锌合金、铝合金光亮中性滚镀镍工艺

Process for bright nickel barrel plating on zinc and aluminum alloys in a neutral bath

介绍了一种近中性(pH=5.5～6.0)滚镀镍工艺,其镀液由硫酸镍、氯化镍、硼酸、开缸剂、柔软剂、主光剂和润湿剂组成。用于锌合金滚镀时,工艺流程主要包括机械或化学除油、活化酸盐活化、预镀碱铜、硫酸活化、镀中性镍和离心机烘干;用于铝合金时,工艺流程主要包括热浸除油、酸活化、一次浸锌、硝酸退锌、二次浸锌、镀中性镍和烘干。给出了各工序的工艺条件及日常维护、故障处理的方法,对比了该中性镀镍液与普通光亮镀镍液对锌杂质的容忍度。采用该中性镀镍工艺可在锌、铝合金工件上获得有亮丽金属光泽的镀镍层,既提高了成品率和生产效率,又节省了生产成本。

A near neutral （pH 5.5-6.0） nickel barrel plating process was introduced. The bath is composed of NiSO4, NiC12, H3BO3, makeup agent, softening agent, primary brightening agent, and wetting agent. The process flow mainly consists of mechanical or chemical degreasing, activating with active acid salt, alkaline copper pre-plating, sulfuric acid activating, neutral nickel plating, and centrifugal drying for barrel plating of zinc alloys, and of hot-dip degreasing, acid activating, first zinc immersion, zinc stripping with nitric acid, secondary zinc immersion, neutral nickel plating, and dry for aluminum alloys. The operation conditions of individual procedure and the methods of routine maintenance and troubleshooting were presented. The tolerance of the neutral nickel plating bath and a conventional bright nickel plating bath to zinc impurity was compared. The neutral nickel plating process produces bright nickel coatings on zinc and aluminum alloys, improving the rate of eligible products as well as production efficiency and saving cost.