Composite nanopowder and method for production thereof

FIELD: chemistry.

SUBSTANCE: invention relates to chemical industry and can be used in producing nanopowder by a plasma-chemical method. The composite nanopowder contains particles consisting of a core, which consists of layers of titanium carbonitride and titanium nitrate, and a cladding which consists of a layer of nickel, with the following ratio of layers of the core and cladding, wt %: TiCxNy, where 0.28≤x≤0.70; 0.27≤y≤0.63; - 24-66; TiN0.6 - 30-67; Ni - 4-9. The method involves feeding a precursor containing titanium nickelide and titanium carbide into a reactor-evaporator, treating in a current of nitrogen plasma at plasma flow rate of 60-100 m/s and at precursor feeding rate of 100-140 g/h, subsequent cooling in a current of nitrogen and trapping the evaporation product on a filter surface. The precursor contains said components in the following ratio TiNi:TiC=25-50:50-75.

EFFECT: obtaining nanocomposite powder which enables to obtain harder alloys.

2 cl, 3 dwg, 2 ex

 

The invention relates to the chemical industry and can be used for nano-powders by plasma-chemical method.

Known nanopowder titanium nitride obtained by the powder supply titanium nickelide with a particle size of not more than 40 μm in the chamber of the evaporator reactor, the processing in the flow of nitrogen plasma, followed by cooling in a stream of nitrogen and the capture of the target product on the filter surface (patent RF №2434716, IPC B05D 5/12, 2011).

However, when using known powder as the source mixture to obtain a solid alloys the hardness of the target product will be determined by microhardness of titanium nitride, which is 20500 MPa, which in some cases is insufficient.

Thus, the authors faced the task of developing the composite nanopowder, and the method of its production, providing its use as a source for solid alloys higher hardness of the target product.

The problem is solved in the composite nanopowder comprising particles consisting of a nucleus containing titanium nitride, and a shell containing Nickel, in which the core consists of layers of titanium carbonitride and titanium nitride, and the shell consists of a layer of Nickel in the following ratio of the layers of the core and shell, wt.%: TiCXNy where to 0.28≤x≤0,70; 0,27≤y≤0,63; - 24÷66; TiNfor 0.6- 30÷67; Ni - 4÷9.

The task is also solved in a method of producing composite nanopowder, including the supply of precursor containing nickelide titanium, into the chamber of the evaporator reactor, the processing in the flow of nitrogen plasma, followed by cooling in a stream of nitrogen and the capture of the target product on the filter surface, wherein the precursor further comprises a titanium carbide in the following ratio of components TiNi:TiC=25÷50:50÷75; and the treatment is carried out at a flow rate of plasma 60-100 m/sec and at a feed rate of the precursor 100-140 g/hour.

At the present time of patent and technical literature is not known composition of the composite nanopowder, the particles of which consist of a nucleus containing layers of titanium carbonitride and titanium nitride, and a shell containing a layer of Nickel, in a certain proportion of the layers.

Experimental studies conducted by the authors, has allowed to determine the conditions of carrying out the process, providing nanopowder, the particles of which are multi-layered. The proposed composite nanopowder consists of a nucleus containing refractory hard compounds of titanium in the role of a wear-resistant base, and shell, in the role of a plastic matrix, allowing the adhesive strength of cha the TIC between them. The multiple layers of powder particles causes an increase in the number of interphase boundaries, which subsequently inhibit crack propagation and high residual stresses in solid alloys, obtained on the basis of the offered powder. The sequence of layers is caused by the melting temperature of the phase composition of each layer, as well as conditions precondensation. As a seed in the formation of particles formed of the titanium carbonitride TiCxNywhere to 0.28≤x≤0,70; 0,27≤y≤0,63 (tPL=3100-3000°C depending on the composition x and y), Microtest which is equal to 36000 MPa, and then the titanium nitride (tPL=3000°C), then Nickel (tPL=1450°C). In the study of the morphological composition of the obtained powder is not observed particles of Nickel in the form of drops and single crystal particles of TiC, TiCN, TiN, TiNi correct cubic form that acknowledges receipt of the particles of complex composition with a nucleus consisting of alternating layers of carbonitride-titanium nitride, and a shell consisting of a Nickel. The reduction in the content of Nickel-titanium in the original precursor of less than stated in the ratio leads to the appearance in the final product of single crystals of carbide phase. The increase in the content of Nickel-titanium source precursor more than stated in the ratio leads to the appearance in the final product of metallic Nickel in the form to the PEL. Obtaining powder of nanoscale possible only in accordance with the declared parameters of the process. So, at a flow rate of plasma is less than 60 m/s and feed rate of the precursor is less than 100 g/hour were observed particles over 100 nm at a flow rate of plasma over 100 m/s and feed rate of the precursor over 140 g/hour of intermetallic NiTi no time to fall apart on Ni and Ti.

The proposed composition of the composite nanopowder can be obtained as follows. A mixture of powders of intermetallic NiTi and titanium carbide TiC particle size of not more than 40 μm is treated in a stream of nitrogen plasma, which is placed in the dispenser piston type and pneumopathy served in the chamber of the reactor evaporator installation, equipped with a plasma torch. Powder (with a speed of 100-140 g/h) is injected against the flow of plasma, the speed of 60-100 m/sec Temperature nitrogen plasma in the reactor chamber evaporator is 4000-6000°C. When processing the mixture of powders power is 25 kW/h, the plasma gas flow is 6.0 nm3/H. as plasma and simultaneously the reaction gas using nitrogen technical grade GOST 9293-74 (N2- 99,95%; O2- 0,05%). As the process gas used argon balloon TU-6-21-12-79. Received the product in a stream of nitrogen and cooled in water-cooled temper is offered by the camera, located in the lower part of the reactor evaporator, and then is captured on the surface of a fabric filter.

The phase composition of the obtained powder was investigated by the methods of x-ray phase analysis (upgraded to digital diffractometer DRON-MIND1), including quantitative phase analysis (program STOE WinXPOW). The shape and size of the particles of the powder mixture were determined by the methods of scanning probe microscopy: scanning electron microscopy (SEM JSM6390LA JEOL) and scanning tunneling microscopy (STM SMM-2000 T company "proton-MIET"). The powder was which in acetone using ultrasound in an ultrasonic washer (UM 0,5 company Unitra). The resulting suspension was lowered conductive substrate (Sitall with TiN coating) with mean square surface roughness less than ten nanometers, which was deposited particles of the investigated powder.

X-ray phase and a quantitative phase analysis of the powder showed that the fabric filter is captured heterogeneous composition of the powder consisting of particles having sequentially alternating layers of TiCN-TiN-Ni in the following ratio of the layers of the core and shell, wt.%: TiCXNywhere to 0.28≤x≤0,70; 0,27≤y≤0,63; - 24÷66; TiNfor 0.6- 30÷67; Ni - 4÷9.

For tunneling microscope as well as for SEM, powder mixture was usbutils in acetone using ultrasound, but was deposited on the substrate is donkey temporary pause, during which large particles have time to settle to the bottom of buxa, which is shaking. Thus, applying a thinner layer of small particles. Figure 1 and figure 2 shows the image obtained using a scanning tunneling microscope, fragment deposited on a substrate made of a fabric filter powders. The image illustrates that the particles have a rounded oblong shape. Figure 3 shows the distribution schedule of the nanopowder particles in size, from which it follows that the average particle size is in the range of 40 microns.

Receiving a proposed structure of a composite nanopowder is illustrated by the following examples.

Example 1. Take 25 g of TiNi intermetallic brand PNT (Ti0,45Ni0,55)synthesized in JSC Polema (Tula, Russia), and 75 g of titanium carbide TiC (TiC0,92received by JSC "KZTS" (Russia (Kirovgrad)). Due to the large particle sizes of the powders they are grinded in a ball mill to a maximum particle sizes of 40 nm. A mixture of crushed powders are placed in a dispenser piston type and is served by PNEVMATIKA into the chamber of the reactor evaporator laboratory setup FOR the "Nitron" (Saratov), equipped with a plasma torch. Installation options: power plasmatron - 25 kW/hour; used mode - 100-110 And, 200-220; total gas flow (nitrogen technical grade according to GOST 9293-74) in PL is Smena the reactor 25-30 nm3per hour, this amount of plasma gas - 6 nm3per hour, the rest is stabilizing and hardening; process gas is argon balloon TU-6-21-12-79. Temperature nitrogen plasma in the reactor chamber of the evaporator is equal to 4000-6000°C. a Mixture of original powders with a feed rate of 100 g/h is injected towards the plasma flow speed of 60 m/s the Product of evaporation in a stream of nitrogen plasma is cooled in water-cooled quenching chamber, located in the lower part of the evaporator, and catch the Cyclops vortex type and on the surface of a fabric filter.

According to the results of x-ray phase and a quantitative phase analyses of the obtained target product is heterogeneous powder consisting of particles containing a core and a shell consisting of layers of TiCN-TiN-Ni in the following ratio of the layers of the core and shell, wt.%: TiCXNywhere to 0.28≤x≤0,70; 0,27≤y≤0,63; - 66; TiNfor 0.6- 30; Ni - 4.

According to the scanning microscopy of the particles have a rounded elongated shape with an average diameter of 40 nm.

Example 2. Take 50 g of TiNi intermetallic brand PNT (Ti0,45Ni0,55)synthesized in JSC Polema (Tula, Russia), and 50 g of titanium carbide TiC (TiC0,92received by JSC "KZTS" (Russia (Kirovgrad)). Due to the large particle sizes of the powders they are grinded in a ball mill to a maximum particle size of the particles 40 microns. The mixture of the crushed powder is amemait in the dispenser piston type and is served by PNEVMATIKA into the chamber of the reactor evaporator laboratory setup FOR the "Nitron" (Saratov), equipped with a plasma torch. Installation options: power plasmatron - 25 kW/hour; used mode - 100-110 And, 200-220; total gas flow (nitrogen technical grade according to GOST 9293-74) in the plasma reactor 25-30 nm3per hour, this amount of plasma gas - 6 nm3per hour, the rest is stabilizing and hardening; process gas is argon balloon TU-6-21-12-79. Temperature nitrogen plasma in the reactor chamber of the evaporator is equal to 4000-6000°C. a Mixture of original powders with a feed rate of 140 g/h is injected towards the plasma flow whose velocity is 100 m/s the Product of evaporation in a stream of nitrogen plasma is cooled in water-cooled quenching chamber, located in the lower part of the evaporator, and catch in the cyclone vortex type and on the surface of a fabric filter.

According to the results of x-ray phase and a quantitative phase analyses of the obtained target product is heterogeneous powder consisting of particles containing a core and a shell consisting of layers of TiCN-TiN-Ni in the following ratio of the layers of the core and shell, wt.%: TiCXNywhere to 0.28≤x≤0,70; 0,27≤y≤0,63; - 24; TiNfor 0.6- 67; Ni - 9.

According to the scanning microscopy of the particles have a rounded elongated shape with an average diameter of 40 nm.

Thus, the authors propose the composition of the composite nanopowder and method thereof that provide long is the Cabinet, particles which consist of a nucleus containing alternating layers of refractory solid titanium compounds, and a shell containing plastic phase is Nickel. The proposed powders can be used as feedstock in the production of hard alloys.

1. Composite nanopowder comprising particles consisting of a nucleus containing titanium nitride, and a shell containing Nickel, characterized in that the core consists of layers of titanium carbonitride and titanium nitride, and the shell consists of a layer of Nickel in the following ratio of the layers of the core and shell, wt.%: TiCxNy24-66, where 0,28≤x≤0,70; 0,27≤y≤0,63; TiNfor 0.630-67; Ni 4-9.

2. A method of obtaining a composite nanopowder according to claim 1, comprising applying a precursor containing nickelide titanium and titanium carbide in the chamber of the evaporator reactor, the processing in the flow of nitrogen plasma at a flow rate of plasma 60-100 m/s and at a feed rate of the precursor 100-140 g/h, followed by cooling in a stream of nitrogen and carbon capture product evaporation on the surface of the filter, while the precursor contains these components in the following ratio TiNi:TiC=25-50:50-75.



 

Same patents:

FIELD: metallurgy.

SUBSTANCE: coatings are obtained from iridium or rhodium; thermal decomposition process is performed at the temperature of 250-450°C and pressure of 0.01-0.05 mm Hg, and as a precursor there used is hydride of iridium tetra-trifluorophosphine of formula HIr(PF3)4 or hydride of rhodium tetra-trifluorophosphine of formula HRh(PF3)4 respectively.

EFFECT: obtaining pore-free microcrystalline coatings with high adhesion to substrate material.

4 tbl, 1 ex

FIELD: chemistry.

SUBSTANCE: apparatus has a reaction chamber, a support means mounted in the reaction chamber for supporting the substrate to be processed, a gas source for feeding into the reaction chamber starting gas containing the element to be deposited, a catalyst wire lying opposite said substrate and made from tantalum wire with a tantalum boride layer which is formed on the surface of the tantalum wire before feeding the starting gas. Said apparatus also has a heat source for heating the catalyst wire in order to deposit onto the substrate decomposition products of the starting gas formed by catalysis or via a thermal decomposition reaction. Said apparatus further includes a control means for activating heating of the catalyst wire with the heat source through continuous supply of energy.

EFFECT: prolonging service life of the catalyst wire by reducing thermal expansion of the catalyst wire and increasing its mechanical strength.

2 cl, 4 dwg, 1 ex

FIELD: metallurgy.

SUBSTANCE: chamber includes a chamber frame. Insert panels are inserted into the frame mechanically detachably and tightly, besides, some of the insert panels carry functional elements. The chamber frame includes at least one main surface with cantilevers cut from a moulded solid metal panel. Cantilevers are bent in the field of attachment to the main surface so that they form chamber frame links. The side surface of the frame is formed from a solid metal part, in which a material with large surface is cut.

EFFECT: holes are produced for insert panels, where insert panels are installed, no welded joints are required.

11 cl, 10 dwg

FIELD: machine building.

SUBSTANCE: reactor comprises reaction chamber with inlet for feeding process gases therein and outlet for discharge of residual gases, and pump to force residual gases from reaction chamber via said outlet. Said pump produces and maintains pressure in reaction chamber equal to or lower than approx. 10 kPa (100 mbar). Besides, reactor comprises appliances to feed liquid diluents into pump to dilute harmful substances precipitated from residual gases on pump inner surfaces. Said appliances are composed of container for diluents communicated with pump delivery and discharge openings to make closed circuit for diluent circulation.

EFFECT: continuous operation.

2 cl, 1 dwg

FIELD: machine building.

SUBSTANCE: at least, first set of porous substrates is arranged in first reaction chamber. Note here that packs of porous substrates arranged along periphery of reaction chamber represent uncompacted porous substrates, partially compacted porous substrates of combination of both aforesaid substrates. One or several packs of partially compacted substrates are located at central part. at least, first set of porous substrate pack set is compacted by chemical infiltration of gas phase. Arrangement and alternation of uncompacted porous substrates and partially compacted substrates allow using thermal characteristics of partially compacted porous substrates for better distribution of heat flow in CVI-furnace chamber.

EFFECT: better quality of compaction, higher efficiency of process.

10 cl, 29 dwg, 4 tbl, 4 ex

FIELD: chemistry.

SUBSTANCE: the invention relates to production of polysilicon, in particular, to the reactor for chemical deposition of polysilicon from steam phase. = The reactor includes a support system fitted with supports for heating elements and the hull attached to the said support system, forming the deposition chamber. The device comprises at least one silicone heating element positioned in the chamber on the supports, and a power source connectable with both ends of the heating element through lead-ins in the support system, used to heat the heating element. The support system has a gas inlet connected with the silicon-containing gas source and a gas outlet. Furthermore, the heating element is U-shaped and has at least one tubular section with the outer diameter of at least 20 mm and the ratio of wall width to the outer diameter less than 1/4.

EFFECT: increased polysilicon production yield.

7 cl, 6 dwg

Heat source // 2439196

FIELD: power engineering.

SUBSTANCE: heat source (1) comprises a container (2) for an initial substance and a cavity (4). The container (2) for the initial substance is made as detachable with the possibility of attachment to the cover (6), having the first heating device (8) to heat the cover (6) so that heat due to heat conductivity is sent to the container (2) and further to the initial substance in the cavity (4). The cover (6) additionally comprises a heated supply channel (14), being in a liquid connection with the cavity (4), to supply the initial substance from the cavity (4) into the reactor so that between the container (2) for the initial substance and the reactor an increasing temperature gradient is achieved.

EFFECT: heat source provides for production of a temperature gradient that increases in direction to the reactor, which prevents condensation of the initial substance.

19 cl, 2 dwg

Coated articles // 2413746

FIELD: chemistry.

SUBSTANCE: invention relates to a method of coating articles made from valve metals which are used as component parts of turbomolecular pumps. An article made from a valve metal selected from aluminium, magnesium, titanium, niobium and/or zirconium and alloys thereof, is coated with an oxide ceramic layer formed from metal using a plasma-chemical method. The ceramic layer has a barrier inter-phase layer adjoining the metal, whose surface is coated with a polymer formed from monomers in form of dimers or halogenated dimers of general formula I where R1 denotes one or more hydrogens or halogens; each R2 denotes hydrogen or halogen; and each R3 denotes a xylylene residue with formation of a dimeric structure. Said monomers are incorporated into a capillary system and then polymerised on the surface of the oxide ceramic layer in a vacuum.

EFFECT: invention enables to obtain coatings with uniform surface porosity and high resistance to aggressive and corrosive media.

10 cl, 1 ex

FIELD: metallurgy.

SUBSTANCE: method for obtaining oriented fluoride coatings by method of chemical deposition from vapour phase involves arrangement of bottom layer in deposition zone of chemical deposition reactor at temperature of 250-400°C, deposition of fluoride coating on the bottom layer by mixing the flow of metal-organic compounds which are evaporated within temperature range of 150-300°C and pressure of 1-20 mbar, and fluoride-forming flow. As metal-organic compounds there used are volatile metal-organic compounds not containing fluor. Fluoride-forming flow is generated from solid precursor as a result of its evaporation directly in chemical deposition reactor at temperature of 50-120°C from solid precursor, and acid nonorganic bifluoride is used as precursor. Flow of metal-organic compounds and fluoride-forming flow is supplied to deposition zone either with counter-flow, or by coaxial introduction of flows in the inert gas flow.

EFFECT: range of used bottom layers and metal-organic reagents is enlarged, corrosion of equipment is eliminated at performing this method, protection of the obtained coatings is provided against oxidation, temperature of the process performed decreases and cost of the obtained coatings is reduced.

6 cl, 2 dwg, 4 ex

FIELD: metallurgy.

SUBSTANCE: in vacuum chamber of reactor for evaporation and pyrolysis containing one or more polymers there arranged is reactor for controlled evaporation of metal, which contains one or more metals, and substrate. There performed is simultaneous heating of reactor for evaporation and pyrolysis for decomposition of polymer to precursor gas and reactor for controlled metal evaporation. Supersonic or subsonic jet is formed when precursor gas passes through reactor nozzle for evaporation and pyrolysis. Then leaking of formed jet is performed to heated wire net installed on reactor nozzle for evaporation and pyrolysis, and formed jet is supplied to substrate. Polymerisation is performed on substrate so that polymer material is formed. Carrying gas is simultaneously supplied to heated reactor for controlled evaporation of metal. Then carrying gas jet together with vapours of one or more metals and/or their oxides is supplied to substrate and vapours of one or more metals and/or their oxides are mixed so that polymer is formed on rotating substrate and metal polymeric material is formed. Process is performed at vacuum chamber pressure of 10-2 -10-1 torr.

EFFECT: metal polymeric materials are obtained with new unique properties; at that, the design is simplified and cost of plant for obtaining metal polymeric coatings is decreased.

5 dwg, 1 ex

FIELD: process engineering.

SUBSTANCE: invention relates to powder metallurgy, particularly, to production of silicon carbide nanopowders. It may be used for production of abrasive and cutting materials, structural ceramics and crystals for microelectronics, catalysts and protective coatings. Initial mix of silicon and carbon powders at molar ratio of reagents equal to 1 is subjected to hard mixing in high-rpm planetary-ball mil for 10-15 minutes in atmosphere of inert gas at 1-5 atm. Weight of balls relates to weight of initial mix in aforesaid mill as (40):1. Diameter of balls makes 2-8 mm while mill drum rpm equals 1800-2500. Mix of silicon and carbon composite nanoparticles is placed in atmosphere of inert gas at 5-20 atm and 300 K to initiate reaction of silicon carbine nanopowders production reaction in self-propagating high-temperature synthesis.

EFFECT: high-phase-purity powder.

4 cl, 1 tbl

FIELD: process engineering.

SUBSTANCE: invention relates to nanotechnology, particularly, to grinding of various particles. Proposed device comprises housing with intake chamber equipped with peripheral stock feed pipe and aligned supersonic nozzle, working gas feed pipe, mixing chamber, diffuser, separator, adjustment body arranged coaxially behind supersonic nozzle throat and composed of a cone or a needle. Note here that nozzle inner surface has rough edges their height making 0.1-0.6 of nozzle neck diameter. Rough edges may be made on spiral path or at the angle to supersonic nozzle inner surface.

EFFECT: grinding of various materials to nano sizes, particle surface processing by surfactants.

3 cl, 3 dwg, 1 tbl

FIELD: medicine, pharmaceutics.

SUBSTANCE: invention refers to chemical-pharmaceutical industry and represents a method for preparing a biologically active disperse system representing a nanoliquid of ferric oxide (II, III) nanoparticles. The method differs by preparing 3-6% low-molecular polyvinyl pyrrolidone 8000±2000 wherein a solvent represents a liquid containing sodium chloride 2.75-5.5 g, potassium chloride 0.21-0.42 g, calcium chloride 0.25-0.5 g, magnesium chloride 0.00025-0.005 g, sodium bicarbonate 0.115-0.23 g and distilled water up to 1 l; the prepared solution is delivered to a mixture of powdered ferric oxide (II, III) USPIO nanoparticles of 5-8 nm deposited on sodium chloride crystals taken at 1-10 mg per one ml of the disperse system, and a substance of 3-hydroxypyridine derivative taken at 1-200 mg per one ml of the disperse system; it is thoroughly mixed and kept at +60°C throughout 2 hours; the prepared liquid is gradually cooled to room temperature (+20°C) followed by sediment detachment.

EFFECT: invention provides one-stage preparation of the nanoliquid with no toxic reagents, and nanoliquid stability; the composite nanoparticle size therein and biological activity of the ingredients provides advanced biomedical application thereof.

3 cl, 4 dwg, 3 ex, 7 tbl

FIELD: construction.

SUBSTANCE: composition comprises glass or basalt roving in amount of 90-100 wt parts, impregnated with polymer binder based on epoxide-diane resin in the amount of 18÷20 wt parts. The polymer binder additionally contains a magnetic-susceptible metal-containing carbon nanostructure in the amount of 0.001÷1.5 wt parts.

EFFECT: improved resistance to operational loads.

2 tbl

FIELD: metallurgy.

SUBSTANCE: initial material consists of mixture of powders of aluminum silicate, crystals and dolomite at their weight ratio equal to 1: 0,06-0,45 : 0.08-0.24, supplied by flow of plasma-forming gas to reactor of gas-discharge plasma at temperature in reactor equal to 5000-6000°C, products of thermal decomposition: are cooled by inert gas and obtained powder of aluminium-silicon alloy is condensed in water-cooling receiving chamber.

EFFECT: invention allows obtainment of nanosized powders of aluminium-silicon alloys with alloy additives of calcium and magnesium thus conferring ductility and corrosive resistance to products made from these powders.

4 cl, 6 ex

FIELD: chemistry.

SUBSTANCE: ceramic aluminium-cobalt oxide pigment is prepared based on nano-sized mesoporous synthetic xonotlite by preparing a reaction solution containing calcium (II), silicate and a high-molecular weight surfactant of the class of quaternary ammonium salts; calcium hydrosilicate is precipitated from the solution while stirring. An aluminium-cobalt phase is then added to the prepared suspension; the formed precursor is separated, washed, dried at 60°C on air and annealed at 800-960°C. The aluminium-cobalt phase is obtained by extracting and concentrating cobalt (II) ions and aluminium from aqueous solutions of salts thereof using monocarboxylic acids and subsequent preparation of an aqueous emulsion of a mixture of cobalt and aluminium carboxylates.

EFFECT: invention enables to obtain environmentally safe, intensely coloured aluminium-cobalt oxide pigments with weight-average particle size of 200-70 nm, having high covering power.

8 cl, 4 ex

FIELD: chemistry.

SUBSTANCE: invention can be applied in electronics, solar energy industry, atomic industry, metallurgy. Pitch coke is tempered at 1200-1300 °C during 2-3 hours. Then its vibration grinding is carried out until middle-sized particles in the range 5-20 microns are obtained. Coal pitch is modified by mixing with carbonaceous nano-additive in quantity 0.2-1.2 wt %, heated with mixing to 280-300 °C, cooled to temperature of the environment and crushed to size 2 mm. Coke, pitch with nano-additive and stearic acid are dosed and mixed in mixing machine at 210-270 °C. Obtained mass is cooled to temperature of the environment, crushed by jaw and hammer crushers, milled by vibration mill until press-powder of required coarseness is obtained, with its further pressing on isostatic press. Obtained work pieces are burned, impregnated, re-burnt, graphitised and mechanically processed.

EFFECT: invention makes it possible to obtain products of large size with high physical-chemical characteristics.

5 cl, 5 tbl

FIELD: nanotechnology.

SUBSTANCE: invention can be used in the chemical industry. In a reactor comprising a housing 1 on which outer side the heating elements 2 and the thermal insulation are located, the solid particulate catalyst is charged. The catalyst particles at a temperature of catalytic pyrolysis are brought in contact with the gas - the carbon source supplied through the tube 7 or several pipes. In the reactor gas medium, the axisymmetric or circular acoustic waves with a resonant frequency of natural oscillations of the gas or gas-powder mass are excited. Acoustic vibration transmitter can be made in the form of an acoustic horn 8 connected by the tube 7 to the lower part of the reactor. The exhaust gas is discharged from the reactor through the upper tube 3, and the resulting carbon nanotubes are discharged through the lower tube 4 into the hopper 5. During the growth of carbon nanotubes the tube 4 is covered with the flap 6.

EFFECT: increased productivity, reduced energy costs, intensified process of synthesis of nanotubes.

5 cl, 5 dwg

FIELD: construction.

SUBSTANCE: electrodes in the form of a system of parallel strings are applied onto two flat-parallel faces of the crystal, which are aligned at the angle of z+36° to the polar axis, wire platinum contracts are connected to electrodes, the assembled cell is placed into a furnace and heated to temperature of phase transition - Curie temperature under action of a heterogeneous electric field, as a result of which two oppositely charged domains of equal volume are formed with a flat domain-to-domain border.

EFFECT: invention makes it possible to change from traditionally used piezoceramic elements of deformation to single-crystal bidomain elements of precise positioning on the basis of single crystals of ferroelectrics with high Curie temperature, which do not have creep and hysteresis.

2 cl, 2 dwg, 1 ex

FIELD: metallurgy.

SUBSTANCE: proposed composite comprises matrix of pure titanium ≤250 nm age-hardened by thermally and chemically stable nano-sized particles of titanium carbide, boride or nitride with particle size of 2-10 nm. Hardening particles are uniformly distributed in composite volume while their fraction therein makes 0.05-0.50 wt %. Composite is obtained by mechanical alloying of pure titanium with particle size of 40-200 mcm in ball triple-action mill in atmosphere of protective gas and after-hot isostatic pressing.

EFFECT: higher strength due to higher yield point, extension limit, fatigue strength and biological compatibility.

13 cl, 1 dwg, 3 tbl, 3 ex

FIELD: process engineering.

SUBSTANCE: invention relates to powder metallurgy, particularly, to production of silicon carbide nanopowders. It may be used for production of abrasive and cutting materials, structural ceramics and crystals for microelectronics, catalysts and protective coatings. Initial mix of silicon and carbon powders at molar ratio of reagents equal to 1 is subjected to hard mixing in high-rpm planetary-ball mil for 10-15 minutes in atmosphere of inert gas at 1-5 atm. Weight of balls relates to weight of initial mix in aforesaid mill as (40):1. Diameter of balls makes 2-8 mm while mill drum rpm equals 1800-2500. Mix of silicon and carbon composite nanoparticles is placed in atmosphere of inert gas at 5-20 atm and 300 K to initiate reaction of silicon carbine nanopowders production reaction in self-propagating high-temperature synthesis.

EFFECT: high-phase-purity powder.

4 cl, 1 tbl

Up!