METHOD OF OBTAINING COMPOSITE ELECTROCHEMICAL COATING ON STEEL Russian patent published in 2017 - IPC C23C28/00 

FIELD: chemistry.

SUBSTANCE: method involves the preparation of a solution for depositing a nickel-phosphorus layer and an electrolyte for depositing a cobalt-polytetrafluoroethylene layer, depositing a nickel-phosphorus layer at a pH of 4.5-5.0, a temperature of 90°C, the deposition time is 30 minutes from a solution of the composition:⋅ NiSO₄⋅7H₂O⋅30 g/l⋅, NaH₂PO₂⋅H₂O 10 g/l, Na(CH₃COO) of 10 g/l and a layer of cobalt-polytetrafluoroethylene, which is deposited on the composite surface of nickel-phosphorus at pH 2-5, temperature 18-90°C, current density 6.25 A/dm², deposition time of 20-30 min in the electrolyte on the basis of the mother liquor of the process of synthesis of fluoroplastic MP F-4D: CoF₂⋅4H₂O⋅119 g/l, Na₂SO_{4 nowater}⋅36 g/l, H₃BO₃⋅45 g/l.

EFFECT: invention makes it possible to obtain a uniform coating on the steel, having increased hardness, strength and wear resistance at a low consumption of the composite material.

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