Steady-states and microstructural evolutions in driven systems

Abstract
There are many cases of practical interest where ordered intermetallic compounds or concentrated alloys are maintained in non-equilibrium conditions by some external dynamical forcing : such is the case for alloys under irradiation, under high energy bal1 milling or under cyclic fatigue. Phase equilibria in such systems cannot be assessed from equilibrium thermodynamics. We briefly review here different approaches based on kinetic descriptions for handling the question of phase stability in these systems, and showing that these methods are also appropriate for following diffusion-controlled microstructural evolutions in systems, either sustained in a non-equilibrium state or during a relaxation toward an equilibrium state.