Silicide coating for protection of C/C composites at 1873 K

To prevent carbon/carbon (C/C) composites from oxidation at 1873 K, a dense SiC–Si–MoSi2 coating toughened with SiC whiskers (SiCw) was prepared by a two-step technique. The first step technique is to prepare a porous SiC coating toughened with SiCw by slurry, and the second one is to fill Si and MoSi2 in the holes of SiC coating by pack cementation. Oxidation test shows that the oxidation protective ability of SiC–Si–MoSi2 coating can be improved largely by adding 5–15 wt.% SiCw. After 38 h oxidation in air at 1873 K, the weight loss of the coated C/C sample without SiCw was up to 3.52%, while the weight loss of the coated sample with 10 wt.% SiCw was only 1.43%.