Sol-Gel Derived Ceramic-Ceramic Composites using Short Fibers

Abstract

ABSTRACTShort ceramic fibers or whiskers may be ideally suited for the fabrication of ceramic-ceramic composites using the sol-gel process. The fibers can be uniformly dispersed in a low viscosity sol and then frozen into the matrix through gelation. Several ceramic composites were prepared by synthesizing an Al2O3 precursor from aluminum sec-butoxide and then dispersing fibers of either zirconia, graphite or SiC. The composites were dried at room temperature and fired up to 1200°C. The fibers reduce the volume shrinkages in comparison to that obtained with pure Al2O3 during processing. Structures with dimensions of several cm2 can be rapidly produced with this method without cracking.