A manufacturing method for controlling the structure and performance of aerospace high-strength aluminum-zinc-magnesium-scandium alloy thick plate
By optimizing the deformation per pass and process parameters, the problem of non-uniform microstructure and properties of high-strength aluminum-zinc-magnesium-scandium alloy thick plates was solved, achieving uniformity and excellent mechanical properties of high-strength aluminum-zinc-magnesium-scandium alloy thick plates for aerospace applications, suitable for aerospace launch vehicles.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NORTHEAST LIGHT ALLOY CO LTD
- Filing Date
- 2023-11-10
- Publication Date
- 2026-06-19
AI Technical Summary
In the existing technology, after machining, the 500MPa grade high-strength aluminum-zinc-magnesium-scandium alloy thick plates used in aerospace launch vehicles exhibit significant differences in microstructure and properties in different regions of the parts, affecting the uniformity of the material and failing to meet the usage requirements.
By rationally matching the deformation amount of each pass, optimizing the layer texture structure, and adopting heating and rolling processes with specific temperatures and times, including resistance heating, two-roll mill rolling, and multi-pass rolling, a manufacturing method for alloy thick plates is formulated.
The microstructure and performance uniformity of high-strength aluminum-zinc-magnesium-scandium alloy thick plates were achieved, meeting the requirements for use in aerospace vehicles. The plates exhibited excellent mechanical properties in the T6 state, with interlayer performance differences of less than 3%.
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Figure CN117655106B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a manufacturing method for controlling the microstructure and properties of high-strength aluminum-zinc-magnesium-scandium alloy thick plates for aerospace applications. Background Technology
[0002] Currently, a certain aerospace vehicle product in my country requires a 500MPa grade high-strength aluminum-zinc-magnesium-scandium alloy thick plate. After being machined into parts, the microstructure and properties of different thicknesses in different areas of the parts vary greatly, which seriously affects the use of the parts and does not meet the requirements for uniformity of internal microstructure and properties of the materials. Summary of the Invention
[0003] The purpose of this invention is to solve the problem of interlayer differences in the microstructure and properties of high-strength aluminum-zinc-magnesium-scandium alloy thick plates, and to provide a manufacturing method for controlling the microstructure and properties of high-strength aluminum-zinc-magnesium-scandium alloy thick plates for aerospace applications.
[0004] The manufacturing method of this invention for controlling the microstructure and properties of high-strength aluminum-zinc-magnesium-scandium alloy thick plates for aerospace applications specifically comprises the following steps:
[0005] I. Ingot preparation: The raw materials are prepared according to the mass fractions of 6.5% Zn, 2.5% Mg, 0.2% Zr, 0.2% Sc, unavoidable impurity elements and the balance Al. After melting, they are cast into square ingots. The square ingots are homogenized and the surface oxide scale is removed by milling at room temperature. The surface is milled by 5 mm on one side to obtain the billet for rolling.
[0006] 2. Billet heating: The billet for rolling is heated in a resistance heating furnace at a temperature of 350℃~450℃ for 4h~20h to obtain the heated rolled billet;
[0007] 3. Plate rolling: The heated billet is rolled using a two-roll mill at an initial rolling temperature of 370℃~440℃. The plate is rolled to a thickness of 100mm~130mm in 6~8 passes, and then rolled to a thickness of 30mm~40mm in 3~5 passes to obtain the intermediate plate rolling billet.
[0008] IV. Heating: The intermediate billet of the rolled plate is heated in a resistance heating furnace at a temperature of 350℃~450℃ for 2h~10h to obtain the heated intermediate billet of the rolled plate.
[0009] V. Final rolling of sheet metal: The heated intermediate billet is rolled in 2 to 3 passes to obtain the final thickness of the rolled sheet metal, which is the aluminum-zinc-magnesium-scandium alloy rolled thick plate.
[0010] The beneficial effects of this invention are:
[0011] This invention optimizes the microstructure of different layers by rationally matching the deformation amounts of each pass, resulting in sheet metal that meets the material microstructure and performance uniformity requirements for aerospace vehicles. Furthermore, the developed process is applicable to industrial production. After solution aging heat treatment (470℃ for 1 hour, 120℃ for 24 hours), the sheet metal is tested according to GB / T16865 "Tension Test Specimens and Methods for Processed Products of Wrought Aluminum, Magnesium and Their Alloys". The surface tensile strength of the T6 temper sheet metal is 515–526 MPa, yield strength is 453–471 MPa, and elongation after fracture is 9–11.8%. The core tensile strength is 518–530 MPa, yield strength is 450–475 MPa, and elongation after fracture is 10–12%. The maximum interlayer performance difference is 3%, indicating good performance uniformity. Attached Figure Description
[0012] Figure 1 This is a diagram showing the deformation microstructure of the longitudinal section of the aluminum-zinc-magnesium-scandium alloy prepared in Example 1.
[0013] Figure 2 This is a cross-sectional image of the deformed microstructure of the core of the aluminum-zinc-magnesium-scandium alloy prepared in Example 1. Detailed Implementation
[0014] Specific Implementation Method 1: This implementation method describes a manufacturing method for controlling the microstructure and properties of high-strength aluminum-zinc-magnesium-scandium alloy thick plates for aerospace applications, which specifically follows these steps:
[0015] I. Ingot preparation: The raw materials are prepared according to the mass fractions of 6.5% Zn, 2.5% Mg, 0.2% Zr, 0.2% Sc, unavoidable impurity elements and the balance Al. After melting, they are cast into square ingots. The square ingots are homogenized and the surface oxide scale is removed by milling at room temperature. The surface is milled by 5 mm on one side to obtain the billet for rolling.
[0016] 2. Billet heating: The billet for rolling is heated in a resistance heating furnace at a temperature of 350℃~450℃ for 4h~20h to obtain the heated rolled billet;
[0017] 3. Plate rolling: The heated billet is rolled using a two-roll mill at an initial rolling temperature of 370℃~440℃. The plate is rolled to a thickness of 100mm~130mm in 6~8 passes, and then rolled to a thickness of 30mm~40mm in 3~5 passes to obtain the intermediate plate rolling billet.
[0018] IV. Heating: The intermediate billet of the rolled plate is heated in a resistance heating furnace at a temperature of 350℃~450℃ for 2h~10h to obtain the heated intermediate billet of the rolled plate.
[0019] V. Final rolling of sheet metal: The heated intermediate billet is rolled in 2 to 3 passes to obtain the final thickness of the rolled sheet metal, which is the aluminum-zinc-magnesium-scandium alloy rolled thick plate.
[0020] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the smelting in step one is carried out in a smelting furnace at a temperature of 760°C for 9 hours. Everything else is the same as in Specific Implementation Method One.
[0021] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One in that the casting in step one is carried out at a casting temperature of 740℃. Everything else is the same as in Specific Implementation Method One.
[0022] Specific Implementation Method Four: This implementation method differs from Specific Implementation Method One in that the thickness of the square ingot mentioned in step one is 200mm and the width is 400mm. Everything else is the same as in Specific Implementation Method One.
[0023] Specific Implementation Method Five: This implementation method differs from Specific Implementation Method One in that the homogenization treatment in step one is performed by maintaining a temperature of 470°C for 24 hours. Everything else is the same as in Specific Implementation Method One.
[0024] Specific Implementation Method Six: This implementation method differs from Specific Implementation Method One in that: in step two, the billet for rolling is heated in a resistance heating furnace at a temperature of 410°C for 12 hours. Everything else is the same as in Specific Implementation Method One.
[0025] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Method One in that, in step three, the heated billet is rolled using a two-roll mill at an initial rolling temperature of 390°C. Everything else is the same as in Specific Implementation Method One.
[0026] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Method One in that: in step three, the sheet material is rolled to a thickness of 110mm in 7 passes, and then rolled to a thickness of 30mm in 4 passes. Everything else is the same as in Specific Implementation Method One.
[0027] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Method One in that: in step four, the intermediate billet for rolling the sheet metal is heated in a resistance heating furnace at a temperature of 410°C for 6 hours. Everything else is the same as in Specific Implementation Method One.
[0028] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Method One in that, in step five, the heated intermediate billet is rolled to a thickness of 15mm in two passes. Everything else is the same as in Specific Implementation Method One.
[0029] The beneficial effects of the present invention are verified using the following embodiments:
[0030] Example 1: A manufacturing method for controlling the microstructure and properties of high-strength aluminum-zinc-magnesium-scandium alloy thick plates for aerospace applications specifically comprises the following steps:
[0031] I. Ingot Preparation: The ingots are prepared by mass fraction of 6.5% Zn, 2.5% Mg, 0.2% Zr, 0.2% Sc, unavoidable impurity elements, and balance Al. The ingots are melted in a furnace at 760℃ for 9 hours and cast at 740℃ to obtain a square ingot with a thickness of 200mm and a width of 400mm. The ingots are then homogenized by holding them at 470℃ for 24 hours and removing the surface oxide scale at room temperature by milling 5mm on one side to obtain the billet for rolling.
[0032] 2. Billet heating: The billet for rolling is heated in a resistance heating furnace at a temperature of 410℃ for 12 hours to obtain the heated rolled billet;
[0033] 3. Plate rolling: The heated billet is rolled using a two-roll mill at an initial rolling temperature of 390℃. The plate is rolled to a thickness of 110mm in 7 passes, and then rolled to a thickness of 30mm in 4 passes to obtain the intermediate plate rolling billet.
[0034] IV. Heating: The intermediate billet of the rolled plate is heated in a resistance heating furnace at a temperature of 410℃ for 6 hours to obtain the heated intermediate billet of the rolled plate.
[0035] V. Final rolling of the plate: The heated intermediate billet is rolled to a thickness of 15mm in two passes, which is the aluminum-zinc-magnesium-scandium alloy rolled thick plate.
[0036] Figure 1 and Figure 2 These are longitudinal section deformation microstructure diagrams of the aluminum alloy edge and core prepared in this embodiment. Figure 1 and 2 It can be seen that the difference in deformation structure between the edge and the core of the plate is small, and the interlayer deformation is uniform.
[0037] Table 1 compares the mechanical properties of different layers of 15mm sheet metal after heat treatment at 470℃ for 1 hour and 120℃ for 24 hours. According to GB / T16865 "Tension Test Specimens and Methods for Processed Products of Deformed Aluminum, Magnesium and Their Alloys", the surface tensile strength of the T6 state sheet metal is 517MPa, the yield strength is 468MPa, and the elongation after fracture is 11.6%. The core tensile strength is 529MPa, the yield strength is 471MPa, and the elongation after fracture is 11.3%. The interlayer properties show little difference.
[0038] Table 1. Comparison of mechanical properties of different layers of 15mm sheet after heat treatment at 470℃ for 1 hour and 120℃ for 24 hours.
[0039]
Claims
1. A method for controlling the microstructure and properties of thick aerospace high-strength aluminum-zinc-magnesium-scandium alloy plates, characterized in that The manufacturing method for controlling the microstructure and properties of high-strength aluminum-zinc-magnesium-scandium alloy thick plates for aerospace applications specifically follows these steps: I. Ingot preparation: The raw materials are prepared according to the mass fractions of 6.5% Zn, 2.5% Mg, 0.2% Zr, 0.2% Sc, unavoidable impurity elements and the balance Al. After melting, they are cast into square ingots. The square ingots are homogenized and the surface oxide scale is removed by milling at room temperature. The surface is milled by 5 mm on one side to obtain the billet for rolling.
2. Billet heating: The billet for rolling is heated in a resistance heating furnace at a temperature of 350℃~450℃ for 4h~20h to obtain the heated rolled billet; 3. Plate rolling: The heated billet is rolled using a two-roll mill at an initial rolling temperature of 370℃~440℃. The plate is rolled to a thickness of 100mm~130mm in 6~8 passes, and then rolled to a thickness of 30mm~40mm in 3~5 passes to obtain the intermediate plate rolling billet. IV. Heating: The intermediate billet of the rolled plate is heated in a resistance heating furnace at a temperature of 350℃~450℃ for 2h~10h to obtain the heated intermediate billet of the rolled plate. V. Final rolling of sheet metal: The heated intermediate billet is rolled in 2 to 3 passes to obtain the final thickness of the rolled sheet metal, which is the aluminum-zinc-magnesium-scandium alloy rolled thick plate.
2. The method for controlling the microstructure and properties of a high-strength aluminum-zinc-magnesium-scandium alloy plate for aerospace applications according to claim 1, characterized in that The smelting described in step one is carried out in a smelting furnace at a temperature of 760°C for 9 hours.
3. The manufacturing method for controlling the microstructure and properties of high-strength aluminum-zinc-magnesium-scandium alloy thick plates for aerospace applications according to claim 1, characterized in that... The casting described in step one is carried out at a casting temperature of 740℃.
4. The manufacturing method for controlling the microstructure and properties of high-strength aluminum-zinc-magnesium-scandium alloy thick plates for aerospace applications according to claim 1, characterized in that... The square ingot mentioned in step one has a thickness of 200mm and a width of 400mm.
5. The manufacturing method for controlling the microstructure and properties of high-strength aluminum-zinc-magnesium-scandium alloy thick plates for aerospace applications according to claim 1, characterized in that... The homogenization process described in step one involves maintaining the temperature at 470℃ for 24 hours.
6. The manufacturing method for controlling the microstructure and properties of high-strength aluminum-zinc-magnesium-scandium alloy thick plates for aerospace applications according to claim 1, characterized in that... In step two, the billet for rolling is heated in a resistance heating furnace at a temperature of 410℃ for 12 hours.
7. The manufacturing method for controlling the microstructure and properties of high-strength aluminum-zinc-magnesium-scandium alloy thick plates for aerospace applications according to claim 1, characterized in that... In step three, the heated billet is rolled using a two-roll mill at an initial rolling temperature of 390°C.
8. The manufacturing method for controlling the microstructure and properties of high-strength aluminum-zinc-magnesium-scandium alloy thick plates for aerospace applications according to claim 1, characterized in that... In step three, the sheet material is rolled to a thickness of 110mm in 7 passes, and then rolled to a thickness of 30mm in 4 passes.
9. A manufacturing method for controlling the microstructure and properties of aerospace high-strength aluminum-zinc-magnesium-scandium alloy thick plates according to claim 1, characterized in that... In step four, the intermediate billet of the rolled sheet is heated in a resistance heating furnace at a temperature of 410℃ for 6 hours.
10. A manufacturing method for controlling the microstructure and properties of aerospace high-strength aluminum-zinc-magnesium-scandium alloy thick plates according to claim 1, characterized in that... In step five, the heated intermediate billet is rolled to a thickness of 15mm in two passes.