Phase Field Crystal Study on the Temporal Evolution and Coarsening Mechanism of Precipitates during Spinodal Decomposition

The spinodal decomposition of symmetric and asymmetric binary alloys has been studied from precipitate evolution and coarsening mechanism by a binary phase field crystal method. The calculated results indicate that when the alloy composition changes from a symmetric point to the asymmetric one, the morphology of decomposed phases transforms gradually from long stripes to spheres, with the coarsening mechanism undergoing a transition from the coalescence of neighboring particles to Ostwald ripening. Only the coarsening kinetics of the binary alloys which is close to the spinodal decomposition line is in a fair agreement with the prediction of the modified LSW theory.