Ultra-low Diffusivity High Temperature Capable Insulation

Hypersonic flight induces severe heat loads so non-load bearing thermal insulation must be compact and erosion/oxidation resistance at high-temperatures up to 1200??C with reduced thermal diffusivity and insulation volumes. Sporian propose to investigate SiCN based porous insulation materials, innovative textile architectures, and multilayer insulations (MLI) for ceramic matrix composite (CMC) thermal protection systems (TPSs). Sporian has developed SiCN based polymer derived ceramics (PDC) for high temperature (>1400??C) applications. As an amorphous material, SiCN based ceramics have low thermal diffusivity/conductivity, low density, high strength, and high fracture toughness. Doped SiCN can withstand oxidation and water vapor corrosion and are thermally stable in inert environments up to 1800??C. We have previously made SiCN foams for 1400??C combustion gas filtering applications. Superior to powder slurries, the liquid polymer processing nature makes it suitable for producing fully dense SiBCN ceramic structures of lightweight foam using the replication approach. With matching thermal expansion coefficients (CTEs), the SiBCN foam can be combined with high strength SiC based CMCs for advanced load bearing insulation applications. In Phase I, we propose to develop proof of concept state-of-the-art SiBCN based insulating foam materials with ultra-low diffusivity achievable through advanced fabrication technologies. Feasibility will be demonstrated.