Effect of laser-arc synergy on melting energy in laser-CMT hybrid welding of aluminum alloy

Abstract

The physical process of laser-arc synergy in laser-cold metal transfer (CMT) hybrid welding of aluminum alloys is extremely complex and difficult to observe, which limits our understanding of laser-arc synergy and the industrial application of laser-CMT hybrid welding. In this paper, the laser-arc synergistic effect is studied quantitatively by the change of melting energy. Therefore, the dimensionless parameter (ψ) is introduced to discuss the effect of heat source guidance, energy distribution and distance of laser and arc (DLA) on melting energy increment. The results show that the novel laser-arc simultaneous co directional hybrid welding (no-guided) process increases ψ by 4.3 times and 1.8 times compared to CMT-guided and laser-guided processes, respectively. The laser-arc synergy is strongest when the laser power is 80% of the total power and DLA is 2 mm. The quantitative analysis method in this paper can be extended to the study of other hybrid heat sources, and this research can facilitate the optimization of the welding process and a better understanding of the hybrid welding mechanism.