A magnetic field-assisted extrusion torsion deformation device and method for light alloys

Abstract

This invention relates to the field of magnetic field-assisted plastic processing, specifically to a magnetic field-assisted extrusion and torsional deformation device for light alloys. The device includes: an extrusion and torsional die, a magnetic field generator, a magnetic field power controller, and a control system. The magnetic field generator is positioned outside the extrusion and torsional die and connected to the magnetic field power controller, used to provide magnetic field assistance to the light alloy billet within the die. The control system is connected to the magnetic field generator and used to adjust the position of the magnetic field generator outside the extrusion and torsional die. This invention combines plastic deformation and magnetic field treatment, comprehensively utilizing the coupling effects of magnetic field, stress field, and temperature field to achieve efficient, energy-saving, and rapid plastic processing of light alloys, further preparing high-strength and high-toughness light alloys.

Description

Technical Field

[0001] This invention belongs to the technical field of magnetic field-assisted plastic processing, specifically relating to a magnetic field-assisted extrusion torsion deformation device and method for light alloys. Background Technology

[0002] Light alloys typically refer to alloys based on light metals such as aluminum, magnesium, and titanium with a density of less than 4.5 g / mm³. 3 Lightweight alloys possess advantages such as low density, high specific strength, good corrosion resistance, and high temperature resistance, playing a significant role in lightweighting in cutting-edge fields such as aerospace technology and deep-sea exploration. For high-end equipment, lightweight alloys are the preferred structural materials for the lightweighting of complex components. Therefore, the comprehensive performance of lightweight alloys directly affects the long-term reliability, safety, and service life of high-end equipment, prompting the development of more reliable strength and toughness properties in lightweight alloys. Consequently, the technology and methods for preparing high-strength and high-toughness lightweight alloys have gradually become a pressing problem to be solved in the manufacturing process of high-end equipment.

[0003] Large plastic deformation methods increase and accumulate strain through extrusion and shear deformation, refining grains, homogenizing microstructure, and achieving synergistic control of microstructure and properties. This represents a cutting-edge concept and effective method for improving the comprehensive mechanical properties of alloy materials and is a research hotspot in the field of metal plastic processing. While large plastic deformation technology refines grains and improves strength, it also introduces internal stress and numerous defects such as dislocations and grain boundaries, which to some extent affect the material's toughness and plasticity. Unfortunately, products obtained through large plastic deformation are relatively small in size, often requiring multiple deformations, mold changes, and repeated heat treatments, resulting in high energy consumption, high cost, and low efficiency, significantly limiting its application. Therefore, there is a need to develop new methods, processes, and technologies that are cleaner, reduce resource and energy consumption, and have strong applicability. Summary of the Invention

[0004] In view of the above-mentioned defects or improvement needs of the existing technology, the purpose of this invention is to provide a magnetic field-assisted extrusion torsion deformation device for light alloys. This device is set on the outside of the extrusion torsion die by a magnetic field generator and connected to a magnetic field power controller. It combines plastic deformation and magnetic field treatment, and makes comprehensive use of the coupling effect of magnetic field, stress field and temperature field to achieve efficient, green and energy-saving and rapid plastic processing of light alloys, further meeting the needs of high-end equipment for titanium alloys.

[0005] To achieve the above objectives, according to a first aspect of the present invention, a magnetic field-assisted light alloy extrusion torsion deformation device is provided, comprising: an extrusion torsion die, a magnetic field generating device, a magnetic field power controller, and a control system; The magnetic field generating device is located on the outside of the extrusion and torsion die and is connected to the magnetic field power controller, and is used to provide magnetic field assistance to the light alloy billet inside the extrusion and torsion die. The control system is connected to the magnetic field generator and is used to adjust the position of the magnetic field generator outside the extrusion and torsion die.

[0006] As a preferred embodiment of the present invention, the magnetic field generating device is either a circular solenoid or an electromagnet. When the magnetic field generating device is a circular solenoid, the circular solenoid is arranged around the outer periphery of the extrusion torsion die; When the magnetic field generating device is an electromagnet, the electromagnet is symmetrically arranged on both sides of the extrusion and torsion die.

[0007] As a preferred embodiment of the present invention, a gap is maintained between the magnetic field generating device and the extrusion torsion die, so that the gap distance is greater than 3 mm.

[0008] As a preferred embodiment of the invention, a support frame is also included for supporting the height of the magnetic field generating device located outside the extrusion torsion die, and the distance between the device and the extrusion torsion die.

[0009] As a preferred embodiment of the present invention, a heat-insulating material protective layer is further included, which is disposed in close contact with the side of the magnetic field generating device near the extrusion and torsion die, and does not directly contact the extrusion and torsion die.

[0010] As a preferred embodiment of the present invention, the extrusion torsion die includes a punch, an extrusion cylinder, an extrusion torsion die, and a torsion cylinder; The extrusion cylinder and the extrusion torsion die are assembled by positioning; the extrusion torsion die and the torsion cylinder are installed by positioning or connected by a key.

[0011] As a preferred embodiment of the present invention, the extrusion torsion die adopts two circular arc transitions, and a transition zone and a sizing zone of the extrusion torsion die are formed sequentially between the two circular arcs; The surface of the first arc is a concave arc, and the surface of the second arc is a convex arc.

[0012] According to a first aspect of the present invention, a method of using a magnetic field-assisted light alloy extrusion torsion deformation device includes the following steps: (1) Heat the light alloy billet and the extrusion torsion die to their respective predetermined temperatures; (2) The position of the magnetic field generating device relative to the extrusion torsion die is adjusted by the control system so that the magnetic field generating device acts on the preset area of ​​the extrusion torsion die; (3) Set the operating parameters of the extrusion and torsion die, as well as the magnetic field strength and direction of the magnetic field generating device, and perform magnetically assisted extrusion and torsion processing on the light alloy billet.

[0013] As a preferred embodiment of the present invention, the preset area of ​​the extrusion and torsion die is the area corresponding to the extrusion cylinder, extrusion and torsion die or torsion cylinder of the extrusion and torsion die.

[0014] As a preferred embodiment of the present invention, in step (1), the predetermined temperature of the light alloy billet is 240 ℃ ~ 980 ℃, and the predetermined temperature of the extrusion torsion die is 200 ℃ ~ 940 ℃; In step (3), the extrusion speed of the extrusion torsion test is 0.4 mm / s ~ 3 mm / s, and the torsion angular velocity is 0.1 rad / s ~ 2 rad / s; In step (3), the magnetic field strength of the magnetic field generating device (8) is 1 T ~ 10 T, and the magnetic field direction is parallel or perpendicular to the extrusion direction of the extrusion torsion die.

[0015] In summary, compared with the prior art, the above-described technical solutions conceived by this invention mainly possess the following technical advantages: (1) The device of the present invention places the magnetic field generator outside the extrusion torsion die, and generates a strong magnetic field by controlling the magnetic field power controller. By adjusting the area of ​​action of the magnetic field generator on the extrusion torsion die, an effective magnetic field assistance effect is achieved. Based on the device of the invention, high-strength and high-toughness ultrafine titanium alloy products are prepared from metal billets under the coupled action of magnetic field, stress field and temperature field. Among them, the metal billet generates magnetoplastic effect and phase transformation process under the action of strong magnetic field, which assists the extrusion ratio deformation and shear deformation to make the alloy deformation uniform, refine the grains, and promote dislocation slip, thereby achieving the purpose of synergistically improving the strength and toughness of the alloy, and obtaining a titanium alloy with optimized performance and reliable service safety.

[0016] (2) The device of the present invention further employs an extrusion torsion die to generate two extrusion ratio deformations and shear deformations. Based on the triaxial compressive stress, shear stress is introduced to accumulate strain, reduce forming load, make deformation more uniform, further achieve the effect of refining grains, and effectively improve the comprehensive mechanical properties of titanium alloys.

[0017] (3) The magnetic field-assisted extrusion torsion deformation method of light alloy provided by the device of the present invention generates a pulsed strong magnetic field or a constant strong magnetic field under the control of the magnetic field power controller, and performs extrusion torsion deformation in a strong magnetic field environment to generate magnetoplastic effect and phase transformation process. It assists in extrusion ratio deformation and shear deformation to make the alloy deformation uniform, refine the grains, and promote dislocation slip. It can achieve the purpose of synergistically improving the strength and toughness of the alloy, and obtain a light alloy with optimized performance and safe and reliable service.

[0018] (4) The magnetic field-assisted extrusion torsion deformation method of the present invention, based on extrusion torsion plastic deformation, in order to better assist the deformation of titanium alloy, magnetic field-assisted extrusion torsion deformation is divided into three cases: First, magnetic field assistance before plastic deformation, using a strong magnetic field to treat the titanium alloy billet in the extrusion cylinder, so as to reduce the resistance to dislocation movement, promote the phase transformation process, increase the plastic deformation capacity of titanium alloy, reduce the deformation resistance, and lay the groundwork for extrusion torsion deformation; Second, magnetic field assistance during plastic deformation, adjusting the range of magnetic field generation so that it acts on the extrusion torsion die, realizing the synergistic effect of magnetic field, extrusion ratio deformation and shear deformation, promoting dislocation unpin rolling, increasing the flexibility of dislocation movement, reducing the deformation resistance, and ensuring the comprehensive mechanical properties of titanium alloy; Third, magnetic field assistance after plastic deformation, adjusting the position of magnetic field so that it acts on the titanium alloy after extrusion torsion deformation in the torsion cylinder. After extrusion and torsion deformation, while refining the grains, a large number of dislocations and defects are introduced, increasing the activation energy of dislocation movement. After applying a strong magnetic field, the obstruction of the dislocation movement is reduced, which plays a role in unpile rolling, increases the flexibility of dislocation movement, and produces a magnetoplastic effect. While ensuring strength, it further improves the toughness and plasticity of titanium alloy. Attached Figure Description

[0019] Figure 1 This is a cross-sectional schematic diagram of an embodiment of the device of the present invention; Figure 2 This is a cross-sectional schematic diagram of AA under the action of a circular solenoid, as exemplified in an embodiment of the present invention; Figure 3 This is a cross-sectional schematic diagram of AA under the action of an electromagnet, as exemplified in an embodiment of the present invention.

[0020] The attached figures are labeled as follows: 1-punch, 2-extrusion cylinder, 3-light alloy billet, 4-extrusion torsion die, 5-torsion cylinder, 6-control system, 7-support frame, 8-magnetic field generating device, 9-heat insulation material protective layer, 10-magnetic field power controller. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0022] In a first aspect of the invention, a cross-sectional view of a specific device is shown as follows: Figure 1 As shown, a magnetic field-assisted extrusion torsion deformation device for light alloys is provided, which employs magnetic field-assisted extrusion torsion deformation.

[0023] The magnetic field-assisted light alloy extrusion torsion deformation device includes an extrusion torsion die, a magnetic field generator 8, a magnetic field power controller 10, and a control system 6; The magnetic field generating device 8 is installed on the outside of the extrusion and torsion die, so that the light alloy billet 3 and the preset part of the extrusion and torsion die are both within the range of the magnetic field. The magnetic field generating device 8 is connected to the magnetic field power controller 10, and the magnetic field power controller 10 controls the generation of a constant strong magnetic field or a pulsed strong magnetic field to achieve magnetic field assistance for the light alloy billet in the extrusion and torsion die.

[0024] The control system 6 is connected to the magnetic field generator 8 and is used to adjust the position of the magnetic field generator 8 outside the extrusion and torsion die. For example, by controlling the control system, the distance or relative height between the magnetic field generator and the extrusion and torsion die can be adjusted so that the magnetic field of the magnetic field generator acts on a preset area of ​​the extrusion and torsion die for magnetic assistance.

[0025] The magnetic field power controller 10 is a device for controlling the magnetic field generating device 8 to generate the magnetic field environment. For example, the magnetic field generating device 8 of the present invention is a circular solenoid or a stable electromagnet.

[0026] In some embodiments, the magnetic field generating device 8 is either a circular solenoid or a steady electromagnet.

[0027] When the magnetic field generating device 8 is a circular solenoid, the gap between the circular solenoid and the extrusion torsion die is greater than 3mm. The circular solenoid encloses the extrusion torsion die inside, and the magnetic field acts on a certain area between the solenoid and the center of the die. Figure 2 This is a schematic cross-sectional view of AA under the action of a circular solenoid, as exemplified in an embodiment of the present invention.

[0028] When the magnetic field generating device 8 is an electromagnet, the electromagnet is set on both sides of the extrusion and torsion die. The magnitude of the magnetic field strength is controlled by adjusting the distance between the electromagnet and the extrusion and torsion die. The direction of the magnetic field is transverse. Figure 3 This is a schematic cross-sectional view of A-A under the action of an electromagnet, as exemplified in an embodiment of the present invention.

[0029] In some embodiments, in principle, since the extrusion and torsion die needs to perform torsion and other movements, a certain gap is maintained between the magnetic field generating device 8 and the extrusion and torsion die, and the distance of the gap is greater than 3 mm.

[0030] In some embodiments, the support frame 7 is placed outside the extrusion torsion die and the magnetic field generating device 8 to support the height of the magnetic field generating device 8 outside the extrusion torsion die and the distance between it and the extrusion torsion die, so that the magnetic field generating device 8 is supported and fixed at the working position outside the extrusion torsion die.

[0031] In some embodiments, the device further includes a heat-insulating material protective layer 9, which is placed between the extrusion and torsion die and the magnetic field generating device 8, and is closely attached to the inner wall of the magnetic field generating device 8, without directly contacting the extrusion and torsion die, in order to isolate the temperature and prevent the temperature from affecting and damaging the magnetic field generating device.

[0032] In some embodiments, the extrusion torsion die is made of non-magnetic die steel, such as high-manganese austenitic steel and austenitic stainless steel.

[0033] In some embodiments, the extrusion torsion die includes a punch 1, an extrusion cylinder 2, an extrusion torsion die 4, and a torsion cylinder 5.

[0034] The extrusion cylinder 2 and the extrusion torsion die 4 are assembled by positioning to ensure correct alignment between them, guaranteeing accurate positioning during assembly and die operation without deviation. The extrusion torsion die 4 and the torsion cylinder 5 are installed by positioning or connected by a key to ensure correct positioning and consistent angular velocity between them.

[0035] In some embodiments, the extrusion torsion die 4 employs two circular arc transitions, resulting in two successive changes in cross-sectional area, corresponding to two extrusion ratio deformations. A transition zone is provided between the two cross-sectional area changes, and a sizing zone is provided after the latter extrusion ratio deformation. In this process, the curved surfaces of the pre- and post-extrusion deformation are concave and convex arcs, respectively, and the extrusion torsion die 4 adopts an arc transition with a radius of 5 mm to 25 mm. The lengths of the transition zone and the sizing zone are both set to 2 mm to 14 mm.

[0036] The light alloy billet undergoes shear deformation under the action of triaxial pressure and shear force within the extrusion torsion die 4.

[0037] In some embodiments, the light alloy billet has a density of less than 4.5 g / mm³. 3 It is an alloy formed by fusing metallic elements (such as aluminum, magnesium, titanium, etc.). For example, the light alloy of this application uses titanium alloy, magnesium alloy and aluminum alloy. In the following embodiments, the light alloy billet 3 is uniformly selected as Ti-6554 metastable β titanium alloy.

[0038] In some embodiments, a heating device is also included, which is disposed on the outer periphery of the extrusion and torsion die to heat the extrusion and torsion die, so as to achieve the coupling effect of magnetic field and temperature field at the corresponding positions of extrusion cylinder 2 and torsion cylinder 5, and the coupling effect of magnetic field, stress field and temperature field at the corresponding position of extrusion and torsion die 4.

[0039] In another aspect of the present invention, based on the magnetic field-assisted titanium alloy extrusion and torsional deformation device described in the above embodiments, the present invention also provides a magnetic field-assisted titanium alloy extrusion and torsional deformation method, comprising the following steps: (1) Heat the light alloy billet 3 to 240 ℃ ~ 980 ℃, and heat the extrusion torsion die to 200 ℃ ~ 940 ℃; (2) Assemble the extrusion and torsion die, fix it on the extrusion and torsion equipment, and apply lubricant evenly inside the die cavity; place the titanium alloy billet 3 inside the extrusion cylinder 2, and place a graphite sheet between the punch 1 and the light alloy billet 3; fix the heat insulation material protective layer 9 on the inner wall of the magnetic field generating device 8. (3) Install the magnetic field generating device 8 on the support frame 7 and place it outside the extrusion torsion die. Adjust its position and height so that it is subjected to strong magnetic field auxiliary treatment before, during and after extrusion torsion deformation. (4) The magnetic field strength and direction of the magnetic field generating device 8 are controlled by the magnetic field power controller 10. The magnetic field direction is parallel or perpendicular to the extrusion direction of the extrusion torsion die. The operating parameters of the extrusion torsion die are set. The extrusion torsion experiment is carried out in a strong magnetic field environment until the magnetic field-assisted deformation is completed, and then the titanium alloy product is taken out.

[0040] In some embodiments, the light alloy billet 3 is selected from Ti-6554 metastable β titanium alloy, the billet heating temperature is 240 ℃ ~ 980 ℃, and the extrusion torsion die heating temperature is 200 ℃ ~ 940 ℃.

[0041] In some embodiments, the extrusion torsion die undergoes two extrusion ratio deformations and two shear deformations, with the extrusion ratios of the two extrusion ratio deformations set to 1.2 ~ 1.7 and 1.5 ~ 2, respectively.

[0042] In some embodiments, the extrusion torsion die and the torsion cylinder move synchronously at the same angular velocity, which ranges from 0.1 rad / s to 2 rad / s.

[0043] In some embodiments, the magnitude of the current and the wiring method of the positive and negative terminals of the magnetic field power controller 10 are adjusted to control the magnitude and direction of the magnetic field generated by the magnetic field generator 8. The magnetic field strength is set to be greater than 1~10 T, and the magnetic field direction is parallel or perpendicular to the extrusion direction of the extrusion torsion die.

[0044] In some embodiments, the extrusion rate of the punch is 0.4 mm / s to 3 mm / s.

[0045] In some embodiments, the lubricant is selected from molybdenum disulfide.

[0046] In some embodiments, the magnetic field generating device is placed at the position corresponding to the extrusion cylinder. Before the extrusion torsion deformation, a strong magnetic field is applied to the Ti-6554 metastable β titanium alloy billet in the extrusion cylinder. After the billet has been subjected to temperature and magnetic field for a period of time, the extrusion torsion experiment is carried out, thereby realizing the coupling pretreatment of temperature field and magnetic field before the extrusion torsion deformation of light alloy.

[0047] In some embodiments, the magnetic field generating device is placed at the position corresponding to the extrusion torsion die, the Ti-6554 metastable β titanium alloy billet is placed in the extrusion cylinder, and then the magnetic field generating device generates a strong magnetic field to act on the billet by controlling the magnetic field power controller, and at the same time the extrusion torsion equipment is started to carry out the extrusion torsion experiment.

[0048] In some embodiments, the magnetic field generating device is placed at the position corresponding to the torsion cylinder to apply a strong magnetic field to the product after the extrusion torsion deformation is completed, and the Ti-6554 metastable β titanium alloy product is taken out after the magnetic field has been applied for a period of time.

[0049] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements 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 magnetic field-assisted light alloy extrusion torsion deformation device, characterized in that, include: The extrusion torsion die, magnetic field generator (8), magnetic field power controller (10), support frame (7) and control system (6); The extrusion and torsion die includes a punch (1), an extrusion cylinder (2), an extrusion and torsion die (4), and a torsion cylinder (5); the extrusion and torsion die is made of non-magnetic die steel; the extrusion and torsion die (4) adopts two circular arc transitions, and the transition area and sizing area of ​​the extrusion and torsion die are formed sequentially between the two circular arcs; wherein, the surface of the first circular arc is an upper concave circular arc, and the surface of the second circular arc is an upper convex circular arc; The magnetic field generating device (8) is located on the outside of the extrusion and torsion die and is connected to the magnetic field power controller (10) for providing magnetic field assistance to the light alloy billet inside the extrusion and torsion die. The support frame (7) is used to support the height of the magnetic field generating device (8) located outside the extrusion torsion die, and the distance between it and the extrusion torsion die; The control system (6) is connected to the magnetic field generating device (8) and is used to adjust the position of the magnetic field generating device (8) outside the extrusion torsion die.

2. The magnetic field-assisted light alloy extrusion torsion deformation device according to claim 1, characterized in that, The magnetic field generating device (8) is either a circular solenoid or an electromagnet; When the magnetic field generating device (8) is a circular solenoid, the circular solenoid is arranged around the outer periphery of the extrusion torsion die; When the magnetic field generating device (8) is an electromagnet, the electromagnet is symmetrically arranged on both sides of the extrusion and torsion die.

3. The magnetic field-assisted light alloy extrusion torsion deformation device according to claim 1, characterized in that, A gap is maintained between the magnetic field generating device (8) and the extrusion torsion die, and the gap is greater than 3 mm.

4. The magnetic field-assisted light alloy extrusion torsion deformation device as described in claim 1, characterized in that, It also includes a heat insulation material protective layer (9), which is closely attached to the side of the magnetic field generating device (8) near the extrusion and torsion mold, and does not directly contact the extrusion and torsion mold.

5. The magnetic field-assisted light alloy extrusion torsion deformation device according to claim 1, characterized in that, The extrusion cylinder (2) and the extrusion torsion die (4) are assembled by positioning; the extrusion torsion die (4) and the torsion cylinder (5) are installed by positioning or connected by key.

6. A method of using the magnetic field-assisted light alloy extrusion torsion deformation device according to any one of claims 1-5, characterized in that, Includes the following steps: (1) Heat the light alloy billet and the extrusion torsion die to their respective predetermined temperatures; (2) The position of the magnetic field generating device relative to the extrusion torsion die is adjusted by the control system so that the magnetic field generating device acts on the preset area of ​​the extrusion torsion die; (3) Set the operating parameters of the extrusion and torsion die, as well as the magnetic field strength and direction of the magnetic field generating device, and perform magnetically assisted extrusion and torsion processing on the light alloy billet.

7. The method of using the magnetic field-assisted light alloy extrusion torsion deformation device according to claim 6, characterized in that, The preset area of ​​the extrusion and twisting die is the area corresponding to the extrusion cylinder, extrusion and twisting die, or twisting cylinder of the extrusion and twisting die.

8. The method of using the magnetic field-assisted light alloy extrusion torsion deformation device according to claim 6, characterized in that, In step (1), the predetermined temperature of the light alloy billet is 240 ℃ ~ 980 ℃, and the predetermined temperature of the extrusion torsion die is 200 ℃ ~ 940 ℃; In step (3), the extrusion speed of the extrusion torsion process is 0.4 mm / s ~ 3 mm / s, and the torsion angular velocity is 0.1 rad / s ~ 2 rad / s; In step (3), the magnetic field strength of the magnetic field generating device (8) is 1 T ~ 10 T, and the magnetic field direction is parallel or perpendicular to the extrusion direction of the extrusion torsion die.

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