透明零膨胀LAS系微晶玻璃的制备和研究

The Research and Preparation of Low-Expansion and Transparent LAS Glass-Ceramics

以TiO_2和ZrO_2作为晶核剂,采用“两步法”热处理工艺,制备了透明、零膨胀的Li_2O-Al_2O_3-SiO_2(LAS)系微晶玻璃。利用X射线衍射分析和扫描电子显微镜对该微晶玻璃的物相和微观结构进行分析,结果表明微晶玻璃中析出大量β-锂辉石晶粒,其晶粒半径仅为50～100nm。LAS系微晶玻璃热膨胀系数在20～400℃范围内趋向于零,而在400～750℃范围内热膨胀系数不断升高,趋向于8×10-7/K。该LAS系微晶玻璃具有良好的透光性能,于可见光范围内透过率为70%。

The low-expansion and transparent Li2O-Al2O3-SiO2 （LAS） system glass-ceramic doped with TiO2 and ZrO2 as nucleation agents was prepared by traditional two-step heated schedule. The microstructure and crystalline phase were analysed by SEM and XRD, respectively. The results showe that： The β-spodumene s. s, with grain size of 50-100nm, were separated in the LAS glass-ceramic. The coefficient of linear expansion of LAS glass-ceramic was almost 0 ×10^-7/K within 20-400℃ and trended to 8 × 10^-7/K when the temperature increased from 400℃ to 700℃. The LAS glass-ceramic had excellent transparency and the coefficient of visible light permeation was 70%.