On the high-temperature oxidation of Fe, Co, Ni and Cu-based alloys with addition of a less noble element

This paper summarizes some of the literature on binary alloys, A–B, such as those based on Fe, Co, Ni or Cu and containing 0–30% of a higher valent, less noble metal, B. The oxidation essentially follows parabolic kinetics and the rate constants reach a maximum with additions of B around 5–10%. The oxygen pressure dependencies and temperature dependencies of the parabolic rate constants are stronger than for the unalloyed metal, A. The oxide morphology is considerably more complex than for unalloyed A and the oxide usually comprises an outer region consisting of AO and an inner two-phase region containing dispersed «BO-particles» and pores in a matrix of AO. Based on this review and a recent extensive study of the oxidation mechanism of Cu–Ni alloys, similarities in the oxidation mechanism of the different alloy systems are discussed.