Dislocation damping in zinc single crystals

Impact shear tests of the Kolsky thin-wafer type were used to determine the effects of temperature and strain rate on the critical resolved shear stress for basal slip in zinc single crystals. At high strain rates the flow stress was found to increase linearly with the plastic strain rate and was independent of temperature. The observed behaviour could be rationalized in terms of Mason's dislocation damping model where the friction force acting on a dislocation results from phonon viscosity.