Mg-Y-Nd-Zr镁合金焊接接头的显微组织与力学性能研究  

Microstructure and Mechanical Properties of Welded Joint for Mg-Y-Nd-Zr Magnesium Alloy

作　　者：陶健全[1] 张艳平[1] 李晓松 柴舒心 李明 刑志辉 TAO Jian-quan;ZHANG Yan-ping;LI Xiao-song;CHAI Shu-xin;LI Ming;XING Zhi-hui(No.59 Institute of China Ordnance Industry,Chongqing 400039,China)

机构地区：[1]中国兵器工业第五九研究所,重庆400039

出　　处：《精密成形工程》2019年第1期76-80,共5页Journal of Netshape Forming Engineering

摘　　要：目的研究Mg-Y-Nd-Zr镁合金焊接接头显微组织和力学性能。方法采用钨极氩弧焊工艺制备Mg-Y-Nd-Zr合金焊接接头,采用金相显微镜、扫描电子显微镜观察焊接接头显微组织,采用能谱测试主要合金元素含量,采用电子万能实验机测试焊接接头的力学性能,采用维氏硬度计测试焊接接头的硬度。结果Mg-Y-Nd-Zr合金母材、焊缝区与热影响区平均晶粒尺寸分别为80, 30, 95μm。焊接接头的抗拉强度、屈服强度和断后伸长率分别为295 MPa, 188 MPa和3.0%。结论 Mg-Y-Nd-Zr合金母材、焊缝和热影响区晶粒均为等轴晶,与母材相比,热影响区未发生晶粒粗化,焊缝区晶粒明显细化,析出相Mg24Y5增多。Mg-Y-Nd-Zr合金焊接接头经525℃×12 h固溶+225℃×12 h时效处理后,各区域的硬度差异不大。抗拉强度达到母材的93%,断后伸长率达到母材的67%。The paper aims to study microstructure and mechanical properties of welded joint for Mg-Y-Nd-Zr alloy.The welded joint of Mg-Y-Nd-Zr alloy was prepared by tungsten argon arc welding process.The microstructure of the welded joint was observed with metallographic microscope and scanning electron microscope.The main alloying elements were tested by energy spectrum.The mechanical properties were tested with a universal material testing machine.The microhardness of the welded joint was tested with a Vickers hardness tester.The results show that the average grain size of Mg-Y-Nd-Zr alloy base metal,weld and heat-affected zone grains was 80,30,95μm respectively.Tensile strength,yield strength and elongation at break of welded joints were 295 MPa,188 MPa and 3.0%respectively.The Mg-Y-Nd-Zr alloy base metal,weld and heat-affected zone grains are equiaxed crystals.Compared with the base metal,no grain coarsening occurs in the heat-affected zone.The grain size in weld zone is obviously refined.The precipitation phase Mg24Y5 increases.After 525℃×12 h+225℃×12 h heat treating,the hardness of each region is not much different.The tensile strength reaches 93%of the base metal,and the percentage elongation after fracture reaches 67%of the base metal.

关 键 词：MG-Y-ND-ZR合金 焊接 显微组织 力学性能 

分 类 号：TG249.2[金属学及工艺—铸造]