Recovery study in pure and copper alloyed aluminum after neutron irradiation at liquid-nitrogen temperatures

Abstract

Samples of pure aluminum and aluminum alloyed with copper (0.025-0.5 at. per cent) were irradiated by neutrons at 78°K. Isochronal annealing was carried out in two series of samples with different heating rates (0.5 and 2.5°K/min) from 78 to 280°K. The annealing of stage III occurs by a second-order process with an activation energy E = 0.58±0.05 eV, for both pure and copper dilute aluminum alloys. From the experimental results of this work, the recovery of stage III can be explained in terms of a model where single vacancies migrate. The magnitude of stage II region sensitively depends on the type of solute atoms in the lattice. The Al-Cu alloys shows almost no recovery until stage III.