激光-电弧复合热源焊接技术由于具有焊接熔深大、效率高、质量好等优点而受到广泛关注。采用低功率脉冲激光-钨极惰性气体保护(Tungsten inert gas, TIG)焊电弧复合热源技术进行镁合金板材的焊接，研究激光脉冲作用消失之后的等离子体行为和激光“匙孔”行为。在上述试验结果的指导下优化工艺参数，对比研究采用单独激光焊、TIG电弧焊和复合热源焊这三种方法实现镁合金板材对接焊相同效果时焊接效率的差异。研究结果表明，激光“匙孔”和“匙孔”等离子体的形成是实现复合热源高效焊接的前提条件，恰当的工艺参数可以使得激光“匙孔”维持稳定的开口状态，这种状态提高了电弧的稳定性和能量密度，延长了镁等离子体的恢复时间，因此能够提高复合热源的焊接效率。达到相同焊接效果时复合热源的焊接效率分别达到单独激光焊接效率的7.14倍和单独TIG电弧焊接效率的4.29倍。
Laser-tungsten inert gas(TIG) hybrid welding has been attracted much attention due to its advantages such as deep penetration, high efficiency and good quality. Laser-TIG hybrid welding processes with different parameters are proposed and the Mg plasma behavior is observed. While butt joints are made by laser welding, TIG welding, and laser-TIG hybrid welding, the welding efficiency in each process is compared and the reasons are discussed. Results indicate that the formation of laser keyhole and keyhole plasma is the premise of efficient hybrid welding. The parameters, including laser peak power, distance between laser and arc, arc current, greatly affect the Mg plasma behavior in hybrid welding. Optimized parameters can keep the keyhole open and stable. This process enhances the stability and the energy density of arc and extends the delay time of Mg plasma. So the welding efficiency can be greatly increased. The welding efficiency of hybrid welding is 7.14 times of laser welding and 4.29 times of TIG welding.
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