Abstract: The invention is a honeycomb structure suitable for use with cryogenic materials. In detail, the invention comprises a honeycomb sandwich structure 10 having a titanium core 14, a first face sheet 12 made of aluminum alloy suitable for high-temperature applications, and a second face sheet 16 made of titanium bonded together by a high-temperature thermoplastic adhesive. Preferably the core 14 is made of Ti-15V-3Cr-3Sn-3 aluminum, Ti-6Al-4V and/or Ti-3Al-2.5V. The first face sheet 12 is, preferably, made out of Al-8Fe-7Ce, Al-13Fe-4.6V, Al-1OFe-1Mo1V and Al-6Fe-6Ni-2Cr or other aluminum alloys suitable for use at temperatures in excess of 600.degree. F. The second face sheet 16 is, preferably, made of Ti-6Al-4V, Ti-6Al-2Sn-4Zr-2Mo or Ti-15V-3Cr-3Sn-3Al. Preferably, the adhesive 18a, 18b is a thermoplastic material such as polyetheretherketone, polyphenylquinoxaline or a polyamide-imide.

Abstract: An improved coating of gasification catalyst for carbon-graphite fibers is provided comprising a mixture of a polyvalent metal such as calcium and a monovalent metal such as lithium. The addition of lithium provides a lighter coating and a more flexible coating when applied to a coating of a carboxyl containing resin such as polyacrylic acid since it reduces the cross-link density. Furthermore, the presence of lithium provides a glass-like substance during combustion which holds the fiber together resulting in slow, even combustion with much reduced evolution of conductive fragments. The coated fibers are utilized as fiber reinforcement for composites.

Abstract: A thin, uniform, firmly adherent coating of metal gasification catalyst is applied to a carbon-graphite fiber by first coating the fiber with a film-forming polymer containing functional moieties capable of reaction with the catalytic metal ions. Multivalent metal cations such as calcium cross-link the polymer such as a polyacrylic acid to insolubilize the film by forming catalytic metal macro-salt links between adjacent polymer chains. The coated fibers are used as reinforcement for resin composites and will gasify upon combustion without evolving conductive airborne fragments.