Anodic oxide films on copper-nickel alloys

Electrochemical behavior of the Cu-xNi alloys (x = 0, 5, 10, 30, 50, 70 at. %) in solutions of a boro-borate buffer and sodium sulfate is studied by t he voltammetry method with a simultaneous measurement of the photocurrent a nd by the contact electroresistance method. The nickel concentration in all oy and the presence of oxygen in solution facilitate the formation of a thi cker passive film of p-type on the surface. The film's conduction type alte rs in a sodium sulfate solution after an alloy activation.