玻璃非等温析晶动力学的研究

Nonisothermal crystallization kineticsof glasses

从玻璃析晶转变的机制出发，考虑了玻璃形核机制对玻璃析晶转变的影响，导出了玻璃非等温析晶动力学公式：－ｌｎ（１－ｘ）＝Ｃαｍｅｘｐ［－１．０５２ｎＥ／（ＲＴ）］。由此求出玻璃的析晶活化能Ｅ和晶体生长指数ｎ具有明确的物理意义。用导出的公式研究了Ｋ／Ｍｇ／Ａｌ／Ｓｉ／Ｔｉ／Ｏ／Ｆ玻璃的析晶动力学。结果表明，析晶参数ｍ反映了玻璃的形核机制。玻璃中析出云母晶体ＫＭｇ３ＡｌＳｉ３Ｏ１０Ｆ２以二维方式生长，析晶活化能为（２３１±１２）ｋＪ／ｍｏｌ。

Based on the microscopic crystallization of glass, a kinetic equation was derived, i.e., -ln(1-x)=Cαmexp-1.052nERT. From this equation, the determined crystallization kinetic parameters have specific physics conception. By using the equation, the crystallization kinetics of the K/Mg/Al/Si/Ti/O/F glass was investigated and the value of crystallization activation energy, E, was determined as (231±12)kJ/mol and the crystal growth index, n, was very close to 2. The results indicate that the growth of mica crystals is a twodimensional process and the conclusion is confirmed by a scanning electron microscopy. The kinetic parameter m reflects the nucleation mechanism of the glass.