Impact performance and microstructures of thick TA1 titanium alloy sheets welded by vacuum electron beam

摘要

Thick TA1 titanium alloy sheets were thoroughly bonded by vacuum electron beam welding (EBW). The results indicated that microstructures in the weld zone (WZ) consisted of coarse alpha columnar grains, serrated alpha as well as needle-shaped alpha'; the microstructure in the heat-affected zone near the WZ side was composed of alpha' and alpha, while the microstructure near the base metal side consisted of alpha '' and alpha. The positional relation between the notches and rolling direction had an important role in the impact performance. The EBW joint exhibited higher absorbed impact energy at the weld seam after local heat treatment. Furthermore, lots of dimples were produced on the impact fracture surfaces, exhibiting ductile fractures.