CERAMIC-MATRIX COMPOSITES (CMC)

High-strength ceramic molds with heat resistance and oxidation resistance have been fabricated, and they are now applied to practical parts such as turbo rotors, bearings and machining tools. However, their fracture toughness and thermal shock resistance are poor and their reliability is also low. In order to improve these characteristics, research work on ceramic matrix composites (CMC) has been extensively studied, and recently CMCs using continuous ceramic fibers are actively being fabricated in Japan, The CMCs are now expected as high-performance materials for severe environments. In this paper, the synthesis and characteristics of the recently developed CMCs are reviewed, and ceramic fibers with ultra-environmental resistance which are necessary for the development of CMCs are discussed.