Non-locality and fluctuations in fast spinodal decomposition controlled by diffusion

Abstract

Spinodal decomposition in a binary system deeply supercooled or superheated into the unstable region of miscibility gap in a phase diagram is analysed. A large driving force for phase separation in the spinodal region leads to the phenomenon of the fast spinodal decomposition, thermodynamic aspects of which are presented for locally nonequilibrium binary system with fluctuations. The role of deterministic and stochastic contributions is clarified for spinodally decomposing phases. Early time kinetics of phase separation is modelled and evaluated by the structure factor. Outcomes of the present model predictions are compared with the results obtained using the CHC(Cahn-Hilliard-Cook)-model and LBM(Langer-Baron-Miller)-model. The practically important cases of the fast spinodal decomposition in alloys are predicted and analyzed in comparison with accessible experimental data.