种子诱导结晶釉中硅酸锌晶化动力学(英文)

Seed-induced Crystallization Kinetics of Zinc Silicate in Crystalline Glaze

以ZnO为晶种,研究了SiO2-Al2O3-ZnO-CaO-MgO-K2O-Na2O系统结晶釉中硅酸锌的可控析晶过程。结果表明:起装饰作用的盘状硅酸锌晶体由冰针形状硅酸锌晶粒组成,受釉层厚度的限制,晶体生长沿<0001>方向。采用John William Mullin以及Johnson-Mehl-Avrami动力学模型模拟灼烧过程中晶体生长,低温下晶体生长主要受前驱体在玻璃相中扩散控制,在高温下,则主要受前驱体和晶核界面反应控制。

A kinetic of the controlled crystallization process was investigated for a decorative ceramic glaze in the SiO2-Al2O3-ZnO-CaO-MgO-K2O-Na2 O system using ZnO grains as crystal seeds.The decorative effect for plate-like spherulites consists of lath-like willemite(Zn2SiO4)crystals growing along their<0001> direction due to the constraint of the glaze thickness.The John William Mullin and Johnson-Mehl-Avrami kinetic models were used to predict the crystal growth in the glaze layer during firing.The predicted results indicate that the crystal growth rate is mainly controlled by the diffusion of the precursors through the glassy phases at low temperatures.Also,the crystal growth rate is mainly controlled by the interface reaction between the precursors and the crystals at high temperatures.