Numerical modelling of directional solidification of metallic alloys

Abstract

A brief review is first given of the important considerations involved in numerical simulation of solidification. This is followed by presentation of an explicit finite-difference treatment for directional freezing of alloys, in which emphasis is laid on modelling the detailed internal response of the metal. Particular attention is devoted to the handling of latent heat evolution (as it is influenced by micro segregation phenomena) and representation of the mushy zone. Techniques for describing convective heat transfer in the melt are also briefly examined. Modelling results are presented for both laboratory experiments and industrial processes, and examples are given of how this type of analysis can assist in process optimization and control. In the course of these treatments, some of the heat-flow features of solidification with a mushy zone are illustrated and discussed.