氧化锌的理化性能对金属氧化物电阻片电性能的影响

Effect of Physical and Chemical Properties of Zinc Oxide on Electrical Performance of Metal Oxide Varistor

氧化锌是生产电阻片的主要原材料,氧化锌的理化性能对电阻片的质量起着至关重要的作用。通过对氧化锌的理化性能:主含量、杂质含量(钾、钠、铁、镉、铅)、粒度、晶型结构、水分、盐酸不溶物及金属锌含量进行测试分析。根据多年测试经验,对氧化锌测试方法及关键技术条件要求进行了可行性改进,并结合生产实际使用情况,跟踪分析电阻片质量状况,判断氧化锌理化性能要求对电阻片电性能的影响。研究表明,氧化锌中铁、金属锌及钠等杂质含量过多能使电阻片的漏流增大,铅杂质含量过多能使电阻片的方波性能下降,铜、钠杂质含量过多能使电阻片的压比升高。为了控制氧化锌中的杂质含量和提高电阻片的产品性能,建议生产上使用0号锌锭间接法生产的氧化锌,粉体颗粒形状最好接近球状,粒度范围最好控制在0.43-0.55μm之间。

Zinc oxide is the main raw material for production of varistor. The physical and chemical properties of zinc oxide on varistor quality play a vital role. Physical and chemical properties of zinc oxide such as main content, impurity content （potassium, sodium, iron, cadmium, lead）, particle size, crystal structure, water content, hydrochloric acid insoluble matter and metal zinc content were tested and analyzed. Testing methods and key technical requirements of the zinc oxide were feasibly improved on basis of years of testing experience. Combined with the actual usage of production, the quality status of the varistor was tracked and analyzed to determine the effect of requirements of physical and chemical properties of zinc oxide on electrical performance of varistor. The study showed that the leakage current of the varistors would increase if the content of impurities such as iron, zinc metal, and sodium in zinc oxide was too high, the square wave current withstanding would decrease if too high content of lead impurity and the residual voltage ratio would increase if too high content of copper and sodium impurities in zinc oxide. In order to control the content of impurities in the zinc oxide and to improve the performance of varistors, for the production of zinc oxide varistors, it was recommended to use zinc oxide powder produced with No 0 zinc ingots by the indirect method. The particle shape of zinc oxide had better close to spherical, the particle size range had better controlled to be between 0.43 and 0.55 μm.