Porous Hybrid Composite for Enhanced Thermal Protection Systems (ComTPS)

ABSTRACT: The proposed research will demonstrate feasibility of a high temperature insulating, load bearing thermal protection system (TPS) using a hybrid composite technology. This program will incorporate a hierarchically porous ceramic core material in a sandwich structure with a conventional polymer matrix composite (PMC) and ceramic matrix composite (CMC) to fabricate an enhanced TPS. This material will protect the underlying structure from high temperatures, variable heating rates (Mach 4-20), and loading schemes. The core will be fabricated using an inexpensive manufacturing process from a pre-ceramic polymer that can be tailored for thickness and gradient of porosity without a substantial increase in weight to the structure. During Phase I, NextGen will focus on the development of the core material and optimization of thermal protection properties to withstand external temperatures of 3000 degrees F and internal temperatures of 600 degrees F. These properties will be modeled to predict thermal performance, and an initial adhesion technique will be developed for 3-component structural assembly. Proof-of-concept test coupons will be manufactured and characterized to verify mechanical and thermal properties of the core and 3-component part. Phase II will focus on the assembly/adhesion technique of the 3-component part, optimization of manufacturing techniques, and continue component validation with larger-scale prototypes. BENEFIT: High temperature materials have conventionally consisted of porous ceramics or fiber reinforced ceramic matrix composites. While porous ceramic materials have attractive TPS properties, they do not perform well as structural components. In contrast, fiber reinforced ceramic matrix composites have structural properties but do not perform well as thermal insulators and are often expensive to manufacture. The proposed program plans to address the drawbacks of these high temperature materials in a hybrid 3-component sandwich structure composite that has both thermal insulating properties and load bearing capability. The porous ceramic core material will allow enhanced thermal insulating properties to accommodate a gradient from an external 3000 degrees F temperature and an internal temperature of 600 degrees F at high heating rates that can be caused by increasing Mach numbers. This will prevent substructure material degradation and breakdown in mechanical properties. The ceramic matrix composite outer surface sandwich material will provide additional thermal protection as well as contribute a structural component along with the lightweight polymer matrix composite inner surface. In addition to material property benefits of the proposed material, manufacturing costs are appreciably less than techniques such as chemical vapor infiltration (CVI) that require highly specialized equipment. Potential applications for this technology include high temperature structures such as hypersonic vehicles, ballistic missiles, various space structures, and re-entry vehicle parts. Other commercial products that would benefit from this technology include automobiles and commercial aircraft. The ComTPS technology could protect surrounding parts from the high temperatures produced by automobile and jet engines or be used as brake disks in aircraft or racecars.