The highest entropy production during diffusion

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 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 Wagner 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. The results show that the theory of the highest entropy production can be applied in determining a proper diffusion path in multicomponent, multiphase system.�