Kinetics of solute driven melting and solidification

Following previous investigations of [Rettenmayr M, Warkentin O, Rappaz M, Exner HE. Acta Mater 2001;49:2499–510] on solute driven melting in the Al–Mg-system, a recently developed thermodynamic model [Svoboda J, Gamsjäger E, Fischer FD, Fratzl P. Acta Mater 2004;52:959–67] has been applied to describe the kinetics of the melting process. By means of this sharp interface model, which is based on the principle of maximum Gibbs energy dissipation, additional insight into the underlying physics is provided. The characteristics of the melting and resolidification process can be described by considering both diffusion processes in the bulk and interfacial reactions. It is shown that, except for a short initial transient stage when the kinetics of melting is controlled by interfacial reactions, the process is diffusion and convection controlled.