DIFFUSION IN MULTICOMPONENT METALLIC SYSTEMS: III. THE MOTION OF PLANAR PHASE INTERFACES

Abstract

Onsager's phenomenological scheme is adapted to unidimensional diffusion in a multiphase, multicomponent system with constant diffusion coefficients. Subject to initial conditions corresponding to the semi-infinite diffusion couple, an exact solution of the multicomponent equations is obtained from which the planar interface motions can be calculated. The similar but unrelated motion of markers that occurs in the diffusion zone of some single-phase couples is discussed and Darken's phenomenological description for binary alloys is extended to multicomponent systems.