A Type of Plastic Deformation New in Metals

SINGLE -CRYSTAL wires of zinc or cadmium' extremely soft in general, are as hard as polycrystalline wires if the glide plane (0001) is nearly parallel to the wire axis, so that the usual glide mechanism cannot work in extension or bending. In an attempt to operate the glide mechanism in cadmium crystals of such orientation, the crystals were axially compressed. As the load increased, they suddenly collapsed by forming peculiar kinks with sharp ridges and regular curvatures ; the two main types of kinks are shown in Fig. 1. The regular curvatures, the non-crystallographic orientation of the planes determined by the ridges, and certain other features show that the phenomenon cannot represent ordinary glide or twinning.