High potential gradient zinc oxide pressure-sensitive resistor material and preparation process thereof

Abstract

The invention relates to a high potential gradient zinc oxide pressure-sensitive resistor material and a preparation process thereof. The high potential gradient zinc oxide pressure-sensitive resistor material with uniform particle sizes is obtained by weighing a main material ZnO, a doping oxide, and a product rare earth oxide obtained by carrying out thermal decomposition on a rare earth oxalate or / and carbonate or / and hydroxide according to proportions, carrying out high energy wet grinding, drying, presintering at 200-800DEG C, carrying out high energy dry grinding, and sintering at 800-1100DEG C. The preparation process of the invention has the advantages of simplicity, low cost, environmental protection and low energy consumption, and the prepared zinc oxide pressure-sensitive resistor material can be used for preparing high quality lightning arrester products for ultrahigh electric power systems.

Description

technical field [0001] The invention relates to the technical field of varistor material preparation, in particular, the invention relates to a high potential gradient zinc oxide varistor material and a preparation method thereof. Background technique [0002] A varistor is a resistor whose resistance value changes with voltage within a certain current and voltage range, or "resistance value is sensitive to voltage". The English name is "Voltage Dependent Resistor" abbreviated as "VDR", or "Varistor". The resistor material of the varistor is a semiconductor, so it is a variety of semiconductor resistors. "Zinc oxide" (ZnO) varistors, which are widely used now, are composed of divalent element (Zn) and hexavalent element oxygen (O) as the main material. So from the material point of view, the zinc oxide varistor is a "II-VI oxide semiconductor". [0003] ZnO has a hexagonal wurtzite structure and is a metal-excess non-stoichiometric n-type semiconductor. ZnO varistors have...

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Problems solved by technology

Among them, although the rare earth oxide obtained by decomposing yttrium nitrate and praseodymium nitrate reduces the production cost, a large amount of atmospheric pollutants such as nitrogen oxides will be released when the nitrate is decomposed, which will cause serious pollution to the environment. At the same time, the invention The sintering temperature is as high as 1200°C, which will increase energy consumption, which is not conducive to the promotion and application of industrialization

[0007] Due to the following problems in the preparation process of the existing high-potential gradient zinc oxide varistor materials: on the one hand, the sintering temperature is high, the energy consumption is large, and the production cost is greatly increased, which is not conducive to industrialization. However, by reducing the varistor When the sintering temperature is used to reduce the growth rate of ZnO grains, or the holding time is shortened to reduce the grain growth time to increase the potential gradient of the ZnO varistor, the volt-ampere nonlinearity, current flow capacity and aging performance of the varistor will be affected. On the other hand, when it comes to the use of rare earth oxide doping to increase the potential gradient of zinc oxide varistors, most of the commercially available rare earth oxides are directly doped, or the nitrate decomposition of rare earth elements is used to obtain doped varistors. The rare earth oxides needed for miscellaneous use, these methods will either increase the production cost, or pollute the environment, and are not conducive to industrial production