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

A method of making polycrystalline diamond material includes providing a fraction of diamond particles or grains and a sintering additive, the sintering additive comprising a carbon source of nano-sized particles or grains, forming the diamond particles and sintering additive into an aggregated mass, consolidating the aggregated mass and a binder material to form a green body, and subjecting the green body to conditions of pressure and temperature at which diamond is more thermodynamically stable than graphite and for a time sufficient to consume the sintering additive, sintering it and forming polycrystalline diamond material that is thermodynamically and crystallographically stable and is substantially devoid of any nano-structures.

Nanodiamonds are grown under conditions where diamond-like organic seed molecules do not decompose. This permits engineered growth of fluorescent nanodiamonds wherein a custom designed seed molecule can be incorporated at the center of a nanodiamond. By substituting atoms at particular locations in the seed molecule it is possible to achieve complex multi-atom diamond color centers or even to engineer complete quantum registers. In addition, it is possible to grow ultra-small nanodiamonds, wherein each nanodiamond, no matter how small, can have at least one bright and photostable fluorescent emitter.

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.

A method of forming a polycrystalline diamond comprises derivatizing a nanodiamond to form functional groups, and combining the derivatized nanodiamond with a microdiamond having an average particle size greater than that of the derivatized nanodiamond, and a metal solvent-catalyst. A polycrystalline diamond compact is prepared by adhering the polycrystalline diamond to a support, and an article such as a cutting tool may be prepared from the polycrystalline diamond compact.

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, at least either of nitrogen and silicon, and a 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; the nitrogen and the silicon 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.

Single-crystal diamond is composed of carbon in which a concentration of a carbon isotope .sup.12C is not lower than 99.9 mass % and a plurality of inevitable impurities other than carbon. The inevitable impurities include nitrogen, boron, hydrogen, and nickel, and a total content of nitrogen, boron, and hydrogen of the plurality of inevitable impurities is not higher than 0.01 mass %. In order to manufacture single-crystal diamond, initially, a hydrocarbon gas in which a concentration of the carbon isotope .sup.12C is not lower than 99.9 mass % is subjected to denitrification.

Disclosed herein is an apparatus and method for growing a diamond. The apparatus for growing a diamond comprises: a reaction cell that is configured to grow the diamond therein; a main heater including a main heating surface that is arranged along a first inner surface of the reaction cell; and a sub-heater including a sub-heating surface that is arranged along a second inner surface of the reaction cell, the second inner surface being non-parallel with the first inner surface.

Systems and methods include a computer-implemented method can be used to make drilling tools from new wurtzite boron nitride (w-BN) superhard material. An ultra-high-pressure, high-temperature operation is performed on pure w-BN powder to synthesize w-BN and cubic boron nitride (c-BN) compact having a first size greater than particles of the pure w-BN powder. The ultra-high-pressure, high-temperature operation includes pressurizing the w-BN powder to a pressure of approximately 20 Gigapascal, heating the w-BN powder at a heating rate of 100° C./minute and cooling the w-BN powder at a cooling rate of 50° C./minute. The compact is cut to a second size smaller than the first size using laser cutting tools. The cut compact is bonded metallurgically, mechanically, or both metallurgically and mechanically onto a tool substrate to form the drilling tool.

A super hard polycrystalline construction is disclosed as comprising a body of super hard material having a first fraction of super hard grains in a matrix of a second fraction of super hard grains. The average grain size of the first fraction is between around 1.5 to around 10 times the average grain size of the second fraction and the first fraction comprises around 5 vol % to around 30 vol % of the grains of super hard material in the body.