The article presents the results of kinetic investigates of electrodeposition of a composite electrochemical coating based on a nickel-boron alloy. Current efficiency, polarization potentiodynamic researches had shown the joint participation in the electrodeposition process of finely dispersed compounds of nickel hydroxides, poorly soluble nickel and boron compounds present in the electrolyte or formed during electrolysis, and ultradispersed diamond introduced into the electrolyte. Comparison of 2D and 3D scans of the surfaces of the formed coatings confirmed the leveling effect of additives, as well as sparingly soluble nickel and boron compounds on the structure of coatings. The proposed composite electrochemical coatings can be used instead of chrome coatings when restoring parts and units of agricultural machinery.

The results of investigations of the anodic processes of electrodeposition of nickel, nickel-boron alloy, composite coatings nickel-ultrafine diamond and nickel-cobalt-aluminum oxide are presented. It was shown that the oxidation of the boron-containing additive occurs at potentials much more positive than the oxidation potential of nickel, which means that oxidation of the boron compound is impossible under real conditions of electrodeposition. During the electrodeposition of CEC, the anode process proceeds without any complications and the dissolution of the anodes occurs in the same way as in nickel-plating electrolytes, and the composite additives of UDD and Al2O3 do not affect the anodic processes.

The article presents the results of investigates of the effect of ultrafine additives - zirconium diboride, silicon carbide, diamond on the physic-mechanical properties of composite electrochemical nickel coatings obtained from colloid-electrolyte baths. It is shown that precipitation containing ultrafine diamond possess optimal values of microhardness, wear resistance and internal stresses. These coatings can be used as an alternative to chrome coatings on parts of agricultural machinery.