Simple model for particle phase transformation kinetics

Abstract We propose a new model for the kinetics of phase transformation of particles starting from surface and internal nucleation sites. The model's analytical equation is very simple, allowing for easy usage and interpretation. We tested the model against the crystallization of glass particles using differential scanning calorimetry, DSC. We used diopside (CaO·MgO·2SiO2) glass particles having different number densities of surface nucleation sites, N S , and also lithium disilicate glass particles, which show simultaneous surface and internal crystallization, having different number densities of internal nuclei, N V . Simulations of DSC traces provided accurate predictions of the transformation kinetics. We compared our model results to those of rigorous (more complex) models in terms of three non-dimensional parameters: the number of surface nuclei, the number of internal nuclei and a non-dimensional time. Our model, with a simpler equation, provided similar results. We believe it may also provide a more realistic approximation for particles that sinter during phase transformation, such as glass particles that simultaneously crystallize during sintering, and for transformations starting from the grain boundaries in polycrystalline materials.