CERAMIC-MATRIX COMPOSITES (CMC)

High-strength ceramic molds with heat resistance and oxidation resista nce have been fabricated, and they are now applied to practical parts such as turbo rotors, bearings and machining tools. However, their fra cture toughness and thermal shock resistance are poor and their reliab ility 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 mat erials for severe environments. In this paper, the synthesis and chara cteristics of the recently developed CMCs are reviewed, and ceramic fi bers with ultra-environmental resistance which are necessary for the d evelopment of CMCs are discussed.