纳米TiO_2陶瓷无压烧结的主烧结曲线

MASTER SINTERING CURVE FOR NANOMETER TiO_2 FOR PRESSURELESS SINTERING

采用纳米金红石相TiO2粉末在空气中进行烧结,用热膨胀仪记录恒定加热速率条件下的烧结过程,测量了烧结体密度,根据烧结3个阶段的全期烧结模型(combined-stage sintering model),建立TiO2主烧结曲线(master sintering curve)。纳米TiO2主烧结曲线对烧结路径不敏感,烧结体的相对密度仅是时间和温度的函数,利用主烧结曲线得到的相对密度和Archimedes法实测的密度吻合,证明了主烧结曲线的有效性;根据纳米金红石的主烧结曲线,得到其在空气中的烧结激活能为105kJ/mol;可以预测烧结收缩量和最终相对密度,准确描述烧结全程的烧结行为。

Based on the combined-stage sintering model, the master sintering curve （MSC） for rutile ZiO2 was constructed for sintering in air with normal pressure and using constant a heating rate in a dilatometer. The relative density of the sample was measured using the Archimedes method. The MSC of the rutile TiO2 samples was constructed and validated under different thermal histories. The MSC, in which the sintered density is a unique function of the integral of a temperature function over time, is not sensitive to the heating path. According to the MSC of TiO2, it is possible to predict the sintering shrinkage and final density and calculate the activation energy （105 kJ/mol）. With one temperature-dependent parameter determined experimentally, it becomes possible to accurately describe the densification behavior of TiO2 from the initial to final stages during the sintering period.