Gradient coating increases the temperature resistance of ceramic fiber fabric

Ceramic fiber fabric embrittlement at 1200 °C, resulting in poor tensile strength. In order to improve the tensile strength of ceramic fiber fabric after high temperature heat treatment. In this study, gradient coating is sprayed on the surface of ceramic fiber fabric by adjusting the composition of two kinds of slurry. The structure and property of ceramic fiber fabric with different coating are thoroughly investigated. The pore size of Al 2 O 3 -SiC porous transition layer is less than 1 μm, which limits the infiltration of the high-emission coating into the ceramic fiber fabric. A weak bond is formed between the ceramic fiber fabric and the porous transition layer, which induces the crack deflection. The flexibility of ceramic fiber fabric after heat treatment is significantly improved. After being heated by butane flame at 1200 °C for 20 min, the tensile strength of fiber fabric with gradient coating is double that of raw ceramic fiber fabric. The silicone cross-links to form a network, which improves the bonding strength of the gradient coating. Due to the high emissivity and low thermal conductivity of the gradient coating, the temperature of the ceramic fiber fabric is below 900 °C when heated by the butane flame.