Extrusion device and method for reinforcing and toughening metal material

Abstract

The invention belongs to the technical field of metal plastic processing, and particularly relates to an extrusion device and method for reinforcing and toughening a metal material. The device comprises a base as well as a first extrusion mechanism and a second extrusion mechanism which are arranged on the base in a mirroring manner, the first extrusion mechanism and the second extrusion mechanism are the same in structure and each comprise a sliding seat, a horizontal movement driving module and an extrusion die, the extrusion dies are slidably connected with the base through the sliding seats, the horizontal movement driving modules are arranged on the base and connected with the sliding seats, and the horizontal movement driving modules provide power for die closing and die opening of the extrusion dies; and after the two extrusion dies in the first extrusion mechanism and the second extrusion mechanism are closed, an extrusion cavity with a corner is formed between the two extrusion dies, and the two extrusion dies complete the plastic friction extrusion process of the metal material through reciprocating reverse rotation extrusion. The method is easy and convenient to operate and high in machining efficiency, grains can be effectively refined, the strength and toughness of the material are improved, and then the mechanical performance of the material is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of metal plastic processing, and particularly relates to an extrusion device and method for strengthening and toughening metal materials. Background Art

[0002] Severe plastic deformation (SPD) is an emerging plastic deformation method. It can introduce large strain during the deformation process (traditional plastic deformation is difficult to achieve true strain greater than 1), thereby effectively refining (submicron or nanometer scale) metals and obtaining complete large-size block specimens. By controlling the microstructure during the deformation process, bulk nanomaterials with high strength and high plasticity can be obtained at the same time. Equal channel angular pressing (ECAP) is the hottest and most studied severe plastic deformation method.

[0003] Although the traditional equal-channel angular extrusion process is an effective way to prepare ultrafine-grained materials, the existing die structure still has the disadvantages of limited plastic deformation capacity of the blank and low die working efficiency in practical applications. During the equal-channel angular extrusion process, the material undergoes strong shear deformation at the corner of the die, which easily causes the blank to deform, crack, or even break along the shear stress direction, ultimately making it impossible to continue the extrusion deformation of the subsequent process. Therefore, how to overcome the problems of limited plastic deformation capacity of metal blanks and low die working efficiency in the existing die structure and obtain process parameters that optimize extrusion efficiency is an urgent need at present. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide an extrusion device and method for strengthening and toughening metal materials, so as to overcome the problems of limited plastic deformation capacity of metal blanks and low working efficiency of molds in existing mold structures, and obtain process parameters for optimizing extrusion efficiency.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: In one aspect, the present invention provides an extrusion device for strengthening and toughening metal materials, comprising a base and a first extrusion mechanism and a second extrusion mechanism symmetrically arranged on the base; The first extrusion mechanism and the second extrusion mechanism have the same structure, and both include a slide, a horizontal movement driving module and an extrusion die, wherein the extrusion die is slidably connected to the base through the slide, the horizontal movement driving module is arranged on the base and connected to the slide, and the horizontal movement driving module provides power for closing and opening the extrusion die; When the two extrusion dies in the first extrusion mechanism and the second extrusion mechanism are closed, an extrusion cavity with a corner is formed between the two extrusion dies, and the two extrusion dies complete the plastic friction extrusion process of the metal material through reciprocating counter-rotating extrusion.

[0006] In one possible implementation, the extrusion chamber includes a central extrusion chamber, a middle annular extrusion chamber, and an outer cylinder extrusion chamber which are connected in sequence from the inside to the outside in the radial direction. After the metal blank is extruded in the central extrusion chamber, it passes through the middle annular extrusion chamber and enters the outer cylinder extrusion chamber, and then is reversely extruded to perform repeated extrusion in both forward and reverse directions.

[0007] In a possible implementation, the extrusion die includes an extrusion drive module, a rotation drive module, an extrusion rod, a rotation extrusion shaft, an extrusion sleeve and an extrusion outer cylinder, wherein the extrusion rod, the rotation extrusion shaft, the extrusion sleeve and the extrusion outer cylinder are slidably matched from the inside to the outside in sequence, and the front ends of the extrusion rod, the rotation extrusion shaft and the extrusion sleeve are the central extrusion cavity, the middle annular extrusion cavity and the outer cylinder extrusion cavity respectively; One end of the rotating extrusion shaft close to the bottom of the extrusion outer cylinder is a closed end, which passes through the bottom of the extrusion outer cylinder and is connected to an extrusion drive module arranged on the slide seat, and the extrusion drive module is used to drive the rotating extrusion shaft to move axially relative to the extrusion outer cylinder; the axial movement of the extrusion rod and the extrusion sleeve is respectively controlled by two hydraulic servos; The rotary drive module is arranged on the extrusion outer cylinder and connected with the rotary extrusion shaft. The rotary drive module is used for driving the rotary extrusion shaft to rotate so that the rotary extrusion shaft can perform rotary extrusion.

[0008] In a possible implementation, the two rotating extrusion shafts in the first extrusion mechanism and the second extrusion mechanism rotate in opposite directions at equal speeds or at differential speeds.

[0009] In one possible implementation, the rotary drive module includes a rotary drive motor, a rotary drive pinion and a large gear, wherein the large gear is fixed on the rotary extrusion shaft, the rotary drive motor is arranged on the extrusion outer cylinder, and the output end is connected to the rotary drive pinion, the rotary drive pinion is meshed with the large gear, and the rotary drive motor is used to provide power for the rotation of the rotary extrusion shaft.

[0010] In one possible implementation, the rotary drive pinion and the large gear are both spur gears.

[0011] In a possible implementation, the extrusion drive module includes a hydraulic cylinder mounted on the rotating extrusion shaft, the rotating extrusion shaft has the freedom of rotation and axial movement relative to the hydraulic cylinder, and the hydraulic cylinder provides power for the axial movement of the rotating extrusion shaft.

[0012] In a possible implementation, a heating module is provided in the extrusion rod, the rotating extrusion shaft and the extrusion sleeve.

[0013] Another aspect of the present invention provides a method for extruding a reinforced and toughened metal material using the device as described above, comprising the following steps: Step S1: initializing the positions of the first extrusion mechanism and the second extrusion mechanism so that the space of the middle annular extrusion chamber and the outer cylinder extrusion chamber is zero and the volume of the central extrusion chamber is the largest; Step S2: the two extrusion dies in the first extrusion mechanism and the second extrusion mechanism are separated, the metal blank is placed in the central extrusion cavity, and then the two extrusion dies are closed; Step S3: servo controls the extrusion rods on both sides to axially extrude the two ends of the metal blank; Step S4: the extrusion drive module drives the rotating extrusion shaft to move outward to open the middle annular extrusion cavity, and the metal blank is extruded into the middle annular extrusion cavity; at the same time, the rotating extrusion shafts on both sides rotate in the opposite direction, and the metal blank is frictionally extruded in the middle annular extrusion cavity; Step S5: The servo controls the extrusion sleeves on both sides to move outwards, gradually opening the extrusion cavity of the outer cylinder, and the metal blank in the middle annular extrusion cavity is extruded and gradually enters the extrusion cavity of the outer cylinder; Step S6: When the extrusion rods on both sides contact each other or move to a set stroke, reverse extrusion is performed; Step S7: Repeat steps S3 to S6 to a specified number of times; Step S8: heat treating the metal by using mold temperature control; Step S9: the first extrusion mechanism and the second extrusion mechanism open the mold to obtain the finished nano-crystal grains; Step S10: Perform macroscopic mechanical property testing and microscopic material science testing on the finished nano-grain product.

[0014] The advantages and positive effects of the present invention are as follows: the extrusion device for reinforced and toughened metal materials provided by the present invention has multiple iterations of yaw bending and rolling precession in the flow direction of equal-channel angular extrusion metal materials, is easy to operate, has high processing efficiency, can effectively refine grains, improve the strength and toughness of materials, and thus improve the mechanical properties of materials; the present invention effectively studies and characterizes the friction of internal grain refinement caused by severe plastic deformation of metals under micro-equal-channel angular extrusion deformation method, and characterizes the relationship with the operation process of the macro-extrusion device (including but not limited to gradient process parameters such as extrusion size, pressure, speed, electric field, temperature field, and ultrasonic wave), thereby obtaining process parameters for optimizing extrusion efficiency.

[0015] The present invention cycles through multiple extrusions, and the gradient of the extrusion chamber changes gradually during the entire process. Since the stirring friction state of coarse-grained and fine-grained metal grains can be adjusted, metal cracking is effectively avoided, material waste is reduced, molding accuracy is high, and extrusion efficiency is optimized. The extrusion process for barrels and cylinders contains back pressure, which effectively avoids cracking.

[0016] In the present invention, the metal flow direction in the middle annular extrusion cavity is parallel to the two rotating friction surfaces, and the differential speed gradient of the two friction surfaces is realized in the process flow, so that the metal material flows and axially rolls and precesses, thereby realizing friction stirring of the internal metal grains, and effectively solving the problem of uneven grain refinement between the static disk and the dynamic disk in the prior art.

[0017] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0018] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 It is an axonometric view of an extrusion device for strengthening and toughening metal materials of the present invention; Figure 2 It is a cross-sectional view of an extrusion device for strengthening and toughening metal materials of the present invention; Figure 3 An exploded view of an extrusion device for strengthening and toughening metal materials according to the present invention; Figure 4 A three-quarter isometric view of a transient extruded metal blank in an embodiment of the present invention; Figure 5 A schematic diagram of the relative motion trajectory of two grains in an embodiment of the present invention; Figure 6 A schematic diagram of the relative motion trajectories of multiple grains in an embodiment of the present invention; Figure 7 It is a planar unfolded diagram of the relative motion trajectories of multiple grains in an embodiment of the present invention.

[0020] In the figure: 1-base, 2-slide, 3-horizontally movable drive module, 4-extrusion die, 401-connecting flange, 5-hydraulic cylinder, 6-rotation drive motor, 7-rotation drive pinion, 8-rotation hydraulic joint, 9-drag chain, 10-extrusion rod, 11-rotation extrusion shaft, 12-extrusion sleeve, 13-large gear, 1001-central extrusion chamber, 1002-inner servo hydraulic chamber, 1101-middle annular extrusion chamber, 1102-middle servo hydraulic chamber, 1201-outer cylinder extrusion chamber, 1202-outer servo hydraulic chamber, 14-extruded outer cylinder, 15-grain I, 16-grain II, 17-transient extrusion metal blank, 171-central cavity part, 172-middle annular cavity part, 173-outer cylinder extrusion cavity part, 18-first extrusion mechanism, 19-second extrusion mechanism. DETAILED DESCRIPTION

[0021] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0023] An embodiment of the present invention provides an extrusion device for strengthening and toughening metal materials, which can effectively study the friction of internal grain refinement in micro-equal channel angular extrusion deformation method and the relationship between the characterization of the operation process of the macro-extrusion device, and thus obtain the process parameters for optimizing the extrusion efficiency. Figures 1 to 7 As shown, the extrusion device for reinforced and toughened metal materials includes a base 1 and a first extrusion mechanism 18 and a second extrusion mechanism 19 symmetrically arranged on the base 1; the first extrusion mechanism 18 and the second extrusion mechanism 19 have the same structure, both including a slide 2, a horizontal movable driving module 3 and an extrusion die 4, wherein the extrusion die 4 is slidably connected to the base 1 through the slide 2, the horizontal movable driving module 3 is arranged on the base 1 and connected to the slide 2, and the horizontal movable driving module 3 provides power for the closing and opening of the extrusion die 4; when the two extrusion dies 4 in the first extrusion mechanism 18 and the second extrusion mechanism 19 are closed, an extrusion cavity with a corner is formed between the two extrusion dies 4, and the two extrusion dies 4 complete the plastic friction extrusion process of the metal material through reciprocating counter-rotating extrusion.

[0024] See also Figure 2As shown, in an embodiment of the present invention, the extrusion chamber includes a central extrusion chamber 1001, a middle annular extrusion chamber 1101 and an outer cylinder extrusion chamber 1201 which are connected in sequence from the inside to the outside in the radial direction. After the metal blank is extruded in the central extrusion chamber 1001, it passes through the middle annular extrusion chamber 1101 and enters the outer cylinder extrusion chamber 1201, and then is reversely extruded to perform repeated extrusion in both forward and reverse directions.

[0025] See also Figures 1 to 3 As shown, in the embodiment of the present invention, the extrusion mold 4 includes an extrusion drive module, a rotation drive module, an extrusion rod 10, a rotation extrusion shaft 11, an extrusion sleeve 12 and an extrusion outer cylinder 14, wherein the extrusion rod 10, the rotation extrusion shaft 11, the extrusion sleeve 12 and the extrusion outer cylinder 14 are slidably matched from the inside to the outside in sequence, and the front ends of the extrusion rod 10, the rotation extrusion shaft 11 and the extrusion sleeve 12 are respectively a central extrusion cavity 1001, a middle annular extrusion cavity 1101 and an outer cylinder extrusion cavity 1201; one end of the rotation extrusion shaft 11 close to the bottom of the extrusion outer cylinder 14 is a closed end, and the closed end passes through the bottom of the extrusion outer cylinder 14 and is connected to the extrusion drive module arranged on the slide 2, and the extrusion drive module is used to drive the rotation extrusion shaft 11 to move axially relative to the extrusion outer cylinder 14; the axial movement of the extrusion rod 10 and the extrusion sleeve 12 is respectively controlled by two hydraulic servos; the rotation drive module is arranged on the extrusion outer cylinder 14 and connected to the rotation extrusion shaft 11, and the rotation drive module is used to drive the rotation extrusion shaft 11 to rotate, so that the rotation extrusion shaft 11 can be rotated and extruded.

[0026] Specifically, the open end of the extruded outer cylinder 14 is provided with a connecting flange 401 , and the connecting flanges 401 of the extruded outer cylinders 14 on both sides are sealed and connected by bolts and sealing rings, and the sealing form is preferably a metal sealing ring high-pressure seal (up to 10 GPa).

[0027] Furthermore, the two rotating extrusion shafts 11 in the first extrusion mechanism 18 and the second extrusion mechanism 19 rotate in opposite directions at equal speeds or differential speeds, and the metal flow direction in the middle annular extrusion chamber 1101 is parallel to the rotating friction surfaces of the two rotating extrusion shafts 11, and a differential gradual change of the two friction surfaces is realized in the process flow, allowing the material to flow and simultaneously roll axially to achieve friction stirring of the internal metal grains, effectively solving the problem of uneven grain size due to grain refinement.

[0028] In the embodiment of the present invention, the rotary drive module includes a rotary drive motor 6, a rotary drive pinion 7 and a large gear 13, wherein the large gear 13 is fixed on the rotary extrusion shaft 11, the rotary drive motor 6 is arranged on the extrusion outer cylinder 14, and the output end is connected to the rotary drive pinion 7, the rotary drive pinion 7 is meshed with the large gear 13, and the rotary drive motor 6 is used to provide power for the rotation of the rotary extrusion shaft 11. The rotary drive motor 6 drives the rotary drive pinion 7 to rotate, and the rotary drive pinion 7 drives the rotary extrusion shaft 11 to rotate through the large gear 13.

[0029] Furthermore, the rotary drive pinion 7 and the large gear 13 are both spur gears and can move axially relative to each other.

[0030] In an embodiment of the present invention, the extrusion drive module includes a hydraulic cylinder 5 mounted on a rotating extrusion shaft 11 . The rotating extrusion shaft 11 has the freedom of rotation and axial movement relative to the hydraulic cylinder 5 . The hydraulic cylinder 5 provides power for the axial movement of the rotating extrusion shaft 11 .

[0031] In this embodiment, the slide 2 includes a slider, and the slide 2 can be servo-moved relative to the base 1 in the length direction of the base 1 under the action of the horizontal movement drive module 3. The horizontal movement drive module 3 uses a servo motor, a planetary reducer and a gear; the base 1 includes a guide rail and a rack, the guide rail and slider form a linear motion pair, and the gear rack forms a driving relationship.

[0032] In the embodiment of the present invention, the extrusion sleeve 12 is cylindrical, the outer diameter of the extrusion sleeve 12 forms a cylindrical sealing pair with the inner surface of the extrusion outer cylinder 14, and the inner diameter of the extrusion sleeve 12 forms a cylindrical sealing pair with the outer surface of the rotating extrusion shaft 11. The front end of the extrusion sleeve 12 is an annular outer cylinder extrusion chamber 1201, and the rear end is an outer servo hydraulic chamber 1202, and the outer servo hydraulic chamber 1202 controls the axial movement of the extrusion sleeve 12. The extrusion rod 10 is a cylinder, and the outer diameter of the extrusion rod 10 forms a cylindrical sealing pair with the inner cavity of the rotating extrusion shaft 11. The front end of the extrusion rod 10 is an equal diameter cylindrical central extrusion chamber 1001, and the rear end is an inner servo hydraulic chamber 1002, and the inner servo hydraulic chamber 1002 controls the axial movement of the extrusion rod 10. The rotating extrusion shaft 11 is a hollow rotary scanning body, the front end of the rotating extrusion shaft 11 is a middle annular extrusion chamber 1101, and the rear end is slidably matched with the hydraulic cylinder 5 through a piston, and the hydraulic cylinder 5 controls the axial movement of the rotating extrusion shaft 11 through the middle servo hydraulic chamber 1102. Since the extrusion rod 10, the rotating extrusion shaft 11 and the extrusion sleeve 12 are all independently controlled, the sizes of the extrusion cavities corresponding to them can be controlled respectively, and then different extrusion process parameters can be obtained by controlling different configurations of the extrusion cavities.

[0033] Furthermore, heating modules are provided inside the extrusion rod 10, the rotating extrusion shaft 11 and the extrusion sleeve 12, and the heat treatment of the metal is performed by using the mold temperature control.

[0034] Furthermore, the rotating extrusion shaft 11 is connected to the hydraulic hose in the drag chain 9 through the rotary hydraulic joint 8, thereby solving the hydraulic connection for the relative rotation of the rotating extrusion shaft 11 and the hydraulic cylinder 5, and solving the hydraulic connection for the relative axial movement of the rotating extrusion shaft 11 and the hydraulic cylinder 5 through the bending of the hydraulic hose in the drag chain 9.

[0035] In this embodiment, the metal blank is a cylinder, and the metal blank preferably includes but is not limited to aluminum, aluminum alloy, copper, copper alloy, pure iron, carbon steel, nickel and other metal alloys. In this embodiment, the preferred grade 6201 aluminum alloy cylindrical blank, the extrusion pressure is 0~10GPa, the rotation speed of the rotating extrusion shaft 11 is 0~30 r / min, and the metal blank finally obtains the shape of a cylinder, a barrel, a water cup or an H-shaped shaft section rotating body after extrusion. The extrusion die 4 can be equipped with an axial ultrasonic vibration device, a heating device, an electrostatic field assisted nano-grain refinement, a temperature control assisted nano-grain refinement, etc.

[0036] Figure 4 It is a three-quarter isometric view of a transient extruded metal blank in an embodiment of the present invention; see Figure 4 As shown, the transient extruded metal blank 17 comprises a central cavity portion 171, a middle annular cavity portion 172 and an outer cylinder extrusion cavity portion 173, and the shape of the transient extruded metal blank 17 continuously changes according to the extrusion process.

[0037] Figure 5 is a schematic diagram of the relative motion trajectory of two grains in an embodiment of the present invention; see Figure 5 As shown, on the side of the first extrusion mechanism 18, the grain I15 moves from the central extrusion chamber 1001 on one side to the middle annular extrusion chamber 1101, and turns once. At the same time, on the side of the second extrusion mechanism 19, the grain II16 moves from the central extrusion chamber 1001 on the other side to the middle annular extrusion chamber 1101, and turns once. In the middle annular extrusion chamber 1101, the grain I15 from the first extrusion mechanism 18 side and the grain II16 from the second extrusion mechanism 19 side rub and stir each other in space, and the grain I15 finally enters the space of the outer cylinder extrusion chamber 1201 on the side of the second extrusion mechanism 19, and turns once again. At the same time, the grain II16 finally enters the space of the outer cylinder extrusion chamber 1201 on the side of the first extrusion mechanism 18, and turns once again. The angle of equal diameter angle refers to the angle change of the extrusion surface of the grain movement, and the angle of this device is 90°.

[0038] Figure 6 A schematic diagram of the relative motion trajectories of multiple grains in an embodiment of the present invention; Figure 7 FIG. 1 is a planar expansion diagram of the relative motion trajectories of multiple grains in an embodiment of the present invention. This embodiment uses twelve axial trajectories of grains for illustration. Figure 6 and Figure 7 As shown, the closer the edge grains are to the friction surface, the greater the axial movement amplitude will be. Therefore, the extrusion process has the characteristic of gradient changing the state of the friction grains. The wire grain density of the middle annular extrusion chamber 1101 is different from that of the central extrusion chamber 1001. Therefore, the flow rate can be controlled by the design ratio of the moving axis section of the middle annular extrusion chamber 1101 and the central extrusion chamber 1001.

[0039] In the embodiment of the present invention, the central extrusion chamber 1001 to the middle annular extrusion chamber 1101 is equivalent to equal channel angular extrusion, which uses pure shearing to refine the grains, and the extrusion flow direction is bent once. In the central extrusion chamber 1001, the extruded material advances in the extrusion flow direction, that is, it rotates spirally, and the spiral rotation has the characteristic of gradually changing the speed. Since the stirring friction state of the coarse-grained and fine-grained metal grains can be adjusted, metal cracking is effectively avoided, material waste is reduced, and the molding precision is high; the extrusion process for tubes and cylindrical metals contains back pressure, which effectively avoids metal cracking.

[0040] The present invention uses multiple cycles of reciprocating extrusion to gradually change the extrusion cavity gradient during the entire process, thereby effectively avoiding metal cracking and exploring and optimizing extrusion efficiency. The present invention has the beneficial effects recorded in all public documents on equal-diameter corner metal crystal refinement, which will not be repeated here.

[0041] In another embodiment of the present invention, there is provided a method for extruding a reinforced and toughened metal material using the above-mentioned device, comprising the following steps: Step S1: The positions of the first extrusion mechanism 18 and the second extrusion mechanism 19 are initialized so that the space of the middle annular extrusion chamber 1101 and the outer cylinder extrusion chamber 1201 is zero and the volume of the central extrusion chamber 1001 is the largest; Step S2: The extrusion dies 4 on both sides are driven to separate by two sets of horizontal moving driving modules 3 respectively, and the metal blank is placed in the central extrusion cavity 1001, and then the two sets of horizontal moving driving modules 3 drive the extrusion dies 4 on both sides to close, completing the mold closing; Step S3: servo controls the extrusion rods 10 on both sides to axially extrude the two ends of the metal blank; Step S4: the extrusion drive module drives the rotating extrusion shaft 11 to move outward, opens the middle annular extrusion chamber 1101, and the metal blank is extruded into the middle annular extrusion chamber 1101. The central extrusion chamber 1001 to the middle annular extrusion chamber 1101 is equivalent to equal channel angular extrusion, and the pure shearing effect is used to refine the grains, and the extrusion flow direction is bent once; at the same time, the rotating extrusion shafts 11 on both sides rotate in the opposite direction, and the metal blank is frictionally extruded in the middle annular extrusion chamber 1101; In the middle annular extrusion cavity 1101, the metal flow direction is parallel to the two rotating friction surfaces, and the differential speed of the two friction surfaces is gradually changed in the process flow, so that the material flow axially rolls and precesses to achieve friction stirring of the internal metal grains, effectively solving the problem of uneven grain refinement between the static disk and the dynamic disk in the prior art; at this time; the metal material in the central extrusion cavity 1001 precesses in the extrusion flow direction, that is, it performs spiral rotation, and the spiral rotation has the characteristic of gradual gradient change in speed; Step S5: The servo controls the extrusion sleeves 12 on both sides to move outwards, gradually opening the outer cylinder extrusion cavity 1201, and the metal blank in the middle annular extrusion cavity 1101 is extruded and gradually enters the outer cylinder extrusion cavity 1201; At this time, the volume of the central extrusion chamber 1001 is reduced, the volume of the middle annular extrusion chamber 1101 is gradually changed according to the friction stirring grain refinement process, and the volume of the outer cylinder extrusion chamber 1201 is increased. The extrusion process is carried out by friction stirring grain refinement through equal-path angular extrusion deformation method; Step S6: When the extrusion rods 10 on both sides contact each other or move to a set stroke, reverse extrusion is performed; Step S7: after the reverse extrusion is completed, repeat steps S3 to S6 for a specified number of processes; Step S8: heat treating the metal by using mold temperature control; Step S9: two groups of horizontally movable driving modules 3 drive the extrusion dies 4 on both sides to open the molds to obtain finished nano-crystal particles; Step S10: Perform macroscopic mechanical property testing and microscopic material science testing on the finished nano-grain product.

[0042] Through the above steps, many nano-grain products with different extrusion processes can be made, and the friction of the internal grain refinement of the metal under severe plastic deformation by the micro-equal-diameter angular extrusion deformation method can be obtained, and the characterization relationship between the operation process of the macro-extrusion device (including but not limited to extrusion size, pressure, speed, electric field, temperature field, ultrasonic and other gradient process parameters) can be obtained, so as to obtain the process parameters for optimizing the extrusion efficiency. The present invention adopts the equal-diameter angular extrusion deformation method to carry out the metal plastic deformation process. Because the friction environment of the internal grain refinement of the metal under severe plastic deformation can be adjusted online, the characterization relationship between the friction ring of the metal under severe plastic deformation by the equal-diameter angular extrusion deformation method and ultrasonic assisted processing, process temperature, auxiliary electric field, etc. is effectively studied. Each cycle needs to pass through the high linear speed area of ​​the equal-diameter angular extrusion deformation method, so the grain uniformity is good and the work efficiency is high.

[0043] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. An extrusion device for strengthening and toughening a metal material, comprising a base (1) and a first extrusion mechanism (18) and a second extrusion mechanism (19) symmetrically arranged on the base (1), characterized in that: The first extrusion mechanism (18) and the second extrusion mechanism (19) have the same structure, and both comprise a slide seat (2), a horizontally movable driving module (3) and an extrusion die (4), wherein the extrusion die (4) is slidably connected to the base (1) via the slide seat (2), the horizontally movable driving module (3) is arranged on the base (1) and connected to the slide seat (2), and the horizontally movable driving module (3) provides power for closing and opening the extrusion die (4); When the two extrusion dies (4) in the first extrusion mechanism (18) and the second extrusion mechanism (19) are closed, an extrusion cavity with a corner is formed between the two extrusion dies (4), and the two extrusion dies (4) complete the plastic friction extrusion process of the metal material through reciprocating counter-rotating extrusion.

2. The extrusion device for strengthening and toughening metal materials according to claim 1, characterized in that: The extrusion chamber comprises a central extrusion chamber (1001), a middle annular extrusion chamber (1101) and an outer cylinder extrusion chamber (1201) which are sequentially connected from the inside to the outside in the radial direction. After the metal blank is extruded in the central extrusion chamber (1001), it passes through the middle annular extrusion chamber (1101) and enters the outer cylinder extrusion chamber (1201), and then is reversely extruded, and extrusion is repeated in both forward and reverse directions.

3. The extrusion device for strengthening and toughening metal materials according to claim 2, characterized in that: The extrusion die (4) comprises an extrusion drive module, a rotation drive module, an extrusion rod (10), a rotation extrusion shaft (11), an extrusion sleeve (12) and an extrusion outer cylinder (14), wherein the extrusion rod (10), the rotation extrusion shaft (11), the extrusion sleeve (12) and the extrusion outer cylinder (14) are slidably matched in sequence from the inside to the outside, and the front ends of the extrusion rod (10), the rotation extrusion shaft (11) and the extrusion sleeve (12) are respectively the central extrusion cavity (1001), the middle annular extrusion cavity (1101) and the outer cylinder extrusion cavity (1201); One end of the rotating extrusion shaft (11) close to the bottom of the extrusion outer cylinder (14) is a closed end, and the closed end passes through the bottom of the extrusion outer cylinder (14) and is connected to an extrusion drive module disposed on the slide seat (2), and the extrusion drive module is used to drive the rotating extrusion shaft (11) to move axially relative to the extrusion outer cylinder (14); the axial movement of the extrusion rod (10) and the extrusion sleeve (12) is respectively controlled by two hydraulic servos; The rotary drive module is arranged on the extrusion outer cylinder (14) and connected to the rotary extrusion shaft (11); the rotary drive module is used to drive the rotary extrusion shaft (11) to rotate, so that the rotary extrusion shaft (11) can perform rotary extrusion.

4. The extrusion device for strengthening and toughening metal materials according to claim 3, characterized in that: The two rotating extrusion shafts (11) in the first extrusion mechanism (18) and the second extrusion mechanism (19) rotate in opposite directions at equal speeds or at differential speeds.

5. The extrusion device for strengthening and toughening metal materials according to claim 3, characterized in that: The rotary drive module comprises a rotary drive motor (6), a rotary drive pinion (7) and a large gear (13), wherein the large gear (13) is fixedly mounted on the rotary extrusion shaft (11), the rotary drive motor (6) is arranged on the extrusion outer cylinder (14), and the output end is connected to the rotary drive pinion (7), the rotary drive pinion (7) is meshed with the large gear (13), and the rotary drive motor (6) is used to provide power for the rotation of the rotary extrusion shaft (11).

6. The extrusion device for strengthening and toughening metal materials according to claim 5, characterized in that: The rotary drive pinion (7) and the large gear (13) are both spur gears.

7. The extrusion device for strengthening and toughening metal materials according to claim 3, characterized in that: The extrusion drive module comprises a hydraulic cylinder (5) sleeved on the rotating extrusion shaft (11); the rotating extrusion shaft (11) has the freedom of rotation and axial movement relative to the hydraulic cylinder (5); the hydraulic cylinder (5) provides power for the axial movement of the rotating extrusion shaft (11).

8. The extrusion device for strengthening and toughening metal materials according to claim 3, characterized in that: The extrusion rod (10), the rotating extrusion shaft (11) and the extrusion sleeve (12) are all provided with heating modules.

9. A method for extruding a reinforced and toughened metal material using the device according to any one of claims 3 to 8, characterized in that: The following steps are involved: Step S1: initializing the positions of the first extrusion mechanism (18) and the second extrusion mechanism (19) so that the spaces of the middle annular extrusion chamber (1101) and the outer cylinder extrusion chamber (1201) are zero and the volume of the central extrusion chamber (1001) is the largest; Step S2: the two extrusion dies (4) in the first extrusion mechanism (18) and the second extrusion mechanism (19) are separated, the metal blank is placed in the central extrusion cavity (1001), and then the two extrusion dies (4) are closed; Step S3: servo controls the extrusion rods (10) on both sides to axially extrude the two ends of the metal blank; Step S4: the extrusion drive module drives the rotating extrusion shaft (11) to move outwards, opens the middle annular extrusion chamber (1101), and the metal blank is extruded into the middle annular extrusion chamber (1101); at the same time, the rotating extrusion shafts (11) on both sides rotate in the opposite direction, and the metal blank is frictionally extruded in the middle annular extrusion chamber (1101); Step S5: the servo controls the extrusion sleeves (12) on both sides to move outwards, gradually opening the outer cylinder extrusion cavity (1201), and the metal blank in the middle annular extrusion cavity (1101) is extruded and gradually enters the outer cylinder extrusion cavity (1201); Step S6: When the extrusion rods (10) on both sides contact each other or move to a set stroke, reverse extrusion is performed; Step S7: Repeat steps S3 to S6 to a specified number of times; Step S8: heat treating the metal by using mold temperature control; Step S9: the first extrusion mechanism (18) and the second extrusion mechanism (19) open the mold to obtain the finished nano-crystal particles; Step S10: Perform macroscopic mechanical property testing and microscopic material science testing on the finished nano-grain product.

Images