XXXVIII. Twin formation, in cadmium

Summary Experiments on the formation of twins in single crystal wires of cadmium under tension demonstrate the essentially discontinuous nature of the process of twin growth, and produce evidence in favour of a critical resolved shear stress law for twinning. Twinning can contribute to creep at room temperature but not at 90° a. A dislocation mechanism for the growth of a twin is discussed in some detail.