Rapid solidification theory revisited – A consistent model based on a sharp interface

Based on recent progress in the thermodynamics of migrating interfaces, the contact conditions (equilibrium concentrations and deviations thereof) at a solid/liquid interface during rapid solidification are modelled numerically. Possible interface concentrations are calculated as a function of interface velocity. Two processes are assumed to dissipate Gibbs Free Energy: the migration of the interface and the redistribution of solute atoms across the interface. Predicted interface concentrations are in reasonable agreement with available experimental data and earlier models. The rigorously derived model that includes realistic free energies ensures physical consistency and allows for the treatment of non-ideal systems.