Polycrystalline diamond

FIELD: chemistry.

SUBSTANCE: invention relates to polycrystalline diamond for use in a variety of instruments. Polycrystalline diamond is characterized in that it comprises a sintered diamond grains having an average grain diameter of more than 50 nm and less than 2500 nm, the purity of 99 % or more and the grain diameter of D90, is (average grain diameter + average grain diameter of × 0.9) or less, wherein the polycrystalline diamond has a lamellar structure and has a hardness of 100 GPa or more.

EFFECT: water jet nozzle cutter for engraving gravure scriber, cutting tool and scribing clip from such material ensures stable processing over a long period of time as compared with conventional tools comprising monocrystalline diamond and the sintered diamond compact containing metal binders.

13 cl, 5 tbl, 62 ex

 



 

Same patents:

FIELD: chemistry.

SUBSTANCE: invention relates to a method of controlling concentration and uniformity of distribution of a dopant in synthetic CVD diamond material used in electronic devices and sensors. The diamond material is obtained in a microwave plasma reactor, having a plasma chamber 102 in which there is one or more substrate regions of a growth surface 105, on top of which the diamond material is deposited, a gas stream system 112 for feeding process gases into the plasma chamber 102 and a system 122 for removing the process gases therefrom. Microwave radiation is transmitted from a microwave generator 106 into the plasma chamber 102 through a microwave link 110 in order to generate plasma above the region of the growth surface 105 or below the region of the growth surface if the microwave plasma reactor is in an inverted configuration with the process gases flowing upwards. The gas stream system 112 includes a gas inlet, having one or more gas inlet pipes 124 located opposite the region of the growth surface 105 and configured to inject process gases towards the region of the growth surface 105, wherein the process gases are injected into the plasma chamber 102 through one or each gas inlet pipe 124 with a Reynolds number in the range of 1-100, integrally formed in the metal wall of the plasma chamber 102 located opposite the region of the growth surface 105. The plasma chamber 102 is configured to support standing microwave modes TM011. The configuration of the microwave link 110 comprises a microwave window 119 for transmitting microwave radiation from the microwave generator 106 into the plasma chamber 102, which is located at the opposite end of the plasma chamber 102 relative to the region of the growth surface 105 and made in the form of an annular dielectric window.

EFFECT: invention enables to achieve a homogeneous chemical composition of diamond material grown in a single growth cycle while maintaining uniform plasma with a large area with very high growth rates and enables to achieve a high degree of controlling the level and distribution of defects and dopants in a diamond film without impurities and damages to the walls and the microwave window of a plasma chamber which can support compact standing microwave mode TM011.

5 cl, 17 dwg

FIELD: chemistry.

SUBSTANCE: invention refers to manufacturing of polycrystalline materials, which can be used, preferentially for producing drilling and dressing tools. A polycrystalline diamond composite with a dispersion-strengthened additive contains a refractory metal coating 0.02-0.15 mm thick containing diamond powder and metals with the metal presented by nickel, cobalt, whereas the dispersion-strengthened additive is tungsten carbide nanopowder in the following proportions, wt %: diamond - 85-90, nickel - 7-9, cobalt - 2-4, tungsten carbide nanopowder - 0.1-3.0.

EFFECT: technical effect consists in increasing the strength and wear resistance of the sintered composite, and selecting the high-melting coating ensures the reliable attachment of the material in the drilling tool.

1 tbl, 1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to production of monocrystalline diamond material by chemical vapour deposition (CVD), which is used in optical, mechanical, fluorescent and/or electronic devices. A diamond layer contains a mesh of nonparallel intercrossing dislocations as seen on an X-ray topographic sectional image or in conditions of a fluorescent technique, wherein the layer has thickness equal to or greater than 1 mcm; the mesh of nonparallel dislocations stretches across a volume which is at least 30% of the total volume of the diamond layer, and wherein the mesh of nonparallel dislocations contains a first set of dislocations propagating in a first direction through the diamond layer, and a second set of dislocations propagating in a second direction through the diamond layer, wherein the angle between the first and second directions is in the range of 40° to 100°, as seen on an X-ray topographic sectional image or in conditions of a fluorescent technique.

EFFECT: invention enables to control the type and/or direction of dislocations in a diamond material without affecting optical and/or electronic properties of devices based on said material and optimise said properties for a specific application.

12 cl, 8 dwg, 2 tbl, 3 ex

FIELD: nanotechnology.

SUBSTANCE: invention relates to nanotechnology and can be used for labelling molecules, quantum information processing, magnetometry, and synthesis of diamond by chemical vapour deposition. Crystalline diamond powder with a maximum particle size of 2 microns to 1 mm is ground by the nitrogen jet for 1-5 hours with the grinding pressure of 500 kPa to obtain the fine powder which is then milled in a planetary mill with balls of tungsten carbide. The resulting nano-ground powder is autoclaved with the mixture of hydrofluoric acid and nitric acid at a temperature of 100-200°C. The fluorescent cubic nanocrystals of diamond of predominantly circular shape are recovered by centrifugation, with a maximum size of not more than 100 nm, comprising up to 2,000 ppm alloy addition, such as nitrogen, and up to 50 ppm of impurities. The surface of the diamond nanocrystal comprises a layer of amorphous carbon.

EFFECT: obtaining diamond nanocrystals.

15 cl, 8 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to technology of producing coloured diamond materials, which can be applied as precious stones or cutting instruments. Method includes stages of growing monocrystalline diamond material in accordance with CVD-technology, with diamond material having concentration of single substituting nitrogen atoms [Ns0] less than 1 ppm; initial CVD-diamond material is colourless, or, in case it is not colourless, then, according to colour gradation brown or yellow, and if it is brown according to colour gradation, then it has level G (brown) of colour gradation or better for diamond stone with 0.5 carat weight with round diamond cut, and if it is yellow according to colour gradation, it has level T (yellow) of colour gradation or better for diamond stone with 0.5 carat weight with round diamond cut, and irradiation of initial CVD-diamond by electrons to introduce isolated vacancies into diamond material in such a way that product of the total concentration of vacancies × way length [Vt]×L, in irradiated diamond material at said stage or after additional processing after irradiation, including annealing irradiated diamond material at temperature at least 300°C and not higher than 600°C, constitutes at least 0.072 ppm cm and not more than 0.36 ppm cm.

EFFECT: diamond material becomes fancy light-blue or fancy light greenish blue in colour.

21 cl, 4 dwg, 3 tbl, 9 ex

FIELD: chemistry.

SUBSTANCE: invention can be used in obtaining jewellery diamonds. method of introduction of NV-centres in monocrystalline CVD-diamond material includes the following stages: irradiation of CVD-diamond material, containing single substituting nitrogen, for introduction of isolated vacancies in concentration at least 0.05 ppm and at most 1 ppm; annealing irradiated diamond to form NV-centres from at least some of defects of single substituting nitrogen and introduced isolated vacancies.

EFFECT: invention makes it possible to obtain pink CVD-diamond material and CVD-diamond material with spintronic properties.

18 cl, 12 tbl, 7 dwg

Diamond material // 2537857

FIELD: chemistry.

SUBSTANCE: inventions can be used in chemical and jewellery industry. Nitrogen-doped diamond material, obtained in accordance with CVD technology, or representing monocrystal or precious stone, demonstrates difference of absorptive characteristics after exposure to radiation with energy of at least 5.5 eV, in particular UV radiation, and thermal processing at temperature 798 K. Defects into diamond material are introduced by its irradiation by electrons, neutrons or gamma-photons. After irradiation, difference in absorptive characteristics decreases.

EFFECT: irradiated diamond material has absorption coefficient lower than 0,01 cm-1 at 570 nm and is capable of changing its colour.

18 cl, 7 dwg, 11 tbl, 15 ex

FIELD: process engineering.

SUBSTANCE: invention relates to production of alloys diamonds to be used in electronics and instrument making s well as jewellery stones. Alloyed diamond is produced by chemical deposition of gas phase on substrate in reaction chamber 2. Alloying solid-state component 7 is placed in alloying chamber 3. The latter has at least three connection flanges. Two of them are designed to connect alloying chamber 3 with working gas feed line 1 while third flange allows passage of pulsed laser radiation 8 via translucent window 5 into alloying chamber 3 for sputter of alloying component 7. Note here that alloying component concentration in diamond is adjusted by varying the laser parameters: laser diode pump current, laser pulse frequency and distance from laser radiation focus to alloying component surface. Working gas can be composed of the mix of hydrogen and methane at the ratio of 98:2% to 90:10%. Additionally, oxygen can be added thereto.

EFFECT: precise alloying in the wide range of concentrations (1014 atom/cm3 to 9×1019 atom/cm3) of boron, sulphur and silicon.

3 cl, 1 dwg, 4 tbl, 4 ex

FIELD: chemistry.

SUBSTANCE: ions of carbon with opposite charges interact with each other for 20-30 hours at a temperature of 850-950 °C in a high frequency electro-field in the range of frequencies of 40-80 kHz in the presence of iron as a catalyst. The process is carried out in a melt of salts, containing, wt %: SiC - 7.5-11.0; Na2CO3 or K2CO3 - 89.0-92.5. Applied is granulated iron, which has a size of granules 1-3 mm, in a quantity of 5-10% from the melt weight.

EFFECT: invention makes it possible to simplify the process of the diamond synthesis and its instrumentation, eliminate harmful and dangerous conditions.

1 tbl, 1 ex

Pcd diamond // 2522028

FIELD: process engineering.

SUBSTANCE: invention relates to PCD diamond to be used in production of water-jet ejectors, engraving cutters for intaglio, scribers, diamond cutters and scribing rollers. PCD diamond is produced by conversion and sintering of carbon material of graphite-like laminar structure at superhigh pressure of up to 12-25 GPa and 1800-2600°C without addition of sintering additive of catalyst. Note here that sintered diamond grains that make this PCD diamond feature size over 50 nm and less than 2500 nm and purity of 99% or higher. Diamond features grain diameter D90 making (grain mean size plus grain mean size × 0.9) or less and hardness of 100 GPa or higher.

EFFECT: diamond features laminar or fine-layer structure, ruled out uneven wear, decreased abrasion.

15 cl, 5 tbl, 5 ex

Pcd diamond // 2522028

FIELD: process engineering.

SUBSTANCE: invention relates to PCD diamond to be used in production of water-jet ejectors, engraving cutters for intaglio, scribers, diamond cutters and scribing rollers. PCD diamond is produced by conversion and sintering of carbon material of graphite-like laminar structure at superhigh pressure of up to 12-25 GPa and 1800-2600°C without addition of sintering additive of catalyst. Note here that sintered diamond grains that make this PCD diamond feature size over 50 nm and less than 2500 nm and purity of 99% or higher. Diamond features grain diameter D90 making (grain mean size plus grain mean size × 0.9) or less and hardness of 100 GPa or higher.

EFFECT: diamond features laminar or fine-layer structure, ruled out uneven wear, decreased abrasion.

15 cl, 5 tbl, 5 ex

FIELD: process engineering.

SUBSTANCE: invention relates to production of synthetic polycrystalline materials based on polycrystalline cubic boron containing diamond grains. Said materials are used for making cutting elements to be incorporated with drill bits, grinding wheel dressing, drilling and cutting of natural and artificial construction materials. Proposed method comprises subjecting the blend containing cubic boron nitride and diamond powder to pressure in the range of thermal stability of aforesaid components at state graphs. Note here that grain sixe of diamond powder used in amount of 5.0-37.5 vol. % makes 200-3000 mcm while that of hexagonal boron nitride makes 1-3 mcm and that of cubic boron nitride makes 1-5 mcm.

EFFECT: higher efficiency in drilling rocks of V-XII rock drillability index.

3 cl

FIELD: process engineering.

SUBSTANCE: invention relates to production of polycrystalline cubic nitride with fine-grain structure. Cubic boron nitride-based polycrystalline material is produced by applying high pressure and temperature to charge containing composite powder with grain size of 4-100 nm including hexagonal boron nitride and aluminium nitride at the ratio of (4-6):1. Composite powder is produced by CBC-technology from boron-aluminium-nitrogen-containing compounds. Process is conducted at 60-120 kbar and 1700-2400°C in the region of thermodynamic stability of cubic boron for 15-60 s.

EFFECT: higher wear resistance and edge stability in processing high-alloyed steel and refractory nickel alloys.

3 cl

FIELD: process engineering.

SUBSTANCE: invention relates to producing cubic boron nitride-based polycrystalline material. Proposed method comprises subjecting charge containing composite powder BNr+AIN with grain size of 4-100 nm obtained in SAA-process from boron-aluminium-nitrogen-containing compounds, cubic boron nitride and catalyst, to high pressure and temperature, at the following ratio of components, in wt %: BNr+AIN - 65-75, cubic BNr - 15-25, catalyst - 3-10. Ratio of hexagonal boron nitride to aluminium nitride in composite powder makes (4-6):1.Grain size of cubic boron nitride powder may make 1-40 mcm. Additionally, powder of hexagonal boron nitride with grain size of 1-40 mcm in amount of 1-15% wt % or silicon in amount of 0.1-1 wt % may be added to said charge. Synthesis is conducted at 60-120 kbar and 1700-2400°C for 15-60 s.

EFFECT: higher wear resistance.

5 cl, 1 tbl

FIELD: process engineering.

SUBSTANCE: invention relates to production of synthetic superhard materials, particularly, polycrystalline cubic boron at high pressure and temperature to be sued in chemical, electronic and other industries. Proposed method comprises preparing mix of wurtzite-like and cubic modifications in relation of 1:4 to 2:1, respectively, processing it in planet mill for mechanical activation and crushing to grain size not exceeding 1 mcm, forming and annealing the mix at 1400-1800°C and 7.0-9.0 GPa, keeping at annealing temperature for time defined by conditions of transition on boron nitride wurtzite modification into cubic one without recrystallisation, equal to 5-30 s. Accurate time of keeping at preset temperature and pressure is defined proceeding from necessity of preservation of 5 to 15% of wurtzite boron nitride amount in initial mix.

EFFECT: lower temperature, pressure and duration of synthesis, improved mechanical and physical properties.

2 cl, 5 ex, 1 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to production of optical materials which are transparent in the infrared (IR) spectrum with high transmission coefficient and high mechanical strength. The method involves preparation of a colloidal solution from finely dispersed γ-Al2O3 powder, from which a transparent supernatant - sol is extracted, which, through ultrasonic treatment, heating, acidification and thickening, is brought into a state gelling takes place after several days - formation of a viscous sol which is poured into a moulding hydrophobic container, where the said sol is kept until a moulded volume of gel is formed - gel workpiece. After removal from the mould, the gel workpiece undergoes thermal treatment in several steps, preferably three steps, where in each subsequent step temperature is approximately doubled, and the obtained polycrystalline mechanical strong material undergoes sintering at 1200-1750°C at pressure of 30-300 MPa for 20-30 minutes, after which temperature of furnace is brought down to ambient temperature under inert conditions.

EFFECT: invention enables to obtain high-quality optical polycrystalline material from structured elements with dimensions of several nanometres and having high optical transparency in the visible an infrared spectra and high mechanical strength which is 3-5 times higher than that of ceramics with micro-sized particles, as well as obtaining material for the input lens of a photodetector which, while retaining main optical parametres, has properties required for material for this purpose - heat resistance, thermophysical stability in a high-temperature plasma current.

6 cl, 1 ex, 1 tbl

FIELD: physics.

SUBSTANCE: proposed laser material is a ceramic polycrystalline microstructure substance with particle size of 3-100 mcm, containing a twinned nanostructure inside the particles with size of 50-300 nm, made from halides of alkali, alkali-earth and rare-earth metals or their solid solutions, with vacancy or impurity laser-active centres with concentration of 1015-1021 cm-3. The method involves thermomechanical processing a monocrystal, made from halides of metals, and cooling. Thermomechanical processing is done until attaining 55-90% degree of deformation of the monocrystal at flow temperature of the chosen monocrystal, obtaining a ceramic polycrystalline microstructure substance, characterised by particle size of 3-100 mcm and containing a twinned nanostructure inside the particles with size of 50-300 nm.

EFFECT: improved mechanical properties, increased microhardness and failure viscosity.

5 cl, 1 tbl, 4 ex, 1 dwg

FIELD: manufacture of polycrystal superhard materials on base of dense modifications of borazon and wurtzite-like boron.

SUBSTANCE: borazon and wurtzite-like boron may be used as materials for parts of high-pressure apparatus and tools in treatment of wear-resistant materials, first in sharpening heat-treated steels, gray and high-strength cast irons, tungsten-containing hard alloys, reinforced concrete, stone and plastics. Proposed method includes subjecting boron nitride to action of pressure from 6.5 to 9 Gpa at high temperature for 2-3 min, after which temperature is reduced to room magnitude and pressure is reduced to atmospheric level at rate of 200°C per Gpa to 250°C per Gpa. Used as borazon is wurtzite-like boron or mixture of wurtzite-like boron and borazon at its content 0f from 0 to 50 mass-%; process is performed at temperature of from 1500°C to 2200°C in field of their stability under isothermal conditions; temperature gradient of from 20°C/mm to 70°C/mm may be additionally created in direction of reaction cell axis. Borazon and wurtzite-like boron are placed in reaction cell layer-by-layer perpendicularly to cell axis; composition of one layer differs from that of adjacent layer in content of wurtzite-like boron and borazon; graininess of borazon ranges from 3/2 mcm to 200/160 mcm.

EFFECT: enhanced efficiency; possibility of producing flaw-free material possessing high strength.

3 cl, 11 dwg, 1 tbl, 11 ex

FIELD: jewelry technology; manufacture of jewelry colored inserts.

SUBSTANCE: synthetic corundum contains alumina, color-forming additives and binder-paraffin. Required color is obtained as follows: for obtaining black color molybdenum oxide is added to alumina in the amount of 0.03%; for obtaining gray color, tungsten oxide is added to alumina in the amount of 0.01%; for obtaining blue color, neodymium oxide is added in the amount of 0.01%; for obtaining pink color, erbium oxide is added to alumina in the amount of 0.01%; for obtaining red color, chromium oxide is added in the amount of 0.05%. Proposed method of manufacture of jewelry articles includes molding in casting machines at a pressure of 4 atm and roasting; first roasting cycle is performed in continuous furnaces for burning-out the binder and is continued for 90 h at temperature of 1150 C; second roasting cycle is performed in batch furnaces at temperature of 1750 C and is continued for 170 h for forming and sintering of microcrystals making translucent crock at density of 4 g/cu cm and hardness of 9 according to Mohs hardness scale; then polishing is performed with the aid of diamond materials. Articles thus made have high-quality miniature texture at hardness which is disadvantage in relation to diamond only.

EFFECT: high quality of articles; enhanced hardness of articles.

7 cl

FIELD: chemical technology, in particular production of polycrystalline batch for wurtzite-structure single crystal growth.

SUBSTANCE: claimed method for production of polycrystalline batch for wurtzite-structure oxide single crystal growth of formula LiMeO2, wherein Me refers aluminum or gallium, includes mixing of metal (Me) oxide with lithium carbonate in stoichiometric ratio and sintering in crucible. Starting materials before mixing are crushed to provide particles of size not more than 2 mum and heated in limits of their stability. Sintering is carried out at temperature being equal to 87-88 % of single crystal melting point, for 6 h in alundum crucible. Said wurtzite-structure single crystals are useful in substrate preparation for epitaxial growth of gallium nitride. Method of present invention makes it possible to obtain batch in form of shaped pallets with various size in limits of crucible diameter.

EFFECT: batch for high quality single crystal growth.

1 tbl, 1 ex

FIELD: chemistry.

SUBSTANCE: method of obtaining a composite material includes the influence on a mixture of a carbon-containing material, filler and sulphur-containing compound by a pressure of 0.1-20 GPa and a temperature of 600-2000°C. As the sulphur-containing compound applied is carbon bisulphide, a compound from the mercaptan group or a product of its interaction with elementary sulphur. As the carbon-containing material applied is molecular fullerene C60 or fullerene-containing soot. As the filler applied are carbon fibres, or diamond, or nitrides, or carbides, or borides, or oxides in the quantity from 1 to 99 wt % of the weight of the carbon-containing material.

EFFECT: obtained composite material can be applied for manufacturing products with the characteristic size of 1-100 cm and is characterised by high strength, low density, solidity not less than 10 GPa and high heat resistance in the air.

11 cl, 3 dwg, 11 ex

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