Thickness-dependent oxidation behaviors of Ti3AlC2 foils at 1100 °C in air

Highlights: • The oxidation behavior of Ti₃AlC₂ is thickness-dependent. • Selective oxidation does't occur for Ti₃AlC₂ foil with thickness of 85 μm. • The 140 μm thick foil possesses more stable Al₂O₃ scale and longer lifetime. • The mechanism of breakaway oxidation of Ti₃AlC₂ is discussed. The oxidation behavior of Ti₃AlC₂ foils at 1100 °C in air has been investigated. It is found that the oxidation behavior of Ti₃AlC₂ is thickness-dependent. For the 85 μm thick sample, breakaway oxidation occurs initially. For the 95 μm thick sample, selective oxidation occurs initially and transforms to breakaway oxidation after 12.5 h. When the thickness exceeds 110 μm, Ti₃AlC₂ foils exhibit much longer lifetime. Continuous Al₂O₃ scale is formed on the 75−120 μm thick wedge-shaped sample, suggesting that diffusion rate of Al is high in the whole body during oxidation. The mechanism of breakaway oxidation of Ti₃AlC₂ is discussed.