铝合金短路过渡熔化极惰性气体保护焊(MIG)焊缝成形较差、熔深浅。利用高速摄像与电信号同步采集系统，研究了铝合金MIG焊短路过渡时的熔滴过渡特性，解释了铝合金采用短路过渡焊接时焊缝成形差的原因。采用激光与电弧旁轴复合焊接形式，发现激光的加入改变了铝合金短路过渡的熔滴特性，当激光功率在某一临界值以下时，熔滴过渡稳定，焊缝成形得到显著改善；当激光功率超过临界值时，熔滴过渡不稳定，焊缝成形改善效果不明显。对比传统MIG和激光-MIG焊在采用短路过渡焊接铝合金时的焊缝宏观形貌，激光的加入使熔滴铺展良好，余高降低，熔深增加。研究表明，激光的加入，将工程上焊接铝合金时不常应用的短路过渡MIG焊接形式变得有实际应用价值。

The weld appearance of short circuiting transfer metal-inert gas (MIG) welded aluminum alloys is poor, and the penetration depth is shallow. Using high-speed camera and synchronous electrical signal acquisition system, the droplets transfer characteristics of aluminum alloys short circuiting transfer MIG welding are studied, and the reasons that the weld appearance is not good are explained. In the process of aluminum alloys laser-arc paraxial hybrid welding, the results show that the droplets transfer characteristics are changed. When the laser power is below the threshold value, the droplets transfer becomes stable, and the appearance of weld are significantly improved. When the laser power exceeds the threshold value, the droplets transfer becomes instable, and there is no obvious improvement of weld appearance. By comparing the weld cross-sections of traditional MIG and laser-MIG welding when using short circuiting transfer welding, it is found that, with the addition of laser, the droplets spread better, residual height decreases, and penetration depth increases. The experiment proves that, to aluminum alloys, the assistance of laser makes the short circuiting transfer MIG welding available and valuable.