A polycrystalline compact comprises a plurality of grains of hard material and a plurality of nanoparticles disposed in interstitial spaces between the plurality of grains of hard material. The nanoparticles have cores of a first material and at least one oxide material on the cores. An earth-boring tool comprises such a polycrystalline compact. A method of forming a polycrystalline compact comprises combining a plurality of hard particles with a plurality of nanoparticles to form a mixture and sintering the mixture to form a polycrystalline hard material comprising a plurality of interbonded grains of hard material. A method of forming a cutting element comprises infiltrating interstitial spaces between interbonded grains of hard material in a polycrystalline material with a plurality of nanoparticles.

A substance includes diamond particles having a maximum linear dimension of less than about 1 m and an organic compound attached to surfaces of the diamond particles. The organic compound may include a surfactant or a polymer. A method of forming a substance includes exposing diamond particles to an organic compound, and exposing the diamond particles in the presence of the organic compound to ultrasonic energy. The diamond particles may have a maximum linear dimension of less than about 1 m. A composition includes a liquid, a plurality of diamond nanoparticles dispersed within the liquid, and an organic compound attached to surfaces of the diamond nanoparticles. A method includes mixing a plurality of diamond particles with a solution comprising a liquid solvent and an organic compound, and exposing the mixture including the plurality of diamond nanoparticles and the solution to ultrasonic energy.

A method of making a thermally stable polycrystalline super hard construction having a plurality of interbonded super hard grains and interstitial regions disposed therebetween to form a polycrystalline super hard construction having a first thermally stable region and a second region, the first thermally stable region forming at least part of a working surface of the construction, comprises treating the polycrystalline super hard material with a leaching mixture to remove non-super hard phase material from a number of interstitial regions in the first region. The step of treating comprises masking the polycrystalline super hard construction along at least a portion of the peripheral side surface up to and/or at the working surface to inhibit penetration of the leaching mixture into the super hard construction through a peripheral side surface of the super hard construction. The material preferably is PCD, polycrystalline diamond, and preferably leaching takes place after forming a chamfer.

A polycrystalline superhard construction comprises a body of polycrystalline superhard material, and a substrate of hard material bonded thereto along an interface. The body of polycrystalline superhard material comprises a first region abutting the substrate along the interface and a second region bonded to the first region. The second region defines a rake face, a cutting edge, a chamfer and at least a part of a flank face, the cutting edge being defined by an edge of the flank face joined to the chamfer, the chamfer extending between the cutting edge and the rake face. The height of the chamfer in a plane parallel to the plane through which the longitudinal axis of the polycrystalline superhard construction extends is less than the thickness of the second region. The first region comprises a material having coarser grains than the second region. There is also disclosed a method of making the same.

A super hard polycrystalline construction comprises a body of polycrystalline super hard material comprising a first fraction of super hard grains and a second fraction of super hard grains, the first fraction having a greater average grain size than the super hard grains in the second fraction, the super hard grains in the first and second fraction having a peripheral surface. The super hard grains in the first fraction are bonded along at least a portion of the peripheral surface to at least a portion of a plurality of super hard grains in the second fraction, the super hard grains in the first fraction being spaced from adjacent grains in the first fraction by a distance of between around 50 to around 500 nm.

A superabrasive compact and a method of making the superabrasive compact are disclosed. A superabrasive compact may comprise a superabrasive volume and a substrate. The substrate may be attached to the superabrasive volume via an interface. The superabrasive volume may be formed by a plurality of polycrystalline superabrasive particles. The superabrasive particles may have nano or sub-micron scale surface texture.

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. A resulting polycrystalline compact may include a high density of inter-granularly bonded hard material with a minimized amount of catalyst material, and may provide improved thermal stability, wear resistance, toughness, and behavior during use of a cutting element incorporating the polycrystalline compact.

Embodiments of the invention relate to methods of modeling leaching behavior of a polycrystalline diamond (PCD) material used in leached polycrystalline diamond compacts (PDCs) and methods of monitoring leaching of a PCD material. In an embodiment, a method of modeling leaching behavior is disclosed. A PCD table is provided, which includes a plurality of bonded diamond grains defining a plurality of interstitial regions in which a metallic material is disposed. The PCD table is leached with a leaching agent to at least partially remove the metallic material from the PCD table. A leach depth of the PCD table is determined. A concentration of at least one constituent of the leaching agent is also determined. The leach depth is correlated with the concentration of the at least one metal to generate the model of leaching behavior.

A polycrystalline super hard construction comprises a body of polycrystalline diamond (PCD) material and a plurality of interstitial regions between inter-bonded diamond grains forming the polycrystalline diamond material. The body of PCD material comprises a working surface positioned along an outside portion of the body, and a first region adjacent the working surface, the first region being a thermally stable region. The first region and/or a further region and/or the body of PCD material has/have an average oxygen content of less than around 300 ppm. A method of forming such a construction is also disclosed.

A superabrasive compact and a method of making the superabrasive compact are disclosed. A superabrasive compact may comprise a superabrasive volume and a substrate. The substrate may be attached to the superabrasive volume via an interface. The superabrasive volume may be formed by a plurality of polycrystalline superabrasive particles. The superabrasive particles may have nano or sub-micron scale surface texture.