Hybird 3-D Textile Gradient Density and Fluted Preforms for C-SiC Structural TPS

Thermal protection materials have been largely parasitic materials adhered to airframe structural materials beneath. Attachment of such disparate and largely non-load-bearing materials incurs weight penalties and encourages failures. Integrated preforms providing enhanced thermal management, improved shock resistance/integrity and thereby enable more efficient re-entry profiles. This project will pursue the formation of Carbon/SiC composites with integrally 3D Braided and 3D woven single ply 3D preforms having a combination of functionally gradient densities, hollow cores, and planned thermal management, using ceramic and non-ceramic fiber types. The preforms will provide continuous fiber connecting the ceramic outer and non-ceramic inner segments of the structure, while internal flutes of the core allow for insulation and/or cooling. With guidance from Northrop Grumman, composite test specimens relevant to known hypersonic TPS and hot structure problems will be designed and fabricated, exploiting the flexibility of the 3BraidTM and 3WeaveTM processes to produce multi-density, and complex shaped hybrid preforms. Partner Starfire Systems will perform ceramization with proven methods for the infiltration of such fiber preforms with gradient ceramic matrices. The preforms will eliminate spalling and de-bonding altogether due to both mitigation of thermal misfits, and by the inherently integral single ply nature of the 3D woven fiber architectures themselves.