SiC_(p)/AZ91镁基复合材料的高温变形行为及组织演变  

High Temperature Deformation and Microstructure Evolution of SiC_(p)/AZ91 Magnesium Matrix Composites

作　　者：王剑 罗经纬 伏淼 Wang Jian;Luo Jingwei;Fu Miao(Jilin Railway Technology College;School of Materials Science and Engineering,Jilin University)

机构地区：[1]吉林铁道职业技术学院,吉林省吉林市132200 [2]吉林大学材料科学与工程学院

出　　处：《特种铸造及有色合金》2022年第7期827-831,共5页Special Casting & Nonferrous Alloys

基　　金：吉林省青年科研基金资助项目(20200520048JH)

摘　　要：采用Gleeble-3800型热模拟试验机对搅拌铸造SiC_(p)/AZ91镁基复合材料在250~400℃、应变速率为0.001~1 s^(-1)下进行了单向压缩变形处理,观察了复合材料变形过程中的微观组织演变,揭示了SiC_(p)/AZ91镁基复合材料的高温变形机制。结果表明,铸态SiC_(p)/AZ91镁基复合材料中只有Mg相和SiC相;应变速率为0.001 s^(-1)时,在压缩温度为250℃已经发生了部分再结晶,在350℃时发生完全再结晶,提高至400℃时,再结晶晶粒快速长大;压缩温度为250℃和350℃时,降低应变速率更加有利于SiC_(p)/AZ91镁基复合材料的动态再结晶。其应力因子n为5,真激活能Q为91 kJ/mol,变形机制为晶界扩散控制的位错攀移。The unidirectional compression deformation of SiC_(p)/AZ91 magnesium matrix composites was carried out by Gleeble-3800 thermal simulation testing machine under the deformation temperature of 250 ℃~400 ℃ and the strain rate of 0.001 s^(-1)~1 s^(-1). The microstructure evolution during the deformation process was observed and the high temperature deformation mechanism of SiC_(p)/AZ91 magnesium matrix composites was revealed. The results indicate that there are only Mg phase and SiC phase in as-cast SiC_(p)/AZ91 magnesium matrix composites. When the strain rate is 0.001 s^(-1), composites are partially recrystallized at 250 ℃, which are fully recrystallized at 350 ℃. When the compression temperature is increased to 400 ℃, the recrystallized grains grow rapidly. The reduction of strain rate is beneficial to dynamic recrystallization of SiC_(p)/AZ91 magnesium matrix composites at 250 ℃ and 350 ℃, where the stress factor is 5, the true activation energy Q is 91 kJ/mol, and the deformation mechanism is dislocation climbing controlled by grain boundary diffusion.

关 键 词：SiC_(p)/AZ91镁基复合材料 高温压缩 变形温度 应变速率 显微组织 

分 类 号：TB333[一般工业技术—材料科学与工程]