玻璃析晶动力学判据研究

THE STUDY OF CRITERION FOR GLASS CRYSTALLIZATION KINETICS

本文综述了各种玻璃析晶动力学判据，在前人的研究基础上提出一种新的析晶动力学判据ｋ＿ｙ（Ｔ）＝ｖ·ｅｘｐ（─Ｅ／ＲＴ·ΔＴ／Ｔ＿ｍ）（其中ΔＴ＝Ｔ＿ｘ─Ｔ＿ｇ），指出ｋ＿ｙ（Ｔ）值越大，玻璃稳定性越差；ｋ＿ｙ（Ｔ）值越小，玻璃稳定性越好。它将动力学因素与热力学因素结合起来，通过对Ｎｄ掺杂的氟锆酸盐玻璃、钛酸盐玻璃及Ｂｉ－Ｃａ－Ｓｒ－Ｃｕ－Ｏ玻璃在不同升温速度，不同温度下的ｋ＿ｙ（Ｔ）计算，结果表明：ｋ＿ｙ（Ｔ）判据个受升温速度α及温度的限制，而ｋ或ｋ（Ｔ＿ｐ）判据则受升温速率和温度的影响，其中ｋ（Ｔ＿ｇ）判据完全不能用于氟锆酸盐玻璃稳定性的判断。ｋ＿ｙ（Ｔ）判据同时指出在氟锆酸盐玻璃、钛酸盐玻璃和Ｂｉ－Ｃａ－Ｓｒ－Ｃｕ－Ｏ玻璃中，Ｂｉ－Ｃａ－Ｓｒ－Ｃｕ－Ｏ玻璃的ｋ＿ｙ（Ｔ）值最大，它最不稳定；而氟锆酸盐玻璃的ｋ＿ｙ（Ｔ）值较小，它相对较稳定，这与玻璃的实际熔制情况完全相符。

A review of various criteria for glass crystallization kinetics is presented.A new criterion k_y(T)=v·exp(─E/RT·ΔT/T_m)(ΔT=T_x─T_g), which has included the kinetic factor and thermodynamlc fac-tor,is first proposed based on the study of previous researchers.k_y(T)is a more reasonable criterion than theexisting criteria k(T)(or k(T_p)) and E(or E/RT_p).High value of k_y(T)means poor stability of the glass,Studyon Nd doped fluorozirconate glass,titanate glass,and Bi-Ca-Sr-Cu_O glass at various heating ratesa and various temperatures has verified that the criterion k_y(T) is neither affected by the heating rate, nor bythe temperature,while k(T)(or k(T_p))varies with the heating rate and the temperature,Among Nd dopedfluorozirconate glass,titanate glass and Bi-Ca-Sr-Cu-O glass,the k_y(T)of Bi-Ca-Sr-Cu-O glass isthe highest,so this kind of glass is most unstable, while the k_y(T) of Nd doped fluorozirconate glass is lower,that kind of glass is relatively more stable,which fits well with the actual melting process of glass.