Corrosion of Ti3AlC2 at 800–1100°C in Ar–0.2% SO2 gas atmosphere

Abstract Ti 3 AlC 2 was corroded between 800 and 1100 °C in an Ar–0.2% SO 2 gas atmosphere according to the equation: Ti 3 AlC 2 + O 2 → rutile-TiO 2 + α-Al 2 O 3 + (CO or CO 2 ). The scales that formed on the Ti 3 AlC 2 were thin and rich in α-Al 2 O 3 , whose growth rate was exceedingly slow. The TiO 2 was present either as the outermost surface scale or a mixture inside the α-Al 2 O 3 -rich scale. In the Ti 3 AlC 2 , the activity and diffusivity of Ti were low, whereas those of Al were high. This was the main reason for the superior corrosion resistance of Ti 3 AlC 2 over TiAl.