An apparatus and method for spark plasma sintering of large size products

Abstract

The application discloses a device and method for making large-size products by using spark plasma sintering technology. The device comprises a hydraulic system, a power supply system, a vacuum assembly, a mold and a cooling assembly. The device further comprises a sub-oil cylinder which is parallel to the pressing direction and is arranged in the same direction. The sub-oil cylinder moves with the pressing assembly and is internally provided with a hollow through hole for accommodating a pipeline of the cooling assembly. The method is realized by using the device. The application overcomes the main obstacles of applying the spark plasma sintering technology to the industrial production of large-size products, realizes stable operation under long stroke, reliable pressing under high pressure and effective heat management of key components, optimizes the operability of industrial production and the uniformity of final products, successfully provides a reliable, efficient and economical device and process for preparing large-size high-performance dense materials, and promotes the transformation of the spark plasma sintering technology from laboratory small sample preparation to industrial product manufacturing.

Description

Technical Field

[0001] This invention relates to the field of powder sintering equipment, and more particularly to a spark plasma sintering apparatus and method. Background Technology

[0002] Spark plasma sintering (SPPS) is a novel powder metallurgy sintering technology that involves loading metal powders into a mold, applying a specific sintering current and pressure to the powder using a positive mold and energized electrodes, and then activating it through discharge, thermoplastic deformation, and cooling to produce high-performance materials. Existing SPPS equipment is generally used for manufacturing small-sized (height-oriented) products, and the stroke of the pressure components during the manufacturing process is relatively short. When it comes to the industrial production of large-sized devices, existing equipment currently suffers from the following problems:

[0003] (1) As the size of the device increases, the power output will also increase to several hundred kilowatts and the pressure will also increase to hundreds of tons. The increase in power output means that the connection between the power supply and the electrode needs to use a water-cooled cable with a larger diameter. The pressurization component for high-sized products has a longer stroke, which will also increase the displacement distance of the water-cooling equipment. In existing equipment, the water-cooling device is often connected from the side of the mold and the side of the vacuum chamber, and then connected to the electrode to achieve cooling (the connection is achieved by opening a hole in the vacuum cover and then sealing it). Excessive displacement distance will cause the pipes of the vacuum system and the water-cooling device to enter the vacuum system, causing them to interfere with each other, resulting in the inability to complete the vacuum, pressurization or atmosphere control smoothly. (2) Currently, the electrodes of the equipment on the market are in direct contact with both ends of the mold in the form of copper plates. After the pressure component contacts the electrodes, it indirectly applies pressure to the mold. At high temperatures (above 200°C), the copper plates are prone to soft deformation, which affects the production of the product. (3) In the pressing of long-size products, the friction between powder particles and between the powder and the inner wall of the die will cause pressure decay and ultimately the difference in density at both ends, thus affecting the performance of the product. Summary of the Invention

[0004] This invention provides a discharge plasma sintering apparatus and method for manufacturing large-size products, in order to solve the technical problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, the technical solution proposed by this invention is as follows: A discharge plasma sintering apparatus for manufacturing large-size products includes a pressurizing component, an electrode assembly, a mold, a vacuum component for controlling the vacuum level in the area surrounding the mold, and a cooling component for cooling the electrode assembly. The pressurizing component includes a first pressure head and a second pressure head, with the mold disposed between the first and second pressure heads. The electrode assembly abuts against the pressurizing component and provides a pulsed current to it. The apparatus is characterized by further including an auxiliary hydraulic cylinder, the axis of which is in the same direction as the movement of the pressurizing component. The auxiliary hydraulic cylinder has a hollow through-hole with the same direction as the movement of the pressurizing component. The auxiliary hydraulic cylinder moves with the pressurizing component, and the cooling pipes of the cooling component pass through the hollow through-hole of the auxiliary hydraulic cylinder to cool the electrode assembly.

[0006] The design concept of the above technical solution lies in the fact that by setting up an auxiliary oil cylinder that moves parallel to and in the same direction as the main pressurizing component, the interference between the cooling component and the vacuum component during the large stroke of the pressurizing component is completely eliminated. The water-cooled cable is confined to the through hole of the auxiliary oil cylinder, and its movement direction is consistent with the movement direction of the pressurizing component. The movement trajectory is fixed and predictable, and there is no possibility of entanglement or collision with other components of the vacuum system (such as the vacuum shroud, the outer wall of the vacuum chamber, and the electrode inlet). The cooling pipe of the cooling component does not need to be introduced from the side of the vacuum chamber, avoiding the problem of difficulty in sealing due to long stroke movement, ensuring the sealing and stability of the vacuum system, and providing a reliable atmospheric environment for the sintering process. In principle, this design allows for a virtually unlimited stroke, providing a basic condition for the preparation of large-size products with a height greater than 450mm.

[0007] As a further preferred embodiment of the above technical solution, the hollow through-hole is filled with high-temperature resistant filler, which tightly wraps the cooling pipes of the cooling assembly. The filler in the auxiliary cylinder effectively isolates the high temperature of the sintering zone from the internal cooling pipes, preventing damage or reduced cooling efficiency due to excessively high pipe wall temperature. It also further enhances the sealing at the through-hole, preventing vacuum leakage, and can fix the cooling pipes, preventing vibration or wear during movement, thereby improving the stability of equipment operation and pipe life.

[0008] As a further preferred embodiment of the above technical solution, the stroke of the pressurizing component and the auxiliary cylinder during operation is greater than 1m.

[0009] As a further preferred embodiment of the above technical solution, the electrode assembly includes a copper mold with a ring-shaped structure. The copper mold is fitted onto the pressure assembly, so that the outer surfaces of the first and second pressure heads are in electrical contact with the inner wall of the copper mold and move together with the pressure assembly. In this invention, the pressure function is directly applied to the mold by the central pressure head passing through the copper ring, while the current conduction function is undertaken by the contact between the copper ring and the side of the pressure assembly. The large-area lateral contact between the copper ring and the pressure head still provides an excellent conductive path, completely avoiding the direct application of high pressure to the copper plate serving as the electrode. This fundamentally solves the problem of soft deformation of the electrode under high pressure, allowing for the application of greater pressure to obtain large-size products with high density.

[0010] As a further preferred embodiment of the above technical solution, the inner wall of the copper mold is an inclined surface relative to the direction of movement of the pressurizing component, and the contour of the pressurizing component matches the inner wall of the copper mold. The inclined conical surface has a self-centering effect, which facilitates the installation and alignment of the copper mold, while increasing the contact area to ensure good surface contact under heat or force, reducing contact resistance, and avoiding local arcing or overheating.

[0011] As a further preferred embodiment of the above technical solution, the copper mold is hollow inside, and the cooling pipes of the cooling component are connected to the copper mold and supply cooling medium to the inside of the copper mold. The fact that the copper mold does not bear any load is a prerequisite for its hollow structure design. The hollow copper mold allows the cooling component to directly and forcibly cool the critical components that conduct current, effectively removing heat and preventing overheating.

[0012] As a further preferred embodiment of the above technical solution, the copper mold is made of pure copper. Pure copper is one of the metals with the best electrical conductivity in industry, which can minimize electrical loss and improve sintering efficiency. It also has good thermal conductivity, which can quickly transfer heat to the cooling medium and has a good heat dissipation effect.

[0013] As a further preferred embodiment of the above technical solution, the electrode assembly further includes a power supply for supplying power to the electrode assembly. The power supply is electrically connected to the electrode assembly via a cable, and the cable connects the electrode assembly, the cooling assembly, and the power supply in the form of a water-cooled cable to the cooling pipe. The water-cooled cable is an integrated flexible pipeline with a conductive core and a cooling medium channel, so as to simultaneously supply power to the electrode assembly and introduce the cooling medium.

[0014] As a further preferred embodiment of the above technical solution, the spark plasma sintering apparatus has a horizontal structure, with the pressurizing component, electrode component, mold, cooling component, and vacuum component arranged horizontally. A set of auxiliary hydraulic cylinders is provided at each end of the mold, and the pressurizing component applies pressure to the mold from both ends, which is beneficial for uniform stress distribution on the product and the uniformity of the internal structure and density at both ends of the product.

[0015] As a further preferred embodiment of the above technical solution, the mold includes a high-temperature resistant outer shell and a graphite core encased within the high-temperature resistant outer shell. The inner graphite core utilizes graphite's excellent high-temperature strength, thermal conductivity, and thermal shock resistance to withstand the main thermal field and sample contact. The outer high-temperature resistant outer shell (which may be high-strength graphite, carbon-carbon composite material, or metal) provides the main mechanical strength, withstands extremely high pressing pressure, and prevents the mold from cracking. Even if the inner graphite core is damaged due to long-term use, only the relatively low-cost core needs to be replaced, without replacing the entire large mold shell, significantly reducing production and maintenance costs.

[0016] As a further preferred embodiment of the above technical solution, the high-temperature resistant outer shell includes a cylindrical high-temperature resistant insulation layer and a steel mold sleeve fitted over the high-temperature resistant insulation layer.

[0017] Based on the same technical concept, the present invention also provides a spark plasma sintering method for manufacturing large-size products, which is carried out using the spark plasma sintering apparatus for manufacturing large-size products described in the above technical solution; including the following steps: S1. The raw material powder is filled into the mold, and the mold is pressed by the pressure component to form a green body; or the raw material powder is pre-compacted to form a green body and then filled into the mold. S2. A pulsed current is passed through the electrode assembly to the mold to heat and sinter the raw material powder to obtain the final product.

[0018] As a further preferred embodiment of the above technical solution, in S2, the heating and sintering process is divided into four stages: preheating stage, heating stage, heat preservation and pressure increase stage, and pressure preservation and cooling stage.

[0019] As a further preferred embodiment of the above technical solution, the diameter of the final product in S2 is 50~300mm and the length is 100~400mm.

[0020] This invention overcomes the main obstacles to applying spark plasma sintering technology to the industrial production of large-size products through a series of highly synergistic technical solutions. It achieves stable operation under long strokes, reliable pressurization under high pressure, and effective thermal management of key components. It optimizes the operability of industrial production and the uniformity of the final product. It successfully provides a reliable, efficient, and economical spark plasma sintering equipment and process for preparing large-scale high-performance dense materials, and promotes the transformation of spark plasma sintering technology from laboratory small sample preparation to industrial product manufacturing. Attached Figure Description

[0021] Figure 1 This is a schematic diagram (top view) of the spark plasma sintering apparatus of Example 1. Figure 2This is a schematic diagram of the spark plasma sintering apparatus of Example 1 (front view). Figure 3 This is a schematic diagram of the copper mold in Example 1 (top view). Figure 4 This is a structural schematic diagram (cross-sectional view) of the copper mold in Example 1. Figure 5 This is a schematic diagram showing the connection relationship between the water-cooled cable and the copper mold in Example 1; Figure 6 This is a schematic diagram of the mold structure in Example 1; Figure 7 The heating and sintering process curve for Example 2; Figure 8 A photograph of the final product produced for Example 2.

[0022] Legend: 1. Pressurizing assembly; 11. First pressure head; 12. Second pressure head; 21. Copper mold; 211. Annular cooling chamber; 212. Cooling medium inlet / outlet; 213. Connecting hole; 23. Power supply; 3. Mold; 31. Female mold; 32. Male mold; 3111. High-temperature resistant insulation layer; 3112. Steel mold sleeve; 312. Graphite mold core; 313. Mold cavity; 4. Vacuum assembly; 41. Vacuum hood; 42. Vacuum pump; 51. Cooling medium tank; 6. Auxiliary oil cylinder; 7. Water-cooled cable; 8. Oil pump. Detailed Implementation

[0023] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways as defined and covered by the claims.

[0024] Example 1: like Figure 1 and Figure 2 As shown, the spark plasma sintering apparatus includes a pressurizing component 1, an electrode assembly, a mold 3, a vacuum assembly 4, and a cooling assembly. The spark plasma sintering apparatus has a horizontal structure, with the pressurizing component 1, electrode assembly, and mold 3 arranged horizontally. The pressurizing component 1 includes a first pressure head 11 and a second pressure head 12, which are oppositely arranged and driven by hydraulic cylinders. The mold 3 is located between the first pressure head 11 and the second pressure head 12. The electrode assembly includes a copper mold 21, a power supply 23, and a cable connecting the two. The copper mold 21 abuts against the pressurizing component 1 and provides a pulsed current to the pressurizing component 1. The vacuum assembly 4 is used to control the vacuum level in the area surrounding the mold 3. The cooling assembly includes a cooling medium tank 51 and cooling pipes for cooling the electrode assembly. In this embodiment, the cooling pipes of the cooling assembly and the cable of the electrode assembly are integrated together in the form of a water-cooled cable 7, which simultaneously provides pulsed current and cooling medium to the copper mold 21.

[0025] The discharge plasma sintering apparatus of this embodiment also includes auxiliary oil cylinders 6. A set of auxiliary oil cylinders 6 is provided near the first pressure head 11 and the second pressure head 12. The axial direction of the auxiliary oil cylinders 6 is the same as the movement direction of the pressurizing component 1. A hollow through hole with the same direction as the movement direction of the pressurizing component 1 is opened inside the auxiliary oil cylinders 6. The auxiliary oil cylinders 6 move together with the pressurizing component 1. The water-cooled cable 7 passes through the hollow through hole of the auxiliary oil cylinders 6 to cool the copper mold 21.

[0026] In this embodiment, the auxiliary oil cylinder 6 is located on one side of the pressurizing component 1, and is identical to the oil cylinder of the pressurizing component 1, both being driven by the oil pump 8. When the pressurizing component 1 moves forward during the pressing process, the auxiliary oil cylinder 6 moves synchronously. The water-cooled cable 7 passes through the hollow through hole from the rear end of the auxiliary oil cylinder 6, exits from the front end of the auxiliary oil cylinder 6, and connects to the copper mold 21 of the electrode assembly. The movement direction of the water-cooled cable 7 within the hollow through hole is consistent with the movement direction of the pressurizing component 1, and its movement trajectory is confined within the hollow through hole, preventing it from tangling or colliding with other components of the vacuum system.

[0027] The hollow through-hole is filled with a high-temperature resistant filler that tightly wraps around the water-cooled cable 7. In this embodiment, the high-temperature resistant filler is an inorganic high-temperature ceramic adhesive. The high-temperature resistant filler fills the annular space between the inner wall of the hollow through-hole and the water-cooled cable 7, serving three functions: first, effectively isolating the high temperature of the sintering region from the water-cooled cable 7; second, enhancing the sealing of the hollow through-hole to prevent vacuum leakage; and third, fixing the water-cooled cable 7 to prevent vibration or wear during the movement of the auxiliary oil cylinder 6.

[0028] Vacuum assembly 4 includes a vacuum cover 41 and a vacuum pump 42. The vacuum cover 41 is positioned over the outside of the mold 3 and the end of the pressurizing assembly 1 closest to the mold 3. The vacuum pump 42 is connected to the vacuum cover 41 via a vacuum pipeline. Since the water-cooled cable 7 is not connected from the side of the vacuum cover 41, but rather passes through the hollow through-hole of the auxiliary oil cylinder 6, the sealing structure of the vacuum cover 41 is simplified, and the sealing reliability is significantly improved.

[0029] like Figure 3 and Figure 4 As shown ( Figure 4 for Figure 3(Cross-sectional view along A-A' direction) The copper mold 21 has a hollow annular structure and is provided with a cooling medium inlet / outlet 212, forming an annular cooling cavity 211 inside. The copper mold 21 is fitted onto the pressurizing assembly 1, so that the outer surfaces of the first pressure head 11 and the second pressure head 12 are in electrical contact with the inner wall of the copper mold 21, and move together with the pressurizing assembly 1. In this embodiment, the copper mold 21 is made of copper with a conductivity of not less than 98% IACS. During operation, the pressure applied by the pressurizing assembly 1 is directly transmitted to both ends of the mold 3 through the first pressure head 11 and the second pressure head 12. The pulse current of the electrode assembly is conducted through the copper mold 21, through the outer surfaces of the first pressure head 11 and the second pressure head 12 to the pressurizing assembly 1, and then through the pressurizing assembly 1 to the mold 3. The pressurizing function is directly applied to the mold 3 by the end faces of the first pressure head 11 and the second pressure head 12, and the conductive function is undertaken by the lateral contact surface between the copper mold 21 and the pressurizing assembly 1. Since the copper mold 21 no longer bears the high pressure of the pressure component 1, it will not undergo soft deformation even in high-temperature environments above 200°C.

[0030] In this preferred embodiment, the inner wall of the copper mold 21 is an inclined surface relative to the direction of movement of the pressure assembly 1, and the contour of the pressure assembly 1 matches the inner wall of the copper mold 21. Specifically, the inner wall of the copper mold 21 is a conical surface with a taper angle of 5°~15° (i.e., the angle between the generatrix of the inner wall and the axis of the first pressure head 11 or the second pressure head 12). The outer surfaces of the first pressure head 11 and the second pressure head 12 that contact the inner wall of the copper mold 21 are matching conical surfaces. The conical surface fit has a self-centering effect, ensuring the coaxiality of the copper mold 21 and the pressure assembly 1, while increasing the contact area and reducing the contact resistance.

[0031] like Figure 5 As shown, the copper mold 21 has a hollow interior forming an annular cooling cavity 211. The water-cooled cable 7 includes an inlet pipe and an outlet pipe, both of which are connected to the annular cooling cavity 211. Cooling medium (such as cooling water) enters the annular cooling cavity 211 from the cooling medium tank 51 through the inlet pipe, flows through the annular cooling cavity 211, and then flows out through the outlet pipe back to the cooling medium tank 51, carrying away the Joule heat generated by the copper mold 21 during conduction. The water-cooled cable 7 is fixedly connected to the copper mold 21 through a connection hole 213 provided on the copper mold 21.

[0032] like Figure 6 As shown, mold 3 includes a matching female mold 31 and a male mold 32. The female mold 31 includes a high-temperature resistant outer shell and a graphite core 312 enclosed within the high-temperature resistant outer shell. The graphite core 312 has a cylindrical structure with a cavity 313 formed inside to accommodate the raw material powder. The graphite core 312 utilizes graphite's excellent electrical conductivity, high-temperature strength, thermal conductivity, and thermal shock resistance to withstand the main thermal field and directly contact the sintered sample. The high-temperature resistant outer shell provides the main mechanical strength and withstands the high pressing pressure applied by the pressurizing assembly 1.

[0033] In this embodiment, the high-temperature resistant outer shell includes a cylindrical high-temperature resistant insulation layer 3111 and a steel mold sleeve 3112 fitted over the high-temperature resistant insulation layer 3111. The high-temperature resistant insulation layer 3111 is made of high-temperature cement or refractory furnace charge, and its temperature resistance rating is not lower than 1800℃. The steel mold sleeve 3112 is a high-strength alloy steel sleeve.

[0034] Example 2: This embodiment provides a spark plasma sintering method for manufacturing large-size products, using the spark plasma sintering apparatus of Embodiment 1, and specifically includes the following steps: S1. The raw material powder (a mixture of SiC powder and 6092 aluminum alloy powder, with a total weight of 14.2 kg and a SiC powder content of 15 wt%) is filled into a mold 3 with a diameter of 155 mm. The powder is compacted by applying a pre-pressure of 2 MPa through auxiliary equipment and then transferred to this equipment.

[0035] S2. A pulsed current is supplied to the mold 3 through the electrode assembly, and pressure is applied through the pressurizing assembly 1 to heat and sinter the raw material powder. The heating and sintering process is as follows: Figure 7 As shown, it is divided into four stages: preheating stage, heating stage, heat preservation and pressurization stage, and cooling stage. Among them: During the preheating stage, a constant pressure of 3 MPa and a constant voltage of 6 V are applied, raising the temperature of mold 3 to 200°C at a heating rate of 4°C / min. After power is applied, the power increases rapidly, while the temperature rises slowly. Due to the expansion of the powder during heating, the pressure increases. During the heating stage, the constant pressure is maintained, and the temperature inside mold 3 is raised to 600°C at a heating rate of 40°C / min. As the power-on time increases, the sintering power also increases rapidly, and the ambient temperature of the sintering space rises, leading to a rapid heating state for the material. As the temperature rises, the material enters a softening stage, and the pressure gradually decreases. During this stage, it is only necessary to maintain the pressing pressure at 3 MPa. In the heat preservation and pressure increase stage, the control of power supply 23 is switched to constant current mode. Maintaining a constant temperature, the pressure is increased to 17.5 MPa at a pressure increase rate of 7 MPa / min, promoting metallurgical bonding in the material, reducing the voids between powder particles, and ultimately achieving complete sintering. During the cooling stage, the pulse current is stopped, the pressure is kept constant to ensure the densification of the material, the cooling water rate is reduced, and the material is slowly cooled to 300°C to obtain the final product.

[0036] Throughout the sintering process, the cooling components work continuously, delivering cooling medium to the copper mold 21 and the pressurizing components 1 through the hollow through-hole of the auxiliary oil cylinder 6, ensuring that the temperature of each component does not exceed the safe threshold.

[0037] Final product such as Figure 8As shown, the product dimensions are 154.8mm in diameter and 275.8mm in length.

[0038] The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A discharge plasma sintering apparatus for manufacturing large-size products, comprising a pressurizing assembly (1), an electrode assembly, a mold (3), a vacuum assembly (4) for controlling the vacuum level in the area surrounding the mold (3), and a cooling assembly for cooling the pressurizing assembly (1) and / or the electrode assembly; the pressurizing assembly (1) includes a first pressure head (11) and a second pressure head (12), the mold (3) being disposed between the first pressure head (11) and the second pressure head (12); the electrode assembly abuts against the pressurizing assembly (1) and provides a pulsed current to the pressurizing assembly (1); characterized in that, It also includes an auxiliary oil cylinder (6), the axis of which is the same as the movement direction of the pressurizing component (1). The auxiliary oil cylinder (6) has a hollow through hole inside, the direction of which is the same as the movement direction of the pressurizing component (1). The auxiliary oil cylinder (6) moves together with the pressurizing component (1). The cooling pipe of the cooling component passes through the hollow through hole of the auxiliary oil cylinder (6) to cool the electrode component. The electrode assembly includes a copper mold (21) with a ring-shaped structure. The copper mold (21) is fitted onto the pressure assembly (1) so that the outer surfaces of the first pressure head (11) and the second pressure head (12) are in electrical contact with the inner wall of the copper mold (21). The inner wall of the copper mold (21) is an inclined surface that is tilted relative to the direction of movement of the pressure assembly (1). The outline of the pressure assembly (1) matches the inner wall of the copper mold (21). The discharge plasma sintering device has a horizontal structure, and the pressurization component (1), electrode component, mold (3), cooling component and vacuum component (4) are arranged in the horizontal direction.

2. The discharge plasma sintering apparatus for manufacturing large-size products according to claim 1, characterized in that, The hollow through-hole is filled with high-temperature resistant filler, which tightly wraps the cooling pipes of the cooling component.

3. The discharge plasma sintering apparatus for manufacturing large-size products according to claim 1, characterized in that, The pressurizing component (1) and the auxiliary oil cylinder (6) have a stroke greater than 1m when they are working.

4. The discharge plasma sintering apparatus for manufacturing large-size products according to claim 1, characterized in that, The copper mold (21) is hollow inside, and the cooling pipe of the cooling component is connected to the copper mold (21) and delivers the cooling medium into the copper mold (21).

5. The discharge plasma sintering apparatus for manufacturing large-size products according to claim 1, characterized in that, The copper mold (21) is made of copper.

6. The discharge plasma sintering apparatus for manufacturing large-size products according to any one of claims 1-3, characterized in that, The electrode assembly also includes a power supply (23) for supplying power to the electrode assembly. The power supply (23) is electrically connected to the electrode assembly via a cable. The cable is connected to the cooling pipe in the form of a water-cooled cable (7) to the electrode assembly, the cooling assembly, and the power supply (23).

7. The discharge plasma sintering apparatus for manufacturing large-size products according to any one of claims 1-3, characterized in that, The mold (3) includes a matching male mold (32) and a female mold (31), the female mold (31) including a high-temperature resistant shell and a graphite core (312) enclosed in the high-temperature resistant shell.

8. The discharge plasma sintering apparatus for manufacturing large-size products according to claim 7, characterized in that, The high-temperature resistant outer shell includes a cylindrical high-temperature resistant insulation layer (3111) and a steel mold sleeve (3112) fitted over the high-temperature resistant insulation layer (3111).

9. A spark plasma sintering method for manufacturing large-size products, characterized in that, The process is carried out using the spark plasma sintering apparatus for manufacturing large-size products as described in any one of claims 1-8; and includes the following steps: S1. The raw material powder is filled into the mold (3), and the mold (3) is pressed by the pressure component (1) to form a blank; or the raw material powder is pre-compacted to form a blank and then filled into the mold (3); S2. Pulse current is passed through the electrode assembly to heat the mold (3), and pressure is applied at the same time to heat and sinter the raw material powder to obtain the final product.

10. The spark plasma sintering method for manufacturing large-size products according to claim 9, characterized in that, In S2, the heating and sintering process is divided into four stages: preheating stage, heating stage, heat preservation and pressure increase stage, and pressure preservation and cooling stage.

Images