Effect of Concentration-Dependent Diffusion Coefficient on the Migration of Interphase Boundaries

Abstract

The diffusion‐controlled interphase‐boundary migration problem is defined by a system of equations in which the boundary conditions for the diffusion equation are determined by capillarity. Numerical computer solutions to these equations were obtained for steady‐state Widmanstätten ferrite plate growth. The effect of a concentration‐dependent diffusion coefficient on the migration rate of some simple interphase boundary shapes was investigated. It was found that a constant diffusion coefficient corresponding to the weighted average coefficient in the matrix gave an exact growth rate.