Zero-flux planes and flux reversals in multicomponent diffusion

Abstract

The development of zero-flux planes (ZFP) and flux reversals of individual components is a phenomenon commonly encountered during isothermal diffusion in multicomponent systems. At a zero-flux plane, the interdiffusion flux of a component goes to zero and exhibits a flux reversal from one side of the plane to the other. The identification of ZFP’s is based on the determination of interdiffusion fluxes directly from the concentration profiles of diffusion couples without the knowledge or use of interdiffusion coefficients. The development of ZFP and flux reversals is reviewed and presented for both single-phase and multiphase isothermal diffusion couples in selected Cu-base multicomponent systems. The significance of ZFP is discussed with the aid of diffusion paths and thermodynamic data.