包覆法制备氧化锌压敏陶瓷粉料的研究

Study of preparing zinc oxide varistor powders by ZnO-coating process

通过对包覆法制备ZnO压敏陶瓷粉体的研究,证明包覆法可以制得恒定组成的复合粉体,该粉体经压制烧结后制成的ZnO压敏陶瓷,与用传统氧化物混合法制备的ZnO压敏陶瓷相比,其一致性更好、耐电流冲击能力更强、击穿电压更高,烧结密度达5.52 g/cm3,明显高于传统机械混合法的5.40 g/cm3;制备出的压敏电阻片性能为:漏电流小于10μA,击穿电压为240 V/mm,最大非线性系数为45。

The study results of preparing varistor powders by ZnO-coating process show that,this process can produce the same constant composite powders as designed;and comparing to the products prepared by conventional mechanical mixing process,the product prepared by this process is more uniform,has stronger current-impact resistant ability and higher spark out voltage,and its density can reach 5.52g/cm^3 which is higher than that of mechanical process(5.4g/cm^3).The prepared varistors using this powder material display much better performances,for example,the leak current less than 10μA,spark out voltage 240V/mm and the biggest non-linearity coefficient 45.