蠕变时效对Mg-8.8Gd-3.4Y-1.5Nd-0.5Zr合金力学性能和微观组织的影响  

Effect of creep aging on mechanical properties and microstructures of Mg-8.8Gd-3.4Y-1.5Nd-0.5Zr alloy

作　　者：张凯[1] 邓运来[1,2] 石洪吉 杨柳[2] ZHANG Kai;DENG Yunlai;SHI Hongji;YANG Liu(School of Light Alloy Research,Central South University,Changsha 410083,China;School of Materials Science and Engineering,Central South University,Changsha 410083,China)

机构地区：[1]中南大学轻合金学院,湖南长沙410083 [2]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2018年第8期1907-1913,共7页Journal of Central South University:Science and Technology

基　　金：国家重点基础研究发展规划(973计划)项目(2012CB619500);国家重点研发项目(2016YFB0300901);国家自然科学基金资助项目(51375503);广西八桂学者资助项目(2013A017)~~

摘　　要：采用蠕变时效实验、维氏硬度、透射电子显微镜(TEM)和拉伸性能测试等手段研究蠕变时效在相同时间下对Mg-8.8Gd-3.4Y-1.5Nd-0.5Zr合金力学性能和显微组织影响。研究结果表明:Mg-8.8Gd-3.4Y-1.5Nd-0.5Zr合金蠕变时效时的稳态蠕变速率随着蠕变应力的增加与温度的升高而增大;蠕变时效能够细化析出相尺寸,加快合金时效析出相析出速率,从而缩短到达峰值时效的时间;外加应力会使合金β′相产生应力位向效应,导致合金形成β′相与β′e交错排列的链状析出相,应力位向效应对合金的力学性能产生不利影响。The effect of creep aging on mechanical properties and microstructure of Mg-8.8Gd-3.4Y-1.5Nd-0.5Zr alloy were investigated by creep aging tests,Vicker hardness(HV)tests,transmission electron microscopy(TEM)and tensile tests.The results show that the steady creep rate of Mg-8.8Gd-3.4Y-1.5Nd-0.5Zr alloy increases with the increase of creep stress and temperature.Creep aging can refine the size of precipitates,accelerate the aging hardening rate and shorten the time to reach the peak age.With the effects of the external stress,the preferential oriented precipitation ofβ′is observed as the chain like precipitated phase consisting ofβ′andβ′e phase,which has an adverse effect on mechanical properties of Mg-8.8Gd-3.4Y-1.5Nd-0.5Zr alloy.

关 键 词：Mg-8.8Gd-3.4Y-1.5Nd-0.5Zr合金 蠕变时效 应力位向效应 显微组织 力学性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]