HIGH TEMPERATURE METAL MATRIX COMPOSITES FOR HYPERSONIC AIRCRAFT STRUCTURES

THE NATIONAL AERO-SPACE PLANE (NASP) PROGRAM WILL DEVELOP MANNED HYPERSONIC AIRPLANES (MACH 6-25) THAT WILL PROVIDE ORBIT-ON-DEMAND CAPABILITY FROM CONVENTIONAL RUNWAYS, THEREBY REVOLUTIONIZING ACCESS TO SPACE. HOWEVER, SUCCESS WILL DEPEND UPON THE DEVELOPMENT OF NEW, LIGHT-WEIGHT STRUCTURAL MATERIALS HAVING UNPRECEDENTED HIGH-TEMPERATURE PERFORMANCE CAPABILITIES. VERY ATTRACTIVE NEAR-TERM CANDIDATESARE LOW-DENSITY HIGH-TEMPERATURE METAL MATRICES REINFORCED WITH CONTINUOUS HIGH-PERFORMANCE CERAMIC OR GRAPHITE FIBERS. SUCH COMPOSITES ARE EXPECTED TO EXHIBIT GOOD MECHANICAL PROPERTIES AT TEMPERATURES IN EXCESS OF 1000C. IN THE PROPOSED WORK, NEWLY DEVELOPED PRECURSOR FABRICATION TECHNOLOGY WILL BE UTILIZED TO MANUFACTURE ULTRA-THIN METAL MATRIX COMPOSITE TAPES LESS THAN 0.001 INCH THICK. CONSOLIDATION PROCEDURES WILL BE DEVELOPED FOR PRODUCING THIN, MULTI-PLY PANELS FROM 0.010 TO 0.060 INCH THICK IN UNIDIRECTIONAL, ORTHOTROPIC, AND QUASI-ISOTROPIC LAYUPS. PRELIMINARY CHARACTERIZATION OF STRUCTURES AND PROPERTIES WILL BE USED TO FORMULATE A PHASE II OPTIMIZATION PROGRAM THAT WILL INCLUDE FABRICATION OF PROTOTYPE STRUCTURES SUCH AS HONEYCOMB PANELS AND THIN-WALLED TUBES FOR EVALUATION OF MECHANICAL BEHAVIOR AND OXIDATION AT ELEVATED TEMPERATURES.