SIC FIBERS WITH SURFACE COATING, PROCESSES FOR THEIR PREPARATION, REINFORCED CERAMIC THEREOF AND PROCESS FOR PREPARING THE SAME

摘要

Coated SiC fibers and process for preparing them, ceramic reinforced by these fibers and process for their preparation. The fibers are SiC I fibers whose surface is coated with a thin carbon layer 0.7 to 10 mm thick, or SiC II fibers coated with a layer of Si3 N4. The fibers I are prepared by dispersing the fibers in a homogeneous solution of a thermosetting resin in an organic solvent, separation and drying of the fibers, hardening and curing of the resin in a non-oxidizing atmosphere between 800 and 1600 degree (s) C. For fibers II, a solution of an organosilicon polymer is used and the coated fibers are heated in a nitriding atmosphere between 1200 and 1600 degree (s) C. A reinforced ceramic is prepared by mixing a ceramic powder with fibers I or II and sintering the mixed powder in an inert atmosphere or under vacuum.