MD simulations of near surface void in copper under thermal compression

Abstract

ABSTRACTDislocation mediated mechanism of surface deformation due to localized stress and strain concentration near a void could give an explanation of field enhancement in conditions relevant to the design of rf accelerating structures of the Compact Linear Collider (CLIC). We have performed molecular dynamics simulations of a near surface void in copper under thermal stressing conditions. The von Mises strain was observed to be concentrated near the void surface with the maximum strain concentration factor of 1.9. To observe the activated slip-planes, we exaggerated the compressive stress to the extent that the dislocations were nucleated on the void surface at sites where von Mises strain was largest. Void depth and size were found to affect the dislocation nucleation. The nucleation was easier for larger voids and for voids which were closer to the surface.