(1. 哈爾濱工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院, 哈爾濱 150001;
2. 北京衛(wèi)星制造廠, 北京 100080)
摘 要: 利用透射電鏡、 掃描電鏡和拉伸試驗等實驗方法，研究了鑄態(tài)和擠壓態(tài)SiCw/ZK51A鎂基復(fù)合材料的組織與力學(xué)性能。 結(jié)果表明， 擠壓鑄造SiCw/ZK51A復(fù)合材料經(jīng)等溫熱擠壓后， 其力學(xué)性能有很大提高。 主要原因是： 擠壓變形能消除鑄造缺陷，增強SiC晶須與ZK51A鎂合金基體的界面結(jié)合， 使復(fù)合材料中SiC晶須發(fā)生定向分布， 沿擠壓方向呈準一維分布特征， 晶須的增強承載能力得到充分發(fā)揮。
關(guān)鍵字: SiC晶須； ZK51A鎂合金；金屬基復(fù)合材料； 擠壓；組織性能
（1. School of Materials Science and Engineering,Harbin Institute of Technology, Harbin 150001, P.R.China；
2. Beijing Satellite Manufacturing Plant, Beijing 100080, P.R.China）
Abstract: The microstructure, fracture morphology, and mechanical properties of both squeeze cast and subsequently isothermally extruded SiCw/ZK51A magnesium matrix composite were experimentally investigated by means of transmission electron microscopy, scanning electron microscopy, and tension test respectively. The results show that the asextruded composite possesses much higher mechanical properties than the ascast composite, especially modulus of elasticity and mechanical strength. The main reason for this lies in that the extrusion deformation not only helps to improve the whisker/matrix interfacial bonding and to eliminate casting defects, but also makes the SiC whiskers tend to align uniformly and quasiunidirectionally in the extrusion direction, leading to excellent reinforcing effect by load transfer.
Key words: SiC whisker； ZK51A magnesium alloy； metal matrix composite； extrusion; microstructure and mechanical properties
