【摘要】 表观烧结激活能是研究陶瓷烧结机理的一个非常重要参量。采用纳米金红石相TiO2陶瓷坯体在空气中进行无压烧结,加热速率分别为1,2,5℃/min,用热膨胀仪记录试样收缩率,阿基米德法测量烧结体相对密度,分别用主烧结曲线法和Arrhenius法计算表观烧结激活能。结果表明:用主烧结曲线得到的激活能是一个定值,而用Arrhenius法得到的激活能是一个变化的值,激活能是相对密度的函数,随相对密度的增加而减小,且激活能和相对密度的变化趋势分成两段,当相对密度大于85%时,激活能随相对密度的增加而减小比小于85%时要快,这意味着在烧结过程中,控制烧结的扩散机制可能发生了变化。更多还原

【Abstract】 The sintering activation energy is essential to determine the sintering controlling mechanism. In this paper,the nanometer rutile ceramics specimens were sintered pressurelessly in air at heating rates of 1,2 and 5 ℃/min. The shrinkages were recorded using heat dilatometer,and the relative densities were measured by Archimedes method. The apparent activation energies of TiO2 ceramics were determined by the master sintering curve (MSC) theory and Arrhenius theory,respectively. The results show that the activation energy determined by the MSC has a single value of 110 KJ/mol. The activation energy determined by the Arrhenius theory does not have a single value and it is a function of relative density. It decreases with the increasing relative density. The tendency of activation energy and relative density is divided into two regions:the activation energy decreases more quickly with the increasing relative density when the relative density is above 85% than below 85%. This means that the diffusion controlling mechanism may change during the sintering.更多还原