High-potential-gradient ZnO voltage-sensitive ceramic based on cold sintering and preparation method thereof

Abstract

The invention relates to a high-potential-gradient ZnO voltage-sensitive ceramic based on cold sintering and a preparation method thereof. The method comprises the following steps of: mixing ZnO, Bi2O3, CoO and Mn2O3 according to a molar ratio of 95-100%:0-5%:0-5%:0-5%; and then carrying out wet ball milling for 12h, drying the mixed powder for 12h at a temperature of 80DEG C, putting the mixed material into a metal mold, performing sintering for 1-3h at a temperature of 200-300DEG C by adopting a cold sintering technology, and conducting natural cooling to obtain the target voltage-sensitiveceramic. According to the method, the voltage-sensitive ceramic is prepared by adopting a cold sintering technology, the sintering temperature and the heat preservation time are greatly reduced, the method is more energy-saving and environment-friendly, the potential gradient of the obtained ZnO voltage-sensitive ceramic reaches up to 3300V / mm or above, and the nonlinear coefficient reaches up toabout 40.

Description

Technical field [0001] The invention relates to pressure-sensitive ceramics, in particular to a preparation method of high-potential gradient ZnO pressure-sensitive ceramics. Background technique [0002] Varistor ceramics refer to non-linear volt-amperes in a specific voltage range ( I-V ) Characteristics, an electronic material whose resistance value decreases sharply as the voltage increases to a certain value (varistor voltage). It is a typical electronic functional material controlled by the grain size and grain boundary structure. The increase in the voltage level of transmission lines puts forward higher requirements for the light weight and miniaturization of overvoltage protection devices. At the same time, the increasing demand for higher integration, high speed, and low power consumption of integrated circuits in information technology also drives power electronics Devices are becoming more and more miniaturized. [0003] The traditional ZnO pressure-sensitive ceramic f...

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Problems solved by technology

[0003] Traditional ZnO varistor ceramics have complex formulations and preparation processes, including complex processes such as material mixing, pre-sintering, sieving, granulation, and debinding. The final sintering temperature is usually at 1100 o More than C, keep warm for more than 2 hours, high energy consumption, and the potential gradient of ZnO varistor ceramics is not high, usually around 200-500V / mm, it is difficult to meet the current miniaturization requirements of power electronic devices

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