A polycrystalline diamond compact including a polycrystalline diamond layer and a cemented carbide substrate. The polycrystalline diamond layer is in the form of a cylinder including an upper surface, a bottom surface, and a side wall connecting the upper surface and the bottom surface. The cemented carbide substrate is bonded to the bottom surface of the polycrystalline diamond layer. The upper surface includes a center part and an edge part. The edge part includes a plurality of radially distributed cutting edges and cutting removal grooves. The plurality of cutting edges and cutting removal grooves are alternately distributed on the upper surface. One end of each of the plurality of cutting edges and cutting removal grooves extends to communicate with the center part, and the other end of each of the plurality of cutting edges and cutting removal grooves extends to communicate with the side wall.

A cutting table comprises a polycrystalline hard material and at least one rhenium-containing structure within the polycrystalline hard material and comprising greater than or equal to about 10 weight percent rhenium. A cutting element, an earth-boring tool, and method of forming a cutting element are also described.

A method for making a polycrystalline diamond compact. The method includes: 1) preparing a workblank of a polycrystalline diamond compact; and 2) thermally- or cold-etching the curved surface of the workblank of the polycrystalline diamond compact using laser. The thermally- or cold-etching the curved surface of the workblank of the polycrystalline diamond compact includes: employing a laser generator to produce a laser beam, expanding the laser beam, focusing the laser beam, to yield an energy concentration area on the surface of the workblank of the polycrystalline diamond compact, and etching the curved surface using the energy concentration area.

A cutter for use with a drill bit includes: a substrate for mounting in a pocket of the drill bit and made from a cermet material; and a head made from a superhard material, mounted to the substrate, and having a chisel or frusto-cone inclined relative to a longitudinal axis of the cutter by an attack angle ranging between fifteen and sixty degrees.

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.

A cutting element for an earth-boring tool includes a substrate and a polycrystalline, superabrasive material secured to an end of the substrate. The polycrystalline, superabrasive material includes a first transition surface extending from an outer peripheral edge of the polycrystalline, superabrasive material and in a first direction oblique to a center longitudinal axis of the substrate and a curved, stress-reduction feature located on at least the first transition surface. Additionally, the stress-reduction feature may include an undulating edge formed in at least the first transition surface and a waveform extending from the undulating edge formed in at least the first transition surface toward the center longitudinal axis of the cutting element.

A cutting element for an earth-boring tool includes a substrate and a polycrystalline, superabrasive material secured to an end of the substrate. The polycrystalline, superabrasive material includes a curved, stress-reduction feature located at least on the first transition surface. The cutting element includes at least one recess defined in the curved, stress-reduction feature of the polycrystalline, superabrasive material. The at least one recess includes sidewalls intersecting with a front surface of the stress-reduction feature of the polycrystalline, superabrasive material and extending to a base wall within the polycrystalline, superabrasive material. The curved, stress-reduction feature includes an undulating edge formed proximate a peripheral edge of the polycrystalline, superabrasive material and a waveform extending from the undulating edge toward the center longitudinal axis of the cutting element.

A cutting element for an earth-boring tool includes a substrate and a polycrystalline, superabrasive material secured to an end of the substrate. The polycrystalline, superabrasive material includes a curved, stress-reduction feature located at least on the first transition surface. The cutting element includes at least one recess defined in the curved, stress-reduction feature of the polycrystalline, superabrasive material. The at least one recess includes sidewalls intersecting with a front surface of the stress-reduction feature of the polycrystalline, superabrasive material and extending to a base wall within the polycrystalline, superabrasive material. The curved, stress-reduction feature includes an undulating edge formed proximate a peripheral edge of the polycrystalline, superabrasive material and a waveform extending from the undulating edge toward the center longitudinal axis of the cutting element.

A cutting element for an earth-boring tool includes a substrate and a polycrystalline, superabrasive material secured to an end of the substrate. The polycrystalline, superabrasive material includes a first transition surface extending from an outer peripheral edge of the polycrystalline, superabrasive material and in a first direction oblique to a center longitudinal axis of the substrate and a curved, stress-reduction feature located on at least the first transition surface. Additionally, the stress-reduction feature may include an undulating edge formed in at least the first transition surface and a waveform extending from the undulating edge formed in at least the first transition surface toward the center longitudinal axis of the cutting element.

A gouging cutter or shock stud for mounting in a drill bit includes: a substrate being cylindrical for at least a portion thereof; and a cap or head made from a superhard material, mounted to the substrate at an interface, having a working face formed in an end thereof opposite to the interface, and having a round periphery connecting the interface and the substrate. The working face has a central tip elevated at a height above a maximum height of the periphery. The working face has a plurality of plows and a plurality of ribs arranged therearound in an alternating fashion. The plows and the ribs each extend from the periphery of the cap inward and upward to the tip. The plows and ribs each have a pair of sides and an apical edge. The plows have a different shape than a shape of the ribs.