Preparation method of low-temperature-sintering chip-type voltage dependent resistor material

Abstract

A preparation method of a low-temperature-sintering chip-type voltage dependent resistor material includes the following steps: (1) raw material preparation: preparing the raw materials including, on the basis of 100 parts by weight, 1-3 parts of ZrO2, 2-5 parts of FeCl2, 1-2 parts of Fe3O4, 1-2 parts of Fe2O3, 1-3 parts of AlCl3, 1-4 parts of nano Cr2O3, 2-5 parts of nano SiO2, 2-5 parts of Mn2O3, and the balanced being ZnO; (2) mixing the raw materials and adding deionized water, performing wet-milling for 48-50 h and drying the mixture at 140-160 DEG C; (3) under the pressure of 5-8 MPa, shaping the mixture into small round chips being 20 mm in diameter [Phi] and being 1.4-1.8 mm in thickness, and sintering the chips in air and naturally cooling the chips to room temperature; and (4) sinter-coating the two surfaces of the sintered ceramic body with silver. The chip-type voltage dependent resistor has low varistor voltage, high non-linear coefficient and stable voltage-dependent characters, is moderated in sintering temperature, has simple and controllable produce technology, and is low in cost.

Description

technical field [0001] The invention relates to a biomass power generation machine, in particular to a retractable and convenient material retrieving structure of a novel belt conveyor dryer for biomass power generation. Background technique [0002] ZnO varistor is made of ZnO powder as the main body, adding a variety of other metal compound additives (such as Bi2O3, Sb2O3, MnCO3, Co2O3, Cr2O3, etc.) Phase semiconductor ceramic components. Since its invention, ZnO varistors have been widely used in power systems and electronics industries due to their low cost, convenient manufacturing, large nonlinear coefficient, fast response time, and large flow capacity. The general sintering temperature of zinc oxide varistor ceramics is 1100-1500°C, while chip varistors are limited in their sintering temperature due to the addition of internal electrodes inside the ceramic body. The internal electrode metals generally used are platinum, palladium, silver-palladium alloy or pure sil...

AI Technical Summary

Problems solved by technology

The general sintering temperature of zinc oxide varistor ceramics is 1100 ~ 1500 ° C, while chip varistors are limited by the sintering temperature due to the addition of internal electrodes inside the ceramic body.

The internal electrode metals generally used are platinum, palladium, silver-palladium alloy or pure silver. Among them, palladium and platinum are extremely expensive. Using these two metals as internal electrodes will lead to a substantial increase in the cost of the varistor, which is not suitable for industrial production. Pure silver Low sintering temperature (below 950°C) is not conducive to the sintering of zinc oxide ceramics. Therefore, silver-palladium alloys are used as internal electrodes in the current chip varistor industry, and the sintering of zinc oxide varistor ceramics is reduced by improving the formula and process of zinc oxide varistors. temperature, the sintering temperature of the existing zinc oxide varistor material can be reduced to 1020~1100°C, so that the chip varistor can use an alloy with a silver-palladium mass ratio of 6 / 4 or 7 / 3 as the internal electrode, but the cost still higher