An arc additive manufacturing method of an aluminum magnesium scandium alloy

Abstract

This invention relates to a method for arc additive manufacturing of high-strength and high-toughness aluminum-magnesium-scandium alloys, belonging to the field of arc additive manufacturing technology for metallic materials. This invention employs arc additive forming of aluminum-magnesium-scandium alloy components, followed by aging heat treatment to obtain a special microstructure with fine grains and grain boundaries pinned by fine precipitates of Al3(Sc,Zr). This prevents recrystallization of the grains during subsequent aging, thereby simultaneously improving the strength and plasticity of the aluminum-magnesium-scandium alloy components, resulting in high-performance aluminum-magnesium-scandium alloy components. This invention enables the direct preparation of near-net-shape aluminum-magnesium-scandium alloy arc additive components, significantly reducing manufacturing cycle and cost, and greatly improving material utilization.

Description

Technical Field

[0001] This invention belongs to the field of arc additive manufacturing technology for metallic materials, and specifically relates to an arc additive manufacturing method for aluminum-magnesium-scandium alloys. Background Technology

[0002] Aluminum alloys are among the most widely used non-ferrous metal materials in industry, particularly in aerospace, transportation, and machinery manufacturing. Aluminum-copper alloys, belonging to the heat-treatable aluminum alloy category, are widely used in the manufacture of structural components such as rocket propellant tanks and transition rings due to their excellent high and low temperature mechanical properties, good corrosion resistance, and weldability. With the increasing demands for low-cost, high-efficiency, and high-reliability manufacturing of aerospace structural components, new requirements have been placed on the manufacturing of complex aluminum alloy components.

[0003] Arc additive manufacturing (AED) technology, based on CAD models, stacks dense metal components layer by layer according to a planned path, followed by a small amount of subsequent machining to produce large metal components. Compared to traditional manufacturing technologies, AED can achieve high-performance manufacturing of large and complex aluminum alloy components. In recent years, AED technology for aluminum-copper alloys has been gradually applied to large aerospace structural components. After AED forming, aluminum-copper alloys still require solution hardening and aging heat treatment to obtain components with better mechanical properties. Typically, aluminum-copper alloy components are prone to deformation during solution hardening and aging, reducing their dimensional accuracy. Therefore, to ensure the geometric dimensional accuracy of AED-manufactured aluminum-copper alloy components, it is necessary to increase the thickness of the formed component and add anti-deformation ribs during arc additive forming to improve the deformation stiffness of the formed component during solution hardening and aging, thus ensuring its geometric dimensional accuracy. This significantly increases the cost cycle, manufacturing cost, and subsequent machining cost of AED, while reducing material utilization and overall manufacturing cost.

[0004] Aluminum-magnesium-scandium alloys (AMSA) are non-heat-treatable aluminum alloys with good plasticity, oxidation resistance, and weldability. AMSA components, after arc additive manufacturing, require only aging heat treatment without solution hardening, making them particularly suitable for high-performance, short-cycle, and low-cost arc additive manufacturing of large and complex components. Currently, institutions such as Northeastern University, Harbin Institute of Technology in China, and Relativity Space in the United States have conducted research on the microstructure and performance control of AMSA arc additive manufacturing. However, existing AMSA arc additive components exhibit low tensile strength (265–335 MPa) and plastic anisotropy in both transverse and longitudinal specimens (transverse elongation approximately 22%, longitudinal elongation approximately 6.5%), which significantly limits their engineering applications. Therefore, there is an urgent need to develop a high-strength and high-toughness AMSA arc additive manufacturing method to meet the requirements of its engineering applications. Summary of the Invention

[0005] The purpose of this invention is to provide an arc additive manufacturing method for aluminum-magnesium-scandium alloys. The method uses arc additive forming to form aluminum-magnesium-scandium alloy components and precisely matches the subsequent aging heat treatment to obtain a special structure with fine grains and grain boundaries pinned by fine precipitates Al3(Sc,Zr). This prevents the grains from recrystallizing during subsequent aging, thereby achieving a simultaneous improvement in the strength and plasticity of the aluminum-magnesium-scandium alloy components, and thus preparing high-performance aluminum-magnesium-scandium alloy components.

[0006] The above-mentioned objectives of the present invention are mainly achieved through the following technical solutions:

[0007] An electric arc additive manufacturing method for aluminum-magnesium-scandium alloys includes the following steps:

[0008] (1) Establish a three-dimensional model of the aluminum-magnesium-scandium alloy component, perform layer slicing and determine the forming path;

[0009] (2) Load aluminum-magnesium-scandium alloy welding wire into the wire feeder, fix the substrate on the working platform of the wire feeder, and dehumidify the forming chamber of the wire feeder. The substrate is used for forming aluminum-magnesium-scandium alloy components.

[0010] (3) After dehumidification, aluminum-magnesium-scandium alloy welding wire is arc-additively formed along the forming path to complete a layer deposition;

[0011] (4) Repeat the deposition operation described in step (3) to continuously deposit and manufacture aluminum-magnesium-scandium alloy components;

[0012] (5) Take out the aluminum-magnesium-scandium alloy component obtained in step (4) from the forming chamber and separate it from the substrate;

[0013] (6) Perform aging heat treatment on the aluminum-magnesium-scandium alloy component obtained in step (5) to obtain the final aluminum-magnesium-scandium alloy component.

[0014] In step (3), the electric arc additive manufacturing process parameters are as follows: the wire elongation is 10-14 mm, the argon gas flow rate is 15-25 L / min, the current is 120-140 A, the wire feeding rate is 8-10 m / min, the deposition rate is 6-10 mm / s, and the overlap ratio is 45-55%.

[0015] In step (3), the energy density of the aluminum alloy deposition zone is 55-65 J / mm, and the cooling rate at the leading edge of the molten pool interface is 10. 2 ~10 2.5 K / s, and the sedimentary layer height is 3-4 mm.

[0016] In step (6), the aging heat treatment includes a first aging heat treatment and a second aging heat treatment. The first aging heat treatment method is as follows: the aluminum-magnesium-scandium alloy component is heated to 300-350°C at a rate of 10-15°C / min, held at that temperature for 0.2-0.5h, and cooled to room temperature at a cooling rate of not less than 30°C / s. Then, the second aging heat treatment is performed. The second aging heat treatment method is as follows: the aluminum-magnesium-scandium alloy component is heated to 250-300°C at a rate of 10-15°C / min, held at that temperature for 0.5-1h, and cooled to room temperature at a cooling rate of not less than 20°C / s.

[0017] In step (4), the interval between deposition layers is 30 to 40 minutes.

[0018] The diameter of the aluminum-magnesium-scandium alloy welding wire is 1.2–1.6 mm.

[0019] The aluminum-magnesium-scandium alloy welding wire has a Sc content of 0.2–0.3 wt.% and a Zr content of 0.1–0.15 wt.%.

[0020] An electric arc additive manufacturing method for aluminum-magnesium-scandium alloys includes the following steps:

[0021] (1) Establish a three-dimensional model of the aluminum-magnesium-scandium alloy component, perform layer slicing and determine the forming path;

[0022] (2) Load the aluminum-magnesium-scandium alloy welding wire into the wire feeder, fix the substrate on the working platform of the wire feeder, and dehumidify the forming chamber of the wire feeder.

[0023] (3) After dehumidification, aluminum-magnesium-scandium alloy welding wire is arc-additively formed along the forming path to complete a layer deposition;

[0024] (4) Repeat the deposition operation described in step (3) to continuously deposit and manufacture aluminum-magnesium-scandium alloy components;

[0025] (5) Take out the aluminum-magnesium-scandium alloy component obtained in step (4) from the forming chamber and separate it from the substrate;

[0026] (6) Perform aging heat treatment on the aluminum-magnesium-scandium alloy component obtained in step (5) to obtain the final aluminum-magnesium-scandium alloy component.

[0027] In step (3), the electric arc additive manufacturing process parameters are as follows: the wire elongation is 10-14 mm, the argon gas flow rate is 15-25 L / min, the current is 120-140 A, the wire feeding rate is 8-10 m / min, the deposition rate is 6-10 mm / s, and the overlap ratio is 45-55%.

[0028] In step (3), the energy density of the aluminum alloy deposition zone is 55-65 J / mm, and the cooling rate at the leading edge of the molten pool interface is 10. 2 ~10 2.5 K / s, and the sedimentary layer height is 3-4 mm.

[0029] In step (6), the aging heat treatment includes a first aging heat treatment and a second aging heat treatment. The first aging heat treatment method is as follows: the aluminum-magnesium-scandium alloy component is heated to 300-350°C at a rate of 10-15°C / min, held at that temperature for 0.2-0.5h, and cooled to room temperature at a cooling rate of not less than 30°C / s. Then, the second aging heat treatment is performed. The second aging heat treatment method is as follows: the aluminum-magnesium-scandium alloy component is heated to 250-300°C at a rate of 10-15°C / min, held at that temperature for 0.5-1h, and cooled to room temperature at a cooling rate of not less than 20°C / s.

[0030] In step (4), the interval between deposition layers is 30 to 40 minutes.

[0031] The diameter of the aluminum-magnesium-scandium alloy welding wire is 1.2–1.6 mm.

[0032] The aluminum-magnesium-scandium alloy welding wire has a Sc content of 0.2–0.3 wt.% and a Zr content of 0.1–0.15 wt.%.

[0033] Compared with the prior art, the present invention has at least the following beneficial effects:

[0034] (1) The present invention directly prepares near-net-shape aluminum-magnesium-scandium alloy arc additive components. Compared with aluminum-copper alloy arc additive components, the manufacturing cycle and manufacturing cost of this technology are significantly reduced, and the material utilization rate is greatly improved.

[0035] (2) By controlling the process of electric arc additive manufacturing and the control of aging heat treatment, the present invention obtains a special structure with grains of 65-75 μm in diameter, grain boundaries containing Al3(Sc,Zr) with a diameter of 0.25-0.35 μm and intragranular precipitates with a diameter of 0.3-0.35 μm, which can significantly improve the room temperature mechanical properties of aluminum-magnesium-scandium alloy components. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the microstructure of the aluminum-magnesium-scandium alloy arc additive manufacturing component of the present invention, wherein... Figure 1 a is a schematic diagram of the microstructure of the component in Comparative Example 1; Figure 1 b is a schematic diagram of the microstructure of the component in Example 2. Detailed Implementation

[0037] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments:

[0038] An electric arc additive manufacturing method for aluminum-magnesium-scandium alloys includes the following steps:

[0039] (1) Load the aluminum-magnesium-scandium alloy welding wire into the wire feeder;

[0040] (2) After cleaning the substrate, fix it on the work platform and turn on the dehumidification equipment to dehumidify.

[0041] (3) Use computer CAD software to draw a three-dimensional model of aluminum-magnesium-scandium components, import it into electric arc additive manufacturing slicing software for layer slicing and formulate the forming path.

[0042] (4) When the humidity in the forming chamber is less than 50%, the welding wire is formed along the preset forming path by using an electric arc as a heat source. After one layer is deposited, the next layer is deposited after a set time interval.

[0043] During the deposition process of arc additive manufacturing, the deposition parameters are as follows: wire elongation 10-14 mm, argon gas flow rate 15-25 L / min, current 120-140 A, wire feed rate 8-10 m / min, deposition rate 6-10 mm / s, layer thickness 3-4 mm, and overlap ratio 45-55%.

[0044] By controlling the process parameters of arc additive forming, the energy density of the aluminum alloy deposition zone is controlled to be 55-65 J / mm, the overlap rate is 45-55%, and the cooling rate at the front edge of the forming molten pool interface is 102-102.5 K / s, a microstructure with grains of 3-4 mm height and 65-75 μm diameter and grain boundaries containing Al3(Sc,Zr) precipitates with a diameter of 0.2-0.3 μm is obtained.

[0045] (5) The sample is placed in a heat treatment furnace for special step-by-step aging heat treatment to obtain the final aluminum-magnesium-scandium alloy component.

[0046] The special step-by-step aging heat treatment is divided into a first aging heat treatment and a second aging heat treatment. The aluminum-magnesium-scandium alloy sample is placed in a heat treatment furnace for the first aging heat treatment, which is specifically: the sample is heated to 300-350℃ at a rate of 10-15℃ / min, held at that temperature for 0.2-0.5h, and cooled to room temperature at a rate of not less than 30℃ / s. After the first heat treatment is completed, the second aging heat treatment is carried out, which includes: the sample is heated to 250-300℃ at a rate of 10-15℃ / min, held at that temperature for 0.5-1h, and cooled to room temperature at a rate of not less than 20℃ / s.

[0047] Example 1

[0048] An electric arc additive manufacturing method for aluminum-magnesium-scandium alloys, specifically comprising:

[0049] (1) Load aluminum-magnesium-scandium alloy welding wire with a diameter of 1.2 mm into the wire feeder. The aluminum-magnesium-scandium alloy wire has a Sc content of 0.22 wt.% and a Zr content of 0.12 wt.%.

[0050] (2) After cleaning the substrate, fix it on the work platform and turn on the dehumidification equipment to dehumidify.

[0051] (3) Use computer CAD software to draw a three-dimensional model of aluminum-magnesium-scandium components, import it into electric arc additive manufacturing slicing software for layer slicing and formulate the forming path.

[0052] (4) When the humidity in the forming chamber is less than 50%, the welding wire is formed along the preset forming path by using an electric arc as a heat source. After one layer is deposited, the cooling time interval of the deposited layer is 30 minutes before the next layer is deposited.

[0053] During the deposition process of arc additive manufacturing, the deposition parameters are as follows: the wire extension is 10 mm, the argon gas flow rate is 15 L / min, the current is 120 A, the wire feed rate is 8 m / min, the deposition rate is 6 mm / s, and the overlap ratio is 45%. A microstructure sample with a deposition layer height of 3 mm and a diameter of 65 μm, containing grains and grain boundaries with precipitates of Al3(Sc,Zr) with a diameter of 0.2 μm, was prepared.

[0054] (5) The sample is placed in a heat treatment furnace for special step-by-step aging heat treatment to obtain the final aluminum-magnesium-scandium alloy component. The special step-by-step aging heat treatment is divided into a first aging heat treatment and a second aging heat treatment. The aluminum-magnesium-scandium alloy sample is placed in a heat treatment furnace for the first aging heat treatment, specifically: the sample is heated to 300°C at 10°C / min, held for 0.2h, and cooled to room temperature at a controlled cooling rate of 30°C / s. After the first heat treatment is completed, the second aging heat treatment is performed. The second aging heat treatment includes: the sample is heated to 250°C at 10°C / min, held for 0.5h, and cooled to room temperature at a controlled cooling rate of 20°C / s.

[0055] Example 2

[0056] An electric arc additive manufacturing method for aluminum-magnesium-scandium alloys, specifically comprising:

[0057] (1) Load aluminum-magnesium-scandium alloy welding wire with a diameter of Φ1.2mm into the wire feeder. The aluminum-magnesium-scandium alloy wire has a Sc content of 0.24wt.% and a Zr content of 0.13wt.%.

[0058] (2) After cleaning the substrate, fix it on the work platform and turn on the dehumidification equipment to dehumidify.

[0059] (3) Use computer CAD software to draw a three-dimensional model of aluminum-magnesium-scandium components, import it into electric arc additive manufacturing slicing software for layer slicing and formulate the forming path.

[0060] (4) When the humidity in the forming chamber is less than 50%, the welding wire is formed along the preset forming path by using an electric arc as a heat source. After one layer is deposited, the cooling time interval of the deposited layer is 35 minutes before the next layer is deposited.

[0061] During the arc additive manufacturing deposition process, the deposition parameters were as follows: the wire extension was 12 mm, the argon gas flow rate was 20 L / min, the current was 130 A, the wire feed rate was 10 m / min, the deposition rate was 10 mm / s, and the overlap ratio was 48%. A microstructure sample with a deposition layer height of 3.5 mm and a diameter of 70 μm was prepared, and the grain boundaries contained Al3(Sc,Zr) precipitates with a diameter of 0.25 μm.

[0062] (5) The sample is placed in a heat treatment furnace for special step-by-step aging heat treatment to obtain the final aluminum-magnesium-scandium alloy component. The special step-by-step aging heat treatment is divided into a first aging heat treatment and a second aging heat treatment. The aluminum-magnesium-scandium alloy sample is placed in a heat treatment furnace for the first aging heat treatment, specifically: the sample is heated to 320°C at 15°C / min, held for 0.3h, and cooled to room temperature at a controlled cooling rate of 35°C / s. After the first heat treatment is completed, the second aging heat treatment is performed. The second aging heat treatment includes: the sample is heated to 280°C at 15°C / min, held for 0.6h, and cooled to room temperature at a controlled cooling rate of 25°C / s.

[0063] Figure 1 The diagram shown is a schematic representation of the microstructure of the aluminum-magnesium-scandium alloy arc additive manufacturing component of the present invention. Figure 1 a represents the grain + grain boundary precipitate Al3(Sc,Zr) microstructure of the deposited sample of the aluminum-magnesium-scandium alloy component manufactured by arc additive manufacturing in Comparative Example 1. Figure 1 b represents the grain structure of the component sample in this embodiment, consisting of Al3(Sc,Zr) precipitates within and at grain boundaries.

[0064] Example 3

[0065] An electric arc additive manufacturing method for aluminum-magnesium-scandium alloys, specifically comprising:

[0066] (1) Load aluminum-magnesium-scandium alloy welding wire with a diameter of Φ1.6mm into the wire feeder. The aluminum-magnesium-scandium alloy wire has a Sc content of 0.25wt.% and a Zr content of 0.15wt.%.

[0067] (2) After cleaning the substrate, fix it on the work platform and turn on the dehumidification equipment to dehumidify.

[0068] (3) Use computer CAD software to draw a three-dimensional model of aluminum-magnesium-scandium components, import it into electric arc additive manufacturing slicing software for layer slicing and formulate the forming path.

[0069] (4) When the humidity in the forming chamber is less than 50%, the welding wire is formed along the preset forming path by using an electric arc as a heat source. After one layer is deposited, the cooling time interval of the deposited layer is 40 minutes before the next layer is deposited.

[0070] During the deposition process of arc additive manufacturing, the deposition parameters are as follows: the wire extension is 14 mm, the argon gas flow rate is 25 L / min, the current is 140 A, the wire feed rate is 9 m / min, the deposition rate is 9 mm / s, and the overlap ratio is 55%. A microstructure sample with a deposition layer height of 4 mm and a diameter of 75 μm, containing grains and grain boundaries with a precipitate phase Al3(Sc,Zr) with a diameter of 0.35 μm was prepared.

[0071] (5) The sample is placed in a heat treatment furnace for special step-by-step aging heat treatment to obtain the final aluminum-magnesium-scandium alloy component. The special step-by-step aging heat treatment is divided into a first aging heat treatment and a second aging heat treatment. The aluminum-magnesium-scandium alloy sample is placed in a heat treatment furnace for the first aging heat treatment, specifically: the sample is heated to 350°C at 12°C / min, held for 0.4h, and cooled to room temperature at a controlled cooling rate of 36°C / s. After the first heat treatment is completed, the second aging heat treatment is performed. The second aging heat treatment includes: the sample is heated to 250°C at 12°C / min, held for 0.5h, and cooled to room temperature at a controlled cooling rate of 28°C / s.

[0072] Example 4

[0073] An electric arc additive manufacturing method for aluminum-magnesium-scandium alloys, specifically comprising:

[0074] (1) Load aluminum-magnesium-scandium alloy welding wire with a diameter of Φ1.6mm into the wire feeder. The aluminum-magnesium-scandium alloy wire has a Sc content of 0.24wt.% and a Zr content of 0.13wt.%.

[0075] (2) After cleaning the substrate, fix it on the work platform and turn on the dehumidification equipment to dehumidify.

[0076] (3) Use computer CAD software to draw a three-dimensional model of aluminum-magnesium-scandium components, import it into electric arc additive manufacturing slicing software for layer slicing and formulate the forming path.

[0077] (4) When the humidity in the forming chamber is less than 50%, the welding wire is formed along the preset forming path by using an electric arc as a heat source. After one layer is deposited, the cooling time interval of the deposited layer is 35 minutes before the next layer is deposited.

[0078] During the arc additive manufacturing deposition process, the deposition parameters were as follows: the wire extension was 13 mm, the argon gas flow rate was 22 L / min, the current was 138 A, the wire feed rate was 10 m / min, the deposition rate was 10 mm / s, and the overlap ratio was 53%. A microstructure sample with a deposition layer height of 3.8 mm and a diameter of 72 μm was prepared, and the grain boundaries contained Al3(Sc,Zr) precipitates with a diameter of 0.32 μm.

[0079] (5) The sample is placed in a heat treatment furnace for special step-by-step aging heat treatment to obtain the final aluminum-magnesium-scandium alloy component. The special step-by-step aging heat treatment is divided into a first aging heat treatment and a second aging heat treatment. The aluminum-magnesium-scandium alloy sample is placed in a heat treatment furnace for the first aging heat treatment, specifically: the sample is heated to 300°C at 14°C / min, held for 0.5h, and cooled to room temperature at a controlled cooling rate of 38°C / s. After the first heat treatment is completed, the second aging heat treatment is performed. The second aging heat treatment includes: the sample is heated to 300°C at 14°C / min, held for 0.6h, and cooled to room temperature at a controlled cooling rate of 29°C / s.

[0080] Example 5

[0081] An electric arc additive manufacturing method for aluminum-magnesium-scandium alloys, specifically comprising:

[0082] The difference from Example 1 is that in the fifth step, the forming interval is 35 minutes.

[0083] The corresponding special step-by-step aging heat treatment process for aluminum-magnesium-scandium alloys is as follows: The first aging heat treatment specifically involves heating the sample to 350℃ at a rate of 12℃ / min, holding it at that temperature for 0.3h, and then cooling it to room temperature at a controlled cooling rate of 34℃ / s. After the first heat treatment is completed, the second aging heat treatment is performed, which includes heating the sample to 300℃ at a rate of 12℃ / min, holding it at that temperature for 0.6h, and then cooling it to room temperature at a controlled cooling rate of 22℃ / s.

[0084] Example 6

[0085] An electric arc additive manufacturing method for aluminum-magnesium-scandium alloys, specifically comprising:

[0086] The difference from Example 1 is that in the fifth step, the forming interval is 38 minutes.

[0087] The corresponding special step-by-step aging heat treatment process for aluminum-magnesium-scandium alloys is as follows: The first aging heat treatment specifically involves heating the sample to 320℃ at a rate of 14℃ / min, holding it at that temperature for 0.4h, and then cooling it to room temperature at a controlled cooling rate of 36℃ / s. After the first heat treatment is completed, the second aging heat treatment is performed, which includes heating the sample to 280℃ at a rate of 14℃ / min, holding it at that temperature for 0.7h, and then cooling it to room temperature at a controlled cooling rate of 24℃ / s.

[0088] Example 7

[0089] An electric arc additive manufacturing method for aluminum-magnesium-scandium alloys, specifically comprising:

[0090] The difference from Example 1 is that the arc additive manufacturing process parameters are different. The arc additive manufacturing parameters are: wire elongation of 13 mm, argon gas flow rate of 24 L / min, current of 132 A, wire feed rate of 8.5 m / min, deposition rate of 8.5 mm / s, and overlap ratio of 48%. A microstructure sample with a deposition layer height of 3.2 mm and a diameter of 72 μm and grain boundaries containing Al3(Sc,Zr) precipitates with a diameter of 0.24 μm was prepared.

[0091] The corresponding special step-by-step aging process is as follows: the first aging heat treatment is as follows: the sample is heated to 330℃ at 12℃ / min, held at that temperature for 0.45h, and cooled to room temperature at a controlled cooling rate of 32℃ / s; after the first heat treatment is completed, the second aging heat treatment is performed, which includes: the sample is heated to 290℃ at 12℃ / min, held at that temperature for 0.8h, and cooled to room temperature at a controlled cooling rate of 22℃ / s.

[0092] Example 8

[0093] An electric arc additive manufacturing method for aluminum-magnesium-scandium alloys, specifically comprising:

[0094] The difference from Example 2 is that the arc additive manufacturing process parameters are different. The arc additive manufacturing parameters are: wire elongation of 13.5 mm, argon gas flow rate of 22 L / min, current of 138 A, wire feed rate of 9.8 m / min, deposition rate of 9.8 mm / s, and overlap ratio of 52%. A microstructure sample with a deposition layer height of 3.8 mm and a diameter of 74 μm, containing grains and grain boundaries with precipitates of Al3(Sc,Zr) with a diameter of 0.34 μm was prepared.

[0095] The corresponding special step-by-step aging process is as follows: the first aging heat treatment is as follows: the sample is heated to 340℃ at 14℃ / min, held at that temperature for 0.48h, and cooled to room temperature at a controlled cooling rate of 35℃ / s; after the first heat treatment is completed, the second aging heat treatment is performed, which includes: the sample is heated to 295℃ at 14℃ / min, held at that temperature for 0.85h, and cooled to room temperature at a controlled cooling rate of 27℃ / s.

[0096] Comparative Example 1

[0097] The difference between the comparative example and Example 1 is that the aging heat treatment methods are different. The specific aging heat treatment method used is as follows: the sample is placed in a heat treatment furnace for special step-by-step aging heat treatment to obtain the final aluminum-magnesium-scandium alloy component; the special step-by-step aging heat treatment is divided into a first aging heat treatment and a second aging heat treatment; the aluminum-magnesium-scandium alloy sample is placed in a heat treatment furnace for the first aging heat treatment, specifically: the sample is heated to 300°C at 10°C / min, held at that temperature for 0.2h, and cooled to room temperature at a controlled cooling rate of 30°C / s; after the first heat treatment is completed, the second aging heat treatment is performed, which includes: the sample is heated to 250°C at 10°C / min, held at that temperature for 0.5h, and cooled to room temperature at a controlled cooling rate of 20°C / s.

[0098] Figure 1 a represents the microstructure of the sedimentary sample obtained in Comparative Example 1. Figure 1 b shows the microstructure of the aluminum-magnesium-scandium alloy obtained in Example 2. The tensile strength Rm, yield strength Rp0.2, and elongation (A%) of the aluminum-magnesium-scandium alloys from the comparative examples and examples were tested, and the results are shown in Table 1.

[0099] like Figure 1 As shown in Table 1, Comparative Example 1 exhibits coarse grains with coarse precipitates of Al3(Sc, Zr) at the grain boundaries. The tensile strength and yield strength of the sample are significantly lower than the application requirements, and the sample shows plastic anisotropy in both directions. Example 2 shows significantly improved tensile strength and elongation, with no plastic anisotropy in either direction, approaching the application requirements. Using the method of this invention, high-strength and high-toughness aluminum-magnesium alloy arc additive manufacturing components can be directly prepared without altering the existing aluminum-magnesium-scandium alloy composition.

[0100] Table 1 Comparison of strength and toughness of aluminum-magnesium-scandium alloy components manufactured by arc additive manufacturing and those manufactured by arc additive manufacturing after special step-by-step aging heat treatment.

[0101]

[0102]

[0103] When the arc current is too low (less than 120A), the wire feed rate is too low (less than 8m / min), and the deposition rate is too low (less than 6mm / s), the heat accumulation during the arc additive forming process is too high, which easily leads to the formation of coarse grains, causing the aluminum-magnesium-scandium alloy components to crack and making them unsuitable for industrial production. When the arc current is too high (greater than 140A), the wire feed rate is too high (greater than 10m / min), and the deposition rate is too high (greater than 10mm / s), coarse grains and precipitated phase structures are formed, and the grain boundary distortion energy is low, which cannot provide sufficient driving force for subsequent special step-by-step aging, and it is impossible to obtain the fine grains and fine grain boundary precipitated phase structures required for high-strength and high-toughness aluminum-magnesium-scandium alloys.

[0104] When the first aging heat treatment temperature is below 300℃ and the holding time is less than 0.2h, the sample cannot obtain fine grains, grain boundaries, and fine intragranular precipitates, and the tensile properties of the sample are lower than the standard requirements. When the first aging heat treatment temperature is above 350℃ and the holding time is above 0.5h, the fine grains and grain boundary precipitates of the sample transform into coarse grains and coarse precipitates, and the tensile properties of the sample are lower than the standard requirements. When the second aging heat treatment temperature is below 250℃ and the holding time is less than 0.5h, the sample cannot obtain fine grains, grain boundaries, and fine intragranular precipitates, and the tensile properties of the sample are lower than the standard requirements. When the second aging heat treatment temperature is above 300℃ and the holding time is above 1h, the sample transforms into a coarse grain and coarse grain boundary precipitate structure, and the tensile properties of the sample are lower than the standard requirements.

[0105] The above description is only the best specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes 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 protection scope of the present invention.

[0106] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A method for arc additive manufacturing of aluminum-magnesium-scandium alloys, characterized in that: Includes the following steps: (1) Establish a three-dimensional model of the aluminum-magnesium-scandium alloy component, perform layer slicing and determine the forming path; (2) Load aluminum-magnesium-scandium alloy welding wire into the wire feeder, fix the substrate on the working platform of the wire feeder, and dehumidify the forming chamber of the wire feeder. The substrate is used for forming aluminum-magnesium-scandium alloy components. (3) After dehumidification, the aluminum-magnesium-scandium alloy welding wire is arc-additively formed along the forming path to complete a layer deposition; (4) Repeat the deposition operation described in step (3) to continuously deposit and manufacture aluminum-magnesium-scandium alloy components; (5) Remove the aluminum-magnesium-scandium alloy component obtained in step (4) from the forming chamber and separate it from the substrate; (6) Perform aging heat treatment on the aluminum-magnesium-scandium alloy component obtained in step (5) to obtain the final aluminum-magnesium-scandium alloy component; In step (3), the electric arc additive manufacturing process parameters are as follows: the wire elongation is 10-14 mm, the argon gas flow rate is 15-25 L / min, the current is 120-140 A, the wire feed rate is 8-10 m / min, the deposition rate is 6-10 mm / s, and the overlap ratio is 45-55%. In step (3), the energy density of the aluminum alloy deposition zone is 55-65 J / mm, and the cooling rate at the leading edge of the molten pool interface is 10. 2 ~10 2.5 K / s, and the sedimentary layer height is 3-4 mm; In step (6), the aging heat treatment includes a first aging heat treatment and a second aging heat treatment. The first aging heat treatment method is as follows: the aluminum-magnesium-scandium alloy component is heated to 300-350°C at a rate of 10-15°C / min, held at that temperature for 0.2-0.5h, and cooled to room temperature at a cooling rate of not less than 30°C / s. Then, the second aging heat treatment is performed. The second aging heat treatment method is as follows: the aluminum-magnesium-scandium alloy component is heated to 250-300°C at a rate of 10-15°C / min, held at that temperature for 0.5-1h, and cooled to room temperature at a cooling rate of not less than 20°C / s. In step (4), the interval between deposition layers is 30 to 40 minutes; The diameter of the aluminum-magnesium-scandium alloy welding wire is 1.2–1.6 mm; The aluminum-magnesium-scandium alloy welding wire has a Sc content of 0.2–0.3 wt.% and a Zr content of 0.1–0.15 wt.%.

2. An aluminum-magnesium-scandium alloy component, characterized in that: It is prepared by the manufacturing method according to claim 1.

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