TiO₂ Added Zn-Bi Based Varistors: Microstructure, I-V, Flow and Aging Characteristics

Abstract:

TiO₂ was added in Zn-Bi based varistors to enhance the grain growth of ceramics and the effects of TiO₂ addition on the microstructure, I-V, flow and aging characteristics of Zn-Bi varistors were studied. The voltage-gradient of samples decreased to minimum value of 30.6 V/mm when the TiO₂ content was 0.6 mol%, but increased with further increasing TiO₂ content. The variation trend of average grain size was just the opposite of the voltage-gradient. 0.6 mol% TiO₂ added samples have a more unify microstructure and excellent three parameter values with I_L=5.7μA, E_1mA=30.6V/mm, α=25.8. After Dc aging at 125 ^oC for 7h, the voltage variation of samples is very slow (~-4.1%).

• Periodical: Key Engineering Materials (Volume 633)
• Pages: 303-307
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.633.303
• Online since: November 2014
• Authors: Shu Zhao Hao, Huan Fu Zhou*, Rui Li Guo, Dong Jin Chu, Xiu Li Chen, Chang Zheng Hu, Bao Cheng Chang, Yuan Dong Qin, Liang Fang
• Keywords: Grain Growth Additives, Low Voltage, Varistor, Voltage-Sensitive Property

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