激光-熔化极脉冲电弧复合焊接的双重导电机制

Double Electric Conduction Mechanism of Nd∶YAG Laser-Pulse MAG Hybrid Welding

对激光-电弧复合焊接的稳弧机理始终存在不同的观点。通过高速摄像机和光谱分析仪对比研究了激光与电弧复合前后电弧形态发生的变化。研究发现复合后电弧呈现一种全新的形态,具有两个独立的导电通道,这种现象被称为"双重导电机制"。这种机制对维持电弧稳定和保证焊缝成型良好具有非常重要的意义,正是激光-电弧复合焊接高速焊接过程中稳弧的关键所在。研究还发现"双重导电机制"的建立过程存在时间顺序,辅助导电通道首先是从激光小孔周围建立起来,然后逐渐扩展到整个电弧区域。各种焊接参数对"双重导电机制"也存在明显的影响。

Different ideas exist on arc stability mechanism of laser-arc hybrid welding process.With high-speed camera and spectrometer,contrast analysis and research are made between method active gas（MAG） arc welding and hybrid arc welding in this paper.The results show that hybrid arc takes on a new shape and has two electric conduction paths independently.This phenomenon is called ＂double electric conduction mechanism＂ of the laser-pulse MAG hybrid welding process.This mechanism plays a very important role in maintaining arc stability and getting good appearance of weld during high speed welding process.It is also shown that the establishment of double electric conduction channel exists time sequence.The additional electric conduction channel ignites originally from the laser keyhole and then extends gradually to the whole space of the arc.Welding parameters,including distance between laser and wire,arc voltage and welding speed,have obvious influence on the double electric conduction mechanism.