High-temperature erosion resistance and aerodynamic oxidation mechanism of multi-layer MoSi2-CrSi2-Si/SiC coated carbon/carbon composites in a wind tunnel at 1873 K

摘要

The high-temperature erosion resistance of multi-layer MoSi2-CrSi2-Si/SiC coated carbon/ carbon (C/C) composites was investigated in a wind tunnel. To study the aerodynamic oxidation mechanism and analyze the failure of the coated C/C composites, the shear force and bending moment distribution of the tested specimens in a wind tunnel were calculated. Flexural strengths and thermogravimetric analysis of the coated specimens were measured. These results show that the multi-layer MoSi2-CrSi2-Si/SiC antioxidation coating can protect the C/C composites from high-temperature erosion in a wind tunnel at 1873 K for more than 86 h. Due to the high viscosity of SiO2, the multi-layer coating lacked effective oxidation resistance from 900 to 1500 K, resulting in extensive mechanical damage and the fracture of the tested specimens.