Effect of Filler Metal on Microstructure and Properties of Titanium Alloy Laser Welding Joints with Filler Wire

Abstract:

Abstract： TC3 solid wire and Ti-Al-V-Mo flux-cored wire were used as filler metals to carry out narrow gap laser welding of TC4 titanium alloy plate. The results show that the micro-scale differences between the two groups are obvious, the length of α" Martensite in the weld zone and coarse grain zone is small, and the width of original β phase grain boundary is narrow in the weld zone The width of α" Martensite lath is about 0.55 μm, a small amount of residual β phase is inserted between α" martensite and a small amount of dislocation is found in α" martensite. The width of acicular α" martensite is about 0.35 μm in Laser flux-cored wire weld, and a small amount of residual β phase is interlaced between Lath α" martensite. Acicular α" martensite contains a small number of fine twins and a large number of dislocation walls, in the same time, more dense dislocations were found at the phase boundary, and the content of residual β phase was a little more. In the weld zone of laser filled solid wire welded joint, the proportion of grain orientation difference greater than 10 ° with large angle grain boundary was about 79.25 %, and that of flux cored wire was about 96.27 %. The average hardness and tensile property of weld zone and HAZ of laser-filled flux-cored wire welded joint is larger than that of laser-filled solid wire welded joint.