Oxidation behavior and residual strength of mini-SiCf/SiC composites in water-oxygen environments up to 1600 °C

SiC f /SiC composites serve as key candidate materials for hot-end parts in the aerospace domain. However, the damage behavior of SiC f /SiC composites under high-temperature water-oxygen environments and its impact on mechanical properties remain to be further clarified. In this work, the microstructural evolution and residual mechanical properties of mini-SiC f /SiC composites oxidized in a 90% O 2 + 10% H 2 O atmosphere at temperatures from 1000 to 1600 °C were investigated. The residual strength of mini-SiC f /SiC composites exhibits a non-monotonic temperature dependence, initially increasing at 1200 °C and subsequently decreasing at temperatures above 1400 °C. The primary mechanisms are as follows: at 1200 °C, the oxidation products of the BN interphase enhance the interfacial bonding strength, thereby improving the mechanical strength; whereas at temperatures ranging from 1400 °C to 1600 °C, SiC grain growth emerges as the dominant factor, leading to the deterioration of mechanical properties.