保护气体组成及其保护方式是决定CO2激光-钨极氩弧焊(TIG)电弧复合焊接工艺稳定性和激光、电弧两种热源能否有效耦合并取得增强的焊接熔深的关键原因。为此,采用不同的气体保护方式在316L不锈钢板上进行了一系列CO2激光-TIG电弧复合焊接实验。结果表明,只有在合理的气体保护方式下才能取得增强的焊接结果,其中气体保护方式对激光等离子体和电弧等离子体相互作用程度的影响是决定能否有效耦合的关键因素。单独TIG焊炬保护不能保证激光和电弧的有效耦合,TIG焊炬加旁轴喷嘴的方式只能在较窄的参数范围内获得有效耦合,而TIG焊炬加同轴喷嘴的保护方式则在较宽的范围内都能保证两种热源的有效耦合。

Shielding gas is the crucial reason for the process stability and the efficient synergetic effects between laser welding and CO2 laser-TIG (tungsten inert gas) hybrid welding, resulting in bigger weld penetration depth. A detailed experiment of CO2 laser-TIG hybrid welding with different shielding gas methods is carried out on the 316L stainless steel plate. The results showed that the welding penetration depth only can be enhanced under the appropriate shielding gas method, and the effect of shielding gas methods on the interaction extent between laser plasma and arc plasma is the main factor for efficient synergetic effect. The pure torch method cannot generate the efficient synergetic effects, and the hybrid protecting method by torch plus paraxial nozzle method has only a narrow parameter range for getting the efficient synergetic effects, while the hybrid protecting method by torch plus coaxial nozzle method can ensure the efficient synergetic effects under a considerable wide parameter range.