Mechanistic simulation of deformation-induced martensite stabilisation

Abstract

Abstract It is known that deformation of shape memory alloys, via either stress-induced martensitic transformation or martensite reorientation, causes stabilisation to the deformed martensite, as manifested in the increase of the critical temperature for the reverse transformation. Whereas a number of hypotheses have been proposed in the literature to explain this phenomenon, an actual mechanism by which the effect can be demonstrated is yet to be established. This paper presents a heuristic mechanistic spring–slide model based on the thermodynamic concept of elastic and frictional energies for thermoelastic martensitic transformations and plasticity concept of grain interior and grain boundary phases. The model is able to demonstrate the alterations to the elastic and irreversible energies caused by deformation and the effects of these alterations in causing the stabilisation of martensite.