Phase-field simulation of spinodal phase separation in the Na2O-SiO2 glasses

Abstract The phase-field method was used for the kinetic simulation of the spinodal phase separation of glasses in the Na2O-SiO2 system. The miscibility gap and spinodal curve were calculated based on the previous interaction parameters of the liquid phase. The kinetic simulations showed that the resultant morphology depended on the initial concentration and the temperature. In the early stages of spinodal decomposition, the interconnected structure developed continuously and in the later stages began to coarsen. During the coarsening stage, the evolution of morphology of the microstructures could result in the discrete spherical particles as well as the interconnected structure, depending on the heat treatment condition. To analyze the phase separation rate, the amplification factors for the initial concentrations were calculated as a function of temperature and could explain the morphology developed from the present simulation. Also, the present work could explain the evolution of experimental morphologies available in the literature reasonably.