摘要
利用烧结法制备化学计量比和高Ba含量的两组BaO-Al_2O_3-SiO_2(BAS)系微晶玻璃,采用等转化率法计算玻璃粉的活化能随析晶过程的变化,利用线性回归的方法确定最概然析晶机理函数,进而对比研究添加ZrO_2和提高Ba含量对BAS系微晶玻璃析晶过程的影响.结果表明,4种成分的BAS系玻璃的最概然析晶机理函数均为SB(m,n)函数,析晶过程中存在自催化的相变机制.在化学计量比的BAS系玻璃中添加ZrO_2或者提高Ba含量,对六方钡长石的析出表现为促进作用,并且随着温度的降低或者析晶过程的进行,促进效果更加明显.在高Ba含量的BAS系玻璃中添加ZrO_2对六方钡长石的析出表现为抑制作用,并且随着温度的升高抑制效果更加明显.
BaO-Al2O3-SiO2（BAS） glass-ceramics with stoichiometric and off-stoichiometric celsian composition were fabricated. Crystallization characters of two groups of BaO-Al2O3-SiO2 （BAS） glassceramics were investigated by differential scanning calorimetry （DSC）, X-ray diffraction（XRD）, isoconversional method and multiple linear regression method. The autocatalytic kinetic model （Sesták- Berggren function） was found to be the most proper description of the studied processes for all glass investigated. Doping with ZrO2 or increasing mass fraction of BaO accelerates the crystallization process of hexagonal-BaAl2Si2O8 in BAS glass-ceramics with stoichiometric celsian composition whose viscosity is high. Moreover, the lower the temperature gets, or the higher the crystallinity gets, the more obvious the accelerating effect gets. While doping with ZrO2 decelerates the crystallization process of hexagonal- BaAl2Si2O8 in BAS glass-ceramics with off-stoichiometric celsian composition whose viscosity is low. Moreover, the higher the temperature gets, the more obvious the decelerating effect gets.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2008年第2期315-321,共7页
Journal of Inorganic Materials
基金
国家"863"计划(2004AA32G090)
关键词
微晶玻璃
钡长石
析晶
等转化率法
SB(m
n)函数
glass-ceramics
celsian
crystallization
isoconversional method
Sesták-Berggren function
