Study of Cu–18Ni–20Zn Nickel Silver and other Cu-based alloys in artificial sweat and physiological solution

The electrochemical behaviour of ternary Nickel Silver Cu–18Ni–20Zn alloy has been investigated in artificial sweat and in Ringer physiological solution. The characteristics of binary Cu–20Zn and Cu–20Ni alloys and pure metal components have been compared under electrochemical polarization. The solid and dissolved products formed on the ternary Cu–18Ni–20Zn alloy have been analysed by X-ray photoelectron spectroscopy and polarographic methods, respectively. In the low potential region (E < 0 V) the surface layer consists primarily of a thin cuprous oxide layer, whereas at high positive potentials (E > 0 V) the layer is composed of a thick copper chloride/oxychloride layer. Its formation is accompanied by increased dissolution of zinc and nickel.