Optimization of welding parameters on pores migration in Laser-GMAW of 5083 aluminum alloy based on response surface methodology

The mathematical model to reveal the relationship between process parameters and pores migration distance of 5083 aluminum alloy Laser-GMAW was established based on the center composed design of response surface methodology. Three of the welding parameters were chosen as the factors: The welding current, welding speed, and the laser-arc distance. The distance between pores and weld bottom was calculated as the response value. The analysis of variance was used to test the significance of the model. According to the result of experiments, the low welding speed and high current were beneficial to decrease the solidification rate of the molten pool, the pores could overflow from the weld in time. When welding speed is increasing, it is necessary to appropriately increase the welding current and the Laser-arc distance, the volume of the molten pool would be expanded, pores were difficult to be caught by solidifying wall. The optimized parameters of the 30mm aluminum alloy Laser-MIG hybrid welding were calculated based on the established model. The maximum pores migration distance can be obtained in 135A/0.6m/min/1.22mm (welding current/welding speed/laser-arc distance).