The program will demonstrate a graded ceramic composite structure design and manufacturing process that supports both sharp edge and large acreage structural TPS fabrication. The ability to combine carbon fibers and silicon carbide fibers in woven reinforcements with graded fiber volume for control of thermal expansion and the ability to form complex shapes integrally into the preform will support fabrication of a graded CMC TPS Leading edge. The proposed innovation will provide a low cost, durable and lightweight CMC structure with an integral Environmental/erosion Barrier (EB) with a low CTE structurally graded CMC TPS system particularly suited for hypersonic vehicle leading edge applications with predicted use temperatures in excess of 3500§F. The grading of the fiber volume in the preform, along with the inclusion of particulates and both SiC and carbon fibers, can be accomplished using a custom gradient density 3WeaveTM 3D woven preform from 3TEX Inc.. The preform can transition from 45% fiber volume to 10% fiber volume through the thickness and the graded matrix is made possible through the use of preceramic polymers that enable the inclusion of particulates or fibers to form low CTE engineered ceramic structures ranging from stoichiometric SiC to solid solutions of HfZrSiC
