Diffuse martensite transitions and the plasticity of crystals with the shape memory effect

Abstract

The mechanism of diffuse martensite transitions in solids is theoretically examined using the thermodynamical approach together with the self-consistent-field order parameter model. Based on the resulting equations, a theory of diffuse martensite transitions is constructed as a kinetic equilibrium theory of heterophase structures which takes into account heterogeneous martensite nucleation and the interaction between interphase boundaries and various types of structural defects in real materials. An extensive comparison is made between the theoretical predictions and the experimental data on thermoelastic martensite transformations in alloys with shape memory. The universal nature of the theory is illustrated by applying it to ferroelectric and ferroelastic transitions in some classical ferroelectrics and high-temperature superconductors.