Study on the mechanical and thermal coupling behavior and damage mechanism of C/SiC ceramic matrix composites under coupled loading at high temperature and high strain rate

Ceramic matrix composites face challenges in harsh operational conditions, including severe temperature environments and potential threats from impact loads during use. This study focuses on 2D-C/SiC composites for high-temperature applications and systematically investigates their compressive and tensile mechanical behaviors under varying conditions: temperatures ranging from room temperature to 1600°C, different gas atmospheres (air and argon), and strain rates of 10−3/s and 103/s. The mechanical properties of 2D-C/SiC ceramic matrix composites are influenced by a combination of loading rate, temperature, oxidation, and coating effects. Strain-rate sensitivity: The material’s strength increases with the loading rate, while its strain-rate sensitivity decreases as temperature rises. Temperature effects: Residual stress release enhances the interfacial strength between fibers and the matrix, leading to an increase in the composite’s strength at higher temperatures. Oxidation effects: Fiber oxidation damage reduces material strength. This damage exhibits time and temperature dependencies, influenced by coupled deformation rates and heating temperatures. However, coatings can effectively mitigate oxidation damage. These factors affecting the mechanical behavior of 2D-C/SiC composites are not isolated but interact collectively, making material failure mechanisms highly complex.