The pressure dependence of grain-boundary diffusion of65Zn in polycrystalline aluminium

Abstract
The pressure dependence of the grain-boundary diffusion of 65Zn in polycrystalline aluminium has been measured in the B-kinetic regime at 593 K in the pressure range 0–1·2 GPa. Separating the subgrain and large-angle grain-boundary segments of the penetration plots, it has been found that the activation volumes are (0·86 ± 0·06)Ω and (0·80 ± 0·10)Ω respectively (Ω is the atomic volume). These results are consistent with the vacancy mechanism of grain boundary diffusion