Oxidation protection of SiC-coated C/C composites by SiC nanowire-toughened CrSi2–SiC–Si coating

Oxidation protective SiC nanowire-toughened CrSi2–SiC–Si coating was prepared on SiC-coated carbon/carbon composites by chemical vapor deposition and pack cementation. SiC nanowires in the coating suppressed the cracking of the coating via various toughening mechanisms including nanowire pullout, microcrack bridging by nanowire and microcrack deflection, resulting in a good oxidation inhibition for the coated samples. The results showed that the maximal weight loss of the coated samples was only 2.55% in thermogravimetric analysis from room temperature to 1500 °C, and the weight loss of the coated samples was only 1.24% after isothermal oxidation at 1500 °C for 316 h.

► SiC nanowire-toughened CrSi2–SiC–Si oxidation protective outer coating was prepared.
► SiC nanowires in the coating suppressed the microcracks in the coating.
► Nanowire pullout, nanowire bridging and crack deflection in the coating can be found.
► The coating had a good oxidation protective ability for C/C composites at 1500 °C.