Features of electrodeposition of “nickel-chromium diboride nanopowder” composite coatings

Conditions for obtaining a nickel-based composite electrochemical coating (CEC) with the use of the CrB 2 nanopowder as a strengthening phase in a standard nickel plating electrolyte are investigated. It is established that the nickel matrix is maximally saturated with the use of chromium nanoboride upon its concentration in the electrolyte of 5–10 kg/m 3 , which is lower by a factor of 8–12 than when adding CrB 2 micropowders. The microhardness of the CEC with the Ni-CrB 2(nano) composition with the content of the strengthening phase of 0.59–0.65% is higher than for the Ni-CrB 2(micro) coatings containing 2.47–2.86% boride by a factor of 1.16–1.19 and for the nickel host by a factor of 1.64–1.86. The optimal conditions of the CEC deposition are a cathode current density of 1.0 kA/m 2 , a nanoboride concentration in the electrolyte of 5–10 kg/m 3 , pH = 5.0–5.5, and a temperature of 323 K.