Pressure and Vacancy-Flow Effects on the Kirkendall Shift in Silver-Gold Alloys

Publisher Website
Google Scholar
Abstract
A series of eight Kirkendall runs plus several supporting measurements were made in silver-gold alloys over the hydrostatic pressure range of 0-8 kbar. Reduction in the size of the Kirkendall shift was found to be due mostly to the effect of pressure on self-diffusion rates, with only about 8% of the reduction being due to changes in the activity-coefficient gradient. Agreement between the magnitude of the measured shift and the predicted value was better than 2%, providing substantial evidence for the validity of the vacancy-flow term in Manning's equation, which constitutes 28% of the total shift. Diffusion porosity was eliminated by the application of pressure for all pressures 10 bar and greater. Evidence was found which indicates that the activation volumes for silver and gold self-diffusion are equal within experimental error.