Crystallization Kinetics of BaO-Al_2O_3-SiO_2 Glass-ceramics

BaO-Al_2O_3-SiO_2(BAS)glass-ceramics with stoichiometric and off-stoichiomctric celsian composition were fabricated.Crystallization characters of two groups of BaO-Al_2O_3-SiO_2(BAS)glass- ceramics were investigated by differential scanning calorimetry(DSC),X-ray diffraction(XRD),iso- conversional method and multiple linear regression method.The autocatalytic kinetic model(Sestak- Berggren function)was found to be the most proper description of the studied processes for all glass investigated.Doping with ZrO_2 or increasing mass fraction of BaO accelerates the crystallization process of hexagonal-BaAl_2Si_2O_8 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 ZrO_2 decelerates the crystallization process of hexagonal- BaAl_2Si_2O_8 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.