等通道角变形对搅拌铸造SiC_P/AZ91复合材料显微组织与室温性能的影响  

Effect of equal channel angular pressing on the microstructure evolution and mechanical property of the SiC_P/AZ91 composite fabricated by stir-casting

作　　者：常海[1] 王金龙[2] 郑明毅[2] 王晓军[2] CHANG Hai WANG Jinlong ZHENG Mingyi WANG Xiaojun(National Center for Materials Service Safety, University of Science and Technology Beijing, Beijing 100083 School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China)

机构地区：[1]北京科技大学材料服役安全科学中心,北京100083 [2]哈尔滨工业大学材料科学与工程学院,哈尔滨150001

出　　处：《复合材料学报》2017年第3期611-618,共8页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(51201006;51071057);高等学校学科创新引智计划(B12012)

摘　　要：采用搅拌铸造法成功制备了SiC_P/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SiC_P/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;SiC_P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SiC_P/AZ91复合材料中的SiC_P"项链状"分布,并且随着ECAP道次的增加,SiC_P分布更加均匀;在ECAP过程中,SiC_P发生了一定断裂但并不明显。SiC_P/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SiC_P分布均匀化是SiC_P/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。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.

关 键 词：搅拌铸造 等通道角挤压变形 SiCP/AZ91 金属基复合材料 显微组织 室温性能 

分 类 号：TB331[一般工业技术—材料科学与工程] TG113.1[金属学及工艺—物理冶金]