EXPERIMENTAL-EVIDENCE OF KINK RELAXATION AND KINK RESONANCE IN DISLOCATIONS OF FCC METALS

Many papers have been devoted to the motion of dislocation lines in cr ystals. The string model and the kink model presented the most relevan t theoretical approach. However, each model independently can not desc ribe all experimental data. In this paper is presented experimental da ta of logarithmic decrement associated to dislocation lines, measured in Hz and MHz ranges, on high purity copper single crystals plasticall y deformed by compression and torsion at room temperature. The experim ental data obtained for the Bordoni Peak, analyzed on the basis of the kink model, shows the predicted temperature dependence of the effecti ve enthalpy, a evidence of the kink diffusion mechanism. The data can be well fitted over all temperature range investigated, assuming the c ontribution of kink relaxation and kink resonance aging simultaneously . From the last mechanism a temperature dependent kink density is assu med. This procedure allows to explain the width and the asymmetry of t he Bordoni peak.