Patent classifications
C04B2235/5454
HIGH TEMPERATURE COMPOSITES AND METHODS FOR PREPARING HIGH TEMPERATURE COMPOSITES
A method for making a high temperature composite, which is a carbon carbon composite, carbon fiber reinforced ceramic matrix composite, ceramic fiber reinforced ceramic matrix composite, or a carbon silica composite, including: a) providing a precursor part including a resin comprising a poly(aryl ether ketone) (PAEK) and at least one reinforcing material, wherein the resin has a degree of crystallinity of 10% or more; b) pyrolyzing the precursor part to a pyrolyzed part; c) infusing a liquid second resin into the pyrolyzed part to make an infused part; and d) pyrolyzing the infused part to make the carbon carbon composite carbon fiber reinforced ceramic matrix composite, ceramic fiber reinforced ceramic matrix composite, or the carbon silica composite, optionally repeating steps c. through d. Also, a carbon carbon composite, carbon fiber reinforced ceramic matrix composite, ceramic fiber reinforced ceramic matrix composite, or carbon silica composite made by the method.
Magnesium aluminate spinel reinforced magnesium oxide-based foam ceramic filter synthesized in situ from magnesium oxide whisker, and preparation method therefor
The present invention provides A magnesium oxide whisker in-situ formed MA spinel-reinforced magnesium oxide-based ceramic foam filter and a method for preparing the same. The method comprising: 1) preparing a ceramic slurry having a solid content of 60%-70% by dosing 15%-25% by mass of a nanometer alumina sol, 0.8%-1.5% by mass of a rheological agent, and the balance magnesium oxide ceramic powder comprising magnesium oxide whiskers, and then adding deionized water and ball milling to mix until uniform, and then vacuum degassing the mixture; 2) soaking a polyurethane foam template into the ceramic slurry, squeezing by a roller press the polyurethane foam template to remove redundant slurry therein to make a biscuit, and drying the biscuit by heating it to 80° C.-1200° C.; 3) putting the dried biscuit into a sintering furnace, elevating the temperature to 1400° C.-1600° C. and performing a high temperature sintering, cooling to the room temperature with the furnace to obtain the magnesium oxide-based ceramic foam filter.
A METHOD OF PRODUCING A CERAMIC SUPPORT AND A CERAMIC SUPPORT
Herein is disclosed a method of producing a ceramic support suitable for a catalyst, the method comprising providing a porous ceramic structure, comprising a body portion with a monomodal macropore structure, wherein the macropores comprises a first mean pore size; washcoating the porous ceramic structure using a suspension comprising oxide and/or hydroxide nanoparticles and drying and calcinating the washcoated porous ceramic structure at a temperature below the melting point of the nanoparticles. In addition, the ceramic support and its structure is disclosed.
PLASMA RESISTANT CERAMIC BODY FORMED FROM MULTIPLE PIECES
Disclosed is a joined ceramic body comprising a first ceramic portion comprising a first ceramic, a second ceramic portion comprising a second ceramic, and a joining layer formed between the first ceramic portion and the second ceramic portion. The joining layer has a bond thickness of from 0.5 to 20 um and comprises silicon dioxide having a total impurity content of 20 ppm and less. A method of making the joined ceramic body and a joining material are also disclosed.
DIELECTRIC COMPOSITION AND MULTILAYER CAPACITOR
A dielectric composition and a multilayer capacitor including the same are disclosed. The dielectric composition including: a BaTiO.sub.3-based main ingredient; a first auxiliary ingredient including rare earth elements; and a second auxiliary ingredient including at least one of Ba and Ca but essentially including Ba, wherein the rare earth elements include Tb and Dy, and the first auxiliary ingredient and the second auxiliary ingredient satisfy a molar content condition of 0.40<(Tb/T_RE)*(Ba+Ca)<0.93, where T_RE is a total molar content of the rare earth elements in the first auxiliary ingredient.
Z-type hexaferrite having a nanocrystalline structure
In an aspect, a Co.sub.2Z ferrite has the formula: (Ba.sub.1-xSr.sub.x).sub.3Co.sub.2+yM.sub.yFe.sub.24-2y-zO.sub.41. M is at least one of Mo, Ir, or Ru. The variable x can be 0 to 0.8, or 0.1 to 0.8. The variable y can be 0 to 0.8, or 0.01 to 0.8. The variable z can be −2 to 2. The Co.sub.2Z ferrite can have an average grain size of 5 to 100 nanometers, or 30 to 80, or 10 to 40 nanometers as measured using at least one of transmission electron microscopy, field emission scanning electron microscopy, or x-ray diffraction.
FULL-FIBER BURNER BRICK AND PREPARATION METHOD THEREOF
A full-fiber burner brick and a preparation method thereof, comprising mixing alumina crystal fiber and amorphous ceramic fiber with both of them being a combination of fibers of different lengths gradations, and moreover adding fine powder fillers of different particle size gradations and supplementing other additives. This enables the internal structure of the product more uniform, increases the bulk density of the product, and also benefits the suction filterability of fiber cotton blank, and is conducive to forming and improving the strength of the blank. The surface of the brick body is further provided with a coating, which can effectively protect the cotton fiber of the brick body fiber from harsh environments, improve its high temperature resistance, and help to extend the service life of the burner brick.
DIELECTRIC BODY, MULTILAYER CERAMIC CAPACITOR, MANUFACTURING METHOD OF DIELECTRIC BODY, AND MANUFACTURING METHOD OF MULTILAYER CERAMIC CAPACITOR
A dielectric body includes a plurality of crystal grains of which a main component is barium titanate, and an additive including Zr, Eu and Mn. At least one of the plurality of crystal grains has a core-shell structure having a core and a shell. A Zr/Ti atomic concentration ratio is 0.02 or more and 0.10 or less. An Eu/Ti atomic concentration ratio is 0.001 or more and 0.03 or less. A Mn/Ti atomic concentration ratio is 0.005 or more and 0.05 or less. A total atomic concentration of the one or more rare elements is smaller than an atomic concentration of Eu when the dielectric body has the one or more rare earth elements. A median diameter of the plurality of crystal grains is 200 nm or more and 400 nm or less.
Zirconia composition, pre-sintered body and sintered body, and method of producing the same
A composition comprises a zirconia powder, in which 55% or more thereof is monoclinic, and a stabilizer capable of suppressing phase transition of zirconia. An average particle diameter of zirconia particles and particles of the stabilizer is 0.06 μm to 0.17 μm. At least a portion of the stabilizer does not form a solid solution with zirconia.
METHOD FOR MANUFACTURING SILICON NITRIDE SINTERED COMPACT
The present invention is directed to a method for producing a silicon nitride sintered material, the method including heating a molded article, which contains a silicon nitride powder having a β phase ratio of 80% or more, a dissolved oxygen content of 0.2% by mass or less, and a specific surface area of 5 to 20 m.sup.2/g, and a sintering auxiliary containing a compound having no oxygen bond, and which has an overall oxygen content controlled to be 1 to 15% by mass and an aluminum element overall content controlled to be 800 ppm or less, to a temperature of 1,200 to 1,800° C. in an inert gas atmosphere under a pressure of 0 MPa.Math.G or more and less than 0.1 MPa.Math.G to sinter the silicon nitride.
In the present invention, there can be provided a method for producing a silicon nitride sintered material, which method is advantageous in that a silicon nitride sintered material having high thermal conductivity can be obtained even when using a silicon nitride powder having a high β phase ratio and conducting calcination under normal pressure or substantially normal pressure.