Economical Manufacture of Refractory Ceramic Matrix Composite Airframe with Integral Thermal Protection System

The thermal, mechanical, and chemical environment generated during launch and flight of hypersonic projectiles is severe. Ultramet has developed a melt infiltration process for rapid fabrication of refractory ceramic matrix composites (CMCs) including matrices of zirconium carbide, hafnium carbide, silicon carbide, and ceramic alloys including two or more of these materials. The carbon fiber reinforcement provides high strength and toughness and can be braided or wrapped into complex shapes that are retained after the melt process and require little or no postprocess machining. Significant ultrahigh temperature testing of these composites has been performed with good results. Ultramet has also developed and tested high temperature, low cost insulators composed of open-cell carbon foam that is filled with a low conductivity carbon aerogel insulator. The potential exists to combine and optimize melt infiltrated CMCs with foam-based insulators that meet the demanding requirements of hypersonic projectile airframes while also demonstrating affordable processing. Ultramet proposes to assemble a development team comprising Materials Research & Design for thermal/mechanical modeling and erosion prediction methodologies, Ocellus for carbon aerogel/carbon foam insulation processing, and Boeing for assistance in defining airframe requirements. In Phase I, cone-shaped prototype components will be fabricated and subjected to high temperature oxidation testing to 2800 K at the Laser Hardened Materials Evaluation Laboratory.