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

• Published in: Journal of alloys and compounds 2022-03, Vol.896, p.162841, Article 162841
• Main Authors: Chumlyakov, Y.I., Kireeva, I.V., Vyrodova, A.V., Saraeva, A.A., Pobedennaya, Z.V.
• Format: Article
• Language: English
• Subjects: Compression; Crystal structure; High temperature; Marforming; Martensite; Martensitic transformations; oriented TiNi single crystals; Quenching; Shape effects; Shape memory alloys; Shape memory effect; Single crystals; Superelasticity
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2021.162841

•Effect of marforming was studied in [001]- oriented Ni50.3Ti49.7 alloy crystals under compression.•Marforming increased superelasticity temperature range and decreased the mechanical hysteresis.•After marforming, the maximum superelasticity value is 4.7%, and the shape memory effect is 3%. 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/dε, in comparison with the crystals after quenching. The reasons for improvements in the functional properties of [001]-oriented single crystals after marforming are discussed.