The calculation of the diffusion coefficients in ternary multiphase Ti-NiAl system.

The experimental concentration profile in Ti-NiAl diffusion couple after diffusion at 1173 K for 100 h. Determination of diffusion coefficients in a ternary multiphase system is discussed as the data on the approximation method allowing to determine the diffusion coefficients in such systems are currently missing in the literature. In the present work, the mass conservation approach (MCA) for calculation the diffusivities in individual phases with the linear differences in composition is proposed. The diffusion data can be determined exclusively based on the experimental results. The method is implemented and validated for the ternary Ti-NiAl system, in which three intermetallic phases are stable. [ABSTRACT FROM AUTHOR]