Analytical model of dislocation nucleation on a near-surface void under tensile surface stress

Abstract

We have analyzed in detail the mechanism leading to tip growth on a surface which operates via nucleation of dislocations on a near-surface void under tensile surface stress. We derived a simplified analytical model describing the relevant physical factors related to the observed linearity between the void radius and the maximum depth of the void for the growth to occur. The model is based on the direct numerical calculation of atomic level stresses in the simulated system. Based on the present model we can estimate this maximum depth for a void of a certain size under a given stress in the size range which is beyond the feasibility of the molecular dynamics simulation method.

Keywords:

• void
• surface protrusion
• dislocations
• metal
• surface
• electrical breakdown
• copper

Acknowledgments

The authors acknowledge the assistance of the Finnish IT Center for Science CSC. The research leading to these results has received funding from the European Commission under the FP7 Research Infrastructures project EuCARD, grant agreement no. 227579, the Academy of Finland MECBETH project and the Finnish Centre of Excellence in Computational Molecular Science (CMS), financed by The Academy of Finland and the University of Helsinki. This work was partly funded by the European Communities under the Contracts of Association between EURATOM and CCFE, and was carried out within the framework of the European Fusion Development Agreement. The views and opinions expressed herein do not necessarily reflect those of the European Commission. Work at CCFE was partially funded by the RCUK Energy Programme under Grant No. EP/I501045.