An aluminum alloy welding material and a method for preparing a high-strength and tough weld seam

Abstract

The present invention relates to an aluminum alloy welding material and a method for preparing a high-strength and tough weld, belonging to the field of welding technology. The aluminum alloy welding material of the present invention combines welding technologies such as cold metal transfer and pulse composite welding, laser welding, etc. with rapid cooling, so that elements such as Mg, Cu, and Zn in the weld are completely solid-solved and in a supersaturated state. The joint strength mainly comes from the solid-solution strengthening contribution of alloy elements such as Mg, Cu, and Zn and the precipitation strengthening contribution of the corresponding strengthening phases; then, through short-term natural aging, the solute-vacancy coupling diffusion mechanism can be realized, promoting the rapid precipitation of high-density strengthening phases in the weld, thereby realizing the strengthening and toughening of the weld, and significantly improving the weld strength and welding coefficient. Thus, the intervention of artificial aging is avoided, the welding cost is reduced, and the welding efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of welding, and particularly relates to an aluminum alloy welding material and a method for preparing a high-strength and high-toughness weld seam. Background Art

[0002] Aluminum alloys have the advantages of low density, high specific strength, good weldability, low cost, etc., and are increasingly widely used in the fields of automobiles, rail transit, ships, aerospace, etc., and have also become the key materials for lightweight development. In actual production and manufacturing, it is inevitable to weld aluminum alloy parts. However, when using traditional commercial welding wires, such as ER4043 (Al-5Si), ER4047 (Al-12Si), etc., the strength of the welded joint seriously depends on the composition dilution of the base material, and the welding coefficient of the joint is generally only 50%-70%, which is difficult to meet the requirements of high-performance welded joints in actual production and manufacturing, and greatly limits the industrial application of aluminum alloys.

[0003] After welding with traditional commercial welding wires, only atomic clusters and GP zones are formed, resulting in serious softening of the weld seam. Post-weld heat treatment is required to strengthen the joint, which increases the welding cost, is not conducive to energy conservation and emission reduction, and in most cases, heat treatment strengthening of the welded parts is not feasible. Therefore, the composition regulation of welding materials and the development of welding processes are effective means to enhance the performance of aluminum alloy welded joints.

[0004] At present, alloying of welding materials is a common way to improve the performance of welded joints. Patent CN118875569A discloses an aluminum-magnesium alloy welding wire and its preparation method, in which a mixture of Mg, Al, Al-Mn alloy and Al-Cr alloy is melted to prepare the welding wire to improve the mechanical properties of the weld seam. Patent CN116005047A discloses an aluminum alloy wire for welding and additive manufacturing and its preparation method, in which elements such as Si, Mn, Sc, Zr, etc. are added on the basis of an Al-Mg welding wire for alloying to improve the strength of the weld seam. Patent CN118875568A discloses an aluminum alloy welding wire for fusion welding of 6-series aluminum alloys and its preparation method, by adding rare earth elements such as La, Ce, etc. during the preparation of the aluminum alloy welding wire to reduce the sensitivity to hot cracks during welding and optimize and regulate the comprehensive performance of the material. However, at present, welding materials need to add rare earth elements and other expensive alloying elements, which increases the cost, and the improvement of the performance of welded joints is still limited, is not suitable for preparing high-strength and high-toughness weld seams, and cannot meet the requirements of industrial production and manufacturing.

[0005] Based on this, the present invention is proposed. Summary of the Invention

[0006] To solve the above technical problems, the present invention provides an aluminum alloy welding material and a method for preparing a high-strength and high-toughness weld, achieving the strengthening and toughening of the weld, improving the strength of the welded joint (greater than 280 Mpa) and the welding coefficient (reaching 74.3%) to meet the requirements for high-performance aluminum alloy welded joints in actual production and manufacturing.

[0007] The first object of the present invention is to provide an aluminum alloy welding material. The elemental composition and its mass percentage of the aluminum alloy welding material are as follows: Si 6.0% - 12.0%, Mg 0.6% - 0.9%, Cu 0.5% - 1.9%, Zn 0.1% - 0.9%, Cr 0.1% - 0.5%, Mn 0.1% - 1.0%, Fe 0 - 0.15%, and the balance is Al and other inevitable impurities, with a total impurity of 0 - 0.15%; the dilution of the aluminum alloy welding material into the weld meets the following points:

[0008] The mass ratio of Mg and Si is (0.16 - 0.83):1;

[0009] The mass fraction of Cu is at least 1.00%, and the mass ratio of Cu and Mg is (1.20 - 1.65):1;

[0010] The mass fraction of Zn is 0.05% - 0.50%, and the mass ratio of (Zn + Cu) and Mg is (1.50 - 2.50):1.

[0011] In one embodiment of the present invention, the form of the aluminum alloy welding material is selected from one or more of powder, thin sheet, and wire.

[0012] In one embodiment of the present invention, the particle size of the powder is 10 μm - 250 μm, the thickness of the thin sheet is 50 μm - 1000 μm, and the diameter of the wire is 0.5 mm - 3.2 mm.

[0013] The second object of the present invention is to provide a method for preparing a high-strength and high-toughness aluminum alloy weld, including the following steps: welding an aluminum alloy base material with a welding material, and combining cooling treatment to make elements such as Mg, Cu, and Zn in the weld completely solid-solved, and then subjecting the weld joint to natural aging treatment to precipitate strengthening phases; the welding material is the aluminum alloy welding material described above; the strengthening phases are selected from one or more of θ'-Al2Cu, β''-Mg5Si6, Q'-AlCuMgSi, S-Al2CuMg, and η'-Mg2Zn5.

[0014] In one embodiment of the present invention, the aluminum alloy base material is selected from one or more of Al-Cu series alloys, Al-Si series alloys, Al-Mg series alloys, Al-Mg-Si series alloys, and Al-Zn series alloys.

[0015] In one embodiment of the present invention, the initial form of the aluminum alloy base material is in the T0 state - T10 state.

[0016] In one embodiment of the present invention, the welding method is selected from cold metal transfer and pulse composite welding and / or laser welding.

[0017] In one embodiment of the present invention, the process parameters of the cold metal transfer and pulse composite welding are as follows: the synchronous pulse frequency is 2 Hz - 10 Hz, the welding speed is 6 mm / s - 12 mm / s, and the wire feeding speed is 3.8 m / min - 5.2 m / min;

[0018] The process parameters of the laser welding are as follows: the oscillation frequency is 80 Hz - 250 Hz, the oscillation amplitude is 1.0 mm - 3.0 mm, the welding speed is 20 mm / s - 33 mm / s, and the wire feeding speed is 3 m / min - 6 m / min.

[0019] In one embodiment of the present invention, the laser in the laser welding is a swinging laser and / or a galvanometer laser, and the laser type is one or more of infrared light, blue light, and green light.

[0020] In one embodiment of the present invention, the cooling treatment method is selected from one or more of high - thermal - conductivity metal substrate cooling, liquid cooling, forced air cooling, and cryogenic fluid cooling; the cooling treatment is cooling during welding, aiming to increase the cooling rate of the molten pool during the welding process to increase the solid solubility of alloying elements and promote the response of precipitates in the natural aging behavior;

[0021] The rate of the cooling treatment is at least 2.94×10 3 K / s.

[0022] In one embodiment of the present invention, the temperature of the natural aging treatment is 15°C - 35°C, and the time is 3 days - 15 days.

[0023] The technical solution of the present invention has the following advantages compared with the prior art:

[0024] (1) The aluminum alloy welding material of the present invention is rapidly cooled by combining welding techniques such as cold metal transfer and pulsed hybrid welding, laser welding, etc., so that the mass ratio of Mg and Si in the weld is (0.16 - 0.83):1. The Mg / Si ratio within this range is conducive to reducing the energy barrier for the precipitation of strengthening phases and the critical nucleation size, enabling the β''-Mg5Si6 phase to precipitate in the form of small size and high density; the mass fraction of Cu is at least 1.00%, and at the same time, the mass ratio of Cu and Mg is (1.20 - 1.65):1, which enables a large amount of θ'-Al2Cu phase to precipitate in the weld, and also precipitates Q'-AlCuMgSi phase and Cu-containing precipitation phases such as S-Al2CuMg; the mass fraction of Zn is 0.05% - 0.50%, and the mass ratio of (Zn + Cu) and Mg is (1.50 - 2.50):1. Within this range, η'-Mg2Zn5 can be formed, and the presence of Cu and Zn can promote the precipitation of the β''-Mg5Si6 phase.

[0025] (2) The preparation method of the present invention combines welding techniques such as cold metal transfer and pulsed hybrid welding, laser welding, etc. with rapid cooling, so that elements such as Mg, Cu, and Zn in the weld are completely solid-solved and in a supersaturated state. The joint strength mainly comes from the solid-solution strengthening contribution of alloying elements such as Mg, Cu, and Zn and the precipitation strengthening contribution of the corresponding strengthening phases; then, through short-term natural aging, the solute-vacancy coupling diffusion mechanism can be realized, promoting the rapid precipitation of high-density strengthening phases in the weld, thereby achieving the strengthening and toughening of the weld, and significantly improving the weld strength (>280 MPa) and the welding coefficient (reaching 74.3%). Thus, the intervention of artificial aging is avoided, the welding cost is reduced, and the welding efficiency is improved.

[0026] (3) The preparation method of the present invention rapidly cools (the cooling rate is at least 2.94×10 3 K / s), which significantly refines the cellular substructure of the weld. The distance between cellular substructures is less than 10 μm, and the denser eutectic Si network provides more nucleation sites for the precipitation of strengthening phases; moreover, the solid solubility of alloying elements such as Mg, Cu, and Zn in the weld is increased, enhancing the precipitation response of natural aging. Description of the Drawings

[0027] In order to make the content of the present invention easier to be clearly understood, the following further details the present invention according to specific embodiments of the present invention and in combination with the drawings, where:

[0028] Figure 1 is a high-resolution image of the precipitation phases of the welded joint of Example 1 of the present invention;

[0029] Figure 2 is a high-resolution image of the precipitation phases of the welded joint of Example 2 of the present invention;

[0030] Figure 3 High-resolution image of the precipitated phase of the welded joint of Comparative Example 1 of the present invention;

[0031] Figure 4 High-resolution image of the precipitated phase of the welded joint of Comparative Example 2 of the present invention;

[0032] Figure 5 Metallographic image of the cellular substructure of the welded joint of Example 2 of the present invention;

[0033] Figure 6 Metallographic image of the cellular substructure of the welded joint of Comparative Example 3 of the present invention;

[0034] Figure 7 Tensile curve diagram of the welded joints of Examples 1-3 and Comparative Examples 1-4 of the present invention;

[0035] Figure 8 Bar chart of the tensile strength and welding coefficient of the welded joints of Examples 1-3 and Comparative Examples 1-4 of the present invention. Detailed implementation manners

[0036] The present invention will be further described below in conjunction with specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. It should be understood that the specific embodiments are only used to explain the present invention, but the exemplified embodiments do not limit the present invention.

[0037] In the present invention, unless otherwise specified, the technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the technical field to which the present invention belongs.

[0038] In the present invention, unless otherwise specified, the term "and / or" includes any and all combinations of one or more of the related listed items.

[0039] In the present invention, unless otherwise specified, the experimental methods used in the embodiments of the present invention are all conventional methods without special instructions, and the materials, reagents, etc. used can be obtained from commercial channels without special instructions.

[0040] In the present invention, unless otherwise specified, the preparation of the solid wire used in the embodiments of the present invention specifically includes the following steps: melting, DC casting, extrusion and drawing.

[0041] In the present invention, unless otherwise specified, the elemental composition and its mass percentage of the Al-Mg-Si-Cu series alloy used in the embodiments of the present invention are: Mg 0.81%, Si 0.97%, Cu 0.43%, Mn 0.50%, Cr 0.23%, Ti 0.03%, and the balance is Al and other inevitable impurities.

[0042] Example 1

[0043] The elemental composition and its mass percentage of the aluminum alloy welding material in this example are: Si 9.0%, Mg 0.8%, Cu 1.9%, Zn 0.9%, Cr 0.1%, Mn 0.1%, Fe 0 - 0.15%, and the balance is Al and other inevitable impurities, with the total impurities < 0.15%, and it is a solid wire with a diameter of 1.2 mm.

[0044] The method for preparing the high-strength and high-toughness weld of the aluminum alloy specifically includes the following steps: filling the aluminum alloy welding material between the welds formed by two aluminum alloy base materials, and using the cold metal transfer and pulse composite welding technology for welding, with the synchronous pulse frequency of 4 Hz, the welding speed of 8 mm / s, and the wire feeding speed of 4.3 m / min; then using the high-thermal-conductivity metal substrate cooling method for rapid cooling (the cooling rate is at least 2.94×10 3 K / s), so that elements such as Mg, Cu, and Zn in the weld are completely solid-solved and in a supersaturated state; finally, standing at room temperature for 15 days to precipitate strengthening phases at the weld joint, thereby realizing the strengthening and toughening of the weld; the aluminum alloy base material is an Al-Mg-Si-Cu series alloy with a size of 60 mm × 100 mm, and the initial state is the T5 state;

[0045] The mass ratio of Mg and Si in the weld is 0.22:1;

[0046] The mass fraction of Cu is 1.03%, and the mass ratio of Cu and Mg is 1.24:1;

[0047] The mass fraction of Zn is 0.34%, and the mass ratio of (Zn + Cu) and Mg is 1.65:1.

[0048] Example 2

[0049] The elemental composition and its mass percentage of the aluminum alloy welding material in this example are: Si 9.0%, Mg 0.8%, Cu 1.9%, Zn 0.9%, Cr 0.1%, Mn 0.1%, Fe 0 - 0.15%, and the balance is Al and other inevitable impurities, with the total impurities < 0.15%, and it is a solid wire with a diameter of 1.2 mm.

[0050] The method for preparing a high-strength and high-toughness weld of aluminum alloy specifically includes the following steps: filling an aluminum alloy welding material between the welds formed by two aluminum alloy base materials, and performing welding using laser welding technology. The swing frequency of the infrared laser is 250 Hz, the swing amplitude is 3.0 mm, the welding speed is 20 mm / s, and the wire feeding speed is 6 m / min; then, a composite cooling method of high-thermal-conductivity metal substrate cooling and forced air cooling is adopted for rapid cooling (the cooling rate is at least 2.94×10 3 K / s), so that elements such as Mg, Cu, and Zn in the weld are completely solid-solved and in a supersaturated state; finally, it is left standing at room temperature for 7 days to precipitate strengthening phases at the weld joint, thereby realizing the strengthening and toughening of the weld; the aluminum alloy base material is an Al-Mg-Si-Cu series alloy with a size of 60 mm×100 mm, and the initial state is T5 state;

[0051] The mass ratio of Mg and Si in the weld is 0.17:1;

[0052] The mass fraction of Cu is 1.23%, and the mass ratio of Cu and Mg is 1.50:1;

[0053] The mass fraction of Zn is 0.46%, and the mass ratio of (Zn + Cu) and Mg is 2.06:1.

[0054] Example 3

[0055] The elemental composition and its mass percentage of the aluminum alloy welding material in this example are: Si 9.0%, Mg 0.8%, Cu 1.9%, Zn 0.1%, Cr 0.1%, Mn 0.1%, Fe 0 - 0.15%, and the balance is Al and other inevitable impurities, with the total impurities < 0.15%, and it is a solid wire with a diameter of 1.2 mm.

[0056] The method for preparing a high-strength and high-toughness weld of aluminum alloy specifically includes the following steps: filling an aluminum alloy welding material between the welds formed by two aluminum alloy base materials, and performing welding using laser welding technology. The swing frequency of the infrared laser is 250 Hz, the swing amplitude is 3.0 mm, the welding speed is 20 mm / s, and the wire feeding speed is 6 m / min; then, a composite cooling method of high-thermal-conductivity metal substrate cooling and forced air cooling is adopted for rapid cooling (the cooling rate is at least 2.94×10 3 K / s), so that elements such as Mg, Cu, and Zn in the weld are completely solid-solved and in a supersaturated state; finally, it is left standing at room temperature for 7 days to precipitate strengthening phases at the weld joint, thereby realizing the strengthening and toughening of the weld; the aluminum alloy base material is an Al-Mg-Si-Cu series alloy with a size of 60 mm×100 mm, and the initial state is T5 state;

[0057] The mass ratio of Mg and Si in the weld is 0.17:1;

[0058] The mass fraction of Cu is 1.23%, and the mass ratio of Cu to Mg is 1.50:1;

[0059] The mass fraction of Zn is 0.08%, and the mass ratio of (Zn + Cu) to Mg is 1.60:1.

[0060] Comparative Example 1

[0061] Basically the same as Example 1, except that: the aluminum alloy welding material is ER4047 welding wire, purchased from Beckhoff (China), and its elemental composition and mass percentage are: Si 11.6%, Mg 0.01%, Mn 0.02%, Fe 0.20%, the balance is Al and other inevitable impurities, and the total impurities < 0.15%;

[0062] The mass ratio of Mg to Si in the weld is 0.12:1;

[0063] The mass fraction of Cu is 0.40%, and the mass ratio of Cu to Mg is 0.68:1;

[0064] The mass fraction of Zn is 0.10%, and the mass ratio of (Zn + Cu) to Mg is 0.85:1.

[0065] Comparative Example 2

[0066] Basically the same as Example 2, except that: the aluminum alloy welding material is ER4047 welding wire;

[0067] The mass ratio of Mg to Si in the weld is 0.08:1;

[0068] The mass fraction of Cu is 0.36%, and the mass ratio of Cu to Mg is 0.73:1;

[0069] The mass fraction of Zn is 0.11%, and the mass ratio of (Zn + Cu) to Mg is 0.96:1.

[0070] Comparative Example 3

[0071] Basically the same as Example 1, except that: the welding method is gas metal arc welding, the synchronous pulse frequency is 4 Hz, the welding speed is 8 mm / s, and the wire feeding speed is 4.5 m / min.

[0072] Comparative Example 4

[0073] Basically the same as Example 2, except that: it is left standing at room temperature for 2 days.

[0074] Test Example 1

[0075] The welded joints obtained in Examples 1-2 and Comparative Examples 1-2 were characterized by TEM, and the results are asFigures 1-4 As shown in Figures 1-2 It can be seen that high-density θ'-Al2Cu, β''-Mg5Si6 and Q'-AlCuMgSi strengthening phases precipitate in the welded joints of the examples, thereby realizing the strengthening and toughening of the welds. From Figures 3-4 It can be seen that only atomic clusters can precipitate in the welded joints of Comparative Example 1, and the strengthening effect on the welds is insufficient; only GP zones and partial β'' precursor phases can precipitate in the welded joints of Comparative Example 2, and the strengthening effect on the welds is insufficient.

[0076] Test Example 2

[0077] The cellular substructure of the welded joints of Example 2 and Comparative Example 3 was characterized by a metallographic microscope, and the results are as Figures 5-6 shown. From Figures 5-6 It can be seen that the average distance between the cellular substructures of Example 2 is 6.72 μm, and the average distance between the cellular substructures of Comparative Example 3 is 14.53 μm. This shows that a welding method with a higher cooling rate can obtain fine cellular structures. The fine cellular structures make the eutectic Si network denser, enhance the strengthening effect of the eutectic Si phase, and at the same time provide more nucleation sites for the precipitation of strengthening phases, promoting the precipitation of strengthening phases, thereby promoting the strengthening and toughening of the welds.

[0078] Test Example 3

[0079] Tensile tests were carried out on the welded joints and Al-Mg-Si-Cu series alloys (base metals) obtained in Examples 1-3 and Comparative Examples 1-4, and the results are as Figure 7 shown. From Figure 7It can be seen that the aluminum alloy welding materials and welding processes of the embodiments can produce welds with higher strength and toughness, improving the strength of the welded joints (greater than 280 Mpa). This is because the welding process with a higher cooling rate can greatly increase the solid solubility of alloying elements such as Mg, Cu, and Zn diluted in the welding materials in the weld, enhancing the precipitation response of natural aging, and enabling the precipitation of strengthening phases such as θ'-Al2Cu, β''-Mg5Si6, and Q'-AlCuMgSi in the weld, thus achieving the strengthening and toughening of the weld. In Comparative Examples 1-2, ER4047 welding wire was used, and the tensile properties of the joints were only 250 MPa - 260 MPa, with insufficient strengthening effect on the weld. This is because the weld prepared with ER4047 welding wire lacks alloying elements such as Cu, Mg, and Zn, and only partial GP zones, atomic clusters, and partial precursor phases can be precipitated. It is difficult to precipitate strengthening phases only through natural aging. In Comparative Example 3, MIG welding was used, and the tensile properties of the joints were seriously insufficient. This is because the heat input during MIG welding is too large, the cooling rate of the molten pool is too small, and the solid solubility of alloying elements such as Cu, Mg, and Zn is insufficient, resulting in serious softening of the joint. The natural aging time of Comparative Example 4 was only 2 days, and the strengthening effect of the joint was average. This is because 2 days of natural aging is not sufficient for the complete precipitation of strengthening phases.

[0080] Tensile strength and welding coefficient tests were conducted on the welded joints and Al-Mg-Si-Cu series alloys (base materials) obtained in Examples 1-3 and Comparative Examples 1-4, and the results are as Figure 8 shown. From Figure 8 it can be seen that the aluminum alloy welding materials and welding processes of the embodiments can produce welds with a higher welding coefficient, and the welding coefficient reaches 74.3%.

[0081] Obviously, the above embodiments are merely examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. An aluminum alloy welding material, characterized in that, The elemental composition and its mass percentage of the aluminum alloy welding material are as follows: Si 6.0% - 12.0%, Mg 0.6% - 0.9%, Cu 0.5% - 1.9%, Zn 0.1% - 0.9%, Cr 0.1% - 0.5%, Mn 0.1% - 1.0%, Fe 0 - 0.15%, and the balance is Al and other inevitable impurities, with a total impurity of 0 - 0.15%; the aluminum alloy welding material diluted into the weld satisfies the following points: The mass ratio of Mg to Si is (0.16 - 0.83):1; The mass fraction of Cu is at least 1.00%, and the mass ratio of Cu to Mg is (1.20 - 1.65):1; The mass fraction of Zn is 0.05% - 0.50%, and the mass ratio of (Zn + Cu) to Mg is (1.50 - 2.50):

1.

2. The aluminum alloy welding material according to claim 1, wherein The form of the aluminum alloy welding material is selected from one or more of powder, sheet, and wire.

3. The aluminum alloy welding material according to claim 2, characterized in that, The particle size of the powder is 10μm - 250μm, the thickness of the sheet is 50μm - 1000μm, and the diameter of the wire is 0.5mm - 3.2mm.

4. A method for preparing a high-strength and tough weld of aluminum alloy, characterized in that, It includes the following steps: Weld the aluminum alloy base material with the welding material, and combine with cooling treatment to make the Mg, Cu, and Zn elements in the weld completely solid - solution, and then through natural aging treatment to make the strengthening phase precipitate in the weld joint; the welding material is the aluminum alloy welding material described in any one of claims 1 - 3; the strengthening phase is selected from one or more of θ'-Al2Cu, β''-Mg5Si6, Q'-AlCuMgSi, S-Al2CuMg, and η'-Mg2Zn5.

5. The method for preparing a high-strength and tough aluminum alloy weld according to claim 4, wherein The aluminum alloy base material is selected from one or more of Al - Cu series alloys, Al - Si series alloys, Al - Mg series alloys, Al - Mg - Si series alloys, and Al - Zn series alloys.

6. The method for preparing a high-strength and tough aluminum alloy weld according to claim 4, wherein The initial form of the aluminum alloy base material is in the T0 state - T10 state.

7. The method for preparing a high-strength and tough weld of aluminum alloy according to claim 4, characterized in that The welding method is selected from cold metal transfer and pulse composite welding and / or laser welding.

8. The method for preparing a high-strength and tough aluminum alloy weld according to claim 7, characterized in that, The process parameters of the cold metal transfer and pulse composite welding are: the synchronous pulse frequency is 2Hz - 10Hz, the welding speed is 6mm / s - 12mm / s, and the wire feeding speed is 3.8m / min - 5.2m / min; The process parameters of the laser welding are: the oscillation frequency is 80Hz - 250Hz, the oscillation amplitude is 1.0mm - 3.0mm, the welding speed is 20mm / s - 33mm / s, and the wire feeding speed is 3m / min - 6m / min.

9. The method for preparing a high-strength and high-toughness aluminum alloy weld according to claim 4, characterized in that, The cooling treatment method is selected from one or more of high - thermal - conductivity metal substrate cooling, liquid cooling, forced air cooling, and cryogenic fluid cooling; The rate of the cooling treatment is at least 2.94×10 3 K / s.

10. The method for preparing a high-strength and tough weld of aluminum alloy according to claim 4, wherein, The temperature of the natural aging treatment is 15℃ - 35℃, and the time is 3 days - 15 days.

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