Abstract: Polycrystalline compacts include a polycrystalline superabrasive material comprising a first plurality of grains of superabrasive material having a first average grain size and a second plurality of grains of superabrasive material having a second average grain size smaller than the first average grain size. The first plurality of grains is dispersed within a substantially continuous matrix of the second plurality of grains. Earth-boring tools may include a body and at least one polycrystalline compact attached thereto. Methods of forming polycrystalline compacts may include coating relatively larger grains of superabrasive material with relatively smaller grains of superabrasive material, forming a green structure comprising the coated grains, and sintering the green structure. Other methods include mixing diamond grains with a catalyst and subjecting the mixture to a pressure greater than about five gigapascals (5.0 GPa) and a temperature greater than about 1,300° C.

Abstract: A method of forming a polycrystalline diamond compact includes forming a polycrystalline diamond material at a temperature and a pressure sufficient to form diamond-to-diamond bonds in the presence of a catalyst; substantially removing the catalyst from a volume of the polycrystalline diamond material from a first surface to a first leach depth; and substantially removing the catalyst from a volume of the polycrystalline diamond material from a second surface to a second, different leach depth. A polycrystalline diamond compact includes a polycrystalline diamond material having a first volume, a second volume, and a boundary between the first volume and the second volume. The first volume includes a catalyst disposed in interstitial spaces between diamond grains. The second volume is substantially free of the catalyst. The boundary's location is selected to control thermal stability and/or impact resistance.

Abstract: An earth-boring tool having at least one cutting element with a multi-friction cutting face provides for the steering of formation cuttings as the cuttings slide across the cutting face. The multi-friction cutting element includes a diamond table bonded to a substrate of superabrasive material. The diamond table has a cutting face formed thereon with a cutting edge extending along a periphery of the cutting face. The cutting face has a first area having an average surface finish roughness less than an average surface finish roughness of a second area of the cutting face, the two areas separated by a boundary having a proximal end proximate a tool crown and a distal end remote from the tool crown.

Abstract: A composite material comprising a plurality of hard particles surrounded by a matrix material comprising a plurality of nanoparticles. Earth boring tools including the composite material and methods of forming the composite material are also disclosed. A polycrystalline material having a catalyst material including nanoparticles in interstitial spaces between inter-bonded crystals of the polycrystalline material and methods of forming the polycrystalline material are also disclosed.

Abstract: Bearings for earth-boring tools may include a first bearing member including a first bearing pad having a first contact surface and a second bearing member including a second bearing pad having a second contact surface in sliding contact with at least a portion of the first contact surface. At least one of the first bearing member and the second bearing member may include a polycrystalline table attached to a portion of a first substrate on which the polycrystalline table was formed. Another substrate may be attached to the portion of the first substrate, the portion of the first substrate interposed between the polycrystalline table and the other substrate.

Abstract: A method of forming a polycrystalline diamond compact includes forming a polycrystalline diamond material at a temperature and a pressure sufficient to form diamond-to-diamond bonds in the presence of a catalyst; substantially removing the catalyst from a volume of the polycrystalline diamond material from a first surface to a first leach depth; and substantially removing the catalyst from a volume of the polycrystalline diamond material from a second surface to a second, different leach depth. A polycrystalline diamond compact includes a polycrystalline diamond material having a first volume, a second volume, and a boundary between the first volume and the second volume. The first volume includes a catalyst disposed in interstitial spaces between diamond grains. The second volume is substantially free of the catalyst. The boundary's location is selected to control thermal stability and/or impact resistance.

Abstract: An earth-boring drilling tool comprises a cutting element. The cutting element comprises a substrate, a diamond table, and at least one sensing element formed from a doped diamond material disposed at least partially within the diamond table. A method for determining an at-bit measurement for an earth-boring drill bit comprises receiving an electrical signal generated within a doped diamond material disposed within a diamond table of a cutting element of the earth-boring drill bit, and correlating the electrical signal with at least one parameter during a drilling operation.

Abstract: A Polycrystalline Diamond Compact (PDC) cutter for a rotary drill bit is provided with an integrated sensor and circuitry for making measurements of a property of a fluid in the borehole and/or an operating condition of the drill bit. A method of manufacture of the PDC cutter and the rotary drill bit is discussed.

Abstract: A method of forming a polycrystalline diamond compact includes forming a polycrystalline diamond material at a temperature and a pressure sufficient to form diamond-to-diamond bonds in the presence of a catalyst; substantially removing the catalyst from a volume of the polycrystalline diamond material from a first surface to a first leach depth; and substantially removing the catalyst from a volume of the polycrystalline diamond material from a second surface to a second, different leach depth. A polycrystalline diamond compact includes a polycrystalline diamond material having a first volume, a second volume, and a boundary between the first volume and the second volume. The first volume includes a catalyst disposed in interstitial spaces between diamond grains. The second volume is substantially free of the catalyst. The boundary's location is selected to control thermal stability and/or impact resistance.

Abstract: Methods of forming polycrystalline diamond compacts include employing field assisted sintering techniques with high temperature and high pressure sintering techniques. For example, a particle mixture that includes diamond particles may be sintered by subjecting the particle mixture to a high temperature and high pressure sintering cycle, and pulsing direct electrical current through the particle mixture during at least a portion of the high temperature and high pressure sintering cycle. The polycrystalline diamond compacts may be used to form cutting elements for earth-boring tools. Sintering systems are configured to perform such sintering processes.

Abstract: A Polycrystalline Diamond Compact (PDC) cutter for a rotary drill bit is provided with an integrated sensor and circuitry for making measurements of a property of a fluid in the borehole and/or an operating condition of the drill bit. A method of manufacture of the PDC cutter and the rotary drill bit is discussed.

Abstract: Coated diamond particles have solid diamond cores and at least one graphene layer. Methods of forming coated diamond particles include coating diamond particles with a charged species and coating the diamond particles with a graphene layer. A composition includes a substance and a plurality of coated diamond particles dispersed within the substance. An intermediate structure includes a hard polycrystalline material comprising a first plurality of diamond particles and a second plurality of diamond particles. The first plurality of diamond particles and the second plurality of diamond particles are interspersed. A method of forming a polycrystalline compact includes catalyzing the formation of inter-granular bonds between adjacent particles of a plurality of diamond particles having at least one graphene layer.

Abstract: A hardfacing material includes a metal matrix material and particles of crushed polycrystalline diamond material embedded within the metal matrix material. An earth-boring tool includes a body comprising particles of fragmented polycrystalline diamond material embedded within a metal matrix material. The particles of fragmented polycrystalline diamond material include a plurality of inter-bonded diamond grains. A method includes forming an earth-boring tool including a metal matrix material and particles of crushed polycrystalline diamond material.

Abstract: Cutting elements include a volume of superabrasive material. The volume of superabrasive material comprises a front-cutting surface, an end-cutting surface, a cutting edge, and lateral side surfaces extending between and intersecting each of the front-cutting surface and the end-cutting surface. An earth-boring tool may comprise a bit body and at least one cutting element attached to the bit body. Methods of forming cutting elements comprise forming a volume of superabrasive material comprising forming a front-cutting surface, an end-cutting surface, a cutting edge, and lateral side surfaces extending between and intersecting each of the front-cutting surface and the end-cutting surface. Methods of forming earth-boring tools comprise forming a cutting element and attaching the cutting element to an earth-boring tool.

Abstract: A method of forming an instrumented cutting element comprises forming a free-standing sintered diamond table having at least one chamber in the free-standing sintered diamond table, providing a doped diamond material within the at least one chamber, and attaching a substrate to the free-standing sintered diamond table to form an instrumented cutting element. The instrumented cutting element includes the doped diamond material disposed within the sintered diamond table on the substrate. A method of forming an earth-boring tool comprises attaching at least one instrumented cutting element to a body of an earth-boring tool. The at least one instrumented cutting element has a diamond table bonded to a substrate. The diamond table has at least one sensing element disposed at least partially within the diamond table. The at least one sensing element comprises a doped diamond material.

Abstract: Cutting elements for use with earth-boring tools include a cutting table having at least two sections where a boundary between the at least two sections is at least partially defined by a discontinuity formed in the cutting table. Earth-boring tools including a tool body and a plurality of cutting elements carried by the tool body. The cutting elements include a cutting table secured to a substrate. The cutting table includes a plurality of adjacent sections, each having a discrete cutting edge where at least one section is configured to be selectively detached from the substrate in order to substantially expose a cutting edge of an adjacent section. Methods for fabricating cutting elements for use with an earth-boring tool including forming a cutting table comprising a plurality of adjacent sections.

Abstract: A cutting element for an earth-boring tool includes a substrate and volume of superabrasive material positioned on the substrate. The volume of superabrasive material includes a cutting face having at least one recess extending into the volume of superabrasive material and/or at least one protrusion extending outward from the volume of superabrasive material. The volume of superabrasive material includes a first chamfer surface having a peripheral edge and a radially innermost edge. The peripheral edge of the first chamfer surface is located proximate a cutting edge of the volume of superabrasive material. A radial width of the first chamfer surface is between about 0.002 inch and about 0.045 inch. The volume of superabrasive material also includes a second chamfer surface having a peripheral edge and a radially innermost edge. The peripheral edge of the second chamfer surface is located adjacent the radially innermost edge of the first chamfer surface.

Abstract: Polycrystalline compacts include a polycrystalline superabrasive material comprising a first plurality of grains of superabrasive material having a first average grain size and a second plurality of grains of superabrasive material having a second average grain size smaller than the first average grain size. The first plurality of grains is dispersed within a substantially continuous matrix of the second plurality of grains. Earth-boring tools may include a body and at least one polycrystalline compact attached thereto. Methods of forming polycrystalline compacts may include coating relatively larger grains of superabrasive material with relatively smaller grains of superabrasive material, forming a green structure comprising the coated grains, and sintering the green structure. Other methods include mixing diamond grains with a catalyst and subjecting the mixture to a pressure greater than about five gigapascals (5.0 GPa) and a temperature greater than about 1,300° C.

Abstract: Methods for forming cutting elements comprising polycrystalline materials, methods for forming polycrystalline compacts for cutting elements of a drilling tool, methods for forming polycrystalline diamond compacts, and resulting polycrystalline compacts and cutting elements are disclosed. Grains of a hard material are introduced to a press and subjected to a high-pressure, high-temperature (HPHT) process to sinter the grains. The system conditions (i.e., temperature and pressure) are then adjusted past a phase or state change point, after which, at least one of the system conditions is held during an anneal stage before the system conditions are adjusted to final levels. The resulting compacts and cutting elements may therefore include inter-granularly bonded hard material grains with a more stable microstructure (e.g., less stressed microstructure) than a polycrystalline compact and cutting element formed without an anneal stage during the HPHT process.

Abstract: Cutting elements for earth-boring tools include one or more recesses and/or one or more protrusions in a cutting face of a volume of superabrasive material. The superabrasive material may be disposed on a substrate. The cutting face may be non-planar. The recesses and/or protrusions may include one or more linear segments. The recesses and/or protrusions may comprise discrete features that are laterally isolated from one another. The recesses and/or protrusions may have a helical configuration. The volume of superabrasive material may comprise a plurality of thin layers, at least two of which may differ in at least one characteristic. Methods of forming cutting elements include the formation of such recesses and/or protrusions in and/or on a cutting face of a volume of superabrasive material. Earth-boring tools include such cutting elements, and methods of forming earth-boring tools include attaching such a cutting element to a tool body.