Al2O3掺杂对Zn-Bi系压敏陶瓷性能的影响

Effect of Al2O3 Doping on Properties of Zn-Bi Varistor Ceramics

采用Al2O3掺杂,通过固相法制备Zn-Bi系压敏陶瓷,研究了不同比例Al2O3对ZnO陶瓷的晶粒大小、显微结构以及电性能的影响。研究表明ZBSCCMY配方中掺杂少量Al2O3制备得到ZnO压敏陶瓷样品的晶粒大小愈加均匀,显微结构更加致密;陶瓷物相主要由ZnO相、少量的Bi2O3相和微量的Zn7Sb2O7尖晶石物相构成;少量Al2O3的掺杂改进了晶粒和晶界结构和成分,活化了晶界,降低烧制压敏陶瓷的烧结温度,优化了压敏陶瓷的非线性特性。当掺杂浓度为0.05wt%、烧结温度为1100℃、保温2h得到性能良好的压敏陶瓷,其压敏电位梯度可达810V/mm,非线性系数为68,漏电流为2.4μA。

Zn-Bi varistor ceramics were prepared by solid phase method with Al2O3 doping.The grain size of ZnO ceramics with different Al2O3 ratios was studied.The effect of microstructures and electrical properties on the microstructure and electrical properties of ZnO varistor ceramics prepared by doping a small amount of Al2O3 in the ZBSCCMY formula shows that the grain size and microstructure of ZnO varistor ceramics become more uniform and denser,and the phase of the ceramics is mainly composed of ZnO phase.A small amount of Bi203 phase and a small amount of Zn7Sb2O7 spinel phase are formed,and a small amount of Al2O3 doping improves the structure and composition of grain and grain boundary,activates the grain boundary and reduces the firing of pressure-sensitive ceramics.The nonlinear characteristics of the varistor ceramics were optimized at the sintering temperature of 0.05 wt%.when the doping concentration was 0.05wt%,the sintering temperature was 1100℃ and the holding time was 2h, the varistor potential gradient could reach 810V/mm,the nonlinear coefficient was 68 and the leakage current was 2.4μA.