Zn对铸态Mg-Y-Nd-Zr合金组织和力学性能的影响  

Effects of Zn on Microstructure and Mechanical Properties of As-cast Mg-Y-Nd-Zr Alloys

作　　者：苏再军 杨树忠[2] 刘楚明 杨新华[2] 刘先兰 

机构地区：[1]邵阳学院机械与能源工程学院,湖南邵阳422000 [2]中南大学材料科学与工程学院,长沙410083 [3]湖南工学院机械工程学院,湖南衡阳421002

出　　处：《材料工程》2017年第9期116-122,共7页Journal of Materials Engineering

基　　金：国家973计划资助项目(2013CB632200);湖南省教育厅优秀青年项目资助(17B069);湖南省科技计划资助项目(2015JC3106)

摘　　要：采用光学显微镜(OM)、扫描电子显微镜(SEM)、X射线衍射分析及力学性能测试等研究Zn元素对Mg-Y-Nd-Zr铸态合金显微组织及力学性能的影响。结果表明:随着Zn含量的增加,Mg-Y-Nd-Zr-xZn(x=0.0%,0.5%,1.0%,1.5%,质量分数)合金的晶粒逐渐细化,平均晶粒尺寸由(57±0.8)μm细化至(30±0.3)μm,晶界处共晶相的体积分数也逐渐增加。Mg-Y-Nd-Zr铸态合金中主要存在Mg12Nd相和Mg24Y5相,加入0.5%Zn后,合金中出现Mg12YZn相。随Zn含量的增加,Mg12YZn相的体积分数不断增大,合金的力学性能逐渐提高。当Zn含量为1.0%时,合金具有最优的力学性能,其抗拉强度、屈服强度和伸长率分别为(208±5.9),(159±3.9)MPa和(7.5±0.2)%,较未加Zn的合金分别提高了18,42MPa和1.2%。Effects of Zn on microstructure and mechanical properties of Mg-Y-Nd-Zr as-cast alloys were investigated by the optical microscopy（OM）,scanning electron microscopy（SEM）,X-ray diffractometry（XRD）and the mechanical properties test.The results show that the grain size of Mg-YNd-Zr-xZn（x=0.0%,0.5%,1.0%,1.5%,mass fraction）alloys is greatly refined with the increase of Zn content,which is refined from（57±0.8）μm to（30±0.3）μm.The volume fraction of eutectic structure at grain boundary increases gradually.Mg12 Nd phase and Mg24Y5 phase exist mainly in MgY-Nd-Zr as-cast alloy.With the addition of 0.5%Zn,Mg12 YZn phase appears at the grain boundary.With the increase of Zn,the volume fraction of Mg12 YZn phase and the mechanical properties of the alloys increases gradually.The alloy containing 1.0%Zn exhibits the optimal mechanical properties,the ultimate tensile strength,yield strength and elongation are（208±5.9）,（159±3.9）MPa and（7.5±0.2）%,respectively;comparing with the alloy without the addition of Zn,the ultimate tensile strength,yield strength and elongation increase by 18,42 MPa and 1.2%.

关 键 词：MG-Y-ND-ZR合金 ZN 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]