A method for electroplating objects with a successive bright nickel and chromium coatings, as well as objects covered by applying this method

摘要

In electroplating objects with successive coatings of bright nickel and chromium, the nickel layer is deposited from a bright nickel bath containing dispersed solid insoluble particles in a concentration c in g/1 not greater than 20 dS where d is the effective mean diameter of the particles in microns and s is the specific gravity of the particles. Where the particles are aspherical d is the diameter of the sphere of the same volume as the particle. The smaller the particles the greater is the dulling effect on the nickel plate. Specified examples of suitable particles are quartz and glass powders, china clay, Al2O3, CeO2, Fe2O3, Cr2O3, B4C, SiC, CaCO3, BaSO4Nc(OH)2, MoS2. Reference is also made to the use of diamond powder, filtering earth and molybdenum oxide. In examples Watts nickel baths are used containing as brighteners saccharin and butynediol or naphthalene disulphonic acid and propargyl alcohol.