Integrated flash sintering device for vacuum and sintering method

Abstract

The application is suitable for powder metallurgy and advanced ceramic material sintering equipment technical field, and provides a vacuum integrated flash sintering device and a sintering method.The device comprises a power supply module, a high vacuum module, a first servo hydraulic machine, a second servo hydraulic machine, a third servo hydraulic machine, a mold rotation switching module, a vacuum feeding module, a green compact pressing module, a demolding and mold cleaning module and a mold transfer module; the application adopts an integrated gear tray design to integrate mold installation, graphite paper processing and green compact pressing functions in one, and realizes online synchronous cleaning of the electrode and the mold through the cleaning brush built in the mold fixing and cleaning rotating drum, so that full-automatic, high-efficiency and high-stability continuous production from powder feeding to finished product collection is realized.

Description

Technical Field

[0001] This invention relates to the field of powder metallurgy and advanced ceramic material sintering equipment technology, specifically an integrated flash sintering device and sintering method for vacuum applications. Background Technology

[0002] Flash sintering, as an emerging electric field-assisted sintering technology, has shown great potential in the preparation of high-performance fine-grained materials due to its outstanding advantages such as low sintering temperature, extremely short time, low energy consumption, and effective suppression of grain growth. However, this technology is currently mostly limited to single-station, batch (intermittent) laboratory equipment. Such equipment completes all processes sequentially within the same chamber, resulting in inherent drawbacks such as low production efficiency, inability to operate continuously, poor process consistency, and difficulty in maintaining a vacuum environment due to frequent loading and sampling, severely restricting its industrial application. To improve production efficiency, some improvement schemes focusing on continuous or integrated processes have emerged in existing technologies. For example, existing technologies (such as CN107321987B) propose a multi-physics field coupled ultra-fast sintering integrated equipment, which uses conveyor belts and robotic arms to achieve material transfer, attempting to automate feeding, sintering, and demolding. Another technology (such as CN117628879A) provides an integrated ultrafast high-temperature sintering furnace that integrates power supply, vacuum system, etc., aiming to improve heating efficiency and reduce equipment size.

[0003] However, after in-depth analysis, the applicant found that these existing technical solutions still have obvious limitations:

[0004] 1. Insufficient functional integration and automation: Existing solutions mostly focus on the automation of the sintering process itself or some local links (such as material conveying or sintering furnace integration), and fail to seamlessly integrate key processes such as vacuum filling and weighing of powder, precision pressing of green bodies, automatic cutting and laying of graphite paper, automatic demolding of sintered products, and online cleaning of molds into a unified high vacuum system; the entire process still has interruptions or relies on multiple independent devices, and cannot achieve truly automated continuous production throughout the entire process;

[0005] 2. Low efficiency in mold handling and maintenance: In continuous production, the cleaning and turnover of molds are key factors affecting efficiency; existing technologies lack efficient mold handling systems; for example, some mold cleaning devices are independent equipment, and cleaning the mold requires interrupting the main process or removing the mold from the system, which disrupts the continuity of production; in addition, after frequent use, impurities will adhere to the surface of the sintering electrode, affecting the sintering quality, and existing equipment generally lacks the function of online electrode cleaning.

[0006] 3. The efficiency of vacuum system maintenance needs to be improved: Although existing technologies have adopted vacuum systems (such as CN220083614U), and some solutions have attempted to maintain vacuum through partition isolation, in actual continuous production, frequent station switching, mold replacement and maintenance operations still cannot avoid interference with the main vacuum environment, resulting in increased energy consumption and slower production cycle.

[0007] 4. Poor space utilization and process connection: Some existing equipment that attempts to integrate multiple functions lacks compactness in the layout of its functional modules, resulting in a large equipment footprint; at the same time, the transition between different processes is not smooth enough, affecting the overall integration and operational continuity of the equipment.

[0008] Therefore, existing technologies still cannot effectively meet the stringent requirements of large-scale, industrialized flash sintering production for full-process automation, high efficiency, high consistency, and a stable vacuum environment. There is an urgent need to provide an integrated flash sintering device and sintering method for vacuum applications to overcome the shortcomings in current practical applications. Summary of the Invention

[0009] The purpose of this invention is to provide an integrated flash sintering apparatus and sintering method for vacuum applications, aiming to solve the problems mentioned in the background art.

[0010] The present invention is implemented as follows: an integrated flash sintering device and sintering method for vacuum applications, comprising a power supply module, a high vacuum module, a first servo hydraulic press, a second servo hydraulic press, a third servo hydraulic press, a mold rotation switching module, a vacuum feeding module, a green pressing module, a demolding and mold cleaning module, and a mold transfer module.

[0011] The vacuum feeding module provides powder to the green compact pressing module, the green compact pressing module provides a sintering mold containing the green compact to the mold transfer module, the mold rotation switching module receives the sintering mold containing the green compact transferred by the mold transfer module and switches to the flash sintering station, the power supply module provides power to the flash sintering station to complete the flash sintering, the mold transfer module is used to transfer the sintering mold containing the sintered product to the demolding and mold cleaning module, the demolding and mold cleaning module is used to complete the demolding and mold cleaning, and then transport the cleaned sintering mold to the green compact pressing module;

[0012] The first and second servo hydraulic presses are located on both sides of the flash sintering station to provide pressing force to the flash sintering station. The third servo hydraulic press is used to provide pressing power to the green compact pressing module. The high vacuum module provides a high vacuum environment for the entire process.

[0013] As a further embodiment of the present invention: the high vacuum module includes a first vacuum chamber, a second vacuum chamber, a powder filling vacuum chamber, and a sampling vacuum chamber;

[0014] The first vacuum chamber is equipped with a first vacuum chamber door, a first sealed welded bellows, a second sealed welded bellows, and a waste discharge vacuum gate valve;

[0015] The second vacuum chamber is equipped with a second vacuum chamber door and a third sealed welded bellows, and the second vacuum chamber is sealed to the first vacuum chamber through a sealing connection flange;

[0016] The powder filling vacuum box is equipped with a powder filling vacuum box door and a powder filling vacuum gate valve;

[0017] The sampling vacuum chamber is equipped with a sampling vacuum chamber door and a sampling vacuum gate valve.

[0018] As a further embodiment of the present invention: the green pressing module includes a fourth sintering mold, a green pressing base, an upper pressing head, a gear conveying unit, a mold mounting unit, a graphite paper cutting and pressing unit, and a green pressing unit;

[0019] The gear conveying unit includes a gear tray, on which a first mounting hole, a second mounting hole, and a third mounting hole are respectively provided for fixing the mold mounting unit, the graphite paper cutting and pressing unit, and the green pressing unit;

[0020] The gear conveying unit also includes a drive gear and a tray support rod. The tray support rod supports the gear tray through an angular contact ball bearing. The second vacuum box has a drive motor base fixed inside, and a gear drive motor is installed on the drive motor base. The drive gear receives the power output from the gear drive motor and drives the gear tray to rotate through inter-tooth meshing, conveying the mold installation unit, the graphite paper cutting and pressing unit and the green pressing unit above the green pressing base.

[0021] As a further embodiment of the present invention: the fourth sintering mold includes a split inner mold and a mold outer mold, the split inner mold is provided with an outer conical surface, the mold outer mold is provided with an inner conical surface, and the inner conical surface of the mold outer mold and the outer conical surface of the split inner mold are in relative contact and sliding.

[0022] The mold installation unit includes a mold outer stamping cylinder, a first spring, and a first bushing. The third servo hydraulic press drives the upper pressure head through its third piston rod, which in turn drives the mold outer stamping cylinder to compress the first spring and pushes the mold outer sleeve to pre-tighten with the inner mold.

[0023] As a further embodiment of the present invention: the graphite paper cutting unit includes a graphite paper positioning punch, a second spring, a graphite paper cutting punch, graphite paper, a second bushing, and a third spring. The second bushing is fixedly installed in a second mounting hole. The graphite paper cutting punch is slidably connected to the second bushing. The graphite paper positioning punch is slidably connected to the graphite paper cutting punch. The two ends of the second spring are respectively fixed to the graphite paper positioning punch and the graphite paper cutting punch. The two ends of the third spring are respectively fixed to the graphite paper cutting punch and the second bushing. The stiffness coefficient of the second spring is greater than that of the third spring.

[0024] The graphite paper passes through the first graphite paper perforation and the second graphite paper perforation provided on the gear tray at both ends, and is wound into a spare graphite paper roll and a recycling graphite paper roll.

[0025] As a further embodiment of the present invention: the mold transfer module includes a first transfer servo motor, a second transfer servo motor, a first transverse slide rail, a second transverse slide rail, a first vertical slide rail, and a second vertical slide rail. The first vertical slide rail and the second vertical slide rail are fixedly installed inside the second vacuum chamber. The first vertical slide rail and the second vertical slide rail are provided with a first vertical slider and a second vertical slider. The first vertical slider and the second vertical slider are fixedly connected to the first transverse slide rail and the second transverse slide rail, respectively. The first vertical slide rail and the second vertical slide rail control the longitudinal movement of the first transverse slide rail and the second transverse slide rail.

[0026] The first transfer servo motor and the second transfer servo motor are slidably connected to the first horizontal slide rail and the second horizontal slide rail respectively through the first horizontal slider and the second horizontal slider. The first horizontal slide rail and the second horizontal slide rail control the first transfer servo motor and the second transfer servo motor to move laterally.

[0027] The first transfer servo motor is equipped with a first arc-shaped electromagnet, and the second transfer servo motor is equipped with a second arc-shaped electromagnet. The magnetic adsorption and desorption of the sintering mold are controlled by electrical signals.

[0028] As a further embodiment of the present invention: the mold rotation switching module includes a mold fixing and cleaning unit, an outer cylinder of the mold fixing and cleaning unit, an electrode cooling unit, a mold pressing unit, a mold lifting unit, and a rotary drum servo drive motor. The mold fixing and cleaning unit is provided with a mold fixing and cleaning rotary drum. The mold fixing and cleaning rotary drum is fixed to the outer cylinder base and outer cylinder cover of the outer cylinder of the mold fixing and cleaning unit by a first tapered roller bearing and a second tapered roller bearing arranged vertically. The outer cylinder cover is fixedly connected to the outer cylinder base through the outer cylinder wall. The outer cylinder base is connected to the first vacuum box through the outer cylinder base support rod.

[0029] The electrode cooling unit includes a lower electrode cooling plate and an upper electrode cooling plate, which are respectively fixedly mounted on the outer cylinder base and the outer cylinder cover. The outer cylinder cover and the outer cylinder base are fixed and cleaned by pressing the mold with upper and lower tapered roller bearings.

[0030] As a further aspect of the present invention: the power supply module includes an upper electrode punch, a lower electrode punch, an upper electrode post, and a lower electrode post, wherein the upper electrode punch and the lower electrode punch are respectively connected to an external power supply through the upper electrode post and the lower electrode post.

[0031] The upper electrode post is sealed to the first vacuum box through a first sealed welded bellows, and is insulated and fixed to the first piston rod of the first servo hydraulic press through a first insulating gasket;

[0032] The lower electrode post is sealed to the first vacuum box through a second sealed welded bellows, and is insulated and fixed to the second piston rod of the second servo hydraulic press through a second insulating gasket.

[0033] As a further embodiment of the present invention: the demolding and mold cleaning module includes a demolding and mold cleaning work platform, a demolding punch, and a mold cleaning push rod;

[0034] The demolding punch is fixedly connected to the upper pressure head via a demolding punch connecting plate, and the mold cleaning push rod is equipped with a cleaning brush head;

[0035] The demolding and mold cleaning work platform is equipped with a sample collection tube.

[0036] The present invention also provides an integrated flash sintering method for vacuum applications, using the above-described apparatus, the method comprising the following steps:

[0037] S1. Vacuuming: Close all vacuum chamber doors and vacuum gate valves, and use the molecular pump group to evacuate the device to the target vacuum level;

[0038] S2, Material Powder Filling and Storage: Vacuum the material powder filling vacuum box, open the material powder filling vacuum gate valve and servo feeding valve, and the material powder falls into the vacuum storage cylinder;

[0039] S3. Mold Installation: The gear pallet rotates and conveys the mold installation unit to complete the pre-tightening of the outer mold and the inner mold of the opening segment;

[0040] S4. Pressing the first layer of graphite paper: The gear tray rotates and conveys the graphite paper cutting and pressing unit to cut and press the graphite paper sheet into the open inner mold.

[0041] S5. Powder loading and pre-pressing: The gear tray rotates and conveys the green compact pressing unit, the vacuum feeding module quantitatively conveys the powder, and the green compact pressing punch presses the powder into green compacts.

[0042] S6. Pressing the second layer of graphite paper: The graphite paper unit is cut again and the graphite paper sheet is pressed onto the upper surface of the green body;

[0043] S7. Flash sintering: The mold rotation switching module switches the sintering mold containing the green blank to the flash sintering station, where the electrode punch applies pressure and current is passed through to complete the sintering.

[0044] S8. Sintering area cleaning: Cleaning brushes simultaneously clean the electrode punch and outer cylinder base, and collect the debris into the waste collection bucket.

[0045] S9. Demolding and mold cleaning: The demolding punch pushes the sintered finished product to demold, and the cleaning brush head cleans the inner wall of the mold.

[0046] S10. Collection of sintered finished products: After the sampling vacuum chamber is evacuated, the sampling vacuum gate valve is opened to collect the finished products and debris, and then the vacuum is released and the products are taken out.

[0047] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0048] 1. Achieved full-process automation and continuous production: This invention constructs a complete production closed loop through the collaborative operation of the mold rotation switching module, the mold transfer module, and various functional modules. From powder feeding, green compact pressing, flash sintering to demolding and mold cleaning, everything is completed automatically within the system, completely eliminating the interruption problem of single-station batch production, significantly improving production efficiency, and laying the foundation for the industrial application of flash sintering.

[0049] 2. Improved equipment integration and space utilization: This invention adopts an integrated gear tray design, integrating three functional units—mold installation, graphite paper cutting and pressing, and green compact pressing—into a single rotary station, sharing a common hydraulic power system. This design significantly reduces the equipment's footprint and complexity. The mold rotation switching module integrates multiple sintering mold station switching, synchronous cleaning of upper and lower electrodes, and waste collection functions within a limited space, resulting in a compact structure and highly integrated functions.

[0050] 3. Ensured process consistency and product quality: Precise metering and feeding of powder materials were achieved through the vacuum weighing sensor and servo screw feeder in the vacuum feeding module, ensuring the stability of green body quality from the source. The entire core process was carried out in the stable environment created by the high vacuum module, effectively preventing material oxidation and improving the density and performance of the sintered products. The mold transfer module used an arc-shaped electromagnet for precise mold gripping and transfer, avoiding the uncertainties of manual operation.

[0051] 4. Improved lifespan and stability of molds and electrodes: The unique mold fixing and cleaning rotary drum design, with its built-in first and second cleaning brushes, automatically cleans the surfaces of the upper and lower electrode punches each time the rotation switches positions, preventing impurity accumulation, significantly improving electrode lifespan and ensuring stable sintering quality. In the demolding and mold cleaning module, the inner wall of the mold is automatically cleaned immediately after demolding via the mold cleaning push rod, ensuring rapid mold recycling and guaranteeing the quality of subsequent products.

[0052] 5. Achieved efficient vacuum maintenance and flexible upkeep: By setting up independent powder filling vacuum chambers and sampling vacuum chambers, and equipping them with vacuum gate valves isolated from the main vacuum chamber, the vacuum level of the main system is maintained during powder loading and finished product removal, significantly reducing vacuuming waiting time and energy consumption. The use of sealed welded bellows as the sealing connection for the power transmission components ensures effective sealing while providing compression and tension strokes, ensuring the stability of the pressing and sintering processes and improving the reliability of the vacuum system.

[0053] 6. Enhanced production flexibility and continuity: The mold rotation switching module can accommodate multiple molds and achieve rapid station rotation, enabling processes such as green preparation, sintering and cooling to be carried out in parallel, forming a highly efficient production cycle and greatly improving equipment capacity. Attached Figure Description

[0054] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0055] Figure 1 This is a front view of the overall structure of the integrated flash sintering apparatus for vacuum applications according to the present invention.

[0056] Figure 2 This is a schematic diagram of the mold rotation switching module structure of the present invention;

[0057] Figure 3 This is a top-view exploded view of the mold rotation switching module of the present invention;

[0058] Figure 4 This is a bottom-view exploded view of the mold rotation switching module of the present invention;

[0059] Figure 5 This is a schematic diagram of the flash sintering station structure of the present invention;

[0060] Figure 6This is a schematic diagram of the high vacuum module structure of the present invention;

[0061] Figure 7 This is a schematic diagram of the mold transfer module structure of the present invention;

[0062] Figure 8 This is a schematic diagram of the left front structure of the demolding, mold cleaning and green pressing module of the present invention;

[0063] Figure 9 This is a schematic diagram of the green pressing module structure of the present invention;

[0064] Figure 10 This is a schematic diagram of the gear conveying unit structure of the green blank pressing module of the present invention;

[0065] Figure 11 This is a schematic diagram of the green pressing base structure of the green pressing module of the present invention;

[0066] Figure 12 This is a schematic diagram of the mold installation unit structure of the green pressing module of the present invention (a: in operation; b: after operation).

[0067] Figure 13 This is a schematic diagram of the graphite paper cutting unit structure of the green pressing module of the present invention (a: in operation; b: after operation).

[0068] Figure 14 This is a schematic diagram of the powder loading and pre-compression unit structure of the green compact pressing module of the present invention (a: in operation; b: after operation).

[0069] Figure 15 This is a lower-angled schematic diagram of the overall structure of the green pressing module of the present invention;

[0070] Figure 16 This is a rear-view schematic diagram of the overall structure of an integrated flash sintering apparatus for vacuum applications according to the present invention.

[0071] In the attached diagram: 0-Mold rotation switching module, 01-Mold fixing and cleaning unit, 011-Mold fixing and cleaning rotary drum, 012-First cleaning brush, 013-Second cleaning brush, 014-First tapered roller bearing, 015-Second tapered roller bearing, 02-Outer cylinder of the mold fixing and cleaning unit, 021-Outer cylinder base, 022-Outer cylinder wall, 023-Outer cylinder cover, 024-Waste collection bin, 025-Outer cylinder base support rod, 03-Electrode cooling unit, 031-Lower electrode cooling plate, 032-Upper electrode cooling plate, 04-Mold pressing unit, 041-Mold pressing push rod, 042-Mold pressing servo electric cylinder, 05-Mold lifting unit, 051-Mold lifting push rod, 052-Mold lifting servo electric cylinder Servo cylinder, 06-rotary drum servo drive motor, 07-first sintering mold, 08-second sintering mold, 09-third sintering mold, 1-vacuum feeding module, 11-receiving cylinder, 12-servo feeding valve, 13-vacuum storage cylinder, 14-servo screw feeder, 15-powder weighing tank, 16-vacuum weighing sensor, 17-servo tilting table, 18-servo tilting table support rod, 2-green pressing module, 21-fourth sintering mold, 211-open inner mold, 212-mold outer sleeve, 22-green pressing base, 221-support column, 222-mold base, 2221-first shaft surface, 2222-first end face, 2223-second end face, 23-upper pressure head, 24-gear conveying unit, 241-gear Wheel tray, 242-Drive gear, 2421-Gear drive motor, 2422-Drive motor base, 243-Pattern support rod, 244-First mounting hole, 245-Second mounting hole, 246-Third mounting hole, 247-First graphite paper perforation, 248-Second graphite paper perforation, 25-Mold mounting unit, 251-Mold outer sleeve stamping cylinder, 252-First spring, 253-First bushing, 26-Graphite paper cutting unit, 261-Graphite paper positioning punch, 262-Second spring, 263-Graphite paper cutting punch, 264-Graphite paper, 265-Graphite paper spare roll, 266-Graphite paper recycling roll, 267-Second bushing, 268-Third spring, 27-Green pressing unit, 271- Green blank pressing punch, 272-Fourth spring, 273-First extension cylinder, 274-Discharge tube, 275-Fifth spring, 276-Third bushing, 3-Demolding and mold cleaning module, 31-Demolding and mold cleaning work platform, 311-Sample collection cylinder, 32-Demolding punch, 321-Demolding punch connecting plate, 33-Mold cleaning push rod, 331-Cleaning brush head, 4-Mold transfer module, 41-First transfer servo motor, 411-First arc-shaped electromagnet, 42-Second transfer servo motor, 421-Second arc-shaped electromagnet, 43-First transverse slide rail, 431-First transverse slider, 44-Second transverse slide rail, 441-Second transverse slider, 45-First vertical slide rail, 451-First vertical slider46-Second vertical slide rail, 461-Second vertical slider, 5-Power supply module, 51-Upper electrode punch, 52-Lower electrode punch, 53-Upper electrode post, 54-Lower electrode post, 6-High vacuum module, 61-First vacuum chamber, 611-First vacuum chamber door, 612-First sealed welded bellows, 613-Second sealed welded bellows, 614-Waste discharge vacuum gate valve, 615-Sealed connection flange, 62-Second vacuum chamber, 621-Second vacuum chamber door, 622- Second extended barrel, 623-Third sealing welded bellows, 63-Powder filling vacuum box, 631-Powder filling vacuum box door, 632-Powder filling vacuum gate valve, 64-Sampling vacuum box, 641-Sampling vacuum box door, 642-Sampling vacuum gate valve, 7-First servo hydraulic press, 71-First piston rod, 72-First insulating gasket, 8-Second servo hydraulic press, 81-Second piston rod, 82-Second insulating gasket, 9-Third servo hydraulic press, 91-Third piston rod. Detailed Implementation

[0072] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0073] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0074] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0075] The present invention will be further explained below with reference to specific embodiments.

[0076] Please see Figures 1-16 This invention provides an integrated flash sintering apparatus for vacuum applications, comprising a mold rotation switching module 0, a vacuum feeding module 1, a green compact pressing module 2, a demolding and mold cleaning module 3, a mold transfer module 4, a power supply module 5, a high vacuum module 6, a first servo hydraulic press 7, a second servo hydraulic press 8, and a third servo hydraulic press 9. The vacuum feeding module 1 supplies powder to the green compact pressing module 2. The green compact pressing module 2 provides a sintering mold containing the green compact to the mold transfer module 4. The mold rotation switching module 0 receives the sintering mold containing the green compact transferred by the mold transfer module 4 and switches the sintering mold containing the green compact to the flash sintering station. The flash sintering station receives electrical energy from the power supply module 5 to complete the flash sintering process and output the flash sintered finished product. The sintering mold containing the flash sintered finished product provided by the mold transfer module 4 is transferred to the demolding and mold cleaning module 3. The demolding and mold cleaning module 3 completes the demolding of the flash sintered finished product and the cleaning of the sintering mold, and provides the cleaned sintering mold to the green compact pressing module 2. The first servo hydraulic press 7 and the second servo hydraulic press 8 provide pressing force for the flash sintering process, while the third servo hydraulic press 9 provides pressing power for the green compact pressing module 2. The high vacuum module 6 provides a high vacuum environment for the entire flash sintering process.

[0077] In this embodiment, the fundamental objective of the present invention is to address a series of problems inherent in existing flash sintering technology, namely, the inability to achieve efficient and continuous production due to the dispersed functional modules, low mold processing efficiency, difficulty in maintaining a vacuum environment, and insufficient automation. Specifically, these problems manifest as low production efficiency, poor process consistency, high energy consumption of the vacuum system, insufficient equipment integration, and difficulty in maintaining key components. This solution utilizes a mold rotation switching module to enable the cyclical use and station switching of multiple sintering molds within a compact space. Combined with the coordinated operation of a vacuum feeding module, a green compact pressing module, a demolding and mold cleaning module, and a mold transfer module, a complete high-vacuum environment production closed loop is constructed. Each module achieves orderly connection and power sharing through a precisely positioned mold transfer system and a unified hydraulic drive system. The system features an integrated gear tray design that integrates mold installation, graphite paper processing, and green compact pressing functions. Furthermore, online synchronous cleaning of the electrodes and molds is achieved through mold fixing and a cleaning brush built into the cleaning drum. This enables fully automated, highly efficient, and highly stable continuous production of flash sintering from powder feeding to finished product collection.

[0078] Among them, reference Figure 6The high vacuum module 6 is equipped with a first vacuum chamber 61, a second vacuum chamber 62, a powder filling vacuum chamber 63, and a sampling vacuum chamber 64. The first vacuum chamber 61 is equipped with a first vacuum chamber door 611, a first sealed welded bellows 612, a second sealed welded bellows 613, and a waste discharge vacuum valve 614. The first vacuum chamber door 611 and the waste discharge vacuum valve 614 seal the first vacuum chamber 61. The first and second sealed welded bellows 612 and 613 provide a certain amount of compression and tension stroke while ensuring a seal. The second vacuum chamber 62 is equipped with a second vacuum chamber door 621 and a third sealed welded bellows 623. The second vacuum chamber door 621 seals the second vacuum chamber 62. The third sealed welded bellows 623 provides a certain amount of compression and tension stroke while ensuring a seal. The second vacuum chamber 62 is sealed to the first vacuum chamber 61 via a sealing flange 615. The powder filling vacuum chamber 63 is equipped with a powder filling vacuum chamber door 631 and a powder filling vacuum gate valve 632. The powder filling vacuum chamber door 631 seals the powder filling vacuum chamber 63, and the powder filling vacuum gate valve 632 isolates the second vacuum chamber 62 from the powder filling vacuum chamber 63. The sampling vacuum chamber 64 is equipped with a sampling vacuum chamber door 641 and a sampling vacuum gate valve 642. The sampling vacuum chamber door 641 seals the sampling vacuum chamber 64, and the sampling vacuum gate valve 642 isolates the second vacuum chamber 62 from the sampling vacuum chamber 64. The setup of the powder filling vacuum box 63 and the sampling vacuum box 64 ensures the stability of the vacuum level of the first vacuum box 61 and the second vacuum box 62 during powder loading and collection of sintered finished products. The first sealed welded bellows 612, the second sealed welded bellows 613 and the third sealed welded bellows 623 ensure sealing while providing a certain amount of compression and stretching stroke, ensuring the stability of the pressing and sintering process and improving the quality of the sintered finished products.

[0079] Reference Figure 1 , Figures 8-16The green pressing module 2 is provided with a fourth sintering mold 21, a green pressing base 22 and an upper pressing head 23, and is also provided with a gear conveying unit 24, a mold mounting unit 25, a graphite paper cutting and pressing unit 26 and a green pressing unit 27. The gear conveying unit 24 is provided with a gear tray 241, which is provided with a first mounting hole 244, a second mounting hole 245 and a third mounting hole 246. The first mounting hole 244, the second mounting hole 245 and the third mounting hole 246 are respectively used to fix the mold mounting unit 25, the graphite paper cutting and pressing unit 26 and the green pressing unit 27. The gear conveying unit 24 is also equipped with a drive gear 242 and a tray support rod 243. The tray support rod 243 supports the gear tray 241 through angular contact ball bearings. The drive gear 242 receives power from the gear drive motor 2421 and drives the gear tray 241 to rotate and convey the mold mounting unit 25, the graphite paper pressing unit 26, and the green pressing unit 27 above the green pressing base 22. The gear drive motor 2421 is fixed inside the second vacuum chamber 62 through the drive motor base 2422. The integrated gear tray 241 integrates the functions of mold mounting, graphite paper pressing, and green pressing into one set of servo hydraulic system, which has a high degree of integration and reduces the footprint of the equipment.

[0080] The drive gear 242 drives the gear tray 241 to rotate and convey the mold mounting unit 25 above the green compact pressing base 22. The mold mounting unit 25 is provided with a mold outer sleeve stamping cylinder 251, a first spring 252, and a first bushing 253. The fourth sintering mold 21 is provided with a split inner mold 211 and a mold outer sleeve 212. The split inner mold 211 is provided with an outer conical surface, and the mold outer sleeve 212 is provided with an inner conical surface. The green compact pressing base 22 is provided with a support column 221 and a mold base 222. The mold base 222 is provided with a first axial surface 2221, a first end surface 2222, and a second end surface 2223. The first end surface 2222 of the mold base 222 is always in contact with the lower end surface of the split inner mold 211 of the fourth sintering mold 21. The first axial surface 2221 and the second end surface 2223 are in periodic contact with the inner surface of the split inner mold 211 and the lower surface of the mold outer sleeve 212, respectively. The first bushing 253 is fixedly installed in the first mounting hole 244, the mold outer stamping cylinder 251 is slidably connected to the first bushing 253, and the two ends of the first spring 252 are fixed to the mold outer stamping cylinder 251 and the first bushing 253. The third servo hydraulic press 9 outputs pressing power to the upper pressure head 23 through its third piston rod 91. The upper pressure head 23 contacts the upper end face of the mold outer sleeve stamping cylinder 251, causing the mold outer sleeve stamping cylinder 251 to compress the first spring 252 and slide downward along the inner surface of the first bushing 253 until the lower end face of the mold outer sleeve stamping cylinder 251 contacts the upper end face of the mold outer sleeve 212. Under the pressing force transmitted by the upper pressure head 23, the mold outer sleeve stamping cylinder 251 pushes the mold outer sleeve 212 downward. The inner conical surface of the mold outer sleeve 212 contacts and slides relative to the outer conical surface of the split inner mold 211, completing the pre-tightening of the mold outer sleeve 212 and the split inner mold 211, and outputting a qualified green blank pressing mold. At this time, the inner surface of the split inner mold 211 is tightly fitted with the first shaft surface 2221, and the lower surface of the mold outer sleeve 212 contacts the second end face 2223. Figure 12 .

[0081] The drive gear 242 drives the gear tray 241 to rotate and convey the graphite paper cutting and pressing unit 26 above the green pressing base 22. The graphite paper cutting and pressing unit 26 is equipped with a graphite paper positioning punch 261, a second spring 262, a graphite paper cutting punch 263, graphite paper 264, a second bushing 267, and a third spring 268. The second bushing 267 is fixedly installed in the second mounting hole 245. The graphite paper cutting punch 263 is slidably connected to the second bushing 267. The graphite paper positioning punch 261 is slidably connected to the graphite paper cutting punch 263. The two ends of the second spring 262 are respectively fixed to the graphite paper positioning punch 261 and the graphite paper cutting punch 263. The two ends of the third spring 268 are respectively fixed to the graphite paper cutting punch 263 and the second bushing 267. The spring constant of the second spring 262 is greater than that of the third spring 268. The graphite paper 264 passes through the first graphite paper perforation 247 and the second graphite paper perforation 248 respectively provided in the gear tray 241 and is wound into the graphite paper spare roll 265 and the graphite paper recycling roll 266. The graphite paper spare roll 265 outputs new graphite paper 264 above the fourth sintering mold 21, and the graphite paper recycling roll 266 receives the old graphite paper 264 after punching. The graphite paper positioning punch 261 receives the downward pressing force transmitted by the upper pressure head 23, which drives the graphite paper cutting punch 263 to move downward through the second spring 262 until the graphite paper cutting punch 263 contacts the upper end face of the split inner mold 211 through the graphite paper 264. The graphite paper cutting punch 263 cuts the graphite paper 264 and outputs a graphite paper sheet of a set specification inside the split inner mold 211. The graphite paper positioning punch 261 continues to move downward and presses the graphite paper sheet to a set depth in the split inner mold 211. Figure 13 As shown.

[0082] Drive gear 242 drives gear tray 241 to rotate and convey green pressing unit 27 above green pressing base 22. The green pressing unit 27 is equipped with a green pressing punch 271, a fourth spring 272, a first extended material cylinder 273, a fifth spring 275, and a third bushing 276. The third bushing 276 is fixedly installed in the third mounting hole 246. The two ends of the fourth spring 272 are fixed to the green pressing punch 271 and the first extended material cylinder 273, respectively. The two ends of the fifth spring 275 are fixed to the first extended material cylinder 273 and the third bushing 276, respectively. The stiffness coefficient of the fourth spring 272 is greater than that of the fifth spring 275. The first extended material cylinder 273 is also fixedly equipped with a feed pipe 274 for receiving powder. The green pressing punch 271 receives the downward pressing force transmitted by the upper pressing head 23, which drives the first extended material cylinder 273 downward through the fourth spring 272 until the first extended material cylinder 273 is in close contact with the upper end face of the split inner mold 211. The vacuum feeding module 1 includes a receiving cylinder 11, a servo discharge valve 12, a vacuum storage cylinder 13, a servo screw feeder 14, a powder weighing tank 15, a vacuum weighing sensor 16, and a servo tilting stage 17. The receiving cylinder 11 is fixedly placed inside the powder filling vacuum box 63. The receiving cylinder 11 receives externally input powder and outputs it to the vacuum storage cylinder 13 through the servo discharge valve 12, the powder filling vacuum gate valve 632, and the second extended cylinder 622 of the second vacuum box 62. The vacuum storage cylinder 13 is fixedly connected to the second vacuum box 62. The vacuum storage cylinder 13 uniformly conveys the powder to the powder weighing tank 15 through the servo screw feeder 14. The vacuum weighing sensor 16, fixedly installed at the lower end of the powder weighing tank 15, measures the weight of the powder in the powder weighing tank 15 and outputs a switch signal to the servo screw feeder 14. The servo tilting stage 17, which is fixedly installed in the second vacuum chamber 62 by the servo tilting stage support rod 18, tilts the powder weighing tank 15 and conveys the powder through the feeding pipe 274 to the first extended cylinder 273 and the open inner mold 211. The green pressing punch 271 continues to move downward and outputs the set pressing force to the powder to press the powder into a green blank.

[0083] Reference Figure 7The mold transfer module 4 is equipped with a first transfer servo motor 41, a second transfer servo motor 42, a first horizontal slide rail 43, a second horizontal slide rail 44, a first vertical slide rail 45, and a second vertical slide rail 46. The first vertical slide rail 45 and the second vertical slide rail 46 are fixedly installed inside the second vacuum chamber 62. The first vertical slide rail 45 and the second vertical slide rail 46 are equipped with a first vertical slider 451 and a second vertical slider 461, which are respectively fixedly connected to the first horizontal slide rail 43 and the second horizontal slide rail 44. The first vertical slide rail 45 and the second vertical slide rail 46 control the longitudinal movement of the first horizontal slide rail 43 and the second horizontal slide rail 44. The first transfer servo motor 41 and the second transfer servo motor 42 are slidably connected to the first horizontal slide rail 43 and the second horizontal slide rail 44 through the first horizontal slider 431 and the second horizontal slider 441, respectively. The first horizontal slide rail 43 and the second horizontal slide rail 44 control the lateral movement of the first transfer servo motor 41 and the second transfer servo motor 42. The first transfer servo motor 41 and the second transfer servo motor 42 are also equipped with a first arc-shaped electromagnet 411 and a second arc-shaped electromagnet 421, respectively. The first arc-shaped electromagnet 411 and the second arc-shaped electromagnet 421 complete the periodic magnetic adsorption and desorption with the first sintering mold 07, the second sintering mold 08, the third sintering mold 09, and the fourth sintering mold 21 through the opening and closing of electrical signals. The mold transfer module 4 completes the conversion of the sintering mold between the mold rotation switching module 0, the green pressing module 2, and the demolding and mold cleaning module 3. The arc-shaped electromagnet cooperates with the steel mold outer shell of the sintering mold to realize the flexible switching of the sintering mold between various workstations in a compact space, which improves the integration of the equipment and enhances the continuity of the process.

[0084] Reference Figures 2-5The mold rotation switching module 0 is equipped with a mold fixing and cleaning unit 01, a mold fixing and cleaning unit outer cylinder 02, an electrode cooling unit 03, a mold pressing unit 04, a mold lifting unit 05, and a rotary drum servo drive motor 06. The mold fixing and cleaning unit 01 is equipped with a mold fixing and cleaning rotary drum 011. The mold fixing and cleaning rotary drum 011 is fixed to the outer cylinder base 021 and outer cylinder cover 023 of the outer cylinder 02 by a first tapered roller bearing 014 and a second tapered roller bearing 015 arranged vertically. The outer cylinder cover 023 is fixedly connected to the outer cylinder base 021 through the outer cylinder wall 022. The outer cylinder base 021 is connected to the first vacuum box 61 through the outer cylinder base support rod 025. The mold fixing and cleaning rotary drum 011 is provided with sintering mold fixing and mounting holes for placing the first sintering mold 07, the second sintering mold 08, and the third sintering mold 09. The mold fixing and cleaning rotary drum 011 is also provided with a first cleaning brush 012 and a second cleaning brush 013. The first cleaning brush 012 cleans the upper surface of the outer cylinder base 021 and the upper surface of the lower electrode punch 52 provided by the power supply module 5. The second cleaning brush 013 cleans the lower surface of the upper electrode punch 51 provided by the power supply module 5. The mold pressing unit 04 is provided with a mold pressing push rod 041 and a mold pressing servo electric cylinder 042. Under the thrust output by the mold pressing servo electric cylinder 042, the mold pressing push rod 041 pushes the first sintering mold 07, which is magnetically decoupled from the first arc-shaped electromagnet 411 and contains the pressed green blank, into the sintering mold fixing and mounting holes provided by the mold fixing and cleaning rotary drum 011. The mold lifting unit 05 is equipped with a mold lifting push rod 051 and a mold lifting servo electric cylinder 052. Under the thrust output by the mold lifting servo electric cylinder 052, the mold lifting push rod 051 pushes the second sintering mold 08 containing the sintered finished product to a set height. The second arc-shaped electromagnet 421 magnetically attracts the second sintering mold 08. The rotary drum servo drive motor 06 drives the mold fixing and cleaning rotary drum 011 to rotate and transport the first sintering mold 07 containing the pressed green blank to the flash sintering station (directly above the lower electrode punch 52). At this time, the third sintering mold 09 containing the sintered finished product is converted into the second sintering mold 08, and the first sintering mold 07 is converted into the third sintering mold 09. The first cleaning brush 012 and the second cleaning brush 013 simultaneously complete the cleaning work. The first cleaning brush 012 sweeps the debris into the waste collection bin 024 set in the outer cylinder base 021. The mold rotation switching module 0 is also equipped with an electrode cooling unit 03, which includes a lower electrode cooling plate 031 and an upper electrode cooling plate 032. The lower electrode cooling plate 031 and the upper electrode cooling plate 032 are respectively fixedly mounted on the outer cylinder base 021 and the outer cylinder cover 023. The outer cylinder cover 023 and the outer cylinder base 021 are pressed together by upper and lower tapered roller bearings to secure the mold fixing and cleaning rotating cylinder 011, ensuring high stability during the rotation of the mold fixing and cleaning rotating cylinder 011.The mold fixing and cleaning rotary drum 011 enables the switching of various sintering molds within a limited space, satisfying the compact design of the equipment. Its integrated first cleaning brush 012 and second cleaning brush 013 periodically clean the upper and lower electrode punches, which not only improves the service life of the electrodes but also ensures the quality of the sintered products. In addition, the design of the outer cylinder cover 023 and the outer cylinder base 021 prevents waste from splashing into the first vacuum chamber 61 during the sintering process and electrode cleaning, reducing the frequency of cleaning the first vacuum chamber 61.

[0085] The power supply module 5 is disposed on the upper electrode punch 51, the lower electrode punch 52, the upper electrode post 53, and the lower electrode post 54. The upper electrode post 53 and the lower electrode post 54 are respectively sealed and connected to the first vacuum box 61 through the first sealed welded bellows 612 and the second sealed welded bellows 613. The upper electrode post 53 and the lower electrode post 54 are connected to the external power supply wires. The upper electrode post 53 and the lower electrode post 54 are respectively insulated and fixedly connected to the first piston rod 71 and the second piston rod 81 through the first insulating gasket 72 and the second insulating gasket 82. The upper electrode post 53 receives the downward pressing power output by the first servo hydraulic press 7 through the first piston rod 71 to compress the first sealed welded bellows 612, which drives the upper electrode punch 51 to move downward until the upper electrode punch 51 extends into the third sintering mold 09 and contacts the green blank through the graphite paper sheet. The upper electrode punch 51 outputs pressing force on the upper surface of the green blank. The lower electrode post 54 receives the upward pressing power output from the second servo hydraulic press 8 via the second piston rod 81, which compresses the second sealed welded bellows 613, causing the lower electrode punch 52 to move upward until it extends into the third sintering mold 09 and contacts the green blank spacer graphite paper sheet. The lower electrode punch 52 outputs pressing force on the lower surface of the green blank. Current passes through the upper electrode post 53, upper electrode punch 51, graphite paper sheet, green blank, graphite paper sheet, lower electrode punch 52, and lower electrode post 54 to complete the sintering of the green blank, and outputs the sintered finished product.

[0086] The demolding and mold cleaning module 3 is equipped with a demolding and mold cleaning work platform 31, a demolding punch 32, and a mold cleaning push rod 33. The demolding and mold cleaning work platform 31 supports the second sintering mold 08 containing the sintered finished product, which is transported by the second transfer servo motor 42. The demolding punch 32 is fixedly connected to the upper pressure head 23 through a demolding punch connecting plate 321. The demolding punch 32 transmits the downward power of the upper pressure head 23 to push the sintered finished product in the second sintering mold 08 to complete the demolding process. The cleaning brush head 331 of the mold cleaning push rod 33 receives the power output from the servo cylinder to clean the inner wall of the second sintering mold 08 after demolding, thus completing the mold cleaning process. The sample collection cylinder 311 collects and stores the sintered finished product and debris generated during cleaning.

[0087] Working Principle: Powder Filling and Storage Stage: When powder needs to be added, close the powder filling vacuum gate valve 632, de-vacuum the powder filling vacuum chamber 63, and wait until the internal pressure of the powder filling vacuum chamber 63 reaches atmospheric pressure. Then, open the powder filling vacuum chamber door 631 and add a fixed weight of powder into the receiving cylinder 11. After the powder filling is completed, close the powder filling vacuum chamber door 631, evacuate the powder filling vacuum chamber 63, and wait until the inside of the powder filling vacuum chamber 63 reaches a vacuum state. Then, open the powder filling vacuum gate valve 632 and the servo discharge valve 12. The powder falls into the vacuum storage cylinder 13 through the servo discharge valve 12, the powder filling vacuum gate valve 632, and the second extended cylinder 622 set in the second vacuum chamber 62, completing the powder filling and storage work.

[0088] Green compact pressing stage: The fourth sintering mold 21, after being cleaned by the demolding and mold cleaning module 3, is transferred by the mold transfer module 4 from the demolding and mold cleaning station to the green compact pressing station (above the green compact pressing base 22). The support column 221 of the green compact pressing base 22 provides a stable base for the green compact pressing process. The mold base 222 is used to place the fourth sintering mold 21. At this time, the inner mold 211 and the outer mold 212 of the fourth sintering mold 21 are in an unlocked state. The lower end face of the inner mold 211 is in contact with the first end face 2222 of the mold base 222, while the lower surface of the outer mold 212 is not in contact with the second end face 2223 of the mold base 222. The drive gear 242 drives the gear tray 241 to rotate and transport the mold mounting unit 25 above the green compact pressing base 22. The die outer sleeve stamping cylinder 251 is slidably connected to the first bushing 253, which is fixedly installed in the first mounting hole 244. The third servo hydraulic press 9 outputs pressing power to the upper pressure head 23 through its third piston rod 91. The upper pressure head 23 contacts the upper end face of the die outer sleeve stamping cylinder 251, causing the die outer sleeve stamping cylinder 251 to compress the first spring 252 and slide downward along the inner surface of the first bushing 253 until the lower end face of the die outer sleeve stamping cylinder 251 contacts the upper end face of the die outer sleeve 212. The die outer sleeve stamping cylinder 251 is pressed by the upper pressure head 244. Under the pressure of the transmitted force, the mold outer sleeve 212 is pushed downward. Since the split inner mold 211, which is in contact with the first end face 2222 of the mold base 222, cannot move downward, the inner conical surface of the mold outer sleeve 212 and the outer conical surface of the split inner mold 211 slide relative to each other, completing the pre-tightening of the mold outer sleeve 212 and the split inner mold 211, and outputting a qualified green pressing mold. At this time, the inner surface of the split inner mold 211 is tightly fitted with the first axial surface 2221 of the mold base 222, and the lower surface of the mold outer sleeve 212 is in contact with the second end face 2223. After the mold is installed, the upper pressure head 23 returns to its original position, and the mold outer sleeve stamping cylinder 251 returns to its original position under the elastic force of the first spring 252. The drive gear 242 drives the gear tray 241 to rotate and convey the graphite paper cutting and pressing unit 26 above the green pressing base 22. The graphite paper recycling roll 266 carries the old graphite paper 264, which has been punched, through the second graphite paper perforation 248 and is wound back into the graphite paper recycling roll 266. At the same time, the graphite paper spare roll 265 outputs new graphite paper 264 through the first graphite paper perforation 247 above the fourth sintering mold 21. The second bushing 267 is fixedly installed in the second mounting hole 245. The graphite paper cutting punch 263 is slidably connected to the second bushing 267, and the graphite paper positioning punch 261 is slidably connected to the graphite paper cutting punch 263.Because the spring constant of the second spring 262 is greater than that of the third spring 268, the graphite paper positioning punch 261 receives the downward pressing force transmitted by the upper pressure head 23. First, the second spring 262 drives the graphite paper cutting punch 263 downward (compressing the third spring 268) until the graphite paper cutting punch 263 contacts the upper surface of the split inner mold 211, separated by the graphite paper 264. The upper pressure head 23 continues to push the graphite paper positioning punch 261 downward, and the graphite paper cutting punch 263 cuts the graphite paper 264 to output a graphite paper sheet of the set specifications. The graphite paper positioning punch 261 continues to move downward (at this time, the second spring 262 is compressed) to press the graphite paper sheet into the split inner mold 211 at the set depth. After the graphite paper sheet is pressed, the upper pressure head 23 returns to its original position, and the graphite paper cutting punch 263 and the graphite paper positioning punch 261 return to their original positions under the action of the third spring 268 and the second spring 262, respectively. Drive gear 242 drives gear tray 241 to rotate and convey green pressing unit 27 above green pressing base 22. Third bushing 276 is fixedly installed in third mounting hole 246, first extended material cylinder 273 is slidably connected to third bushing 276, and green pressing punch 271 is slidably connected to first extended material cylinder 273. Since the stiffness coefficient of fourth spring 272 is greater than that of fifth spring 275, green pressing punch 271 receives the downward pressing force transmitted by upper pressing head 23 and first drives first extended material cylinder 273 downward through fourth spring 272 (fifth spring 275 is compressed) until first extended material cylinder 273 is in close contact with the upper end face of open inner mold 211. At this time, the servo screw feeder 14 at the bottom of the vacuum storage cylinder 13 uniformly conveys the powder into the powder weighing tank 15. The vacuum weighing sensor 16 weighs the powder in the powder weighing tank 15. After the powder weight reaches the set requirement, the vacuum weighing sensor 16 outputs a shut-off signal to the servo screw feeder 14, and the servo screw feeder 14 stops working. The servo tilting table 17 tilts the vacuum weighing sensor 16 and the powder weighing tank 15 as a whole. The powder slides from the powder weighing tank 15 into the feed pipe 274 and is conveyed through the feed pipe 274 to the first extended cylinder 273 and the open inner mold 211. At this time, the powder is in a loose state. The green pressing punch 271 continues to move downward and outputs the set pressing force to the powder to press the powder into a dense green. After the green pressing is completed, the upper pressing head 23 returns to its original position. The first extended cylinder 273 and the green pressing punch 271 return to their original positions under the action of the fifth spring 275 and the fourth spring 272, respectively. The drive gear 242 drives the gear tray 241 to rotate again, conveying the graphite paper cutting and pressing unit 26 above the green blank pressing base 22. The graphite paper cutting and pressing unit 26 cuts and presses the graphite paper for the second time 264 and outputs graphite paper sheets above the green blank. At this time, there is a graphite paper sheet on each of the upper and lower sides of the green blank.

[0089] In the flash sintering process: The first vertical slide rail 45 of the mold transfer module 4 drives the first horizontal slide rail 43 to move to the height of the fourth sintering mold 21 for green compact pressing through the first vertical slider 451. The first horizontal slide rail 43 drives the first transfer servo motor 41 to move to the station of the fourth sintering mold 21 for green compact pressing through the first horizontal slider 431. The first transfer servo motor 41 drives the first arc electromagnet 411 to rotate to the direction of the fourth sintering mold 21 for green compact pressing. At this time, the first arc electromagnet 411 outputs electromagnetic force to firmly attract the fourth sintering mold 21 through the opening of the electrical signal. Then, under the combined action of the first vertical slide rail 45, the first horizontal slide rail 43 and the first transfer servo motor 41, the first arc electromagnet 411 attracts the fourth sintering mold 21 and transfers it to the position directly below the mold pressing push rod 041. The fourth sintering mold 21 is converted into the first sintering mold 07. The mold pressing push rod 041 is pushed by the thrust output by the mold pressing servo electric cylinder 042 to push the first sintering mold 07 containing the pressed green blank, which is magnetically desorbed by the first arc electromagnet 411, into the sintering mold fixing and cleaning drum 011. The rotary drum servo drive motor 06 drives the mold fixing and cleaning rotary drum 011 to rotate and transport the first sintering mold 07 containing the pressed green blank to the flash sintering station (directly above the lower electrode punch 52). The first sintering mold 07 is converted into the third sintering mold 09. At this time, the upper electrode column 53 receives the downward pressing power output by the first servo hydraulic press 7 through the first piston rod 71 to compress the first sealed welded bellows 612 and drive the upper electrode punch 51 to move downward until the upper electrode punch 51 extends into the interior of the third sintering mold 09 and contacts the green blank through the graphite paper. The lower electrode column 54 receives the upward pressing power output by the second servo hydraulic press 8 through the second piston rod 81 to compress the second sealed welded bellows 613 and drive the lower electrode punch 52 to move upward until the lower electrode punch 52 extends into the interior of the third sintering mold 09 and contacts the green blank through the graphite paper. The upper electrode punch 51 and the lower electrode punch 52 jointly output pressing force on the upper and lower surfaces of the green blank. Current flows through the upper electrode post 53, upper electrode punch 51, graphite paper sheet, green blank, graphite paper sheet, lower electrode punch 52, and lower electrode post 54. The Joule heating and non-thermal effects of the electric field complete the flash sintering of the green blank, outputting the sintered finished product. After sintering, all components return to their original positions, with the upper electrode punch 51 and lower electrode punch 52 returning to their initial upper and lower limit positions, respectively. The upper electrode cooling plate 032 and lower electrode cooling plate 031 cool the upper electrode punch 51 and lower electrode punch 52 respectively by pressing them together. The rotary drum servo drive motor 06 drives the mold fixing and cleaning rotary drum 011 to rotate and transport the third sintering mold 09 containing the sintered finished product to directly above the mold lifting push rod 051. The third sintering mold 09 is converted into the second sintering mold 08. Under the thrust output by the mold lifting servo electric cylinder 052, the mold lifting push rod 051 pushes the second sintering mold 08 containing the sintered finished product to the set height. The second arc-shaped electromagnet 421 magnetically attracts the second sintering mold 08.The first cleaning brush 012 and the second cleaning brush 013, installed on the mold fixing and cleaning drum 011, simultaneously clean the upper surface of the outer cylinder base 021, the upper surface of the lower electrode punch 52, and the lower surface of the upper electrode punch 51 when the mold fixing and cleaning drum 011 rotates. The long brush of the first cleaning brush 012 sweeps the debris into the waste collection bucket 024 set on the outer cylinder base 021. The waste discharge vacuum valve 614 opens periodically to release the debris in the waste collection bucket 024.

[0090] Demolding and mold cleaning process: Under the combined action of the second vertical slide rail 46, the second horizontal slide rail 44 and the second transfer servo motor 42, the second arc-shaped electromagnet 421 magnetically attracts the second sintering mold 08 and transfers it to the demolding station (directly below the demolding punch 32) of the demolding and mold cleaning work platform 31. The demolding punch 32 transmits the downward force of the upper pressure head 23 to push the sintered product in the second sintering mold 08. After the sintered product slides relative to the open inner mold of the second sintering mold 08, it falls into the sample collection cylinder 311, and the open inner mold and the outer mold of the second sintering mold 08 separate. The second arc-shaped electromagnet 421 magnetically attracts the second sintering mold 08 and transfers it to the mold cleaning station (directly below the cleaning brush head 331) of the demolding and mold cleaning work platform 31. The cleaning brush head 331 receives power from the servo cylinder and slides relative to the open inner mold to clean the inner wall of the second sintering mold 08 after demolding. The generated debris falls into the sample collection cylinder 311.

[0091] When collecting sintered products, the sampling vacuum chamber 64 is evacuated. Once the vacuum level inside the sampling vacuum chamber 64 is consistent with that inside the second vacuum chamber 62, the sampling vacuum gate valve 642 is opened, and the sintered products and debris in the sample collection cylinder 311 fall into the sampling vacuum chamber 64. After the sintered products and debris have been collected, the sampling vacuum gate valve 642 is closed, and the vacuum in the sampling vacuum chamber 64 is released. Once the vacuum level inside the sampling vacuum chamber 64 is consistent with that of the external atmosphere, the sampling vacuum chamber door 641 is opened, and the sintered products and debris are removed.

[0092] Under the combined action of the second vertical slide rail 46, the second horizontal slide rail 44, and the second transfer servo motor 42, the second arc-shaped electromagnet 421 continues to magnetically adsorb the demolded and cleaned second sintering mold 08 and transfer it to the green pressing station (above the green pressing base 22) to complete the green pressing work. At this time, the second sintering mold 08 is converted into the fourth sintering mold 21.

[0093] An integrated flash sintering method for vacuum applications, using the aforementioned integrated flash sintering apparatus for vacuum applications, includes the following steps:

[0094] S1: Vacuuming: Close the first vacuum chamber door 611, the second vacuum chamber door 621, the waste discharge vacuum gate valve 614, the powder filling vacuum gate valve 632, and the sampling vacuum gate valve 642, and use the molecular pump group to evacuate the vacuum integrated flash sintering device to the target vacuum level.

[0095] S2: Material powder filling and storage: Vacuum the material powder filling vacuum box 63, open the material powder filling vacuum gate valve 632 and the servo feeding valve 12, and the material powder falls from the receiving cylinder 11 through the servo feeding valve 12, the material powder filling vacuum gate valve 632 and the second extended material cylinder 622 set in the second vacuum box 62 into the vacuum storage cylinder 13 to complete the material powder filling and storage work;

[0096] S3: Mold installation: Drive gear 242 drives gear tray 241 to rotate and transport mold installation unit 25 above green pressing base 22. The mold outer sleeve stamping cylinder 251 of mold installation unit 25 receives the pressing force transmitted by upper pressure head 23 and pushes mold outer sleeve 212 downward to complete the pre-tightening of mold outer sleeve 212 and open inner mold 211, and outputs qualified green pressing mold.

[0097] S4: Pressing the first layer of graphite paper: The drive gear 242 drives the gear tray 241 to rotate and convey the graphite paper cutting and pressing unit 26 above the green pressing base 22. The graphite paper recycling roll 266 drives the graphite paper spare roll 265 to output new graphite paper 264 above the fourth sintering mold 21. The graphite paper positioning punch 261 receives the pressing force transmitted by the upper pressing head 23 and drives the graphite paper cutting punch 263 through the second spring 262 to cut out graphite paper sheets of the set specifications. The graphite paper positioning punch 261 presses the graphite paper sheets into the open inner mold 211 at the set depth.

[0098] S5: Powder Loading and Pre-pressing: The drive gear 242 drives the gear tray 241 to rotate and convey the green compact pressing unit 27 above the green compact pressing base 22. The feed pipe 274 receives the powder material quantitatively conveyed by the vacuum storage cylinder 13 and conveys it to the first extended cylinder 273 and the open inner mold 211. The green compact pressing punch 271 transmits the descending pressing force of the upper pressing head 23 to the upper surface of the powder material to complete the pressing of the green compact.

[0099] S6; Pressing the second layer of graphite paper: Drive gear 242 drives gear tray 241 to rotate and convey graphite paper cutting and pressing unit 26 above green pressing base 22. Graphite paper cutting and pressing unit 26 outputs graphite paper sheets on the upper surface of the green. At this time, there is one graphite paper sheet on each of the upper and lower surfaces of the green.

[0100] S7: Flash Sintering: The mold rotation switching module 0 switches the sintering mold containing the green blank to the flash sintering station (directly above the lower electrode punch 52). The upper electrode punch 51 and the lower electrode punch 52 respectively output pressing force to the green blank through the upper and lower graphite paper sheets. At the same time, the current passes through the upper electrode post 53, the upper electrode punch 51, the graphite paper sheet, the green blank, the graphite paper sheet, the lower electrode punch 52 and the lower electrode post 54. The green blank powder particles undergo rapid accelerated sintering under the action of the critical electric field / temperature, and the qualified sintered product is output.

[0101] S8: Sintering area cleaning: The first cleaning brush 012 and the second cleaning brush 013 installed on the mold fixing and cleaning drum 011 simultaneously clean the upper surface of the outer cylinder base 021, the upper surface of the lower electrode punch 52 and the lower surface of the upper electrode punch 51 when the mold fixing and cleaning drum 011 rotates. The long brush of the first cleaning brush 012 sweeps the debris into the waste debris collection bucket 024 set in the outer cylinder base 021. The waste debris discharge vacuum gate valve 614 is periodically opened to release the debris in the waste debris collection bucket 024.

[0102] S9: Demolding and mold cleaning: The demolding punch 32 transmits the downward power of the upper pressure head 23 to push the sintered product in the sintering mold containing the sintered product. The sintered product slides relative to the split inner mold in the sintering mold, completing the demolding work; the cleaning brush head 331 receives the power output from the servo electric cylinder and slides relative to the split inner mold to clean the inner wall of the split inner mold after demolding, completing the mold cleaning work.

[0103] S10: Sintered Product Collection: Evacuate the sampling vacuum chamber 64 until the vacuum level inside the sampling vacuum chamber 64 matches that inside the second vacuum chamber 62. Then open the sampling vacuum gate valve 642, and the sintered products and debris in the sample collection cylinder 311 fall into the sampling vacuum chamber 64. After the sintered products and debris have been collected, close the sampling vacuum gate valve 642 and devastate the sampling vacuum chamber 64. When the vacuum level inside the sampling vacuum chamber 64 matches that of the external atmosphere, open the sampling vacuum chamber door 641 and remove the sintered products and debris.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An integrated flash sintering apparatus for vacuum applications, comprising a power supply module (5), a high vacuum module (6), a first servo hydraulic press (7), a second servo hydraulic press (8), and a third servo hydraulic press (9), characterized in that, It also includes a mold rotation switching module (0), a vacuum feeding module (1), a green pressing module (2), a demolding and mold cleaning module (3), and a mold transfer module (4); The vacuum feeding module (1) provides powder to the green pressing module (2), the green pressing module (2) provides a sintering mold containing green blanks to the mold transfer module (4), the mold rotation switching module (0) receives the sintering mold containing green blanks transferred by the mold transfer module (4) and switches to the flash sintering station, the power supply module (5) provides power to the flash sintering station to complete the flash sintering, the mold transfer module (4) is used to transfer the sintering mold containing the sintered finished product to the demolding and mold cleaning module (3), the demolding and mold cleaning module (3) is used to complete the demolding and mold cleaning, and then transport the cleaned sintering mold to the green pressing module (2). The first servo hydraulic press (7) and the second servo hydraulic press (8) are located on both sides of the flash sintering station to provide pressing force to the flash sintering station. The third servo hydraulic press (9) is used to provide pressing power to the green compact pressing module (2). The high vacuum module (6) provides a high vacuum environment for the entire process. The high vacuum module (6) includes a first vacuum chamber (61), a second vacuum chamber (62), a powder filling vacuum chamber (63), and a sampling vacuum chamber (64). The first vacuum chamber (61) is provided with a first vacuum chamber door (611), a first sealed welded bellows (612), a second sealed welded bellows (613), and a waste discharge vacuum gate valve (614). The second vacuum chamber (62) is provided with a second vacuum chamber door (621) and a third sealed welded bellows (623), and the second vacuum chamber (62) is sealed to the first vacuum chamber (61) through a sealing connection flange (615); The powder filling vacuum box (63) is equipped with a powder filling vacuum box door (631) and a powder filling vacuum gate valve (632). The sampling vacuum chamber (64) is equipped with a sampling vacuum chamber door (641) and a sampling vacuum slide valve (642). The green pressing module (2) includes a fourth sintering mold (21), a green pressing base (22), an upper pressing head (23), a gear conveying unit (24), a mold installation unit (25), a graphite paper cutting and pressing unit (26), and a green pressing unit (27). The gear conveying unit (24) includes a gear tray (241), on which a first mounting hole (244), a second mounting hole (245), and a third mounting hole (246) are respectively provided for fixing the mold mounting unit (25), the graphite paper cutting and pressing unit (26), and the green pressing unit (27). The gear conveying unit (24) also includes a drive gear (242) and a tray support rod (243). The tray support rod (243) supports the gear tray (241) through an angular contact ball bearing. The second vacuum box (62) has a drive motor base (2422) fixed inside, and a gear drive motor (2421) is provided on the drive motor base (2422). The drive gear (242) receives the power output by the gear drive motor (2421) and drives the gear tray (241) to rotate and convey the mold mounting unit (25), the graphite paper cutting and pressing unit (26), and the green pressing unit (27) above the green pressing base (22) through inter-tooth meshing.

2. The integrated flash sintering apparatus for vacuum applications according to claim 1, characterized in that, The fourth sintering mold (21) includes a split inner mold (211) and a mold outer mold (212). The split inner mold (211) has an outer conical surface, and the mold outer mold (212) has an inner conical surface. The inner conical surface of the mold outer mold (212) and the outer conical surface of the split inner mold (211) are in relative contact and slide. The mold installation unit (25) includes a mold outer sleeve stamping cylinder (251), a first spring (252) and a first bushing (253). The third servo hydraulic press (9) drives the upper pressure head (23) through its third piston rod (91), which drives the mold outer sleeve stamping cylinder (251) to compress the first spring (252) and push the mold outer sleeve (212) to pre-tighten with the inner mold (211).

3. The integrated flash sintering apparatus for vacuum applications according to claim 1, characterized in that, The graphite paper cutting unit (26) includes a graphite paper positioning punch (261), a second spring (262), a graphite paper cutting punch (263), graphite paper (264), a second bushing (267), and a third spring (268). The second bushing (267) is fixedly installed in the second mounting hole (245). The graphite paper cutting punch (263) is slidably connected to the second bushing (267). The graphite paper positioning punch (261) is slidably connected to the graphite paper cutting punch (263). The two ends of the second spring (262) are respectively fixed to the graphite paper positioning punch (261) and the graphite paper cutting punch (263). The two ends of the third spring (268) are respectively fixed to the graphite paper cutting punch (263) and the second bushing (267). The spring constant of the second spring (262) is greater than that of the third spring (268). The graphite paper (264) passes through the first graphite paper perforation (247) and the second graphite paper perforation (248) provided on the gear tray (241) at both ends, and is wound into a graphite paper spare roll (265) and a graphite paper recycling roll (266).

4. The integrated flash sintering apparatus for vacuum applications according to claim 1, characterized in that, The mold transfer module (4) includes a first transfer servo motor (41), a second transfer servo motor (42), a first horizontal slide rail (43), a second horizontal slide rail (44), a first vertical slide rail (45), and a second vertical slide rail (46). The first vertical slide rail (45) and the second vertical slide rail (46) are fixedly installed inside the second vacuum box (62). The first vertical slide rail (45) and the second vertical slide rail (46) are provided with a first vertical slider (451) and a second vertical slider (461). The first vertical slider (451) and the second vertical slider (461) are fixedly connected to the first horizontal slide rail (43) and the second horizontal slide rail (44) respectively. The first vertical slide rail (45) and the second vertical slide rail (46) control the first horizontal slide rail (43) and the second horizontal slide rail (44) to move longitudinally. The first transfer servo motor (41) and the second transfer servo motor (42) are slidably connected to the first horizontal slide rail (43) and the second horizontal slide rail (44) respectively through the first horizontal slider (431) and the second horizontal slider (441). The first horizontal slide rail (43) and the second horizontal slide rail (44) control the first transfer servo motor (41) and the second transfer servo motor (42) to move laterally. The first transfer servo motor (41) is equipped with a first arc-shaped electromagnet (411), and the second transfer servo motor (42) is equipped with a second arc-shaped electromagnet (421). The magnetic adsorption and desorption of the sintering mold are controlled by electrical signals.

5. The integrated flash sintering apparatus for vacuum applications according to claim 1, characterized in that, The mold rotation switching module (0) includes a mold fixing and cleaning unit (01), a mold fixing and cleaning unit outer cylinder (02), an electrode cooling unit (03), a mold pressing unit (04), a mold lifting unit (05), and a rotary drum servo drive motor (06). The mold fixing and cleaning unit (01) is provided with a mold fixing and cleaning rotary drum (011). The mold fixing and cleaning rotary drum (011) is fixed to the outer cylinder base (021) and outer cylinder cover (023) provided on the outer cylinder of the mold fixing and cleaning unit outer cylinder (02) by the first tapered roller bearing (014) and the second tapered roller bearing (015) arranged above and below. The outer cylinder cover (023) is fixedly connected to the outer cylinder base (021) through the outer cylinder wall (022). The outer cylinder base (021) is connected to the first vacuum box (61) through the outer cylinder base support rod (025). The electrode cooling unit (03) includes a lower electrode cooling plate (031) and an upper electrode cooling plate (032). The lower electrode cooling plate (031) and the upper electrode cooling plate (032) are respectively fixed on the outer cylinder base (021) and the outer cylinder cover (023). The outer cylinder cover (023) and the outer cylinder base (021) are fixed and cleaned by the upper and lower tapered roller bearings pressing mold.

6. The integrated flash sintering apparatus for vacuum applications according to claim 1, characterized in that, The power supply module (5) includes an upper electrode punch (51), a lower electrode punch (52), an upper electrode post (53), and a lower electrode post (54). The upper electrode punch (51) and the lower electrode punch (52) are respectively connected to an external power supply through the upper electrode post (53) and the lower electrode post (54). The upper electrode post (53) is sealed to the first vacuum box (61) through the first sealed welded bellows (612), and is insulated and fixed to the first piston rod (71) of the first servo hydraulic press (7) through the first insulating gasket (72); The lower electrode post (54) is sealed to the first vacuum box (61) through the second sealed welded bellows (613), and is insulated and fixed to the second piston rod (81) of the second servo hydraulic press (8) through the second insulating gasket (82).

7. The integrated flash sintering apparatus for vacuum applications according to claim 1, characterized in that, The demolding and mold cleaning module (3) includes a demolding and mold cleaning work platform (31), a demolding punch (32), and a mold cleaning push rod (33). The demolding punch (32) is fixedly connected to the upper pressure head (23) through the demolding punch connecting plate (321), and the mold cleaning push rod (33) is provided with a cleaning brush head (331). The demolding and mold cleaning work platform (31) is equipped with a sample collection tube (311).

8. An integrated flash sintering method for vacuum applications, characterized in that, Using the apparatus according to any one of claims 1-7, the method comprises the following steps: S1. Vacuuming: Close all vacuum chamber doors and vacuum gate valves, and use the molecular pump group to evacuate the device to the target vacuum level; S2, Material powder filling and storage: Vacuum the material powder filling vacuum box (63), open the material powder filling vacuum gate valve (632) and servo discharge valve (12), and the material powder falls into the vacuum storage cylinder (13). S3, Mold Installation: The gear tray (241) rotates and conveys the mold installation unit (25) to complete the pre-tightening of the mold outer sleeve (212) and the flap inner mold (211); S4, Pressing the first layer of graphite paper: The gear tray (241) rotates and conveys the graphite paper cutting and pressing unit (26), cutting and pressing the graphite paper sheet into the open inner mold (211); S5. Powder loading and pre-pressing: Gear tray (241) rotates and conveys green pressing unit (27), vacuum feeding module (1) quantitatively conveys powder, green pressing punch (271) presses powder into green billet; S6, Pressing the second layer of graphite paper: Cut and press the graphite paper unit (26) again and press the graphite paper sheet onto the upper surface of the green blank; S7, Flash Sintering: The mold rotation switching module (0) switches the sintering mold containing the green blank to the flash sintering station, and the electrode punch applies pressure and current to complete the sintering. S8. Sintering area cleaning: Clean the electrode punch and outer cylinder base simultaneously with the cleaning brush, and collect the debris into the waste collection bucket (024). S9. Demolding and mold cleaning: Demolding punch (32) pushes the sintered finished product to demold, and cleaning brush head (331) cleans the inner wall of the mold; S10. Collection of sintered finished products: After the sampling vacuum box (64) is evacuated, the sampling vacuum gate valve (642) is opened to collect the finished products and debris, and then the vacuum is released and the products are taken out.

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