Submicron plasticity: Yield stress, dislocation avalanches, and velocity distribution

Péter Dusán Ispánovity, István Groma, Géza Györgyi, Ferenc F. Csikor, Daniel Weygand

Research output: Contribution to journalArticle

66 Citations (Scopus)

Abstract

The existence of a well-defined yield stress, where a macroscopic crystal begins to plastically flow, has been a basic observation in materials science. In contrast with macroscopic samples, in microcrystals the strain accumulates in random bursts, which makes controlled plastic formation difficult. Here we study by 2D and 3D simulations the plastic deformation of submicron objects under increasing stress. We show that, while the stress-strain relation of individual samples exhibits jumps, its average and mean deviation still specify a well-defined critical stress. The statistical background of this phenomenon is analyzed through the velocity distribution of dislocations, revealing a universal cubic decay and the appearance of a shoulder due to dislocation avalanches.

Original languageEnglish
Article number085503
JournalPhysical review letters
Volume105
Issue number8
DOIs
Publication statusPublished - Aug 19 2010

    Fingerprint

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this