The invention relates to a PCD composite compact element comprising a PCD structure integrally bonded at an interface to a cemented carbide substrate; the PCD structure comprising coherently bonded diamond grains having a mean size no greater than 15 microns; the cemented carbide substrate comprising carbide particles dispersed in a metallic binder, the carbide particles comprising a carbide compound of a metal; wherein the ratio of the amount of metallic binder to the amount of the metal at points in the substrate deviates from a mean value by at most 20 percent of the mean value. The invention further relates to a method for making a PDC compact element comprising a PCD structure integrally bonded to a substrate formed of cemented carbide; the method including introducing a source of excess carbon to the substrate at a bonding surface of the substrate to form a carburised substrate; contacting an aggregated mass of diamond grains with the carburised substrate; and sintering the diamond grains in the presence of a solvent/catalyst material for diamond; wherein the mean size of the diamond grains in the aggregated mass is no greater than 30 microns.

A method for making a polycrystalline diamond construction is disclosed, which includes the steps of treating a polycrystalline diamond body having a plurality of bonded together diamond crystals and a solvent catalyst material to remove the solvent catalyst material therefrom, wherein the solvent catalyst material is disposed within interstitial regions between the bonded together diamond crystals, replacing the removed solvent catalyst material with a replacement material, and treating the body having the replacement material to remove substantially all of the replacement material from a first region of the body extending a depth from a body surface, and allowing the remaining amount of the replacement material to reside in a second region of the body that is remote from the surface.

A polycrystalline diamond construction may be made by subjecting diamond grains to a high pressure/high temperature condition in the presence of a catalyst material to form a polycrystalline diamond material comprising a matrix phase of bonded together diamond grains and interstitial regions disposed between the diamond grains including the catalyst material, treating the polycrystalline diamond material to remove the catalyst material therefrom to form a diamond body that is substantially free of the catalyst material, and attaching a substrate to the diamond body with a layer of eruption minimization material having a thickness from about 2 m to 8 m on at least one attachment interface surface of the substrate and/or diamond body.

Polycrystalline diamond bodies having an annular region of diamond grains and a core region of diamond grains and methods of making the same are disclosed. In one embodiment, a polycrystalline diamond body includes an annular region of inter-bonded diamond grains having a first characteristic property and a core region of inter-bonded diamond grains bonded to the annular region and having a second characteristic property that differs from the first characteristic property. The annular region decreases in thickness from a perimeter surface of the polycrystalline diamond body towards a centerline axis.

A cutting element may include a substrate; and an ultrahard layer on the substrate, the substrate and the ultrahard layer defining a non-planar working surface of the cutting element such that the ultrahard layer forms a cutting portion and the substrate is at least laterally adjacent to the ultrahard layer. Another cutting element includes a pointed region having a side surface extending from the pointed region outer perimeter to a peak. An ultrahard material body forms a portion of the pointed region including the peak, and a base region extends a depth from the pointed region outer perimeter. The ultrahard material body has a height to width aspect ratio with the height and width measured between two points of the body having the greatest distance apart along a dimension parallel with a longitudinal axis (i.e., height) along a dimension perpendicular to the longitudinal axis (i.e., width).

A carburized steel component, comprising a steel base including, by weight percent, from 0.08% to 0.35% carbon, 0.5% to 1.3% manganese, 0% to 0.35% silicon, 0.2% to 2.0% chromium, 0% to 4% nickel, 0% to 0.50% molybdenum, 0% to 0.06% niobium, and a remaining weight percent of iron, and a carburized layer of above 0.35% by weight carbon from a surface of the carburized layer to a carburized layer depth, wherein the carburized layer depth is from 0.5 mm to 3.0 mm, wherein the carburized layer comprises a microstructure including martensite, retained austenite, carbide, and less than 2% by volume non-martensitic transformation products (NMTP), and wherein the carburized layer includes a prior austenite average grain size of 3.0-8.0 microns from the surface to a depth of at least 0.2 mm.

Polycrystalline diamond compacts (PDCs) include a polycrystalline diamond (PCD) table in which cobalt is alloyed with phosphorous to improve the thermal stability of the PCD table. For example, a PDC includes a substrate and a PCD table including an upper surface spaced from an interfacial surface that is bonded to the substrate. The PCD table includes a plurality of diamond grains defining a plurality of interstitial regions. The PCD table further includes an alloy comprising at least one Group VIII metal and phosphorous. The alloy is disposed in at least a portion of the plurality of interstitial regions.

A cutter comprises a superhard construction, the cutter having a cutting edge defined by a rake face, and a flank extending therefrom. The cutter also has first and second regions, the first region abutting the second region along a boundary, the first region having a different material composition from the second region. At least the second region comprises superhard material, the material of the first region has a different coefficient of thermal expansion (CTE) from the material of the second region. The second region extends around the peripheral edge of the first region defined by the boundary to form a collar therearound, the first region and/or the second region extending to and/or forming at least a part of the rake face.

A polycrystalline diamond (PCD) compact and method for making the compact are provided. The method includes bringing a first PCD wafer and a second PCD wafer together at an interface in the presence of a bonding agent to form an unbonded assembly and bonding the wafers together at the interface at a pressure and temperature at which diamond is thermodynamically stable. The first PCD wafer is more thermally stable than the second PCD wafer.

Methods of attaching a polycrystalline diamond compact (PDC) element to a substrate include maintaining a gap between the PDC element and an adjacent substrate, and at least substantially filling the gap with a deposition process. Methods of forming a cutting element for an earth-boring tool include forming a PDC element by pressing diamond crystals together, forming a substrate including a particulate carbide material and a matrix material, leaving a gap between at least portions of the PDC element and the substrate, masking surfaces of the PDC element and of the substrate that do not face the gap, and forming an adhesion material on surfaces of the PDC element and of the substrate that face the gap. Cutting elements for earth-boring tools include a PDC element attached to a substrate with at least one of diamond, diamond-like carbon, a carbide material, a nitride material, and a cubic boron nitride material.