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Method of producing nanodispersed mixture for producing nitride ceramic Method of producing a nanodispersed mixture for producing nitride ceramic involves electric explosion of an aluminium conductor coated with a yttrium oxide-containing coating in a sealed reactor in a medium of nitrogen gas at excess pressure. When charging voltage of the capacitive storage increases from 15 to 25 kV, the average volume-surface dimension of the nanoparticles decreases from 94 to 75 nm, but content of aluminium nitride also decreases from 19.0 to 12.3 wt %. |
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Method of producing titanium boride powder for aluminium electrolytic cell wetted cathode material Invention relates to powder metallurgy. Titanium boride powder is produced by carbothermic reaction between fine powder components of the blend of anhydrous titanium boride, boric anhydride or boric acid and carbon in the form of soot. Boric acid or boric anhydride are added to powder mix in the form of solution while synthesis is conducted at the temperature not over 1473 K for 3-4 hours. |
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Method of producing composite materials from cubic boron nitride Invention relates to production of various types of metal-processing tools: cutters, millers, lapping tools, particularly production of sintered composite material made from cubic boron nitride powder. The method involves moulding cubic boron nitride powder and saturating the obtained moulded article with molten binder made from silicon and nickel at pressure of 20-40 kbar and temperature of 1200-1400°C, lying the range of stability of cubic boron nitride of a phase diagram. The amount of saturating material is equal to 10.0-25.0 wt %. The amount of nickel in the alloy with silicon is equal to 50-75 wt %. |
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Method of obtaining fire-proof material based on silicon beta-nitride β-si3n4 Invention relates to methods of obtaining fire-proof materials on non-oxide basis, namely to fire-proof materials based on silicon beta-nitride β-Si3N4, which can be used as strengthening additives into non-formed fire-proof masses. Ferrosilicium powder, representing two-phase alloy of silicon with iron, is selected as initial raw material for high-temperature processing of silicon-containing powder-like alloy in atmosphere of nitrogen-containing gas under its higher pressure. Powder of initial ferrosilicium, with particle size not exceeding 2.0 mm, is mixed with powder of initial fire-proof material based on Si3N4, with particle size not exceeding 1.0. Obtained mixture is placed into nitrogen-containing atmosphere, which contains not less than 97.5% vol. of nitrogen, in which pressure is supported in the interval 0.15-25.0 MPa during entire process. After that mixture is set in fire by local heating to the temperature of beginning of exothermal reaction of silicon with nitrogen interaction. Nitration is carried out first in mode of layer-by-layer burning at temperature 1750-2250°C and further in mode of volumetric burning at temperature 2250-1250°C for the time, sufficient for converting more than 50% of initial silicon into silicon nitride, which consists of nitride of beta-modification β-Si3N4 for not less than 90 wt %. |
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Method of producing ceramics and composite materials based on ti3sic2 Invention relates to production of high-temperature structural ceramic materials, and specifically to a method of producing a ceramic composite with a Ti3SiC2 based matrix. The method of producing ceramics and composite materials based on Ti3SiC2 from titanium, silicon and carbon in a composition of silicon carbide involves laying alternating layers in form of a multilayer pack of titanium foil and isometric dispersed silicon carbide particles and carbon in the composition of highly filled polymer films. The multilayer pack is subjected to force SHS compacting in a vacuum or in an atmosphere of inert gas under a mechanical load of 0.2 MPa or higher, which is applied in a direction perpendicular to the plane of the layers. |
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Method of making polycrystalline material based on cubic boron nitride containing diamonds 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. |
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Method of producing protective coating and composition of protective coating mixture Invention relates to a composition and a method of producing protective coatings. The method of producing a protective coating involves preparation of a mixture by mixing starting components containing silicon, zirconium boride and boron, with the following ratio of components, wt %: Si - 65-75, ZrB2 - 10-30, B - 10-30. Slip is then prepared with addition of an organic binder and the slip is deposited on a substrate. The obtained workpiece is heat treated in an air medium at temperature of 650-1000°C for 10-15 minutes. |
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Method of obtaining charge material for synthesis of silicon nitride Invention relates to powder technology and is meant for producing, via self-propagating high-temperature synthesis, silicon nitride with high content of basic substance, fine particle size of the basic mass with considerably narrow grain-size distribution. The method involves mixing powdered silicon and silicon nitride as a diluent, wherein a filling layer of silicon powder is first formed, silicon is then activated by autogenous grinding of particles in a high-speed jet of compressed gas, e.g., nitrogen or air, at excess pressure of not less than 6 kg/cm2 for not less than 2 recycles of the charge mass with movement thereof by an ascending gas stream from the filling layer to the zone of centrifugal forces generated by the rotor of a centrifugal classifier; the powdered material is recycled by outputting the coarse fraction from the zone of centrifugal forces and returning to the filling layer; air-centrifugal separation of particles smaller than 5 mcm is carried out, after which in the nitrogen jet, activated silicon is mixed with powdered silicon nitride having average particle size δ50 smaller than 1 mcm and distribution function width Span=(δ90-δ10)/δ50 of not more than 2, in amount of 10-25% of total weight, for 7-8 recycles at excess nitrogen pressure of not less than 4 kg/cm2, where δ50 is the size where particles of smaller size account for weight ratio of 50% (average particle size), δ10 is the size where particles of smaller size account for weight ratio of 10% and δ90 is the size where particles of smaller size account for weight ratio of 90%. As a result, silicon nitride is obtained in form of a fragile sinter from fine particles while significantly cutting the amount of inert diluent in the charge material and increasing output of the end product. |
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Method of producing protective coatings on articles with carbon-containing base Invention relates to production of carbon articles and materials and is meant for protecting articles operating in oxidative medium conditions at high temperatures, for example in metallurgy industry, aircraft building and other industries, from oxidation. The method involves formation on the surface of the article of a slurry coating based on a composition consisting of a mixture of fine powder of carbon and a refractory metal or compound thereof and a binder, heating the article in silicon vapour in a vacuum in the volume of a reactor with subsequent ageing and cooling. The refractory metal or compound thereof used is Mo and/or W and/or "И", and/or Zr and/or Hf, which are active towards silicon, and/or compounds thereof such as carbides and lower silicides of these metals, e.g., Mo2C, MoC, W2C, WC, TiC, ZrC, HfC, Mo5Si3, W5Si3, Ti5Si3, Zr5Si3, Hf5Si3 or similar. The article is heated in silicon vapour at pressure 1-36 mm Hg to temperature 1500-1750°C and held in said temperature interval and pressure for 1-3 hours, after which the article is cooled in silicon vapour. Heating from 1000°C to 1500-1750°C is preferably carried out at a rate of not more than 150°/h with isothermic ageing at temperatures where chemical reactions for forming silicides are intense. |
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Mixture for ceramic material based on zirconium and aluminium oxides and zirconium nitride Invention relates to ceramic material science, particularly to production of ceramic material based on heat-resistant non-oxygen and oxide compounds, characterised by high strength and crack-resistance, and can be used to make a cutting tool, in oil and gas industry (valve devices and sealing rings of pumps), in making nozzle extensions for air-sand blowers and chemical solution sprayers. The ceramic material is obtained from a mixture which contains components in the following ratio, wt %: Al2O3 10-40, ZrN 20-65, ZrO2 - the balance, at sintering temperature 1700-1800°C and nitrogen pressure during sintering of 0.10-0.12 MPa without a complex operation for isostatic moulding using high pressure. |
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Method to develop structural ceramic material Charge is prepared, containing the following components, mol. %: SiC - 53-62, BN - 3-7, Al - 35-40, at the same time the rated quantity of aluminium is introduced in it in full volume, doing mechanical activation. Primary stocks are shaped from the charge, dried, exposed to vacuum sintering and grinding. After the secondary shaping the stocks are dried, sintered in vacuum, nitrified at the temperature of 1050°C, and thermal treatment is carried out at 1400°C. Vacuum sintering is carried out at the temperature of 1150±2°C. The produced structural ceramic material is characterised by higher density and strength: withstands compression stress of at least 450 MPa, bending stress - of at least 130 MPa at high working temperatures of the material (at least 1400°C). Shrinkage at the stage of cermet conversion into ceramics - not more than 0.5%. |
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Method of producing polycrystalline cubic boron nitride with fine-grain structure 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. |
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Method of producing cubic boron nitride-based polycrystalline material 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. |
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Method of producing superconducting three-component boride Invention relates to chemical industry, particularly, to production of new superconducting boron-containing compounds. Proposed boride including lithium, vanadium and boron and having transition to superconducting state at 27 K is produced by sold-phase high-temperature synthesis of initial components made up of the mix of vanadium and boron powders with molar ratio of 1:2 and 0.3-0.5 mol of metallic lithium at 1000°C in vacuum of 10-4 Pa for 5 minutes. |
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Method of producing aluminium nitride-based heat-conducting ceramic Invention relates to production of aluminium nitride-based heat-conducting ceramic which can be used in electronics and electrical engineering, particularly as substrate material for powerful microwave and power semiconductor devices, as well as other devices where there is need for good dielectric properties, strength and heat conductivity of the material. Powder of aluminium nitride with particle size less than 1 mcm, containing not less than 10% cubic phase of aluminium nitride with particle size less than 100 nm, and a technical additive selected from Y2O3, CaO, MgO in amount of not more than 6 wt % is used to prepare a mixture, with addition of not more than 65 vol. % organic component containing a solvent (mixture of methylethyl ketone with ethanol in ratio of 1:2), a dispersant (phosphate ether), binder (polyvinyl butyral) and a plasticiser (mixture of polyethylene glycol with dibutyl phthalate), followed by stirring with simultaneous deaeration for not less than 30 minutes rarefaction of air of not less than 0.15 atm. A belt is formed from the obtained slip, dried and cooled to room temperature. A plate is formed from the belt. The organic component is removed at temperature 150-500°C. The obtained half-finished product is sintered at pressure 0.1-1.0 MPa in the atmosphere of a nitrogen-containing gas at temperature 1650-1820°C for 1-3 hours and then cooled under given conditions. |
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Invention relates to production of superhard material which contains CVD diamond and which can be used in making a wheel dressing tool, a cutting, drilling tool etc. The surface of the CVD diamond is partially or completely covered by a shell under high pressure and temperature, where the said shell has a frame made from polycrystalline diamond (PCD) or polycrystalline cubic boron nitride (PCBN) with a bond between diamond-diamond grains or cBN-cBN grains, between which an activating additive is placed. The surface area of the shell surrounding the CVD diamond is not less than 40% of the surface of the CVD diamond; said shell contains 70-95 wt % PCD or PCBN and 5-30 wt % activating additive. If the shell is made from polycrystalline material based on PCD, the activating additive contains silicon and/or at least one transition metal, and if made from polycrystalline material based on PCBN, the activating additive contains aluminium and/or nitrides, borides and/or salicides of group IlIa, IVa, IVb, Vb, VIb, VIIb and VIII metals. The CVD diamond component of the superhard material can be polycrystalline as well as monocrystalline and can have different shapes and dimensions. |
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Material of moistened cathode of aluminium electrolyser Material of moistened cathode of aluminium electrolyser consists of refractory compound of titanium boride and non-organic binding on base of high dispersed aluminium oxide moistened with liquid aluminium. Also, contents of titanium boride in finished material are not less 30 wt %. As binding on base of high dispersed aluminium oxide there is used "Al-corit-98" at amount of 10 wt %. It additionally contains electro-conducting powders of graphite or copper, or iron. |
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Wettable cathode material for aluminium electrolysis cell Wettable cathode material for an aluminium electrolysis cell consists of titanium diboride wettable by liquid aluminium and binder - saturated solution of a hexa-hydrate of aluminium trichloride with ratio of titanium diboride to binder between 1:50 and 1:15. |
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Method of producing polycrystalline cubic boron nitride 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. |
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Method of making non-shrinking structural ceramic article Invention can be used to make articles from high-strength, non-shrinking ceramic materials working in high thermal-cycle loads in an oxidative, corrosive and aggressive atmosphere, and particularly in power generation installations. The starting material undergoes screening and deep cleaning. A mixture is prepared from components in the following ratio in mol %: boron nitride 12.5-17.5, aluminium 37-43, silicon carbide 42.5-46 and the mixture is mechanically activated. Primary workpieces are moulded from the mixture, dried and vacuum sintering is carried out at temperature between 1150 and 1250°C with residual pressure of 0.05 atm. The sintered workpieces are ground up and mechanically activated, after which articles are moulded and then vacuum sintered in conditions given above, mechanically processed, nitrogen hardened and oxidised. |
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Method of obtaining composite material based on diamond and/or cubic boron nitride powder Invention relates to mechanical engineering and particularly to obtaining composite materials based on diamond and/or cubic boron nitride powder, which can be used, for instance as cutting elements in different instruments: drilling, driving instruments, in stone working instruments and instruments used in building industry etc. The method of obtaining composite material involves putting diamond and/or cubic nitride powder into a mould, packing and saturation with metals and/or alloys. The diamond and/or cubic nitride powder with different strength is used and packing is carried out at pressure whose value is selected from the condition Σst.>P>Σl st., where P is value of pressure during packing, Σst. is strength of powder with greater strength, Σl st. is strength of powder with less strength. |
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Composite material for moistened cathode of aluminium electrolytic cell Composite material for moistened cathode of aluminium electrolytic cell relates to field of non-ferrous metallurgy and, particularly to production techniques of aluminium by method of electrolysis of cryolite-aluminous melts. Composite material consists of moistened by liquid aluminium high-melting compound - titanium boride and binding agent, where in the capacity of binding agent it is used high-aluminous cement, herewith correlation of components of titanium boride: cement is selected 9:1. |
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Method of producing moulded aluminium oxynitride in burning mode Invention relates to making heat resistant ceramic materials, particularly to methods of producing aluminium nitride in burning mode. The method of producing aluminium oxynitride involves preparation of a reaction mixture of initial components, containing chromium (VI) oxide, aluminium oxide, aluminium and aluminium nitride, putting the reaction mixture into an SHS reactor in form of heat resistant material, made from quartz, graphite or stainless steel, ignition of the mixture with subsequent reaction of its components in burning mode under 0.1-10 MPa pressure in a nitrogen medium, or mixture nitrogen and air, or mixture of nitrogen and argon. After synthesis of the end product in form of an ingot, aluminium oxynitride is separated from the chromium aluminide ingot. Components of the reaction mixture are in the following ratio, wt %: chromium (VI) oxide 37.3-41.0; aluminium 31.0-34.0; aluminium oxide 22.7-25.0; aluminium nitride up to 9.0. A functional layer of aluminium oxynitride powder can be put between the reaction mixture of components and the wall of the mould. |
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Method of connecting ceramic units from silicon nitride Invention relates to methods of connecting separate units from silicon nitride, which are used in manufacturing of constructional products, for instance nozzle apparatuses, long thermosteam covers and pipes (chlorine inputs), operating in aluminium melt at temperature 1200°C, glass-melting apparatuses for glass fibre stretching at temperature to 1600°C. Said technical result is achieved by the following: method includes preparing of glue mixture based on silicon nitride, which contains, wt %: 0.5-1.0 - melted magnesium oxide, 0.5-3.0 milted aluminuim oxide, 35-41 aluminiumboronphosphate binding agent and separately - similar mixture with alumochromephosphate binding agent, application on connected surfaces of units first mixture with aluminumboronphosphate binding agent, then mixture with alumochromephosphate binding agent with further coupling of said surfaces. Burning of connected product is carried out at temperature 1000°C with staying for 2 hours. |
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Method of charge receiving containing aluminium nitride of cubic phase Method includes mixture preparation of superdispersed powders of aluminium and additions, burning of mixture on air up to achieving of maximal combustion temperature and quenching. In the capacity of addition it is used powder of tungsten or molybdenum at following correlation of components, wt %: superdispersed powder of aluminium - 97-98, superdispersed powder of tungsten or molybdenum - the rest. |
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Structural material as per the invention is received from the charge material containing cilicide of carbon in the form of ultra fine fiber, ultra fine boron nitride and carbon fiber having periodically recurring internal volumes filled with helium at the following components ratio, volume %: boron nitride B11N15 30-94.6, carbon fiber 5-25, ultra fine cilicide of carbon 0.2-15, helium 0.2-30. Diamond - like layers are located in the contact spots of ultra fine fiber with carbon fiber, and cubic boron nitride layers are located in the contact spots with boron nitride. Helium and boron nitride have isotopic composition with light section of thermal neutron capture. |
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Method of furnace charge preparation for zirconium boride products Invention refers to ceramic product industry, specifically to methods of furnace charge preparation for boron-carbide zirconium boride products. According to method qualitative composition of the additive activating product compaction is chosen from impurities contained in crude zirconium boride, namely from ZrO2 and/or ZrC2 and/or B4C. Its qualitative composition is calculated from stoichiometry of zirconium boride production from impurities and additive. |
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Composite ceramic material for high-temperature application (versions) Composite ceramic material is produced on the base of refractory oxygen-free and oxide compounds to use in conditions which require high rigidity, firmness and oxidation stability: for manufacturing cutting tools, thermowells for temperature control in molten metals, nozzle extensions for air sand blowers, in gas and oil industry. Composite ceramic material containing ZrB2 and ZrO2, in the fist version additionally contains TiN and Y2O3 with following mixture ratio: wt %: ZrB2 20-40, Y2O3 4.5-10, TiN 10-25.5, ZrO2 - the rest, and in the second variant - ZrN and Y2O3 with following mixture ratio: wt %: ZrB2 20-40, Y2O3 4.5-10, ZrN 10-25.5, ZrO2 - the rest. |
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Pre-oxidised ceramics for zinc anode Additive to claimed zinc anode mass is an electroconductive fine ceramic powder of titanium nitride (TiN), oxidised in air or pure oxygen medium at 150 to 800°C for a period from 5 minutes to 15 hours before introduction to composition of active zinc anode mass. |
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Sintered metal-ceramic materials Proposed sintered material contains the following components, mass-%: boron nitride, 15.0-20.0; boron carbide, 15.0-20.0; titanium boride, 15.0-20.0; aluminum, 5.0-10.0; chromium, 15.0-20.0; the remainder being nickel. |
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Burden for manufacture of refractory articles Proposed burden contains the following components, mass-%: boron nitride, 25-55; synthetic corundum, 15-40; molten mullite, 10-15; alumina, 10-25; fire clay and kaoline, 5-15; rare-earth metal oxide from groups La2O3, Nd2O3 and Gd2O3, 0.5-5; alumo-containing compound, 0.1-5. Used as alumo-containing compound is aluminum hydroxide, aluminum chloride or aluminum carbonate. |
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The invention is pertaining to the field of the tool-and-die industry, in particular, to production of the composite materials for the cutting tools on the basis of the ultra-hard particles with their volumetric contents in the material of 75÷ 92 %. For production of the composite materials the method provides for preparation of the charge, which consists of the binding agent and the ultra-hard particles, at least, of two sizes, from which as one size the ultra-hard particles use the diamond, and as the ultra-hard particles of the other size use the cubic boron nitride of 8÷40 microns. At that they take diamond particles with the size equal to (5.1-8) sizes of the cubic boron nitride. The charge is subjected to the thermal pressing at the temperature of the binding agent melting. Besides, the charge is additionally introduced with the diamond particles of the size equal (4-6) sizes of the main diamond grains. At that the main diamonds grains are taken with the size of 81-320 microns. The method allows manufacture the composite material with the wide range of the operational characteristics. |
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Method of production of the powders of the chemical elements nitrides The invention is pertaining to production of the refractory materials and may be used in aerospace industry, chemical metallurgy, tool-and-die industry and other industries for the synthesis of the powders of the chemical elements nitrides used for manufacture of the products having the high thermal stability, hardness, wear-resistance, erosion resistance, resistance to the corrosive mediums action, stability of the physical properties in the wide temperature ranges and used in the various engineering fields. The substance of the invention consists, that the method of production of the powders of nitrides provides for preparation the exothermal mixture consisting of the azotizing chemical element, the inorganic azide and the haloid salt and the mixture ignition in the nitrogen medium under pressure. At that as the haloid salt use the complex fluoride salts of the following alkaline metals:Na2SiF6, Na3AlF6, KBF4, Na2TiF6. The technical result of the invention is the fact, that the method allows to synthesize the base products with the nitration degree close to 1, and also to produce the powders of nitrides of the high-degree purity and the improved crystal structure. |
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Method comprises steps of activating and chemically copper plating powder of cubic boron nitride with fraction size no more than 10 micrometers; then mechanically mixing copper coated powder of cubic boron nitride and titanium powder with fraction size no more than 10 micrometers; subjecting prepared mixture to thermal vacuum treatment according to schedule: soaking at temperature 650 - 980°C and evacuation degree 1 x 10-5 - 5 x 10-5 Hg mm; soaking at 250 - 350°C and evacuation degree 300 -400 Hg mm; soaking at 700 - 900°C and evacuation degree 1 x 10 -5 - 5 x 10 -5 Hg mm; cooling mixture; increasing pressure till atmospheric one and mechanically mixing prepared mixture with aluminum powder. Prepared charge is placed in container and subjected to hot extrusion at 1100 - 1300°C and 3.5 -4.0 GPa for producing compacted product. Then temperature and pressure are lowered. In second variant of invention before thermal vacuum treatment one of alloys Mo -Al, V - Al, Ni - Al is introduced into mixture and hot extrusion is performed at 1100 - 1300°C or 5.0 - 5.5 GPa. |
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Method for treating melt non-ferrous metals in contact with refractory material Novelty is usage of titanium carbosilicide Ti3 SiC2 as hard refractory material. |
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Method of production of a ceramic charge The invention is pertaining to the technology of production of the technical ceramics, in particular, to the technical ceramics resistant to the high temperatures and possessing a high thermal conductivity, which may be used in production of a charge for ceramic ware, including, the multilayered ceramic substrates, ceramic heaters, ceramic emitters and refractory structural materials. The offered development allows to form the charge with the required ratio of aluminum nitride and aluminum oxide by incineration of the ultradispersive powder of aluminum in a gas medium at the atmospheric pressure. The incineration of the aluminum powder is conducted in the chamber, which is connected by the free cross-flow to the gasholder filled with an artificial gaseous mixture of nitrogen and oxygen with the preset ratio. The technical result of the invention is the ratio control of an aluminum nitride and aluminum oxide in combustion materials by formation of the gases mixture with a preset amount of nitrogen and oxygen. |
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Method of production of composite materials Proposed method includes molding the blanks from borazon powders followed by heat treatment of blanks in hydrocarbon medium and impregnation with liquid silicon at temperature of 1420-1700°C and pressure no less than 1000 mm Hg. Heat treatment in hydrocarbon medium is continued till increase of mass of blank by 3-25%. Borazon grains are bonded by silicon carbide matrix; proposed method excludes losses of superhard materials in forming silicon carbide due to diamond. |
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Furnace charge for production of aluminum oxynitride The invention is pertaining to the field of production high-refractory ceramic materials, in particular, to production of aluminum oxynitride, which may be used as a component of ceramics and cermet for manufacture of cutting tools, heat-resistant and heat-conducting components of constructions, and also in thee oxidizing mediums instead of aluminum nitride and in a combination with it. The technical result of the invention is reduction of the end product cost price due to utilization of the more low-cost components. The premixed source charge consisting of an aluminum powder with the size of the specific surface area less than 0.01 m2/g with the content of the main substance of 79.4-99.8 mass % and a powder of aluminum oxide with the size of the specific surface less than 2.2 m2/g, burn in the air. The components are taken in the following ratio (in mass %): aluminum powder - 5-20, a dust of aluminum oxide - the rest. |
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The invention presents a method of production of strongly nestled superconductive massive bodies made out of MgB2 having the density close to the theoretical value. At that the method includes the following stages: a mechanical activation of a crystalline boron with formation of the activated powders; formation of a porous workpiece out of the indicated powders; assembly of the porous workpiece out of boron and the massive forerunners of the metallic magnesium in a container and its pressurization in an aerosphere of a noble gas or with low oxygen content; the thermal treatment of boron and magnesium assembled as stated above, at the temperature above 700°C during a time interval exceeding 30 minutes. As a result of it the liquid phase of magnesium infiltrates through the activated powders of the crystalline boron. Mechanical activation of the crystalline boron is conducted by comminution of flakes of the crystalline boron with the help of a repeated crushing at compression under a heavy pressure. The technical result of the invention is simplification of the method of production of strongly nestled products out ofMgB2 with improved characteristics. |
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Claimed material is sintered under pressure and contains (mass %): hexagonal boron nitride 45-80 and second material 55-20. The second material represents solid aluminum oxide solution in silicium nitride containing 35 % or less of oxygen. |
Another patent 2513130.