Pure aluminum and its dilute alloys are deformed by about 10% at 4.2 K with a tensile testing machine. A recovery of the electrical resistivity due to isochronal and isothermal annealings is measured at temperatures ranging from 30 to 170 K. The main recovery peak observed up to 170 K appears around 85 K with associated activation energies of (0.21 ± 0.02) eV for pure aluminum and (0.24 ± 0.01) eV for AlGe alloy. The suppressive effect of impurities on the recovery is ordered as Ge > Si > Cu > Ag > Mg. An interpretation of stage II recovery is proposed on the basis of these results.

The structure of differential isochronal recovery curves between 60 and 100 K (stage 1 1~) in aluminium cold-drawn by 5 to 16% a t 4.2 K is investigated by the measurement of residual electrical resistivity. The recovery curves consist of two different sub-peaks a t about 75 and about 90 K. The ratio of P,,/Pg, decreases with increasing the amount of extention, where P , , is the height of the first peak and P,, is that of the second one. The ratio decreases by a prior deformation and a low-temperature anneal. An interpretation of these recoveries is made in terms of pipe diffusion of vacancies along dislocations.Die Struktur der isochronen differentiellen Erholungskurven zwischen 60 und 100 K (Erholungsstufe IIA) von um 5 bis 16% bei 4,2 K deformiertem Aluminium wird durch Messung des elektrischen Restwiderstandes untersucht. Die Erholungskurven bestehen aus zwei verschiedenen Submaxima bei etwa 75 und 90 K. Das Verhaltnis P,,/P,o nimmt mit zunehmendem Dehnungsgrad zu, wobei P , , die Hohe des ersten Maximums und P,, die des zweiten ist. Das Verhaltnis nimmt durch eine vorhergehende Deformation und eine Niedertemperaturtemperung ab. Eine Interpretation dieser Erholung wird mit Pipe-Diffusion von Leerstellen entlang von Versetzungen gemacht.

Wire drawn aluminum specimens of about 0.2 mm diameter are deformed by about 16% at 4.2 K. An isochronal annealing experiment of electrical resistivity for 1, 3, or 10 min after the deformation is carried out every 5 K temperatures ranging from 30 to 150 K. The recovery sub‐peaks appear at around 75 and 90 K and are shifted toward the lower temperature with increasing annealing time. The observed differential isochronal recovery curves give support to a model in which excess vacancies induced by the deformation annihilate at the jogs.

A new rate equation for the state IIA (60 to 100 K) recovery in cold‐worked aluminum is developed. The equation is based on the annihilation of vacancies by pipe diffusion along an edge dislocation, taking into account the boundary and the initial conditions of diffusing vacancies. An interpretation of the two recovery sub‐peaks in stage IIA (75 and 90 K) is made by using the above rate equation and the result shows a close agreement between experimental facts and computer simulations.

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.