Microstructure and creep behavior of Al₂O₃-SiC ceramic matrix composites

The microstructure and creep behavior of monolithic Al₂O₃ and 10 vol% SiC particle reinforced Al₂O₃ matrix composites were investigated in air atmosphere at 1260°C. Two kinds of SiC particles were used, one with the average size 2.7 μm has 3.4 vol% SiO₂ impurities and the other with the average size 0.6 μm has 1.7 vol% SiO₂ impurities. Compared to the creep behavior of monolithic Al₂O₃, the creep resistance of the composites with 0.6 μm SiC particles (ASS) was not improved, but the creep strain rate of the composites with 2.7 μm SiC particles (ASL) decreased apparently. This difference was related to the different microstructure and oxidation behavior of the composites. Moreover, the composites exhibited a significant anelastic recovery on load removal, especially for ASL.