Probing the oxidation behavior of Ti2AlC MAX phase powders between 200 and 1000 °C

Oxidation of commercial Ti2AlC MAX phase powders at 200-1000 °C has been investigated by XRD, XPS, SEM, STA and TGA coupled with FTIR. These powders are a mixture of Ti2AlC, Ti3AlC2, TiC and Ti1.2Al0.8. Oxidation at 400 °C led to disappearance of carbide phases from Ti 2p, Al 2p and C 1s XPS spectra. At 600 °C, powders changed from dark grey to light grey with a significant volume increase due to crack formation. Powders were severely oxidized by detecting rutile with minor anatase TiO2. At 800 °C, α-Al2O3 was detected while anatase transformed into rutile TiO2. The cracks were healed and disappeared. At 1000 °C, the Ti2AlC powders were fully oxidized into rutile TiO2 and α-Al2O3 with a change of powder color from light grey to yellow. FTIR detected the release of C as CO2 from 200 °C onwards but with additional CO above 800 °C.