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Journal of Manufacturing and Materials Processing
Number of Followers: 0  Open Access journalISSN (Online) 2504-4494 Published by MDPI  [84 journals]
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- JMMP, Vol. 6, Pages 49: Fabrication of Punch and Die Using Plasma-Assisted
3D Printing Technology for Piercing Sheet Metals
Authors: Tatsuhiko Aizawa, Yohei Suzuki, Tomoaki Yoshino, Tomomi Shiratori
First page: 49
Abstract: A pair of punch and die was often fabricated using subtractive manufacturing processes such as milling and other machining processes. However, additive manufacturing could be used to perform the same processes. This study explored this possibility. In particular, this study fabricated a pair of T-shaped punch and die made of AISI316L austenitic stainless steel using an additive manufacturing process called plasma-assisted 3D printing. Accordingly, T-shaped negative and positive 2D patterns were screen-printed onto the mirror-polished surfaces of the substrates made of AISI316L austenitic stainless steel. The printed film worked like a mask to prevent the printed substrate surfaces from nitriding. In order to form a thick nitrided layer, the unprinted substrate surfaces were selectively nitrided at 673 K for 14.4 ks. The un-nitrided segments of the substrates were uniformly removed by sand-blasting that involved shooting silica particles on the substrate’s surfaces. As a result, the substrates printed with negative and positive T-shaped patterns were transformed into the punch head and die cavity. In order to see the efficacy of the fabricated punch and die pair, this pair was used for piercing the electrical steel sheets under a controlled clearance. Scanning Electron Microscopy with Energy Dispersive X-ray (SEM-EDX) was used to measure surface topography after piercing. In addition, SEM and a 3D profilometer were used to measure the punch and die profiles after piercing. The abovementioned measurement results showed that the fabricated punch and die exhibited highly accurate piercing behavior. Thus, the plasma-assisted 3D printing was useful for punch and die fabrication.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-04-20
DOI: 10.3390/jmmp6030049
Issue No: Vol. 6, No. 3 (2022)
- JMMP, Vol. 6, Pages 50: Experimental and Numerical Investigations of the
Deep Rolling Process to Analyze the Local Deformation Behavior of Welded
Joints
Authors: Steffen Heikebrügge, Bernd Breidenstein, Benjamin Bergmann, Christian Dänekas, Peter Schaumann
First page: 50
Abstract: Welded joints show a comparably low fatigue strength compared to the base material. Thus, different post-weld treatment methods are used to enhance the fatigue strength of welded joints. A promising method to enhance the fatigue strength of metallic components is the deep rolling process, but this has rarely been applied to welds. For the qualification of the deep rolling process as an effective post-weld treatment method, knowledge about its influence on the surface and subsurface properties at the fatigue critical weld toe is necessary. Here, geometrical and metallurgical inhomogeneities lead to complex contact states between deep rolling tools and weld toes. Thus, for a first analysis of the local deformation behavior during deep rolling of welded joints, experimentally and numerically generated deep rolling single tracks are compared. Cyclic strain-controlled tests to determine the material behavior were carried out for the numerical analyses using finite element simulation. The presented study shows that it is possible to describe the local deformation of welded joints during deep rolling using finite element simulation. A correct depiction of material behavior is crucial for such an analysis. It was shown that certain irregularities in material behavior lead to lower coincidences between simulation and experiment, especially for the investigated welds, where only low differences in hardness between base material, heat-affected zone, and filler material were found.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-04-20
DOI: 10.3390/jmmp6030050
Issue No: Vol. 6, No. 3 (2022)
- JMMP, Vol. 6, Pages 51: Characterization of the Interaction of
Metalworking Fluids with Grinding Wheels
Authors: Lukas Schumski, Nikolai Guba, Björn Espenhahn, Dirk Stöbener, Andreas Fischer, Daniel Meyer
First page: 51
Abstract: The thermal load that occurs during grinding can be reduced with the aid of an optimized metalworking fluid (MWF) supply. In previous work, mainly the free jet was considered for the determination of the conditions required for an optimized MWF supply. An investigation of the interaction area between the MWF and the grinding wheel has not yet been carried out due to the lack of suitable measurement techniques. In the presented work, both the free jet and the interaction area are analyzed with the aid of new metrological analysis and evaluation methods based on high-speed records (shadowgraphy and shadogram imaging velocimetry) in order to assess the free jet geometry and velocities, as well as the velocity distribution and the MWF amount in the interaction area. Using this approach, the following main results were derived: (1) The free jet velocity remains approximately constant in a defined free jet cross-section even at high distances from the nozzle outlet. (2) The velocity distribution in the interaction area is mainly influenced by the flow rate. (3) A new image parameter (black pixel fraction) was derived for the evaluation of the MWF supply to the contact zone.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-04-21
DOI: 10.3390/jmmp6030051
Issue No: Vol. 6, No. 3 (2022)
- JMMP, Vol. 6, Pages 52: Effects of Heat Treatment on Microstructure and
Mechanical Properties of AlSi10Mg Fabricated by Selective Laser Melting
Process
Authors: Catherine Dolly Clement, Julie Masson, Abu Syed Kabir
First page: 52
Abstract: AlSi10Mg is the most widely additively manufactured and commercialized aluminum alloy and has been used in this study to analyze the effect of heat treatment on its microstructure and mechanical properties. Although research indicates AlSi10Mg parts produced by selective laser melting have characteristically very fine microstructures, there is a need for more intensive study to comprehend the effect of heat treatment on the mechanical properties of this alloy by analyzing its microstructure. In this study, AlSi10Mg specimens heat-treated at varying temperatures were analyzed by optical and electron microscopes. Micro-indentation hardness and tensile tests were performed to evaluate mechanical properties while considering the specimen build orientation. Observation shows that it is nearly impossible to completely dissolve the evolved second phase silicon-rich particles, which may have significant effects on the mechanical characteristics. Electron microscopy images show the evolution of iron-rich particles in the Al matrix, which may have a significant influence on the mechanical properties of the alloy.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-04-22
DOI: 10.3390/jmmp6030052
Issue No: Vol. 6, No. 3 (2022)
- JMMP, Vol. 6, Pages 53: Influence of the Reaction Injection Moulding
Process on the Thermomechanical Behaviour of Fast Curing Polyurethane
Authors: Peter Lehmenkühler, Markus Stommel
First page: 53
Abstract: In this contribution, the influence of the reaction injection moulding process on the thermomechanical material behaviour of aliphatic hexamethylene diisocyanate (HDI) based fast curing polyurethane is demonstrated. Uniaxial tensile tests, temperature-frequency dependent dynamic mechanical thermal analysis (DMTA) and Differential Scanning Calorimetry (DSC) are used to show the differences in properties for ten different sets of process parameters. The mould and resin components temperature, the mass flow during the filling process and the residence time during the reaction process of the polyurethane are varied in several stages. Further experiments to determine the molar mass of the molecular chain between two crosslinking points of the polyurethane are used to explain the process influences on the thermomechanical properties. Thus, a direct correlation between manufacturing and material properties is shown. In addition, the mutual effect of the different parameters and their overall influence on the material behaviour is presented.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-05-03
DOI: 10.3390/jmmp6030053
Issue No: Vol. 6, No. 3 (2022)
- JMMP, Vol. 6, Pages 54: Additive Surface Graining in Prototype Tooling for
Injection Molding
Authors: Peter Burggräf, Georg Bergweiler, Josef Andrew Abrams, Anna Dunst
First page: 54
Abstract: Surface properties of injection molded parts have a strong effect on the visual and haptic perception of the parts by customers. Especially for injection molded automotive interior parts, grained surfaces can often be found. In conventional tooling, graining requires separate process steps. This makes the realization of grained injection molded prototype parts very complex. By additive manufacturing of injection molds in prototype tooling, it is possible to print micro structures into the mold surface in one printing operation. An injection mold with four different graining structures varying in depth and distance was designed and additively manufactured. The specification regarding the surface graining was analyzed by means of roughness measurements of the CAD model, injection mold and injection molded parts. Results show the feasibility of highly controllable additive surface graining.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-05-05
DOI: 10.3390/jmmp6030054
Issue No: Vol. 6, No. 3 (2022)
- JMMP, Vol. 6, Pages 55: Insight into the Expected Impact of Sustainable
Development in the Context of Industry 4.0: A Documentary Analysis
Approach Based on Multiple Case Studies across the World
Authors: Wilian Jesús Pech-Rodríguez, Eddie Nahúm Armendáriz-Mireles, Gladis Guadalupe Suárez-Velázquez, Carlos Adrián Calles-Arriaga, Enrique Rocha-Rangel
First page: 55
Abstract: Although industry 4.0 has gained increased attention in the industry, academic, and governmental fields, there is a lack of information about the relationship between this digital transformation and sustainable development. This work explores the concept of sustainability applied in industry 4.0 and the main advantages that this revolution incorporates into society. To this end, a conscientiously documented investigation was conducted by reviewing actual case studies or scenarios where sustainability was applied in different manufacturing industries, enterprises, or research fields worldwide. A critical and descriptive analysis of the information was performed to identify the main tools and procedures that can be implemented in the industry to address the triple bottom line perspective of industry 4.0, and the results are presented in this document. From the analysis, it was observed that currently, I4.0 has been mainly adopted to improve efficiency and cost reduction in manufacturing companies. However, since only a few enterprises embrace the social paradigm of I4.0, a significant gap in understanding and unbalance is visualized. Therefore, we conclude that there is a lack of information on social benefits and the barriers that must be overcome from the social perspective. On the other hand, this work highlights the importance of adopting industry 4.0 as a positive way to improve the performance of emerging technologies, such as fuel cells, solar cells, and wind turbines, while producing products or services with high efficiency and profitability incomes. For practitioners, this work can provide insightful information about the real implications of I4.0 from a sustainability perspective in our daily life and the possible strategies to improve sustainable development.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-05-20
DOI: 10.3390/jmmp6030055
Issue No: Vol. 6, No. 3 (2022)
- JMMP, Vol. 6, Pages 56: Comparative Analysis of the Solid Conveying of
Regrind, Virgin and Powdery Polyolefins in Single-Screw Extrusion
Authors: Kai S. Johann, Adrian Reißing, Christian Bonten
First page: 56
Abstract: The shape and size of processed materials play a crucial role in the solid conveying characteristics of single-screw extruders. Thus, the increasing amount of plastic regrind leads to new challenges in screw extrusion. This work investigates the conveying behavior of three distinctly different material shapes in an axially as well as a helically grooved solid conveying zone. A uniform virgin polypropylene (PP) granule, an irregularly plate-shaped PP regrind and a powdery polyethylene (PE) are processed at screw speeds up to 1350 rpm. Thereby, frictionally engaged conveying in the grooves is visualized for the utilized powder. Similarly, the virgin granule is subject to forced conveying by interlocking in the grooves. The experimentally determined throughput is furthermore compared to analytical calculations which assume a so-called nut–screw conveying. It is found that these calculations perfectly predict the throughput when processing the virgin granule and the powder in a helically grooved barrel. In contrast, the analytical calculation significantly underestimates the throughput for the regrind. This underestimation is expected to be mainly caused by its plate shape and a difference in bulk density. The actual bulk density in the extruder is probably significantly higher due to both orientation and compaction effects compared to the measured bulk density that is used for the analytical calculation. Additionally, the regrind exhibits a fluctuating throughput due to the non-constant bulk density, which results from an irregular regrind shape and a broad size distribution.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-05-24
DOI: 10.3390/jmmp6030056
Issue No: Vol. 6, No. 3 (2022)
- JMMP, Vol. 6, Pages 57: Investigating the Influence of Material Extrusion
Rates and Line Widths on FFF-Printed Graphene-Enhanced PLA
Authors: Javaid Butt, Raghunath Bhaskar, Vahaj Mohaghegh
First page: 57
Abstract: Fused filament fabrication (FFF) is a widely used additive manufacturing process that can produce parts from thermoplastics. Its ease of operation and wide variety of materials make it a popular choice for manufacturing. To leverage such benefits, the commonly used thermoplastics (e.g., PLA and ABS) are impregnated with nanoparticles, short or continuous fibers, and other additives. The addition of graphene nanoplatelets to PLA makes for a high-quality filament possessing enhanced mechanical, electrical, and thermal properties. Even with the advancement in materials, the optimisation of the process parameter remains the most complex aspect for FFF. Therefore, this study investigates the influence of two under-researched and overlooked processing parameters (material extrusion rates and line widths) on commercially available graphene-enhanced PLA (GPLA). Nine different material extrusion rates (70% to 150%) and five different line widths (0.2 mm to 1 mm) were used to manufacture GPLA specimens using a low-cost, desktop-based 3D printer, as per British and international standards. The study analyses the influence of these two processing parameters on mass, dimensional accuracy, surface texture, and mechanical properties of GPLA specimens. A non-destructive test has also been conducted and correlated with three-point flexural test to establish its applicability in evaluating flexural properties of GPLA. The results how that small line widths provide more accuracy with longer print times whereas large line widths offer more strength with shorter printing times. Increase in material extrusion rates adversely affect the surface finish and hardness but positively influence the flexural strength of GPLA specimens. The study shows that the manipulation of material extrusion rates and line widths can help designers in understanding the limitations of the default printing settings (100% material extrusion rate and 0.4 mm line width) on most desktop 3D printers and identifying the optimal combination to achieve desired properties using the FFF process.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-05-24
DOI: 10.3390/jmmp6030057
Issue No: Vol. 6, No. 3 (2022)
- JMMP, Vol. 6, Pages 58: Modelling and Optimization of Machining of
Ti-6Al-4V Titanium Alloy Using Machine Learning and Design of Experiments
Methods
Authors: José Outeiro, Wenyu Cheng, Francisco Chinesta, Amine Ammar
First page: 58
Abstract: Ti-6Al-4V titanium is considered a difficult-to-cut material used in critical applications in the aerospace industry requiring high reliability levels. An appropriate selection of cutting conditions can improve the machinability of this alloy and the surface integrity of the machined surface, including the generation of compressive residual stresses. In this paper, orthogonal cutting tests of Ti-6Al-4V titanium were performed using coated and uncoated tungsten carbide tools. Suitable design of experiments (DOE) was used to investigate the influence of the cutting conditions (cutting speed Vc, uncut chip thickness h, tool rake angle γn, and the cutting edge radius rn) on the forces, chip compression ratio, and residual stresses. Due to the time consumed and the high cost of the residual stress measurements, they were only measured for selected cutting conditions of the DOE. Then, the machine learning method based on mathematical regression analysis was applied to predict the residual stresses for other cutting conditions of the DOE. Finally, the optimal cutting conditions that minimize the machining outcomes were determined. The results showed that when increasing the compressive residual stresses at the machined surface by 40%, the rake angle should be increased from negative (−6°) to positive (5°), the cutting edge radius should be doubled (from 16 µm to 30 µm), and the cutting speed should be reduced by 67% (from 60 to 20 m/min).
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-05-27
DOI: 10.3390/jmmp6030058
Issue No: Vol. 6, No. 3 (2022)
- JMMP, Vol. 6, Pages 59: Assembly Line Overall Equipment Effectiveness
(OEE) Prediction from Human Estimation to Supervised Machine Learning
Authors: Péter Dobra, János Jósvai
First page: 59
Abstract: Nowadays, in the domain of production logistics, one of the most complex planning processes is the accurate forecasting of production and assembly efficiency. In industrial companies, Overall Equipment Effectiveness (OEE) is one of the most common used efficiency measures at semi-automatic assembly lines. Proper estimation supports the right use of resources and more accurate and cost-effective delivery to the customers. This paper presents the prediction of OEE by comparing human prediction with one of the techniques of supervised machine learning through a real-life example. In addition to descriptive statistics, takt time-based decision trees are applied and the target-oriented OEE prediction model is presented. This concept takes into account recent data and assembly line targets with different weights. Using the model, the value of OEE can be predicted with an accuracy of within 1% on a weekly basis, four weeks in advance.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-05-27
DOI: 10.3390/jmmp6030059
Issue No: Vol. 6, No. 3 (2022)
- JMMP, Vol. 6, Pages 60: Powder Metallurgical Processing of Sn-Reinforced
Authors: Yagnesh Shadangi, Vikas Shivam, Kausik Chattopadhyay, Nilay Krishna Mukhopadhyay
First page: 60
Abstract: The present work deals with powder metallurgical processing of Sn-reinforced Al-Cu-Fe icosahedral quasicrystalline (IQC) composites processed through mechanical milling (MM) followed by hot pressing and pressureless sintering. The structure, microstructure and toughening behavior of the nanocomposite powders and bulk samples were investigated through X-ray diffraction (XRD), optical metallography (OM), scanning electron microscopy (SEM) and indentation techniques. The XRD pattern suggested the coexistence of IQC and λ-Al13Fe4 (mC102; a = 1.549 nm, b = 0.808 nm, c = 1.248 nm) and B2-type Al (Cu, Fe) (cP2; a = 0.29 nm) crystalline phases in milled as well as sintered samples. The face-centered icosahedral (FCI) ordering was persistent even after 40 h of milling and sintering. The structural transformation during MM influences the indentation behavior of IQC-Sn nanocomposite powders, and the microhardness was found to be in the range of ~5.3 to 7.3 GPa. Further, efforts were made to study the indentation behavior of IQC-Sn composite prepared by pressureless sintering and hot pressing. The fracture toughness of the IQC-10Sn hot-pressed sample was found to be ~1.92 MPa.√m, which is ~22% higher than that of the as-cast and annealed IQC. The enhancement in the fracture toughness resulted mainly from the inhibition of cracks by Sn reinforcement particles. This suggests that powder metallurgical processing can produce the IQC-Sn composite with an optimal combination of microhardness and fracture toughness.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-05-31
DOI: 10.3390/jmmp6030060
Issue No: Vol. 6, No. 3 (2022)
- JMMP, Vol. 6, Pages 61: On the Accurate Prediction of Residual Stress in a
Three-Pass Slot Nickel-Base Repair Weld by Numerical Simulations
Authors: Vasileios Akrivos, Ondrej Muransky, Lionel Depradeux, Michael C. Smith, Anastasia Vasileiou, Viorel Deaconu, Priyesh Kapadia
First page: 61
Abstract: The activities within a European network to develop accurate experimental and numerical methods to assess residual stresses in structural weldments are reported. The NeT Task Group 6 or NeT-TG6 project examined an Alloy 600 plate containing a three-pass slot weld made with Alloy 82 consumables. A number of identical specimens were fabricated and detailed records of the manufacturing history were kept. Parallel measurement and simulation round robins were performed. Residual stresses were measured using neutron diffraction via five different instruments. The acquired database is large enough to generate reliable mean profiles, to identify clear outliers, and to establish the systematic uncertainty associated with this non-destructive technique. NeT-TG6 gives a valuable insight into the real-world variability of diffraction-based residual stress measurements, and forms a reliable foundation against which to benchmark other measurement methods. The mean measured profiles were used to validate the accuracy achieved by the network in the prediction of residual stresses.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-06-01
DOI: 10.3390/jmmp6030061
Issue No: Vol. 6, No. 3 (2022)
- JMMP, Vol. 6, Pages 62: Tooling and Infusion Design Strategies to Reduce
Trade-Offs in Forming and Infusion Quality of Multi-Textile CFRPs
Authors: Nikita Budwal, Kent Kasper, Jon Goering, Carwyn Ward
First page: 62
Abstract: Achieving right-first-time-manufacture (RFTM) of co-infused textile assemblies is challenging, without improving the accessibility to design knowledge of trade-offs between different tooling and infusion strategies. As demonstrated in previous work, the choice between a flexible or rigid mould material can result in trade-offs between dimensional accuracy and geometrical precision. Similarly, the choice of an infusion strategy can result in trade-offs in infusion quality and time. Building on past work, an investigation into forming variability across the length of six co-infused multi-textile components, with three different tooling inserts and two infusions set-ups, was conducted. To quantitatively assess variation, a method adapting principles of statistical process control was employed to analyse the yarn crimp measured from high-resolution cross-sectional scans of the components. The results were compared to a geometrical and dimensional analysis of the manufactured parts presented in a previous work. The analysis represents a method for capturing forming differences in textile preforms, which can be used to inform designs for the manufacture of textile CFRPs. The results were used to improve a hybrid rigid-flexible tooling design for an infused multi-textile component.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-06-09
DOI: 10.3390/jmmp6030062
Issue No: Vol. 6, No. 3 (2022)
- JMMP, Vol. 6, Pages 63: A Combination of Alloy Modification and Heat
Treatment Strategies toward Enhancing the Properties of LPBF Processed Hot
Working Tool Steels (HWTS)
Authors: Iris Raffeis, Frank Adjei-Kyeremeh, Simon Ewald, Johannes Henrich Schleifenbaum, Andreas Bührig-Polaczek
First page: 63
Abstract: Hot working tool steels (HWTS) are popular for industrial applications such as injection molding tools, and casting dies because of their high wear resistance, fatigue, strength, and toughness properties, even at elevated temperatures. Conventionally, they go through multi-stage heat treatments in order to attain targeted microstructures. Achieving such microstructures with a laser powder bed fusion (LPBF) process will require tailor-made process parameters since it is characterized by non-equilibrium conditions, non-uniform temperature distribution, and metastable phase formation. Recent advances in the LPBF qualification of 1.2343/4 HWTS have shown commendable results but are still fraught with the limitations of poor ductility or extra post-heat treatment steps. For the industrial competitiveness of LPBF HWTS, the enhancement of strength and ductility and elimination of post processing is critical. Therefore, minimizing retained austenite in the as-built samples through pre-heat treatment or alloying to reduce post heat treatments without sacrificing strength will be economically important for industry. In this work, 1.2343 HWTS and its modified form were LPBF printed both in the as-built, pre- and post-heat-treated conditions. The results are discussed based on the correlations of the powder properties with LPBF—part density, microstructure, and mechanical properties.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-06-10
DOI: 10.3390/jmmp6030063
Issue No: Vol. 6, No. 3 (2022)
- JMMP, Vol. 6, Pages 64: Physical Simulation of Laser Surface Treatment to
Study Softening Effect on Age-Hardened Aluminium Alloys
Authors: Maria Emanuela Palmieri, Luigi Tricarico
First page: 64
Abstract: The automotive industry is interested in manufacturing components with tailored mechanical properties. To this end, advanced heating treatments can be exploited to obtain the so-called Tailored Heat-Treated Blanks (THTB). However, mechanical properties are strongly affected by the process parameters of heating treatments, which require a preliminary design. Physical simulation can be a decisive tool in this phase to obtain useful information at the laboratory scale, even when heat treatments such as those carried out with laser technologies impose high heating and cooling rates on the material. This work uses physical simulation to investigate the changes in strength and ductility caused by laser heat treatment (LHT) on aluminum alloys hardened by aging; the methodology was implemented on the EN AW 6082 T6 alloy. First, a finite-element (FE) transient thermal model was developed to simulate LHT by varying the process parameters (laser power/peak temperature and treatment speed). Second, the resulting thermal cycles were physically simulated by means of the Gleeble 3180 system. Third, the strength and the ductility of physically simulated specimens were evaluated through micro-hardness and tensile tests; to study aging effects, investigations were performed both (i) right after Gleeble tests (samples in the supersaturated solid state, i.e., as-physically simulated (APS) state) and (ii) after one week from Gleeble tests (aged specimens—T4 state). The obtained results show that there are peak temperatures that guarantee maximum softening levels for each investigated state (T4 and APS). The optimal peak temperature ranges are in agreement with the data in the literature, demonstrating that the proposed methodology is suitable for the study of softening phenomena on aging-hardened aluminum alloys.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-06-10
DOI: 10.3390/jmmp6030064
Issue No: Vol. 6, No. 3 (2022)
- JMMP, Vol. 6, Pages 65: Additive Manufacturing: An Opportunity for the
Fabrication of Near-Net-Shape NiTi Implants
Authors: Mir Saman Safavi, Aydin Bordbar-Khiabani, Jafar Khalil-Allafi, Masoud Mozafari, Livia Visai
First page: 65
Abstract: Nickel–titanium (NiTi) is a shape-memory alloy, a type of material whose name is derived from its ability to recover its original shape upon heating to a certain temperature. NiTi falls under the umbrella of metallic materials, offering high superelasticity, acceptable corrosion resistance, a relatively low elastic modulus, and desirable biocompatibility. There are several challenges regarding the processing and machinability of NiTi, originating from its high ductility and reactivity. Additive manufacturing (AM), commonly known as 3D printing, is a promising candidate for solving problems in the fabrication of near-net-shape NiTi biomaterials with controlled porosity. Powder-bed fusion and directed energy deposition are AM approaches employed to produce synthetic NiTi implants. A short summary of the principles and the pros and cons of these approaches is provided. The influence of the operating parameters, which can change the microstructural features, including the porosity content and orientation of the crystals, on the mechanical properties is addressed. Surface-modification techniques are recommended for suppressing the Ni ion leaching from the surface of AM-fabricated NiTi, which is a technical challenge faced by the long-term in vivo application of NiTi.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-06-14
DOI: 10.3390/jmmp6030065
Issue No: Vol. 6, No. 3 (2022)
- JMMP, Vol. 6, Pages 66: Carbonated 3D-Printable Polymer Composite for
Thermo-Mechanically Stable Applications
Authors: Fareed Dawan, Melvin Givens, Lakeira Williams, Patrick Mensah
First page: 66
Abstract: In this report, we investigate the infusion of carbon dioxide into a 3D-printable photosensitive polymer. The result is a carbonated polymer composite material. In use, polymer composite materials expect to succeed where ordinary polymers and metals fail. This is due to the tailorability of composite materials for specific applications. Usually, micro/nano-particulates are embedded as fillers within a polymer matrix, enhancing the overall material properties. Here, carbon dioxide (CO2) microbubbles serve as the filler within a nylon-like polymer matrix. Additive manufacturing by stereolithography (SLA) of the carbonated polymer composite proved possible using the digital light projection (DLP) 3D printing technique. Post-heat treatment using thermogravimetric analysis of the samples at elevated temperatures resulted in a 33% mass reduction, indicative of nearly complete solvent removal and curing. An initial increase in polymer carbonation duration showed a 16% increase in porosity, more stable thermal profiles, and a 40% decrease in specific heat capacity. Thermo-mechanical compressive tests on an optimal carbonated sample revealed a 70% increase in compressive strength over its neat counterpart and a peak modulus at 50 °C of 60 MPa. Such 3D-printable carbonated polymer composites may find use in applications requiring high strength-to-weight ratio thermally stable polymers and applications requiring a versatile and convenient storage medium for on-demand CO2 deposition or supercritical fluid phase transformation.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-06-15
DOI: 10.3390/jmmp6030066
Issue No: Vol. 6, No. 3 (2022)
- JMMP, Vol. 6, Pages 27: Improvement of Cooling Effect and Dimensional
Accuracy of Wire and Arc Additive Manufactured Magnesium Alloy by
Active-Cooling-Based Contacting Copper Blocks
Authors: Hideaki Nagamatsu, Hiroyuki Sasahara
First page: 27
Abstract: Wire and arc additive manufacturing (WAAM) employing a magnesium (Mg) alloy is superior in terms of safety, energy efficiency, and deposition rate when compared with a process that utilizes lasers and powder materials. However, problems with WAAM employing an Mg alloy include poor dimensional accuracy due to low viscosity of the molten Mg alloy. In addition, since Mg alloys cause a combustion reaction with water, an effective cooling method, such as direct water cooling, cannot be applied. In this study, a solid contact-based active cooling method employing copper blocks with high thermal conductivity was proposed to improve the dimensional accuracy and cooling efficiency of fabricated objects using AZ31. Moreover, the proposed method renders it possible to fabricate a wall structure with high flatness as the molten AZ31 solidifies upon direct contact with the flat surface of copper blocks. In addition, the copper blocks harboring an internal water circulation system achieved a higher cooling efficiency and shortened the interval cooling time between the deposition of subsequent layers. Meanwhile, it was discovered that the arc deflected toward the copper blocks, not onto the substrate or the previous layer when the wire tip approached too close to the blocks.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-02-24
DOI: 10.3390/jmmp6020027
Issue No: Vol. 6, No. 2 (2022)
- JMMP, Vol. 6, Pages 28: Spark Plasma Sintering of Electric Discharge
Machinable 1.5Yb-1.5Sm-TZP-WC Composites
Authors: Ella Walter, Maximilian Rapp, Frank Kern
First page: 28
Abstract: Electrically conductive zirconia tungsten carbide composites are attractive materials for manufacturing precision components by electrical discharge machining due to their high strength, toughness and electrical conductivity. In this study, nanocomposite ceramics with a ytterbia samaria co-stabilized zirconia 1.5Yb-1.5Sm-TZP matrix and 24–32 vol.% tungsten carbide dispersion were manufactured by spark plasma sintering (SPS) at 1400 °C for 15 min at 60 MPa pressure. The materials exhibited high strengths of 1300–1600 MPa, a moderate fracture resistance of 6 MPa√m and an ultrafine microstructure with grain sizes in the 150 nm range. Scanning electron microscopy and RAMAN spectroscopy revealed the in situ formation of carbon during the SPS process and carbon formation scales with tungsten carbide content, and this apparently impedes bending strength.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-02-24
DOI: 10.3390/jmmp6020028
Issue No: Vol. 6, No. 2 (2022)
- JMMP, Vol. 6, Pages 29: Boronizing of CoCrFeMnNi High-Entropy Alloys Using
Spark Plasma Sintering
Authors: Hiroaki Nakajo, Akio Nishimoto
First page: 29
Abstract: In this study, we investigated the formation of a protective coating on a face-centered cubic high-entropy alloy (HEA). The coating was formed by a diffusion coating method. In the conventional diffusion coating method, the degradation of the mechanical properties of the base material owing to prolonged high-temperature treatment is a major issue. Therefore, we formed a ceramic layer using spark plasma sintering (SPS), which suppresses grain growth with rapid heating and enables fast, low-temperature processing. The objective of this study was to form borides on the surface of CoCrFeMnNi HEAs using the SPS method and to investigate their properties. A CoCrFeMnNi HEA prepared by the casting method was used as the base material, and a powdered mixture of B4C and KBF4 was used as the boron source. The analysis of the surfaces of the SPS-treated samples revealed the formation of M2B, MB, and Mn3B4-type borides on the HEA surface. The surface hardness was 2000–2500 HV owing to the formation of a ceramic layer on the HEA surface, and elemental analysis showed that certain elements exhibited characteristic diffusion behaviors.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-02-27
DOI: 10.3390/jmmp6020029
Issue No: Vol. 6, No. 2 (2022)
- JMMP, Vol. 6, Pages 30: Benchmarking of 316L Stainless Steel Manufactured
by a Hybrid Additive/Subtractive Technology
Authors: Sheida Sarafan, Priti Wanjara, Javad Gholipour, Fabrice Bernier, Mahmoud Osman, Fatih Sikan, Josh Soost, Robert Amos, Prakash Patnaik, Mathieu Brochu
First page: 30
Abstract: This research study investigated the hybrid processing of 316L stainless steel using laser powder bed (LPB) processing with high-speed machining in the same build envelope. Benchmarking at four laser powers (160 W, 240 W, 320 W, and 380 W) was undertaken by building additively with machining passes integrated sequentially after every ten deposited layers, followed by the final finishing of select surfaces. The final geometry was inspected against the computer-aided design (CAD) model and showed deviations smaller than 280 µm for the as-built and machined surfaces, which demonstrate the good efficacy of hybrid processing for the net-shape manufacturing of stainless steel products. The arithmetic average roughness values for the printed surfaces, Ra (linear) and Sa (surface), were 11.4 um and 14.9 um, respectively. On the other hand, the vertical and horizontal machined surfaces had considerably lower roughness, with Ra and Sa values ranging between 0.33 µm and 0.70 µm. The 160 W coupon contained layered, interconnected lack of fusion defects which affected the density (7.84 g·cm−3), yield strength (494 MPa), ultimate tensile strength (604 MPa), Young’s modulus (175 GPa), and elongation at break (17.3%). By contrast, at higher laser powers, near-full density was obtained for the 240 W (7.96 g·cm−3), 320 W (7.94 g·cm−3), and 380 W (7.92 g·cm−3) conditions. This, combined with the isolated nature of the small pores, led to the tensile properties surpassing the requirements stipulated in ASTM F3184—16 for 316L stainless steel.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-03-05
DOI: 10.3390/jmmp6020030
Issue No: Vol. 6, No. 2 (2022)
- JMMP, Vol. 6, Pages 31: Nozzle Condition Monitoring System Using Root Mean
Square of Acoustic Emissions during Abrasive Waterjet Machining
Authors: Jeong-Uk Kim, Roh-Won Kim, Sung-Ryul Kim, Hyun-Hee Kim, Kyung-Chang Lee
First page: 31
Abstract: Machining of difficult-to-cut materials such as titanium alloys, stainless steel, Inconel, ceramic, glass, and carbon fiber-reinforced plastics used in the aerospace, automobile, and medical industries is being actively researched. One non-traditional machining method involves the use of an abrasive waterjet, in which ultra-high-pressure water and abrasive particles are mixed and then ejected through a nozzle, and the thin jet stream cuts materials. The nozzle greatly affects the machining quality, as does the cutting tool of general machining, so it is very important to monitor the nozzle condition. If the nozzle is damaged or worn, or if the bore size increases or the bore becomes clogged with abrasive, the material may not be cut, or the surface quality of the cut may deteriorate. Here, we develop a nozzle monitoring system employing an acoustic emission sensor that detects the nozzle condition in real time.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-03-07
DOI: 10.3390/jmmp6020031
Issue No: Vol. 6, No. 2 (2022)
- JMMP, Vol. 6, Pages 32: Influence of the L-PBF Process Atmosphere on the
Microstructure and Tensile Properties of AISI 318LN Duplex Stainless Steel
Authors: Markus Mirz, Simone Herzog, Christoph Broeckmann, Anke Kaletsch
First page: 32
Abstract: Duplex stainless steels (DSSs) have excellent mechanical properties, owing to their austenitic-ferritic microstructure. The phase equilibrium strongly depends on solidification conditions and chemical composition, where elemental nitrogen significantly stabilizes the austenitic phase. When DSSs are processed by laser powder bed fusion (L-PBF) under an argon atmosphere, the rapid cooling rates result in an undesirable fully ferritic microstructure. To better understand the microstructure formation, this study examined the influence of the L-PBF process atmosphere on the porosity, microstructure, and mechanical properties of DSS AISI 318LN. Gaseous argon and nitrogen were used as a protective atmosphere, and specimens were analyzed in the as-built and post-processed conditions via optical and electron microscopy, electron backscatter diffraction, and tensile testing. Specimens processed under a nitrogen atmosphere showed a lower initial density in the as-built conditions, and tended to form more lack-of-fusion and gas pores compared to specimens processed under argon. The different defect types in nitrogen-processed specimens were still present after solution-annealing and quenching, leading to a 13% lower tensile strength and 43% lower elongation at fracture. Differences in phase equilibrium caused by the process atmosphere could not be established. All differences in porosity can be minimized by hot isostatic pressing, thus resulting in comparable mechanical properties of argon- and nitrogen-processed specimens.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-03-10
DOI: 10.3390/jmmp6020032
Issue No: Vol. 6, No. 2 (2022)
- JMMP, Vol. 6, Pages 33: A Realistic Full-Scale 3D Modeling of Turning
Using Coupled Smoothed Particle Hydrodynamics and Finite Element Method
for Predicting Cutting Forces
Authors: Nishant Ojal, Ryan Copenhaver, Harish P. Cherukuri, Tony L. Schmitz, Kyle T. Devlugt, Adam W. Jaycox
First page: 33
Abstract: Computational modelling is an effective technique for understanding the complex physics of machining. Large deformations, material separation, and high computational requirements are the key challenges faced while simulating machining. This work introduces a full-scale three-dimensional model of turning operations using a combined approach based on the Smoothed Particle Hydrodynamics (SPH) and Finite Element (FE) methods. By exploiting the advantages of each method, this approach leads to high-fidelity coupled SPH-FE machining models. Cutting forces and chip morphology are the primary results of interest. The machining models are validated with the results of turning experiments. Two-dimensional machining model underpredicts the cutting force and feed force by approximately 49% and 70%, respectively. Moreover, passive force cannot be predicted using the two-dimensional model. On the other hand, with the three-dimensional models developed in this manuscript, the difference between the total simulated force and experimentally measured force is ∼17%. The chip morphologies correlate with experiments in terms of the direction of the chip movement and the “long” continuous chips observed while turning Al 6061. This work expands the realm of machining simulations from two-dimensional orthogonal machining or sectional three-dimensional model to a full-scale realistic simulation. The encouraging simulation results show the potential to study more complex phenomena, such as machining stability and tool path modulation.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-03-11
DOI: 10.3390/jmmp6020033
Issue No: Vol. 6, No. 2 (2022)
- JMMP, Vol. 6, Pages 34: Optimisation of Operator Support Systems through
Artificial Intelligence for the Cast Steel Industry: A Case for
Optimisation of the Oxygen Blowing Process Based on Machine Learning
Algorithms
Authors: Álvaro Ojeda Roldán, Gert Gassner, Martin Schlautmann, Luis Enrique Acevedo Galicia, Doru Stefan Andreiana, Mikko Heiskanen, Carlos Leyva Guerrero, Fernando Dorado Navas, Alejandro del Real Torres
First page: 34
Abstract: The processes involved in the metallurgical industry consume significant amounts of energy and materials, so improving their control would result in considerable improvements in the efficient use of these resources. This study is part of the MORSE H2020 Project, and it aims to implement an operator support system that improves the efficiency of the oxygen blowing process of a real cast steel foundry. For this purpose, a machine learning agent is developed according to a reinforcement learning method suitable for the dynamics of the oxygen blowing process in the cast steel factory. This reinforcement learning agent is trained with both historical data provided by the company and data generated by an external model. The trained agent will be the basis of the operator support system that will be integrated into the factory, allowing the agent to continue improving with new and real experience. The results show that the suggestions of the agent improve as it gains experience, and consequently the efficiency of the process also improves. As a result, the success rate of the process increases by 12%.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-03-12
DOI: 10.3390/jmmp6020034
Issue No: Vol. 6, No. 2 (2022)
- JMMP, Vol. 6, Pages 35: Effect of the Laser Processing Parameters on the
Selective Laser Melting of TiC–Fe-Based Cermets
Authors: Himanshu S. Maurya, Lauri Kollo, Marek Tarraste, Kristjan Juhani, Fjodor Sergejev, Konda Gokuldoss Prashanth
First page: 35
Abstract: The influence of laser pulse shaping on the formation of TiC-Fe-based cermets with different laser process parameters is investigated. The impact of pulse shaping and laser melting peak power on the microstructural development and mechanical properties of SLM-built parts is addressed. This research focuses primarily on the process parameters required to produce crack-free components and includes investigations of mechanical properties such as microhardness and fracture toughness. To acquire optimal process parameters, samples were manufactured using pulse shaping technology with varying laser melting peak power and exposure time. The influence of laser melting peak power and pulse shape on microstructure development and phases was analyzed using a scanning electron microscope and X-ray diffraction.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-03-13
DOI: 10.3390/jmmp6020035
Issue No: Vol. 6, No. 2 (2022)
- JMMP, Vol. 6, Pages 36: Mechanical Analysis of Parameter Variations in
Large-Scale Extrusion Additive Manufacturing of Thermoplastic Composites
Authors: Nevine Tagscherer, André Marcel Bär, Swen Zaremba, Klaus Drechsler
First page: 36
Abstract: Large structural parts manufactured by Extrusion Additive Manufacturing (EAM) are limited by strong anisotropy due to insufficient bond formation and reduced molecular entanglement along the layer interface. To understand the correlation between process and material parameters and to enable digital modeling of EAM, the effect of different substrate temperatures and layer heights on tensile strength was investigated. A simple testing methodology for pelletized carbon fiber-filled polyamide 6 was developed. Tensile tests were performed in a full factorial Design of Experiments (DoE) to determine the tensile properties. For bulk simulation, the nominal strength and modulus were also determined based on contact width obtained by optical microscopy. The results demonstrated high anisotropy, with the maximum transverse tensile strength reaching only 27% of the corresponding longitudinal results and the transverse tensile modulus reaching only 20% of its longitudinal value. The effects of varying layer height were less significant than varying substrate temperature. The results support the hypothesis that sufficient transverse tensile strength is achieved between the extrapolated crystallization onset and melt temperature. The methodology of this study can be used as a benchmark method to qualify new thermoplastic polymers for EAM processes and to determine optimal process parameters for improved fusion bonding.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-03-16
DOI: 10.3390/jmmp6020036
Issue No: Vol. 6, No. 2 (2022)
- JMMP, Vol. 6, Pages 37: Adapting the Surface Integrity of High-Speed Steel
Tools for Sheet-Bulk Metal Forming
Authors: Wolfgang Tillmann, Dominic Stangier, Alexander Meijer, Eugen Krebs, Alexander Ott, Timo Platt, Nelson Filipe Lopes Dias, Leif Hagen, Dirk Biermann
First page: 37
Abstract: New manufacturing technologies, such as Sheet-Bulk Metal Forming, are facing the challenges of highly stressed tool surfaces which are limiting their service life. For this reason, the load-adapted design of surfaces and the subsurface region as well as the application of wear-resistant coatings for forming dies and molds made of high-speed steel has been subject to many research activities. Existing approaches in the form of grinding and conventional milling processes do not achieve the surface quality desired for the forming operations and therefore often require manual polishing strategies afterward. This might lead to an unfavorable constitution for subsequent PVD coating processes causing delamination effects or poor adhesion of the wear-resistant coatings. To overcome these restrictions, meso- and micromilling are presented as promising approaches to polishing strategies with varying grain sizes. The processed topographies are correlated with the tribological properties determined in an adapted ring compression test using the deep drawing steel DC04. Additionally, the influence of the roughness profile as well as the induced residual stresses in the subsurface region are examined with respect to their influence on the adhesion of a wear-resistant CrAlN PVD coating. The results prove the benefits of micromilling in terms of a reduced friction factor in the load spectrum of Sheet-Bulk Metal Forming as well as an improved coating adhesion in comparison to metallographic finishing strategies, which can be correlated to the processed roughness profile and induced compressive residual stresses in the subsurface region.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-03-18
DOI: 10.3390/jmmp6020037
Issue No: Vol. 6, No. 2 (2022)
- JMMP, Vol. 6, Pages 38: Punching of Ultra-High-Strength Spring Strips:
Evolution of Cutting Edge Radius up to 1,000,000 Strokes for Three Punch
Materials
Authors: Sven Winter, Karsten Richter, Elmar Galiev, Matthias Nestler, Verena Psyk, Verena Kräusel
First page: 38
Abstract: Punching of ultra-high-strength spring steel causes critical stresses in the tools. Pronounced wear and even spontaneous failure may occur. Wear of the punches influences the quality of the cutting surfaces of the blanked parts, which is predominantly determined by the cutting edge radius. The radius differs with an increasing number of strokes depending on the punch material. However, there are no studies characterizing the influence of the cutting edge radius on the cutting surface quality on an industrial scale, i.e., considering a very high number of strokes. In the presented study, punches made of high-speed steel, powder metallurgical steel and carbide were used to punch the ultra-high-strength steel 1.4310 (Rm = 1824 MPa) up to 1,000,000 strokes. The experiments were stopped at defined number of strokes, the punches were removed, nondestructively characterized regarding cutting edge radius and wear and reinstalled. It turned out that the radius differed significantly over the number of strokes and, further, varied depending on the punch material. Remarkably, the most low-cost material, precisely the high-speed steel, showed the smallest cutting edge radius of 16 µm and brought the parts with the best cutting surface quality (more than 30% burnish zone) after the maximum number of strokes. The results indicate clearly that the cutting edge radius develops differently for each regarded material and at different number of strokes. Therefore, it is of utmost importance to perform wear tests on different numbers of strokes under industrial conditions. With the knowledge gained, it will be possible to design optimized punches with lower costs and increased lifetime.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-03-19
DOI: 10.3390/jmmp6020038
Issue No: Vol. 6, No. 2 (2022)
- JMMP, Vol. 6, Pages 39: Top Surface Roughness Modeling for Robotic Wire
Arc Additive Manufacturing
Authors: Heping Chen , Ahmed Yaseer, Yuming Zhang
First page: 39
Abstract: Wire Arc Additive Manufacturing (WAAM) has many applications in fabricating complex metal parts. However, controlling surface roughness is very challenging in WAAM processes. Typically, machining methods are applied to reduce the surface roughness after a part is fabricated, which is costly and ineffective. Therefore, controlling the WAAM process parameters to achieve better surface roughness is important. This paper proposes a machine learning method based on Gaussian Process Regression to construct a model between the WAAM process parameters and top surface roughness. In order to measure the top surface roughness of a manufactured part, a 3D laser measurement system is developed. The experimental datasets are collected and then divided into training and testing datasets. A top surface roughness model is then constructed using the training datasets and verified using the testing datasets. Experimental results demonstrate that the proposed method achieves less than 50 μm accuracy in surface roughness prediction.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-03-21
DOI: 10.3390/jmmp6020039
Issue No: Vol. 6, No. 2 (2022)
- JMMP, Vol. 6, Pages 40: Hybrid Manufacturing of Aluminium Parts Combining
Additive and Conventional Technologies—Mechanical and Thermal
Properties
Authors: Eva C. Silva, Josué A. Candiango, Sérgio J. Rodrigues, Álvaro M. Sampaio, António J. Pontes
First page: 40
Abstract: Metal additive-manufacturing technologies enable the production of complex geometries. However, high manufacturing costs hinder these technologies being employed in some industries. In this sense, a hybrid strategy is presented in this paper, to achieve the best of additive and subtractive technologies, offering economic advantages. AlSi10Mg aluminium powder was deposited on AW-6082 pre-machined substrates and mechanical and thermal properties of these specimens were evaluated considering the application of a stress relief heat treatment. The results were especially good in the compressive mechanical properties and in the thermal properties: compressive properties were improved by up to 27%, and the specific heat capacity and coefficient of thermal expansion were reduced by up to 38%, compared to additively manufactured AlSi10Mg. Therefore, hybrid manufacturing can be a profitable solution (i) in thermal management applications, (ii) when compressive loads are presented, or (iii) to repair damaged parts, providing a circular economy, as presented in a case study of this paper.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-03-23
DOI: 10.3390/jmmp6020040
Issue No: Vol. 6, No. 2 (2022)
- JMMP, Vol. 6, Pages 41: Flexural Fatigue Test—A Proposed Method to
Characterize the Lifetime of Conductor Tracks on Polymeric Substrates
Authors: Simon Petillon, Andrea Knöller, Philipp Bräuer, David Helm, Tobias Grözinger, Sascha Weser, Wolfgang Eberhardt, Jörg Franke, André Zimmermann
First page: 41
Abstract: High quality and long product life are two fundamental requirements for all circuit carriers, including molded interconnect devices (MID), to find application in various fields, such as automotive, sensor technology, medical technology, and communication technology. When developing a MID for a certain application, not only the design, but also the choice of material as well as the process parameters need to be carefully considered. A well-established method to evaluate the lifetime of such MID, respective of their conductor tracks, is the thermal shock test, which induces thermomechanical stresses upon cycling. Even though this method has numerous advantages, one major disadvantage is its long testing time, which impedes rapid developments. Addressing this disadvantage, this study focuses on the laser direct structuring of thermoplastic LCP Vectra E840i LDS substrates and the subsequent electroless metallization of the commonly used layer system Cu/Ni/Au to force differences in the conductor tracks’ structure and composition. Performing standardized thermal shock tests alongside with flexural fatigue tests, using a customized setup, allows comparison of both methods. Moreover, corresponding thermomechanical simulations provide a direct correlation. The flexural fatigue tests induce equivalent or even higher mechanical stresses at a much higher cycling rate, thus drastically shorten the testing time.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-04-01
DOI: 10.3390/jmmp6020041
Issue No: Vol. 6, No. 2 (2022)
- JMMP, Vol. 6, Pages 42: Analysis of Spindle AE Signals and Development of
AE-Based Tool Wear Monitoring System in Micro-Milling
Authors: Bing-Syun Wan, Ming-Chyuan Lu, Shean-Juinn Chiou
First page: 42
Abstract: Acoustic emission (AE) signals collected from different locations might provide various sensitivities to tool wear condition. Studies for tool wear monitoring using AE signals from sensors on workpieces has been reported in a number of papers. However, it is not feasible to implement in the production line. To study the feasibility of AE signals obtained from sensors on spindles to monitor tool wear in micro-milling, AE signals obtained from the spindle housing and workpiece were collected simultaneously and analyzed in this study for micro tool wear monitoring. In analyzing both signals on tool wear monitoring in micro-cutting, a feature selection algorithm and hidden Markov model (HMM) were also developed to verify the effect of both signals on the monitoring system performance. The results show that the frequency responses of signals collected from workpiece and spindle are different. Based on the signal feature/tool wear analysis, the results indicate that the AE signals obtained from the spindle housing have a lower sensitivity to the micro tool wear than AE signals obtained from the workpiece. However, the analysis of performance for the tool wear monitoring system demonstrates that a 100% classification rate could be obtained by using spindle AE signal features with a frequency span of 16 kHz. This suggests that AE signals collected on spindles might provide a promising solution to monitor the wear of the micro-mill in micro-milling with proper selection of the feature bandwidth and other parameters.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-04-07
DOI: 10.3390/jmmp6020042
Issue No: Vol. 6, No. 2 (2022)
- JMMP, Vol. 6, Pages 43: Effects of Magnetic Abrasive Finishing on
Microstructure and Mechanical Properties of Inconel 718 Processed by Laser
Powder Bed Fusion
Authors: Yunhao Zhao, Jason Ratay, Kun Li, Hitomi Yamaguchi, Wei Xiong
First page: 43
Abstract: Surface finishing is challenging in the context of additively manufactured components with complex geometries. Magnetic abrasive finishing (MAF) is a promising surface finishing technology that can refine the surface quality of components with complex shapes produced by additive manufacturing. However, there is insufficient study regarding the impact of MAF on microstructure–property relationships for additively manufactured builds, which is critical for evaluating mechanical performance. In this work, we studied the effects of different combinations of MAF and heat treatment steps on the microstructure–property relationships of Inconel 718 superalloys made by laser powder bed fusion (LPBF). The application of MAF was found to significantly reduce the surface roughness and refine the grain size of aged alloys. Moreover, MAF was able to increase the alloy elongation, which could be further influenced by the sequence of MAF and different heat treatment steps. The highest elongation could be achieved when MAF was performed between homogenization and aging processes. This work indicates that an effective combination of surface finishing and heat treatment is critical for the improvement of alloy performance. Furthermore, it demonstrates a promising solution for improving the performance of LPBF Inconel 718 by integrating MAF and heat treatment, which provides new perspectives on the post-processing optimization of additively manufactured alloys.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-04-08
DOI: 10.3390/jmmp6020043
Issue No: Vol. 6, No. 2 (2022)
- JMMP, Vol. 6, Pages 44: Development of In-Process Temperature Measurement
of Grinding Surface with an Infrared Thermometer
Authors: Yukio Ito, Yoshiyuki Kita, Yoshiya Fukuhara, Mamoru Nomura, Hiroyuki Sasahara
First page: 44
Abstract: Heat generation is a critical issue in grinding. If the grinding point generates significant heat, dimensional and shape accuracy may decrease due to thermal deformation, and the machined surface may deteriorate due to grinding burn. Therefore, monitoring the temperature during grinding is important to obtain ideal machining results. In this research, we develop a new method to measure the grinding surface and grinding wheel surface temperature during in-process machining. The proposed method measures the temperature of the grinding surface through small holes in a rotating grinding wheel. Using this method, we measured the temperature of the grinding surface during the dry grinding of carbon fiber reinforced plastics (CFRP). Temperature of the grinding surface was measured every 1/4 rotation of the grinding wheel at any depth of cut, assuming precision grinding, rough grinding, and high-efficiency grinding. The measurement value changed depending on the temperature measurement position of the infrared thermometer from numerical analysis of the grinding surface temperature. We also found that when the cut depth was small, the temperature, including the surface of the workpiece before machining, was measured at a specific temperature measurement position. The newly developed temperature measurement method was capable of in-process measurement of the grinding surface temperature and of detecting temperature rise when the grinding wheel was clogged.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-04-08
DOI: 10.3390/jmmp6020044
Issue No: Vol. 6, No. 2 (2022)
- JMMP, Vol. 6, Pages 45: Green Bioprinting with Layer-by-Layer
Photo-Crosslinking: A Designed Experimental Investigation on Shape
Fidelity and Cell Viability of Printed Constructs
Authors: Ketan Thakare, Laura Jerpseth, Zhijian Pei, Hongmin Qin
First page: 45
Abstract: Process variables of bioprinting (including extrusion pressure, nozzle size, and bioink composition) can affect the shape fidelity and cell viability of printed constructs. Reported studies show that increasing extrusion pressure or decreasing nozzle size would decrease cell viability in printed constructs. However, a smaller nozzle size is often necessary for printing constructs of higher shape fidelity, and a higher extrusion pressure is usually needed to extrude bioink through nozzles with a smaller diameter. Because values of printing process variables that increase shape fidelity can be detrimental to cell viability, the optimum combination of variables regarding both shape fidelity and cell viability must be determined for specific bioink compositions. This paper reports a designed experimental investigation (full factorial design with three variables and two levels) on bioprinting by applying layer-by-layer photo-crosslinking and using the alginate-methylcellulose-GelMA bioink containing algae cells. The study investigates both the main effects and interaction effects of extrusion pressure, nozzle size, and bioink composition on the shape fidelity and cell viability of printed constructs. Results show that, as extrusion pressure changed from its low level to its high level, shape fidelity and cell viability decreased. As nozzle size changed from its low level to its high level, shape fidelity decreased while cell viability increased. As bioink composition changed from its low level (with more methylcellulose content in the bioink) to its high level (with less methylcellulose content in the bioink), shape fidelity and cell viability increased.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-04-09
DOI: 10.3390/jmmp6020045
Issue No: Vol. 6, No. 2 (2022)
- JMMP, Vol. 6, Pages 46: A Methodology for Tribo-Mechanical
Characterization of Metallic Alloys under Extreme Loading and Temperature
Conditions Typical of Metal Cutting Processes
Authors: Afonso V. L. Gregório, Tiago E. F. Silva, Alcino P. Reis, Abílio M. P. de Jesus, Pedro A. R. Rosa
First page: 46
Abstract: The present paper proposes a combined tribo-mechanical methodology for assessing friction under conditions representative of metal cutting, without resorting to machining process monitoring. The purpose is to withdraw the size effect’s contribution due to tool edge radius to the well-known overestimation of the friction coefficient. Comparative numerical analysis of several tribological tests led us to conclude that the ring compression test is one of the most suitable for reproducing the frictional conditions at the chip–tool interface. Two distinct metallic alloys were selected to demonstrate the application of the proposed methodology (UNS L51120 lead alloy and 18Ni300 maraging steel in conventional and additively manufactured conditions). The results help to better explain the influences of process parameters on the friction coefficient value under high temperature and high strain rate conditions. Results showed a typical increase in the coefficient of friction of up to 20% due to both temperature and strain rate parameters for 18Ni300. The results are of interest because they allow considering potential sources of error in the numerical simulation of metal cutting when the same friction coefficient value is considered for a wide range of cutting parameters.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-04-13
DOI: 10.3390/jmmp6020046
Issue No: Vol. 6, No. 2 (2022)
- JMMP, Vol. 6, Pages 47: Deformation Heating and Temperature Changes in a
Near-β Titanium Alloy during β-Processed Forging
Authors: Tomonori Kitashima, Lingjian Meng
First page: 47
Abstract: We investigated the temperature increase caused by heat generation from plastic deformation during β-processed forging in a near-β titanium alloy, Ti-17 alloy (Ti-5Al-2Sn-2Zr-4Cr-4Mo, wt%), by inserting thermocouples into large workpieces (100 mm in diameter and 50 mm in height). The workpiece was initially heated and held at 1193 K (920 °C) in the single-β region. It was subsequently forged between hot dies in surrounding heaters at a compression percentage of 75% at strain rates of 0.05 and 0.5 s−1 at 1023–1123 K in the (α + β) region. At 0.05 s−1, the temperature logarithmically increased by 39 K in 28 s for 1023 K; it increased by 30 K in 28 s for 1073 K. However, at 0.5 s−1, the material temperature increased, in 3 s, beyond or close to the β-transus temperature during forging at 1023 and 1073 K. In addition, as the forging temperature decreased, the increase in material temperature moderated, resulting in a difference of 27 K in the last forging stage, between the conditions of 1023 and 1073 K. This would reduce the temperature difference effect on microstructure formation during β-processed forging.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-04-15
DOI: 10.3390/jmmp6020047
Issue No: Vol. 6, No. 2 (2022)
- JMMP, Vol. 6, Pages 48: Enhanced Abrasion Resistance of Spark Plasma
Sintered and HVOF Sprayed Hadfield High Manganese Steel by Turning and
Diamond Smoothing
Authors: Thomas Lindner, Hendrik Liborius, Bianca Preuß, Niclas Hanisch, Andreas Schubert, Thomas Lampke
First page: 48
Abstract: Austenitic high-manganese steels (HMnS) offer very high wear resistance under dynamic loading due to their high work hardening capacity. However, resistance to static abrasive loading is limited. Various approaches to increasing abrasion resistance are known from traditionally manufactured metallurgical components. These confirm the high potential for surface protection applications. In this work, the powder of the Hadfield HMnS X120Mn12 is prepared and processed by high-velocity oxy-fuel (HVOF) spraying and spark-plasma sintering (SPS). A good correlation was observed between the results of the HVOF and SPS specimen. Different surface conditions of the coatings and the sintered specimens were prepared by machining. Compared to the polished state, turning and diamond smoothing can increase the surface hardness from 220 HV to over 700 HV significantly. Regardless of the surface finish condition, similar good wear resistance can be demonstrated due to strong work hardening under sliding and reciprocating wear loading. In contrast, the finish machining process clearly influences abrasion resistance in the scratch test with the best results for the diamond smoothed condition. Especially against the background of current trends toward alternative coating systems, the presented results offer a promising approach for the development of HMnS in the field of coating technology.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-04-17
DOI: 10.3390/jmmp6020048
Issue No: Vol. 6, No. 2 (2022)
- JMMP, Vol. 6, Pages 6: Development and Evaluation of the Ultrasonic
Welding Process for Copper-Aluminium Dissimilar Welding
Authors: Rafael Gomes Nunes Silva, Sylvia De Meester, Koen Faes, Wim De Waele
First page: 6
Abstract: The demand for joining dissimilar metals has exponentially increased due to the global concerns about climate change, especially for electric vehicles in the automotive industry. Ultrasonic welding (USW) surges as a very promising technique to join dissimilar metals, providing strength and electric conductivity, in addition to avoid metallurgical defects, such as the formation of intermetallic compounds, brittle phases and porosities. However, USW is a very sensitive process, which depends on many parameters. This work evaluates the impact of the process parameters on the quality of ultrasonic spot welds between copper and aluminium plates. The weld quality is assessed based on the tensile strength of the joints and metallographic examination of the weld cross-sections. Furthermore, the welding energy is examined for the different welding conditions. This is done to evaluate the influence of each parameter on the heat input resulting from friction at the weld interface and on the weld quality. From the obtained results, it was possible to optimise parameters to achieve satisfactory weld quality in 1.0 mm thick Al–Cu plate joints in terms of mechanical and metallurgical properties.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-01-01
DOI: 10.3390/jmmp6010006
Issue No: Vol. 6, No. 1 (2022)
- JMMP, Vol. 6, Pages 7: Significant Reduction in Energy Consumption and
Carbon Emission While Improving Productivity in Laser Drilling of CFRP
Sheets with a Novel Stepped Process Parameter Parallel Ring Method
Authors: Menghui Zhu, Chao Wei, Wei Guo, Zhizhou Zhang, Jinglei Ouyang, Paul Mativenga, Lin Li
First page: 7
Abstract: Although laser drilling of carbon fibre-reinforced polymer (CFRP) composites offers the advantages of zero tool-wear and avoidance of fibre delamination compared with mechanical drilling, it consumes considerably more energy during the drilling process. This research shows that by using a new, stepped parameter parallel ring laser hole drilling method, an energy saving of 78.10% and an 18.37 gCO2 reduction for each hole, while improving productivity by more than 300%, can be achieved in laser drilling of 6 mm diameter holes in CFRP sheets of 2 mm in thickness, compared with previous laser drilling methods under the same drilling quality. The key reason for this is an increase in energy input to the inner rings enabling more rapid removal of the material, while the lower energy input for the outer ring provides a shielding trench to reduce the heat loss into the parent material. The results are compared with single-ring laser drilling and multiple-ring laser drilling with constant processing parameters, and a discussion is given on comparing with mechanical drilling and future prospects, including a combined mechanical drilling and laser pre-scribing process.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-01-05
DOI: 10.3390/jmmp6010007
Issue No: Vol. 6, No. 1 (2022)
- JMMP, Vol. 6, Pages 8: Modelling the Heating Process in the Transient and
Steady State of an In Situ Tape-Laying Machine Head
Authors: Jhonny de Sá Rodrigues, Paulo Teixeira Gonçalves, Luis Pina, Fernando Gomes de Almeida
First page: 8
Abstract: As the use of composite materials increases, the search for suitable automated processes gains relevance for guaranteeing production quality by ensuring the uniformity of the process, minimizing the amount of scrap generated, and reducing the time and energy consumption. Limitations on production by traditional means such as hand lay-up, vacuum bagging, and in-autoclave methods tend not to be as efficient when the size and shape complexity of the part being produced increases, motivating the search for alternative processes such as automated tape laying (ATL). This work aims to describe the process of modelling and simulating a composite ATL with in situ consolidation by characterizing the machine elements and using the finite differences method in conjunction with energy balances in order to create a digital twin of the process for further control design. The modelling approach implemented is able to follow the process dynamics when changes are made to the heating element and to predict the composite material temperature response, making it suitable for use as a digital twin of a production process using an ATL machine.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-01-11
DOI: 10.3390/jmmp6010008
Issue No: Vol. 6, No. 1 (2022)
- JMMP, Vol. 6, Pages 9: Characterization of Wire-Bonding on LDS Materials
and HF-PCBs for High-Frequency Applications
Authors: Thomas Guenther, Kai Werum, Ernst Müller, Marius Wolf, André Zimmermann
First page: 9
Abstract: Thermosonic wire bonding is a well-established process. However, when working on advanced substrate materials and the associated required metallization processes to realize innovative applications, multiple factors impede the straightforward utilization of the known process. Most prominently, the surface roughness was investigated regarding bond quality in the past. The practical application of wire bonding on difficult-to-bond substrates showed inhomogeneous results regarding this quality characteristic. This study describes investigations on the correlation among the surface roughness, profile peak density and bonding quality of Au wire bonds on thermoplastic and thermoset-based substrates used for high-frequency (HF) applications and other high-end applications. FR4 PCB (printed circuit board flame resitant class 4) were used as references and compared to HF-PCBs based on thermoset substrates with glass fabric and ceramic filler as well as technical thermoplastic materials qualified for laser direct structuring (LDS), namely LCP (liquid crystal polymer), PEEK (polyether ether ketone) and PTFE (polytetrafluoroethylene). These LDS materials for HF applications were metallized using autocatalytic metal deposition to enable three-dimensional structuring, eventually. For that purpose, bond parameters were investigated on the mentioned test substrates and compared with state-of-the-art wire bonding on FR4 substrates as used for HF applications. Due to the challenges of the limited thermal conductivity and softening of such materials under thermal load, the surface temperatures were matched up by thermography and the adaptation of thermal input. Pull tests were carried out to determine the bond quality with regard to surface roughness. Furthermore, strategies to increase reliability by the stitch-on-ball method were successfully applied.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-01-11
DOI: 10.3390/jmmp6010009
Issue No: Vol. 6, No. 1 (2022)
- JMMP, Vol. 6, Pages 10: Causal Discovery in Manufacturing: A Structured
Literature Review
Authors: Matej Vuković, Stefan Thalmann
First page: 10
Abstract: Industry 4.0 radically alters manufacturing organization and management, fostering collection and analysis of increasing amounts of data. Advanced data analytics, such as machine learning (ML), are essential for implementing Industry 4.0 and obtaining insights regarding production, better decision support, and enhanced manufacturing quality and sustainability. ML outperforms traditional approaches in many cases, but its complexity leads to unclear bases for decisions. Thus, acceptance of ML and, concomitantly, Industry 4.0, is hindered due to increasing requirements of fairness, accountability, and transparency, especially in sensitive-use cases. ML does not augment organizational knowledge, which is highly desired by manufacturing experts. Causal discovery promises a solution by providing insights on causal relationships that go beyond traditional ML’s statistical dependency. Causal discovery has a theoretical background and been successfully applied in medicine, genetics, and ecology. However, in manufacturing, only experimental and scattered applications are known; no comprehensive overview about how causal discovery can be applied in manufacturing is available. This paper investigates the state and development of research on causal discovery in manufacturing by focusing on motivations for application, common application scenarios and approaches, impacts, and implementation challenges. Based on the structured literature review, four core areas are identified, and a research agenda is proposed.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-01-14
DOI: 10.3390/jmmp6010010
Issue No: Vol. 6, No. 1 (2022)
- JMMP, Vol. 6, Pages 11: Study of Tailored Hot Stamping Process on Advanced
High-Strength Steels
Authors: Maria Emanuela Palmieri, Francesco Rocco Galetta, Luigi Tricarico
First page: 11
Abstract: Ultra-high-strength steels (UHSS) combined with tailor-stamping technologies are increasingly being adopted in automotive body production due to crashworthiness improvements and part weight reduction, which meet safety and energy saving demands. Recently, USIBOR®2000 (37MnB5) steel has been added to the family of UHSS. This new material allows higher performance with respect to its predecessor USIBOR®1500 (22MnB5). In this work, the two steels are compared for the manufacturing of an automotive B-Pillar by press-hardening with a tailored tool tempering approach. A Finite Element (FE) model has been developed for the numerical simulation of thermomechanical cycles of the press-hardening process. The FE-simulations have been performed with the aim of obtaining soft zones in the part, by varying the quenching time and the temperature of heated tools. The effects of these parameters on the mechanical properties of the part have been experimentally evaluated thanks to hardness and tensile tests performed on specimens subjected to the numerical thermo-mechanical cycles using the Geeble-3180 physical simulator. The results show that for both UHSS, an increase in quenching time leads to a decrease in hardness up to a threshold value, which is lower for the USIBOR®1500. Moreover, higher mechanical resistance and lower elongation at break values are derived for the USIBOR®2000 steel than for USIBOR®1500 steel.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-01-18
DOI: 10.3390/jmmp6010011
Issue No: Vol. 6, No. 1 (2022)
- JMMP, Vol. 6, Pages 12: Wind Tunnel Experiments on an Aircraft Model
Fabricated Using a 3D Printing Technique
Authors: Katarzyna Szwedziak, Tomasz Łusiak, Robert Bąbel, Przemysław Winiarski, Sebastian Podsędek, Petr Doležal, Gniewko Niedbała
First page: 12
Abstract: Experimental tests regarding the M-346 aircraft model made via 3D printing were carried out in order to obtain numerical data and characteristics in the form of graphs of basic aerodynamic forces and coefficients. The tests were carried out for the left side of the airframe model in a clean configuration, without additional suspension equipment; the flight control surfaces and the aerodynamic brake were in neutral positions. Based on the scan of the base model in 1:48 scale using a Nikon Model Maker MMDx laser scanning head, followed by the generation and optimization of some of the airframe elements in SolidWorks software, a test model ready for printing was prepared. Using the MakerBot Print program, the printing parameters were set, and the process itself was completed using a MakerBot Replicator Z18 3D printer. The next step was manual treatment in order to remove the material excess from the melted thermoplastic material, join the elements and appropriately polish the surface of the tested model in order to obtain the desired quality. The test was carried out using a Gunt HM 170 wind tunnel for fixed airflow velocities at variable angles of attack. On this basis, the numerical values of lift force, Pz, and drag force, Px, were obtained; then, the lift force indices, Cz, and drag force indices, Cx, were computed for the steady states, which were for angle α from −12 to 16°. The use of 3D printing contributed to the generation of geometry, which, for research purposes, was scaled down in order to fully use the available measurement space of the wind tunnel. The final stage of the work was to compare the obtained curves of particular characteristics with the literature data.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-01-18
DOI: 10.3390/jmmp6010012
Issue No: Vol. 6, No. 1 (2022)
- JMMP, Vol. 6, Pages 13: Separation of Multi-Material Polymer Combinations
Produced by Joining Using Pin-like Structures
Authors: Michael Wolf, Dietmar Drummer
First page: 13
Abstract: In industrial applications, multi-material joints are becoming increasingly important to achieve a sustainable and resource-saving production. Not only high mechanical properties during the component use have to be given, but also possibilities to separate the joint after end of life are crucial. The recycling and re-use of the materials plays an increasing role in the process chain. Conventional multi-material joints can be separated by cutting out the joining zone, solvents, or thermal degradation. However, these methods result in a loss of material, damage to the base material, or high energy consumption. Therefore, novel joining methods are desirable, such as the joining using pin-like structures. The potential of this novel method for joining adhesion incompatible materials has been demonstrated in previous studies. This paper studies the separability of these connections. Therefore, joints between polyamide 66 (PA66) and polypropylene (PP) as well as PA66 and polymethylmethacrylate (PMMA) are investigated by means of thermal separation and shredding with subsequent sorting using the density difference of the materials. The separated components were investigated by analytical methods (including dissolution tests, viscosity number analysis, and Fourier-transform infrared spectroscopy) with respect to varietal purity and possible degradation effects. It could be shown that shredding allows a complete separation of the multi-material joint into its individual components without material residues or material loss. For thermal separation, material residues of PP or PMMA could be detected in the pin gaps of the PA66. For both separation methods, an influence on the base materials due to degradation effects could be excluded. It can be stated that joining using pin-like structures in vibration welding technology offers a sustainable production of multi-material joints with high recyclability.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-01-19
DOI: 10.3390/jmmp6010013
Issue No: Vol. 6, No. 1 (2022)
- JMMP, Vol. 6, Pages 14: Study on Magnetic Abrasive Finishing Combined with
Electrolytic Process–Precision Surface Finishing for SUS 304
Stainless Steel Using Pulse Voltage
Authors: Baijun Xing, Yanhua Zou, Masahisa Tojo
First page: 14
Abstract: In order to further study the Magnetic Abrasive Finishing with Electrolytic (EMAF) Process, we attempted to use rectangular wave pulse voltage for EMAF processing of SUS304 stainless steel, and the finishing characteristics were analyzed based on the experimental results in this paper. The EMAF process has been studied for years, but the study of Magnetic Abrasive Finishing with the. Pulse Electrolytic (P-EMAF) process has not been published. Therefore, in this study, the finishing characteristics of the P-EMAF process corresponding to different frequencies (1 Hz, 10 Hz, 100 Hz, 1 kHz) and duty ratios (25%, 50%, 75%) are explored. The evaluation of the P-EMAF processing includes the surface roughness (SR) and the amount of material removal (MR); the surface of the workpiece was also observed by an optical microscope before and after processing. After analyzing the experimental results of P-EMAF processing, a set of comparative experiments between P-EMAF processing and MAF processing was carried out. In this study, when the Urms 6 V pulse voltage of rectangular wave with 1 Hz and duty ratio 50% was used, a better processing result could be obtained. The processing efficiency of the P-EMAF process was also higher than that of the MAF process under the same experimental conditions.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-01-19
DOI: 10.3390/jmmp6010014
Issue No: Vol. 6, No. 1 (2022)
- JMMP, Vol. 6, Pages 15: Advanced Processing and Machining of Tungsten and
Its Alloys
Authors: Samuel Omole, Alexander Lunt, Simon Kirk, Alborz Shokrani
First page: 15
Abstract: Tungsten is a refractory metal with the highest melting temperature and density of all metals in this group. These properties, together with the high thermal conductivity and strength, make tungsten the ideal material for high-temperature structural use in fusion energy and other applications. It is widely agreed that the manufacture of components with complex geometries is crucial for scaling and optimizing power plant designs. However, there are challenges associated with the large-scale processing and manufacturing of parts made from tungsten and its alloys which limit the production of these complex geometries. These challenges stem from the high ductile-to-brittle transition temperature (DBTT), as well as the strength and hardness of these parts. Processing methods, such as powder metallurgy and additive manufacturing, can generate near-net-shaped components. However, subtractive post-processing techniques are required to complement these methods. This paper provides an in-depth exploration and discussion of different processing and manufacturing methods for tungsten and identifies the challenges and gaps associated with each approach. It includes conventional and unconventional machining processes, as well as research on improving the ductility of tungsten using various methods, such as alloying, thermomechanical treatment, and grain structure refinement.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-01-20
DOI: 10.3390/jmmp6010015
Issue No: Vol. 6, No. 1 (2022)
- JMMP, Vol. 6, Pages 16: A Review on the Processing of Aero-Turbine Blade
Using 3D Print Techniques
Authors: Ayush Sinha, Biswajit Swain, Asit Behera, Priyabrata Mallick, Saswat Kumar Samal, H. M. Vishwanatha, Ajit Behera
First page: 16
Abstract: Additive manufacturing (AM) has proven to be the preferred process over traditional processes in a wide range of industries. This review article focused on the progressive development of aero-turbine blades from conventional manufacturing processes to the additive manufacturing process. AM is known as a 3D printing process involving rapid prototyping and a layer-by-layer construction process that can develop a turbine blade with a wide variety of options to modify the turbine blade design and reduce the cost and weight compared to the conventional production mode. This article describes various AM techniques suitable for manufacturing high-temperature turbine blades such as selective laser melting, selective laser sintering, electron beam melting, laser engineering net shaping, and electron beam free form fabrication. The associated parameters of AM such as particle size and shape, powder bed density, residual stresses, porosity, and roughness are discussed here.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-01-21
DOI: 10.3390/jmmp6010016
Issue No: Vol. 6, No. 1 (2022)
- JMMP, Vol. 6, Pages 17: Vat Photopolymerization Additive Manufacturing of
Functionally Graded Materials: A Review
Authors: Serkan Nohut, Martin Schwentenwein
First page: 17
Abstract: Functionally Graded Materials (FGMs) offer discrete or continuously changing properties/compositions over the volume of the parts. The widespread application of FGMs was not rapid enough in the past due to limitations of the manufacturing methods. Significant developments in manufacturing technologies especially in Additive Manufacturing (AM) enable us nowadays to manufacture materials with specified changes over the volume/surface of components. The use of AM methods for the manufacturing of FGMs may allow us to compensate for some drawbacks of conventional methods and to produce complex and near-net-shaped structures with better control of gradients in a cost-efficient way. Vat Photopolymerization (VP), a type of AM method that works according to the principle of curing liquid photopolymer resin layer-by-layer, has gained in recent years high importance due to its advantages such as low cost, high surface quality control, no need to support structures, no limitation in the material. This article reviews the state-of-art and future potential of using VP methods for FGM manufacturing. It was concluded that improvements in printer hardware setup and software, design aspects and printing methodologies will accelerate the use of VP methods for FGMs manufacturing.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-01-21
DOI: 10.3390/jmmp6010017
Issue No: Vol. 6, No. 1 (2022)
- JMMP, Vol. 6, Pages 18: A Novel Approach for Real-Time Quality Monitoring
in Machining of Aerospace Alloy through Acoustic Emission Signal
Transformation for DNN
Authors: David Adeniji, Kyle Oligee, Julius Schoop
First page: 18
Abstract: Gamma titanium aluminide (γ-TiAl) is considered a high-performance, low-density replacement for nickel-based superalloys in the aerospace industry due to its high specific strength, which is retained at temperatures above 800 °C. However, low damage tolerance, i.e., brittle material behavior with a propensity to rapid crack propagation, has limited the application of γ-TiAl. Any cracks introduced during manufacturing would dramatically lower the useful (fatigue) life of γ-TiAl components, making the workpiece surface’s quality from finish machining a critical component to product quality and performance. To address this issue and enable more widespread use of γ-TiAl, this research aims to develop a real-time non-destructive evaluation (NDE) quality monitoring technique based on acoustic emission (AE) signals, wavelet transform, and deep neural networks (DNN). Previous efforts have opted for traditional approaches to AE signal analysis, using statistical feature extraction and classification, which face challenges such as the extraction of good/relevant features and low classification accuracy. Hence, this work proposes a novel AI-enabled method that uses a convolutional neural network (CNN) to extract rich and relevant features from a two-dimensional image representation of 1D time-domain AE signals (known as scalograms), subsequently classifying the AE signature based on pedigreed experimental data and finally predicting the process-induced surface quality. The results of the present work show good classification accuracy of 80.83% using scalogram images, in-situ experimental data, and a VGG-19 pre-trained neural network, establishing the significant potential for real-time quality monitoring in manufacturing processes.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-01-25
DOI: 10.3390/jmmp6010018
Issue No: Vol. 6, No. 1 (2022)
- JMMP, Vol. 6, Pages 19: Acknowledgment to Reviewers of JMMP in 2021
Authors: JMMP Editorial Office JMMP Editorial Office
First page: 19
Abstract: Rigorous peer-reviews are the basis of high-quality academic publishing [...]
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-01-26
DOI: 10.3390/jmmp6010019
Issue No: Vol. 6, No. 1 (2022)
- JMMP, Vol. 6, Pages 20: Microstructure Evolution in Inconel 718 Produced
by Powder Bed Fusion Additive Manufacturing
Authors: Judy Schneider, Laura Farris, Gert Nolze, Stefan Reinsch, Grzegorz Cios, Tomasz Tokarski, Sean Thompson
First page: 20
Abstract: Inconel 718 is a precipitation strengthened, nickel-based super alloy of interest for the Additive Manufacturing (AM) of low volume, complex parts to reduce production time and cost compared to conventional subtractive processes. The AM process involves repeated rapid melting, solidification and reheating, which exposes the material to non-equilibrium conditions that affect elemental segregation and the subsequent formation of solidification phases, either beneficial or detrimental. These variations are difficult to characterize due to the small length scale within the micron sized melt pool. To understand how the non-equilibrium conditions affect the initial solidification phases and their critical temperatures, a multi-length scale, multi modal approach has been taken to evaluate various methods for identifying the initial phases formed in the as-built Inconel 718 produced by laser-powder bed fusion (L-PBF) additive manufacturing (AM). Using a range of characterization tools from the bulk differential thermal analysis (DTA) and x-ray diffraction (XRD) to spatially resolved images using a variety of electron microscopy tools, a better understanding is obtained of how these minor phases can be properly identified regarding the amount and size, morphology and distribution. Using the most promising characterization techniques for investigation of the as-built specimens, those techniques were used to evaluate the specimens after various heat treatments. During the sequence of heat treatments, the initial as-built dendritic structures recrystallized into well-defined grains whose size was dependent on the temperature. Although the resulting strength was similar in all heat treated specimens, the elongation increased as the grain size was refined due to differences in the precipitated phase distribution and morphology.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-01-29
DOI: 10.3390/jmmp6010020
Issue No: Vol. 6, No. 1 (2022)
- JMMP, Vol. 6, Pages 21: Microstructure and Mechanical Properties of
Ti-6Al-4V Additively Manufactured by Electron Beam Melting with 3D Part
Nesting and Powder Reuse Influences
Authors: Priti Wanjara, David Backman, Fatih Sikan, Javad Gholipour, Robert Amos, Prakash Patnaik, Mathieu Brochu
First page: 21
Abstract: To better support the transition to more industrial uses of additive manufacturing, this study examined the use of an Arcam Q20+ industrial 3D printer for producing heavily nested Ti-6Al-4V parts with both in-specification (IS) and out of specification (OS) oxygen content in reused grade 5 powder chemistries. Both the OS and IS powder chemistries were evaluated to understand their impact on build integrity and on static and fatigue performance. The results from our evaluations showed that controlling the bed preheat temperature in the Q20+ to relatively low values (326–556 °C) was effective in limiting microstructural coarsening during the long build time and enabled adequate/balanced performance vis à vis the tensile strength and ductility. Overall, the tensile properties of the IS Ti-6Al-4V material in the as-built and machined states fully met the requirements of ASTM F2924-14. By contrast, the ductility was compromised at oxygen levels above 0.2 wt.% (OS) in Ti-6Al-4V produced by EBM. Removal of the surface layer by machining increased the consistency and performance of the IS and OS Ti-6Al-4V materials. The fatigue behaviour of the EBM Ti-6Al-4V material was in the range of properties produced by casting. Due to the strong influence of both the surface finish and oxygen content on the fatigue strength, the IS Ti-6Al-4V material exhibited the highest performance, with results that were in the range of parts that had been cast plus hot isostatically pressed.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-02-01
DOI: 10.3390/jmmp6010021
Issue No: Vol. 6, No. 1 (2022)
- JMMP, Vol. 6, Pages 22: Systematic Development of a Powder Deposition
System for an Open Selective Laser Sintering Machine Using Analytic
Hierarchy Process
Authors: Foivos Psarommatis, George-Christopher Vosniakos
First page: 22
Abstract: This work reports on the design and manufacture of an efficient system for powder deposition into layers in an open Selective Laser Sintering machine. The system comprises mainly two subsystems, i.e., one that deposits a dose of powder onto the worktable and another that levels the powder upon its deposition. The design was conducted in two phases, namely conceptualization of the system and its detailed design. The conceptualization phase exploited the Analytic Hierarchy Process to evaluate alternative mechanical systems and determine the most suitable one. This was subsequently detail-designed using a CAD software package and then followed by selection of the necessary electronics for imparting and controlling motion of the individual mechanisms comprising the system. As regards manufacturing, custom designed components were obtained by CNC machining and the entire mechanism was assembled on an open Selective Laser Sintering machine. Functionality testing of the system was performed with satisfactory results.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-02-08
DOI: 10.3390/jmmp6010022
Issue No: Vol. 6, No. 1 (2022)
- JMMP, Vol. 6, Pages 23: Stability Evaluation for a Damped,
Constrained-Motion Cutting Force Dynamometer
Authors: Michael Gomez, Tony Schmitz
First page: 23
Abstract: This paper describes the dynamic stability evaluation of a constrained-motion dynamometer (CMD) with passive damping. The CMD’s flexure-based design offers an alternative to traditional piezoelectric cutting force dynamometers, which can exhibit adverse effects of the complex structural dynamics on the measurement accuracy. In contrast, the CMD system’s structural dynamics are nominally single degree of freedom and are conveniently altered by material selection, flexure element geometry, and element arrangement. In this research, a passive damping approach is applied to increase the viscous damping ratio and, subsequently, the stability limit. Cutting tests were completed and the in situ CMD displacement and velocity signals were sampled at the spindle rotating frequency. The periodic sampling approach was used to determine if the milling response was synchronous with the spindle rotation (stable) or not (chatter) by constructing Poincaré maps for both experiment and prediction (time-domain simulation). It was found that the viscous damping coefficient was increased by 130% and the critical stability limit was increased from 4.3 mm (no damping) to 15.4 mm (with damping).
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-02-10
DOI: 10.3390/jmmp6010023
Issue No: Vol. 6, No. 1 (2022)
- JMMP, Vol. 6, Pages 24: Effect of Rotation Speed and Steel Microstructure
on Joint Formation in Friction Stir Spot Welding of Al Alloy to DP Steel
Authors: Hadi Torkamani, Javier Vivas Méndez, Clement Lecart, Egoitz Aldanondo Begiristain, Pedro Alvarez Moro, Marta-Lena Antti
First page: 24
Abstract: In this work, friction stir spot welding of 5754 aluminum alloy to dual phase steel was investigated using two different ratios of martensite and ferrite (0.38 and 0.61) for steel sheet initial microstructure and varying tool rotation speed (800, 1200 and 2000 rpm). The effect of these parameters on the joint formation was evaluated by studying the plunging force response during the process and the main characteristics of the joint at (i) macrolevel, i.e., hook morphology and bond width, and (ii) microlevel, i.e., steel hook and sheet microstructure and intermetallic compounds. The plunging force was reduced by increased tool rotation speed while there was no significant effect from the initial steel microstructure ratio of martensite and ferrite on the plunging force. The macrostructural characterization of the joints showed that the hook morphology and bond width were affected by the steel sheet initial microstructures as well as by the tool rotation speed and by the material flow driver; tool pin or shoulder. At microstructural level, a progressive variation in the ratio of martensite and ferrite was observed for the steel hook and sheet microstructure. The zones closer to the tool presented a fully martensitic microstructure while the zones away from the tool showed a gradual increase in the ferrite amount until reaching the ratio of ferrite and martensite of the steel sheet initial microstructure. Different types of FexAly intermetallic compounds were found in three zones of the joint; the hook tips, in the hooks close to the exit hole and in the corner of the exit hole. These compounds were characterized by a brittle behavior with hardness values varying from 456 to 937 HV01.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-02-15
DOI: 10.3390/jmmp6010024
Issue No: Vol. 6, No. 1 (2022)
- JMMP, Vol. 6, Pages 25: Build Surface Roughness and Internal Oxide
Concentration for Laser Powder Bed Fusion of IN718
Authors: Lonnie A. Smith, Petrus Christiaan Pistorius
First page: 25
Abstract: Oxidation of hot spatter during laser powder bed fusion results in the deposition of oxides on the build surface. In the case of IN718—as studied in this work—the oxide is alumina. While some of this surface oxide may be incorporated in the build, an oxygen mass balance indicates some oxygen removal during the building process. This work tested an expected effect of the roughness of the build surface on the concentration of micron-sized oxide inclusions that are incorporated in test coupons during building. The roughness of the build surface responded to changes in hatch spacing, in line with a simple geometric model of the overlap between adjacent beads. Samples with deeper grooves retained more oxide, resulting in a much larger concentration of oxide inclusions within the samples. The conclusion is that parts with lower inclusion concentrations can be produced by decreasing the hatch spacing, at the cost of a lower build rate.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-02-16
DOI: 10.3390/jmmp6010025
Issue No: Vol. 6, No. 1 (2022)
- JMMP, Vol. 6, Pages 26: Reprocessability of PLA through Chain Extension
for Fused Filament Fabrication
Authors: Carlos Correia, Tiago E. P. Gomes, Idalina Gonçalves, Victor Neto
First page: 26
Abstract: As additive manufacturing (AM) technologies have been gaining popularity in the plastic processing sector, it has become a major concern to establish closed-loop recycling strategies to maximize the value of the materials processed, therefore enhancing their sustainability. However, there are challenges to overcome related to the performance of recycled materials since, after mechanical recycling, the molecular degradation of thermoplastics shifts their performance and processability. In this work, it was hypothesized that the incorporation of a chain extender (CE) during the reprocessing would allow us to overcome these drawbacks. To attest this conjecture, the influence of 1,3-Bis(4,5-dihydro-2-oxazolyl)benzene (PBO), used as a CE, on mechanical, thermal, and rheological properties of polilactic acid (PLA) was studied. Furthermore, a closed-loop recycling system based on Fused Filament Fabrication (FFF) was attempted, consisting of the material preparation, filament extrusion, production of 3D components, and mechanical recycling steps. PBO partially recovered the recycled PLA mechanical performance, reflected by an increase in both tensile modulus (+13%) and tensile strength (+121%), when compared with recycled PLA without PBO. Printability tests were conducted, with the material’s brittle behavior being the major constraint for successfully establishing a closed-loop recycling scheme for FFF applications.
Citation: Journal of Manufacturing and Materials Processing
PubDate: 2022-02-19
DOI: 10.3390/jmmp6010026
Issue No: Vol. 6, No. 1 (2022)
