天然沸石多孔陶瓷的烧结动力学

SINTERING KINETICS OF POROUS CERAMICS FROM NATURAL ZEOLITE

用阶梯等温热膨胀法（stepwise isothermal dilatometry，SID），结合X射线衍射分析、扫描电镜和孔隙率测试等手段研究了天然沸石多孔陶瓷的烧结动力学。结果发现：在850～1150℃，随烧结温度的升高，天然沸石多孔陶瓷的孔隙率逐渐降低；平均孔径的变化分为两个阶段，烧结温度低于1050℃时，温度越高，平均孔径越低；烧结温度为1100℃时，在液相作用下，平均孔径反而由1050℃的2．61μm激增至5．77μm。运用Makipirtti-Meng经验速率方程处理SID数据，可以导出相关烧结动力学参数，在850～1150℃，材料的表观烧结活化能为1016kJ／mol。

The sintering kinetics of the porous ceramics from natural zeolite was investigated by stepwise isothermal dilatometry （SID） , and X-ray diffration, scanning electron microscope, and porosity measurement. The results show the porosity of these ceramics decreases slowly with sintering temperature, while the mean pore size is reduced when the material is sintered below 1 050℃ and dramatically increases up to 5.7μm when sintered at 1 100℃. The isothermal shrinkage data from SID can be well analyzed to get kinetic parameters according to the empirical rate equation developed by Makipirtti - Meng and the value of apparent activation energy obtained at 850-1 150℃ is 1 016 kJ/mol.