A linear stability analysis of an interface in an isothermal phase transformation with a concentration‐dependent diffusion coefficient

摘要

A linear stability analysis of a moving planar interface between the liquid and solid phases in an isothermal phase transformation is carried out with the diffusion coefficient assumed to be a slowly varying function of concentration. The results of this analysis show that for the precipitation system under consideration (one in which the distribution coefficient, a ratio of the equilibrium concentration of solute on the solid side of the interface to that on the liquid side, is greater than unity), there is a destabilizing influence if the diffusion coefficient is an increasing function of concentration and a stabilizing one if it is a decreasing function.