Carbon-carbon composites reinforced with discontinuous fibers have had a very limited range of applications. Perhaps the most important application is that of high-temperature insulation for vacuum or inert atmosphere furnaces. Porous carbon is cost competitive with ceramic furnace insulation and offers an economical alternative to refractory metal heat shields. Short carbon fibers impart sufficient rigidity and toughness to high (-90%) porosity carbon for machining and shape retention. Since thermal conductivity in CC composite is considered a fiber dominated property, all the fibers should be oriented randomly in-plane or in concentric circles in the case of cylindrical pieces, and should be perpendicular to the thickness of the material. Freestanding CC composite insulating materials are available in various shapes for use at temperatures up to 3000C. A typical component is illustrated in figure 1.
porous CC furnace insulation