APPLICATION OF SOL-GEL PROCESSING TECHNIQUES FOR THE MANUFACTURE OF FIBER-REINFORCED CERAMICS

This paper discusses the application of freeze gelation of silica sols for the manufacture of low-cost, net-shape components in ceramic-matr ix composites (CMCs). A brief analysis is made of the central features which determine the stiffness, strength, and toughness of composite m aterials insofar as they may be applied to this particular class of CM Cs. The critical processing parameters, relating mainly to the matrix phase, are reviewed and the results of the program so far obtained are interpreted in the context of this analysis. It is clear that interac tions between processing parameters make optimization a complex proces s. In short-fiber composites, matrix porosity dominates composite prop erties, while in continuous-fiber systems, it is fiber degradation tha t controls the composite performance.