Aircraft engine OGV hollow blade aluminum alloy cover plate manufacturing method

Abstract

The application provides a manufacturing method of an aero-engine OGV hollow blade aluminum alloy cover plate, which can realize the manufacturing of the cover plate through stamping, does not need to design and manufacture a complicated high-efficiency inner cooling structure stamping die, consumes less raw material, is convenient to process, and can effectively guarantee the processing quality. The method comprises the following steps: placing an aluminum alloy raw material plate into a heating furnace for solid solution treatment; using a stamping die with reverse pre-deformation design to stamp the plate after the solid solution treatment; quickly opening the stamping die after the stamping die is stamped in place, and spraying water on the plate in the stamping die through normal temperature water to cool the plate to room temperature; closing the stamping die to perform pressure holding forming on the plate cooled to room temperature; taking the plate out of the stamping die, placing the plate into a heating furnace, and performing aging treatment on the plate in a hanging manner; and placing the plate after the aging treatment on a vacuum adsorption clamp to perform numerical control processing on the outer contour of the plate.

Description

Technical Field

[0001] This invention relates to the field of aero-engine blade assembly manufacturing technology, specifically a method for manufacturing aluminum alloy cover plates for aero-engine OGV hollow blades. Background Technology

[0002] like Figure 1 , Figure 2 The images show the front and top views of the aluminum alloy cover plate for the OGV (outlet guide vane) hollow blade of an aero-engine. It is a component of the OGV hollow blade and was designed and manufactured in China for the first time. The material is aerospace aluminum alloy, including 2-series and 7-series aluminum alloys. The cover plate is 1-2mm thick, 400-700mm long, and 150-250mm wide. The cover plate profile profile requirement is ≤1.5mm.

[0003] Because the component is very thin and has a small curvature, coupled with the characteristics of aerospace aluminum alloy, it is extremely difficult to stamp it at room temperature. Moreover, stamping requires the design and manufacture of complex and efficient internal cooling stamping dies. This would result in very high manufacturing costs for small-batch, multi-variety cover plates. Therefore, for small-batch, multi-variety cover plates, thicker (e.g., 20mm) aluminum alloy sheet forgings are generally used for CNC milling. However, this method consumes more raw materials, takes longer to process, and is difficult to control deformation during milling, resulting in poor surface contour. Summary of the Invention

[0004] To address the problems of high raw material consumption, difficult processing, and poor product quality in the manufacture of aluminum alloy cover plates for hollow OGV blades of aero engines using existing technologies, this invention provides a method for manufacturing aluminum alloy cover plates for hollow OGV blades of aero engines. This method can achieve the manufacturing of cover plates through stamping, which not only eliminates the need to design and manufacture complex and efficient internal cooling structure stamping dies, but also consumes less raw materials, is easy to process, and can effectively ensure processing quality.

[0005] The technical solution is as follows: A method for manufacturing aluminum alloy cover plates for hollow OGV blades of aero-engines, used to manufacture aluminum alloy cover plates with curved upper and lower surfaces, a plate thickness of 1~2mm, and a cover plate profile requirement of ≤1.5mm, characterized by comprising the following steps: 1. Place the aluminum alloy raw material sheet into a heating furnace for solution treatment. The thickness of the aluminum alloy raw material sheet is selected between the basic size of the aluminum alloy cover plate and the maximum limit size of the aluminum alloy cover plate. 2. Quickly transfer the solution-treated sheet to a room-temperature stamping die for stamping; 3. After the stamping die is in place, it is quickly opened, and the sheet metal in the stamping die is cooled to room temperature by spraying water with room temperature water. 4. Close the stamping die to hold the sheet metal, which has cooled to room temperature, under pressure to form the sheet metal. 5. Remove the sheet metal from the stamping die and place it in a heating furnace for aging treatment by hanging. 6. Place the aged sheet material on a vacuum adsorption fixture and CNC machine its outer contour.

[0006] Preferably, before manufacturing the stamping die, the springback amount of the aluminum alloy cover plate is simulated to obtain springback data, and the forming surface contour of the stamping die is designed by reverse pre-deformation based on the springback data; the stamping die includes an upper die, a lower die, a positioning block and a cutting mechanism, the positioning block is installed on the lower die, and the upper die is provided with a positioning groove corresponding to the positioning block.

[0007] Preferably, in step 1, a protective heating frame is first placed in the heating furnace, and then the plate is placed on the protective heating frame. The protective heating frame is hollow and relies on its ends to support the lower surface of the plate.

[0008] Preferably, when transferring the sheet material, a protective clamp with a clamping part made of fireproof cotton is used for the transfer.

[0009] Preferably, the material of the sheet is 7075 aluminum alloy; in step 1, after being placed in the heating furnace, the temperature is raised to 460~482℃, and then held at that temperature for ≥60 minutes; in step 2, it is transferred to the stamping die within 10 seconds; in step 3, water is sprayed onto the sheet by setting nozzles on both sides of the stamping die, the water spraying cooling time is 30~45 seconds, and the water spray pressure is 0.15~0.3MPa; in step 4, the pressure holding and forming time is 30~120 seconds.

[0010] Preferably, the material of the sheet is 2219 aluminum alloy; in step 1, after being placed in the heating furnace, the temperature is raised to 529~541℃, and then held for ≥60 minutes; in step 2, it is transferred to the stamping die within 10 seconds; in step 3, water is sprayed onto the sheet by setting nozzles on both sides of the stamping die, the water spraying cooling time is 30~45 seconds, and the water spray pressure is 0.15~0.3MPa; in step 4, the pressure holding and forming time is 30~120 seconds.

[0011] The beneficial effects of this invention are as follows: Firstly, this process uses contact water cooling instead of cold mold quenching to complete the full solution treatment process of aerospace aluminum alloy plates, effectively ensuring the material strength meets design requirements.

[0012] Secondly, the pre-deformed stamping die corrects the springback during hot stamping of aerospace aluminum alloy sheets, ensuring the dimensional accuracy of the final product.

[0013] Third, the aluminum alloy cover plate for OGV hollow blades of aero-engines is a product with multiple varieties and small batches. This process effectively reduces manufacturing costs and eliminates the need to design and manufacture complex, high-efficiency internal cooling structure stamping dies. This significantly shortens the process development cycle for this type of product.

[0014] Fourth, the design and use of the protective heating frame and protective calipers solve the problem of surface contamination and scratches on aerospace aluminum alloy sheets during the hot stamping heating-transfer process.

[0015] Fifth, the suspended aging heat treatment effectively solves the deformation problem of aerospace aluminum alloy plates during aging heat treatment, with surface contour deformation ≤0.5mm after aging.

[0016] Sixth, the process route of this method ensures the surface contour dimensions (≤1.5mm) of the stamped thin-walled aerospace aluminum alloy parts with small curvature while also guaranteeing material strength, and can perfectly replace the previous milling manufacturing process for this type of product.

[0017] Seventh, the use of vacuum adsorption fixtures allows the outer contour of aerospace aluminum alloy cover plates to be clamped and machined in one go, eliminating the machining errors caused by the two positioning processes of conventional clamping fixtures and improving the machining efficiency of the outer contour of parts. Attached Figure Description

[0018] Figure 1 Front view of the aluminum alloy cover plate for the hollow blades of an aero-engine OGV; Figure 2 A top view of the aluminum alloy cover plate for the hollow blades of an aero-engine OGV. Figure 3 This is a schematic diagram of the process route of the present invention; Figure 4 This is a schematic diagram of the stamping die structure; Figure 5 This is a schematic diagram illustrating the suspension period. Figure 6 This is a schematic diagram of the overall machining of the outer contour of the vacuum adsorption fixture. Detailed Implementation

[0019] A method for manufacturing aluminum alloy cover plates for hollow OGV blades of aero-engines, which are used to manufacture such... Figure 1 , Figure 2 The aluminum alloy cover plate shown has curved upper and lower surfaces, a thickness of 1-2mm, and a profile tolerance of ≤1.5mm. Figure 3 It includes the following steps: 1. First, place the protective heating rack 7 into the heating furnace 6, then place the aluminum alloy raw material sheet 100 ( Figure 3A is a front view of the plate and B is a top view. The plate is a flat plate and is placed on the protective heating frame 7 for solution treatment. The protective heating frame 7 is hollow and supports the lower surface of the plate by its ends. The thickness of the aluminum alloy raw material plate 100 is selected between the basic size of the aluminum alloy cover plate and the maximum limit size of the aluminum alloy cover plate (110% of the basic size), which consumes less raw materials.

[0020] 2. Using protective clamps with fire-resistant cotton as a clamping part, the solution-treated sheet metal is quickly transferred to the stamping die 8 on the room-temperature stamping equipment 9 for stamping. Before manufacturing the stamping die, the springback amount of the aluminum alloy cover plate is simulated to obtain springback data. Based on the springback data, the profile of the forming surface of the stamping die is designed through reverse pre-deformation. The structure of the stamping die is as follows: Figure 4 As shown, the stamping die includes an upper die 1, a lower die 2, a positioning block 3, and a cutting mechanism 4. The positioning block 3 is mounted on the lower die 2, and the upper die 1 is provided with a positioning groove corresponding to the positioning block 3. Figure 4 5 is a stamped sheet material.

[0021] 3. After the stamping die 8 is stamped into place, it is quickly opened, and the spray nozzles 10 set on both sides of the stamping die 8 spray water with room temperature water to cool the stamped plate in the stamping die 8 to room temperature.

[0022] 4. Close the stamping die 8 to hold the stamped sheet metal after it has cooled to room temperature and form it under pressure.

[0023] 5. Remove the stamped sheet from the stamping die 8. Figure 5 As shown, the stamped sheet is placed in a heating furnace and subjected to aging treatment by suspension. During suspension, holes are made along the line where the center of gravity of the sheet is located to suspend the stamped sheet in the heating furnace.

[0024] 6. Place the aged stamped sheet in a... Figure 6 The outer contour is CNC machined on the vacuum adsorption fixture 11 shown.

[0025] Example 1: OGV aviation aluminum alloy blade cover for a certain type of engine, made of 7075 aluminum alloy, with a length of 600mm, width of 230mm, thickness of 1.5mm (with a deviation of ±10%), and surface profile ≤1.5mm. The implementation steps are as follows: 1. First, place the protective heating rack 7 into the heating furnace 6. Then, use protective clamps to place the 1.6mm thick aluminum alloy raw material sheet 100 into the heating area of ​​the protective heating rack 7 in the aluminum alloy heating furnace 6 at a temperature of 460~482℃. After the raw material sheet is heated to 460~482℃ in the heating furnace, it is kept at that temperature for ≥60 minutes.

[0026] 2. Using protective calipers, the solution-treated sheet metal is quickly (≤10 seconds) transferred to the stamping die 8 on the room-temperature stamping equipment 9 for stamping. Before manufacturing the stamping die 8, the springback amount of the aluminum alloy cover plate is simulated to obtain springback data. Based on the springback data, the profile of the forming surface of the stamping die is designed through reverse pre-deformation.

[0027] 3. After the stamping die 8 is stamped into place, it is quickly opened, and the sheet metal in the stamping die 8 is cooled by spraying water with room temperature water through the nozzles 10 set on both sides of the stamping die 8 for 30~45 seconds to cool it to room temperature. The water spray pressure is 0.15~0.3MPa.

[0028] 4. Close the stamping die 8 and hold the platen, which has cooled to room temperature, under pressure for 30~120 seconds.

[0029] 5. Remove the sheet metal from the stamping die 8. Figure 5 As shown, the material is placed in a heating furnace and suspended for aging treatment. During suspension, holes are made along the line where the center of gravity of the material is located to suspend the material in the heating furnace.

[0030] 6. Place the aged sheet on the vacuum adsorption fixture 11, and CNC mill the outer contour of the sheet to make its length, width and shape meet the requirements of the product. At the same time, the thickness of the sheet obtained by stamping can meet the thickness requirements of the cover plate.

[0031] 7. Scan the surface contour of the product. The average measured value is 1.07mm, which is less than 1.5mm and meets the product requirements.

[0032] 8. Mechanical property retest. The average measured tensile strength was 503 MPa (acceptance standard ≥ 462 MPa), the average measured yield strength was 433 MPa (acceptance standard ≥ 386 MPa), and the average measured elongation was 10.0% (acceptance standard ≥ 8%). The results meet the specifications.

[0033] Example 2: OGV aviation aluminum alloy blade cover for a certain type of engine, made of 2219 aluminum alloy, with a length of 420mm, a width of 170mm, a thickness of 2.0mm (with a deviation of ±10%), and a surface profile ≤1.5mm. The implementation steps are as follows: 1. First, place the protective heating rack 7 into the heating furnace 6. Then, use protective clamps to place the 2.0mm thick aluminum alloy raw material sheet 100 into the heating area of ​​the protective heating rack 7 in the aluminum alloy heating furnace 6 at a temperature of 529~541℃. After the raw material sheet is heated to 529~541℃ in the heating furnace, it is kept at that temperature for ≥60 minutes.

[0034] 2. Using protective calipers, the solution-treated sheet metal is quickly (≤10 seconds) transferred to the stamping die 8 on the room-temperature stamping equipment 9 for stamping. Before manufacturing the stamping die 8, the springback amount of the aluminum alloy cover plate is simulated to obtain springback data. Based on the springback data, the profile of the forming surface of the stamping die is designed through reverse pre-deformation.

[0035] 3. After the stamping die 8 is stamped into place, it is quickly opened, and the sheet metal in the stamping die 8 is cooled by spraying water with room temperature water through the nozzles 10 set on both sides of the stamping die 8 for 30~45 seconds to cool it to room temperature. The water spray pressure is 0.15~0.3MPa.

[0036] 4. Close the stamping die 8 and hold the platen, which has cooled to room temperature, under pressure for 30~120 seconds.

[0037] 5. Remove the sheet metal from the stamping die 8. Figure 5 As shown, the material is placed in a heating furnace and suspended for aging treatment. During suspension, holes are made along the line where the center of gravity of the material is located to suspend the material in the heating furnace.

[0038] 6. Place the aged sheet on the vacuum adsorption fixture 11, and CNC mill the outer contour of the sheet to make its length, width and shape meet the requirements of the product. At the same time, the thickness of the sheet obtained by stamping can meet the thickness requirements of the cover plate.

[0039] 7. Scan the surface contour of the product. The average measured value is 0.96mm, which is less than 1.5mm and meets the product requirements.

[0040] 8. Mechanical property retest. The average measured tensile strength was 483 MPa (acceptance standard ≥ 427 MPa), the average measured yield strength was 397 MPa (acceptance standard ≥ 345 MPa), and the average measured elongation was 10.5% (acceptance standard ≥ 6%). The results meet the specifications.

[0041] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for manufacturing an aluminum alloy cover plate for hollow OGV blades of an aero-engine, characterized in that it is used to manufacture an aluminum alloy cover plate with curved upper and lower surfaces, a plate thickness of 1~2mm, and a cover plate profile tolerance of ≤1.5mm. It includes the following steps:

1. Place the aluminum alloy raw material sheet into a heating furnace for solution treatment. The thickness of the aluminum alloy raw material sheet is selected between the basic size of the aluminum alloy cover plate and the maximum limit size of the aluminum alloy cover plate.

2. Quickly transfer the solution-treated sheet to a room-temperature stamping die for stamping; 3. After the stamping die is in place, it is quickly opened, and the sheet metal in the stamping die is cooled to room temperature by spraying water with room temperature water.

4. Close the stamping die to hold the sheet metal, which has cooled to room temperature, under pressure to form the sheet metal.

5. Remove the sheet metal from the stamping die and place it in a heating furnace for aging treatment by hanging.

6. Place the aged sheet material on a vacuum adsorption fixture and CNC machine its outer contour; Before manufacturing the stamping die, the springback amount of the aluminum alloy cover plate is simulated to obtain springback data. Based on the springback data, the forming surface contour of the stamping die is designed by reverse pre-deformation. The stamping die includes an upper die, a lower die, a positioning block and a cutting mechanism. The positioning block is installed on the lower die, and the upper die is provided with a positioning groove corresponding to the positioning block.

2. The method for manufacturing an aluminum alloy cover plate for an aero-engine OGV hollow blade according to claim 1, characterized in that: In step 1, a protective heating frame is first placed in the heating furnace, and then the plate is placed on the protective heating frame. The hollow protective heating frame supports the lower surface of the plate by its ends.

3. The method for manufacturing an aluminum alloy cover plate for an aero-engine OGV hollow blade according to claim 1, characterized in that: When transferring the sheet material, protective clamps with a clamping part made of fireproof cotton are used.

4. A method for manufacturing an aluminum alloy cover plate for an aero-engine OGV hollow blade according to any one of claims 1-3, characterized in that: The sheet material is 7075 aluminum alloy; in step 1, after being placed in the heating furnace, the temperature is raised to 460~482℃ and then held for ≥60 minutes; in step 2, it is transferred to the stamping die within 10 seconds; in step 3, water is sprayed onto the sheet by setting nozzles on both sides of the stamping die, the water spraying cooling time is 30~45 seconds, and the water spray pressure is 0.15~0.3MPa; in step 4, the pressure holding and forming time is 30~120 seconds.

5. A method for manufacturing an aluminum alloy cover plate for an aero-engine OGV hollow blade according to any one of claims 1-3, characterized in that: The sheet material is 2219 aluminum alloy; in step 1, after being placed in the heating furnace, the temperature is raised to 529~541℃, and then held for ≥60 minutes; in step 2, it is transferred to the stamping die within 10 seconds; in step 3, water is sprayed onto the sheet by setting nozzles on both sides of the stamping die, the water spraying cooling time is 30~45 seconds, and the water spray pressure is 0.15~0.3MPa; in step 4, the pressure holding and forming time is 30~120 seconds.

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