铝合金激光—小功率脉冲MIG电弧复合热源焊接特性分析

Welding characteristics of laser-low power pulse MIG hybrid welding aluminium alloy

针对5A06铝合金,通过一系列对比数据综合分析了MIG焊和激光-MIG复合热源焊接技术在焊缝熔深、焊缝成形、焊接速度、焊接热输入等方面的优缺点。结果表明,在MIG平均电流小于200A的小功率脉冲MIG电弧区域内,等热输入且等焊接速度条件下,激光-MIG复合热源焊接技术与MIG相比可以提高焊缝深宽比1～2倍,增加焊缝熔深0.43～2.5倍;等热输入且等平均焊接电流条件下,与MIG相比,激光-MIG复合热源焊接技术可以提高焊接速度0.6～1.5倍,增加焊缝熔深0.5～5.9倍;激光-MIG复合热源焊接技术可以用高于MIG焊0.6～6.5倍的焊接速度和更小的焊接热输入获得与MIG同样的焊缝熔深;与MIG焊相比,激光-MIG复合热源焊缝的铺展性更好,更适合于高速焊接;MIG复合2kW的激光能量后会增加平均电弧电压、减小平均电流。

The weld penetration, formation of weld, welding speed and weld heat input of MIG(metal inert-gas) welding and laser-MIG hybrid welding are analyzed for welding 5A06 aluminum alloy. It is shown that comparing with MIG welding, laser-MIG hybrid welding will increase depth-to-width ratio 100%-200% and increase weld penetration 43%-250%, as average current is less than 200 A and welding heat input and welding speed are equal. If welding heat input and average welding current are equal, welding speed of laser-MIG hybrid welding is higher 0.6-1.5 times than that of MIG welding, and weld penetration of laser-MIG hybrid welding is deeper 1.5-6.9 times than that of MIG welding. Equal weld penetration of laser-MIG hybrid welding and MIG welding can be obtained if lower welding heat input is applied in the hybrid welding and welding speed of the hybrid welding is 0.6-6.5 times higher than the one of MIG welding. Laser-MIG hybrid welding has good weld spreadability and is fit for high speed welding. It also was found that 2 kW laser power compounding with MIG will increase average arc voltage and decrease average welding current of MIG welding.