烧结工艺对ZnO压敏陶瓷微观结构与电学性能影响

Effect of sintering process on microstructure and electrical properties of ZnO varistor ceramics

以ZnO粉末为主要原料,添加TiO2、Bi2O3、MnO2、Co2O3、Sb2O3为组元,在不同烧结温度(1100~1250℃)与保温时间(1.0~2.5h)下制备ZnO压敏陶瓷。采用SEM观察陶瓷形貌,利用压敏电阻直流参数仪测试陶瓷的电学性能,研究烧结温度与保温时间对陶瓷结构和性能的影响。结果表明,随烧结温度升高,压敏电压、漏电流逐渐降低,而非线性系数先减小后增加。制备ZnO压敏陶瓷的适宜烧结温度与保温时间分别为1250℃、1h,压敏电压为17.0V/mm、漏电流为0.014mA、非线性系数为14.2,陶瓷内部晶粒可长大至128.7μm。

ZnO varistor ceramics was prepared by sintering at different temperatures( 1100-1250 ℃) for different time( 1-2. 5 h) using ZnO as raw materials. The effect of sintering process on microstructure and electrical properties of the ZnO varistor ceramics was studied.The morphology of the ceramics was observed by SEM and the electrical properties were analyzed by varistor DC parameter instrument. The results show that with the increasing of sintering temperature,the varistor voltage and the leakage current decrease,while the nonlinear coefficient firstly decreases and then increases. The optimum sintering temperature and holding time of ZnO varistors are 1250 ℃ and 1 h,and the varistor voltage is 17. 0 V / mm,leakage current is 0. 014 mA,nonlinear coefficient is 14. 2,internal grain is 128. 7 μm.