Patent classifications
C04B35/6325
INORGANIC STRUCTURE AND METHOD FOR PRODUCING SAME
Provided is an inorganic structure including a plurality of zirconium silicate particles; and a binding part that covers a surface of each of the zirconium silicate particles and binds the zirconium silicate particles together. The binding part contains an amorphous compound containing silicon, a metallic element other than silicon, and oxygen, and contains substantially no alkali metal, B, V, Te, P, Bi, Pb and Zn. Also provided is a method for producing an inorganic structure including: a step for obtaining a mixture by mixing a plurality of zirconium silicate particles, a plurality of amorphous silicon dioxide particles, and an aqueous solution containing a metallic element other than silicon; and a step for pressurizing and heating the mixture under conditions of a pressure of 10 to 600 MPa and a temperature of 50 to 300° C.
POLYMER-DERIVED, GRAPHENE REINFORCED CERAMIC MATRIX COMPOSITES
Polymer-derived, graphene reinforced ceramic matrix composites and processes for producing graphene-ceramic ceramic matrix composites are provided. An example process mechanically delaminates graphite mixed in a thermosettable, liquid preceramic polymer through a mechanical, high shear process to generate a composition of a preceramic polymer in which graphene is homogeneously dispersed. This example process does not require high temperatures and pressures to produce the graphene. The resulting composition can be pyrolytically converted to a graphene-reinforced ceramic matrix composite. A polysilazane can be used as the preceramic polymer, in some cases providing ammonia or an amine in the process to facilitate delamination of the graphite to graphene. Ceramic, metal, mineral or carbon particulates, platelets, or fibers may be added to the composition to impart enhanced mechanical and/or electrical properties to the finished graphene-reinforced ceramic matrix composites.
METHOD FOR MAKING YBCO SUPERCONDUCTOR
A method of producing polycrystalline Y.sub.3Ba.sub.5Cu.sub.8O.sub.y (Y-358) whereby powders of yttrium (III) oxide, a barium (II) salt, and copper (II) oxide are pelletized, calcined at 850 to 950° C. for 8 to 16 hours, ball milled under controlled conditions, pelletized again and sintered in an oxygen atmosphere at 900 to 1000° C. for up to 72 hours. The polycrystalline Y.sub.3Ba.sub.5Cu.sub.8O.sub.y thus produced is in the form of elongated crystals having an average length of 2 to 10 μm and an average width of 1 to 2 μm, and embedded with spherical nanoparticles of yttrium deficient Y.sub.3Ba.sub.5Cu.sub.8O.sub.y having an average diameter of 5 to 20 nm. The spherical nanoparticles are present as agglomerates having flower-like morphology with an average particles size of 30 to 60 nm. The ball milled polycrystalline Y.sub.3Ba.sub.5Cu.sub.8O.sub.y prepared under controlled conditions shows significant enhancement of superconducting and flux pinning properties.
EXTRUDABLE CERAMIC PRECURSOR MIXTURES AND METHODS OF USE
An extrudable ceramic precursor mixture and method of use includes: an inorganic ceramic-forming component, a first siloxane prepolymer, a second siloxane prepolymer with a different composition than the first siloxane prepolymer, a catalyst adapted to catalyze polymerization of the first siloxane prepolymer with the second siloxane prepolymer into a siloxane-based polymer, and a thermally curable siloxane-based cross-linking agent adapted to crosslink the siloxane-based polymer. Comprised is a polydimethylsiloxane having a vinyl functional group and a polydimethylsiloxane having a silicon hydride functional group.
HYDROFLUX-ASSISTED DENSIFICATION
Embodiments relate to an improved hydroflux assisted densification process that introduces a transport phase (formed by the introduction of water during the process to suppress melting temperatures) for sintering, the transport phase being a non-aqueous solution. The process can facilitate sintering at low temperature ranges (at or below 300° C.) to yield densification>90% without the need for additional post-processing steps that otherwise would be needed if conventional processes were used. Control of the pressures and water content used during the process can enhance densification mechanisms related to dissolution-reprecipitation, allowing for a greater range of compositional spectra of materials that can be densified, a reduction of the amount of transport phase needed, a reduction of impurities and an improvement of properties in the densified material. Certain hydrated acetate powders can be used to generate a hydroxide mixture flux that is better for the low-temperature densification process.
TUNGSTATE- AND MOLYBDATE-BASED CERAMIC COATING FOR PROTECTION OF METAL SURFACES, PREPARATION PROCEDURE AND USE THEREOF
The present invention relates to different inorganic ceramic coatings whose chemical compositions comprise silicates, acids, metallic oxysalts such as tungstates and molybdates, water, and non-metallic oxides such as silicon oxide. Said water-based inorganic ceramic coatings improve the ceramic, anti-corrosive and resistance properties of the metal substrates that are coated with same. Likewise, the present invention relates to a sol-gel process for synthesizing said coatings in which the non-metallic oxide, before being mixed with the rest of the components of the chemical compositions as claimed, can be pre-treated with hydrochloric acid and ammonium hydroxide, or can be sonicated to achieve a particle size in the range from approximately 160 to approximately 180 nm. Finally, the present invention also relates to a method for coating the metal parts with the inorganic ceramic coatings as claimed in the present invention.
Method for making yttrium-barium-copper-oxide having high offset superconducting transition temperature
A method of producing polycrystalline Y.sub.3Ba.sub.5Cu.sub.8O.sub.y (Y-358) whereby powders of yttrium (III) oxide, a barium (II) salt, and copper (II) oxide are pelletized, calcined at 850 to 950° C. for 8 to 16 hours, ball milled under controlled conditions, pelletized again and sintered in an oxygen atmosphere at 900 to 1000° C. for up to 72 hours. The polycrystalline Y.sub.3Ba.sub.5Cu.sub.8O.sub.y thus produced is in the form of elongated crystals having an average length of 2 to 10 μm and an average width of 1 to 2 μm, and embedded with spherical nanoparticles of yttrium deficient Y.sub.3Ba.sub.5Cu.sub.8O.sub.y having an average diameter of 5 to 20 nm. The spherical nanoparticles are present as agglomerates having flower-like morphology with an average particles size of 30 to 60 nm. The ball milled polycrystalline Y.sub.3Ba.sub.5Cu.sub.8O.sub.y prepared under controlled conditions shows significant enhancement of superconducting and flux pinning properties.
Method for preparing composite materials with an oxide matrix and oxide reinforcements by means of a calefaction process
Method for the preparation, by means of a heating technique, of a composite material composed of a matrix of at least a first oxide of at least one metal and/or at least one metalloid reinforced by reinforcements in at least a second oxide of at least one metal and/or at least one metalloid, characterised in that the following successive steps are carried out: the reinforcements are placed in at least one liquid precursor of the first oxide of at least one metal and/or at least one metalloid; said reinforcements and the liquid precursor are heated so as to form the first oxide by means of the thermal decomposition of said liquid precursor, and to deposit the first oxide thus formed around the reinforcements and between the reinforcements thus forming the matrix.
Preform for making a component of a braking system
A preform for making a component of a braking system having a fibre-reinforced ceramic composite material, obtained by forming and subsequent pyrolysis of a pre-preg is described. Also described is a component of a braking system made wholly or in part from the preform, and a method for making a preform in a fibre-reinforced ceramic composite material.
ALUMINUM-CONTAINING NITRIDE CERAMIC MATRIX COMPOSITE, METHOD OF MAKING, AND METHOD OF USE
Embodiments of disclosure may provide a method for forming an aluminum-containing nitride ceramic matrix composite, comprising heating a green body, an aluminum-containing composition, ammonia and a mineralizer composition in a sealable container to a temperature between about 400 degrees Celsius and about 800 degrees Celsius and a pressure between about 10 MPa and about 1000 MPa, to form an aluminum-containing nitride ceramic matrix composite characterized by a phosphor-to-aluminum nitride (AlN) ratio, by volume, between about 1% and about 99%, by a porosity between about 1% and about 50%, and by a thermal conductivity between about 1 watt per meter-Kelvin and about 320 watts per meter-Kelvin. The green body comprises a phosphor powder comprising at least one phosphor composition, wherein the phosphor powder particles are characterized by a D50 diameter between about 100 nanometers and about 500 micrometers, and the green body has a porosity between about 10% and about 80%. The aluminum-containing composition has a purity, on a metals basis, between about 90% and about 99.9999%. The fraction of free volume within the sealable container contains between about 10% and about 95% of liquid ammonia prior to heating the green body, the aluminum-containing composition, ammonia and the mineralizer composition in the sealable container.