Thermodynamics of phase equilibrium of binary alloys containing nanprecipitates

A model of phase equilibrium in binary alloys has been developed taking into account the formation of phase precipitates of arbitrary (including nanometer) size. It has been shown that the phase composition of alloys substantially depends on the size of phase precipitates and, in the case of the formation of nano-precipitates, the phase composition can differ by a factor of several times from the phase composition of macroscopic precipitates. The proposed model has been used for calculating the dependence of the phase composition of some binary alloys (α-Fe-Cr at the temperature T = 773 K and Zr-Nb at the temperature T = 853−873 K) on the size of precipitates. The results of the calculation agree with experimental data obtained by other authors.