SBIR-STTR Award

The development of a ceramic-polymer composite structure offers the promise of air vehicle structure with integrated load bearing and thermal protection capability. The outer skin which is exposed to high heating rates will be fabricated from a C/SiC composite. The inner structure will be fabricated from a high-performance polymide (PETI) composite. The connecting structure will be low density ceramic foam developed to provide mechanical and thermal coupling. The polymer to ceramic composite joining will be by co-curing the foam directly to the polymer composite.Typical Air Force missions will be identified to define loads and thermal requirements. Thermal/structural finite element analysis correlated with coupon testing will define material properties necessary to prevent failures. The experimental program will conclude with the test of a small scale integrated panel . Performance and cost benefits will be assessed comparing this approach to the current technology of an aluminum structure with a parasitic thermal protection system.

Our TPS approach is to develop a foam core integrated structure consisting of a 3-D fabric reinforced ceramic matrix composite (CMC) outer skin connected to ceramic foam which in turn is connected to a polymer matrix composite (PMC) inner structure. The high temperature foam core element is load carrying and can have graded properties to optimize thermal/mechanical performance. Numerous parameters can be varied to optimize this structural element including geometry, fiber type and architecture, matrix type, foam type and bond line morphology. Radiation heat transfer is minimized through the foam by using low density ceramic microballoons bonded in a ceramic matrix which is formed by pyrolyzing a preceramic polymer. Analytic tools – thermal and FEM – have been developed and demonstrate promising results. A developmental/experimental program has been formulated and a Phase II project team is in place to ultimately build and test AF mission capable prototype integrated structure.

Keywords:
Ceramics, Re-Entry, Thermal Protection, Hypersonics, High Temperature Structure