Simulation of shrinkage-induced macrosegregation in a multicomponent alloy during reduced-gravity solidification

Segregation is a key phenomenon responsible for altering alloys’ properties during solidification. The factors that lead to solute partitioning at the scale of the solidified parts are related to movements of liquid and solid phases. However, when considering a reduced gravitational field, convection forces become less significant compared to other factors. Consequently, predicting segregation in this context requires considering other prevailing driving forces, namely solidification shrinkage that arises from the density difference between the liquid and solid phases. We propose a numerical model that accounts for energy conservation via a thermodynamic database, together with fluid momentum conservation and species conservation to predict segregation driven by solidification shrinkage in a multicomponent alloy. We apply it on a specific steel grade for which reduced-gravity experiments were performed via parabolic flights.