Thermal trapping and kinetics of martensitic phase boundaries

Abstract

In this paper we study the influence of latent heat on kinetics of martensitic phase transitions and derive a relation between the velocity of an adiabatic phase boundary and the corresponding driving force (kinetic relation). Inside the phase transition front we adopt a non-isothermal version of the viscosity-capillarity model. We show that if the latent heat is different from zero, a finite value of the driving force must be reached, before the transition front can move; this effect of thermal trapping may contribute to martensitic hysteresis. In the adiabatic case the kinetic relations are non-monotone and non-single-valued, reproducing some fine features of the kinetic relations obtained previously for purely mechanical discrete models with bi-stable elements. We show that in its gross features, our kinetic model is similar to the conventional model of dry friction.