Abstract:
A precursor batch composition that can be used to make porous ceramic articles is provided. The batch composition includes a polysaccharide gum. The batch composition may optionally include a linear water soluble polymer having a molecular weight of at least one million Daltons.
Abstract:
A process for producing a ceramic membrane in the form of a hollow fibre, which process comprises: forming a suspension by mixing inorganic oxide precursor particles with a solution of a polymer binder dissolved in a solvent for the binder; feeding the suspension through a spinneret to form hollow fibres; passing the fibres through an air gap and into a coagulant to solidify the fibres; heating the fibres to remove the polymer binder; and sintering the fibres to render them gas tight, wherein the polymer binder is selected so that it may be removed from the fibres by heating without leaving any residual species within the ceramic that will impair the oxygen permeability of the fibres.
Abstract:
Process for producing a ceramic composite structure (10) includes impregnating a reinforcing material with a suitable precursor slurry composition (110) including thermosetting resin, a suitable curing agent, a ceramic component, a carbonaceous solids component, and optionally, a suitable solvent. Exemplary thermosetting resins include polyesters, vinyl esters, epoxy resins, bismaleimide resins, and polyimide resins. The carbonaceous solids component provides a suitable amount of carbon char upon pyrolization. The preform may be dried prior to curing to remove solvents and thereby provide a working material comprising up to 70 volume% solids. The preform is cured (120), pyrolized (130), and infiltrated with molten silicon (140) to form a composite article. The thermosetting resin is selected for processibility, green strength, and relatively fast cure cycle.
Abstract:
The present invention relates to a valve metal oxide formulation having organic excipients, wherein the molding pressure necessary for achieving a green density of at least 50% of the theoretic density is 200 MPa or higher, and the force required for the destruction of the blank is 10 MPa or higher in the axial and radial direction, and to a method for the production thereof.
Abstract:
The present invention comprises a novel process for the preparation of carbon based structured materials with controlled topology, morphology and functionality. The nanostructured materials are prepared by controlled carbonization, or pyrolysis, of precursors comprising phase separated copolymers. The carbon based structures can find application in photovoltaics, supercapacitors, batteries, fuel cells, computer memory, carbon electrodes, carbon foams, actuators and hydrogen storage.
Abstract:
An improved carbon-carbon composite and method of preparation. Thp carbon-carbon composite comprises a plurality of carbon fibers agglomerated and joined or consolidated together typically into a preform. The carbon fibers are impregnated with pitch prior to carbonization in order to enhance the density of the carbonized preform. The method comprises adding pitch powder to a preform and melting the pitch powder so as to uniformly impregnate the carbon fibers, thus enhancing the carbonized density of the preform.
Abstract:
The invention relates to the field of ceramics, more specifically to a corundum material that is suitable for imitating colored corundum gems (rubies and sapphires) due to the optical properties thereof, and a method for producing molded objects from said material. The aim of the invention is to develop a corundum material that is provided with a corundum grain size which is as small as possible and a chromophoric dopant distribution which is as homogeneous as possible. Said aim is achieved by a colored transparent corundum material which is made of a polycrystalline sub-µm structure having an average particle size of
Abstract:
Methods for dispersing and binding ceramic materials in aqueous media are disclosed. The methods utilize water-soluble polymers having pendant derivatized amide, ester or ether functionalities for dispersing and binding various classes of ceramic materials.