A superhard polycrystalline construction (30) comprises a first region (34) comprising a body of thermally stable polycrystalline superhard material having an exposed surface forming a working surface (4), and a peripheral side edge (6), a second region (32) forming a substrate to the first region, and a third region (36) at least partially interposed between the first and second regions wherein the third region comprises a material more acid resistant than polycrystalline diamond material having a binder-catalyst phase comprising cobalt, and/or more acid resistant than cemented carbide material.

Grains of superabrasive material may be infiltrated with a molten metal alloy at a relatively low temperature, and the molten metal alloy may be solidified within interstitial spaces between the grains of superabrasive material to form a solid metal alloy having the grains of superabrasive material embedded therein. The solid metal alloy with the grains of superabrasive material embedded therein may be subjected to a high pressure and high temperature process to form a polycrystalline superabrasive material. A polycrystalline superabrasive material also may be formed by depositing material on surfaces of grains of superabrasive material in a chemical vapor infiltration process to form a porous body, which then may be subjected to a high pressure and high temperature process. Polycrystalline compacts and cutting elements including such compacts may be formed using such methods.

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 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.

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.