Abstract:
Nano polycrystalline diamond is composed of carbon and a plurality of impurities other than carbon. A concentration of each of the plurality of impurities is not higher than 0.01 mass %, and the nano polycrystalline diamond has a crystal grain size (a maximum length) not greater than 500 nm. The nano polycrystalline diamond can be fabricated by preparing graphite in which a concentration of an impurity is not higher than 0.01 mass % and converting graphite to diamond by applying an ultra-high pressure and a high temperature to graphite.
Abstract:
A polycrystalline superhard material comprises a sintered mass of superhard grains having a mean superhard grain contiguity of at least 62 percent and at most 92 percent. There is also disclosed a method of making such a polycrystalline superhard material. The method comprises providing a precursor body comprising superhard grains and interstices between the superhard grains, and introducing additive particles into the interstices to form a pre-sinter body. The pre-sinter body is submitted to a temperature and pressure at which superhard material is thermodynamically stable, sintering it and forming polycrystalline superhard material.
Abstract:
Superabrasive tools and methods for the making thereof are disclosed and described. In one aspect, superabrasive particles are chemically bonded to a matrix support material according to a predetermined pattern by a braze alloy. The brazing alloy may be provided as a powder, thin sheet, or sheet of amorphous alloy. A template having a plurality of apertures arranged in a predetermined pattern may be used to place the superabrasive particles on a given substrate or matrix support material.
Abstract:
A superabrasive tools having uniformly leveled superabrasive particles and associated methods are provided. In one aspect, for example, a superabrasive can include a metal matrix configured for bonding superabrasive particles and a plurality superabrasive particles held in the metal matrix at specific positions according to a predetermined pattern, wherein tips of each of the plurality of the superabrasive particles protrude from the metal matrix to a uniform height.
Abstract:
A high pressure high temperature (HPHT) method for synthesizing single crystal diamond, wherein a single crystal diamond seed having an aspect ratio of at least (1) and a growth surface substantially parallel to a {110} crystallographic plane is utilised is described. The growth is effected at a temperature in the range from 1280° C. to 1390° C.
Abstract:
In a method of synthesising diamond, a reaction mixture of a carbon source and a solvent/catalyst is pretreated at a high temperature and a high vacuum to remove substantially all of the atmospheric gases and other light volatile atoms. Then, at a reduced temperature, the removed gas is replaced with a desirable process gas. The pre-treated reaction mixture is then subjected to elevated temperature and pressure conditions in the diamond stable region of the carbon phase diagram in the presence of the process gas to produce the diamond. The process gas is selected to enhance the diamond growth rate, reduce solvent/catalyst inclusions, shift the morphology of the synthesised diamond (grown crystals) towards major crystal faces and blocker shape, reduce cracking and strain in the grown crystals, preferably at a desirably high growth rate, and permit the controlled and uniform doping of the diamond crystal with a hetero-atom such as P (phosphorus) or S (sulphur).
Abstract:
The invention relates to a method for manufacture of diamond, the method including the steps of providing a first coating of solvent metal or solvent metal alloy on a diamond seed to create a coated diamond seed, situating the coated diamond seed adjacent a catalyst system comprising a solvent metal and/or a source of carbon, and subjecting the coated diamond seed and catalyst system to increased temperature wherein the melting point of the first coating is at least 20 deg C. below that of the catalyst system. The invention further relates to a compact comprising a plurality of diamond seeds wherein at least one seed includes a first coating comprising a solvent metal and/or solvent metal based alloy, the compact further comprising a catalyst system comprising a solvent metal and/or a source of carbon wherein the melting point of the first coating is at least 20 deg C. below that of the catalyst system.
Abstract:
An improved method for synthesizing superabrasive particles provides high quality industrial superabrasive particles with high yield and a narrow size distribution. The synthesis method can include forming a growth precursor of a substantially homogeneous mixture of raw material and catalyst material or layers of raw material and metal catalyst. The growth precursor can have a layer of adhesive over at least a portion thereof. A plurality of crystalline seeds can be placed in a predetermined pattern on the layer of adhesive. The growth precursor can be maintained at a temperature and pressure at which the superabrasive crystal is thermodynamically stable for a time sufficient for a desired degree of growth. Advantageously, the patterned placement of crystalline seeds and disclosed processes allow for production of various morphologies of synthetic diamonds, including octahedral and cubic diamonds, and improved growth conditions generally. As a result, the grown superabrasive particles typically have a high yield of high quality particles and a narrow distribution of particle sizes.
Abstract:
This invention is a method of making a synthetic gem comprising elements recovered from remains of a species of the Kingdom Animalia, comprising the steps of collecting substantially pure carbon from the remains and creating gems from the carbon using crystal growth sublimation.
Abstract:
A self-grown monopoly compact grit and high pressure, high temperature process for preparing the same. The high pressure, high temperature sintered/synthesized monopoly compact grit is used in various industrial tools such as saw blades, grinding wheels, cutting tools and drill bits. Further, the monopoly compact grit of the present invention is produced from a seed of a mono-crystal of diamond or cubic boron nitride surrounded by either a self-grown crystal layer or an integrally bonded poly-crystalline sintered compact layer. The self-grown crystal layer is a new grown crystal structure where the seed crystal grows into a new phase through a normal diamond or cubic boron nitride synthesis process in the presence of a catalyst metal solvent. The compact layer is composed of about 50 to about 90 volume percent of diamond or cubic boron nitride, a typical binder material, which is a catalyst for crystal-to-crystal bonding, and a cementing agent which is a binding agent capable of forming stable carbide and nitride bonds.