摘要
对碱性锌酸盐体系电镀Zn -Fe合金阴极电流效率的影响因素进行了系统的研究 ,并分析了镀层中铁原子的引入对Zn -Fe合金电镀阴极电流效率的影响原因及合金镀层中铁含量与阴极电流效率的关系 ,以期通过控制镀液组成及工艺条件在一定程度上提高阴极电流效率。增加电镀液中锌铁离子总摩尔浓度 ,提高镀液中锌铁离子摩尔比 ,降低铁离子浓度 ,适当控制阴极电流密度 ,升高镀液温度均可提高锌铁合金电沉积的阴极电流效率。添加剂ZFA的加入使Zn -Fe合金电镀的阴极电流效率降低。合金镀层中引入Fe明显降低了电沉积的阴极电流效率 ,镀层中的Fe含量从 0升高至 0 .73% ,合金电沉积的阴极电流效率却从 79.4 8%降低至 6 8.2 3%。这是由于碱性溶液中 ,氢气在金属Fe上析出的过电势明显小于在金属Zn上的过电势 ,使析氢容易进行引起的。
Effect factors of cathodic current efficiency in zincate Zn-Fe alloy electroplating were systematically studied, and the influence of iron atom in plating on current efficiency and their correlation were analyzed, thus the current efficiency could be improved to some extent by controlling bath ingredients and process conditions. Increasing the total concentration or mol ratio of zinc ion and iron ion in electrolyte, decreasing the iron ion content, or controlling adequate cathodic current density, all can increase the current efficiency of Zn Fe alloy electroplating. Whereas adding of additive ZFA and introducing Fe in plating will reduce the current efficiency, in evidence current efficiency decreases from 79.48 % to 68.23 % while Fe content in plating increases from 0 to 0.73 % . The cause is that hydrogen evolution become easy on metal Fe for lower overpotential than metal Zn in alkaline solution.
出处
《材料保护》
CAS
CSCD
北大核心
2004年第5期16-18,共3页
Materials Protection
