A cutter for a well construction tool has a cutting structure affixed to a substrate, which defines a monotonically decreasing diameter with respect to an axial distance from an interface between the cutting structure and the substrate. A shear surface formed in the cutting structure intersects a surface of the cutting structure between the interface and an apex of the cutting structure, and defines a smaller angle with respect to a reference than the cutting structure proximate the interface and a larger angle with respect to the reference than the cutting structure proximate the apex. The apex is rotationally symmetric about a centerline of the cutting structure in all rotational directions, and a radius of curvature of the apex is at most 75 percent of a diameter of the substrate. A well construction tool includes a tool body with at least one such cutter attached to the tool body.

A super hard polycrystalline construction is disclosed as comprising a body of super hard material bonded to a substrate. The body of super hard material comprises an outer peripheral region formed of interbonded grains of super hard material extending peripherally around one or more inner regions, the outer peripheral region having a radial thickness proportional to the square of the ratio of the fracture toughness of the material forming said outer peripheral region to the transverse rupture strength of the material forming said outer peripheral region (K.sub.IC/TRS).sup.2 where TRS is the transverse rupture strength and K.sub.IC is the fracture toughness.

A cutter element for a drill bit includes a base portion having a central axis, a first end, a second end, and a radially outer surface extending axially from the first end to the second end. In addition, the cutter element includes a cutting layer fixably mounted to the first end of the base portion. The cutting layer includes a cutting face distal the base portion and a radially outer surface extending axially from the cutting face to the radially outer surface of the base portion. The cutting face includes a planar central region centered relative to the central axis and disposed in a plane oriented perpendicular to the central axis. Further, the cutting face includes a plurality of circumferentially-spaced cutting regions disposed about the planar central region. Still further, the cutting face includes a plurality of circumferentially-spaced relief regions disposed about the planar central region. The plurality of cutting regions and the plurality of relief regions are circumferentially arranged in an alternating manner such that one relief region is circumferentially disposed between two circumferentially adjacent cutting regions of the plurality of cutting regions. Each relief region is defined by a first edge at an intersection of the relief region and one circumferentially adjacent cutting region and a second edge at an intersection of the relief region and another circumferentially adjacent cutting region. The first edge and the second edge of each relief region are angularly spaced apart about the central axis by an angle α that ranges from 45° to 75°.

The disclosure relates to a multiple ridge diamond compact for a drill bit, comprising a hard alloy substrate (cemented carbide substrate) (102) and a diamond composite layer (101), wherein an end surface of the diamond composite layer is provided with at least two ridges angled relative to each other, and converging ends of two adjacent ridges extend to an edge of the diamond composite layer (101) so as to form a concave cutting edge portion on the edge. The plurality of ridges angled relative to each other are set as a cutting surface group to simultaneously cut a formation, the formation is first pre-crushed by means of the ridges angled relative to each other, the ridges first enter the formation from sharp surfaces (the converging ends of the ridges), a crushing pit in the direction of the ridges is further enlarged, and then the formation is further extruded and crushed by inclined surfaces on two sides of the group of ridges, such that the cutting surfaces thereof have a plowing effect, thus improving the crushing and drilling performance of the diamond compact, reducing the drilling cutting resistance, and further increasing the mechanical drilling speed (rate of penetration) of the diamond drill bit.

A cutter element for an earth-boring tool, comprising a polycrystalline diamond (PCD) volume joined at an interface boundary to a cemented carbide substrate. The PCD volume includes a rake face opposite the interface boundary, an edge of the rake face being suitable as a cutting edge of the cutter element. The PCD volume comprises a plurality of strata directly joined to each other at inter-strata boundaries, in which each of a first plurality of the strata comprises PCD material having a first diamond content; each of a second plurality of the strata comprises PCD material having a second diamond content; the second diamond content being greater than the first diamond content; and the strata of the first and second pluralities disposed in an alternating arrangement with respect to each other. The strata are configured and arranged such that a radial line through the edge and a centroid of the interface boundary intersects, within 1,000 microns from the edge, each of the inter-strata boundaries, and the respective tangent plane to each inter-strata boundary at the respective intersection is disposed relative to the radial line at no less than a minimum angle of 30°.

A cutting element includes a body, a non-planar cutting face formed on a first end of the body, and an edge formed around a perimeter of the cutting face. The cutting face includes a central raised portion, and the edge has an edge angle defined between the cutting face and a side surface of the body. The edge angle varies around the perimeter of the cutting face and includes an acute edge angle defined by a portion of the cutting face extending downwardly from the edge to a depth from the cutting angle. The portion of the edge defining the acute edge angle may be directly adjacent: a side surface of the cutting element; a bevel of the cutting element; or a flat region at the perimeter of the cutting element or bevel.

Embodiments of the invention relate to polycrystalline diamond compacts (“PDCs”) including a polycrystalline diamond (“PCD”) table having a structure for enhancing at least one of abrasion resistance, thermal stability, or impact resistance. In an embodiment, a PDC includes a PCD table. The PCD table includes a lower region including a plurality of diamond grains exhibiting a lower average grain size and at least an upper region adjacent to the lower region and including a plurality of diamond grains exhibiting an upper average grain size. The lower average grain size may be at least two times greater than that of the upper average grain size. The PDC includes a substrate having an interfacial surface that is bonded to the lower region of the PCD table. Other embodiments are directed methods of forming PDCs, and various applications for such PDCs in rotary drill bits, bearing apparatuses, and wire-drawing dies.

Embodiments of the present invention provides cutting elements for use on rotary drill bits for drilling subterranean formations. More specifically, the present disclosure relates to cutting elements having a shaped upper surface including at least one spoke for cutting and/or failing subterranean formations during drilling. The present disclosure also relates to drill bits incorporating one or more of such cutting elements.

The present invention provides non-planar cutting tooth and a diamond drill bit. The non-planar cutting tooth and the diamond drill bit have great ability of impact resistance and balling resistance. According to the features of drilled formation, cutting teeth are arranged on the drill bit with different mode, which can improve the mechanical speed and footage of the drill bit.

A cutting element is provided having a substrate and an ultra hard material cutting layer over the substrate. The cutting layer includes a surface portion for making contact with a material to be cut by the cutting element. The surface portion in cross-section has a curvature that has a varying radius of curvature. A bit incorporating such a cutting element is also provided.