Element Redistribution During Early Stages of Oxidation in a Ni 38 Cr 22 Fe 20 Mn 10 Co 10 Multi-Principal Element Alloy

Element redistributions after initial oxidation of a Ni38Cr22Fe20Mn10Co10 (at. %) multi-principle element alloy at 120 °C and 300 °C is captured via in situ atom probe tomography. All cations contribute to the oxide in both conditions, consisting of Cr-rich inner oxide and Fe, Mn, Co and Ni-rich outer oxide. At lower temperature, Ni tends to be trapped at the outer/inner oxide interface, while Ni enriches at the oxide/metal interface at higher temperature in tandem with Cr metal depletion. These observations confirm oxidation of complex alloys involves the formation of metastable, multi-layered oxide films, with a distinct tendency for solute trapping.