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.

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.

Cutting elements for earth-boring tools may include a substrate and a polycrystalline superabrasive material secured to the substrate. The polycrystalline superabrasive material may include a first region including catalyst material in interstitial spaces among interbonded grains of the polycrystalline superabrasive material. A second region at least substantially free of catalyst material in the interstitial spaces among the interbonded grains of the polycrystalline superabrasive material may be located adjacent to the first region. An undulating boundary defined between the first region and the second region may include bumps and dimples formed by crests and troughs of a repeating pattern of concentric circles encircling a longitudinal axis of the cutting element.

Embodiments relate to a polycrystalline diamond compact (PDC) including a polycrystalline diamond (PCD) table bonded to a cemented carbide substrate including tungsten carbide grains having a fine average grain size to provide one or more of enhanced wear resistance, corrosion resistance, or erosion resistance, and a PDC with enhanced impact resistance. In an embodiment, a PDC includes a cemented carbide substrate having a cobalt-containing cementing constituent cementing tungsten carbide grains together exhibiting an average grain size of about 1.5 m or less. The substrate includes an interfacial surface and a depletion zone depleted of the cementing constituent that extends inwardly from the interfacial surface to a depth of, for example, about 30 m to about 60 m. The PDC includes a PCD table bonded to the interfacial surface of the substrate. The PCD table includes diamond grains bonded together exhibiting an average grain size of about 40 m or less.

Embodiments relate to polycrystalline diamond compacts (PDCs), methods of fabricating PDCs, and applications for such PDCs. In an embodiment, a method includes providing an at least partially leached polycrystalline diamond (PCD) body. A residual amount of acid may remain in and/or on the at least partially leached PCD body. The method further includes removing and/or neutralizing at least some of the residual amount of acid from the at least partially leached PCD body and/or a substrate to which the at least partially leached PCD body is attached.

A method for producing a machining segment from a first powdered matrix material and first hard material particles arranged according to a defined first particle pattern, includes: applying a powdered supporting material as a supporting layer with a melting temperature higher than the first matrix material, arranging the first hard material particles according to the defined first particle pattern in the supporting material with a depth of penetration, applying a first layer of the first matrix material to the first hard material particles and the supporting material and fusing the first layer by a powder bed fusion method, and performing a sequence of a plurality of steps N times, N1, wherein, in a first step of the sequence, a layer of the first matrix material is applied to the layer structure, and in a second step of the sequence, the layer of the first matrix material is fused by the powder bed fusion method and connected to the layer structure.

Embodiments relate to polycrystalline diamond compacts (PDCs) including a polycrystalline diamond (PCD) table having a diamond grain size distribution selected for improving performance and/or leachability. In an embodiment, a PDC includes a PCD table bonded to a substrate. The PCD table includes a plurality of diamond grains exhibiting diamond-to-diamond bonding therebetween. The plurality of diamond grains includes a first amount being about 5 weight % to about 65 weight % of the plurality of diamond grains and a second amount being about 18 weight % to about 95 weight % of the plurality of diamond grains. The first amount exhibits a first average grain size of about 0.5 m to about 30 m. The second amount exhibits a second average grain size that is greater than the first average grain size and is about 10 m to about 65 m. Other embodiments are directed to methods of forming PDCs, and various applications for such PDCs in rotary drill bits, bearing apparatuses, and wire-drawing dies.

An abrasive segment can include an inner segment portion, an outer segment portion, and a central segment portion connected thereto. The inner segment portion can include an inner circumferential wall and an outer circumferential wall. Leading and trailing radial sidewalls can extend between the inner circumferential wall and the outer circumferential wall opposite each other. The outer segment portion can include an inner circumferential wall and an outer circumferential wall. Leading and trailing radial sidewalls can extend between the inner circumferential wall and the outer circumferential wall opposite each other. The central segment portion can include a leading radial sidewall and a trailing radial sidewall. The leading radial sidewall of the central segment portion can establish an acute angle, , with respect to the outer circumferential wall of the inner segment portion and an obtuse angle, , with respect the inner circumferential wall of the outer segment portion.

A cutting element may be formed by sintering together a plurality of metal carbide grains and a metal binder to form a substrate, forming at least one binder gradient in the substrate, and mounting an abrasive layer to the substrate at an interface. The concentration of metal binder material may decrease along at least one direction to form the at least one binder gradient.

Embodiments relate to polycrystalline diamond compacts (PDCs) including a polycrystalline diamond (PCD) table having a diamond grain size distribution selected for improving leachability. In an embodiment, a PDC includes a PCD table bonded to a substrate. The PCD table includes diamond grains exhibiting diamond-to-diamond bonding therebetween. The diamond grains includes a first amount being about 30 to about 65 volume % of the diamond grains and a second amount being about 18 to about 65 volume % of the diamond grains. The first amount exhibits a first average grain size of about 8 m to about 22 m. The second amount exhibits a second average grain size that is greater than the first average grain size and is about 15 m to about 50 m. Other embodiments are directed methods of forming PDCs, and various applications for such PDCs in rotary drill bits, bearing apparatuses, and wire-drawing dies.