Preparation and properties of short-fiber-reinforced C/SiC composites

Short-fiber-reinforced C/SiC composites were fabricated by mixing the raw materials of T700 or Nicalon-SiC short fiber, carbon powder, silicon powder,silicon carbide powder and then hot-pressing sintered at 1 900 ℃. The properties of short-fiber-reinforced C-SiC composites show that the density and room temperature bending strength of SiC-fiber-rein-forced composites(SiCf/C-SiC)are higher than those of C-fiber-reinforced composites (Cf/C-SiC). Carbon fiber is damaged seriously during the hot-pressing sintered process. The mass of the composites specimens decreases quickly at the initial stage of oxidation because of the oxidization of C phase, and increases slightly instead after being oxidized some time due to the passive oxidization of SiC phase when composites are oxidized at 1 300 ℃. The oxidation resistance of SiCf/C-SiC is better than that of Cf/C-SiC. The higher the oxidation temperature, the less the oxidation mass loss when the composites are oxidized in the temperature range of 1000-1400 ℃.