METHOD OF PRODUCING A POROUS COMPOSITE COATING Russian patent published in 2020 - IPC C25D11/02 C25D15/00 

FIELD: technological processes.

SUBSTANCE: invention relates to electroplating and can be used in machine building in order to improve functional characteristics of mechanisms operating in aggressive media, as well as in oil refining products. Method includes micro-arc oxidation (MAO) of metal surface and subsequent cathodic electrodeposition of nickel with formation of solid coating, wherein MAO is carried out in silicate-phosphate-alkaline electrolyte with density of anode direct current of 5–15 A/dm² in the voltage range of 300–700 V for 15–60 minutes with formation of ceramic oxide coating in thickness range of 20–60 mcm with open porosity of not more than 15 % with average pore diameter of 15–25 mcm, having mainly round shape and uniformly distributed on surface, and nickel cathode electrodeposition is carried out inside pores of oxide film in water-based electrolyte for 40–60 minutes.

EFFECT: high microhardness, corrosion resistance of coatings and their thickness.

3 cl, 1 ex