Parametric investigation of microstructure after laser melting of metal powder layer

Powder shrinkage, low heat conductivity of powder layer and self-consistency of all equations are taken into account in the developed selective laser melting model. New marker function is used to account for thermal properties of the powder layer. Shrinkage speed is incorporated into the equation for free boundary evolution as a porosity dependent source term. Average crystalline size reduction is shown with the scanning speed increase and its growth - with laser power increase. Crystalline size is shown to grow with the powder height only with presence of the overhang effect. The results can be used for processing window estimation of powder layer laser melting as regards the required microstructure. (C) 2017 The Authors. Published by Elsevier Ltd.