Ultra-stable and large elastocaloric effect in a nano-precipitated bulk TiNiCuCo shape memory alloy

Hongyang Lin; Peng Hua; Yang Li; Qiao Li; Kaiping Yu; Jie Yan; Yusuke Onuki; Qiuhong Wang; Changfeng Su; Guoan Zhou; Shigeo Sato; Kai Huang; Junhua Luan; Yi-Kuen Lee; Mingxin Huang; Yong Yang; Yang Ren; Qingping Sun

doi:10.1016/j.msea.2025.149449

Ultra-stable and large elastocaloric effect in a nano-precipitated bulk TiNiCuCo shape memory alloy

Hongyang Lin (Co-first Author)
, Peng Hua^* (Co-first Author)
, Yang Li
, Qiao Li
, Kaiping Yu
, Jie Yan
, Yusuke Onuki
, Qiuhong Wang
, Changfeng Su
, Guoan Zhou
, Shigeo Sato
, Kai Huang
, Junhua Luan
, Yi-Kuen Lee
, Mingxin Huang
, Yong Yang
, Yang Ren
, Qingping Sun^*

^*Corresponding author for this work

Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review

7 Citations (Scopus)

Abstract

Elastocaloric cooling utilizes the latent heat of shape memory alloys (SMAs) during cyclic phase transition and has emerged as an environmentally-friendly technology. However, existing SMAs exhibit either unsatisfactory cyclic stability or insufficient adiabatic temperature drop (ΔT), constraining the development of this technology. Here, we develop a nano-precipitated bulk TiNiCuCo SMA which retains a stable and large ΔT of 17 K over 1 × 10⁸ phase-transition cycles. The large ΔT originates from the large entropy change of B2-B19′ phase transition in the Cu-lean B2 matrix. The ultra-high cyclic stability is realized by inhibiting dislocation motion via precipitation hardening of uniformly distributed Ti(Ni,Cu)₂ nanoprecipitates. Our nano-precipitated bulk TiNiCuCo demonstrates high competitiveness among existing SMAs, serving as a cornerstone for the development of high-performance elastocaloric cooling devices. © 2025 Elsevier B.V.

Original language	English
Article number	149449
Journal	Materials Science and Engineering: A
Volume	949
Online published	11 Nov 2025
DOIs	https://doi.org/10.1016/j.msea.2025.149449
Publication status	Published - Jan 2026

Funding

This work was supported by the Hong Kong Research Grants Council (RGC-STG Project No. STG2/E-605/23-N, GRF Project No. 16212322), the Innovation and Technology Commission of Hong Kong (ITC project No. GHP/127/22SZ) and the Sustainable Smart Campus project of the Hong Kong University of Science and Technology. The research of Dr. Peng Hua is supported by the National Natural Science Foundation of China, the Shenzhen Science and Technology Program (Project No. JCYJ20240813105107011 and SGDX20230116091247009) and the startup fund (Project No. HA45001146) from Harbin Institute of Technology Shenzhen. The research of Prof. Yang is supported by the Research Grants Council (RGC) through the general research fund with the grant number of CityU 11201721.

Research Keywords

Cyclic response
Elastocaloric effect
Martensitic transformation
Precipitation hardening
Shape memory alloys (SMAs)

RGC Funding Information

RGC-funded

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10.1016/j.msea.2025.149449

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Lin, H., Hua, P., Li, Y., Li, Q., Yu, K., Yan, J., Onuki, Y., Wang, Q., Su, C., Zhou, G., Sato, S., Huang, K., Luan, J., Lee, Y.-K., Huang, M., Yang, Y., Ren, Y., & Sun, Q. (2026). Ultra-stable and large elastocaloric effect in a nano-precipitated bulk TiNiCuCo shape memory alloy. Materials Science and Engineering: A, 949, Article 149449. https://doi.org/10.1016/j.msea.2025.149449

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abstract = "Elastocaloric cooling utilizes the latent heat of shape memory alloys (SMAs) during cyclic phase transition and has emerged as an environmentally-friendly technology. However, existing SMAs exhibit either unsatisfactory cyclic stability or insufficient adiabatic temperature drop (ΔT), constraining the development of this technology. Here, we develop a nano-precipitated bulk TiNiCuCo SMA which retains a stable and large ΔT of 17 K over 1 × 108 phase-transition cycles. The large ΔT originates from the large entropy change of B2-B19′ phase transition in the Cu-lean B2 matrix. The ultra-high cyclic stability is realized by inhibiting dislocation motion via precipitation hardening of uniformly distributed Ti(Ni,Cu)2 nanoprecipitates. Our nano-precipitated bulk TiNiCuCo demonstrates high competitiveness among existing SMAs, serving as a cornerstone for the development of high-performance elastocaloric cooling devices. {\textcopyright} 2025 Elsevier B.V.",

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author = "Hongyang Lin and Peng Hua and Yang Li and Qiao Li and Kaiping Yu and Jie Yan and Yusuke Onuki and Qiuhong Wang and Changfeng Su and Guoan Zhou and Shigeo Sato and Kai Huang and Junhua Luan and Yi-Kuen Lee and Mingxin Huang and Yong Yang and Yang Ren and Qingping Sun",

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doi = "10.1016/j.msea.2025.149449",

language = "English",

volume = "949",

journal = "Materials Science and Engineering: A",

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TY - JOUR

T1 - Ultra-stable and large elastocaloric effect in a nano-precipitated bulk TiNiCuCo shape memory alloy

AU - Lin, Hongyang

AU - Hua, Peng

AU - Li, Yang

AU - Li, Qiao

AU - Yu, Kaiping

AU - Yan, Jie

AU - Onuki, Yusuke

AU - Wang, Qiuhong

AU - Su, Changfeng

AU - Zhou, Guoan

AU - Sato, Shigeo

AU - Huang, Kai

AU - Luan, Junhua

AU - Lee, Yi-Kuen

AU - Huang, Mingxin

AU - Yang, Yong

AU - Ren, Yang

AU - Sun, Qingping

PY - 2026/1

Y1 - 2026/1

N2 - Elastocaloric cooling utilizes the latent heat of shape memory alloys (SMAs) during cyclic phase transition and has emerged as an environmentally-friendly technology. However, existing SMAs exhibit either unsatisfactory cyclic stability or insufficient adiabatic temperature drop (ΔT), constraining the development of this technology. Here, we develop a nano-precipitated bulk TiNiCuCo SMA which retains a stable and large ΔT of 17 K over 1 × 108 phase-transition cycles. The large ΔT originates from the large entropy change of B2-B19′ phase transition in the Cu-lean B2 matrix. The ultra-high cyclic stability is realized by inhibiting dislocation motion via precipitation hardening of uniformly distributed Ti(Ni,Cu)2 nanoprecipitates. Our nano-precipitated bulk TiNiCuCo demonstrates high competitiveness among existing SMAs, serving as a cornerstone for the development of high-performance elastocaloric cooling devices. © 2025 Elsevier B.V.

AB - Elastocaloric cooling utilizes the latent heat of shape memory alloys (SMAs) during cyclic phase transition and has emerged as an environmentally-friendly technology. However, existing SMAs exhibit either unsatisfactory cyclic stability or insufficient adiabatic temperature drop (ΔT), constraining the development of this technology. Here, we develop a nano-precipitated bulk TiNiCuCo SMA which retains a stable and large ΔT of 17 K over 1 × 108 phase-transition cycles. The large ΔT originates from the large entropy change of B2-B19′ phase transition in the Cu-lean B2 matrix. The ultra-high cyclic stability is realized by inhibiting dislocation motion via precipitation hardening of uniformly distributed Ti(Ni,Cu)2 nanoprecipitates. Our nano-precipitated bulk TiNiCuCo demonstrates high competitiveness among existing SMAs, serving as a cornerstone for the development of high-performance elastocaloric cooling devices. © 2025 Elsevier B.V.

KW - Cyclic response

KW - Elastocaloric effect

KW - Martensitic transformation

KW - Precipitation hardening

KW - Shape memory alloys (SMAs)

UR - https://www.scopus.com/pages/publications/105021484148

UR - https://www.scopus.com/pages/publications/105021484148#tab=impact

U2 - 10.1016/j.msea.2025.149449

DO - 10.1016/j.msea.2025.149449

M3 - RGC 21 - Publication in refereed journal

SN - 0921-5093

VL - 949

JO - Materials Science and Engineering: A

JF - Materials Science and Engineering: A

M1 - 149449

ER -

Ultra-stable and large elastocaloric effect in a nano-precipitated bulk TiNiCuCo shape memory alloy

Abstract

Funding

Research Keywords

RGC Funding Information

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STG-ExtU-Lead: Decarbonization Solutions for Buildings in Hong Kong: Development, Assessment and Deployment

GRF: Development of Hysteresis Free Super-Elastic High Entropy Alloys: From Fundamental Understanding to Alloy Design

Cite this

Ultra-stable and large elastocaloric effect in a nano-precipitated bulk TiNiCuCo shape memory alloy

Abstract

Funding

Research Keywords

RGC Funding Information

Access Output

Other Access Options

Permanent Link

Other Files and Links

Fingerprint

Projects

STG-ExtU-Lead: Decarbonization Solutions for Buildings in Hong Kong: Development, Assessment and Deployment

GRF: Development of Hysteresis Free Super-Elastic High Entropy Alloys: From Fundamental Understanding to Alloy Design

Cite this