Articles techniques et présentations

Materials such as aluminium with high thermal and electrical conductivities are of industrial interest, particularly for the automotive industry in the current context of increasing production of electric vehicles. The reflective properties of this material make it difficult to process by laser welding. In addition, advances in laser technology offer a broad range of operating parameters and pose a challenge in identifying optimal process parameters. These reasons explain the need for numerical simulation to predict melt pool instabilities and the potential resulting defects such as porosity. A 2D axisymmetric thermohydrodynamic model under static pulse is developed with COMSOL Multiphysics®. The laser-matter interaction is described using an equivalent approach to represent the multiple reflections effect of the laser. Vaporisation is simulated by adding a source term to the continuity equation. Tracking of the free interface is treated with a modified Level Set method that preserves mass loss. The results are validated by experiments.