High-pressure synthesis assembly structure

Abstract

The invention provides a high-pressure synthesis assembly structure which comprises pyrophyllite with a through hole, a shielding cup containing alloy and diamond samples is arranged in the through hole, the outer side of the shielding cup is sleeved with a heat preservation and pressure transmission assembly, plugs are arranged at the two ends of the shielding cup, and conductive assemblies are arranged at the ends, away from the shielding cup, of the plugs. The plug and the conductive assembly are positioned in the through hole; and a pressure transmission ring coaxial with the through hole is arranged in the pyrophyllite. According to the invention, a secondary pressurization effect is achieved through the pressure transfer ring, the secondary pressurization units are ingeniously arranged in the cubic top, and compared with the previous pressurization, the number of the secondary pressurization units is increased in the radial direction in more consideration of the axial direction, so that the pressure difference between the axial direction and the radial direction is reduced, and an integral pressure field balance state is achieved; pressure imbalance is avoided, and pressure loss is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of superhard materials, in particular to a high-pressure synthesis structure for a six-sided top press. Background Art

[0002] Pressure and temperature are two important basic thermodynamic elements that determine the state of existence of matter. Under high pressure and extreme conditions, many substances will show properties that are completely different from those under normal temperature and pressure, and even new structures and new characteristics will appear. Therefore, high pressure is widely used in research fields such as materials, geology, planetary science, and national defense. The six-sided top press is one of the devices that generate ultra-high pressure, and is widely used in domestic and foreign research institutes and superhard material production fields. The six-sided top press includes a tie rod type six-sided top press, a hinged six-sided top press, and a six-sided top press based on a two-sided top press frame. The hinged six-sided top press used in industry to generate high temperature and high pressure conditions mainly uses heating elements to heat the primary pressure chamber and the secondary pressure chamber to generate high pressure and ultra-high pressure. Carbide cemented carbide top hammers and pressure transmission media such as pyrophyllite and magnesium oxide are usually used. The pressure transmission medium is squeezed by the cemented carbide top hammer to generate pressure inside the synthesis unit. However, the six-sided top press on the current market still has many shortcomings in high-pressure assembly, which limits the further improvement of its performance and the expansion of its application range. At present, the assembly of six-sided top press mainly relies on traditional structures and processes. Although these traditional methods have been widely used and verified in the past few decades, with the advancement of technology, many researchers have innovated and improved the assembly methods of six-sided top press and applied for relevant patents.

[0003] The Chinese utility model with the announcement date of 2015.05.20 and the announcement number of CN 204338115 U discloses a pyrophyllite assembly block for ultra-high pressure synthesis, including a cubic pyrophyllite block with a cylindrical high-pressure cavity in the middle and a prefabricated sealing edge, the six sides of the pyrophyllite block are provided with grooves, and the grooves of two adjacent sides are formed with prefabricated sealing edges, and the bottom of each groove is also provided with a boosting groove downward, the longitudinal section of the boosting groove is an isosceles trapezoid, and the transverse cross-sectional area of ​​the boosting groove decreases with the increase of the depth of the boosting groove, and a matching boosting block is provided in the boosting groove. The utility model has a high-pressure cavity pressure of up to 8GPa or more, which can effectively improve the physical and mechanical properties of the diamond sintered body or the cubic boron nitride sintered body.

[0004] However, the pressure of the booster block in the above patent is directly applied to the talc block, and does not directly participate in the pressurization in the ultra-high pressure synthesis chamber; therefore, the structure of the assembly block is relatively complex and the production cost is high; and when in use, six booster blocks are required at the same time to make the high-pressure chamber pressure reach more than 8GPa, which will increase the risk of explosion.

[0005] The Chinese invention patent with the announcement date of 2009.05.13 and the announcement number of CN 100486684C discloses a new device for generating ultra-high pressure, including six top hammers driven synchronously by a six-sided top press, a booster unit composed of eight cubes with one corner cut off, and an octahedral synthesis block for containing synthetic raw materials, wherein the booster unit is placed in a matching hexahedral high-pressure cavity surrounded by six top hammers, and the octahedral synthesis block is placed in a matching octahedral high-pressure cavity surrounded by cubes, and the eight cubes constituting the booster unit are filled with deformable supports with a hardness lower than that of the corner-cut cube. The patent allows the cavity pressure to reach 50GPa. However, the size of the synthesized sample is too small and can only be used in the research field.

[0006] A Chinese invention patent with a publication date of 2018.06.29 and a publication number of CN 108211995 A discloses an ultra-high pressure pyrophyllite assembly block, including a pyrophyllite body in the form of a regular polyhedron, a high-pressure mold cavity penetrating the pyrophyllite body is provided on the pyrophyllite body, and steel pads, conductive steel rings, boosting columns, and boosting tubes are provided at both ends of the high-pressure mold cavity from outside to inside in sequence, and a heating component for heating the sample to be synthesized is provided inside the boosting tube.

[0007] However, the ultra-high pressure pyrophyllite assembly block mainly considers the increase of axial pressure, but the radial pressure is not as good as the axial pressure, which easily leads to overall pressure imbalance, thereby easily leading to large residual stress on the synthesized product. This residual stress can cause the existence of product performance to be prone to delamination and uncovering. In addition, the boost column of the ultra-high pressure pyrophyllite assembly block is tungsten, molybdenum, titanium or iron and its alloy. The alloy will have obvious volume shrinkage under high temperature and pressure, and it is easy to react under high pressure, and new phases will be generated, which will cause the overall cavity pressure to have obvious loss. Summary of the invention

[0008] In view of the above technical problems, the present invention proposes a high-pressure synthesis assembly structure for solving the problems of pressure imbalance and cavity pressure loss in the high-pressure synthesis structure used for a six-sided top press in the prior art.

[0009] In order to achieve the above object, the technical solution of the present invention is achieved as follows:

[0010] A high-voltage synthesis assembly structure comprises pyrophyllite with a through hole, a shielding cup containing alloy and diamond samples is arranged in the through hole, a heat-insulating pressure-transmitting component is sleeved on the outer side of the shielding cup, plugs are arranged at both ends of the shielding cup, a conductive component is arranged at one end of the plug away from the shielding cup, and the plug and the conductive component are located in the through hole; a pressure-transmitting ring coaxial with the through hole is arranged in the pyrophyllite.

[0011] Furthermore, in order to gradually enhance the pressure transmission effect of the pressure transmission ring, the pressure transmission ring includes a first pressure transmission ring, the cross section of the first pressure transmission ring along the axial direction is a pair of isosceles trapezoids, and the upper base of the trapezoid faces inward and is parallel to the axis of the through hole.

[0012] Furthermore, in order to prevent current conduction, the heat preservation and pressure transmission component includes a sodium chloride tube sleeved on the outside of the shielding cup and a heating tube sleeved on the outside of the sodium chloride tube.

[0013] Furthermore, in order to achieve the effect of pressurization and heat preservation, the heat preservation and pressure transmission component also includes a pressure transmission sleeve sleeved on the outside of the heating tube, and the inner wall of the pressure transmission sleeve fits with the outer wall of the heating tube.

[0014] Furthermore, in order to further enhance the pressurization and heat preservation effects of the pressure transmission sleeve due to the difference between the inner and outer diameters, the two ends of the pressure transmission sleeve are provided with outwardly opened bell mouths, and the two ends of the heating tube are provided with conical rings that fit with the bell mouths, and the plug is arranged in the conical ring and fits with the conical ring.

[0015] Furthermore, in order to make the heating tube fit with the inner wall of the pressure transmission sleeve, the heating tube includes a straight section and the tapered rings arranged at both ends of the straight section, and the small end of the tapered ring is connected to the end of the straight section.

[0016] Furthermore, in order to enhance the cavity pressure, the inner wall of the pressure transmission sleeve includes a straight wall in the middle and tapered inner walls at both ends of the straight wall, and the tapered inner wall is used to form the bell mouth; the outer wall of the pressure transmission sleeve is in contact with the inner wall of the through hole.

[0017] Furthermore, in order to achieve a significant increase in the cavity pressure, the ratio of the height of the straight cylinder wall to the outer wall of the pressure-transmitting sleeve is greater than or equal to 0.4 and less than 1.0.

[0018] Furthermore, in order to achieve a better pressure transmission effect, the height of the upper bottom edge of the trapezoid is consistent with and flush with the height of the pressure transmission sleeve.

[0019] Furthermore, the plug is made of mica, MgO, ZrO, sodium chloride or dolomite; the pressure transmission sleeve is made of ZrO, MgO or dolomite.

[0020] Furthermore, in order to enhance the pressure transmission effect of the pressure transmission ring, the pressure transmission ring also includes a second pressure transmission ring arranged on the inner side of the first pressure transmission ring, the inner wall of the first pressure transmission ring is in contact with the outer wall of the second pressure transmission ring, and the inner wall of the first pressure transmission ring is flush with the outer wall of the second pressure transmission ring.

[0021] Furthermore, in order to significantly increase the pressure during the transmission process, the ratio of the inner wall height of the first pressure transmission ring to the outer wall height of the first pressure transmission ring is 0.6 to 1.0.

[0022] Furthermore, the first pressure transmission ring and the second pressure transmission ring are made of the same material, which is alloy or magnesium oxide or zirconium oxide or dolomite; or the first pressure transmission ring and the second pressure transmission ring are made of different materials, the second pressure transmission ring is made of PCD, and the first pressure transmission ring is made of cemented carbide.

[0023] Furthermore, in order to perform a conductive function, the conductive component includes conductive steel caps arranged at both ends of the through hole and conductive pads located inside the conductive steel caps. The inner side of the conductive steel cap is tightly pressed against the end of the plug and the heat preservation and pressure transmission component through the conductive pads.

[0024] Furthermore, in order to achieve a better heating effect, the heating tube is made of graphite.

[0025] Furthermore, in order to avoid volume shrinkage of metal at high temperature and pressure loss, a filler is provided inside the conductive steel cap, and the filler is dolomite.

[0026] Beneficial effects of the present invention:

[0027] 1. The present invention provides a pyrophyllite block with a through hole, and a pressure transmission ring is provided in the pyrophyllite block. The pressure transmission ring is high outside and low inside, so as to achieve a secondary pressurization effect, so that the pressure transmission can be effectively improved;

[0028] 2. The present invention uses a pressure transmission sleeve with a bell mouth, so that the pressure transmission sleeve can also achieve the effect of pressurization and heat preservation due to the difference in inner and outer diameters;

[0029] 3. The present invention increases the thickness of the conductive steel cap and the thickness of the filler in the axial direction, so that the rigidity of the assembly structure is enhanced in the axial direction, which is more beneficial for pressure transmission. At the same time, the thickness of the filler is increased, so that the distribution of the temperature field in the cavity is more uniform;

[0030] 4. The present invention places plugs at both ends of the sleeve, and the cross-section of the plugs at both ends is circular, and the longitudinal section is set to a structure that is approximately trapezoidal, which can also increase the pressure in the cavity and has a significant effect on the stability of the temperature field in the cavity;

[0031] 5. The pressure transmission ring of the present invention cleverly has a two-stage pressure-increasing unit built into the six-sided top, so that the combined structure can increase pressure in the radial direction in addition to the axial direction, so that the pressure difference between the axial direction and the radial direction becomes smaller, thereby achieving a state of overall pressure field balance;

[0032] 6. The raw materials of the assembly structure of the present invention are cheap, easy to assemble, and the cavity pressure is stable, so it can be used for large-scale industrial production. At the same time, the assembly has excellent pressure transmission and heat preservation performance, which can increase the service life of the top hammer, save energy, and reduce energy consumption;

[0033] 7. The assembly structure of the present invention can be used for the production of large-size high-end PDC, wire drawing dies, and PCBN products. It is simple to operate, low-cost, and easy to industrialize. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 It is a structural schematic diagram of the present invention.

[0036] Figure 2 It is a structural schematic diagram of comparative example 1 of the present invention.

[0037] Figure 3 This is a schematic diagram of the structure of Example 4 of the present invention.

[0038] Figure 4 This is a schematic diagram of the structure of Example 5 of the present invention.

[0039] Figure 5 This is a photograph of the ground edge in the wear resistance test of the present invention.

[0040] Figure 6 This is a photograph of a sample subjected to an impact test of the present invention.

[0041] Reference numerals in the figures:

[0042] 1. Pyrophyllite, 2. Pressure transmission ring, 21. First pressure transmission ring, 22. Second pressure transmission ring, 4. Pressure transmission sleeve, 5. Conductive steel cap, 6. Conductive pad, 7. Plug, 8. Heating tube, 9. Sodium chloride tube, 10. Sample. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] Example 1

[0045] like Figure 1As shown, a high-pressure synthetic assembly structure described in the present invention includes pyrophyllite 1, which has a cubic shape and a longitudinal through hole. A shielding cup is placed in the middle of the through hole, and a sample 10 of alloy and diamond (PCD) is contained in the shielding cup. The outer sleeve of the shielding cup is provided with a heat-insulating pressure-transmitting component, and plugs 7 are provided at both ends of the shielding cup. A conductive component is provided on the side of the plug 7 away from the shielding cup, and the plug 7 and the conductive component are located in the through hole. A pressure-transmitting ring 2 coaxial with the through hole is provided in the pyrophyllite 1. By providing the pressure-transmitting ring 2 in the pyrophyllite 1, the pressure transmission is uniformly increased during the extrusion process. The pyrophyllite 1 and the pressure-transmitting ring 2 are fired by cold isostatic pressing and a corresponding roasting process.

[0046] Further, the pressure transmission ring 2 includes a first pressure transmission ring 21, and the cross section of the first pressure transmission ring 21 along the axial direction is a pair of isosceles trapezoids, namely, a first trapezoid, and the upper base of the first trapezoid faces inward and is parallel to the axis of the through hole. In another preferred embodiment, the ratio of the inner wall height of the first pressure transmission ring 21 to the outer wall height of the first pressure transmission ring 21 is 0.6 to 1.0, so that the pressure will be significantly increased during the transmission process.

[0047] Furthermore, the pressure transmission ring 2 further comprises a second pressure transmission ring 22 disposed inside the first pressure transmission ring 21, the inner wall of the first pressure transmission ring 21 is in contact with the outer wall of the second pressure transmission ring 22, and the inner wall of the first pressure transmission ring 21 is flush with the outer wall of the second pressure transmission ring 22. Figure 1 As shown, the cross-section of the second pressure transmission ring 22 along the axial direction is a pair of rectangles, that is, the second pressure transmission ring 22 has the same height inside and outside.

[0048] like Figure 1 As shown, the first pressure transmission ring 21 and the second pressure transmission ring 22 are made of different materials, the second pressure transmission ring 22 is made of PCD, i.e. diamond, and the first pressure transmission ring 21 is made of cemented carbide. The first pressure transmission ring 21 and the second pressure transmission ring 22 are made of PDC, i.e. polycrystalline diamond.

[0049] Furthermore, if Figure 1 As shown, the heat preservation and pressure transmission component includes a sodium chloride tube 9 sleeved on the outside of the shielding cup and a heating tube 8 sleeved on the outside of the sodium chloride tube 9. The end of the sodium chloride tube 9 is flush with the end of the shielding cup. The heating tube 8 is sleeved on the outside of the heating tube 8 and the plug 7, and the two end faces of the heating tube 8 are flush with the outer end faces of the plugs 7 at both ends away from the shielding cup. The sodium chloride tube 9 mainly plays a role in heat preservation and pressure transmission, and at the same time separates the shielding cup from the heating tube 8 to prevent current conduction.

[0050] Furthermore, if Figure 1As shown, the heat-insulating pressure-transmitting assembly further includes a pressure-transmitting sleeve 4 sleeved on the outside of the heating tube 8, and the inner wall of the pressure-transmitting sleeve 4 fits with the outer wall of the heating tube 8. The two end faces of the pressure-transmitting sleeve 4 are flush with the two end faces of the heating tube 8. The side of the conductive assembly close to the shielding cup fits with the end faces of the pressure-transmitting sleeve 4 and the heating tube 8 as well as the outer end face of the plug 7.

[0051] Specifically, Figure 1 As shown, the conductive component includes a conductive steel cap 5 and a conductive pad 6 arranged at both ends of the through hole. The conductive pad 6 is located on the side of the conductive steel cap 5 facing the shielding cup. Both sides of the conductive pad 6 are flat. The side of the conductive pad 6 close to the shielding cup is in contact with the end faces of the pressure transmission sleeve 4 and the heating tube 8 and the outer end face of the plug 7. At the same time, the inner side of the conductive steel cap 5 is tightly pressed against the end faces of the pressure transmission sleeve 4 and the heating tube 8 and the outer end of the plug 7 through the conductive pad 6.

[0052] In addition, the conductive steel cap 5 is provided with a filler inside, and one side of the filler is exposed to the inner side of the conductive steel cap 5, and the side of the filler is in contact with the conductive pad 6. The thickness of the filler shall not be less than 1 mm, and the thickness of the steel on the side of the conductive steel cap 5 that is located away from the shielding cup shall not be less than the thickness of the filler. The temperature in this area is relatively low, which will not cause metal deformation, and pressure transmission can be effectively achieved. And the thicker the steel thickness, the more effective it is for pressure transmission. In this embodiment, the thickness of the steel on the side of the conductive steel cap 5 that is located away from the shielding cup is equal to the thickness of the filler.

[0053] Furthermore, the filler is a filler with a heat-insulating effect. The conductive steel cap 5 is placed inside for heat-insulating effect, and the outside is a rigid material to avoid volume shrinkage of the metal at high temperature and avoid pressure loss. Thus, a pressure increase and good heat-insulating effect are achieved. In this embodiment, the filler is dolomite.

[0054] Furthermore, in order to further enhance the pressure-increasing and heat-insulating effect of the pressure-transmitting sleeve due to the difference in inner and outer diameters, the two ends of the pressure-transmitting sleeve 4 are provided with bell mouths that open outward. Specifically, the inner wall of the pressure-transmitting sleeve 4 includes a straight cylinder wall in the middle and tapered inner walls at both ends of the straight cylinder wall, and the tapered inner wall is used to form the bell mouth. The outer wall of the pressure-transmitting sleeve 4 fits the inner wall of the through hole, and both are straight cylinder-shaped. The height of the straight cylinder wall in the pressure-transmitting sleeve 4 is inconsistent with the height of the outer wall, so that the pressure will be significantly increased during the transmission process.

[0055] Furthermore, the ratio of the height of the straight tube wall to the outer wall of the pressure transmission sleeve 4 is greater than or equal to 0.4 and less than 1.0. The straight tube wall is shorter than the outer wall to enhance the cavity pressure.

[0056] In addition, the height of the upper bottom side of the first trapezoid is consistent with and flush with the height of the outer wall of the pressure transmission sleeve 4, that is, the inner side height of the first pressure transmission ring 21 is consistent with the height of the outer wall of the pressure transmission sleeve 4, thereby achieving uniform and increasing pressure transmission and preventing uneven pressure transmission.

[0057] Furthermore, if Figure 1 As shown, both ends of the heating tube 8 are provided with conical rings that fit with the bell mouth, so that the heating tube 8 can better fit the inner wall of the pressure transmission sleeve 4. The plug 7 is arranged in the conical ring and fits with the conical ring. The plug 7 also plays the role of heat preservation and pressure transmission, and the pressure transmission method is similar to that of the pressure transmission sleeve 4.

[0058] Furthermore, the heating tube 8 includes a straight section and the tapered rings arranged at both ends of the straight section, the small end of the tapered ring is connected to the end of the straight section, and the thickness of the tapered ring is consistent with the thickness of the straight section, so that the thickness of the heating tube 8 is uniform.

[0059] Furthermore, a portion of the plug 7 is located in the straight tube section and a portion is located in the conical ring, so that the structure of the plug 7 includes a truncated cylindrical section and a truncated frustum section, the small end of the frustum section is smoothly connected to the cylindrical section, and the large end is in contact with the conductive pad 6.

[0060] Furthermore, the plug 7 is made of mica, MgO, ZrO2, sodium chloride or dolomite; the pressure transmission sleeve 4 is made of ZrO2, MgO or dolomite.

[0061] In this embodiment, the plug 7 is made of MgO, and the pressure transmission sleeve 4 is made of MgO.

[0062] The cavity pressure test experiment of this embodiment is carried out, taking a six-sided top press with a cylinder diameter of 650mm as an example. The pressure test experiment is carried out by using tin as the pressure measuring material. The tin is placed at the center of two PCDs in the cavity, and the pressure is slowly increased. When the oil pressure is 58MPa, the cavity pressure can reach 9.4GPa. The pressure transmission efficiency reaches 84%.

[0063] Embodiment 2 is different from Embodiment 1 in that the plug 7 is made of MgO and the pressure transmitting sleeve 4 is made of ZrO2.

[0064] The cavity pressure test experiment of this embodiment is carried out, taking a six-sided top press with a cylinder diameter of 650mm as an example. The pressure test experiment is carried out by using tin as the pressure measuring material. The tin is placed in the center of the cavity and the pressure is slowly increased. When the oil pressure is 62MPa, the cavity pressure can reach 9.4GPa. The pressure transmission efficiency reaches 78%.

[0065] Embodiment 3 is different from Embodiment 1 in that the plug 7 is made of ZrO2 and the pressure transmission sleeve 4 is made of ZrO2.

[0066] The pressure test experiment of the inlet cavity of this embodiment is carried out by taking a six-sided top press with a cylinder diameter of 650mm as an example. The pressure test experiment is carried out by using tin as the pressure measuring material. The tin is placed in the center of the cavity and the pressure is slowly increased. When the oil pressure is 69MPa, the cavity pressure can reach 9.4GPa. The pressure transmission efficiency reaches 70%.

[0067] Comparative Example 1

[0068] like Figure 2 As shown, it is a comparative embodiment of the invention. The talc 1a without a pressure transmission ring is formed by cold isostatic pressing and a corresponding roasting process; a longitudinal through hole is set in the middle of the talc, and the through hole is sequentially arranged from top to bottom with a conductive steel cap 5, the thickness of the conductive steel cap steel is the same as the thickness of the filler, and a conductive pad 6 is arranged on the lower side of the conductive steel cap 5, and further downward is a circular plug 7a, the material of the circular plug 7a is ZrO2, and the upper and lower surfaces of the circular plug 7a have the same diameter, and under the circular plug 7a is a sample 10 filled with diamond and cemented carbide, and the sample is wrapped in a shielding cup. There are sodium chloride tubes 9 on both sides of the shielding cup, and a straight-tube heating tube 8a is outside the sodium chloride tube 9. The sodium chloride tube 9 mainly plays a role in heat preservation and pressure transmission, and at the same time separates the shielding cup from the straight-tube heating tube 8a to prevent current conduction. The outside of the sodium chloride tube 9 is a straight-cylinder pressure-transmitting sleeve 4a, and the inside and outside of the straight-cylinder pressure-transmitting sleeve 4a have the same height. The straight-cylinder heating tube 8a is made of graphite, and the straight-cylinder pressure-transmitting sleeve 4a is made of ZrO2. It can play a role in heat preservation and pressure transmission. This assembly has a significant improvement in the control distribution of the temperature field, and the assembly can be used to synthesize PDC, wire drawing dies, and PCBN products.

[0069] For the pressure test experiment of the comparative example, a six-sided top press with a cylinder diameter of 650mm was used as an example. The pressure test was carried out by using tin as the pressure measuring material. The tin was placed in the center of the cavity and the pressure was slowly increased. When the oil pressure was 73MPa, the 9.4GPa phase transition point was not detected in the cavity.

[0070] The same pressure (here, oil pressure) was used to synthesize PDC products in Examples 1, 2, and 3, and the wear resistance, impact toughness, and thermal stability of the polycrystalline diamonds prepared in Examples 1-3 and Comparative Example 1 were tested under the same test conditions. In particular, according to the method specified in JB / T3235-2013 "Method for Determining the Wear Ratio of Sintered Artificial Diamonds", CNC vertical lathes were used to grind granite, and the wear resistance of Examples 1, 2, 3, and Comparative Example 1 was tested. The grinding mouth photos are shown in FIG. Figure 5 The test results are shown in Table 1 below.

[0071] Table 1

[0072]

[0073]

[0074] like Figure 5 As shown, from the grinding mouth photos in the figure, we can see that: the grinding mouths of Examples 1-3 are all smaller than that of Comparative Example 1, and the wear ratio obtained according to the grinding mouth is the lowest than that of Comparative Example 1, indicating that the wear resistance of the Comparative Example is the worst; in the case where there is only a difference in assembly, we can believe that the diamonds of Examples 1-3 are denser. The reason why the diamonds are denser is that the cavity pressure is greater than that of Comparative Example 1. From the wear resistance, we can see that the new assembly can produce a higher cavity pressure, which has a significant effect on improving the wear resistance.

[0075] The impact toughness test of Examples 1, 2, 3 and Comparative Example 1 was carried out by using a drop hammer impact method. Figure 6 As shown, the process uses a CEAST9340 drop hammer impact tester, that is, a 10kg hammer falls freely at a height of 40cm, and uses this energy to impact the corners of the sample for testing. The impact is stopped when micro cracks appear on the surface of the sample or serious damage appears on the surface of the pressure transmission ring, and the impact resistance grade is obtained. The more times, the better the impact resistance. The alternating impact method is adopted. The thermal stability is tested using an L15 thermal expansion instrument, and the setting conditions are N2 heating and a heating rate of 10℃ / min. The test results are shown in Table 2 below.

[0076] Table 2

[0077] PDC Impact resistance level (times) Example 1 50 Example 2 46 Example 3 45 Comparative Example 1 34

[0078] like Figure 6 As shown, from the impact photos in the figure, we can see that the impact damage morphology of Examples 1-3 is better than that of Comparative Example 1. There is no peeling or delamination phenomenon in Examples 1 and 2, one piece of delamination phenomenon in Example 3, and three pieces of delamination phenomenon in Comparative Example 1. In addition, the three pieces of delamination of Sample 10 in Comparative Example 1 are basically separated at the interface between the alloy and PCD, i.e., diamond. It can be seen that the bonding strength between the alloy and PCD is relatively weak. In actual drilling, this phenomenon will cause the drilling to slow down, and the drill to be pulled back and forth, wasting time, manpower and financial resources.

[0079] Secondly: From the figure, it can be seen that the impact resistance level of comparative example 1 is also lower, indicating that the PCD of sample 10, that is, the diamond and alloy are damaged or PCD cracked at a lower number of impacts. It can be considered that the internal DD bond and interface bonding strength are weak, and the density is low. Due to the pressure difference, the product also contains high residual stress, which leads to cracks inside under a certain impact force, resulting in the final failure of the product. The impact resistance level of Examples 1-3 is significantly better than that of the comparative example. The new assembly design makes the temperature field inside the cavity more stable, and there is no obvious pressure difference in the axial and radial directions of the pressure field. The residual stress inside the product is smaller, and the overall impact resistance is significantly improved.

[0080] The heat resistance temperature of Examples 1, 2, 3 and Comparative Example 1 was tested: The heat resistance of Examples 1, 2 and 3 was tested using a thermal expansion meter. The thermal expansion meter is a push rod type thermal expansion meter, which mainly studies the volume change of the sample caused by temperature change. Since the thermal expansion coefficients of the PDC composite layer and the adhesive are different, their volume changes are different with increasing temperature. At a certain temperature point, the PDC composite layer is separated from the matrix, and its temperature point is recorded as the heat resistance temperature point of the sample. The high or low temperature reflects the interfacial bonding strength of the product. The higher the heat resistance temperature, the higher the interfacial bonding strength. The reason for the increase in interfacial bonding strength is (the increase in assembly pressure, the stability of temperature field and pressure field). In the actual drilling process, a higher temperature will be generated. As the bottom layer gradually becomes deeper, the drill bit will generate a higher temperature. A high heat resistance temperature is an indicator for judging the strength of a product's interface bonding, and it is also a prerequisite for whether the product can be used safely.

[0081] The specific test method is to place the sample sideways on the stage, pass N2 protection in the chamber, and the heating rate is 10℃ / min.

[0082] The comparison of the results of the three experiments is shown in Table 3 below.

[0083] Table 3

[0084] PDC Wear ratio (ten thousand) Impact resistance level (times) Failure temperature(℃) Example 1 1534 50 928 Example 2 1432 46 916 Example 3 1300 45 910 Comparative Example 1 1050 34 895

[0085] The results show that the wear resistance of Example 1 is about 46% better than that of Comparative Example 1, the impact resistance is improved by about 47%, and the failure temperature is increased by 33°C. The impact resistance of Examples 2 and 3 is basically the same, which may be due to the more balanced temperature field inside Example 3.

[0086] In addition, the present invention has other embodiments. For example, Embodiment 4 is different from Embodiment 1 in that: Figure 3 As shown, the second pressure transmission ring adopts a trapezoidal cross-section second pressure transmission ring 22a, and its cross-section along the axial direction is a pair of isosceles trapezoids, namely, a second trapezoid, and the upper base of the second trapezoid faces inward and is parallel to the axis of the through hole. The lower base of the second trapezoid is aligned with the upper base of the first trapezoid; and the waist of the second trapezoid is on the extension line of the waist of the first trapezoid. In addition, the shielding cup can contain samples 10a of other materials.

[0087] Embodiment 5 is different from Embodiment 1 in that Figure 4 As shown, the first pressure transmission ring and the second pressure transmission ring are made of the same material, such as alloy, magnesium oxide, zirconium oxide or dolomite, and the first pressure transmission ring and the second pressure transmission ring are made into an integral pressure transmission ring 2a. In addition, the shielding cup can contain samples 10a of other materials.

[0088] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that any modification to the technical solutions described in the aforementioned embodiments, or any equivalent replacement of some or all of the technical features therein, within the spirit and principles of the present invention, and such modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A high pressure synthetic assembly structure, characterized in that: The invention comprises a pyrophyllite (1) having a through hole, wherein a shielding cup containing an alloy and a diamond sample (10) is arranged in the through hole, a heat-insulating pressure-transmitting component is arranged on the outer sleeve of the shielding cup, plugs (7) are arranged at both ends of the shielding cup, a conductive component is arranged at one end of the plug (7) away from the shielding cup, and the plug (7) and the conductive component are located in the through hole; and a pressure-transmitting ring (2) coaxial with the through hole is arranged in the pyrophyllite (1).

2. The high pressure synthesis assembly structure according to claim 1, characterized in that: The pressure transmission ring (2) comprises a first pressure transmission ring (21), the cross section of the first pressure transmission ring (21) along the axial direction being a pair of isosceles trapezoids, and the upper bases of the trapezoids facing inwards and parallel to the axis of the through hole.

3. The high pressure synthesis assembly structure according to claim 2, characterized in that: The heat-insulating and pressure-transmitting component comprises a sodium chloride tube (9) sleeved on the outside of the shielding cup and a heating tube (8) sleeved on the outside of the sodium chloride tube (9).

4. The high pressure synthesis assembly structure according to claim 3 or 4, characterized in that: The heat-insulating pressure-transmitting assembly further comprises a pressure-transmitting sleeve (4) sleeved on the outside of the heating tube (8), the inner wall of the pressure-transmitting sleeve (4) being fitted with the outer wall of the heating tube (8).

5. The high pressure synthesis assembly structure according to claim 4, characterized in that: The two ends of the pressure transmission sleeve (4) are provided with bell mouths that open outwards, and the two ends of the heating tube (8) are provided with conical rings that fit with the bell mouths, and the plug (7) is arranged inside the conical ring and fits with the conical ring.

6. The high pressure synthesis assembly structure according to claim 5, characterized in that: The height of the upper base of the trapezoid is consistent with and flush with the height of the pressure transmission sleeve (4).

7. The high pressure synthesis assembly structure according to claim 5, characterized in that: The material of the plug (7) is mica, MgO, ZrO2, sodium chloride or dolomite; the material of the pressure transmission sleeve (4) is ZrO2, MgO or dolomite.

8. The high pressure synthesis assembly structure according to any one of claims 2 or 3, 5 to 7, characterized in that: The pressure transmission ring (2) further comprises a second pressure transmission ring (22) arranged on the inner side of the first pressure transmission ring (21), the inner side of the first pressure transmission ring (21) being in contact with the outer side of the second pressure transmission ring (22), and the inner wall of the first pressure transmission ring (21) being flush with the outer wall of the second pressure transmission ring (22).

9. The high pressure synthesis assembly structure according to claim 8, characterized in that: The first pressure transmission ring (21) and the second pressure transmission ring (22) are made of the same material, namely, alloy, magnesium oxide, zirconium oxide or dolomite; or the first pressure transmission ring (21) and the second pressure transmission ring (22) are made of different materials, namely, the second pressure transmission ring (22) is made of PCD and the first pressure transmission ring (21) is made of cemented carbide.

10. The high pressure synthesis assembly structure according to any one of claims 1 to 3, 5 to 7 and 9, characterized in that: The conductive component comprises conductive steel caps (5) arranged at both ends of the through hole and conductive pads (6) located inside the conductive steel caps (5), and the inside of the conductive steel caps (5) is tightly pressed against the plug (7) and the end of the heat-insulating pressure-transmitting component through the conductive pads (6).

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