A new and effective semisolid slurry preparation process with air-cooled stirring rod(ACSR)is reported,in which the compressed air is constantly injected into the inner cavity of a stirring rod to cool the melt.The sl...A new and effective semisolid slurry preparation process with air-cooled stirring rod(ACSR)is reported,in which the compressed air is constantly injected into the inner cavity of a stirring rod to cool the melt.The slurry of a newly developed high thermal conductivity Al?8Si alloy was prepared,and thin-wall heat dissipation shells were produced by the ACSR process combined with a HPDC machine.The effects of the air flow on the morphology ofα1-Al particles,mechanical properties and thermal conductivity of rheo-HPDC samples were studied.The results show that the excellent slurry of the alloy could be obtained with the air flow exceeding3L/s.Rheo-HPDC samples that were produced with the air flow of5L/s had the maximum UTS,YS,elongation,hardness and thermal conductivity of261MPa,124MPa,4.9%,HV99and153W/(m·K),respectively.Rheo-HPDC samples show improved properties compared to those formed by HPDC,and the increasing rates of UTS,YS,elongation,hardness and thermal conductivity were20%,15%,88%,13%and10%,respectively.展开更多
The modification effect of Er on hypoeutectic Al-8Si alloy was investigated by KH-2200 optical microscope, JXA-8800R electron probe microanalysis (EPMA) and CMT5105 electromechanical universal testing machine. The res...The modification effect of Er on hypoeutectic Al-8Si alloy was investigated by KH-2200 optical microscope, JXA-8800R electron probe microanalysis (EPMA) and CMT5105 electromechanical universal testing machine. The results show that the eutectic silicon is modified from a coarse flake-like to refined plate-like structure and the tensile properties are improved. With the additional level of Er up to 0.5%, the tensile strength of the Al-8Si alloy is increased by 24%. The Al-8Si-0.5Er alloy has a ductile fractured surface, while the unmodified Al-8Si alloy possesses a brittle fractured surface.展开更多
基金Project (2013B091300016) supported by the Department of Science and Technology of Guangdong Province,China
文摘A new and effective semisolid slurry preparation process with air-cooled stirring rod(ACSR)is reported,in which the compressed air is constantly injected into the inner cavity of a stirring rod to cool the melt.The slurry of a newly developed high thermal conductivity Al?8Si alloy was prepared,and thin-wall heat dissipation shells were produced by the ACSR process combined with a HPDC machine.The effects of the air flow on the morphology ofα1-Al particles,mechanical properties and thermal conductivity of rheo-HPDC samples were studied.The results show that the excellent slurry of the alloy could be obtained with the air flow exceeding3L/s.Rheo-HPDC samples that were produced with the air flow of5L/s had the maximum UTS,YS,elongation,hardness and thermal conductivity of261MPa,124MPa,4.9%,HV99and153W/(m·K),respectively.Rheo-HPDC samples show improved properties compared to those formed by HPDC,and the increasing rates of UTS,YS,elongation,hardness and thermal conductivity were20%,15%,88%,13%and10%,respectively.
文摘The modification effect of Er on hypoeutectic Al-8Si alloy was investigated by KH-2200 optical microscope, JXA-8800R electron probe microanalysis (EPMA) and CMT5105 electromechanical universal testing machine. The results show that the eutectic silicon is modified from a coarse flake-like to refined plate-like structure and the tensile properties are improved. With the additional level of Er up to 0.5%, the tensile strength of the Al-8Si alloy is increased by 24%. The Al-8Si-0.5Er alloy has a ductile fractured surface, while the unmodified Al-8Si alloy possesses a brittle fractured surface.
基金National Key Research and Development Program(2018YFB2001800)National Natural Science Foundation of China(51961021,52001152)Undergraduate Innovation and Entrepreneurship Training Program(DC2021011,DC2021018,DC2021036)。
