Atomic mobilities and vacancy wind effects for diffusion in ternary Silver-zinc-cadmium solid solutions

Abstract

Diffusion in the silver-zinc-cadmium system was investigated at 600°C with semiinfinite, vapor-solid couples in order to determine the atomic mobilities and contribution of the vacancy wind effect to the intrinsic diffusion fluxes of silver, zinc and cadmium in the alpha phase region. Atomic mobilities and vacancy wind parameters were computed at selected compositions in the alpha phase along isoconcentration lines of 11 at. pct Zn, 18 at. pct Zn, 5 at. pct Cd and 9 at. pct Cd. The existence of significant interactions between the diffusing species was indicated by the results of an earlier investigation; consequently, the vacancy wind effect was taken into consideration in the calculation of the mobilities. The mobilities of zinc and cadmium, determined by the method of Dayananda, were found to increase with increasing zinc and cadmium concentrations with the mobility of zinc being greater than that of cadmium. The results of the investigation show that the vacancy wind effect significantly affects the total intrinsic flux of each of the three species for diffusion in ternary silver-zinc-cadmium alloys. This investigation reports the experimental observation of the vacancy wind effect in a ternary system.