The Experts below are selected from a list of 13032 Experts worldwide ranked by ideXlab platform
A K Ariffin - One of the best experts on this subject based on the ideXlab platform.
-
development of a finite element model of metal Powder Compaction process at elevated temperature
Applied Mathematical Modelling, 2009Co-Authors: Mujibur Rahman, A K AriffinAbstract:This paper presents the finite element modelling of metal Powder Compaction process at elevated temperature. In the modelling, the behaviour of Powder is assumed to be rate independent thermo-elastoplastic material where the material constitutive laws are derived based on a continuum mechanics approach. The deformation process of metal Powder has been described by a large displacement based finite element formulation. The Elliptical Cap yield model has been used to represent the deformation behaviour of the Powder mass during the Compaction process. This yield model was tested and found to be appropriate to represent the Compaction process. The staggered-incremental-iterative solution strategy has been established to solve the non-linearity in the systems of equations. Some numerical simulation results were validated through experimentation, where a good agreement was found between the numerical simulation results and the experimental data.
-
the effect of lubrication in reducing net friction in warm Powder Compaction process
Journal of Materials Processing Technology, 2008Co-Authors: Mujibur Rahman, Faris Tarlochan, B Shahida, A K AriffinAbstract:Abstract Warm Powder Compaction process is an advanced type of the conventional cold Compaction process in producing a green compact, which is conducted at elevated temperature. Metal Powder inside a die is compressed completely after heating the whole system at elevated temperature ranges from 100 °C to 150 °C. During the Compaction process, friction occurs between the metal Powder, the die surface and between the Powders itself. The entire Compaction phases as well as the density of green compact are eventually affected because of the process. The aim of this paper is to discuss the effect of lubrication in term of the mixing time, weight percent of lubricant and the density of metal Powder through warm Compaction. The metal Powder that used was in the process was an iron ASC 100.29. The Compaction experiments have been conducted at 130 °C and the lubricants used was zinc stearate and carbon. It was found that the Compaction phases (Compaction and ejection) are strongly dependant on the variables used.
-
Simulation of Crack Propagation in Metal Powder Compaction
International Journal for Computational Methods in Engineering Science and Mechanics, 2006Co-Authors: Suraya Mohd Tahir, A K AriffinAbstract:This paper presents the fracture criterion of metal Powder compact and simulation of the crack initiation and propagation during cold Compaction process. Based on the fracture criterion of rock in compression, a displacement-based finite element model has been developed to analyze fracture initiation and crack growth in iron Powder compact. Estimation of fracture toughness variation with relative density is established in order to provide the fracture parameter as Compaction proceeds. A finite element model with adaptive remeshing technique is used to accommodate changes in geometry during the Compaction and fracture process. Friction between crack faces is modelled using the six-node isoparametric interface elements. The shear stress and relative density distributions of the iron compact with predicted crack growth are presented, where the effects of different loading conditions are presented for comparison purposes.
-
Fracture in metal Powder Compaction
International Journal of Solids and Structures, 2006Co-Authors: Suraya Mohd Tahir, A K AriffinAbstract:This paper presents a preliminary assessment and qualitative analysis on fracture criterion and crack growth in metal Powder compact during the cold Compaction process. Based on the fracture criterion of granular materials in compression, a displacement based finite element model has been developed to analyse fracture initiation and crack growth in metal Powder compact. Approximate estimation of fracture toughness variation with relative density is established in order to provide the fracture parameter as Compaction proceed. A single crack initiated from the boundary of a multi-level component made of iron Powder is considered in this work. The finite element simulation of the crack propagation indicates that shear crack grows during the Compaction process and propagates in the direction of higher shear stress and higher relative density. This also implies that the crack grows in the direction where the Compaction pressure is much higher, which is in line with the conclusion made by previous researchers on shear crack growth in materials under compression. In agreement with reported work by previous researchers, high stress concentration and high density gradient at the inner corner in multi-level component results in fracture of the component during preparation.
Nobuhiro Yoshikawa - One of the best experts on this subject based on the ideXlab platform.
-
large scale aluminum foam plate fabricated by enhanced friction Powder Compaction process based on sintering and dissolution process
Journal of Materials Processing Technology, 2014Co-Authors: Yoshihiko Hangai, Kousuke Zushida, Osamu Kuwazuru, Nobuhiro YoshikawaAbstract:Abstract An enhanced friction Powder Compaction (FPC) process was proposed for fabricating a large plate of aluminum foam by the sintering and dissolution process. In this process, the rotating tool plunged into the die filled with a Powder mixture of aluminum and NaCl during the FPC process was made to traverse perpendicularly to the direction of plunging as in the case of friction stir welding. In the enhanced FPC process, no external heat source, such as an electric furnace or a spark plasma sintering, was necessary for fabricating aluminum foam, except for the friction heat generated by traversing the rotating tool. It was found that a long plate of aluminum foam can be fabricated with a length equal to the tool traversing length. By X-ray computed tomography (CT) and scanning electron microscopy (SEM) observations of the pore structures of the fabricated aluminum foam, it was found that the entire sample had a pore structures that was similar to the NaCl morphology, regardless of the position along the traversing direction. The fabricated aluminum foam had a similar stress–strain curve to that of aluminum foam fabricated by spark plasma sintering and exhibited ductile fracture. This is considered to be attributed to the good bonding between aluminum particles in the entire sample. The fabricated aluminum foam exhibited almost the same plateau stress regardless of the position along the traversing direction.
-
friction Powder Compaction process for fabricating open celled cu foam by sintering dissolution process route using nacl space holder
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2013Co-Authors: Yoshihiko Hangai, Kousuke Zushida, Osamu Kuwazuru, Hidetoshi Fujii, Rintaro Ueji, Nobuhiro YoshikawaAbstract:Abstract Open-celled metal foams have received considerable attention in various fields and are expected to be used as engineering materials where heat exchange, sound absorption and filtration are required. In this study, Cu foam specimens with NaCl volume fractions of 60%, 70% and 80% were successfully fabricated by the friction Powder Compaction (FPC) process with the sintering and dissolution process (SDP) using NaCl as space holders. In the FPC process, no external heat source was used for fabricating Cu foam except for the friction heat generated by the rotating tool plunged into the die and Powders. From the X-ray CT and SEM observation of the pore structures of the fabricated Cu foam, it was found that almost the entire specimen had a pore structure similar to the NaCl morphology, regardless of the NaCl volume fraction. This is mainly because the sintering process for Cu particles in the FPC process was achieved at a temperature lower than the melting point of NaCl. From compression tests of the fabricated Cu foam, Cu foam exhibited ductile fracture regardless of its NaCl volume fraction, which is considered to be attributed to the good bonding between Cu particles. The plateau stress and energy absorption decreased with increasing NaCl volume fraction, indicating strong relationships between them. The Cu foam with the highest energy absorption per unit volume up to the specific stress changed from the high-NaCl-volume-fraction Cu foam to the low-NaCl-volume-fraction Cu foam with increasing compression stress. Consequently, it was shown that the mechanical properties of Cu foam can be controlled by adjusting the volume fraction of NaCl.
-
effect of die material on compressive properties of open cell porous aluminum fabricated by friction Powder Compaction process
Materials Transactions, 2013Co-Authors: Yoshihiko Hangai, Hiroaki Yoshida, Osamu Kuwazuru, Nobuhiro YoshikawaAbstract:Porous Al is expected to be used for a variety of applications such as automotive components and building materials owing to its high functionality and light weight.1) Among the numerous fabrication processes of porous Al, the sintering and dissolution process (SDP) is a promising route for fabricating open-cell porous Al.28) In this process, a mixture of Al Powder and NaCl Powder is sintered by applying appropriate pressure and heat using an electric furnace25) or by spark plasma sintering (SPS).68) Then, the sintered mixture is placed in water to remove the NaCl and obtain porous Al. Recently, a new friction Powder Compaction (FPC) process, which requires no external heat source for Powder sintering, has been developed.9,10) Porous Al can be fabricated by combining the SDP and the FPC process.9) In this combined process, the sintering of the Powder mixture is conducted simply by plunging a rotating tool into a die filled with the mixture, and sintering is induced by the friction heat and pressing load generated by the rotating tool plunging into the die. It is considered that the pressing load and temperature during the sintering process directly affect the degree of sintering of the mixture, namely, the mechanical properties of the obtained porous Al. In friction stir welding (FSW), it is known that the welding temperature and load are significantly different in the FSW of Cu and that of Al.11) In this study, Cu (referred to as FPC-Cu hereinafter) and Al (FPC-Al) dies were used and the effect of the difference in the die material on the mechanical properties of the obtained porous Al was investigated. In addition, the mechanical properties of the obtained porous Al were compared with those of other porous Al samples fabricated by the SDP route, in which the sintering of the mixture is conducted by SPS.68)
-
Friction Powder Compaction for Fabrication of Open-Cell Aluminum Foam by the Sintering and Dissolution Process Route
Metallurgical and Materials Transactions A, 2012Co-Authors: Yoshihiko Hangai, Hiroaki Yoshida, Nobuhiro YoshikawaAbstract:A new friction Powder Compaction (FPC) process by the sintering and dissolution process (SDP) route for fabricating open-cell aluminum (Al) foam, which requires no external heat sources, was developed. Foams with porosities of 74 and 83 pct were successfully fabricated and their compressive responses were investigated. The sintered mixture during the removal process was observed nondestructively by X-ray computed tomography (CT) to reveal the progress of the removal of soluble particles and to confirm that they were completely dissolved.
Mujibur Rahman - One of the best experts on this subject based on the ideXlab platform.
-
development of a finite element model of metal Powder Compaction process at elevated temperature
Applied Mathematical Modelling, 2009Co-Authors: Mujibur Rahman, A K AriffinAbstract:This paper presents the finite element modelling of metal Powder Compaction process at elevated temperature. In the modelling, the behaviour of Powder is assumed to be rate independent thermo-elastoplastic material where the material constitutive laws are derived based on a continuum mechanics approach. The deformation process of metal Powder has been described by a large displacement based finite element formulation. The Elliptical Cap yield model has been used to represent the deformation behaviour of the Powder mass during the Compaction process. This yield model was tested and found to be appropriate to represent the Compaction process. The staggered-incremental-iterative solution strategy has been established to solve the non-linearity in the systems of equations. Some numerical simulation results were validated through experimentation, where a good agreement was found between the numerical simulation results and the experimental data.
-
an experimental investigation of metal Powder Compaction at elevated temperature
Mechanics of Materials, 2009Co-Authors: Mujibur RahmanAbstract:Abstract The warm Compaction process was initiated in the nineties and found that metal Powder formed at elevated temperature gives significant impact on the entire Compaction process and the quality of the green compact as well as the final product. Mechanical properties of green compact are largely influenced by the forming temperature, lubricant and lubrication mechanism, and loading condition. This paper presents the Powder Compaction study from experimental investigation covering full scale Compaction phases. The optimum forming temperature, amount of lubricant content, and loading conditions are also presented. Several experiments have been conducted using T-shape die to generate green compacts from iron Powder. The forming temperature has been ranged from room temperature (30 °C) to 150 °C. Finally, the generated green compacts are tested mechanically to justify the mechanical properties. It has been found that the optimum forming temperature for iron Powder is about 130–150 °C whereas the lubricant content is about 0.5 wt%.
-
the effect of lubrication in reducing net friction in warm Powder Compaction process
Journal of Materials Processing Technology, 2008Co-Authors: Mujibur Rahman, Faris Tarlochan, B Shahida, A K AriffinAbstract:Abstract Warm Powder Compaction process is an advanced type of the conventional cold Compaction process in producing a green compact, which is conducted at elevated temperature. Metal Powder inside a die is compressed completely after heating the whole system at elevated temperature ranges from 100 °C to 150 °C. During the Compaction process, friction occurs between the metal Powder, the die surface and between the Powders itself. The entire Compaction phases as well as the density of green compact are eventually affected because of the process. The aim of this paper is to discuss the effect of lubrication in term of the mixing time, weight percent of lubricant and the density of metal Powder through warm Compaction. The metal Powder that used was in the process was an iron ASC 100.29. The Compaction experiments have been conducted at 130 °C and the lubricants used was zinc stearate and carbon. It was found that the Compaction phases (Compaction and ejection) are strongly dependant on the variables used.
Charles Manière - One of the best experts on this subject based on the ideXlab platform.
-
A spark plasma sintering densification modeling approach: from polymer, metals to ceramics
Journal of Materials Science, 2018Co-Authors: Charles Manière, Lise Durand, Geoffroy Chevallier, Claude EstournesAbstract:© 2018, Springer Science+Business Media, LLC, part of Springer Nature. The Powder Compaction modeling of advanced sintering techniques such as spark plasma sintering is a crucial step in the conception of complex shape objects and the understanding of the process. The complete identification of common Powder Compaction models requires lengthy experimental investigations based on creep and Compaction tests. In order to circumvent this problem, a semi-theoretical approach can be employed whereby the mechanical behavior of the Powder material is determined theoretically and the temperature-dependent equivalent creep behavior of the material is determined experimentally. Extending the use of this approach to polymers, metals and ceramics is discussed and compared to other independent methods.
-
porosity dependence of Powder Compaction constitutive parameters determination based on spark plasma sintering tests
Scripta Materialia, 2017Co-Authors: Charles Manière, Eugene A OlevskyAbstract:Abstract The modeling of Powder Compaction process, such as spark plasma sintering (SPS), requires the determination of the visco-plastic deformation behavior of the particle material including the viscosity moduli. The establishment of these parameters usually entails a long and difficult experimental campaign which in particular involves several hot isostatic pressing tests. A more straightforward method based on the coupled sinter-forging and die Compaction tests, which can be easily carried out in a regular SPS device, is presented. Compared to classical creep mechanism studies, this comprehensive experimental approach can reveal the in situ porous structure morphology influence on the sintering process.
-
identification of the norton green Compaction model for the prediction of the ti 6al 4v densification during the spark plasma sintering process
Advanced Engineering Materials, 2016Co-Authors: Charles Manière, Lise Durand, Ronan Mainguy, Denis Delagnes, Julitte Huez, Claude EstournesAbstract:One of the main challenges for the industrialization of the spark plasma sintering (SPS) is to resolve issues linked to the Compaction of real parts with complex shapes. The modeling of Powder Compaction is an interesting tool to predict how the densification field varies during sintering. However, expressing the behavior law which reflect the Powder Compaction is often a difficult and long step in the model establishment. In this paper, a simple methodology for the identification of the densification parameters is proposed. Dense and porous creep tests combined with SPS die Compaction tests are employed to determine a complete densification law on a Ti–6Al–4V alloy directly in a SPS machine. The Compaction model obtained is successfully validated through prediction of the densification of new SPSed samples.
-
Identification of the Norton-Green Compaction Model for the Prediction of the Ti–6Al–4V Densification During the Spark Plasma Sintering Process
Advanced Engineering Materials, 2016Co-Authors: Charles Manière, Lise Durand, Ugras Kus, Ronan Mainguy, Denis Delagnes, Julitte Huez, Claude EstournesAbstract:© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim One of the main challenges for the industrialization of the spark plasma sintering (SPS) is to resolve issues linked to the Compaction of real parts with complex shapes. The modeling of Powder Compaction is an interesting tool to predict how the densification field varies during sintering. However, expressing the behavior law which reflect the Powder Compaction is often a difficult and long step in the model establishment. In this paper, a simple methodology for the identification of the densification parameters is proposed. Dense and porous creep tests combined with SPS die Compaction tests are employed to determine a complete densification law on a Ti–6Al–4V alloy directly in a SPS machine. The Compaction model obtained is successfully validated through prediction of the densification of new SPSed samples.
Eugene A Olevsky - One of the best experts on this subject based on the ideXlab platform.
-
porosity dependence of Powder Compaction constitutive parameters determination based on spark plasma sintering tests
Scripta Materialia, 2017Co-Authors: Charles Manière, Eugene A OlevskyAbstract:Abstract The modeling of Powder Compaction process, such as spark plasma sintering (SPS), requires the determination of the visco-plastic deformation behavior of the particle material including the viscosity moduli. The establishment of these parameters usually entails a long and difficult experimental campaign which in particular involves several hot isostatic pressing tests. A more straightforward method based on the coupled sinter-forging and die Compaction tests, which can be easily carried out in a regular SPS device, is presented. Compared to classical creep mechanism studies, this comprehensive experimental approach can reveal the in situ porous structure morphology influence on the sintering process.