B_2O_3掺杂Li_2O-Al_2O_3-SiO_2低膨胀透明微晶玻璃的制备及性能表征

Preparation and Characterization of B_2O_3 Doped Li_2O-Al_2O_3-SiO_2 Transparent Glass-ceramics with Low Thermal Expansion

为了降低微晶玻璃的熔化温度、改善玻璃的化学稳定性、机械性能和玻璃的熔化质量,在Li2O-Al2O3-SiO2三元玻璃系统中加入5%的B2O3。但加入氧化硼容易产生玻璃分相,生成的主晶相β-石英固溶体就会减少,引起透光性下降。作者以TiO2、ZrO2作为复合晶核剂,通过改变成核温度、成核时间、晶化温度、晶化时间,控制晶体颗粒度大小,制备出了晶粒较小、主晶相为β-石英固溶体的低膨胀透明微晶玻璃,其透过率大于80%,膨胀系数为2.0×10-6/K-1。采用差热分析仪分析了晶化前后玻璃的放热情况,用X射线衍射仪分析了微晶玻璃的主晶相为β-石英固溶体,采用SEM分析了透明微晶玻璃和半透明微晶玻璃的晶体结构。

B2O3 was doped into Li2O-Al2O3-SiO2 glass ceramics to reduce melting point, to enhance chemical stability, and to improve mechanical property of the glass ceramics. In order to solve the problem of phase separation brought by B23 doping, TiO2 and ZrO2 were added as multi-nucleating agents. The effects of nucleation temperature and time, crystallization temperature and time on the final quality of the product were investigated. Glass-ceramics with a transmittance of 81.67% and a thermal expansion coefficient of 2.0×10^-6/K^-1 were obtained. The exothermic behavior, crystalline phase composition and microstructure of the glass-ceramics were analyzed by differential thermal analyzer, X-ray diffractometer and scanning electron microscope respectively.