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

摘要

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