锌酸盐镀锌阴极电流效率的研究

对碱性锌酸盐镀锌阴极电流效率的影响因素进行系统的研究。通过控制镀液组成及工艺条件可以在一定程度上提高阴极电流效率。增加镀液中锌离子质量浓度、适当控制阴极电流密度，升高镀液温度均可提高阴极电流效率；铁离子配合剂ZFC及添加剂ZFA的加入，使阴极电流效率降低。碱性锌酸盐镀锌阴极电流效率低的原因是配合离子Zn(OH)4^2-电沉积的阴极电势很负引起阴极大量析氢。合金镀层中引入铁明显降低了电沉积的阴极电流效率。

A Study of the Cathodic Current Efficency in Zincate Zinc Plating

The factors affecting the cathodic current efficiency of zincate zinc plating are systematically studied. The results show that the cathodic current efficiency can be improved to a certain extent by controlling bath composition and process conditions. By increasing Zn 2+ concentration, properly controlling current density and raising electrolye temperature, a better current efficiency can be obtained. Addition of complexing agent Fe 2+ (ZFC) and additive ZFA will reduce the current efficiency. The reason for low cathodic current efficiency in alkaline zinc plating is that the electrodeposition potential of complexing ion Zn(OH) 4 2- is so negative that H 2 is released greatly at cathode. The existing of iron in the alloy coating evidently reduces the cathodic current efficiency of electro deposition.