Non-equilibrium transients during solidification – A numerical study

In an extension of a recently developed model [M. Buchmann, M. Rettenmayr, Scripta Mater. 57 (2007) 169] non-equilibrium transients during solidification of a binary metal alloy are studied. Interface velocity and interface concentrations are calculated during the transient towards interface equilibrium in an undercooled alloy. The rigorously derived model includes realistic free energies and real concentration gradients in both phases. The evolution of the interface concentrations and velocity is modelled as a function of the initial driving force on the phase boundary. The time necessary for re-equilibration of the interface is quantified.