Ti_2AlNb合金瞬时液相扩散连接接头界面组织及性能分析  

Interfacial microstructures and mechanical properties of transient liquid phase(TLP) bonding of Ti_2AlNb alloy with Ti/Ni interlayer

作　　者：蔡小强 王颖[1] 杨振文[1] 王东坡[1] CAI Xiaoqiang;WANG Ying;YANG Zhenwen;WANG Dongpo(Tianjin Key Lab of Advanced Joining Technology,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学天津市现代连接技术重点实验室,天津300072

出　　处：《焊接学报》2018年第2期24-28,130,共6页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(51574177)

摘　　要：采用Ti/Ni作为中间层实现了Ti_2AlNb合金的连接(transient liquid phase,TLP),研究了TLP连接接头的界面组织及其形成机制,并且分析了不同保温时间对接头界面组织和力学性能的影响规律.结果表明,Ti_2AlNb合金TLP连接接头主要表现为等温凝固区和冷却凝固区两个明显的特征区域.接头的典型界面组织为Ti_2AlNb/B_2/Nb_3Al+B2+τ_3+Ti2Ni/Ti_2AlNb.随着保温时间的延长,接头中Nb_3Al和Ti_2Ni相消失,τ_3相不断减少,B2相不断增多.当连接温度为1 180℃,保温时间为20 min时,接头的室温抗剪强度最大,达到428 MPa,高温(650℃)抗剪强度达到407 MPa.接头的断裂主要发生在冷却凝固区的τ_3相上.A reliable Ti 2AlNb alloy joint was successfully obtained by transient liquid phase(TLP)bonding technique with Ti/Ni interlayer.The effects of bonding time on the interfacial microstructures and mechanical properties of the TLP bonded Ti 2AlNb joints were investigated.The results showed that the joint is primarily consisted of two characteristic zones of isothermal solidification zone(ISZ)and thermal solidification zone(ASZ),and the typical interfacial microstructures of the joints are Ti 2AlNb/B2/Nb 3Al+B2+τ3+Ti 2Ni/Ti 2AlNb.With the increase of time,Nb 3Al and Ti2Ni phases vanish.Additionally,theτ3 phase in the joint is gradually decreased and B2 phase increases with the increase of time.The maximum shear strength at room temperature reached up to 428 MPa when the joint was bonded at 1 180℃for 20 min,while it was 407 MPa at 650℃.The crack primarily propagates atτ3 phase in ASZ.

关 键 词：钛铝铌合金 瞬时液相扩散连接 界面组织 高温性能 抗剪强度 

分 类 号：TG454[金属学及工艺—焊接]