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Shyam Kishore - One of the best experts on this subject based on the ideXlab platform.
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influence of size and volume fraction of sic particulates on properties of ex situ reinforced al 4 5cu 3mg metal matrix composite prepared by direct metal Laser Sintering Process
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2010Co-Authors: Subrata Ghosh, Partha Saha, Shyam KishoreAbstract:Direct metal Laser Sintering (DMLS) Process has a great potential to prepare metal matrix composites (MMCs) in fabrication of arbitrary shaped jobs through rapid manufacturing. In the present work, silicon carbide particulates reinforced aluminium based metal matrix composite was developed by direct metal Laser Sintering Process. Influences of SiC particulate (SiCp) on density, porosity and microhardness of the composite were investigated. It shows that SiCp having 300 mesh size provides higher density and lower porosity because of lower clustering effect. Higher microhardness was achieved at 1200 mesh of reinforcement because of lower grain size. Microhardness increases with increase of volume fraction of SiCp and higher value was achieved at high reinforcement content of 30 vol.%. Microstructure was studied through scanning electron microscopy (SEM) and X-ray elemental mapping. Interfacial microstructure was also investigated and cracks were found in number of cases due to difference between co-efficient of thermal expansion of matrix alloy and SiCp.
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influence of size and volume fraction of sic particulates on properties of ex situ reinforced al 4 5cu 3mg metal matrix composite prepared by direct metal Laser Sintering Process
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2010Co-Authors: Subrata Kumar Ghosh, Partha Saha, Shyam KishoreAbstract:Direct metal Laser Sintering (DMLS) Process has a great potential to prepare metal matrix composites (MMCs) in fabrication of arbitrary shaped jobs through rapid manufacturing. In the present work, silicon carbide particulates reinforced aluminium based metal matrix composite was developed by direct metal Laser Sintering Process. Influences of SiC particulate (SiCp) on density, porosity and microhardness of the composite were investigated. It shows that SiCp having 300 mesh size provides higher density and lower porosity because of lower clustering effect. Higher microhardness was achieved at 1200 mesh of reinforcement because of lower grain size. Microhardness increases with increase of volume fraction of SiCp and higher value was achieved at high reinforcement content of 30 vol.%. Microstructure was studied through scanning electron microscopy (SEM) and X-ray elemental mapping. Interfacial microstructure was also investigated and cracks were found in number of cases due to difference between co-efficient of thermal expansion of matrix alloy and SiCp.
Partha Saha - One of the best experts on this subject based on the ideXlab platform.
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development of an in situ multi component reinforced al based metal matrix composite by direct metal Laser Sintering technique optimization of Process parameters
Materials Characterization, 2014Co-Authors: Subrata Kumar Ghosh, Kaushik Bandyopadhyay, Partha SahaAbstract:Abstract In the present investigation, an in-situ multi-component reinforced aluminum based metal matrix composite was fabricated by the combination of self-propagating high-temperature synthesis and direct metal Laser Sintering Process. The different mixtures of Al, TiO 2 and B 4 C powders were used to initiate and maintain the self-propagating high-temperature synthesis by Laser during the Sintering Process. It was found from the X-ray diffraction analysis and scanning electron microscopy that the reinforcements like Al 2 O 3 , TiC, and TiB 2 were formed in the composite. The scanning electron microscopy revealed the distribution of the reinforcement phases in the composite and phase identities. The variable parameters such as powder layer thickness, Laser power, scanning speed, hatching distance and composition of the powder mixture were optimized for higher density, lower porosity and higher microhardness using Taguchi method. Experimental investigation shows that the density of the specimen mainly depends upon the hatching distance, composition and layer thickness. On the other hand, hatching distance, layer thickness and Laser power are the significant parameters which influence the porosity. The composition, Laser power and layer thickness are the key influencing parameters for microhardness.
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crack and wear behavior of sic particulate reinforced aluminium based metal matrix composite fabricated by direct metal Laser Sintering Process
Materials & Design, 2011Co-Authors: Subrata Ghosh, Partha SahaAbstract:In this investigation, crack density and wear performance of SiC particulate (SiCp) reinforced Al-based metal matrix composite (Al-MMC) fabricated by direct metal Laser Sintering (DMLS) Process have been studied. Mainly, size and volume fraction of SiCp have been varied to analyze the crack and wear behavior of the composite. The study has suggested that crack density increases significantly after 15 volume percentage (vol.%) of SiCp. The paper has also suggested that when size (mesh) of reinforcement increases, wear resistance of the composite drops. Three hundred mesh of SiCp offers better wear resistance; above 300 mesh the specific wear rate increases significantly. Similarly, there has been no improvement of wear resistance after 20 vol.% of reinforcement. The scanning electron micrographs of the worn surfaces have revealed that during the wear test SiCp fragments into small pieces which act as abrasives to result in abrasive wear in the specimen.
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influence of size and volume fraction of sic particulates on properties of ex situ reinforced al 4 5cu 3mg metal matrix composite prepared by direct metal Laser Sintering Process
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2010Co-Authors: Subrata Ghosh, Partha Saha, Shyam KishoreAbstract:Direct metal Laser Sintering (DMLS) Process has a great potential to prepare metal matrix composites (MMCs) in fabrication of arbitrary shaped jobs through rapid manufacturing. In the present work, silicon carbide particulates reinforced aluminium based metal matrix composite was developed by direct metal Laser Sintering Process. Influences of SiC particulate (SiCp) on density, porosity and microhardness of the composite were investigated. It shows that SiCp having 300 mesh size provides higher density and lower porosity because of lower clustering effect. Higher microhardness was achieved at 1200 mesh of reinforcement because of lower grain size. Microhardness increases with increase of volume fraction of SiCp and higher value was achieved at high reinforcement content of 30 vol.%. Microstructure was studied through scanning electron microscopy (SEM) and X-ray elemental mapping. Interfacial microstructure was also investigated and cracks were found in number of cases due to difference between co-efficient of thermal expansion of matrix alloy and SiCp.
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influence of size and volume fraction of sic particulates on properties of ex situ reinforced al 4 5cu 3mg metal matrix composite prepared by direct metal Laser Sintering Process
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2010Co-Authors: Subrata Kumar Ghosh, Partha Saha, Shyam KishoreAbstract:Direct metal Laser Sintering (DMLS) Process has a great potential to prepare metal matrix composites (MMCs) in fabrication of arbitrary shaped jobs through rapid manufacturing. In the present work, silicon carbide particulates reinforced aluminium based metal matrix composite was developed by direct metal Laser Sintering Process. Influences of SiC particulate (SiCp) on density, porosity and microhardness of the composite were investigated. It shows that SiCp having 300 mesh size provides higher density and lower porosity because of lower clustering effect. Higher microhardness was achieved at 1200 mesh of reinforcement because of lower grain size. Microhardness increases with increase of volume fraction of SiCp and higher value was achieved at high reinforcement content of 30 vol.%. Microstructure was studied through scanning electron microscopy (SEM) and X-ray elemental mapping. Interfacial microstructure was also investigated and cracks were found in number of cases due to difference between co-efficient of thermal expansion of matrix alloy and SiCp.
Subrata Ghosh - One of the best experts on this subject based on the ideXlab platform.
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crack and wear behavior of sic particulate reinforced aluminium based metal matrix composite fabricated by direct metal Laser Sintering Process
Materials & Design, 2011Co-Authors: Subrata Ghosh, Partha SahaAbstract:In this investigation, crack density and wear performance of SiC particulate (SiCp) reinforced Al-based metal matrix composite (Al-MMC) fabricated by direct metal Laser Sintering (DMLS) Process have been studied. Mainly, size and volume fraction of SiCp have been varied to analyze the crack and wear behavior of the composite. The study has suggested that crack density increases significantly after 15 volume percentage (vol.%) of SiCp. The paper has also suggested that when size (mesh) of reinforcement increases, wear resistance of the composite drops. Three hundred mesh of SiCp offers better wear resistance; above 300 mesh the specific wear rate increases significantly. Similarly, there has been no improvement of wear resistance after 20 vol.% of reinforcement. The scanning electron micrographs of the worn surfaces have revealed that during the wear test SiCp fragments into small pieces which act as abrasives to result in abrasive wear in the specimen.
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influence of size and volume fraction of sic particulates on properties of ex situ reinforced al 4 5cu 3mg metal matrix composite prepared by direct metal Laser Sintering Process
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2010Co-Authors: Subrata Ghosh, Partha Saha, Shyam KishoreAbstract:Direct metal Laser Sintering (DMLS) Process has a great potential to prepare metal matrix composites (MMCs) in fabrication of arbitrary shaped jobs through rapid manufacturing. In the present work, silicon carbide particulates reinforced aluminium based metal matrix composite was developed by direct metal Laser Sintering Process. Influences of SiC particulate (SiCp) on density, porosity and microhardness of the composite were investigated. It shows that SiCp having 300 mesh size provides higher density and lower porosity because of lower clustering effect. Higher microhardness was achieved at 1200 mesh of reinforcement because of lower grain size. Microhardness increases with increase of volume fraction of SiCp and higher value was achieved at high reinforcement content of 30 vol.%. Microstructure was studied through scanning electron microscopy (SEM) and X-ray elemental mapping. Interfacial microstructure was also investigated and cracks were found in number of cases due to difference between co-efficient of thermal expansion of matrix alloy and SiCp.
Abdolreza Simchi - One of the best experts on this subject based on the ideXlab platform.
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Effect of C and Cu addition on the densification and microstructure of iron powder in direct Laser Sintering Process
Materials Letters, 2008Co-Authors: Abdolreza SimchiAbstract:Abstract Laser Sintering of Fe–C–Cu steel powder for rapid manufacturing of sintered components for functional testing was studied. The effects of C and Cu addition on the densification and the attendant microstructural features were investigated. The influence of iron particle size on the Sintering kinetics was also examined. It is shown that the alloying elements significantly improve the densification rate when fine iron particles and high Laser intensity are used. The mechanism of particle bonding and the effect of the alloying elements are presented.
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direct Laser Sintering of iron graphite powder mixture
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2004Co-Authors: Abdolreza Simchi, Haiko PohlAbstract:Abstract In the present work, the role of graphite addition on the Laser Sintering of iron powder was studied. Powder mixtures containing iron and 0.4, 0.8, 1.2, and 1.6 wt.% graphite were prepared by blending elemental powders. These powders were sintered layer-by-layer under nitrogen atmosphere using a continuous wave CO 2 Laser beam. A Laser power of 70–225 W, scan rate of 50–600 mm s −1 , scan line spacing of 0.1–0.3 mm, and layer thickness of 0.1 mm was used. It was found that the Processing parameters play a key role on the densification of the iron–graphite powder mixtures. The addition of graphite enhances the densification of the iron powder and improves the surface quality of the Laser sintered parts when optimized manufacturing conditions are applied. The graphite content has a significant influence on the internal pore structure of the sintered parts. They are gradually changed from interconnected networks to closed and spherical shaped pores with increasing graphite content. The metal matrix structure consists of different phases such as ferrite, austenite, and tempered martensite, which highlights the heterogeneous distribution of dissolved carbon in the iron matrix. This article presents the experimental details of the microstructural evolution in Laser sintered iron–graphite powder mixtures. The role and key importance of graphite addition to iron powder in the Laser Sintering Process is addressed.
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The role of particle size on the Laser Sintering of iron powder
Metallurgical and Materials Transactions B-Process Metallurgy and Materials Processing Science, 2004Co-Authors: Abdolreza SimchiAbstract:The effects of powder particle size on the densification and microstructure of iron powder in the direct Laser Sintering Process were investigated. Iron powders with particle sizes ranging from 10 to 200 mum were used. It was found that the sintered density increases as the Laser energy input is increased. There is, however, a saturation level at which higher density cannot be obtained even at very intensive energy input. This saturation density increases as the size of the iron particles decreases. Meanwhile fine powders with narrow particle size distributions have a tendency toward agglomeration, and coarse powders with broad particle size distributions have a tendency toward segregation, both of them resulting in lower attainable density. In order to investigate the role of particle size, a "densification coefficient (K)" was defined and used. This coefficient depends on the particle size and the oxygen content of iron powder. The results of this investigation demonstrate that the presence of oxygen significantly influences the densification and pore morphology of Laser-sintered iron. At higher oxygen concentrations, the iron melt pool is solidified to agglomerates, and formation of pores with orientation toward the building direction is more likely to occur. When the oxygen concentration is kept constant, the densification coefficient decreases with decreasing the particle size, meaning the densification kinetics enhances. This article presents the role of powder characteristics and the Processing parameters in the Laser Sintering of iron powder as a model material. The mechanism of particle bonding and microstructural features of Laser-sintered parts are addressed.
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on the development of direct metal Laser Sintering for rapid tooling
Journal of Materials Processing Technology, 2003Co-Authors: Abdolreza Simchi, Frank Petzoldt, Haiko PohlAbstract:Abstract An iron based powder blend has been developed for rapid tooling using a direct Laser Sintering Process. The powder consists of a mixture of different elements including Fe, C, Cu, Mo and Ni. High Sintering activities were obtained by tailoring the powder characteristics and optimizing the chemical constituents. The manufacturing of complex-shaped parts is possible at rates of 6.75 cm 3 /h according to CAD data. The residual porosity is less than 5 vol.%. The bending strength is around 900 MPa and the artifact hardness is 490 HV30. To further improve the service life of tools, the Processed parts are sintered again in a vacuum furnace at 1260 °C for 30 min. This enables to manufacture precision parts with the density around 7.7 g/cm 3 (Sintering shrinkage is nearly zero). The dimensional accuracy of the sintered parts is improved by using a beam compensation technique that is integrated in the computer program of the Laser Sintering system. In this article the Sintering behavior, mechanical properties, and microstructural features of the multi-component iron based powder are given and implications of the material for industrial applications are presented. A case study was performed to present the applicability of the material for rapid tooling.
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direct metal Laser Sintering material considerations and mechanisms of particle rand tooling of powdered metal parts
International Journal of Powder Metallurgy, 2001Co-Authors: Abdolreza Simchi, Frank Petzoldt, Haiko PohlAbstract:Most of the rapid prototyping Processes with a high potential for the fabrication of metal or ceramic parts involve powder materials. Direct metal Laser Sintering is now an established method for the production of functional prototypes and mold inserts using computer-controlled Laser/scanning with a powder feed system. The characteristics of the powder materials and the Processing parameters influence the properties of prototypes and tools. This article addresses material consideration in the direct metal Laser Sintering Process. Mechanisms of particle bonding and resulting microstructural features are described and the influence of manufacturing parameters and the basic principles of the Process are delineated.
Subrata Kumar Ghosh - One of the best experts on this subject based on the ideXlab platform.
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development of an in situ multi component reinforced al based metal matrix composite by direct metal Laser Sintering technique optimization of Process parameters
Materials Characterization, 2014Co-Authors: Subrata Kumar Ghosh, Kaushik Bandyopadhyay, Partha SahaAbstract:Abstract In the present investigation, an in-situ multi-component reinforced aluminum based metal matrix composite was fabricated by the combination of self-propagating high-temperature synthesis and direct metal Laser Sintering Process. The different mixtures of Al, TiO 2 and B 4 C powders were used to initiate and maintain the self-propagating high-temperature synthesis by Laser during the Sintering Process. It was found from the X-ray diffraction analysis and scanning electron microscopy that the reinforcements like Al 2 O 3 , TiC, and TiB 2 were formed in the composite. The scanning electron microscopy revealed the distribution of the reinforcement phases in the composite and phase identities. The variable parameters such as powder layer thickness, Laser power, scanning speed, hatching distance and composition of the powder mixture were optimized for higher density, lower porosity and higher microhardness using Taguchi method. Experimental investigation shows that the density of the specimen mainly depends upon the hatching distance, composition and layer thickness. On the other hand, hatching distance, layer thickness and Laser power are the significant parameters which influence the porosity. The composition, Laser power and layer thickness are the key influencing parameters for microhardness.
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influence of size and volume fraction of sic particulates on properties of ex situ reinforced al 4 5cu 3mg metal matrix composite prepared by direct metal Laser Sintering Process
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2010Co-Authors: Subrata Kumar Ghosh, Partha Saha, Shyam KishoreAbstract:Direct metal Laser Sintering (DMLS) Process has a great potential to prepare metal matrix composites (MMCs) in fabrication of arbitrary shaped jobs through rapid manufacturing. In the present work, silicon carbide particulates reinforced aluminium based metal matrix composite was developed by direct metal Laser Sintering Process. Influences of SiC particulate (SiCp) on density, porosity and microhardness of the composite were investigated. It shows that SiCp having 300 mesh size provides higher density and lower porosity because of lower clustering effect. Higher microhardness was achieved at 1200 mesh of reinforcement because of lower grain size. Microhardness increases with increase of volume fraction of SiCp and higher value was achieved at high reinforcement content of 30 vol.%. Microstructure was studied through scanning electron microscopy (SEM) and X-ray elemental mapping. Interfacial microstructure was also investigated and cracks were found in number of cases due to difference between co-efficient of thermal expansion of matrix alloy and SiCp.
