Abstract
By using an electrochemical method, ICP (Inductive Coupled Plasma) atomic emission spectrometry and AES (Auger Electron Spectroscopy), the dissolution behavior and film compositions of pure copper, Cu-Ni alloys (10%Ni, 30%Ni and 42%Ni), and pure nickel under one-hour oxidation condition have been investigated in 0.5kmol/m3 ammonium acetate solution of pH 7.11 at room temperature. The compositions of dissolved metal ions estimated from the amounts of dissolved ions show that the preferential dissolution of Ni takes place at the active region over the whole Ni content. In the passive and transpassive regions, the preferential dissolution of Cu occurs at the lower Ni content (10%Ni), whereas that of Ni occurs at the higher Ni content. The film formed on Cu-10%Ni alloy has the enrichment of Ni in the active and passive regions. The behavior of the preferential dissolution may be explained in terms of a composition and property of a film formed on the surface.
