中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 22 No. 6 June 2012 |
（1. School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, China;
2. Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors,
Chinese Academy of Sciences, Beijing 100083, China;
3. State Key Laboratory of Electrical Insulation and Power Equipment,
Xi’an Jiaotong University, Xi’an 710049, China;
4. Changzhou Engineering Research Institute of Jiangsu University, Changzhou 213000, China;
5. State Key Laboratory of Inorganic Synthesis and Preparative Chemistry,
College of Chemistry, Jilin University, Changchun 130012, China）
Abstract:ZnO varistor ceramics doped with Bi2O3, Sb2O3, Co2O3, Cr2O3, and MnO2 were prepared separately by two high-energy ball milling processes: oxide-doped and varistor ceramic powder. A comparison in the electrical and microstructural properties of the samples obtained by both methods was made. The best results on these characteristics were achieved through the high-energy ball milling varistor ceramic powder route, obtaining a nonlinear coefficient of 57 and a breakdown field of 617 V/mm at a sintering temperature of 1000 °C for 3 h. The samples synthesized by this technique show not only high density value, 95% of the theoretical density, but also a homogeneous microstructure, which compete with those obtained by the high-energy ball milling oxide-doped powder route. With the advantage that the high-energy ball milling varistor ceramic powder route can refine grain, increase the driving force of sintering, accelerate the sintering process, and reduce the sintering temperature.
Key words: varistor; ZnO; high-energy ball milling; electrical characteristic; microstructure
