Three-dimensional heat and fluid flow modeling of laser welding and experimental validation

To understand the origin of defects in laser welding, a model taking into account heat transfer, fluid flow and free surface deformation under the effect of the recoil pressure is proposed. Almost all known phenomena are taken into account. The model is first applied to an axisymmetric configuration to describe a static laser shot. Then a 3D model representing a fusion line and containing all known phenomena is presented (capillary creation, instabilities, flow in the melt pool...). The model is validated by comparing the numerical results to the measured temperatures at the surface of the workpiece in the solid and liquid phases as well as the velocities at the surface of the melt pool.