Improving the Cyclic-Oxidation Resistance of Ti3AlC2 at 550 degree C and 650 degree C by Preoxidation at 1100 degree C

Preoxidation of Ti3AlC2 at 1100 degree C for 2 h was conducted to improve its cyclic-oxidation resistance at the testing temperature of 550 degree C and 650 degree C in air. The cyclic oxidation of the preoxidized Ti3AlC2 was found to follow a parabolic rate law rather than the linear oxidation rate for that without preoxidation. Through the X-ray diffraction and SEM analysis, the remarkable improvement of the cyclic-oxidation resistance of preoxidation Ti3AlC2 is suggested due to the existence of protective alpha -Al2O3 layers formed during the preoxidation treatment, which inhibits the formation of amorphous Al2O3, which can result in larger thermal stress and stress-induced microcracks.