Abstract: A processable blend having high temperature and thermal shock resistance properties includes a resin blend which includes at least one first silicone polymer and at least one second silicone polymer. The processable blend is ceramitizable at a temperature above about 1100.degree. F. A method of producing an article with high temperature and thermal shock resistance properties includes forming a silicone blend of at least one first silicone polymer and at least one second silicone polymer, wherein the blend is ceramitizable at a temperature above about 1100.degree. F.; forming the blend into the shape of the desired article; and, at least partially curing at least one of said silicone polymers at a temperature below the ceramitization temperature.

Abstract: A processable blend having high temperature and thermal shock resistance properties includes a resin blend which includes at least one first silicone polymer and at least one second silicone polymer. The processable blend is ceramitizable at a temperature above about 1100.degree. F. A method of producing an article with high temperature and thermal shock resistance properties includes forming a silicone blend of at least one first silicone polymer and at least one second silicone polymer, wherein the blend is ceramitizable at a temperature above about 1100.degree. F.; forming the blend into the shape of the desired article; and, at least partially curing at least one of said silicone polymers at a temperature below the ceramitization temperature.

Abstract: A material for smoothing the outside surface of a woven fabric composite lay up in which a layered sandwich structure is formed of continuous fiber woven material, resin films and a mat of randomly oriented discontinuous fibers and the sandwiched layers are integrated into a single sheet of resin impregnated material by application of pressure and heat.

Abstract: A material for smoothing the outside surface of a woven fabric composite lay up in which a layered sandwich structure is formed of continuous fiber woven material, resin films and a mat of randomly oriented discontinuous fibers and the sandwiched layers are integrated into a single sheet of resin impregnated material by application of pressure and heat.

Abstract: The subject invention relates to a toughened epoxy matrix formulation useful as a prepreg for fiber reinforcements comprising at least two epoxy components, an amine hardener and about 10%-25% of a micropulverized polyimide thermoplastic having a molecular weight of from about 20,000 to about 100,000 and Tg of at least about 220.degree. C. The invention further relates to a process for preparing a toughened epoxy matrix formulation comprising:a. preheating a blend of at least two epoxy compounds to a temperature of about 130.degree. F. to about 140.degree. F.;b. blending into the epoxy blend from step (a) a micropulverized polyimide thermoplastic;c. mixing the blend of epoxy and thermoplastic at a temperature of about 110.degree. F. to about 130.degree. F.; andd. adding to the blend of epoxy and thermoplastic an amine hardener and mixing at about 110.degree. F. to about 130.degree. F. until a low mix viscosity is obtained.

Abstract: This invention relates to an improved pack mixture composition useful for the formation of a SiC pack cementation coating for protecting a carbonaceous substrate from degradation at temperatures above about 800.degree. F. comprising: Si from about 15% to about 50% by weight of the total composition; B up to about 25% by weight of the total composition when present; SiO.sub.2 from about 0.01% to about 3% by weight of the total composition; and SiC from about 40% to about 85% by weight of the total composition.The invention also relates to a method for protecting a carbonaceous substrate from degradation at temperatures above about 800.degree. F. comprising: preparing a pack mixture composition of from about 15% to about 50% Si, up to about 25% B, from about 0.01% to about 3% SiO.sub.

Abstract: This invention relates to an improved pack mixture composition useful for the formation of a SiC pack cementation coating for protecting a carbonaceous substrate from degradation at temperatures above about 800.degree. F. comprising: Si from about 15% to about 50% by weight of the total composition; B up to about 25% by weight of the total composition when present; SiO.sub.2 from about 0.01% to about 3% by weight of the total composition; and SiC from about 40% to about 85% by weight of the total composition and method thereof.The invention further relates to a cork release agent composition for providing the clean release of spent pack composition from a carbonaceous substrate.

Abstract: High tensile carbon fibers are provided with a high yield process in which, after oxidation of a precursor, the fibers are first precarbonized in an inert atmosphere to to about 600.degree. C. while imparting 5-10% stretch. In precarbonizing, the fibers are intially heated in a sweeping manner with substantial volumes of hot inert gas which is extracted along with products of decomposition before the fibers are cooled to a low, non-reactive exit temperature. The arrangement minimizes redeposition of tars on the fibers and stretches the fibers in a range in which substantial off-gassing occurs. Thereafter the fibers are finally carbonized at a higher temperature with a different tension being applied, to provide a more reliable less sensitive process that enables oxidation to be effected more rapidly.

Abstract: An integrally woven multi-apertured multi-ply angle interlock fabric is woven so as to have a plurality of apertures which extend across the width of the fabric and are completely contained within the thickness of the fabric. The fabric is comprised of a first yarn system in which yarns extending across the width of the fabric in parallel, spaced-apart fashion form a laminate of spaced-apart, generally parallel yarn layers between the opposite top and bottom surfaces. The fabric is also comprised of a second yarn system having weaver yarns arranged into yarn layers which repeatedly extend through portions of the thickness of the fabric between the top and bottom surfaces and which interweave with a plurality of the yarn layers of the frist yarn system on one side of and one or more yarn layers of the first yarn system on the other side of the plurality of apertures being formed within the thickness of the fabric.

Abstract: A multi-layer angle interlock fabric is woven from warp yarns that extend in straight fashion in a common direction along the length of the fabric and fill yarns which repeatedly extend through the thickness of the fabric along angled paths between opposite broad surfaces of the fabric and interweave within the relatively straight warp yarns. The fabric can be woven using a conventional fly shuttle loom with a programmable Jacquard machine which controls the loom's harness lines to selectively raise and lower the fill yarns extending through a weaving area of the loom as the loom shuttle reciprocates through the weaving area to repeatedly extend a fill yarn across the width of the fabric being formed. Stuffer yarns can be provided by periodically extending the fill yarn across the fabric width betweem adjacent sheets of the warp yarns during weaving.

Abstract: In a multi-layer woven fabric in which a first yarn system forms yarn layers between the opposite broad surfaces of the fabric and a second yarn system extends through the fabric thickness between the opposite broad surfaces and is interwoven with the yarn layers, at least one of the first and second yarn systems is comprised of two or more different yarn groups of different material composition disposed within different portions of the thickness of the fabric. This enables different materials such as carbon, ceramics, metals and organics to be disposed uniformly throughout the fabric thickness or to be concentrated within particular portions of the fabric thickness. In this manner multi-layer woven fabrics can be customized for particular applications in terms of their chemical, electrical, thermal, ablative, optical or other properties while retaining the advantageous structural characteristics of such fabrics. Both angle interlock and layer-to-layer weaving configurations may be used.

Abstract: Metal complexes are obtained by reacting furfurylamine with a metal carbonyl selected from the group consisting of tungsten carbonyl, molybdenum carbonyl and chromium carbonyl. Multi-cycle reimpregnation polymers are obtained by reacting one of these metal complexes with furfuryl alcohol. A carbon/carbon composite is formed by impregnating a carbon/carbon composite containing voids with said polymer and curing and carbonizing said polymer.

Abstract: The composite stud is mainly a corrosion-resistant alloy, but is provided with a steel tip for flawless welding to a steel plate for use in a marine environment. The steel tip is friction-welded to the corrosion-resistant alloy before machining of the stud.

Abstract: The rate of preoxidation-stabilization of polyacrylonitrile carbon fiber precursors is substantially increased by applying an aqueous solution of an accelerator compound containing a C.dbd.N group such as guanidine carbonate to the fiber, suitably by immersing the fiber in a bath of the solution.

Abstract: There are disclosed thermosetting resoles containing chemically bonded boron, tungsten and/or zirconium atoms. The metal containing resoles of this invention are useful, for example, as reimpregnation resins.

Abstract: A retracting tensioning mechanism for dispensing an elongated member such as a length of yarn wound on a carrier tube in a creel utilizes a rotatably mounted disk coupled to the carrier tube and having a plurality of outwardly extending, spaced-apart elements in the form of pegs disposed in a circular array about the outer periphery thereof. An elongated lever which is at least partly disposed within the circular array of pegs is rotatably mounted about a pivot axis offset from and generally parallel to the axis of rotation of the disk and the carrier tube and has an elongated tongue extending outwardly from the pivot axis and into contact with the pegs.

Abstract: Metal complexes are obtained by reacting furfurylamine with a metal carbonyl selected from the group consisting of tungsten carbonyl, molybdenum carbonyl and chromium carbonyl. Multi-cycle reimpregnation resins are obtained by reacting one of these metal complexes with furfuryl alcohol.

Abstract: In a method of making a fluted core radome from resin impregnated glass cloth, an outer skin, a fluted core, an inner skin, an edge band and a drain cap are individually fabricated from plies of resin impregnated glass cloth which are laid up on a mold and then subjected to pressure using a vacuum bag and to resin curing heat using an autoclave. The fluted core is formed on a mold having recesses in the surface thereof by placing silicone rubber mandrels within the recesses and on top of the plies of glass cloth, the mandrels tending to expand in response to the application of heat thereto and at the same time tending to contract in response to the application of pressure thereto so that an equilibrium is reached which provides a tight fit of the glass plies over the mold and a relatively even flow of resin within the glass cloth.

Abstract: In a process for continuously pulling a web of tows of carbonizable material under tension through an oxidizing oven, the web is introduced into the oxidizing oven by initially feeding a leader in the form of a web of heat-resistant cloth through the oven and then heating the oven if the oven is not already hot. The trailing edge of the leader which remains outside of the oven is then spliced to the leading edge of the web of carbonizable tows, and the leader is used to pull the web of carbonizable tows into and through the hot oven. Use of the heat-resistant leader greatly minimizes wastage within the web of carbonizable tows. Splicing of the trailing edge of the lead to the leading edge of the web of carbonizable tows is accomplished by taping, stitching and folding the two edges to form loops therein into which elongated rods are inserted. The two edges are then secured within a splice bar, the opposite halves of which define slots for receiving the two edges and the included rods.

Abstract: High tensile carbon fibers are provided with a high yield process in which, after oxidation of a precursor, the fibers are first precarbonized in an inert atmosphere to to about 600.degree. C. while imparting 5-10% stretch. In precarbonizing, the fibers are initially heated in a sweeping manner with substantial volumes of hot inert gas which is extracted along with products of decomposition before the fibers are cooled to a low, non-reactive exit temperature. The arrangement minimizes redeposition of tars on the fibers and stretches the fibers in a range in which substantial off-gassing occurs. Thereafter the fibers are finally carbonized at a higher temperature with a different tension being applied, to provide a more reliable less sensitive process that enables oxidation to be effected more rapidly.