A cutting element has a thermally stable polycrystalline diamond layer formed on an upper side of a polycrystalline diamond layer. The cutting element has a cutting face opposite the polycrystalline diamond layer, a transition layer on a side of the polycrystalline diamond layer opposite the thermally stable polycrystalline diamond layer, and a non-planar interface between the transition layer and the polycrystalline diamond layer. The non-planar interface has a perimeter exposed around a side surface of the cutting element encircling an interior of the non-planar interface and an uppermost portion of the perimeter is a distance from the cutting face greater than an axial distance between the cutting face and the interior.

Induced material segregation methods of manufacturing a polycrystalline diamond compact (PDC) cutter result in formation of a polycrystalline diamond/tungsten carbide (WC) composite material having a smooth compositional gradient from maximum WC concentration at one face to maximum diamond concentration at another face. Because the compositional gradient is smooth, very little or no mismatch of coefficient of thermal expansion occurs, which improves a service lifetime of the PDC cutter.

A polycrystalline diamond (PCD) composite compact element has a body of polycrystalline diamond material and a cemented carbide substrate bonded to the body of polycrystalline material along an interface. The cemented carbide substrate has tungsten carbide particles bonded together by a binder material, the binder material including an alloy of Co, Ni and Cr. The tungsten carbide particles form at least 70 weight percent and at most 95 weight percent of the substrate and the binder material has between about 60 to 90 wt. % Ni, between about 10 to 40 wt. % Co, and about 0.25 to 1.0 wt % Cr.sub.3C.sub.2.

A polycrystalline diamond (PCD) composite compact element has a body of polycrystalline diamond material and a cemented carbide substrate bonded to the body of polycrystalline material along an interface. The cemented carbide substrate has tungsten carbide particles bonded together by a binder material, the binder material including an alloy of Co, Ni and Cr. The tungsten carbide particles form at least 70 weight percent and at most 95 weight percent of the substrate and the binder material has between about 60 to 90 wt. % Ni, between about 10 to 40 wt. % Co, and about 0.25 to 1.0 wt % Cr.sub.3C.sub.2.

A drilling tip according to the disclosure has a tip body which is provided with a tip portion tapered toward a tip side of the tip body; and a hard layer which is formed on a surface of the tip portion of the tip body, an outermost layer of the hard layer is a cBN sintered material having 70 to 95 vol % of cBN grains, and when a cross-sectional structure of the outermost layer is observed, a binder phase having a width of 1 nm or greater and 30 nm or less and containing Al, B, and N, and in which a ratio of an O content to an Al content is 0.1 or less exists between neighboring cBN grains.

Polycrystalline diamond includes a working surface and a peripheral surface extending around an outer periphery of the working surface. The polycrystalline diamond includes a first volume including an interstitial material and a second volume having a leached region that includes boron and titanium. A method of fabricating a polycrystalline diamond element includes positioning a first volume of diamond particles adjacent to a substrate, the first volume of diamond particles including a material that includes a group 13 element, and positioning a second volume of diamond particles adjacent to the first volume of diamond particles such that the first volume of diamond particles is disposed between the second volume of diamond particles and the substrate, the second volume of diamond particles having a lower concentration of material including the group 13 element than the first volume of diamond particles. Various other articles, assemblies, and methods are also disclosed.

A polycrystalline diamond compact includes a polycrystalline diamond material having a plurality of grains of diamond bonded to one another by inter-granular bonds and an intermetallic gamma prime () or -carbide phase disposed within interstitial spaces between the inter-bonded diamond grains. The ordered intermetallic gamma prime () or -carbide phase includes a Group VIII metal, aluminum, and a stabilizer. An earth-boring tool includes a bit body and a polycrystalline diamond compact secured to the bit body. A method of forming polycrystalline diamond includes subjecting diamond particles in the presence of a metal material comprising a Group VIII metal and aluminum to a pressure of at least 4.5 GPa and a temperature of at least 1,000 C. to form inter-granular bonds between adjacent diamond particles, cooling the diamond particles and the metal material to a temperature below 500 C., and forming an intermetallic gamma prime () or -carbide phase adjacent the diamond particles.

The present disclosure relates a spark plasma sintered polycrystalline diamond and methods of spark plasma sintering leached polycrystalline diamond. Spark plasma sintering produces plasma from a reactant gas found in the pores left by catalyst removal from leached polycrystalline diamond. The plasma forms diamond bonds and/or carbide structures in the pores, which may produce polycrystalline diamond that is has a higher impact strength than the leached polycrystalline diamond or other improved properties.

Polycrystalline diamond compacts having interstitial diamonds and methods of forming polycrystalline diamond compact shaving interstitial diamonds with a quench cycle are described herein. In one embodiment, a polycrystalline diamond compact includes a substrate and a polycrystalline diamond body attached to the substrate. The polycrystalline diamond body includes a plurality of inter-bonded diamond grains that are attached to one another in an interconnected network of diamond grains and interstitial pockets between the inter-bonded diamond grains, and a plurality of interstitial diamond grains that are positioned in the interstitial pockets. Each of the plurality of interstitial diamond grains are attached to a single diamond grain of the interconnected network of diamond grains or other interstitial diamond grains.

A tool having a cutting edge that includes a sintered body containing cubic boron nitride. The sintered body integrally and inseparably includes an inner region and a binder phase enriched layer formed on at least part of a surface of the inner region. The inner region includes: 15-90 volume % of cubic boron nitride; and 10-85 volume % of a mixture of a binder phase and impurities. The binder phase enriched layer includes: 90-100 volume % of the binder phase and impurities mixture; and 0-10 volume % of cubic boron nitride; and the binder phase contains at least one kind selected from the group consisting of: at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Al, Co, Ni and Si; and a compound of the element and at least one element selected from the group consisting of C, N, O and B.