Mg-Sc二元合金微观组织和力学性能研究  

Microstructures and Mechanical Properties of Mg-Sc Binary Alloy

作　　者：张曼玉 应韬 曾小勤[1] 李德江[1] 丁文江[1] ZHANG Manyu;YING Tao;ZENG Xiaoqin;LI Dejiang;DING Wenjiang(Light Alloy Net Forming National Engineering Research Center, Shanghai Jiao Tong University, Shanghai 200240, Chin)

机构地区：[1]上海交通大学轻合金精密成型国家工程研究中心,上海200240

出　　处：《铸造技术》2018年第5期947-951,共5页Foundry Technology

基　　金：包头市科技发展计划项目(CX2015-32);航天先进技术联合研究中心技术创新项目(USCAST2016-17)

摘　　要：制备了Mg-2%Sc,Mg-5%Sc,Mg-10%Sc 3种二元合金,并通过光学显微镜、扫描电子显微镜、XRD以及室温拉伸等试验,研究了Sc元素的加入对纯镁显微组织和力学性能的影响。结果表明,Sc在三种合金中均以固溶形式存在,未有明显第二相的析出。随着Sc含量的升高,晶粒不断细化,合金的强度,硬度和塑性也随着Sc含量的增加而提高。其中,Mg-10%Sc表现出最优异的综合性能,屈服强度,抗拉强度,伸长率和硬度分别为101 MPa,143.3 MPa,10.27%,48.6 HV。细晶强化和固溶强化是Mg-Sc合金屈服强度提升的主要原因,且随着Sc含量的增加,固溶强化的贡献比例逐渐提升。断口形貌显示Sc的加入使得合金由脆性断裂向韧性断裂转变。The Mg-Sc alloy Mg-2%Sc, Mg-5%Sc and Mg-10%Sc binary alloys were prepared by gravity casting and the effect of element Sc on microstructure and mechanical properties of purity magnesium alloy were investigated by optical microscopy （OM）, X-ray diffraction （XRD）, scanning electron microscopy （SEM） analysis, tensile test and hardness test. The results show that the three components of Mg-Sc alloy Mg-2%Sc, Mg-5%Sc, Mg-10%Sc are monophase solid solution and no second phase is formed. With the increase of Sc content, the grain is refined. The yield strength, tensile strength, elongation and hardness of the alloy increase with the increase of Sc content. Mg-10%Sc has the best mechanical properties and the yield strength, tensile strength, elongation and hardness are 101 MPa, 143.3 MPa, 10.27%, 48.6 HV, respectively. Both fine grain strengthening and solid solution strengthening have contribution to the improvement of the mechanical properties of Mg-Sc alloy. With the increase of Sc content, the effect of solid solution strengthening becomes more and more obvious. With the addition of Sc content, the fracture mode changes from brittle fracture to ductile fracture.

关 键 词：Mg—Sc合金 显微组织 晶粒度 力学性能 固溶强化 

分 类 号：TG113[金属学及工艺—物理冶金]