Boride nanofilm or nanowire and method of their production (versions)
SUBSTANCE: inventions can be used in the field of nanotechnologies and inorganic chemistry. The method of production of boride nanofilm or nanowire comprises depositing on the alumina nanowire or on fiberglass of low-melting glass in vacuum the multiple alternating layers of titanium and boron, after which the resulting composition is gradually heated to a temperature of 1500°C. In another embodiment, the method of production of boride nanofilm comprises depositing of titanium boride layer of nanothickness on alumina nanofilm of the gas phase comprising titanium halogenide and boron.
EFFECT: inventions enable to obtain boride nanostructures.
4 cl, 2 ex
The invention relates to nanotechnology and is intended to generate boride tubular or composite filament, film or tape (the only difference in width Anatoliy.
Analogs and prototypes invention has not.
Boride nanoslick or nanowire is composed of borides of metals structure in the layer Anatoliy.
METHOD - 1 obtain nanolayers or nanowires is that any fiber or film (hereinafter "the Foundation") is deposited a layer of metal or boron, which is then deposited a layer of boron or metal, respectively, or on the basis of precipitates multiple alternating layers of metal and boron with a total thickness of not more nanoscale, which are then subjected to gradual heating to a temperature of 1500 degrees C (hereinafter - "the process of boriginal", see "encyclopedia of Chemical", "B", article "the Borides"). Thus there is a gradual reaction formation boride metal.
If the film or fiber is so heat-resistant that do not evaporate or do not decompose under the above-mentioned process (for example, corundum nanowire), they can remain in the structure. There will be a combined nanoprene or tubular composite nanowire.
If you want to get clean boride structure, we choose the base material such that it has evaporated or disintegrated at high temperatures the process is and britishly, or when additional heat after britishly.
HOW 2 get nanolayers or nanowires is that any fiber or film (hereinafter "the Foundation") is the deposition of boride from the gas phase by the interaction of metal halides and boron (see "encyclopedia of Chemical", "B", article "the Borides", section "Obtaining borides").
As the boron compounds with the same metal can vary in composition, it is necessary to control the ratio of metal and boron to achieve the desired connection.
Example 1. On corundum nanowire or a glass of low-melting glass in a vacuum deposited several alternating layers of titanium and boron, after which the composition is gradually heated to a temperature of 1500 degrees C. the Formed tubular boride nanowire. It should be noted that the total thickness of the composition will be more nano, but the thickness of the boride layer tubular film will correspond to the nano range.
After the process is finished, the glass can be removed by heating and subsequent evaporation.
Example 2. On the corundum nanoplasma from the gas phase containing a halide of titanium and boron, is deposited a layer of boride titanium Anatoliy. Moreover, it is possible that they will be deposited on both sides of the film. And the resulting composition may be again applied the PSS is (or two layers on both sides) corundum, etc. Can get a "package" of alternating nanolayers with unpredictable until the property.
1. The method of obtaining boride nanolayers or nanowires, characterized in that on corundum nanowire or a glass of low-melting glass in a vacuum precipitated several alternating layers of titanium and boron, after which the composition is gradually heated to a temperature of 1500°C.
2. Boride nanoslick or nanowire, characterized in that it is obtained by the method according to claim 1.
3. The method of obtaining boride nanolayers, characterized in that the corundum nanoplasma from the gas phase containing a halide of titanium and boron, precipitated layer of boride titanium nanotools.
4. Boride nanoslick, characterized in that it is obtained by the method according to claim 3.
SUBSTANCE: invention relates to a composition of a biodegradable ceramic fibre for high-temperature heat insulation. The composition of the biodegradable ceramic fibre for high-temperature heat insulation contains the following components in wt %: SiO2 - 58-67; CaO - 26-34; MgO - 2-8; Al2O3 - 0-1; B2O3 - 0.2-1.1; B2O3+Na2O - 0.3-1.1; admixtures, selected from TiO2 and Fe2O3 - less or equal to 1.
EFFECT: increased heat resistance of products.
8 cl, 2 ex, 3 tbl
FIELD: process engineering.
SUBSTANCE: invention relates to the parts of composite with ceramic matrix and can be used in aircraft engines, particularly, gas turbines or turbo machines of said engines. Surfacing of composite part consisting of fibres compacted by ceramic matrix with wavy and rough surface includes forming of ceramic coat on part surface. Liquid composition (20) containing polymer, a ceramics precursor, and hard refractory filler for cross-linking (40) of polymer and converting cross-linked polymer (50) into ceramic by heat treatment. After heat treatment, ceramic coating is impregnated with liquid metal composition that features thermal compatibility with part material. The part of composite C/SiC furnished with ceramic coating can be impregnated with composition of silicon-germanium or silicon-nickel.
EFFECT: high aerodynamic properties of the surface.
7 cl, 6 dwg
SUBSTANCE: invention relates to ceramics and particularly to a composite material and a method for production thereof. The ceramic composite material includes a matrix of aluminium oxide doped with magnesium oxide, and multilayer carbon nanotubes, with the following ratio of components, vol.%: magnesium oxide - 0.1-0.4; multilayer carbon nanotubes - 0.1-20; aluminium oxide - the balance.
EFFECT: obtaining a ceramic composite material.
6 cl, 1 ex, 3 tbl
FIELD: radio engineering, communication.
SUBSTANCE: volume-reinforced woven materials made of silica and quartz fibres are impregnated with aqueous silica sol solution, followed by drying and heat treatment. The "impregnation, drying, heat treatment" cycle is repeated until density of the workpieces reaches 1400±100 kg/m3. Drying is carried out on air and heat treatment is carried out as follows: raising temperature to 120±50°C and holding for 3.0±0.5 hours; raising temperature to 230±50°C and holding for 3.0±0.5 hours; raising temperature to 500±50°C and holding for 5.0±0.5 hours. Further, impregnation is continued with water-soluble zirconium compounds with concentration of 30-55%. Heat treatment is carried out as follows: raising temperature to 150±100°C and holding for 3.0±0.5 hours; raising temperature to 600±100°C and holding for 6.0±0.5 hours until density of the workpieces reaches 1600±100 kg/m3. The zirconium compounds used are zirconyl nitrate solution or zirconyl chloride solution.
EFFECT: high operating temperature of radio engineering material with maximum preservation of dielectric properties of the material.
2 cl, 2 tbl
SUBSTANCE: invention can be used in chemical industry and nanotechnology. The nano-film or nano-thread is obtained by depositing on a base - fluoroplastic fibre or film - a layer of boron or silicon with nano-thickness, which is then treated in carbon monoxide gas in the presence of coal or soot at temperature of 1400-1500°C. A silicon layer or a boron layer is the deposited on the formed layer of boron carbide or silicon carbide, respectively. The formed composition is held in a vacuum or in an atmosphere of an inert gas at temperature of 1400-1500°C and then at the same temperature in carbon monoxide gas in the presence of coal or soot. The base used can be corundum fibre or film.
EFFECT: obtained nano-film or nano-thread has high strength.
6 cl, 4 ex
SUBSTANCE: invention relates to construction, namely to production of fireproof products. Composition for manufacturing heat-insulating products includes fireproof fibre, fireproof clay, slightly foamed polystyrene and swollen pearlite sand, with the following component ratio, wt %: fireproof fibre - 40; fireproof clay - 30; slightly foamed polystyrene - 10 (above 100% by weight); swollen pearlite sand - 30.
EFFECT: reduction of density, heat conductivity of products, total shrinkage, fibre consumption, reduction of drying time and expenditures on heat carriers.
SUBSTANCE: fibrous ceramic slurry is prepared. By means of vacuum moulding, a fibrous mat is produced with its further drying. Then the mat is submerged into a binding sol-gel for 1/4-3/4 of its height. Heat treatment of a gelled mat is carried out according to a stepwise mode including heating to (80-100)°C, soaking for 8-72 hours, heating to (250-350)°C with speed of (20-50)°C/hr, soaking for 2-4 hours, heating to (1000-1400)°C with speed of (100-200)°C/hr, soaking for 1-4 hours.
EFFECT: increased working temperature of a ceramic material having high elasticity, low density and heat conductivity.
3 cl, 1 tbl, 1 dwg
SUBSTANCE: invention relates to structural materials operating in conditions of high thermal load and oxidative medium, and can be used in chemical and metallurgical industry, as well as aircraft engineering. The method involves making a carbon-plastic workpiece based on carbon fibre and thermoreactive binder, thermal treatment thereof until formation of a coke matrix reinforced with carbon fibres, subsequent compacting of the coke matrix via saturation with pyrolytic carbon and silicon impregnation. Saturation with pyrolytic carbon is carried out until achieving intermediate density of the carbon workpiece of 78-87% of the maximum apparent density of the carbon material, after which preliminary silicon impregnation at temperature 1500-1650°C and residual pressure 1-36 mm Hg is carried out, with subsequent distillation of free Si at temperature 1800-1850°C and residual pressure 1-36 mm Hg, and the material is then impregnated with coke binder, carbonised and subjected to final silicon impregnation using a vapour-phase technique.
EFFECT: obtaining carbon-silicon carbide material with high content of SiC (>30 wt %) and low content of free silicon, having high stability of shape and possibility of prolonged operation in an oxidative medium at temperature 1600-1800°C.
2 cl, 1 tbl
SUBSTANCE: invention relates to engineering ceramics and can be used to make structural components operating under high mechanical loads. The ceramic-matrix composite material, having a hardened reinforcing component in form bundles of carbon filaments coated with a layer of silicon carbide, and a silicon carbide-based matrix, contains carbon filaments inside bundles joined with each other by a carbon inter-filament phase which is reinforced with carbon nanotubes. The silicon carbide layer contains nanosized grains and the matrix further contains free silicon. When producing the ceramic-matrix composite materials, bundles of carbon filaments are treated under the action of ultrasonic vibrations with a suspension containing 2-8 wt % carbon nanotubes and 5-20 wt % polymer binder in an organic solvent, after which a polymer layer is then deposited onto the bundles via treatment thereof with a suspension containing 10-30 wt % polymer binder and 3-15 wt % thermal expanded graphite. Synthesis of the matrix and silicon carbide layer containing nanosized grains on the bundles is carried out through carbonisation and siliconisation.
EFFECT: obtained material has low porosity, high flexural strength and impact viscosity; production method is suitable for mass economic manufacture of articles.
3 cl, 3 tbl, 6 ex, 2 dwg
SUBSTANCE: invention relates to ceramic composite materials and can be used in making heat-loaded assemblies and components of prospective gas-turbine units and engines of gas and oil pumping, transportation and energy systems operating at high thermal cyclic loads at temperatures of up to 1650°C in air and in fuel combustion products. The disclosed ceramic composite material contains carbon fibre and a matrix obtained from a composition having the following chemical composition, wt %: Si 20-35, C 25-40, SiO2 5.5-6.0, HfO2 5-8, SiC - the rest.
EFFECT: high reliability and longer service life of articles under high thermal cyclic loads at operating temperature of up to 1650°C.
SUBSTANCE: feedstock used to produce oxynitride ceramic is products of burning composite mixtures on air, said mixtures being based on coarse titanium powder with addition of 20-40 wt % fine titanium oxide powder TiO2 and (over 100%) 10 wt % aluminium nanopowder. The obtained mixture is treated by hot pressing in a nitrogen atmosphere at 1500°C for 30 minutes.
EFFECT: simple synthesis techniques, using air as a nitrogen-containing reactant at the sintering mixture synthesis step.
SUBSTANCE: 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 %.
EFFECT: simple process.
FIELD: process engineering.
SUBSTANCE: 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.
EFFECT: better manufacturability, properties of wetted electrode, power savings, lower costs.
SUBSTANCE: 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 %.
EFFECT: using a silicon and nickel alloy enables deeper saturation an article made from cubic boron nitride powder at sufficiently low pressure and obtain a composite material with high heat-resistance, heat-conductivity, wear-resistance and electroconductivity, which enables to use the material for make articles of the required dimensions and shape using simple methods such as electro-erosion machining.
2 cl, 1 tbl
SUBSTANCE: 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 %.
EFFECT: creation of novel method of obtaining fire-proof material based on silicon β-nitride, which would make it possible to produce components of non-formed grogs for protection of metallurgical thermal aggregates, based on silicon nitride with crystalline structure β-Si3N4, with practically absent energy consumption.
1 ex, 1 tbl
SUBSTANCE: 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.
EFFECT: easier moulding of articles which does not require use of special press moulds, and avoiding energy-consuming procedures for post-firing preparation of reagents.
6 ex, 2 dwg
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.
SUBSTANCE: 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.
EFFECT: low temperature for heat treatment of the coating.
3 cl, 4 ex, 2 tbl
SUBSTANCE: 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.
EFFECT: method enables to increase efficiency and carryout synthesis with low nitrogen pressure, which makes SHS technology safer.
SUBSTANCE: 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.
EFFECT: high heat resistance and wider range of obtained coatings.
2 cl, 3 tbl
SUBSTANCE: coating is based on titanium carbonitride with addition of additional elements which provide the required set of mechanical and tribological properties, as well as biologically active and antibacterial properties. Overall concentrations of basic and additional elements are in the following ratio:
EFFECT: coating has high hardness, low modulus of elasticity, high value of elastic recovery, low coefficient of friction and rate of wear in different physiological media.
1 tbl, 2 ex