Effects of an ion nitriding treatment on the oxidation behaviour of an ODS FeAl alloy

A B2 oxide-dispersion-strengthened (ODS) iron aluminide has been treated at 400 °C with a high flux and low energy nitrogen ion beam. The oxidation resistance has been investigated by in situ thermogravimetric experiments and related to structural changes studied by X-ray diffraction, scanning electron microscopy and chemical analysis of the surface. After the nitriding process the hexagonal AlN phase is detected, and during the oxidation tests between 800 and 950 °C a hematite layer is formed.