Abstract: This invention relates to tape casting a silicon carbide slip to eventually produce a silicon carbide wafer having a thickness of between 0.5 and 1 mm and a diameter of at least 150 mm, the wafer preferably having a strength of at least 30 MPa, and a porosity wherein at least 85% of the pores are no larger than 12 microns.
Abstract: This invention relates to a biojoint prosthesis comprising:a) a prosthetic comprising a first component having an outer surface comprising at least 90 mol% zirconia, andb) a second component having a surface shaped to receive the outer surface of the first component,wherein the outer surface of the first component is received on the surface of the second component, andwherein a) at least a portion of the surface of the second component receiving the first component comprises a ceramic having a surface roughness of no more than 100 nm, and b) the outer surface of the first component has a surface roughness of no more than 100 nm.
Abstract: A method for producing a diamond film is disclosed, which comprises the steps of providing a substrate having a Young's modulus of less than 50 GPa; applying a coating material comprising a glass-forming oxide binder and diamond grit to the substrate; and depositing said diamond film on said coating by CVD.
Abstract: Diamond film is deposited by chemical vapor deposition on the surface of a graphite mandrel which is covered with a protective coating to which the diamond film adheres. After completion of the deposition, the diamond is removed from the mandrel by sawing through the substrate to saw off a layer thereof which includes the deposition surface and the diamond film. The graphite and protective coating may be left in place for some applications or be removed either chemically or by mechanical abrasion to separate the diamond therefrom.
Abstract: A method for forming thin green ceramic igniter shapes having a thickness characterized by a tolerance of no more than about +/-0.001 inch includes providing an apparatus having a porous mold having a well which defines a pair of opposing porous walls, and a plurality of vertical dividers positioned in the well in substantially parallel, substantially spaced relation where each divider contacting each opposing wall to define a plurality of compartments. A ceramic slip formed from a ceramic powder and a liquid carrier is poured into the compartments of the apparatus, dewatered through the opposing porous walls to form a plurality of green ceramic igniter shapes. The plurality of green ceramic igniter shapes are removed from the plurality of compartments.
Abstract: Methods for preparing a cutting tool substrate material for diamond coating include providing a grooved pattern on selected portions of at least the top surface and preferably also the sides of the substrate material. The pattern may be a cross-hatching, a diamond-hatching, or another design. The pattern is preferably applied to the tool substrate by scribing with a laser ablation tool. The pattern is designed to optimize adhesion of CVD diamond on the portions of the tool substrate which are expected to be most challenged during a cutting process. The dimensions of the pattern (e.g. the depth and spacing of scribe lines) are selected to provide the optimum combination of mechanical bonding and diamond nucleation during the CVD coating of the tool substrate. According to preferred aspects of the invention, the pattern is applied only to the portions of the surface not immediately adjacent to the cutting edge of the tool substrate, thereby sparing the geometry of the cutting edge itself.
Abstract: A method is disclosed for depositing diamond film, including the following steps: providing an environment comprising hydrogen gas and a hydrocarbon gas; dissociating hydrogen gas of the environment by dielectric barrier discharge to obtain atomic hydrogen; and providing a deposition surface in the environment and implementing diamond deposition on the deposition surface from the hydrocarbon gas, assisted by the atomic hydrogen. In a preferred embodiment, the atomic hydrogen is transported by molecular diffusion from its dissociation site to the deposition surface.
February 23, 1996
Date of Patent:
July 7, 1998
Saint Gobain/Norton Industrial Ceramics Corp.
Stephen M. Jaffe, Matthew Simpson, Cecil B. Shepard, Michael S. Heuser
Abstract: This invention relates to an apparatus comprising:a) a article having a composition selected from the group consisting of graphite, carbon/carbon, carbon/graphite, and mixtures thereof, andb) a ceramic coating thereon, wherein the ceramic coating comprises a material selected from the group consisting of:i) a ceramic having an average thermal expansion coefficient of between 2 and 8.times.10.sup.-6 /.degree. C. between 22.degree. C. and 1200.degree. C. which is also phase stable in the temperature range of 22.degree. C. and 1450.degree. C., andii) alumina having at least 99% purity.
Abstract: The process is an arc jet CVD diamond deposition process with very low methane, less than 0.07%, and the addition of water. The resulting material has is characterized by a narrow Raman peak, a relatively large lattice constant, and a charge carrier collection distance of at least 25 microns.
Abstract: Diamond film with substantially no non-diamond carbon and a high thermal conductivity is deposited by means of a direct current arc jet apparatus with a substrate temperature below about 975 degrees Celsius, an arc power of between about 20 and 40 kw. a pressure of about 12 torr, and an enthalpy greater than 30 from a activated gas jet fed with hydrogen and methane, the methane being supplied at a concentration of less than 0.07%. The resulting material has a high transparency and thermal conductivity.Also disclosed is the use of the diamond material made by the present method for cutting tool applications, particularly milling.
Abstract: The present invention relates to a refractory shield for protecting a superheater tube against fluid attack comprising first and second partial-tubes, each partial-tube having a C-shaped cross-section, the C-shaped cross section defining first and second ends; wherein the ends of the partial-tubes are opposably engaged, and wherein the partial-tubes comprise means for preventing radial movement of the first partial-tube relative to the second partial-tube.
Abstract: A method for ablating a synthetic diamond having a pitted surface includes applying a colloidal graphite to the surface of the diamond and subjecting it to an oxygen plasma so that preferably approximately 50 microns are removed from the surface of the synthetic diamond. The resulting surface of the diamond is virtually pit free. Preferably, the diamond is then mechanically lapped for finishing.
Abstract: This invention relates to a method for producing a crack-free sintered silicon carbide body, comprising the steps of:a) providing a raw powder batch comprising:i) at least 40 w/o fine grain fraction having a particle size of less than 10 microns, the fine grain fraction comprising silicon carbide,ii) at least 40 w/o coarse grain fraction having a particle size of at least 30 microns, the coarse grain fraction comprising silicon carbide and less than 0.10 w/o free carbon,the raw batch having a total silica content of at least 0.5 w/o,the raw batch having a total silicon carbide content of at least 96 w/o,b) forming the raw batch into a green body, andc) recrystallizing the green body to provide a recrystallized silicon carbide body having a density of between 2.0 g/cc and 2.8 g/cc.
Abstract: The process is an arc jet CVD diamond deposition process with very low methane, less than 0.07%, and the addition of water. The resulting material has is characterized by a narrow Raman peak, a relatively large lattice constant, and a charge carrier collection distance of at least 25 microns.Also disclosed is a particle detector device which makes use of the diamond material according to the invention.
Abstract: A cutting tool of the type having a tool support with a cutting tip of CVD diamond film brazed to it has the diamond material so oriented that the general direction of grain boundaries is not normal to the general plane of the rake face.
Abstract: A heat-sinked electronic component includes a first layer of synthetic diamond having a relatively low thermal conductivity. A second layer of synthetic diamond is adjacent the first layer, the second layer of synthetic diamond having a relatively high thermal conductivity, the second layer being thinner than the first layer. An electronic component is mounted on the second layer of synthetic diamond. In a disclosed embodiment, the thermal conductivity of the diamond of the second layer is at least fifteen percent higher than the thermal conductivity of the diamond of the first layer, and the first layer is at least twice as thick as second layer.
May 17, 1995
Date of Patent:
July 15, 1997
Saint Gobain/Norton Industrial Ceramics Corp.
Abstract: A method of making a diamond-coated insert includes, obtaining a substrate of durable and diamond adherent material having a substantially smooth surface on which is coated a diamond layer using any known CVD technique, and partitioning the diamond covered substrate with a laser beam into multiple inserts with desired geometries. If desired, the insert edges and corners may be thereafter machined or ablated until the desired smoothness and finish are achieved, and a fastening throughbore may be preformed or drilled in the center of each insert. The diamond-coated inserts as formed have a top surface entirely coated by a surface layer of diamond of a first thickness, and at least one rake face which is not diamond-coated beyond the surface layer of diamond.