High-temperature oxidation of Fe-Al alloys studied by in situ x-ray diffraction

The high-temp. oxidn. of Fe-Al alloys with Al contents of 5-30% was studied at 900.degree. by high-temp. x-ray diffractometry. The technique allowed the in-situ identification of the oxidn. products and their modifications. A protective .alpha.-Al2O3 scale was formed on Fe-Al alloys with 30 and 20% Al. The Fe-Al alloy with 10% Al formed .alpha.-Fe2O3 and .alpha.-Al2O3, whereas the alloy with 5% Al formed only .alpha.-Fe2O3 at 900.degree.. The formation of the oxides was obsd. simultaneously at each state of the oxidn. yielding the qual. formation kinetics of the oxides