The goal of this research effort is to model complex diffusional processes with simple, but rigorous equations. These equations have already been derived for single phase systems in terms of the square root diffusivity. Experimental studies are made using diffusion couples containing small concentration differences in order to satisfy a constant diffusivity assumption. A computer program is being developed to predict concentration profiles in diffusion couples that contain up to eight alloying elements. This research is important to high temperature processing techniques such as pack cementation, oxidation and annealing. Diffusion causes property degradation in high temperature materials systems such as coated turbine blades and metal-matrix composites. This research should provide valuable predictive capabilities for these and similar processes.
