CaO对CaO-Al_2O_3-SiO_2系微晶玻璃析晶行为的影响

利用烧结工艺制备微晶玻璃以CaO Al2O3 SiO2三元系微晶玻璃为研究对象,通过DTA,XRD,SEM分析方法,对玻璃析晶动力学进行研究·利用Kissinger方程来计算微晶玻璃析晶转变的活化能E,发现随着氧化钙含量的增加,析晶温度降低,析晶活化能降低,并最终推导出析晶机理参数n=2,体系属于整体析晶·实验结果发现:微晶玻璃的析晶相均为硅灰石结构;氧化钙含量的增加有利于微晶玻璃的晶化,但表面缺陷更明显,如:坑点、突起、断裂等·

Effect of CaO on Crystallization Behavior of CaO-Al2O3-SiO2 System Glass Ceramics

Several glass ceramics of CaO-Al_2O_3-SiO_2 system were prepared via sintering process and investigated by means of DTA, XRD and SEM, based on crystallization kinetics. The activation energy E for the crystallization transform of such glasses are calculated by Kissinger equation, and it is found that the activation energy decreases with increasing CaO content and decreasing crystallization temperature. As a result, an inference is drawn that the system is integrally crystallized if the characteristic parameter n=2. Experimental results reveal that the crystallization phase of such glasses are all of wollastonite, and the increasing CaO content is beneficial to the further crystallization of glass ceramic. But, at the same time, it brings more obvious defects to glass surface, such as pits, outshoots and cracks.