Fluxes and interface migration in diffusion driven phase transformations.

An analysis is presented for the mass and vacancy fluxes within the reacting phases and at the interface for a diffusion-driven phase transformation between disordered binary solid solutions. As decided by the intrinsic diffusion coefficients and the initial and interface concentrations for each phase, vacancies must either be created or annihilated in the bulk phases but also at their interface. A general analysis is formulated for the growth or recession of a phase in terms of the Kirkendall reference frame, and this result is compared to the analysis based on the reference frame centered on the number of moles. Specific example calculations demonstrate the various possibilities for vacancy creation/annihilation and for the growth/recession of phases .