Anomalous Behavior of the Internal Oxidation of Dilute Cu–Ni Alloys Under 1 atm. O2 at 900 °C

Abstract

The internal oxidation of Ni in dilute Cu–Ni alloys exposed to 1 atm. O2 at 900 °C, and thus in the presence of external CuOx scales, is absent for Ni levels below a critical value, extremely close to that required for the simultaneous equilibrium between the alloy and the oxides of the two components. For Ni contents not largely exceeding this limit the internal oxidation of Ni deviates from the classical behavior described by Wagner, approaching that predicted by Morral et al. for the precipitation of compounds with limited thermodynamic stability.