Frenkel defect recombination in Ni and Ni‒containing concentrated solid‒solution alloys

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

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Author(s)

  • Shijun Zhao
  • Yuri Osetsky
  • Alexander V. Barashev
  • Yanwen Zhang

Related Research Unit(s)

Detail(s)

Original languageEnglish
Pages (from-to)184-194
Journal / PublicationActa Materialia
Volume173
Online published7 May 2019
Publication statusPublished - Jul 2019

Abstract

Recombination of Frenkel defects is an important process that contributes to the performance of materials under irradiation. In this work, the recombination mechanisms of Frenkel defects in face-centered cubic Ni and Ni‒containing solid‒solution alloys are investigated based on interatomic potentials and ab initio calculations. It is found that, in pure Ni, the spontaneous recombination volume for a [100] dumbbell interstitial is 18Ω and 34Ω (Ω is the atomic volume) with the empirical potential and ab initio method respectively. Addition of Fe atoms increases the spontaneous recombination volume of Frenkel defects significantly. For those stable Frenkel defects that cannot recombine, a stronger attractive force between the interstitial and the vacancy is found in concentrated Ni‒Fe alloys compared to in pure Ni, which provides the driving force for enhanced recombination. The distribution of life-time for Frenkel defects at finite temperature suggests that recombination in Ni‒Fe alloys is delayed due to the sluggish diffusion of interstitials. Finally, recombination in Ni‒Fe‒Cr alloys is studied by substituting a portion of Fe in Ni‒Fe with Cr. A remarkable increase in recombination probability is observed in this case because of the presence of less stable Cr‒containing than Fe‒containing dumbbell interstitials and lower migration barriers of vacancies. This work reveals that higher defect recombination probability in concentrated alloys is responsible for the experimentally observed enhanced irradiation resistance.

Research Area(s)

  • Atomistic simulations, Concentrated solid-solution alloys, Frenkel defect recombination, Irradiation effects, Metallic alloys

Citation Format(s)

Frenkel defect recombination in Ni and Ni‒containing concentrated solid‒solution alloys. / Zhao, Shijun; Osetsky, Yuri; Barashev, Alexander V.; Zhang, Yanwen.

In: Acta Materialia, Vol. 173, 07.2019, p. 184-194.

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