SBIR-STTR Award

Significant resources have been invested to develop high temperature structural materials for access to space. Development has focused primarily on systems with operating temperatures in excess of 2000F. The idea of these high temperature materials is to provide thermal shock resistance, protection to substructure materials, and structural performance. Currently these materials have fallen short of their goals. Reasons for this include joining of dissimilar materials, poor interlaminar properties, and oxidation protection. As a result many vehicles depend on a stand-alone non-structural thermal protection system (TPS) which protects an underlying conventional structure. The philosophy of one material system which can react structural loads and withstand extreme thermal loading is sound. The problem is that high temperature systems needed to react thermal shock are not structurally efficient. The team of Aztex and Boeing propose to demonstrate a hybrid high temperature (+2000F) and conventional (350F) composite structure. High temperature oxide matrix material would be used on the outside surface where the temperature is intense. This structure would be integrally connected to a conventional structure such as BMI which would react the structural loads. This proposal introduces novel high temperature core materials and through-thickness attachment techniques which are essential to achieve success. This program will demonstrate a hybrid structure which can serve both as a TPS and load bearing structure. As part of this activity new high temperature core options not currently available will be demonstrated. Successful completion of the Phase I program will enable designers to more seriously consider the use of high temperature material systems. Potential applications include uncooled engine components, aft deck structures, and space systems.

Keywords:
Hybrid Structures, Oxide, Integral Attachment, High Temperature Core, Composites

The vision for routine space access and rapid turn around rates requires space vehicles to be more aircraft-like in their reliability. To achieve this reliability requires robust, high temperature material systems. Systems under consideration include ceramic or carbon matrix reinforced composite structures. The history of these structures however, suggests their brittle nature and limited design options provides a barrier to their reliable availability to the Military Space Plane. Aztex has recognized this limitation and has developed technologies for through-thickness reinforcement, thermal tailoring, and high temperature cures. The proposed Phase II program targets the development of robust durable multi-functional structure and thermal protection systems for SOV. Together with our team partner, Boeing Space Systems, we will demonstrate a reinforced high temperature core system, which will serve both as the TPS and the primary load carrying structure. This system will be a major improvement over the redundant TPS and airframe structure considered baseline today. The Aztex/Boeing team understands however, that it is not just one effective structure that makes reliable space flight feasible but robust, design flexible material systems. Thus a key activity will be to demonstrate basic materials improvements in interlaminar properties, thermal capability and stiffener attachment.

Keywords:
Ceramic Composite, K-Cor(Tm), Aetb Core , X-Cor(Tm), Z-Fiber(Tm), Nextel