Dislocation-defect dragging in electron-irradiated copper over the temperature range 4.2--3500K

The effects of electron irradiation on the Bordoni peak and on dislocation drag were investigated by means of internal friction and modulus defect measurements over the temperature range 4.2--350 0K. These measurements were made during dynamic irradiations as a function of time and prior to and following irradiation as a function of temperature. It was found that (1) with a moderate dose irradiation the Bordoni peak height decreased 100-fold and (2) that a well-defined defect-dragging peak evolved during electron irradiation at 4.2 0K. This peak is similar but somewhat subdued in height in comparison to the peak previously observed at room temperature by the authors. The reduction in the Bordoni peak height following irradiation is examined in terms of several existing kink models, as well as in terms of stress-assisted defect drag