High-Temperature Oxidation of Fe3Al and Fe3Al–Zr Intermetallics

• Published in: Oxidation of metals Vol. 73; no. 1-2; pp. 43 - 64
• Main Authors: Chevalier, S., Juzon, P., Borchardt, G., Galerie, A., Przybylski, K., Larpin, J. P.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.02.2010; Springer
• Subjects: Aluminum oxide; Applied sciences; Chemistry and Materials Science; Corrosion; Corrosion and Coatings; Corrosion environments; Exact sciences and technology; Inorganic Chemistry; Materials Science; Metallic Materials; Metals. Metallurgy; Original Paper; Tribology; High-temperature oxidation; Intermetallics; Iron aluminide; Oxidation mechanisms; Zr segregation; Corrosion mechanism; Temperature; Segregation; Intermetallic compound; Aluminium alloy; High temperature; Iron Aluminides; Oxidation; Microstructure; High temperature corrosion; Iron base alloys
• ISSN: 0030-770X; 1573-4889
• DOI: 10.1007/s11085-009-9168-8

The oxidation behavior of Fe 3 Al and Fe 3 Al–Zr intermetallic compounds was tested in synthetic air in the temperature range 900–1200 °C. The addition of Zr showed a significant effect on the high-temperature oxidation behavior. The total weight gain after 100 h oxidation of Fe 3 Al at 1200 °C was around three times more than that for Fe 3 Al–Zr materials. Zr-containing intermetallics exhibited abnormal kinetics between 900 and 1100 °C, due to the presence and transformation of transient alumina into stable α-Al 2 O 3 . Zr-doped Fe 3 Al oxidation behavior under cyclic tests at 1100 °C was improved by delaying the breakaway oxidation to 80 cycles, in comparison to 5 cycles on the undoped Fe 3 Al alloys. The oxidation improvements could be related to the segregation of Zr at alumina grain boundaries and to the presence of Zr oxide second-phase particles at the metal–oxide interface and in the external part of the alumina scale. The change of oxidation mechanisms, observed using oxygen–isotope experiments followed by secondary-ion mass spectrometry, was ascribed to Zr segregation at alumina grain boundaries.