Electrolytic deposition of magnetisable coatings

摘要

The magnetisable alloys to be deposited are cobalt nickel compositions. Solutions containing more than 100 gm./litre of cobalt ions and nickel ions (60-40 or 40-60) and containing 6 to 12 gms./litre of hypophosphite ions H2PO2- and 60- 140 gms./litre of ammonium ions NH4+ are used at a pH of 1.8 to 5.5 and at 40 to 80 80 degrees C. and a current density of 9-100 amps./dm2. Preferred conditions are 120-140 gms/litre cobalt and nickel 47-53 degrees C. and pH 3.4-3.6. Alloys deposited for preference are 78-82% Co and 18-22% Ni. High current densities and ion concentrations can be used.