Comparative analysis between the laser beam welding and low current pulsed GMA assisted high-power laser welding by numerical simulation

Abstract

By introducing the low current pulsed gas metal arc (GMA), the bridging ability of the laser beam welding (LBW) can be effectively improved. However, the impact mechanism of the additive GMA is hard to investigate by experimental methods. In this paper, the three-dimensional transient mass and heat transfer models of the low current pulsed GMA assisted high-power laser welding and single LBW are established. The pulsed arc and laser heat source models are optimized based on the arc morphology images, arc voltage and welding current. The drop transfer and arc pressure models are improved by comprehensively considering the effect of the molten pool surface deformation and the interaction of laser and arc on the arc heat flow distribution. Based on the established welding models, a comparative analysis is conducted to investigate the evolution characteristics of the temperature and flow fields in the molten pool. The simulated results show that the additive low current pulsed GMA in novel hybrid welding significantly increases the high temperature region of the molten pool, while allowing the liquid metal to expand transversely, thereby increasing the length and width of the molten pool. These greatly improve the bridging ability of LBW and extend its application range.