Yielding and Irreversible Deformation below the Microscale: Surface Effects and Non-Mean-Field Plastic Avalanches
Abstract
Nanoindentation techniques recently developed to measure the mechanical response of crystals under external loading conditions reveal new phenomena upon decreasing sample size below the microscale. At small length scales, material resistance to irreversible deformation depends on sample morphology. Here we study the mechanisms of yield and plastic flow in inherently small crystals under uniaxial compression. Discrete structural rearrangements emerge as series of abrupt discontinuities in stress-strain curves. We obtain the theoretical dependence of the yield stress on system size and geometry and elucidate the statistical properties of plastic deformation at such scales. Our results show that the absence of dislocation storage leads to crucial effects on the statistics of plastic events, ultimately affecting the universal scaling behavior observed at larger scales.
- Publication:
-
PLoS ONE
- Pub Date:
- June 2011
- DOI:
- 10.1371/journal.pone.0020418
- arXiv:
- arXiv:1102.0019
- Bibcode:
- 2011PLoSO...620418M
- Keywords:
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- Condensed Matter - Materials Science;
- Condensed Matter - Mesoscale and Nanoscale Physics;
- Condensed Matter - Soft Condensed Matter;
- Condensed Matter - Statistical Mechanics
- E-Print:
- Supporting Videos available at http://dx.plos.org/10.1371/journal.pone.0020418