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.

中文翻译：

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粒子相变动力学的简单模型

摘要 我们提出了一种从表面和内部成核位点开始的粒子相变动力学的新模型。该模型的分析方程非常简单，易于使用和解释。我们使用差示扫描量热法（DSC）针对玻璃颗粒的结晶测试了模型。我们使用具有不同表面成核点数密度 NS 的透辉石 (CaO·MgO·2SiO2) 玻璃颗粒，以及同时显示出表面和内部结晶、具有不同内部核数密度 NV 的二硅酸锂玻璃颗粒。DSC 迹线的模拟提供了对转化动力学的准确预测。我们在三个无量纲参数方面将我们的模型结果与严格（更复杂）模型的结果进行了比较：表面核数、内核数和无量纲时间。我们的模型具有更简单的方程，提供了类似的结果。我们相信它还可以为在相变过程中烧结的颗粒（例如在烧结过程中同时结晶的玻璃颗粒）以及从多晶材料中的晶界开始的转变提供更现实的近似。