Abstract:
In the present paper, the theory of the highest entropy production is discussed. It allows to predict, which phases will
grow during the multiphase ternary interdiffusion process. Moreover, the theory says, that phase with the highest entropy
production value will nucleate as first in the reaction zone. To verify the theory the mathematical formula for calculating
the entropy production was formulated. The formula bases on the generalized Darken method. Two diffusion couples:
pure titanium with high purity copper-nickel alloys with different initial composition: Ni10Cu90-Ti and Ni90Cu10-Ti (at
at.%) were annealed to obtain the thermodynamic and kinetic data. The integral diffusion coefficients for each component
in each phase were determined using Wagners method. The reaction zones in ternary system have been analyzed: the
microstructure was observed and chemical compositions were measured. Based on obtained results the entropy
production was calculated. It can be expected, that the theory of the highest entropy production can be applied in
determining a proper diffusion path in multicomponent, multiphase system.
Key words: diffusion, Cu-Ni-Ti system, entropy production, diffusion path
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