摘要
采用相同的工艺制备了氧化锌(Zn O)陶瓷坯体,然后在1 140℃下常压和高压(20 MPa)烧结2 h形成压敏陶瓷块样品。为了比较烧结方式对Zn O压敏陶瓷的微结构和电学性质的影响,利用扫描电子显微镜观察了压敏陶瓷的微结构,并测试了Zn O压敏陶瓷的I—U和C—U曲线。结果表明,热压烧结得到的样品晶粒较小,析出相的含量较低。I—U曲线的测试也表明,热压烧结和普通烧结的Zn O陶瓷的电位梯度分别为5 230 V/cm和3 980 V/cm,非线性系数分别为32和19,说明热压烧结Zn O陶瓷的压敏性能得到了较大的提高。C—U曲线表明,压敏性能提高的机理是热压烧结导致Zn O晶粒内部的掺杂浓度大大提高,这也与观察到的微结构相吻合。
In this paper,the Zn O ceramics were prepared using a conventional ceramic process. Then varistors were fabricated by conversional sintering（ CS） and hot-press sintering（ HP,20 MPa） at 1 140 ℃. In order to investigate the influence of the sintering method on the Zn O varistors,the scanning electron microscopy（ SEM） was used to observe the microstructure. The electrical properties of the two types of Zn O varistors,including current-voltage（ I—U） and capacitance-voltage（ C—U） were measured. The results show that there are smaller grain size and less precipitated phase in the HP samples. The breakdown electrical field of the HP and CS sample are 5 230 V / cm and 3 980 V / cm,respectively. The nonlinear coefficients of the HP and CS sample are 32 and 19 respectively. So the hot-press sintering can improve the voltage-sensitive properties. The mechanism is demonstrated by the C—U curve that the improved doping concentration in the Zn O grains,the result is consistent with the SEM observation.
出处
《实验室研究与探索》
CAS
北大核心
2016年第5期46-48,59,共4页
Research and Exploration In Laboratory
关键词
氧化锌压敏陶瓷
热压烧结
微结构
电学性质
ZnO varistor
hot-press sintering
microstructure
electrical properties
