IMPROVED CVD SIC FIBERS

HIGHER THRUST/WEIGHT ENGINES AND HYPERSONIC VEHICLES REQUIREHIGH TEMPERATURE STRUCTURAL MATERIALS THAT DO NOT EXIST TODAY. ADVANCES IN STATE OF THE ART MATERIALS, PARTICULARLYFIBER REINFORCEMENTS, ARE REQUIRED TO MEET THE NEEDS OF THESE APPLICATIONS. COMMERCIALLY AVAILABLE CVD SIC FIBERS SUFFER FROM POOR CREEP RESISTANCE, A RESULT OF FREE SILICON FOUND AT THE GRAIN BOUNDARIES. THIS PROBLEM, A DIRECT RESULT OF THE PROCESS USED TO MAKE THE FIBER, LIMITS THEIR USE TO LOWER TEMPERATURES (<1000 DEGREES CENTIGRADE). A UNIQUE CVD SOURCE REAGENT HAS BEEN DEVELOPED FOR THE ELECTRONICS COMMUNITY WHICH ENABLES THE REPRODUCIBLE GROWTH OF STOICHIOMETRIC SINGLE CRYSTAL SILICON CARBIDE FOR HIGH POWER ELECTRONIC DEVICES. THIS REAGENT SHOULD ENABLE THE FABRICATION OF A SILICON FREE SILICON CARBIDE FIBER, WHICH SHOULD BE CREEP RESISTANT TO 1550 DEGREES CENTIGRADE. THE PHASE I PROGRAM WILL DETERMINE THE PHYSICAL PROPERTIES AND THE HIGH TEMPERATURE MECHANICAL PROPERTIES OF CVD MONOFILAMENTS MADE USING THIS INNOVATIVE "MOLECULAR SOURCE" REAGENT. A PHASE II PROGRAM WILL MORE FULLY DEVELOP THE PROPERTIES OF THE FIBER AND DEVELOP A MANUFACTURING PROCESS FOR ITS PRODUCTION.