METHOD FOR PRODUCING PRE-SHAPED ALPHA-SILICON NITRIDE WHISKER COMPACTS AND LOOSE WHISKERS FOR COMPOSITE MATERIAL REINFORCEMENT

摘要

ABSTRACTMethod for producing pre-shaped .alpha.-silicon nitride whisker compactsand loose whiskers for composite material reinforcement, lies in thefield of producing uncontaminated silicon nitride whiskers, which pre-viously could not be accomplished without high cost. The present in-vention provides for production of contaminated .alpha.-silicon nitridewhiskers at a reasonable cost as either shaped preform or individualwhiskers by blending silicon particles with composition particles,compacting the blend of silicon and composition particles to a shapedpreform, subliming the composition particles to produce a shapedporous silicon precursor, and reacting the precursor with nitrogen.The shaped whisker compact can be impregnated with various materialsto form composites, or can be broken down to individual whiskers tobe used in molding powders.