This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Lee, C.-L. Articles by Shaofan Li Search for Related Content Social Bookmarking                         What's this?

The Size Effect of Thin Films on the Peierls Stress of Edge Dislocations

Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720, USA

Shaofan Li

Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720, USA

In this paper, we have developed a half-space Peierls—Nabarro (HSPN) model to evaluate dislocation mobility on material surface. The free-surface induced size effect on the mobility of an edge dislocation in thin films is investigated by using the model. The thickness of the thin layer between the dislocation and the free surface significantly influences the mobility of the dislocation. The Peierls stress of the edge dislocation in a thin film may be expressed as a function of the thickness of the thin film. A closed-form solution is obtained for the scaling factor, defined as the ratio of the modified Peierls stress to the conventional one in bulk materials, which allows for the characterization of the size (depth) effect on the Peierls stress of the edge dislocation in the half-space. Depending on the core size of the dislocation, the Peierls stress of a surface edge dislocation is about 5% to 25% less than that found in bulk materials.

Key Words: Dislocations • lattice friction • Peierls—Nabarro model • scaling law • size effects

Mathematics and Mechanics of Solids, Vol. 13, No. 3-4, 316-335 (2008)
DOI: 10.1177/1081286507086904


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?