A method and apparatus for sintering of metal-based powder activated by magnetic pulse induced electric field

Abstract

The application provides a metal-based powder sintering method and device activated by magnetic pulse induced electric field, and belongs to the technical field of powder metallurgy. The device comprises a mold, an electromagnetic drive assembly and a current heating assembly arranged coaxially. The first and second pressure heads are coaxially arranged in the mold, and the metal-based powder is placed between the first and second pressure heads. The current heating assembly is arranged around the metal-based powder and is used for applying a direct current electric field to the metal-based powder. The electromagnetic drive assembly is arranged on the side of the first pressure head away from the metal-based powder and is used for driving the first pressure head to move towards the second pressure head to press the metal-based powder at a high speed, and the current heating assembly is used for inducing pulse discharge between the metal-based powder particles under the direct current electric field. The metal-based powder sintering method and device provided by the application have the two advantages of magnetic pulse high-speed pressing and electric field activation, and have the comprehensive characteristics of high speed, high pressure, electric field activation, uniform density, high performance and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of powder metallurgy, in particular to a metal-based powder sintering method and device induced by magnetic pulse and electric field activation. BACKGROUND

[0002] With the rapid development of micro-electro-mechanical systems towards miniaturization, integration and intelligentization, higher requirements are put forward for the manufacturing of high-performance micro parts. Powder metallurgy has the advantages of high material utilization, simple process and high forming precision, and is widely used in the manufacturing of micro parts. The use of force, heat, electricity, magnetism and other multi-energy fields can realize the precise forming and manufacturing of micro-electro-mechanical high-performance parts by the super-normal action of densification and organization performance control of powder materials.

[0003] Electric field activated sintering is a method that uses an electric field formed by an external pulse current to clean the surface impurities of metal-based powder particles, improves the diffusion capacity of the surface of metal-based powder, and then uses strong current to heat the metal powder for a short time under low pressure. This method has the advantages of surface cleaning and activation of powder particles, but the electric field activated sintering process needs to discharge pulse current and strong current alternately, and the applied pressure is low, which limits the improvement of sintering rate and density.

[0004] Magnetic pulse pressing sintering under heating conditions is a metal-based powder compaction sintering method developed on the basis of magnetic pulse compaction, which combines the effects of temperature field and magnetic pulse pressure on metal-based powder, improves the plasticity of metal-based powder particles, and makes metal-based powder particles achieve close combination. This method has the advantages of fast speed and high pressure, but it lacks the activation effect of metal-based powder, and the powder heating is achieved by heat conduction inward of the mold, which is easy to cause uneven heating, slow heating speed and density gradient defects of sintered parts. Therefore, it is of great significance to develop a sintering method that combines electric field activation and magnetic pulse pressing sintering to solve the above problems. SUMMARY

[0005] In view of the technical problems in the background art, the present application provides a metal-based powder sintering method and device induced by magnetic pulse and electric field activation, which aims to solve the technical problem of poor sintering effect of metal powder particles in the existing electric field activated sintering and magnetic pulse pressing sintering methods.

[0006] To solve the above technical problems, the first solution provided by the present application is a metal-based powder sintering device induced by magnetic pulse and electric field activation, comprising: a mold, an electromagnetic driving assembly and a current heating assembly arranged coaxially.

[0007] The mold has a hollow inner cavity, and a first pressing head and a second pressing head are coaxially arranged in the inner cavity, and the metal-based powder is placed between the first pressing head and the second pressing head.

[0008] The current heating assembly is arranged around the metal-based powder and is used for applying a direct current field to the metal-based powder;

[0009] The electromagnetic driving assembly is arranged on the side of the first pressing head away from the metal-based powder and is used for driving the first pressing head to move towards the second pressing head to press the metal-based powder at a high speed and induce the pulse discharge between the metal-based powder particles under the direct current field in cooperation with the current heating assembly.

[0010] In the present application, the pulse discharge induced in situ between the metal-based powder particles is self-adjusted and self-adapted according to the impact and friction of the particles, the discharge is weak in the areas with high density and weak impact and friction, and the discharge is strong in the areas with low density and strong impact and friction, so that the overall density is more uniform; the electromagnetic driving assembly and the current heating assembly can well meet the time synchronization of high-speed pressing and high-speed discharging.

[0011] Preferably, the mold further comprises a base, a guide sleeve and a protection cylinder arranged coaxially; the base is arranged around the second pressing head and detachably connected with the second pressing head; the guide sleeve is embedded in the protection cylinder on one side and detachably connected with the base on the other side.

[0012] The current heating assembly comprises an electrode, an electrode sheet and a direct current circuit; the electrode is in contact with the metal-based powder around, the electrode is vertically connected with the electrode sheet, and the electrode sheet is electrically connected with the direct current circuit, which is used for providing a direct current field for the metal-based powder.

[0013] Preferably, the base comprises a base plate and two bosses, the base plate is vertically connected with the bosses on the side close to the guide sleeve, the base plate is provided with a through hole for accommodating the second pressing head, and the two bosses are alternately arranged around the electrode and cooperatively form the side wall of the accommodating cavity of the metal-based powder.

[0014] In the embodiment of the present application, the electrode sheet is provided with an arc-shaped opening, the electrodes are stacked on the arc-shaped opening of the electrode sheet, are placed in pairs on the base plate of the base, and cooperatively form the side wall of the accommodating cavity of the metal-based powder with the two bosses of the base; the electrode sheet is further provided with a round hole, and the electrode sheet is connected with the direct current circuit through the round hole.

[0015] In the embodiment of the present application, the base is in the shape of a circular ring, and the second pressing head is in the shape of a cylinder and is installed in the through hole of the base in an interference fit.

[0016] Preferably, the guide sleeve is provided with a coaxial first cavity and a second cavity inside along the direction from the first pressing head to the second pressing head; the first cavity is slidably connected with the end of the first pressing head away from the electromagnetic driving assembly and is used for controlling the axial movement of the first pressing head along the guide sleeve; the second cavity is provided with the electrode and the metal-based powder inside, and the inner diameter of the second cavity is greater than the inner diameter of the first cavity.

[0017] Preferably, the end face of the guide sleeve close to the base side is further provided with an electrode sheet accommodating groove for fixing the electrode sheet.

[0018] In the embodiment of the present application, the guide sleeve is further provided with a threaded hole, the base substrate is provided with a screw mounting hole, the threaded hole corresponds to the screw mounting hole, and the guide sleeve and the base are detachably connected through the screw.

[0019] Preferably, the protection cylinder is internally provided with a coaxial third cavity, a fourth cavity and a fifth cavity along the direction from the first pressing head to the second pressing head; the electromagnetic driving assembly is fixedly installed in the third cavity, the fourth cavity is in sliding connection with the first pressing head close to one end of the electromagnetic driving assembly, and the fifth cavity is in nesting connection with the guide sleeve away from the base side.

[0020] The inner diameter of the fourth cavity is smaller than the inner diameter of the third cavity and the inner diameter of the fifth cavity.

[0021] Preferably, the electromagnetic driving assembly comprises a discharge circuit, a coil, a magnetic concentrator, an insulating sheet and a driving plate which are coaxially arranged in sequence along the direction from the first pressing head to the second pressing head; the coil, the magnetic concentrator and the insulating sheet are packaged in the protection cylinder through an insulating material.

[0022] The coil is spirally coaxially wrapped outside the magnetic concentrator, the discharge circuit is electrically connected with the coil, the discharge circuit discharges the coil, the coil generates an induced current in the magnetic concentrator, an electromagnetic force generated by the induced current acts on the driving plate, and the driving plate is used for driving the first pressing head to perform high-speed pressing on the metal-based powder.

[0023] In the embodiment of the present application, two parallel grooves are arranged along the tangential direction of the third cavity of the protection cylinder for accommodating the coil.

[0024] Preferably, the magnetic concentrator is a cylindrical structure with a slit on the side face, and is internally provided with a coaxial first inner hole and a second inner hole along the direction from the first pressing head to the second pressing head; the first inner hole is in the shape of a horn, the second inner hole is in the shape of a cylinder, the diameter of the first inner hole is larger than the diameter of the second inner hole; and the magnetic concentrator is used for concentrating the magnetic field.

[0025] Preferably, the first pressing head is a three-section rotary body, and comprises a disc body, a circular truncated cone and a cylinder which are fixedly connected in sequence along the direction from the first pressing head to the second pressing head; the diameter of the disc body is larger than the diameter of the cylinder; and the first pressing head is used for transmitting the concentrated electromagnetic force in sections.

[0026] To solve the above technical problems, the second solution provided by the present application is a metal-based powder sintering method using the above-mentioned magnetic pulse induced electric field activated metal-based powder sintering device, which comprises the following steps:

[0027] The metal-based powder to be sintered is placed in the mold, and the metal-based powder is located between the first pressing head and the second pressing head.

[0028] The current heating assembly passes direct current to the metal-based powder, and the electromagnetic driving assembly is energized to drive the first pressing head to move towards the second pressing head, so that the metal-based powder is pressed at high speed, and the electric field activation sintering of the metal-based powder is completed by magnetic pulse induction.

[0029] In the present application, the direct current density in the current heating assembly is 3000-30000A, and the discharge voltage in the electromagnetic driving assembly is 2000-4000V, and the specific parameters can be determined according to the composition and state of the metal-based powder.

[0030] The principle of the technical scheme of the present application is that the present application fully utilizes the superimposed effects of the three of direct current electric field, magnetic pulse high-speed pressing, high-speed impact and friction-induced pulse discharge between powder particles. Under the condition of a single direct current electric field, a capacitor is formed between the metal-based powder particles, and the capacity of the capacitor is changed by driving the metal-based powder to collide and rub at high speed through the magnetic pulse, so that pulse discharge is induced between the metal-based powder particles, thereby realizing the electric field activation effect of the metal-based powder particles.

[0031] The reason why the present application selects a direct current electric field is that the direct current electric field has the advantages of uniform heating and constant current direction, which can prevent sintering defects such as excessively large crystal grains. The pulse discharge induced in situ between the metal-based powder particles has the advantages of self-adjustment and self-adaptation according to the impact and friction conditions, so that the impact and friction are not very serious in the places with high density, and the discharge is weak; the discharge is strong in the places with low density; and thus the overall density is more uniform. The high-speed induced pulse can well meet the time synchronization of high-speed pressing and high-speed discharge.

[0032] Compared with the prior art, the present application has the following beneficial effects:

[0033] The application provides a metal-based powder sintering method and device induced by magnetic pulse electric field, and the metal-based powder can be rapidly and uniformly sintered through the cooperation of the mold, the electromagnetic drive assembly and the current heating assembly. Under the condition of a single direct current electric field, the gap between the metal-based powder particles forms a capacitor, the high-speed collision and friction of the metal-based powder is driven by the magnetic pulse, the capacity formed by the metal-based powder is changed, the pulse discharge between the metal-based powder particles is induced, and thus the surface cleaning and activation of the metal-based powder particles are realized. The metal-based powder sintering method and device have the advantages of high speed, high pressure, electric field activation, uniform density, high performance and the like, and the two advantages of high-speed magnetic pulse pressing and electric field activation effect. Compared with the electric field activation sintering, the circuit control is simplified without multiple charging and discharging. Compared with the magnetic pulse pressing under the heating condition, the electric field activation effect of the metal-based powder is increased on the basis of high pressing forming speed and high pressure, the temperature distribution is more uniform, and the heating speed is faster. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 It is a schematic diagram of an embodiment of the metal-based powder magnetic pulse induced electric field activation sintering device in the application.

[0035] Figure 2 It is a partial exploded view of an embodiment of the metal-based powder magnetic pulse induced electric field activation sintering device in the application.

[0036] Figure 3 It is a macroscopic comparison diagram of the sintered samples of example 1 and comparative example 1 in the application.

[0037] Figure 4 It is a Vickers hardness comparison diagram of the sintered samples of example 1 and comparative example 1 in the application.

[0038] The figure mark explanation: 1-mold, 2-electromagnetic drive assembly, 3-current heating assembly, 4-metal-based powder, 5-protection cylinder, 51-groove, 52-third cavity, 53-fourth cavity, 54-fifth cavity, 6-first pressure head, 61-disc body, 62-circular truncated cone, 63-cylinder, 7-guide sleeve, 71-thread hole, 72-electrode piece displacement slot, 73-first cavity, 74-second cavity, 8-second pressure head, 9-base, 91-base plate, 92-convex, 93-screw mounting hole, 94-through hole, 10-coil, 11-magnetic collector, 111-slit, 112-first inner hole, 113-second inner hole, 12-insulating sheet, 13-driving plate, 14-discharge circuit, 15-electrode piece, 151-arc-shaped opening, 152-round hole, 16-electrode, 17-direct current circuit. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of the present application.

[0040] Embodiment 1

[0041] Please refer to Figure 1 and Figure 2 The present embodiment provides a kind of metal-based powder sintering device of magnetic pulse induced electric field activation, comprising: coaxial setting mould 1, electromagnetic drive component 2 and current heating component 3.

[0042] In the present embodiment, the mould has hollow inner cavity, and first ram 6 and second ram 8 are coaxially arranged in the inner cavity thereof, and metal-based powder 4 is placed between the first ram 6 and the second ram 8;Current heating component 3 is arranged at the lower part of mould 1 around metal-based powder, and the current heating component is used to apply direct current field to metal-based powder 4;

[0043] Electromagnetic drive component 2 is arranged at the upper part of mould 1, for driving first ram 6 to move to the direction of second ram 8 to high-speed press metal-based powder 4, and cooperate with current heating component 3 to induce pulse discharge between metal-based powder 4 particles under direct current field, so as to realize electric field activation sintering of metal-based powder 4 particles.

[0044] The pulse discharge induced in situ between metal-based powder 4 particles itself can be self-adjusted and self-adapted according to the impact and friction of itself, the impact and friction are not very serious in the place with very high density, the discharge is weak, the discharge is strong in the place with low density, so that the overall density is more uniform;Electromagnetic drive component 2 and current heating component 3 can well meet the time synchronization of high-speed pressing and high-speed discharging.

[0045] The specific structure of each component of the metal-based powder sintering device of magnetic pulse induced electric field activation and the positional relationship between them will be described in detail below.

[0046] Mould 1 includes first ram 6, second ram 8, base 9, guide sleeve 7 and protection cylinder 5;First ram 6 and second ram 8 are arranged from top to bottom, and metal-based powder 4 is placed between first ram 6 and second ram 8;Electromagnetic drive component 2 includes coil 10, magnet collector 11, insulating plate 12, drive plate 13 and discharge circuit 14;Current heating component 3 includes electrode sheet 15, electrode 16 and direct current circuit 17.

[0047] The first pressing head 6 is a three-section rotary body, the upper section is a disc body 61, the middle section is a circular truncated cone 62, and the lower section is a cylindrical body 63; the diameter of the disc body 61 of the upper section of the first pressing head is larger than the diameter of the cylindrical body 63 of the lower section; the driving plate 13 is attached to the upper end of the first pressing head 6; the electromagnetic force received by the driving plate 13 is transmitted and concentrated through the upper section of the first pressing head 6 in sections, which greatly improves the energy utilization rate of the metal-based powder 4 in the magnetic pulse pressing activation process.

[0048] The base 9 is a circular ring and has a flat base plate 91 with a through hole 94 in the center; the second pressing head 8 is a cylindrical body and is installed in the through hole 94 of the base 9 in an interference fit; the base plate 91 is vertically provided with two bosses 92 which cooperate with the second cavity 74 of the guide sleeve 7 to limit the electrode 16; the periphery is uniformly provided with four screw mounting holes 93 which correspond to the threaded holes 71 on the guide sleeve 7; the base 9 and the guide sleeve 7 are detachably connected by screws.

[0049] The guide sleeve 7 is a cylindrical body with two stepped cavities, and is internally provided with a first cavity 73 and a second cavity 74 which are through from top to bottom; the inner diameter of the second cavity 74 is larger than that of the first cavity 73; the periphery of the guide sleeve 7 is uniformly provided with four threaded holes 71 which correspond to the screw mounting holes 93 of the base 9; the guide sleeve 7 and the base 9 are detachably connected by screws; the bottom surface of the guide sleeve 7 is provided with an electrode sheet accommodation groove 72 for fixing the electrode sheet 15; the first cavity 73 of the guide sleeve 7 is in sliding connection with the cylindrical body 63 of the lower section of the first pressing head 6, which ensures the axial movement of the first pressing head along the guide sleeve 7; the second cavity 74 of the guide sleeve 7 cooperates with the two bosses 92 of the base 9 to limit the electrode 16; the second cavity 74 contains the electrode and the metal-based powder.

[0050] The protective cylinder 5 is a cylindrical body with three stepped cavities, and is internally provided with a third cavity 52, a fourth cavity 53 and a fifth cavity 54 which are coaxially through from top to bottom; the third cavity 52 of the protective cylinder provides installation and fixation for the electromagnetic driving assembly 2; two parallel grooves 51 are provided along the tangential direction of the third cavity 52 to accommodate the coil 10; the magnetic collector 11, the insulating sheet 12 and the coil 10 are encapsulated in the third cavity 52 of the protective cylinder 5 by an insulating material; the fourth cavity 53 of the protective cylinder provides a space for the first pressing head 6; the fifth cavity 54 of the protective cylinder is nested with the upper end of the guide sleeve 7.

[0051] The current heating assembly 3 includes the electrode 16, the electrode sheet 15 and a direct current circuit 17; the electrode 16 is in contact with the metal-based powder 4; the electrode 16 is stacked on the arc-shaped opening 151 of the electrode sheet 15, and is placed in pairs on the base 9 and cooperates with the two bosses 92 of the base 9 to form the side wall of the containing cavity of the metal-based powder 4; the electrode sheet 15 is connected to the direct current circuit 17 through the round hole 152; the current heating assembly 3 is used to apply a direct current field to the metal-based powder 4; the current is amplified at the electrode 16 after flowing through the electrode sheet 15, and directly passes through the metal-based powder 4.

[0052] The electromagnetic drive assembly 2 includes a discharge circuit 14 and a coil 10, a magnet collector 11, an insulating sheet 12, and a drive plate 13 arranged coaxially. The insulating sheet 12 is disposed at the bottom of the magnet collector 11. The coil 10 is spirally wrapped around the outside of the magnet collector 11. The coil 10 is connected to the discharge circuit 14. The discharge circuit 14 discharges to the coil 10, and the coil 10 generates an induced current in the magnet collector 11. The magnet collector 11 is a cylindrical structure with a slit 111 on the side. It has a first inner hole 112 and a second inner hole 113 that run from top to bottom. The first inner hole 112 is trumpet-shaped and the second inner hole 113 is cylindrical. The bottom diameter of the first inner hole 112 is larger than the diameter of the second inner hole 113. When the coil 10 is discharged through the discharge circuit 14, the induced current in the coil 10 in the magnet collector 11 is mainly concentrated on the surface area of ​​the magnet collector 11. Under the action of the slit 111, the induced current flows to the inner wall of the magnet collector 11, thereby forming a loop to realize the current convergence to the first inner hole 112 on the inner wall of the magnet collector 11. This concentrates the magnetic field at the end of the inner wall of the magnet collector 11, so that the drive plate 13 obtains a greater electromagnetic force. The drive plate 13 is located below the insulating sheet and is close to the upper end of the first pressure head 6. It is used to drive the first pressure head 6 to press the metal base powder 4 at high speed.

[0053] This embodiment also provides a method for sintering metal-based powder activated by a magnetic pulse-induced electric field, including the following steps:

[0054] Step S1: Insert the second pressure head 8 into the through hole 94 in the center of the base 9; place the electrode plate 15 into the electrode plate recess 72, and place the electrode 16 symmetrically on the electrode plate 15 corresponding to the two protrusions 92 of the base 9; use four screws to fix the guide sleeve 7 to the base 9 through the screw mounting hole 93 and the threaded hole 71; place the metal base powder 4 above the second pressure head 8; after inserting the first pressure head 6 from the first cavity 73 of the guide sleeve 7, attach the drive plate 13 above the first pressure head 6; place the insulating sheet 12 into the third cavity 52 of the protective cylinder 5; surround the magnet collector 11 with a spiral coil 10, place it into the third cavity 52 of the protective cylinder 5, and encapsulate it with insulating material; embed the protective cylinder 5 into the guide sleeve 7; connect the discharge circuit 14 to the coil 10 and the DC circuit 17 to the electrode plate 15;

[0055] Step S2: the direct current circuit 17 discharges the electrode sheet 15, and the direct current flows through the electrode 16 to the metal-based powder 4; the discharge circuit 14 discharges the coil 10 to generate an electromagnetic force, and the driving plate 13 is driven by the electromagnetic force to drive the first pressing head 6 to move downward to high-speed press the metal-based powder 4; under the condition of the single direct current electric field, the gap between the metal-based powder 4 particles forms a capacitor, the magnetic pulse generated by the electromagnetic driving assembly 2 drives the metal-based powder 4 to collide and rub at high speed, and the capacity formed by the metal-based powder 4 also changes, which induces the pulse discharge between the metal-based powder 4 particles, so as to realize the electric field activated sintering of the metal-based powder 4 particles;

[0056] Step S3: the direct current circuit 14 and the direct current circuit 17 are disconnected, the protection cylinder 5 is opened, and the first pressing head 6 is taken out, and the second pressing head 8 is knocked from the bottom of the mold 1 to eject the sintered product.

[0057] In the embodiment, 5.32 g of silver-based powder is used as the metal-based powder to be sintered, and the sintering conditions are as follows: the direct current in the current heating assembly is 22000 A; and the voltage of the discharge circuit in the electromagnetic driving assembly is 3500 V. The density of the sintered sample is measured to be 10.52 g / cm 3 .

[0058] Comparative Example 1

[0059] The silver-based powder 5.32 g is sintered by using the electric field activated sintering, the pressing force used is 350 MPa, the pulse current is 22000 A, and the pulse interval is 10 ms. The density of the sintered sample is measured to be 9.48 g / cm 3 , Figure 3 The macroscopic comparison diagram of the sintered samples in the embodiment and comparative example 1 is shown, and the Vickers hardness of five equidistant points on the upper surface along the diameter is measured, Figure 4 The Vickers hardness comparison diagram of the embodiment and comparative example 1 is shown.

[0060] The results of the embodiment 1 and comparative example 1 show that the Vickers hardness of the sintered sample in the embodiment is more uniform and higher than that in comparative example 1. Generally, the hardness is proportional to the relative density, and the test results show that the uniformity of the density of the embodiment 1 is better than that of comparative example 1.

[0061] The direct current electric field used in the sintering method of the metal-based powder activated by the magnetic pulse induced electric field has the advantages of uniform heating and constant current direction, the in-situ induced pulse discharge between the metal-based powder particles has the advantages of self-adjustment and self-adaption according to the impact and friction, the impact and friction are not very serious in the place with high density, the discharge is weak, the discharge is strong in the place with low density, so that the overall density is more uniform, and the high-speed induced pulse can meet the time synchronization of high-speed pressing and high-speed discharge.

[0062] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and embodiments having the same technical idea and substantially the same function and effect within the scope of the technical solution of the present application are included in the technical scope of the present application. In addition, within the scope of the main idea of the present application, various modifications that can be thought of by those skilled in the art are applied to the embodiments, and other ways constructed by combining part of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A magnetic pulse induced electric field activated metal matrix powder sintering apparatus, characterized by, The application relates to a coaxial mold, an electromagnetic driving assembly and a current heating assembly. The mold has a hollow inner cavity, and a first pressing head and a second pressing head are coaxially arranged in the inner cavity; the metal-based powder is arranged between the first pressing head and the second pressing head. The current heating assembly is arranged around the metal-based powder and is used for applying a direct-current electric field to the metal-based powder. The electromagnetic driving assembly is arranged on the side of the first pressing head far from the metal-based powder and is used for driving the first pressing head to move towards the second pressing head to press the metal-based powder at a high speed and cooperate with the current heating assembly to induce pulse discharge between metal-based powder particles under the direct-current electric field. The current heating assembly comprises an electrode, an electrode sheet and a direct-current circuit; the electrode is in contact with the metal-based powder, the electrode is vertically connected with the electrode sheet, and the electrode sheet is electrically connected with the direct-current circuit and is used for providing a direct-current electric field to the metal-based powder. The mold further comprises a base, a guide sleeve and a protection cylinder which are coaxially arranged; the base is arranged around the second pressing head and is detachably connected with the second pressing head; one side of the guide sleeve is embedded in the protection cylinder, and the other side of the guide sleeve is detachably connected with the base.

2. A magnetic pulse induced electric field activated metal-based powder sintering device according to claim 1, characterized in that, The base comprises a base plate and two convex blocks; the base plate is vertically connected with the convex blocks on the side close to the guide sleeve; the base plate is provided with a through hole for accommodating the second pressing head; and the two convex blocks are alternately arranged around the electrode and cooperate to form a side wall of a containing cavity of the metal-based powder.

3. A magnetic pulse induced electric field activated metal-based powder sintering device according to claim 2, characterized in that, The guide sleeve is internally provided with coaxial first and second cavities along the direction from the first pressing head to the second pressing head; the first cavity is slidably connected with the end of the first pressing head far from the electromagnetic driving assembly and is used for controlling the axial movement of the first pressing head along the guide sleeve; and the second cavity is internally provided with the electrode and the metal-based powder, and the inner diameter of the second cavity is larger than that of the first cavity.

4. A magnetic pulse induced electric field activated metal-based powder sintering device according to claim 2, characterized in that, The end face of the guide sleeve on the side close to the base is further provided with an electrode sheet accommodation groove for fixing the electrode sheet.

5. A magnetic pulse induced electric field activated metal-based powder sintering device according to claim 4, characterized in that, The protection cylinder is internally provided with coaxial third, fourth and fifth cavities along the direction from the first pressing head to the second pressing head; the electromagnetic driving assembly is fixedly installed in the third cavity; the fourth cavity is slidably connected with the end of the first pressing head close to the electromagnetic driving assembly; and the fifth cavity is nestedly connected with the guide sleeve on the side far from the base.

6. A magnetic pulse induced electric field activated metal-based powder sintering device according to claim 2, characterized in that, The inner diameter of the fourth cavity is smaller than that of the third cavity and that of the fifth cavity. The electromagnetic driving assembly comprises a discharge circuit, a coil, a magnetic concentrator, an insulating sheet and a driving plate which are coaxially arranged in sequence along the direction from the first pressing head to the second pressing head; the coil, the magnetic concentrator and the insulating sheet are packaged in the protection cylinder through an insulating material; 7. A magnetic pulse induced electric field activated metal-based powder sintering device as claimed in claim 2, wherein, The coil is coaxially arranged around the outer side of the magnetic concentrator in a spiral shape; the discharge circuit is electrically connected with the coil; the discharge circuit discharges the coil; the coil generates an induced current in the magnetic concentrator; an electromagnetic force generated by the induced current acts on the driving plate; and the driving plate is used for driving the first pressing head to press the metal-based powder. ​ 8. A magnetic pulse induced electric field activated metal-based powder sintering device according to claim 7, characterized in that, The magnetic collector is a cylindrical structure with slits on the side, and coaxial through holes are arranged in the first pressure head to the second pressure head direction, the first inner hole is a horn shape, and the second inner hole is a cylinder, and the diameter of the first inner hole is larger than the diameter of the second inner hole.

9. A magnetic pulse induced electric field activated metal-based powder sintering device as claimed in claim 2, wherein, The first pressure head is a three-section rotating body, including a disc body, a circular truncated cone and a cylinder which are fixedly connected in sequence along the first pressure head to the second pressure head direction; the diameter of the disc body is larger than the diameter of the cylinder.

10. A method of sintering a metal-based powder activated by an electric field induced by a magnetic pulse using the sintering apparatus for a metal-based powder activated by an electric field induced by a magnetic pulse according to any one of claims 1 to 9, characterized in that, The method comprises the following steps: Placing the metal-based powder to be sintered in the mold, the metal-based powder is located between the first pressure head and the second pressure head; The current heating assembly passes direct current to the metal-based powder, at the same time, the electromagnetic drive assembly is energized to drive the first pressure head to move to the second pressure head, and the metal-based powder is pressed at high speed, and the electric field activation sintering of the metal-based powder induced by the magnetic pulse is completed.

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