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

Abstract

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.

Electrodeposition of Nickel matrix composite coatings via various Boride particles: A review

“…As with many other transition metal borides, chromium diboride (CrB 2 ) is an inorganic compound that is exceedingly strong and hard and transmits electricity and heat similar to many metallic alloys, with a high melting point [88]. Nozdrin et al [89] studied the features of the electrical deposition of nickel-based composite coatings, which contain CrB 2 nano-powder as a strengthening phase. With the existence of the nano-dispersed phase, the maximum limit of the working density of the electrolyte current is 1.0 , which is greater than that for achieving nickel coatings in this electrolyte (0.5…”