Phase field simulation of the second phase particle precipitation at boundaries and its pinning effect

Alloys containing different equilibrium volume fraction of second-phase particles were studied based on phase field model. The second-phase particle precipitating at grain boundaries and the growth were also investigated as well as its pinning effect on matrix phase grain boundaries. The simulation result indicates that the more the equilibrium volume fraction of second-phase particles is, the shorter the nucleation incubation period becomes, and the quicker the rate of nucleation and coarsening becomes. However, during the growth stage, the second-phase particles with high equilibrium volume fraction (15%-25%) grow more slowly than that with low fraction (10%). The pinning effect on grain boundaries increases along with the higher equilibrium volume fraction of second-phase particles. However, when the equilibrium volume fraction increases to a certain degree, the pinning effect will tend to be stable. The effect of second-phase particles on the final grain radius follows Zener relation.