NOVEL MULLITE FELT REINFORCED COMPOSITES FOR ADVANCED RADOME APPLICATIONS

A STABLE LOW, DIELECTRIC CONSTANT, HIGH STRENGTH, A GOOD THERMAL SHOCK RESISTANCE ARE THE MAJOR CRITERIA FOR SELECTING A RADOME MATERIAL. A FIBEROUS MULLITE FELT REINFORCEMENT OFFERS MANY OF THESE PROPERTIES TO MAKE SUITABLE RADOME COMPOSITE MATERIAL. CERAMATEC, INC. PROPOSES TO REINFORCE A MULLITE FELT USING SOL-GEL TECHNIQUE WHICH OFFERS MAJOR ADVANTAGES OVER CONVENTIONAL SLURRY IMPREGNATION OR EXPENSIVE CHEMICAL VAPOR DEPOSITION TECHNIQUE. ADVANTAGES OF SOL-GEL TECHNIQUE INCLUDE LOWER SINTERING TEMPERATURE, ULTRAFINE HOMOGENEITY AND SUPERIOR MICROSTRUCTURE. DURING PHASE I RESEARCH, THE OVERALL OBJECTIVE IS TO DEMONSTRATE THE FEASIBILITY OF FABRICATTING A MULLITE FELT-MULLITE MATRIX COMPOSITE FOR RADOME APPLICATIONS. THE MULLITE FELT WILL BE VACUUM IMPREGNATED WITH A MULLITE SOL. THE IN-SITU SOL-TO-GEL TRANSITION WILL BE ACHIEVED USING AN INTERNAL GELATION TECHNIQUE. THE IMPREGNATED FELT WILL BE SINTERED AND CHARACTERIZED FOR MICROSTRUCTURE, FIBER-MATRIX INTERFACE, MECHANICAL AND DIELECTRIC PROPERTIES. THE ULTIMATE OBJECTIVE IS TO MAKE COMMERCIALLY FEASIBLE MULLITE FELT-MULLITE MATRIX COMPOSITE HAVING SUPERIOR STRENGTH AND DIELECTRIC PROPERTIES.