Abstract: A new heat source model of laser-TIG hybrid welding that based upon rotary-Gauss body heat source model and Gauss area heat source is established. The model must consider the physical characteristics of material and hybrid welding because two heat sources are not repeated addition simply. On this basis, the numerical simulation of hybrid welding temperature field and welding seam sectional form is performed and the advice of parameters modification is brought forward. Compared with the experimentally measured value, the result shows that the new model can simulate the AZ31 magnesium alloy hybrid welding accurately. The characteristics of hybrid welding including high welding speed, energy increased and narrow heat affected zone are verified by the calculated result of numerical simulation.

Key words: Heat source model, Hybrid welding, Magnesium alloy