MgO-Al₂O₃-SiO₂系微晶玻璃微观结构的分子动力学模拟

Molecular Dynamics Simulation for the Micro-Structure of MgO-Al₂O₃-SiO₂ Glass-Ceramics

摘要: 本文对MgO-Al₂O₃-SiO₂ (MAS)微晶玻璃的高温体系的微观结构进行了分子动力学模拟，得出该体系微观体系结构特点以及SiO₂含量对其网络结构的影响。计算结果显示：在MAS高温体系中，Mg²⁺的均方位移最大，其次是Al³⁺，然后是O²⁺，Si⁴⁺的均方位移最小。MAS系微晶玻璃中Si和O之间的作用力最强，Al和O之间的作用力次之，Mg和O之间的结合力最弱。四面体数量由多到少依次是[SiO₄]、[AlO₄]，随着SiO₂含量增多[SiO₄]数量逐渐增加，[AlO₄]数量随SiO₂含量的增加呈现先增加然后减少最终趋向平稳的现象。

Abstract: In this paper, MgO-Al₂O₃-SiO₂ glass-ceramics were calculated by using a molecular dynamics method in this paper, and the microstructure characteristics of the system and the influence of SiO₂ content on its network structure were obtained. It is shown by the calculation results that: In the MAS system at high temperature, the mean square displacement (MSD) of Mg²⁺ is the largest, followed by Al³⁺, followed by O²⁺ and the MSD of Si⁴⁺ is the smallest. The binding force between Si and O in MAS glass-ceramics is the strongest, followed by the force between Al and O, and the binding force between Mg and O is the weakest. The number of tetrahedrons is from more to less, followed by [SiO₄] and [AlO₄]. With the increase of SiO₂ content, the number of [SiO₄] tetrahedrons gradually increased, and the number of [AlO₄] tetrahedrons increased at first and then decreased, and finally reached a state of equilibrium.