中文摘要：

采用搅拌铸造法成功制备了SiCP/Mg（AZ91）复合材料并对铸态复合材料进行了等通道角挤压变形（Equal channel angular pressing,ECAP）。结果表明,搅拌铸造态SiCP/AZ91复合材料的基体组织致密,颗粒与基体结合良好,没有出现宏观团聚;SiCP大部分聚集在晶界附近区域并呈＂项链状＂分布。ECAP变形可以有效地消除铸态SiCP/AZ91复合材料中的SiCP＂项链状＂分布,并且随着ECAP道次的增加,SiCP分布更加均匀;在ECAP过程中,SiCP发生了一定断裂但并不明显。SiCP/AZ91复合材料基体晶粒随着变形道次的提高而逐渐细化。基体晶粒细化以及SiCP分布均匀化是SiCP/AZ91复合材料屈服强度和抗拉强度随着道次提升而逐渐增加的主要原因。

英文摘要：

The SiCP/AZ91 composite was fabricated by stir-casting and then processed by equal channel angular pressing（ECAP）at different temperature successfully.No obvious SiCPclusters and porosities are observed in the cast SiCP/AZ91 composite.Most SiCP particles are segregated at a microscopic scale near the grain boundary regions,which is typical＂necklace-type＂particle distribution for SiCP/AZ91 composite fabricated by stir casting.With increasing of ECAP passes,the SiCPdistribution is improved and no obvious particle broken is discovered in SiC/AZ91 after ECAP.The grains of the AZ91 matrix are refined gradually due to the dynamic recrystallization.The matrix grain refinement and the improved particle distribution result in the increase of tensile yield strength and ultimate strength of the composite during ECAP processing.