Experimental and numerical studies on gas tungsten arc welding of Ti–6Al–4V tailor-welded blank

Abstract

The effect of gas tungsten arc welding (GTAW) process parameters and its impact on the titanium TWB was studied experimentally as well as using numerical simulation. Bead characteristics of BoP trials (bead on plate) were analyzed based on Taguchi L27 orthogonal array by taking welding current (115 A, 125 A, 135 A), welding speed (4.1 mm/s, 5.8 mm/s, 7.5 mm/s) and arc length (3 mm, 4 mm, 5 mm) as process parameters. The bead width and depth of penetration for all trials were measured by using the weld expert system. Based on the bead characteristics, optimized GTAW process parameters (135 A, 4.1 mm/s and 3 mm) were identified for making the TWB by joining 2–1.6-mm-thick Ti–6Al–4V sheets. The tensile test of the prepared Ti–6Al–4V TWB was conducted in the universal testing machine. The COMSOL and ABAQUS software packages were used for the numerical simulation of TWB to assess the bead profile and tensile properties. The prediction made from the temperature distribution curve related to phase change near weld zone, exactly matched with the experimental work. The joint strength of TWB observed to be around 982 MPa and 1005 MPa was evaluated experimentally and conducting ABAQUS simulation work. The tensile test results were comparable with each other within the acceptable error level.