PROCESSING AND PERFORMANCE OF AN ALL-OXIDE CERAMIC COMPOSITE

Continuous fiber ceramic composites (CFCCs) based on oxides are of int erest for high-temperature applications owing to their inherent oxidat ive stability. An enabling element is a matrix with an optimum combina tion of toughness and strength, which may be achieved by incorporating a controlled amount of fine, well-distributed porosity. Implementatio n of this concept by vacuum infiltration of aqueous mullite-alumina sl urries into two-dimensional woven preforms of alumina fibers has been investigated. Evaluation of these materials shows stress-strain charac teristics similar to other CFCCs, especially carbon-matrix composites. Moreover, promising notch and creep properties have been found. Micro structural and processing issues relevant to the attainment of these b ehaviors are discussed.