An Inhomogeneous Model for Laser Welding of Industrial Interest

An innovative non-homogeneous dynamic model for recovering the absolute temperature during the laser welding process of Al-Si 5% alloy plates, as per the industrial activity of an Italian company with proven experience operating in the laser welding area, is presented here. Firstly, the model considers that, metallurgically, during welding, the alloy melts with the presence of solid/liquid phases until total melting, and after-wards re-solidifies with the reverse process. Further, a particular polynomial substitute thermal capacity of the alloy has been chosen, according to experimental evidence, so that the volumetric solid state fraction is easily identifiable. Moreover, to the usual radiative/convective boundary conditions, to make the model more realistic, the contribution due to the positioning of the plates on the workbench is considered (endowing the model with Cauchy-Stefan-Boltzmann boundary conditions). Having verified the well-posedness of the problem, a Galerkin-FEM approach has been implemented on MatLab PDE ToolBox to numerically recover the absolute temperature maps, obtained by modeling the heat sources due to the laser with formulations depending on the laser sliding speed. The results achieved have shown good adherence to the experimental evidence, opening up interesting future scenarios for technology transfer.