NASA SBIR 2006 Solicitation


SUBTOPIC TITLE:Materials and Structures for Future Aircraft
PROPOSAL TITLE:Ceramic Composite Mechanical Fastener System for High-Temperature Structural Assemblies

SMALL BUSINESS CONCERN (Firm Name, Mail Address, City/State/Zip, Phone)
Hyper-Therm High-Temperature Composites
18411 Gothard St Units B&C
Huntington Beach, CA 92648-1208
(714) 375-4085

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Wayne S. Steffier
18411 Gothard St Units B&C
Huntington Beach, CA  92648-1208
(714) 375-4085

TECHNICAL ABSTRACT ( Limit 2000 characters, approximately 200 words)
Hot structures fabricated from ceramic composite materials are an attractive design option for components of future high-speed aircraft, re-entry vehicles and propulsion systems to reduce weight and increase performance. One important detail in the design of such structures is that of joining and attachment. Large-area hot structures will likely be fabricated by mechanically joining smaller component sub-assemblies. Conventional metallic fasteners and fastening techniques do not provide structurally tight joints over a wide temperature range. A metallic fastener, which is snug at room temperature, will loosen at elevated temperature due to its relatively high thermal expansion. Excessive preloading at room temperature to maintain a tight joint at elevated temperature may be detrimental to the structural integrity of the joint. Ceramic composite fasteners on the other hand can be designed with near-perfect thermo-elastic compatibility with the adherends, however their prohibitively high cost to produce severely restricts their utility. The objective of this proposed program is to demonstrate the feasibility of a unique, cost-effective thermal stress-free ceramic composite mechanical fastener system suitable for assembly of high-temperature ceramic composite structures. The innovative fastener design facilitates joining load-bearing hot structural assemblies and can be produced at a cost much lower then other competing designs and methods. Ceramic composite fasteners will be produced and experimentally evaluated to determine the shear and tensile properties of the fasteners both individually and of respective lap-joined ceramic composite assemblies.

POTENTIAL NASA COMMERCIAL APPLICATIONS ( Limit 1500 characters, approximately 150 words)
Fiber-reinforced ceramic-matrix composites are recognized an enabling class of materials for a variety of high-temperature applications in chemical rocket engine throat inserts, combustion chambers and nozzles; aero-engine combustors, turbines and exhaust nozzles; hypersonic airframe hot structure and thermal protection systems; spacecraft re-entry heatshields; and a variety of industrial power generation radiant burner and heat exchanger tubes. One of the most important details in the design of high-temperature ceramic composite structures is that of joining and attachment. This proposal offers a high-temperature fastener that guarantees the lowest possible manufacturing cost and highest production rate over all other competing fastener designs and production methods.

POTENTIAL NON-NASA COMMERCIAL APPLICATIONS ( Limit 1500 characters, approximately 150 words)
Viable near-term applications for ceramic composites include expendable chemical rocket thrusters for orbital insertion, attitude control system and/or divert thrust chamber components for commercial and military communication spacecraft and/or various ballistic missile defense KE intercept weapons. Opportunities for retrofit application in turbine engine augmentors (e.g., converging/diverging exhaust nozzle flaps and seals) for military aero-propulsion systems also exist. Applications for ceramic composites in advanced airbreathing combined-cycle propulsion systems and control surfaces for reusable hypervelocity and exo/transatmospheric aerospace vehicles are currently being addressed. However, the issues of durability, survivability and maintainability are major concerns. For nuclear (e.g., fission and fusion) energy systems, SiC-matrix composites have been identified as enabling materials for heat exchangers, moderators, first wall plasma containment, liner, and diverter component applications. Similar requirements for high-temperature materials exist for commercial/industrial applications as well. Although less aggressive than the aerospace/defense and nuclear energy-related initiatives, programs are in place for evaluating reinforced ceramics for land-based turbine components, catathermal combustion devices, heat exchangers and radiant burners, which represent opportunities in energy and pollution abatement technologies that may mature over the next 10 or so years.

NASA's technology taxonomy has been developed by the SBIR-STTR program to disseminate awareness of proposed and awarded R/R&D in the agency. It is a listing of over 100 technologies, sorted into broad categories, of interest to NASA.

Aircraft Engines
Launch and Flight Vehicle

Form Printed on 09-08-06 18:19