铝合金CO2激光电弧复合焊保护气体影响研究

为了研究保护气体对铝合金CO2激光-熔化极惰性气体保护电弧复合焊的焊缝成形和熔深等的影响,采用不同流量的He和Ar混合保护气体在5052铝合金板上进行激光-熔化极电弧复合焊工艺试验的方法,进行了理论分析和实验验证,取得了焊缝成形、熔深、焊接电压等数据。结果表明,复合焊时采用单He气会造成熔化极惰性气体保护焊的电弧电压增大,电弧稳定性变差,从而影响铝合金CO2激光-熔化极惰性气体保护焊复合焊的熔深,少量的Ar气加入有利于改善焊缝表面质量和稳定电弧,提高焊缝熔深的效果,当V(Ar):V(He)=5:25时,熔深最大,但He气中加入大量的Ar气会降低焊缝熔深,甚至抑制激光深熔焊接;当采用纯Ar气作为保护气体时,虽然焊缝成形美观,但焊缝熔深很小。这一结果对铝合金CO2激光-熔化极惰性气体保护电弧复合焊焊缝成形质量分析具有较好的理论和工艺指导意义。

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.