Protective gas for CO2 laser arc hybrid welding Al alloy

The protective gas plays an important role in the CO2 laser metal intertia gas(MIG)hybrid welding of aluminum alloy.The laser-MIG hybrid welding was carried out on 5052 Al alloy plates at different flow rates of He,Ar mixed protective gas,and the data about penetration depth and welding voltages were obtained.The results show when He is added to protective gas,the arc voltage of MIG will increase,and Arc stability reduces so that the weld penetration is affected by the pure He protective gas.The surface quality and the arc stability are improved when a little Ar gas is mixed with He protective gas,and the weld penetration is added.When the ratio of V(Ar):V(He)=5:25,the weld penetration is maximum.When a great amount of Ar is added to He protective gas,the weld penetration is decreased,even the deep penetration of laser welding is prevented.When using pure Ar gas,although the weld appearance is beautiful,but the weld penetration is very small.The results have an important role in the weld quality of the CO2 laser-MIG arc hybrid welding aluminum.