Formation and Recovery of Defects in Quenched β-Brass

Foils of β-brass were quenched from 800°C in brine at -5°C and examined by transmission electron microscopy. The fine structures of defects, distributed in a network pattern, are shown to be composed of small irregularly-shaped dislocation loops. The Burgers vectors of these dislocation loops are found to be both a/2<111> and a<110>. These fine structures coarsen during annealing at various temperatures from 100° to 200°C, while their density decreases. This fact is discussed considering both bulk and pipe diffusion mechanisms, and it is shown that the recovery of these fine structures is controlled by pipe diffusion at low temperatures, but by bulk diffusion at high temperatures.