Method of obtaining nanosized hydroxylapatite
SUBSTANCE: invention relates to technology of obtaining inorganic materials, namely to methods of obtaining nanosized highly pure hydroxylapatite (HAP) in form of colloid solution or gel, which can be used for production of medico-preventive preparations for stomatology, for application on bone implants. Method of obtaining nanosized colloid hydroxylapatite includes synthesis of hydroxylapatite in saturated solution of calcium hydroxide, decanted after 24-hour settling from sedimented aggregates Ca(OH)2, by adding at rate 1.5-2.2 ml/min per litre of alkali solution 10-20% solution of orthophosphoric acid with constant mixing until pH value of reaction mixture is not lower than 10.5±0.5. Mixture is mixed during 20-30 minutes, settled during 1-2 hours and decanted until liquid phase stops forming on the surface. Obtain product represents colloid solution of highly pure hydroxylapatite with concentration 1.5-2%. Increase of hydroxylapatite concentration within the range from 2 to 30% is carried out by evaporation at temperature not higher than 60°C, and for obtaining nanosized hydroxylapatite with concentration 40±2% initial colloid solution is subjected to complete freezing with further unfreezing at temperature not more than 60°C and liquid phase decanting.
EFFECT: obtaining stable product with set in advance concentration, possessing higher penetrating ability and biochemical activity.
3 cl, 4 ex
The invention relates to the technology of inorganic materials, namely the method of production of high-purity nano-hydroxyapatite (HAP), which can be used for the production of medical materials, stimulating regeneration of bone defects.
In modern dentistry and orthopedics hydroxylapatite calcium displaces metals and other traditionally used materials (J. Amplantol, 1987, 13, No. 1, s-127; Med. Progr. Technol. 1982, No. 9, 129-136), as it provides sufficient strength and porosity of ceramics and thus has no antigenic properties and does not cause microcentro inflammatory response due to the identity of the mineral part of bone and enamel.
Known for a large number of methods for producing hydroxyapatite, for example, patent RF №2100274 (publ. 1997.12.27), No. 2038293 (publ. 1995.06.27).
A disadvantage of known methods is that they do not set a goal of obtaining nanosized particles of hydroxyapatite and is aimed at solving the problem of obtaining the finished product with a high purity of the phase composition in powder form, so at the final stage require high temperatures.
The closest selected for the prototype, is the method according to the patent of Russian Federation №2104924 (publ. 20.02.1998), which involves mixing calcium hydroxide and phosphoric acid, from taiwania, filtration and drying of the finished product. The advantage of this method is that it allows you to get hydroxylapatite when the molar ratio of the starting components of 1.33:2,50, in a fairly wide range without complex hardware design. The yield of hydroxyapatite is 100%.
The disadvantage of this method is that it does not seek to obtain nanosized particles of hydroxyapatite and, in addition, requires a sufficiently high temperature for drying (over 100° (C) and annealing (over 1000°). The use of hydroxyapatite in the form of powder provides before applying mandatory dilution liquid base that makes it difficult to obtain the necessary concentration and uniformity, particularly when it comes to achieve a colloidal state. Modern requirements to the quality of coatings on bone implants include the need to increase their adhesive characteristics and osteoconductive properties.
Object of the present invention is to provide a method of producing high-purity nano-hydroxyapatite with particle size not more than 200 nm in length and not more than 40 nm in width in the form of ready-to-use product with a predetermined concentration in a colloidal solution or gel.
The technical result is to increase the Prony the surrounding abilities and biochemical activity of hydroxyapatite, which provides:
- in relation to dentistry - extended re-mineralizing effect on tooth tissue, an increase in the adhesion characteristics to the organic and inorganic components of dentin,
- in relation to Orthopaedics, surgery and traumatology - the possibility of increasing the adhesion characteristics and osteoconductive properties of bioactive coatings on bone implants.
An additional effect is the possibility of getting the finished product with a predetermined concentration, which provides convenience when using it.
The problem is solved due to the fact that for the synthesis of hydroxyapatite, comprising mixing calcium hydroxide and phosphoric acid at room temperature, sedimentation, filtration and drying of the finished product, unlike the prototype used a saturated solution of calcium hydroxide obtained by decanting the aqueous solution from the precipitated aggregates of CA(Oh)2after the daily advocate, which is poured with stirring at a rate of 1.5-2.2 ml/min per liter of the alkaline solution of 10-20%solution of orthophosphoric acid, continue stirring for 20-30 minutes, then assert within 1-2 hours and decanted, repeated settling and decantation until, while on the surface will not cease to form the liquid phase. In poluchaut,5-2% colloidal solution of high purity hydroxyapatite with particle size not more than 200 nm in length and not more than 40 nm in width. To increase the concentration of a colloidal solution of nanosized hydroxyapatite in the range from 1.5-2% to 30% are dried by evaporation at a temperature not above 60°C. And to obtain nanosized hydroxyapatite with a concentration of 40±2%, the resulting colloidal solution of high-purity nano-sized hydroxyapatite concentration of 1.5-2% is subjected to a complete freezing with subsequent thawing at a temperature of not more than 60°separating precipitated precipitated gel-like agglomerates of high-purity nano-sized hydroxyapatite from the liquid phase by decantation.
Distinctive signs, confirming the novelty and inventive step of the claimed method:
- synthesis of hydroxyapatite is carried out in a saturated solution of calcium hydroxide, obtained by decanting from the settled aggregates of calcium hydroxide day, after settling at room temperature. This technical solution allows for the synthesis of hydroxyapatite in ion-molecular solution of calcium hydroxide, which does not contain certain components that results in the receipt of hydroxyapatite particles not larger than 200 nm in length and not more than 40 nm in width;
- with constant stirring poured 10-20%solution of phosphoric acid at a rate of 1.5-2.2 ml/min per liter of alkaline rest the RA to achieve pH=10,5± 0.5 and continue stirring for 20-30 minutes. It must comply with the condition: the higher the concentration of the acid, the lower the speed prilipanie and Vice versa. The fulfillment of these conditions (the dependence of the rate of prilipanie from acid concentration and volume of a saturated solution of calcium hydroxide) allows to synthesize nano-sized particles of hydroxyapatite evenly in full of the reaction mixture and gently bring the pH to 10.5±0,5, but not below, in order to avoid the formation of other CA-P compounds;
after one two-hour settling decanted clarified upper layer by repeating the procedure of settling and decanting, until the termination of the appearance on the surface of the liquid phase, which allows to obtain a colloidal solution of nanosized hydroxyapatite with a concentration of 1.5-2%;
- an increase in the concentration of a colloidal solution of hydroxyapatite in the range of 2 to 30% is carried out by evaporation at a temperature not more than 60°C. This solution allows you to stop the drying process at the time the required concentration of the finished product in the form of a colloidal solution or gel. An additional advantage is energy saving, as it does not require the use of high temperatures at the time of receipt of hydroxyapatite in the form of powder, as well as the usability of the finished item is of oducti with known concentration. Increasing the concentration above 30% by evaporation is undesirable - this leads to the formation on the surface of the gel hydroxyapatite solid agglomerates. The temperature of evaporation below 40°extend the process of evaporation, and above it there is the threat of crystallization of hydroxyapatite;
- to obtain nanosized hydroxyapatite with a concentration of 40±2% of the formed colloidal solution of hydroxyapatite concentration of 1.5-2% is subjected to a complete freezing with subsequent thawing at a temperature of not more than 60°With, in the hydroxylapatite receive in the form of precipitated in the sediment of large gel-like agglomerates, which are separated from the liquid phase by decantation. The obtained gel-like agglomerates having the property of plasticity, consist of nano-sized particles of high purity hydroxyapatite.
The particles of the dispersed phase in a colloidal system at a concentration of 1.5-2% of hydroxyapatite evenly fill the entire volume of the dispersion medium, and the system is sedimentation-resistant. In the evaporation process when reaching 8-30% concentration or freeze with obtaining a concentration of 40±2% structuring of colloidal solution, and it transforms into a gel. The use of the proposed method are nanoscale hydroxylapatite with the size of the piece is the length of 100-200 nm, width of 30-40 nm in the form of a colloidal solution or gel with a predetermined concentration of preserving without changing its properties for at least 3 months. The use of the finished product with a predetermined concentration increases ease of use.
Prepare a saturated solution of calcium hydroxide CA(Oh)2thoroughly mix and stand for 1 day at t(solution)=20-25°and pH(solution)=12,50±0,2.
The obtained alkaline solution decanted by draining the clarified upper layer. Saturated alkaline solution should be transparent and without aggregates of CA(Oh)2. The precipitate Ca(OH)2you can fill with distilled water for reuse.
To the obtained after decanting the saturated alkaline solution of calcium hydroxide in the amount of 1 liter slowly with constant stirring and a temperature of 20-25°poured With 10%solution of orthophosphoric acid with a speed of 2.2 ml/min, continuously monitoring the pH using a pH meter, to achieve in the reaction mixture a pH above 10.5±0.5 in. The result is often a colloidal solution of hydroxyapatite with particle sizes along the length of 100-200 nm, width of 30-40 nm.
The solution is stirred for 20-30 minutes and allow to settle for 1-2 hours a colloidal solution of hydroxyapatite deposited and is about 1/3 of the volume, the mixture is decanted by draining the clarified upper layer. The procedure of settling and decantation, repeat until, while on the surface will not cease to form the liquid phase.
The resulting product is a 1.5 to 2% colloidal solution of high purity hydroxyapatite with particle sizes along the length of 100-200 nm, width of 30-40 nm.
Prepare a saturated solution of calcium hydroxide Ca(OH)2thoroughly mix and stand for 1 day at t(solution)=20-25°and pH(solution)=12,50±0,2.
The obtained alkaline solution decanted by draining the clarified upper layer. Saturated alkaline solution should be transparent and without aggregates of CA(Oh)2. The precipitate of CA(Oh)2you can fill with distilled water for reuse.
To the obtained after decanting the saturated alkaline solution of calcium hydroxide in the amount of 1 liter slowly with constant stirring and a temperature of 20-25°poured With a 20%solution of orthophosphoric acid with a speed of 1.5 ml/min, continuously monitoring the pH using a pH meter, to achieve in the reaction mixture a pH above 10.5±0.5 in. The result is often a colloidal solution of hydroxyapatite with particle sizes along the length of 100-200 nm, width of 30-40 nm.
The solution is stirred for 20-30 minute allow to settle, 1-2 hours a colloidal solution of hydroxyapatite deposited and is 1/3 of the total volume of the mixture is decanted by draining the clarified upper layer. The procedure of settling and decantation, repeat until, while on the surface will not cease to form the liquid phase.
The resulting product is a 1.5 to 2% colloidal solution of high purity hydroxyapatite with particle sizes along the length of 100-200 nm, width of 30-40 nm.
A colloidal solution of high purity hydroxyapatite obtained in example 1 or example 2 is subjected to drying by evaporation at a temperature not more than 60°to increase the concentration of the hydroxyapatite is in the range from 1.5-2% to 30%. Maintaining control over the changes in the concentration and stop the evaporation process in the moment of reaching the required concentration of hydroxyapatite. The result is high-purity nano-hydroxylapatite in the form of a colloidal solution or gel with a predetermined concentration in the range from 1.5-2% to 30%.
A colloidal solution of high purity hydroxyapatite obtained in example 1 or example 2 is subjected to a complete freeze in the freezer. Defrost at a temperature not above 60°C. In the hydroxylapatite precipitate large gel agglomerates of particles retained the nano (the length of 100-200 nm, width of 30-40 nm), hold the decantation of the liquid phase. Cryoablate allows you to increase the concentration of the finished product up to 40±2%.
Thus, the authors propose a simple and reliable method of obtaining high-purity nano-hydroxyapatite with particle size of hydroxyapatite on the length of 100-200 nm, width of 30-40 nm in the form of ready-to-use colloidal or gel-like product with a predetermined concentration.
1. Method of producing nanoscale hydroxyapatite, comprising the synthesis of hydroxyapatite in a saturated solution of calcium hydroxide, dekotirovaniem day, after settling from the settled units of CA(Oh)2by prilipanie with a speed of 1.5-2.2 ml/min per liter of the alkaline solution of 10-20% solution of orthophosphoric acid with constant stirring until the pH of the reaction mixture above 10.5±0,5; continue stirring for 20-30 minutes, then assert within 1-2 h and decanted, repeated settling and decantation until, while on the surface will not cease to form the liquid phase.
2. Method of producing nanoscale hydroxyapatite, comprising the synthesis of hydroxyapatite in a saturated solution of calcium hydroxide, dekotirovaniem day, after settling from the settled units of CA(Oh)2by prilipanie with a speed of 1.5-2.2 ml/min on the ITR alkaline solution of 10-20% solution of orthophosphoric acid with constant stirring, before reaching the pH value of the reaction mixture above 10.5±0,5; continue stirring for 20-30 minutes, then assert within 1-2 h and decanted, repeated settling and decantation until, while on the surface will not cease to form a liquid phase, conduct drying the formed colloidal solution of hydroxyapatite concentration of 1.5-2% by evaporation at a temperature not above 60°C.
3. Method of producing nanoscale hydroxyapatite, comprising the synthesis of hydroxyapatite in a saturated solution of calcium hydroxide, dekotirovaniem day, after settling from the settled units of CA(Oh)2by prilipanie with a speed of 1.5-2.2 ml/min per liter of the alkaline solution of 10-20% solution of orthophosphoric acid with constant stirring, until the pH of the reaction mixture above 10.5±0,5; continue stirring for 20-30 minutes, then assert within 1-2 h and decanted, repeated settling and decantation until, while on the surface will not cease to form a liquid phase, the obtained colloidal solution of hydroxyapatite concentration of 1.5-2% is subjected to cryoablate, including full freezing with subsequent thawing at a temperature of not more than 60°, hold the decantation of the liquid phase.
SUBSTANCE: method of processing of residual products containing phosphoric acid to calcium phosphates comprises its mixing with calcium-containing compounds, separation of derived slurry with filtration and drying. The limestone is used as calcium-containing compound, initially it is fed for mixing in quantity necessary for monocalcium phosphate, then derived slurry is divided to two flows in ratio 1:(1.5-4), the major flow is mixed with lime taken in quantity necessary for dicalcium phosphate formation, derived slurry is separated with filtration and minor flow of monocalcium phosphate slurry is added to separated dicalcium phosphate before drying and granulating. Preparation of monocalcium phosphate slurry is carried out in two stages, at first stage the phosphoric acid is mixed with limestone up to mixture pH =2.9-3.1, at second stage - up to mixture pH =3.5-3.7, during mixing of monocalcium phosphate slurry with lime pH is maintained in the range 5.4-5.6. Drying and granulating are carried out at the same time in drum granulator-dryer.
EFFECT: method enables to process the residual products to granulated calcium phosphates with usage the lowest-cost raw materials.
3 cl, 1 tbl, 1 ex
FIELD: paint and varnish industry.
SUBSTANCE: anticorrosive pigment comprises , in mass per cents, 3.0-4.7 of calcium chromate and waterless dicalciumphosphate as the balance.
EFFECT: improved anticorrosion capabilities.
FIELD: production of pure phosphoric acid and calcium monohydrophosphate.
SUBSTANCE: proposed method includes decomposition of phosphate ore by first hydrochloric acid solution at concentration not exceeding 10 mass-%, separation of liquid decomposition product into insoluble solid phase containing admixtures and separate aqueous phase containing phosphate, chloride and calcium ions in form of solution, neutralization of aqueous phase separated from liquid decomposition product by adding calcium compound for obtaining insoluble settled-out calcium phosphate by means of phosphate ions, separation of neutralized aqueous phase into aqueous phase containing calcium and chloride ions in form of solution and settled solid phase on base of water-insoluble calcium phosphate and dissolving of at least part of separated settled solid phase in second aqueous hydrochloric acid solution containing hydrochloric acid in the amount exceeding its content in first hydrochloric acid solution, thus forming aqueous solution containing phosphate, chloride and calcium ions extracted by organic extracting agent at extraction in "liquid-liquid" system. Proposed method makes it possible to avoid fine grinding or roasting of ore.
EFFECT: enhanced efficiency of extraction for production of pure concentrated phosphoric acid solution with no contamination of surrounding medium.
24 cl, 2 dwg, 1 tbl, 4 ex
FIELD: inorganic chemistry, chemical technology.
SUBSTANCE: invention relates to technology for preparing fodder calcium phosphates, namely to producing monocalcium phosphate. Method involves mixing wet-process phosphoric acid with a calcium-containing component in the presence of recycle, granulation and drying the product. Mixing process is carried out for two stages. At the first stage wet-process phosphoric acid with the concentration 62-65% of P2O5 is fed and process is carried out at recycle index = 1:(0.3-0.5) up to decomposition degree of calcium-containing raw = 0.89-0.92 at this stage. The second stage is combined with granulation and carried out its in high-speed mixer in water addition to obtain moisture in mixture 9.5-13%. The rate and time for mixing are regulated to provide the decomposition degree of calcium-containing raw = 0.93-0.99, and temperature at the next drying stage is maintained in the level 105-115°C. Method provides simplifying the process, reducing energy consumption and preparing product with the high content of P2O5 in water-soluble form and low content of fluorine.
EFFECT: improved method for preparing.
2 cl, 3 ex
FIELD: industrial inorganic synthesis.
SUBSTANCE: monocalcium phosphate, widely applied in agriculture, is prepared by mixing extraction phosphoric acid with calcium-containing component followed by granulation and drying of product. During mixing of components, appropriate temperature and moisture are maintained to ensure viscosity of mixture 3-7 mPa*s, and granulation and drying are carried out simultaneously in drum-type granulator drier. Calcium-containing component is either calcium carbonate or mixture thereof with limestone, whose does not exceed 15% of total weight of calcium-containing raw material. Moisture content in worked out drying agent leaving drum-type granulator drier equals 70-80 g per 1 kg dry air.
EFFECT: simplified process flowsheet, enabled granule size control, and increased strength of granules.
3 cl, 3 ex
SUBSTANCE: present invention pertains to means of forming a structure based on carbon nanotubes and can be used when making flexible optically transparent conducting coatings, flexible small-scale integration integrated circuits, test structures for a scanning probe microscope, resistive sensors etc. A drop of colloid solution of carbon nanotubes, containing a surface active substance in quantity, sufficient for stabilisation of the colloidal state of the solution, as well as 5-60 vol.% glycerine, sufficient for formation of a drop colloidal solution of a give size, are deposited on a given point on a substrate. For this purpose, the colloidal solution is put into the device, which transfers it to the printing head of a jet-printer. The device is in form of a catridge or a system for continuous supply of the colloidal solution. The substrate is moved using a system, in form of a paper-moving mechanism of a jet printer, or in form of a compact disc movement system. Removal of all components of the colloidal solution except carbon nanotubes, is achieved by evaporation and/or washing in a solvent. To obtain a composite film, carbon nanotubes are deposited on a substrate, in turns, with liquid components of a polymer or simultaneously with the liquid components of the polymer. The liquid components of the polymer are solidified while fusing their microdroplets, or under the effect of electromagnetic radiation, heating or as a result of evaporation of volatile components under atmospheric conditions. Viscosity of liquid components of the polymer corresponds to the microhydraulic system of the jet-printer. The liquid components of the polymer are deposited on the substrate by transferring them to the printing head of the jet printer. The method is characterised by high output and resolving power of depositing carbon nanotubes and composite films on a substrate and reduced cost.
EFFECT: highly productive and cheap method.
2 cl, 2 ex
SUBSTANCE: present invention pertains to vertical structures of semiconductor devices, containing nanotubes as a structural element, and methods of making such structures. Proposal is given of a vertical structure of a semiconductor device, comprising a substrate, forming a horizontal plane at the base, a gate electrode, vertically extending from the substrate, semiconductor nanotubes, running vertically through the gate electrode between their opposite first and second ends, a gate dielectric, electrically insulating the semiconductor nanotubes from the gate electrode, a drain, electrically connected to the second end of the semiconductor nanotubes, and a source contact, located at the same side as the drain, and formed by making a contact window in the insulating layer, insulating it from the gate electrode. The source contact is electrically connected to the first end of the semiconductor nanotubes.
EFFECT: obtaining semiconductor devices with nanotubes as a structural element using technologies, compatible with mass production techniques for making integrated circuit chips.
19 cl, 10 dwg
FIELD: technological processes.
SUBSTANCE: onto solid acetate substrate extruded on supporting copper mesh, metal layer is sputtered, above which layer of material is sputtered with lower coefficient of sputtering, acetate substrate is removed, and ion etching of prepared double-layer film is carried out until top layer is removed, and nano-openings are created in metal layer. As a result, metal membrane is produced with average radius of openings of 28.98 nm and density of openings of -23.6-106 1/mm3.
EFFECT: production of nanosize metal membranes with openings from 5 to 100 nm.
7 cl, 3 dwg
SUBSTANCE: nanodispersive fluoroorganic material is obtained by polytetrafluoroethylene thermal destruction in air atmosphere with further cooling, thermal destruction being carried out in electric discharge plasma in alternating electric field with alternating voltage amplitude not less than 2kV.
EFFECT: efficient application for creation of fluoropolymer additives and fillers, obtaining liquid reagents for fluoroorganic synthesis, for creation of fluoroorganic microcrystals, film coatings and fluoropolymer quantum points.
5 dwg, 1 ex
SUBSTANCE: present invention can be used in laser technology as anti-reflection filters - saturable absorbers for lasers, working in the near infrared range of the spectrum. Formation of nanoparticles in the glass, with size ranging from 1.2 to 10 nm and size distribution closer to monodisperse distribution, is achieved as a result of secondary thermal treatment of the glass, at temperature close to glass transition temperature. The proposed glass consists of the following components with the given ratios, in wt %: P2O5 45-55, Ga2O3 14-30, Na2O 15.5-16.5 ZnO 3.5-6.1, NaF 1.3-2, AlF3 1-2.6, PbF2 0.3-2.0, PbSe 2.4-2.8.
EFFECT: formation of nanoparticles of lead selenide with small dimensions, characterised by high concentration and narrow size distribution, providing for spectral absorption and anti-reflection in the near infrared range of the spectrum.
FIELD: chemistry; electricity.
SUBSTANCE: proposed device contains a cold airtight chamber filled with helium. On opposite walls of the camera casing 1 with the help of ports 4 and 5 anode current leads 6 and 7 are installed, in which electrodes 8 and 9 in the form of rods are placed in line with each other. Current leads 6 and 7 are connected to different power sources. Between rods 8 and 9 is placed a graphite electrode in the form of disk 10 with the formation of a discharge gap between them. Disk 10 is installed in a fixed position on the cathode current 11, which is placed on the upper flange of camera 2 and is connected to the electric motor 12 for ensuring the possibility of the rotation of disk 10 on a plane parallel to the plane of flange 2. Burnt rods 8 and 9 are installed with the capability of moving in the discharge gap zone. On the outside of ports 4 and 5 are connected vacuum loaders of rods 13 each of which consists of cover 14, connected to its own port 4 and 5, vibration-layer 15, which contains the reserve rods, supply device, made, for example in the form of a closed chain for supply 16 tooth-pushers 17 with the capability of catching and moving rods 8 and 9, and intermittent drive 18. Cathode current lead 11 is supplied with knives 19 to prevent the possibility of outgrowths forming on disk 10. The lower flange 3 is connected to the soot accumulator 20.
EFFECT: doubling the productivity of the device with continuous submission of the burnt rods to the zone of the discharge gap due to the organisation of two arc processes in one chamber.
FIELD: chemistry; electricity.
SUBSTANCE: in a horizontal cylindrical air-tight discharge chamber 1, with a residue collector, graphite electrodes 2, 3 which are put in-line, and set in cold current leads 8, 9. Fullerene containing soot is obtained in an arc between the electrodes 2, 3. At least one of the electrodes 2, 3 is set with the capability of axial reciprocative movement. Circulatory system 10 for inert gas, which creates two turned annular streams for removal of the resulting products, contains at least two nozzles mounted on the end wall of the discharge chamber 1 at a tangent to the side wall and laying in planes, perpendicular to the axis of the electrodes 2, 3. Device 14 for collecting fullerene containing soot is made in the form of at least one cyclone 15, 16 or 17 with tangential input of gas.
EFFECT: increase in the production of soot and fullerene with minimal energy use, blow out and burning of the walls of the discharge chamber walls are eliminated.
23 cl, 11 dwg
FIELD: technological processes.
SUBSTANCE: in integrated hollow nanoneedle tube is connected with crystal-base via bent film element and it is rigidly secured. Tube and bent film element are made of film structure with mechanically stressed layers grown on crystal-base as pseudo-morph monocrystal substance films with different lattice spacing liberation. The contour of a segment of film structure to be released from connection with crystal-base is formed. The released segment contains sectors intended for formation of tube and bent film element. Configuration of sectors, inner mechanical stresses, and thickness of layers determine with precision tube positioning and its diameter. Directional material etching under released mechanically stressed layers separates the first sector from crystal-base transforming it into tube owing to stresses, then the second sector is separated bending owing to stresses and securing tube positioning. Rigid connection is effected by fixing element.
EFFECT: workability increase and expansion of articles' functional range.
17 cl, 9 dwg
FIELD: technological processes.
SUBSTANCE: hollow billet is prepared, and its surface is further processed by rolling in roll matrix with fixation of billet ends. Processing of external surface of billet is carried out simultaneously with reciprocal motion of one or more rollers that have section of larger diameter.
EFFECT: increased mechanical properties of metal bushings and reduction of metal consumption in their manufacturing.
1 dwg, 1 ex
FIELD: metallurgy, coating.
SUBSTANCE: method includes actuation gas feed into evacuated vessel, pulsed lasing of plasma stream and high-energy ion beam and its alternate action to support in distance. Discrete plasma stream is created by means of firing of high-current high-voltage diffusive discharge which is formed by means of passing through stationary plasma of magnetron discharge of current pulse duration 10-6...1 s, density 0.3-100 A/sm2 and repetition rate till 103 Hz. Specified distance is chosen more than time of plasma recombination of high-current high-voltage diffusive discharge in volume of evacuated capsule. Effect to support by pulsed beam of high-energy ions is implemented with energy which is not more than 106 eV and with repetition rate till 103 Hz. At that it is implemented rejection of high-voltage fault of accelerating gaps from secondary electrons of actuation gas and plasma electrons.
EFFECT: providing of high velocity of coating, ability to effect on coating features and increased adherence of coating to support.
6 cl, 3 dwg, 2 ex
FIELD: carbon materials.
SUBSTANCE: weighed quantity of diamonds with average particle size 4 nm are placed into press mold and compacted into tablet. Tablet is then placed into vacuum chamber as target. The latter is evacuated and after introduction of cushion gas, target is cooled to -100оС and kept until its mass increases by a factor of 2-4. Direct voltage is then applied to electrodes of vacuum chamber and target is exposed to pulse laser emission with power providing heating of particles not higher than 900оС. Atomized target material form microfibers between electrodes. In order to reduce fragility of microfibers, vapors of nonionic-type polymer, e.g. polyvinyl alcohol, polyvinylbutyral or polyacrylamide, are added into chamber to pressure 10-2 to 10-4 gauge atm immediately after laser irradiation. Resulting microfibers have diamond structure and content of non-diamond phase therein does not exceed 6.22%.
EFFECT: increased proportion of diamond structure in product and increased its storage stability.