Study on the Crystallization Kinetics of Fluorozirconate Glasses
Yang Qiuhong; Jiang Zhonghong(Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences Shanghai 501800 China)
The effect of NaF and NaCl addition on the crystallization kinetics of fluorozirconate glasses was studied by differential thermal analysis (DTA). The activation energy for crystallization was obviously decreased, Tx-Tg increased and the glass-forming ability improved by the addition of NaF and NaCl.DTA experimental results were analysed by Augis-Bennett method and modified Kissinger method. The crystallization activation energies obtained from both Augis-Bennett and modified Kissinger methods are almost the same, while the frequency faCtor v obtained from Augis-Bennett method is one magnitude lower than that from modified Kissinger method. The stability of fluorozirconate glasses was evaluated by a new crystallization kinetic criterion ky(T)=vexp(-E/RT ×△T/Tm) (△T = Tx-Tg) and correlated with the activation energy and compared with those evaluated by other criteria.