彩电用氧化锌压敏电阻器的研制

氧化锌压敏电阻器是一种新型的非线性元件,可广泛用于过压保护、浪涌吸收、消噪等方面。彩色电视机中的压敏电阻器主要用于抑制交流电源侵入的暂态过电压、吸收扫描电路的尖峰脉冲和保护显象管。为了满足彩电元器件国产化的需要,我们研制了MYH-621型压敏电阻器。对电阻体的瓷料配方和制造工艺进行了设计和研究,在对微观结构进行分析的基础上,提出了控制压敏电压、提高通流容量、减小固有电容的一些措施。     

氧化锌压敏电阻器的导电机理及实验

叙述了ZnO压敏电阻器的结构和性能,分析了它的导电机理。并依据此理论进行了工艺实验,研制出了彩电用压敏电阻器。其压敏电压、漏电流和非线性系数等重要参数都达到了彩电元件国产化标准的要求,经用户上机实验,证明设计合理,性能良好。     

ZnO压敏电阻器低压化研究

提出一种低压氧化锌压敏电阻器的制造方法．研究了该电阻器的微观结构和导电机理．在五元配方的基础上加入ＴｉＯ２，并用适当的工艺可制得性能优良的低压产品     

ZnO压敏电阻器低压化研究

提出一种低压氧化锌压敏电阻器的制造方法。研究了该电阻器的微观结构和导电机理。在五元配方的基础上加入ＴｉＯ２并用适当的工艺可制得性能优良的低压产品。     

氧化钐掺杂对氧化锌压敏陶瓷电学特性的影响

以氧化锌、氧化镨、氧化亚钴、氧化铬和氧化钐作为原料,经配料、球磨、造粒、压片和烧结等工序制得压敏电阻片,采用电流-电压特性测试、X射线衍射和扫描电子显微镜分别获得陶瓷的电性能参数,材料成分和微观结构图.实验结果表明:随着氧化钐含量的增加,氧化锌压敏陶瓷的非线性和压敏电压呈现先增大后降低的趋势.当氧化钐摩尔百分比低于0.3时,非线性系数和压敏电压随氧化钐含量的增加而增大.而氧化钐摩尔分数为0.3%时,压敏陶瓷具有最佳非线性电学特性,非线性系数为35,压敏电压为435伏/毫米;继续增加氧化钐至摩尔分数为0.5%时,非线性系数和压敏电压将会降低.氧化钐绝大多数聚集在晶界层,抑制晶粒生长,从而提高了压敏陶瓷的压敏电压.而极少数氧化钐与氧化锌发生置换反应,降低了氧化锌颗粒的电阻,从而提高了非线性.因此氧化锌压敏陶瓷因掺杂氧化钐提高了电性能而有望应用在高压领域.     

氧化锌压敏陶瓷的制备与表征

简析纳米氧化锌压敏陶瓷材料的概念、特性、表征、应用现状,以及制备纳米氧化锌的常见方法和工艺流程,并探讨了纳米氧化锌压敏陶瓷的结构、电参数和导电机理.     

ZnO环形压敏电阻器消噪特性研究及其敏感电压的控制方法

ZnO环形压敏电阻器广泛应用于消除录音机的噪声．理论分析表明,在消除大能量噪声方面,突变型压敏电阻器优于缓变型;在消除小能量噪声时,缓变型效果更佳．本文给出了压敏电压的具体控制方法,对普遍存在的焊后（压）降增大问题提出了解决方案．实验结果表明,理论分析正确,控制方法简便、有效．     

ZnO环形压敏电阻器消噪特性研究及其敏感电压的控制方法

摘要：ZnO环形压敏电阻器广泛应用于消除录音机的噪声. 理论分析表明,在消除大能量噪声方面,突变型压敏电阻器优于缓变型;在消除小能量噪声时,缓变型效果更佳. 本文给出了压敏电压的具体控制方法,对普遍存在的焊后(压)降增大问题提出了解决方案. 实验结果表明,理论分析正确,控制方法简便、有效.     

Nd2O3对氧化锌压敏电阻片压敏电位梯度与组织的影响

研究了微量Nd2O3添加剂对氧化锌压敏电阻片的压敏电位梯度的影响，并通过SEM测试手段对其微观组织进行了分析。结果表明，在0～0．04％(mol)成分范围内，随着Nd2O3含量的增加，氧化锌压敏电阻片的压敏电位梯度明显提高，当Nd2O3含量为0．04％(mol)时，氧化锌压敏电阻片的压敏电位梯度达到最大值，约为583．25V／mm，比不含Nd2O3的原始成分的氧化锌压敏电阻片的压敏电位梯度(约354．42V／mm)增加了约65％。其原因是加入到氧化锌压敏电阻片中的Nd2O3主要分布在晶界上，阻碍了ZnO晶界的迁移，从而抑制了ZnO晶粒的长大，使ZnO晶粒更为细小均匀。     

氧化锌晶须/环氧树脂复合材料减振性能

对氧化锌晶须／环氧树脂复合板材减振阻尼特性进行了研究分析。自由振动实验表明,渗入氧化锌晶须的环氧树脂阻尼效果明显,阻尼系数随晶须渗入量增加呈线性关系。分析认为,氧化锌晶须渗入在复材中将形成微观的阻尼结构,起到降低固有振动频率和增大衰减率的作用。     

Influence of soaking time on nonlinear electrical behavior and dielectric properties of TiO2-based varistor ceramics

The influence of soaking time on the nonlinear electrical behavior and dielectric properties of TiO₂-based varistor ceramics was investigated. Based on single sintering process, six disk samples of (Sr, Bi, Si, Ta)-doped TiO₂-based varistor ceramics were fabricated by sintering at 1 250 °C for 0.5–5.0 h. The samples were characterized by X-ray diffraction, voltage-current characteristics, energy spectra, metallographs, breakdown voltages, and apparent dielectric constant. It is found that the breakdown electrical field intensity at a current density of 10 mA/cm² decreases from 5.5 to 4.1 V/mm first and then increases to 7.0 V/mm, the nonlinear coefficient increases from 2.39 to 2.62 first and then decreases to 2.42, and the apparent dielectric constant increases from 98 200 to 115 049 first and then decreases to 73 865 with the soaking time increasing from 0.5 to 5.0 h. These indicate that the optimal soaking time is 2.0–3.0 h considering both nonlinear electrical behavior and dielectric properties.     

Influence of grain size on distribution of temperature and thermal stress in ZnO varistor ceramics

The nonuniformity of temperature distribution within ZnO varistor ceramics would decrease its energy absorption capability. In this paper, the distributions of current, temperature and thermal stress within the microstructures of ZnO varistor ceramics are simulated using Voronoi diagram models. The results show that the current concentrates through a few paths in ZnO varistor due to the nonuniformity of ZnO grain size and the variety of electrical characteristics of grain boundaries, which induces local high temperature and great thermal stress when injecting impulse current into ZnO varistor, and leads to melting puncture or cracking failure. The influence of the ZnO grain size on the distributions of temperature and thermal stress within ZnO varistor ceramics is analyzed in detail. The energy absorption capability of ZnO varistor ceramics can be greatly improved by increasing the uniformity of ZnO grain size or decreasing the average size of ZnO grains.     

Microstructure and electrical properties of Y2O3-doped ZnO-based varistor ceramics prepared by high-energy ball milling

Y2O3-doped ZnO-based varistor ceramics were prepared using high-energy ball milling （HEBM） and low-temperature sin- tering technique, with voltage-gradient of 1934-2197 V/mm, non-linear coefficients of 20.8-21.8, leakage currents of 0.59-1.04 μA, and densities of 5.46-5.57 g/cm3. With increasing Y2O3 content, the voltage-gradient increases because of the decrease of ZnO grain size; the non-linear coefficient and the leakage current improve but the density decreases because of more porosity; the donor con- centration and density of interface states decrease, whereas the barrier height and width increase because of the acceptor effect of Y2O3 in varistor ceramics.     

SrTiO_3系复合功能陶瓷的一次烧成机理

采用一次烧成法制备了SrTiO3系复合功能陶瓷,测试了样品的介电性能和压敏性能．分析了晶粒和晶界的电学特性,讨论了样品的一次烧成机理。     

ZnO导电陶瓷的制备及电性能研究

采用注浆成型法制得ZnO导电陶瓷 ,通过添加Al2 O3、Cr2 O3、Fe2 O3、La2 O3,探讨了各添加剂对ZnO陶瓷电性能的影响。结果表明 ,聚丙烯酸胺 (PMMA)是ZnO粉体良好的分散剂 ,其质量分数在 0 3%时可得到低粘度、高固含量的ZnO悬浮体。各种氧化物添加剂的添加量对ZnO陶瓷的室温电阻率及电阻温度特性具有较大的影响。随着Al2 O3添加量的增加 ,ZnO陶瓷体的电阻率先略微减小然后增大 ;添加Cr2 O3与添加Al2 O3的效果相反 ;随着Fe2 O3、La2 O3添加量的增加 ,ZnO陶瓷体的电阻率增大。添加Al2 O3、Cr2 O3、Fe2 O3、La2O3的ZnO陶瓷呈现负电阻温度特性。     

Coprecipitation preparation and voltage sensitive characteristics of doped ZnO varistor

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ZnO varistors with high voltage gradient and low leakage current by doping rare-earth oxide

The surge arrester of 1000 kV gas-insulated substation (GIS) needs ZnO varistor with high voltage gradient to effectively improve the potential distribution along ZnO varistor column inside the metal-oxide surge arresters. In this paper, the electrical and structural parameters of ZnO varistors are changed by doping with some rare-earth oxides, and the mechanism which leads these changes is discussed. When rare-earth oxide additives are added into ZnO varistors, the growing speed is slowed down due to the stabilization of the new spinel phases formed in the grain-boundary by rare-earth oxide additives, then the size of ZnO grains is smaller, and the voltage gradient of varistor increases obviously. By adding suitable amount of oxides of metal Co and Mn, the leakage current can be effectively decreased and the nonlinearity coefficient increased. The novel ZnO varistor samples sintered with the optimal additives have a voltage gradient of 492 V/mm, and the nonlinearity coefficient of 76, but their leakage currents are only 1 μA. Supported by the National Nature Science Foundation of China (Grant Nos. 50425721 and 50737001), and the 11th Five-Year National S&T Supporting Plan (Grant No. 2006BAA02A16)     

氧化锌压敏电阻片侧面绝缘性能研究综述

目前,国外的抗大电流冲击绝缘涂层主要为无机侧面釉,而国内此种涂层主要为有机绝缘涂层,在耐大电流冲击性能方面,国外无机产品明显优于国内有机侧面绝缘涂层．综述了国内外近10年来避雷器阀片侧面抗大电流冲击绝缘涂层的研究进展。     

陶瓷蜗轮的研制及材料摩擦磨损机理的研究

通过疲劳磨损比较试验、接触疲劳强度试验和Mg-PSZ陶瓷蜗轮的模拟试验，分析出了陶瓷材料的疲劳磨损计算公式，试验结果表明：陶瓷试件的磨损量较金属试件小；磨损机制主要是磨粒磨损．在不同的振动条件下，Mg—PSZ陶瓷较Al2O3和ZTA（ZrO2增韧Al2O3）陶瓷的接触疲劳强度高，疲劳寿命长，最适合作轻微冲击载荷作用下陶瓷摩擦副零件．