Abstract: The residual stresses that are experienced in polycrystalline diamond cutters, which lead to cutter failure, can be effectively modified by selectively thinning the carbide substrate subsequent to high temperature, high pressure (sinter) processing, by selectively varying the material constituents of the carbide substrate, by subjecting the PDC cutter to an annealing process during sintering, by subjecting the formed PDC cutter to a post-process stress relief anneal, or a combination of those means.

Abstract: The residual stresses that are experienced in polycrystalline diamond cutters, which lead to cutter failure, can be effectively modified by selectively thinning the carbide substrate subsequent to high temperature, high pressure (sinter) processing, by selectively varying the material constituents of the carbide substrate, by subjecting the PDC cutter to an annealing process during sintering, by subjecting the formed PDC cutter to a post-process stress relief anneal, or a combination of those means.

Abstract: The residual stresses that are experienced in polycrystalline diamond cutters, which lead to cutter failure, can be effectively modified by selectively thinning the carbid substrate subsequent to a high-temperature, high-pressure (sinter) processing, by selectively varying the material constituents of the carbide substrate, by subjecting the PDC cutter to an annealing process during sintering, by subjecting the formed PDC cutter to a post-process stress relief anneal, or by a combination of those means.

Abstract: The residual stresses that are experienced in polycrystalline diamond cutters, which lead to cutter failure, can be effectively modified by selectively thinning the carbide substrate subsequent to high temperature, high pressure (sinter) processing, by selectively varying the material constituents of the cutter substrate, by subjecting the PDC cutter to an annealing process during sintering, by subjecting the formed PDC cutter to a post-process stress relief anneal, or a combination of those means.

Abstract: A cutting element for use in drilling subterranean formations. The cutting element includes a superabrasive table mounted to a supporting substrate. The superabrasive table includes a two-dimensional cutting face having a cutting edge along at least a portion of its periphery, and a first surface extending forwardly and inwardly from a location radially interior of the cutting edge at a first angle of orientation with respect to the longitudinal axis of the cutting element. The cutting face also includes at least a second surface located between the first surface and the cutting edge and oriented at a different, greater angle to the longitudinal axis than the angle of orientation of the first surface.

Abstract: An earth-boring bit has a bit body and at least one cantilevered bearing shaft depending inwardly and downwardly from the bit body. A cutter is mounted for rotation on the bearing shaft and includes a plurality of cutting elements. At least one of the cutting elements has a generally cylindrical body formed of hard metal with a convex cutting end. A plurality of substantially recesses are formed on the cutting end of the body. The recesses are configured such that a line parallel to the longitudinal axis of the body may extend from any point of each of the recess without touching any other point on the same recess. This enables the cutting element body and the recess to be formed simultaneously by conventional powder metallurgical techniques. A layer of super-hard material is formed on the cutting end of the body and overlays the recesses formed thereon.

Abstract: Polycrystalline diamond cutter (PDC) designs which substantially improve the penetration rate of fixed cutter drill bits while simultaneously reducing the wear on the bit during drilling operations are disclosed. The designs are based upon the observation that: 1) the wear pattern of a PDC is roughly a conic section and is parallel to bit rotation, and 2) the cutting surface is perpendicular to the rotation of the bit. The inventive PDC designs provide cutting action both perpendicular and parallel to the direction of bit rotation.

Abstract: A cutting element for use in drilling subterranean formations. The cutting element includes a superabrasive table between about 0.070 inch and 0.150 inch thickness, mounted to a supporting substrate. The superabrasive table includes a two-dimensional cutting face having a cutting edge along at least a portion of its periphery, and a rake land extending forwardly and inwardly from the cutting edge at an angle of between about 10.degree. and 80.degree. to the longitudinal axis of the cutting element for a width, measured along the surface of the rake land, of not less than about 0.050 inch. The interface between the superabrasive volume and the substrate, taken to the rear of the cutting edge, is located no less than about 0.015 inch to the rear of the cutting edge.

Abstract: A cutting element is provided for use with drill used in the drilling and boring through subterranean formations. This new cutter has improved wear characteristics while maximizing the manufacturability and cost effectiveness of the cutter. This invention accomplishes these objectives by incorporating a single chamfer of increased size. This chamfer is introduced on the periphery of the abrasive cutting face of the cutter. This chamfer has been found to reduce the tensile stress within the cutter, which tensile stress is primarily responsible for spalling and delamination of the abrasive layer of the cutter.

Abstract: A composite body cutting instrument formed of a polycrystalline diamond layer sintered to a carbide substrate with a carbide/diamond transition layer. The transition layer is made by creating carbide projections perpendicular to the plane of the carbide substrate face in a random or nonlinear orientation. The transition layer manipulates residual stress caused by both thermal expansion and compressibility differences between the two materials and thus increases attachment strength between the diamond and carbide substrate by adjusting the pattern, density, height and width of the projections.

Abstract: A manufacturing method and a drill bit composite insert for performing mechanical actions that require high wear and impact resistance are provided. The composite insert has improved interface strength and improved residual stress distribution. These improved features are achieved by chemically and mechanically attaching the layer of abrasion and corrosion resistant polycrystalline material to the substrate that ordinarily is tungsten carbide. The chemical bond is formed during high pressure and high temperature sintering. Mechanically, the abrasion and corrosion resistant layer is attached to the substrate by means of irregularities on the substrate's top surface. These irregularities are designed to distribute stress and minimize the number of features that would lead to crack formation and subsequent failure of the insert.

Abstract: An earth-boring bit has a bit body. At least one cantilevered bearing shaft depends inwardly and downwardly from the bit body and a cutter is mounted for rotation on the bearing shaft. The cutter includes a plurality of cutting elements, at least one of which has a generally cylindrical element body of hard metal. A pair of flanks extend from the body and converge to define a crest. The crest defines at least one sharp cutting edge at its intersection with one of the flanks.

Abstract: An earth-boring bit has a bit body and at least one cantilevered bearing shaft depending inwardly and downwardly from the bit body. A cutter is mounted for rotation on the bearing shaft and includes a plurality of cutting elements. At least one of the cutting elements has a generally cylindrical body formed of hard metal with a convex cutting end. A plurality of substantially linear, parallel lands are formed on the cutting end of the body. The lands have arcuate top surfaces and define grooves between the land having arcuate bottom surfaces. A layer of super-hard material is formed on the cutting end of the body and engages the lands and grooves formed thereon.

Abstract: A cutting element for use in drilling subterranean formations. The cutting element includes a superabrasive table between about 0.070 inch and 0.150 inch thickness, mounted to a supporting substrate. The superabrasive table includes a two-dimensional cutting face having a cutting edge along at least a portion of its periphery, and a rake land extending forwardly and inwardly from the cutting edge at an angle of between about 10.degree. and 80.degree. to the longitudinal axis of the cutting element for a width, measured along the surface of the rake land, of not less than about 0.050 inch. The interface between the superabrasive volume and the substrate, taken to the rear of the cutting edge, is located no less than about 0.015 inch to the rear of the cutting edge.

Abstract: In an improved single piece earth boring bit of the type having a body including a solid bit face on one end and a shank on the opposite end for connection in a drill string, an improved cutting structure having diamond filled compacts used as a wear resistant inserts. The improved compacts have hard metal jackets and integrally formed diamond cores. The improved compacts are advantageously used as wear resistant inserts in the gage and heel rows of the bit.

Abstract: In an improved earth boring bit of the type having one or more rotable cones secured to bearing shafts, an improved cutting structure having diamond filled compacts used as a wear resistant inserts. The improved compacts have hard metal jackets and integrally formed diamond cores. The improved compacts are advantageously used as gage and heel row compacts when inserted in mating recesses provided on the exteriors of the rotatable cones.

Abstract: A method is shown for manufacturing a diamond filled compact of the type used as a cutting insert which is received in a cutting insert pocket in a drill bit. A hard metal jacket is provided having an open end and an open interior. The open interior is substantially filled with diamond. The diamond filled jacket is subjected to a temperature and a pressure sufficient to sinter the diamond and integrally form a diamond core within the hard metal jacket. The outer dimensions of the hard metal jacket are then reduced to a size selected to conform to a cutting insert pocket provided on the face of a drill bit.

Abstract: In an improved single piece earth boring bit of the type having a body including a solid bit face on one end and a shank on the opposite end for connection in a drill string, an improved cutting structure having diamond filled compacts used as a wear resistant inserts. The improved compacts have hard metal jackets and integrally formed diamond cores. The improved compacts are advantageously used as wear resistant inserts in the gage and heel rows of the bit.

Abstract: A method is shown for forming a diamond impregnated carbide containing dispersed diamond crystals, the crystals being formed via in-situ conversion of graphite to diamond. Graphite particles are blended with tungsten carbide power and a binder containing elemental powders known to be diamond catalyst. After blending, the powder is pressed into a green body of a desired shaped and sintered. After sintering, the body is loaded into a high temperature and pressure apparatus and exposed to conditions sufficient to convert the graphite to diamond.

Abstract: In an improved earth boring bit of the type having one or more rotable cones secured to bearing shafts, an improved cutting structure having diamond filled compacts used as a wear resistant inserts. The improved compacts have hard metal jackets and integrally formed diamond cores. The improved compacts are advantageously used as gage and heel row compacts when inserted in mating recesses provided on the exteriors of the rotatable cones.