Mechanical and Thermomechanical Characteristics of the Ni50Ti47.5Hf2.5 Alloy with a High-Temperature Shape Memory Effect

• Published in: Inorganic materials : applied research Vol. 15; no. 1; pp. 54 - 62
• Main Authors: Popov, N. N., Presnyakov, D. V., Grishin, E. N., Sysoeva, T. I., Morozova, T. A., Glukhareva, S. V., Kostyleva, A. A.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.02.2024; Springer Nature B.V
• Subjects: Annealing; Chemistry; Chemistry and Materials Science; Heat resistant alloys; High temperature; Industrial Chemistry/Chemical Engineering; Inorganic Chemistry; Martensitic transformations; Materials Science; Nuclear power plants; Phase composition; Pressure reduction; Shape effects; Shape memory alloys; Transformation temperature; mechanical characteristics; alloy; strain-inducing conditions; high-temperature shape memory effect; Ti; metallographic study; differential thermal analysis; effect of annealing; elemental and phase analysis; thermomechanical characteristics; Ni; band; Hf
• DOI: 10.1134/S207511332401026X
• ISSN: 2075-1133

The properties of the Ni 50 Ti 47.5 Hf 2.5 alloy with a high-temperature shape memory effect have been comprehensively studied on samples made from a 2.34-mm-thick strip in the initial state and after high-temperature annealing in vacuum. Data on the elemental and phase compositions and structural state have been obtained. The results of investigations of the phase transformation temperatures and the mechanical and thermomechanical characteristics of the alloy are reported. Using annealing and selecting the strain-inducing conditions, the shape recovery temperatures A s SME = 137°C and A f SME = 150°C have been determined. These values are acceptable for creating the required depressurization device. The maximum ε SME and η SME values have been found to be 3.4 and 43%, respectively. These are not very large values for creating an efficient depressurization device for nuclear power plants. The desired displacement values in such a device can be obtained by optimizing the geometry of a thermosensitive element.