The growth of prismatic dislocation loops during annealing

Abstract

Recent observations of the growth of quenched-in dislocation loops during annealing are discussed. A mechanism for the coalescence of loops is proposed. The mechanism depends on short-circuit diffusion around the periphery of prismatic dislocation loops. This mechanism is contrasted with the theory of loop coalescence by vacancy diffusion through the matrix. It is shown that the experimental observations are in better accord with the short-circuit diffusion theory. Interpretation of the experimental observations on the basis of the short-circuit mechanism leads to a value for the activation energy for diffusion along a dislocation line. For aluminium this value is calculated to be 0·7 ev.