Abstract: A mandrel for use in a diamond deposition process has surfaces with different diamond adhesion properties. According to one embodiment, a mandrel is provided and has first and second surfaces on which a diamond film is deposited, with the second surface forming a perimeter around the first surface. The first surface of the mandrel has a first diamond bonding strength which is less than a second diamond bonding strength of the second surface. In an embodiment for forming a cup-shaped diamond film, the mandrel is a titanium nitride (TiN) coated molybdenum (Mo) substrate having a stepped solid cylindrical shape with a central mesa having a side wall or flank. The side wall is etched near the top surface of the mesa to expose a molybdenum band and to form a second surface which bounds the TiN first surface.

Abstract: A mandrel for use in a diamond deposition process has surfaces with different diamond adhesion properties. According to one embodiment, a mandrel is provided and has first and second surfaces on which a diamond film is deposited, with the second surface forming a perimeter around the first surface. The first surface of the mandrel has a first diamond bonding strength which is less than a second diamond bonding strength of the second surface. In an embodiment for forming a cup-shaped diamond film, the mandrel is a titanium nitride (TiN) coated molybdenum (Mo) substrate having a stepped solid cylindrical shape with a central mesa having a side wall or flank. The side wall is etched near the top surface of the mesa to expose a molybdenum band and to form a second surface which bounds the TiN first surface.

Abstract: An IC package includes a high thermal conductivity insulating material substrate, such as polycrystalline diamond, on which the IC is mounted for thermal management. The electrical lead pins of the package are electrically connected to the IC and thermally connected to the substrate.

Abstract: A deposition target medium is disclosed for use in CVD of a diamond film wherein a hydrocarbon gas and atomic hydrogen are utilized in depositing the diamond film on the deposition target medium, which comprises a substrate having a Young's modulus of less than 50 GPa; and a coating on said substrate, said coating comprising a binder and diamond grit, said binder comprising a glass-forming oxide.

Abstract: A method for selective controlled etching of a material particularly by sequentially switching between two (2) or more modes of radiofrequency waves and/or by distance from a source of the microwaves. The modes and/or distance are selected depending upon the surface of the material to be etched. The etching is rapidly conducted at 0.5 mtorr to 10 torr, preferably using microwave plasma etching.

Abstract: This invention relates to a densified zirconia ceramic partially stabilized by between 3.8 mol % and 4.4 mol % yttria, wherein the ceramic has a flexural strength of at least 900 MPa after immersion in liquid water having a temperature of 250.degree. C. for 48 hours in an autoclave.

Abstract: Shaped ceramic articles can be obtained by screen printing the desired shapes from a dimensionally stable dispersion of a precursor of the ceramic onto a surface, drying the screen printed shapes so obtained and firing them to generate the shaped ceramic articles.

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: A raw batch for producing a crack-free recrystallized silicon carbide body, the raw 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 and fine free carbon, wherein the fine free carbon is present in an amount of at least 0.10 w/o of the raw batch, the fine free carbon having a surface area of at least 10 m.sup.2 /g,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 coarse free carbon, wherein the coarse free carbon is present in an amount of at least 0.10 w/o of the coarse grain fraction,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.

Abstract: The present invention relates to a highly smooth zirconia-containing disk substrate produced by polishing a defect-free surface with fine diamond and/or alumina.

Abstract: At least the surface region of a cutting tool substrate made of tungsten carbide in a cobalt matrix is carburized to chemically passivate the cobalt prior to deposition of diamond film on it. The passivation improves adhesion by preventing reaction of the cobalt with the diamond in the course of the deposition process.

Abstract: This invention is a process for making crack-free silicon carbide components wherein the level of free silica in the raw batch is controlled.

Abstract: A wire is used to cut or slice diamond by passing the wire rapidly and under light load over and into the diamond surface along a line to be cut. In one form of the invention, the wire comprises a metal that dissolves diamond, such as iron or nickel and the wire and/or diamond is preferably heated to approach the metal-carbon eutectic temperature and create sensible reaction rates of the carbon on the wire surface. In another form of the invention, the moving wire carries a molten oxidant to enhance the cutting rate. The molten oxidant may be, for example, sodium nitrate, which oxidizes carbon.

Abstract: Output variations of individual channels of radiation detector arrays and particularly the outer channels of the scintillator crystal array are reduced by modifying the reflectivity of the surfaces of the individual crystal elements according to the output. This is accomplished by creating a specific difference in the reflectivity of the internal channel reflectors compared to the external reflector material to enhance or reduce the output of specific channels to achieve a balance in the outputs. The specific difference in reflectivity may be obtained by using different color pigments, different color cements and various colored foils, for example.

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.

Abstract: A mandrel for use in a diamond deposition process for generating free standing diamond films has a segmented surface forming a plurality of surfaces for deposition of diamond. The segmented surface is formed of a plurality of mesa segments on a common supporting base surfaces for the mesas. The mesa segments are preferably removably attached to the common base by any suitable means such as by bolts through the mandrel substrate which extend into the mesa segments. The mesa segments may vary in shape, size, and number, thus permitting different shaped diamond films to be made simultaneously from the same run if desired. The provided arrangement increases yield by reducing losses due to premature lifting of the diamond film during deposition, due to violent lifting after deposition upon cooling of the mandrel, and due to cracking.

Abstract: A process comprising the steps of:a) providing a fiber preform comprising a non-oxide ceramic fiber with at least one coating, the coating comprising a coating element selected from the group consisting of carbon, nitrogen, aluminum and titanium, and the fiber having a degradation temperature of between 1400.degree. C. and 1450.degree. C.,b) impregnating the preform with a slurry comprising silicon carbide particles and between 0.1 wt % and 3 wt % added carbonc) providing a cover mix comprising:i) an alloy comprising a metallic infiltrant and the coating element, andii) a resin,d) placing the cover mix on at least a portion of the surface of the porous silicon carbide body,e) heating the cover mix to a temperature between 1410.degree. C. and 1450.degree. C. to melt the alloy, andf) infiltrating the fiber preform with the melted alloy for a time period of between 15 minutes and 240 minutes, to produce a ceramic fiber reinforced ceramic composite.

Abstract: A method for producing a crack-free recrystallized silicon carbide body, icluding the steps of:a) providing a raw powder batch including:i) at least 40 w/o fine fraction having a particle size of less than 10 microns, the fine grain fraction including silicon carbide and fine free carbon, wherein the fine free carbon is present in an amount of at least 0.10 w/o of the raw batch, the fine free carbon having a surface area of at least 10 m.sup.2 /g,ii) at least 40 w/o coarse grain fraction having a particle size of at least 30 microns, the coarse grain fraction including silicon carbide and coarse free carbon, wherein the coarse free carbon is present in an amount of at least 0.10 w/o of the coarse grain fraction,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.

Abstract: There is provided an improved kiln furniture assembly:wherein the improvement comprises vertical posts comprising:i) a vertically disposed channel, andii) a spacer block (13a) vertically separating the upper and lower horizontal beams which extend from the same post,wherein at least a portion of the spacer block or the horizontal beam is positioned within the vertically disposed channel.

Abstract: This invention relates to polishing YTZP zirconia disk substrates with colloidal silica to achieve a surface roughness Ra of no more than 8 angstroms.