The interaction of point defects with dislocations in high purity copper above room temperature

Damping and modulus measurements were made +- 0.04 on high purity copper following quenching from 7000C. An analysis of the annealing data yielded 0.54 +- 0.4 eV for the value of the migration energy minus the binding energy of a divacancy (Esub(2ν)sup(m) - Bsub(2ν)). Following quenching from 7000C and during isothermal annealing near room temperature, a monotonic decrease in the logarithmic decrement with a concurrent increase in the modulus, is observed. However, this same sample, when subjected to electron irradiation exhibits a pronounced peaking effect in the logarithmic decrement at the onset of irradiation. Depinning studies were carried out following both quenching and electron irradiation - the results were very similar for both types of experiments. (author)