摘要
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.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
1994年第5期419-426,共8页
Journal of The Chinese Ceramic Society
关键词
析晶
氟锆酸盐玻璃
钛酸盐玻璃
glass crystallization kinetics,criterion,fluorozirconate glass,titanate glass,Bi-Ca-Sr-Cu -O glass