基于Matlab的ZnO压敏陶瓷几何效应研究

ZnO压敏陶瓷击穿场强E1mA由晶粒尺寸和单个晶界击穿电压两个因素共同决定,沿用之前提出的微观结构模型,在晶粒尺寸一定,晶界电压服从正态分布;晶界电压一定,晶粒尺寸服从正态分布;和晶粒尺寸、晶界电压都服从正态分布三种条件下,用Matlab分别模拟击穿场强随厚度的变化关系,结果表明ZnO压敏陶瓷击穿场强的几何效应主要来自晶粒尺寸和分布的影响。在此基础上,对初始厚度不同的试样进行击穿场强与厚度的关系模拟,从结果可以看到,无论是高击穿场强还是低击穿场强的试样,都存在几何效应。

Research on the Dimensional Effect of ZnO Varistor Ceramics Based on Matlab

Breakdown electric field E1mA(electric field corresponding to the current density 1 mA cm-2) of Zinc oxide(ZnO) varistor ceramics is determined by the size of the ZnO grains and the breakdown voltage of the individual grain boundary.Based on the model of the microstructure proposed before,under the conditions of the grain size is certain,the breakdown voltage of grain boundary is normal distributed;the grain boundary is certain,the grain size is normal distributed;and the grain boundary and grain size are normal distributed,the relation of breakdown field strength and the thickness is simulated by Matlab,the result shows that dimensional effect of ZnO varistor ceramics breakdown field strength is mainly influenced by grain size and distribution.The relation of breakdown field strength and thickness is simulated on samples with different initial thickness.The result shows that dimensional effect is in existence both in the high and the low breakdown field samples.