高应变速率多向锻造对AZ31镁合金组织及耐腐蚀性能的影响  

Influence of high strain rate multi-directional forging on microstructure and corrosion resistance property for AZ31 magnesium alloy

作　　者：邓彬 李庆芬 吴远志 刘超 叶拓 刘伟 马斌 刘安民 Deng Bin;Li Qingfen;Wu Yuanzhi;Liu Chao;Ye Tuo;Liu Wei;Ma Bin;Liu Anmin(Research Institute of Auto Parts Technology,Hunan Institute of Technology,Hengyang 421002,China;School of Mechanical Engineering,Hunan Institute of Technology,Hengyang 421002,China)

机构地区：[1]湖南工学院汽车零部件技术研究院,湖南衡阳421002 [2]湖南工学院机械工程学院,湖南衡阳421002

出　　处：《锻压技术》2021年第8期7-11,25,共6页Forging & Stamping Technology

基　　金：湖南省自然科学基金资助项目(2019JJ30009);湖南省教育厅科学研究项目(20C0567,19C0508);衡阳市科技计划项目基础研究专项(202002042096)。

摘　　要：对均匀化处理后AZ31镁合金进行高应变速率多向锻造,使用金相显微镜(OM)与电子背散射衍射仪(EBSD)等测试手段研究了不同累积应变量对AZ31镁合金显微组织的影响;采用电化学测试等方法研究不同累积应变量对合金在质量分数为3.5%的NaCl溶液中的腐蚀行为。实验结果表明:相对于锻造前,高应变速率多向锻造后,合金平均晶粒尺寸大幅度减小、耐腐蚀性能提升。当累积应变量为1.32时,合金获得了均匀细小的晶粒组织,其平均晶粒度为7.8218μm,再结晶比例分数为79.40683%,平均腐蚀速率Vi=0.072 mm·a^(-1),合金耐腐蚀性能最优;当累积应变量大于1.32时,在自激活的作用下,引起了再结晶晶粒的长大,合金的再结晶程度与组织的均匀性下降,耐腐蚀性能降低。The AZ31 magnesium alloy after homogenization treatment was subjected to high strain rate multi-directional forging,and the influences of different cumulative strains on the microstructure of AZ31 magnesium alloy were studied by the testing methods such as optical microscope(OM)and electron backscatter diffractometer(EBSD).Then,the corrosion behavior of alloy in NaCl solution with the mass fraction of 3.5%under different cumulative strains was studied by electrochemical tests and other methods.The experiment results show that compared with before forging,the average grain size of alloy after high strain rate multi-directional forging is greatly reduced and the corrosion resistance property is improved.When the cumulative strain is 1.32,the alloy has a uniform and fine grain structure with the average grain size of 7.8218μm,the recrystallization fraction is 79.40683%,the average corrosion rate is Vi=0.072 mm·a^(-1),the corrosion resistance property of alloy is the best.However,when the cumulative strain is beyond 1.32,the recrystallized grains grow up due to the action of self-activation,and the recrystallization degree and microstructure uniformity of alloy decrease as well as the corrosion resistance property.

关 键 词：AZ31镁合金 高应变速率多向锻造 累积应变量 再结晶晶粒 耐腐蚀性能 

分 类 号：TG132.25[一般工业技术—材料科学与工程]