Abstract: A template (10) configured for use with an annular preform (26) having a periphery (32) and an inner opening (34), the template (10) having an annular body with an outer periphery (16) and an inner opening (18) and a plurality of spacer openings (12) through its body each for receiving a spacer (25), one of the template inner opening (18) and the template outer periphery (16) having a width equal to the width of the preform inner opening (34) or the preform outer periphery (32). Also a method for densifying preforms that includes a step of positioning spacers using a template.

Abstract: Carbon-carbon composite brake discs are manufactured by processes that include the use of PAN or pitch fibers and their combinations, combined with pitch, resin, or CVD/CVI matrix carbons. An additional process step is provided, in which a controlled amount of a carbon additive, such as carbon black and/or activated carbon, is infiltrated in to the bulk porosity of the composite prior to one or more of the densification cycles. Typical methods of infiltration include use of a solution or suspension of the powdered carbon in water or solvent solution so as to uniformly distribute the particulates throughout porosity within the carbon fiber preform prior to one or more of the densification cycles. The presence of the activated carbon and/or carbon black additive, distributed throughout the carbon-carbon composite brake disc, facilitates the adsorption and retention of available moisture in the composite.

Abstract: The method comprises: using chemical vapor infiltration to form a first continuous interphase on the fibers of a fiber structure made of refractory fibers, the interphase having a thickness of no more than 100 nanometers; impregnating the fiber structure with a consolidation composition comprising a carbon or ceramic precursor resin; forming a fiber preform that is consolidated by shaping the impregnated fiber structure and using pyrolysis to transform the resin into a discontinuous solid residue of carbon or ceramic; using chemical vapor infiltration to form a second continuous interphase layer; and densifying the preform with a refractory matrix. This preserves the capacity of the fiber structure to deform so as to enable a fiber preform to be obtained that is of complex shape, while nevertheless guaranteeing the presence of a continuous interphase between the fibers and the matrix.

Abstract: Highly effective carbon fibre-reinforced ceramic automotive brake and clutch discs are manufactured by siliconising incompletely densified carbon-carbon fibre preforms produced by a single stage and relatively short duration (e.g. 7-14 day) chemical vapour infiltration process.

Abstract: Method for making carbon-carbon composite friction product, by: fabricating carbon fiber preform; heat-treating the carbon fiber preform; infiltrating the carbon fiber preform with a high carbon-yielding pitch using VPI (vacuum pressure infiltration) or resin transfer molding (RTM) processing; carbonizing the preform with an intermediate heat-treatment at 800-2000° C.; repeating the pitch infiltration and carbonization steps to achieve a final density of >1.75 g/cc; machining the surfaces of the preform; and applying an oxidation protection system. This approach overcomes problems inherent in lower density carbon-carbon composites by employing high carbon-yielding pitches to densify the carbon-carbon composites to a high density. The high carbon yielding pitches may include isotropic pitches, 100% anisotropic (mesophase) pitches, or mixtures of the two. They may be derived from petroleum, coal tar, or synthetic feedstocks.

Abstract: The present invention provides methods for conformally or superconformally coating and/or uniformly filling structures with a continuous, conformal layer or superconformal layer. Methods of the present invention improve conformal or superconformal coverage of surfaces and improve fill in recessed features compared to conventional physical deposition and chemical deposition methods, thereby minimizing formation of voids or gaps in a deposited conformal or superconformal layer. The present methods are capable of coating or filling features useful for the fabrication of a broad class of electronic, electrical and electromechanical devices.

Abstract: Method for manufacturing pitch-densified carbon-carbon composite brake discs from carbon fiber preforms, by the following sequential steps: (a) providing a carbon-carbon composite brake disc preform; (b) heat treating the preform; (c) subjecting the heat-treated preform to Chemical Vapor Deposition/Chemical Vapor Infiltration processing; (d) infiltrating the preform with an isotropic low to medium char-yield pitch by Vacuum Pitch Infiltration processing or Resin Transfer Molding processing; (e) carbonizing the pitch-infiltrated preform; (f) machining the surfaces of the resulting carbonized preform; and (g) repeating steps (d) through (f) until the density of the carbon-carbon composite preform is at least 1.70 g/cc. The use of VPI equipment with isotropic, low to medium char-yield pitches for all densification steps following an initial CVD densification reduces capital and pitch materials cost.

Abstract: Thermostructural composite structure having a compositional gradient, formed from a porous core (5) made of a refractory having a pore volume content of greater than or equal to 80%. The core (5) lies between two intermediate layers (6a, 6b) comprising the carbon fiber reinforcement, densified by a matrix composed of the carbon phase and of a ceramic phase, and a refractory solid filler. Two monolithic ceramic shells (7a, 7b) cover the intermediate layers in order to give stiffness to the entire structure.

Abstract: A brake disk (10) includes an annular core (12, 60, 82) formed from a plurality of non-annular pieces (40, 66, 68, 84), a first friction disk (14) mounted on a first side of the annular core (12, 60, 82), a second friction disk (14) mounted on a second side of the core (12, 60, 82) opposite from the first friction disk (14), and at least one fastener (58) connecting the first and second friction disks (14, 14) to the core (12, 60, 82). Also a method of assembling a brake disk from a core and friction elements.

Abstract: A coherent fiber preform made of carbon fibers presents holes formed from at least a first face of the preform, and the preform is densified by depositing therein a material constituting a matrix by means of a chemical vapor infiltration type process. The holes are formed by causing a plurality of non-rotary elongate tools to penetrate simultaneously, the tools being substantially mutually parallel and presenting on their surfaces roughnesses or portions in relief suitable for breaking and/or transferring fibers they encounter, the tools being caused to penetrate simultaneously by moving a support carrying the tools, and the tools being selected to have a cross-section that makes it possible to obtain in the carbon fiber preform holes that present a cross-section with a mean dimension lying in the range 50 ?m to 500 ?m.

Abstract: A method and apparatus for forming polycrystalline diamond composites comprising forming a preform shape with at least 60 volume percent diamond, and then depositing diamond by chemical vapor methods. The chemical vapor deposition may be chemical vapor infiltration with a thermal gradient applied through a thickness of the preform shape. The thermal gradient may be selected to provide sufficient temperature variation to produce a diamond layer on a hot surface of the preform shape but is too low to produce a diamond layer on a hot surface of the preform shape but is too low to produce a diamond layer on a cooler surface of the preform shape. Diamond may be deposited on the surface of a preform shape that is subsequently removed.

Abstract: A method and apparatus for manufacture of carbon nanotubes, in which a substrate is contacted with a hydrocarbonaceous feedstock containing a catalytically effective metal to deposit the feedstock on the substrate, followed by oxidation of the deposited feedstock to remove hydrocarbonaceous and carbonaceous components from the substrate, while retaining the catalytically effective metal thereon, and contacting of the substrate having retained catalytically effective metal thereon with a carbon source material to grow carbon nanotubes on the substrate. The manufacture can be carried out with a petroleum feedstock such as an oil refining atmospheric tower residue, to produce carbon nanotubes in high volume at low cost. Also disclosed is a composite including porous material having single-walled carbon nanotubes in pores thereof.

Abstract: A metal strip member (1) comprising a metal strip (2) having a thickness of less than 3 mm, and at least adjacent one side (3) consists of a substrate alloy with a chromium content of at least 10 wt %. The substrate alloy is on at least one side of the metal strip provided with a surface layer (4) of nickel, ruthenium, cobalt, palladium or an alloy thereof. Carbon and/or nitrogen atoms (5) are dissolved in the substrate alloy adjacent the surface layer providing compressive stresses, and essentially no carbides and/or nitrides are present in the substrate alloy. The invention also relates to resilient electrical contact spring member made of such a metal strip member and a method of manufacturing such a metal strip member.

Abstract: An actively-cooled, fiber-reinforced ceramic matrix composite thrust chamber for liquid rocket propulsion systems is designed and produced with internal cooling channels. The monocoque tubular structure consists of an inner wall, which is fully integrated to an outer wall via radial coupling webs. Segmented annular void spaces between the inner wall, outer wall and adjoining radial webs form the internal trapezoidal-shaped cooling channel passages of the tubular heat exchanger. The manufacturing method enables producing any general tubular shell geometry ranging from simple cylindrical heat exchanger tubes to complex converging-diverging, Delaval-type nozzle structures with an annular array of internal cooling channels. The manufacturing method allows for transitioning the tubular shell structure from a two-dimensional circular geometry to a three-dimensional rectangular geometry.

Abstract: A method of chemical vapor infiltration and deposition includes stacking a number of porous structures in a stack in a furnace. The stack has a center opening region extending through the porous structures and an outer region extending along the porous structures. A first portion of a reactant gas is introduced to the center opening region. A second portion of the reactant gas is introduced to the outer region. The first portion and the second portion are controlled proportions thereby introducing predetermined portions of the reactant gas to both the center opening region and the outer region. The change in weight of the entire furnace, including contents, is measured during the chemical vapor infiltration and deposition process. The rate of weight change is monitored.

Abstract: A firing jig for a honeycomb molded body includes a housing body configured to place a pillar-shaped honeycomb molded body including silicon carbide as a main component with a side face of the honeycomb molded body facing down, and a coat layer formed on at least a placing face of the housing body configured to place the honeycomb molded body thereon. A main component of the coat layer is silicon carbide, the coat layer having an arithmetic average height Ra of about 10 ?m or less obtained in conformity with JIS B 0601 (2001).

Abstract: Carbon-ceramic brake discs, the remaining porosity in which, after infiltration with a carbide-forming element and reaction of this element with at least part of the carbon in the preliminary body of the carbon-ceramic brake disc to form carbides, is at least partly filled with particles whose average diameter is in the range from 0.5 nm to 20 nm, and a process for producing carbon-ceramic brake discs with reduced porosity, wherein carbon-ceramic brake discs are treated with a solution of organic compounds of boron, zirconium, titanium, silicon or aluminum or mixtures of such compounds, the cited organic compounds being present as sols in an organic solvent, after removal from the sol bath the brake discs treated in this way are dried in an oven at a heating rate of between 30 K/h and 300 K/h under air or protective gas and are then tempered at a final temperature of between 350° C. and 800° C.

Abstract: One or more porous substrates for densification (10) are loaded into an oven (12) into which there is admitted a reaction gas containing a pyrolytic carbon precursor gas comprising at least one gaseous hydrocarbons CxHy in which x and y are integers and x is such that 1<x<6, together with a vector gas comprising at least one gas selected from methane and inert gases. Effluent gas containing residual components of the admitted gas together with reaction products, including hydrogen, is extracted from the oven and at least a fraction of a gas stream extracted from the effluent gas and containing pyrolytic carbon precursor reagent gas is recycled (circuit 80) into the reaction gas admitted into the oven, the recycling being performed after eliminating heavy hydrocarbons (treatment 40) contained in the effluent gas.

Abstract: Carbon nanotubes are incorporated in the fiber structure by growing them on the refractory fibers of the substrate so as to obtain a three-dimensional substrate made of refractory fibers and enriched in carbon nanotubes. The substrate is densified with a matrix to form a part of composite material such as a friction part of C/C composite material.

Abstract: Method of chemical vapor infiltration of a deposable carbon material into a porous carbon fiber preform in order to densify the carbon fiber preform. The method includes the steps of: situating the porous carbon fiber preform in the reaction zone; providing a linear flow of a reactant gas comprising deposable carbon material in the reaction zone at an initial reaction pressure of at most 50 torr to produce deposition of the deposable carbon material into the preform; and adjusting the pressure of the gas to reaction pressures lower than said initial reaction pressure while deposable carbon material continues to be deposited into the porous carbon fiber preform. This method enables attainment of a target increased density in a carbon fiber preform much more quickly than known processes. A programmed pressure swing throughout the CVI/CVD run may be set in order to provide a linear increase in density.

Abstract: A process for producing-vapor grown carbon fiber (VGCF) reinforced continuous fiber performs for the manufacture of articles with useful mechanical, electrical, and thermal characteristics is disclosed. Continuous fiber preforms are treated with a catalyst or catalyst precursor and processed to yield VGCF produced in situ resulting in a highly entangled mass of VGCF infused with the continuous fiber preform. The resulting continuous fiber preforms are high in volume fraction of VGCF and exhibit high surface area useful for many applications. Furthermore, this invention provides for a continuous fiber preform infused with VGCF so that the carbon nanofibers are always contained within the fiber preform. This eliminates the processing steps for isolated carbon nanofibers reported in other carbon nanofiber composite approaches and therefore greatly reduces risk of environmental release and exposure to carbon nanofibers.

Abstract: Method for densifying a porous carbon preform (5). The method includes the steps of: (a) providing the apparatus (11); (b) charging the apparatus (11) with a plurality of stacks of annular porous carbon preforms (5), the preforms being separated from one another by spacers (15); (c) locating the charged apparatus (11) in a furnace at a temperature in the range of 950-1100° C. and a pressure in the range of 5-40 torr; and (d) circulating a natural gas reactant blended with up to 15% propane through the apparatus for a period of from 150 to 900 hours. Carbon-carbon composite preforms made by this method may be configured as aircraft landing system brake discs or racing car brake discs.

Abstract: A method for producing a fiber-reinforced composite member from prepregs of reinforcing fibers impregnated with a matrix resin, comprising placing the prepregs in a cavity of a molding die, cutting off excess margins of the prepregs along the edges of the cavity, and curing the matrix resin.

Abstract: A method for making a ceramic matrix composite turbine engine component, wherein the method includes providing a plurality of biased ceramic plies, wherein each biased ply comprises ceramic fiber tows, the tows being woven in a first warp direction and a second weft direction, the second weft direction lying at a preselected angular orientation with respect to the first warp direction, wherein a greater number of tows are woven in the first warp direction than in the second weft direction. The plurality of biased plies are laid up in a preselected arrangement to form the component, and a preselected number of the plurality of biased plies are oriented such that the orientation of the first warp direction of the plies lie about in the direction of maximum tensile stress during normal engine operation. A coating is applied to the plurality of biased plies. The coated component preform is then densified.

Abstract: A method of making a carbon fiber-carbon matrix reinforced ceramic composite wherein the result is a carbon fiber-carbon matrix reinforcement is embedded within a ceramic matrix. The ceramic matrix does not penetrate into the carbon fiber-carbon matrix reinforcement to any significant degree. The carbide matrix is a formed in situ solid carbide of at least one metal having a melting point above about 1850 degrees centigrade. At least when the composite is intended to operate between approximately 1500 and 2000 degrees centigrade for extended periods of time the solid carbide with the embedded reinforcement is formed first by reaction infiltration. Molten silicon is then diffused into the carbide. The molten silicon diffuses preferentially into the carbide matrix but not to any significant degree into the carbon-carbon reinforcement.

Abstract: A microfluidic sieve having a substrate with a microfluidic channel, and a carbon nanotube mesh. The carbon nanotube mesh is formed from a plurality of intertwined free-standing carbon nanotubes which are fixedly attached within the channel for separating, concentrating, and/or filtering molecules flowed through the channel. In one embodiment, the microfluidic sieve is fabricated by providing a substrate having a microfluidic channel, and growing the intertwined free-standing carbon nanotubes from within the channel to produce the carbon nanotube mesh attached within the channel.

Abstract: A method for increasing the compressive modulus of aerogels comprising: providing aerogel substrate comprising a bubble matrix in a chamber; providing monomer to the chamber, the monomer comprising vapor phase monomer which polymerizes substantially free of polymerization byproducts; depositing monomer from the vapor phase onto the surface of the aerogel substrate under deposition conditions effective to produce a vapor pressure sufficient to cause the vapor phase monomer to penetrate into the bubble matrix and deposit onto the surface of the aerogel substrate, producing a substantially uniform monomer film; and, polymerizing the substantially uniform monomer film under polymerization conditions effective to produce polymer coated aerogel comprising a substantially uniform polymer coating substantially free of polymerization byproducts.

Abstract: A process is disclosed for producing a high temperature stable fiber composite ceramic by chemical vapor infiltration (CVI) with a silicon carbide precursor in a suitable carrier gas on carbon fiber preforms or silicon carbide fiber preforms. This process is characterized by the use of a process pressure of ?0.6 bar absolute and a process temperature of ?1100° C. Also disclosed are structural component parts, particularly for aircraft and spacecraft engineering, which are commonly exposed to high thermal and mechanical loading and which have been produced by the above process.

Abstract: The method applies to a process such as cementation or chemical vapor infiltration or deposition, the process being carried out in an oven and the method comprising setting operating parameters of the oven, introducing a reagent gas into the oven, the reagent gas containing at least one gaseous hydrocarbon, and extracting from the oven an effluent gas containing reaction by-products of the reagent gas. The effluent gas is subjected to washing in oil that absorbs tars contained in the effluent gas, and information about the progress of the process is obtained by measuring the quantity of tar absorbed by the oil.

Abstract: An aerogel material with surfaces containing fluorine atoms which exhibits exceptional hydrophobicity, or the ability to repel liquid water. Hydrophobic aerogels are efficient absorbers of solvents from water. Solvents miscible with water are separated from it because the solvents are more volatile than water and they enter the porous aerogel as a vapor across the liquid water/solid interface. Solvents that are immisicble with water are separated from it by selectively wetting the aerogel. The hydrophobic property is achieved by formulating the aerogel using fluorine containing molecules either directly by addition in the sol-gel process, or by treating a standard dried aerogel using the vapor of fluorine containing molecules.

Abstract: Annular substrates (20) are stacked in an enclosure where they define an inside volume (24) and an outer volume (26) outside the stack. A gas containing at least one precursor of a matrix material to be deposited within the pores of the substrates is channeled inside the enclosure to a first one (24) of the two volumes, and a residual gas is extracted from the enclosure from the other one (26) of the volumes. One or more leakage passages (22) allow the volumes to communicate with each other, other than through the substrates. The total section of the leakage passages has a value lying between a minimum value for ensuring that a maximum gas pressure in the first volume is not exceeded until the end of densification, and a maximum value such that a pressure difference is indeed established between the two volumes from the beginning of densification.

Abstract: The electron impact surface of an anode/collector is coated with a carbon nanotube coating to reduce the production of secondary electrons and, concomitantly, to suppress the formation of neutral gases and plasma. A carbonizable resin is first applied to the electron impact surface, followed by a coating comprised of carbon nanotubes. The coating is pyro-bonded to the surface by heating the anode/collector to over 700° C. in a non-oxidizing atmosphere. Next, the anode/collector is heated to over 1000° C. while a low-pressure hydrocarbon gas, for example, methane, is flowed over the carbon nanotube coating. The gas decomposes and creates a smooth, non-porous, rigid surface on the carbon nanotube coating. The anode/collector is then heated in a vacuum to evaporate any residual water in the carbon nanotube coating.

Abstract: Method of improving humidity resistance in a coated article (19) comprising a carbon-carbon composite component (10), a graphite component (10), or a ceramic matrix composite component based on carbon fibers and/or graphite (10). The component (10) is preferably configured as an aircraft landing system brake disc. The method includes the steps of: (A) providing a carbon-carbon composite component (10), a graphite component (10), or a ceramic matrix composite component based on carbon fibers and/or graphite (10); (B) covering the component (10) with a phosphorus-containing antioxidant undercoating (11) having a thickness of approximately 1–10 mil; and (C) covering the resulting undercoated component (10, 11) with a boron-containing glass overcoating (12) having a thickness of approximately 1–10 mil. The overcoating includes 20–50 wt-% alkali or alkaline earth metal silicates, 3–25 wt-% alkali metal hydroxide, up to 10 wt-% boron nitride, and one or both of 5–40 wt-% elemental boron and 5–40 wt-% boron carbide.

Abstract: Refractory carbide particles are located in a defined area of a matrix, specifically silicon carbide particles are encapsulated within a porous matrix or carbon precursor, by locating particles of refractory carbide-forming material or a precursor thereof in a defined area of the matrix followed by depositing carbon within the matrix at a temperature below that of the melting point of the carbide-forming material.

Abstract: A one-piece or otherwise unitary annular shim member made from a carbon material or a metallic is used to maintain a space between stacked annular preforms during a manufacturing process, such as densification. The one-piece structure advantageously simplifies the arrangement of the preforms in a process chamber and causes less deformation in the preforms. The carbon composition also provides beneficial thermal effects that improve the densification process. A debonding coating is provided on the carbon annular shim member in order to facilitate separation of the annular preforms from the shim members. The metallic annular shim member does not require a debonding coating.

Abstract: The invention relates to processes for the synthesis of 2-D and 3-D periodic porous silicon structures and composites with improved properties having the advantages of porous silicon and photonic bandgap materials. Photonic crystals comprise a two dimensionally periodic or three dimensionally periodic microporous structural matrix of interconnecting, crystallographically oriented, monodispersed members having voids between adjacent members, and said members additionally having randomly nanoporous surface porosity. The silicon nanofoam material shows enhanced and spectrally controlled/tunable photoluminescence and electroluminesce and finds use as transparent electrodes, high-lumonosity light emitting diodes (LEDs), wavelength division multiplexors, high-active-area catalyst supports, photonic bandgap lasers, silicon-based UV detectors, displays, gas sensors, and the like.

Abstract: A porous substrate having a concave inside face and an outside face is disposed in an enclosure, and reactive gas is introduced into the enclosure to densify the substrate. At least a portion of the gas is divided into two non-zero fractions. The first fraction of the gas is fed to the inside face of the substrate. The second fraction of the gas is fed to only the outside face of the substrate. Alternatively, the first fraction of the gas is fed via a tooling extending into an inside volume defined by the concave inside face of the substrate.

Abstract: A method and apparatus for a continuous coating of a part may include providing a separation layer made of a material that is weaker than the material of the coating to be made. The part may be placed on one or more supports, the supports coated with the separation layer. A continuity layer of a component material of the coating to be made is interposed between the part and the or each support, at least in vicinity of the or each support zone. The coating is formed by chemical vapor infiltration or deposition, and the part is then separated from the or each support by rupture within the separation layer, the continuity of the coating of the part in the or each support zone being provided by the portion of the coating that comes from the continuity layer that remains in place on the part.

Abstract: A method and apparatus for sealing gas ports in CVD/CVI furnaces and processes is disclosed. A fluid direction nozzle (160) is positioned between a top lip (101) of a gas inlet port (100) delivering a reactant gas (G) to a furnace compartment(200) in a CVD/CVI furnace (10) and corresponding holes (151) of a CVD/CVI process apparatus such as a hearth plate (150). The fluid direction nozzle 160 reduces leakage of reactant gases (G) and ensures a smooth transition of gas flow direction between the gas inlet port (100) and the corresponding holes (151). CVD/CVI process times are significantly reduced with the use of the reusable/replaceable flow direction nozzles (160).

Abstract: A CVI furnace is described in which single layer of a porous material or multiple layers of porous materials stacked in a module are loaded into a furnace. The modules are loaded into the furnace singularly or as multiple units stacked vertically or side by side. The modules can be moved through the furnace continuously or step-wise. The furnace comprises a separate CVI chamber. The porous material is heated and subjected to densification, thereby ensuring a dispersion of the reactant gas onto the porous material. A process of densifying a sheet of porous material is also described.

Abstract: A method of making a high softening point coal tar pitch using high efficiency evaporative distillation, as well as the uses and applications of such pitch. According to the method, a feed coal tar pitch having a softening point in the range of 70° C. to 160° C. is fed into a processing vessel wherein the processing vessel is heated to a temperature in the range of 300° C. to 450° C. and wherein a pressure inside the processing vessel is in the range of 5 Torr or less. An output coal tar pitch is withdrawn from the processing vessel. The output coal tar pitch has a softening point in the range of 140° C. to 300° C. and has less than 5% mesophase.

Abstract: The invention relates to pressure gradient processes for forcing infiltration of a reactant gas into a porous structure. The process comprises the steps of partially densifying a porous structure with a pressure gradient CVI/CVD process in which a first potion of the porous structure is subjected to greater pressure than a second portion of the porous structure. The process is suited for the simultaneous CVI/CVD processing of large quantities of aircraft brake.

Abstract: Improved articles of manufacture are disclosed, together with methods for preparing such articles, whereby the surface of a graphite or comparable substrate is first densified with carbon to reduce surface porosity while still retaining sufficient surface texture to enhance the adherence of a subsequently applied boron coating.

Abstract: A method of processing a ceramic preform is disclosed having the steps of: coating with a preceramic polymer at least one fabric panel formed of silicon carbide fibers coated with a high temperature boron nitride; shaping the at least one fabric panel into a preliminary preform; curing the preceramic polymer to impart rigidity to the preform, and inserting the rigidized preform into a reactor without tooling for a chemical vapor infiltration process to form the ceramic preform.

Abstract: A method for preparing carbon molecular sieve membrane is invented. A thin carbon-containing film is first deposited on a porous substrate. The thin film is then bombarded by high energy ions for surface modification. The surface modified film is then baked or calcined at a high temperature. The carbon molecular sieve membrane prepared according to the present invention can be used for gas separation as well as liquid separation, ions or solvents, etc., exhibiting improved permeance and improved selectivity simultaneously in gas separation. The ion bombardment includes generating plasma and ions in a gas phase, and applying a negative bias voltage to the substrate.

Abstract: An organic silicon polymer is infiltrated and charged into gaps in a matrix phase of a formed fiber fabric, and its airtightness is increased by (a) CVI infiltration process 2 for forming the SIC matrix phase on the surface of the fiber fabric formed, (b) pressurized infiltrations process 4 for pressurizing the organic silicon polymer in the direction operating pressure is applied to the fiber fabric during use and infiltrating the organic silicon polymer into gaps in the aforementioned matrix phase, and (c) heating process 5 for heating the infiltrated fiber fabric at a high temperature. Thus, airtightness can be increased quickly, and fired work can be applied practically even to thrust chambers etc.

Abstract: A method for fabricating a CMC (Ceramic Matrix Composite) article, comprising: performing a CVI (Chemical Vapor Infiltration) treatment for forming a SiC matrix layer on the surface of a woven fabric; performing a machining process, after the CVI treatment, for machining the woven fabric; and performing a PIP (Polymer Impregnation and Pyrolysis) treatment, after the machining process, for impregnating an organic silicon polymer as a base material into voids in the matrix layer and pyrolyzing the organic silicon polymer. By this method, the throughput of CMC articles can be preferably increased. The throughput may be further increased by performing a slurry impregnation treatment before or after the PIP treatment, in which slurried SiC is impregnated into the voids in the matrix layer.

Abstract: The present methods make fluid diffusion layers having reduced surface roughness. The methods used for adhering the loading material to the substrate surface can reduce the average surface roughness of the fluid diffusion layers, thereby reducing leaks in and damage to ion exchange membranes. When fluid diffusion layers and electrodes having reduced surface roughness are employed in membrane electrode assemblies, better reliability and performance are obtained. A method of calculating the surface roughness of a fluid diffusion layer may be used.

Abstract: A part (10) on which a continuous coating is to be formed is put into place on one or more supports provided with a separation layer (26) made of a material that is weaker than the material of the coating to be made. A continuity layer (24) of a component material of the coating to be made is interposed between the part and the or each support, at least in vicinity of the or each support zone. The coating (12) is formed by chemical vapor infiltration or deposition, and the part is then separated from the or each support by rupture within the separation layer (26), the continuity of the coating of the part in the or each support zone being provided by the portion of the coating that comes from the continuity layer (24) that remains in place on the part.

Abstract: A hardware assembly is provided for controlling a first portion of gas and a second portion of gas in a furnace. The first portion of the gas is introduced to a center opening region of a stack of porous structures. The second portion of the gas is introduced to an outer region of the stack of porous structures. Most of the gas flows out of the hardware assembly from either the center opening region or the outer region while some of the gas flows out through small holes from the other region. A densification method is also provided with two densification processes in which the gas flows in opposite directions in the two densification processes.