焊接速度对镁合金与镀铜钢CMT熔钎焊接头组织和力学性能的影响  

Effect of Welding Speed on Microstructure and Mechanical Properties of CMT Brazing-welding Joints of Magnesium Alloy and Copper Plated Steel

作　　者：张超[1,2] 靳广胜[1] ZHANG Chao;JIN Guangsheng(School of Materials Science and Engineering,Jiangsu University of Science and Technology,Zhenjiang 212003,China;School of Public Utilities,Jiangsu Urban and Rural Construction Vocational College,Changzhou 213000,China)

机构地区：[1]江苏科技大学材料科学与工程学院,江苏镇江212003 [2]江苏城乡建设职业学院公用事业学院,江苏常州213000

出　　处：《热加工工艺》2019年第5期22-24,29,共4页Hot Working Technology

基　　金：国家自然科学基金项目(50975126;51179076);江苏省研究生创新计划项目(CX08S008Z)

摘　　要：采用AZ31镁合金焊丝为填充材料,对AZ31B镁合金和镀铜钢进行冷金属过渡(CMT)熔钎焊连接,利用光学显微镜、SEM、XRD、万能拉伸试验机分析了不同焊接速度对焊接接头的微观组织和力学性能的影响。实验结果显示:焊接接头主要分为富铜区、焊缝区、钎焊区、热影响区和母材;焊缝区是由α-Mg固溶体、Mg-Al相和Mg-Cu相组成。在焊接速度为300 mm/min时,镁合金在镀铜钢表面润湿铺展较好,所得焊接接头成型美观,焊接接头载荷最大,可达3.99 kN。The AZ31 magnesium alloy welding wire was used as filler material to conduct cold metal transition(CMT)brazing-welding connection between AZ31 magnesium alloy and copper plated steel.The effect of different welding speeds on the microstructure and mechanical properties of welded joints was analyzed by means of optical microscope,SEM,XRD and universal tensile testing machine.The experimental result shows that the joint is mainly divided into copper-rich zone,weld zone,brazing zone,heat affected zone and base metal.The weld zone is composed of α-Mg solid solution,Mg-Al phase and Mg-Cu phase.When the welding speed is 300 mm/min,the wetting and spreading of magnesium alloy on the surface of copper-plated steel is better.The obtained welded joints are beautifully formed and the load of welded joints is maximum,which can reach 3.99 kN.

关 键 词：镁合金 镀铜钢 CMT 力学性能 微观组织 

分 类 号：TG442[金属学及工艺—焊接] TG454