A high-entropy alloy with hierarchical nanoprecipitates and ultrahigh strength

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 fabricati...

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Bibliographic Details
Published in:Science advances 2018-10, Vol.4 (10), p.eaat8712-eaat8712
Main Authors: Fu, Zhiqiang, Jiang, Lin, Wardini, Jenna L, MacDonald, Benjamin E, Wen, Haiming, Xiong, Wei, Zhang, Dalong, Zhou, Yizhang, Rupert, Timothy J, Chen, Weiping, Lavernia, Enrique J
Format: Article
Language:English
Subjects:
Engineering
Materials Science
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Summary: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 Fe Co Ni Al Ti 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 ) 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%.
ISSN:2375-2548
2375-2548
DOI:10.1126/sciadv.aat8712