Modelling diffusion controlled solid state kinetics in equilibrium and driven alloys

We propose a simple model for thermally activated atomic migration on a lattice and several techniques to handle it. For thermodynamical systems close to equilibrium, the simplest mean field approximation of the model yields the classical treatment of irreversible thermodynamics and gives a microscopic interpretation of the related phenomenological coefficients (mobilities, interfacial transfer coefficients, coupled relaxation of order and concentration fields⋯). The possible applications of the model to complex alloys of practical interest is indicated. Further away from equilibrium, the non-linearities can be taken into account in a systematic manner. For driven alloys, forced atomic migration is added to the model and new features result. Typical behaviours predicted from such models (mainly obtained from computer simulations) are presented.