A method for preparing a door-shaped arc frame aluminum alloy aviation die forging

Abstract

The application relates to a preparation method of a door-shaped arc frame aluminum alloy aviation die forging, and belongs to the technical field of metal materials. The method solves the problems of non-forming, folding defects and substandard mechanical properties in the preparation of the existing door-shaped arc frame aluminum alloy aviation die forging. The method comprises the following steps: S1, casting an aluminum alloy ingot; S2, forging a blank; S3, center punching; S4, sawing; S5, locally elongating; S6, after heating, four times of die forging are carried out, and etching, pre-fire inspection, quenching treatment and aging treatment are sequentially carried out, so that the preparation is completed. The door-shaped arc frame aluminum alloy aviation die forging manufactured by the application not only meets the standard requirements in size, but also is easy to form, has high material utilization rate, is not prone to folding defects, increases the service life of the die forging, meets the performance requirements of the door-shaped arc frame aluminum forging of an airplane, and improves the stress deformation characteristics in the machining process and the use process of the user. The application is suitable for manufacturing the door-shaped arc frame aluminum alloy aviation die forging.

Description

Technical Field

[0001] This invention belongs to the field of metal materials technology, specifically relating to a method for preparing aluminum alloy aerospace die forgings with portal-shaped arc frames. Background Technology

[0002] With the rapid development of the aerospace industry, the performance requirements for high-strength aluminum alloy structural components are becoming increasingly stringent. Structural components are evolving towards higher performance, precision, and complexity. Some load-bearing structural components in advanced trainer aircraft, influenced by the operating environment, need to be designed in a portal shape. These components not only require high performance but also a defect-free surface to prevent deformation during use, placing even higher demands on these irregularly shaped structural components.

[0003] The existing forgings of this type have a gate-shaped structure. If the blank size is not up to standard, the forgings will be unformed and defective after molding. The arc stress is large after quenching, which often leads to deformation and inability to process. There are many reinforcing ribs on the arc. After molding, there are folding defects. If the defects are not repaired properly, the parts are very easy to break along the folds during use, which can lead to aircraft safety hazards. Summary of the Invention

[0004] The purpose of this invention is to solve the problems of incomplete forming, folding defects and substandard mechanical properties in the preparation of existing portal-shaped arc frame aerospace die forgings, and to provide a manufacturing method for portal-shaped arc frame aluminum alloy aerospace die forgings.

[0005] The present invention discloses a method for preparing an aluminum alloy aerospace die forging with a portal-shaped arc frame, which comprises the following steps:

[0006] I. Cast aluminum alloy ingots: The mass percentage of elements in the aluminum alloy ingots is as follows: Si ≤0.7%~1.2%, Fe ≤0.7%, Cu 1.8%~2.6%, Mn ≤0.4%~0.8%, Mg 0.4%~0.8%, Ni ≤0.10%, Zn ≤0.30%, Fe+Ni ≤0.7%, Ti ≤0.15%, individual impurities ≤0.05%, total impurities ≤0.10%, and the remainder is Al;

[0007] 2. After the cast aluminum alloy ingot is loaded into the furnace, it is heated to 460℃~480℃. The initial forging temperature of the blank is 440℃. Then, it is forged in multiple directions on a 5000-ton vertical free forging hydraulic press. The die temperature is 350℃~400℃. It is forged to 880+10×850+10×125+5mm.

[0008] 3. Heat the blank from step 2 to 350-420℃, and then perform center punching on a 5000-ton vertical free forging hydraulic press with a punching diameter of Ф300mm.

[0009] IV. Break the blank in two along its length from the center of the punch (e.g., ...Figure 1 );

[0010] V. Partial Elongation During Blank Heating: Heat the blank obtained in step four to 420℃~450℃. The initial forging temperature for the first piece is 430℃~440℃, the final forging temperature for the first piece is 400℃~430℃, the initial forging temperature for the last piece is 430℃~450℃, the final forging temperature for the last piece is 400℃~430℃, and the die temperature is 360℃~380℃. Partially elongate the blank and punch a Ф200mm center hole at the center of the top of the arc to obtain the forging blank (e.g., Figure 2 );

[0011] VI. Heating and molding the blank obtained in step five: The blank obtained in step five is heated to 420℃~450℃, the first forging temperature is 430℃~440℃, the first final forging temperature is 400℃~430℃, the last forging temperature is 430℃~450℃, the last final forging temperature is 400℃~430℃, and the die temperature is 360℃~380℃. Four forging processes are performed, followed by etching and cleaning, pre-fire inspection, quenching treatment, and aging treatment, thus completing the preparation of the aforementioned portal-shaped arc frame aluminum alloy aerospace die forging.

[0012] The aluminum alloy ingot is a cylindrical ingot with dimensions of Φ405×750mm.

[0013] In step one of this invention, the aluminum alloy ingot is cast using conventional methods. In step five, the punching position and size must meet specified dimensions to facilitate the forming of the forging.

[0014] Further, the mass percentage of elements in the aluminum alloy ingot mentioned in step one is as follows: Si 0.80%, Fe 0.6%, Cu 2.5%, Mn 0.70%, Mg 0.6%, Ni 0.1%, Zn 0.30%, Ti 0.10%, individual impurities ≤0.05%, total impurities ≤0.10%, and the remainder is Al.

[0015] Furthermore, in step one, the aluminum alloy ingot is a cylindrical ingot with dimensions of Φ405×750mm.

[0016] Furthermore, the multi-face forging described in step two involves two blocks and two pulls.

[0017] The present invention employs a multi-faceted forging process (two upsetting and two drawing) to ensure sufficient deformation of the aluminum alloy and to guarantee the qualified performance of the aluminum alloy after subsequent molding.

[0018] Furthermore, in step three, the heating temperature is as follows: the blank is heated to 350-400℃, and then a center hole is punched on a 5000-ton vertical free forging hydraulic press with a punching diameter of Ф300mm.

[0019] Further, in step five, the forging and drawing process involves heating the blank to 420°C–450°C, then performing localized drawing on a 5000-ton vertical free forging hydraulic press, and punching a Ф200mm center hole at the top center of the arc to obtain the forging blank.

[0020] Furthermore, the heating regime in steps five and six is ​​the same: the blank is heated to 430℃~440℃, the first forging temperature is 430℃~440℃, the first final forging temperature is 410℃~420℃, the last forging temperature is 440℃~450℃, the last final forging temperature is 410℃~420℃, and the die temperature is 370℃~380℃.

[0021] Furthermore, in step six, the four-stage die forging process involves: before die forging, using compressed air to remove impurities from the die cavity, installing the upper and lower dies and lubricating them with sand oil; when the forgings exit the furnace, ensuring that the initial and final forging temperatures of the first and last pieces in each horizontal stack are 420℃~450℃; die forging is performed in a 5000-ton vertical free forging hydraulic press; the forgings undergo four die forging processes, with four rounds of lubrication and pressing during the final pressing; then the machine is lifted to release air before pressing is resumed; the first piece is inspected, and the marking is printed in the specified position; then the burrs are removed, with the remaining burrs being less than or equal to 8mm, and undercutting is not allowed.

[0022] Furthermore, the fourth lubrication process uses a mixture of abrasive oil and graphite as the lubricant; the mass ratio of the abrasive oil to graphite is 7:(2-3).

[0023] Further, in step six, the etching and repair process involves placing the workpiece upright in a stainless steel etching basket and etching and degreasing it in an alkaline bath of 15%–20 wt% NaOH at 50°C–70°C for 10–20 minutes. Then, it is rinsed in a cold water bath at room temperature to remove the alkaline solution, followed by neutralization and whitening in an acid bath of 30–40 wt% HNO3 at room temperature for 5–8 minutes. The acid solution is then rinsed in a cold water bath at room temperature, and finally, the workpiece is rinsed in a hot water bath at 50–70°C. After rinsing, the workpiece is placed on a repair area with aluminum pads on the ground for repair, and any defects in the forging are inspected and removed.

[0024] Furthermore, the aging treatment described in step six involves aging at 153℃~160℃, with a holding time of 8 hours for the metal and a total heating time of 8 hours~14 hours.

[0025] The purpose of the side-standing placement described in this invention is to prevent the etching liquid from flowing in and out of the inner cavity of the forging, thus ensuring incomplete etching.

[0026] The defects in the forgings described in this invention refer to defects such as folding, lack of form, and dents.

[0027] In this invention, the forgings are placed upright in a special stainless steel etching basket, and care must be taken to prevent them from being bumped or damaged during the process.

[0028] Further, the quenching treatment described in step six: the forgings and test materials that have completed the pre-quenching inspection are placed flat in the quenching basket and quenched at 510℃~516℃. The air holding time is 210~240min, and the temperature of the water used for quenching is 50℃~60℃. The quenching transfer time is less than or equal to 15s, and the quenching basket is raised and lowered in the water more than 5 times. After staying in the water for 15min, it is lifted out of the water. When marking the quenching furnace number, it must be marked to the specified position.

[0029] In this invention, the imprint is printed in a specified position, and the characters must be neat and clear.

[0030] Furthermore, the aging treatment described in step six involves aging at 153℃~160℃, with a holding time of 8 hours for the metal and a total heating time of 8 hours~14 hours.

[0031] When loading the material into the aging furnace, the material rack of this invention must be arranged to facilitate the smooth flow of circulating air, so as to ensure uniform and rapid heating.

[0032] In this invention, after aging treatment, the sample is taken for analysis and performance testing.

[0033] Further, in step six, the four-stage die forging process involves: before die forging, using compressed air to remove impurities from the die cavity, installing the upper and lower dies and lubricating them with sand oil; when the forgings exit the furnace, ensuring that the initial and final forging temperatures of the first and last pieces in each horizontal stack are both 400℃~450℃; die forging is performed in a 5000-ton vertical free forging hydraulic press; the forgings undergo four die forging processes, with four rounds of lubrication and pressing during the final pressing; then the machine is lifted to release air before pressing is resumed; the first piece is inspected, and the marking is printed in the specified position; then the burrs are removed, with the remaining burrs being less than or equal to 8mm, and undercutting is not allowed.

[0034] In this invention, the workpiece is placed flat in a square quenching basket to facilitate the flow of water within the forging cavity.

[0035] In this invention, the imprint is printed in a specified position, and the characters must be neat and clear.

[0036] Furthermore, in step two, the aluminum alloy ingots must be cleaned of dust, aluminum shavings, and burrs before being loaded into the furnace; during loading, the aluminum alloy ingots must be placed neatly and stably on the material tray.

[0037] Furthermore, the test sample is obtained by randomly selecting one die forging from the same batch that has completed the pre-fire inspection, cutting and sampling it.

[0038] The present invention has the following beneficial effects:

[0039] This invention solves the problems of incomplete molding and folding defects in door-shaped arc frames. By optimizing the process, stress deformation is resolved, mechanical properties meet standards, and stable supply can be achieved.

[0040] The portal-shaped arc frame aluminum alloy aerospace die forging manufactured by this invention not only meets the standard requirements in terms of size, but also improves the overall performance of the portal-shaped forging, improves the stress deformation characteristics during the machining and use process, reduces defects in low-magnification structure, improves the load-bearing capacity of the die forging, and increases the service life of the portal-shaped arc frame aluminum alloy aerospace die forging, thus meeting the requirements of portal-shaped arc frame aluminum alloy aerospace die forging.

[0041] This invention discloses a method for manufacturing aluminum alloy aerospace forgings with portal-shaped arc frames. Characterized by improved load-bearing capacity of irregularly shaped forgings, the method facilitates easy forming, high material utilization, and minimizes the risk of folding defects, thereby increasing the service life of the forgings and meeting the performance requirements of aluminum forgings with portal-shaped arc frames for aircraft. This invention enables stable production of irregularly shaped structural components, reducing the manufacturing cost of advanced jet trainers. This technology has broad application value in the aerospace field, and can be used in the actual production of similar irregularly shaped forgings to improve their load-bearing capacity and service life. It also has significant social implications for strengthening national defense modernization and offers substantial economic benefits.

[0042] This invention is applicable to the manufacture of aluminum alloy aerospace die forgings with portal-shaped arc frames. Attached Figure Description

[0043] Figure 1 This invention is illustrated in Figure 1, showing a two-part pattern along the length of the blank, with the center of the punch hole in between.

[0044] Figure 2 This is a schematic diagram of a forging blank;

[0045] Figure 3 The images shown are photographs of forgings folded according to an embodiment. In Figure A, the forging with folds is shown, and in Figure B, the forging folding defect is resolved using the solution described in the embodiment. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the spirit of the contents disclosed in the present invention will be described in detail below. After understanding the embodiments of the present invention, any person skilled in the art can make changes and modifications based on the technology taught in the present invention without departing from the spirit and scope of the present invention.

[0047] The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

[0048] The beneficial effects of the present invention are verified through the following embodiments:

[0049] Example:

[0050] The preparation method of aluminum alloy aerospace die forgings with portal-shaped arc frames is carried out according to the following steps:

[0051] I. Casting of Aluminum Alloy Ingots: The aluminum alloy ingots are cylindrical ingots with dimensions of Φ405×750mm; the mass percentage of elements in the aluminum alloy ingots is as follows: Si 0.80%, Fe 0.6%, Cu 2.5%, Mn 0.70%, Mg 0.6%, Ni 0.1%, Zn 0.30%, Ti 0.10%, with individual impurities ≤0.05%, total impurities ≤0.10%, and the remainder being Al;

[0052] 2. After the above-mentioned aluminum alloy ingots are loaded into the furnace, they are heated to 460℃~480℃. The initial forging temperature of the blank is 440℃. Then, multi-directional forging (two upsetting and two drawing) is carried out on a 5000-ton vertical free forging hydraulic press. The die temperature is 350℃~400℃. The forging is 880+10×850+10×125+5mm.

[0053] 3. The above-mentioned blanks are heated to 350-420℃, and then the center is punched on a 5000-ton vertical free forging hydraulic press with a punching diameter of Ф300mm.

[0054] IV. Break the blank in two along its length from the center of the punch (see...) Figure 1 );

[0055] V. Local Elongation of the Blank by Heating: The blank obtained in step 4 is heated to 420℃~450℃, the initial forging temperature of the first piece is 430℃~440℃, the final forging temperature of the first piece is 400℃~430℃, the initial forging temperature of the last piece is 430℃~450℃, the final forging temperature of the last piece is 400℃~430℃, and the die temperature is 360℃~380℃. The blank is locally elongated, and a Ф200mm center hole is punched at the center of the top of the arc to obtain the forging blank.

[0056] VI. The forgings obtained in step V are forged four times, and then subjected to etching and cleaning repair, pre-fire inspection, quenching treatment and aging treatment in sequence to complete the manufacturing of the aluminum alloy aerospace forgings with portal-shaped arc frames.

[0057] In step two of this embodiment, the aluminum alloy ingots must be cleaned of dust, aluminum shavings, and burrs before being loaded into the furnace; when loading into the furnace, the aluminum alloy ingots must be placed neatly and stably on the material tray.

[0058] In step two of this embodiment, the billet preparation is as follows: after the alloy ingot is loaded into the furnace, it is heated to 460℃~480℃. The initial forging temperature of the billet is 440℃. Then, it is forged in multiple directions (two upsettings and two drawings) on a 5000-ton vertical free forging hydraulic press. The die temperature is 350℃~400℃, and it is forged to 880+10×850+10×125+5mm.

[0059] In step three of this embodiment, the heating temperature is as follows: the blank is heated to 350-420°C, and then a center hole is punched on a 5000-ton vertical free forging hydraulic press with a punching diameter of Ф300mm.

[0060] In step five of this embodiment, the forging and drawing process is as follows: the blank is heated to 420℃~450℃, and then the blank is partially drawn on a 5000-ton vertical free forging hydraulic press. A Ф200mm center hole is punched at the center of the top of the arc to obtain the forging blank.

[0061] In this embodiment, the heating regime in steps five and six is ​​the same: the blank is heated to 420℃~450℃, the first forging temperature is 430℃~440℃, the first forging temperature is 400℃~430℃, the last forging temperature is 430℃~450℃, the last forging temperature is 400℃~430℃, and the die temperature is 360℃~380℃.

[0062] The etching and repair process described in step six of this embodiment is as follows: The part to be cleaned is placed upright in a stainless steel etching basket and etched and degreased in an alkaline bath of 15wt% NaOH at 60°C for 20 minutes. Then, it is washed off the alkaline solution in a cold water bath at room temperature, then neutralized and washed off in an acid bath of 30wt% HNO3 at room temperature for 5 minutes, then washed off the acid solution in a cold water bath at room temperature, and finally rinsed in a hot water bath at 60°C. After being removed, it is placed on a repair area with aluminum pads on the ground for repair, and defects in the forging are inspected and removed.

[0063] In step six of this embodiment, the four-stage die forging process is as follows: Before die forging, the impurities in the die cavity are removed with compressed air. The upper and lower dies are installed and lubricated with sand oil. When the die forgings are taken out of the furnace, the initial forging temperature and final forging temperature of the first and last pieces of each horizontal stack are 430°C. The die forging is carried out in a 5000-ton vertical free forging hydraulic press. The die forgings are subjected to four die forgings. During the final pressing, four lubrication and pressing are performed. Then, the machine is lifted to release the air and then pressurized again. The first piece is inspected, and the mark is printed in the specified position. Then, the burrs are removed. The residual amount of burrs after cutting is equal to 8mm, and undercut is not allowed.

[0064] The four lubrication processes described in this embodiment use a mixture of sand oil and graphite as lubricating oil; the mass ratio of sand oil to graphite is 7:3.

[0065] The quenching process described in step six of this embodiment is as follows: the forgings and test materials that have completed the pre-quenching inspection are placed flat in the quenching basket and quenched at 513°C. The holding time is 240 minutes based on air holding. The temperature of the water used for quenching is 50°C. The quenching transfer time is less than or equal to 15 seconds, and the quenching basket is raised and lowered in the water 8 times. After staying in the water for 15 minutes, it is lifted out of the water. When marking the quenching furnace number, it must be marked to the specified position.

[0066] The aging treatment described in step six of this embodiment is as follows: aging treatment is carried out at 157°C, the heat preservation time is 8 hours for metal, and the total heating time is 12 hours.

[0067] The sample material described in this embodiment is obtained by randomly selecting one die forging from the same batch that has completed pre-fire inspection, cutting and sampling it.

[0068] In this embodiment, aluminum alloy aerospace die forgings with portal-shaped arc frames were manufactured. Samples were taken from materials with the same melting batch, the same alloy grade, and the same forging conditions for analysis and performance testing.

[0069] Brinell hardness: sample height 27.28 mm, indentation diameter 3.20 mm, hardness value 121.

[0070] Metallographic test: conforms to GB / T 3246.1-2012 inspection standard.

[0071] Tensile test: GB / T 228.1-2010 is used as the test standard, which specifies a non-proportional elongation force of 7801.26 N, a specified non-proportional elongation stress of 399.23 MPa, a maximum force of 9384.10 N, a tensile strength of 480.23 MPa, an absolute elongation after fracture of 3.13%, and a relative elongation after fracture of 12.52%.

[0072] This invention combines multiple forging processes, center punching, sawing, and local elongation followed by punching to achieve a reasonable metal distribution across the cross-sections of the forging blank, facilitating die forming. Hydraulic press operators must follow instructions, cooperate effectively, and appropriately adjust and control the number of oiling cycles and the amount of pressure applied each time. For forgings with closed ribs, an effective oiling method is employed: less oil is applied to the inner cavity and web, and oiling is controlled along the rib tops and outer edges. This increases the frictional resistance between the metal on the inner cavity and web surfaces and the die surface, allowing the metal to flow internally while preventing surface metal flow, thus avoiding forging folding and effectively solving the problems of incomplete forming and folding in die forgings in this patent (see...). Figure 3 ).

[0073] The portal-shaped arc frame aluminum alloy aerospace die forging manufactured in this embodiment meets the standard requirements in terms of size, and improves the overall performance of the portal-shaped aerospace forging. It also improves the stress deformation characteristics during the machining and use process, reduces the defects of low-magnification structure non-compliance, improves the load-bearing capacity of the die forging, and increases the service life of the portal-shaped arc frame aluminum alloy aerospace die forging, thus meeting the requirements of portal-shaped arc frame aluminum alloy aerospace die forging.

Claims

1. A method for preparing an aluminum alloy aerospace die forging with a portal-shaped arc frame, characterized in that... It proceeds in the following steps: I. Cast aluminum alloy ingots: The mass percentage of elements in the aluminum alloy ingots is as follows: Si ≤0.7%~1.2%, Fe ≤0.7%, Cu 1.8%~2.6%, Mn ≤0.4%~0.8%, Mg 0.4%~0.8%, Ni ≤0.10%, Zn ≤0.30%, Fe+Ni ≤0.7%, Ti ≤0.15%, individual impurities ≤0.05%, total impurities ≤0.10%, and the remainder is Al; 2. After the cast aluminum alloy ingot is loaded into the furnace, it is heated to 460℃~480℃. The initial forging temperature of the blank is 440℃. Then, it is forged in multiple directions on a 5000-ton vertical free forging hydraulic press. The die temperature is 350℃~400℃. It is forged to 880+10×850+10×125+5mm.

3. Heat the blank from step 2 to 350-420℃, and then perform center punching on a 5000-ton vertical free forging hydraulic press with a punching diameter of Ф300mm.

4. Break the blank in two along the length of the blank at the center of the punch; V. Local Elongation of the Blank by Heating: The blank obtained in step 4 is heated to 420℃~450℃, the initial forging temperature of the first piece is 430℃~440℃, the final forging temperature of the first piece is 400℃~430℃, the initial forging temperature of the last piece is 430℃~450℃, the final forging temperature of the last piece is 400℃~430℃, and the die temperature is 360℃~380℃. The blank is locally elongated, and a Ф200mm center hole is punched at the center of the top of the arc to obtain the forging blank. VI. Heating and molding the blank obtained in step five: Heating the blank obtained in step five to 420℃~450℃, the first forging temperature is 430℃~440℃, the first final forging temperature is 400℃~430℃, the last forging temperature is 430℃~450℃, the last final forging temperature is 400℃~430℃, and the die temperature is 360℃~380℃. Four forging processes are performed, followed by etching and cleaning, pre-fire inspection, quenching, and aging treatment. This completes the preparation of the aforementioned portal-shaped arc frame aluminum alloy aerospace die forging. Step six describes four-stage die forging: Before die forging, compressed air is used to remove impurities from the die cavity. The upper and lower dies are installed and lubricated with sand oil. When the die forgings exit the furnace, the initial forging temperature and final forging temperature of the first and last pieces of each horizontal material tray are both 400℃~450℃. Die forging is carried out in a 5000-ton vertical free forging hydraulic press. The die forgings undergo four die pressings. During the final pressing, four lubrications are applied and the pressure is increased. Then, the machine is lifted to release air and then the pressure is increased again. The first piece is then inspected, and the mark is printed in the specified position. Then, the burrs are removed. The residual burrs after cutting are less than or equal to 8mm, and undercut is not allowed. The four lubrications use a mixture of sand oil and graphite as lubricant. The mass ratio of sand oil to graphite is 7:(2~3). The quenching process described in step six: The forgings and test samples that have completed the pre-quenching inspection are placed flat in the quenching basket and quenched at 510℃~516℃. The air holding time is 210~240min, and the temperature of the water used for quenching is 50℃~60℃. The quenching transfer time is less than or equal to 15s, and the quenching basket is raised and lowered in the water more than 5 times. After staying in the water for 15min, it is lifted out of the water. When marking the quenching furnace number, it must be marked to the specified position.

2. The method for preparing a portal-shaped arc frame aluminum alloy aerospace die forging according to claim 1, characterized in that... The mass percentage of elements in the aluminum alloy ingot mentioned in step one is as follows: Si 0.80%, Fe 0.6%, Cu 2.5%, Mn 0.70%, Mg 0.6%, Ni 0.1%, Zn 0.30%, Ti 0.10%, with individual impurities ≤0.05% and total impurities ≤0.10%, the remainder being Al.

3. The method for preparing a portal-shaped arc frame aluminum alloy aerospace die forging according to claim 1, characterized in that... In step one, the aluminum alloy ingot is a cylindrical ingot with dimensions of Φ405×750mm.

4. The method for preparing a portal-shaped arc frame aluminum alloy aerospace die forging according to claim 1, characterized in that... The multi-face forging process described in step two involves two blocks and two pulls.

5. The method for preparing a portal-shaped arc frame aluminum alloy aerospace die forging according to claim 1, characterized in that... The heating temperature in step three is as follows: the blank is heated to 350-400℃, and then a center hole is punched on a 5000-ton vertical free forging hydraulic press with a punching diameter of Ф300mm.

6. The method for preparing a portal-shaped arc frame aluminum alloy aerospace die forging according to claim 1, characterized in that... Step 5 describes the blank heating and molding process: the blank is heated to 420℃~450℃, and then locally elongated on a 5000-ton vertical free forging hydraulic press, and a Ф200mm center hole is punched at the center of the top of the arc to obtain the forging blank.

7. The method for preparing a portal-shaped arc frame aluminum alloy aerospace die forging according to claim 1, characterized in that... Step six describes the etching and repair process: Place the workpiece upright in a stainless steel etching basket, and etch and degrease it in an alkaline bath of 15%–20wt% NaOH at 50℃–70℃ for 10–20 minutes. Then, rinse the workpiece in a cold water bath at room temperature to remove the alkaline solution. Next, neutralize and wash it in an acid bath of 30–40wt% HNO3 at room temperature for 5–8 minutes. Then, rinse the workpiece in a cold water bath at room temperature to remove the acid solution. Finally, rinse the workpiece in a hot water bath at 50–70℃. After rinsing, place the workpiece on a repair area with aluminum pads on the ground for repair. Inspect and remove any defects in the forging.

8. The method for preparing a portal-shaped arc frame aluminum alloy aerospace die forging according to claim 1, characterized in that... The aging treatment described in step six involves aging at 153℃ to 160℃, with a holding time of 8 hours for the metal and a total heating time of 8 to 14 hours.

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