Preparation and oxidation resistance of 2D C/SiC composites modified by partial boron carbide self-sealing matrix

The C/SiC composites with partial boron carbide (BCx) self-healing matrix were prepared by isothermal chemical vapor infiltration technique (ICVI). SEM results showed that the multilayer SiC-BCx matrix exist among fiber bundles, nevertheless there were still SiC matrix among monofilaments. The mechanical properties at room temperature were tested and compared with conventional C/SiC composites. The modified composites hold better strain to fracture than the conventional C/SiC composites, although the other mechanical properties of the two kinds of composites were similar. The pull-out of multilayer matrices was the main factor of the increase of strain to fracture. The high residual strengths were demonstrated after oxidized at static air and simulation combustion environments. The improvement for oxidation resistances of the modified composites were contributed to the self-healing of crack and pore during oxidation in static air and simulation combustion environments, compared with conventional C/SiC composites.