A forming method for aviation aluminum alloy thin-walled structural parts

Abstract

The present invention discloses a forming method for aviation aluminum alloy thin-walled structural parts, which relates to the field of metal sheet metal forming and manufacturing technology, and includes the following steps: step one, pre-forming an O-state blank by warm drawing, deforming it to a shape close to the final geometry of the component, and forming a preform; step two, transferring the preform to a belt heating furnace for a first temperature treatment; step three, performing a second temperature treatment on the preform through the belt heating furnace; step four, final forming and quenching treatment on the preform to obtain the component; step five, performing an aging treatment on the component. The present invention uses low-cost O-state aluminum alloy blanks, and forms large-scale thin-walled aviation aluminum alloy parts with large displacement and local features through warm drawing and hot forming. During the forming process, the temperature evolution of the blank is controlled, and the structure and mechanical properties of the component are guaranteed through intermediate and subsequent heat treatments. This method can replace the multi-step cold drawing and annealing process, simplify the operating procedures, and improve production efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of metal sheet metal forming and manufacturing, and in particular to a forming method for aviation aluminum alloy thin-walled structural parts. Background Art

[0002] For aerospace structural components, lightweighting them not only reduces energy consumption but also improves performance. Material lightweighting is an effective approach to lightweighting aviation equipment. High-strength aluminum alloys, with their high strength-to-density ratio and excellent corrosion resistance, have been widely used in aircraft structural components in recent years.

[0003] This type of aluminum alloy thin-walled components has the following characteristics: 1) It adopts an integral structure, and the presence of welds will affect service reliability, so the petal welding process route is not applicable; 2) The large size wall thickness is ultra-thin and the uniformity requirements are high. The characteristic size of this type of component is often greater than 1m, and the wall thickness is only 2mm, which is relatively ultra-thin. In order to ensure service reliability, high requirements for wall thickness uniformity are placed on it; 3) The shape is complex, and the shape often has deep cavities, large displacements and local features, and high dimensional accuracy; 4) The strength requirements are high, and the components are usually required to reach T62 strength.

[0004] The existing forming route for aluminum alloy thin-walled structural parts is a multi-step cold forming + annealing process. During cold forming, aluminum alloy has poor plasticity at room temperature and is prone to cracking, and has a low elastic modulus, which makes it easy to rebound after forming. When it is necessary to form components with a larger forming depth, it is difficult to obtain the shape of the target component in one cold forming. Therefore, it is necessary to split a forming process into multiple steps, and anneal the component between each drawing step to eliminate the work hardening phenomenon. This process has many steps and is complicated to operate, which greatly reduces production efficiency. In addition, the existing route is limited to the forming of parts with simple shapes, and it is impossible to achieve overall forming for parts with complex local features.

[0005] The hydroforming process uses a liquid medium instead of a rigid die. When the metal blank is pulled into the die by the rigid punch, the pressure of the liquid medium is used to press it against the punch to achieve the forming process. Compared with traditional cold forming, the friction is significantly reduced due to the lubricating effect of the liquid. In addition, the metal drawing ratio is higher and the surface quality of the resulting component is better. However, the forming equipment of the hydroforming process is complex and the manufacturing efficiency is lower. Although it can effectively eliminate springback, additional heat treatment is required after forming to improve the strength of the component. The overall manufacturing cost is also higher.

[0006] Hot gas forming uses a pressurized gas medium to achieve the forming of the blank under heated conditions. Hot gas forming can be divided into superplastic forming and rapid plastic forming. Superplastic forming uses the superplasticity of metals under certain specific conditions to achieve its forming. This process can effectively solve the problem of poor plasticity during aluminum alloy forming. However, the superplastic forming process has low production efficiency and requires the blank to have fine grains and slow growth during forming, which increases the cost. Compared with superplastic forming, rapid plastic forming has lower requirements for the blank and improved production efficiency, but the complexity of the shape of the formable component is not as good as superplastic forming. Its core disadvantage is that the material is bulged and deformed during the hot gas forming process, and the desired shape is obtained by thinning the wall thickness. It is not suitable for the forming of components with large displacement characteristics, and it is difficult to ensure the uniformity of wall thickness.

[0007] Increasing the heating temperature can effectively improve the formability of aluminum alloys and reduce their springback. However, the traditional warm forming temperature range tends to coarsen the precipitate phase in high-strength aluminum alloys, destroying their ideal microstructure. Subsequent heat treatment can easily cause shape distortion in the component during heat treatment. Hot stamping with a rigid die is an advanced forming method for forming high-strength aluminum alloy components. The integrated hot forming-quenching process combines hot forming with heat treatment, quenching the component in the die after hot forming. However, this process requires the alloy billet to be initially in the T4 or T6 state. Furthermore, when forming highly quench-sensitive alloys, very high heating and quenching rates are required to prevent coarsening of the precipitate phase in the alloy during heating.

[0008] In summary, existing forming methods cannot well meet the forming requirements of high-strength aluminum alloy thin-walled parts for aviation. Therefore, a new forming controllable integrated technology is urgently needed to ensure both the forming quality and performance of the parts. Summary of the Invention

[0009] The purpose of the present invention is to provide a forming method for aviation aluminum alloy thin-walled structural parts to solve the problems existing in the above-mentioned prior art. It directly uses low-cost O-state aluminum alloy billets, and through warm drawing and hot forming, forms large-scale aviation aluminum alloy thin-walled parts with large displacement and local characteristics. During the forming process, the temperature evolution of the billet is controlled, and the microstructure and mechanical properties of the components are guaranteed through intermediate and subsequent heat treatment processes. This method can replace the traditional multi-step cold drawing and annealing process, simplify the operating procedures, and improve production efficiency.

[0010] To achieve the above object, the present invention provides the following solutions:

[0011] The present invention provides a forming method for aviation aluminum alloy thin-walled structural parts, which is characterized by comprising the following steps:

[0012] Step 1: warm drawing the O-state blank to preform it into a shape close to the final geometry of the component to form a preform;

[0013] Step 2: quickly transfer the preform to a belt heating furnace for a first temperature treatment;

[0014] Step 3: performing a second temperature treatment on the preform in a belt heating furnace, wherein the temperature of the second temperature treatment is lower than the temperature of the first temperature treatment;

[0015] Step 4: final forming and quenching the preform to obtain a component;

[0016] Step five: perform aging treatment on the components.

[0017] Preferably, the O-state billet is a 2xxx aluminum alloy, a 6xxx aluminum alloy or a 7xxx aluminum alloy.

[0018] Preferably, in step 1, the temperature range of warm drawing preforming is 0.4T m Up to 0.6T m , T m The melting point of the O-state blank is 0.04°C / s to 20.04°C / s, and the preforming speed of the blank is 2mm / s to 200mm / s.

[0019] Preferably, the temperature of the first temperature treatment in step 2 and the temperature of the second temperature treatment in step 3 are both no higher than the solution treatment temperature.

[0020] Preferably, the temperature of the first temperature treatment in step 2 and the temperature of the second temperature treatment in step 3 depend on the phase transition temperature of the aluminum alloy precipitation phase.

[0021] Preferably, the temperature of the second temperature treatment in step three is the same as the final forming temperature in step four.

[0022] Preferably, the component material obtained in step 4 is in a state of a precipitated phase with controlled size.

[0023] Preferably, the final forming temperature in step 4 is lower than the solution treatment temperature.

[0024] Preferably, the final forming in step 4 is performed by rapid hot stamping, with a forming speed of 150 mm / s to 400 mm / s.

[0025] Preferably, the apparatus used in the forming method of the aviation aluminum alloy thin-walled structural parts includes a preforming press, a belt heating furnace, a final forming press and an aging furnace, the preforming press is used to perform warm deep drawing preforming on the O-state blank, the belt heating furnace is used to perform a first temperature treatment and a second temperature treatment on the preform, the final forming press is used to perform final forming and quenching treatment on the preform, and the aging furnace is used to perform aging treatment on the component.

[0026] Preferably, the belt heating furnace includes a furnace body and a conveyor belt, the furnace body includes a high-temperature zone and a low-temperature zone, the high-temperature zone and the low-temperature zone are both provided with heating wires, the high-temperature zone is used to perform a first temperature treatment on the preform, and the low-temperature zone is used to perform a second temperature treatment on the preform, a furnace door is provided between the high-temperature zone and the low-temperature zone, and the conveyor belt is used to transport the preform from the high-temperature zone to the low-temperature zone.

[0027] Compared with the prior art, the present invention has achieved the following technical effects:

[0028] The present invention combines forming and property control of aviation aluminum alloy thin-walled structural components. This method directly utilizes low-cost, O-state aluminum alloy billets and employs a two-step, differential temperature forming process involving warm drawing and hot forming. This method creates large, thin-walled aviation aluminum alloy components that exhibit both large displacements and localized features. The excellent hardenability of O-state aluminum alloy is leveraged to ensure excellent wall thickness uniformity. Pre-forming at a lower temperature can not only avoid the formation of low melting point phases in 2××× and 7××× aluminum alloys, but also make the aluminum alloy stronger and less prone to adhesion. Compared with hot forming, it can effectively reduce friction between interfaces and avoid the use of lubricants. During the first temperature treatment and the second temperature treatment, the coarse precipitate phase is dissolved. During the aging treatment, a fine precipitate phase is precipitated. Under the joint action of the two, the microstructure of the final component has fine and dispersed precipitates of different sizes. The smaller precipitate phases have a strengthening effect, and the larger precipitate phases can improve the corrosion resistance of the aluminum alloy. Through the intermediate and subsequent heat treatment processes, the high-temperature coarse precipitate phase is dissolved, and the size of the coarse medium-temperature precipitate phase is reduced to ensure the organization and mechanical properties of the component. The obtained component can ensure that its strength meets the corresponding requirements while ensuring shape accuracy and wall thickness uniformity. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 This is a flow chart of the forming method of the aviation aluminum alloy thin-walled structural part of the present invention;

[0031] Figure 2 Schematic diagram of a curve showing the temperature change of a component over time in the forming method of an aviation aluminum alloy thin-walled structural component of the present invention;

[0032] Figure 3 A schematic diagram of the equipment used in the method for forming thin-walled aviation aluminum alloy structural parts of the present invention;

[0033] Figure 4 A schematic structural diagram of a belt-type heating furnace with a single conveyor belt used in the forming method of aviation aluminum alloy thin-walled structural parts of the present invention;

[0034] Figure 5 A schematic structural diagram of a belt heating furnace with two conveyor belts used in the forming method of aviation aluminum alloy thin-walled structural parts of the present invention;

[0035] Figure 6 True stress-strain curves obtained from hot uniaxial tensile tests of O-state 7075 aluminum alloy used in the forming of thin-walled aviation aluminum alloy structural parts;

[0036] Figure 7 This is a graph showing the changes in temperature and Vickers hardness during the forming experiment of 7075 aviation aluminum alloy thin-walled structural parts;

[0037] Figure 8 Schematic diagram of the microstructure evolution of the alloy during the forming process of aviation aluminum alloy thin-walled structural parts;

[0038] Among them: 1-preforming press, 2-belt heating furnace, 3-final forming press, 4-aging furnace, 5-furnace body, 6-conveyor belt, 7-furnace wall, 8-furnace chamber, 9-high temperature zone, 10-low temperature zone, 11-electric heating wire, 12-furnace door. DETAILED DESCRIPTION

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] The purpose of the present invention is to provide a forming method for aviation aluminum alloy thin-walled structural parts to solve the problems existing in the above-mentioned prior art. It directly uses low-cost O-state aluminum alloy billets, and through warm drawing and hot forming, forms large-scale aviation aluminum alloy thin-walled parts with large displacement and local characteristics. During the forming process, the temperature evolution of the billet is controlled, and the microstructure and mechanical properties of the components are guaranteed through intermediate and subsequent heat treatment processes. This method can replace the traditional multi-step cold drawing and annealing process, simplify the operating procedures, and improve production efficiency.

[0041] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] like Figure 1-Figure 2As shown: This embodiment provides a forming method for aviation aluminum alloy thin-walled structural parts, comprising the following steps:

[0043] Step 1: Using the good ductility and hardening properties of the O-state blank, the O-state blank is preformed by warm drawing. The temperature of warm drawing preforming is T F-1 Below the recrystallization temperature, the range is 0.4T m Up to 0.6T m , T m The melting point of the O-state blank. For aluminum alloys, the temperature range of warm deep drawing preforming is approximately 150°C to 350°C. The blank can be heated by common methods such as furnace heating, induction heating, and current heating. The heating rate of the blank is 1°C / s to 20°C / s, and the preforming speed of the blank is 2mm / s to 200mm / s, so that it is deformed to a geometric shape close to the final component to form a preform.

[0044] The temperature of the mold used for preforming can be room temperature or isothermal. If it is an isothermal mold, the mold can be heated by a built-in heating element, and the mold temperature is not higher than the billet temperature;

[0045] Step 2: The preform is quickly transferred to the belt heating furnace 2 for the first temperature treatment, and is quickly heated to a temperature higher than the preforming temperature and drawing temperature T F-1 The first temperature treatment temperature T H-1 The first temperature treatment is performed, which is a high temperature treatment. The temperature of the first temperature treatment is T H-1 The high-temperature coarse precipitate phase of the aluminum alloy should be dissolved; the type of high-temperature precipitate phase varies for different types of aluminum alloys; for 2××× (Al-Cu, Al-Cu-Mg and Al-Cu-Li) series aluminum alloys, such as 2219 aluminum alloy, the high-temperature precipitate phase is θ phase; for 6××× (Al-Mg-Si) series aluminum alloys, such as 6082 aluminum alloy, the high-temperature precipitate phase is β phase; for 7××× (Al-Zn-Mg and Al-Zn-Mg-Cu) series aluminum alloys, such as 7075 aluminum alloy, the high-temperature precipitate phase is S phase;

[0046] Temperature T of the first temperature treatment of different types of aluminum alloys H-1 The values ​​of are different; for 2××× (Al-Cu, Al-Cu-Mg and Al-Cu-Li) series aluminum alloys, such as 2219 aluminum alloy, the temperature range of the first temperature treatment is approximately 400°C to 500°C; for 6××× (Al-Mg-Si) series aluminum alloys, such as 6082 aluminum alloy, the temperature range of the first temperature treatment is approximately 450°C to 500°C; for 7××× (Al-Zn-Mg and Al-Zn-Mg-Cu) series aluminum alloys, such as 7150 aluminum alloy, the temperature range of the first temperature treatment is approximately 400°C to 450°C;

[0047] Step 3: The preform is transferred from the high temperature zone 9 in the belt heating furnace 2 to the low temperature zone 10 via the conveyor belt 6, so that its temperature is increased from the first temperature treatment temperature T H-1 Drop to the final forming temperature T F-2 The second temperature treatment is carried out continuously. The second temperature treatment is low temperature treatment. The temperature of the second temperature treatment is lower than that of the first temperature treatment. The final forming temperature T F-2 The coarse medium-temperature precipitated phase should be dissolved to reduce its size, so that it has a certain strengthening effect. The types of medium-temperature precipitated phases vary for different types of aluminum alloys. For 2××× (Al-Cu, Al-Cu-Mg and Al-Cu-Li) series aluminum alloys, such as 2219 aluminum alloy, the medium-temperature precipitated phase is θ' phase; for 6××× (Al-Mg-Si) series aluminum alloys, such as 6082 aluminum alloy, the medium-temperature precipitated phases are β' and β" phases; for 7××× (Al-Zn-Mg and Al-Zn-Mg-Cu) series aluminum alloys, such as 7075 aluminum alloy, the medium-temperature precipitated phase is η phase.

[0048] Final forming temperature T of different types of aluminum alloys F-2 The values ​​of are different; for 2××× (Al-Cu, Al-Cu-Mg and Al-Cu-Li) series aluminum alloys, such as 2219 aluminum alloy, the final forming temperature range is approximately 300℃~400℃; for 6××× (Al-Mg-Si) series aluminum alloys, such as 6082 aluminum alloy, the final forming temperature range is approximately 300℃~400℃; for 7××× (Al-Zn-Mg and Al-Zn-Mg-Cu) series aluminum alloys, such as 7150 aluminum alloy, the final forming temperature range is approximately 300℃~350℃.

[0049] The temperature of the first temperature treatment in step 2 and the temperature of the second temperature treatment in step 3 should not be higher than the solution treatment temperature. The specific temperature depends on the phase transition temperature of the aluminum alloy precipitation phase (such as β phase or S phase). For 2××× (Al-Cu, Al-Cu-Mg and Al-Cu-Li) aluminum alloys, 6××× (Al-Mg-Si) aluminum alloys and 7××× (Al-Zn-Mg and Al-Zn-Mg-Cu) aluminum alloys, the temperature is 420~585℃, which can be carried out continuously in the variable temperature belt heating furnace 2 without the need for a hot and cold cycle process of heating and cooling the components after keeping them at ultra-low temperature. The treatment holding time is less than 30min to avoid coarse grains.

[0050] Step 4: Maintain the temperature of the preform after the first temperature treatment and the second temperature treatment at the final forming temperature T F-2The aluminum alloy is transferred to the final forming press 3 for final forming to form the local features of the component and is quenched in the mold to obtain a component. The material state of the component is not a supersaturated solid solution, but a state with a precipitate phase of controlled size (obtained by dissolving the coarse precipitate phase of the original O-state aluminum alloy);

[0051] Final forming is performed by rapid hot stamping at a forming speed of 150 mm / s to 400 mm / s. The final forming temperature is the same as that of the second temperature treatment and is lower than the solution treatment temperature. This ensures the formation of local features while avoiding the formation of low-melting-point phases. For 2×××, 6×××, and 7××× aluminum alloys, the forming temperature range is approximately 300°C to 400°C.

[0052] Step 5: Perform a short and rapid artificial aging treatment on the component to improve the strength of the component to the use requirements. When it is necessary to improve the strength of the component to a certain extent, the selected temperature is the standard aging temperature of the material, and the aging temperature of 2××× (Al-Cu, Al-Cu-Mg and Al-Cu-Li) series aluminum alloys, 6××× (Al-Mg-Si) series aluminum alloys and 7××× (Al-Zn-Mg and Al-Zn-Mg-Cu) series aluminum alloys is 120°C to 240°C.

[0053] Furthermore, the rapid aging conditions for different types of aluminum alloys are different; for 2××× (Al-Cu, Al-Cu-Mg and Al-Cu-Li) series aluminum alloys, such as 2219 aluminum alloy, the rapid aging conditions are 220℃~240℃×5min+175℃×4h; for 6××× (Al-Mg-Si) series aluminum alloys, such as 6082 aluminum alloy, the rapid aging conditions are 210℃×30min~55min+180℃×30min; for 7××× (Al-Zn-Mg and Al-Zn-Mg-Cu) series aluminum alloys, such as 7075 aluminum alloy, the rapid aging conditions are 125℃~135℃×10min+180℃×30min.

[0054] The forming method of the aviation aluminum alloy thin-walled structural component of this embodiment first performs warm deep drawing pre-forming on the O-state billet to deform it to a geometric shape close to the final geometric shape of the component; secondly, the preform is quickly transferred to a belt heating furnace 2 with a segmented temperature distribution, and continuously treated with the first temperature and the second temperature to dissolve the high-temperature coarse precipitate phase and reduce the size of the coarse medium-temperature precipitate phase; then the preform treated with the first temperature and the second temperature is transferred to the final forming press 3 to form the local features of the component, and quenched in the mold to obtain a component with a target shape; finally, the component is subjected to a short and rapid artificial aging treatment to precipitate a large number of fine-sized strengthening phases to improve the strength of the component to the use requirements.

[0055] In this embodiment, Figure 3 As shown, the device used in the forming method of aviation aluminum alloy thin-walled structural parts includes a preforming press 1, a belt heating furnace 2, a final forming press 3 and an aging furnace 4. The preforming press 1 is used to perform warm deep drawing preforming on the O-state blank, the belt heating furnace 2 is used to perform a first temperature treatment and a second temperature treatment on the preform, the final forming press 3 is used to perform final forming and quenching treatment on the preform, and the aging furnace 4 is used to perform aging treatment on the component.

[0056] In this embodiment, Figure 4-Figure 5 As shown, the belt heating furnace 2 includes a furnace body 5 and a conveyor belt 6. The furnace chamber 8 in the furnace wall 7 includes a high-temperature zone 9 and a low-temperature zone 10. Both the high-temperature zone 9 and the low-temperature zone 10 are provided with electric heating wires 11. The temperature of the high-temperature zone 9 is T1, which is used to perform a first temperature treatment on the preform. The temperature of the low-temperature zone 10 is T2, which is used to perform a second temperature treatment on the preform. A furnace door 12 is provided between the high-temperature zone 9 and the low-temperature zone 10. The conveyor belt 6 is used to transport the preform from the high-temperature zone 9 to the low-temperature zone 10.

[0057] In this embodiment, Figure 4 As shown, the conveyor belt 6 can be one, the conveying speed is v, and both ends of the conveyor belt 6 are located outside the furnace body 5; Figure 5 As shown, there may be two conveyor belts 6, one conveyor belt 6 is located in the high temperature zone 9, and the conveying speed is v1, and the other conveyor belt 6 is located in the low temperature zone 10, and the conveying speed is v2.

[0058] The forming method of the aviation aluminum alloy thin-walled structural parts of this embodiment directly uses low-cost O-state aluminum alloy billets, adopts a two-step differential temperature forming method, and forms large-scale aviation aluminum alloy thin-walled parts with large displacement and local features through warm drawing and hot forming. During the forming process, the temperature evolution of the billet is controlled, and the intermediate and subsequent heat treatment processes are used to ensure the microstructure and mechanical properties of the component. This method first performs warm drawing on the O-state billet, and the forming temperature range is generally (0.4-0.6)T m , T m The melting point of the material is 1.5°C. Its excellent hardening properties are utilized to achieve large displacement characteristics within the formed component's depth, while deep drawing deformation ensures uniform wall thickness. After warm drawing, the warm-drawn preform is subjected to sequential first and second temperature treatments using a variable-temperature belt heating furnace 2. The first temperature treatment rapidly dissolves the coarse precipitates within the component material, while the subsequent second temperature treatment reduces the precipitates, controlling their size and imparting a certain strengthening effect. Finally, the preform is transferred to the final forming press 3, where local features are rapidly stamped and formed, followed by quenching within the mold. The formed component then undergoes aging treatment, allowing the non-steady-state structure to precipitate fine strengthening phases before aging, meeting the component's performance and strength requirements.

[0059] This embodiment can produce aviation aluminum alloy thin-walled parts with large depth and local features, replacing the traditional multi-step cold drawing and annealing process, simplifying the operation process and improving production efficiency; directly using O-state material for forming not only effectively saves costs, but also can use its good hardening performance to ensure the uniformity of component wall thickness; through high temperature and second temperature treatment, the high-temperature coarse precipitate phase is dissolved, and the size of the medium-temperature precipitate phase is reduced to a level close to that of the strengthening phase, and fine precipitate phases of different sizes are obtained in the subsequent aging treatment, while ensuring the quality of component forming, its strength and corrosion resistance can also meet the use requirements.

[0060] Application Example 1

[0061] The material used for forming aviation aluminum alloy thin-walled structural parts is O-state 7075 aluminum alloy, and the true stress-strain curve obtained from the hot uniaxial tensile test is as follows: Figure 6 When the temperature is below 350°C, the flow stress in the plastic stage increases significantly compared to when the temperature is above 350°C. This indicates that within this temperature range, the aluminum alloy has good hardening properties, which is conducive to deep drawing deformation. After deformation, it can better resist subsequent deformation, which is conducive to repeated alternating deformation inside the component, thereby ensuring the uniformity of component deformation and wall thickness.

[0062] The forming method of the aviation aluminum alloy 7075 thin-walled structural part comprises the following steps:

[0063] Step 1: heating the O-state 7075 aluminum alloy billet to 350° C. at a heating rate of 1° C. / s and preforming at 350° C.;

[0064] Step 2: The preform is taken out from the preforming press 1 and then placed in a belt heating furnace 2, where it is heated to about 535° C. for about 200 seconds for a first temperature treatment;

[0065] Step 3: The preform is transported from the high temperature zone 9 to the low temperature zone 10 in the belt heating furnace 2, and its temperature is lowered to about 390°C for a second temperature treatment;

[0066] Step 4: Transfer the preform to the final forming press 3, perform final forming under non-isothermal conditions, and then quench in the mold to quickly cool it to room temperature;

[0067] Step five: subject the component to aging treatment at 125°C~135°C×10min+180°C×30min.

[0068] Figure 7 This figure shows the changes in temperature and Vickers hardness during the forming experiments of thin-walled structural components made of 7075 aviation aluminum alloy. After aging treatment, the component's Vickers hardness reaches HV116, a nearly 90% increase compared to its initial hardness of HV61.5. Figure 8This diagram illustrates the evolution of the alloy microstructure during the forming process of thin-walled aviation aluminum alloy components. Steps 2 through 4 dissolve the coarse, high-temperature precipitates still present in the O-state aluminum alloy from step 1, reducing the size of the coarse, intermediate-temperature precipitates. In step 5, a large number of fine, reinforcing phases precipitate, resulting in the formation of fine, dispersed precipitates of varying sizes within the aluminum alloy matrix, ultimately ensuring the component's strength and corrosion resistance meet service requirements.

[0069] Application Example 2

[0070] A method for forming a thin-walled structural part of aviation aluminum alloy 2219 includes the following steps:

[0071] Step 1: heating the 2219 aluminum alloy blank in an O state to about 350° C. at a heating rate of 1° C. / s to 20° C. / s, and performing warm deep drawing preforming at the same temperature;

[0072] Step 2: The preform is taken out from the preforming press 1 and then placed in a belt heating furnace 2 to be heated to about 450° C. for a first temperature treatment;

[0073] Step 3: The preform is transported from the high temperature zone 9 to the low temperature zone 10 in the belt heating furnace 2, and its temperature is lowered to about 350°C to 450°C for a second temperature treatment;

[0074] Step 4: The preform is transferred to the final forming press 3, quenched in the mold after final forming, and the formed component is quickly cooled to room temperature in the mold;

[0075] Step 5: Perform aging treatment on the component at 175°C to 240°C, with the aging time not less than 20 minutes.

[0076] This specification uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A method for forming thin-walled aviation aluminum alloy structural parts, characterized by: The following steps are involved: Step 1: warm drawing the O-state blank to preform it into a shape close to the final geometry of the component to form a preform; Step 2: transferring the preform to a belt heating furnace for a first temperature treatment; Step 3: performing a second temperature treatment on the preform in a belt heating furnace, wherein the temperature of the second temperature treatment is lower than the temperature of the first temperature treatment; Step 4: final forming and quenching the preform to obtain a component; Step five, perform aging treatment on the components; The temperature of the first temperature treatment in step 2 and the temperature of the second temperature treatment in step 3 are both not higher than the solution treatment temperature; The temperature of the first temperature treatment in step 2 and the temperature of the second temperature treatment in step 3 depend on the precipitation phase transition temperature of the aluminum alloy; The temperature of the second temperature treatment in step 3 is the same as the final forming temperature in step 4; The temperature of the first temperature treatment ensures that the high-temperature coarse precipitate phase of the aluminum alloy is dissolved; The final forming temperature ensures that the coarse medium-temperature precipitate phase dissolves.

2. The method for forming an aviation aluminum alloy thin-walled structural part according to claim 1, wherein: The O-state blank is 2××× series aluminum alloy, 6××× series aluminum alloy or 7××× series aluminum alloy; in the step 1, the temperature range of warm deep drawing preforming is 0.4T m Up to 0.6T m , T m The melting point of the O-state blank is 0.04°C / s to 20.04°C / s, and the preforming speed of the blank is 2mm / s to 200mm / s.

3. The forming method of aviation aluminum alloy thin-walled structural parts according to claim 1, characterized in that: The component material obtained in step 4 is in a state of a precipitated phase with controlled size.

4. The method for forming an aviation aluminum alloy thin-walled structural part according to claim 1, wherein: The final forming temperature in step 4 is lower than the solution treatment temperature.

5. The method for forming an aviation aluminum alloy thin-walled structural part according to claim 1, wherein: The final forming in step 4 is performed by rapid hot stamping, with a forming speed of 150 mm / s to 400 mm / s.

6. The method for forming an aviation aluminum alloy thin-walled structural part according to claim 1, wherein: The apparatus used in the forming method of aviation aluminum alloy thin-walled structural parts includes a preforming press, a belt heating furnace, a final forming press and an aging furnace. The preforming press is used to perform warm deep drawing preforming on O-state blanks, the belt heating furnace is used to perform first temperature treatment and second temperature treatment on preforms, the final forming press is used to perform final forming and quenching treatment on preforms, and the aging furnace is used to perform aging treatment on components.

7. The method for forming an aviation aluminum alloy thin-walled structural part according to claim 1, wherein: The belt heating furnace includes a furnace body and a conveyor belt. The furnace body includes a high-temperature zone and a low-temperature zone. Both the high-temperature zone and the low-temperature zone are provided with heating wires. The high-temperature zone is used to perform a first temperature treatment on the preform, and the low-temperature zone is used to perform a second temperature treatment on the preform. A furnace door is provided between the high-temperature zone and the low-temperature zone, and the conveyor belt is used to transport the preform from the high-temperature zone to the low-temperature zone.

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