焦磷酸盐-柠檬酸盐体系电镀光亮Zn-Ni合金的研究

Bright Zn-Ni alloy Electroplating in Pyrophosphate Citrate Bath

介绍了一种电镀光亮Zn-Ni合金的新工艺。应用赫尔槽试验、小槽电镀、扫描电子显微镜等方法,研究了溶液中ρ(Ni2+)/ρ(Zn2+)、温度、pH、阴极电流密度等对合金镀层中含Ni量的影响。其溶液组成是:100～120g/L焦磷酸钾,45～55g/l柠檬酸钠,25～35g/L ZnSO4.7H2O,35～45g/L NiSO4.6H2O,0.2～0.4g/L添加剂A,0.1～0.2g/L添加剂B。实验结果表明,在θ=10～35℃,pH=8～10,Jκ=0.5～5A/dm2条件下,可得到w(Ni)为12%～18%的光亮的、耐蚀性能好的Zn-Ni合金镀层。

A new technology of bright Zn-Ni alloy electroplating was proposed in this paper.The effects of ρ（Ni2＋）/ρ（Zn2＋）,temperature,pH value,cathodic current density on the content of Ni in Zn-Ni alloy coating were investigated by Hull cell tests,small bath electroplating and scanning electronic microscopy.The optimum composition of plating electrolyte was 100~120g/L potassium pyrophosphate,45~55g/L sodium citrate,25~35g/L ZnSO4·7H2O,35~45g/L NiSO4·6H2O,0.2~0.4g/L additive A and 0.1~0.2g/L additive B.Under the conditions of 10~35℃ temperature,pH value of 8~10,cathodic current density of 0.5~5.0A/dm2,a bright Zn-Ni alloy coating with Ni content of 12%~18% and higher corrosion resistance was obtained.