Numerical investigations of the thermal efficiency in laser-assisted plasma arc welding

Numerical investigations on the thermal efficiency in laser-assisted plasma arc welding (LAPAW) have been carried out by the combination of a magneto-hydrodynamic (MHD) arc model and a smoothed-particle-hydrodynamics (SPH) model of the weld pool. The comparison of the calculated weld seam cross-sections gained from numerical simulation as well as experimental examinations shows a good agreement. By the use of the weld pool model, the sensitivity of different influencing variables was investigated. The analysis clearly reveals the major influence of the central heat flux density on the penetration profile and on the thermal efficiency of the process. The higher the heat flux of the laser beam and the higher the constriction of the heat flux profile of the arc, the higher the thermal efficiency of the process.