Solidification of binary alloys: Thermal effects studied with the phase-field model

We developed a phase-field model for solidification of binary alloys, accounting for thermal effects due to the release of latent heat at the solid-liquid interface. The model is utilized to study the planar growth of a solid germ nucleated in its undercooled melt. Steady state solutions, predicted by previous investigations in the isothermal limit, are lost, and the front velocity decays with time according to the diffusion power law v∝${\mathrm{t}}^{\mathrm{-}1\mathrm{/}2}$ . Due to the transient characteristics of the growth process, the solute segregation at the interface, as described by the present model, is substantially different from the predictions of the continuous growth model of Aziz and Kaplan [Acta Metall. 36, 2335 (1988)], that is derived assuming isothermal and steady growth conditions.