Intrinsic diffusion coefficients of Al and Ni in Ni3Al were determined using Ni/NiAl couples. The composition of the NiAl was controlled so that the Kirkendall interface was present in the Ni3Al phase formed in the couple. Concentration profiles were measured across the interface and interdiffusion coefficients of Ni3Al were determined from the profiles using the Sauer-Freise technique. The Darken equation was applied to the determination of the intrinsic diffusion coefficients. It was shown that the intrinsic diffusion coefficients of Al and Ni in Ni3Al were in almost the same magnitude. The self-diffusion coefficients of Al and Ni in Ni3Al were also estimated using the Manning equation. The present results were consistent with the diffusion mechanisms considering anti-site defects.

Intrinsic Diffusion in Ni3Al. Fujiwara, K., Horita, Z.: Defect and Diffusion Forum, 2001, 194-199[1], 565-70