High-gradient ZnO varistor ceramic material without Bi, Pr or V and preparation method of varistor ceramic material

A varistor ceramic and high-gradient technology, which is applied in the field of varistor ceramic materials, can solve the problems of poor performance, impact on stable performance, and small storage capacity, and achieve the goals of increasing nonlinear coefficient, excellent comprehensive performance, and improving varistor voltage Effect

Active Publication Date: 2019-07-09
SHANGHAI INST OF CERAMIC CHEM & TECH CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the potential gradient of most ZnO varistors developed in my country is around 300 V / mm, which cannot meet the application requirements of miniaturization.
[0004] In addition, the current ZnO varistor ceramics mainly contain ZnO / Bi 2 o 3 system, ZnO / Pr 6 o 11 system, ZnO / V 2 o 5 system, ZnO / BaO system, but these types of materials have the following problems: (1) At high temperature, Bi 2 o 3 It will volatilize a lot. During the cooling process, the rich Bi with low eutectic melting point 2 o 3 Due to the poor wettability of the liquid phase with the ZnO crystal grains, the crystallization at the intersection of polycrystals has a certain impact on the stability; (2) Pr 6 o 11 The price is expensive, and there is less storage on the earth, which is not conducive to industrial production; (3) V 2 o 5 It has high toxicity and is not conducive to industrial production. In addition, ZnO / V 2 o 5 (4) ZnO / BaO series varistor ceramics, although its modified additives are non-toxic and cheap, but the performance of the varistor ceramics in this system is unstable, Its performance will deteriorate over time, mainly because BaO will react with moisture and gas in the air, making its performance decline
[0005] Although Patent Document 1 (Chinese Publication No. CN106747404A) discloses a novel ZnO varistor ceramic material without Bi, Pr, V, the varistor voltage of the resulting zinc oxide varistor is not high, ranging from 360 to 700 V / mm, cannot meet the application requirements of the development of the transmission and transformation voltage in the direction of ultra-high voltage and ultra-high voltage, and the development of electronics and circuits in the direction of ultra-integration and miniaturization. Therefore, it is necessary to develop high-gradient ZnO varistor ceramic materials

Method used

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  • High-gradient ZnO varistor ceramic material without Bi, Pr or V and preparation method of varistor ceramic material

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Embodiment 1

[0043] The formula of the present embodiment is as follows: ZnO (97.56mol%), CaCO 3 (2mol%), Co 2 o 3 (0.33mol%), Cr 2 o 3 (0.1mol%), Sb 2 o 3 (0.01mol%);

[0044] Put the above materials together into a nylon tank, use zirconia balls or stainless steel balls, and use water as the medium for wet grinding in a planetary ball mill, with a rotation speed of 500rpm, a material-to-ball ratio of 10:1, and ball milling for 8 hours; bake the slurry at 120°C After drying, calcinate at 450°C for 2 hours to obtain composite powder; then add 10% PVA binder, artificially granulate, and then press out a green body with a diameter of 12mm; / min increased to 1200°C, held for 3 hours and then cooled with the furnace to obtain a dense ZnO ceramic material. A zinc oxide varistor ceramic material with a varistor voltage of 650 V / mm, a nonlinear coefficient of 52 and a leakage current of 0.1 μA can be obtained.

Embodiment 2

[0046] The formula of the present embodiment is as follows: ZnO (97.47mol%), CaCO 3 (2mol%), Co 2 o 3 (0.33mol%), Cr 2 o 3 (0.1mol%), Sb 2 o 3 (0.1mol%);

[0047] The experimental conditions were operated as described in Example 1, and a zinc oxide varistor ceramic material with a varistor voltage of 880 V / mm, a nonlinear coefficient of 67, and a leakage current of 0.1 μA could be obtained.

Embodiment 3

[0049] The formula of the present embodiment is as follows: ZnO (97.42mol%), CaCO 3 (2mol%), Co 2 o 3 (0.33mol%), Cr 2 o 3 (0.1mol%), Sb 2 o 3 (0.15mol%);

[0050] The experimental conditions were operated as described in Example 1, and a zinc oxide varistor ceramic material with a varistor voltage of 1230 V / mm, a nonlinear coefficient of 165 and a leakage current of 0.1 μA could be obtained.

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Abstract

The invention relates to a high-gradient ZnO varistor ceramic material without Bi, Pr or V and a preparation method of the varistor ceramic material. The high-gradient ZnO varistor ceramic material iscomposed of zinc oxide and a modification additive, wherein the content of the zinc oxide is 87.5-99.69 mol%, the content of the modification additive is 0.31-12.5 mol%, and a sum of the molar contents is 100 mol%; and the modification additive also includes Sb2O3 in addition to CaCO3, Co2O3, Cr2O3 and La2O3, wherein the molar content of the Sb2O3 is 0.01-1 mol%.

Description

technical field [0001] The invention relates to a high-gradient zinc oxide (ZnO) pressure-sensitive ceramic material without Bi, Pr, V, Ba, etc. and a preparation method thereof, belonging to the technical field of pressure-sensitive ceramic materials. Background technique [0002] Compared with traditional surge arresters, ZnO varistors have excellent electrical properties such as large nonlinear coefficient, fast response time, and strong flow capacity, and the process is simple. Therefore, ZnO varistors quickly become the leading material for making varistors, and are widely used in communications, electric power, transportation, industrial control, automotive electronics, medical equipment and household appliances. [0003] In recent years, with the development of transmission and transformation voltage towards ultra-high voltage and ultra-high voltage and the development of electronics and circuits towards ultra-integration and miniaturization, it is particularly urgent...

Claims

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Application Information

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Patent Type & AuthorityApplications(China)
IPC IPC(8): C04B35/453
CPCC04B35/453C04B2235/3227C04B2235/3241C04B2235/3275C04B2235/3294C04B2235/442C04B2235/96
Inventor田甜李国荣郑嘹赢曾江涛阮学政
OwnerSHANGHAI INST OF CERAMIC CHEM & TECH CHINESE ACAD OF SCI