Droplet detachment and motion behaviors in laser-MIG hybrid welding of aluminum alloy

Current studies have shown that laser-arc interaction affects droplet transfer behaviors, but the mecha-nisms remain unclear. This study quantitatively analyzed the effects of laser power on droplet transfer frequency, detachment time, and motion behaviors in laser-metal inert gas (MIG) hybrid welding of alu-minum alloy. It provided a comprehensive explanation for the variation of droplet transfer frequency by considering the full-cycle behaviors from droplet formation to fusion into the molten pool. The results revealed that the droplet growth and detachment in hybrid welding was accelerated by 22%, while the droplet flight motion was prolonged by 36% at maximum. The shortening of the growth-detachment pro -cess and the prolongation of the flight motion are the decisive factors for the increase and decrease of the droplet transfer frequency, respectively. Moreover, laser-arc interaction significantly changed the motion characteristics of droplet flight motion. Compared to arc welding, the initial velocity of droplet detaching from the wire tip increased by 8%, but the final velocity of droplet impacting the molten pool decreased by 10% at laser power of 6 kW. The mechanism was discussed based on droplet force analysis. These new findings will deepen the understanding of laser-arc interaction and improve the control capacity of the hybrid welding process.(c) 2023 Elsevier Ltd. All rights reserved.

Automated summary

Current studies have shown that laser-arc interaction affects droplet transfer behaviors. This study quantitatively analyzed the effects of laser power on droplet transfer frequency, detachment time, and motion behaviors in laser-MIG hybrid welding of aluminum alloy. The results revealed that the droplet growth and detachment in hybrid welding was accelerated by 22%, while the droplet flight motion was prolonged by 36% at maximum. The mechanism of these effects was discussed based on droplet force analysis.