摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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. When processing of the warp tows is completed, the fill yarns are easily removed simply by pulling on those portions of the fill yarns extending between the successive loops. Methods and apparatus for weaving the fabric employ spaced-apart members such as rotatable rollers for supporting the warp tows and reciprocating, out-of-phase heddle arrangement disposed between the rollers and engaging the warp tows to periodically momentarily lift alternate ones of the warp tows relative to the remaining warp tows and then momentarily lift the remaining ones of the warp tows relative to the alternate warp tows. Each time the warp tows are momentarily separated, a loop from each of the opposite fill yarns is placed between the separated warp tows such as by use of opposite rapier assemblies which employ hollow, elongated members for feeding in the warp yarns to form the loops.
摘要:
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.