Benefits of Modeling of Melting for the Understanding of Solidification Processes

Melting and solidification are both phase transformations involving a liquid and a solid phase. In a simplifying procedure melting could be treated as the inverse process of solidification. However, there are substantial differences in the thermodynamics and kinetics of melting and solidification. The elaboration of a model for melting of binary alloys has lead to the possibility to also describe solidification processes more consistently. Input parameters in the model are the Gibbs Free Energy curves and the diffusion coefficients in the liquid and solid phase, respectively. Assumptions about the thermodynamic state of the interface like local equilibrium are not necessary, recently developed interface thermodynamics is coupled with the kinetic equations. Simulations results for steady-state melting and solidification are compared. The treatment of both solidification and melting yields some insight in the proper¬ties of the liquid/solid interface and its role during the phase transformation.