Abstract:
In the proposed apparatus, each plunger shaped as a truncated pyramid is provided with grooves extending along the edges of the smaller base of the pyramid and forming circular passages round a working chamber in the gaps between adjacent plungers. The cross section of each passsge is defined by smooth curves, the passages being filled with a sealing material. In each gap between plungers, there may be provided a plurality of parallel passages which, in some cases, are filled with materials of different compressibility.
Abstract:
A device for generating high pressures and temperatures, in which in the pressure chamber of a high strength metallic pressure container, a charge of material laterally surrounded by electrically insulating material by means of two piston rams movable in opposite direction with regard to each other and sealed relative to the pressure container is subjected to pressure while being electrically heated. The pressure container comprises at least two axially aligned metallic ring members of high strength hard metal which define a pressure chamber, while between the rings and between the rings and a matrix surrounding the rings, pressure resistant electrically insulating material is provided. Outside the pressure chamber, sealing means of plastically deformable strong metallic material are provided between the piston rams and the rings.
Abstract:
To synthesize diamond a carbonaceous material in the presence of metals, such as zinc, magnesium, lead, cadmium, bismuth, tin, indium, antimony, thallium, aluminium, mercury and compounds thereof is subjected to a pressure of at least 60 kbar at a temperature of at least 1700*C within the range of diamond stability.
Abstract:
This invention gives bonded or compact bodies of polycrystalline cubic system boron nitride and substantially uniform composites of polycrystalline cubic system boron nitride and other hard materials, for example, metal borides, such as titanium boride and zirconium boride, covalent or metallic cabides, such as boron carbide, silicon carbide, titanium, carbide, tungsten carbide and chromium carbide, metal nitrides, such as titanium nitride, tantalum nitride, silicon nitride and aluminum nitride, metal oxides, such as alumina and silica, complex oxide such as garnet and agate, and diamond. Further, this invention provides a process of obtaining the bonded body of these materials which comprises subjecting hexagonal system boron nitride powder, or a mixture of hexagonal system boron nitride powder and cubic system boron nitride crystal powder or powders of the above-mentioned hard materials to high temperatures and high pressures.
Abstract:
Diamond-nondiamond carbon polycrystalline composites particularly useful as abrasives are made by sintering diamond particles at temperatures above about 1440*K but at pressures below which diamond is stable or metastable with respect to its conversion to graphite.
Abstract:
The diamond and cement materials to be sintered are placed in a hermetic graphite sheathing which is, in turn, arranged inside a sheathing of some low-melting metal. The latter is to be made from a metal whose melting point is lower than the temperature at which diamond will be sintered with the cermet material. The filled-up graphite sheathing is placed into a high-pressure reaction chamber and heated up until the low-melting metal gets soft. Thereafter the temperature and the pressure are raised until they are adequate for diamond to be sintered with cermet material. The softened sheathing of the low-melting material is a hydrostatic medium which provides for a uniform distribution of pressure and temperature over the entire volume of materials being sintered.
Abstract:
DIAMOND IS SYNTHESIZED BY SUBJECTING A MIXTURE OF GRAPHITE AND A METAL CATALYST TO A TEMPERATURE OF AT LEAST 1150*C. AND A PRESSURE OF AT LEAST 40 KBARS, THROUGHOUT THE ENTIRE VOLUME OF THE CATALYST THERE BEING DISPERSED GRAPHITE CRYSTALLITES. THE PROCESS ENABLES ONE TO PREPARE A LARGE NUMBER OF SEPARATE, SMALL, WELL DEFINED DIAMOND MONOCRYSTALS IN A RELATIVELY SHORT TIME. THE DIAMOND PRODUCT HAS HIGH ABRASION PROPERTIES.
Abstract:
A die pair for use in high temperature high pressure apparatus for use in the synthesis of super hard materials such as diamonds, cubic boron nitride or the like in which the dies include an annular step structure on confronting cooperating faces of the dies to afford over an extended period of time stable, repetitive temperatures in the order of thousands of degrees centigrade and pressures in the order of 60 thousand atmospheres; the confronting die faces having recesses forming a pressure chamber and step structure cooperating with a deformable container of a thermo-and-electro-insulating material such as lithographic stone etc. which deforms as heated and has pressure applied thereto to form an annular sealing ''''burr'''' of a greater volume than an outer surrounding annular slot filled with a porous plastic, electro-insulating material such as ''''technical rubber'''' etc.; the deformable container being of a volume to fill the space both inwardly and outwardly of the material being treated up to the confronting edge of annular surrounding steps; the outer steps having radial, transverse slots; staggered in confronting relation; for readily accommodating the porous plastic outer seal.
Abstract:
DIAMOND IS SYNTHESIZED BY SUBJECTING CARBON-CONTAINING MATERIAL IN CONTACT WITH A COMPOUND OF MERCURY OR LEAD, SUCH AS MERCURY OXIDE OR LEAD OXIDE, TO A TEMPERATURE OF AT LEAST 2000* C. AND A PRESSURE CORRESPONDING TO A SELECTED TEMPERATURE WITHIN THE DIAMOND STABILITY REGION.
Abstract:
This invention relates to high-pressure dies normally used for use in the synthesis of diamonds. The die comprises a die ring having a through cavity within which there is formed a pressure chamber that is lined with a pyrophyllite sleeve. Respectively entering the ends of the sleeve are two plungers. These plungers are capable of sliding in the sleeve until near the end of their compressive strokes so that little or no axial pressure is applied to the ends of the sleeve.