低压高通流量ZnO压敏电阻的研究

发布时间：2018-03-30 06:32

本文选题：低压　切入点：ZnO　出处：《华中科技大学》2015年硕士论文

【摘要】：ZnO压敏电阻是一种以氧化锌为主体,掺杂若干其他氧化物改性的陶瓷材料,具有优良的非线性系数,大的浪涌吸收能力,在稳态工作状态下漏流值很小。随着家用电器、电子计算机、通讯技术等方面的发展,对保障这些系统正常运行的低压压敏电阻器的需求越来越大,而国内相应产品的通流量和漏电流值难以满足要求,因此本课题的目的在于研究低压高通流量ZnO压敏电阻的制备。首先,本文对ZnO压敏电阻的材料配方进行改进,分别通过掺杂TiO2来降低实验样品的压敏场强、掺杂SiO2来提高其致密度、掺杂Al2O3来改善其大电流特性。研究发现,在本论文掺杂范围内,TiO2在降低样品的压敏场强的同时降低了非线性系数和增大了漏电流,SiO2在提高样品致密度的同时增大了压敏场强,Al2O3在改善样品大电流特性的同时降低了非线性系数和增大了漏电流。本论文通过调整TiO2、Si O2、Al2O3的掺杂量来获得一个综合性能较好的材料配方。此外,本文还研究了Bi2O3、Sb2O3的掺杂量对制备低压高通流量ZnO压敏电阻性能的影响。其次,在对材料配方改进后,本文研究了烧结过程中的降温速率,以及Al2O3的掺杂方式对实验样品性能的影响。研究发现,适当的降低降温速率会有助于提高样品的晶界电阻,从而提高样品非线性系数和减小漏电流。同时,研究发现将Al2O3通过先和ZnO混合再预烧的方式掺杂后,使得样品在具有较低的晶粒电阻的同时具有较高的晶界电阻,从而提高了样品的非线性系数和减小了漏电流。通过材料配方和制备工艺的改进,最终得到的实验样品压敏场强为123.5 V/mm,非线性系数为58.5,漏电流为1.2μA,残压比K100A为1.56,在承受5 kA的8/20μs脉冲电流后压敏电压变化率U1mA为7%。
[Abstract]:ZnO varistor is a kind of ceramic material with zinc oxide as the main body and some other oxides modified. It has excellent nonlinear coefficient, large surge absorption ability and low leakage value in steady state. With the development of computer and communication technology, the demand for low-voltage varistors, which can guarantee the normal operation of these systems, is increasing, but the flux and leakage current of the corresponding domestic products are difficult to meet the requirements. Therefore, the purpose of this paper is to study the preparation of low-voltage and high-flow ZnO varistor. Firstly, the material formula of ZnO varistor is improved to reduce the varistor field strength by doping TiO2, respectively. Doping SiO2 to improve its density, doping Al2O3 to improve its high current characteristics. In the range of doping in this thesis, TIO _ 2 decreases the varistor field strength and decreases the nonlinear coefficient and increases the leakage current. Sio _ 2 increases the density of the sample and increases the voltage field strength of Al _ 2O _ 3 in improving the high current characteristics of the sample. In this paper, the doping amount of TIO _ 2O _ 2Si _ 2O _ 2O _ 2O _ 3 is adjusted to obtain a material formula with better comprehensive properties. The influence of doping amount of Bi _ 2O _ 3 and SB _ 2O _ 3 on the properties of ZnO varistor with low voltage and high flux was also studied. Secondly, the cooling rate during sintering was studied after the material formulation was improved. And the influence of doping mode of Al2O3 on the properties of experimental samples. It is found that a proper decrease of cooling rate will help to increase the grain boundary resistance of the samples, thus increase the nonlinear coefficient of the samples and reduce the leakage current, at the same time, It is found that the doping of Al2O3 by mixing with ZnO before sintering makes the sample with lower grain resistance and higher grain boundary resistance. Thus, the nonlinear coefficient of the sample is improved and the leakage current is reduced. The experimental results show that the varistor field strength is 123.5 V / mm, the nonlinear coefficient is 58.5, the leakage current is 1.2 渭 A, the residual voltage ratio K100A is 1.56, and the variable-rate of variable-voltage is 7 after withstanding 8 / 20 渭 s pulse current of 5 Ka.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ174.756

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