Hydrogen embrittlement resistance of precipitation-hardened FeCoNiCr high entropy alloys

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

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Author(s)

  • Fan Zhang
  • Bairu Lu
  • Xiongjun Liu
  • Hui Wang
  • Suihe Jiang
  • Yuan Wu
  • Zhaoping Lu

Related Research Unit(s)

Detail(s)

Original languageEnglish
Article number107800
Journal / PublicationIntermetallics
Volume153
Online published13 Dec 2022
Publication statusPublished - Feb 2023

Abstract

Precipitation-hardened high-entropy alloys (HEAs) with coherent nanoprecipitates are considered promising candidates for structural application as they have shown a unique combination of high strength and good ductility. Nevertheless, the hydrogen embrittlement resistance of this kind of alloy remains unclear, which prevents the precipitation-hardened HEAs from practical uses in the environment with existence of hydrogen. In this work, we systematically investigated the influences of hydrogen on the mechanical properties and deformation behavior of a series of Fe–Co–Ni–Cr precipitation-hardened HEAs. Our results demonstrated that the hydrogen penetrating into precipitation-hardened HEAs can enhance localized plastic deformation and cause stress concentration near the fracture, but the response of mechanical properties is closely related to the number of nanoprecipitates. In the precipitation-hardened HEAs with a proper amount of nanoprecipitates, the localized plastic deformation promoted the formation of deformation twinning which relieved stress concentration and enhanced the strength and ductility concurrently. In those with excessive nanoprecipitates, however, the fracture process was accelerated and hydrogen embrittlement occurred with decreased ductility due to the increased critical twinning stress resulted from the small interspaces between precipitates. Our findings are helpful not only for understanding the hydrogen embrittlement mechanism in complex alloys, but also for the future design of high-performance HEAs with good hydrogen embrittlement resistance.

Research Area(s)

  • Deformation mechanism, High-entropy alloys, Hydrogen embrittlement, Precipitate hardening

Citation Format(s)

Hydrogen embrittlement resistance of precipitation-hardened FeCoNiCr high entropy alloys. / Zhang, Fan; Lu, Bairu; Liu, Xiongjun et al.
In: Intermetallics, Vol. 153, 107800, 02.2023.

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review