VERY HIGH TEMPERATURE FIBERS OF VANADIUM CARBIDE AND NIOBIUMCARBIDE

COMPOSITE MATERIALS FOR ADVANCED COMPONENTS OFFER PERFORMANCE, WEIGHT, AND COST ADVANTAGES OVER COMPETING MATERIALS. INCREASING DEMANDS ON THE STRENGTH AND TEMPERATURE TOLERANCE FOR THESE MATERIALS WILL REQUIRE INNOVATIVE APPROACHES IN COMPOSITION AND FABRICATION. COMPOSITE MATERIALS COMPOSED OF SINGLE CRYSTAL WHISKERS SHOW PROMISING TENSILE STRENGTH BUT HAVE PROVEN DIFFICULT TO GROW AND HAVE NOT BEEN PRODUCED IN USEFUL LENGTHS. LASERGENICS CORPORATION IS PROPOSING TO INVESTIGATE THE GROWTH OF SINGLE CRYSTAL FIBERS OF VC AND NBC BY THE LASER-HEATED PEDESTAL-GROWTH TECHNIQUE. THE MELTING POINT OF VC IS 2810 DEGREES CENTIGRADE AND THAT OF NBC IS 3900 DEGREES CENTIGRADE. FIBERS OF THESE MATERIALS WILL BE GROWN, THEIR MORPHOLOGY CHARACTERIZED, X-RAY DIFFRACTION AND STRENGTH MEASUREMENTS MADE DURING THE PHASE I EFFORT. SINGLE CRYSTAL FIBERS OF MULTI-METER LENGTHS OF THESE VERY HIGH MELTING POINT MATERIALS WILL BE THE BASIS OF A PHASE IIPROGRAM. WE WILL ALSO INVESTIGATE THE FORMING OF MATRIX COMPOSITE MATERIALS WITH THE FIBERS AND TEST THE EFFECTS THE FIBERS HAVE ON THE STRENGTH OF THE MATERIALS.