Lubrication agents of dislocation motion at very low temperature in cold-worked and irradiated aluminium

Low frequency IF and modulus measurements are presented to get a better understanding of a lubrication process introduced to explain the very high mobility of dislocation in the low temperature range of FCC metals. Two distinct experimental conditions are used. First irradiation with fast electrons at very low temperature. The salient result is the decrease of the modulus during irradiation. Second, just after low temperature plastic deformation an important decrease of the low temperature modulus is also observed. This softening is associated with the disappearance of the Bordoni relaxation. The annealing process shows that only vacancies are responsible of the lubrication process. (orig.)