体积分数为65%SiCp/A356 复合材料的 微观结构和界面反应研究.

65 % (volume fraction，the same below) SiCp/A356 composites with different holding time (6,12 h) were prepared by powder metallurgy. The microstructure and interfacial reaction of 65% SiCp/A356 composites were characterized by Optical Microscopy(OM)，X ray Diffraction(XRD)，Scanning Electron Microscopy(SEM) and Transmission Electron Microscopy(TEM). The results show that at 630 °C hot pressing temperature, the density of the material after holding for 12 h is better than that of holding for 6 h，and there is obvious precipitation of Si phase; slight interfacial reaction occurs, the reaction product is mainly Mg Ab O4, and no harmful phase AI4C3 is found. The elastic modulus，thermal conductivity and thermal expansion coefficient of the material were 210 GPa, 216 W/(m • K) and 7. 3 X 10-6/°C (50 300 °C)respectively. [ABSTRACT FROM AUTHOR]