Carbon foams have attracted considerable recent interest because of their multi-functionality, offering a combination of high strength, low density, low thermal expansion, and a wide, controllable range of thermal conductivities. Among the many potential applications of carbon foam is use as core material in tooling for the high-rate production of composite materials. In tooling applications, a face sheet is applied to the foam to provide durability to the working surface. The coefficient of thermal expansion of the carbon foam material is low, making it an ideal match for carbon fiber composites typically used as such laminates. This paper describes working solutions that enable the use of carbon foam (0.16-0.32 g/cm~3) as a core material in composite tooling. These solutions include techniques for machining carbon foam, bonding foam blocks together to produce larger-sized tools, adhering uncured carbon-fiber-based laminates to the foam surface, and drying and venting the material to remove unwanted moisture. Adhesive materials are evaluated for bonding foam blocks; those that performed well are suitable for use up to 200-250°C. Flexural testing of bonded foam demonstrates that the bond is in many cases stronger than the foam itself. Adhesive sealant materials to be applied between the foam surface and several pre-preg composite layers are also evaluated. Optical micrographs demonstrate that a resin-based sealing material offers good adhesion and sealing of the porous foam surface. Minimum sizes for venting channels to remove unwanted moisture from fully-sealed composite tools are also determined. The results presented here are discussed with respect to use in production rate tooling applications.
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