Abstract

We characterize how size and shape affects the hardness of nanoscale metallic contacts using large-scale molecular dynamics (MD) simulations. High-aspect-ratio contacts continue the experimentally observed trend of hardening with decreasing contact size down to the sub-10-nm regime. However, we find that this effect is shape dependent and the rate of hardening with decreasing contact size diminishes as the aspect ratio of the asperities becomes smaller. Interestingly, low-aspect-ratio asperities that can support simple dislocation glide exhibit softening with decreasing size. A detailed analysis of the MD trajectories reveals the dislocation mechanisms that govern these complex size effects.

Comments

This is the published version of Hojin Kim and Alejandro Strachan. (6 August 2012). "Size-dependent hardness of nanoscale metallic contacts from molecular dynamics simulations". First published in the Physical Review B Vol. 86, Iss. 6 — 1 August 2012 and is available online at: http://dx.doi.org/10.1103/PhysRevB.86.064101

Keywords

PLASTICITY; DEFORMATION; INDENTATION; COPPER

DOI

10.1103/PhysRevB.86.064101

Citation

rom molecular dynamics simulations Hojin Kim and Alejandro Strachan Phys. Rev. B 86, 064101 – Published 6 August 2012

Date of this Version

8-6-2012

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