High Temperature Oxidation of Fe-Al Alloys Studied by In Situ X-Ray Diffraction

摘要

The high temperature oxidation of Fe-Al alloys with Al contents from 5 to 30percent was studied at 900deg C by high temperature X-ray diffraction. The technique allows the in situ identification of the oxidation products and of their modifications and yields information about their formation kinetics. A protective alpha-Al_2O_3 scale was formed on Fe-Al alloys with 30 and 20percent Al. The Fe-Al alloy with 10percent Al forms alpha-Fe_2O_3 besides of alpha-Al_2O_3 and the alloy with 5percent Al forms at 900deg C alpha-Fe_2O_3 and no alumina. The formation of the oxides is observed simultaneously at each state of the oxidation yielding the qualitative formation kinetics for each oxide.