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: Alkali halide crystal is grown from a melt in a novel graphite crucible which has a surface depth region of its inside surface impregnated with glassy carbon to eliminate porosity, so that the melt does not leak through or wet the carbon. Additionally, the graphite may be coated with glassy carbon to provide a smoother surface. Also disclosed is a porous graphite crucible lined with a layer of graphitic pyrolytic carbon to prevent wetting of the surface by the melt and to permit release of the cooled crystal without remelting.

Abstract: At least one of the mating wear surfaces of a sliding mechanical seal is coated with diamond. The coating includes an underlayer of high resistance to wear and an overlayer with a reduced resistance to wear as compared to that of the underlayer. The reduced wear resistance of the overlayer prevents damage by the diamond to the opposing mating surface during the wear-in period of use.

Abstract: A process for coating a tungsten carbide base material substrate with CVD diamond film includes carburization and gas-assisted vaporization of cobalt from the surface with simultaneous recrystallization of surface grains of tungsten carbide to change their stoichiometry for improved adherence.Also disclosed is a WC-Co cutting tool having a relatively fine WC grain size and coated with adherent CVD diamond.

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: A scintillation crystal module having an epoxy seal which has a coefficient of thermal expansion which is substantially the same as the backcap of the gamma camera. Among the suitable epoxy systems, the CTE of the epoxy could be modified somewhat by choosing a different catalyst or by adjusting the resin:catalyst ratio. The presently preferred epoxy system is a STYCAST.RTM. 2850 FT system available from W. R. Grace & Co. Using "catalyst 9" or "catalyst 11" from that system, a CTE of approximately 17.33.times.10.sup.-6 to approximately 19.4.times.10.sup.-6 in/in.degree. F. can be easily achieved. It has been discovered through analysis using FEA that an epoxy with a CTE in the range of 9.0 to 20.0.times.10.sup.-6 in/in.degree. F. provides satisfactory results in preventing seal separation during .+-.40.degree. F. temperature cycles.

Abstract: A scintillation detector (10) includes a scintillation crystal (14) and a shock absorbing member (76) circumscribing the crystal (14). A sleeve (98) circumscribes the shock absorbing member (76) which, in turn, is circumscribed by a housing (12). The sleeve (98) provides for substantial controlled radial loading on the crystal (14). A method of manufacturing the detector (10) includes placing the crystal (14) and shock absorbing member (76) into the sleeve (98), compressing the sleeve 98 and inserting the compressed sleeve (98) into the housing (12) such that the sleeve (98) substantially maintains its compression. The radial stiffness causes vibration induced counts to occur at an excitation frequency which is above the operational bandwidth of the radiation measurements, thereby excluding vibration induced counts for radiation measurements.

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: 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 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.

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: 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: 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 well logging instrument and method that remove vibration induced noise from the output of a detector including a scintillation crystal. The invention is based on a realization that pulses induced by vibration during MWD operations are characteristically periodic, whereas pulses generated down hole by gamma rays occur at random intervals and are characteristically non-periodic. The instrument and method involve positioning a scintillation crystal package in the high vibration environment for interaction with incident radiation, using a light sensing device to convert photons received from the scintillation crystal package into an electrical signal which over time is composed of radiation induced events that are non-periodic and vibration induced events that are periodic, distinguishing the periodic events using a time history of the electrical signal, and removing the periodic events from the electrical signal to provide a corrected electrical signal from which vibration induced components have been removed.

Abstract: The reliability of a braze joint formed between a diamond film and a tungsten carbide body is increased by use of a vanadium-containing braze. The braze joint exhibits an average shear strength greater than about 40,000 pounds per square inch, (276 MPa) and the braze exhibits a contact angle with the diamond film of less than about 15.degree..

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 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: An IC package includes a high thermal conductivity insulating material substrate, such as polycrystalline diamond or diamond-coated silicon carbide or molybdenum, 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. The thermal connection can be by bonding the pins directly to the substrate.