Variable Intrinsic Diffusivities in Ternary and Higher Alloys

摘要

Two different attempts to describe the interdiffusion process in a multi-component system showing concentration dependent intrinsic diffusivities are compared. In the first case the type of a function which can be used to approximate the intrinsic diffusivity is postulated. An alternative way using thermodynamic data to calculate the intrinsic diffusivities is also demonstrated. Using both these approaches and the Generalised Darken's Method (GDM) the interdiffusion processes in the Ni-Pd and Ni-Fe-Cr systems are analysed. A comparison of the theoretically calculated drift velocity with the experimental markers' velocity obtained from a 'multi-foil' diffusion experiment in Pd-Ni diffusion couple is presented.