TY - JOUR

T1 - Palladium-free multicomponent high temperature shape memory alloys

AU - Resnina, N.

AU - Belyaev, S.

AU - Bazlov, A.

AU - Ponikarova, I.

AU - Sibirev, A.

AU - Ivanov, A.

AU - Bikbaev, R.

AU - Strochko, I.

N1 - Export Date: 04 March 2024; Cited By: 0; CODEN: IJESA

PY - 2024/4/1

Y1 - 2024/4/1

N2 - One of the challenges is the design of the relatively cheap Pd-free multicomponent high-temperature shape memory alloys. This paper presents the route for solving this problem by an increasing the Hf concentration in Ti–Hf–Zr–Ni–Cu–Co alloys. It was found that an increase in the Hf concentration from 23 to 32 at.% increased the transformation temperatures: Af changed from 90 °C to 220 °C, Ms varied from 35 °C to 172 °C, while the hysteresis was constant and equal to 45–48 °C. Further increase in the Hf concentration increased the Af temperature by 20 °C but hardly affected the Ms temperatures. Recoverable strain variation was studied on cooling under stress (in torsion mode) and heating without stress. Strain jumps were observed on γ(T) curves which were attributed to a large martensite plate appeared on cooling or disappeared on heating within large grain, which was accompanied by the abrupt strain variation. An increase in the Hf concentration decreased recoverable strain, as well as the strain up to failure. This was due to an increase in the size and volume of the brittle [Ti]2[Ni] and [Hf]2[Ni] precipitates. A maximum recoverable strain of 5 % was found in the alloy with 23 at.% of Hf, whereas the recoverable strain did not exceed 1 % in the alloys with 32 and 38 at.% of Hf. © 2024 Elsevier Ltd

AB - One of the challenges is the design of the relatively cheap Pd-free multicomponent high-temperature shape memory alloys. This paper presents the route for solving this problem by an increasing the Hf concentration in Ti–Hf–Zr–Ni–Cu–Co alloys. It was found that an increase in the Hf concentration from 23 to 32 at.% increased the transformation temperatures: Af changed from 90 °C to 220 °C, Ms varied from 35 °C to 172 °C, while the hysteresis was constant and equal to 45–48 °C. Further increase in the Hf concentration increased the Af temperature by 20 °C but hardly affected the Ms temperatures. Recoverable strain variation was studied on cooling under stress (in torsion mode) and heating without stress. Strain jumps were observed on γ(T) curves which were attributed to a large martensite plate appeared on cooling or disappeared on heating within large grain, which was accompanied by the abrupt strain variation. An increase in the Hf concentration decreased recoverable strain, as well as the strain up to failure. This was due to an increase in the size and volume of the brittle [Ti]2[Ni] and [Hf]2[Ni] precipitates. A maximum recoverable strain of 5 % was found in the alloy with 23 at.% of Hf, whereas the recoverable strain did not exceed 1 % in the alloys with 32 and 38 at.% of Hf. © 2024 Elsevier Ltd

KW - High temperature shape memory alloys

KW - High-entropy shape memory alloys

KW - Martensitic transformation

KW - Shape memory effect

UR - https://www.mendeley.com/catalogue/bc28b83d-1134-3775-9f7c-2c8f8b65fc47/

U2 - 10.1016/j.ijengsci.2024.104027

DO - 10.1016/j.ijengsci.2024.104027

M3 - статья

VL - 197

JO - International Journal of Engineering Science

JF - International Journal of Engineering Science

SN - 0020-7225

ER -