Oxygen-Ion Implantation into Cu50Ni50 Alloy: Effect on the Surface Composition and the Electrochemical and Corrosion Properties

— The composition and certain properties of the surface layer produced by oxygen-ion implantation into the Cu 50 Ni 50 alloy are studied. Oxygen-ion implantation is shown to result predominantly in the oxidation of nickel, which is the more electronegative component of the alloy. Different forms of nickel oxide are concentrated mainly on the alloy surface. These oxide layers enhance the propensity of the alloy to passivation and a decrease in anodic currents in alkaline media. The effect of oxygen-ion implantation on the behavior of the alloy in neutral and acidic media is less obvious. Oxygen-ion implantation enhances the electrochemical activity of the alloy toward the oxygen-reduction reaction.