The annealing of vacancies and vacancy aggregates in quenched gold, silver and copper

Abstract

It is shown, using electrical resistance measurements and transmission electron microscopy, that the annealing behaviour of copper quenched from high temperature is similar to that of silver, provided that care is taken in both cases to avoid contamination by oxygen. To achieve this, copper was quenched from an atmosphere of carbon monoxide. The results obtained under these conditions suggest that the divacancy is the principal defect retained in copper after quenching from high temperatures. The temperatures at which stacking-fault tetrahedra anneal out in silver and gold were studied by transmission microscopy. In silver, tetrahedra are stable up to at least 930°c. The stability of tetrahedra in gold depends on their size, being greater the larger the tetrahedra. Finally it has been shown that dislocation loops, not tetrahedra, predominate as the clustered vacancy defect in gold if, after quenching from high temperature to 0°c, the gold is rapidly upquenched to 100°c.