Oxidation behaviors of yttrium silicate modified SiCf/SiC composites in air and water‐oxygen environments

SiC f /SiC composites have emerged as one of the most promising materials for aero‐engine hot‐end structures. However, their performance is limited by their susceptibility to oxidation and corrosion reactions with oxygen and water vapor. To overcome this challenge, antioxidant‐modified phases are introduced into matrices of SiC f /SiC composites which improve their water and oxygen resistance. In this study, the resistance of SiC f /SiC composites modified by yttrium silicate matrix (SiC f /SiC‐YS composites) to air at 1000–1400°C and water‐oxygen environments at 1200°C was investigated. The diffusion paths of oxygen in SiC f /SiC‐YS composites and the antioxidant behavior of the yttrium silicate matrix were discussed. Additionally, the differences in oxygen and water‐oxygen corrosion resistance of SiC f /SiC‐YS composites at the same temperature were compared. The strength retention of SiC f/ SiC‐YS composites after oxidation and water‐oxygen corrosion at 1200°C were 138.6% and 108.8%, respectively. This indicates that the addition of water vapor accelerated the degradation of SiC f /SiC‐YS composites. By comparing with SiC f /SiC composites, it can be concluded that the modification of the yttrium silicate matrix considerably improved the oxidation resistance of SiC f /SiC composites.