Interactions between laser and arc plasma during laser–arc hybrid welding of magnesium alloy

This paper presents the results of the investigation on the interactions between laser and arc plasma during laser–arc hybrid welding on magnesium alloy AZ31B using the spectral diagnose technique. By comparably analyzing the variation in plasma information (the shape, the electron temperature and density) of single tungsten inert gas (TIG) welding with the laser–arc hybrid welding, it is found that the laser affects the arc plasma through the keyhole forming on the workpiece. Depending on the welding parameters there are three kinds of interactions taking place between laser and arc plasma.

► Interaction between laser and arc plasma is investigated by spectral diagnosing.
► Laser affects the arc plasma through the laser keyhole forming on the workpiece.
► There are about three kinds of interactions between the two heat sources.
► Positional relationship between the two heat sources dominants the interaction.