Modeling of phase decomposition of supersaturated solid solutions using the free-energy density functional method

The nucleation and growth of particles of the second phase in a one-dimensional binary alloy is considered based on the Cahn–Hilliard equation with allowance for fluctuations. Using the results of modeling, it is shown that the second phase is occupied by the mechanism of solid solution decomposition, which involves simultaneous processes of the fluctuational nucleation of the second phase, diffusion-type growth of precipitations, and absorption of small clusters by coarse ones at the coalescence stage. Composition fluctuations are among the main factors influencing the distribution of solid solution phases.