Non Equilibrium Phase Transitions in Intermetallics

Abstract

Intermetallics are operating under conditions where theatomic order is permanently disturbed from it's thermodynamical optimum, phase equilibria may no more be predicted from the classical free energy functions. Nevertheless, under simplifying assumptions, one may construct a new function, playing a similar role for assessing the respective stability of various phases: the latter is based on microscopic data such as atomic jump frequencies and interatomic binding energies, but does not imply an internal energy! After giving some examples of practical relevance of the present theory, we present the guiding ideas on which it relies, show it's present limitations and some examples where it is applied, at least as a qualitative guide, for rationalizing e.g. complex processing techniques such as mechanical alloying or subtile irradiation effects on the stability of intermetallics.