Meso-scale simulation of grain nucleation, growth and interaction in castings

It is shown that thermal effects dominate the interaction between neighbouring growing dendritic crystals in alloy solidification, for the majority of the growth stage between nucleation and impingement in typical castings. It is only near final impingement between growing grains that their solutal boundary layers overlap. Relevant predictions of a meso-scale front tracking computational model are presented for two scenarios that are usually simplified. The pitfalls of assuming temperature a priori (as done in some recent models) are highlighted.