Dislocation nucleation during nanoindentation in a body-centered cubic TiZrHfNb high-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)64-68
Journal / PublicationScripta Materialia
Volume130
Online published20 Nov 2016
Publication statusPublished - 15 Mar 2017
Externally publishedYes

Abstract

Pop-in behavior of a single-phase, body-centered cubic TiZrHfNb high-entropy alloy was characterized using instrumented nanoindentation. The critical shear stress required for the first pop-in was close to the theoretical strength, indicating it was controlled by dislocation nucleation. Data were collected and analyzed using a model based upon the transition-state theory and Weibull statistics. The activation volume for the pop-in events was evaluated to be about 3–5 atomic volumes, much larger than that in pure metals (~one atomic volume), suggesting cooperative migration of multiple atoms. The activation energy was also estimated and compared favorably with the nucleation of a full-dislocation.

Research Area(s)

  • High-entropy alloy, Nanoindentation, Dislocation nucleation, Activation volume and energy