Modeling of the melted bath movement induced by the vapor flow in deep penetration laser welding

In this article we are interested in a moving mechanism occurring in the melted bath that is produced during the deep penetration laser welding process. It concerns the displacement of the melted metal induced by the friction effect due to the interaction with the metallic vapor when it flows toward the keyhole exit. Boundary conditions resulting from a ray-tracing procedure are used in the numerical solving of the unsteady Navier-Stokes conservation equation for both liquid and gaseous phases. The melted metal is considered for the liquid phase, whereas the metallic vapor and the environing air are taken as gaseous phases. The volume of fluid approach used in our modeling allows the tracking of the vapor-liquid wall interface evolution. We will present sequences of the melted bath profiles evolution as the vapor flows and interacts with it. An estimation of the velocity of the displaced liquid boundary layer allows a comparison with experimental results concerning the expelled melted metal velocity. (c) 2006 Laser Institute of America.