High-performance zinc oxide composite ceramic voltage dependent resistor material and preparation method

Abstract

The invention relates to high-performance zinc oxide composite ceramic voltage dependent resistor material and a preparation method, which belongs to the technical field of electronic ceramic preparation and application. The ceramics takes zinc oxide as main phase, adopts praseodymium oxide as nonlinear initial phase, adopts a small amount of oxides of Co, Cr, Fe or W as potential gradient and nonlinear reinforcing agent, and comprises the following components by mole percent: 80 to 95 percent of ZnO, 0.01 to 15 percent of Pr6O, 0.01 to 10.0 percent of CoO, 0.01 to 8.0 percent of Cr2O3, 0.0 to 5.0 percent of Fe2O3 and 0.0 to 3.0 percent of WO3. The material preparation method comprises the following processing step in sequence: mixing->high-energy ball milling->drying->mixing and pelletizing->sifting->compression moulding forming->sintering->silver-layer coating. The voltage dependent resistor material has the advantages that the crystal grain is fine, the microscopic structure is uniform, the potential gradient E (the potential gradient value corresponding to 1 mA / cm<2> current density) is increased to 570 to 750 V / mm, the nonlinear coefficient alpha is 24 to 32, and the leakage current IL (the current density value corresponding 75 percent E) is 0.004 to 0.006 mA / cm<2>, and has excellent over-all electrical properties. The voltage dependent resistor material can be used for manufacturing the lightning arresters of ultra high voltage / extra high voltage power systems, and can realize the miniaturization of the lightning arrester. The invention can also be used for manufacturing cell phones and household appliance chip or multiplayer chip voltage dependent resistors.

Description

technical field [0001] The invention relates to a high-performance zinc oxide composite ceramic varistor material and a preparation method, belonging to the technical field of electronic ceramic preparation and application. Background technique [0002] Zinc oxide composite ceramic varistor material is a widely used electronic ceramic material to limit transient surge voltage. The material composition and microstructure of zinc oxide varistors have a great influence on material performance, and the requirements for material formulation and firing process are very strict; currently commercial zinc oxide varistors use bismuth-based (non-linear initial phase is bismuth oxide) varistors. Formulation of Resistive Materials (Gupta TK. Journal of the American Ceramic Society, 1990; 73: p1817). However, the material formula of this system requires many types of trace additives, and bismuth oxide has strong volatility and high reactivity during the sintering process. The former chan...

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Problems solved by technology

However, the material formula of this system requires many types of trace additives, and bismuth oxide has strong volatility and high reactivity during the sintering process. The former changes the relative ratio of each component and thus changes the performance of the varistor. The latter It destroys the micro-resistance structure that composes the overall resistor, and at the same time, it is easy to generate an insulating spinel phase in the bismuth-based varistor material, thereby greatly reducing the surge absorption capacity of the varistor.

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