In-situ XRD investigations of FeAl intermetallic phase-based alloy oxidation

Abstract The oxidation behavior of FeAl-based Fe40Al5Cr0.2TiB alloy is investigated by the high-temperature in-situ X-ray diffraction performed in air, in temperature range of 100−1150 °C. Complex oxidation behavior, with the formation of different Fe oxides and phase transformation of the alloy substrate in 400−700 °C is reported. Oxidation at higher temperatures leads to the formation of Al2O3 and its subsequent phase transitions (γ → θ → α). Relatively higher thermal expansion of the alloy with respect to the alumina scale results in the spallation of the latter.