Spectral Diagnosis Of Arc Plasma In Laser-double Wire Pulse MIG Hybrid Welding

Laser hybrid welding is a new efficient welding technology which couples laserwelding with arc welding. This new welding method get extensive attention after itwas proposed and has good prospect in ship and automotive industry. Laser-doublewire pulse MIG hybrid welding proposed in this task is the development of laserhybrid welding. Currently, hybrid welding researches mainly focus on theapplications of welding procedure and simulation of laser-single arc hybrid welding,but less on spectrum diagnosis of laser-twin arc hybrid welding.Laser-double wire pulse MIG hybrid welding system and electrical signal,spectrum signal as well as high-speed video signal collection system are built in thispaper and welding experiment is designed according to different parameters.Thisexperiment has been divided to two part.The first part is to collect electrical signaland spectrum signal and the second one is to collect electrical signal and high-speedvideo signal. In this paper, distribution regularity of electron temperature and densityis studied by calculating spectrum signal.The arc behavior and metal transfer in laser-double wire pulse MIG hybridwelding are recorded by high-speed camera. The results indicate that the hybrid arcsare attracted to the laser point.Study on spatial distribution of radiation intensity, electron temperature anddensity of hybrid plasma indicate line spectrum of hybrid welding and two arcwelding is the same and there is no new line spectrum appearing after joining laser,but radiation intensity gets enhanced. The electron temperature of arc plasma can becalculated by means of Boltzmann plot. The results show that electron temperatureincreases obviously, especially in laser point. Laser power, wire distance, arc powerand welding heat input have a great influence on electron temperature. The electrondensity can be calculated by means of Stark expansion. The distribution of twin arcwelding and hybrid welding electron density are M type. Electron density of hybridwelding is higher than twin arc welding on the whole. In the laser-heated spot,electron density gets sharp increase.