Amplitude-dependent internal friction and plasticity of crystals

Abstract

The effects of temperature, prestrain and in situ plastic deformation on the amplitude dependences of the internal friction and Young's modulus defect were studied on a number of alkali halides and metals at a frequency of about 10 5 Hz. In order to study the effect of the frequency the amplitude dependence of internal friction and Young's modulus defect were investigated at 10 −3−10 Hz. The correlation between micro- and macroplasticity is discussed. These results are considered phenomenologically on the basis of the assumption that dislocations overcome long- and short-range obstacles by means of force and thermofluctuation mechanisms.