Study on improvement of tensile strength in lap-welding of pure titanium using disk laser

Laser welding has the benefit of hardly causing welding deformation as it requires less heat input than existing welding methods. The heat input is determined by the laser output and welding speed, and the penetration depth, bead width, joining length, and bead shape are varied depending on these two welding parameters. In this study, bead and lap welding were performed on a thin pure titanium plate with a thickness of 0.5 mm using a disk laser with a maximum output of 3.3 kW. Weldability was evaluated by observing the penetration depth, bead width, joining length, and bead shape for different laser outputs and welding speeds. Results show that a weld zone with excellent joining length can be obtained for an output of 1.1 kW and speed of 2.5 m/min, as well as for an output of 1.3 kW and speed of 3.5 m/min in lap welding. Tensile-shear test was conducted with the specimens under these two conditions to investigate their mechanical characteristics.