热处理对挤压态Mg-6Gd-5Y-1Zn合金组织与性能的影响  

Effect of heat treatment on microstructure and properties of as-extruded Mg-6Gd-5Y-1Zn alloy

作　　者：许恒源 甄睿[1,2] 毛忠峰 吴震 戴圣朋 Xu Hengyuan;Zhen Rui;Mao Zhongfeng;Wu Zhen;Dai Shengpeng(School of Materials Science and Engineering,Nanjing Institute of Technology,Nanjing Jiangsu 211167,China;Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology,Nanjing Jiangsu 211167,China;Nanjing Les Information Technology Co.,Ltd.,Nanjing Jiangsu 210014,China)

机构地区：[1]南京工程学院材料科学与工程学院,江苏南京211167 [2]江苏省先进结构材料与应用技术重点实验室,江苏南京211167 [3]南京莱斯信息技术股份有限公司,江苏南京210014

出　　处：《金属热处理》2020年第8期161-165,共5页Heat Treatment of Metals

基　　金：江苏省大学生创新创业训练计划(201911276034Y);南京工程学院大学生科技创新基金(TB202002028);江苏高校优秀科技创新团队。

摘　　要：通过对Mg-6Gd-5Y-1Zn(质量分数,%)合金在固溶和时效处理状态下显微组织和力学性能的研究发现,α-Mg基体、沿挤压方向分布的条状18R-LPSO相、少量的Mg24(Gd YZn)5相以及细层片状的14H-LPSO相构成了挤压态合金的组成相。挤压态合金经固溶(T4)处理后,一部分18R-LPSO相溶入基体,并且基体中的14H-LPSO相伸长同时粗化。挤压态合金经过固溶加时效(T6)处理后,大量β’相从α-Mg基体中析出。T6态合金的室温力学性能最好,其屈服强度、抗拉强度及伸长率分别为272 MPa、406 MPa和6.1%。β’相沉淀也发生在挤压态合金的直接人工时效(T5)处理过程,但相比于T6处理,14H-LPSO相和β’相在基体中的体积分数均偏低。Microstructure and mechanical properties of as-extruded Mg-6 Gd-5 Y-1 Zn( mass fraction,%) alloy after solid solution and aging treatment were investigated.The results show that the as-extruded alloy is composed of α-Mg matrix,strip shaped 18 R-LPSO phase arranged parallel to extrusion direction,Mg24( Gd YZn)5 phase and fine lamellar 14 H-LPSO phase.Solid solution( T4) treatment of the as-extruded alloy at high temperature results in the dissolution of 18 R-LPSO phase into the matrix and the lengthening and coarsening of the 14 H-LPSO phase.A large number of β’ precipitates exist in the microstructure of the T6 treated specimens.The T6 treated specimen shows the best tensile properties at room temperature with tensile strength of 406 MPa,yield strength of 272 MPa and elongation of 6.1%.T5 treatment also results in the β’ precipitation but its volume fraction,as well as the volume fraction of the 14 H-LPSO phase are much lower than that of the T6 treated specimens.

关 键 词：镁合金 长周期结构 沉淀相 热挤压 固溶 时效 

分 类 号：TG146.22[一般工业技术—材料科学与工程]