Electroplated nickel coating contg. fine graphite dispersion - for reducing wear or relay components or other parts

摘要

Bath for the electrodeposition of nickel-graphite dispersion coatings, using an aq. soln. contg. 300-450 g/l nickel sulphamate, 2-50 g/l fine graphite, 0.05-1 g/l wetting agent suitable for an acid bath, 20-50 g/l nickel chloride, and 20-40 g/l boric acid. The wetting agent is pref. sodium lauryl sulphate, and the graphite pref. has size 1 mu m - 5 mu m. The bath pref. has a Ni ion concn. of 1.3-2 mole/l, pH 2-4, and a current density 1-20, esp. 5-10 A/dm2 at 40-60 degrees C. using intensive stirring and a large anode to cathode distance. Used for the redn. of mechanical wear or friction on surfaces. The bath can be used continuously to provide smooth and uniform coatings, i.e. uniform distribution of the graphite, even when a thick coating of ca. 10 mu m is employed.