Method of production of ultrahard polycrystalline material

FIELD: technological processes.

SUBSTANCE: invention may be used for production of parts and cutting tools for processing of wear resistant materials, in particular, silicon-containing aluminium alloys. Layers of diamond powder and material of impregnation that are in contact are placed layer by layer on charge. Layer of diamond powder is divided into two layers. In one of the layers, which contacts with impregnation material, diamond powder is used with size of particles from 20/14 to 2/1 mcm. Additionally detonating diamond powder is introduced with size of particles in the range from 1 to 100 nanometers in the amount from 1 to 30 percents from the volume of diamond powder of this layer. In the second layer, which contacts the first one, diamond powder is used with size of particles in the range from 40/28 to 28/20 mcm, at that height of this layer in respect to the first one amounts from 2:1 to 3:1. As impregnation material silicon or silicon-containing materials are used, for example, mixture of silicon powders, flaked graphite and detonating diamond. Stock prepared by this method is affected with high pressure - from 3 to 8 GPa and temperature of 1200 - 2000°C, for 40 - 120 sec. Prior to effect of high pressure and temperature stock may be shaped in round, square, rhombic, triangular, hexagonal and other forms. Ultrahard compact is prepared with high cutting ability and output of serviceable products.

EFFECT: permits to provide high purity of processed materials surface.

2 cl, 2 dwg, 1 tbl, 6 ex

 

The invention relates to methods of producing polycrystalline superhard materials based on dense modifications of carbon and can be used for the manufacture of various parts and cutting tools for processing various kinds of wear-resistant materials, in particular silicon-containing aluminum alloys.

A method of obtaining superhard materials (CDs), including the effects of high pressure and temperature on the mixture of diamond powder and a metal binder (U.S. Patent No. 3141746, CL 51-307, 21.07.64).

The disadvantages of this method are a violation of the contacts of the diamond grains, hidden microporosity, and hence the low strength of the resulting compacts.

A method of obtaining diamond compacts (Ed. mon. The USSR №411724, class SW 31/06, from 10.07.69), including the effects of high pressure and temperature on the diamond powder and binder are located in separate layers. Creating a pressure tight diamond frame and the removal of gases by means of impregnation allows to obtain a compact with enhanced mechanical properties.

The disadvantage of this method is the small height of the obtained compacts defined impregnating ability of the binder and the grain size of the original diamond powder. When the grain size of the diamond powder is and 5/3 μm and material impregnation (55 wt.% Ti and 45 wt.% Cu) the height of the CD does not exceed 5 mm When a smaller size diamond powder (2/1 micron and submicron sizes) height impregnation or less, does not exceed tenths of a mm.

Known two-layer cutting plate (Autospid. The USSR №795734, publication 15.01.81, class WW 27/20)containing the cutting layer of the diamond composite material in contact with the metal strip, the surface of the cutting layer facing to the lining, made with protrusions in the form of spikes that pierce the gasket and the mating surfaces of the cutting layer and the gaskets are made of relief and are in engagement. The lining is made of plastic material. The disadvantages of such cutting inserts are manufacturing complexity and the limitations of its use.

A known method of manufacturing a diamond tool (AVT. mon. The USSR №1192955, publication 23.11.85, class 24D 17/00), which is prepared with a lot of mixing of polycrystalline diamond with grain size 315 -2000 µm, single-crystal diamond with the size of 60-250 μm in the amount of 10-50 wt.% of the mass of polycrystalline diamond and ligaments, and 40-80 wt.% ligaments pre-roll on polycrystalline diamonds and remaining ligament is mixed with crystals of diamond and continue the roll-polycrystalline diamonds. Then the workpiece is subjected to cold pressing and is sintered under pressure 812 kbar and a temperature of 950-1050° C.

Received the diamond tool can be used as drill bits, grinding wheels, drill bits. However, manufactured tools for the proposed method are of limited use.

A known method of manufacturing a cutting element (Ed. mon. The USSR №1218564, priority 22.12.83., publication 1998, class B22F 3/14, 24D 3/06), according to which the influence of high pressure and temperature are located in contact with each other the layers of the metal binder powder superhard material and the substrate material. As the substrate, a mixture of diamond, cubic boron nitride or a mixture with 35-65% components metal binder with a melting point of 5-15% higher than the melting point of the metal binder and the particle size of 50-600 μm. The heating is carried out until the melting point metal binder with the speed of 150-350°C/C, and then lower the pressure to atmospheric within 1-3 C.

As the metal binder used alloys titanium-copper-cobalt and copper-titanium with different content components. Receive cutting elements of the brand "we have", for high-speed cutting steels hardness 38-58 HRC (v=150 m/min or more) and cutting elements of the brand Almet, for turning and milling "fiberglass materials."

However the com of such a method is not sufficiently high purity of the processed material.

A known method of manufacturing abrasive element (Patent RF №1380109, with priority from 19.08.85, class 24D 3/10), including the effects of high pressure and temperature layers on layers of powder superhard material, metal binding and metal-ceramic substrate and between the metal-ceramic substrate and the superhard material is placed layers of an alloy of transition metals with melting temperature of 1000-1300°With, the process is conducted at a pressure of 20 to 35 kbar and a temperature of 1000-1300°C.

As a superhard material using powder of cubic boron nitride and/or diamond powder with SIC, boride or microabrasion supplements, taken as 1-30% of the volume of the superhard material. As the metal binder take alloy Nickel-titanium (40-60 wt.%), zirconium-copper (70-30 wt.%).

Get the cutting layer of composite material is a dense polycrystalline sintered layer of cubic boron nitride, is firmly connected to the substrate of the solid alloy, and is characterized by high abrasion resistance. The disadvantage is not high enough purity of the processed materials when turning.

The closest technical solution to the claimed is a method for superhard compacts (RF Patent No. 597159, with priority from 04.0.74,, class SW 31/06, 24D 3/06), including the effects of high temperature pressure on superhard, in particular, diamond powder and a layer of metal binder in contact with each other, and superhard powder stack layers with density decreasing from the contact surface of superhard powder with a metallic binder.

In the container place the heater. At the bottom of the stack layer of the metal binder (alloy Ti-Cu-or Ni-Ti-Cr), on top of it is placed a layer of diamond powder with a particle size 3/5 and 10/14 μm in the ratio of 1:5 and the layer of diamond powder with a particle size of 10/14. From the walls of the heater, the mixture is isolated by a layer of mica, from the bottom - layer of boron nitride. Top the mixture is closed by a cover made of graphite. This Assembly is affected by the pressure of 45 to 50 kbar and temperatures 1200-1250°C.

The obtained compacts were used as parts of high-pressure apparatus.

However, in this method, there are difficulties associated with the fact that very fine diamond powder (submicron) practically does not accumulate, and the strength and other physical and mechanical properties and their associated cutting ability and purity of the workpiece, the magnitude of the yield of the product is directly dependent on the grain size of the diamond powder, and it increases with decreasing grain.

adaca of the proposed method is to eliminate the above mentioned drawbacks, as well as increasing the cutting ability, the surface of the processed materials, increasing yield and reducing the cost of final processing of the received material.

Tasked with securing the superhard polycrystalline material is solved by exposure to high pressure and temperature on the charge with layers located and in contact with the layer of diamond powder and material impregnation.

Diamond powder is divided into two layers, one of which is in contact with the material impregnation, using diamond powder with particle sizes in the range from 20/14 to 2/1 μm, and optionally in it enter detonation diamond powder with a particle size of from 1 to 100 nanometers, and in an amount of from 1 to 30 percent of the total volume of diamond powder in the layer. Nanodispersed in the future detonation diamond, receive feedback detonation (explosion) on soot and fine graphite (Physics pulsed processing of materials, edited by Prof. ARV - D, ART PRESS, 2003, p.45-82). The distribution of the fractions is carried out after purification of the products of detonation and subsequent sedimentation. In the second diamond layer in contact with the first use of diamond powder with a particle size in the range from 40/28 to 28/20 μm, and the height of this layer in relation to the first the leaves from 2:1 to 3:1. As the material impregnation use silicon or a material containing silicon, such as silicon 50 wt.%, scaly graphite 30 wt.% and detonation diamond 20 wt.% (Shulzhenko A. A., Kargin VG, V.A. Shishkin, a little cask AA Polycrystalline materials based on diamond. - Kiev, Nauk. Dumka, 1989. - 192 pages).

The workpiece prior to exposure to high pressure and temperature give a round, square, rhombic, triangular, hexagonal or other shaped cross-section.

1 shows a diagram of the container, the implementation of the proposed method.

The method is as follows.

In the container of catlinite 1 located therein a cylindrical graphite heater is placed a layer of material impregnation 6. As the material impregnation of the diamond powder used silicon or a material containing, for example consisting of 50 wt.% silica, 30 wt.% scaly graphite, 20 wt.% detonation diamond. Additive silicon graphite and detonation diamond allows you to almost completely prevent ready parts availability in the pores of the diamond powder, in addition to the binder of silicon carbide, pure silicon. Liquid silicon during solidification increases in volume, resulting in a sintered compact of various defects, such as cracks, voids, and other aggravating its physico-mechanical properties. On top of which the material impregnation have 6 layers of diamond powder 4 and 5 with different grain sizes, moreover, the grain layer 4 is less grain layer 5 and the layer 4, which are in direct contact with the material impregnation add from one to thirty volume percent of detonation diamond with a particle size of from 1 to 100 nanometers, which partially fills the pores between grains larger diamond powder having a particle size from 20/14 to 2/1 μm. The presence of detonation diamond powder in the pores are larger, due to its highly developed surface and consequently a higher reactivity, allows you to get during the impregnation of high-strength compact with high cutting properties, with small roughness of the processed surface, with a high yield without cracks and other defects. The presence of free silicon in the cutting layer is completely excluded.

In layer 5, which is the substrate for cutting layer after sintering was observed only traces of free silicon. On top of the layer of diamond powder 5 sleep powder of boron carbide 8, having a grain size not less than 60/40 μm, which absorbs gases and pollution arising during the aimed compound. The top and bottom of the Assembly is closed with a lid of graphite 9 and 10. From the lower cover 10 charge isolate a thin layer of thermal and electrical insulating material, such as hexagonal boron nitride 7, and from the walls of the graphite is first heater 2 - mica 3.

The reaction cell with the charge placed in the office of the high temperature and pressure, creating a pressure in the range of 3-8 GPA and a temperature in the range of 1200-2000°C, the sintering is carried out in the time interval 40-180 C. Sintered billet is removed from the high-pressure apparatus, after which the element is attached by grinding and polishing the form on GOST. To reduce the high energy consumption during processing, for example the production of superhard elements from samples of circular cross section is square, the blanks give a defined shape and bake. Thus, the finished element shape in cross section is a square, rhombus, triangle, hexagon, etc. with decreasing particle size diamond powder in layer 4 from 20/14 to 2/1 in various examples increase the size of the particles of the diamond powder in the layer 5 from 28/20 to 40/28 μm, and also increases the height of the layer 5 with respect to the layer 4 from 2:1 to 3:1 and thus the total height of the two layers of diamond powder remains constant. This is necessary so that after sintering the billet exceeded both in axial and radial direction only by 0.2-0.4 mm size cutting elements according to GOST, which are obtained by grinding and polishing with minimal material and energy costs. For example, the size of the cutting elements of square section, with p the GOST dimensions: square side 9,52 mm, the thickness of 3.18 mm; or the side of the square 12.7 mm, thickness 4,76 mm

Examples of specific performance.

Example 1. In the container 1 (Fig 1) place the graphite heater 2 having an inner diameter of 16 mm, an external 19 mm, height 8 mm At the bottom of the stack impregnation layer 6, a mixture of silicon 50 wt.%, scaly graphite 30 wt.% and detonation diamonds 20 wt.% height of 1.5 mm on Top of it is placed a layer 4, which is a mixture of diamond powder with a particle size 20/14 μm and nanopowder detonation diamond with a particle size of 50-100 nanometers when the content of the last 20% of the total volume of this layer, a height of 2 mm and a layer 5 of diamond powder with a particle size 28/20 μm, a height of 4 mm From the walls of the heater, the charge is isolated by a layer of mica 3, and the bottom layer 7 of hexagonal boron nitride with a thickness of 0.5 mm on Top of the mixture fall asleep layer 8 of boron carbide with a thickness of 1.5 mm, and the top and bottom closed lids 9 and 10 of the graphite a thickness of 1 mm. Collected reaction cell is placed in a high-pressure apparatus "dual toroid 35", create a pressure of 8 GPA and a temperature of 1600°C for 120 C. the resulting CD after removing the temperature and pressure removed from the machine, give it by grinding and polishing the shape of the cutting element, for example a square cross section with dimensions according to GOST - side square 9,52 mm, height 3,18 mm After this study the t x-ray structure, optical and electron diffraction microstructure and microhardness of both sides, using ultrasound to measure the moduli of elasticity, tested the limit of compressive strength and other physical and mechanical properties, and then test on the cutting wear resistance and surface finish when machining solid carbide VC - 15, obtained according to GOST 3882-74, hardness 89-92% HRA by the standard method:

- the radius of the cutter of the composite should be not more than 0.05 mm

Challenge mode:

the cutting speed, m/min10
longitudinal feed, mm/Rev0,04
cutting depth, mm0,1
testing cutting ability, min10
radial wear should not exceed mm0,15

Example 2. The same as in example 1, except that graphite heater 2 (figa) has an outside cylindrical surface and inside the cavity of square cross section with sides of the square 11.5 mm, coaxially with the reaction cell, and the layer 4 (figure 1) consists of diamond powder with grain 14/10 μm and detonation diamond sizes 50-100 nanometers when the content of the last 20% of the total volume of this layer, the layer height 4 -2 mm, layer 5 - 4 mm.

Example 3. The same thing and when the ore 1, only graphite heater 2 (figb) is within a cavity of a rhombic cross-section with corners 80 and 100°, diagonals 17 and 14.3 mm, and layer 4 (figure 1) consists of diamond powder with grain 10/7 μm and detonation diamond with a particle size of 30-50 nm when the content of the last 15% of the total volume of this layer, the thickness of the layer 4 to 1.8 mm, layer 5 - 4.2 mm, and the sintering is conducted at a temperature of 1800°C.

Example 4. The same as in example 1, except that graphite heater 2 (high) is within a cavity of a hexagonal cross-section with a side of 8.5 mm, and layer 4 (figure 1) consists of diamond powder with grain 5/3 μm and detonation diamond with a particle size of 20-30 nm when the content of the last 10% of the total volume of this layer, the thickness of the layer 4 is 1.6 mm, the layer 5 and 4.4 mm, and the sintering is conducted at a temperature of 1900°C.

Example 5. The same as in example 1, except that graphite heater 2 (pigv) is within a cavity of triangular cross-section with a side of 14.1 mm and angles 60°and layer 4 (figure 1) consists of diamond powder with grain 2/1 μm and detonation diamond with a particle size of 1-10 nanometers when the content of the last 1% of the total volume of this layer, the thickness of the layer 4 is 1.5 mm, the layer 5 is 4.5 mm, and the sintering is conducted at a temperature of 2000°within 180 C.

Example 6. The same as in example 1, except that graphite heater 2 (figa) is outside cilindri the definition surface with a diameter of 25 mm, inside the square hole with a side of 15 mm and a height of the reaction cell of 12.3 mm dimensions of the components of the charge (figure 1). The cutting layer 4 consisting of diamond powder with grain 20/14 μm, to which is added the detonation diamond with a particle size of 50-100 nanometers when the content of the last 30% of the total volume of this layer has a thickness of 2.25 mm Diamond powder substrate 5 grain 28/20 μm has a thickness of 4.5 mm Material impregnation 8-2 mm Thickness of hexagonal boron nitride 7 is 0.5 mm, the thickness of the boron carbide 8 - 1,8 mm Thick graphite caps 9 and 10 - 1 mm Sintering conducted at the office of the high pressure and temperature "dual toroid 50", which is the geometric similarity apparatus "dual toroid 35"' with the ratio of the diameter of the working chambers 50:35, at a pressure of 3 GPA and a temperature of 1200°With over 40 C. the Sintered samples were processed from all sides before receiving element according to GOST side of the square 12.7 mm, height 4,78 mm, and then investigated their physico-mechanical properties and cutting ability.

In examples 1, 2, 6 layer of diamond powder 5 (substrate) made with particle sizes 28/20, and in examples 3, 4, 5 layer of diamond powder 5 is made with particle sizes 40/28.

To map the cutting ability of the obtained diamond compacts and prototype samples were made according to the method prototype. A comparative test is summarized in table. They showed that the diamond compact according to this invention, the cutting ability, the yield and purity of the surface of the processed materials superior to CDs in the method prototype. The last quality is especially important, for example, for the manufacture of critical parts of car engines, made of silicon-containing aluminum alloys and other materials, which considerably increases the duration of engine operation.

Table
A method of obtaining a superhard materialThe initial charge of the cutting layer*The sintering conditionsThe dimensions of the superhard material after processingThe composition of the cutting layerRadial wear, mmThe roughness of the processed surface, micronsThe yield of products, %
PressureTemperature, °The sintering time,Diameter, mmThe side of the square, mmLarge size diamond mmThe side of the triangle, mmThe side of the hexagon mmThe plate thickness, mm
123456789101112131415
Method 1Diamond powder 20/14 μm and detonation diamond 50-100 nm when the content of the last 20% of the total volume of the layer8160012014,53,18Diamond and silicon carbide90
Method 2Diamond powder 14/10 μm and detonation diamond 50-100 nm when the content of the last 20% of the total volume of the layer816001209,523,18Diamond and silicon carbide0,100,8595
Method 3Diamond powder 10/7 μm and detonation diamond 30-50 nm when the content of the last 15% of the total volume of the layer8180012014,53,18Diamond and micro-grain tungsten is silicon 0,110,8090
Method 4Diamond powder 5/3 μm and detonation diamond 20-30 nm when the content of the last 10% of the total volume of the layer8190012083,18Diamond and silicon carbide0,120,7595
According to the method 5Diamond powder 2/1 μm and detonation diamond 1-10 nm when the content of the last 1% of the total volume of the layer82000180113,18Diamond and silicon carbide0,130,8090
Method 6Diamond powder 20/14 μm and detonation diamond 50-100 nm when the content of the last 30% of the total volume of the layer3120040a 12.74,76Diamond and silicon carbide, traces of free silicon0,140,8580
PrototypeDiamond powder 14/10 μm and 5/3 in the ratio 5:1 816001209,523,18Diamond and silicon carbide, a few percent of free silicon0,150,8875
*The substrate 5 is made of diamond powder with a particle size 40/28 μm in examples 3, 4, 5, and particle sizes 28/20 μm in examples 1, 2, 6

1. A method of obtaining a polycrystalline superhard material comprising a high pressure and temperature on the charge with layers located and in contact with the layer of diamond powder and material impregnation, characterized in that the layer of diamond powder is divided into two layers, one of which is in contact with the impregnation layer, use diamond powder with particle sizes in the range from 20/14 to 2/1 μm, and optionally in it enter detonation diamond powder with particle sizes in the range from 1 to 100 nm in an amount of from 1 to 30 percent by volume of diamond powder layer, while in the second layer, in contact with the first use of diamond powder with a particle size in the range from 40/28 to 28/20 μm, and the height of this layer in relation to the first is from 2:1 to 3:1, and the material impregnation use silicon or a material which, it contains, for example a mixture of powders of silicon, scaly graphite and detonation diamond.

2. The method according to claim 1, characterized in that the workpiece prior to exposure to high pressure and temperature give a round, square, rhombic, triangular, hexagonal and other shapes.



 

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1 ex

FIELD: heat conductors.

SUBSTANCE: invention relates to diamond-containing composites, which show high heat-conductivity and high temperature-conductivity for use in heat absorbers, heat distributors, and in other cases where heat-conducting materials are required. Material contains 55-81% diamond particles, 3-39% silicon carbide, and up to 41% silicon showing heat-conductivity at least 400 W/(m·K) and temperature-conductivity at least 2.1 cm2/sec. Diamond particles are made up of at least two fractions with different particle size, at least 50% of particles having diameter 80 μm and larger.

EFFECT: increased heat conductivity of material.

7 cl, 2 dwg, 3 tbl

FIELD: blasting.

SUBSTANCE: blasting chamber comprises a vertically mounted cylindrical shell with bottoms, an access door and means for securing an explosive charge inside the chamber. The chamber is made of steel-plated reinforced concrete, the chamber walls contain pipes being evenly distributed over the chamber inner surface. The centrelines of said pipes are directed to the centre of the chamber, wherein the pipes are connected with air-tight water tanks that are connected with a compressed air receiver through solenoid valves, wherein the chamber bottoms have a conical shape and in the centre of each bottom there is an expander having the shape of a cylinder or a polygon, on the side face of which there is a door for loading a charge into the chamber and discharging explosion solid products. Said means for securing the explosive charge have the form of a steel wire rope extending along the chamber centerline and capable of moving, lifting and holding the charge by means of an electric hoist mounted on the top expander bottom and of a section wire, one end of which is attached to the wire rope, and another - to the charge.

EFFECT: improving the efficiency of the chamber; safety and ease of its use requiring no personnel entry inside the chamber.

2 cl, 1 dwg

FIELD: chemistry.

SUBSTANCE: process of hard monocrystalline diamond preparation compises fixing of inoculating diamond in the holder and its growing by the way of chemical deposition from gaseous phase induced by microwave plasma. The process is implemented at temperature ca 1000°C - 1100°C in medium N2/CH4=0.2-5.0 and CH4/H2=12-20% at total pressure 120-220 torr. Derived monocrystalline diamond has the hardness in the range 50-90GPa and fracture strength 11-20MPa m1/2.

EFFECT: increasing of diamond hardness.

7 cl, 4 dwg

FIELD: blasting operations.

SUBSTANCE: explosion chamber contains cylindrical hull, plain bottom, cover and fastening tools for charge of explosive substance inside the chamber, installed in cooling casing. The vertical hull and the chamber bottom is faced by steel of reinforced concrete, and as cooling casing it is used the water, partly filling the internal chamber volume, on the chamber bottom it is fixed the perforated tubes, connected with gas system or with water pump, on the inside hull surface it is fixed the vertical splitter of the air-blast wave with rectangular section, connected by several steel rings, the hull is provided with hatch, which is opened inside the chamber, nipples for gas and water excluding from the chamber and nipples for gas feeding to perforated tubes, the hatch is steel hermetical cistern filled with the water, which has nipples for water and water feeding, and also nipples for water feeding from cistern to the chamber, which are made as curved tubes, that the curve is situated higher then the water level in the cistern.

EFFECT: it is exceeded the productivity of the chamber as well as the convenience of using without stuff entering inside.

4 cl, 2 dwg

FIELD: inorganic chemistry, possible use in bio-medical research and during manufacture of non-magnetic materials, sorbents.

SUBSTANCE: in accordance to the method, industrial mixture of diamond with graphite and metals is processed by mixture of acids and oxidizing compounds. The suspension is additionally processed by cleaned concentrated hydrochloric acid with concentration of nano-diamonds in the hydrochloric acid not exceeding two percents with simultaneous ultrasound processing. Temperature of suspension is measured. Then temperature increases by at least ten degrees, irradiation is stopped. Suspension is settled. Aforementioned operations are repeated at least three times. Then suspension is washed by cleaned concentrated hydrochloric acid until coloration disappears and thiocyanate sample reaction becomes positive. Final washing is performed by deionized water until suspension stops settling.

EFFECT: resulting nano-diamonds do not contain admixtures of iron.

4 ex

FIELD: crystal growth.

SUBSTANCE: method comprises separating the inoculation from the source of carbon by a metal-dissolver made of an alloy of ferrous, aluminum, and carbon when a 20-30°C temperature gradient is produced between the carbon source and inoculation. The growth zone is heated up to a temperature higher than the melting temperature of the alloy by 10-20°C, and the melt is allowed to stand at this temperature for 20 hours. The temperature then suddenly increases above the initial temperature by 10-25°C and decreases down to the initial value with a rate of 0.2-3 degree per minute.

EFFECT: improved quality of crystal.

1 tbl, 2 ex

FIELD: inorganic chemistry; mining industry; electronics; other industries; methods of the synthesis of the needle-shaped and lengthened diamonds.

SUBSTANCE: the invention is pertaining to the field of the inorganic chemistry, in particular, to the method of production of the needle shape synthetic diamonds and may be used in the industrial production of the special-purpose diamonds, for example, for manufacture of the boring crown bits and the dressers, and also in the capacity of the blocks details of the audio-video playback equipment, for manufacture of the feeler probes, in the micro-mechanical devices etc. The method provides for commixing of the fusion charge composed of the alloy of Mn-Ni-Fe in the mass ratio of 60±5÷30±5÷10±5 and the powder of the carbon-containing substance and treatment of the mixture at the pressure exceeding 40 kbar and the temperature over 950°С at heating rate less than 100°C/minutes. In the capacity of the carbon-containing substance use the needle-shaped coke or graphite on the coke basis with the single-component anisotropic structure with the degree of graphitization of no less than 0.55 relative units. The invention allows to simplify the production process of the synthesis of the needle-shaped and lengthened diamonds and to increase the percentage of their output within one cycle of the production process.

EFFECT: the invention ensures simplification of the production process of the synthesis of the needle-shaped and lengthened diamonds, the increased percentage of their output within one cycle of the production process.

2 ex, 2 dwg

FIELD: chemical industry; methods of processing of the diamond-containing concentrates.

SUBSTANCE: the invention is pertaining to separation of the diamonds from the diamonds-containing rock and the marks of technological processes concentration and may be used in the production shops of the final treatment of the diamond- -containing concentrates in the mining-and-processing integrated works of the diamond-mining firms. For creation of the self-contained ecologically safe cycle of production of pure diamonds the processing of the diamond-containing concentrates is conducted in the autoclave at the temperatures of 200-400° С using the saturated solution of the sodium carbonate with addition of 3-5 % of the weight % of sodium hydroxide in the field of the ultrasonic radiation, then the autoclave is cooled and in the reaction mass, which contains the non-reacted water solution of the sodium carbonate, they route oppositely to the gravitational force the stream of the concentrated hydrochloric and nitrogen acids for formation of the conditions of the flotation-gravitational division and separation of the diamonds from the products of the production process. At that for creation of the closed cycle of the production process at flotation-gravitational separation of the diamonds from the products of the production process use the concentrated acids, which have remained after the final cleaning of the diamonds. The invention ensures the high quality of the cleaning of the diamonds at the minimal usage of the toxic mediums, which allows the considerable reduction of the cost of the production process.

EFFECT: the invention ensures the high quality of the diamonds cleaning, the minimal usage of the toxic mediums in the production process, the considerable reduction of its cost.

2 cl, 2 ex

FIELD: chemical industry; mining industry; other industries; methods of production of the heat-resistant composite diamond sintered articles.

SUBSTANCE: the invention is pertaining to the heat-resistant composite diamond sintered articles used in the capacity of the cutting tools, the tool used for the high-precision machining and to the jewelry branch. The diamond composite sintered article contains in the capacity of the article the diamond crystal and the very small amount of the non-diamond carbon and has the hardness according to Vickers of 85 GPa or more. The article is produced by the method providing for inclusion of the synthetic diamond powder having the average size of the grains of 200 nanometers or less, in the tantalum or molybdenum capsule, both heating and application of the pressure at usage of the apparatus for the synthesis under the super-high pressure in the thermodynamically stable conditions including the temperature of 2100°С or more and the pressure of 7.7 GPa or more. The technical result of the invention is production of the articles having the electric conductivity, the high thermal stability and having the brilliance and the glaze.

EFFECT: the invention ensures production of the articles having the electric conductivity, the high thermal stability and having the brilliance and the glaze.

6 cl, 4 ex, 3 dwg

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