Physicomechanical properties of nickel coating deposited from sulfate nickel plating electrolyte using preliminary underpotential deposition

A study of nickel coatings electroplated from electrolytes of the compositions (M) NiSO₄ 0.5, NiCl₂ 0.3, and H₃BO₃ 0.404 (electrolyte 1) and NiSO₄ 0.5, NiCl₂ 0.3, and H₃BO₃ 0.404 with the addition of 2 mg L^–1 RADO (electrolyte 2) in the constant-current mode after preliminary potentiostatic treatment (underpotential deposition) of the support revealed the formation of Fe–Ni alloy in the initial moment of formation of the nickel coating. Pretreatment of the steel surface in the underpotential deposition mode allows preparation of uniform finely crystalline nickel coatings with enhanced levels of the wear resistance, microhardness, and corrosion resistance.