钛/铝异种合金电弧熔钎焊接头界面特征及力学性能  

Interfacial characteristic and property of Ti/Al dissimilar alloys joint with arc welding-brazing

作　　者：吕世雄[1] 敬小军[1] 黄永宪[1] 程晋笠 郑传奇[1] 

机构地区：[1]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 [2]西安航天发动机厂,西安710100

出　　处：《焊接学报》2012年第6期23-26,114,共4页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(50974046和50904020);哈尔滨市青年科技创新人才基金资助项目(2009RFQXG050);中央高校基础科研业务费专项资金资助项目(HIT.NSRIF.2012007);国家博士后科学基金资助项目(20090-460883和201003419)

摘　　要：采用AlSi5焊丝和交流TIG电弧实现了TC4钛合金和6056铝合金的熔钎焊连接,通过金相显微镜(OM)、扫描电镜(SEM)、能谱分析仪(EDS)和拉伸试验等方法评价了接头界面微观组织特征和力学性能.结果表明,当焊接电流为30,40和60 A时,界面反应层分别呈棒状、块状和锥状分布,过大的热输入使界面产生了粗大柱状金属间化合物层,冷却时在焊接内应力作用下产生了冷裂纹.金属间化合物主要为TiAl3相,Si元素偏聚其内形成过饱和固溶体.接头强度-焊接电流曲线出现了两次峰值强度.焊接电流为30 A时,熔钎焊接头平均抗拉强度为103 MPa.焊接电流为60 A时,电弧形态扩张使能量密度降低,接头强度出现第二次峰值.Ti/Al dissimilar alloys were successfully joined by AlSi5 filler metal and TIG-AC arc,and the joints with the characters welding and brazing were gained.The interfacial microstructure and property of Ti/Al welding brazing joints were analyzed by optical microscope（OM）,scanning electron microscopy（SEM）,energy dispersive X-ray spectrometer（EDS） and tensile test.The results indicate that interfacial layers exhibit club-shaped,diamond-shaped and coniform-shaped respectively,with welding current changes from 30 A to 60 A.The excessive heat input resulted in oversized column interfacial layer,cold cracks were produced during cooling stage under influence of welding stress.TiAl3 is the main phase of the interfacial layer,which is a typical supersaturated solid solution of Si element.The strength-current curve exhibits two peak values.The maximum average tensile strength is 103 MPa with welding current of 30 A,while the curve exhibits the second peak value with welding current of 60 A due to the decreasing of arc energy density.

关 键 词：钛/铝异种合金 电弧熔钎焊 金属间化合物 力学性能 

分 类 号：TG454[金属学及工艺—焊接]