Electric arc additive manufacturing method for aluminum-magnesium-scandium alloy

Abstract

The invention relates to an electric arc additive manufacturing method for a high-toughness aluminum-magnesium-scandium alloy, and belongs to the technical field of electric arc additive manufacturing of metal materials. An aluminum-magnesium-scandium alloy component is formed through electric arc additive, and a special structure with fine grains and grain boundaries pinned by fine precipitated phases Al3 (Sc and Zr) is obtained through subsequent aging heat treatment; and recrystallization of crystal grains in subsequent aging is prevented, so that synchronous improvement of the strength and plasticity of the aluminum-magnesium-scandium alloy component is realized, and the high-performance aluminum-magnesium-scandium alloy component is obtained. According to the method, the near-net-shaped aluminum-magnesium-scandium alloy electric arc additive component is directly prepared, the manufacturing period is shortened, the manufacturing cost is remarkably reduced, and the material utilization rate is greatly increased.

Description

Technical Field

[0001] The present invention belongs to the technical field of arc additive manufacturing of metal materials, and in particular relates to an arc additive manufacturing method for an aluminum-magnesium-scandium alloy. Background Art

[0002] Aluminum alloy is the most widely used nonferrous metal material in industry, in the fields of aerospace, transportation and machinery manufacturing. Aluminum-copper alloy is a heat-treated strengthened aluminum alloy. It is widely used in the manufacture of launch vehicle tanks, transition rings and other structural parts due to its good high and low temperature mechanical properties, good corrosion resistance and weldability. With the further improvement of the demand for low cost, high efficiency and high reliability in the manufacture of aerospace structural parts, new requirements have been put forward for the manufacture of complex aluminum alloy components.

[0003] Arc additive manufacturing technology is based on CAD models. It forms dense metal components layer by layer according to the planned path, and then prepares large metal components with a small amount of subsequent machining. Compared with traditional manufacturing technology, arc additive manufacturing technology can achieve high-performance manufacturing of large and complex aluminum alloy components. In recent years, arc additive manufacturing technology of aluminum-copper alloys has gradually been applied to large aerospace structures. After arc additive forming of aluminum-copper alloys, solid solution quenching and aging heat treatment is still required to obtain components with better mechanical properties. Usually, aluminum-copper alloy components are prone to deformation during solid solution quenching and aging, which reduces the dimensional accuracy of their components. Therefore, in order to ensure the geometric dimensional accuracy of aluminum-copper alloy arc additive manufacturing components, it is necessary to increase the thickness of the formed components and add anti-deformation ribs in arc additive forming to improve the solid solution quenching deformation stiffness of the formed components and ensure their geometric dimensional accuracy. This greatly increases the arc additive manufacturing cost cycle, manufacturing cost and subsequent machining cost, and reduces material utilization and overall manufacturing cost.

[0004] Aluminum-magnesium-scandium alloy is a non-heat-treatable strengthened aluminum alloy with good plasticity, oxidation resistance and welding properties. After arc additive forming, aluminum-magnesium-scandium alloy components do not need solid solution quenching treatment and only need aging heat treatment to meet the use requirements. They are especially suitable for high-performance, short-cycle and low-cost arc additive forming of large and complex components. At present, Northeastern University, Harbin Institute of Technology and Relativity Space Company in the United States have conducted relevant research on the organization and performance regulation of arc additive manufacturing of aluminum-magnesium-scandium alloys. However, the tensile strength of existing aluminum-magnesium-scandium alloy arc additive components is low (265-335MPa) and there is plastic anisotropy in transverse and longitudinal specimens (the elongation of transverse specimens is about 22%, and the elongation of longitudinal specimens is about 6.5%), which greatly limits its engineering application. Therefore, it is urgent to propose an arc additive manufacturing method for high-strength and tough aluminum-magnesium-scandium alloy components to meet their engineering application needs. Summary of the invention

[0005] The purpose of the present invention is to provide an aluminum-magnesium-scandium alloy arc additive manufacturing method, which adopts arc additive forming to form aluminum-magnesium-scandium alloy components, accurately matches the subsequent aging heat treatment, and obtains a special structure with fine grains and grain boundaries pinned by fine precipitated phases Al3 (Sc, Zr), thereby preventing 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 further preparing high-performance aluminum-magnesium-scandium alloy components.

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

[0007] An arc additive manufacturing method for an aluminum-magnesium-scandium alloy comprises the following steps:

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

[0009] (2) loading the aluminum-magnesium-scandium alloy welding wire into a wire feeder, fixing a substrate on a working platform of the wire feeder, and dehumidifying a forming chamber of the wire feeder, wherein the substrate is used for forming an aluminum-magnesium-scandium alloy component;

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

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

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

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

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

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

[0016] In the 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-scB alloy component is heated to 300-350°C at a rate of 10-15°C / min, kept at the 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, and the second aging heat treatment method is as follows: the aluminum-magnesium-scB alloy component is heated to 250-300°C at a rate of 10-15°C / min, kept at the temperature for 0.5-1h, and cooled to room temperature at a cooling rate of not less than 20°C / s.

[0017] In the step (4), the interval time 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-sc alloy welding wire has an Sc content of 0.2-0.3 wt.%, and a Zr content of 0.1-0.15 wt.%.

[0020] An arc additive manufacturing method for an aluminum-magnesium-scandium alloy comprises the following steps:

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

[0022] (2) Loading the aluminum-magnesium-scandium alloy welding wire into the wire feeder, fixing the substrate on the working platform of the wire feeder, and dehumidifying the forming chamber of the wire feeder;

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

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

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

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

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

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

[0029] In the 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-scB alloy component is heated to 300-350°C at a rate of 10-15°C / min, kept at the 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, and the second aging heat treatment method is as follows: the aluminum-magnesium-scB alloy component is heated to 250-300°C at a rate of 10-15°C / min, kept at the temperature for 0.5-1h, and cooled to room temperature at a cooling rate of not less than 20°C / s.

[0030] In the step (4), the interval time 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-sc alloy welding wire has an 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 manufacturing components. Compared with aluminum-copper alloy arc additive manufacturing components, this technology significantly reduces the manufacturing cycle and manufacturing cost, and greatly improves the material utilization rate.

[0035] (2) The present invention obtains a special structure with grains with a diameter of 65 to 75 μm, a precipitated phase Al3 (Sc, Zr) with a diameter of 0.25 to 0.35 μm at the grain boundary and a precipitated phase Al3 (Sc, Zr) with a diameter of 0.3 to 0.35 μm in the grain through the control of the arc additive manufacturing process and the aging heat treatment, which can significantly improve the room temperature mechanical properties of aluminum-magnesium-scandium alloy components. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 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 of comparative example 1; Figure 1 b is a schematic diagram of the microstructure of the component in Example 2. DETAILED DESCRIPTION

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

[0038] An arc additive manufacturing method for an aluminum-magnesium-scandium alloy comprises 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 working platform and start the dehumidification equipment to perform dehumidification work;

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

[0042] (4) When the humidity in the forming chamber is lower than 50%, the arc is used as a heat source to form the welding wire along a preset forming path for arc additive forming. After one layer is deposited, the next layer is deposited after a set time interval;

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

[0044] By controlling the arc additive forming process parameters, 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 of the forming molten pool interface is 102-102.5 K / s, and a microstructure with a layer height of 3-4 mm, a diameter of 65-75 μm, and a precipitated phase Al3 (Sc, Zr) with a diameter of 0.2-0.3 μm at the grain boundary is prepared;

[0045] (5) placing the sample into a heat treatment furnace for special step-by-step aging heat treatment to obtain a 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, specifically: the sample is heated to 300-350°C at 10-15°C / min, kept warm for 0.2-0.5h, and cooled to room temperature at a cooling rate of not less than 30°C / s; after the first heat treatment is completed, the second aging heat treatment is carried out, and the second aging heat treatment includes: the sample is heated to 250-300°C at 10-15°C / min, kept warm for 0.5-1h, and cooled to room temperature at a cooling rate of not less than 20°C / s.

[0047] Example 1

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

[0049] (1) Load an aluminum-magnesium-sc-alloy welding wire with a diameter of 1.2 mm into a wire feeder. The aluminum-magnesium-sc-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 working platform and start the dehumidification equipment to perform dehumidification work;

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

[0052] (4) When the humidity in the forming chamber is lower than 50%, the arc is used as a heat source to form the welding wire along the preset forming path for arc additive forming. After one layer is deposited, the deposited layer is cooled for 30 minutes before the next layer is deposited;

[0053] During the arc additive manufacturing deposition process, the deposition parameters are as follows: the wire elongation is 10 mm, the argon gas flow rate is 15 L / min, the current is 120 A, the wire feeding rate is 8 m / min, the deposition rate is 6 mm / s, and the overlap rate is 45%. The microstructure sample with a deposition layer height of 3 mm, a grain diameter of 65 μm, and a precipitated phase Al3 (Sc, Zr) with a diameter of 0.2 μm at the grain boundary is prepared;

[0054] (5) placing the sample in a heat treatment furnace for a special step-by-step aging heat treatment to obtain a final aluminum-magnesium-scB alloy component; the special step-by-step aging heat treatment is divided into a first aging heat treatment and a second aging heat treatment; placing the aluminum-magnesium-scB alloy sample in a heat treatment furnace for a first aging heat treatment, specifically: heating the sample to 300°C at a rate of 10°C / min, keeping the temperature for 0.2h, and cooling it to room temperature at a controlled cooling rate of 30°C / s; after the first heat treatment is completed, performing a second aging heat treatment, the second aging heat treatment comprising: heating the sample to 250°C at a rate of 10°C / min, keeping the temperature for 0.5h, and cooling it to room temperature at a controlled cooling rate of 20°C / s.

[0055] Example 2

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

[0057] (1) Loading an aluminum-magnesium-sc-alloy welding wire with a diameter of Φ1.2 mm into a wire feeder, wherein the aluminum-magnesium-sc-alloy wire has a Sc content of 0.24 wt.% and a Zr content of 0.13 wt.%;

[0058] (2) After cleaning the substrate, fix it on the working platform and start the dehumidification equipment to perform dehumidification work;

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

[0060] (4) When the humidity in the forming chamber is lower than 50%, the arc is used as a heat source to form the welding wire along the preset forming path for arc additive forming. After one layer is deposited, the deposited layer is cooled for 35 minutes before the next layer is deposited;

[0061] In the arc additive manufacturing deposition process, the deposition parameters are as follows: the wire elongation is 12 mm, the argon gas flow rate is 20 L / min, the current is 130 A, the wire feeding rate is 10 m / min, the deposition rate is 10 mm / s, and the overlap rate is 48%. The microstructure sample with a deposition layer height of 3.5 mm, a grain diameter of 70 μm, and a precipitated phase Al3 (Sc, Zr) with a diameter of 0.25 μm at the grain boundary is prepared;

[0062] (5) placing the sample in a heat treatment furnace for a special step-by-step aging heat treatment to obtain a final aluminum-magnesium-scB alloy component; the special step-by-step aging heat treatment is divided into a first aging heat treatment and a second aging heat treatment; placing the aluminum-magnesium-scB alloy sample in a heat treatment furnace for a first aging heat treatment, specifically: heating the sample to 320°C at a rate of 15°C / min, keeping the temperature for 0.3h, and cooling it to room temperature at a controlled cooling rate of 35°C / s; after the first heat treatment is completed, performing a second aging heat treatment, the second aging heat treatment comprising: heating the sample to 280°C at a rate of 15°C / min, keeping the temperature for 0.6h, and cooling it to room temperature at a controlled cooling rate of 25°C / s.

[0063] Figure 1 The figure shows the microstructure of the component manufactured by arc additive manufacturing of aluminum-magnesium-scandium alloy of the present invention, wherein Figure 1 a is the grain + grain boundary precipitation phase Al3 (Sc, Zr) structure of the deposited sample of the aluminum-magnesium-scandium alloy arc additive manufacturing component in comparative example 1; Figure 1 b is the grain + intragranular and grain boundary precipitation phase Al3 (Sc, Zr) structure of the component sample of this embodiment.

[0064] Example 3

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

[0066] (1) Loading an aluminum-magnesium-sc alloy welding wire with a diameter of Φ1.6 mm into a wire feeder, wherein the aluminum-magnesium-sc alloy wire has a Sc content of 0.25 wt.% and a Zr content of 0.15 wt.%;

[0067] (2) After cleaning the substrate, fix it on the working platform and start the dehumidification equipment to perform dehumidification work;

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

[0069] (4) When the humidity in the forming chamber is lower than 50%, the arc is used as a heat source to form the welding wire along the preset forming path for arc additive forming. After one layer is deposited, the deposited layer is cooled for 40 minutes before the next layer is deposited;

[0070] During the arc additive manufacturing deposition process, the deposition parameters are as follows: the wire elongation is 14 mm, the argon gas flow rate is 25 L / min, the current is 140 A, the wire feeding rate is 9 m / min, the deposition rate is 9 mm / s, and the overlap rate is 55%. The microstructure sample with a deposition layer height of 4 mm, a grain diameter of 75 μm, and a precipitated phase Al3 (Sc, Zr) with a diameter of 0.35 μm at the grain boundary is prepared;

[0071] (5) placing the sample in a heat treatment furnace for a special step-by-step aging heat treatment to obtain a final aluminum-magnesium-scB alloy component; the special step-by-step aging heat treatment is divided into a first aging heat treatment and a second aging heat treatment; placing the aluminum-magnesium-scB alloy sample in a heat treatment furnace for a first aging heat treatment, specifically: heating the sample to 350°C at a rate of 12°C / min, keeping the temperature for 0.4h, and cooling it to room temperature at a controlled cooling rate of 36°C / s; after the first heat treatment is completed, performing a second aging heat treatment, the second aging heat treatment comprising: heating the sample to 250°C at a rate of 12°C / min, keeping the temperature for 0.5h, and cooling it to room temperature at a controlled cooling rate of 28°C / s.

[0072] Example 4

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

[0074] (1) Loading an aluminum-magnesium-sc alloy welding wire with a diameter of Φ1.6 mm into a wire feeder, wherein the aluminum-magnesium-sc alloy wire has a Sc content of 0.24 wt.% and a Zr content of 0.13 wt.%;

[0075] (2) After cleaning the substrate, fix it on the working platform and start the dehumidification equipment to perform dehumidification work;

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

[0077] (4) When the humidity in the forming chamber is lower than 50%, the arc is used as a heat source to form the welding wire along the preset forming path for arc additive forming. After one layer is deposited, the deposited layer is cooled for 35 minutes before the next layer is deposited;

[0078] During the arc additive manufacturing deposition process, the deposition parameters are as follows: the wire elongation is 13 mm, the argon gas flow rate is 22 L / min, the current is 138 A, the wire feeding rate is 10 m / min, the deposition rate is 10 mm / s, and the overlap rate is 53%. The microstructure sample with a deposition layer height of 3.8 mm, a grain diameter of 72 μm, and a precipitated phase Al3 (Sc, Zr) with a diameter of 0.32 μm at the grain boundary is prepared;

[0079] (5) placing the sample in a heat treatment furnace for a special step-by-step aging heat treatment to obtain a 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; placing the aluminum-magnesium-scandium alloy sample in a heat treatment furnace for a first aging heat treatment, specifically: heating the sample to 300°C at a rate of 14°C / min, keeping the temperature for 0.5h, and cooling it to room temperature at a controlled cooling rate of 38°C / s; after the first heat treatment is completed, performing a second aging heat treatment, the second aging heat treatment comprising: heating the sample to 300°C at a rate of 14°C / min, keeping the temperature for 0.6h, and cooling it to room temperature at a controlled cooling rate of 29°C / s.

[0080] Example 5

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

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

[0083] The corresponding special step-by-step aging heat treatment process of aluminum-magnesium-scandium alloy is as follows: the first aging heat treatment is as follows: the sample is heated to 350°C at 12°C / min, kept warm for 0.3h, and cooled to room temperature at a controlled cooling rate of 34°C / s; after the first heat treatment is completed, the second aging heat treatment is carried out, and the second aging heat treatment includes: the sample is heated to 300°C at 12°C / min, kept warm for 0.6h, and cooled to room temperature at a controlled cooling rate of 22°C / s.

[0084] Example 6

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

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

[0087] The corresponding special step-by-step aging heat treatment process of aluminum-magnesium-scandium alloy is as follows: the first aging heat treatment is as follows: the sample is heated to 320°C at 14°C / min, kept warm 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 carried out, and the second aging heat treatment includes: the sample is heated to 280°C at 14°C / min, kept warm for 0.7h, and cooled to room temperature at a controlled cooling rate of 24°C / s.

[0088] Example 7

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

[0090] The difference from Example 1 is that the arc additive manufacturing process parameters are different; the arc additive manufacturing parameters are: welding wire dry wire elongation 13mm, argon gas flow rate 24L / min, current 132A, wire feeding rate 8.5m / min, deposition rate 8.5mm / s, overlap rate 48%, and a microstructure sample with a deposition layer height of 3.2mm, a grain diameter of 72μm, and a grain boundary containing a precipitated phase Al3(Sc,Zr) with a diameter of 0.24μm is 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°C at 12°C / min, kept at this temperature for 0.45h, and cooled to room temperature at a controlled cooling rate of 32°C / s; after the first heat treatment is completed, the second aging heat treatment is performed, and the second aging heat treatment includes: the sample is heated to 290°C at 12°C / min, kept at this temperature for 0.8h, and cooled to room temperature at a controlled cooling rate of 22°C / s.

[0092] Example 8

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

[0094] The difference from Example 2 is that the arc additive manufacturing process parameters are different; the arc additive manufacturing parameters are: the dry wire elongation of the welding wire is 13.5 mm, the gas flow rate of argon is 22 L / min, the current is 138 A, the wire feeding rate is 9.8 m / min, the deposition rate is 9.8 mm / s, the overlap rate is 52%, and the microstructure sample with a deposition layer height of 3.8 mm, a grain diameter of 74 μm, and a grain boundary containing a precipitated phase Al3 (Sc, Zr) with a diameter of 0.34 μm is 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°C at 14°C / min, kept at this temperature for 0.48h, 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, and the second aging heat treatment includes: the sample is heated to 295°C at 14°C / min, kept at this temperature for 0.85h, and cooled to room temperature at a controlled cooling rate of 27°C / s.

[0096] Comparative Example 1

[0097] The difference between the comparative example and Example 1 is that the aging heat treatment method is inconsistent. The specific aging heat treatment method is: placing the sample in a heat treatment furnace for special step-by-step aging heat treatment to obtain a 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; placing the aluminum-magnesium-scandium alloy sample in a heat treatment furnace for a first aging heat treatment, specifically: heating the sample to 300°C at 10°C / min, keeping it warm for 0.2h, and cooling it to room temperature at a controlled cooling rate of 30°C / s; after the first heat treatment is completed, performing a second aging heat treatment, the second aging heat treatment comprising: heating the sample to 250°C at 10°C / min, keeping it warm for 0.5h, and cooling it to room temperature at a controlled cooling rate of 20°C / s.

[0098] Figure 1 a is the microstructure of the deposited sample obtained in comparative example 1, Figure 1 b is the aluminum-magnesium-scandium alloy structure obtained in Example 2. The aluminum-magnesium-scandium alloys of the comparative example and the example were tested for tensile strength Rm, yield strength Rp0.2, and elongation (A%). The test results are shown in Table 1.

[0099] like Figure 1 As shown in Table 1, Comparative Example 1 presents coarse grains, with coarse precipitation phase Al3 (Sc, Zr) on the grain boundaries, the tensile strength and yield strength of the sample are significantly lower than the application requirements, and the samples in two directions have plastic anisotropy. The tensile strength and elongation of the sample in Example 2 are significantly improved, and the samples in two directions have no plastic anisotropy, which is close to the application requirements. By adopting the method of the present invention, high-strength and tough aluminum-magnesium alloy arc additive manufacturing components can be directly prepared without changing the composition of the existing aluminum-magnesium-scandium alloy.

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

[0101]

[0102]

[0103] When the arc current is too low (less than 120A), the wire feeding rate is too low (less than 8m / min) and the deposition rate is too low (less than 6mm / s), the heat accumulation in the arc additive forming process is too high, and coarse grains are easily formed, causing cracking of the aluminum-magnesium-scandium alloy components, which cannot be used in industrial production; when the arc current is too high (greater than 140A), the wire feeding rate is too high (greater than 10m / min) and the deposition rate is too high (greater than 10mm / s), coarse grains and precipitate 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 the fine grains and fine precipitate phase structures at the grain boundaries required for high-strength and tough aluminum-magnesium-scandium cannot be obtained.

[0104] When the first aging heat treatment temperature is lower than 300℃ and the holding time is lower than 0.2h, the sample cannot obtain fine grains, grain boundaries and fine precipitation phases in the crystals, and the tensile properties of the sample are lower than the standard requirements; when the first aging heat treatment temperature is higher than 350℃ and the holding time is higher than 0.5h, the fine grains and fine precipitation phases at the grain boundaries of the sample are transformed into coarse grains and coarse precipitation phases, and the tensile properties of the sample are lower than the standard requirements; when the second aging heat treatment temperature is lower than 250℃ and the holding time is lower than 0.5h, the sample cannot obtain fine grains, grain boundaries and fine precipitation phases in the crystals, and the tensile properties of the sample are lower than the standard requirements; when the second aging heat treatment temperature is higher than 300℃ and the holding time is higher than 1h, the sample is transformed into coarse grains and coarse grain boundary precipitation phase structure, and the tensile properties of the sample are lower than the standard requirements.

[0105] The above description is only the best specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

[0106] The contents not described in detail in the specification of the present invention belong to the common knowledge of the professionals in this field.

Claims

1. An arc additive manufacturing method for aluminum-magnesium-scandium alloy, characterized in that: The following steps are involved: (1) Establish a three-dimensional model of the aluminum-magnesium-scandium alloy component, perform layered slicing, and formulate a forming path; (2) loading the aluminum-magnesium-scandium alloy welding wire into a wire feeder, fixing a substrate on a working platform of the wire feeder, and dehumidifying a forming chamber of the wire feeder, wherein the substrate is used for forming an aluminum-magnesium-scandium alloy component; (3) After dehumidification is completed, the aluminum-magnesium-scandium alloy welding wire is subjected to arc additive forming along the forming path to complete a layer of deposition; (4) Repeat the deposition operation in step (3) to continuously deposit and manufacture an aluminum-magnesium-scandium alloy component; (5) taking the aluminum-magnesium-scandium alloy component obtained in step (4) out of the forming chamber and separating it from the substrate; (6) Performing aging heat treatment on the aluminum-magnesium-scandium alloy component obtained in step (5) to obtain a final aluminum-magnesium-scandium alloy component.

2. The method for arc additive manufacturing of aluminum-magnesium-scandium alloy according to claim 1, characterized in that: In the step (3), the arc additive forming process parameters are as follows: the dry wire elongation of the welding wire is 10 to 14 mm, the argon gas flow rate is 15 to 25 L / min, the current is 120 to 140 A, the wire feeding rate is 8 to 10 m / min, the deposition rate is 6 to 10 mm / s, and the overlap rate is 45 to 55%.

3. The arc additive manufacturing method of aluminum-magnesium-scandium alloy according to claim 1, characterized in that: In the step (3), the energy density of the aluminum alloy deposition zone is 55-65 J / mm, and the cooling rate at the front of the forming molten pool interface is 10 2 ~10 2.5 K / s, the sedimentary layer height is 3-4 mm.

4. The method for arc additive manufacturing of aluminum-magnesium-scandium alloy according to claim 1, characterized in that: In the 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-scB alloy component is heated to 300-350°C at a rate of 10-15°C / min, kept at the 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, and the second aging heat treatment method is as follows: the aluminum-magnesium-scB alloy component is heated to 250-300°C at a rate of 10-15°C / min, kept at the temperature for 0.5-1h, and cooled to room temperature at a cooling rate of not less than 20°C / s.

5. The arc additive manufacturing method of aluminum-magnesium-scandium alloy according to claim 1, characterized in that: In the step (4), the interval time between deposition layers is 30 to 40 minutes.

6. The arc additive manufacturing method of aluminum-magnesium-scandium alloy according to claim 1, characterized in that: The diameter of the aluminum-magnesium-scandium alloy welding wire is 1.2-1.6 mm.

7. The arc additive manufacturing method of aluminum-magnesium-scandium alloy according to claim 1, characterized in that: The aluminum-magnesium-sc alloy welding wire has an Sc content of 0.2-0.3 wt.%, and a Zr content of 0.1-0.15 wt.%.

8. An aluminum-magnesium-scandium alloy component, characterized in that it is prepared according to the manufacturing method according to any one of claims 1 to 7.

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