Orientation Dependence of Cyclic Stability of Superelasticity of Ti50.2Ni49.8 Alloy Single Crystals under Compression

• Published in: Physics of metals and metallography 2024-08, Vol.125 (8), p.902-909
• Main Authors: Kireeva, I. V., Chumlyakov, Yu. I., Vyrodova, A. V., Saraeva, A. A., Pobedennaya, Z. V., Marchenko, E. S.
• Format: Article
• Language: English
• Subjects: Chemistry and Materials Science; Compressive strength; Crystal structure; Deformation effects; Diffusion; Heat resistant alloys; High temperature; Low temperature; Marforming; Martensite; Materials Science; Metallic Materials; Orientation effects; Phase (cyclic); Phase Transformations; Single crystals; Stability; Structure; Superelasticity; Temperature dependence
• ISSN: 0031-918X; 1555-6190
• DOI: 10.1134/S0031918X24601021

The effect of marforming (low-temperature compression deformation of В 19ꞌ-martensite at 203 K and subsequent annealing at 713 K for 0.5 h) on superelasticity (SE), temperature range of SE, and cyclic stability of superelastic behavior at 323 K are studied on [001] В 2 and В 2 single crystals of the Ti 50.2 Ni 49.8 (at %) alloy under compression. It is shown that marforming leads to an increase in the offset yield strength σ 0.1 of the high-temperature В 2-phase and to the development of SE, which was not observed in quenched crystals. The orientation dependence of the SE temperature range and the cyclic stability of superelastic behavior, which is determined by the orientation dependence of the σ 0.1 stresses of the В 2-phase, is established. The maximum SE temperature range is 87 K, and the cyclic stability of superelastic behavior at a temperature of 323 K is found in the [001] В 2 orientation with a high σ 0.1 stress level of the В 2-phase.