Abstract: The present invention provides a method of densifying porous structures by chemical vapor infiltration. In characteristic manner, said densification method is implemented using toluene as a precursor for carbon. Said toluene is generally used mixed with at least one carrier gas.

Abstract: A method of producing a carbon-carbon part having a filamentized composite fiber substrate is provided. A substrate having a plurality of discontinuous filamentized fibers and a binder that binds said filaments together to form a composite substrate is provided, and carbon atoms are deposited onto the filaments at a predetermined temperature so that the binder is removed completely from the filaments and replaced with carbon atoms to from a dense carbon-carbon part.

Abstract: A matrix formation process 10 is configured with CVI process 12 and PIP process 14, 15, 16 in which a co-polymer containing at least polycarboxysilane (PCS) and polymethylsilane (PMS) is applied. Crosslinking of each polymer is performed at an intermediate temperature which is lower than the pyrolysis temperature of the polymeres. Polymer impregnation process 15 for infiltrating the co-polymer into a matrix, and inert gas firing process 16 for firing the material at a high temperature in an inert gas atmosphere. In the crosslink process, the mixed polymer is held at about 573K to 723K for a predetermined time. The conversion ratio of the co-polymer crosslinked into SiC in the subsequent firing process is increased, efficiency of filling SiC in the PIP process is increased, and an airtight ceramic-based composite material can be manufactured efficiently within a short time.

Abstract: Silicon carbide fibers having an excellent mechanical strength and a superior heat resistance can be produced by the process in which activated carbon fibers having a thickness of 1 to 30 &mgr;m and a BET specific surface area of 700 to 1500 m2/g are reacted with a silicon and/or silicon oxide gas at 1200 to 1500° C. under a reduced pressure or in an inert gas atmosphere; and the resultant SiC fibers are heat treated in the presence of a boron-containing substance and optionally a carbon-containing substance at 1700 to 2300° C. in an inert gas atmosphere, wherein the fibers may be in the form of a shaped article, for example, a sheet or honeycomb structure.

Abstract: A laminated matrix composite made of a reinforcement phase and coated with several layers of a metallic, ceramic, or polymeric matrix material, the average thickness of the layers of matrix material being between 0.005 and 5 &mgr;m thick.

Abstract: There is disclosed a method of forming a fabric 1 on the surface of a mandrel 10, infiltrating the formed fabric with matrix, and leaving portions 12a, 12b of the mandrel as integral with the fabric and removing the mandrel before the fabric adheres to the mandrel by matrix infiltration. Subsequently, a remaining portion of the mandrel is used as a reference surface and machining is performed. Without possibility of adhesion to the mandrel and resulting breakage, machining bases (axial center and reference surface) during machining can accurately be provided, and this can largely enhance machining precision and yield of a final product.

Abstract: A method for the densification of a porous structure comprises providing the structure with a body of material (13, 14) which includes a susceptor element foil (14) which is more susceptible to heating by electromagnetic radiation than the other material (13) of the body, exposing said porous structure to hydrocarbon gas and simultaneously applying an electromagnetic field to said porous structure whereby said susceptor element (14) at least in part causes heating of the porous structure to a temperature at which the gas infiltrating the porous structure deposits carbon within the porous structure.

Abstract: A coating is applied to reinforcing fibers arranged into a tow by coaxially aligning the tow with an adjacent separation layer and winding or wrapping the tow and separation layer onto a support structure in an interleaved manner so that the separation layer separates a wrap of the tow from an adjacent wrap of the tow. A coating can then be uniformly applied to the reinforcing fibers without defects caused by fiber tow to fiber tow contact. The separation layer can be a carbon fiber veil.