The rates of nucleation and growth of intercrystalline voids in silver, strained plastically at constant rate to near fracture, were determined for various temperatures from 680' to 1150OK. The voids observed grow from pre-existent nuclei so that the number of voids is a constant for given conditions of preannealing and testing. The mean void radius increases linearly with time of strain. On the basis of existing theoretical treatments, such a growth law is ascribed to bulk generation and difision of vaoanties or vacancy pairs (divacancies).
With this model a defect migration energy of 0.35 & 0.1 eV is obtained from the void growth data. Thus, it seems likely that bulk productionanddiffusionofdivacancies is the controlling mechanism in void growth under the above conditions.
CINETIQUE DE LA CROISSANCE DES VIDES DANS L'ARGENT DEFORME
Les auteurs ont determine 8. des tempbratures variant entre 680 et 1150ยฐK les vitesses de germination et croissance des vides intercristallins dans I'argent deform6 plastiquement 8. vitesse con&ante jusqu'au voisinage de la rupture. Les vides observ& se d&eloppent A partir de germes pr&existants de telle man&e que le nombre de vides soit constant pour des conditions d&erminees de recuit et de dbformation. Le rayon moyen des vides s'accroit