LIGHT WEIGHT AEROSTRUCTURAL COMPOSITES FOR 1800 F TO 4000 F FASTENER APPLICATIONS

CRITICAL TO DEVELOPMENT OF A TRANSATMOSPHERIC VEHICLE ARE LIGHT WEIGHT MATERIALS FOR ABOVE 1800 F STRUCTURAL APPLICATIONS. CARBONCARBON COMPOSITES WITH OXIDATION RESISTANCE WILL BE REQUIRED IN A TAW AIRFRAME AS 2500 F HIGH STRENGTH FASTENERS. RESEARCH IN JOINING, REINFORCEMENTS, MATRICES, AND OXIDATION PROTECTION REMAINS. HIGH TEMPERATURE FASTENERS TO WITHSTAND AERODYNAMIC HEATING OF THE AIRFRAME WILL BE A MAJOR CHALLENGE. BECAUSE OF SUSTAINED HYPERSONIC VELOCITIES WITHIN THE ATMOSPHERE, TOTAL STRUCTURAL HEAT LOAD WILL DOMINATE THE DESIGN. JOINING TECHNIQUES EMPLOYING CARBON BONDS MIGHT IMPOSE WEIGHT PENALTY RESTRICTIONS ON SIZE OF AERODYNAMIC SURFACES FOR DESIGN CONSIDERATIONS, AND THERMAL EXPANSION MISMATCH PROBLEMS WITH REGENERATIVELY COOLED SUBSTRUCTURES. A MECHANICAL FASTENER, OPERABLE AT 2500 F, WOULD PERMIT THE DESIGNER AN APPROACH FOR THE AEROVEHICLE PROJECT. PHASE I INCLUDES EXPERIMENTAL INVESTIGATIONS TO EXAMINE FIBERS, MATRICES, UNIQUE CHEMICAL AND MECHANICAL INTERACTIONS; BATCH AND CONTINUOUS PROCESSING, AND COMPOSITE PROPERTIES. PHASE II, KAISER AEROTECH, FOCUSES ON SPECIMENS FOR STRENGTHS AT OXIDIZING TEMPERATURES AND POTENTIAL PAYOFFS/PROBLEMS OF LARGE COMPONENTS. PHASE III, KAISER AEROTECH, FABRICATES LARGE COMPONENTS WITH DEVELOPED FASTENERS, REPRESENTATIVE OF A LARGE AEROVEHICLE.