Analysis on the interaction between laser and MIG plasma

Abstract

In order to study the interaction between laser and MIG plasma, the radiation of YAG laser-pulsed MIG hybrid plasma is collected with fiber spectrometer. High speed video is also applied to study the coupling effect of laser-MIG hybrid welding plasma. Absorption of laser beam by the plasma is the main reason for the interaction, among which inverse bremsstrahlung process and photoionization are the dominant process. The spatial distribution of spectrum is also acquired to provide experimental base for interaction analysis. The result shows that there is a high radiation intensity zone with great gradient in the center of laser-MIG hybrid plasma. An `ionized duct zone' is formed near the laser acting point. The above coupling effect provides a satisfied explanation for the better bead formation and more stable arc in the laser-MIG hybrid welding process.