汽车端子表面酸性镀硬化锡工艺

Acid hard tin electroplating process applied to surface of automotive electrical terminals

介绍了一种用于汽车端子表面处理的酸性镀硬化锡工艺,配方和工艺条件为:硫酸亚锡35~50 g/L,浓硫酸100~120 m L/L,硬化剂Z 15~25 m L/L,开缸剂P 30~40 m L/L,温度15~25°C,阴极电流密度2~5 A/dm^2,滚速6~8次/min,连续过滤。介绍了工艺参数控制和镀液维护的注意事项。所得硬化锡层呈光亮、均匀的银白色,结晶致密,耐蚀性、插拔力和防变色能力均合格。

An acid hard tin electroplating process applied to surface treatment of automotive electrical terminal was introduced. The bath composition and process conditions are as follows： stannous sulfate 35-50 g/L, concentrated sulfuric acid 100-120 mL/L, hardening agent Z 15-25 mL/L, makeup P 30-40 mL/L, temperature 15-25 ℃, cathodic current density 2-5 A/dm2, rolling rate 6-8 times per minute, and continuous filtration. Matters needing attentions in process parameters control and bath maintenance were described. The hardened tin coating obtained thereby is bright, uniform, and silvery white, and features compact grains and qualified corrosion resistance, mating/unmating force and anti-tarnish property.