Abstract: Methods of forming a polycrystalline element comprise disposing a first plurality of particles comprising a superabrasive material, a second plurality of particles comprising the superabrasive material, and a catalyst material in a mold. The first and second pluralities of particles are sintered to form a polycrystalline table comprising a first region having a first permeability and a second region having a second, greater permeability. Catalyst material is at least substantially removed from the polycrystalline table. The polycrystalline table is attached to an end of a substrate, the at least a second region being interposed between the first region and the substrate. Polycrystalline elements comprise a substrate. A polycrystalline table comprising a superabrasive material and having a first region exhibiting a first permeability and at least a second region exhibiting a second, greater permeability is attached to an end of the substrate.

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 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: Cutting elements for earth-boring tools may include a polycrystalline table attached to a portion of a first substrate on which the polycrystalline table was formed. The portion of the first substrate may exhibit a thickness less than a thickness of the first substrate before a remainder of the first substrate was removed to form the portion of the first substrate. Another substrate may be attached to the portion of the first substrate, the portion of the first substrate being interposed between the polycrystalline table and the other substrate. Earth-boring tools may include such cutting elements secured to bodies of the earth-boring tools. Bearings for earth-boring tools may include a polycrystalline table attached to a portion of a first substrate on which the polycrystalline table was formed, the polycrystalline table defining a contact surface. Another substrate may be attached to the portion of the first substrate.

Abstract: Earth-boring tools may comprise a body comprising a first region and a second region. The first region may be located closer to a rotational axis of the body than the second region. A first cutting element may be located in the first region and a second cutting element may be located in the second region. A first polycrystalline table of the first cutting element may be substantially free of catalyst material to a first depth and a second polycrystalline table of the second cutting element may be substantially free of catalyst material to a second, greater depth.

Abstract: A cutting element for an earth-boring tool includes a substrate and a volume of superabrasive material disposed over the substrate. The volume of superabrasive material may include a cutting face and a longitudinal extension extending longitudinally along a lateral side surface of the substrate. An outer peripheral surface of the longitudinal extension may define at least a portion of a lateral side surface of the cutting element and may have a surface roughness less than about 10 ?in. (about 0.254 ?m) RMS. Earth-boring tools may include such cutting elements. Methods may include forming such cutting elements.

Abstract: Rotary drag bits comprise a body comprising a face at a leading end of the body. An abrasive-impregnated cutting structure is located at the face of the body. The abrasive-impregnated cutting structure comprises abrasive particles dispersed within a matrix material. The abrasive-impregnated cutting structure exhibits an anisotropic wear resistance. The wear resistance varies at least substantially continuously within the abrasive-impregnated cutting structure.

Abstract: Polycrystalline compacts include a hard polycrystalline material comprising first and second regions. The first region comprises a first plurality of grains of hard material having a first average grain size, and a second plurality of grains of hard material having a second average grain size smaller than the first average grain size. The first region comprises catalyst material disposed in interstitial spaces between inter-bonded grains of hard material. Such interstitial spaces between grains of the hard material in the second region are at least substantially free of catalyst material. In some embodiments, the first region comprises a plurality of nanograins of the hard material. Cutting elements and earth-boring tools include such polycrystalline compacts.

Abstract: Methods for forming cutting elements, methods for forming polycrystalline compacts, and related polycrystalline compacts are disclosed. Grains of a hard material are subjected to a high-pressure, high-temperature process to form a polycrystalline compact. Inclusion of at least one relatively quick spike in system pressure or temperature during an otherwise plateaued temperature or pressure stage accommodates formation of inter-granular bonds between the grains. The brevity of the peak stage may avoid undesirable grain growth. Embodiments of the methods may also include at least one of oscillating at least one system condition (e.g., pressure, temperature) and subjecting the grains to ultrasonic or mechanical vibrations.

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: 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: Cutting elements for earth-boring tools may generate a shear lip at a wear scar thereon during cutting. A diamond table may exhibit a relatively high wear resistance, and an edge of the diamond table may be chamfered, the combination of which may result in the formation of a shear lip. Cutting elements may comprise multi-layer diamond tables that result in the formation of a shear lip during cutting. Earth-boring tools include such cutting elements. Methods of forming cutting elements may include selectively designing and configuring the cutting elements to form a shear lip. Methods of cutting a formation using an earth-boring tool include cutting the formation with a cutting element on the tool, and generating a shear lip at a wear scar on the cutting element. The cutting element may be configured such that the shear lip comprises diamond material of the cutting element.

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: 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: A method of forming a cutting element for an earth-boring tool includes forming a table of superabrasive material over a substrate in an HTHP environment such that the table of superabrasive material is bonded to the substrate. The table of superabrasive material and the substrate form a cutting element. The method includes removing the cutting element from the HTHP environment, ascertaining predictable residual stresses within the table of superabrasive material, and marking the cutting element with at least one mark. The at least one mark provides indication of a region of the table of superabrasive material having a maximum or minimum residual stress therein. An additional method includes obtaining such a marked cutting element and affixing the cutting element on an earth-boring tool in a preferential orientation as indicated at least partially by the mark.

Abstract: Methods for forming cutting elements, methods for forming polycrystalline compacts, and related polycrystalline compacts are disclosed. Grains of a hard material are subjected to a high-pressure, high-temperature process to form a polycrystalline compact. Inclusion of at least one relatively quick spike in system pressure or temperature during an otherwise plateaued temperature or pressure stage accommodates formation of inter-granular bonds between the grains. The brevity of the peak stage may avoid undesirable grain growth. Embodiments of the methods may also include at least one of oscillating at least one system condition (e.g., pressure, temperature) and subjecting the grains to ultrasonic or mechanical vibrations.

Abstract: A cutting element for an earth-boring tool includes a volume of superabrasive material having a cutting face and a shaped feature on the cutting face. The shaped feature may include at least one of a recess extending into the volume of superabrasive material from the cutting face and a protrusion extending outward from the cutting face. A first portion of the cutting face may have a first surface roughness, and a second portion of the cutting face may have a second surface roughness greater than the first surface roughness of the first portion of the cutting face. The volume of superabrasive material may be disposed on a substrate. Methods of forming cutting elements may include forming one or more shaped features in a cutting face of the cutting elements. Earth-boring tools may include such cutting elements.

Abstract: Polycrystalline compact tables for cutting elements include regions of grains of super hard material. One region of grains (“first grains”) and another region of grains (“second grains”) have different properties, such as different average grain sizes, different super hard material volume densities, or both. The region of first grains and the region of second grains adjoin one another at grain interfaces that may include a curved portion in a vertical cross-section of the table. In some embodiments, discrete regions of the first grains may be vertically disposed between discrete regions of the second grains. As such, the tables have ordered grain regions of different properties that may inhibit delamination and crack propagation through the table when used in conjunction with a cutting element. Methods of forming the tables include forming the regions and subjecting the grains to a high-pressure, high-temperature process to sinter the grains.

Abstract: Methods of forming a polycrystalline table may involve disposing a plurality of particles comprising a superabrasive material, a substrate comprising a hard material, and a catalyst material in a mold. The plurality of particles may be partially sintered in the presence of the catalyst material to form a brown polycrystalline table having a first permeability attached to an end of the substrate. The substrate may be removed from the brown polycrystalline table and catalyst material may be removed from the brown polycrystalline table. The brown polycrystalline table may then be fully sintered to form a polycrystalline table having a reduced, second permeability. Intermediate structures formed during a process of attaching a polycrystalline table to a substrate may include a substantially fully leached brown polycrystalline table. The substantially fully leached brown polycrystalline table may include a plurality of interbonded grains of a superabrasive material.

Abstract: A cutting element for an earth-boring drilling tool comprises a cutting body having a cutting surface thereon, and a sensor coupled with the cutting surface, the sensor configured to determine resistivity of a contacting formation. An earth-boring drilling tool comprises a bit body and an instrumented cutting element coupled with the bit body. The cutting element includes a cutting body having a cutting surface thereon, and at least one sensor located proximate the cutting surface. The at least one sensor is oriented and configured to determine resistivity of a contacting formation. A method of determining resistivity of a subterranean formation during a drilling operation comprises energizing a sensor of an instrumented cutting element of a drill bit, sensing a return signal flowing on or through the subterranean formation through the instrumented cutting element, and determining a resistivity of the subterranean formation based, at least in part, on the return signal.