Effects of welding parameters on weld pool characteristics and shape in hybrid laser-TIG welding of AA6082 aluminum alloy: numerical and experimental studies

The effects of three important welding parameters including laser power, welding current and welding speed on the weld pool characteristics, shape and dimensions in hybrid laser-TIG welding of AA6082 aluminum alloy are studied by numerical, experimental, and statistical approaches. For this aim, first, a 3D numerical model is used to simulate heat transfer and fluid flow in the weld pool and then resultant weld shape for various welding conditions. Besides, a set of experiments are performed to validate and calibrate the model. Finally, analysis of variance (ANOVA) method is applied to investigate more precisely how welding parameters affect weld dimensions. The simulation results show with increasing the laser power and welding current and decreasing the welding speed, the Marangoni and buoyancy forces increase. With increasing the laser power, the weld depth increases more significantly than the weld width. The weld half width increases with increasing the welding current, whereas the weld pool depth is relatively unchanged. Furthermore, with increasing the welding speed, both weld pool depth and half width decrease with similar slope. Generally, the presented model showed a good capability to predict the weld geometry and characteristics under various applied welding conditions which can reduce number of needed experiments.