镁铝硅系堇青石基微晶玻璃的制备及性能研究

Preparation and Properties of Cordierite-based MgO-Al_2O_3-SiO_2 Glass-ceramic

2采用高温熔融法制备了MgO—Al2O3-SiO2（MAS）系堇青石基微晶玻璃。借助x射线衍射仪（XRD）、扫描电镜（SEM）及热膨胀系数仪研究了晶化热处理工艺、MgO／A12O3质量比以及晶核剂种类（TiO2／ZrO2）与含量对MAS系堇青石基微晶玻璃理化性能和晶化特性的影响。结果表明2在核化温度750℃、保温时间1h，晶化温度1050℃、保温时间2．5h，升温速率5％／min时，微晶玻璃中堇青石含量最高，析品性能最好；当MgO／A12O3质量比为1左右时，在30～700℃温度范围内，平均热膨胀系数最小，在4．4～4．8×10^-6K^-1范围内可调；TiO2是MAS系堇青石基微晶玻璃的有效晶核剂，而ZrO2的加入并不利于基础玻璃的晶化。

The cordierite-based MgO-Al2O3-SiO2 （MAS） glass-ceramics were prepared by a melting method. The crystallization heat treatment process, ratio of MgO/Al2O3, and different type and quantity of nucleation agent were identified as having significant effects on physical and crystallization properties of the cordierite-based glass-ceramic. The optimized conditions for the enhancement of these performances were investigated by X-Ray Diffraction （XRD）, Scanning Electron Microscope （SEM） and Thermal Expansion Coefficient Differential Apparatus. It is found that good crystallization performance and low thermal expansion coefficient （4.50×10^-6K^-1） are obtained when calcining at the nucleation temperature （750℃ ） for 1 h, and the crystallization temperature （ 1050℃） for 2.5 h with the heating rate of 5℃/ min ; when the ratio of MgO/Al2O3 is around 1, the thermal expansion coefficient is among 4.4 - 4.8×10^-6K^-1, which is in good agreement with the predicted results; an analysis of obtained results indicate that TiO2 is an efficient nucleation agent for the cordierite-based MAS glass-ceramic rather than ZrO2.