Stability of laser-MIG hybrid welding process with filling wire for aluminum alloy

Weld appearance, the stabilities of penetration depth, reinforcement as well as porosity, laser keyhole characteristic and plasma characteristic were studied by using a new laser-MIG hybrid welding process with filling wire of aluminum alloy. The results were also compared with those by conventional laser-MIG hybrid welding process. It is found that with the suitable process parameters, this new welding process for aluminum alloy was stable. The extra wire deposited continuously and the keyhole had obvious periodic variations, including formation, growth and annihilation. The final weld bead had fine appearance. Compared to conventional laser-MIG hybrid welding process, during this new welding process the stabilities of penetration depth and reinforcement were similar, while the keyhole opening area had differences of 15.34%, the total area of plasma and arc had differences of 1.95%.