Mg-8Li-4Al-0.3Y合金的微观组织与力学性能  

Microstructure and Mechanical Properties of Mg-8Li-4Al-0.3Y Alloys

作　　者：杨艳[1,2] 张雪平 任凤娟 彭晓东[1,2] 谢卫东[1,2] 张振宇 Yang Yan;Zhang Xueping;Ren Fengjuanl;Peng Xiaodong;Xie Weidong;Zhang Zhenyu(College of Materials Science and Engineering,Chongqing University,Chongqing 400044,China;National Engineering Research Center for Magnesium Alloys,Chongqing University,Chongqing 400044,China)

机构地区：[1]重庆大学材料科学与工程学院,重庆400044 [2]重庆大学国家镁合金材料工程技术研究中心,重庆400044

出　　处：《稀有金属材料与工程》2018年第8期2518-2524,共7页Rare Metal Materials and Engineering

基　　金：国家重点研发计划项目(2016YFB0700403);国家自然科学基金(51601024);重庆市基础科学与前沿技术研究项目(cstc2016jcyjA0418);中央高校基本科研业务费(106112015CDJXY130011)

摘　　要：利用光学显微镜(OM)、扫描电子显微镜(SEM)和X射线衍射仪(XRD)等手段系统研究了铸态、固溶处理态和挤压态Mg-8Li-4Al-0.3Y(质量分数,%)合金的微观组织,测试了其室温力学性能。实验结果表明:铸态实验合金主要由α-Mg、β-Li、Al2Y和AlLi相以及MgAlLi_2相组成;固溶处理后合金中在相界处分布的MgAlLi_2化合物相消失,大量AlLi相发生分解并固溶于合金基体中,仅剩下部分尺寸较大的AlLi相。在挤压过程中合金发生动态再结晶,显微组织明显细化,组织更加均匀。固溶处理后合金基体硬度明显高于铸态合金;与铸态相比,挤压态合金的综合力学性能得到大幅提升,其抗拉强度和延伸率分别达到208 MPa和25.1%。The microstructure and mechanical properties of as-cast, solution-treated and as-extruded Mg-8Li-4A1-0.3Y alloys were studied by optical microscope （OM）, scanning electron microscope （SEM）, X-ray diffraction analysis （XRD） and tensile test machines. The results show that as-cast Mg-8Li-4A1-0.3Y alloy is composed of a-Mg, β-Li, A12Y, A1Li and MgA1Li2 phases. MgA1Li2 compound at the grain boundaries disappears in the solution-treated alloy and most of A1Li phase decompose and dissolve into the matrix, while only part of larger A1Li particles are left during the solution treatment. The microstructure of the as-extruded alloy is refined obviously and more uniform due to the dynamic recrystallization during the extrusion process. The microhardness of the solution-treated alloy is much higher than that of as-cast one due to solution strengthening. The mechanical properties of Mg-8Li-4A1-0.3Y alloys are improved a lot by extrusion and the ultimate strength and elongation of the extrude alloy reach 208 MPa and 25.1%, respectively.

关 键 词：MG-LI合金 固溶处理 挤压变形 微观组织 力学性能 

分 类 号：TG146.22[一般工业技术—材料科学与工程]