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%.