Mechanism of microplastic deformation under reversed loading in the kilohertz range of frequencies

Abstract

To obtain information on the nature of the processes occurring in material under the effect of reversed loading, we investigated properties such as the modulus of elasticity and the vibration decrement. The relation between the amplitude-dependent part of the vibration decrement δ_h and the corresponding change of the modulus of elasticity ΔE/E was used for the analysis of the nature of the barriers hindering the motion of dislocations at small amplitudes of the vibrations. To obtain quantitative data, we had recourse to the corresponding theoretical models of describing microdeformations in the range of small amplitudes. The measurements were carried out with the aid of the method of resonance flexural vibrations in the kilohertz range of frequencies. The relative change of the modulus of elasticity ΔE/E in consequence of increased strain amplitude was found from the change of the resonance frequency of the vibrations of the specimen. We dealt with the mechanisms of formation of a defective structure in alloys with different composition.