Composite tooling
Carbonaceous, composite tooling fabricated from pitch-based or coal-based cellular or porous products, “carbonaceous foams” having a density of preferably between about 0.1 g/cm 3 and about 0.8 g/cm 3 that are produced by: 1) conventional pitch foaming processes or; 2) the controlled beating of coal particulate preferably up to ¼ inch in diameter in a “mold” and under a non-oxidizing atmosphere. According to a specifically preferred embodiment, the starting material coal has a free swell index as determined by ASTM test D720 of between about 3.5 and about 5.0.
1. Tooling for the fabrication of composite materials comprising a tool body comprising carbonaceous foam, wherein the carbonaceous foam provides structural support for at least a portion of the composite material, and wherein the carbonaceous foam has a density ranging from about 0.10 to about 0.80 g/cm 3 , a coefficient of thermal expansion ranging from about 0.5 to about 6.5 ppm/° C. and a thermal conductivity below about 1 W/m/° K, wherein the tool body is adapted for fabricating members from composite materials.
2. The tooling of claim 1 wherein said carbonaceous foam is pitch-based or coal-based.
3. The tooling of claim 2 wherein said carbonaceous foam is a semi-crystalline, largely isotropic, porous coal-based product produced from particulate coal exhibiting a free swell index of about 3.5 to about 5.0.
4. The tooling of claim 3 wherein said coal exhibits a free swell index of about 3.75 to about 4.5.
5. The tooling of claim 2 wherein the carbonaceous foam has a compressive strength below about 6000 psi.
6. The tooling of claim 2 wherein said carbonaceous foam has been carbonized.
7. The tooling of claim 2 wherein said carbonaceous foam has been graphitized.
8. The tooling of claim 1 further including a facesheet of a dissimilar material coated on the tool body.
9. The tooling of claim 1 wherein the density of said carbonaceous foam varies in density throughout the mass thereof.
10. The tooling of claim 1 , wherein the tool body is formed of carbonaceous foam that was controllably cooled to a temperature below about 100° C. at a rate of 10° C./min or more to provide an outer surface of the carbonaceous foam with a density higher than a density of an outer surface of the carbonaceous foam when the carbonaceous foam is cooled at a rate of less than 10° C./min.
11. The tooling of claim 1 , wherein the coefficient of thermal expansion of the carbonaceous foam is substantially similar to the coefficient of thermal expansion of the composite material.