Thermal expansion coefficient of alumina films developed by oxidation of a FeCrAl alloy determined by a deflection technique

Thermal expansion coefficients of α alumina films formed by oxidation of an oxide dispersion strengthened (ODS) FeCrAl alloy have been determined between 20 and 900 °C using an original deflection test. This technique is based on the curvature of a dissymmetrical sample consisting of a thin and elongated metallic substrate covered on one of its large sides by an oxide film. The average value of the expansion coefficient of the compact columnar α alumina film is found to equal 10.3 × 10−6 K−1 which is higher than most values given in the literature.