Influence of partial shape memory deformation on the burst character of its recovery in heated Ni–Fe–Ga–Co alloy crystals

Resumo

Room-temperature stress–strain curves of Ni₄₉Fe₁₈Ga₂₇Co₆ alloy single crystals possessing shape memory (SM) have been studied. Specific features of these diagrams are revealed upon compressive loading of these single crystals in the [110]_A direction. The influence of preliminary SM deformation on the process of its recovery during the reverse martensite transformation has been studied. It is established that SM deformation above 4.2% leads to a sharp increase in the shape recovery on heating and the process exhibits a burst character, involving motion of the entire crystal. The experimental data are analyzed and stress–strain curves are simulated in the framework of the theory of diffuse martensitic transitions.