CN116159483A - Assembly structure of polycrystalline diamond synthetic block - Google Patents

Abstract

The invention discloses an assembly structure of a polycrystalline diamond synthetic block, which comprises a cylindrical synthetic column, carbon tubes arranged outside the circumference of the synthetic column, conductive steel rings arranged at two ends of the carbon tubes, and pyrophyllite blocks wrapping the carbon tubes and the conductive steel rings, wherein the carbon tubes are arranged on the outer sides of the circumference of the synthetic column; dolomite sheets are arranged at two ends of the synthetic column and embedded into two ends of the inner side of the carbon tube; a titanium belt wrapping the synthetic column is arranged between the synthetic column and the carbon tube; titanium sheets are arranged at the two ends of the outer side of the carbon tube in a fit manner, the titanium sheets are communicated with a conductive steel ring, the conductive steel ring is of a reversely buckled bowl-shaped structure, and dolomite powder pressing materials are filled in the conductive steel ring; the end part of the titanium belt is in contact conduction with the titanium sheet; the composite insulating tube is sleeved outside the carbon tube, the metal pressurizing component is added to the assembly structure of the polycrystalline diamond synthetic block, the unbalance of the pressure field is compensated by the shape adjustment of the metal pressurizing component, the controllability of the pressure field is improved, the pressure required by synthesis is reduced, the loss of a press is reduced, and the service life of a top hammer is prolonged.

Description

Assembly structure of polycrystalline diamond synthetic block

Technical Field

The invention relates to the technical field of polycrystalline diamond synthesis, in particular to an assembly structure of a polycrystalline diamond synthetic block.

Background

The synthesis of the polycrystalline diamond is required to be carried out in a specific high-temperature and high-pressure environment, and the accuracy of temperature and pressure is required to be strictly controlled in order to achieve an even and stable high-temperature and high-pressure environment; mechanical stability of the high voltage device; chemical stability of the insulating, pressure transmitting material; the accuracy of the assembly dimensions of the composite block; and a reliable process. At present, the domestic polycrystalline diamond synthesis equipment mostly adopts a small-cavity hexahedral top press with the cylinder diameter of 650mm, 750mm and the like; the single yield of the synthetic block is lower due to the restrictions of the synthetic cavity and the synthetic process. Aiming at the problem of low yield, a main manufacturer in industry coats nickel-based catalyst materials through a seed crystal method or a seed crystal, regulates and controls a synthesis process, promotes nucleation in the synthesis process, and further improves the single yield of polycrystalline diamond; if a large-cavity hexahedral top press with the cylinder diameter of 850mm or more is adopted to synthesize polycrystalline diamond, the required pressure and temperature are higher, and the loss to equipment is very large; in the growth process of the polycrystalline diamond, the pressure fluctuation and the uneven pressure distribution obviously reduce the quality of the polycrystalline diamond; and the high pressure causes the formation of polycrystalline around the synthetic column; the pressure is uneven, so that generated polycrystalline diamond air holes and impurities are easy to dope, and particles are small; even though the yield per unit is increased, the quality is reduced, with the end result being a loss.

Disclosure of Invention

The invention aims to overcome the existing defects, provides an assembly structure of a polycrystalline diamond synthetic block, adds a metal pressurizing part, adjusts the shape of a metal pressurizing part, compensates the unbalance of a pressure field, improves the controllability of the pressure field, reduces the pressure required for synthesis, reduces the loss of a press, prolongs the service life of a top hammer, and can effectively solve the problems in the background art.

In order to achieve the above purpose, the present invention provides the following technical solutions: an assembling structure of a polycrystalline diamond synthetic block comprises a cylindrical synthetic column, a carbon tube arranged outside the circumference of the synthetic column, conductive steel rings arranged at two ends of the carbon tube, and pyrophyllite blocks wrapping the carbon tube and the conductive steel rings;

dolomite sheets are arranged at two ends of the synthetic column and embedded into two ends of the inner side of the carbon tube;

a titanium belt wrapping the synthetic column is arranged between the synthetic column and the carbon tube;

titanium sheets are arranged at the two ends of the outer side of the carbon tube in a fit manner, the titanium sheets are communicated with a conductive steel ring, the conductive steel ring is of a reversely buckled bowl-shaped structure, and dolomite powder pressing materials are filled in the conductive steel ring;

the end part of the titanium belt is in contact conduction with the titanium sheet;

the carbon tube is sleeved with a composite insulating tube;

the composite insulating tube is sleeved with a dolomite tube, and the dolomite tube is sleeved with a special-shaped iron ring; the section of the special-shaped iron ring is an inner circle and an outer square, and the corners of the special-shaped iron ring are provided with arc chamfers;

the conductive steel ring is sleeved with a pyrophyllite ring, and the outer circumferential surface of the pyrophyllite ring is the same as the axial projection of the special-shaped iron ring;

the pyrophyllite ring and the special-shaped iron ring are sleeved with pyrophyllite blocks together, and the pyrophyllite blocks are coaxially arranged in an upper group and a lower group.

As a preferable technical scheme of the invention, the synthetic column comprises a catalyst and graphite, wherein the catalyst adopts 7:3 nickel-iron alloy powder, the granularity is 120-230 meshes, and the graphite adopts high-purity flake graphite, and the granularity range is 200-500 meshes.

As a preferable technical scheme of the invention, the composite insulating tube is NaCl and ZrO ₂ The mixing ratio of the mixture is 3.5:1.5-4.5:0.5.

A polycrystalline diamond synthesis method based on the above-described assembly structure; manufacturing a synthetic column, namely mixing a catalyst and graphite in a mass ratio of 1:5-1:3 in a three-dimensional mixer for 10-15 hours; granulating by an isostatic press, wherein the granulating pressure is 10-20Mpa; pressing the four-column press into a columnar reaction core;

assembling the composite block assembly structure;

pretreating the synthetic block, filling nitrogen-protected incubator, and preserving heat at 120 ℃ for 1-2 hours;

pressing the synthetic block, slowly boosting the pressure in a hexahedral top press by 60-85Mpa, and synthesizing with 1300-1450W power.

Compared with the prior art, the invention has the beneficial effects that: the assembly structure of the polycrystalline diamond synthetic block adopts a metal titanium belt with the thickness of 0.1-0.5mm, combines titanium sheets at the upper end and the lower end to form a closed space, solves the problems of high brittleness and easy cracking of the traditional carbon tube, effectively prevents the entry of impurities, and simultaneously ensures that the metal titanium bears the functions of electric conduction and heat conduction so that the internal and external temperature fields are more balanced;

the composite insulating tube 5 with the ratio of NaCl to ZrO2 of 3.5:1.5-4.5:0.5 is sleeved outside the carbon tube, and the NaCl has good heat preservation and pressure transmission performance, but can spontaneously nucleate and crystallize at high temperature and high pressure, so that the heat preservation performance is reduced, the temperature loss is reduced by doping ZrO2, and the stability of a cavity is improved;

the dolomite has larger thermal expansion coefficient, smaller performance change under high temperature and high pressure, good pressure transmission effect, but poor heat preservation performance, thus being used as an inner liner tube;

the dolomite tube is sleeved with a special-shaped iron ring, the special-shaped iron ring is in an inner circle convex shape, and in the synthesis process of the polycrystalline diamond, the pressure distribution is that the pressure of four sides of the pyrophyllite block is high and the pressure of four corners of the pyrophyllite block is low; the iron ring is used as a pressurizing block, so that the pressure required by synthesis can be obviously reduced from 95MPa to 85MPa; the pressurizing is mainly related to the thickness of the iron ring, and the larger the thickness is, the more obvious the pressurizing is; in order to make up the pressure difference between the pressure in the four corners and the pressure in the four sides of the pyrophyllite, the iron ring is of a special-shaped structure, the thickness of the four sides of the iron ring is 1mm, the thickness of the iron ring at the four corners is gradually increased to 2-3mm, and the pressure can be more balanced in the four corners of the pyrophyllite compared with the thickness of the iron ring at the four sides of the pyrophyllite by 1-2 mm;

the pyrophyllite block has good early-stage creep property, and has a hysteresis phenomenon in the process of boosting and reducing pressure, thereby playing a role in sealing; however, the phase change occurs under high temperature and high pressure, the layered structure gradually disappears, and the heat preservation, sealing and pressure transmission performances are poor, so that the dolomite inner liner tube can be sleeved inside to increase the sealing and pressure transmission performances;

meanwhile, the pyrophyllite blocks adopt a structure which is transversely cut and divided into two parts, so that the thickness unevenness of the pyrophyllite blocks caused by the flow sealing of the pyrophyllite blocks during synthesis of a press is reduced;

when the pretreatment of the synthetic block is carried out, nitrogen is adopted for heat preservation, so that the secondary oxidation or moisture absorption of the external air is prevented;

through selecting the thickness of the iron ring, proper pressure and temperature are selected, so that the synthetic block is pressed in a low-pressure and low-temperature environment, the polycrystalline diamond in the press is always in a stable balance state, and the loss of the press is effectively reduced;

and after the pressure is balanced, the conversion rate and the yield are effectively improved.

Drawings

FIG. 1 is a schematic diagram of the structure of the present invention;

FIG. 2 is a top view of a pyrophyllite block of the present invention;

FIG. 3 is a top view of the profiled bead of the present invention;

FIG. 4 is a top view of a pyrophyllite ring of the present invention;

FIG. 5 is an enlarged view of the invention at A;

FIG. 6 shows the distribution of the pressure field inside and outside the profiled bead and pyrophyllite block.

In the figure: 1. pyrophyllite blocks; 2. a special-shaped iron ring; 3. pyrophyllite ring; 4. a dolomite tube; 5. a composite insulating tube; 6. a carbon tube; 7. a titanium belt; 8. a conductive steel ring; 9. a filler material; 10. titanium sheets; 11. dolomitic stone chips.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Referring to fig. 1-6, the present invention provides a technical solution: an assembling structure of a polycrystalline diamond synthetic block comprises a cylindrical synthetic column, a carbon tube 6 arranged outside the circumference of the synthetic column, conductive steel rings 8 arranged at two ends of the carbon tube 6, and pyrophyllite blocks 1 wrapping the carbon tube 6 and the conductive steel rings 8;

both ends of the synthetic column are provided with dolomite sheets 11, and the dolomite sheets 11 are embedded into both ends of the inner side of the carbon tube 6;

a titanium belt 7 wrapping the synthetic column is arranged between the synthetic column and the carbon tube 6;

titanium sheets 10 are arranged at the two ends of the outer side of the carbon tube 6 in a fit manner, the titanium sheets 10 are communicated with the conductive steel ring 8, the conductive steel ring 8 is of a reversely buckled bowl-shaped structure, and dolomite powder pressed materials are filled in the conductive steel ring 8;

the end part of the titanium belt 7 is in contact conduction with the titanium sheet 10;

the carbon tube 6 is sleeved with a composite insulating tube 5;

the composite insulating tube 5 is sleeved with the dolomite tube 4, and the dolomite tube 4 is sleeved with the special-shaped iron ring 2; the section of the special-shaped iron ring 2 is the outer side of the inner circle, and the corners are provided with arc chamfers;

the conductive steel ring 8 is sleeved with the pyrophyllite ring 3, and the axial projection of the outer circumferential surface of the pyrophyllite ring 3 is the same as that of the special-shaped iron ring 2;

the pyrophyllite ring 3 and the special-shaped iron ring 2 are sleeved with the pyrophyllite block 1 together, and the pyrophyllite block 1 is coaxially arranged in an upper group and a lower group.

The synthetic column comprises a catalyst and graphite, wherein the catalyst adopts 7:3 nickel-iron alloy powder, the granularity is 120-230 meshes, the graphite adopts high-purity flake graphite, and the granularity range is 200-500 meshes.

The composite insulating tube 5 is NaCl and ZrO ₂ The mixing ratio of the mixture is 3.5:1.5-4.5:0.5.

Also discloses a polycrystalline diamond synthesis method based on the assembly structure;

manufacturing a synthetic column, namely mixing a catalyst and graphite in a mass ratio of 1:5-1:3 in a three-dimensional mixer for 10-15 hours; granulating by an isostatic press, wherein the granulating pressure is 10-20Mpa; pressing the four-column press into a columnar reaction core;

assembling the composite block assembly structure;

pretreating the synthetic block, filling nitrogen-protected incubator, and preserving heat at 120 ℃ for 1-2 hours;

pressing the synthetic block, slowly boosting the pressure in a hexahedral top press by 60-85Mpa, and synthesizing with 1300-1450W power.

In the course of the fabrication of the assembly,

a metal titanium belt 7 with the thickness of 0.2mm is combined with titanium sheets 10 with the thickness of 0.8mm at the upper end and the lower end to form a closed space, and the metal titanium belt replaces a carbon tube 6 to conduct electricity and heat, and is combined with a dolomite sheet 11 to conduct insulation and heat preservation;

meanwhile, the conductive steel ring 8 at the top adopts a reversely buckled bowl-shaped structure, the bowl wall part is in contact conduction with the titanium sheet 10, the bowl wall thickness is smaller, the heat loss is less, and the dolomite powder pressed material in the conductive steel ring 8 is used as the filling material 9, and has the same force conduction performance and heat preservation performance under high temperature and high pressure, so that the transmission of the internal temperature of the synthetic column to the jack hammer is further reduced;

the carbon tube 6 is sleeved with 3.5:1.5 NaCl and ZrO ₂ A composite insulating tube 5 made of a composite material of (a);

the assembled synthetic block is put into a heat preservation oven filled with nitrogen for heat preservation for 1.5 hours at 120 ℃, then is put into a top press, is synthesized by adopting power of 1300-1450W under the condition of slow pressure rising of 60-85Mpa, and is obtained after the slow pressure rising, the polycrystalline diamond particles are obtained after the column core is processed and purified, and the single yield is increased to 500 g/block from the original 120 g/block.

Wherein, the liquid crystal display device comprises a liquid crystal display device,

in the synthesis process of the polycrystalline diamond, the pressure distribution is that the pressure of the four sides of the pyrophyllite is high and the pressure of the four corners of the pyrophyllite is low; the iron ring is used as a pressurizing block, so that the synthesis pressure can be obviously reduced from 95MPa to 85MPa; the pressurizing is mainly related to the thickness of the iron ring, and the larger the thickness is, the more obvious the pressurizing is; in order to make up the pressure difference between the pressure in the four corners and the pressure in the four sides of the pyrophyllite, the iron ring is set to be of a special-shaped structure, the thickness of the iron ring at the 2 four sides of the special-shaped iron ring is 1mm, the thickness of the iron ring at the four corners is gradually increased to 2-3mm, and the thickness of the iron ring at the four corners of the pyrophyllite is 1-2mm thicker than that of the iron ring at the four sides of the pyrophyllite, so that the pressure can be more balanced.

The special-shaped iron ring is used as a metal pressurizing piece, so that the internal pressure of the synthetic column is balanced, the conversion rate is effectively improved, and the single yield is improved by about 30 percent; after the lining guide pipes of the pyrophyllite block 1 and the dolomite tube 4 are combined, the heat preservation performance is effectively improved, the internal temperature is balanced, and the granularity concentration rate and the yield of the product are improved by about 10%;

meanwhile, the novel synthesis column assembly structure effectively reduces the pressure required by the synthesis of the polycrystalline diamond, the pressure maintaining pressure can be reduced from 95MPa to about 85MPa, about 10% is reduced, and the energy consumption and the equipment loss are further reduced; and the synthetic pressure is reduced, so that the pressure change in the column core is reduced, the internal pressure field tends to be stable, the power is further reduced, the loss of the press is further reduced, the service life of the top hammer is prolonged, and the energy consumption and the cost are saved.

Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (4)

1. The utility model provides an assembled structure of polycrystalline diamond synthetic piece, includes columniform synthetic post, the outside carbon tube (6) that set up of synthetic post circumference, electrically conductive steel ring (8) that carbon tube (6) both ends set up and parcel carbon tube (6) and electrically conductive steel ring (8) pyrophyllite piece (1), its characterized in that:

both ends of the synthetic column are provided with dolomite sheets (11), and the dolomite sheets (11) are embedded into both ends of the inner side of the carbon tube (6);

a titanium belt (7) wrapping the synthetic column is arranged between the synthetic column and the carbon tube (6);

titanium sheets (10) are arranged at the two ends of the outer side of the carbon tube (6) in a fit manner, the titanium sheets (10) are communicated with a conductive steel ring (8), the conductive steel ring (8) is of a reversely buckled bowl-shaped structure, and dolomite powder pressed materials are filled in the conductive steel ring;

the end part of the titanium belt (7) is in contact conduction with the titanium sheet (10);

the carbon tube (6) is sleeved with a composite insulating tube (5);

the composite insulating tube (5) is sleeved with the dolomite tube (4), and the dolomite tube (4) is sleeved with the special-shaped iron ring (2); the section of the special-shaped iron ring (2) is the outside of the inner circle, and the corners are provided with arc chamfers;

the conductive steel ring (8) is sleeved with the pyrophyllite ring (3), and the axial projection of the outer circumferential surface of the pyrophyllite ring (3) is the same as that of the special-shaped iron ring (2);

the pyrophyllite ring (3) and the special-shaped iron ring (2) are sleeved with the pyrophyllite blocks (1) together, and the pyrophyllite blocks (1) are coaxially arranged in an upper group and a lower group.

2. An assembled structure of polycrystalline diamond compact according to claim 1, wherein: the synthetic column comprises a catalyst and graphite, wherein the catalyst adopts 7:3 nickel-iron alloy powder, the granularity is 120-230 meshes, the graphite adopts high-purity flake graphite, and the granularity range is 200-500 meshes.

3. An assembled structure of polycrystalline diamond compact according to claim 1, wherein: the composite insulating tube (5) is NaCl and ZrO ₂ The mixing ratio of the mixture is 3.5:1.5-4.5:0.5.

4. A method of polycrystalline diamond synthesis based on the assembled structure of claim 1, characterized by: manufacturing a synthetic column, namely mixing a catalyst and graphite in a mass ratio of 1:5-1:3 in a three-dimensional mixer for 10-15 hours; granulating by an isostatic press, wherein the granulating pressure is 10-20Mpa; pressing the four-column press into a columnar reaction core;

assembling the composite block assembly structure;

pretreating the synthetic block, filling nitrogen-protected incubator, and preserving heat at 120 ℃ for 1-2 hours;

pressing the synthetic block, slowly boosting the pressure in a hexahedral top press by 60-85Mpa, and synthesizing with 1300-1450W power.

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