Exceptional damage-tolerance of a medium-entropy alloy CrCoNi at cryogenic temperatures

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalNot applicablepeer-review

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Author(s)

  • Bernd Gludovatz
  • Anton Hohenwarter
  • Keli V.S. Thurston
  • Hongbin Bei
  • Zhenggang Wu
  • Easo P. George

Detail(s)

Original languageEnglish
Article number10602
Journal / PublicationNature Communications
Volume7
Early online date2 Feb 2016
Publication statusPublished - 2016
Externally publishedYes

Abstract

High-entropy alloys are an intriguing new class of metallic materials that derive their properties from being multi-element systems that can crystallize as a single phase, despite containing high concentrations of five or more elements with different crystal structures. Here we examine an equiatomic medium-entropy alloy containing only three elements, CrCoNi, as a single-phase face-centred cubic solid solution, which displays strength-toughness properties that exceed those of all high-entropy alloys and most multi-phase alloys. At room temperature, the alloy shows tensile strengths of almost 1 GPa, failure strains of ∼70% and KJIc fracture-toughness values above 200 MPa m1/2; at cryogenic temperatures strength, ductility and toughness of the CrCoNi alloy improve to strength levels above 1.3 GPa, failure strains up to 90% and KJIc values of 275 MPa m1/2. Such properties appear to result from continuous steady strain hardening, which acts to suppress plastic instability, resulting from pronounced dislocation activity and deformation-induced nano-twinning.

Citation Format(s)

Exceptional damage-tolerance of a medium-entropy alloy CrCoNi at cryogenic temperatures. / Gludovatz, Bernd; Hohenwarter, Anton; Thurston, Keli V.S.; Bei, Hongbin; Wu, Zhenggang; George, Easo P.; Ritchie, Robert O.

In: Nature Communications, Vol. 7, 10602, 2016.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalNot applicablepeer-review