HIGH STRENGTH SILICON NITRIDE AND OXYNITRIDE GLASS FIBERS

A NEW TECHNOLOGY OF PREPARING SILICON NITRIDE AND SILICON OXYNITRIDE GLASS FIBERS IS PROPOSED. CONTINUOUS SILICON NITRIDE AND OXYNITRIDE FIBERS WILL BE PREPARED AT LOW PROCESSING TEMPERATURES AND AT LOW MATERIAL, EQUIPMENT AND OPERATING COST. SILICA AND OTHER SELECTED POROUS HIGH SILICA (NANOMETER PORE SIZE; ~96WT%. SIO(2)) GLASS FIBERS WILL BE PREPARED. THESE GLASS FIBERS WILL BE NITRIDED IN A SEPARATE PROCESS IN AMMONIA USING PROVEN PROCEDURES. THE KEY DEVELOPMENT WILL BE ESTABLISHING A DYNAMIC NITRIDING PROFILE THAT TAKES INTO ACCOUNT THE PROPERTY CHANGES AS MORE NITROGEN IS CHEMICALLY DISSOLVED/DIFFUSED INTO THE GLASS FIBER. IMPORTANT PARAMETERS SUCH AS OPTIMUM NITRIDING TEMPERATURE AND TIME, AND OPTIMUM NITROGEN CONTENT IN THESE FIBERS WILL BE INVESTIGATED. ANTICIPATED BENEFITS/POTENTIAL APPLICATIONS - POTENTIAL APPLICATIONS FOR THIS WORK INCLUDE THE USE OF SILICON NITRIDE AND OXYNITRIDE FIBERS AS REINFORCEMENT IN HIGH STRENGTH/HIGH TEMPERATURE COMPOSITE COMPONENTS FOR ENGINES, HEAT ENGINES, AND LIGHT WEIGHT ARMOR. ALSO, THE LOWER COST WILL PERMIT SUCH FIBERS TO BE USED IN POLYMER COMPOSITE SYSTEMS.