Average yielding and weakest link statistics in micron-scale plasticity

Péter Dusán Ispánovity, Ádám Hegyi, I. Groma, G. Györgyi, Kitti Ratter, Daniel Weygand

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

Micron-scale single-crystalline materials deform plastically via large intermittent strain bursts that make the deformation process non-deterministic. Here we investigate this stochastic phenomenon by analyzing the plastic response of an ensemble of specimens differing only in the initial arrangement of dislocations. We apply discrete dislocation dynamics simulations and microcompression tests on identically fabricated Cu single-crystalline micropillars. We find that a characteristic yield stress can be defined in the average sense for a given specimen ensemble, where the average and the variance of the plastic strain start to increase considerably. In addition, in all studied cases the stress values at a given strain follow a Weibull distribution with similar Weibull exponents, which suggests that dislocation-mediated plastic yielding is characterized by an underlying weakest-link phenomenon. These results are found not to depend on fine details of the actual set-up; rather, they represent general features of micron-scale plasticity.

Original languageEnglish
Pages (from-to)6234-6245
Number of pages12
JournalActa Materialia
Volume61
Issue number16
DOIs
Publication statusPublished - Sep 2013

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Plasticity
Statistics
Plastics
Crystalline materials
Weibull distribution
Yield stress
Plastic deformation
Computer simulation

Keywords

  • Dislocation dynamics
  • Flow stress
  • Microcompression
  • Plastic deformation
  • Single crystal

ASJC Scopus subject areas

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

Cite this

Average yielding and weakest link statistics in micron-scale plasticity. / Ispánovity, Péter Dusán; Hegyi, Ádám; Groma, I.; Györgyi, G.; Ratter, Kitti; Weygand, Daniel.

In: Acta Materialia, Vol. 61, No. 16, 09.2013, p. 6234-6245.

Research output: Contribution to journalArticle

Ispánovity, Péter Dusán ; Hegyi, Ádám ; Groma, I. ; Györgyi, G. ; Ratter, Kitti ; Weygand, Daniel. / Average yielding and weakest link statistics in micron-scale plasticity. In: Acta Materialia. 2013 ; Vol. 61, No. 16. pp. 6234-6245.
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