The influences of SiC content on the microstructure, porosity, hardness and wear resistance of A356？SiCp composites processed via two different methods of compocasting and vibrating cooling slope （VCS） were compare...The influences of SiC content on the microstructure, porosity, hardness and wear resistance of A356？SiCp composites processed via two different methods of compocasting and vibrating cooling slope （VCS） were compared with each other. In the as-cast condition, the matrix of VCS and compocast processed composites exhibited globular and dendritric structures, respectively. While a more uniform distribution of SiC particulates in the matrix alloy as well as higher hardness values were obtained for the VCS processed samples, the composites produced via compocasting exhibited less porosity. The increased SiC content （up to 20% in volume fraction） resulted in a more uniform distribution of SiC particles within the matrix alloy and improved wear resistance for both the composite series. However, for the VCS processed composites, the increased SiC content, resulted in the decreased size and shape factor of globules as well as better tribological properties when compared with compocast composites. It was concluded that the improved properties of the VCS processed composites when compared with their compocast counterparts was a consequence of a more uniform distribution of SiC particulates in the matrix alloy as well as the globular microstructure generated during the VCS process.展开更多
A review made on the research progress of wear behavior of PM steels has been made in recent years. Wear is not an intrinsic property of PM steels, which is strongly influenced by the wear test conditions. However, ma...A review made on the research progress of wear behavior of PM steels has been made in recent years. Wear is not an intrinsic property of PM steels, which is strongly influenced by the wear test conditions. However, many other factors that determine the mechanical properties of PM steels also affect the wear behavior. Porosity has different effects on the wear of PM steels depending on the application conditions. Under dry sliding condition, a higher porosity results in a lower wear resistance. The influence of microstructure on wear resistance is in the order: carbide, martensite, bainite and lamellar pearlite. The wear resistance increases with hardness, but this relationship changes with the porosity and microstructure of PM steels and wear test conditions.展开更多
文摘The influences of SiC content on the microstructure, porosity, hardness and wear resistance of A356？SiCp composites processed via two different methods of compocasting and vibrating cooling slope （VCS） were compared with each other. In the as-cast condition, the matrix of VCS and compocast processed composites exhibited globular and dendritric structures, respectively. While a more uniform distribution of SiC particulates in the matrix alloy as well as higher hardness values were obtained for the VCS processed samples, the composites produced via compocasting exhibited less porosity. The increased SiC content （up to 20% in volume fraction） resulted in a more uniform distribution of SiC particles within the matrix alloy and improved wear resistance for both the composite series. However, for the VCS processed composites, the increased SiC content, resulted in the decreased size and shape factor of globules as well as better tribological properties when compared with compocast composites. It was concluded that the improved properties of the VCS processed composites when compared with their compocast counterparts was a consequence of a more uniform distribution of SiC particulates in the matrix alloy as well as the globular microstructure generated during the VCS process.
基金OEAD (Austriad Academic Exchange Service)and the CME (Chinese Minister Of Educations for partly financial seaport.
文摘A review made on the research progress of wear behavior of PM steels has been made in recent years. Wear is not an intrinsic property of PM steels, which is strongly influenced by the wear test conditions. However, many other factors that determine the mechanical properties of PM steels also affect the wear behavior. Porosity has different effects on the wear of PM steels depending on the application conditions. Under dry sliding condition, a higher porosity results in a lower wear resistance. The influence of microstructure on wear resistance is in the order: carbide, martensite, bainite and lamellar pearlite. The wear resistance increases with hardness, but this relationship changes with the porosity and microstructure of PM steels and wear test conditions.
