Melt Flow

Abstract

During laser material processing the material is often heated so strongly that it melts. In the case of laser surface alloying the melt convection is forced by gradients of the surface tension which are utilized for the mixing of the basis material and the alloying material. During cutting and ablation the material is expelled partly or entirely as melt, during deep penetration welding the melt flows around the keyhole. A solution of the system of mass, momentum, and energy conservation equations is, as in the case of heat conduction, only possible when appropriate initial and boundary conditions are prescribed. Boundary and initial conditions strongly depend on the specific problem at hand. In the present presentation only simple models will be discussed that help to comprehend the main principles.