METHOD FOR NICKEL-PHOSPHORUS COATING ELECTRODEPOSITION Russian patent published in 2017 - IPC C25D5/18 

FIELD: chemistry.

SUBSTANCE: method comprises application of an electrolyte coating containing nickel sulphate heptahydrate, aminoacetic acid, chloride ion, sodium hypophosphite monohydrate, saccharin and sodium lauryl sulfate, at a current density of 2-7 A/dm² using symmetric reversible current. Anodic pulses duration is 1.6 seconds, and cathode pulses duration is 3-10 s, at their ratio in the range of 0.20-0.75 from electrolyte containing 120-170 g/l of nickel sulphate heptahydrate, 12-20 g/l of aminoacetic acid, 4-7 g/l chloride ion, 4-7 g/l sodium hypophosphite monohydrate, 1.5-2.5 g/l of saccharin and 0.05-0.1 g/l of sodium lauryl sulfate, with pH of 2.2-2.6 and electrolyte temperature of 48-53°C.

EFFECT: provision of the same phosphorus content in the coating in all parts of the surface and, consequently, the same high hardness of the coating, increased scattering ability of the nickel-phosphorus electrolyte.

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