ELECTROLYTE COMPOSITION AND METHOD FOR OBTAINING NANOCRYSTALLINE COMPOSITE COATINGS BASED ON NICKEL-PHOSPHORUS-TUNGSTEN SYSTEM Russian patent published in 2023 - IPC C25D3/56 C25D5/50 

FIELD: electroplating.

SUBSTANCE: invention can be used to obtain coatings with high microhardness for products of the aviation industry, mechanical engineering and shipbuilding. Electrolyte for nanocrystalline composite coating of nickel-phosphorus-tungsten on the parts made of steel and copper alloys contains, g/l: nickel sulfate heptahydrate 40-45, sodium hypophosphite 5.0-5.5, sodium tungstate 115-130, sodium citrate 280 -290, ammonium chloride 26-27, water - the rest. The method includes degreasing and chemical treatment of the surface of the part, electrochemical deposition of the coating is carried out in a membrane electrolyzer at pH 8-9, temperature 65± 5°C, current density 4-7 A/dm² from the specified electrolyte and final heat treatment.

EFFECT: obtaining nanocrystalline composite coatings based on the nickel-phosphorus-tungsten system with high microhardness, equal to the microhardness of hard chromium coatings on parts made of low-carbon and stainless steel and copper alloys.

3 cl, 2 ex