High temperature oxidation behavior and mechanism of Ti3SiC2–SiC nanocomposites in air

In this work, the oxidation kinetics and morphology of the oxide phases of Ti3SiC2–SiC nanocomposites in air from 1000 to 1400 °C is reported. The incorporation of ultra-fine SiC were found to have beneficial effects on the oxidation behavior of Ti3SiC2, and the weight gain decreased with the increment of SiC. The parabolic rate constant of Ti3SiC2–30 vol.%SiC composite oxidized at 1200 °C for 12 h decreased about one order of magnitude compared to that of the monolithic Ti3SiC2. At the same time, the thickness of the oxide scale as well as the oxide surface grain size of Ti3SiC2–30 vol.%SiC composite changed little with the prolonging oxidation time. At above 1200 °C, however, the oxidation process speeded up, and the adhesive and protective oxide scales were destroyed. The worsening oxidation resistance of Ti3SiC2 and the passive–active oxidation transition of ultra-fine grain size of SiC were the possible reasons.