THE EFFECT OF DILUTE COPPER AND GERMANIUM ATOMS FOR STAGE IIA RECOVERY IN COLD-WORKED ALUMINUM

Wires of pure aluminum and Al-Ge, Al-Cu dilute alloys are deformed about 10% in length at 4.2 K. The electrical resistivity after isochronal annealing in the temperature range from 20 to 160 K is measured at 4.2 K. A recovery consisting of two sub-peaks at around 75 and 90 K is observed in stage IIa (60 to 100 K). The 90 K recovery peak is suppressed effectively by Ge atoms, while Cu atoms suppress both 75 and 90 K peaks uniformly. The suppression effects increase with increasing impurity concentration in the alloys and are discussed from the point of view of the solubility of Ge and Cu atoms.