Wet oxidation behavior of SiC/(SiC- SiBCN)x composites prepared by CVI combined with PIOP process

Self-healing capability in wet oxygen atmospheres is the key issue for long term service of SiC/SiC composites in aero-engines. Polymer derived SiBCN ceramic (PDC SiBCN) was introduced into SiC fiber reinforced SiC as a self-healing component to obtain SiC/(SiC-SiBCN)x composites by a newly developed method, namely chemical vapor infiltration combined with polymer infiltration online pyrolysis (CVI + PIOP) process. The weight loss behavior and three-point bending performance of the samples under different temperatures (1200, 1300 and 1400°C) and different wet oxygen partial pressures were tested up to 100 hours to demonstrate the oxidation behavior of the samples in wet oxygen environments. According to these tests, the antioxidant capacities of samples prepared from different preforms were compared. It has been found that the 2D plain weave samples with higher density have the best resistance to wet oxygen corrosion while the 2D plain weave samples have the worst resistance to wet oxidation and the antioxidant capacities of 2D satin weave samples is between them.