A coupled Cellular Automaton–Lattice Boltzmann model for grain structure simulation during additive manufacturing

Abstract

A 2D coupled Cellular Automaton (CA)–Lattice Boltzmann (LB) model has been developed to simulate grain structure evolution during powder–bed–based, layer by layer, additive manufacturing (AM). The presented model includes algorithms for random powder layer generation, electron beam energy absorption, evaporation, capillarity and wetting, meltpool dynamics, its temperature evolution and face centered cubic grain solidification. The model is first validated against the experimental findings of single track electron beam melting and solidification of a baseplate and then applied to simulate the grain structure produced during AM. Influence of the hatching strategy on grain structure is presented as well as stray grain formation resulting from partially molten powder particles.