High temperature oxidation resistance of Ti3SiC2 in air and low oxygen atmosphere

The oxidation resistance of high-purity and dense Ti3SiC2 bulk ceramic which was prepared by hot-pressing was investigated at 700-1200°C for 5-40 hours in air and low oxygen atmosphere, respectively. After oxidation, the mass gain curves of Ti3SiC2 were obtained, and the oxide layer was analyzed qualitatively and quantitatively. The results showed that the oxide layer was mainly TiO2 and SiO2 mixture below 1100°C in air. When the oxidation temperature reached 1100°C and above, the oxidation proceeded rapidly, and the mass gain curves followed the parabolic law. The oxide layer changed from single-layer to double-layer structure, which comprised of an inner layer of TiO2 with SiO2 solid solution and an outer layer of TiO2. In low oxygen atmosphere, the oxidation was fainter than that in air. But the double-layer structure would also occur. These two oxide layers could protect the substrate to be further oxidized. In summary, Ti3SiC2 bulk materials possess good high temperature oxidation resistance both in air and low oxygen atmosphere below 1100°C.