High-temperature oxidation and hot corrosion of Cr2AlC

High-temperature oxidation and hot corrosion behaviors of Cr2AlC were investigated at 800–1300 °C in air. Thermogravimetric–differential scanning calorimetric test revealed that the starting oxidation temperature for Cr2AlC is about 800 °C, which is 400 °C higher than other ternary transition metal aluminum carbides. Thermogravimetric analyses demonstrated that Cr2AlC displayed excellent high-temperature oxidation resistance with parabolic rate constants of 1.08 × 10−12 and 2.96 × 10−9 kg2 m−4 s−1 at 800 and 1300 °C, respectively. Moreover, Cr2AlC exhibited exceptionally good hot corrosion resistance against molten Na2SO4 salt. The mechanism of the excellent high-temperature corrosion resistance for Cr2AlC can be attributed to the formation of a protective Al2O3-rich scale during both the high-temperature oxidation and hot corrosion processes.