MgO-Al_2O_3-SiO_2系微晶玻璃微观缺陷与性能  

Microscopic defects and performance of MgO-Al_2O_3-SiO_2 system glass ceramic

作　　者：袁秋华[1] 惠文彬[1] 张培新[1] 邓文[2] 张冬云[1] 汪静伟[1] 任祥忠[1] 

机构地区：[1]深圳大学化学与化工学院,深圳518060 [2]广西大学物理科学与工程技术学院,南宁530004

出　　处：《深圳大学学报（理工版）》2015年第4期357-364,共8页Journal of Shenzhen University(Science and Engineering)

基　　金：国家自然科学基金资助项目(50674068;50974090;21471102)~~

摘　　要：采用差热分析、X射线衍射、扫描电子显微镜、电子自旋共振、正电子湮没和显微硬度等测试方法,对Mg O-Al2O3-Si O2(MAS)系微晶玻璃的晶化和微观结构进行研究,讨论晶核剂Ti O2对MAS微晶玻璃晶化行为、微观缺陷以及性能的影响.结果表明,玻璃在晶化过程中,易形成Si空位正电子缺陷和O空位负电子缺陷,且由于离子迁移、交换和异位等运动产生掺杂缺陷;同时有部分Ti4+转变为Ti3+,产生顺磁缺陷并处于带四方畸变的Ti O6八面体配位场中.在晶化过程中产生的各种缺陷,促使晶核产生并诱导玻璃析晶进而改变玻璃的微观结构组成,使基础玻璃转变为内部含有微小晶粒的微晶玻璃,从而影响微晶玻璃的抗弯强度和显微硬度.We study the crystallization and mierostructure of MgO-AlzO3-SiO2 （MAS） system glass ceramics by means of differential thermal analysis （ DTA ）, X-ray diffraction （ XRD）, scanning electron microscopy （ SEM ）, electron spin resonance （ ESR）, positron annihilation technology （ PAT）, and micro-hardness testing, and investi- gate the effects of nucleating agents TiO2 on the crystallization behavior, performance and microscopic defects of MAS system glass ceramics. The results show that it is easy to form vacancy defects of Si positron and O negative electron besides doping defects attributed to the motion of ionic migration and ectopic exchange in the crystallization process of the glass. At the same time, partial Ti4＋ is transformed into Ti3＋ , leading to the generation of paramagnetic defects in the TiO6 octahedral field with tetragonal distortion. All sorts of defects formed in the crystallization process can facilitate the generation of crystal nucleus and induce crystallization, then alter the microstructure and the composition of the glasses. As a result, common glass is transformed into glass ceramics containing tiny grains, which affect the bending strength and micro-hardness of the glass ceramics

关 键 词：硅酸盐玻璃 镁铝硅系微晶玻璃 二氧化钛 微观结构 晶化 电子自旋共振 

分 类 号：TQ171.1[化学工程—玻璃工业]