Influence of temperature and strain on the amplitude-dependent internal friction of high-purity aluminum

Abstract

The dislocation amplitude-dependent friction (ADIF) of high-purity (99.999%) polycrystalline aluminum is investigated in the temperature range 7–300K at vibrational strain amplitudes of 10−7–10−4 for samples in the annealed and deformed (by quasistatic, shock, and ultrasonic loading) states. The ADIF is a multistage effect in the indicated temperature and vibration amplitude ranges. Analysis of the amplitude-temperature spectra of the ADIF permits separation of components attributable to: interaction between dislocations, the interaction of dislocations with pinning points, and pure dislocation relaxation (the interaction of dislocations with the Peierls relief). ADIF is observed to depend nonmonotonically on the initial quasistatic strain determined by strain hardening and recovery processes.