Zhiyong Mao

Verification of strength mis-match of electron beam welded heavy thickness titanium alloy

Abstract Electron beam welding was employed on Ti-6Al-4V ELI alloy with 50 mm thickness. The weld morphologies were I and T shape, respectively with and without oscillation. The microhardness profiles and tensile properties of the welds were measured along the penetration, and the mis-match was investigated. The maximum microhardness was in the welds and was at least 1.06 times that of the base metal. In addition, the hardness distribution of the I shape weld was more homogeneous than that of the T shape. The tensile strengths of the welds were higher than the base metal, and the properties of the I shape weld were more homogeneous. The mis-match factors of the welds were above 1.0, and the strengths of the joints were equivalent to the base metal, which verified the overmatching. The microstructure and hardness difference resulted in inhomogeneous stress–strain behavior of the joint, which contributed to the overmatching.