Self-interstitial solute complexes in e--irradiated dilute Al-Ag and Al-Si alloys.

Abstract

Ultrasonic attenuation and velocity measurements were performed to probe the structure and annealing behavior of self-interstitial solute complexes in electron-irradiated (T70 K) dilute Al-Ag and Al-Si alloys. In both alloy systems, a similar attenuation peak structure is observed. Three peaks are observed to anneal in unison during stage II, suggesting that they arise from the presence of a single defect structure. The annealing of this defect structure follows a first-order rate equation which has a prefactor proportional to the solute concentration. The diaelastic effect associated with this defect is found to be comparable in magnitude and anisotropy to that attributed to 〈100〉 self-interstitial dumbbells in pure aluminum. A 〈110〉 monoclinic mixed dumbbell model which can account for much of the observed behavior of this defect structure is proposed.