Novel General Solution for the Analysis of a Multicomponent Interdiffusion Couple

In this paper, we draw attention to the investigation of the novel exact solution [1.Scripta Mat. 210:114430; M.A. Dayananda, in JPED, this issue, (2022);] that is applicable to a multicomponent (n-component) interdiffusion couple where the interdiffusion matrix may change with alloy composition. In the derivation of this solution the interdiffusion flux Jj of a component j is related to (n-1) independent composition gradients for an isothermal, diffusion couple using the well-known continuity equation. Novel exact expressions are then derived for all of the interdiffusion coefficients, D~nij(i, j = 1, 2, …..n − 1), where the partial derivatives of the product Jj(y−y0)with respect to composition Ci(y0is the Matano plane) are used. In this paper, it is shown that the novel solution leads to a computational procedure similar to the Boltzmann-Matano analysis. Note that the derivatives ∂(Jj(y−y0))/∂Ci,i,j=1,…,n−1(that are required for the solution) can only be calculated along the diffusion path and therefore, for n>2,a single couple will not be enough to calculate all of them correctly.