脉冲电弧对激光脉冲电弧复合焊熔滴过渡与飞溅的影响

采用高速摄影技术、宏观金相和焊接电信号采集对激光脉冲电弧复合焊焊缝成形形貌、熔滴过渡和焊接飞溅进行了研究。结果表明:采用激光脉冲电弧复合焊能改善焊缝成形,同时明显改变了焊接电流、电弧电压以及熔滴过渡模式。激光非脉冲电弧复合焊的熔滴和熔池以及熔滴和焊丝之间形成的液桥在过大电磁收缩力的作用下发生爆炸,此外,熔池表面的熔滴在电弧力和内部气体膨胀的作用下发生爆炸,从而产生飞溅。而采用激光脉冲电弧复合焊接工艺能明显降低焊接飞溅,这主要是因为脉冲电弧降低了短路过渡时的电流以及熔池的震荡。

Effects of Pulse Arc on Droplet Transfer and Spatter of Laser Pulsed-Arc Hybrid Welding

The weld morphologies, droplet transfer, and spatters of laser pulsed-arc hybrid welding were studied using high-speed photography, macro-metallograph, and welding electrical signal acquisition. Results show that laser pulsed-arc hybrid welding can improve the welding morphologies. The weld morphologies were improved. The welding current, the arc voltage, and the droplet transfer mode were changed significantly during the laser pulsed-arc hybrid welding. The liquid bridge formed between the droplet and the molten pool as well as the wire and the droplet explored under the action of excessive electromagnetic contraction force, and the droplets on the surface of molten pool exploded under the action of the arc force and expansion of gases, so the welding spatters were produced. Spatters are significantly reduced during laser pulsed-arc hybrid welding, mainly because the pulse arc reduces the short circuit transfer current and pool oscillations.