Hybrid SiC-SiC/C-SiC Thermal Protection Structural Material

Thermal protection materials for ballistic missile kill vehicles must retain strength and stiffness at temperatures around 1500-2000oC in an oxygen rich environment, and isolate payload electronics from excessive heating. Weight is a concern, since lighter weight translates to higher velocity and kinetic energy. Further, the TPS materials must have a long service life, including the ability to withstand low level impact loads. Ceramic matrix composites provide an appealing material choice, with high strength at temperature, light weight, and resistance to thermal shock and impact. SiC-SiC composites exhibit oxidation resistance up to 1600oC, where C-SiC composites exhibit oxidation resistance, as well as high strength up to 1600„aC in inert environments. 3TEX, in conjunction with COI Ceramics, proposes a hybrid CMC structural material that combines an outer skin of SiC/SiC and an inner skin of C/SiC based on a unitary 3-D braided preform. The SiC/SiC outer skin will act as the thermal protection system (TPS) while the C/SiC inner skin will provide high specific stiffness and strength. Further, the C/SiC can be manufactured with pitch carbon yarns oriented to draw heat away from the leading edge surfaces, without allowing heat through the thickness of the skin into the payload.