LOW-TEMPERATURE INTERNAL-FRICTION PEAKS ASSOCIATED WITH THE INTERACTION BETWEEN DISLOCATIONS AND POINT-DEFECTS IN DILUTE ALUMINUM-MAGNESIUM SOLID-SOLUTIONS

Low-temperature internal friction peaks in cold-worked and quenched AlMg solid solutions were systematically studied. Two internal friction peaks were observed around -70°C (PL2 peak) and -50°C (PL1 peak) when measured with a frequency of about 1 Hz. Effect of magnesium content, amount and mode of cold-working, annealing and aging, and quenching on the appearance and behavior of these two peaks were examined. Conclusions were reached that PL1 peak is associated with the interaction of dislocations with "Mg atom-single vacancy" pairs and PL2 peak is associated with the interaction of dislocations with "Mg atom-divacancy" pairs. © 1990.