Structure and oxidation behaviors of C/C-SiC coated with AI2O3-CrAI0.42Si1.58-SiC-Al4SiC4 oxidation protection system.

A multicomposition resistant coating for SiC coated carbon/carbon (C/C) composites was produced by pack cementation technique in an argon atmosphere. This multicomposition coating was characterized by X-ray diffraction and scanning electron microscopy technique, and the oxidation behaviors of C/C with this multicomposition coating were also investigated in air using thermogravimetry. The results indicate that a dense coating with an average thickness of 200 μm can be got using pack cementation technique. The coating is composed of Al2O3, CrAl0.42Si1.58, SiC, and AI4SiC4, This multicomposition costing could effectively protect the composites from exposure to atmosphere at 1873 K for 49 h with the weight loss of the coated C/C composites being only 1.84%. [ABSTRACT FROM AUTHOR]