Current forming and heat treatment composite manufacturing technology for aluminum alloy component

Abstract

The invention relates to the cross technical field of non-traditional machining forming and heat treatment of metal materials, in particular to a current forming and heat treatment composite manufacturing technology for an aluminum alloy component. The method comprises the steps that S1, first current is applied to an aluminum alloy blank for solution treatment, the blank is heated to the solution temperature, and heat preservation is conducted; s2, the blank obtained after solid solution is quenched and cooled to the aging temperature; and S3, a second current is applied to the cooled blank, meanwhile, a load is applied for plastic deformation, and aging treatment is completed in the deformation process. According to the method, current rapid solid solution is used for replacing traditional long-time solid solution, and forming, namely strengthening, is achieved through current forming-aging compounding. Compared with the prior art, the heat treatment period is shortened from more than 26 hours to less than 15 minutes, and the production efficiency is improved by hundreds of times; the forming precision of the obtained component reaches the submillimeter level, precipitated phase gradient regulation and control are achieved through multi-field coupling, the strength and toughness limit of traditional heat treatment is broken through, and the method has wide application prospects in the fields of aerospace and automobile carrying equipment.

Description

Technical Field

[0001] This invention relates to the field of special processing and forming of metal materials and heat treatment technology, specifically to a composite manufacturing technology for current forming and heat treatment of aluminum alloy components. Background Technology

[0002] Aluminum alloy components play an irreplaceable role in aerospace and automotive transportation equipment. Traditional aluminum alloy forming technology involves first forming the geometry and then heat-treating for strengthening. However, the heat treatment process is time-consuming (>26 hours), inefficient, and cannot match the actual production pace. More importantly, traditional heat treatment has limitations in controlling the precipitated phases, making it difficult to achieve higher strength and toughness, which restricts the further application of aluminum alloy components in high-end transportation equipment.

[0003] Currently, the industrial sector commonly employs a "multi-step series" approach to manufacturing complex high-strength aluminum alloy components, such as warm forming (solution treatment - room temperature cold forming - manual shaping - artificial aging) and hot forming (thermal resistance furnace heating - high-temperature hot forming - quenching - artificial aging). Although these traditional processes based on classical heat transfer and classical dislocation theory are relatively mature, the existing technological approaches cannot achieve breakthroughs due to the increasing demands of modern equipment on the production efficiency, precision, and performance of aluminum alloy components.

[0004] For example, the long processing cycles of hot solution treatment (>2h) and hot aging (>24h) in traditional forming processes result in low manufacturing efficiency. Traditional heat treatment (such as T6 and T7 states) achieves precipitation strengthening by controlling the aging temperature and time, relying on the long-range diffusion of solute atoms. However, this method is limited by the thermodynamic equilibrium path, and the structure, size distribution, and interaction of the precipitated phase with dislocations are difficult to control precisely.

[0005] Therefore, there is an urgent need to develop a new high-efficiency forming-strengthening integrated technology based on current energy field, which can realize the short-process preparation and precise control of microstructure of aluminum alloy components by utilizing the thermal and non-thermal effects of current. Summary of the Invention

[0006] In view of this, the present invention proposes a composite manufacturing technology for aluminum alloy components using current forming and heat treatment. By introducing the effect of current energy field, current solution treatment for 1-5 minutes achieves the effect of hot solution treatment for more than 2 hours. Through current forming-aging composite (1-10 minutes), aging is completed during the forming process through the thermal and non-thermal effects of current, achieving strengthening during forming. In addition, by introducing the effect of current energy field, the precipitates are gradient-precipitated on and outside defects such as dislocations and subgrains. By controlling the process parameters of deformation and current, the precipitates can be precisely controlled, breaking through the strength and toughness limits.

[0007] The technical solution of this invention is implemented as follows: In a first aspect, the present invention proposes a composite manufacturing technology for aluminum alloy components using current forming and heat treatment, comprising the following steps: S1. Apply a first current to the aluminum alloy billet for solution treatment, raise the billet to the solution temperature and hold it at that temperature; S2. Quench and cool the billet processed in step S1 to the aging temperature. S3. Apply a second current and a load to the cooled billet from step S2 to perform plastic deformation, and complete the aging treatment during the deformation process.

[0008] Preferably, in step S1, the first current density is 10-100 A / mm². 2 The solution temperature is 400-600℃, and the holding time is 1-5 minutes.

[0009] More preferably, in step S1, the heating rate is 50-200℃ / s.

[0010] Specifically, this invention utilizes the extremely high Joule heating rate and non-thermal effects (electron wind accelerating atomic diffusion) to enable the billet to reach the target solid solution temperature range transiently at an extremely high heating rate; short-term heat preservation allows the coarse second phase to fully dissolve back, and the extremely short heat exposure time strictly inhibits grain boundary migration and grain growth from a kinetic perspective.

[0011] Preferably, in step S2, the aging temperature is 50-200℃.

[0012] Preferably, in step S3, the second current density is 10-100 A / mm². 2 .

[0013] Preferably, the quenching cooling method includes any one of water quenching, oil quenching, die pressing quenching, or mold quenching.

[0014] Specifically, after the electrosolidation is completed, the current loading is immediately released and the blank is quenched to instantly freeze the single-phase supersaturated state at high temperature to the aging temperature, which can suppress the premature desolvation and precipitation of alloying elements.

[0015] Preferably, in step S3, while applying current, a mechanical load is applied to the billet through a loading system, causing the billet to undergo plastic deformation and be formed into the final component shape.

[0016] Preferably, the current applied in steps S1 and S3 includes continuous or pulsed alternating current or direct current.

[0017] Preferably, in step S3, the total time for plastic deformation and aging treatment is 1-10 minutes.

[0018] Specifically, step S3 utilizes the "electroplastic effect" of electric current to greatly reduce the yield strength and deformation resistance of the material, achieving one-time precise forming of complex morphologies; at the same time, by utilizing the coupling effect of the applied stress field and the current field, the nucleation barrier of the precipitated phase is significantly reduced (dynamic current aging), prompting the nanoscale strengthening phase to precipitate rapidly in a high-density, fine and dispersed manner during the deformation process, thus completing the simultaneous shaping and strengthening of the component.

[0019] In a second aspect, the present invention provides an aluminum alloy component manufactured using the composite manufacturing technology described in the first aspect.

[0020] Thirdly, the present invention provides a manufacturing apparatus for implementing the composite manufacturing technology described in the first aspect, comprising: An energized circuit is used to clamp the aluminum alloy blank and apply a first current and a second current to it. A forming loading system is used to apply mechanical loads to a blank under energized conditions to induce plastic deformation. The cooling system is used to quench and cool the billet after solution treatment.

[0021] Compared with the prior art, the advantages of the present invention are as follows: (1) The production efficiency of the present invention is effectively improved. The solution treatment time is reduced from several hours (>2h) to 1-5min, and the forming and aging time is reduced from several hours (>24h) to 1-10min, realizing an efficient forming and manufacturing process.

[0022] (2) The components obtained by the present invention have high forming accuracy. In the current aging composite forming, the high density current promotes the rapid annihilation and rearrangement of dislocations, so that the internal stress in the forming process can be relaxed instantly. At the same time, the Joule heating (thermal effect) of the current realizes the thermal stress gradient, suppresses the springback problem, and makes the component accuracy reach the sub-millimeter level.

[0023] (3) Compared with traditional processes, the multi-field coupling of current in this invention enables the strength and plasticity to break through the performance limits of traditional heat treatment, achieving a perfect balance between ultra-high strength and excellent plasticity. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a flowchart of the aluminum alloy component manufacturing process proposed in an embodiment of the present invention; Figure 2This is a comparison chart showing the cycle time of the aluminum alloy component manufacturing process proposed in this invention and the traditional HFQ (heat treatment quenching) process. Detailed Implementation

[0026] The embodiments of the present invention are described in detail below. These embodiments are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0027] In this invention, current-induced solid solution rapidly reaches the required temperature within 1-5 minutes, while the directional drag force of electron wind (non-thermal effect) greatly accelerates the dissolution rate of the second phase. Due to the extremely short high-temperature residence time, grain boundaries do not have time to undergo large-scale migration, thus preserving fine initial grains with a strong strengthening effect. In traditional processes, water quenching is necessary after solid solution for rapid cooling, aiming to "freeze" and retain a large number of high-temperature vacancies at room temperature. These vacancies are indispensable nucleation cores for subsequent aging precipitation. When the quenching stage of this invention cannot match the effect of traditional water quenching, the "electro-induced vacancy proliferation" effect (non-thermal effect) induced by current in the crystal lattice can be used to actively generate a high concentration of non-equilibrium vacancies within the material, which also lays a solid thermodynamic and kinetic foundation for subsequent high-density aging precipitation. In current-forming composite aging treatment, the current promotes the high-density dispersed precipitation of the strengthening phase. Under the combined effects of non-thermal effects of electric current (electro-induced vacancy multiplication, electron wind drag, etc.), Joule heating effect, and defects introduced by deformation, materials can overcome the long-range diffusion barrier of solute atoms. Deformation introduces defects such as dislocations, subgrains, and small-angle grain boundaries. Utilizing the targeting effect of the electric current, heterogeneous phases precipitate on these defects, while small-sized dislocation-adsorbable phases precipitate outside the defects. The precipitated phase sizes range from 1 nm to 20 nm, and the heterogeneous precipitates range from 5 nm to 50 nm. This synergistic effect of the gradient precipitate structure contributes to high strength. This invention innovatively proposes a "current forming heat treatment composite manufacturing" technology. By utilizing the multiple effects of electric current to promote material phase transformation and enhance its strength, cross-scale synergistic control of macroscopic deformation and microstructure evolution is achieved.

[0028] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0029] In this document, the terms “containing,” “comprising,” or “including” are open-ended expressions, meaning they include the contents specified in this invention but do not exclude other aspects.

[0030] In this document, the terms “optional,” “optionally,” or “optional” generally refer to an event or condition that may, but may not, occur, and the description includes both cases in which the event or condition occurs and cases in which the event or condition does not occur.

[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0032] Example 1 This embodiment provides a composite manufacturing technology for aluminum alloy components using current forming and heat treatment. Taking the forming and manufacturing of a 7A09 high-strength aluminum alloy aerospace reinforcing frame (7-series aluminum alloy component) as an example, the technology includes the following steps: S1. Clamp the aluminum alloy blank (provided by Southwest Aluminum Co., Ltd.) between the two electrodes of the energized circuit and apply an A / mm² pressure. 2 The pulsed current was used to heat the temperature to 470±5℃ at a heating rate of 200℃ / s and hold it for 3 min. S2. Immediately after the solution treatment and heat preservation are completed, cut off the current and immerse the billet in the quenching water tank for water quenching. Cool it to 120±5℃ and control the transfer time within 5s.

[0033] S3. Transfer the quenched blank to a forming press. The blank temperature is 120±5℃. Apply a pressure with a density of 50 A / mm² to the blank at room temperature (25~35℃). 2 A pulsed current is applied, and a servo bending machine is started to apply a load to the blank for plastic deformation. The tensile force during the forming process is 50 t, and the pressure is held for 2 minutes. The current is then unloaded and the blank is removed.

[0034] Example 2 This embodiment provides a method for processing and forming aluminum alloy components coupled with electric and thermal fields. Taking the forming and manufacturing of a 7A09 high-strength aluminum alloy aerospace reinforcing frame (7-series aluminum alloy component) as an example, the method includes the following steps: S1. Clamp the aluminum alloy blank between the two electrodes of the energized circuit and apply an A / mm² pressure. 2 A pulsed current was applied to heat the material to 400±5℃ at a heating rate of 200℃ / s, and the temperature was maintained for 5 min. S2. Immediately after the solution treatment and heat preservation are completed, cut off the current and immerse the billet in the quenching water tank for water quenching. Cool it to 200±5℃ and control the transfer time within 5s.

[0035] S3. Transfer the quenched blank to the forming press, with the blank temperature at 200±5℃; apply a pressure of 10 A / mm² to the blank. 2 A pulsed current is applied, and a servo bending machine is started to apply a load to the blank for plastic deformation. The tensile force during the forming process is 50 t, and the pressure is held for 10 min. The current is then unloaded and the blank is removed.

[0036] Example 3 This embodiment provides a method for processing and forming aluminum alloy components coupled with electric and thermal fields. Taking the forming and manufacturing of a 7A09 high-strength aluminum alloy aerospace reinforcing frame (7-series aluminum alloy component) as an example, the method includes the following steps: S1. Clamp the aluminum alloy blank between the two electrodes of the energized circuit and apply an A / mm² pressure. 2 A pulsed current was applied to heat the material to 600±5℃ at a heating rate of 200℃ / s, and the temperature was maintained for 1 min. S2. Immediately after the solution treatment and heat preservation are completed, cut off the current and immerse the billet in the quenching water tank for water quenching. Cool it to 50±5℃ and control the transfer time within 5s.

[0037] S3. Transfer the quenched blank to the forming press. The blank temperature is 50±5℃. Apply a cooling medium with a density of 100 A / mm² to the blank. 2 A pulsed current is applied, and a servo bending machine is started to apply a load to the blank for plastic deformation. The tensile force during the forming process is 50 t, and the pressure is held for 1 min. The current is then unloaded and the blank is removed.

[0038] Example 4 The difference between this embodiment and Embodiment 1 is that in step S3, a density of 50 A / mm³ is applied to the blank under air-cooling conditions. 2 The current includes: adding an assemblable circulating air device to the outside of the component forming mold for air cooling, and the rest is consistent with Example 1.

[0039] Example 5 The difference between this embodiment and Embodiment 1 is that in step S3, a density of 50 A / mm is applied to the blank under the condition of a cooling medium. 2 The current includes: adding an assemblable cooling device to the component forming mold, with water as the cooling medium, and the rest being consistent with Example 1.

[0040] Comparative Example 1 This comparative example provides a conventional solution heat treatment cold molding and quenching (HFQ) method, including the following steps: S1. Heat the aluminum alloy billet to 470±5℃ at a heating rate of 50℃ / s and hold it at that temperature to allow the alloying elements to fully dissolve. Hold for 30 minutes.

[0041] S2. Quickly transfer the heated blank to the cold mold and stamp it at a high temperature.

[0042] S3. After forming, keep the billet in the mold and use the cooling channel of the mold to quickly quench and cool the component to obtain a supersaturated solid solution structure.

[0043] S4. Place the quenched component in a heat treatment furnace and age it at 120±5℃ for 24 hours to allow the strengthening phase to precipitate and achieve the required mechanical properties.

[0044] Comparative Example 2 The difference between this comparative example and Example 1 is that the current density applied in steps S1 and S3 is 5 A / mm². 2 Everything else is consistent with Example 1.

[0045] Comparative Example 3 The difference between this comparative example and Example 1 is that the current density applied in steps S1 and S3 is 8 A / mm². 2 Everything else is consistent with Example 1.

[0046] Comparative Example 4 The difference between this comparative example and Example 1 is that the current density applied in steps S1 and S3 is 80 A / mm². 2 Everything else is consistent with Example 1.

[0047] Comparative Example 5 The difference between this comparative example and Example 1 is that the current density applied in steps S1 and S3 is 120 A / mm². 2 Everything else is consistent with Example 1.

[0048] Strength tests were conducted on the aluminum alloy components obtained in Examples 1-5 and Comparative Examples 1-5. Tensile specimens were cut and tested for tensile strength, yield strength, and elongation after fracture at room temperature (25-35℃) according to GB / T 228.1 standard. Individual tensile tests were performed to test the mechanical properties after forming, and the average value of multiple tensile specimens was taken. A coordinate measuring machine was used to detect the deviation between the key dimensions of the components and the design model. The test performance of the obtained components is shown in Table 1 below. Table 1 Performance Test Results

[0049] In summary, the data comparison between Examples 1-5 and Comparative Examples 1-5 shows that the aluminum alloy components prepared by the method of the present invention shorten the overall heat treatment and forming cycle from several hours to less than 15 minutes, which can efficiently complete the forming and manufacturing of aluminum alloy components. At the same time, the obtained aluminum alloy components have higher strength, exceeding that of the T6 state, and the components have good plasticity and ductility. The forming accuracy deviation is reduced to the sub-millimeter level (0.3 mm), which fully verifies the decisive role of the multiple effects of the electric field in improving production efficiency and breaking through the limits of traditional heat treatment.

[0050] The embodiments described above are some, but not all, of the embodiments of the present invention; the detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention; all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A composite manufacturing technology for aluminum alloy components using current forming and heat treatment, characterized in that, Includes the following steps: S1. Apply a first current to the aluminum alloy billet for solution treatment, raise the billet to the solution temperature and hold it at that temperature; S2. Quench and cool the billet processed in step S1 to the aging temperature. S3. Apply a second current and a load to the cooled billet from step S2 to perform plastic deformation, and complete the aging treatment during the deformation process.

2. The composite manufacturing technology according to claim 1, characterized in that, In step S1, the first current density is 10-100 A / mm. 2 The solution temperature is 400-600℃, and the holding time is 1-5 minutes.

3. The composite manufacturing technology according to claim 1, characterized in that, In step S2, the aging temperature is 50-200℃.

4. The composite manufacturing technology according to claim 1, characterized in that, In step S3, the second current density is 10-100 A / mm². 2 .

5. The composite manufacturing technology according to claim 1, characterized in that, The quenching and cooling method includes any one of water quenching, oil quenching, die pressing quenching, or mold quenching.

6. The composite manufacturing technology according to claim 1, characterized in that, In step S3, while applying current, a mechanical load is applied to the billet through a loading system, causing the billet to undergo plastic deformation and be formed into the final component shape.

7. The composite manufacturing technology according to claim 1, characterized in that, The current applied in steps S1 and S3 includes continuous or pulsed alternating current or direct current.

8. The composite manufacturing technology according to claim 1, characterized in that, In step S3, the total time for plastic deformation and aging treatment is 1-10 minutes.

9. An aluminum alloy component manufactured using the composite manufacturing technology described in any one of claims 1 to 8.

10. A manufacturing apparatus for implementing the composite manufacturing technology according to any one of claims 1 to 8, characterized in that, include: An energized circuit is used to clamp the aluminum alloy blank and apply a first current and a second current to it. A forming loading system is used to apply mechanical loads to a blank under energized conditions to induce plastic deformation. The cooling system is used to quench and cool the billet after solution treatment.

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