Activation energy of pinning during the recovery of internal friction in pure and doped aluminium

Abstract

The phenomenon of internal friction recovery of as-quenched and aged specimens of pure aluminium and Al-0.35 wt% Fe alloy at different working temperatures was studied using the free decay method. The recovery in pure material was generally found less sensitive to temperature variation. The activation energy for the pinning process was found to have average values of 0.078 and 0.043 eV in the alloy and the pure material, respectively. Accordingly, a binding energy of 0.035 eV for iron-vacancy pairs was estimated. The lower values of activation energy obtained in this work confirm a point of view previously reported, which considered the pinning process to be due to binding between pinners and dislocation segments.