Ti-22Al-27Nb/TC4异种合金激光焊接组织性能研究  

Microstructure and Mechanical Properties of Laser Welded Ti-22Al-27Nb/TC4 Dissimilar Alloys

作　　者：董智军[1] 胡明华[1] 罗志强[1] 

机构地区：[1]上海航天精密机械研究所

出　　处：《航空制造技术》2015年第3期71-74,81,共5页Aeronautical Manufacturing Technology

摘　　要：研究激光焊接对2.5mm厚Ti-22Al-27Nb/TC4异种合金焊接接头组织和力学性能的影响。结果表明,激光焊接可得到表面成型良好、内部无气孔裂纹的接头。Ti-22Al-27Nb侧热影响区O相和α_2相逐渐转变为B2相。TC4侧热影响区由α'马氏体和初始α相构成。焊缝区由B2相和α'马氏体构成。Ti-22Al-27Nb/TC4异种合金激光焊接接头平均拉伸强度为1043MPa,接近Ti-22A1-27Nb母材的强度。焊接接头平均延伸率为5.65%,为Ti-22Al-27Nb母材的49%。拉伸断裂位置均位于焊缝区域,断口形貌为韧窝花样。Laser welding is applied to join2.5mm thick dissimilar metals of Ti-22Al-27 Nb alloy and TC4 alloy.The microstructure characterization and the mechanical properties of the laser welded joints are investigated.The results show that a well-quality joint without crack or porosity can be obtained using laser welding method.The O phase and a2 phase gradually transforms to B2 phase in heat affected zone（HAZ） of Ti-22Al-27 Nb alloy.The heat affected zone of TC4 alloy mainly consists of martensitic a＇ and primary a phase.The weld metal is mainly composed of B2 phase and martensitic a＇ phase.The average tensile strength of the laser welded joints is1043 MPa,which is comparable to Ti-22Al-27 Nb parent metal.The average elongation tested to be 5.65%is 49%of the Ti-22Al-27 Nb parent metal.The tensile fractures are all located in the weld metal and the fracture surfaces are characterized by a ductile dimple feature.

关 键 词：激光焊接 异种合金 显微组织 力学性能 

分 类 号：TG456.7[金属学及工艺—焊接]