Abstract: An annular body, which may be a die for drawing wire, comprises an annular transparent CVD diamond body having an opening of uniform diameter with an interior surface in a region of smaller diamond grains and an external surface in a region of larger diamond grains.

Abstract: Graphite substrate holders for employment in apparatus for chemical vapor deposition of diamond decrease the tendency of the formed diamond sheets to crack or shatter upon separation from the substrates. Said holders and the substrates therein preferably have rounded edges, to suppress crack formation at sharp corners. The holders are preferably coated, at least in part, with a tie-layer and a hydride-forming metal such as niobium. Also, certain maximum distances between the edges of the holder and substrates are preferably maintained in order to prevent contact of diamond with a heated filament employed for thermal activation.

Abstract: The present invention provides a method for forming uniform CVD diamond coatings on a substrate wherein diamond is deposited on a plurality of substrates which are rotated in unison during the coating process to provide for more uniform radial growth. An advantageous substrate is a wire which can be coated with a layer of CVD diamond for making components in water-jet cutting apparatus, wire-drawing dies, or other tubular articles when the wire is separated from the resulting diamond tube. Identical tubes with higher uniformity in wall thickness are among the products which can be obtained. In addition, tubes having a uniform particle size distribution along their wall thickness which supports columnar diamond growth are also provided.

Abstract: Chemical vapor deposition method for producing a diamond film substantially free of thermal stress-induced cracks in which diamond growth occurs on both sides of a thin substrate so that two diamond coatings with identical opposing tensile forces are formed on each side of the substrate at a thickness greater than the thickness of the thin substrate.

Abstract: A chemical vapor deposition method for producing a flat diamond film substantially free of cracks by forming the diamond film on the surface of a substrate having a convex growth surface wherein the radius of curvature is matched with the tensile stress within the diamond coating produced to compensate for distortion when the film is separated from the substrate.

Abstract: An oversize compact blank having a surface and edges that establish it as oversized is provided. A chip breaker pattern is formed on the compact blank surface. Preferred means for forming the chip breaker pattern include use of a laser, a plunge EDM apparatus, or by ultrasonic abrading. Thereafter, the edges of the patterned oversized compact blank are finished to reduce the size of the blank. When pluge EDM apparatus fitted with a patterned plunger is used, the compact blank must be electrically conductive.

Abstract: Disclosed is an improved implement comprising a cemented carbide supported composite abrasive compact which is brazed to a cemented carbide substrate with a brazing filler metal having a liquidus substantially above 700.degree. C. The composite compact preferably is a composite polycrystalline diamond compact. The brazing filler metal is a brazing alloy having a liquidus not substantially above 1,004.degree. C. and which has the following composition, by weight:Au: 18-39.5%Ni: 3.5-14.5%Pd: 2.5-10.5%Mn: 7.5-9.0%Cu: Balance.

Abstract: A component comprised of a composite compact, preferably diamond, and a substrate bonded to the compact. A preferred embodiment of the component is a cutter for a drill bit. The compact is comprised of a layer of bonded diamond or boron nitride particles and a base layer of cemented carbide bonded, preferably under high temperatures and pressures, to the particulate layer. The particulate layer is degradable by expvsure to temperatures above a predetermined temperature. The substrate is bonded to the base layer of the compact with a filler metal which, to form a bond, requires the exposure of the surface to be bonded to a temperature substantially greater than the degradation temperature of the particulate layer. The component is fabricated by heating the base layer, filler metal and substrate to a temperature in excess of the degradation temperature while maintaining the temperature of the particulate layer below the degradation temperature via a heat sink.

Abstract: A component comprised of a composite compact, preferably diamond, and a substrate bonded to the compact. A preferred embodiment of the component is a cutter for a drill bit. The compact is comprised of a layer of bonded diamond or boron nitride particles and a base layer of cemented carbide bonded, preferably under high temperatures and pressures, to the particulate layer. The particulate layer is degradable by exposure to temperatures above a predetermined temperature. The substrate is bonded to the base layer of the compact with a filler metal which, to form a bond, requires the exposure of the surfaces to be bonded to a temperature substantially greater than the degradation temperature of the particulate layer. The component is fabricated by heating the base layer, filler metal and substrate to a temperature in excess of the degradation temperature while maintaining the temperature of the particulate layer below the degradation temperature via a heat sink.

Abstract: A method for fabricating a drill bit comprising a plurality of composite compact cutters by furnace brazing each cutter in a recess in the crown of the drill bit. In one embodiment, each cutter is comprised of a mass of bonded polycrystalline abrasive, a substrate bonded to said abrasive mass and a thin layer of brazing filler metal coating the exposed surface of the substrate. In another embodiment, the cutter comprises a composite compact cutter blank bonded to one end of a cemented carbide pin, and a thin layer of brazing filler material coating the substrate of the blank and the carbide pin. In both embodiments, the coating of brazing filler metal is applied to the cutters by dipping in a molten bath of the filler metal.