Breakdown of Self-Similar Hardening Behavior in Au Nanopillar Microplasticity

DOI: 10.1615/IntJMultCompEng.v5.i3-4.100
pages 287-294

Jaime Marian
Chemistry, Materials, and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94551, USA

Jaroslaw Knap
Chemistry, Materials, and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA 94551, USA

Abstrakt

This article is concerned with the study of scale effects in Au nanopillars under compression. We propose that plastic yielding in these nanostructures is characterized by a critical length scale at which a transition from volumetric to surface-dominated plasticity takes place. This transition effectively sets a lower bound on the self-similar behavior commonly assumed in nanostrength models. Using quasi-continuum simulations, we study the subcritical regime and find that plasticity at these scales is governed by dislocation emission at surface irregularities.