A high-entropy alloy with hierarchical nanoprecipitates and ultrahigh strength

Zhiqiang Fu; Lin Jiang; Jenna L Wardini; Benjamin E MacDonald; Haiming Wen; Wei Xiong; Dalong Zhang; Yizhang Zhou; Timothy J Rupert; Weiping Chen; Enrique J Lavernia

doi:10.1126/sciadv.aat8712

A high-entropy alloy with hierarchical nanoprecipitates and ultrahigh strength

Sci Adv. 2018 Oct 12;4(10):eaat8712. doi: 10.1126/sciadv.aat8712. eCollection 2018 Oct.

Authors

Zhiqiang Fu^{1

2}, Lin Jiang^{2

3}, Jenna L Wardini², Benjamin E MacDonald², Haiming Wen⁴, Wei Xiong⁵, Dalong Zhang², Yizhang Zhou², Timothy J Rupert², Weiping Chen¹, Enrique J Lavernia²

Affiliations

¹ Guangdong Key Laboratory for Advanced Metallic Materials Processing, South China University of Technology, Guangzhou, Guangdong 510640, China.
² Department of Materials Science and Engineering, University of California, Irvine, CA 92697, USA.
³ Materials and Structural Analysis, Thermo Fisher Scientific, Hillsboro, OR 97124, USA.
⁴ Department of Materials Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409, USA.
⁵ Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, PA 15261, USA.

Abstract

High-entropy alloys (HEAs) are a class of metallic materials that have revolutionized alloy design. They are known for their high compressive strengths, often greater than 1 GPa; however, the tensile strengths of most reported HEAs are limited. Here, we report a strategy for the design and fabrication of HEAs that can achieve ultrahigh tensile strengths. The proposed strategy involves the introduction of a high density of hierarchical intragranular nanoprecipitates. To establish the validity of this strategy, we designed and fabricated a bulk Fe₂₅Co₂₅Ni₂₅Al₁₀Ti₁₅ HEA to consist of a principal face-centered cubic (fcc) phase containing hierarchical intragranular nanoprecipitates. Our results show that precipitation strengthening, as one of the main strengthening mechanisms, contributes to a tensile yield strength (σ_0.2) of ~1.86 GPa and an ultimate tensile strength of ~2.52 GPa at room temperature, which heretofore represents the highest strength reported for an HEA with an appreciable failure strain of ~5.2%.

Publication types

Research Support, Non-U.S. Gov't