SiCP/ZL 109 复合材料中SiC 的界面行为

以常规TEM 为工具, 研究了SiCP/ ZL 109 复合材料中数十个SiC 颗粒及其界面,Si 优先在SiC 表面上形核、长大, 形成界面Si, 并形成大量SiC/S i 界面。靠近SiC 界面的Al 基体中, 普遍存在一层厚度小于1Lm 的“亚晶铝带”, 其内有大量位错。SiC 与Al、SiC 与Si 之间虽然没有固定的晶体学位向关系, 但是存在下列优先关系: (1103) _SiC//(111)_Al, 1120]_SiC//110]_Al; (1101) _SiC//(111) _Si; 1120]_SiC//112]_Si。

SiC PARTICLES AND THEIR INTERFACIAL BEHAVIOR IN SiCP/ZL109 COMPOSITES

SiC P/ZL109 composites fabricated by centrifugal casting and squeeze casting were characterized by conventional TEM. The leading phase Si in the (Al+Si) eutectic tended to nucleate and grow preferentially at the SiC surface(facets), thus forming the characteristic “interfacial Si” and the SiC/Si interfaces. A “subgrain Al layer” was usually observed at the Al side of a SiC/Al interface, which was less than 1μm thick with high density of dislocation generated in it. Measurements of crystallographic orientation relationship between SiC and Al and between SiC and Si were made at tens of SiC/Si and SiC/Al interfaces. ITis shown that no fixed and unique orientation relationships were determined, though the following preferential ones were observed: (1103)SiC //(111) Al ,1120] SiC //110] Al ; (1101) SiC //(111) Si ,1120] SiC //112] Si .