Laser Penetration in a Powder Bed during Selective Laser Sintering of Metal Powders: Simulations versus Experiments

To gain a better understanding and control of the Selective Laser Sintering (SLS) process, more fundamental and modeling work is needed. A simple analytical ray-tracing model has been developed to simulate the energy absorption and penetration in SLS. The model is applied to FeCu and WC-Co powder mixtures, irradiated by Nd-YAG or CO2 laser. It gives an evaluation of the total energy incoupling and optical penetration of the laser beam in a powder bed and an estimation of the sintering zone dimensions. Another model, which considers heat flow by conduction in the bed, has also been used to estimate the sintering dimensions of one laser track.