APFIM and XPS study of the first stages of low temperature air oxidation of industrial CuNi alloys

This paper will present the first results concerning the study of oxidation of Cu-10wt%Ni industrial alloys. One of the aims of this investigation is to study the behaviour of Fe and Mn alloying elements during oxidation. This first paper is mainly devoted to the characterisation of the bulk alloy and of the very first stages of air oxidation (several layers of oxides formed). Atom probe analysis is used to measure the oxide scale composition as its depth resolution is equal to one atomic layer. We observed that during the early stages of oxidation, both copper (Cu2O) and nickel (NiO) oxides are present. In addition, minor alloying elements Fe and Mn are shown to be located within the oxide scale at a rather large amount.