Influences of Twin Boundaries on Microstructural Characteristics of ZnO Varistors Simulated by Voronoi Network
The presence of twins in ZnO varistors raises interesting questions concerning the potential role of those electrically distinctive twin boundaries in the characteristics of ZnO varistors.The paper uses Voronoi networks to simulate the microstructures of ZnO varistors.The relation between the relative standard deviation of grain size and the ratio of twin number to grain number is obtained.It indicates that the relative standard deviation decreases with the increasing of the twin ratio.On the other hand,ZnO varistor samples with different content of Al2O3 additive were prepared to gain different twin ratios.The simulation has the same conclusion as that obtained from experiments.The probable mechanism of ZnO grain growth inhibition by twins is that the twins increase the mobility viscosity of ZnO grains and grain boundaries,and drag ZnO grains and liquid grain boundaries during the sintering course,then the grain growth is inhibited,and the microstructure becomes more uniform.
ZnO varistor Voronoi network Microstructural characteristics Twin boundary
Jinliang He Jun Hu Fengchao Luo
State Key Lab of Power Systems,Dept.of Electrical Engineering,Tsinghua University,Beijing 100084,P.R.China
国际会议
The Fifth China International Conference on High-Performance Ceramics (第五届先进陶瓷国际研讨会(CICC-5))
长沙
英文
490-492
2007-05-10（万方平台首次上网日期，不代表论文的发表时间）