Stacking Fault Driven Phase Transformation in CrCoNi Medium Entropy Alloy

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

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Author(s)

Detail(s)

Original languageEnglish
Pages (from-to)1419–1426
Journal / PublicationNano Letters
Volume21
Issue number3
Online published19 Jan 2021
Publication statusPublished - 10 Feb 2021

Abstract

Phase transformation is an effective means to increase the ductility of a material. However, even for a commonly observed face-centered-cubic to hexagonal-close-packed (fcc-to-hcp) phase transformation, the underlying mechanisms are far from being settled. In fact, different transformation pathways have been proposed, especially with regard to nucleation of the hcp phase at the nanoscale. In CrCoNi, a so-called medium-entropy alloy, an fcc-to-hcp phase transformation has long been anticipated. Here, we report an in situ loading study with neutron diffraction, which revealed a bulk fcc-to-hcp phase transformation in CrCoNi at 15 K under tensile loading. By correlating deformation characteristics of the fcc phase with the development of the hcp phase, it is shown that the nucleation of the hcp phase was triggered by intrinsic stacking faults. The confirmation of a bulk phase transformation adds to the myriads of deformation mechanisms available in CrCoNi, which together underpin the unusually large ductility at low temperatures.

Research Area(s)

  • deformation-induced phase transformation, in situ neutron diffraction measurement, medium entropy alloy, ultralow temperature deformation

Citation Format(s)

Stacking Fault Driven Phase Transformation in CrCoNi Medium Entropy Alloy. / He, Haiyan; Naeem, Muhammad; Zhang, Fan; Zhao, Yilu; Harjo, Stefanus; Kawasaki, Takuro; Wang, Bing; Wu, Xuelian; Lan, Si; Wu, Zhenduo; Yin, Wen; Wu, Yuan; Lu, Zhaoping; Kai, Ji-Jung; Liu, Chain-Tsuan; Wang, Xun-Li.

In: Nano Letters, Vol. 21, No. 3, 10.02.2021, p. 1419–1426.

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