It was recalled that multi-component diffusion induced zero-flux planes, that were the locations in a diffusion couple where the fluxes of individual components vanished. The kinetics of multi-component diffusion near to zero-flux planes were analyzed. In contrast to the usual mixing that occurred between alloys in a diffusion couple, where the average component compositions were approached by the so-called global exchange of atoms, the presence of a zero-flux plane required that mixing of the blocked component occurred via the release of coupled diffusion waves that consisted of a so-called depletion wave that reduced the blocked component concentration in the component-rich alloy, and a repletion wave that increased the concentration in the component-poor alloy. Each wave established the average (equilibrium) concentration unilaterally on each side of the Matano plane. Multi-component diffusion behaviors, such as slowed diffusive spreading and reduced atomic transport, were associated with the near collocation of multiple zero-flux planes, and the proximity of a zero flux plane for the major component.

Dynamics of Multicomponent Diffusion with Zero Flux Planes. M.E.Glicksman, A.O.Lupulescu: Acta Materialia, 2003, 51[4], 1181-93