Relationship between oxidation resistance and structure of B4C–SiC/C composites with self-healing properties Original Research Article

The oxidation behavior of B4C–SiC/C composites of various compositions at temperatures up to 1500°C was analyzed by the thermal gravimetric/differential thermal analysis (TG/DTA) technique and the surface morphology of the composites after isothermal oxidation at 800, 1000 and 1200°C was examined by scanning electron microscopy. The results indicated that the composites exhibited variable oxidation resistance at high temperatures depending on composition and oxidation temperature. The variance of self-healing properties was attributed to the difference of the compositions and the properties of the decarbonized layers including wetting ability, viscosity, volatility and oxygen permeability. The rate-limiting steps of oxidation and the concentration distribution of oxygen across the decarbonized layers of the composites after oxidation are discussed.