Laser–arc hybrid welding of Ti6Al4V titanium alloy: mechanical characterization of joints and gap tolerance

This paper reports the results of a comparison between the mechanical characteristics of butt joints in 3.0 mm thick Ti6Al4V titanium alloy sheets, made by laser welding with no filler material and by laser-arc hybrid welding. Vickers hardness tests have been performed on cross-sections of the beads obtained. In particular, the influence of the gap between the sheets in test welds performed using CO2 laser-MIG hybrid welding has been analysed. Cross-sections of the weld beads obtained with several different gap sizes have been analysed morphologically. The welded joints have been subjected to draw testing, and joint deformation behaviour has been analysed using an optical deformation measurement system based on stereoscopic image capture (ARAMIS 3D analysis system)