MECHANICAL AND THERMODYNAMICAL STUDY OF A MACROSCOPICALLY COHERENT PHASE-TRANSITION - CASE OF THE MARTENSITIC-TRANSFORMATION

In the general framework of a macroscopically coherent phase transition, the mechanical and thermodynamical behaviour of a two-phase volume element under structural evolution will be investigated and discussed. The identification of internal entropy production will then allow to formulate a general evolution condition for such a system and the internal stress state will appear to influence strongly the transformation behaviour, via the interface. The case of a martensitic transformation is considered. From that rigourous mechanical approach, we obtain the thermodynamical balance equation used for martensitic transformation.