焊接电流对AZ31镁合金接头的影响  

Effect of welding current on welding joint of AZ31 magnesium alloy

作　　者：刘政军[1] 贾华[1] 张文[1] 苏明[1] 

机构地区：[1]沈阳工业大学材料科学与工程学院,沈阳110870

出　　处：《沈阳工业大学学报》2010年第1期40-44,共5页Journal of Shenyang University of Technology

基　　金：辽宁省自然科学基金资助项目(20072041)

摘　　要：为了研究AZ31镁合金的焊接性,对AZ31镁合金板进行交流钨极氩弧(TIG)焊.试验采用x-射线衍射仪、扫描电子显微镜、光学金相显微镜对试样的焊缝显微组织进行分析,并对不同焊接电流下的试样进行抗拉强度和硬度测试.研究发现:随焊接电流的增加,焊缝成形变差,晶粒逐渐粗化,同时易产生气孔和裂纹等缺陷,使接头性能降低;焊缝区由基体α-Mg和附集于晶界的β-Al12Mg17两相组成.结果表明:焊接电流对AZ31镁合金接头的熔池形状及焊接质量有显著的影响.In order to study the weldability of AZ31 magnesium alloy,AC tungsten inert gas welding （TIG） was conducted for the AZ31 magnesium alloy plate. The microstructure of the welding seam was analyzed using x-ray diffractometer,scanning electron microscope and optical microscope. In addition,the hardness and ultimate tensile strength of the samples obtained with different welding current were determined. The results show that with an increase in welding current,the formability of welding seam becomes worse and the grains get coarsed. At the same time,both gas porosity and crack are easy to generate,which will reduce the properties of the joint. The microstructure of the welding seam is composed of α-Mg matrix and β-Al12Mg17phase. It is also noted that the welding current significantly influences the shape of molten pool and the welding quality of welding joint.

关 键 词：焊接电流 镁合金 TIG焊 焊缝成形系数 显微组织 抗拉强度 硬度 气孔 裂纹 

分 类 号：TG421[金属学及工艺—焊接]