Temperature and strain-rate dependence of surface dislocation nucleation

Dislocation nucleation is essential to the plastic deformation of small-volume crystalline solids. The free surface may act as an effective source of dislocations to initiate and sustain plastic flow, in conjunction with bulk sources. Here, we develop an atomistic modeling framework to address the p...

Full description

Saved in:
Bibliographic Details
Published in:Physical review letters 2008-01, Vol.100 (2), p.025502-025502, Article 025502
Main Authors: Zhu, Ting, Li, Ju, Samanta, Amit, Leach, Austin, Gall, Ken
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Dislocation nucleation is essential to the plastic deformation of small-volume crystalline solids. The free surface may act as an effective source of dislocations to initiate and sustain plastic flow, in conjunction with bulk sources. Here, we develop an atomistic modeling framework to address the probabilistic nature of surface dislocation nucleation. We show the activation volume associated with surface dislocation nucleation is characteristically in the range of 1-10b3, where b is the Burgers vector. Such small activation volume leads to sensitive temperature and strain-rate dependence of the nucleation stress, providing an upper bound to the size-strength relation in nanopillar compression experiments.
ISSN:0031-9007
1079-7114
DOI:10.1103/physrevlett.100.025502