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Isothermal Oxidation of Ti3Al0.6Ga0.4C2 MAX Phase Solid Solution in Air at 1000 °C to 1300 °C

ElMeligy, Tarek A. and Epifano, Enrica and Sokol, Maxim and Hug, Gilles and Hans, Marcus and Schneider, Jochen M. and Barsoum, Michel W. Isothermal Oxidation of Ti3Al0.6Ga0.4C2 MAX Phase Solid Solution in Air at 1000 °C to 1300 °C. (2022) Journal of The Electrochemical Society (JES), 169 (3). 031510. ISSN 0013-4651

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Official URL: https://doi.org/10.1149/1945-7111/ac58c1


The atomically laminated Ti2AlC, Ti3AlC2 and Cr2AlC MAX phases, with A = Al, form adherent, passivating α-alumina, Al2O3, oxide scales when heated in air. The effect of solid solutions on the A layers in affecting the oxidation kinetics remains a subject of open research. Herein we synthesize a dense bulk polycrystalline Ti3Al1−xGaxC2 (x ≈ 0.4) solid-solution and investigate its isothermal oxidation in ambient air, in the 1000 °C–1300 °C temperature range, for times varying between 15 and 300 h. At 1000 °C, a passivating dense Al2O3 layer ( ≈ 1–2.6 μm thick) with near cubic kinetics and an overall weight gain that is slightly less than either Ti3AlC2 or Ti2AlC is formed. At 1200 °C, the Al2O3 layer thickens (3.5–12 μm thick) with some scale delamination on the corners initiating at 15 h. At 1300 °C, the Al2O3 layer (7.6–20.7 μm thick) wrinkles and Al2TiO5 forms. Though the Al2O3 grains coarsen at 1200 °C and 1300 °C, the weight gain is higher than that for Ti3AlC2 or Ti2AlC. At around 7 at. %, this is one of the lowest, if not lowest, Al mole fraction in a Ti-based alloy/compound that forms an Al2O3 passivating layer. We further provide compelling microstructural evidence, in the form of a duplex oxide, that at 1000 °C, the outward Al flux, JAl, and the inward O flux, JO, are related such that 2 JAl = 3 JO. A fraction of these fluxes combine, at the duplex oxide interface, to nucleate small grains

Item Type:Article
HAL Id:hal-03658095
Audience (journal):International peer-reviewed journal
Uncontrolled Keywords:
Institution:French research institutions > Centre National de la Recherche Scientifique - CNRS (FRANCE)
Other partners > Drexel University (USA)
Université de Toulouse > Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)
French research institutions > Office National d'Etudes et Recherches Aérospatiales - ONERA (FRANCE)
Université de Toulouse > Université Toulouse III - Paul Sabatier - UT3 (FRANCE)
Other partners > Rheinisch Westfaelische Technische Hochschule Aachen University - RWTH (GERMANY)
Other partners > Tel Aviv University (ISRAEL)
Laboratory name:
Deposited On:03 May 2022 13:27

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