2. Thermomechanical properties

2.1 Deformation in the martensitic state

Consider a mother-phase single crystal cooled to below M _f : it transforms into all possible variants, as these are equiprobable. The associated shears compensate each other so that the macroscopic shape remains unchanged. If the sample is then subjected to mechanical stress (figure 4 ), it undergoes significant deformation ε _c , a large proportion of which ε _r remains after the stress ceases. This pseudoplastic deformation is essentially due to movements of the interfaces...