Plastic Deformation of Copper and Silver Whiskers

Abstract

By rapidly reducing the stress after yielding, it was possible to study the plastic deformation of copper and silverwhiskers. The whiskers exhibit extremely sharp yield points and extensive easy ``glide'' regions which are due to the propagation of Lüders bands. It is unlikely that the sharp yield points are caused by dislocation pinning. The propagation of the Lüders bands often becomes obstructed giving rise to repeated yielding in the plastic region. The nature of these obstructions and the mechanism of Lüders band propagation are not clear.