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

[Display omitted] •A 2D coupled Lattice Boltzmann-Cellular Automata (CALB) model for additive manufacturing is presented.•Powder related stochastic effects are included.•CALB model is applied to simulate multilayer hatching solidification of powder beds.•The model is able to reproduce main morphological aspects of competitive grain growth and grain penetration from side walls.•The phenomenon of grain boundary wiggling observed in experiments is well captured and explained by CALB model. 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.