Secondary tungsten carbide anvil cell for octahedral pressure cavity static high-pressure device and preparation method of secondary tungsten carbide anvil cell

Abstract

The invention belongs to the technical field of preparation of superhard materials, and particularly relates to a secondary tungsten carbide anvil cell for an octahedral pressure cavity static high-pressure device and a preparation method of the secondary tungsten carbide anvil cell. An anvil; a base; the base and the anvil are of an integrated structure; by controlling the grain size of WC to be smaller than 0.5 micron, reducing the cobalt content, accurately controlling the carbon content of an anvil, controlling the grain size of WC, strengthening and toughening a binding phase, densifying sintering and controlling the structure uniformity of a product, the compactness and the internal structure uniformity of the product are improved by adopting a cold isostatic pressing forming process, and the carbon content of a sintered body is balanced through an air pressure positive carbon sintering method, so that the quality of the product is improved. The fracture toughness and thermal fatigue resistance of the product are improved, and the service life of the product is prolonged; through heat treatment and cold treatment, the internal stress of the product is effectively staging and reduced, and the comprehensive performance is improved; through the geometric design of the anvil face, the pressure generation efficiency and stability of the octahedral pressure cavity static high-pressure device are effectively improved, the pressure limit of 35 GPa or above is broken through, and the pressure reaches 36-38 GPa.

Description

Technical Field

[0001] The invention belongs to the technical field of superhard material preparation, in particular to a secondary tungsten carbide anvil used for an octahedral pressure chamber static high pressure device and a preparation method thereof. Background Art

[0002] The domestic octahedral pressure chamber static high-pressure device is a two-stage high-pressure device independently developed based on the first-stage pressure chamber of the domestic six-sided top press. The maximum pressure and temperature of the first-stage pressure chamber of the six-sided top press are relatively low, and the pressure is generally around 5.5GPa. It is often used in the production of single crystal materials such as diamond and cubic boron nitride. The production of high-performance materials such as polycrystalline diamond and polycrystalline cubic boron nitride requires relatively higher temperature and pressure, and the first-stage pressure chamber cannot meet their production requirements.

[0003] Tungsten carbide anvils are the intermediate carriers for high-pressure devices to transfer high temperature and high pressure to synthetic materials, and are their key core components. At present, most of the high-performance tungsten carbide anvils are still dependent on imports, especially the high-performance secondary low-cobalt tungsten carbide anvils required for ultra-high pressure (above 35GPa) key technologies, which have long been controlled by foreign countries.

[0004] A Chinese patent with publication number CN117465052A discloses a primary anvil based on tungsten carbide in an ultra-high pressure device, wherein the primary anvil includes an anvil base whose top surface contacts the secondary anvil, and the anvil base is made of cobalt-containing tungsten carbide. Compared with the use of steel primary anvils, the use of the cobalt-containing tungsten carbide primary anvil of the present invention in a secondary large-cavity static high-pressure device greatly improves the ultimate pressure and loading efficiency, greatly reduces the consumption ratio of the ultimate pressure to the side length of the secondary anvil size, greatly reduces the cost of raw materials for a single experiment or production, and has better operation stability.

[0005] In the above technology, due to the high cobalt content and the lack of precise control of the carbon content of the anvil, the ultimate pressure of the secondary anvil is low, and the anvil surface performance may be insufficient under high pressure, resulting in plastic deformation of the anvil surface, thereby damaging the pressure generation efficiency and operating stability of the system; the WC grain size is not reasonably controlled, and it is difficult to achieve high temperature, high pressure or even ultra-high pressure.

[0006] To this end, the present invention provides a secondary tungsten carbide anvil for an octahedral pressure chamber static high pressure device and a preparation method thereof. Summary of the invention

[0007] In order to make up for the deficiencies of the prior art, at least one technical problem raised in the background technology is solved.

[0008] The technical solution adopted by the present invention to solve the technical problem is: the two-stage tungsten carbide anvil for the static high-pressure device of the octahedral pressure chamber of the present invention comprises:

[0009] anvil surface;

[0010] anvil;

[0011] Mounting seat;

[0012] The mounting seat and the anvil are configured as an integrated structure; both the mounting seat and the anvil are made of tungsten carbide cemented carbide material, wherein the grain size of tungsten carbide is less than 0.5 μm; the tungsten carbide cemented carbide material contains cobalt material, and the mass fraction of the cobalt material is 0.2% to 1%; the anvil surface adopts a geometric design, and the ultimate pressure of the anvil surface is greater than 35 GPa; the anvil adopts a gas pressure positive carbon sintering method, wherein the sintering temperature is 1500 to 1700°C.

[0013] Preferably, a method for preparing a secondary tungsten carbide anvil for an octahedral pressure chamber static high pressure device comprises the following steps:

[0014] S1: Super WC powder is used as the main raw material, and a small amount of Co, inhibitors and additives are added and ball milled using a ball milling equipment;

[0015] S2: using inert gas spray drying and granulation to obtain a uniform mixture, and pressing it into a product blank through a cold isostatic pressing process;

[0016] S3: obtain a sintered product by vacuum dewaxing sintering and gas pressure positive carbon sintering;

[0017] S4: After heat treatment of the sintered product, the anvil surface geometry is designed and processed to obtain the final product.

[0018] Preferably, the ball mill in S2 comprises a base; two fixed plates are fixedly connected to the top of the base; a rotating shaft and a mounting shaft are rotatably connected to the fixed plates through bearings respectively; an inner cylinder and an outer cylinder are arranged on the outer side of the rotating shaft; a shift mechanism is arranged at one end of the inner cylinder; the shift mechanism comprises a connecting rod; plug-in rods are fixedly connected to both ends of the connecting rod, plug-in grooves are arranged on the side walls of the rotating shaft and the mounting seat, and the plug-in rods cooperate with the plug-in grooves; a protective shell is fixedly connected to the side wall of the fixed plate close to the connecting rod, A first electric push rod is fixedly connected in the protective shell, a rotating block is fixedly connected to the output end of the first electric push rod, and the rotating block is rotatably connected to the plug-in rod through a rotating shaft; a first plug-in block and a third plug-in block are fixedly connected to the outer side walls at both ends of the connecting rod, and a second plug-in block is fixedly connected to the middle outer side wall of the connecting rod, and the first plug-in block, the second plug-in block and the third plug-in block are respectively sleeved on one end of the inner cylinder and the outer cylinder; a plurality of rotating rods are fixedly connected to the outer side wall of the rotating shaft; a plurality of grinding balls are arranged in the inner cylinder, and a rotating assembly is arranged between the inner cylinder and the outer cylinder.

[0019] Preferably, the rotating assembly includes an outer gear ring fixedly connected to the outer wall of the inner cylinder; an inner gear ring is fixedly connected to the inner wall of the outer cylinder; the outer gear ring and the inner gear ring are vertically aligned; a mounting frame is rotatably connected to the rotating shaft via a bearing, one end of the mounting frame is rotatably connected to four gears via a rotating shaft, and the two sides of the gears are respectively meshed with the inner gear ring and the outer gear ring.

[0020] Preferably, a first motor is fixedly connected to the fixed plate away from the first electric push rod, and the output shaft of the first motor is rotatably connected to the fixed plate through a bearing and is fixedly connected to a first rotating wheel; a second rotating wheel is fixedly connected to the outer wall of the rotating shaft, and a belt is provided between the first rotating wheel and the second rotating wheel.

[0021] Preferably, the inner cylinder is rotatably connected to a reciprocating screw via a bearing, the outer side wall of the outer cylinder is fixedly connected to a second motor, the output shaft of the second motor passes through the outer cylinder and is fixedly connected to one end of the reciprocating screw, and the reciprocating screw is threadedly connected to an annular scraper.

[0022] Preferably, two guide rods are fixedly connected to the inner cylinder, and the annular scraper slides on the two guide rods, and the annular scraper is in close contact with the inner wall of the inner cylinder.

[0023] Preferably, a filter plate is fixedly connected to the inner cylinder; a material pipe is connected and fixedly connected to the inner cylinder, and the material pipe cooperates with the filter plate.

[0024] Preferably, a second electric push rod is fixedly connected to the inner wall of the inner cylinder, a sealing plate is fixedly connected to the output end of the second electric push rod, and the sealing plate is slidably connected to the material pipe.

[0025] Preferably, one end of the rotating shaft is fixedly connected to a first sleeve, and one end of the connecting rod is slidably connected in the first sleeve; one end of the mounting shaft is fixedly connected to a second sleeve, and the other end of the connecting rod is slidably connected in the second sleeve.

[0026] The beneficial effects of the present invention are as follows:

[0027] 1. The secondary tungsten carbide anvil and preparation method for the octahedral pressure chamber static high-pressure device described in the present invention control the WC grain size to be less than 0.5 μm, reduce the cobalt content, accurately control the carbon content of the anvil, control the WC grain size, strengthen the bonding phase, densify the sintering, and control the uniformity of the product structure. A cold isostatic pressing process is adopted to improve the density and internal structure uniformity of the product. The carbon content of the sintered body is balanced by a gas pressure positive carbon sintering method, and the fracture toughness and thermal fatigue resistance of the product are improved, thereby extending the service life of the product. Through heat treatment and cold treatment, the internal stress of the product is effectively staged and reduced, thereby improving its comprehensive performance. Through the geometric design of the anvil surface, the pressure generation efficiency and stability of the octahedral pressure chamber static high-pressure device are effectively improved, breaking through the pressure limit of more than 35 GPa and reaching 36-38 GPa.

[0028] 2. The secondary tungsten carbide anvil and preparation method for the static high-pressure device of the octahedral pressure chamber described in the present invention, through the cooperation of the first plug block, the second plug block and the third plug block, the first electric push rod is turned on, and the connecting rod is driven to move through the output end of the first electric push rod. When the connecting rod moves, the third plug block is plugged and matched with the inner cylinder, and the second plug block is plugged and matched with the outer cylinder, the rotating shaft is driven to rotate, and the connecting rod is driven to rotate through the rotating shaft, and the third plug block is driven to move through the connecting rod, and the inner cylinder is driven to rotate through the third plug block. During the rotation of the inner cylinder, the grinding balls mill the powder; after a period of time, the first electric push rod is turned on. The push rod contracts, and the second plug-in block is plugged into the inner cylinder, and the first plug-in block is plugged into the outer cylinder, driving the rotating shaft to rotate, and the connecting rod is driven to rotate through the rotating shaft, and the first plug-in block is driven to move through the connecting rod, and the outer cylinder is driven to rotate through the first plug-in block, and the outer cylinder drives the inner gear ring to rotate, and the gear is driven to rotate through the inner gear ring, and the outer gear ring is driven to rotate in the opposite direction through the gear, and the inner cylinder is driven to rotate in the opposite direction through the outer gear ring. In the reverse process, the original centrifugal force of the grinding balls and the powder is destroyed, and the powder is scattered in the inner cylinder, increasing the contact area between the grinding balls and the powder. Repeat the operation several times to achieve the function of rapid and sufficient grinding. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be further described below in conjunction with the accompanying drawings.

[0030] Figure 1 is a method flow chart of an embodiment of the present invention;

[0031] Figure 2 is a first stereogram of the present invention;

[0032] Figure 3 is a second stereogram of the present invention;

[0033] Figure 4 is a cross-sectional view of the present invention;

[0034] Figure 5 It is a schematic diagram of the structure of the first sleeve and the second sleeve in the present invention;

[0035] Figure 6 It is a structural schematic diagram of the plug-in rod in the present invention;

[0036] Figure 7 It is a schematic diagram of the structure of the inner gear ring and the outer gear ring in the present invention;

[0037] Figure 8 It is a cross-sectional view of the inner cylinder and the outer cylinder in the present invention;

[0038] In the figure: 1, base; 11, fixed plate; 12, first motor; 13, first rotating wheel; 14, belt; 15, second rotating wheel; 2, outer cylinder; 21, inner gear ring; 3, inner cylinder; 31, outer gear ring; 32, filter plate; 4, rotating shaft; 41, rotating rod; 42, protective shell; 43, first electric push rod; 44, connecting rod; 45, mounting shaft; 46, first sleeve; 47, second sleeve; 48, first plug-in block; 481, second plug-in block; 482, third plug-in block; 49, plug-in rod; 410, rotating block; 5, gear; 51, mounting frame; 6, annular scraper; 61, guide rod; 62, reciprocating screw rod; 63, second motor; 7, material pipe; 71, sealing plate; 72, second electric push rod. DETAILED DESCRIPTION

[0039] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0040] like Figure 1 As shown, the secondary tungsten carbide anvil for the static high-pressure device of the octahedral pressure chamber described in the embodiment of the present invention includes: anvil surface; anvil platform; mounting seat; the mounting seat and the anvil platform are configured as an integrated structure; the mounting seat and the anvil platform are both made of tungsten carbide cemented carbide material, wherein the grain size of tungsten carbide is less than 0.5 μm; the tungsten carbide cemented carbide material contains cobalt material, and the mass fraction of the cobalt material is 0.2% to 1%; the anvil surface adopts a geometric design, and the ultimate pressure of the anvil surface is greater than 35 GPa; the anvil platform adopts a gas pressure positive carbon sintering method, wherein the sintering temperature is 1500 to 1700°C.

[0041] When in use, the secondary tungsten carbide anvil provided by the present invention adopts a cold isostatic pressing process to improve the compactness and internal structure uniformity of the secondary tungsten carbide anvil, and balances the carbon content of the sintered body through a gas pressure positive carbon sintering method, thereby improving the fracture toughness and thermal fatigue resistance of the product and extending the service life of the product; through heat treatment and cold treatment, the internal stress of the product is effectively staged and reduced, thereby improving its comprehensive performance; through the anvil surface geometric design, the pressure generation efficiency and stability of the octahedral pressure chamber static high-pressure device are effectively improved, breaking through the pressure limit of more than 35GPa and reaching 36-38GPa.

[0042] like Figure 1 As shown, a method for preparing a secondary tungsten carbide anvil for an octahedral pressure chamber static high pressure device comprises the following steps:

[0043] S1: Super WC powder is used as the main raw material, and a small amount of Co, inhibitors and additives are added and ball milled using a ball milling equipment;

[0044] S2: using inert gas spray drying and granulation to obtain a uniform mixture, and pressing it into a product blank through a cold isostatic pressing process;

[0045] S3: obtain a sintered product by vacuum dewaxing sintering and gas pressure positive carbon sintering;

[0046] S4: After heat treatment of the sintered product, the anvil surface geometry is designed and processed to obtain the final product.

[0047] The preparation method provided by the present invention: in order to improve the high temperature and high pressure resistance and other properties of the product, ultrafine WC is used as a raw material, a small amount of Co is added, and additives such as VC, Cr3C2, NbC, TaC, TiC, B4C are added for ball milling to inhibit grain growth and improve the toughness of the material, and an inert gas spray drying reduction is used to obtain a uniform mixture to reduce the activity of the powder;

[0048] In order to overcome the defects of internal cracks, delamination, uneven density, low density, etc. of pressed products, isostatic pressing is used as the main forming method of the product;

[0049] In order to further improve the density of the product, the process parameters such as sintering temperature, sintering time and sintering pressure are optimized, and the gas pressure positive carbon sintering method is adopted to balance the carbon content of the sintered body;

[0050] In order to improve the pressure generation efficiency of the device, the secondary tungsten carbide anvil is heat treated to reduce the internal stress of the product, and then the anvil surface geometry is designed to effectively improve the pressure generation efficiency and stability of the device.

[0051] like Figures 2 to 8As shown, the ball mill in S2 includes a base 1; two fixed plates 11 are fixedly connected to the top of the base 1; the fixed plates 11 are rotatably connected to a rotating shaft 4 and a mounting shaft 45 through bearings; an inner cylinder 3 and an outer cylinder 2 are arranged on the outer side of the rotating shaft 4; a shift mechanism is arranged at one end of the inner cylinder 3; the shift mechanism includes a connecting rod 44; plug-in rods 49 are fixedly connected to both ends of the connecting rod 44, plug-in grooves are provided on the side walls of the rotating shaft 4 and the mounting seat, and the plug-in rod 49 cooperates with the plug-in grooves; a protective shell 42 is fixedly connected to the side wall of the fixed plate 11 near the connecting rod 44, and the protective shell 42 is fixed inside A first electric push rod 43 is connected, and a rotating block 410 is fixedly connected to the output end of the first electric push rod 43, and the rotating block 410 is rotatably connected to the plug-in rod 49 through a rotating shaft; a first plug-in block 48 and a third plug-in block 482 are fixedly connected to the outer side walls at both ends of the connecting rod 44, and a second plug-in block 481 is fixedly connected to the middle outer side wall of the connecting rod 44, and the first plug-in block 48, the second plug-in block 481 and the third plug-in block 482 are respectively sleeved on one end of the inner cylinder 3 and the outer cylinder 2; a plurality of rotating rods 41 are fixedly connected to the outer side wall of the rotating shaft 4; a plurality of grinding balls are arranged in the inner cylinder 3, and a rotating assembly is arranged between the inner cylinder 3 and the outer cylinder 2.

[0052] When grinding, the grinding balls and the powder are affected by the centrifugal force and move in the same direction in the inner cylinder 3, with a single movement trajectory, which makes it difficult for the grinding balls to contact more powders. In addition, the powders are easily piled up due to the centrifugal force, which increases the thickness of the powders and prevents the grinding balls from contacting the bottom powders. Under the same grinding time, the grinding and mixing effects are limited.

[0053] When the shift mechanism provided by the present invention is used, the first electric push rod 43 is turned on, and the connecting rod 44 is driven to move through the output end of the first electric push rod 43. When the connecting rod 44 moves, the third plug block 482 is plugged and matched with the inner cylinder 3, and the second plug block 481 is plugged and matched with the outer cylinder 2, the rotating shaft 4 is driven to rotate, and the connecting rod 44 is driven to rotate through the rotating shaft 4, and the third plug block 482 is driven to move through the connecting rod 44, and the inner cylinder 3 is driven to rotate through the third plug block 482. During the rotation of the inner cylinder 3, the grinding balls perform ball milling on the material powder;

[0054] After a period of time, the first electric push rod 43 contracts, and the second plug block 481 is plugged into the inner cylinder 3, and the first plug block 48 is plugged into the outer cylinder 2, driving the rotating shaft 4 to rotate, and the connecting rod 44 is driven to rotate, and the first plug block 48 is driven to move through the connecting rod 44, and the outer cylinder 2 is driven to rotate through the first plug block 48. The outer cylinder 2 drives the inner cylinder 3 to rotate in the opposite direction through the rotating assembly. In the reverse process, the original centrifugal force of the grinding balls and the powder is destroyed, and the powder is scattered in the inner cylinder 3, increasing the contact area between the grinding balls and the powder. Repeating the operation several times can achieve the function of rapid and sufficient grinding.

[0055] like Figure 4 and Figure 7 As shown, the rotating assembly includes an outer gear ring 31 fixedly connected to the outer wall of the inner cylinder 3; an inner gear ring 21 is fixedly connected to the inner wall of the outer cylinder 2; the outer gear ring 31 and the inner gear ring 21 are vertically aligned; a mounting frame 51 is rotatably connected to the rotating shaft 4 through a bearing, and one end of the mounting frame 51 is rotatably connected to four gears 5 through a rotating shaft, and the two sides of the gear 5 are respectively meshed with the inner gear ring 21 and the outer gear ring 31.

[0056] When the inner gear ring 21 and the outer gear ring 31 provided by the present invention are in use, when the rotating shaft 4 drives the outer cylinder 2 to rotate, the inner gear ring 21 is driven to rotate through the outer cylinder 2, the gear 5 is driven to rotate through the inner gear ring 21, the outer gear ring 31 is driven to rotate in the opposite direction through the gear 5, and the inner cylinder 3 is driven to rotate in the opposite direction through the outer gear ring 31, thereby realizing the reverse rotation of the inner cylinder 3; similarly, when the inner cylinder 3 rotates, it can drive the outer cylinder 2 to rotate in the opposite direction, so as to maintain the synchronous movement of the inner cylinder 3 and the outer cylinder 2.

[0057] like Figure 3 As shown, a first motor 12 is fixedly connected to the fixed plate 11 away from the first electric push rod 43, and the output shaft of the first motor 12 is rotatably connected to the fixed plate 11 through a bearing, and is fixedly connected to a first rotating wheel 13; a second rotating wheel 15 is fixedly connected to the outer wall of the rotating shaft 4, and a belt 14 is sleeved between the first rotating wheel 13 and the second rotating wheel 15.

[0058] The first rotating wheel 13 and the second rotating wheel 15 provided by the present invention are used to drive the rotating shaft 4 to rotate when in use. By turning on the first motor 12, the first rotating wheel 13 is driven to rotate by the output shaft of the first motor 12, the first rotating wheel 13 drives the belt 14 to rotate, the belt 14 drives the second rotating wheel 15 to rotate, and the rotating shaft 4 is driven to rotate by the second rotating wheel 15.

[0059] like Figure 4 and Figure 7 As shown, the inner cylinder 3 is rotatably connected to a reciprocating screw 62 via a bearing, the outer wall of the outer cylinder 2 is fixedly connected to a second motor 63, the output shaft of the second motor 63 passes through the outer cylinder 2 and is fixedly connected to one end of the reciprocating screw 62, and the reciprocating screw 62 is threadedly connected to an annular scraper 6.

[0060] The annular scraper 6 provided by the present invention is used to scrape off the inner cylinder 3 and the powder on the inner wall of the inner cylinder 3 when in use. By turning on the second motor 63, the output shaft of the second motor 63 drives the reciprocating screw 62 to rotate, and the reciprocating screw 62 drives the annular scraper 6 to move. The residual material in the inner cylinder 3 and the powder on the inner wall of the inner cylinder 3 are scraped into the material pipe 7 by the annular scraper 6, thereby realizing the function of cleaning the powder.

[0061] like Figure 7As shown, two guide rods 61 are fixedly connected to the inner cylinder 3 , and the annular scraper 6 slides on the two guide rods 61 . The annular scraper 6 is in close contact with the inner wall of the inner cylinder 3 .

[0062] When the guide rod 61 provided by the present invention is in use, the annular scraper 6 moves on the guide rod 61 during movement, and the guide rod 61 limits the annular scraper 6 in a horizontal direction.

[0063] like Figure 4 As shown, a filter plate 32 is fixedly connected to the inner cylinder 3 ; a material pipe 7 is connected and fixedly connected to the inner cylinder 3 , and the material pipe 7 cooperates with the filter plate 32 .

[0064] The filter plate 32 provided by the present invention is used to filter powder when in use, the grinding balls remain in the inner cylinder 3, and the powder is discharged through the material pipe 7. A hose is fixedly connected to the outer wall of the outer cylinder 2. During filtering, the hose and the material pipe 7 are aligned, which facilitates the discharge of the material into the next process.

[0065] like Figure 1 to Figure 2 As shown, a second electric push rod 72 is fixedly connected to the inner wall of the inner cylinder 3 , a sealing plate 71 is fixedly connected to the output end of the second electric push rod 72 , and the sealing plate 71 is slidably connected to the material pipe 7 .

[0066] When the sealing plate 71 provided by the present invention is in use and ball milling is required, the inner cylinder 3 needs to be sealed, and the sealing plate 71 is driven to move by the output end of the second electric push rod 72, and the sealing plate 71 blocks the material pipe 7 to achieve sealing of the inner cylinder 3.

[0067] like Figure 4 and Figure 5 As shown, one end of the rotating shaft 4 is fixedly connected to a first sleeve 46, and one end of the connecting rod 44 is slidably connected in the first sleeve 46; one end of the mounting shaft 45 is fixedly connected to a second sleeve 47, and the other end of the connecting rod 44 is slidably connected in the second sleeve 47.

[0068] When in use, the first sleeve 46 and the second sleeve 47 provided by the present invention sleeve one end of the rotating shaft 4 and the installation shaft 45 to protect the plug rod 49 and improve the stability of the rotating shaft 4 and the installation shaft 45.

[0069] Working principle: When working, the first motor 12 is turned on, the output shaft of the first motor 12 drives the first rotating wheel 13 to rotate, the first rotating wheel 13 drives the belt 14 to rotate, the belt 14 drives the second rotating wheel 15 to rotate, and the second rotating wheel 15 drives the rotating shaft 4 to rotate;

[0070] By adjusting the position of the connecting rod 44, the first electric push rod 43 is turned on, and the connecting rod 44 is driven to move by the output end of the first electric push rod 43. When the connecting rod 44 moves, the third plug block 482 is plugged into the inner tube 3, and the second plug block 481 is plugged into the outer tube 2, and the rotating shaft 4 is driven to rotate, and the connecting rod 44 is driven to rotate by the rotating shaft 4, and the third plug block 482 is driven to move by the connecting rod 44, and the inner tube 3 is driven to rotate by the third plug block 482. During the rotation of the inner tube 3, the grinding balls mill the powder. After a period of time, the first electric push rod 43 shrinks, and the second plug block 481 is plugged into the inner tube 3, and the first plug block 48 is plugged into the outer tube 2, and the rotating shaft 4 is driven to rotate, and the connecting rod 44 is driven to rotate by the rotating shaft 4, and the inner tube 3 is driven to rotate by the third plug block 482. The connecting rod 44 drives the first plug block 48 to move, and the first plug block 48 drives the outer cylinder 2 to rotate, and the outer cylinder 2 drives the inner gear ring 21 to rotate, and the inner gear ring 21 drives the gear 5 to rotate, and the gear 5 drives the outer gear ring 31 to rotate in the opposite direction, and the outer gear ring 31 drives the inner cylinder 3 to rotate in the opposite direction. In the reverse process, the original centrifugal force of the grinding balls and the powder is destroyed, and the powder is scattered in the inner cylinder 3, increasing the contact area between the grinding balls and the powder. The operation is repeated several times to achieve the function of rapid and sufficient grinding. By turning on the second motor 63, the output shaft of the second motor 63 drives the reciprocating screw 62 to rotate, and the reciprocating screw 62 drives the annular scraper 6 to move, and the residual material in the inner cylinder 3 and the powder on the inner wall of the inner cylinder 3 are scraped into the material pipe 7 by the annular scraper 6, so as to achieve the function of cleaning the powder.

[0071] In order to improve the product's resistance to high temperature and high pressure, ultrafine WC is used as raw material, a small amount of Co is added, and additives such as VC, Cr3C2, NbC, TaC, TiC, B4C are added for ball milling to inhibit grain growth and improve the toughness of the material. Inert gas spray drying reduction is used to obtain a uniform mixture and reduce the activity of the powder; in order to overcome defects such as internal cracks, stratification, uneven density, and low density of the pressed products, isostatic pressing is used as the main forming method of the product; in order to further improve the density of the product, the process parameters such as sintering temperature, sintering time, and sintering pressure are optimized, and the gas pressure positive carbon sintering method is used to balance the carbon content of the sintered body; in order to improve the pressure generation efficiency of the device, the secondary tungsten carbide anvil is heat treated to reduce the internal stress of the product, and then the anvil surface geometry is designed to effectively improve the pressure generation efficiency and stability of the device.

[0072] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A secondary tungsten carbide anvil for an octahedral pressure chamber static high pressure device, comprising: anvil surface; anvil; Mounting seat; The invention is characterized in that: the mounting seat and the anvil are set as an integrated structure; the mounting seat and the anvil are both made of tungsten carbide cemented carbide material, wherein the grain size of tungsten carbide is less than 0.5μm; the tungsten carbide cemented carbide material contains cobalt material, and the mass fraction of the cobalt material is 0.2% to 1%; the anvil surface adopts a geometric design, and the ultimate pressure of the anvil surface is greater than 35GPa; the anvil adopts a gas pressure positive carbon sintering method, wherein the sintering temperature is 1500 to 1700°C.

2. A method for preparing a secondary tungsten carbide anvil for an octahedral pressure chamber static high pressure device, which is applicable to the secondary tungsten carbide anvil for an octahedral pressure chamber static high pressure device according to claim 1, characterized in that: The preparation method comprises the following steps: S1: Super WC powder is used as the main raw material, and a small amount of Co, inhibitors and additives are added and ball milled using a ball milling equipment; S2: using inert gas spray drying and granulation to obtain a uniform mixture, and pressing it into a product blank through a cold isostatic pressing process; S3: obtain a sintered product by vacuum dewaxing sintering and gas pressure positive carbon sintering; S4: After heat treatment of the sintered product, the anvil surface geometry is designed and processed to obtain the final product.

3. The method for preparing a secondary tungsten carbide anvil for an octahedral pressure chamber static high pressure device according to claim 2, characterized in that: The ball milling device in S2 comprises a base (1); two fixed plates (11) are fixedly connected to the top of the base (1); a rotating shaft (4) and a mounting shaft (45) are rotatably connected to the fixed plate (11) through bearings; an inner cylinder (3) and an outer cylinder (2) are provided on the outer side of the rotating shaft (4); a shift mechanism is provided at one end of the inner cylinder (3); the shift mechanism comprises a connecting rod (44); plug-in rods (49) are fixedly connected to both ends of the connecting rod (44); plug-in grooves are provided on the side walls of the rotating shaft (4) and the mounting seat, and the plug-in rod (49) cooperates with the plug-in grooves; a protective shell (42) is fixedly connected to the side wall of the fixed plate (11) near the connecting rod (44), and a A first electric push rod (43), the output end of which is fixedly connected to a rotating block (410), and the rotating block (410) is rotatably connected to a plug-in rod (49) via a rotating shaft; a first plug-in block (48) and a third plug-in block (482) are fixedly connected to the outer side walls at both ends of the connecting rod (44), and a second plug-in block (481) is fixedly connected to the middle outer side wall of the connecting rod (44); the first plug-in block (48), the second plug-in block (481) and the third plug-in block (482) are respectively sleeved on one end of the inner cylinder (3) and the outer cylinder (2); a plurality of rotating rods (41) are fixedly connected to the outer side wall of the rotating shaft (4); a plurality of grinding balls are arranged in the inner cylinder (3), and a rotating assembly is arranged between the inner cylinder (3) and the outer cylinder (2).

4. The method for preparing a secondary tungsten carbide anvil for an octahedral pressure chamber static high pressure device according to claim 3, characterized in that: The rotating assembly comprises an outer gear ring (31) fixedly connected to the outer side wall of the inner cylinder (3); an inner gear ring (21) fixedly connected to the inner side wall of the outer cylinder (2); the outer gear ring (31) and the inner gear ring (21) are vertically aligned; a mounting frame (51) is rotatably connected to the rotating shaft (4) via a bearing, one end of the mounting frame (51) is rotatably connected to four gears (5) via a rotating shaft, and two sides of the gears (5) are respectively meshed with the inner gear ring (21) and the outer gear ring (31).

5. The method for preparing a secondary tungsten carbide anvil for an octahedral pressure chamber static high pressure device according to claim 4, characterized in that: A first motor (12) is fixedly connected to the fixed plate (11) away from the first electric push rod (43); an output shaft of the first motor (12) is rotatably connected to the fixed plate (11) via a bearing and is fixedly connected to a first rotating wheel (13); a second rotating wheel (15) is fixedly connected to the outer side wall of the rotating shaft (4); a belt (14) is sleeved between the first rotating wheel (13) and the second rotating wheel (15).

6. The method for preparing a secondary tungsten carbide anvil for an octahedral pressure chamber static high pressure device according to claim 5, characterized in that: A reciprocating screw (62) is rotatably connected to the inner cylinder (3) via a bearing, a second motor (63) is fixedly connected to the outer wall of the outer cylinder (2), an output shaft of the second motor (63) passes through the outer cylinder (2) and is fixedly connected to one end of the reciprocating screw (62), and an annular scraper (6) is threadedly connected to the reciprocating screw (62).

7. The method for preparing a secondary tungsten carbide anvil for an octahedral pressure chamber static high pressure device according to claim 6, characterized in that: Two guide rods (61) are fixedly connected to the inner cylinder (3), and the annular scraper (6) slides on the two guide rods (61). The annular scraper (6) is in close contact with the inner wall of the inner cylinder (3).

8. The method for preparing a secondary tungsten carbide anvil for an octahedral pressure chamber static high pressure device according to claim 7, characterized in that: A filter plate (32) is fixedly connected to the inner cylinder (3); a material pipe (7) is connected and fixedly connected to the inner cylinder (3), and the material pipe (7) cooperates with the filter plate (32).

9. The method for preparing a secondary tungsten carbide anvil for an octahedral pressure chamber static high pressure device according to claim 8, characterized in that: A second electric push rod (72) is fixedly connected to the inner wall of the inner cylinder (3), a sealing plate (71) is fixedly connected to the output end of the second electric push rod (72), and the sealing plate (71) is slidably connected to the material pipe (7).

10. The method for preparing a secondary tungsten carbide anvil for an octahedral pressure chamber static high pressure device according to claim 9, characterized in that: One end of the rotating shaft (4) is fixedly connected to a first sleeve (46), and one end of the connecting rod (44) is slidably connected in the first sleeve (46); one end of the mounting shaft (45) is fixedly connected to a second sleeve (47), and the other end of the connecting rod (44) is slidably connected in the second sleeve (47).

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