铝/铜异种金属熔钎焊接头微观组织与力学性能  

Microstructure and mechanical properties of Al/Cu dissimilar metals welding-brazing joint

作　　者：周相龙 石玗[1] 朱明[1] 顾玉芬[1] 

机构地区：[1]兰州理工大学省部共建有色金属先进加工与再利用国家重点试验室,兰州730050

出　　处：《焊接学报》2018年第5期59-62,共4页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(51675256);省部共建有色金属先进加工与再利用国家重点实验室开放基金资助项目(SKLAB 020114208);甘肃省基础研究创新群体计划项目资助项目(17JR5RA107);甘肃省高效协同创新团队项目资助项目(2017C-07)

摘　　要：采用ER5356铝镁焊丝对1060纯铝与T2紫铜进行了脉冲旁路耦合电弧MIG熔钎焊,并对接头宏观形貌、微观组织及力学性能进行了分析.结果表明,在合适的焊接工艺参数下,可以获得成形美观、连续均匀、无缺陷的铝/铜异种金属接头.焊接接头从铜侧以金属间化合物层、Al-Cu共晶体向焊缝过渡,金属间化合物主要由脆硬的Al_2Cu相组成,而焊缝区主要由先析出的α(Al)固溶体以及从其晶界上析出的网状(Al)+S(Al_2Cu Mg)/θ(Al_2Cu)共晶组织组成.随着焊接热输入的增加,金属间化合物层厚度明显增大,而焊接接头拉伸载荷先升高后下降,这与焊缝在铜母材上润湿铺展有关.接头拉伸时,主要在铝母材热影响区和焊缝与铜母材界面处发生断裂.Dissimilar metals of 1060 aluminum and T_2 copper were joined with lap joint by pulsed double electrode gas metal arc welding-brazing with ER5356 AlM g5 filler wire. Microstructure,elements composition and mechanical properties of joint were studied. The results showed that good-looking,continuous and uniform,defectless welds could be obtained with proper welding parameters. Welded joints transit from copper side with intermetallic compound( IMC) layer,Al-Cu eutectic to welding seam. The IMC layer is composed of Al_2 Cu phase,and the weld zone is composed of α( Al) solid solutions and α( Al) + S( Al_2 CuM g)/θ( Al_2 Cu) eutectic in the grain boundary. The thickness of IMC layers increases with the increase of welding heat input,while the tensile load of joint increases at first and then decreases,which is related to the wetting and spreading of the weld on the copper base material. Tensile test results show that the joint fractures at the heat affected zone of aluminum base metal or interface layer between the weld and the copper base metal.

关 键 词：异种金属 脉冲旁路耦合电弧MIG熔钎焊 金属间化合物 拉伸载荷 

分 类 号：TG401[金属学及工艺—焊接]