Annealing of Secondary Defects in Quenched Aluminum

抄録

Annealing behaviors of secondary defects in quenched pure aluminum have been studied by electron microscopy. Frank sessile dislocation loops begin to shrink at first among various kinds of secondary defects at about 140°C. Corresponding to low or high shrinking rate, these loops are either hexagonal or roundish. A triangular double layer stacking fault in the double loops grow remarkably during annealing and become hexagonal. Octahedral voids begin to shrink at about 170°C from their edges and corners and become spherical, and disappear by annealing at 220°C for fifteen minutes. The activation energy of this process was estimated to be about 1.3 eV. The type of small loops which can not be determined only from their image are concluded to be Frank sessile. The phenomenon which suggests the existence of short circuit diffusion of vacancies along Frank sessile dislocations has been observed. Some discussions are given on the basis of these experimental results.