Quenched pinning and collective dislocation dynamics

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Journal Title
Journal ISSN
Volume Title
School of Science | A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2015
Major/Subject
Mcode
Degree programme
Language
en
Pages
10580/1-8
Series
Scientific Reports, Volume 5
Abstract
Several experiments show that crystalline solids deform in a bursty and intermittent fashion. Power-law distributed strain bursts in compression experiments of micron-sized samples, and acoustic emission energies from larger-scale specimens, are the key signatures of the underlying critical-like collective dislocation dynamics - a phenomenon that has also been seen in discrete dislocation dynamics (DDD) simulations. Here we show, by performing large-scale two-dimensional DDD simulations, that the character of the dislocation avalanche dynamics changes upon addition of sufficiently strong randomly distributed quenched pinning centres, present e.g. in many alloys as immobile solute atoms. For intermediate pinning strength, our results adhere to the scaling picture of depinning transitions, in contrast to pure systems where dislocation jamming dominates the avalanche dynamics. Still stronger disorder quenches the critical behaviour entirely.
Description
Keywords
crystalline solids, deformation process
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Citation
Ovaska, Markus & Laurson, Lasse & Alava, Mikko J. 2015. Quenched pinning and collective dislocation dynamics. Scientific Reports. Volume 5. 10580/1-8. ISSN 2045-2322 (printed). DOI: 10.1038/srep10580.