Effect of marforming on superelasticity and shape memory effect of [001]-oriented Ni50.3Ti49.7 alloy single crystals under compression

Abstract The shape memory effect (SME) and superelasticity (SE) of Ni50.3Ti49.7 alloy single crystals were studied after quenching and marforming (deformation in the martensite phase, followed by annealing at 713 K for 0.5 h) along the [001] direction, under compression, in the high-temperature B2 phase. It was shown that marforming leads to the following: strengthening of the high-temperature B2-phase; an increase in the temperature range of SE; a decrease in the mechanical Δσ and thermal ΔТh hysteresis; and an increase in the transformation hardening coefficient Θ=dσ/de, in comparison with the crystals after quenching. The reasons for improvements in the functional properties of [001]-oriented single crystals after marforming are discussed.