Effect of air-oxidation on the thermal diffusivity of the nuclear grade 2-dimensional carbon fiber reinforced carbon/carbon composite

Sogabe, Toshiaki; Ishihara, Masahiro ; Baba, Shinichi; Tachibana, Yukio ; Yamaji, Masatoshi*; Iyoku, Tatsuo; Hoshiya, Taiji*

2D-C/C composite is one of the promising materials as a next-generation core material in gas-cooled reactors. Effect of air-oxidation on the thermal diffusivity up to 1673K of the 2D-C/C composite was investigated. The C/C composite specimens for measurement of thermal diffusivity were oxidized from 1 to 11 percent weight loss in air at 823K. Thermal diffusivity at room temperature declined 1020 percent for parallel to lamina direction and 59 percent for that of perpendicular within 11 percent weight loss by oxidation. Thermal diffusivity tended to decrease gradually as the increase of oxidation loss in parallel to lamina, however, it decreased in the beginning of oxidation pretty much and not so changed by further oxidation loss in perpendicular to lamina. Change in thermal conductivity under oxidation condition was also estimated.