Excellent combination of compressive strength and ductility of (CoCrFeNi)x(Co0.26Cr0.07Fe0.16Ni0.31Hf0.4) high-entropy alloys

Tongbin Xie; Zhiping Xiong; Zhe Liu; Guanyu Deng; Xingwang Cheng

Materials & Design (Apr 2021)

Excellent combination of compressive strength and ductility of (CoCrFeNi)x(Co0.26Cr0.07Fe0.16Ni0.31Hf0.4) high-entropy alloys

Tongbin Xie,
Zhiping Xiong,
Zhe Liu,
Guanyu Deng,
Xingwang Cheng

Affiliations

Tongbin Xie: School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China; National Key Laboratory of Science and Technology on Materials under Shock and Impact, Beijing 100081, China
Zhiping Xiong: School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China; National Key Laboratory of Science and Technology on Materials under Shock and Impact, Beijing 100081, China; Corresponding author at: School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China.
Zhe Liu: School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China; National Key Laboratory of Science and Technology on Materials under Shock and Impact, Beijing 100081, China
Guanyu Deng: School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong, North Wollongong, NSW 2522, Australia
Xingwang Cheng: School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China; National Key Laboratory of Science and Technology on Materials under Shock and Impact, Beijing 100081, China

Journal volume & issue: Vol. 202
p. 109569

Abstract

Read online

Instead of conventional CoCrFeNiHfx high-entropy alloys (HEAs), we investigated the evolution of microstructure and compressive mechanical properties of (CoCrFeNi)x(Co0.26Cr0.07Fe0.16Ni0.31Hf0.4) HEAs with varying x. Increasing x from 0.5 to 1.0, the microstructure changes from hyper-eutectic ones consisting of primary Laves phase and eutectic structure (x 0.8). Interestingly, two different morphologies of eutectic microstructures are observed when x = 0.7 and 0.8 probably due to different fusion entropies of each phase. Increasing x from 0.5 to 1.0 reduces the yield strength from 1661 ± 64 to 688 ± 17 MPa but enhances the compressive ductility due to an increased fraction of soft FCC phase from ~0.39 to ~0.74. The second phase strengthening is the main strengthening mechanism. Importantly, when x = 0.9 and 1.0, these two alloys are not fractured when the strain reaches 0.5, one of which shows a large yield strength of 1028 ± 45 MPa (x = 0.9). Compared with conventional CoCrFeNiHfx, the studied HEAs exhibit a much better combination of compressive strength and ductility.

Published in Materials & Design

ISSN: 0264-1275 (Print); 1873-4197 (Online)
Publisher: Elsevier
Country of publisher: United Kingdom
LCC subjects: Technology: Electrical engineering. Electronics. Nuclear engineering: Materials of engineering and construction. Mechanics of materials
Website: https://www.journals.elsevier.com/materials-and-design

About the journal

Abstract

Keywords