FEM simulation of metal sheets laser welding with wire filler material

Worldwide manufacturers have already recognized the advantages of using laser welding for a number of applications. Although laser welding is usually performed autogenously, the use of wire filler allows a broader range of welding applications. In this paper a finite element model for key-hole laser welding sources based on experimental observations is presented. The shape for the heat source can be easily changed so to simulate both autogeneous and wire filler laser welding. In the thermal and mechanical calculations the material properties were considered with full temperature dependence. Austenitic stainless and aluminum alloy welds were chosen to validate the model. Simulations of out-of-plane welds were computed using a local coordinates system. A personal computer was used for the calculations. For different plate thicknesses and weld geometries, the calculated fused zones were found in very good agreement with the experimental ones, which proved that the thermal history was computed correctly. When materials with thermal induced microstructure changes are welded, the microstructure in every point of the heat affected zones can be determined as a function of the local temperature cycle.