A synthetic diamond synthesis apparatus

Abstract

The present application relates to the field of diamond synthesis, and discloses a kind of synthetic diamond synthesis device, including six top press machine main body, six top hammer, synthesis bowl, electric component and raw material synthesis block;The six top press machine main body is the basic support and power compression component of device.This application, by optimizing the structure design of synthesis bowl, realize synthesis cavity full dimension uniform pressure transmission, effectively improve the quality and consistency of synthetic diamond finished product, the inner layer of synthesis bowl uses the high density pyrophyllite sintered body of purity as pressure equalizing transmission layer, can the pressure transmitted by top hammer evenly, losslessly conduct to spherical pressure equalizing synthesis cavity, ensure that the cavity is balanced in each direction, at the same time, synthesis bowl adopts spherical structure design, with top hammer inner concave arc top pressure surface precision adaptation, further improve the stability of pressure transmission, provide uniform pressure environment for the conversion of graphite to diamond under the action of catalyst, significantly reduce the internal defects of finished diamond, improve product pass rate.

Description

Technical Field

[0001] This invention relates to the field of diamond synthesis, and more particularly to an apparatus for synthesizing synthetic diamond. Background Technology

[0002] Diamond, as the hardest superhard material, is widely used in precision machining, geological exploration, semiconductors and other fields. Its artificial synthesis is mainly achieved through the high temperature and high pressure method. The core equipment is a six-sided top press. The principle is to use graphite as a carbon source under high temperature and high pressure, and transform it into diamond crystals under the action of a catalyst.

[0003] In traditional six-sided diamond synthesis devices, the top hammer typically has a square pressing surface, which, combined with square or cylindrical pyrophyllite assembly blocks, presents significant technical drawbacks: First, pressure transmission is uneven; the gap between the square pressing surface and the cylindrical cavity leads to large pressure differences at different locations on the raw material synthesis block, easily resulting in uneven diamond crystal growth. Second, thermal imbalance occurs; the traditional conductive structure consists of independent conductive steel rings and electrodes, which can easily cause current deviation, resulting in uneven heating rates and temperature distribution in the raw material synthesis block, affecting synthesis efficiency. Third, the structure has limited functionality; the pyrophyllite only performs pressure transmission and heat insulation functions, the conductive structure only conducts current, and pressure detection requires additional sensors, leading to complex device assembly, poor coordination among components, and susceptibility to impurity contamination and pressure fluctuations, ultimately reducing the quality of the finished diamond product.

[0004] Although existing technologies have developed pressure-equalizing synthesis devices with spherical top pressure chambers and spherical raw material synthesis blocks, which have improved pressure uniformity to some extent, they still suffer from poor structural linkage. Each component is still independently designed, failing to achieve multi-functionality of a single structure. Furthermore, issues such as impurity adsorption and real-time pressure monitoring during the synthesis process have not been resolved. Therefore, there is still room for improvement in the stability and yield of diamond synthesis. To address these issues, a synthetic diamond synthesis device is proposed. Summary of the Invention

[0005] To overcome the above shortcomings, the present invention provides a synthetic diamond synthesis device, which aims to improve the problems of uneven pressure transmission, heat imbalance and single structure and function in the traditional device in the prior art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: It includes a six-sided top press body, six top hammers, a synthesis bowl, a conductive component, and a raw material synthesis block; the six-sided top press body serves as the basic support and power pressing component of the device; the six top hammers are symmetrically distributed in a hexahedral spatial arrangement inside the six-sided top press body; the end of each top hammer facing the center of the device is the pressing end, which is machined into a concave arc-shaped pressing surface; the concave arc-shaped pressing surfaces of the six top hammers have identical shape, curvature, and size; when the six top hammers press towards the center to a designated position, they enclose and form a pressing cavity; the synthesis bowl is detachably installed within the pressing cavity; a spherical pressure equalization synthesis cavity is formed in the center of the synthesis bowl; the raw material synthesis block is disposed within the spherical pressure equalization synthesis cavity; the conductive component is installed in the middle of two opposing top hammers, achieving synchronous linkage between pressing and conduction.

[0007] As a further description of the above technical solution: The synthetic bowl is formed by fastening two identical hemispherical bowls together to form a complete sphere, and the fastened synthetic bowl is fitted with the inner wall of the top pressure cavity with a clearance fit.

[0008] As a further description of the above technical solution: The main body of the top hammer is made of a superhard alloy, which is a tungsten-cobalt alloy. The surface of the concave arc-shaped top pressing surface is coated with a wear-resistant and thermally conductive coating, which is a composite material of diamond micro powder and copper-based alloy.

[0009] As a further description of the above technical solution: The top hammer has a mounting cavity in the middle and a mounting groove on the side of the top hammer near the synthesis bowl. The mounting cavity and the mounting groove are connected.

[0010] As a further description of the above technical solution: The synthesis bowl has a double-layer structure, with a heat insulation and impurity removal layer and a pressure equalization and transmission layer arranged sequentially from the outside to the inside. An annular buffer cavity is provided between the heat insulation and impurity removal layer and the pressure equalization and transmission layer, and the annular buffer cavity is filled with filler.

[0011] As a further description of the above technical solution: The heat insulation and impurity removal layer is a pyrophyllite sintered body with 5%-8% Ti / Zr composite powder added. The Ti / Zr composite powder is uniformly doped into the pyrophyllite. The pressure equalization and transmission layer is a high-density pyrophyllite sintered body with a purity of ≥99%. The filler is flexible pressure transmission and heat insulation cotton, which is aluminum silicate cotton or alumina cotton.

[0012] As a further description of the above technical solution: The synthetic bowl includes an upper bowl body and a lower bowl body. The lower bowl body has an annular groove on its lower side, and the top surface of the lower bowl body has an annular flange that matches the groove. A sealing gasket is embedded between the flange and the groove. The sealing gasket is a high-temperature resistant asbestos rubber gasket.

[0013] As a further description of the above technical solution: The upper and lower bowls of the synthesis bowl each have a circular insertion hole at their center. An insulating and wear-resistant sleeve is embedded in the inner wall of the insertion hole. The insulating and wear-resistant sleeve is a cylindrical sleeve made of silicon nitride ceramic. A conductive seat is fixedly connected to the side of the insulating and wear-resistant sleeve near the spherical pressure equalization synthesis cavity. The side of the conductive seat near the center of the bowl is in electrical contact with the raw material synthesis block.

[0014] As a further description of the above technical solution: The conductive component includes a wire, a conductive cap, and an insulating cap. The wire passes through the mounting cavity of the top hammer. The conductive cap is installed at the end of the wire near the synthesis pot and can be inserted into the insulating wear-resistant sleeve to abut against the conductive seat. The insulating cap is sleeved on the outside of the connection between the conductive cap and the wire and is fitted into the mounting groove of the top hammer. The insulating cap is made of high-temperature resistant polyimide and has an arc-shaped contact surface on the side near the synthesis pot. The curvature of the arc-shaped contact surface is exactly the same as the curvature of the concave arc-shaped pressing surface of the top hammer.

[0015] As a further description of the above technical solution: The raw material synthesis block is made by mixing graphite powder and catalyst powder, wherein the catalyst is Co or Ni.

[0016] The present invention has the following beneficial effects: 1. In this invention, by optimizing the structural design of the synthesis bowl, uniform pressure transmission in all dimensions of the synthesis cavity is achieved, effectively improving the quality and consistency of the finished synthetic diamond. The inner layer of the synthesis bowl uses a high-density pyrophyllite sintered body with a purity of ≥99% as a pressure equalization and transmission layer, which can uniformly and losslessly transmit the pressure transmitted by the top hammer to the spherical pressure equalization synthesis cavity, ensuring that the cavity is under balanced pressure in all directions. At the same time, the synthesis bowl adopts a spherical structural design, which is precisely matched with the concave arc-shaped top pressure surface of the top hammer, further improving the pressure transmission stability and providing a uniform pressure environment for the conversion of graphite into diamond under the action of catalyst, significantly reducing the internal defects of the finished diamond and improving the product qualification rate.

[0017] 2. In this invention, the multi-layer composite protective structure and material optimization of the synthesis bowl achieve integrated heat insulation, impurity removal, and buffering, which not only improves the purity of diamond but also extends the service life of the core components of the device. The outer heat insulation and impurity removal layer of the synthesis bowl is made of pyrophyllite sintered body doped with 5%-8% Ti / Zr composite powder, which can effectively isolate the high temperature in the synthesis chamber from the transmission to the top hammer. At the same time, Ti / Zr elements can react with impurities such as nitrogen and oxygen in the synthesis process, purifying the diamond growth environment. The flexible pressure-transmitting heat insulation cotton in the annular buffer chamber can buffer the impact force of the top pressure, preventing the synthesis bowl from breaking. It also assists in heat insulation and pressure transmission, taking into account the dual effects of impurity purification and component protection, and greatly improving the operational stability of the device.

[0018] 3. In this invention, the conductive components and the synthesis bowl are designed in a coordinated manner to achieve synchronous linkage between pressing and conduction. The conductive cap of the conductive components is precisely matched with the conductive seat and insulating wear-resistant sleeve of the synthesis bowl. The components move synchronously with the top hammer to achieve synchronous completion of pressing and conduction, ensuring that the temperature inside the synthesis chamber is stable and controllable. The synthesis bowl adopts a detachable structure with two hemispherical snap-fit, and with the sealing design of grooves, flanges and sealing gaskets, it is convenient for raw material placement and finished product removal, while ensuring the sealing performance under high temperature and high pressure. The materials of each core component are conventional and readily available, and the assembly is simple. Attached Figure Description

[0019] Figure 1 This is a three-dimensional structural schematic diagram of the main body of the six-sided top press in this invention; Figure 2 This is a three-dimensional internal schematic diagram of the main body of the six-sided top press in this invention; Figure 3 This is a partial cross-sectional schematic diagram of the three-dimensional structure of the top hammer and the synthesis bowl in this invention; Figure 4 This is a partial three-dimensional structural diagram of the conductive component in this invention; Figure 5 This is a three-dimensional structural diagram of the synthetic bowl in this invention. Figure 6 In this invention Figure 3 Enlarged schematic diagram of the structure at point A in the middle; Figure 7 In this invention Figure 3 Enlarged schematic diagram of the structure at point B.

[0020] Legend: 1. Six-sided top press body; 2. Top hammer; 3. Synthesis bowl; 4. Conductive component; 5. Raw material synthesis block; 21. Mounting cavity; 22. Mounting groove; 201. Wear-resistant and heat-conducting coating; 31. Upper bowl; 32. Lower bowl; 301. Heat insulation and impurity removal layer; 302. Pressure equalization and transmission layer; 303. Annular buffer cavity; 304. Filler; 305. Insertion hole; 306. Insulating and wear-resistant sleeve; 307. Conductive base; 41. Wire; 42. Conductive cap; 43. Insulating cap; 311. Groove; 321. Flange; 322. Sealing gasket. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Reference Figures 1-7 This invention provides an apparatus for synthesizing synthetic diamond, comprising: The six-sided press body 1 is the basic support and power pressing component of the device, representing mature existing technology. The six-sided press body 1 contains six push hammers 2, which are the core components of the synthetic diamond device. The six push hammers 2 are symmetrically distributed in a regular hexahedral shape. The end of each push hammer 2 facing the center of the device is the pressing end. When the six-sided press body 1 is activated, it drives the push hammers 2 to press towards the center of the device. The pressing end of each push hammer 2 is machined into a concave arc-shaped pressing surface. The concave arc-shaped pressing surfaces of the six push hammers 2 are identical in shape, curvature, and size. When the six push hammers 2 press towards the center to the designated position, a pressure surface is formed between the six concave arc-shaped pressing surfaces. A hollow chamber, namely the top pressure chamber, is formed. A synthesis bowl 3 is placed inside the hollow chamber. The synthesis bowl 3 is a detachable structure, which is formed by two hemispherical bowls of the same size being snapped together. After snapping together, it can form a complete sphere. The snapped bowls can fit with the inner wall of the top pressure chamber. A spherical pressure equalization synthesis cavity can be formed in the middle of the synthesis bowl 3. A raw material synthesis block 5 is set in the spherical pressure equalization synthesis cavity. The raw material synthesis block 5 is made by mixing graphite powder and catalyst powder. The catalyst can be made of materials such as Co and Ni. Among the six top hammers 2, the two top hammers 2 that are opposite each other are equipped with conductive components 4 in the middle, so that the device can complete the conductive contact at the same time as pressing, realizing the synchronous linkage of pressing and conductive contact.

[0023] The main body of the top hammer 2 is made of ultra-hard alloy such as tungsten-cobalt alloy to ensure pressure resistance and wear resistance. The surface of the concave arc-shaped top pressing surface is sprayed with a layer of wear-resistant and heat-conducting coating 201. The coating is a composite material of diamond micro powder and copper-based alloy. The top hammer 2 has an installation cavity 21 in the middle and an installation groove 22 on the side of the top hammer 2 near the synthesis bowl 3. The installation cavity 21 and the installation groove 22 are connected.

[0024] The synthesis bowl 3 includes an upper bowl body 31 and a lower bowl body 32, both of which are hemispherical and identical in size. The synthesis bowl 3 has a double-layer structure. From the outside to the inside, i.e., from the top hammer 2 side to the pressure equalization and synthesis cavity side, a heat insulation and impurity removal layer 301 and a pressure equalization and transmission layer 302 are sequentially arranged. An annular buffer cavity 303 is arranged between the heat insulation and impurity removal layer 301 and the pressure equalization and transmission layer 302. The interior of the annular buffer cavity 303 is filled with filler 304. The heat insulation and impurity removal layer 301 is the outer main layer of the bowl body. The body is made of pyrophyllite sintered body with 5%-8% Ti / Zr composite powder. The Ti / Zr composite powder is uniformly doped in the pyrophyllite. This material structure achieves a dual effect: firstly, it isolates the high temperature inside the cavity from the transfer to the top hammer 2, achieving heat insulation; secondly, the Ti / Zr elements can react with impurities such as nitrogen and oxygen in the synthesis process to form stable nitrides and oxides, achieving the dual effect of cavity heat insulation and impurity adsorption and removal, purifying the diamond growth environment, and improving the purity of the finished product. The pressure equalization and transmission layer 302 is... The inner main body of the bowl is closely attached to the inner side of the annular buffer cavity 303. Its shape perfectly matches the outer heat insulation and impurity removal layer 301. The material is a high-density pyrophyllite sintered body with a pyrophyllite purity of ≥99% and high density. Its effect is to uniformly and losslessly transmit the pressure of the top hammer 2 to the internal spherical pressure equalization and synthesis cavity, ensuring that the pressure in all directions of the synthesis cavity is consistent. The annular buffer cavity 303 is an annular hollow area located between the inner and outer layers. The filler 304 inside is a flexible pressure-transmitting heat insulation cotton, which is made of silicate. The aluminum wool or alumina wool material is high temperature resistant and elastic. Its effect is to buffer the impact force when the top hammer 2 is pressed, to prevent the bowl from breaking. At the same time, it further improves the heat insulation effect and can also help the uniform transmission of pressure. When the main body 1 of the six-sided top press is opened, the six top hammers 2 are synchronously driven by the servo control system to press towards the center. The concave arc-shaped top pressing surface is in contact with the outer wall of the double-layer protective pyrophyllite composite bowl 3. The pressure is evenly transmitted to the spherical pressure equalizing composite cavity through the inner pressure equalizing transmission layer 302, so as to achieve uniform pressure in all dimensions.

[0025] The lower side of the upper bowl 31 has a groove 311, which is circular. The top surface of the lower bowl 32 has a flange 321 that matches the groove 311. A sealing gasket 322 made of high-temperature resistant asbestos rubber is embedded between the flange 321 and the groove 311. The purpose of the gasket is to ensure the sealing performance of the bowl after it is closed and to prevent leakage of the medium inside the cavity under high temperature and high pressure. At the center of the upper bowl 31 and the lower bowl 32, a circular insertion hole 305 is opened. The inner wall of the insertion hole 305 is inlaid with an insulating wear-resistant sleeve 306 made of silicon nitride ceramic in the shape of a cylindrical sleeve. This sleeve can prevent current leakage and avoid wear of the insertion hole 305. A conductive seat 307 is fixedly connected to the side of the insulating wear-resistant sleeve 306 near the pressure equalization and synthesis cavity. The side of the conductive seat 307 near the center of the bowl is directly connected to the spherical pressure equalization and synthesis cavity. Its function is to cooperate with the conductive component 4 to ensure stable conductive contact with the raw material synthesis block 5 inside the synthesis cavity.

[0026] The conductive component 4 includes a wire 41 that passes through the mounting cavity 21. Its function is to connect to an external power supply, enabling current input and output. A conductive cap 42 is installed at the end of the wire 41 closest to the synthesis bowl 3. The conductive cap 42 is located closest to the center of the component and is the contact part with the conductive base 307. It can be inserted into the insulating wear-resistant sleeve 306 and abuts against the conductive base 307. When the six top hammers 2 press synchronously, the conductive cap 42 moves synchronously with the top hammers 2, completing conductive contact while the device is pressing. The conductive cap 42 can supply power to the spherical equalizing synthesis cavity, enabling electric heating. When the pressure inside the synthesis bowl 3... When the force reaches 2.1 to 5.8 GPa and the temperature rises to 1100 to 1500℃, the temperature and pressure are maintained for 2 to 5 minutes to convert the graphite in the raw material synthesis block 5 into diamond under the action of a catalyst. The insulating cap 43 is sleeved on the outside of the connection between the conductive cap 42 and the wire 41. The insulating cap 43 is embedded in the mounting groove 22. The insulating cap 43 is made of high-temperature resistant polyimide. Its effect is to ensure stable conductive contact with the synthesis cavity and prevent current leakage to the top hammer 2. The side of the insulating cap 43 near the synthesis bowl 3 is provided with an arc-shaped contact surface. The curvature of the curved surface is exactly the same as the curvature of the concave arc-shaped top pressing surface of the top hammer 2.

[0027] Working principle: First, the device is assembled. The raw material synthesis block 5, which is made by mixing graphite powder with catalyst powders such as Co and Ni, is placed into the spherical pressure equalization synthesis cavity of the synthesis bowl 3. Then, the upper bowl 31 and the lower bowl 32 are fastened and fixed by the groove 311 and the flange 321. The high-temperature resistant asbestos rubber sealing gasket 322 between the flange 321 and the groove 311 seals the bowl body to prevent leakage of the medium in the cavity under high temperature and high pressure. The fastened synthesis bowl 3 is placed in the reserved space formed by the six top hammers 2 to ensure that the inner concave arc top pressure surface of the synthesis bowl 3 and the top hammer 2 are precisely aligned, and that the conductive components 4 on the two opposite top hammers 2 can be aligned with the insertion hole 305 on the synthesis bowl 3.

[0028] After assembly, the device is started. The main body 1 of the six-sided press serves as the basic support and power pressing component, driving six hexahedral symmetrically distributed top hammers 2 to synchronously press towards the center of the device under the action of the servo control system. The main body of the top hammer 2 is made of tungsten-cobalt alloy, and the surface of its concave arc-shaped pressing surface at the pressing end is coated with a wear-resistant and heat-conducting coating 201 composed of diamond micro powder and copper-based alloy. This coating can not only ensure the pressure resistance and wear resistance during the pressing process, but also assist in subsequent heat conduction. As the top hammer 2 continues to move towards the center, the six concave arc-shaped pressing surfaces gradually surround and form a pressing cavity. The composite bowl 3 is fitted with the inner wall of the pressing cavity with a clearance, and the concave arc-shaped pressing surface of the top hammer 2 is tightly attached to the outer wall of the composite bowl 3, completing the pressing pretreatment.

[0029] During the pressing process, the conductive component 4 installed in the middle of the upper and lower top hammers 2 synchronously achieves conductive contact. The wire 41 of the conductive component 4 passes through the mounting cavity 21 in the middle of the top hammer 2 and connects to the external power supply. The conductive cap 42 at the end of the wire 41 moves synchronously with the top hammer 2 and is inserted into the silicon nitride ceramic insulating wear-resistant sleeve 306 in the insertion hole 305 of the synthesis bowl 3, and abuts against the conductive seat 307 on the inner side of the insulating wear-resistant sleeve 306. The conductive seat 307 directly contacts the raw material synthesis block 5 in the spherical equalizing synthesis cavity to achieve current conduction. The high-temperature resistant polyimide insulating cap 43 between the conductive cap 42 and the wire 41 is embedded in the mounting groove 22 of the top hammer 2. Its arc-shaped contact surface has the same curvature as the concave arc-shaped pressing surface of the top hammer 2, which can ensure the conductivity stability and prevent the current from leaking to the top hammer 2, realizing the synchronous linkage of pressing and conduction.

[0030] Current is conducted to the raw material synthesis block 5 through the conductive component 4 and the conductive base 307, realizing electric heating. At the same time, the top hammer 2 continuously applies pressure. The multi-layer structure of the synthesis bowl 3 works together. The outer heat insulation and impurity removal layer 301 is made of pyrophyllite sintered body doped with 5%-8% Ti / Zr composite powder. On the one hand, it isolates the high temperature in the cavity from the transmission to the top hammer 2, avoiding damage to the top hammer 2 due to high temperature. On the other hand, the Ti / Zr elements react with impurities such as nitrogen and oxygen generated during the synthesis process to form stable nitrides and oxides, purifying the diamond growth environment. The filler 304 filled in the annular buffer cavity 303 buffers the impact force when the top hammer 2 is pressed, preventing the synthesis bowl 3 from breaking, and at the same time assists in heat insulation and pressure transmission. The inner high-density pyrophyllite sintered body pressure equalization and transmission layer 302 with a purity ≥99% transmits the pressure of the top hammer 2 evenly and without loss to the spherical pressure equalization synthesis cavity, ensuring that the raw material synthesis block 5 is under consistent pressure in all directions, achieving uniform pressure in all dimensions.

[0031] When the pressure inside the synthesis bowl 3 reaches 2.1–5.8 GPa and the temperature rises to 1100–1500 °C, the control device maintains these parameters and keeps the temperature and pressure for 2–5 minutes. Under this high temperature and high pressure environment, the graphite powder in the raw material synthesis block 5 undergoes a phase transition under the catalytic action of Co and Ni catalysts, transforming into artificial diamond. After the temperature and pressure are maintained, the external power supply is turned off, the main body 1 of the six-sided press drives the top hammer 2 to reset synchronously, the detachable synthesis bowl 3 is opened, the synthesized artificial diamond is taken out, and one synthesis process is completed.

[0032] Finally, it should be noted that 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 foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A device for synthesizing synthetic diamond, characterized in that: The device includes a six-sided press body (1), six top hammers (2), a synthesis bowl (3), a conductive component (4), and a raw material synthesis block (5). The six-sided press body (1) serves as the basic support and power pressing component of the device. The six top hammers (2) are symmetrically distributed in a hexahedral space inside the six-sided press body (1). The end of each top hammer (2) facing the center of the device is the pressing end. The pressing end is processed into a concave arc-shaped pressing surface. The concave arc-shaped pressing surfaces of the six top hammers (2) are identical in shape, curvature, and size. When the six top hammers (2) are pressed towards the center to a designated position, they enclose a pressing cavity. The synthesis bowl (3) is detachably installed in the pressing cavity. A spherical pressure equalization synthesis cavity is formed in the middle of the synthesis bowl (3). The raw material synthesis block (5) is installed in the spherical pressure equalization synthesis cavity. The conductive component (4) is installed in the middle of two top hammers (2) that are opposite each other, realizing synchronous linkage between pressing and conduction. The synthetic bowl (3) has a double-layer structure, with a heat insulation and impurity removal layer (301) and a pressure equalization and transmission layer (302) arranged sequentially from the outside to the inside. An annular buffer cavity (303) is provided between the heat insulation and impurity removal layer (301) and the pressure equalization and transmission layer (302), and the annular buffer cavity (303) is filled with filler (304). The heat insulation and impurity removal layer (301) is a pyrophyllite sintered body with 5%-8% Ti / Zr composite powder added. The Ti / Zr composite powder is uniformly doped in the pyrophyllite. The pressure equalization and transmission layer (302) is a high-density pyrophyllite sintered body with a purity ≥99%. The filler (304) is a flexible pressure transmission and heat insulation cotton. The flexible pressure transmission and heat insulation cotton is aluminum silicate cotton or alumina cotton.

2. The synthetic diamond synthesis apparatus according to claim 1, characterized in that: The composite bowl (3) is formed by fastening two hemispherical bowls of the same size together, forming a complete sphere after fastening, and the composite bowl (3) after fastening is fitted with the inner wall of the top pressure cavity with a gap.

3. The synthetic diamond synthesis device according to claim 1, characterized in that: The main body of the top hammer (2) is made of superhard alloy, which is a tungsten-cobalt alloy. The surface of the concave arc-shaped top pressing surface is sprayed with a wear-resistant and thermally conductive coating (201), which is a composite material of diamond micro powder and copper-based alloy.

4. The synthetic diamond synthesis device according to claim 1, characterized in that: The top hammer (2) has an installation cavity (21) in the middle and an installation groove (22) on the side of the top hammer (2) near the synthesis bowl (3). The installation cavity (21) and the installation groove (22) are connected.

5. The synthetic diamond synthesis apparatus according to claim 4, characterized in that: The composite bowl (3) includes an upper bowl body (31) and a lower bowl body (32). The lower bowl body (31) has an annular groove (311) on its lower side. The top surface of the lower bowl body (32) is provided with an annular flange (321) that matches the groove (311). A sealing gasket (322) is embedded between the flange (321) and the groove (311). The sealing gasket (322) is a high-temperature resistant asbestos rubber gasket.

6. The synthetic diamond synthesis apparatus according to claim 5, characterized in that: The upper bowl (31) and lower bowl (32) of the synthesis bowl (3) are provided with circular insertion holes (305) at their center positions. An insulating wear-resistant sleeve (306) is embedded in the inner wall of the insertion hole (305). The insulating wear-resistant sleeve (306) is a cylindrical sleeve made of silicon nitride ceramic material. A conductive seat (307) is fixedly connected to the side of the insulating wear-resistant sleeve (306) near the spherical pressure equalization synthesis cavity. The side of the conductive seat (307) near the center of the bowl is in electrical contact with the raw material synthesis block (5).

7. The synthetic diamond synthesis apparatus according to claim 6, characterized in that: The conductive component (4) includes a wire (41), a conductive cap (42), and an insulating cap (43). The wire (41) passes through the mounting cavity (21) of the top hammer (2). The conductive cap (42) is installed at one end of the wire (41) near the synthesis bowl (3) and can be inserted into the insulating wear-resistant sleeve (306) to abut against the conductive seat (307). The insulating cap (43) is sleeved on the outside of the connection between the conductive cap (42) and the wire (41) and is fitted into the mounting groove (22) of the top hammer (2). The insulating cap (43) is made of high-temperature resistant polyimide and has an arc-shaped contact surface on the side near the synthesis bowl (3). The curvature of the arc-shaped contact surface is exactly the same as the curvature of the concave arc-shaped top pressing surface of the top hammer (2).

8. The synthetic diamond synthesis apparatus according to claim 1, characterized in that: The raw material synthesis block (5) is made by mixing graphite powder and catalyst powder, wherein the catalyst is Co or Ni.

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