【摘要】 应用晶粒生长动力学唯象理论研究了TiO2 对ZnO压敏陶瓷的晶粒生长规律的影响 ,应用晶粒生长动力学方程确定了晶粒生长动力学指数和激活能 ,探讨了TiO2 掺杂对ZnO压敏陶瓷晶粒生长的作用机理 .实验结果表明 :对于TiO2 掺杂ZnO压敏陶瓷 ,当烧结温度低于 10 5 0℃时 ,其动力学指数n =3 ,激活能为 30 0± 2 5kJ/mol ,此时晶粒生长的速度控制机理是ZnO在Bi4 Ti3O12 液相中的扩散 .而当烧结温度大于 110 0℃时 ,其动力学指数 n =6 ,激活能为 36 0± 2 9kJ/mol.这是由于Zn2 TiO4 尖晶石颗粒钉扎在ZnO压敏瓷的晶粒边界 ,通过颗粒阻滞机理抑制ZnO晶粒的长大 ,从而使ZnO压敏瓷的晶粒生长激活能增大更多还原

【Abstract】 The grain growth of ZnO with TiO 2 addition was studied. The grain growth exponent and apparent activation energy were determined by applying the phenomenological kinetic grain growth equation. The mechanism of ZnO grain growth is discussed. The results show that the grain growth exponent is 3 and apparent activation energy is 300±25?kJ/mol for ZnO ceramics varistor with TiO 2 addition sintered at the temperature below 1?050?℃. The grain growth mechanism for ZnO ceramics is diffusion of ZnO in the Bi 4Ti 3O 12 liquid phase. The grain growth exponent is 6 and apparent activation energy is 360±29?kJ/mol for ZnO ceramics varistor with TiO 2 additon sintered at the temperature higher than 1?100?℃. This is because ZnAl 2O 4 spinel particle pin the ZnO grain-boundaries creating a drag mechanism that reduces the grain boundary mobility and increases the apparent activation energy.更多还原