Abstract: An embodiment of a PCD insert comprises an embodiment of a PCD element joined to a cemented carbide substrate at an interface. The PCD element has internal diamond surfaces defining interstices between them. The PCD element comprises a masked or passivated region and an unmasked or unpassivated region, the unmasked or unpassivated region defining a boundary with the substrate, the boundary being the interface. At least some of the internal diamond surfaces of the masked or passivated region contact a mask or passivation medium, and some or ail of the interstices of the masked or passivated region and of the unmasked or unpassivated region are at least partially filled with an infiltrant material.

Abstract: A polycrystalline diamond (PCD) composite compact element comprising a PCD structure bonded to a cemented carbide substrate, in which at least a peripheral region of the substrate comprises cemented carbide material having a mean free path (MFP) characteristic of at least about 0.1 microns and at most about 0.7 microns; and an elastic limit of at least about 1.9 GPa.

Abstract: A polycrystalline diamond (PCD) composite compact element 100 comprising a substrate 130, a PCD structure 120 bonded to the substrate 130, and a bond material in the form of a bond layer 140 bonding the PCD structure 120 to the substrate 130; the PCD structure 120 being thermally stable and having a mean Young's modulus of at least about 800 GPa, the PCD structure 120 having an interstitial mean free path of at least about 0.05 microns and at most about 1.5 microns; the standard deviation of the mean free path being at least about 0.05 microns and at most about 1.5 microns. Embodiments of the PCD composite compact element may be for a tool for cutting, milling, grinding, drilling, earth boring, rock drilling or other abrasive applications, such as the cutting and machining of metal.

Abstract: A polycrystalline diamond (PCD) compact and method for making the compact are provided. The method includes bringing a first PCD wafer and a second PCD wafer together at an interface in the presence of a bonding agent to form an unbonded assembly and bonding the wafers together at the interface at a pressure and temperature at which diamond is thermodynamically stable. The first PCD wafer is more thermally stable than the second PCD wafer.

Abstract: An earth boring bit is shown having a bit body and at least one cutter rotatably secured to the bit body. The cutter has a plurality of teeth formed integrally thereon and arranged in circumferential rows. Each of the teeth includes an outer end, an inner end, a pair of flanks and a crest which transversely connects the ends and flanks. During the manufacturing process, a temporary protective coating is applied at a region of the tooth root which comprises a sharp corner at the intersection of the flanks and ends in order to prevent a carburized case from forming in that region during subsequent carburization of the cutter. The cutter is then carburized, heat treated and mounted on a bit body.

Abstract: An earth-boring bit has a bit body and a cantilevered bearing shaft depending from the bit body. The cutter is mounted for rotation on the bearing shaft. Cutting elements are secured within holes formed in the cutter. At least some of the cutting elements include a body of hard metal which has a cylindrical base inserted in an interference fit within one of the holes. The body has a contact surface on its cutting end. A layer of super-hard material is bonded to the contact surface to provide a tip for the cutting end. The layer may be formed of a free-standing film of diamond which is brazed to the contact surface. It may also be formed with a high temperature, high pressure process directly onto the body of tungsten carbide.

Abstract: An earth-boring bit is formed having a bit body in a cantilevered bearing shaft that depends from the bit body. The bearing shaft is provided with a journal bearing surface. A cutter is mounted to the bearing shaft and has a mating bearing surface for engagement with the journal bearing surface of the bearing shaft. Provided on the bearing shaft is a layer of diamond film that is formed by chemical vapor deposition (CVD) as a free standing film. This layer of diamond film is brazed to the bearing shaft so that it forms the journal bearing surface. By utilizing the CVD methods of forming diamond film, the bearing surface can be formed in a variety of shapes and contours and with a surface texture or configuration as desired.

Abstract: An earth-boring bit of the rolling cutter variety is provided with hard gage inserts that protrude from the gage surface of the cutter to engage the side of the borehole for holding gage. The gage insert has a substantially flat face with sharp cutting edges formed thereon and has cutting surfaces that define a negative rake angle with respect to the sidewall of the borehole that is being sheared by the gage insert. The cutting surfaces are comprised of multiple chamfers. The face, cutting edge, and cutting surfaces of the gage insert are formed of a super-hard and abrasion-resistant material such as polycrystalline diamond or cubic boron nitride. The body of the insert is formed of a hard, fracture-tough material such as cemented tungsten carbide. The improved gage inserts provide an actively cutting gage surface that engages the sidewall of the borehole to promote shearing removal of the sidewall material.

Abstract: An earth-boring bit has a bit body, at least one cantilevered bearing shaft, including a base and a cylindrical journal bearing surface extending inwardly and downwardly from the bit body, and at least one cutter mounted for rotation on the cylindrical journal bearing surface of the bearing shaft. A seal assembly is disposed between the cylindrical journal bearing surface and the cutter proximally to the base of the cantilevered bearing shaft. The seal assembly includes at least one rigid seal ring having a seal face in contact with a second seal face. At least one of the seal faces is at least partially formed of a super-hard material having wear-resistance greater than, and a coefficient of sliding friction less than, that of the rigid seal ring material.

Abstract: A combination metal milling and earth drilling tool, for use in performing a single trip kickoff from a casing in a well bore. The combination milling and drilling tool has a first, relatively more durable cutting structure, such as tungsten carbide, and a second, relatively harder cutting structure, such as polycrystalline diamond. The more durable first cutting structure is better suited for milling metal casing, while the harder second cutting structure is better suited for drilling through a subterranean formation, especially a rock formation. The first cutting structure is positioned outwardly relative to the second cutting structure, so that the first cutting structure will mill through the metal casing while shielding the second cutting structure from contact with the casing. The first cutting structure can wear away while milling through the casing and upon initial contact with the rock formation, thereby exposing the second cutting structure to contact with the rock formation.

Abstract: An earth boring bit is shown of the type used to drill subterranean formations. The bit body has an upper extent which is threaded for connection in a drill string extending to the earth's surface. A lower extent of the bit body has a number of cutting elements mounted thereon which engage an earthen formation and cut the formation. At least selected ones of the cutting elements incorporate a nanocrystalline diamond material.

Abstract: An earth-boring bit has a bit body and at least one cutter rotatably secured to the bit body. The cutter has a cutter shell surface including a gage surface and a heel surface. A plurality of cutting elements inserts are arranged in generally circumferential rows on the cutter. At least one scraper cutting element is secured at least partially to the heel surface of the cutter. The scraper cutting element includes an outermost surface, generally aligned with the gage surface of the cutter, that defines a plow edge or point for shearing engagement with the sidewall of the borehole while redirecting cuttings up the borehole.

Abstract: An earth-boring bit is provided with hard gage inserts that protrude from the gage surface of the cutter to engage the side of the borehole for holding gage. The cutting end of the gage insert has a cutting end defining at least one sharp cutting edge and at least one cutting surface that define a negative rake angle with respect to the sidewall of the borehole that is being sheared by the gage insert. The cutting end, cutting edge, and cutting surface of the gage insert are formed of a super-hard and abrasion-resistant material such as polycrystalline diamond or cubic boron nitride. The body of the insert is formed of a hard, fracture-tough material such as cemented tungsten carbide. The improved gage inserts provide an actively cutting gage surface that engages the sidewall of the borehole to promote shearing removal of the sidewall material. Such an improved gage insert provides an earth-boring bit with improved gage-holding ability, and improved steerability in directional drilling operations.