Strategies were presented for extracting fundamental atomistic information from measured diffusion coefficients in a ternary alloy system. These were exemplified using Cu–Ni–Fe alloys at 1271K, for which extensive new interdiffusion coefficients and tracer diffusion coefficients for all 3 components had become available. New defining phenomenological expressions for the vacancy-wind factors were developed in terms of the diffusion coefficients. It was shown that the measured tracer diffusion coefficients could be processed by using the Manning and Moleko, Allnatt and Allnatt random alloy diffusion kinetics formalisms (with and without the assumption of a Gibbs–Duhem relationship between the thermodynamic activities) to give jump frequencies, tracer correlation factors, vacancy-wind factors and phenomenological coefficients. It was shown that Cu was generally the most correlated component in its diffusion behavior, and that the off-diagonal phenomenological coefficients could be as high as 64% of the smallest of the diagonal phenomenological coefficients. It was also shown that the Darken formalism (which ignored off-diagonal phenomenological coefficients) was a reasonable approximation for expressing the diagonal phenomenological coefficients in terms of the tracer diffusion coefficients. It was then shown how the measured interdiffusivities could be processed, using these formalisms, to give tracer diffusivities, vacancy-wind factors and phenomenological coefficients. Finally, it was shown how a straightforward strategy, starting with a Darken analysis and followed by a Manning or Moleko, Allnatt and Allnatt analysis, could be used to access the vacancy-wind factors and the off-diagonal phenomenological coefficients.

Theoretical Analysis of Experimental Tracer and Interdiffusion Data in Cu–Ni–Fe Alloys. I.V.Belova, G.E.Murch, R.Filipek, M.Danielewski: Acta Materialia, 2005, 53[17], 4613-22