Glide in metal single crystals

Abstract

A method is described for producing single crystals of cadmium and of lead which are not affected by annealing, and, in general, show great regularity of mechanical behaviour. A simple recording extensometer also is described. With the cadmium crystals very consistent results have been obtained, and the effects of rate of glide and of impurities on the measured critical shear stress have been investigated. Experiments have been carried out on hardening and recovery of the cadmium crystals, and on the spacing of glide planes in lead crystals, which has been shown to be independent of a range of factors, and so to have a physical significance. It is shown that the results relating to hardening can be explained by a hardening on individual glide lamellae which is proportional to the glide, and it is suggested that the mechanism of the permanent hardening is mainly a rotation of crystallites in the lamellae.