Does irradiation enhance or inhibit strain bursts at the submicron scale?

Yinan Cui, Giacomo Po, Nasr Ghoniem

Research output: Contribution to journalArticlepeer-review

28 Scopus citations

Abstract

Irradiation-induced defects have been experimentally observed either to inhibit or promote strain bursts and lead to plastic flow localization. Through three dimensional discrete dislocation dynamics simulations, this work unravels the mystery of how and why irradiation-induced defects enhance or inhibit strain bursts in submicron BCC iron and FCC Cu single crystals. It is shown that smaller strain burst amplitudes in irradiated nano- and micro-pillars are obtained under stress control conditions. However, under strain control conditions, bursts are found not to be sensitive to irradiation, despite the arresting effect of radiation defects. This feature is a result of rapid stress relaxation truncating the strain burst, compared with the influence of irradiation-induced defects. In heavily irradiated materials, dislocation avalanches and strain bursts are shown to be promoted. The influence of dislocation-defect interaction mechanisms, cross slip, irradiation dose, as well as loading mode on strain bursts is systematically investigated, and the results compared with experimental observations.

Original languageEnglish (US)
Pages (from-to)285-297
Number of pages13
JournalActa Materialia
Volume132
DOIs
StatePublished - Jun 15 2017
Externally publishedYes

Keywords

  • Dislocations
  • Irradiation effects
  • Micropillars
  • Strain bursts
  • Submicron plasticity

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Polymers and Plastics
  • Metals and Alloys

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