新型光纤激光器具有光束质量好、电光转换效率高、维护费用低、抽运寿命长、可光纤传输及体积小等显著优势，并且由于波长短，几乎可以被大多数的金属和合金吸收，因此可适用于各种材料的焊接和切割，受到工业界广泛的关注。采用光纤激光与惰性气体保护(MIG)电弧复合热源进行了TC4钛合金的焊接工艺试验，研究了激光引导电弧(LL)和电弧引导激光(AL)两种焊接方向对钛合金焊缝表面成形、横截面形貌、熔深、熔宽和余高的影响。试验结果表明，与AL方向焊接获得的焊缝相比，LL方向焊接获得焊缝的表面成形较好，焊缝的熔宽较宽，但熔深较小，而改变焊接方向对焊缝的余高影响很小。

With excellent beam quality, high wall-plug efficiency, low maintenance costs, long lifetime of pump diodes, flexible beam delivery and compact size, the new fiber lasers are very attractive for welding and cutting various kinds of materials in industrial applications since the short wavelength laser beams can be absorbed by almost all metals and alloys. Fiber laser- metal inert gas (MIG) hybrid welding is carried out onto TC4 alloy. The effects of laser-leading (LL) and arc-leading (AL) welding direction on top bead appearance, cross section, penetration depth, width and reinforcement of welds are investigated. The results show that the fiber laser-MIG hybrid welding in LL welding direction leads to better top bead appearance, wider weld width and shallower penetration depth, than those in AL welding direction. The weld direction has little influence on the reinforcement of the welds.