Numerical Analysis of Plasma in CO2 Laser and Arc Hybrid Welding

Abstract

Lasers and electric arcs are well known heat sources for the welding of a metal. For the sake of a synergic effect, the two sources can be combined and used at the same time. When the two sources are used simultaneously for material processing, complex phenomena are observed, such as the absorption of the laser in arc plasma and a concentration of plasma caused by the metal vapor generated by laser irradiation. In this paper; temperature distributions of plasma for a CO2 laser and arc hybrid welding are calculated and investigated by use of a numerical analysis. Two types of shielding gases are considered For argon plasma, the CO2 laser is dramatically absorbed; however, for helium gas, there is little absorption of the laser light in the plasma. Therefore, improper welding results can be expected in the case of a CO2 laser and an argon arc. From the analysis, it was shown that the maximum temperature for a CO2 laser and argon arc hybrid plasma is about 30,000K It was also noticed that hybrid plasma was concentrated on the position of laser irradiation for helium-shielding gas.