Effect of dislocations on the Langer-Schwartz model of nucleation and growth

The Langer-Schwartz model of nucleation and growth has been extended to include the presence of dislocations. The increased nucleation rate of precipitates lying on dislocations, the growth rate of these ellipsoidal precipitates and the effects of heterogeneous site saturation have been included in the model. It is shown that the presence of dislocations can have a large effect on the overall phase separation kinetics at low initial supersaturations, but it is concluded that heterogeneous nucleation cannot account for the observed discrepancies between the Langer-Schwartz theory and previously reported data on the Al-Zn system.