A composite polycrystal contains polycrystalline diamond formed of diamond grains that are directly bonded mutually, and compressed graphite dispersed in the polycrystalline diamond.

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. The 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.

Provided is polycrystalline diamond having a diamond single phase as basic composition, in which the polycrystalline diamond includes a plurality of crystal grains and contains boron, hydrogen, oxygen, and the remainder including carbon and trace impurities; the boron is dispersed in the crystal grains at an atomic level, and greater than or equal to 90 atomic % of the boron is present in an isolated substitutional type; hydrogen and oxygen are present in an isolated substitutional type or an interstitial type in the crystal grains; each of the crystal grains has a grain size of less than or equal to 500 nm; and the polycrystalline diamond has a surface covered with a protective film.

A method of making molecularly doped nanodiamond. A versatile method for doping diamond by adding dopants into a carbon precursor and producing diamond at high pressure, high temperature conditions. Molecularly doped nanodiamonds that have direct incorporation of dopants and therefore without the need for ion implantation. Molecularly-doped diamonds that have fewer lattice defects than those made with ion implantation.

Polycrystalline compacts include a polycrystalline superabrasive material comprising a first plurality of grains of superabrasive material having a first average grain size and a second plurality of grains of superabrasive material having a second average grain size smaller than the first average grain size. The first plurality of grains is dispersed within a substantially continuous matrix of the second plurality of grains. Earth-boring tools may include a body and at least one polycrystalline compact attached thereto. Methods of forming polycrystalline compacts may include coating relatively larger grains of superabrasive material with relatively smaller grains of superabrasive material, forming a green structure comprising the coated grains, and sintering the green structure. Other methods include mixing diamond grains with a catalyst and subjecting the mixture to a pressure greater than about five gigapascals (5.0 GPa) and a temperature greater than about 1,300 C. to form a polycrystalline diamond compact.

A hydrocarbon is produced by applying mechanical energy to a metal body containing stainless steel by solid-solid contact so that a contact pressure per unit area is 30 kPa or more, in the presence of a gas containing carbon dioxide and a hydrogen source, thereby adding hydrogen to carbon dioxide. Further, a hydrocarbon is produced by providing a reaction vessel for applying mechanical energy to a metal body by solid-solid contact in the presence of a gas containing carbon dioxide and a hydrogen source, a gas introduction unit for introducing the gas containing carbon dioxide to the reaction vessel, a hydrogen source introduction unit for introducing the hydrogen source to the reaction vessel, and a gas discharge unit for discharging a gas containing the hydrocarbon produced in the reaction vessel, and adding hydrogen to the carbon dioxide in the reaction vessel.

A transition metal catalyst free polycrystalline diamond compact having enhanced thermal stability is disclosed herein. The diamond compact may be attached to a hard metal substrate. The polycrystalline diamond body includes a plurality of diamond grains bonded to adjacent diamond grains by diamond-to-diamond bonds. Sintering of the PCD and the formation of diamond-to-diamond bonding is achieved by transforming graphene treated diamond crystals that are blended with non-metal additives at high pressure and high temperature into a diamond compact that is free of transition metal catalysts. Non-metal additives include vitreous and other non-equilibrium forms of carbon as well as Sr-, K- and Ca-containing carbon sources.

Methods and apparatuses for controlling the size of microbubbles are provided herein. The methods include forming a microbubble in a liquid at an inlet end of a liquid microchannel, the liquid microchannel having an outlet end spaced from the inlet end and a liquid microchannel conduit extending therebetween. As the liquid is propelled along a length of the liquid microchannel, the liquid carry the microbubble, a negative pressure is applied to a first very low pressure microchannel having a first end, a second end spaced from the first end and a first very low pressure microchannel conduit extending between the first end and the second end and having a portion thereof being laterally spaced from and adjacent to a portion of the liquid microchannel conduit. The negative pressure withdraws air from the microbubble in the liquid microchannel to shrink the microbubble as the microbubble travels along the portion of the liquid microchannel conduit.

Embodiments of methods of altering the color of diamonds are disclosed. In an embodiment, a method for altering the color of diamonds includes identifying and selecting a diamond having a suitable nitrogen content, HPHT processing the selected diamond under diamond-stable conditions to alter the color of the selected diamond from a first color to a second color, irradiating the HPHT-processed diamond with an electron source having an energy between about 1 MeV and about 20 MeV so as to alter the color of the selected diamond from the second color to a third color, and annealing the irradiated diamond either under partial vacuum conditions, or under HPHT diamond-stable conditions so as to alter the color from the third color to a fourth color (e.g., pink, red, or purple, depending on the nitrogen content of the selected diamond).

Roller cutters comprise a diamond-bonded body joined to an infiltration substrate. An extension is joined to the substrate and includes first section having a diameter sized the same as the substrate, and an integral second section having a diameter smaller than the substrate. The extension is joined to the substrate during an HPHT process. The first section has a thickness greater than that of the infiltration substrate. The second section has an axial length greater than the combined thickness of the substrate and the first section. The extension has a strength and/or toughness greater than the substrate as a result of its material composition, e.g., the amount of binder phase material and/or the size of hard phase material. The roller cutter is rotatably disposed within a pocket internal cavity, wherein the pocket is attached to a drill bit.