On the surface stress and plastic deformation of ion-bombarded conical microcrystals

Abstract

The stress associated with the surface tension acting on conical microcrystals has been determined. When values of the cone angle and surface tension appropriate to argon-bombarded copper are used it is found that the stress resolved along the {111} planes can reach a value greater than the critical shear stress for distances of the order of 1 μm or less from the cone vertex. It is predicted that deformation by slip is probable if the orientation of the microcrystal is such that there is an anisotropy in the resolved shear stress, and the maximum resolved stress is aligned with the slip direction. The theoretical predictions of the nature and degree of deformation agree well with experimental observations.