Effect of the incorporation of SiC nanowire on mullite/SiC protective coating for carbon/carbon composites

An oxidation resistant SiC nanowire-toughened mullite coating for SiC pre-coated carbon/carbon composites (SiCC/C) was prepared by a two-step technique of hydrothermal electrophoretic deposition with a later pulse arc discharge deposition. Sic nanowires could efficiently decrease the size of microcracks and baffle the propagation of the microcracks by various toughening mechanisms, including devitrification, crack deflection, bridging and pull out of SiC nanowire. The results showed that the weight loss of the coated samples was only 0.03% after 50 thermal cycles, and the weight loss of the coated samples was only 107 g m−2 after oxidation in air at 1773 K for 235 h.