Improved wet-oxidation resistance of SiCf/SiC composites modified with Y2O3

Y2O3 was introduced into the SiC matrix to improving the wet-oxidation resistance of SiCf/SiC composites. The effects of Y2O3 on the mechanical properties and the wet-oxidation resistance of the composites were investigated. The results indicate that Y2O3 presents little negative effect on the mechanical properties. Besides, the introduction of Y2O3 effectively improves the wet-oxidation resistance of SiCf/SiC composites by forming a continuous Y2Si2O7 layer on the surface during the oxidation process. Compared with original SiCf/SiC composites, the strength retention rates of SiCf/SiC-Y2O3 composites oxidized for 20 h, 60 h and 100 h at 1400 ℃ respectively increase 5.62%, 17.58% and 23.08%.