Patent classifications
C04B35/632
Graphite-containing refractory and method of producing graphite-containing refractory
A method of producing a graphite-containing refractory within which carbon fiber bundles are placed, the graphite constituting 1% to 80% by mass, the method including a bundling step of bundling carbon fibers to form the carbon fiber bundles; a mixing step of mixing a refractory raw material with graphite to prepare a graphite-containing refractory raw material; a pressing step of pressing the graphite-containing refractory raw material in which the carbon fiber bundles are placed to prepare a formed product; and a drying step of drying the pressed product, wherein the bundling step includes bundling 1000 to 300000 of the carbon fibers with a fiber diameter of 1 to 45 μm/fiber to form carbon fiber bundles 100 mm or more in length.
TWO-STAGE SINTERING METHOD FOR PREPARING POROUS BIPHASIC CALCIUM PHOSPHATE CERAMIC FROM CALCIUM-CONTAINING BIOLOGICAL WASTE
The present invention relates to a two-stage sintering method for preparing a porous biphasic calcium phosphate ceramic from calcium-containing biological waste, wherein hydroxyapatite prepared from calcium-containing waste is mixed with a foaming agent to prepare a bone graft material having medicinal use through two-stage sintering.
Methods of extracting volatiles from ceramic green bodies
Methods of producing a ceramic article include heating the ceramic green body containing a quantity of one or more organic materials to extract only a fraction of the organic materials from the ceramic green body by exposing the ceramic green body to a process atmosphere which is heated to a hold temperature of from 225° C. to about 400° C. and has from 2% to 7% O.sub.2 by volume of the process atmosphere. The method further includes cooling the ceramic green body to a temperature of below 200° C., exposing the ceramic green body to a higher concentration of O.sub.2 than in the process atmosphere of the heating step, and firing the ceramic green body to form the ceramic article. Volatile extraction units for implementing the methods are also described.
Pre-impregnated fibre-reinforced composite material and fibre-reinforced composite ceramic material, obtained by forming and subsequent pyrolysis of said pre-impregnated material
The invention relates to a pre-impregnated fibre-reinforced composite material in laminar form, obtained impregnating a fibrous mass with a polymeric binder composition and intended to be subjected to successive forming and pyrolysis operations to produce a fibre-reinforced composite ceramic material. The polymeric binder composition is based on one or more resins chosen from the group consisting of siloxane resins and silsesquioxane resins, and can optionally comprise one or more organic resins. The polymeric binder composition is a liquid with viscosity between 55000 and 10000 mPas at temperatures between 50° C. and 70° C. The polymeric binder composition forms a polymeric binding matrix, not cross-linked or only partially cross-linked that fills the interstices of the fibrous mass. The invention also relates to a method for making said pre-impregnated fibre-reinforced composite material in laminar form. The invention further relates to a fibre-reinforced composite ceramic material, obtained by forming and subsequent pyrolysis of a pre-impregnated fibre-reinforced composite material, as well as a method for making said material.
SINTERED BODY, SUBSTRATE, CIRCUIT BOARD, AND MANUFACTURING METHOD OF SINTERED BOY
A sintered body includes a crystal grain containing silicon nitride, and a grain boundary phase. If dielectric losses of the sintered body are measured while applying an alternating voltage to the sintered body and continuously changing a frequency of the alternating voltage from 50 Hz to 1 MHz, an average value ε.sub.A of dielectric losses of the sintered body in a frequency band from 800 kHz to 1 MHz and an average value ε.sub.B of dielectric losses of the sintered body in a frequency band from 100 Hz to 200 Hz satisfy an expression |ε.sub.A−ε.sub.B|≤0.1.
TRANSPARENT CERAMICS FABRICATED BY MATERIAL JET PRINTING
A method for forming a transparent ceramic, in accordance with one embodiment, includes forming a green body by material jetting an ink, and processing the green body to form the ceramic to transparency. A product, in accordance with one embodiment, includes an ink for forming a transparent ceramic. The ink is physically characterized as having a density, surface tension, and viscosity configured to enable material jetting of the ink in contained, sequential droplets having a volume in the range of about 1 picoliter to about 1 nanoliter when jetted from a nozzle having an inner diameter in the range of about 10 microns to about 300 microns. A product, in accordance with another embodiment, includes a transparent ceramic, at least a portion of the transparent ceramic having layers of less than 50 microns per layer with physical characteristics of formation by material jetting.
METHOD FOR THE PREPARATION OF A LEAD-FREE PIEZOELECTRIC MATERIAL AND PRECURSOR SOLUTION
The present disclosure relates to a method for the preparation of a precursor solution for a ceramic of the BZT-aBXT type wherein X is selected from Ca, Sn, Mn and Nb and a is a molar fraction selected in the range between 0.10 and 0.90 comprising the steps of: a) dissolving at least one barium precursor compound and at least one precursor compound selected from the group consisting of a calcium precursor compound, a tin precursor compound, a manganese precursor compound and a niobium precursor compound in a linear or branched anhydrous alkyl alcohol containing from 2 to 6 carbon atoms and, after dissolution, dehydrating by stripping, to obtain a first solution; b) dissolving at least one zirconium precursor compound and at least one titanium precursor compound in a linear or branched anhydrous alkyl alcohol containing from 2 to 6 carbon atoms in the presence of an anhydrous chelating agent to obtain a second solution; c) joining said first and second solutions in an anhydrous environment and dehydrating by stripping to obtain said precursor solution. It also relates to a precursor solution, to a method for the preparation of a film of a piezoelectric material, to a piezoelectric material and to an electronic device comprising this piezoelectric material.
CURABLE COMPOSITION FOR THE MANUFACTURE, BY STEREOLITHOGRAPHY, OF GREEN PARTS OF CERAMIC OR METALLIC MATERIAL BY PHOTO-THERMAL ROUTE
Disclosed is a curable composition for the manufacture, by stereolithography, of a green part made of a ceramic or metallic material, the curable composition including at least one ceramic and/or metallic powder; at least one polymerizable monomer and/or oligomer; at least one initiator for the polymerization of the polymerizable monomer(s) and/or oligomer(s). The initiator(s) are selected from iodonium, sulphonium and diazonium salts and onium salts in combination with at least one amine and/or at least one phosphine to form a charge transfer complex. The initiator(s) may generate the initiation of a thermal polymerization under the exposure to at least one source of UV, visible or IR irradiation.
SYSTEM, PROCESS AND RELATED SINTERED ARTICLE
A process of forming a sintered article includes heating a green portion of a tape of polycrystalline ceramic and/or minerals in organic binder at a binder removal zone to a temperature sufficient to pyrolyze the binder; horizontally conveying the portion of tape with organic binder removed from the binder removal zone to a sintering zone; and sintering polycrystalline ceramic and/or minerals of the portion of tape at the sintering zone, wherein the tape simultaneously extends through the removal and sintering zones.
SYSTEM, PROCESS AND RELATED SINTERED ARTICLE
A process of forming a sintered article includes heating a green portion of a tape of polycrystalline ceramic and/or minerals in organic binder at a binder removal zone to a temperature sufficient to pyrolyze the binder; horizontally conveying the portion of tape with organic binder removed from the binder removal zone to a sintering zone; and sintering polycrystalline ceramic and/or minerals of the portion of tape at the sintering zone, wherein the tape simultaneously extends through the removal and sintering zones.