通过差热分析(DTA)、X射线衍射分析(XRD)和扫描电镜(SEM)等方法,研究了形核条件对Li2O-Al2O3-SiO2(LAS)玻璃晶化和性能的影响.研究发现,当玻璃在最佳形核温度745℃形核2h和6h后,Avrami常数n为3.6和3.5,晶体生长激活能为276kJ/mol和280kJ/mol.这表明在此形核温度下,改变晶化时间对玻璃的晶化影响较小.当晶化温度发生变化,晶化条件为760℃/2h时,Avrami常数降低到2.8,晶体生长激活能增加到312kJ/mol.在850℃晶化后,均获得了h-石英固溶体为主晶相的微晶玻璃.SEM观察发现晶粒均为等轴晶粒,表明析晶方式均为体积析晶.但随形核温度偏离最佳形核温度,从745℃增加到760℃,晶化后样品的晶粒尺寸加大,同时强度硬度以及断裂韧度等性能下降.
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