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:
A material treatment heater tube is provided in which the axial thermal conductivity is less than 10% of the circumferential thermal conductivity.
Abstract:
An apparatus and method for processing materials in supercritical fluids is disclosed. The apparatus includes a capsule configured to contain a supercritical fluid, a high strength enclosure disposed about the capsule and a sensor configured to sense pressure difference between an interior and an exterior of the capsule. The apparatus also includes a pressure control device configured to adjust pressure difference of the capsule in response to the pressure difference sensed by the sensor. The apparatus further includes at least one dividing structure disposed within the capsule that divides the capsule into a seed growing chamber and a nutrient chamber.
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:
null-ZrNCl polycrystalline powder prepared by chemical transport method and NH4Cl are mixed in a molar ratio of 1:2. The mixture is encapsulated in a Au capsule (6 mm in inner diameter and 6 mm in depth) of a reaction vessel 2, which is then enclosed in a highly heat-conductivitive sodium chloride block as an electrically insulating pressure medium 6. The mixture held in the sodium chloride block is placed in a carbon tube 8 for serving as a heater. In a cubic-pressing apparatus using a pyrophyllite 12 as a pressure-transmitting medium, the mixture is heated at 900null C. for 2 hours under an applied pressure of 3 GPa. After the mixture is allowed to stand until it is cooled down to room temperature, the Au capsule is taken out and light green null-ZrNCl single crystals are obtained. A large single crystal among them had a hexagonal plate-like habit and is transparent with dimensions about 2 mm in diameter, and 0.3 mm in thickness.
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.
Abstract:
A gallium nitride growth process forms crystalline gallium nitride. The process comprises the steps of providing a source gallium nitride; providing mineralizer; providing solvent; providing a capsule; disposing the source gallium nitride, mineralizer and solvent in the capsule; sealing the capsule; disposing the capsule in a pressure cell; and subjecting the pressure cell to high pressure and high temperature (HPHT) conditions for a length of time sufficient to dissolve the source gallium nitride and precipitate the source gallium nitride into at least one gallium nitride crystal. The invention also provides for gallium nitride crystals formed by the processes of the invention.
Abstract:
An element-doped diamond crystal is disclosed herein. The crystal includes at least one dopant element which has a greater concentration toward or near an outermost surface of the crystal than in the center of the crystal. The concentration of the dopant element is at a local minimum at least about 5 micrometers below the surface. The concentration-profile of the dopant element for these diamond crystals causes an expansion of the diamond lattice, thereby generating tangential compressive stresses at the surface of the diamond crystal. These stresses beneficially increase the compressive fracture strength of the diamond.
Abstract:
The present invention describes a novel metal bond superabrasive tool that contains a superabrasive such as diamond or CBN grits distributed in a predetermined or an uniform pattern. Such a pattern is produced by fabricating plurality layers of metal matrix with superabrasive grits distributed therein in a predetermined pattern and concentration and subsequently assembling and consolidating the layers into a tool segment. Superabrasive particles may be incorporated during the process of making these layers, or they may be planted afterwards into these layers that contains the metal matrix powder. In the latter case, the planting may be guided by a template with apertures laid in a specific pattern.