for Journals by Title or ISSN for Articles by Keywords help
 Subjects -> ENGINEERING (Total: 2291 journals)     - CHEMICAL ENGINEERING (192 journals)    - CIVIL ENGINEERING (187 journals)    - ELECTRICAL ENGINEERING (105 journals)    - ENGINEERING (1209 journals)    - ENGINEERING MECHANICS AND MATERIALS (385 journals)    - HYDRAULIC ENGINEERING (55 journals)    - INDUSTRIAL ENGINEERING (68 journals)    - MECHANICAL ENGINEERING (90 journals) ENGINEERING (1209 journals)                  1 2 3 4 5 6 7 | Last
 Arabian Journal for Science and Engineering   [SJR: 0.345]   [H-I: 20]   [5 followers]  Follow         Hybrid journal (It can contain Open Access articles)    ISSN (Print) 1319-8025    Published by Springer-Verlag  [2352 journals]
• Development and Analysis of a Multi-evaporator Cooling System with
Electronic Expansion Valves
• Authors: Şafak Ataş; Mustafa Aktaş; İlhan Ceylan; Hikmet Doğan
Pages: 4513 - 4521
Abstract: Abstract In this study, a vapor compression cooling system with three evaporators and electronic expansion valves was designed, manufactured and tested experimentally. Compressor of this system was converted to be inverter driven which enabled it to run at variable speeds. Temperature values of cold rooms were controlled more sensitive by using electronic expansion valves. Energy analysis was done by comparing the operating parameters of the system with constant and variable speeds. Programmable logic control (PLC) and cold room controls were used to control the system. The PLC device provided the variable operation of the system by determining the required operation frequency of the compressor according to the changes at the suction line. Using this program, the desired values are set on the PLC screen and the multi-evaporator cooling system was tested at various conditions. The desired conditions are determined for the system at 0, $$+5$$ and $$-5\,^{\circ }\hbox {C}$$ temperatures. Calculations on the experimental results revealed that the cooling coefficient of performance is 1.86 for the constant frequency operation and 2.22 for the variable frequency operation. Besides, it was determined experimentally that the system running on variable frequency consumed 20% less electrical energy than the constant frequency system.
PubDate: 2017-11-01
DOI: 10.1007/s13369-017-2523-1
Issue No: Vol. 42, No. 11 (2017)

• Frequency Domain Long-Term Efficiency of Viscous Damper in Jacket
• Authors: Mohammad Reza Tabeshpour; Hossein Janbazi Rokni
Pages: 4523 - 4534
Abstract: Abstract Various types of controlling mechanisms have been investigated to decrease vibrations of different structures, and in many cases, the reliability has been increased with respect to conventional methods of structural optimization. Among them, using passive viscous damper is one of the useful methods to control structure response due to environmental loads. Hence, in this study, the effect of viscous damper on vibration control of jacket platform (case study oil platform SPD2 and Resalat) exposed to wave loads is investigated, and with the sea state, long-term performance of damper to reduce the structural response is introduced for the first time the more suitable than the responses in an especial case. To keep up this purpose, the platform is modeled by finite element method, and wave spectra are radiated to it. Spectral analysis is adopted to investigate the structural response of the jacket platform equipped with viscous dampers, and also, conventional arrangements of dampers are analyzed to acquire optimal one. Then, the economically optimal arrangement of damper is determined. The novelty of this paper is that the results based on the sea states recorded in the long term help one find the optimal arrangement of damper.
PubDate: 2017-11-01
DOI: 10.1007/s13369-017-2534-y
Issue No: Vol. 42, No. 11 (2017)

• The Effect of Lanthanum Addition on the Microstructure and Mechanical
Properties of A390 Aluminium Alloy
• Authors: Salem A. Bagaber; Tijjani Abdullahi; Zawati Harun; Nateq Daib; Mohd Hafiz D. Othman
Pages: 4559 - 4564
Abstract: Abstract Aluminium alloys are widely used in the industries and for biomedical applications, because when compared with other materials they provide a high strength-to-weight ratio, better wear resistance, less density, and low coefficient of thermal expansion. However, these alloys possess some limitations in terms of the interactive effects of additives. Therefore, the target of this research is to study the influence of Lanthanum addition of 0.5, 1.0, and 1.5 wt% on the microstructure and mechanical properties of hypereutectic Al–Si alloy. Optical microscopic test, FESEM spectroscopy, XRD, and mechanical properties testing, such as tensile, impact, and hardness test were carried out for characterization purposes. The result indicates the formation of intermetallic compounds, while the value of the secondary dendrite arm spacing became smaller with increasing La addition. The optimum modification of A390 alloy eutectic structure was at 1.0 wt% of La, which improved the ductility from 0.7 to 1.8% and a recorded increase in tensile strength from 100 to 150 MPa.
PubDate: 2017-11-01
DOI: 10.1007/s13369-017-2553-8
Issue No: Vol. 42, No. 11 (2017)

• Effect of External Perimeter on Flexural Strength of FDM Build Parts
• Authors: Swayam Bikash Mishra; Rameez Malik; S. S. Mahapatra
Pages: 4587 - 4595
Abstract: Abstract Current manufacturing trend adopts newer technology that can reduce both the design and manufacturing lead time in order to face the challenging demands of the customer in an effective manner. In this regard, rapid prototyping technology, among all newly developed technologies, is reliable one because it is capable of manufacturing accurate and durable parts with 3D complex geometry within a stipulated time with less material waste. In this research work, effect of six relevant controllable input parameters (contour number or external perimeter, layer thickness, raster width, part orientation, air gap and raster angle) on flexural strength of the fused deposition modelling (FDM) build parts is analysed. Experimentation has been carried out using face-centred central composite design to reduce the number of experimentation. Contour number appears to be more influencing parameter because it helps to move the stress concentration zone from outer edge to the centre avoiding premature failure of the specimen. The study develops a statistically valid empirical model relating flexural strength with process parameters to ease prediction of flexural strength by tool engineers. Scanning electron microscope micrographs are used to explain the microstructure behaviour of FDM build parts when subjected to three point bend test. Finally, one nature-inspired metaheuristic approach known as Firefly algorithm is adopted to obtain optimal parameter setting for improving the flexural strength.
PubDate: 2017-11-01
DOI: 10.1007/s13369-017-2598-8
Issue No: Vol. 42, No. 11 (2017)

• Microstructure and Wear Properties of Laser-Cladded cBN/Ti $$_{3}$$ 3 Al
on Pure Titanium
• Authors: K. K. Sobiyi; E. T. Akinlabi
Pages: 4597 - 4604
Abstract: Abstract In order to improve the tribological properties of titanium alloys at high temperature, the possibility of producing Ti $$_{3}$$ Al intermetallic with the addition of ceramic (cBN) coatings on titanium substrate using laser technique cladding was investigated. cBN is generally known for its high hot hardness, wear resistance and chemical stability. Laser cladding is an emerging material processing technique which is an efficient and cost-effective technique for improving the surface properties of general metallic materials. This paper presents the effects of laser cladding on the phase combination, microstructure, hardness and wear resistance of titanium aluminide/cBN IMC composites at different variations in quantity of cBN in the composite. Optical microscopy, X-ray diffraction and scanning electron microscopy with EDX were used for characterising the microstructure of the coating. In addition, the composite coating was subjected to wear testing using the ball-on-disc, friction and wear apparatus. The XRD results revealed phases with small cBN, $$\hbox {Ti}_{2}\hbox {N}$$ and $$\hbox {TiB}_{2}$$ peaks in addition to the rich $$\gamma$$ -Ti, $$\alpha 2\hbox {-Ti}_{3}\hbox {Al}$$ and TiAl intermetallics phases in the coatings after cladding process, whereas the microstructure of the cBN cladded layer contained partially melted cBN grains evenly dispersed within the laths of alpha Widmanstätten phase in the form of dendrites, precipitate of $$\alpha _{2}\hbox {-Ti}_{3}\hbox {Al}$$ and spherical-shaped pure titanium. The effect of the addition of cBN into $$\hbox {Ti}_{3}\hbox {Al}$$ alloy at increasing weight percentages showed an improvement in the hardness and wear resistance of the coatings. The increase is attributed to reacted boron nitrides particles with titanium, being distributed uniformly in the intermetallic matrix.
PubDate: 2017-11-01
DOI: 10.1007/s13369-017-2585-0
Issue No: Vol. 42, No. 11 (2017)

• Experimental and Numerical Investigation of the Performance of a
Centrifugal Pump When Pumping Water and Light Crude Oil
• Authors: M Hamid Siddique; Sayed Ahmed Imran Bellary; Abdus Samad; Jin-Hyuk Kim; Young-Seok Choi
Pages: 4605 - 4615
Abstract: Abstract In the oil and gas industry, crude oil is frequently transported and centrifugal pumps are used extensively. The pump impeller works under both design and off-design conditions in the applications, and the flow pattern deviates from the ideal case because of viscosity and density changes. An experimental as well as a numerical study was conducted to study the performance of a pump delivering water and light crude oil under design and off-design conditions. A 3D steady incompressible flow in the centrifugal pump was simulated by solving the Reynolds-averaged Navier–Stokes equations and SST turbulence model. At a low flow rate, extensive reverse flow occurs at the inlet of the impeller in the case of water, whereas the opposite was found for light crude oil. Recirculation was observed in the impeller flow passage for both water and the crude oil, but this diminished at higher flow rates.
PubDate: 2017-11-01
DOI: 10.1007/s13369-017-2592-1
Issue No: Vol. 42, No. 11 (2017)

• An Experimental Work on Tool Wear Affected by Die Clearance and Punch
Hardness
• Authors: Ferhat Akyürek; Kemal Yaman; Zafer Tekiner
Pages: 4683 - 4692
Abstract: Abstract Die clearance is a widely known parameter affecting both tool life and edge quality of parts in blanking operations. Selecting the optimum punch–die clearance can give a longer tool life and better product quality by minimizing tool wear. In experimental studies, the effects of cutting die clearance and punch hardness on the punch edge and face wear were investigated. AISI D2 cold work steel with 50, 55 and 60 HRC-hardness punches was used as tool material. Three different cutting die clearances 3, 5 and 8% of sheet thickness were used. A modular punch–die set was prepared, and 2000, 4000, 6000 and 8000 samples are pressed. The results of the experiments showed that the punch edge and face wear decreased with increasing punch hardness and that smooth-sheared parts are strongly dependent on the clearance.
PubDate: 2017-11-01
DOI: 10.1007/s13369-017-2621-0
Issue No: Vol. 42, No. 11 (2017)

• Control, Modeling and Evaluation of a Magnetic Piston Miniature Pump
• Authors: A. T. Al-Halhouli; N. A. Rawashdeh; M. Sanna; S. Büttgenbach; A. Dietzel
Pages: 4693 - 4700
Abstract: Abstract This paper presents the control design and performance evaluation of a novel meso-scale electromechanical fluid pump. Such pumps have the potential for applications in biomedical, chemical and pharmaceutical engineering fields. The pumping concept is based on reciprocating a hard magnet working as a double-acting piston in a circular channel, and synchronizing this movement with two electromagnetically actuated valves located at the pump inlet and outlet ports. The actuation system is programmed to allow sequential energization of a set of coils that control the magnet positions. Each pump port has an inlet and outlet channel. According to the piston movement direction, i.e. clockwise or counter clockwise, the valve magnets will change their positions to allow for inflow or outflow. The pump concept was tested using three control configurations, where piston stroke length, stroke frequency, and energization schemes were varied. Calculations showed that the second configuration has the highest volumetric efficiency of about 90% and the maximum flow rate of 8 mL/min at 78 piston strokes per minute (spm). The maximum pressure was achieved using the third configuration with about 575 Pa at 70 spm.
PubDate: 2017-11-01
DOI: 10.1007/s13369-017-2575-2
Issue No: Vol. 42, No. 11 (2017)

• Deposition-Path Generation of SS308 Components Manufactured by TIG
Welding-Based Shaped Metal Deposition Process
• Authors: Adnan A. Ugla; Oguzhan Yilmaz
Pages: 4701 - 4711
Abstract: Abstract Wire plus arc-based shaped metal deposition is a metal rapid manufacturing technique whereby 3D complex parts are produced by building up metallic parts in layer by layer. In the present work, a type of shaped metal deposition using tungsten inert gas welding plus SS308LSi Wire technique was developed and integrated it with a new computer-aided metal deposition machine (CAMDM). The intent of this paper is to investigate the CAMDM system capabilities about the part modeling and slicing, deposition-path planning, and the part depositing processes. Additionally, this paper highlights the capabilities and limitations of the developed system. The results show that the current manufacturing system is capable to produce various features for metal components with accepted surface quality and free internal defects. The most suitable deposition-path strategy for depositing the solid and hollow components is the combined pattern method, which comprises of the spiral/contour path pattern for the outside/inside boundaries of the part and either spiral or zigzag/raster path pattern for the interior spaces. The controlling system of the present setup allows tuning the deposition parameters during deposition process which usually contributes with selecting of the proper path pattern to manufacture a free defects deposited parts.
PubDate: 2017-11-01
DOI: 10.1007/s13369-017-2582-3
Issue No: Vol. 42, No. 11 (2017)

• Using an Imaginary Planar Rack Cutter to Create a Spherical Gear Pair with
Continue Involute Teeth
• Authors: Hsueh-Cheng Yang
Pages: 4725 - 4735
Abstract: Abstract This paper presents an imaginary planar rack cutter having two parameters of motion to create a spherical gear pair with two degrees of freedom. The working region of the imaginary planar rack cutter is that of symmetrical straight lines. The relationship between the coordinate system of the imaginary planar rack cutter and that of the spherical gear pair having two parameters of motion is illustrated. The two-parameter family of imaginary planar rack cutter surfaces is obtained by using the homogeneous coordinate transformation matrix to transfer the coordinate system of the planar rack cutter to that of the spherical pinion or the spherical gear. Based on the two-parameter enveloping theory, the mathematical models of the spherical gear pair with two degrees of freedom were proposed. The developed mathematical model of the gear pair with two degrees of freedom can be used to analyze undercutting analysis of the imaginary planar rack cutter. Based on the undercutting equation, a minimum number of teeth of the spherical pinion are determined. A line of singular points on the spherical pinion’s teeth are displayed. Results show that a minimum number of teeth of the spherical pinion can be determined in order to avoid undercutting.
PubDate: 2017-11-01
DOI: 10.1007/s13369-017-2630-z
Issue No: Vol. 42, No. 11 (2017)

• Influence of Substrate Temperature on Adhesion Strength of TiN Coating of
Biomedical Ti–13Zr–13Nb Alloy
• Authors: A. Shah; S. Izman; Mohammed Rafiq Abdul-Kadir; H. Mas-Ayu
Pages: 4737 - 4742
Abstract: Abstract Adhesion strength between the coating and the substrate is considered as a significant factor, which may help determine both the successful implantation and the long-term stability of any coated implant. A weakly adhered coating on a medical implant may delaminate after the process of implantation, which in turn may severely limit the effectiveness along with the life of the implant itself. Related previous studies have shown that process parameters may have a direct influence on the quality of TiN coating. In the present work, the effect of substrate temperature on adhesion strength of TiN coating on Ti–13Zr–13Nb biomedical grade alloy was investigated. The coating parameter, which varied in this study, was the substrate temperature (i.e., 100, 200 and $$300\,^{\circ }\hbox {C}$$ ). The adhesion strength of TiN coating was examined by means of scratch testing method. In addition, calibrated optical images were also used to verify the total coating failures on the scratched coated samples. Results indicated that an increase observed in the substrate temperature may have resulted in a decrease in the microdroplet form on TiN coating. In contrast, the adhesion strength of TiN coating was observed to equally increase when substrate temperature increased. It is believed that the higher mobility of atom at a higher substrate temperature (i.e., $$300\,^{\circ }\hbox {C}$$ ) filling up the defect appears on the surface to provide a mechanical interlock and thus providing better adhesion strength.
PubDate: 2017-11-01
DOI: 10.1007/s13369-017-2647-3
Issue No: Vol. 42, No. 11 (2017)

• Study on the Fluid–Structure Interaction at Different Layout of Stacked
Chip in Molded Packaging
• Authors: M. H. H. Ishak; M. Z. Abdullah; M. S. Abdul Aziz; A. A. Saad; M. K. Abdullah; W. K. Loh; R. C. Ooi; C. K. Ooi
Pages: 4743 - 4757
Abstract: Abstract This study investigates fluid–structure interaction (FSI) analysis of stacked chip in the encapsulation of molded underfill packaging using ANSYS Coupling Work bench with fluid and structural solvers. During encapsulation, FSI analysis is applied to a molded package with different layouts, namely cases 1–4 of stacked chip. An even ratio of inlet and outlet gate pressures is used to produce a regular melt front advancement. An experimental setup is fabricated to validate the simulation results in the FSI study. A digital camera is used to capture the melt front advancement and structural deformation. The interaction between structures (silicon chip) and epoxy molding compound (EMC) is displayed in the displacement profile. Maximum deformation is evaluated during the final stage of filling. The silicon die experiences von Mises stresses, which are monitored to observe the risk of die cracking. The results of this study showed that, the EMC flow front advancement was the fastest in case 4. The pressure distribution of each case was nearly identical, and the maximum von Mises stress was distributed unevenly at the middle of the stacked chip. The proposed analysis can serve as a reference and guide in designing and improving 3D integration packages in industry.
PubDate: 2017-11-01
DOI: 10.1007/s13369-017-2659-z
Issue No: Vol. 42, No. 11 (2017)

• The Recrystallization Behavior in Ultrafine-Grained Structure Steel
Fabricated by Cold Rolling and Annealing
• Authors: Qing Yuan; Guang Xu; Jun-yu Tian; Wei-cheng Liang
Pages: 4771 - 4777
Abstract: Abstract A simple process of 50% cold-rolled and annealed at different temperatures and times to obtain ultrafine-grained structured low-carbon steel with superior mechanical properties is utilized in this investigation. The microstructure evolves from bulky austenite to lathy martensite and then ultrafine ferrite grain with nanocarbide particles. Recovery occurs in the specimen annealed at about $$500\,{^{\circ }}$$ C and 30 min, while recrystallization happens in the specimen annealed at $$550\,{^{\circ }}$$ C and 30 min. The optimal balance between the tensile strength (867 MPa) and elongation (16.7%) is obtained in the specimen annealed at $$550\,{^{\circ }}$$ C and 30 min, in which the mean size of ferrite grains and nanocarbides is 330 and 55 nm, respectively. Moreover, the distribution of ferrite grain conforms to the Gaussian distribution. The recrystallization activation energy of low-carbon steel with ultrafine grain is calculated to be $$320,682\,\hbox {J}\, \hbox {mol}^{-1}$$ based on the Arrhenius equation.
PubDate: 2017-11-01
DOI: 10.1007/s13369-017-2633-9
Issue No: Vol. 42, No. 11 (2017)

• Dynamic Modeling and Feedback Linearization Control of Wheeled Mobile
Cable-Driven Parallel Robot Considering Cable Sag
• Authors: M. H. Korayem; M. Yousefzadeh; S. Susany
Pages: 4779 - 4788
Abstract: Abstract Cable robots are one of the subcategories of parallel robots used particularly for the applications where the large workspace is required. This type of robots can cover larger workspace compared with serial robots or parallel robots with rigid links. The main issues of cable robots are the cable flexibility due to the need to long cable length as well as inappropriate cable tension distribution in the proximity of the workspace boundaries. By combining a cable robot with a wheeled mobile robot, an unlimited area of workspace can be reached with shorter cable length. Moreover, as the end-effector does not need to come close to its boundary in the mobile platform frame to reach any desired point in the workspace, the tensions are distributed appropriately. The cable sagging in the cable robots is another issue that increases the system error and deviation of the end-effector from the desired trajectory. Therefore, this paper presents the dynamic modeling and control of a cable-suspended parallel robot with a wheeled mobile platform considering the weight of the cable. To this end, the dynamic equations of the wheeled mobile cable robot are obtained using Gibbs–Appel method. Then, the equations related to the weight and sagging of the cable are added to the equations of motion. Control of the system using feedback linearization method is presented. Furthermore, investigating the effect of cable sag on the tension and the end-effector pose of the closed-loop system is demonstrated. Finally, verification is carried out by comparing the simulation and experimental results.
PubDate: 2017-11-01
DOI: 10.1007/s13369-017-2658-0
Issue No: Vol. 42, No. 11 (2017)

• Load Assessment on the Horizontal Braces of Semi-submersible Drilling
Platform Under Ocean Wave
• Authors: Wang Fei; Liang Zheng
Pages: 4789 - 4799
Abstract: Abstract In order to make sure the horizontal braces of semi-submersible drilling platform are safe during its service life, this research studies the load assessment on the horizontal braces of a platform under harsh wave loads. The hydrodynamic structure model of the platform has been established, and hydrodynamic conditions have been determined firstly. The model test in a wave tank is used to verify the accuracy of the established model in this research. Then, the loads response of the horizontal braces under several typical wave loads which affect the strength of floating structures greatly are evaluated. The results of the research indicate that (a) the splitting force between pontoons and vertical bending moment are found affecting the strength of the horizontal braces greater than the other loads; (b) both the splitting force and vertical bending moment would occur when the platform encounter beam wave; (c) the horizontal braces are loaded on 4.16% of splitting force between pontoons and 2.78% of the vertical bending moment respectively during its service life.
PubDate: 2017-11-01
DOI: 10.1007/s13369-017-2676-y
Issue No: Vol. 42, No. 11 (2017)

• Effect of PCA on Nanosized Ulexite Material Prepared by Mechanical Milling
• Authors: Sezai Kutuk; Tuba Kutuk-Sert
Pages: 4801 - 4809
Abstract: Abstract Raw ulexite (U-3 mm) mineral used as a initial material was milled by using mechanical milling method, the milling time of which is from 0 to 8 h. Particle size, morphology, elemental and crystal structure measurements of the U-3 mm material and milled powder (U_3%, process control agent amount: 3%) were performed. In particle size analysis, minimum $$d_{50},d_{10}$$ and $$d_{\mathrm{min}}$$ values of U_3% powder have been found to be 5.921  $$\upmu \hbox {m}$$ , 641 nm and 240 nm, respectively. Therefore, it has been reached to submicron level in particle size for the U_3% powder. Besides, optimum milling time has been detected to be 0.5 h. In morphology analysis, the U_3% powder has been observed to be more homogeneous compared to the U-3 mm material. In the analysis of element, the U_3% powder has been determined not to be a pure compound ( $$\hbox {Na}_{2}\hbox {O}{\cdot }2\hbox {CaO}{\cdot } 5\hbox {B}_{2}\hbox {O}_{3}{\cdot } 16\hbox {H}_{2}\hbox {O}$$ ). In crystal structure analysis, crystalline size of the U_3% powder has reduced to 10.3 nm at the end of 8 h. Moreover, crystal structure deformation caused by milling process of the U-3 mm material has improved thanks to PCA. The findings obtained from this work will be beneficial for nanoworks and industrial applications, e.g., civil engineering-pavement engineering materials, of ulexite (boron mineral) material.
PubDate: 2017-11-01
DOI: 10.1007/s13369-017-2643-7
Issue No: Vol. 42, No. 11 (2017)

• Fuzzy TOPSIS-Based Selection of Laser Beam Micro-marking Process
Parameters
Pages: 4825 - 4831
Abstract: Abstract The process parameter selection in any machining process is one of the most challenging criteria for effective machining. Selection of an optimal parametric combination always results in efficient machining. In the current work, a fuzzy TOPSIS method for selection of optimal laser beam micro-marking process parameters, such as current, pulse frequency, and scanning speed, during laser beam marking on gallium nitride is adopted. Response surface methodology (central composite design) is adopted for the experimental design. The mark width, mark depth, and mark intensity are considered as the process responses. The mark width and mark depth are measured with the help of a precision optical microscope. Microscopic images are then treated using image processing software to calculate the mark intensity. A multi-criteria decision-making model is developed considering the effect of process parameters on process response for selection of optimal process parameter in the laser beam micro-marking process. The triangular fuzzy number is used to calculate the weight of each performance criteria, and the fuzzy TOPSIS hybrid approach is used for selection of optimal parametric combination. The results indicate that a small pulse frequency and high current and scanning speed lead to increase in mark intensity.
PubDate: 2017-11-01
DOI: 10.1007/s13369-017-2673-1
Issue No: Vol. 42, No. 11 (2017)

• Computational Assessment of the Heat Transfer Coefficient Under Forced
Convection of Multiple Metal Foam Fins Heat Sinks
• Authors: Khaled S. Al-Athel
Pages: 4853 - 4861
Abstract: Abstract The use of metal foams in thermal applications such as heat sinks, heat exchangers, and other heat recovery systems has been increased in the last 2 decades. That being said, the studies were mostly experimental in nature. Due to the complexity of metal foams, most of the results were useful from a qualitative point of view rather than quantitative. With the improvement in computational means, micro-CT scan has been used to develop realistic 3D metal foam models. These models in the literature mostly focus on extracting mechanical and thermal properties, or study the behavior of the metal foam material. In this work, a micro-CT scan metal foam heat sink model is used to study the effect of having multiple metal foam fins on the heat transfer coefficient (h). The calibration of the heat transfer coefficients show that the assumption used in the literature of a fixed h value is not valid. The variation of the h value of each metal foam fin is used to study its effect on the performance of a two and three metal foam fins heat sinks by investigating the thermal resistance and the effectiveness of the heat sink. It was found that even though there is an increase in the thermal resistance, increasing the number of fins will improve the effectiveness in a nonlinear fashion. It is suggested that even with the improvement in the effectiveness, a variation in the height of the metal foam fins will improve the efficiency.
PubDate: 2017-11-01
DOI: 10.1007/s13369-017-2656-2
Issue No: Vol. 42, No. 11 (2017)

• Effect of Composition and Thickness on the Hardness and Scratch Resistance
of Copper and Copper Alloy Coatings
• Authors: Khaled S. Al-Athel; Mohamed Ibrahim; Abul Fazal M. Arif; Syed Sohail Akhtar
Pages: 4895 - 4904
Abstract: Abstract Coatings are extensively used as corrosion resistance, wear resistance, and antibacterial surfaces. Copper and copper alloys are among the most widely applied coating materials for industrial and medical applications. In this work, mechanical assessment of Cu, Cu 4%Sn, Cu 17%Ni 10%Zn (German Silver), and Cu 17%Al 1%Fe coatings deposited on stainless steel 316L substrates using twin wire arc thermal spraying is studied experimentally. Microstructure, hardness, and scratch resistance were studied for all coated samples. The effects of having different coating compositions on the mechanical properties are analyzed. The effect of the coatings thickness is also investigated for Cu 17%Ni 10%Zn and Cu 17%Al 1%Fe coatings with different thicknesses between 200 and $$400\,\upmu \hbox {m}$$ . The study focused on how the scratch resistance increases with increasing the coating thickness on the expense of the adhesion. A comparison of the coating hardness profile between different copper and copper alloy compositions was presented. An interesting observation was that even though scratch hardness increases with the coating thickness, hardness decreases as a function of the distance from the interface.
PubDate: 2017-11-01
DOI: 10.1007/s13369-017-2661-5
Issue No: Vol. 42, No. 11 (2017)

• Erratum to: The Efficacy of Process Capability Indices Using Median
Absolute Deviation and Their Bootstrap Confidence Intervals
Pages: 4957 - 4957
PubDate: 2017-11-01
DOI: 10.1007/s13369-017-2807-5
Issue No: Vol. 42, No. 11 (2017)

JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327

Home (Search)
Subjects A-Z
Publishers A-Z
Customise
APIs