The Experts below are selected from a list of 7962 Experts worldwide ranked by ideXlab platform
A B Phillion - One of the best experts on this subject based on the ideXlab platform.
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a mesoscale Solidification Simulation of fusion welding in aluminum magnesium silicon alloys
Acta Materialia, 2014Co-Authors: H Zareie R Rajani, A B PhillionAbstract:Abstract A 3-D granular model has been developed to simulate Solidification during fusion welding of Al alloys. The model simulates the gradual development of the weld mushy zone composed of both continuous liquid films and solidifying grains by coupling thermal fields based on the Rosenthal equation, a modified Voronoi tessellation to provide grain structure at the mesoscale, and the evolution of solid fraction within a grain based on the Scheil equation. The shape and geometry of the columnar and equiaxed grains within the weld pool has been characterized from experiments, and therefore the model can be used to link the Solidification behaviour of individual grains to the macroscopic properties of the weld. The gradual formation of microscale liquid channels lying along the grain boundaries within the mushy zone is investigated and the role of welding parameters, including amperage and welding speed, on transitions in the semisolid microstructure is explored. The study reveals that the ability of the microscale liquid channels to feed molten metal into the solidifying areas is not uniform through the weld, and is strongly affected by grain size since smaller grains hinder the feeding ability of the mushy zone.
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A mesoscale Solidification Simulation of fusion welding in aluminum–magnesium–silicon alloys
Acta Materialia, 2014Co-Authors: H.r. Zareie Rajani, A B PhillionAbstract:Abstract A 3-D granular model has been developed to simulate Solidification during fusion welding of Al alloys. The model simulates the gradual development of the weld mushy zone composed of both continuous liquid films and solidifying grains by coupling thermal fields based on the Rosenthal equation, a modified Voronoi tessellation to provide grain structure at the mesoscale, and the evolution of solid fraction within a grain based on the Scheil equation. The shape and geometry of the columnar and equiaxed grains within the weld pool has been characterized from experiments, and therefore the model can be used to link the Solidification behaviour of individual grains to the macroscopic properties of the weld. The gradual formation of microscale liquid channels lying along the grain boundaries within the mushy zone is investigated and the role of welding parameters, including amperage and welding speed, on transitions in the semisolid microstructure is explored. The study reveals that the ability of the microscale liquid channels to feed molten metal into the solidifying areas is not uniform through the weld, and is strongly affected by grain size since smaller grains hinder the feeding ability of the mushy zone.
Young-chan Kim - One of the best experts on this subject based on the ideXlab platform.
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Thin-Wall Aluminum Die-Casting Technology for Development of Notebook Computer Housing
Journal of Materials Science & Technology, 2009Co-Authors: Chang-seog Kang, Jae-ik Cho, Chang-yeol Jeong, Se-weon Choi, Young-chan KimAbstract:gating systems, tangential and split type, and vent design. Furthermore, computational Solidification Simulation was also conducted. The results showed that split type gating system was preferable gating design than tangential type gating system at the point of view of soundness of casting and distortion generated after Solidification. It was also found that proper vent design was one of the most important factors for producing thin-wall casting components because it was important for the fulfillment of the thin-wall cavity and the minimization of the casting distortion.
Rainer Schmidfetzer - One of the best experts on this subject based on the ideXlab platform.
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phosphorus in al si cast alloys thermodynamic prediction of the alp and eutectic si Solidification sequence validated by microstructure and nucleation undercooling data
Acta Materialia, 2014Co-Authors: Songmao Liang, Rainer SchmidfetzerAbstract:Abstract A self-consistent thermodynamic description of the Al–Si–P ternary system was developed. Based on that, the first consistent and experimentally supported Al–Si–P phase diagram was calculated. The P-threshold – excluding the formation of potent AlP nucleants before eutectic (Si) – was elaborated using both normal Scheil and equilibrium Solidification Simulation. Its quantitative dependence on the Si content of the alloy was determined and a precipitation sequence map, covering all Si and P compositions relevant for Al–Si cast alloys, was predicted from these thermodynamic calculations. The predicted map was validated by independent experimental studies on hypoeutectic Al–Si alloys and it is in perfect agreement with microstructure observation and undercooling measurements. Moreover, a constrained Scheil Solidification Simulation technique was applied to predict the undercooling under clean heterogeneous nucleation conditions and these data are in perfect agreement with dedicated experimental observations from the entrained droplet technique. Even for extremely low P-content and large undercooling the direct nucleation of (Si) on primary (Al) does not occur but is triggered by the formation of AlP under clean conditions. The P-threshold is not trivial since it varies from zero to 7.4 ppm P for hypoeutectic alloys, which is just in or below the commercial purity range of regular Al–Si cast alloys.
Chen Kang - One of the best experts on this subject based on the ideXlab platform.
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Application of the software ProCAST in the casting of Solidification Simulation
Materials Science and Technology, 2006Co-Authors: Chen KangAbstract:For researching the influence of casting process on the quality of castings,the Solidification Simulation of casting is developed by computer.Composing modules and functions of the FEM software ProCAST are introduced and the defects of the casting process are simulated.We then present an example for the ProCAST software to instruct the design of casting process.Workflow of ProCAST is described.The shrinkage defects of castings cast by sand molding process have been predicted using FEM software ProCAST.The simulated result laid down a foundation for improving the cast technology of the castings.The parameters of pouring system and riser system are optimized.The optimized process improved the casting yields and decreased the costs.The Simulation way and approach used in this paper can be seen as a guideline in the design of other casting processes.
Songmao Liang - One of the best experts on this subject based on the ideXlab platform.
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Nucleants of Eutectic Silicon in Al-Si Hypoeutectic Alloys: β-(Al, Fe, Si) or AlP Phase
Metallurgical and Materials Transactions A, 2014Co-Authors: Songmao Liang, Rainer Schmid-fetzerAbstract:A thermodynamic description of the Al-Si-P-Fe quaternary system focused on Al-(Si)-rich alloys is developed. The Solidification sequence in typical Al-7Si cast alloys is derived using thermodynamic calculations of the phase diagrams and Solidification Simulation under Scheil and constrained Scheil conditions. The previously claimed nucleation of eutectic silicon by β -(Al,Fe,Si) particles is not possible because under all conditions, β -(Al,Fe,Si) precipitates after (Si) in pertinent alloys. Variation of P in the ppm range is crucial because it changes the Solidification sequence of AlP and (Si).
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phosphorus in al si cast alloys thermodynamic prediction of the alp and eutectic si Solidification sequence validated by microstructure and nucleation undercooling data
Acta Materialia, 2014Co-Authors: Songmao Liang, Rainer SchmidfetzerAbstract:Abstract A self-consistent thermodynamic description of the Al–Si–P ternary system was developed. Based on that, the first consistent and experimentally supported Al–Si–P phase diagram was calculated. The P-threshold – excluding the formation of potent AlP nucleants before eutectic (Si) – was elaborated using both normal Scheil and equilibrium Solidification Simulation. Its quantitative dependence on the Si content of the alloy was determined and a precipitation sequence map, covering all Si and P compositions relevant for Al–Si cast alloys, was predicted from these thermodynamic calculations. The predicted map was validated by independent experimental studies on hypoeutectic Al–Si alloys and it is in perfect agreement with microstructure observation and undercooling measurements. Moreover, a constrained Scheil Solidification Simulation technique was applied to predict the undercooling under clean heterogeneous nucleation conditions and these data are in perfect agreement with dedicated experimental observations from the entrained droplet technique. Even for extremely low P-content and large undercooling the direct nucleation of (Si) on primary (Al) does not occur but is triggered by the formation of AlP under clean conditions. The P-threshold is not trivial since it varies from zero to 7.4 ppm P for hypoeutectic alloys, which is just in or below the commercial purity range of regular Al–Si cast alloys.