Full Content is available to subscribers

Subscribe/Learn More  >

Dislocation Nucleation at Heterogeneities of Crystal Surfaces

[+] Author Affiliations
Chengzhi Li, Guanshui Xu

University of California at Riverside

Paper No. IMECE2004-60857, pp. 413-419; 7 pages
  • ASME 2004 International Mechanical Engineering Congress and Exposition
  • Applied Mechanics
  • Anaheim, California, USA, November 13 – 19, 2004
  • Conference Sponsors: Applied Mechanics Division
  • ISBN: 0-7918-4702-0 | eISBN: 0-7918-4178-2, 0-7918-4179-0, 0-7918-4180-4
  • Copyright © 2004 by ASME


Dislocation nucleation at surface heterogeneities such as steps is analyzed based on the Peierls-Nabarro dislocation model. By modeling a surface step as part of a three-dimensional crack surface, the half space problem is transferred into an equivalent three dimensional crack problem in an infinite medium. The profiles of embryonic dislocations, corresponding to the relative displacements between the two adjacent atomic layers along the slip planes, are then rigorously solved through the variational boundary integral method. The critical conditions for dislocation nucleation are determined by solving the stress dependent activation energies required to activate embryonic dislocations from their stable to unstable saddle point configurations. The effects of step geometry are analyzed in detail. The results show that the atomic scale steps can significantly facilitates dislocation nucleation from stressed crystal surfaces. While the presented methodology of incorporating atomic information into continuum approach is noteworthy for providing insights of energetics of the atomic process involved in dislocation nucleation, further direct atomic simulation appears to be in need to correlate the effectiveness of this approach.

Copyright © 2004 by ASME



Interactive Graphics


Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In