Abstract: A multi-dimensional (e.g., 3D braided) preform formed of reinforcement strands or filaments is rigidized by impregnating the preform with a resin solution (e.g., silicone resin solution), curing the resin to impart a selected shape to the preform and then heating the shaped preform to convert the cured resin to inorganic solids (e.g., silica solids) so dispersed in an effective amount between the strands as to rigidize the preform. The rigidized preform is then infiltrated with an inorganic matrix (e.g., a ceramic material) to form a composite article.

Abstract: A composite gas turbine engine blade is made by braiding a plurality of fibers to form a preform having an airfoil precursor portion and an integral root precursor portion. A plurality of fiber shaping inserts are positioned in the root precursor portion, either by braiding the root precursor portion around the inserts or inserting the fiber shaping inserts into the root precursor portion after braiding, to impart an enlarged, divergent shape (e.g., dovetail precursor shape) to the braided root precursor portion. The braided preform with the enlarged, shaped root precursor portion is infiltrated with matrix material and shaped to near net shape to provide the composite blade with a dovetail shaped root.

Abstract: An annular fluid seal is provided between a pair of spaced apart machine components, such as a rotor and a stator. The rotatable component includes an annular sealing surface of increasing diameter in a given direction (e.g., along its length or along a radially extending shoulder). An annular fibrous sealing element is disposed proximate the clearance space between the components in such a manner that a sealing portion thereof engaging the other component moves in the direction of increasing diameter as the sealing portion may wear so as to maintain sealing contact with the annular sealing surface. A fluid seal is thereby maintained between the components.

Abstract: A composite gas turbine engine blade is made by braiding a plurality of fibers to form a preform having an airfoil precursor portion and an integral root precursor portion. A plurality of fiber shaping inserts are positioned in the root precursor portion, either by braiding the root precursor portion around the inserts or inserting the fiber shaping inserts into the root precursor portion after braiding, to impart an enlarged, divergent shape (e.g., dovetail precursor shape) to the braided root precursor portion. The braided preform with the enlarged, shaped root precursor portion is infiltrated with matrix material and shaped to near net shape to provide the composite blade with a dovetail shaped root.

Abstract: A braided gas turbine engine blade preform includes an airfoil precursor portion and an integral root precursor portion. A plurality of fiber shaping inserts are disposed in the root precursor portion, to impart an enlarged, divergent shape (e.g., dovetail precursor shape) to the braided root precursor portion. The braided preform with the enlarged, shaped root precursor portion is infiltrated with matrix material and shaped to near net shape to provide a composite blade with a dovetail shaped root.

Abstract: The method involves braiding a plurality of fiber bundles, each comprising a reinforcing fiber overwrapped by a plurality of glass or metal matrix-forming fibers, to form a 3D braided preform having stuffer fiber bundles extending longitudinally therethrough and heating the preform at a temperature and applying pressure to form the matrix-forming fibers into a bonded matrix in which the reinforcing fibers are disposed in a 3D braided pattern and in a longitudinal (stuffer) pattern.

Abstract: The apparatus includes a plurality of fiber strand carrier members that are movable on a carrier surface defined by multiple, movable, side-by-side support members and a plurality of fiber guides affixed on the support members for dispensing axial stuffer fiber strands as the carrier members move along predetermined paths to intertwine the fiber strands from the fiber guides. The carrier members are disposed on the support members for movement therewith and for movement from one support member to abother. The fiber guides are affixed on the support members for movement only with the respective support member. The stuffer fiber strand for each fiber guide is dispensed from a spool that is carried on a respective support member or is mounted on a stationary base.

Abstract: The method involves braiding a plurality of fiber bundles, each comprising a reinforcing fiber overwrapped by a plurality of glass or metal matrix-forming fibers, to form a 3D braided preform having stuffer fiber bundles extending longitudinally therethrough and heating the preform at a temperature and applying pressure to form the matrix-forming fibers into a bonded matrix in which the reinforcing fibers are disposed in a 3D braided pattern and in a longitudinal (stuffer) pattern.

Abstract: A composite article is made by braiding a 3D article shaped preform including non-fugative braider reinforcing fibers and fugative fibers and removing the fugative fibers to form a plurality of matrix-ingress passages in the braided preform. During impregnation of the braided preform with a matrix material, matrix material is supplied to the interior of the preform via the passages. The fugative fibers typically comprise fugative monofilaments which are substantially larger in size than the non-fugative fibers to permit one or more dimensions of the preform and thus the composite article to be increased beyond the capacity of the particular braiding apparatus employed.

Abstract: An aqueous base coating system consisting primarily of an emulsion of an extensible halogenated polymer and water insoluble fillers which release non-combustible gases on heating is provided for exterior application to combustible substrates. On drying of the coating system, the resultant coating is no longer redispersible by water. The dried coating is highly adherent to substrates such as wood and upon sustained combustion leaves a high percentage of non-combustible residue. A substantial degree of fire resistance is provided to ignition and spread of flame by 0.1 to 0.3 pounds of dried coating per square foot of the exposed combustible substrate.

Abstract: A method is provided for splicing carbonized PAN tows in which the tows to be spliced are cut square and coated at the ends thereof with a resin solution, following which the coated ends are joined together, heated so as to cure the resin solution and then pinched to compact the resulting splice. The resin solution is comprised of a mixture of a solid acrylic polymer, a liquid acrylic polymer, a solid epoxy resin and a solvent.

Abstract: A composition is disclosed for treating carbon fibers to provide an epoxy finish thereon, comprising an epoxy resin and an effective amount of a non-ionic emulsifier in the form of a block polymer consisting of a poly(oxypropylene) chain having poly(oxyethylene) groups at both ends of said chain, said polymer terminating in a primary hydroxyl group, said polymer having a molecular weight ranging from about 1100 to about 14,000. The process for treating the carbon fibers comprises applying the aqueous resin emulsion to the fibers and thereafter drying the fibers.

Abstract: A method is provided for splicing carbonized PAN tows in which the tows to be spliced are cut square and coated at the ends thereof with a resin solution, following which the coated ends are joined together, heated so as to cure the resin solution and then pinched to compact the resulting splice. The resin solution is comprised of a mixture of a solid acrylic polymer, a liquid acrylic polymer, a solid epoxy resin and a solvent.

Abstract: There is disclosed a method of treating carbon fibers to provide an epoxy resin finish thereon. An aqueous emulsion of an epoxy resin is applied to the fibers and the fibers are thereafter dried. An effective amount of two different emulsifying components are used in the epoxy resin emulsion. One of the emulsifying components is a long chain aliphatic alcohol containing from eight to 18 carbon atoms. The other emulsifying component is a quaternary ammonium salt having the formula: ##STR1## wherein R is an aliphatic radical containing from 12 to 18 carbon atoms, or a mixture of such radicals, each R' may be the same or different radicals selected from methyl and ethyl, and x is bromine or chlorine.

Abstract: A plurality of generally parallel, side-by-side warp tows of carbonaceous precursor material are interwoven with fill yarns forming a fabric of low density cross weave to facilitate handling of the warp tows for oxidation, carbonization and other processing thereof. A different fill yarn is interwoven with the warp tows from each of the opposite edges of the fabric so as to form a succession of generally V-shaped loops in each warp yarn with the loops of the two different warp yarns being staggered along the length of the fabric. Each loop of warp yarn is comprised of a pair of lengths of warp yarn which enter the fabric from spaced-apart locations along an edge of the fabric and undulate under and over the warp tows in a like sense which is opposite the sense of the undulations of the immediately adjacent loops prior to joining at a point across part but not all of the width of the fabric.

Abstract: A water soluble sizing for fibrous carbonaceous material consists of either 1,3-diglycidyl-5,5-dimethylhydantoin or 1,3-diglycidylhydantoin. The carbonaceous material is sized by immersion in an aqueous solution of the sizing having a concentration of 0.1-10%, preferably 1-2%, by weight, followed by drying. In addition to being highly water soluble, non-toxic and non-flammable, the sizing provides excellent filament control so as to minimize fuzzing during subsequent handling of the carbonaceous material and is compatible with an epoxy resin matrix system.

Abstract: A finish composition for fibrous material such as carbon, graphite or silica fibers comprises an aqueous emulsion of an elastomer and a lubricious substance which are both dispersed in the aqueous emulsion. The elastomer comprises a latex of butyl rubber or butadiene/nitrile type rubbers, and the lubricious substance comprises an emulsion of a hydrocarbon type wax such as paraffin. The aqueous emulsion which includes a dispersant such as water proportioned to provide the emulsion with a solids concentration of up to about 1% is applied as a size to the fibrous material, following which the water is driven off such as by use of elevated temperatures to cause the lubricious substance to separate from the elastomer and exude to the surface of the elastomeric sheath surrounding the fibrous material. The finish may be used as an aid to weaving, in which event it is applied to fibers such as carbon or graphite fibers prior to weaving and then removed after the weaving is completed.

Abstract: A two piece brake disc includes an outer ring shaped member and an inner ring shaped member disposed concentrically within and joined to the outer member. One of the members comprises a structural member for mounting the disc with the other member comprising a wear member having one or more frictional surfaces and being replaceable because of the two piece construction. The members are essentially all-carbon composites which may differ chemically from one another such as through use of additives in the structural member to increase its oxidation resistance. The all-carbon composites may include carbon fibers with at least some of the fibers in the structural member being longer and circularly oriented to provide portions of the structural member with added strength.