Abstract: Layered carbon-carbon composites having improved interlaminar tensile strength are disclosed together with a process for making such composites. A metal catalyst is first deposited on a panel comprising a plurality of layers of carbon fiber cloth. The panel is then exposed to a gaseous hydrocarbon in an inert atmosphere at elevated temperature in order to promote the growth of graphite whiskers between the carbon cloth layers.

Abstract: Layered carbon-carbon composites having improved interlaminar tensile strength are disclosed together with a process for making such composites. A metal catalyst is first deposited on a panel comprising a plurality of layers of carbon fiber cloth. The panel is then exposed to a gaseous hydrocarbon in an inert atmosphere at elevated temperature in order to promote the growth of graphite whiskers between the carbon cloth layers.

Abstract: Monocrystalline ceramic fibers are disclosed together with a process for preparing such fibers. Polycrystalline ceramic fibers in a tow are coated with a coating that is chemically substantially non-reactive with the ceramic (e.g. alumina fibers coated with molybdenum), and the coated fibers are drawn through a heating zone maintained at a temperature high enough to melt the fibers without melting the coating. The coated fibers are withdrawn from the heating zone and cooled rapidly enough to form a substantially monocrystalline ceramic. The protective coating may thereafter be removed to leave a tow of substantially single-crystal ceramic fibers. Monocrystalline ceramic fibers about 8-20 microns in diameter are prepared by the disclosed process.

Abstract: An apparatus for assembling or disassembling a mast comprising a plurality elongate mast sections adapted to be attached together in end-to-end configuration. The apparatus includes a lifting assembly for raising or lowering the mast from its bottom end, and a plurality of winches for reeling in or feeding out guy lines attached to the mast. The apparatus also includes a computer for controlling the operation of the winches so as to ensure the length of guy line fed out of the winches is such that the mast is supported in a substantially vertical position.

Abstract: Method of forming a hollow, carbon/carbon composite article around an axis of symmetry, in which method a heat refractory mandrel is shaped to provide a desired inner surface configuration and tolerances of the article, and one or more plies of thermally stable carbon filaments are braided over the surface of the mandrel. The filaments have a diameter of substantially not greater than about 6 microns and a modulus of elasticity of substantially not less than about 45.times.10.sup.6 psi. The plies are then impregnated with a carbonizable liquid impregnant, and the assembly of impregnated plies and mandrel is heat treated so as to carbonize the impregnant. The resulting composite article has a high translation of the original strength of the filaments and has an inner surface defined by the outer surface of the mandrel.

Abstract: Glass or ceramic fibers or other fibers such as graphite properly protected by a suitable adherent ceramic or metal coating are immersed in a liquid metallo-organic solution containing a noble metal compound as a primary ingredient, then dried and fired in air or in a slightly oxidizing atmosphere so as to produce a noble metal coating on the fibers. Fibers may be in the form of individual filaments, as a multifilament tow or yarn or as a woven fabric. The fibers coated with a nobel metal are then incorporated into a metal matrix composite material by immersion in a molten bath of the desired matrix metal, placing the fibers in a suitable mold and casting the molten matrix metal around them or placing the fibers between solid sheets of matrix metal and effecting consolidation by diffusion bonding. The coating thickness on the fibers should be at least 0.30 microns and should not exceed 0.50 microns.

Abstract: A flame-retardant polymer is created by forming a first resin typically by reacting resorcinol with furfural in a ratio of one mole of the former to less than a mole of the latter in the presence of an alkaline catalyst. A resole is then formed by reacting typically phenol with formaldehyde in a ratio of one mole of phenol to more than a mole of the aldehyde in the presence of an alkaline catalyst. The first resin and resole are mixed together with a powered oxyborate compound such as zinc borate and allowed to polymerize to form the polymer.

Abstract: A carbonizable body is formed by infusing a plurality of preoxidized, preferably stabilized by known processing to have about 17 to 30 weight percent oxygen, fibers prepared from pitch, in a non-polar liquid plasticizer, typically quinoline, capable of extracting a tarry leachate from the fibers. The infusion of the fibers in the plasticizer is continued for a sufficient time for a substantial amount of leachate to form on the surface of the fibers. The treated fibers are then consolidated or diffusion-bonded to one another or other fibers, as by orienting the treated fibers in a mold and subjecting them to isostatic pressing at relatively low temperatures and pressure. Further processing of the consolidated fibers with appropriate heat treatment in an inert atmosphere will produce a carbonized bulk product with higher values of Young's modulus for the carbonized material than have been previously achieved at such carbonization temperatures.

Abstract: A carbonizable body is formed by infusing a plurality of preoxidized, preferably stabilized by known processing to have about 9 to 14 weight percent oxygen, polyacrylonitrile fibers in a polar liquid plasticizer, preferably water, capable of extracting a tarry leachate from the fibers. The infusion of the fibers in the plasticizer is continued for a sufficient time for a substantial amount of leachate to form on the surface of the fibers, and are then consolidated or diffusion-bonded to one another or other fibers, as by orienting the treated fibers in a mold and subjecting them to isostatic pressing at relatively low temperatures and pressure. Further processing of the consolidated fibers with appropriate heat treatment in an inert atmosphere will produce a carbonized bulk product with higher values of Young's modulus for the carbonized material than have been previously achieved at such carbonization temperatures.

Abstract: A carbonizable body is formed by infusing a plurality of preoxidized (preferably stabilized by known processing to have about 9 to 14 weight percent oxygen) polyacrylonitrile fibers in a polar liquid plasticizer, preferably water, capable of extracting a tarry leachate from the fibers. The infusion of the fibers in the plasticizer is continued for a sufficient time for a substantial amount of leachate to form on the surface of the fibers, and are then consolidated or diffusion-bonded to one another or other fibers, as by orienting the treated fibers in a mold and subjecting them to isostatic pressing at relatively low temperatures and pressure. Further processing of the consolidated fibers with appropriate heat treatment in an inert atmosphere will produce a carbonized bulk product with higher values of Young's modulus for the carbonized material than have been previously achieved at such carbonization temperatures.

Abstract: In a coating composition for application to a substrate for curing thereon to form an ablative coating of the type including a reactive mixture of epoxy and polysulfide resins, an amine curing agent, and inorganic materials serving as a source of one or more Lewis acids and being capable of forming a glassy reaction product when exposed to heat, the improvement comprising adding carbonaceous pre-ox fibers thereto in a weight amount between about 15 to 40%. When applied to a substrate, the solvent-free composition cures to a tightly adhering, flexible coating capable of providing thermal protection in a very high temperature, erosive environment.

Abstract: A coating composition for application to a substrate for curing thereon to form an ablative coating. The composition comprises a reactive mixture of epoxy and polysulfide resins, an amine curing agent, refractory fibers and inorganic materials serving as a source of one or more Lewis acids and being capable of forming a glassy reaction product when exposed to heat. When applied to a substrate, the solvent-free composition cures to a tightly adhering, flexible coating capable of providing thermal protection in a very high-temperature, erosive environment.

Abstract: A single piece carbon fiber composite article suitable for use as a hot-press mold is has an inner volume of chopped fiber and an outer volume of continuous carbon fiber all in a common graphite support matrix. The article is assembled by winding continuous carbon fiber around a mandrel formed of chopped carbon fiber in a matrix of carbon, impregnating the interstice in the winding and mandrel with graphite precursor material. The precursor material is converted to graphite, creating a common matrix between the internal mandrel and the external windings. The internal volume is machinable to form a graphite mold cavity, and has essentially the same coefficient of thermal expansion as the external volume.

Abstract: A novel process is provided for the formation of improved carbonized fibrous materials with increased modulus of elasticity and strength as well as decreased diameter. Preferably, the precursor material is acrylonitrile, typically copolymerized with a minor amount of an acrylic monomer such as methyl acrylate. Drawing of the polymer fiber during oxidation is effected at an elevated temperature in the presence of a carboxylic acid (other than formic acid), or its anhydride, within the fiber. It is believed that the acid and/or its anhydride which is formed at the oxidizing temperature serves as a plasticizer and reduces the fiber yield stress and increases fiber plasticity so that the fibers may be drawn by as much as 300% or more in the presence of the acid and/or its anhydride during oxidation, thereby providing the desired improvement in increased modulus of elasticity and tensile strength of carbon fibers formed subsequently by carbonization of the oxidized fibers.

Abstract: A novel polymer is provided as the condensation reaction product of a non-aqueous mixture of a phenol and an aldehyde in a molar ratio of about 0.5 to 1 phenol to aldehyde, containing refractory fibers, such as carbon, graphite, silica, having an aspect and metal oxides and silicates, which fibers have an aspect ratio of about 10. The phenol is selected from metacresol, orthocresol, 3,5-dimethylphenol, resorcinol and substituted resorcinols, the preferred material being mostly resorcinol. The aldehyde is selected from furfural and mixtures of furfural and paraformaldehyde. The condensation polymerization reaction can be effected by adding an acid catalyst to the mixture or by employing a curing agent which provided a polyfunctional amine reactive with either or both the aldehyde and the phenol.

Abstract: A novel polymer is provided as the condensation reaction product of a non-aqueous mixture of a phenol and an aldehyde in a molar ratio of about 0.5 to 1 phenol to aldehyde, containing refractory fibers, such as carbon, graphite, silica, having an aspect and metal oxides and silicates, which fibers have an aspect ratio of about 10. The phenol is selected from metacresol, orthocresol, 3,5-dimethylphenol, resorcinol and substituted resorcinols, the preferred material being mostly resorcinol. The aldehyde is selected from furfural and mixtures of furfural and paraformaldehyde. The condensation polymerization reaction can be effected by adding an acid catalyst to the mixture or by employing a curing agent which provided a polyfunctional amine reactive with either or both the aldehyde and the phenol.

Abstract: Flame retardant polymer resins formed by an acid condensation reaction from a mixture of resorcinol and furfural with a molar excess of the aldehyde. In one particular embodiment the resin is formed of a mixture of two prepolymer solutions with at least a boric acid catalyst, one or both of the prepolymer solutions being an acid-condensation reaction product of resorcinol and furfural with excess aldehyde functionality, or one of the prepolymers being a mix of substantially unreacted resorcinol and furfural with a slight molar excess of aldehyde.

Abstract: Flame retardant polymer resins formed by an acid condensation reaction from a mixture of resorcinol and furfural with a molar excess of the aldehyde. In one particular embodiment the resin is formed of a mixture of two prepolymer solutions with at least a boric acid catalyst, one or both of the prepolymer solutions being an acid-condensation reaction product of resorcinol and furfural with excess aldehyde functionality, or one of the prepolymers being a mix of substantially unreacted resorcinol and furfural with a slight molar excess of aldehyde.

Abstract: An acoustical insulating material comprises a fiber reinforced lead composite sheet or panel. In a preferred embodiment of the invention the fibers are substantially axially parallel aligned with one another. The frequency absorption and transmission characteristics of the material may be varied by mechanically stressing the material, e.g. as by placing the material under tension in the direction of fiber orientation.

Abstract: The ablative response at predetermined locations in a carbon-carbon reinforced composite material are selectively modified by one or more implants of a compatible, non-carbon material disposed at selected sites in the material. The implants of non-carbon material, which should have a melting point below the sublimation temperature of the surrounding carbon matrix and thermal expansibility having a force below the strength of the surrounding carbon matrix, preferably are arranged essentially parallel to one another at selected axial sites in the direction of expected thermal flux.