Mesoscopic simulation of selective beam melting processes

A 2D lattice Boltzmann model is developed to investigate melting and re-solidification of a randomly packed powder bed under the irradiation of a Gaussian beam during selective beam melting processes. Numerical simulation results are presented where individual powder particles are considered. This approach makes many physical phenomena accessible which cannot be described in a standard continuum picture, e.g. the influence of the relative powder density, the stochastic effect of a randomly packed powder bed, capillary and wetting phenomena. The proposed model, although still 2D, is able to predict many experimental observations such as the well known balling effect. A process map is used to demonstrate the effect of the process parameters, beam powder and scan speed. The simulation results are compared with experimental findings during Selective Electron Beam Melting (SEBM). The comparison shows good agreement between simulation results and experiments.