BT基Y5V高压电容瓷织构对抗电强度的影响

在研制BaTiO3(BT)基Y5V高压电容器瓷料基础上,对不同配方的试样进行交流高压试验,SEM显微结构分析结果显示,当试样晶粒较小时(3~10μm),抗电强度较高(≥4.3MV/m),强交流电场引起的晶粒应力、应变不足以导致晶粒击穿;而晶粒较粗时(≥20μm),其应力、应变导致抗电强度明显降低。瓷体中次相对强交流电场有缓冲作用,随含量增加而抗电强度提高,但介电常数降低。在此基础上探讨了瓷体织构对抗电强度影响机制。

Influence of Ceramics Structure on the Breakdown Voltage of BaTiO3-based Y5V Capacitors

Researched and prepared were the BaTiO3-based Y5V capacitor ceramic materials, choosing samples to have a strong A.C voltage test. Analyzed was the microstructure of the samples by SEM. The results show that the samples with small grain size (3~10 μm) have high breakdown voltage, that the stress and strain caused by the strong A.C electric field won’t cause the breakdown ; while the grain size was large (≥20 μm),the affection of the stress and strain on the breakdown voltage were obvious. The second phases have a buffering against the strong A.C electric field. As the content of second phases increases, the breakdown voltage increases, but its dielectric constant decreases. The mechanism of influence the ceramics structure on the breakdown voltage was also discussed.