一种简便的评价TiO_2晶核剂效果的方法

A Study on Role of TiO 2 in Process of Crystallization of Glasses Through Measuring Nucleation and Growth Rates Curve

使用差热分析（ＤＴＡ）方法测定玻璃的转变温度Ｔｇ和液化温度Ｔｍ。假定与形核方程和生长方程相联系的几个参数是固定不变的，作样品的形核和生长速率曲线，发现样品中ＴｉＯ２的含量越高，在形核和生长速率曲线间的距离越大，同时相应于最大形核和生长速率的相对温度越低。相应于最大形核速率的相对温度随ＴｉＯ２含量的变化发生大的改变，而相应于最大生长速率的相对温度随ＴｉＯ２含量的变化只发生小的改变。低含量的ＴｉＯ２（小于５％）不是一种有效的形核剂。当ＴｉＯ２的含量超过１０ｗｔ％时，ＴｉＯ２是玻璃系统的一种主要组分，此时它能有效地促进玻璃的形核和生长。

The method of differential thermal analysis(DTA) is used to measure the glass transition temperature,T g and glass liquefied temperature,T m. Several parameters associated with the nucleation equation and growth equation are assumed to be fixed.The curves of nucleation and growth rates are plotted for every samples.It is found that the higher the content of TiO 2, thelarger the gap between nucleation and growth rate curves,and the lower the reduced temperature corresponding to the highest nucleation rate and growth rate.The reduced temperature corresponding to the largest rate of nucleation has a large change with the content of TiO 2,but he reduced temperature corresponding to the largest rate of growth has a little change with the content of TiO 2.A little content of TiO 2(<5%)do not play an effective role in improving the nucleation and growth.When the content of TiO 2 exceeds the mass percendtage 10%,TiO 2 become a main component of glass system and can play an effective role in advancing the nuleation and growth.