1509 results about "Oxide ceramic" patented technology

A method is disclosed for the fabrication of feedthrough devices that can transmit a single or plurality of electrical signal(s) to or from within a leak-tight (hermetic) chamber from or to the outside of said leak-tight (hermetic) chamber. The invention allows materials known to be well-tolerated within the human body such as alumina-oxide ceramic and platinum to be used as raw materials in the fabrication of body-compatible, single or multi-channel leak-tight (hermetic) feedthroughs.

PCT No. PCT/EP95/03347 Sec. 371 Date Nov. 19, 1997 Sec. 102(e) Date Nov. 19, 1997 PCT Filed Aug. 23, 1995 PCT Pub. No. WO96/20902 PCT Pub. Date Jul. 11, 1996A ceramic formed body containing a) 5 to 70 vol % of at least on intermetallic aluminide phase which additionally may contain aluminum or/and aluminum alloy, and b) 30 to 95 vol % of one or more ceramic phases which form a solid interconnecting skeleton and wherein the intermetallic phase or phases consist of predominantly interconnected areas with average sizes of 0.1 to 10 mu m, is obtained by sintering, in a non-oxidizing atmosphere, of a powder metallurgically green body which consists of a mixture of finely dispersed powder of aluminum, one or more ceramic substances and maybe further metals such that the mixture contains at least one oxide ceramic or/and metallic powder which, during sintering, reacts with aluminum thereby forming an aluminide and maybe Al2O3.

The invention discloses a composite wear-resistant antifriction coating on a titanium alloy surface and a preparation method thereof. The coating comprises a laser texturing surface, an oxide ceramic layer and a self-lubricating coating which are connected in sequence, wherein micropore arrays are uniformly distributed on the laser texturing surface; the oxide ceramic layer is a hard oxide ceramic coating; and the self-lubricating coating is a MoS2 coating, PTFE (polytetrafluoroethylene) coating or graphite coating. In the invention, the laser surface texturing technology is combined with the plasma electrolytic oxidation technology, and a texturing/ceramization composite coating is prepared on the titanium alloy surface which is then coated with a solid lubricant to improve the friction performance of the surface.

A solid oxide fuel cell has anode, cathode and electrolyte layers each formed essentially of a multi-oxide ceramic material and having a far-from-equilibrium, metastable structure selected from the group consisting of nanocrystalline, nanocomposite and amorphous. The electrolyte layer has a matrix of the ceramic material, and is impervious and serves as a fast oxygen ion conductor. The electrolyte layer has a matrix of the ceramic material and a dopant dispersed therein in an amount substantially greater than its equilibrium solubility in the ceramic matrix. The anode layer includes a continuous surface area metallic phase in which electron conduction is provided by the metallic phase and the multi-oxide ceramic matrix provides ionic conduction.

The invention discloses a method for preparing a shuttering for a precision investment casting TiAl-based alloy, and relates to a method for preparing an oxide ceramic shuttering. The method solves the problems of slow drying for making the shuttering, longer production period for cast and high cost during production of a TiAl-based alloy precise cast. The preparation method comprises: firstly, adopting SLS technology to prepare a fusible pattern; secondly, coating polyvinyl alcohol on the surface of bauxite and grinding the bauxite into granules; thirdly, smearing a shuttering surface layer; fourthly, smearing a shuttering back layer; fifthly, removing wax from the shuttering, and roasting the shuttering; and sixthly, casting the TiAl-based alloy in vacuum to obtain the TiAl-based alloy cast. The method only needs 13 to 15 days to obtain the TiAl-based alloy precise cast from CAD design, but the prior method at least needs 45 to 60 days, so the method saves nearly two thirds of production period, and the manufacturing cost is correspondingly lowered.

A silicon carbide-based porous structure material maintaining the shape of a cardboard or sponge-like porous structure, with a great relative surface area, and a process for producing the same, is provided. To this end, a cardboard or sponge-like shaped framework of silicon carbide-based porous structure material is impregnated with a slurry comprising a resin, as a carbon source, and silicon powder, and subjected to reactive sintering in a vacuum or inert atmosphere, or in a nitrogen gas atmosphere, generating silicon carbide. At the same time pores are generated due to volume reduction reaction, thereby allows obtaining a silicon carbide-based porous structure material with a great relative surface area. Furthermore, excess carbon is removed from the fabricated silicon carbide-based porous structure material, and impregnated with a solution which becomes an oxide ceramic coating upon firing, whereby oxidization resistance is excellent and relative surface area is markedly improved.

A low-cost oxide ceramic mould for the precise casting of Ti-alloy is prepared through preparing paint and wax mould of casting, immersing the wax mould in paint for 10-20 min, leveling the paint, uniformly applying the white electro-corundum powder to the paint layer of wax mould, drying, and high-pressure dewaxing.

The invention relates to a graphene and oxide ceramic composite material and a preparation method. Graphite oxide is used as a graphene precursor, the graphite oxide is mixed with zirconium oxide ceramic powder according to a certain proportion, and the mixture is molded and sintered so as to form the graphene and oxide ceramic composite material. The graphene and oxide ceramic composite material has a nanometer composite structure with network connections, nanometer layered graphene is uniformly distributed on a ceramic matrix to form the nanometer composite structure, the nanometer composite structure is conductive to strengthening of strength of the ceramic and endows the ceramic with the functional characteristics of semiconductor, electric conduction, heat conduction, electrochemistry, and the like, and the composite material can be used for developing sensors, electromagnetic shielding, electric heating devices, heat conduction materials, energy-storage electrodes, and the like and is used for the fields of aerospace, electronics, chemical engineering and energy sources. The graphene and oxide ceramic composite material is formed by one step in the sintering process, does not need the processes of functionalizing, mixing and the like, is simple in preparation process and is suitable for large-scale production.

Ion transport membrane system comprising (a) a pressure vessel comprising an interior, an exterior, an inlet, an inlet conduit, an outlet, and an outlet conduit; (b) a plurality of planar ion transport membrane modules disposed in the interior of the pressure vessel and arranged in series, each membrane module comprising mixed metal oxide ceramic material and having an interior region and an exterior region, wherein the inlet and the outlet of the pressure vessel are in flow communication with exterior regions of the membrane modules; (c) a gas manifold having an interior surface wherein the gas manifold is in flow communication with the interior region of each of the planar ion transport membrane modules and with the exterior of the pressure vessel; and(d) a liner disposed within any of the inlet conduit, the outlet conduit, and the interior surface of the gas manifold.

The invention discloses a method for preparing a porous implant through gelcasting 3D printing and electroreduction. The preparation method comprises steps as follows: according to the human body features of a to-be-implanted part, a personalized gradient porous implant negative-type mold adopting a microstructure is designed by the aid of a medical image data reverse solution model; a gradient porous implant negative-type resin mold is prepared through photo-curing forming equipment; metal oxide ceramic slurry is injected into the negative-type resin mold through a gel injection mold and sintered at the high temperature, and a metal oxide ceramic porous scaffold is obtained; a primary porous metal implant is produced through molten salt in-situ reduction; a metal coating is deposited on the surface of the primary porous metal implant with a chemical vapor deposition method. The defects that implants with complex shapes, precise sizes and uncontrollable microstructures cannot be produced with a traditional porous implant preparation method are overcome, structure nanosizing can be realized, and a new way for preparing the porous implant is expected to be developed.

The invention relates to a preparation method of a low-concentration acetone gas sensor, and belongs to the technical field of preparation processes of metal oxide semiconductor gas sensors. The gas sensor is mainly characterized in that double layers of nanometer sensitive materials with porous structures are coated on the surface of an aluminum oxide ceramic pipe, an inner substrate material is Pt doped nanometer porous SnO2, and an outer sensitizing material is nanometer porous Al2O3. After a gas-sensitive element coating the Pt doped porous SnO2 substrate material is roasted for 2 hours at the temperature of 500 DEG C, the porous Al2O3 sensitizing material is uniformly coated on the outer surface of the gas-sensitive element, and the gas-sensitive element is welded according to a thick-film semiconductor gas-sensitive element manufacturing process after dried at the indoor temperature (comprises a platinum wire and a nickel-cadmium heating wire in a cavity of a ceramic pipe), aged and packaged to make the low-concentration acetone gas sensor. The made sensor has the advantages of low detection limit, fast response and recovery, fine stability and the like for acetone gas.

The invention discloses three-dimensional alumina fiber fabric reinforced oxide ceramic. Al2O3, SiO2 and SiOC ceramics are used as a substrate, a three-dimensional alumina fiber fabric is used as a reinforcing body, alumina and silicon dioxide in the substrate are introduced by a sol-gel process, and the SiOC ceramic is obtained by high-temperature cracking of polysiloxane. The preparation method of the three-dimensional alumina fiber fabric reinforced oxide ceramic comprises the following steps: performing vacuum soaking, gelating and high-temperature ceramic treatment on oxide sol serving as a precursor, and repeating for multiple times to obtain an alumina fiber reinforced oxide blank body; soaking the blank body in vacuum by using a polysiloxane-ethanol solution as a precursor, and performing crosslinking and high-temperature ceramic treatment to complete a densifying process; and repeating the steps for multiple times to obtain the oxide ceramic blank body, and oxidizing to prepare the three-dimensional alumina fiber fabric reinforced oxide ceramic. The three-dimensional alumina fiber fabric reinforced oxide ceramic has the advantages of high bending strength, high modulus, good interlaminar shear strength and the like.

A solid oxide ceramic includes a substrate defining a surface, the substrate including at least one material selected from the group consisting of yttria-stabilized zirconia (YSZ), lanthanum strontium titanate (LST), lanthanum strontium manganite (LSM), and nickel oxide-YSZ composite. The solid oxide ceramic further includes a seal coating at least a portion of the surface, the seal including a Sanbornite (BaO.2SiO₂) crystal phase, a Hexacelsian (BaO.Al₂O₃.2SiO₂) crystal phase, and a residual glass phase, wherein the seal has a coefficient of thermal expansion equal to or less than that of the substrate at said surface. The glass composition can have a difference between a glass crystallization temperature and a glass transition temperature in a range of between about 200° C. and about 400° C. at a heating rate of about 20° C./min.

The invention relates to a preparation method for an oxide fiber-reinforced oxide porous ceramic matrix composite. The method comprises the following steps: firstly, mixing an oxide ceramic precursorsolution, ceramic powder and sintering aid powder, thus obtaining ceramic slurry; brushing the slurry on an oxide fiber fabric surface, thus obtaining an oxide fiber prepreg; paving the prepreg, hot-pressing and sintering, thus obtaining a continuous fiber reinforced porous ceramic matrix composite. According to the preparation method, in order to prepare a porous matrix, the ceramic powder and the sintering aid powder with different grain sizes and sintering properties are mixed with the oxide ceramic precursor solution so as to obtain the slurry; when the porous matrix is formed, a frameworkof the porous matrix is formed by the large-size and hardly sintered ceramic powder; a continuous phase of the porous matrix is formed by the small-size and easily sintered ceramic powder; a bridgingfiber lap joint is formed between the framework of the porous matrix and the continuous phase of the porous matrix by the sintering aid powder; the sintering of the matrix is accelerated and the mechanical property of the porous matrix is guaranteed.