Interdiffusion: mechano-chemical problem in three dimensions

Abstract

The interdiffusion and stress in multicomponent solid solution are analyzed. We simulate the deformation field during the diffusion caused by the gradients of the chemical potential of all elements. The method is based on the Darken concept and calorimetric equation of state. We effectively couple the mass conservation (continuity equations) with the energy and momentum conservation laws. The diffusion fluxes ofthe components are given by the Nernst-Planck formulae and take into account the chemical and mechanical potentials. We are presenting the numerical results for Cu-Fe-Ni alloy. The simulations shows that the model is compatible with experimental results, and can be effectively used for modeling the energy, momentum and mass transport problems in compressible multicomponent solid solutions. The mechano-chemical transport is a multi-scale problem. The transport is governed by strain field characterized by "sound velocity" in the medium (~104ms-1) and slow diffusion process characterized by self-velocity of diffusion (~10-2ms-1). The theoretical and numerical problems and methods of solution are presented.