On model of microstructure formation during selective laser melting of metal powder bed

Abstract

A model of phase field has been developed to investigate the microstructure evolution during selective laser melting (SLM) of metal powder bed. A two-component (degree of order, orientation field) ordering parameter has been used, for which the permissive relationships have been derived reasoning from the principle of entropy production positivity. The application of this principle has made possible obtaining the thermodynamically agreed evolutionary equations for the components of the ordering parameter, conjugate with the fields of temperature, admixture concentration and elastic deformations for the non-isothermal conditions of crystallization of pure metal melts and multicomponent alloys. The model of the microstructure is adjoint with the macroscopic thermodynamic model of SLM that accounts for the processes of heat transfer, thermo-capillary convection and evolution of the melt free surface.