The effect of grain boundary cavities on vacancy diffusion

Abstract
The effects of cavities on vacancy diffusion processes have been studied by the annealing of quenched-in dislocation loops and helices. In material containing thermodynamically stable grain boundary cavities, growth of the loops and helices was prevented as the excess vacancies present could be absorbed by the cavities. Precipitation of a second phase was also affected by the presence of cavities. The results indicate that cavities become thermodynamically stable at the onset of tertiary creep.