A thermal model of laser cladding by powder injection

A two-dimensional (2-D) finite element model is presented for laser cladding by powder injection. The model simulates the quasi-steady temperature field for the longitudinal section of a clad track. It takes into account the melting of the powder in the liquid pool and the liquid/ gas free surface shape and position, which must conform to the thermal field in order to obtain a self-consistent solution. The results for an idealized problem, where there is almost no melting of the substrate material, demonstrate the linear relationship between the laser power, the processing velocity, and the thickness of the deposited layer. The calculated clad heights agreed well with the experimental values for the conditions where a cobalt-based hard-facing alloy is clad onto mild steel with a linearly focused laser source. Formerly Postdoctoral Fellow, Ecole Polytechnique Fédérale de Lausanne