High-temperature shape memory properties of Cu15Ni35Ti25Hf12.5Zr12.5 high-entropy alloy

Shan-Hsiu Chang; Wei-Pin Kao; Kai-Yuan Hsiao; Jien-Wei Yeh; Ming-Yen Lu; Che-Wei Tsai

Journal of Materials Research and Technology (Sep 2021)

High-temperature shape memory properties of Cu15Ni35Ti25Hf12.5Zr12.5 high-entropy alloy

Shan-Hsiu Chang,
Wei-Pin Kao,
Kai-Yuan Hsiao,
Jien-Wei Yeh,
Ming-Yen Lu,
Che-Wei Tsai

Affiliations

Shan-Hsiu Chang: Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan, ROC
Wei-Pin Kao: Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan, ROC
Kai-Yuan Hsiao: Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan, ROC
Jien-Wei Yeh: Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan, ROC; High Entropy Materials Center, National Tsing Hua University, Hsinchu 30013, Taiwan, ROC
Ming-Yen Lu: Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan, ROC; High Entropy Materials Center, National Tsing Hua University, Hsinchu 30013, Taiwan, ROC
Che-Wei Tsai: Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan, ROC; High Entropy Materials Center, National Tsing Hua University, Hsinchu 30013, Taiwan, ROC; Corresponding author.

Journal volume & issue: Vol. 14
pp. 1235 – 1242

Abstract

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The major challenges hindering the application of high-temperature shape memory alloys are their decreased mechanical strength and thermal stability. Herein, we present high-temperature shape memory properties of the Cu15Ni35Ti25Hf12.5Zr12.5 high-entropy alloy with improved mechanical properties and superior shape memory characteristics. Under an immense stress of 1400 MPa, the alloy exhibited a shape recovery ratio of 88.7%. Using an in-situ high-temperature X-ray diffractometer, the alloy was established to undergo phase transformation from B19′ to B2 phase. Additionally, the alloy exhibited a martensitic transformation temperature higher than 100 °C. The fracture strength and ductility were 1670 MPa and 24.7%, respectively, as measured by compression tests. The deformation mechanism and shape recovery phenomenon of this shape memory alloy are also discussed. This study demonstrates the potential of high-entropy shape memory alloys for high-temperature applications.

Published in Journal of Materials Research and Technology

ISSN: 2238-7854 (Print); 2214-0697 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Technology: Mining engineering. Metallurgy
Website: https://www.journals.elsevier.com/journal-of-materials-research-and-technology/

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