First Three-Dimensional Atomic Resolution Investigation of Thermally Grown Oxide on a FeCrAl Alloy

Journal article, 2015

Thermally grown Al2O3 scales formed on a FeCrAl alloy, Kanthal APMT, were successfully analysed using pulsed green laser atom probe tomography. The alloy was exposed to 5 vol.% O-2 + 95 vol.% N-2 at 900 A degrees C for 1 h, and covered by a thin layer of Al2O3. Cr segregation to some of the Al2O3 grain boundaries was observed. The continuous Cr-rich band, which contains a large number of Cr- and/or Fe- enriched nano-sized particles, was studied in detail. Four types of nanoparticles were found and analysed. Oxidation mechanisms at the initial stages are discussed based on the observations.