铝/钛异种金属旁路分流MIG电弧熔钎焊特性  

Characteristics and mechanical properties of bypass-current MIG welding-brazed dissimilar Al/Ti joints

作　　者：苗玉刚 王腾 周玥[2] 韩端锋 

机构地区：[1]哈尔滨工程大学水下机器人技术重点实验室,哈尔滨150001 [2]哈尔滨工业大学先进焊接与连接国家重点实验室,哈尔滨150001

出　　处：《焊接学报》2015年第1期47-50,115,共5页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(51005049);哈尔滨市高新技术产业专项资金资助项目(ZX2012ZC006015)

摘　　要：以1 mm厚6061铝合金与TC4钛合金板为试验材料,进行旁路分流MIG电弧熔钎焊工艺试验,得到均匀美观的焊缝成形.分别采用金相显微镜、扫描电镜、万能拉伸试验机进行研究.结果表明,界面层上方金属间化合物以柱状晶形式存在,呈现短而密集的状态.界面层靠近钛侧易形成Al Ti,而界面层靠近铝侧易形成Al3Ti,Ti Si2等金属间化合物,由于焊接过程中熔池内部温度的变化不均,会使界面层中出现Al11Ti5过渡相.拉伸试验表明,接头最高抗剪强度达182.6 MPa,约为铝母材的97.6%,断裂发生在铝母材热影响区,断口出现一定量的颈缩.Joining of 1 mm thick aluminum 6061 to titanium TC4 was conducted by using bypass-current MIG weldingbrazed,and stable welding process and good bead appearance were obtained.The joint profile and microstructure of Ti/Al joints were observed by optical microscopy and SEM,and then the structure of the interfarial reaction layers were analyzed in details.It was found the intermetallic compound layer at the interfacial top is in the form of columnar crystal,which is in short and dense state.A mount of AlTi were observed at the interfacial layer near the Ti base metal while intermetallic compound like Al_3Ti,TiSi_3 were formed near the Al base metal,and the Al_(11)Ti_5 transition phase was found in the center of the interface layer due lo the uneven distribution inside the weld pool during the welding process.Tensile test results show that the average tensile strength of joints is up to 182.6 MPa,which is about97.6%of aluminum base metal.Fracture is prone to occur in the base metal with a certain amount of necking.

关 键 词：旁路分流MIG电弧熔钎焊 异种金属 接头特性 力学性能 

分 类 号：TG454[金属学及工艺—焊接]