FIBER COATINGS FOR INTERMETALLIC MATRIX COMPOSITES

THE PROPOSED RESEARCH WILL EXAMINE THE UTILITY OF DUPLEX COATINGS, CONSISTING OF AN INNER, WEAKLY-BONDED COATING IMMEDIATELY ADJACENT TO THE FIBER AND AN OUTER, CHEMICAL-COMPATIBILITY COATING ADJACENT TO THE MATRIX. MODEL DUPLEX COATING SYSTEMS, WHERE EACH CONSTITUENT MATERIAL IS THERMOCHEMICALLY COMPATIBLE WITH THE ADJACENT MATERIALS, WILL BE PREPARED BY LOW-PRESSURE CHEMICAL VAPOR DEPOSITION ON COMMERICAL CARBON, SILICON CARBIDE, BORON AND ALUMINUM OXIDE YARNS AND FILAMENTS. COATED YARNS AND FILAMENTS WILL BE INCORPORATED INTO TIAL MATRICES, AND THE MECHANICAL PROPERTIES OF THE PRODUCT COMPOSITES EVALUATED. THE PRODUCT COMPOSITES ARE EXPECTED TO BE USEFUL AS STRUCTURAL MATERIALS FOR BOTH HYPERSONIC VEHICLES AND ADVANCED TURBOJET ENGINES. THE PROJECT WILL BE PERFORMED WITH THE ENGINEERING AND TECHNICAL ASSISTANCE OF THE UNIVERSITY OF CALIFORNIA-SANTA BARBARA FOR COMPOSITE PREPARATION AND EVALUATION.