Characterization of Oxide Scales Formed on Fe_3Al-(0, 2, 4, 6)Cr Alloys

摘要

Thermomechanically treated Fe_3Al-(0, 2, 4, 6 at percent)Cr alloys were oxidized at 1000 deg C in air, and the oxide scales were characterized using XRD, SEM, EPMA and TEM. The oxide scales formed were thin, but non-adherent. The oxide scales were primarily composed of submicron-sized #alpha#-Al_2O_3 oxide grains, which contained small amounts of dissolved ions of Fe and Cr. Beneath the oxide scale, numerous voids particularly along the grain boundaries of the matrix alloy were observed, indicating that the outward diffusion of Al occurred to form the Al_2O_3 oxide layer.