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 Fe25Co25Ni25Al10Ti115 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 (σ0.2) 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%.

Department(s)

Materials Science and Engineering

Keywords and Phrases

Aluminum alloys; Cobalt alloys; Compressive strength; Entropy; High strength alloys; Iron alloys; Precipitation (chemical); Titanium alloys, Face centered cubic phase; High entropy alloys; Metallic material; Precipitation strengthening; Strengthening mechanisms; Tensile yield strength; Ultimate tensile strength; Ultrahigh strength, Tensile strength

International Standard Serial Number (ISSN)

2375-2548

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2018 The Authors, Some rights reserved.

Creative Commons Licensing

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

PubMed ID

30333993

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