Shape memory effect in TiNi single crystals with thermal-induced martensite transformation or strain glass transition

Timofeeva, Ekaterina E.; Panchenko, Elena Yu.; Zherdeva, M. V.; Eftifeeva, Anna S.; Surikov, N. Yu.; Tagiltsev, Anton I.; Fatkullin, I. D.; Tokhmetova, A. B.; Yanushonite, E. I.; Chumlyakov, Yuri I.

Shape memory effect in TiNi single crystals with thermal-induced martensite transformation or strain glass transition

Timofeeva, Ekaterina E., Panchenko, Elena Yu., Zherdeva, M. V., Eftifeeva, Anna S., Surikov, N. Yu., Tagiltsev, Anton I., Fatkullin, I. D., Tokhmetova, A. B., Yanushonite, E. I., Chumlyakov, Yuri I.

Дата публикации: 2022

Дата публикации в реестре: 2022-10-06T22:37:48Z

Аннотация:

In present work, we investigated the thermoelastic B2-B19' martensitic transformations in thermocycles under constant stress, σapp, (ε(Т) curves) and in loading/unloading cycles (σ(ε) curves) in quenched [001]-oriented single crystals of Ti-50.7 at%Ni and Ti-51.7 at%Ni alloys. Single crystals undergo either thermal-induced В2-В19' martensitic transformation (Ti-50.7 at%Ni) or strain glass transition (Ti-51.7 at%Ni), depending on their chemical composition. The transformation type defines the morphology of a martensite during cooling under stress. In Ti-50.7 at%Ni alloys during stress-assisted cooling the morphology is the mix of self-accommodation martensite and oriented martensite. In opposite, in Ti-51.7 at%Ni alloys the morphology consists of oriented martensite only. The following parameters in stress-assisted cooling/heating cycles are determined by transformation type and morphology of a martensite: the minimal stress, σmin, for oriented martensite formation; the coefficient dεfor/dσ that defines the strain dependence on stress, εfor(σapp), and the presence of additional stage in the dependence Msσ(σapp). Similar in loading/unloading cycles the transformation type defines the energy barrier that should be overcome in order to start the stress-induced martensitic transformation, and, so, the stress level, σcr(Ms0).

Ключевые слова:
мартенситные превращения, саморегулирующиеся структуры, эффект памяти формы, монокристаллы

Тип: статьи в журналах

Источник: Journal of alloys and compounds. 2022. Vol. 922. P. 166275 (1-8)