Isothermal Oxidation of Ti₃Al_0.6Ga_0.4C₂ MAX Phase Solid Solution in Air at 1000 °C to 1300 °C

The atomically laminated Ti 2 AlC, 3 AlC and Cr MAX phases, with A = Al, form adherent, passivating ? -alumina, Al O , oxide scales when heated in air. effect of solid solutions on the layers affecting oxidation kinetics remains a subject open research. Herein we synthesize dense bulk polycrystalline 1?x Ga x C (x ? 0.4) solid-solution investigate its isothermal ambient air, 1000 °C–1300 °C temperature range, for times varying between 15 300 h. At °C, layer ( 1–2.6 ? m thick) near cubic an overall weight gain that is slightly less than either or formed. 1200 thickens (3.5–12 some scale delamination corners initiating at 1300 (7.6–20.7 wrinkles TiO 5 forms. Though grains coarsen higher AlC. around 7 at. %, this one lowest, if not mole fraction Ti-based alloy/compound forms layer. We further provide compelling microstructural evidence, duplex oxide, outward flux, J inward are related such . these fluxes combine, interface, to nucleate small