晶核剂及热处理对锂铝硅系微晶玻璃晶化和性能的影响  

Effects of Nucleation Agents and Heat Treatment on the Crystallization and Properties of LAS Glass-ceramics

作　　者：陆雷[1] 赵莹[1] 张乐军[1] 王浩[1] 

机构地区：[1]南京工业大学材料科学与工程学院,江苏南京210009

出　　处：《材料科学与工程学报》2008年第3期441-445,405,共6页Journal of Materials Science and Engineering

摘　　要：采用差热分析法研究了LAS玻璃的析晶动力学,讨论了4.5wt%TiO2和2 wt%TiO2+2.5 wt%ZrO2两种晶核剂对该系统玻璃晶化过程的影响。通过正交实验确定了玻璃晶化的最优热处理制度,并研究了热处理对微晶玻璃的晶相、显微结构及热膨胀性能的影响。结果表明:与采用TiO2单一晶核剂相比,采用TiO2+ZrO2复合晶核剂的玻璃析晶活化能E降低,晶化指数n加大,体积析晶趋势增大。热处理制度能控制晶相的析出,析晶初始温度下首先析出的晶体为β-石英固溶体,晶化温度升高转变为β-锂辉石固溶体,可以使样品的热膨胀性能符合要求,最优的热处理制度(使热膨胀系数最小)为:核化温度720℃,核化时间1.5小时,晶化温度810℃,晶化时间2.5小时。Crystallization kinetics of LAS glasses was investigated by differential thermal analysis （DTA）. The effects of 4.5wt% TiO2 and 2 wt% TiO2＋2.5 wt% ZrO2 which played the role of nucleating agents on the crystallization of LAS glasses were discussed. The influences of heat treatment on the crystalline phases, microstructure and the thermal expansion properties of the glass-ceramics were investigated. And the heat treatment schedule was determined by Orthogonal Testing Method. The results show that when TiO2 ＋ ZrO2 was used as nucleation agent, the crystallization activation energy E decreased and the Avrami exponent n increased in comparison with single TiO2. The bulk crystallization tendency of the glass added with TiO2 ＋ ZrO2 was larger than that of the glass added with single TiO2. The heat treatment schedule could control the major crystalline phase in glass-ceramics. β-quartz solid solution precipitated first at the initial crystallization temperature, then β-spodumene solid solution precipitated as the temperature increases. When the glass was heated at 720 ℃ for 1.5h and then at 810 ℃ for 2.5h, the glass-ceramics with lowest thermal expansion coefficient can be obtained.

关 键 词：LAS微晶玻璃 晶核剂 热处理 晶化 

分 类 号：TQ171.733[化学工程—玻璃工业]