Formation of silicon carbide nanowire coatings on C/C composites using an in situ catalytic strategy for improved oxidation resistance

Abstract

A low-cost in situ catalytic reaction strategy was employed to successfully prepare SiC–Si coatings on the C/C matrix. The addition of catalysts enabled the fabrication of SiC nanowire coatings at lower temperatures. The effect of catalyst amount (Fe(NO3)3·9H2O) and preparation temperature on the interface microstructure and oxidation resistance of SiC–Si coated C/C composites was systematically investigated. Results demonstrated that the nanowires with a addition of Fe(NO3)3–9H2O at 2 wt% showed maximum density and yield. Additionally, it was observed that the oxidation resistance of the coatings exhibited an initial rise followed by a subsequent decline as the sintering temperature increased. The superior oxidation resistance of the coatings obtained at 1300 °C can be attributed to the in-situ formation of a substantial silicon oxide layer on the surface. This layer effectively fills the cracks and pores within the coating. Furthermore, the failure of the coating was mainly attributed to oxygen diffusion through the microcracks and pores.