablation process in atmosphere using picosecond laser pulses at a wavelength of 1064 nm. The analysis of the RFP was carried out on two sets of experiments, where two parameters of the laser (repetition rate of laser (RRL) and power of laser (PL)) were varied while other parameters remained constant. In addition to the RFP measurement during the laser processing, the spatter area (SA), which is defined in this paper, and the depth of the ablated hole were measured post-process using a 3D microscope. It was observed that there is a direct relationship between (RFP)2 and SA. Accordingly, an appropriate RF calibration was performed, which leads to the definition of a quantity called the RF regulation % (RFR%). By comparing the RFR and PL/RRL variations, to which the laser beam fluence is proportional in these experiments, a diagnostic process (i.e., flowchart) for real-time depth evaluation was proposed and experimentally confirmed. This diagnostic process can indicate if the depth of the laser ablated crater is less than or exceeds a predetermined depth, which in this study was set to 15 µm. It is also demonstrated that the SA variation can be estimated in real-time by analysing the received RF power and, secondly, the depth of ablation can be measured in real time using a combination of information from the received RF power and laser parameters.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-03-03
DOI: 10.3390/jmmp7020056
Issue No: Vol. 7, No. 2 (2023)
- JMMP, Vol. 7, Pages 57: A Comprehensive Review of High-Pressure
Laser-Induced Materials Processing, Part III: Laser Reactive Synthesis
within Diamond Anvil Cells
Authors: Mohamad E. Alabdulkarim, Wendy D. Maxwell, Vibhor Thapliyal, James L. Maxwell
First page: 57
Abstract: The synthesis of advanced materials at high pressures has been an area of growing research interest for several decades. This article is the third in a three-part series that reviews Laser Materials Processing Within Diamond Anvil Cells (L-DACs). Part III focuses on the practice of Laser Reactive Synthesis Within Diamond Anvil Cells (LRS-DAC). During LRS-DAC processing, chemicals are precompressed within diamond anvil cells, then microscale chemical reactions are induced by focused laser beams. The method is distinguished from the well-known Laser-Heated Diamond Anvil Cell (LH-DAC) technique (see Part I) through the existence of chemical precursors (reactants), end-products, and quantifiable changes in chemical composition upon reaction. LRS-DAC processing provides at least three new degrees of freedom in the search for advanced materials (beyond adjusting static pressures and temperatures), namely: laser-excitation/cleavage of chemical bonds, time-dependent reaction kinetics via pulsed lasers, and pressure-dependent chemical kinetics. All of these broaden the synthetic phase space considerably. Through LRS-DAC experimentation, it is possible to obtain increased understanding of high-pressure chemical kinetics—and even the nature of chemical bonding itself. Here, LRS-DAC experimental methods are reviewed, along with the underlying chemistry/physics of high-pressure microchemical reactions. A chronology of key events influencing the development of LRS-DAC systems is provided, together with a summary of novel materials synthesised, and unusual chemical reactions observed. Current gaps in knowledge and emerging opportunities for further research are also suggested.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-03-03
DOI: 10.3390/jmmp7020057
Issue No: Vol. 7, No. 2 (2023)
- JMMP, Vol. 7, Pages 58: Investigation of LCD 3D Printing of Carbon Fiber
Composites by Utilising Central Composite Design
Authors: Raveen Mohammed Salih, Abdulkader Kadauw, Henning Zeidler, Rezo Aliyev
First page: 58
Abstract: The technology of additive manufacturing (AM) has transformed the fields of machinery, aerospace, and electronics. Adopting cost-effective, precise, and rapid procedures in AM is one of the major concerns of today’s industry. Stereolithography is a promising AM technique that is thought to meet these requirements. However, the fact that materials printed with stereolithography do not have good mechanical properties limits their application, such as in biomedicine and aerospace. Previous studies have shown the shortcomings of stereolithography printers. This research focuses on enhancing the mechanical characteristics of the polymer resin used in stereolithography (SLA)-like liquid crystal display (LCD) 3D printers by fabricating a new AM composite material with carbon fibers. For this reason, chopped carbon fibers (0.1 mm size) at amounts of 0.25 wt% and 0.5 wt% have been used with Acrylonitrile butadiene styrene (ABS)-like photopolymer transparent resin during the printing process, and three different print layer thicknesses were tested. For the design of the experiment (DoE), Q-DAS software was used to analyze the resulting data. A tensile-testing machine was utilized to determine the ultimate strength using the ASTM D638 standard. The results show an increase in the ultimate strength by adding carbon fiber to some extent, but after a certain percentage of carbon fiber added, the strength drops off.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-03-04
DOI: 10.3390/jmmp7020058
Issue No: Vol. 7, No. 2 (2023)
- JMMP, Vol. 7, Pages 59: A Hybrid Approach to Surface Engineering Based on
Laser Texturing and Coating
Authors: Matilde Barili, Adrian H. A. Lutey, Corrado Sciancalepore, Luca Romoli
First page: 59
Abstract: A hybrid approach based on laser texturing and surface coating for the combined modification of surface topography and chemistry has been proposed to provide a versatile approach for the development of functional surfaces. The experimental procedure comprised nanosecond pulsed laser texturing of AISI 304 stainless steel substrates followed by the deposition of thin (<1 µm) coatings with two different technologies, sol–gel deposition and PE-CVD, with the aim of independently modifying the surface topography and chemical composition. Laser texturing with different scanning strategies achieved a variety of surface morphologies with an arithmetic mean height (Sa) in the range 0.2–6.4 µm. Coatings were then deposited on laser-textured substrates to quantify the deposition effectiveness and the influence of the coating type and parameters on the resulting surface topography and chemistry. Sol–gel deposition was found to be more effective with a polymeric interlayer, improving adhesion between the coating and the textured surface; however, this also led to an increase in Sa of approximately 0.5 µm. Conversely, PE-CVD was effective in modifying the surface chemistry while inducing no measurable differences in surface morphology, effectively decoupling the texturing and coating processes. Analysis of the surface chemistry showed a higher concentration of silicon for PE-CVD than sol–gel deposition and therefore a more pronounced effect on the surface chemical composition.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-03-04
DOI: 10.3390/jmmp7020059
Issue No: Vol. 7, No. 2 (2023)
- JMMP, Vol. 7, Pages 60: Laser Tracker-Based on-the-Fly Machine Tool
Calibration without Real-Time Synchronization
Authors: Mark P. Sanders, Matthias Bodenbenner, Philipp Dahlem, Dominik Emonts, Benjamin Montavon, Robert H. Schmitt
First page: 60
Abstract: Consistent high volumetric performance of machine tools is an essential requirement for high-quality machining. Periodic machine tool calibration ensures said performance and allows for timely corrective actions preventing scrap or rework. Reducing the duration of the calibration process decreases associated cost through non-productive downtime and allows for data acquisition in thermal real-time. The authors enhance an indirect calibration method based on measuring points within the machine volume using a laser tracker by removing the necessity for standstill. To circumvent requiring high fidelity space and time synchronization between metrology system and machine tool, only deviations perpendicular to the path are considered. To do so, the 3D laser tracker data are rotationally transformed such that one axis aligns with the motion direction and can subsequently be omitted as input data for the system of equations solving for geometric errors. Due to the absence of unique measurement-point-to-machine-point mapping, data alignment between nominal path and measurement data is proposed as an iterative alignment process of points to path. The method is tested simulatively and experimentally. It demonstrated conformity to the simulation as well as to the pre-existing calibration method based on laser trackers and shows good agreement with the direct calibration device API XD Laser.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-03-07
DOI: 10.3390/jmmp7020060
Issue No: Vol. 7, No. 2 (2023)
- JMMP, Vol. 7, Pages 61: Experimental Research on the Dynamic Stability of
Internal Turning Tools for Long Overhangs
Authors: Wallyson Thomas Alves da Silva, Jozef Peterka, Tomas Vopat
First page: 61
Abstract: The roughness origin of machined surfaces is caused by the following physical causes: the copying of the shape and the roughness of the cutting part of the tool into the workpiece, the existence of vibration of the tool, and the existence of the build-up edge (BUE) on the cutting edge. The current work aims to analyze the vibration amplitude of tools. The roughness of the machined surfaces was observed on hardened steel workpieces. Internal turning technology was used, and we used several different boring bars (steel; carbide; tuned mass damper—TMD; impact damper—ID) and an internal turning operation using CBN inserts. We revealed the tool’s slenderness coefficient (TSC) values for stable cutting operations. For the steel holder, the value is TSC ≤ 4.25; for the carbide holder, the value is TSC ≤ 5.5; for the TMD holder, the value is 4.5 ≤ TSC ≤ 7.75; and for the ID holder, the value is TSC ≤ 8. The surface’s roughness was practically unchanged within the limits of stable machining. However, if the tools exceed the presented stable limits, vibration and roughness parameters deteriorate significantly; an example parameter (Ra) deteriorated from 0.350 μm to 1.832 μm.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-03-09
DOI: 10.3390/jmmp7020061
Issue No: Vol. 7, No. 2 (2023)
- JMMP, Vol. 7, Pages 62: An Innovative Approach of Surface Polishing for
SRF Cavity Applications
Authors: Oleksandr Hryhorenko, Claire Z. Antoine, William Magnin, Monish Rajkumar, François Brisset, Stephane Guilet, David Longuevergne
First page: 62
Abstract: The damage layer produced during the Niobium sheets and cavity fabrication processes is one of the main reasons why cavities have to undergo an extensive surface preparation process to recover optimal superconducting properties. Today, this includes the use of lengthy, costly, and dangerous conventional polishing techniques as buffered chemical polishing (BCP), or electro-polishing (EP). We propose to avoid or at least significantly reduce the use of acids. We developed a novel method based on metallographic polishing of Nb sheets, consisting of 2–3 steps. We demonstrate that this surface processing procedure could be transferred to large dimensions and an industrialized scale thanks to the limited number of steps and its compatibility with standard lapping polishing devices.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-03-09
DOI: 10.3390/jmmp7020062
Issue No: Vol. 7, No. 2 (2023)
- JMMP, Vol. 7, Pages 63: Thermal Intra-Layer Interaction of Discretized
Fractal Exposure Strategies in Non-Isothermal Powder Bed Fusion of
Polypropylene
Authors: Samuel Schlicht, Dietmar Drummer
First page: 63
Abstract: Additive manufacturing of material systems sensitive to heat degradation represents an essential prerequisite for the integration of novel functionalized material systems in medical applications, such as the hybrid processing of high-performance thermoplastics and gelling polymers. For enabling an inherent process stability under non-isothermal conditions at reduced ambient temperatures in laser-based additive manufacturing, maintaining a homogeneous layer formation is of vital significance. To minimize crystallization-induced deflections of formed layers while avoiding support structures, the temporal and spatial discretization of the melting process is combined with the subsequent quenching of the polymer melt due to thermal conduction. Based on implementing superposed, phase-shifted fractal curves as the underlying exposure structure, the locally limited temporal and spatial discretization of the exposure process promotes a mesoscale compensation of crystallization shrinkage and thermal distortion, enabling the essential homogeneous layer formation. For improving the understanding of local parameter-dependent thermal intra-layer interactions under non-isothermal processing conditions, geometric boundary conditions of distinct exposure vectors and the underlying laser power are varied. Applying polypropylene as a model material, a significant influence of the spatial distance of fractal exposure structures on the thermal superposition of distinct exposure vectors can be derived, implicitly influencing temporal and temperature-dependent characteristics of the material crystallization and the emerging thermal material exposure. Furthermore, the formation of sub-focus structures can be observed, contributing to the spatial discretization of the layer formation, representing a decisive factor that influences the structure formation and mesoscopic part properties in non-isothermal powder bed fusion of polymers. Consequently, the presented approach represents a foundation for the support-free, accelerated non-isothermal additive manufacturing of both polymers and metals, demonstrating a novel methodology for the mesoscale compensation of thermal shrinkage.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-03-10
DOI: 10.3390/jmmp7020063
Issue No: Vol. 7, No. 2 (2023)
- JMMP, Vol. 7, Pages 64: Recoater-Induced Distortions and Build Failures in
Selective Laser Melting of Thin-Walled Ti6Al4V Parts
Authors: Xufei Lu, Michele Chiumenti, Miguel Cervera, Mehdi Slimani, Iban Gonzalez
First page: 64
Abstract: Additively manufactured thin-walled structures through selective laser melting (SLM) are of great interest in achieving carbon-neutral industrial manufacturing. However, residual stresses and warpages as well as recoater crashes often occur in SLM, leading to the build failure of parts, especially for large-scale and lightweight geometries. The challenge in this work consists of investigating how the recoater affects the warpage and (sometimes) causes the failure of different thin-walled Ti6Al4V parts (wall thickness of 1.0 mm). All these parts are printed on the same platform using a commercial SLM machine. After the loose powder removal and before the cutting operation, a 3D-scanner is used to obtain the actual warpage of each component. Next, an in-house coupled thermo-mechanical finite element model suitable for the numerical simulation of the SLM process is enhanced to consider the recoater effects. This numerical framework is calibrated to predict the thin-walled warpage as measured by the 3D-scanner. The combination of numerical predictions with experimental observations facilitates a comprehensive understanding of the mechanical behavior of different thin-walled components as well as the failure mechanism due to the recoater. The findings show that the use of a higher laser energy input causes larger residual stresses and warpage responsible for the recoater crashes. Finally, potential solutions to mitigate the warpage and the recoater crashes in the SLM of lightweight structures are assessed using the validated model.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-03-13
DOI: 10.3390/jmmp7020064
Issue No: Vol. 7, No. 2 (2023)
- JMMP, Vol. 7, Pages 65: Joining Strength of Self-Piercing Riveted
Vibration-Damping Steel and Dissimilar Materials
Authors: Keong Hwan Cho, Jin Hyeok Joo, Min Gyu Kim, Dong Hyuck Kam, Jedo Kim
First page: 65
Abstract: A vibration-damping steel panel is used for lightweight vehicles to block any noise subjected to the passenger cabin replacing heavy fiber-based insulators. Conventional weld joining methods often encounter problems due to the presence of viscoelastic compounds reducing the joint quality and making the joining process unproductive. In this work, we present experimental results that show the self-piercing riveting (SPR) process can be used to produce high-quality joints between vibration-damping steel and (i) commonly used steel alloy (SPFC590DP), (ii) carbon-fiber-reinforced-plastic (CFRP) panels. Various die shapes are used to investigate the resulting interlock width and bottom thickness of the joints and tensile shear load tests were performed to evaluate the joining strength. The results show that high-quality joints between vibration-damping steel and the steel alloy are possible for all the dye types and panel configurations, used in this study, producing up to 6.2 kN of tensile shear load. High-quality joints were also possible with CFRP producing up to 4.0 kN, however, acceptable joints were formed only when the CFRP panels were on top during the riveting process due to severe cracking.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-03-13
DOI: 10.3390/jmmp7020065
Issue No: Vol. 7, No. 2 (2023)
- JMMP, Vol. 7, Pages 66: Laser In Situ Synthesis of Gradient Fe-Ti
Composite during Direct Energy Deposition Process
Authors: Igor Shishkovsky, Nina Kakovkina, Ekaterina Nosova, Alexander Khaimovich
First page: 66
Abstract: The suitability of the direct energy deposition process of exothermic powders Fe-Ti in joining dissimilar metals to produce small parts of a complete shape for various applications is considered. The procedure of the direct energy deposition of commercial pure iron and titanium in various proportions and the modes of the process are described. Optical microscopy and SEM with EDX analysis, X-ray analysis, and microhardness measurements of laser-fabricated intermetallics are applied. Intermetallic compounds of FeTi, Fe2Ti, eutectoids, complex titanium oxides and nitrides, and iron carbides are found. Interlayer and trans-layer cracks and pores are observed. A microhardness growth from 150 HV to 900 HV was obtained for all samples due to the precipitation of brittle intermetallic phases in the gradient Fe-Ti system during the DED. The dispersion of microhardness values becomes significant in Ti-rich areas; there, pores and cracks are found. The revealed structure features are considered in relation to published results and explained. Increased concentrations of Ti to Ti + Fe = 3:1 on the Fe- and Fe + Ti -substrate with concentrations of Ti + Fe = 1:1 and Ti + Fe = 1:3 lead to increasing hardness and its distribution, but also increases in residual microstress. Recommendations are given to reduce the power during the direct energy deposition of titanium layers and to apply Fe-substrate, which can reduce residual stress, pores, and cracks.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-03-14
DOI: 10.3390/jmmp7020066
Issue No: Vol. 7, No. 2 (2023)
- JMMP, Vol. 7, Pages 67: Tribological Properties of Multilayer CVD Coatings
Deposited on SiAlON Ceramic Milling Inserts
Authors: Luke Osmond, Ian Cook, Tom Slatter
First page: 67
Abstract: This work characterises the structure and mechanical properties, such as adhesion, of two different chemical vapour deposition (CVD) coatings deposited onto silicon aluminium oxynitride (Si3N4 + Al2O3 + Y2O3) round (RNGN) milling cutter tooling inserts. These inserts are often known by the trade abbreviation “SiAlON”. Wear was produced on the inserts using unidirectional sliding (pin-on-disc type) and scratch testing. Two coatings were investigated: a multilayer CVD coating (Coating A) with a composition of TiN + TiCN + Al2O3 and a bilayer coating (Coating B) with a composition of Al2O3 + TiN. Microstructural analysis was conducted after wear testing and Coating B demonstrated high stability when subjected to high alternating shear and tensile stresses, high abrasion resistance and very high adhesion to the SiAlON ceramic insert substrate when compared to Coating A. Coating A demonstrated a low capacity to distribute alternating shear and tensile stresses during the pin-on-disc and scratch testing, which led to failure. The scratch and pin-on-disc results from this study correlate highly with completed machining insert wear analysis that has used Coating A and Coating B SiAlON inserts to machine aged Inconel 718.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-03-15
DOI: 10.3390/jmmp7020067
Issue No: Vol. 7, No. 2 (2023)
- JMMP, Vol. 7, Pages 68: The Experimental and Modeling Study of Femtosecond
Laser-Ablated Silicon Surface
Authors: Yi-Hsien Liu, Chung-Wei Cheng
First page: 68
Abstract: In this study, monocrystalline silicon was ablated by a single 1030 nm femtosecond laser pulse. Variable laser fluence (0.16–3.06 J/cm2) was used, and two ablation thresholds (0.8 and 1.67 J/cm2) were determined experimentally. A two-temperature model was established based on the dynamic optical model, the carrier density model, and the phase explosion model for comparison with experimental results. The melting (0.25 J/cm2) and vaporization (0.80 J/cm2) thresholds were determined when the lattice temperature reached melting and boiling points, so as to overcome the latent heat. Finally, the ablation depth was calculated using the phase explosion model, and the ablation threshold was 1.5 J/cm2. The comparisons show that the proposed model can predict the ablation depth obtained by a single femtosecond laser pulse.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-03-16
DOI: 10.3390/jmmp7020068
Issue No: Vol. 7, No. 2 (2023)
- JMMP, Vol. 7, Pages 69: Experimental Investigation on the Cutting of
Additively Manufactured Ti6Al4V with Wire-EDM and the Analytical Modelling
of Cutting Speed and Surface Roughness
Authors: Manuela Galati, Paolo Antonioni, Flaviana Calignano, Eleonora Atzeni
First page: 69
Abstract: Additive manufacturing (AM) technologies for metallic materials allow for the manufacturing of high-performance components optimised in weight, geometry, and mechanical properties. However, several post-processing operations are needed after production, including removing parts from the build platform. This operation is essential and must be performed rapidly, precisely, and with a good surface finishing. This work presents an experimental investigation of the wire electric discharge machining (W-EDM) process of Ti6Al4V specimens produced by AM technologies. The influence of cutting parameters is analysed compared to the material produced by conventional technology. Models of cutting speed and surface roughness obtained by a W-EDM are inferred from the collected data. Remarkably, the results show that the manufacturing process used to produce the components plays a crucial role in defining the final surface roughness and the most significant parameters affecting the machining performance.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-03-16
DOI: 10.3390/jmmp7020069
Issue No: Vol. 7, No. 2 (2023)
- JMMP, Vol. 7, Pages 14: Friction Resistance of Uncured Carbon/Epoxy
Prepregs under Thermoforming Process Conditions: Experiments and Modelling
Authors: David Aveiga, David Garoz Gómez, Davide Mocerino, Bernardo López-Romano, Carlos González
First page: 14
Abstract: The numerous prepreg characteristics benefit industries like the aerospace and automotive ones, producing a wide range of high-performance components for primary or secondary applications. Parts production is usually assisted by a thermoforming process in which the prepreg is heated and reshaped employing a moulding system. The ply-ply and ply-tool sliding behaviours in the Thermoforming govern the defects generation, such as wrinkles, making its study a crucial step. This work analyses ply-ply and ply-tool friction coefficients for UD AS4/8552 Carbon/Epoxy prepreg. A pull-out test method was employed to determine the friction coefficients at different velocities, pressures, and temperatures related to the thermoforming process conditions, supplying a detalied report of friction parameters and mechanisms. The measurements of the interlaminar resin layer thickness and the surface roughness geometry resulted respectively in a range of 11–14 μm and 3–4 μm were taken into account in the Lubrication Theory approach to developing an analytical model. Based on the Stribeck curve and Reynolds equation for a viscous fluid, the developed model accurately predicts friction coefficients for prepreg composite materials in the process and contact conditions mentioned below.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-01-01
DOI: 10.3390/jmmp7010014
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 15: Powder Bed Fusion of Multimaterials
Authors: Thywill Cephas Dzogbewu, Deon de Beer
First page: 15
Abstract: Powder bed fusion (PBF) process has been used successfully to produce 3D structures using single material properties. The current industrial demand is to use the technology to produce 3D structures of multimaterial properties. An electron beam melting (EBM) process has been used to produce 3D structures of multimaterial properties. However, due to the large beam size, the EBM process lacks geometrical accuracy, requiring a large machining allowance. A laser powder bed fusion (LPBF) process could be used to produce multimaterials with geometrical precision. However, the thermal gradient within the molten pool and the thermophysical difference between the multimaterials leads to defects (weak interfacial bonds, interlayer and intralayer cracks). Other challenges such as poor powder delivery system, powder cross-contamination, and lack of appropriate data processing software for producing 3D multimaterial structures are not yet fully resolved. Nonetheless, there have been encouraging results for producing the next generational multimaterial 3D components of intricate geometrical characteristics.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-01-01
DOI: 10.3390/jmmp7010015
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 16: An Experimental and Numerical Study on Aluminum
Alloy Tailor Heat Treated Blanks
Authors: Rui Pereira, Nuno Peixinho, Vítor Carneiro, Delfim Soares, Sara Cortez, Sérgio L. Costa, Vítor Blanco
First page: 16
Abstract: Information is presented on the conceptualization, experimental study, and numerical process simulation of tailor heat treated aluminum alloy blanks. This concept is intended to improve the forming behavior of aluminum parts in challenging conditions. The implementation requires precise control of laser heat treatment parameters within a suitable industrial framework. The study details material properties, heat treatment parameters, and experimental results for the strength and elongation properties of an AA6063-T6 aluminum alloy. Constitutive modeling is applied using the Hocket–Sherby equation, which allowed us to establish a correlation between laser heat treatment maximum temperature and the corresponding material softening degree. Based on the generated flow stress–strain curves, a numerical simulation of a representative case study was performed with Abaqus finite element software highlighting potential improvements of tailor heat treated blanks (THTB). The influence and effectiveness of heat-affected zone (HAZ) dimensions and material softening were analyzed.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-01-04
DOI: 10.3390/jmmp7010016
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 17: An Objective Metallographic Analysis Approach
Based on Advanced Image Processing Techniques
Authors: Xabier Sarrionandia, Javier Nieves, Beñat Bravo, Iker Pastor-López, Pablo G. Bringas
First page: 17
Abstract: Metallographic analyses of nodular iron casting methods are based on visual comparisons according to measuring standards. Specifically, the microstructure is analyzed in a subjective manner by comparing the extracted image from the microscope to pre-defined image templates. The achieved classifications can be confused, due to the fact that the features extracted by a human being could be interpreted differently depending on many variables, such as the conditions of the observer. In particular, this kind of problem represents an uncertainty when classifying metallic properties, which can influence the integrity of castings that play critical roles in safety devices or structures. Although there are existing solutions working with extracted images and applying some computer vision techniques to manage the measurements of the microstructure, those results are not too accurate. In fact, they are not able to characterize all specific features of the image and, they cannot be adapted to several characterization methods depending on the specific regulation or customer. Hence, in order to solve this problem, we propose a framework to improve and automatize the evaluations by combining classical machine vision techniques for feature extraction and deep learning technologies, to objectively make classifications. To adapt to the real analysis environments, all included inputs in our models were gathered directly from the historical repository of metallurgy from the Azterlan Research Centre (labeled using expert knowledge from engineers). The proposed approach concludes that these techniques (a classification under a pipeline of deep neural networks and the quality classification using an ANN classifier) are viable to carry out the extraction and classification of metallographic features with great accuracy and time, and it is possible to deploy software with the models to work on real-time situations. Moreover, this method provides a direct way to classify the metallurgical quality of the molten metal, allowing us to determine the possible behaviors of the final produced parts.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-01-04
DOI: 10.3390/jmmp7010017
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 18: Evaluation of the Metallurgical Quality of Nodular
Cast Iron in the Production Conditions of a Foundry
Authors: Rafał Dwulat, Krzysztof Janerka
First page: 18
Abstract: The aim of this research was to determine the factors affecting the metallurgical quality of cast iron during serial production of castings using a campaign cupola and a holding furnace. The problem to be solved, which was to obtain cast iron with the required mechanical properties while reducing the internal porosity, results from the foundry’s need to increase the metallurgical quality of the alloy. The increasing difficulty and complicated constructions of castings, for which it is not possible to introduce risers at the stage of technological design, make the stage of proper preparation of cast iron the only way to obtain castings without shrinkage defects. The article presents the results of the study of physicochemical and mechanical properties, microstructure and shrinkage tendency of ductile iron depending on the charge materials used, the amount of Mg used during spheroidization and the type of final inoculants. Step castings and wedge tests were produced on a vertical molding line. The spheroidization was carried out by injecting a core wire containing Mg alloy into the cast iron. The final inoculation of 0.2% was performed using a pneumatic dispenser equipped with a vision system to control the effectiveness of the inoculation. The ITACA Meltdeck thermal analysis system was used to study the physicochemical properties of the initial cast iron, and the ITACA X system to analyze the state of the final cast iron on the molding line. Mechanical tests were performed on samples cut from a stepped casting, and microstructure tests were carried out using a light microscope and a scanning electron microscope. The results of thermal analyses show that increasing the share of pig iron at the expense of steel increases the minimum solidification temperature of eutectic, and thus, increases the potential for graphite nucleation in cast iron. Increasing the nucleation potential can be obtained by adding anthracite, FeSi and SiC. A very important factor in obtaining cast iron of high metallurgical quality is the possible limitation during spheroidization of the length of the core wire containing Mg, which is a carbide-forming element. The lower the initial sulfur level, the greater the possibility of reducing the amount of cored wire. The inoculants containing Ce and Bi were the most advantageous final inoculants from the point of view of obtaining the best microstructure parameters and plastic properties of cast iron.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-01-04
DOI: 10.3390/jmmp7010018
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 19: Influence of the Process Parameters on the
Properties of Cu-Cu Ultrasonic Welds
Authors: Koen Faes, Rafael Nunes, Sylvia De De Meester, Wim De De Waele, Felice Rubino, Pierpaolo Carlone
First page: 19
Abstract: Ultrasonic welding (USW) is a solid-state welding process based on the application of high frequency vibration energy to the workpiece to produce the internal friction between the faying surface and the local heat generation required to promote the joining. The short welding time and the low heat input, the absence of fumes, sparks or flames, and the automation capacity make it particularly interesting for several fields, such as electrical/electronic, automotive, aerospace, appliance, and medical products industries. The main problems that those industries have to face are related to the poor weld quality due the improper selection of weld parameters. In the present work, 0.3 mm thick copper sheets were joined by USW varying the welding time, pressure, and vibration amplitude. The influence of the process variables on the characteristics of the joints and weld strength is investigated by using the analysis of variance. The results of the present work indicate that welding time is the main factor affecting the energy absorbed during the welding, followed by the pressure and amplitude. The shear strength, on the other hand, resulted mostly influenced by the amplitude, while the other parameters have a limited effect. Regardless the welding configuration adopted, most welds registered a failure load higher than the base material pointing out the feasibility of the USW process to join copper sheets.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-01-07
DOI: 10.3390/jmmp7010019
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 20: Image Analysis Based Evaluation of Print Quality
for Inkjet Printed Structures
Authors: Tim Horter, Holger Ruehl, Wenqi Yang, Yu-Sheng Chiang, Kerstin Glaeser, André Zimmermann
First page: 20
Abstract: Inkjet printing for printed electronics is a growing market due to its advantages, including scalability, various usable materials and its digital, pixel based layout design. An important quality factor is the wetting of the ink on the substrate. This article proposes a workflow to evaluate the print quality of specific layouts by means of image analysis. A self-developed image analysis software, which compares a mask with the actual layout, enables a pixel-based analysis of the wetting behavior by the implementation of two parameters called over- and underwetting rate. A comparison of actual and targeted track widths can be performed for the evaluation of different parameters, such as the tested plasma treatment, drop spacing (DS) and substrate temperature. To prove the functionality of the image analyses tool, the print quality of Au structures inkjet printed on cyclic olefin copolymer (COC) substrates was studied experimentally by varying the three previously mentioned parameters. The experimental results showed that the wetting behavior of Au ink deposited on COC substrates influences various line widths differently, leading to higher spreading for smaller line widths. The proposed workflow is suitable for identifying and evaluating multiple tested parameter variations and might be easily adopted for printers for in-process print quality control in industrial manufacturing.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-01-10
DOI: 10.3390/jmmp7010020
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 21: Three-Body Abrasive Wear-Resistance
Characteristics of a 27Cr-Based 3V-3Mo-3W-3Co Multicomponent White Cast
Iron with Different Ti Additions
Authors: Riki Hendra Purba, Kazumichi Shimizu, Kenta Kusumoto
First page: 21
Abstract: A multicomponent white cast iron containing 5 wt.% each of Cr, V, Mo, W, and Co (MWCI) is known to have excellent wear-resistance properties due to the precipitation of some very hard carbides, such as MC, M2C, and M7C3. However, it seems possible to improve the wear resistance of MWCI by increasing the carbide volume fraction (CVF). Thus, 27 wt.% Cr based on 3 wt.% each of V, W, Mo, and Co was simultaneously added into the white cast iron. To avoid the tendency of carbides to crack due to high M7C3 precipitation levels, titanium (0–2 wt.% Ti) was also added. A rubber wheel abrasive machine test according to the ASTM G65 standard with two different abrasive particle sizes (average: 75 and 300 μm) was used to evaluate the wear characteristics of the alloy. The results show that the wear resistance of these new alloys (0Ti, 1Ti, and 2Ti) is lower than that of MWCI in small silica sand, owing to the lower hardness. However, a different condition is present in large silica sand, for which the abrasive wear resistance of MWCI is lower than that of the 0Ti and 1Ti specimens. In addition, TiC precipitation effectively refined the size of M7C3 carbides and reduced their cracking tendency. Thus, the wear resistance of 1Ti is comparable to that of 0Ti, although it has a lower hardness factor. However, the wear resistance of the alloy significantly decreased following the addition of Ti by more than 1 wt.% due to the lower hardness and CVF. Therefore, it can be said that the abrasive wear characteristics of the alloy are not only affected by the hardness, but also by the micro-structural constituents (type, size, and volume fraction of carbides) and silica sand size.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-01-10
DOI: 10.3390/jmmp7010021
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 22: Multi-Response Optimization of Ti6Al4V Support
Structures for Laser Powder Bed Fusion Systems
Authors: Antonios Dimopoulos, Ilias Zournatzis, Tat-Hean Gan, Panagiotis Chatzakos
First page: 22
Abstract: Laser Powder Bed Fusion (LPBF) is one of the most commonly used and rapidly developing metal Additive Manufacturing (AM) technologies for producing optimized geometries, complex features, and lightweight components, in contrast to traditional manufacturing, which limits those characteristics. However, this technology faces difficulties with regard to the construction of overhang structures and warping deformation caused by thermal stresses. Producing overhangs without support structures results in collapsed parts, while adding unnecessary supports increases the material required and post-processing. The purpose of this study was to evaluate the various support and process parameters for metal LPBF, and propose optimized support structures to minimize Support Volume, Support Removal Effort, and Warping Deformation. The optimization approach was based on the Design of Experiments (DOE) methodology and multi-response optimization, by 3D printing and studying overhang geometries from 0° to 45°. For this purpose, EOS Titanium Ti64 Grade 5 powder was used, a Ti6Al4V alloy commonly employed in LPBF. For 0° overhangs, the optimum solution was characterized by an average Tooth Height, large Tooth Top Length, low X, Y Hatching, and high Laser Speed, while for 22.5° and 45° overhangs, it was characterized by large Tooth Height, low Tooth Top Length, high X, Y Hatching, and high Laser Speed.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-01-13
DOI: 10.3390/jmmp7010022
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 23: Modeling of Surface Roughness in Honing Processes
by Using Fuzzy Artificial Neural Networks
Authors: Irene Buj-Corral, Piotr Sender, Carmelo J. Luis-Pérez
First page: 23
Abstract: Honing processes are abrasive machining processes which are commonly employed to improve the surface of manufactured parts such as hydraulic or combustion engine cylinders. These processes can be employed to obtain a cross-hatched pattern on the internal surfaces of cylinders. In this present study, fuzzy artificial neural networks are employed for modeling surface roughness parameters obtained in finishing honing operations. As a general trend, main factors influencing roughness parameters are grain size and pressure. Mean spacing between profile peaks at the mean line parameter, on the contrary, depends mainly on tangential and linear velocity. Grain Size of 30 and pressure of 600 N/cm2 lead to the highest values of core roughness (Rk) and reduced valley depth (Rvk), which were 1.741 µm and 0.884 µm, respectively. On the other hand, the maximum peak-to-valley roughness parameter (Rz) so obtained was 4.44 µm, which is close to the maximum value of 4.47 µm. On the other hand, values of the grain size equal to 14 and density equal to 20, along with pressure 600 N/cm2 and both tangential and linear speed of 20 m/min and 40 m/min, respectively, lead to the minimum values of core roughness, reduced peak height (Rpk), reduced valley depth and maximum peak-to-valley height of the profile within a sampling length, which were, respectively, 0.141 µm, 0.065 µm, 0.142 µm, and 0.584 µm.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-01-15
DOI: 10.3390/jmmp7010023
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 24: Fundamental Investigations to Evaluate the
Influence of Notching Processes on a Subsequent Cyclic Bending Process for
the Production of Wire Cores
Authors: Alina Biallas, Sophia Ohmayer, Marion Merklein
First page: 24
Abstract: The production of wire cores by notch rolling and cyclic bending promises an ecologically and economically efficient manufacturing option for steel fibers. The paper at hand evaluates the influence of wire strips on cyclic bending by applying rolled wire strips of DP600 sheet metal (t0 = 0.8 mm) and a new cyclic bending testing tool. Analysis of material separation with varying parameters, rolling gap d and bending angle β, proves the interdependency of both process step, but indicates reduced adjustability of the notch rolling process. To enable better adjustability of the wire strip’s characteristics and analysis of their effects, wire strip production in the laboratory by notch stamping instead of rolling is aspired. The prior interaction analysis states the web height b, the notch angle α, and the hardening distribution as relevant wire strip’s characteristics to be replicated. Based on experimental analysis, an equivalent of notch rolling by notch stamping is deduced by considering the web height b identical for stamping and rolling, by adjusting the tool’s notch angle αt based on an equation considering geometric evaluations of α, and by taking advantage of the asymmetric hardening distribution of the outer notch which is comparable to rolled wire strip.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-01-17
DOI: 10.3390/jmmp7010024
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 25: Strain-Based Fatigue Experimental Study on
Ti–6Al–4V Alloy Manufactured by Electron Beam Melting
Authors: Alberto David Pertuz-Comas, Octavio Andrés González-Estrada, Elkin Martínez-Díaz, Diego Fernando Villegas-Bermúdez, Jorge Guillermo Díaz-Rodríguez
First page: 25
Abstract: Additive manufacturing (AM) by electron beam melting (EBM) is a technique used to manufacture parts by melting powder metal layer-by-layer with an electron beam in a high vacuum, thereby generating a 3D topology. This paper studies the low-cycle fatigue of Ti–6Al–4V specimens obtained by EBM. Static tests were carried out according to ASTM E8 for a yield stress of 1023 MPa, a fracture stress of 1102 MPa, and a maximum tensile strength of 1130 MPa with a maximum true normal strain at fracture εmax = 9.0% and an elastic modulus of 120 GPa. Then, fatigue tests were conducted at a load inversion rate of R = −1. It was observed that the material exhibited plastic strain softening, which was attributed to the Bauschinger effect. These results were plotted on a strain vs. life (ε−N) curve using the Ong version of the Coffin–Manson rule and the Baumel–Seager and Meggiolaro–Castro rules. The results were compared to forged Ti–6Al–4V alloys. The cyclic stress–strain behavior was described with the Ramberg–Osgood model. Finally, the fracture surface was analyzed using scanning electron microscopy (SEM) to observe the formation of primary cracks. The fracture morphology showed a mixed surface, also known as a “quasi-cleavage”, which is characterized by dimples, cleavage facets, extensive primary cracks with broken slipping planes, and a large number of inclusions. This phenomenon caused a possible brittle behavior in the material.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-01-18
DOI: 10.3390/jmmp7010025
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 26: Introduction of a New Test Methodology for
Determining the Delayed Cracking Susceptibility
Authors: Anton Hopf, Moritz Klug, Kürşat Durmaz, Klaus Goth, Sven Jüttner
First page: 26
Abstract: A missing test methodology that allows for the determination of delayed cracking susceptibility of laser welds of high-strength sheet steel is presented. Unlike other cold crack testing methods, this test is based on a self-restraint testing of specimens welded from thin sheet materials without welding consumables and external loading. The potential test procedure with sample geometry, clamping device and documentation of the cracks is described. It is shown that the position of the weld on the specimen is a critical parameter and the susceptibility to cold cracking increases with increasing edge distance. The test methodology in combination with the most critical seam position is successfully used to rank two different steels regarding their susceptibility to delayed cracking. Further investigations are conducted evaluating the cold cracking susceptibility at different energy levels and lubricating conditions. It is proven that the lubrication has a significant influence on the susceptibility to cold cracking. Nevertheless, a narrow but safe process window is found.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-01-18
DOI: 10.3390/jmmp7010026
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 27: Acknowledgment to the Reviewers of JMMP in 2022
Authors: JMMP Editorial Office JMMP Editorial Office
First page: 27
Abstract: High-quality academic publishing is built on rigorous peer review [...]
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-01-19
DOI: 10.3390/jmmp7010027
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 28: Simulated Study of the Machinability of the Nomex
Honeycomb Structure
Authors: Tarik Zarrouk, Mohammed Nouari, Hamid Makich
First page: 28
Abstract: The Nomex honeycomb core has been widely used in many industrial fields, especially the aircraft and aerospace industries, due to its high strength and stiffness to heaviness ratio. Machining of the Nomex honeycomb structure is usually associated with tearing of the walls, deformations of the cells and the appearance of burrs. Therefore, milling of the Nomex honeycomb structure represents an industrial hurdle challenge for scientists and researchers about the quality of the machined surface and the integrity of the cutting tool. In response to this problem, we have developed a three-dimensional numerical model of finite elements based on the real conditions of experimental work by means of the analysis software Abaqus. Based on the developed numerical model, an experimental validation was performed by comparing the quality of the surface and the adhesive wear of the cutting tool determined from the numerical simulation and that established by the experiment. In addition, the effect of geometric parameters in terms of wedge angle and cutting tool diameter on material accumulation, chip size, generated surface and cutting forces was analyzed. The results of the quantitative analysis prove that the choice of cutting conditions and cutting tool geometry in terms of favorable rake angle and tool diameter improves the surface quality of the generated part and optimizes the integrity of the cutting tool.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-01-20
DOI: 10.3390/jmmp7010028
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 29: The Development of an Assembled Truss Core
Lightweight Panel and Its Method of Manufacture
Authors: Zhilei Tian, Chenghai Kong, Jingchao Guan, Wei Zhao, Apollo B. Fukuchi, Xilu Zhao
First page: 29
Abstract: In this study, a new assembled truss core panel and the method for processing it were proposed in order to improve the performance of the lightweight panel structure. The proposed assembled truss core panel can be easily processed by simple punching and bending. A processing experiment on an assembled truss core panel was conducted using an aluminum plate with a thickness of 1.0 mm, and the validity and performance of the proposed processing method were verified. A three-point bending test was performed using an assembled truss core panel obtained using the processing experiment. The assembled truss core panel had a relatively high bending stiffness in its early elastic deformation and a relatively long-lasting bending deformation after the initial failure. Its application as a lightweight panel has been confirmed. In order to compare it with the most commonly used honeycomb lightweight panel, FEM (finite element method) analysis was performed on the assembled truss core panel and on the honeycomb panel under the same conditions. The bending stiffness of the assembled truss core panel was found to be 10.60% higher than that of the honeycomb panel. Furthermore, to improve the productivity of the assembly-type truss core panel, construction of a production line using progressive dies was proposed, and the possibility of practical development for mass production was examined.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-01-23
DOI: 10.3390/jmmp7010029
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 30: Design Optimization of Hot Isostatic Pressing
Capsules
Authors: Samaneh Sobhani, Marc Albert, David Gandy, Ali Tabei, Zhaoyan Fan
First page: 30
Abstract: Power metallurgy hot isostatic pressing (PM-HIP) is a manufacturing technique capable of producing net shape or near-net shape components with complicated geometries from materials that are difficult to melt and cast, mechanically deform or weld. However, the process and soundness of the outcome are extremely sensitive to the geometric design of the capsule (also known as the die or can) that is used in the process. The capsule design for each new component involves several trial–error iterations to achieve the desired geometry and shape of the component. For each iteration, costly HIP experiments need to be conducted and new capsules need be manufactured with small modifications. In this study, a robust finite element analysis (FEA) model of the HIP process is developed, then wrapped in a multi-objective genetic algorithm (MOGA) optimization framework to obtain the optimal pre-HIP capsule design, which yields the desired post-HIP component geometry in one HIP run. The FEA-based optimization algorithm is validated by HIP experiments, showing excellent agreement between the experiment and the model.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-01-25
DOI: 10.3390/jmmp7010030
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 31: Evaluation of Processing Conditions in the
Performance of Purging Compounds for Polypropylene Injection Molding
Authors: Miguel Carrasco, Jorge Guerrero, Miriam Lazo, Estephany Adrián, Jorge Alberto Medina-Perilla, Andrés Rigail-Cedeño
First page: 31
Abstract: Purging is a fundamental process in the injection molding sector, aiding in color transition, material shifts, and the removal of contaminants. The purging compounds can be classified according to physical or chemical mechanisms and are affected by processing parameters, such as temperature, pressure, or soaking period. Despite some studies on the effect of processing parameters in purging action, an analysis of the rheological behavior and physico-chemical changes is still required for a deeper understanding of this type of system. This study explored shear viscosity, activation energy behavior in the torque rheometer, injection molding process, and energy consumption for two polyolefin-based purging compounds: one on polypropylene (PP) and another on polyethylene (PE). The results showed that the PP-based compound is a highly viscous material with low thermal sensibility and low energy consumption. The PE-based chemical compound, which includes an expanding and scrubbing agent, presented higher thermal sensitivity. Lower purging times and specific energy consumption were observed for the mechanical purge regardless of the processing temperature in the injection molding machine. However, torque and specific total mechanical energy differed due to viscosity and possible filler particle agglomeration. These findings demonstrated the influence of processing temperature on rheology and performance. Nonetheless, further studies regarding pressure, soaking time, and rheological modeling are recommended.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-01-26
DOI: 10.3390/jmmp7010031
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 32: Effect of Heat Treatment on the Mechanical and
Tribological Properties of Dual-Reinforced Cold-Sprayed Al Coatings
Authors: Kia Min Phua, Thomas Stapel, Troy Y. Ansell
First page: 32
Abstract: The aluminum cold spray feedstock powder was single- and dual-reinforced with no greater than 2 vol% boron nitride nanoplatelets (BNNP) and/or nanometric boron carbide (nB4C). These powders were cold sprayed onto Al-6061 substrates and then heat-treated in an argon environment. In addition, micro- and nano-indentation hardness and wear testing were performed on the heat-treated samples. Further microscopy and optical profilometry were used to characterize the microstructure and wear track volumes. Minimal changes to the splat structure were observed after heat treatment. However, when compared to the pure Al coating, microhardness improved with reinforcement after treatment at 500 °C, while nanohardness improved only in the dual-reinforced coatings, again after treatment at 500 °C. The elastic modulus generally decreased for the reinforced coatings after treatment; however, indentation test results were mixed. The wear testing done on samples heat treated at 500 °C for one hour showed increases in the specific wear rate for single-reinforced coatings but decreases in the dual-reinforced coatings. These results indicate that both dual-reinforcement and heat treatment are required for improvements in the mechanical and tribological properties of Al nanocomposites.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-01-28
DOI: 10.3390/jmmp7010032
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 33: Process-Structure-Property Interdependencies in
Non-Isothermal Powder Bed Fusion of Polyamide 12
Authors: Samuel Schlicht, Simon Cholewa, Dietmar Drummer
First page: 33
Abstract: Non-isothermal laser-based powder bed fusion (LPBF) of polymers suggests the potential for significantly extending the range of materials applicable for powder-based additive manufacturing of polymers, relying on the absence of a material-specific processing window. To allow for the support-free manufacturing of polymers at a build chamber temperature of 25 °C, applied processing strategies comprise the combination of fractal exposure strategies and locally quasi-simultaneous exposure of distinct segments of a particular cross section for minimizing crystallization-induced part deflection. Based on the parameter-dependent control of emerging cooling rates, formed part morphologies and resulting mechanical properties can be modified. Thermographic in situ measurements allow for correlating thermal processing conditions and crystallization kinetics with component-specific mechanical, morphological, and microstructural properties, assessed ex situ. Part morphologies formed at crystallization temperatures below 70 °C, induced by reduced laser exposure times, are characterized by a nano-spherulitic structure, exhibiting an enhanced elongation at break. An ambient temperature of 25 °C is associated with the predominant formation of a combined (α + γ)-phase, induced by the rapid cooling and subsequent laser-induced tempering of distinct layers, yielding a periodic microstructural evolution. The presented results demonstrate a novel approach for obtaining nano-spherulitic morphologies, enabling the exposure-based targeted adaption of morphological properties. Furthermore, the thermographic inline assessment of crystallization kinetics allows for the enhanced understanding of process-morphology interdependencies in laser-based manufacturing processes of semi-crystalline polymers.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-01-30
DOI: 10.3390/jmmp7010033
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 34: On Friction, Heat Input, and Material Flow
Initiation during Friction Stir Welding: Tool and Process Optimization
Authors: Max Hossfeld
First page: 34
Abstract: The Friction Stir Welding (FSW) process depends entirely upon mechanical contact between the tool and the workpiece. As a result of this, all process phenomena and process outcomes such as weld geometry and mechanical properties are governed by FSW’s frictional system. The following work characterizes this system with a focus on process initialization, heat input and material flow. For this purpose, an experimental program for the isolated investigation of the frictional system was carried out. Short-term effects such as contact initiation, run-in behavior and frictional transitions are considered as well as the influences of process parameters and geometry. The system and its behavior are analyzed quantitatively and qualitatively by experiments altering the normal pressure, relative velocity, and tool geometry. The experiments demonstrate a self-similar behavior of the process, including an important wear transition which initiates the material flow, and a subsequent equilibrium of forces, heat balance, and temperatures. The interaction between the tool and the welded material is described, as is the link between the frictional interface and material flow initialization. Based on these findings, recommendations are provided for process optimization and tool design.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-01-31
DOI: 10.3390/jmmp7010034
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 35: Liquid-Based 4D Printing of Shape Memory
Nanocomposites: A Review
Authors: Mohamad Alsaadi, Eoin P. Hinchy, Conor T. McCarthy, Vicente F. Moritz, Shuo Zhuo, Evert Fuenmayor, Declan M. Devine
First page: 35
Abstract: Significant advances have been made in recent years in the materials development of liquid-based 4D printing. Nevertheless, employing additive materials such as nanoparticles for enhancing printability and shape memory characteristics is still challenging. Herein, we provide an overview of recent developments in liquid-based 4D printing and highlights of novel 4D-printable polymeric resins and their nanocomposite components. Recent advances in additive manufacturing technologies that utilise liquid resins, such as stereolithography, digital light processing, material jetting and direct ink writing, are considered in this review. The effects of nanoparticle inclusion within liquid-based resins on the shape memory and mechanical characteristics of 3D-printed nanocomposite components are comprehensively discussed. Employing various filler-modified mixture resins, such as nanosilica, nanoclay and nanographene, as well as fibrous materials to support various properties of 3D printing components is considered. Overall, this review paper provides an outline of liquid-based 4D-printed nanocomposites in terms of cutting-edge research, including shape memory and mechanical properties.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-01-31
DOI: 10.3390/jmmp7010035
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 36: Influence of Deposition Parameters on Hardness
Properties of InconelTM 718 Processed by Laser Powder Bed Fusion for Space
Applications
Authors: Raffaella Sesana, Cristiana Delprete, Marco Pizzarelli, Matteo Crachi, Luca Lavagna, Domenico Borrelli, Antonio Caraviello
First page: 36
Abstract: InconelTM 718 is widely used for commercial application in aerospace industry and additive manufacturing process allows for versatile design and manufacturing opportunities. In the present research, the results of a wide experimental campaign run on additive manufactured InconelTM 718 specimens obtained with different processing parameters are presented. In particular, the influence of process parameters (for both vertical and horizontal planes with respect to the building direction) on the hardness properties are investigated. A further investigation is performed on the optimal hardness testing procedure for additive manufacturing. The research is extended to as-built and heat-treated specimens. The new insight gained is that the orientation of the printing direction with respect to indentation direction can be responsible for scattering in hardness measurements and indentation size effect. As-built specimens show a strong anisotropy for in-plane and growth directions and an increment of hardness with respect to increasing energy density. The difference between hardness value with respect to the energy density and the measurements scattering are reduced by the heat treatment. A careful handling of hardness data is required when dealing with additive manufactured materials.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-02-01
DOI: 10.3390/jmmp7010036
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 37: Load Introduction Specimen Design for the
Mechanical Characterisation of Lattice Structures under Tensile Loading
Authors: Justin Jung, Guillaume Meyer, Matthias Greiner, Christian Mittelstedt
First page: 37
Abstract: In recent years, it has been demonstrated that the lightweight potential of load-carrying structural components could be further enhanced using additive manufacturing technology. However, the additive manufacturing process offers a large parameter space that highly impacts the part quality and their inherent mechanical properties. Therefore, the most influential parameters need to be identified separately, categorised, classified and incorporated into the design process. To achieve this, the reliable testing of mechanical properties is crucial. The current developments concerning additively manufactured lattice structures lack unified standards for tensile testing and specimen design. A key factor is the high stress concentrations at the transition between the lattice structure and the solid tensile specimen’s clamping region. The present work aims to design a topology-optimised transition region applicable to all cubic unit cell types that avoids high samples potentially involved in structural grading. On the basis of fulfilling the defined objective and satisfying the constraints of the stress and uniaxiality conditions, the most influential parameters are identified through a correlation analysis. The selected design solutions are further analysed and compared to generic transition design approaches. The most promising design features (compliant edges, rounded cross-section, pillar connection) are then interpreted into structural elements, leading to an innovative generic design of the load introduction region that yields promising results after a proof-of-concept study.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-02-01
DOI: 10.3390/jmmp7010037
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 38: Mechanical Performance over Energy Expenditure in
MEX 3D Printing of Polycarbonate: A Multiparametric Optimization with the
Aid of Robust Experimental Design
Authors: Nectarios Vidakis, Markos Petousis, Constantine N. David, Dimitrios Sagris, Nikolaos Mountakis, Emmanuel Karapidakis
First page: 38
Abstract: Sustainability and energy efficiency of additive manufacturing (AM) is an up-to-date industrial request. Likewise, the claim for 3D-printed parts with capable mechanical strength remains robust, especially for polymers that are considered high-performance ones, such as polycarbonates in material extrusion (MEX). This paper explains the impact of seven generic control parameters (raster deposition angle; orientation angle; layer thickness; infill density; nozzle temperature; bed temperature; and printing speed) on the energy consumption and compressive performance of PC in MEX AM. To meet this goal, a three-level L27 Taguchi experimental design was exploited. Each experimental run included five replicas (compressive specimens after the ASTM D695-02a standard), summating 135 experiments. The printing time and the power consumption were stopwatch-derived, whereas the compressive metrics were obtained by compressive tests. Layer thickness and infill density were ranked the first and second most significant factors in energy consumption. Additionally, the infill density and the orientation angle were proved as the most influential factors on the compressive strength. Lastly, quadratic regression model (QRM) equations for each response metric versus the seven control parameters were determined and evaluated. Hereby, the optimum compromise between energy efficiency and compressive strength is attainable, a tool holding excessive scientific and engineering worth.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-02-01
DOI: 10.3390/jmmp7010038
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 39: Investigation of Welding Parameters of Dissimilar
Weld of SS316 and ASTM A36 Joint Using a Grey-Based Taguchi Optimization
Approach
Authors: Diah Kusuma Pratiwi, Amir Arifin, Gunawan, Alim Mardhi, Afriansyah
First page: 39
Abstract: A grey-based Taguchi method was applied to investigate the optimal operating conditions in shielded metal arc welding (SMAW) to join SS316 and ASTM A36. This work aims to set optimal parameters for the mechanical properties of the weld joint. The effects of various welding factors on electrode type, welding current, arc welding, and welding speed have to be characterized and optimized to achieve an optimum condition. An L9 orthogonal array was used to group the various components. The mechanical properties of a dissimilar weld joints were described through hardness, tensile and flexural strength tests. The optimum welding parameters were obtained simultaneously as an electrode type E309, a welding current of 100 A, an arc voltage of 14 V, and a welding speed of 4 cm/min, which predicted improve 23.0% in its performance.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-02-02
DOI: 10.3390/jmmp7010039
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 40: Investigation of Pressure Fields Generated by Two
Simultaneous Discharges in Liquid Initiated by Wires
Authors: Mykhaylo Knyazyev, Maik Holzmüller, Werner Homberg
First page: 40
Abstract: The pressure fields generated by two simultaneous discharges have not been investigated on any notable scale for the electrohydraulic impulse forming method. In this study, the synchronicity of two discharges is ensured by the sequential connection of two wires mounted in two spark gaps in a common volume of liquid. The objective is to experimentally confirm the equilibrium of the energies evolved in two spark gaps by means of pressure measurements. In addition, multipoint membrane pressure gauges demonstrated the feasibility of easily recording detailed pressure maps. Based on the membrane deformation mechanism and material strengthening under static and impulse conditions, the processing procedure is further developed so as to achieve better accuracy in the determination of pressure field parameters. The practical equality of the pressure fields on the left and right halves of the flat-loaded area confirms the equality of energies evolved in the two spark gaps. The direct shock waves create zones with the most intensive loading. These results provide a basis for the development of new electrohydraulic technologies involving the application of two simultaneous discharges with equal energy and pressure parameters.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-02-02
DOI: 10.3390/jmmp7010040
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 41: Development and Practical Implementation of
Digital Observer for Elastic Torque of Rolling Mill Electromechanical
System
Authors: Vadim R. Gasiyarov, Andrey A. Radionov, Boris M. Loginov, Alexander S. Karandaev, Olga A. Gasiyarova, Vadim R. Khramshin
First page: 41
Abstract: The strategic initiative aimed at building “digital metallurgy” implies the introduction of diagnostic monitoring systems to trace the technical condition of critical production units. This problem is relevant for rolling mills, which provide the output and determine the quality of products of metallurgical companies. Making up monitoring systems requires the development of digital shadows and coordinate observers, the direct measurement of which is either impossible or associated with numerous difficulties. These coordinates include the spindle torque applied by the spring-transmitting torque from the motor to the rolling stand rolls. The development and research are conducted by the example of the electromechanical systems of the horizontal stand at the plate mill 5000. The stand electric drive characteristics are given, and the emergency modes that cause mechanical equipment breakdowns are analyzed that. The relevance of analyzing transient torque processes in emergency modes has been accentuated. The paper points to the shortcomings of the system for elastic torque direct measurement, including low durability due to the harsh operating conditions of precision sensors. It also highlights the need to install the measuring equipment after each spindle. The disadvantage of the previously developed observer is the function of calculating the electric drive speed derivative. This causes a decrease in noise immunity and signal recovery accuracy. The contribution of this paper is building a digital elastic torque observer that has advantages over conventional technical solutions, based on the theoretical and experimental studies. The technique for virtual observer adjustment was developed and tested in the Matlab-Simulink software package. For the first time, a comprehensive analysis was conducted for spindle elastic torques in emergency modes that caused equipment damage. An algorithm was developed for an emergency shutdown of a stand electric drive in the worst-case mode of strip retraction between work and backup rolls, due to the overlap of the strip on the roll. Further, the algorithm was tested experimentally. The criteria for diagnosing pre-emergencies was then justified. An adaptive motor-braking rate controller was developed. The developed observer and emergency braking system are in operation at the mill 5000. Long experimental research proved the efficiency of dynamic load monitoring and the reduction in the number of equipment breakdowns.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-02-04
DOI: 10.3390/jmmp7010041
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 42: Investigation of the Pull-Out Behaviour of Metal
Threaded Inserts in Thermoplastic Fused-Layer Modelling (FLM) Components
Authors: Tobias Kastner, Juliane Troschitz, Christian Vogel, Thomas Behnisch, Maik Gude, Niels Modler
First page: 42
Abstract: To provide detachable, secure and long-term stable joints in fused-layer modelling (FLM) components or assemblies, metal threaded inserts are widely used as extrinsic interfaces. However, the load-bearing capacity of such inserts is influenced by the inhomogeneous, anisotropic material structure of the FLM components. This work evaluates the influence of the joining zone design and the printing process parameters on the achievable joint properties. Therefore, we printed thermoplastic FLM test specimens with varying parameters for infill density, wall thickness, layer height and nozzle temperature. Subsequently, metal threaded inserts were warm-embedded into the test specimens and investigated in quasi-static pull-out tests. The results show that the infill density in the joining zone has the largest impact on the joint strength and should be 70% or higher. Furthermore, an analysis of different wall thicknesses around the pre hole shows that a minimum value of 2.4 mm is required for the selected insert geometry to achieve a high pull-out force. Increasing the wall thickness beyond this value does not significantly affect the joint strength. The results provide an improved base for detailed understanding and interface design in FLM components for the integration of metal threaded inserts as well as for further investigations regarding different printing materials and load types.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-02-07
DOI: 10.3390/jmmp7010042
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 43: Building Orientation and Post Processing of
Ti6Al4V Produced by Laser Powder Bed Fusion Process
Authors: Rosaria Rovetta, Paola Ginestra, Rosalba Monica Ferraro, Keren Zohar-Hauber, Silvia Giliani, Elisabetta Ceretti
First page: 43
Abstract: Laser powder bed fusion, particularly the selective laser melting (SLM), is an additive manufacturing (AM) technology used to produce near-net-shaped engineering components for biomedical applications, especially in orthopaedics. Ti6Al4V is commonly used for producing orthopaedic implants using SLM because it has excellent mechanical qualities, a high level of biocompatibility, and corrosion resistance. However, the main problems associated with this process are the result of its surface properties: it has to be able to promote cell attachment but, at the same time, avoid bacteria colonization. Surface modification is used as a post-processing technique to provide items the unique qualities that can improve their functionality and performance in particular working conditions. The goal of this work was to produce and analyse Ti6Al4V samples fabricated by SLM with different building directions in relation to the building plate (0° and 45°) and post-processed by anodization and passivation. The results demonstrate how the production and post processes had an impact on osteoblast attachment, mineralization, and osseointegration over an extended period of time. Though the anodization treatment result was cytotoxic, the biocompatibility of as-built specimens and specimens after passivation treatment was confirmed. In addition, it was discovered that effective post-processing increases the mineralization of these types of 3D-printed surfaces.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-02-07
DOI: 10.3390/jmmp7010043
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 44: Influence of Ambient Temperature and Crystalline
Structure on Fracture Toughness and Production of Thermoplastic by
Enclosure FDM 3D Printer
Authors: Supaphorn Thumsorn, Wattanachai Prasong, Akira Ishigami, Takashi Kurose, Yutaka Kobayashi, Hiroshi Ito
First page: 44
Abstract: Fused deposition modeling (FDM) 3D printing has printed thermoplastic materials layer-by-layer to form three dimensional products whereby interlayer adhesion must be well controlled to obtain high mechanical performance and product integrity. This research studied the effects of ambient temperatures and crystalline structure on the interlayer adhesion and properties of thermoplastic FDM 3D printing. Five kinds of poly(lactic acid) (PLA) filaments, both commercially available and the laboratory-made, were printed using the enclosure FDM 3D printer. The ambient temperatures were set by the temperature-controlled chamber from room temperature to 75 °C with and without a cooling fan. The interlayer adhesion was characterized by the degree of entanglement density, morphology, and fracture toughness. In addition, PLA filament with high crystallinity has induced heat resistance, which could prevent filament clogging and successfully print at higher chamber temperatures. The ambient temperature increased with increased chamber temperature and significantly increased when printed without a cooling fan, resulting in improved interlayer bonding. The crystalline structure and dynamic mechanical properties of the 3D printed products were promoted when the chamber temperature was increased without a cooling fan, especially in PLA composites and PLA containing a high content of L-isomer. However, although the additives in the PLA composite improved crystallinity and the degree of entanglement density in the 3D-printed products, they induced an anisotropic characteristic that resulted in the declination of the interlayer bonding in the transverse orientation products. The increasing of chamber temperatures over 40 °C improved the interlayer bonding in pristine PLA products, which was informed by the increased fracture toughness. Further, it can be noted that the amorphous nature of PLA promotes molecular entanglement, especially when printed at higher chamber temperatures with and without a cooling fan.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-02-08
DOI: 10.3390/jmmp7010044
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 45: A Review on Wire-Fed Directed Energy Deposition
Based Metal Additive Manufacturing
Authors: Tuğrul Özel, Hamed Shokri, Raphaël Loizeau
First page: 45
Abstract: Metal additive manufacturing has reached a level where products and components can be directly fabricated for applications requiring small batches and customized designs, from tinny body implants to long pedestrian bridges over rivers. Wire-fed directed energy deposition based additive manufacturing enables fabricating large parts in a cost-effective way. However, achieving reliable mechanical properties, desired structural integrity, and homogeneity in microstructure and grain size is challenging due to layerwise-built characteristics. Manufacturing processes, alloy composition, process variables, and post-processing of the fabricated part strongly affect the resultant microstructure and, as a consequence, component serviceability. This paper reviews the advances in wire-fed directed energy deposition, specifically wire arc metal additive processes, and the recent efforts in grain tailoring during the process for the desired size and shape. The paper also addresses modeling methods that can improve the qualification of fabricated parts by modifying the microstructure and avoid repetitive trials and material waste.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-02-08
DOI: 10.3390/jmmp7010045
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 46: Using 3D Density-Gradient Vectors in Evolutionary
Topology Optimization to Find the Build Direction for Additive
Manufacturing
Authors: Dylan Bender, Ahmad Barari
First page: 46
Abstract: Given its layer-based nature, additive manufacturing is known as a family of highly capable processes for fabricating complex 3D geometries designed by means of evolutionary topology optimization. However, the required support structures for the overhanging features of these complex geometries can be concerningly wasteful. This article presents an approach for studying the manufacturability of the topology-optimized complex 3D parts required for additive manufacturing and finding the optimum corresponding build direction for the fabrication process. The developed methodology uses the density gradient of the design matrix created during the evolutionary topology optimization of the 3D domains to determine the optimal build orientation for additive manufacturing with the objective of minimizing the need for support structures. Highly satisfactory results are obtained by implementing the developed methodology in analytical and experimental studies, which demonstrate potential additive manufacturing mass savings of 170% of the structure’s weight. The developed methodology can be readily used in a variety of evolutionary topology optimization algorithms to design complex 3D geometries for additive manufacturing technologies with a minimized level of waste due to reducing the need for support structures.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-02-09
DOI: 10.3390/jmmp7010046
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 47: Metal Additive Manufacturing and Its
Post-Processing Techniques
Authors: Hao Wang, Jerry Ying Hsi Fuh
First page: 47
Abstract: Metal additive manufacturing has made substantial progress in the advanced manufacturing sector with competitive advantages for the efficient production of high-quality products [...]
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-02-10
DOI: 10.3390/jmmp7010047
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 48: Development of a Computationally Efficient Model
of the Heating Phase in Thermoforming Process Based on the Experimental
Radiation Pattern of Heaters
Authors: Hadi Hosseinionari, Milad Ramezankhani, Rudolf Seethaler, Abbas S. Milani
First page: 48
Abstract: In this study, an accurate and computationally efficient model for the heating process of thin thermoplastic sheets during thermoforming is developed. This model opens the door to efficient training of model-free control approaches in thermoforming applications, which often require extensive training data that would be significantly costly and time-consuming to generate using physical setups. This model takes into account heat transfer via radiation between heaters and the sheet, heat transfer via conduction through the sheet, and heat transfer via convection between the sheet and the ambient. In this paper, rather than using an analytical relationship for the view factor, an experiment is designed to determine the exact radiation pattern of the heater on the sheet and the fraction of infrared emission absorbed by the sheet. Comparing the output temperature profile on the sheet from the designed model to IR images from a laboratory-scale heating system indicates that the mean square error is reduced by around four times when compared to traditional models with analytical view factors. Moreover, a comparison of the computation time with COMSOL software for a scenario with the same configuration of computation hardware reveals that the designed model is almost ten times faster.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-02-10
DOI: 10.3390/jmmp7010048
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 49: Study on Elucidation of the Roundness Improvement
Mechanism of the Internal Magnetic Abrasive Finishing Process Using a
Magnetic Machining Tool
Authors: Jiangnan Liu, Yanhua Zou
First page: 49
Abstract: The magnetic abrasive finishing process using the magnetic machining tool was proposed to finish the internal surface of the thick tube (the thickness of the tube is 5~30 mm). It has been proved that this process can improve the roundness while improving the roughness. In this paper, we mainly study the machining mechanism of roundness improvement. Firstly, the influence of finishing characteristics on the roundness improvement was discussed, including the rotational speed of the magnetic machining tool and the rotational speed of the tube. It was concluded that the roundness improvement increases with the increase in the rotational speed through the analysis of finishing force and finishing times. Furthermore, the influence on roundness improvement of different distributions of magnetic particles were experimentally compared. After finishing, due to the magnetic force generated by the magnetic machining tool and the magnetic pole unit exerting pressure on the magnetic particles, a fixed magnetic brush is formed. The experimental results show that the circumferential length of the fixed magnetic brush is different due to the different distribution areas of magnetic particles. It was concluded that the roundness improvement increases with the circumferential length of the fixed magnetic brush increases by discussing the relationship between the circumferential length of the fixed magnetic brush and the wavelength of the roundness curve. When the circumferential length of the fixed magnetic brush is 76 mm, the roundness was improved from 379 μm to 236 μm after 60 min of finishing.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-02-13
DOI: 10.3390/jmmp7010049
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 50: Real-Time Cutting Temperature Measurement in
Turning of AISI 1045 Steel through an Embedded Thermocouple—A
Comparative Study with Infrared Thermography
Authors: Bruno Guimarães, José Rosas, Cristina M. Fernandes, Daniel Figueiredo, Hernâni Lopes, Olga C. Paiva, Filipe S. Silva, Georgina Miranda
First page: 50
Abstract: During machining processes, a high temperature is generated in the cutting zone due to deformation of the material and friction of the chip along the surface of the tool. This high temperature has a detrimental effect on the cutting tool, and for this reason, it is of the utmost importance to assess the cutting temperature in real time during these processes. Despite all the advances and investigation in this field, accurately measuring the cutting temperature remains a great challenge. In this sense, this work intends to contribute to solving this problem by experimentally evaluating the potential of the developed approach for embedding thermocouples into the rake face of cutting tools for measuring cutting temperature in real time during dry turning of AISI 1045 steel for different cutting parameters and comparing the obtained results with infrared thermography measurements at the exact same point. A well-defined, smooth micro-groove with good surface quality was produced by laser surface modification. Then a laser-welded K-type thermocouple was fixated in the micro-groove with a MgO ceramic adhesive, ensuring protection from wear and chips, which allowed the creation of WC-Co cutting inserts with the ability to measure cutting tool temperature with a maximum error of 0.96%. Results showed that, despite yielding the same trend, the tool temperature measured by the IR thermographic camera was always lower than the temperature measured by the K-type embedded thermocouple. The proposed embedded thermocouple method proved to be a reliable, precise, accurate, and cost-effective approach for real-time temperature measurement capable of providing useful information for cutting parameter optimization, thus allowing increased productivity and tool life.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2023-02-15
DOI: 10.3390/jmmp7010050
Issue No: Vol. 7, No. 1 (2023)
- JMMP, Vol. 7, Pages 1: Numerical Modeling of Titanium Alloy Ti10V2Fe3Al
Milling Process
Authors: Michael Storchak, Thomas Stehle, Hans-Christian Möhring
First page: 1
Abstract: The simulation of material machining using finite element models is a powerful tool for the optimization of simulated processes and tools, as well as for the determination of cutting process characteristics that are difficult or practically impossible to determine by experiment. The paper presents results of the numerical simulation of the titanium alloy Ti10V2Fe3Al (Ti-1023). The behavior of the machined material was modeled with the Johnson–Cook constitutive equation, and its damage mechanism was modeled using the Cockcroft and Latham model. The parameters of the constitutive equation for machined material behavior and damage were determined using a DOE sensitivity analysis during orthogonal cutting. The values of the cutting force components, as well as the minimum and maximum chip thicknesses, were used as target functions for the DOE analysis. The generalized values of the constitutive equation parameters and the fracture stress values determined by the DOE analysis were calculated as the set intersection of individual multitude values of these parameters. The simulation results of the studied cutting processes showed an acceptable agreement with the experimental data when the cutting speed and tool feed changed significantly. The deviation in the simulated values of the cutting forces from their measured values ranged from about 10% to about 20%.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-12-22
DOI: 10.3390/jmmp7010001
Issue No: Vol. 7, No. 1 (2022)
- JMMP, Vol. 7, Pages 2: Ultrasonic Welding of Additively Manufactured PEEK
and Carbon-Fiber-Reinforced PEEK with Integrated Energy Directors
Authors: Bilal Khatri, Manuel Francis Roth, Frank Balle
First page: 2
Abstract: The thermoplastic polymer polyether ether ketone (PEEK) offers thermal and mechanical properties comparable to thermosetting polymers, while also being thermally re-processable and recyclable as well as compatible with fused filament fabrication (FFF). In this study, the feasibility of joining additively manufactured PEEK in pure and short carbon-fiber-reinforced form (CF-PEEK) is investigated. Coupon-level samples for both materials were fabricated using FFF with tailored integrated welding surfaces in the form of two different energy director (ED) shapes and joined through ultrasonic polymer welding. Using an energy-driven joining process, the two materials were systematically investigated with different welding parameters, such as welding force, oscillation amplitude and welding power, against the resulting weld quality. The strengths of the welded bonds were characterized using lap-shear tests and benchmarked against the monotonic properties of single 3D-printed samples, yielding ultimate lap-shear forces of 2.17kN and 1.97kN and tensile strengths of 3.24MPa and 3.79MPa for PEEK and CF-PEEK, respectively. The weld surfaces were microscopically imaged to characterize the failure behaviors of joints welded using different welding parameters. Samples welded with optimized welding parameters exhibited failures outside the welded region, indicating a higher weld-strength compared to that of the bulk. This study lays the foundation for using ultrasonic welding as a glue-free method to join 3D-printed high-performance thermoplastics to manufacture large load-bearing, as well as non-load-bearing, structures, while minimizing the time and cost limitations of FFF as a fabrication process.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-12-23
DOI: 10.3390/jmmp7010002
Issue No: Vol. 7, No. 1 (2022)
- JMMP, Vol. 7, Pages 3: Influence of Wire Arc Additive Manufacturing
Beads’ Geometry and Building Strategy: Mechanical and Structural
Behavior of ER70S-6 Prismatic Blocks
Authors: Ahmed Elsokaty, Omar Oraby, Sameha Sadek, Hanadi G. Salem
First page: 3
Abstract: Wire arc additive manufacturing (WAAM) with high deposition rates has attracted industry interest for the demonstrated economic production of medium-to-large-scale metallic components. The structural integrity and mechanical properties of the built parts depend on the selection of the optimum deposition parameters and the tool path strategy. In this study, an alternate orthogonal deposition strategy was employed. The influence of the beads’ geometry and the associated heat input on the mechanical and structural behavior of mild steel (ER70S-6) were investigated. The influence of the bead width (BW) and the overlapping percentage (OP) between the adjacent beads on the average and layer-by-layer hardness of the blocks along the building direction were evaluated. Tensile strength was also characterized. The alternate orthogonal building strategy enhanced the geometrical uniformity of the built blocks and the microstructural isotropy along the building direction. Increasing the BW increased the total heat input per bead per layer, which significantly reduced the hardness and tensile strength of the built blocks by 19% and 17% compared to 8% and 7% when increasing the OP, respectively. Total heat input, number of heating cycles, and cooling rates triggered the phases formed, and their morphologies along the building direction were also characterized.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-12-24
DOI: 10.3390/jmmp7010003
Issue No: Vol. 7, No. 1 (2022)
- JMMP, Vol. 7, Pages 4: Binder Jetting Additive Manufacturing: Powder
Packing in Shell Printing
Authors: Guanxiong Miao, Mohammadamin Moghadasi, Ming Li, Zhijian Pei, Chao Ma
First page: 4
Abstract: Shell printing is an advantageous binder jetting technique that prints only a thin shell of the intended object to enclose the loose powder in the core. In this study, powder packing in the shell and core was investigated for the first time. By examining the density and microstructure of the printed samples, powder packing was found to be different between the shell and core. In addition, the powder particle size and layer thickness were found to affect the powder packing in the shell and core differently. At a 200 µm layer thickness, for the 10 µm and 20 µm powders, the core was less dense than the shell and had a layered microstructure. At a 200 µm layer thickness, for the 70 µm powder, the core was denser and had a homogeneous microstructure. For the 20 µm powder, by reducing the layer thickness from 200 µm to 70 µm, the core became denser than the shell, and the microstructure of the core became homogeneous. The different results could be attributed to the different scenarios of particle rearrangement between the shell and core for powders of different particle sizes and at different layer thicknesses. Considering that the core was denser and more homogeneous than the shell when the proper layer thickness and powder particle size were selected, shell printing could be a promising method to tailor density and reduce anisotropy.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-12-27
DOI: 10.3390/jmmp7010004
Issue No: Vol. 7, No. 1 (2022)
- JMMP, Vol. 7, Pages 5: Microhardness Distribution of Long Magnesium Block
Processed through Powder Metallurgy
Authors: Jiaying Wang, Qizhen Li
First page: 5
Abstract: Powder metallurgy is a popular method of making raw powders into specific shaped samples. However, the pressure distribution and the microhardness difference within the sample are nonnegligible and unclear when the sample is long or exceeds a specific size. In this study, the long magnesium blocks, with a ratio of about 2.8 between the sample height and the sample side length, are successfully synthesized under three uniaxial and two biaxial conditions. Then, the sample hardness values on the outer surface and the center plane are tested to study the microhardness distribution. The modified analytical expression indicates that the normal pressure exponentially decreases along the compression direction, which is consistent with the hardness distribution trend. Because higher pressure leads to a more compact arrangement of the powders, more metal bonds are formed after sintering. During the first pressing, the sidewall pressure makes the surface hardness higher. The secondary reverse compression mainly improves the bottom and core hardness due to the re-orientation and re-location of the powders. The obtained relationship between the applied pressure and the hardness distribution is instructive in predicting and improving the sample quality.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-12-27
DOI: 10.3390/jmmp7010005
Issue No: Vol. 7, No. 1 (2022)
- JMMP, Vol. 7, Pages 6: A New Perspective of Post-Weld Baking Effect on
Al-Steel Resistance Spot Weld Properties through Machine Learning and
Finite Element Modeling
Authors: Wei Zhang, Dali Wang, Jian Chen, Hassan Ghassemi-Armaki, Blair Carlson, Zhili Feng
First page: 6
Abstract: The root cause of post-weld baking on the mechanical performance of Al-steel dissimilar resistance spot welds (RSWs) has been determined by machine learning (ML) and finite element modeling (FEM) in this study. A deep neural network (DNN) model was constructed to associate the spot weld performance with the joint attributes, stacking materials, and other conditions, using a comprehensive experimental dataset. The DNN model positively identified that the post-weld baking reduces the joint performance, and the extent of degradation depends on the thickness of stacking materials. A three-dimensional finite element (FE) model was then used to investigate the root cause and the mechanism of the baking effect. It revealed that the formation of high thermal stresses during baking, from the mismatch of thermal expansion between steel and Al alloy, causes damage and cracking of the brittle intermetallic compound (IMC) formed at the interface of the weld nugget during welding. This in turn reduces the joint performance by promoting undesirable interfacial fracture when the welds were subjected to externally applied loads. The FEM model further revealed that increase in structural stiffness, because of increase in steel sheet thickness, reduces the thermal stresses at the interface caused by the thermal expansion mismatch and consequently lessens the detrimental effect of post-weld baking on the joint performance.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-12-28
DOI: 10.3390/jmmp7010006
Issue No: Vol. 7, No. 1 (2022)
- JMMP, Vol. 7, Pages 7: Tensile Strength and Microstructure of
Rotary-Friction-Welded Carbon-Steel and Stainless-Steel Joints
Authors: Hudiyo Firmanto, Susila Candra, Mochammad Arbi Hadiyat, Yesa Priscilla Triastomo, Ivan Wirawan
First page: 7
Abstract: Due to the different properties of the materials, the fusion welding of dissimilar metals may be difficult. Structural irregularities may form as a result of various phase transformations during welding. Solid-state welding, as opposed to fusion welding, occurs below the melting temperature. As a result of the melting and solidification phenomena that happen in fusion welding, solid-state welding is expected to reduce the potential for phase transformation. This paper describes the use of a rotary friction welding technique to join carbon steel and 304 stainless steel. The purpose of this work is to investigate the characteristics of rotary friction welding (RFW) when joining 304 stainless steel to carbon steels with different carbon contents. Experiments were carried out on the RFW of low- and medium-carbon steels with 304 stainless steel. The investigation was carried out using the Taguchi method of experimental design. The joints’ tensile strengths and microstructures were evaluated. The parameters that had the greatest influence on the tensile strengths of the welding results were identified. The combination of parameters resulting in the greatest tensile strength is also suggested. A microstructural examination of the weldment revealed mechanical mixing and interlocking.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-12-28
DOI: 10.3390/jmmp7010007
Issue No: Vol. 7, No. 1 (2022)
- JMMP, Vol. 7, Pages 8: Additive Manufacturing of Slow-Moving Automotive
Spare Parts: A Supply Chain Cost Assessment
Authors: Levin Ahlsell, Didar Jalal, Siavash H. Khajavi, Patrik Jonsson, Jan Holmström
First page: 8
Abstract: This study develops a cost model for the additive manufacturing (AM)-produced spare parts supply chain in the automotive industry. Moreover, we evaluate the economic feasibility of AM for slow-moving automotive spare parts by comparing the costs of the traditional manufacturing (TM) spare parts supply chain (SPSC) with centralized, outsourced AM SPSC. Data from a multiple case study of an OEM in the automotive industry regarding SPSC is utilized. The supply chain costs of 14 individual spare parts were analyzed, and the total SPSC cost for the AM and TM, were compared. Three of the fourteen parts showed potential for cost-savings, if they were produced with AM instead of TM. In this context, AM polymer parts showed greater potential than metal to replace TM as the more economical option of manufacturing from a total supply chain cost perspective. This study shows that the AM competitiveness to TM, from a financial perspective, increases for spare parts with low demand, high minimum order quantity, and high TM production price. The SPSC cost model included: cost of production, transport, warehousing, and service costs. This study contributes to the emerging field of part identification for AM and the existing literature regarding cost modeling in SPSCs.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-12-28
DOI: 10.3390/jmmp7010008
Issue No: Vol. 7, No. 1 (2022)
- JMMP, Vol. 7, Pages 9: Convexity and Surface Quality Enhanced Curved
Slicing for Support-Free Multi-Axis Fabrication
Authors: Don Pubudu Vishwana Joseph Jayakody, Tak Yu Lau, Ravindra Stephen Goonetilleke, Kai Tang
First page: 9
Abstract: In multi-axis fused deposition modeling (FDM) printing systems, support-free curved layer fabrication is realized by continuous transition of the printer nozzle orientation. However, the ability to print 3D models with complex geometric (e.g., high overhang) and topological (e.g., high genus) features is often restricted by various manufacturability constraints inherent to a curved layer design process. The crux in a multi-axis printing process planning pipeline is to design feasible curved layers and their tool paths that will satisfy both the support-free condition and other manufacturability constraints (e.g., collision-free). In this paper, we propose a volumetric curved layer decomposition method that strives to not only minimize (if not prevent) collision-inducing local shape features of layers, but also enable adaptive layer thickness to comply with a new volumetric error-based surface quality criterion. Our method computes an optimal Radial Basis Functions (RBF) field to modify the fabrication sequence field, from which, the iso-surface layers are extracted to design the corresponding multi-axis printing tool paths. A method to fine-tune variable nozzle orientations on each resulting curved layer is then proposed to overcome possible collisions in high-genus geometries. To validate the concept and exhibit its potential, several support-free fabrication experiments and comparisons with the conventional geodesic field-based slicing are presented, and the results give a preliminary confirmation of the feasibility and advantages of the proposed method.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-12-28
DOI: 10.3390/jmmp7010009
Issue No: Vol. 7, No. 1 (2022)
- JMMP, Vol. 7, Pages 10: Underlying Methodology for a Thermal Process
Monitoring System for Wire and Arc Additive Manufacturing
Authors: Daniel Baier, Tobias Weckenmann, Franz Wolf, Andreas Wimmer, Michael F. Zaeh
First page: 10
Abstract: The Wire and Arc Additive Manufacturing (WAAM) process has a high potential for industrial applications in aviation. The interlayer temperatures influence the dimensions and geometric deviations of the part. Monitoring the absolute interlayer temperature values is necessary for quantifying these influences. This paper presents an approach for determining the absolute values of the interlayer temperatures during the process using Ti-6Al-4V. The emissivity and transmittance are determined and calibrated, enabling precise thermographic measuring during the WAAM process. The recorded thermographic data are then compared to signals of thermocouples so that the absolute temperature values can be aligned. The methodology is validated by its transfer to measure the interlayer temperature at different regions of interest. The effect of a heat accumulation using Ti-6Al-4V in WAAM was determined. The methodology enables a reproducible and non-tactile measurement of the interlayer temperature during the WAAM process. The results show that with an interlayer temperature of 200 °C, a heat accumulation occurs within a layer. The heat accumulates in the center of the layer because the free ends of the layer cool down faster than the center of the layer.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-12-28
DOI: 10.3390/jmmp7010010
Issue No: Vol. 7, No. 1 (2022)
- JMMP, Vol. 7, Pages 11: Microstructural and Mechanical Characterization of
Ledeburitic AISI D2 Cold-Work Tool Steel in Semisolid Zones via Direct
Partial Remelting Process
Authors: M. N. Mohammed, M. Z. Omar, Adnan Naji Jameel Al-Tamimi, Hakim S. Sultan, Luay Hashem Abbud, Salah Al-Zubaidi, Oday I. Abdullah, M. Abdulrazaq
First page: 11
Abstract: The success of the thixoforming process largely depends on the created microstructure, which must be globular in the liquid phase. The solid–liquid structural changes that occur on as-annealed D2 tool steel when it is subjected to the so-called DPRM are described in this work (direct partial remelting method). The paper discusses phase changes and how carbide dissolution affects grain boundary liquation and grain spheroidization. Equiaxed grains with undissolved carbide particles have been found in the microstructural analysis at 1250 °C; however, the carbides gradually disappear as the temperature rises. Additionally, the equiaxed grains were transformed to a globular structure, which improves the shape factor and grain size for the thixoforming process. For AISI D2 thixoforming, which produced grains with a diameter of 50 μm and a shape factor of 1.18, temperatures of 1300 °C and a holding period of 5 min were the optimum parameters. The outcomes also showed that the mechanical properties of the AISI D2 were greatly enhanced after using direct partial remelting, where hardness was increased from 220 Hv to 350 Hv and tensile strength from 791 MPa to 961 MPa.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-12-28
DOI: 10.3390/jmmp7010011
Issue No: Vol. 7, No. 1 (2022)
- JMMP, Vol. 7, Pages 12: Tube Joining by a Sheet Flange Connection
Authors: Rafael M. Afonso, Luís M. Alves
First page: 12
Abstract: Joining of tubes to tubes by means of plastic deformation at ambient temperature allows one to solve the main limitations produced by the necessity of joining thin-walled tubes of low-to-medium diameter size made from materials that are not suitable to be welded and/or have reduced contact interfaces. The new joining solution allows one to obtain permanent mechanical joints of tubes or pipes by means of an accessory lightweight sheet metal flange subjected to annular indentation and subsequent injection of its material towards the tube walls to produce a mechanical interlock between the different elements. The sheet-flange connection can then be utilized to affix the joined tube assembly to walls or other different structures and equipment, by means of fasteners or other joining accessories attached to the sheet flange. Similar or dissimilar material combinations can be easily and safely produced while guaranteeing levels of leak-tightness within the maximum internal operating pressure of the individual tubes. A combined numerical–experimental approach is employed to identify the operative parameters as well as to explain the deformation conditions. Pull-out loads and internal fluid pressure are applied to the manufactured joint to evaluate its behavior under typical operating conditions that it may be subjected to during its service life depending on the application.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-12-29
DOI: 10.3390/jmmp7010012
Issue No: Vol. 7, No. 1 (2022)
- JMMP, Vol. 7, Pages 13: Material Behavior around the FSW/FSP Tool
Described by Molecular Dynamics
Authors: Bentejui Medina, Ricardo Fernández
First page: 13
Abstract: Friction stir welding and processing (FSW/FSP) involves severe plastic deformation of metals or polymers at high temperature around a rotating tool. The material’s flow is usually modelled by FEM using a complex combination of thermomechanical and friction models. However, the description of the behavior of the first atomic layers in contact with the tool cannot be undertaken by continuum mechanics modelling such as FEM. Among the available simulation techniques, molecular dynamics (MD) where friction and heat are generated by material layers’ relative movement, allows the simulation of the behavior of the first atomic layers of the work piece in contact with the tool. In this work, in aluminum, the effect of temperature and advancing and rotating speeds on FSW/FSP material’s flow and crystallography in the vicinity of the tool are discussed. The data analyzed demonstrate that a normalization of the weld-pitch parameter by the pin radius allows obtaining reliable heat input, momentum, and temperatures typical of this critical region in the FSW/FSP processes by MD. The results show that MD provide reliable data as an input for the FEM in a multiscale FSW/FSP modelling.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-12-30
DOI: 10.3390/jmmp7010013
Issue No: Vol. 7, No. 1 (2022)
- JMMP, Vol. 6, Pages 134: Irregular Shape Effect of Brass and Copper Filler
on the Properties of Metal Epoxy Composite (MEC) for Rapid Tooling
Application
Authors: Radhwan Hussin, Safian Sharif, Shayfull Zamree Abd Rahim, Allan Rennie, Mohd Azlan Suhaimi, Abdellah El-hadj Abdellah, Norshah Afizi Shuaib, Mohd Tanwyn Mohd Khushairi, Aurel Mihail Titu
First page: 134
Abstract: Due to their low shrinkage and easy moldability, metal epoxy composites (MEC) are recognized as an alternative material that can be applied as hybrid mold inserts manufactured with rapid tooling (RT) technologies. Although many studies have been conducted on MEC or reinforced composite, research on the material properties, especially on thermal conductivity and compressive strength, that contribute to the overall mold insert performance and molded part quality are still lacking. The purpose of this research is to investigate the effect of the cooling efficiency using MEC materials. Thus, this research aims to appraise a new formulation of MEC materials as mold inserts by further improving the mold insert performance. The effects of the thermal, physical, and mechanical properties of MEC mold inserts were examined using particles of brass (EB), copper (EC), and a combination of brass + copper (EBC) in irregular shapes. These particles were weighed at percentages ranging from 10% to 60% when mixed with epoxy resin to produce specimens according to related ASTM standards. A microstructure analysis was made using a scanning electron microscope (SEM) to investigate brass and copper particle distribution. When filler composition was increased from 10% to 60%, the values of density (g/cm3), hardness (Hv), and thermal conductivity (W/mK) showed a linear upward trend, with the highest value occurring at the highest filler composition percentage. The addition of filler composition increased the compressive strength, with the highest average compressive strength value occurring between 20% and 30% filler composition. Compressive strength indicated a nonlinear uptrend and decreased with increasing composition by more than 30%. The maximum value of compressive strength for EB, EC, and EBC was within the range of 90–104 MPa, with EB having the highest value (104 MPa). The ANSYS simulation software was used to conduct a transient thermal analysis in order to evaluate the cooling performance of the mold inserts. EC outperformed the EB and EBC in terms of cooling efficiency based on the results of thermal transient analysis at high compressive strength and high thermal conductivity conditions.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-11-02
DOI: 10.3390/jmmp6060134
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 135: Key Technology of Intelligentized Welding
Authors: Qiang Liu, Chao Chen, Shanben Chen
First page: 135
Abstract: With the development of the Internet of Things (IoT), Big Data, Artificial Intelligence technology, and the emergence of modern information technologies such as intelligent manufacturing, welding systems are changing, and intelligentized welding manufacturing and systems (IWMS) utilizing these technologies are attracting attention from both academia and industry. This paper investigates sensing technology, multi-information sensor fusion technology, feature recognition technology, the quality prediction method, control method, and intelligent welding production line application in the IWMS. Combining IoT technology and multi-agent systems, a hierarchical structure model welding manufacturing system (IoT-MAS) in the form of “leader-following” was constructed. The multi-agent welding manufacturing system has the advantages of distribution, intelligence, internal coordination and so on. The IoT-MAS consists of several sub-agents, which are divided into five categories according to their functions and internal processing logic. Combined with the functions of the intelligent welding manufacturing system, the agent structure of the whole welding process was proposed, and the matching communication technology and algorithm were designed. The intelligent welding manufacturing system based on IoT-MAS proposed in this paper can effectively solve the integrated design problem of large welding manufacturing systems.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-11-05
DOI: 10.3390/jmmp6060135
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 136: Critical Barriers to Industry 4.0 Adoption in
Manufacturing Organizations and Their Mitigation Strategies
Authors: Ahmed Sayem, Pronob Kumar Biswas, Mohammad Muhshin Aziz Khan, Luca Romoli, Michela Dalle Mura
First page: 136
Abstract: The fourth industrial revolution, fueled by automation and digital technology advancements, enables us to manage manufacturing systems effectively. Its deployment in enterprises has now become increasingly important in developed and emerging economies. Many experts believe that barriers associated with Industry 4.0 implementation are critical to its success. Therefore, this study aimed to identify the major hurdles to Industry 4.0 adoption and reveal their interrelationships. Initially, the literature was thoroughly studied to determine the sixteen barriers impeding I4.0 adoption. Then, based on experts’ opinions, an integrated fuzzy-DEMATEL approach was utilized to examine the most significant challenges to I4.0 deployment. The results demonstrated the distribution of barriers in which the economic dimension played a decisive role, affecting technological, regulatory, and organizational dimensions. As observed in the barrier mapping, the lack of qualified workforce was a typical adoption barrier. Finally, the mitigation strategies developed would help managers to overcome the identified critical obstacles.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-11-07
DOI: 10.3390/jmmp6060136
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 137: Virtual Sensor for Accuracy Monitoring in CNC
Machines
Authors: Felix Doerrer, Andreas Otto, Martin Kolouch, Steffen Ihlenfeldt
First page: 137
Abstract: Vibrations are limiting the productivity and the process quality of cutting machine tools. For the monitoring of these vibrations, often external sensors, such as acceleration sensors, are used. These external systems require additional cost and maintenance effort. This paper presents a virtual sensor, which is capable of detecting vibrations at the tool center point, based on internal machine data. External sensors are only necessary once for model identification. This reduces the overall cost of the system significantly. The virtual sensor uses the high-quality data of the linear position encoder near the ball screw nut and calculates the vibrations at the tool tip by using transmissibility functions. This paper explains the theory behind the used transmissibility functions and describes how they are measured, by comparing different experimental approaches to identify the modal parameters of cutting machine tools. After the identification of the sensor, a dynamical test cycle is used to prove the physical correctness.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-11-11
DOI: 10.3390/jmmp6060137
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 138: Tribological Behavior of Additively Manufactured
Metal Components
Authors: Raj Shah, Nikhil Pai, Andreas Rosenkranz, Khosro Shirvani, Max Marian
First page: 138
Abstract: Additive manufacturing (AM) has recently become an increasingly popular form of production due to its advantages over traditional manufacturing methods, such as accessibility, the potential to produce parts with complex geometry, and reduced waste. For the widespread industry adoption of AM components, metal AM has the most potential. The most popular methods of metal AM are powder-based manufacturing techniques. Due to the layer-by-layer nature of AM, the mechanical and tribological properties of an additive manufactured part differs from those of traditionally manufactured components. For the technology to develop and grow further, the tribological properties of AM components must be fully explored and characterized. The choice of material, surface textures, and post-processing methods are shown to have significant impact on friction and wear. Therefore, this paper focuses on reviewing the existing literature with an emphasis on the development of advanced materials for AM applications as well as the optimization of the resulting surface quality via post-processing and presents areas of interest for further examination in this prospective technology.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-11-11
DOI: 10.3390/jmmp6060138
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 139: Laser Powder Bed Fusion Tool Repair: Statistical
Analysis of 1.2343/H11 Tool Steel Process Parameters and Microstructural
Analysis of the Repair Interface
Authors: Sandra Megahed, Raphael Koch, Johannes Henrich Schleifenbaum
First page: 139
Abstract: High pressure die casting (HPDC) tools undergo several repairs during their life cycle. Traditional repair methods (e.g., welding) cannot always be applied on damaged tools, necessitating complete replacement. Usually, direct energy deposition (DED) is considered and applied to repair tools. In this study, the potential of laser powder bed fusion (LPBF) for HPDC tool repair is investigated. LPBF of the hot work tool steel 1.2343/H11 normally requires preheating temperatures above 200 °C to overcome cracking. Therefore, a process window for the crack-susceptible hot work tool steel 1.2343/H11 with no preheating was developed to avoid preheating an entire preform. Laser power, hatch distance, and scan speed are varied to maximize relative density. Since the correlation of LPBF process parameters and resulting build quality is not fully understood yet, the relationship between process parameters and surface roughness is statistically determined. The identification of suitable process parameters with no preheating allowed crack-free processing of 1.2343/H11 tool steel via LPBF in this study. The LPBF repair of a volume of ~2000 cm3 was successfully carried out and microstructurally and mechanically characterized. A special focus lays on the interface between the worn HPDC tool and additive reconstruction, since it must withstand the mechanical and thermal loads during the HPDC process.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-11-11
DOI: 10.3390/jmmp6060139
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 140: Towards an Ideal Energy Absorber: Relating
Failure Mechanisms and Energy Absorption Metrics in Additively
Manufactured AlSi10Mg Cellular Structures under Quasistatic Compression
Authors: Shinde, Ramirez-Chavez, Anderson, Fait, Jarrett, Bhate
First page: 140
Abstract: A designer of metallic energy absorption structures using additively manufactured cellular materials must address the question of which of a multitude of cell shapes to select from, the majority of which are classified as either honeycomb, beam-lattice, or Triply Periodic Minimal Surface (TPMS) structures. Furthermore, there is more than one criterion that needs to be assessed to make this selection. In this work, six cellular structures (hexagonal honeycomb, auxetic and Voronoi lattice, and diamond, gyroid, and Schwarz-P TPMS) spanning all three types were studied under quasistatic compression and compared to each other in the context of the energy absorption metrics of most relevance to a designer. These shapes were also separately studied with tubes enclosing them. All of the structures were fabricated out of AlSi10Mg with the laser powder bed fusion (PBF-LB. or LPBF) process. Experimental results were assessed in the context of four criteria: the relationship between the specific energy absorption (SEA) and maximum transmitted stress, the undulation of the stress plateau, the densification efficiency, and the design tunability of the shapes tested—the latter two are proposed here for the first time. Failure mechanisms were studied in depth to relate them to the observed mechanical response. The results reveal that auxetic and Voronoi lattice structures have low SEA relative to maximum transmitted stresses, and low densification efficiencies, but are highly tunable. TPMS structures on the other hand, in particular the diamond and gyroid shapes, had the best overall performance, with the honeycomb structures between the two groups. Enclosing cellular structures in tubes increased peak stress while also increasing plateau stress undulations.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-11-13
DOI: 10.3390/jmmp6060140
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 141: Automated Defect Analysis of Additively
Fabricated Metallic Parts Using Deep Convolutional Neural Networks
Authors: Saber Nemati, Hamed Ghadimi, Xin Li, Leslie G. Butler, Hao Wen, Shengmin Guo
First page: 141
Abstract: Laser powder bed fusion (LPBF)-based additive manufacturing (AM) has the flexibility in fabricating parts with complex geometries. However, using non-optimized processing parameters or using certain feedstock powders, internal defects (pores, cracks, etc.) may occur inside the parts. Having a thorough and statistical understanding of these defects can help researchers find the correlations between processing parameters/feedstock materials and possible internal defects. To establish a tool that can automatically detect defects in AM parts, in this research, X-ray CT images of Inconel 939 samples fabricated by LPBF are analyzed using U-Net architecture with different sets of hyperparameters. The hyperparameters of the network are tuned in such a way that yields maximum segmentation accuracy with reasonable computational cost. The trained network is able to segment the unbalanced classes of pores and cracks with a mean intersection over union (mIoU) value of 82% on the test set, and has reduced the characterization time from a few weeks to less than a day compared to conventional manual methods. It is shown that the major bottleneck in improving the accuracy is uncertainty in labeled data and the necessity for adopting a semi-supervised approach, which needs to be addressed first in future research.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-11-13
DOI: 10.3390/jmmp6060141
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 142: A Comprehensive Review of High-Pressure
Laser-Induced Materials Processing, Part II: Laser-Driven Dynamic
Compression within Diamond Anvil Cells
Authors: Mohamad E. Alabdulkarim, Wendy D. Maxwell, Vibhor Thapliyal, James L. Maxwell
First page: 142
Abstract: The field of high-pressure materials research has grown steadily over the last seven decades, with many remarkable discoveries having been made. This work is part II of a three-part series summarising recent progress in laser material processing within diamond anvil cells (L-DACs); this article focuses on the practice of laser-driven dynamic compression within diamond anvil cells (i.e., LDC–DAC experimentation). In this case, materials are initially pre-compressed within diamond anvil cells, then further dynamically compressed through the use of a high-power pulsed laser, often with the intent to isentropically compress, rather than to heat samples. The LDC–DAC approach provides a novel route to much higher dynamic pressures (approaching 1 TPa), as compared to conventional static compression within a single-stage DAC (<300 GPa) and provides a route to mapping Hugoniot curves. Recent proliferation of low-cost, high-power laser sources has led to increased research activity in LDC–DAC materials processing over the last two decades. Through LDC–DAC experiments, a greater understanding of the properties/structure of cold- and warm-dense matter has been obtained, and novel material phases have been realised. In this article, LDC–DAC experimental methods are reviewed, together with the underlying physics of laser dynamic compression in confined spaces. In addition, a chronology of important events in the development of LDC–DAC processing is provided, and emerging trends, gaps in knowledge, and suggestions for further work are considered.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-11-14
DOI: 10.3390/jmmp6060142
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 143: Investigating the Friction Behavior of
Turn-Milled High Friction Surface Microstructures under Different
Tribological Influence Factors
Authors: Jonathan Schanner, Roman Funke, Andreas Schubert, Alexander Hasse
First page: 143
Abstract: The coefficient of friction (COF) is an important parameter for mechanical engineers to consider when designing frictional connections. Previous work has shown that a surface microstructuring of the harder friction partner leads to a significant increase in the COF. However, the impact of the changes in the tribological system on the COF are not known in detail. In this study, the tribological influence factors such as the nominal surface pressure, the material pairing, lubrication, and the surface properties of the counterbody are investigated. Microstructuring is applied by turn-milling of an annular contact surface of cylindrical specimens. A torsional test bench is used to measure the torque depending on the displacement of the two specimens, thus enabling the determination of the COF. All tests with the microstructured specimens result in higher COF than the reference test with unstructured samples. The manufacturing process of the counterbody surface, the nominal surface pressure, and the materials in contact have a significant influence on the COF. While lubrication reduces friction in the case of unstructured specimens, the COF does not change significantly for microstructured samples. This proves that the deformative friction component dominates over the adhesive. Microstructuring the harder friction partner increases the transmittable torque in frictional connections and reduces the sensitivity towards possible contamination with lubricants.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-11-15
DOI: 10.3390/jmmp6060143
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 144: Improved Coil Design for Magnetic Pulse Welding
of Metallic Sheets
Authors: Rishabh Shotri, Koen Faes, Guillaume Racineux, Amitava De
First page: 144
Abstract: Magnetic pulse welding of overlapping dissimilar metallic sheets is an emerging technique and usually employs flat electromagnetic coils with rectangular-, H-, I-, and E-shaped cross-sections. The asymmetric cross-section of these coils results in a non-uniform electromagnetic field and in a non-uniform connection in the interface between the overlapping sheets. In this article, the use of a novel O-shaped flat coil is proposed to join an aluminium flyer sheet with a target steel sheet. A finite element-based numerical model is developed to calculate the electromagnetic field, flyer velocity, and its gradual impact onto the target, and the deformations of the sheet assembly. The calculated results with the O-shaped coil show a high-intensity electromagnetic field, the concentration of which decreases radially outwards in a uniform manner. The numerically computed and experimentally measured flyer velocity are found to be in fair agreement. The calculated results show a regularly decreasing impact behaviour between the flyer and target and their resulting deformation. The measured results show the formation of an annular ring-shaped joint profile that is generally found to be stronger compared to that obtained with flat coils with a rectangular cross-section.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-11-16
DOI: 10.3390/jmmp6060144
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 145: Prediction of Machining Condition Using Time
Series Imaging and Deep Learning in Slot Milling of Titanium Alloy
Authors: Faramarz Hojati, Bahman Azarhoushang, Amir Daneshi, Rostam Hajyaghaee Khiabani
First page: 145
Abstract: Low surface quality, undesired geometrical and dimensional tolerances, and product damage due to tool wear and tool breakage lead to a dramatic increase in production cost. In this regard, monitoring tool conditions and the machining process are crucial to prevent unwanted events during the process and guarantee cost-effective and high-quality production. This study aims to predict critical machining conditions concerning surface roughness and tool breakage in slot milling of titanium alloy. Using the Siemens SINUMERIK Edge Box integrated into a CNC machine tool, signals were recorded from main spindle and different axes. Instead of extraction of features from signals, the Gramian angular field (GAF) was used to encode the whole signal into an image with no loss of information. Afterwards, the images obtained from different machining conditions were used for training a convolutional neural network (CNN) as a suitable and frequently applied deep learning method for images. The combination of GAF and trained CNN model indicates good performance in predicting critical machining conditions, particularly in the case of an imbalanced dataset. The trained classification CNN model resulted in recall, precision, and accuracy with 75%, 88%, and 94% values, respectively, for the prediction of workpiece surface quality and tool breakage.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-11-16
DOI: 10.3390/jmmp6060145
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 146: Characterisation of Fibre Bundle Deformation
Behaviour—Test Rig, Results and Conclusions
Authors: Andreas Borowski, Benjamin Gröger, René Füßel, Maik Gude
First page: 146
Abstract: Deformation of continuous fibre reinforced plastics during thermally-assisted forming or joining processes leads to a change of the initial material structure. The load behaviour of composite parts strongly depends on the resultant material structure. The prediction of this material structure is a challenging task and requires a deep knowledge of the material behaviour above melting temperature and the occurring complex forming phenomena. Through this knowledge, the optimisation of manufacturing parameters for a more efficient and reproducible process can be enabled and are in the focus of many investigations. In the present paper, a simplified pultrusion test rig is developed and presented to investigate the deformation behaviour of a thermoplastic semi-finished fiber product in a forming element. Therefore, different process parameters, like forming element temperature, pulling velocity as well as the forming element geometry, are varied. The deformation behaviour in the forming zone of the thermoplastic preimpregnated continuous glass fibre-reinforced material is investigated by computed tomography and the resultant pulling forces are measured. The results clearly show the correlation between the forming element temperature and the resulting forces due to a change in the viscosity of the thermoplastic matrix and the resulting fiber matrix interaction. In addition, the evaluation of the measurement data shows which forming forces are required to change the shape of the thermoplastic unidirectional material with a rectangular cross-section to a round one.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-11-17
DOI: 10.3390/jmmp6060146
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 147: Residual Stresses in a High- and a Medium-Entropy
Alloy due to TIG and Friction Stir Welding
Authors: Tim Richter, Dirk Schroepfer, Michael Rhode
First page: 147
Abstract: The new alloying concept of multi-element systems with defined entropy (HEA—high-entropy alloy; MEA—medium-entropy alloy) is gaining increasing importance in materials research. Significantly improved properties or combinations of properties are shown by some HEA/MEA systems. Thus, primarily the production and resulting microstructures of HEA, as well as its properties, have been investigated so far. Furthermore, processing is a main issue in transferring HEA systems from the laboratory to real components. Since welding is the most important joining process for metals, it is crucial to investigate the influence of welding to guarantee component integrity. Welding leads to residual stresses, which significantly affect the component integrity. Hence, the focus of this study is the residual stress formation and distribution in a CoCrFeMnNi HEA and ternary CoCrNi MEA using two different welding processes: tungsten inert gas (TIG) welding and solid-state friction stir welding (FSW). As a pathway for the application of HEA in this investigation, for the first time, residual stress analyses in realistic near-component specimens were performed. The residual stresses were determined by X-ray diffraction (XRD) on the surfaces of top and root weld side. The results were correlated with the local welding microstructures. The results show that both FSW and TIG generate significant tensile residual stresses on the weld surfaces in, and transverse to, the welding direction. In the case of FSW of the CoCrFeMnNi HEA, the longitudinal residual stresses are in the range of the yield strength of approx. 260 MPa in the weld zone.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-11-18
DOI: 10.3390/jmmp6060147
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 148: Al-Cu-Mg Alloy Powder Reinforced with Graphene
Nanoplatelets: Morphology, Flowability and Discrete Element Simulation
Authors: Mulla Ahmet Pekok, Rossitza Setchi, Michael Ryan, Heng Gu, Quanquan Han, Dongdong Gu
First page: 148
Abstract: Research in metal matrix composites (MMCs) indicates that superior mechanical properties may be achieved by embedding reinforcement materials. However, the development of new composite powder for additive manufacturing requires an in-depth understanding of its key characteristics prior to its use in the fabrication process. This paper focuses on the low-energy ball milling (LEBM) of aluminium 2024 alloy (AA2024) reinforced with graphene nanoplatelets (GNPs). The main aim is to investigate the effect of the milling time (from 0.5 to 16 h) on the morphology and flowability of the powder. The study shows that, while short milling times (under 2 h) could not break the Van der WaRals forces between nanoparticles, GNPs were well separated and sufficiently covered the powder surface after 4 h of milling, thanks to the continuously applied impact energy. Longer milling time provides increasingly similar flowability results, confirmed by both the experimental work and discrete element model (DEM) simulations. Moreover, the ball milling process decreases the crystallite size of the milled powder by 24%, leading to a 3% higher microhardness. Lastly, the surface energy of the powder was determined as 1.4 mJ/m2 by DEM, using the angle of repose of the as-received powder from experimental work.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-11-21
DOI: 10.3390/jmmp6060148
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 149: High Precision Nut Threading Using Real-Time
Tapping Torques Monitoring
Authors: Tsung-Chun Lin, Michael Schabacker, Guan-Shong Hwang, Jau-Woei Perng, Der-Min Tsay
First page: 149
Abstract: With the increasing demand for safety and automatically locking nuts, it’s important to guarantee a consistent nut quality. Traditionally, a floating tapping machine has been used for high-speed production, but it has unstable thread quality because of the existing gap between the tap and nuts holder. To overcome this problem, a stable tapping machine must be considered for tapping high precision threaded nuts and the tapping process must be monitored in real-time for the internal threads quality to reduce the inspection time. First, this article used the relative movement between a nut and its tap to establish the dimensionless tapping material removal rate. Furthermore, for creating the tapping torque curve of a specific nut, a few nuts were tapped to obtain the maximum value and variation of the tapping torque at various tapping speeds. Then, based on the differences in the hole sizes, chamfer depths, and material nature, the quality assurance range can be constructed as a real-time monitoring model for high precision thread manufacturing. To demonstrate the feasibility of the proposed procedure, tapping for carbon steel, alloy steel, and titanium alloy nuts was performed and the monitored tapping torques matched the nut quality classification of Japanese Industrial Standards (JIS).
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-11-21
DOI: 10.3390/jmmp6060149
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 150: Optimization of Wire-EDM Process Parameters for
Al-Mg-0.6Si-0.35Fe/15%RHA/5%Cu Hybrid Metal Matrix Composite Using TOPSIS:
Processing and Characterizations
Authors: Jatinder Kumar, Shubham Sharma, Jujhar Singh, Sunpreet Singh, Gurminder Singh
First page: 150
Abstract: The current experimental study concerns obtaining the optimal set of wire-EDM processing factors for a novel Al-Mg-0.6Si-0.35Fe/15%RHA/5%Cu hybrid aluminum matrix composite. The composite exhibits hardness of 64.2 HRB, tensile strength 104.6 MPa, impact energy 4.8 joules, when tested using standard testing techniques. For this, composite is formulated with the help of a stir casting route. The tests are conducted as per Taguchi’s L27 OA, to explore the influence of processing factors on the surface roughness (Ra), radial overcut (ROC) and material removal rate (MRR). The optimization is executed using the Taguchi approach, followed by multiple objective optimizations with TOPSIS (one of the MADM techniques). For optimal values of Ra, MRR and ROC, the optimum set of input variables is suggested as 150 A of current, 125 μs of pulse duration, 50 μs of pulse interval and 8 mm/min of wire feed-rate. Predicted performance index value was calculated and was compared with the experiment value. It has been observed that both values are very close to each other with only 1.33% error, which means the results are validated. ANOVA confirms that current is a predominant factor influencing response characteristic parameters, which contributes 24.09%, followed by pulse duration (16.78%) and pulse interval (15.18%). The surface characterization using a scanning electron microscope (SEM), X-ray diffraction (XRD), energy dispersive spectroscope (EDS) and optical microscope (OM) has also been carried out to affirm the existence of the reinforcing particles in the base matrix.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-11-22
DOI: 10.3390/jmmp6060150
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 151: Quality Analysis of Weld-Line Defects in Carbon
Fibre Reinforced Sheet Moulding Compounds by Automated Eddy Current
Scanning
Authors: Nessa Fereshteh-Saniee, Neil Reynolds, Danielle Norman, Connie Qian, David J. Armstrong, Paul Smith, Richard Kupke, Mark A. Williams, Kenneth Kendall
First page: 151
Abstract: Discontinuous fibre reinforced composites enable the manufacture of integrated structural components via the complex flow process of compression moulding. However, such processes can lead to the formation of detrimental weld-lines. Here, the meso-structure of carbon fibre sheet moulding compounds (C-SMC) was analysed using conventional non-destructive techniques and automated eddy current (EC) scanning, as well as destructive methods, in an attempt to identify defects such as weld-lines in this class of materials. Compression-moulded plaques with forced weld-lines in two different configurations (adjacent and opposing flow joints) were analysed, showing up to 80% strength reduction versus a defect-free plaque. The EC-determined local fibre orientation and elucidated local microstructure matched those obtained using conventional techniques, showing a dramatic fibre tow alignment parallel to the weld-lines. It was found that failure occurred in proximity to the “non-uniformity” defect regions identified by EC analyses, demonstrating the use of robot-guided EC for successful defect detection in C-SMC structures.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-11-22
DOI: 10.3390/jmmp6060151
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 152: Springback Behavior of
Aluminum/Polypropylene/Aluminum Sandwich Laminates
Authors: Caroline K. Kella, Pankaj K. Mallick
First page: 152
Abstract: The springback of sheet metals after forming has been widely studied for decades using numerical and experimental methods. Many of these springback studies involve aluminum alloys. This study aims to understand the springback behavior of aluminum-polypropylene-aluminum laminates as they are being used increasingly in automotive and other applications because of their weight saving potential. A finite element model of the draw bending of a U-channel based on Numisheet’93 benchmark study is built using LS-DYNA. First, the model is validated and studied for springback prediction of single AA5182-O aluminum alloy sheets, and then it is extended to the study of the springback behaviors of AA5182-O/polypropylene/AA5182-O laminates with various combinations of core and skin thicknesses. The numerical model is also validated by experiment. Effects of various tool design and process parameters, such die radius, punch radius and blank holder force, on the springback of the sandwich laminates are studied. The effect of numerical modeling parameters is also considered.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-11-23
DOI: 10.3390/jmmp6060152
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 153: Residual Heat Effect on the Melt Pool Geometry
during the Laser Powder Bed Fusion Process
Authors: Subin Shrestha, Kevin Chou
First page: 153
Abstract: The continuous back-and-forth melting of the powder bed during the laser powder bed fusion (LPBF) process leads to the development of residual heat, which affects the melt pool geometry as the laser scan progresses. The magnitude of the residual heat depends on the scan length, hatch spacing, location on the track, etc. In this regard, back-and-forth raster scanning was performed to investigate the effect of the scan length and hatch spacing on the melt pool size at different locations along the laser travel direction. Multi-track specimens with different scan lengths (0.5 mm, 1 mm, and 1.5 mm) were fabricated using 195 W laser power, three scan speeds (375 mm/s, 750 mm/s, and 1500 mm/s), and two hatch spacings (80 µm and 120 µm). A white light interferometer was used to analyze the surface morphologies of the fabricated samples, and metallography was performed to observe the melt pool boundary. The melt pool boundary obtained at different locations revealed that the effect of the residual heat was maximal in the laser-turn region. In addition, a powder scale numerical model was developed to investigate the effect of temperature distribution on the melt pool geometry. The numerical results show that the laser-turn region was most affected by the residual heat, as the melt pool from the two tracks merged. The depth of the melt pool increased with increasing track numbers, while the track height decreased. The addition of a second layer of powder showed that the inherent surface variation in the first layer leads to the difference in the actual layer thickness of the second layer.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-11-30
DOI: 10.3390/jmmp6060153
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 154: On the Lubricity and Comparative Life Cycle of
Biobased Synthetic and Mineral Oil Emulsions in Machining Titanium
Ti-6Al-4V at Low Cutting Speed
Authors: Paul Wood, Fathi Boud, Wayne Carter, Hirbod Varasteh, Urvashi Gunputh, Marzena Pawlik, Jenny Clementson, Yiling Lu, Syed Hossain, Matthew Broderick, Munusamy Raguraman, Andy Smith, Andy Mantle, Jamie McGourlay
First page: 154
Abstract: The paper discusses an instrumented tapping test method using a CNC machine tool to compare the lubricity of MWFs by cutting threads in a Ti-6Al-4V alloy at low speed. The method uses a spiral flute tap size typical of industrial practice. A soft synchronous tap holder and spindle mounted dynamometer were incorporated on the machine to measure torque and thrust force. The tapping test method was demonstrated on three groups of MWFs that were commercially available and classified by ASTM E2523-13:2018. The method developed stable results free of chip clogging in tool flutes which could otherwise mask their comparative lubricity. The fully synthetic (FS) group displayed the best lubricity and within this group the FS from renewables (FS-bio) was the best overall. The method was shown to be effective in mitigating biasing effects on lubricity performance due to the generous tool chamfer angle tolerance and was practical and economical to implement. The significance of the results is discussed enabling an understanding of friction effects in tapping using a soft synchronous tap holder. A life cycle assessment of each MWF group found total Greenhouse Gas emitted from the FS group was 17% of the hydrocarbon group whilst FS-bio emitted just 7%.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-12-02
DOI: 10.3390/jmmp6060154
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 155: Localized Defects in Cold Die-Compacted Metal
Powders
Authors: Elisa Torresani, Gloria Ischia, Alberto Molinari
First page: 155
Abstract: In powder metallurgy (PM), the compaction step is fundamental to determining the final properties of the sintered components. The deformation and defectiveness introduced in the powder material during uniaxial die compaction can be correlated to the activation and enhancement of the dislocation pipe diffusion, a lattice diffusion mechanism during the sintering process. Its coefficient depends on the dislocation density. The powder particles are mostly deformed along the direction of the compaction (longitudinal direction) rather than along the compaction plane; consequently, the contact areas perpendicular to the direction of the compaction present a higher density of dislocations and lattice defects. This high density intensifies the shrinkage along the direction of compaction. To demonstrate the influence of uniaxial cold compaction on the material’s stress state the powder particles and their contacts were modeled using spheres made of pure copper. These spheres are compacted in a die at different pressures to better analyze the system’s response at the grade of deformation and the consequent influence on the material’s behavior during the sintering. In the different zones of the sphere, the micro-hardness was measured and correlated to the concentration of dislocations using the model for indentation size effect (ISE). After the compaction, the spheres were more deformed along the longitudinal than the transversal direction. The results obtained using hardness indentation show differences in the dislocation density between the undeformed and deformed spheres and, in the case of the compacted sphere, between the contact area along the longitudinal and the transversal direction.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-12-06
DOI: 10.3390/jmmp6060155
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 156: Laser Additive Manufacturing of High-Strength
Aluminum Alloys: Challenges and Strategies
Authors: Som Dixit, Shunyu Liu
First page: 156
Abstract: Metal additive manufacturing (AM)-fabricated high-strength aluminum (HS-Al) alloys (2xxx, 6xxx, and 7xxx) tend to produce fatal metallurgical defects such as porosity and cracks. Since Al is the most important lightweight structural material in automotive and aviation industries, successful printing of HS-Al alloys is in high demand. Therefore, this review focuses on the formation mechanisms and research advancements to address these metallurgical defects. Firstly, the process optimization strategies, including AM parameter optimization, hybrid AM processes, and post-processing treatment, and their effectiveness and limitations have been reviewed thoroughly. However, process optimization can address defects such as porosity, surface roughness, and residual stresses but has limited effectiveness on cracking alleviation. Secondly, the research efforts on composition modification to address cracking in AM of HS-Al alloys are critically discussed. Different from process optimization, composition modification alters the solidification dynamics in AM of HS-Al alloys and hence is considered the most promising route for crack-free printing.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-12-08
DOI: 10.3390/jmmp6060156
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 157: Extrusion Additive Manufacturing of PEI Pellets
Authors: Matteo Fabrizio, Matteo Strano, Daniele Farioli, Hermes Giberti
First page: 157
Abstract: The simplest, most cost-efficient, and most widespread Additive Manufacturing (AM) technology is Extrusion Additive Manufacturing (EAM). Usually, EAM is performed with filament feedstock, but using pellets instead of filaments yields many benefits, including significantly lower cost and a wider choice of materials. High-performance polymers offer high strength even when produced with AM technique, allowing to produce near-net-shape functional parts. The production of these materials in filament form is still limited and expensive; therefore, in this paper, the possibility of producing AM components with engineering polymers from pellets will be thoroughly investigated. In this work, the effectiveness of a specially designed AM machine for printing high-performance materials in pellet form was tested. The material chosen for the investigation is PEI 1000 which offers outstanding mechanical and thermal properties, giving the possibility to produce with EAM functional components. Sensitivity analyses have been carried out to define a process window in terms of thermal process parameters by observing different response variables. Using the process parameters in the specified range, the additive manufactured material has been mechanically tested, and its microstructure has been investigated, both in dried and undried conditions. Finally, a rapid tool for sheet metal forming has been produced.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-12-08
DOI: 10.3390/jmmp6060157
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 158: Laser-Based Additive Manufacturing of Magnesium
Authors: Fard, Sharifianjazi, Kazemi, Rostamani, Bathaei
First page: 158
Abstract: Metallic biomedical implants are made from materials such as stainless steel, titanium, magnesium, and cobalt-based alloys. As a degradable biometal, magnesium (Mg) and its alloys are becoming more popular for applications in bone tissue engineering. Mg-based alloys have been found to be biocompatible, bioabsorbable, and bioactive, allowing them to be used as orthopedic implants with a low Young’s modulus. Computer-aided design can be used to design scaffolds with intricate porous structures based on patient-specific anatomical data. These models can be materialized rapidly and with reasonably acceptable dimensional accuracy by additive manufacturing (AM) techniques. It is known that lasers are the most widely investigated energy source for AM’ed Mg, as they offer some distinct advantages over other forms of energy. Recent studies have focused on developing biodegradable Mg scaffolds by using laser-based AM techniques. In this paper, we aim to review the recent progress of laser-based AM for Mg alloys and survey challenges in the research and future development of AM’ed Mg scaffolds for clinical applications.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-12-10
DOI: 10.3390/jmmp6060158
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 159: New Self-Clinching Fasteners for Electric
Conductive Connections
Authors: Rui F. V. Sampaio, João P. M. Pragana, Ricardo G. Clara, Ivo M. F. Bragança, Carlos M. A. Silva, Paulo A. F. Martins
First page: 159
Abstract: This paper presents new rotational and longitudinal symmetric self-clinching fasteners to fabricate reliable connections in busbars with low electrical resistance for energy distribution systems. Connections consist of form-closed joints that are hidden inside regions where two busbars overlap. The investigation into the fabrication and performance of the new self-clinched joints involved finite element modelling and experimentation to determine the required forces and to evaluate the electric current flow and the electrical resistance at different service temperatures. The original design of the joints that was proposed in a previous work was modified to account for busbar strips of copper and/or aluminum with similar or dissimilar thicknesses, connected by means of self-clinching fasteners made from the same materials of the busbars, instead of steel. The effectiveness of the new self-clinched joints was compared to that of conventional bolted joints that are included in the paper for reference purposes. The results show that rotational symmetric self-clinching fasteners yield lighter fabrication and more compact joints with a similar electrical resistance to that of bolted joints. They also show that longitudinal symmetric self-clinching fasteners aimed at replicating the resistance-seam-welding contact conditions yield a reduction in electrical resistance to values close to that of ideal joints, consisting of two strips in perfect contact and without contaminant or oxide films along their overlapped surfaces.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-12-12
DOI: 10.3390/jmmp6060159
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 160: Friction Stir Weldability at High Welding Speed
of Two Structural High Pressure Die Casting Aluminum Alloys
Authors: Vivas, Fernández-Calvo, Aldanondo, Irastorza, Álvarez
First page: 160
Abstract: In this work, the friction stir weldability of two structural high-pressure die casting aluminum alloys designed to manufacture thin-walled automotive components is investigated and compared. AlSi10MnMg and AlMg4Fe2 alloys were friction stir welded at a high welding speed (from 500 to 2000 mm/min) for a fixed rotation speed of 1500 RPM. The investigation was performed by studying the material flow influence on defect formation and microstructure, the mechanical properties of the welds and the forces that act during the friction stir welding process. The AlSi10MnMg alloy shows a lower incidence of defects than the AlMg4Fe2 alloy at all welding speeds investigated. Both materials present a great friction stir welding performance at 500 mm/min with a high joint efficiency in terms of ultimate tensile strength: 92% in AlSi10MnMg alloy and 99% in AlMg4Fe2 alloy.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-12-12
DOI: 10.3390/jmmp6060160
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 161: Sustainable Manufacturability of Archimedes Screw
Turbines: A Critical Review
Authors: Aristotle T. Ubando, Isidro Antonio V. Marfori, Marnel S. Peradilla, Charlle L. Sy, Andre Marvin A. Calapatia, Wei-Hsin Chen
First page: 161
Abstract: Archimedes screw turbines are considered a new technology in small- or microscale hydropower. Archimedes screw turbines are easy and practical to operate. However, their manufacturing presents some challenges owing to their screw-shaped design. Most of the previous works on Archimedes screw turbines focused on the turbines’ design, while limited studies were found on their manufacturing processes. In addition, no review work was found on the manufacturability of the Archimedes screw turbine. Hence, this work aims to address this gap by reviewing the various manufacturing methods of Archimedes screw turbines. Moreover, one of the objectives of the study is to assess the sustainable manufacturability of the Archimedes screw turbine. The results show that Archimedes screw turbines are mainly manufactured using conventional manufacturing methods for larger turbines and 3D printers for relatively smaller ones. Traditional methods of manufacturing entailed high skill proficiency, while 3D-printing methods for Archimedes screw turbines are still in their early developmental stages. Sustainable assessment studies have identified additive manufacturing as having a relatively lower environmental impact than conventional manufacturing on turbine blades. These trade-offs must be accounted for in the design and development of Archimedes screw turbines. Moreover, integrating sustainability assessment and the employment of Industry 4.0 enables the smart production and sustainable assessment of AST manufacturability.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-12-13
DOI: 10.3390/jmmp6060161
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 162: Latest Developments and Insights of Orthopedic
Implants in Biomaterials Using Additive Manufacturing Technologies
Authors: Asarudheen Abdudeen, Jaber E. Abu Qudeiri, Ansar Kareem, Anasmon Koderi Valappil
First page: 162
Abstract: The additive manufacturing (AM) process is used for joining materials to make objects from 3D model data, usually layer upon layer, contrary to subtractive manufacturing methods. This technology plays a significant role in fabricating orthopedic implants, especially parts of hip implants (HI), such as femoral head, stem, neck, polyethylene linear, acetabular shell, and so on, using biomaterials. These biodegradable resources are those that can be utilized as tissue substitutes since they are accepted by live tissues. Here, the study is to examine the most preferable AM process and biomaterial used for making HI, including its manufacturing methods, compositions, types, advantages, and defects and cross-examining the limitations to bring some new technology in the future. Then we elaborate on the outlook of the most preferable material, followed by evaluating its biocompatibility, detailed application, and structural defects occurring while using it as an HI. Subsequently, the physical characteristics and design constraints are also reviewed in the paper. We assess the current stage of the topology optimization technique (TO) with respect to the characteristics of newly designed implants. The review concludes with future perspectives and directions for research.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-12-14
DOI: 10.3390/jmmp6060162
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 163: Investigating the Properties of ABS-Based Plastic
Composites Manufactured by Composite Plastic Manufacturing
Authors: Raghunath Bhaskar, Javaid Butt, Hassan Shirvani
First page: 163
Abstract: Additive manufacturing (AM) technologies have revolutionized the manufacturing sector due to their benefits, such as design flexibility, ease of operation, and wide material selection. The use of AM in composites production has also become quite popular to leverage these benefits and produce products with customized properties. In this context, thermoplastic materials are widely used in the development of plastic-based composites due to their affordability and availability. In this work, composite plastic manufacturing (CPM) has been used to manufacture plastic-based composites with bespoke properties in a cost- and time-effective manner. Various plastic-based composites have been manufactured using CPM by interlacing acrylonitrile butadiene styrene (ABS) with thermally activated materials. Three different thermally activated materials (graphene–carbon hybrid paste, heat cure epoxy, and graphene epoxy paste) have been used in this work to produce plastic-based composites. Thermally activated materials that are commercially available include graphene–carbon hybrid paste and heat cure epoxy. The graphene epoxy paste was a concoction made by incorporating three different weight percentages of graphene nanoplatelets (0.2 wt.%, 0.4 wt.%, and 0.6 wt.%) with heat cure epoxy. The composites were manufactured with multiple layers of thermally activated materials at different intervals to investigate their effect. The parts were manufactured and tested according to British and international standards. Experimental tests of mass, dimensions, ultrasonics, tensile strength, hardness, and flexural strength were conducted to evaluate the properties of composites manufactured by CPM. The parts manufactured by CPM showed superior mechanical properties compared to commercially available ABS. The increase was shown to be in the range of 8.1% to 33% for tensile strength, 17.8% to 30.2% for hardness, and 6.2% to 24.4% for flexural strength, based on the composite configurations. The results demonstrate that the CPM process can produce high-quality plastic composites and can be used to create products with customized properties in a time-effective manner.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-12-17
DOI: 10.3390/jmmp6060163
Issue No: Vol. 6, No. 6 (2022)
- JMMP, Vol. 6, Pages 164: Lamellar Spacing Modelling for LPBF Aluminum
Parts
Authors: Eva Anglada, José Carlos García, Mario Arrue, Xabier Cearsolo, Iñaki Garmendia
First page: 164
Abstract: The high cooling rates reached during metal additive manufacturing (MAM) generate microstructures very different from those obtained by other conventional manufacturing methods. Therefore, research about the modeling of this type of microstructure is of great interest to the MAM community. In this work, the prediction of the lamellar spacing of an AlSi10Mg sample manufactured by laser powder bed fusion (LPBF), is presented. A multiscale approach is used, combining a CALPHAD (Computer Coupling of Phase Diagrams and Thermochemistry) model to predict the material properties, with a macroscale model of the sample manufacturing and with a microscale model to predict the microstructure. The manufacturing and metallographic characterization of the sample is also included. The results prove that the multiscale strategy followed is a valid approximation to simulate this type of manufacturing process. In addition, it is shown that the use of a generic simulation software focused on metal casting processes can be useful in predicting the lamellar spacing of the microstructure manufactured by LPBF. Finally, the relationship between the cooling rate and the resulting lamellar spacing has been established for this AlSi10Mg under the specific manufacturing conditions considered.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-12-17
DOI: 10.3390/jmmp6060164
Issue No: Vol. 6, No. 6 (2022)
