TY - JOUR

T1 - Grain growth in Ni50Ti30Hf20 high-temperature shape memory alloy processed by high-pressure torsion

AU - Shuitcev, A.V.

AU - Ren, Y.

AU - Gunderov, D.V.

AU - Vasin, R.N.

AU - Li, L.

AU - Valiev, R.Z.

AU - Zheng, Y.F.

AU - Tong, Y.X.

N1 - Export Date: 10 November 2024 Сведения о финансировании: National Natural Science Foundation of China, NSFC, 52201207, 52271169 Сведения о финансировании: National Natural Science Foundation of China, NSFC Сведения о финансировании: Fundamental Research Funds for the Central Universities, 3072024LJ1002 Сведения о финансировании: Fundamental Research Funds for the Central Universities Сведения о финансировании: Russian Science Foundation, RSF, 22-19-00445 Сведения о финансировании: Russian Science Foundation, RSF Текст о финансировании 1: Authors express gratitude to Tatiana Vershinina (FLNP JINR) for her help with X-ray experiments. This study is supported by National Natural Science Foundation of China [grant numbers 52201207, 52271169], and the Fundamental Research Funds for the Central University [grant number 3072024LJ1002]. R.Z.V. acknowledges the support from Russian Science Foundation (grant number 22-19-00445) for his part.

PY - 2024/12

Y1 - 2024/12

N2 - Grain refinement and precipitation hardening play critical important role for stabilization and improving functional properties of shape memory alloys. However, the relationship between precipitation and nanocrystalline grain growth behavior in NiTiHf alloys is still unclear. This work aims to investigate the role of precipitation in the nanocrystalline grain growth behavior of HPT-processed Ni50Ti30Hf20 high-temperature shape memory alloy. An abnormally low grain growth rate (n = 0.08) was observed after post-deformation annealing (PDA) at 550 °C for 1 h. It was proposed that grain growth suppression may be caused by the presence of relatively large H-phase precipitates, which act as barriers to grain boundary movement. A detailed analysis of the grain growth kinetics during PDA suggests that the coarsening process is controlled by Ni diffusion. Additionally, the dependence of strength and transformation temperatures on grain size in NiTiHf alloy is found to follow the Hall-Petch relation with some exceptions due to H-phase precipitation. The results of this research may be useful for the development of methods and strategies to stabilize the nanocrystalline structure in metallic materials. © 2024 Elsevier B.V.

AB - Grain refinement and precipitation hardening play critical important role for stabilization and improving functional properties of shape memory alloys. However, the relationship between precipitation and nanocrystalline grain growth behavior in NiTiHf alloys is still unclear. This work aims to investigate the role of precipitation in the nanocrystalline grain growth behavior of HPT-processed Ni50Ti30Hf20 high-temperature shape memory alloy. An abnormally low grain growth rate (n = 0.08) was observed after post-deformation annealing (PDA) at 550 °C for 1 h. It was proposed that grain growth suppression may be caused by the presence of relatively large H-phase precipitates, which act as barriers to grain boundary movement. A detailed analysis of the grain growth kinetics during PDA suggests that the coarsening process is controlled by Ni diffusion. Additionally, the dependence of strength and transformation temperatures on grain size in NiTiHf alloy is found to follow the Hall-Petch relation with some exceptions due to H-phase precipitation. The results of this research may be useful for the development of methods and strategies to stabilize the nanocrystalline structure in metallic materials. © 2024 Elsevier B.V.

KW - Grain growth

KW - High temperature shape memory alloy

KW - High-pressure torsion

KW - NiTiHf

KW - Severe plastic deformation

KW - Brinell Hardness

KW - Coarsening

KW - Grain boundaries

KW - Grain refinement

KW - Hafnium alloys

KW - Nanocrystalline alloys

KW - Nanocrystals

KW - Nickel alloys

KW - Shape-memory alloy

KW - Torsional stress

KW - 20 highs

KW - Functional properties

KW - Grain growth behavior

KW - Grains refinement

KW - High pressure torsions

KW - High-temperature shape memory alloys

KW - Nanocrystalline grain growths

KW - Post-deformation annealing

KW - Severe plastic deformations

KW - Shape-memory

KW - Titanium alloys

UR - https://www.mendeley.com/catalogue/65d0a4dc-96b6-382a-96f8-e7ad8fe6cf97/

U2 - 10.1016/j.msea.2024.147478

DO - 10.1016/j.msea.2024.147478

M3 - статья

VL - 918

JO - Materials Science and Engineering: A

JF - Materials Science and Engineering: A

SN - 0921-5093

M1 - 147478

ER -