Effect of Fluctuations on the Formation of Secondary Phase Precipitates at Grain Boundaries

Resumo

Based on the free energy density functional method (modified Cahn–Hillard–Cook equation), the formation kinetics of secondary phases in binary alloys is considered in the presence of composition fluctuations and with inclusion of the grain boundaries influences. It is revealed that the existence of grain boundaries and the fluctuations at the initial stage of the phase transition can lead to the appearance of anomalous growth rate of the average precipitate size due to a competition of various decomposition mechanisms.