Aluminum alloy welding wire materials and their preparation methods and aluminum alloy additive manufacturing products

Abstract

This application discloses an aluminum alloy welding wire material, its preparation method, and aluminum alloy additive manufacturing products, belonging to the field of aluminum alloy technology. The method includes: melting raw materials to obtain a melt; temperature 780~820℃; purifying, casting, and heat-treating the melt to obtain a billet; casting length 150~220mm, casting speed 5~12mm / min, cooling water pressure 0.07~0.15MPa; length 220~580mm, speed 19~26, water pressure 0.17~0.22; length 580~2800mm, speed 32~44, water pressure 0.19~0.28; extruding and air-cooling the billet to obtain an extruded billet; temperature 435~455℃, extrusion ratio 3.5~5.8, air pressure 8~10bar; hot rolling, water cooling, air cooling, annealing, cold drawing, and wire scraping of the extruded billet. The tensile strength of the aluminum alloy additive manufacturing product reaches over 400MPa.

Description

Technical Field

[0001] This application relates to the field of aluminum alloy technology, and more specifically, to an aluminum alloy welding wire material, its preparation method, and an aluminum alloy additive manufacturing product. Background Technology

[0002] Additive manufacturing, as a novel near-net-shape forming technology, boasts significant advantages such as high material utilization, high forming efficiency, and the ability to manufacture complex structures and small precision parts. It has become an important manufacturing method in high-end equipment fields such as aerospace and transportation. In recent years, with the increasing demand for high-performance and lightweight materials, various industries have continuously developed new ultra-high-strength aluminum alloy materials with strengths exceeding 600 MPa to meet the dual requirements of weight reduction and load-bearing capacity in structural components.

[0003] However, existing aluminum alloy systems for additive manufacturing generally have a tensile strength of only around 350 MPa in the printed state, which is insufficient to meet the performance requirements of high specific strength components in the aerospace and transportation sectors. Therefore, there is an urgent need to develop high-strength aluminum alloy welding wire materials for additive manufacturing that achieve a printed strength of over 400 MPa without heat treatment, while also possessing excellent weldability and thermal stability. Summary of the Invention

[0004] The main objective of this application is to provide an aluminum alloy welding wire material, its preparation method, and aluminum alloy additive manufacturing products, so as to solve the problem of low strength of aluminum alloy wires used in arc additive manufacturing in the prior art.

[0005] To achieve the above objectives, according to one aspect of this application, a method for preparing aluminum alloy welding wire material is provided, comprising the following steps:

[0006] Step S1: Melt each raw material according to its elemental content to obtain a melt; wherein the melting temperature is 780~820℃;

[0007] Step S2: The melt is sequentially purified, cast, and homogenized under heat treatment to obtain a homogenized billet; wherein, casting includes a first casting, a second casting, and a third casting performed sequentially; the first casting includes: an initial casting length of 150~220mm, a casting speed of 5~12mm / min, and a cooling water pressure of 0.05~0.15MPa; the second casting includes: a casting length of 220~580mm, a casting speed of 19~26mm / min, and a cooling water pressure of 0.17~0.22MPa; the third casting includes: a casting length of 580~2800mm, a casting speed of 32~44mm / min, and a cooling water pressure of 0.19~0.28MPa;

[0008] Step S3: The homogenized billet is extruded and then subjected to a first air cooling process to obtain an extruded billet; wherein, the extrusion process includes: an extrusion temperature of 435~455℃ and an extrusion ratio of 3.5~5.8; and the cooling air pressure of the first air cooling process is 8~10 bar.

[0009] Step S4: The extruded billet is subjected to hot rolling, water cooling and second air cooling in sequence to obtain rolled billet;

[0010] Step S5: Perform intermediate annealing and cold drawing on the rolled billet in sequence to obtain a cold-drawn billet;

[0011] Step S6: Scrape the cold-drawn billet to obtain aluminum alloy welding wire material; wherein, scraping includes: scraping 3 to 5 times, scraping amount per pass is 0.05 to 0.15 mm, and total scraping amount is 0.15 to 0.30 mm.

[0012] Further, in step S1, the content of each element, by weight percentage, includes: Mg 3.2~6.8%, Zn 2.2~4.6%, Zr 0.06~0.28%, Ti 0.02~0.08%, Re 0.06~0.38%, Si 0.01~0.10%, Fe 0.15~0.20%, with the balance being Al; Re is at least one of Er, Sc, Y, Yb, La and Ce.

[0013] Furthermore, the melting temperature is 795~820℃.

[0014] Further, in step S1, the elemental content, by weight percentage, includes: Mg 3.2~6.8%, Zn 2.2~4.6%, Zr 0.06~0.28%, Ti 0.02~0.08%, Re 0.06~0.38%, Si 0.01~0.10%, Fe 0.15~0.20%, with the balance being Al.

[0015] Furthermore, Re is at least one of Sc, Er, Yb, and Y, wherein the weight ratio of Zr to Re is (0.15~4.6):1.

[0016] Furthermore, in step S4, the extruded billet is held at a temperature of 423~453℃ for 2.5~8h before hot rolling.

[0017] Furthermore, in step S4, the initial rolling temperature of hot rolling is 415~450℃, the final rolling temperature of hot rolling is 235~350℃, and the exit speed of hot rolling is 3~9m / s.

[0018] Furthermore, in step S4, the cooling water pressure for water cooling is 0.5~3.5MPa; and the cooling air pressure for the second air cooling is 2~9bar.

[0019] Furthermore, in step S4, the extruded billet is kept at a temperature of 435~450℃ for 6.5~8h before hot rolling.

[0020] Furthermore, in step S4, the initial rolling temperature of hot rolling is 435~450℃, the final rolling temperature is 260~320℃, and the exit speed is 6~8m / s.

[0021] Furthermore, in step S4, the water pressure used for water cooling is 0.5~2.0MPa; the cooling air pressure for the second air cooling is 3~5bar.

[0022] Further, in step S5, the intermediate annealing includes: heating to 420-465°C at a heating rate of 40-100°C / h, holding at that temperature for 2-4 hours, then cooling to 320-360°C for 1-3 hours, and then cooling to 15-35°C for 7-10 hours.

[0023] Furthermore, in step S5, the deformation amount per pass of cold drawing is 10-37%, the total number of passes is 8-12, the drawing speed is 35-70 m / min, and the temperature of the drawing lubricant is 5-20℃.

[0024] Further, in step S5, intermediate annealing and cold drawing are repeated sequentially to obtain a cold-drawn billet; wherein, the repetition is performed 7 to 11 times.

[0025] Further, in step S2, the first casting includes: an initial casting length of 200~220mm, a casting speed of 7~12mm / min, and a cooling water pressure of 0.05~0.12MPa.

[0026] Furthermore, the second casting includes: a casting length of 220~380mm, a casting speed of 20~22mm / min, and a cooling water pressure of 0.17~0.19MPa.

[0027] Furthermore, the third casting includes: when the casting length is 580~2300mm, the casting speed is 32~38mm / min, and the cooling water pressure is 0.20~0.22MPa.

[0028] Furthermore, in step S2, the diameter of the cast rod blank obtained by casting is 280~320mm.

[0029] Furthermore, in step S3, the diameter of the extruded billet is 132~148mm.

[0030] Furthermore, in step S4, the diameter of the rolled billet is 6~10mm.

[0031] Furthermore, in step S5, the diameter of the cold-drawn blank is 1.8~2.0mm.

[0032] Furthermore, in step S6, the diameter of the aluminum alloy welding wire material is 1.2~1.6mm.

[0033] Furthermore, in step S2, purification includes: the melt is sequentially refined, slag removed, allowed to stand, and degassed to obtain purified melt.

[0034] Furthermore, in step S2, the homogenization heat treatment temperature is 468~474℃, and the holding time is 28~42h.

[0035] According to a second aspect of this application, an aluminum alloy welding wire material is provided, which is prepared by the above-described preparation method; wherein the tensile strength of the aluminum alloy welding wire material is >340MPa.

[0036] According to a third aspect of this application, an aluminum alloy additive manufacturing article is provided, which is an aluminum alloy welding wire material obtained by the above-mentioned method for preparing aluminum alloy welding wire material or an aluminum alloy welding wire material obtained by additive manufacturing; wherein, the aluminum alloy additive manufacturing article has a tensile strength > 400 MPa, a yield strength > 280 MPa, and an elongation > 8%.

[0037] Compared with the prior art, this application has the following beneficial effects:

[0038] This application achieves comprehensive control over the wire melting and casting temperature, ingot cooling rate, extrusion and hot rolling cooling rate and method, intermediate annealing regime, and wire scraping amount. This reduces moisture ingress, reduces coarse phase formation, fully dissolves soluble phases, and refines wire grain size throughout the entire processing flow. This effectively avoids the formation of internal pores and the negative mechanical properties caused by coarse phases due to moisture residue during wire printing, thereby maximizing the quality of the finished product. After arc additive printing, the tensile strength in the printed state is >400MPa, yield strength >280MPa, and elongation >8%. Attached Figure Description

[0039] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0040] Figure 1 This is a scanning electron microscope (SEM) image of the casting rod in the aluminum alloy welding wire preparation process of Example 1 of this application.

[0041] Figure 2 This is a scanning electron microscope (SEM) image of the extruded rod in the aluminum alloy welding wire preparation process of Example 1 of this application.

[0042] Figure 3 This is a scanning electron microscope (SEM) image of the coarse grains at the edge of the aluminum alloy welding wire material of Embodiment 1 of this application.

[0043] Figure 4 This is a scanning electron microscope (SEM) image of the casting rod in the aluminum alloy welding wire preparation process of Comparative Example 1 of this application.

[0044] Figure 5 This is a scanning electron microscope (SEM) image of the extruded rod in the aluminum alloy welding wire preparation process of Comparative Example 2 of this application.

[0045] Figure 6 This is a scanning electron microscope (SEM) image of the coarse grains at the edge of the welding wire material in the aluminum alloy welding wire preparation process of Comparative Example 3 of this application. Detailed Implementation

[0046] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present application will now be described in detail with reference to the embodiments.

[0047] As mentioned in the background section, existing aluminum alloy systems for additive manufacturing (with a tensile strength of only about 350 MPa in the printed state) cannot meet the performance requirements of high-strength components, and their printed strength is less than 400 MPa. Therefore, it is necessary to develop a high-strength aluminum alloy welding wire material for additive manufacturing that has both excellent weldability and thermal stability.

[0048] According to one aspect of this application, a method for preparing aluminum alloy welding wire material is provided, comprising the following steps:

[0049] Step S1: Prepare raw materials according to the proportions of each element, and melt the raw materials; the melting temperature is 780~820℃;

[0050] Step S2: The melt is sequentially purified, cast, and homogenized under heat treatment to obtain a homogenized billet; wherein, casting includes a first casting, a second casting, and a third casting performed sequentially; the first casting includes: a first initial casting length of 150~220mm, a first casting speed of 5~12mm / min, and a first cooling water pressure of 0.05~0.15MPa; the second casting includes: a second casting length of 220~580mm, a first casting speed of 19~26mm / min, and a first cooling water pressure of 0.17~0.22MPa; the third casting includes: a third casting length of 580~2800mm, a third casting speed of 32~44mm / min, and a third cooling water pressure of 0.19~0.28MPa;

[0051] Step S3: The homogenized billet is extruded and then air-cooled in sequence to obtain an extruded billet; wherein the extrusion temperature is 435~455℃, the extrusion ratio is 3.5~5.8, and the cooling air pressure of the first air-cooling is 8~10 bar.

[0052] Step S4: The extruded billet is subjected to hot rolling, water cooling and second air cooling in sequence to obtain rolled billet;

[0053] Step S5: Perform intermediate annealing and cold drawing on the rolled billet in sequence to obtain a cold-drawn billet;

[0054] Step S6: Scrape the cold-drawn billet to obtain aluminum alloy welding wire material; wherein, the number of scraping passes is 3 to 5, the scraping amount per pass is 0.05 to 0.15 mm, and the total scraping amount is 0.15 to 0.30 mm.

[0055] This application develops a high-strength weldable wire preparation process. It employs high-temperature melting to fully dissolve rare earth elements, rapid ingot cooling to prevent excessive precipitation of coarse primary phases and refine the as-cast grains, pre-extrusion of the ingot to break up primary phases and weld casting defects to prevent hot rolling cracking, temperature-controlled hot continuous rolling and rapid cooling to refine rolled grains and prevent phase growth during hot working, annealing and rapid cooling combined with large-deformation cold rolling and cold drawing to prevent coarse phase formation and maintain fine grains, and finally, 3-5 passes of wire scraping and cleaning to produce large-coil, high-strength aluminum alloy wire with a tensile strength of over 400 MPa in the CMT additive manufacturing process. This wire is suitable for the preparation and repair of complex-shaped high-strength industrial parts and is highly practical.

[0056] Specifically, in the high-strength weldable wire preparation process provided in this application, step S1 involves high-temperature melting at 780~820℃. The melting temperature can be any value among 780℃, 790℃, 800℃, 810℃, and 820℃, or any value between the two. Using this melting temperature can fully melt the Al-Re master alloy, allowing rare earth elements to dissolve to the maximum extent in the alloy matrix, and avoiding the precipitation of primary Al3Re coarse phases during the cooling process.

[0057] In step S2, the casting cooling rate and cooling water pressure are controlled in three stages. In the initial stage, low-speed casting is combined with high-pressure rapid cooling. For example, when the initial casting length is 150~220mm, the casting speed is any value from 5, 6, 7, 8, 9, 10, 11, 12 mm / min or any value between any two. The cooling water pressure is any value from 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15 MPa or any value between any two. As casting progresses, the casting speed is gradually increased, along with increased water pressure, to ensure a high cooling rate. For example, when the casting length is 220~580mm, the casting speed is any value from 19, 20, 21, 22, 23, 24, 25, 26 mm / min or any value between any two. The casting length is 580, 880, 1100, 1300, 1500, 1800, 2000, 2200, 2400, 2600, 2800 mm, and the casting speed is 32, 35, 38, 40, 42, 44 mm / min or a range between any two. The cooling water pressure is 0.19, 0.20, 0.22, 0.25, 0.28 MPa or a range between any two. By adopting the above segmented casting conditions, the precipitation of Mg2Si phase, MgZn2 phase, and rare earth alloy second phase can be reduced, the as-cast grains can be refined, and the tensile strength, yield strength and suitable elongation of the material can be improved.

[0058] In step S3, because the high-strength alloy wire uses a Re rare earth microalloying formula, coarse primary phases containing rare earth are inevitably generated during the casting process. Therefore, the pre-extrusion method is used to pre-extrude the cast ingot after homogenization, controlling the extrusion temperature to 435~455℃; for example, any value of 435℃, 440℃, 445℃, 450℃, 455℃ or any range between two of these values; and controlling the extrusion ratio to 3.5~5.8; for example, any value of 3.5, 3.8, 4.0, 4.2, 4.5, 4.8, 5.0, 5.2, 5.5, 5.8 or any range between two of these values. Controlling the extrusion temperature and extrusion ratio within the above range can break the coarse rare earth phases and the low-melting-point phases that cannot be dissolved during homogenization. During extrusion, the existing Type I cracks in the ingot gradually transform into Type II cracks, which can effectively prevent the ingot from cracking during hot rolling.

[0059] In steps S3-S4, high-pressure air cooling is used during extrusion, with cooling air pressures of 8, 9, and 10 bar. This air pressure increases the ingot cooling rate and reduces second-phase precipitation. During hot rolling, a suitable wire exit speed is used, followed by high-pressure water cooling to prevent second-phase precipitation and grain growth caused by slow cooling. Then, high-pressure air cooling is used to compensate for insufficient water cooling due to excessively fast wire take-up speed, and to dry the wire body to avoid large pores in the additively printed parts caused by residual moisture.

[0060] In step S6, the high-strength filament inevitably suffers from surface oil residue and coarse outer grains after multiple annealing and cold deformation processes. Therefore, to improve the mechanical properties of the additively manufactured part in the printed state, the filament scraping amount is 0.05~0.10 mm per pass, and the total scraping amount is 0.15~0.30 mm after 3~5 passes; for example, scraping 2, 3, and 4 passes; the scraping amount per pass is any value or a range between 0.05, 0.06, 0.07, 0.08, 0.09, and 0.10 mm; the total scraping amount is any value or a range between 0.15, 0.18, 0.20, 0.22, 0.25, 0.28, and 0.30 mm; under the above scraping conditions, the surface oxide layer, oil layer, stress layer, and coarse grain layer can be fully removed.

[0061] This application achieves comprehensive control over the wire melting and casting temperature, ingot cooling rate, extrusion and hot rolling cooling rate and method, intermediate annealing regime, and wire scraping amount. This reduces moisture ingress, reduces coarse phase formation, fully dissolves soluble phases, and refines wire grain size throughout the entire processing flow. This effectively avoids the formation of internal pores and the negative mechanical properties caused by coarse phases due to moisture residue during wire printing, thereby maximizing the quality of the finished product. After arc additive printing, the tensile strength in the printed state is >400MPa, yield strength >280MPa, and elongation >8%.

[0062] To further optimize the aluminum alloy welding wire for additive manufacturing by improving its tensile strength, yield strength, and elongation, in some specific embodiments, the content of each element in step S1 includes, by weight percentage: Mg 3.2~6.8%, Zn 2.2~4.6%, Zr 0.06~0.28%, Ti 0.02~0.08%, Re 0.06~0.38%, Si 0.01~0.10%, Fe 0.15~0.20%, with the balance being Al; Re is at least one of Er, Sc, Y, Yb, La, and Ce. The elemental proportions in the aluminum alloy welding wire material described in this application are as follows: Mg is any value or a range between any two of the following: 3.2%, 3.5%, 4.0%, 4.5%, 5.0%, 5.5%, 6.0%, 6.5%, and 6.8%; Zn is any value or a range between any two of the following: 2.2%, 2.5%, 2.8%, 3.0%, 3.2%, 3.5%, 3.8%, 4.0%, 4.2%, and 4.6%; and Zr is 0.06%, 0.1%, 0.15%, 0.18%, 0.20%, 0.22%, and 0.25%. The values ​​are: 0.28% or any value within a range of two; Ti is any value within a range of two, including 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, and 0.08%; Re is any value within a range of two, including 0.06%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, and 0.38%; Si is any value within a range of two, including 0.01%, 0.03%, 0.05%, 0.08%, and 0.10%; Fe is any value within a range of two, including 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, and 0.20%. Furthermore, the elemental composition includes: Mg 3.2~6.8%, Zn 2.2~4.6%, Zr 0.06~0.28%, Ti 0.02~0.08%, Re 0.06~0.38%, Si 0.01~0.10%, Fe 0.15~0.20%, with the balance being Al; Re is at least one of Sc, Er, Yb, and Y, wherein the weight ratio of Zr to Re is (0.15~4.6):1. Controlling the elemental composition within the above range is beneficial for improving the mechanical properties of the material and is compatible with the process conditions such as smelting, casting, extrusion, hot rolling, annealing, cold drawing, and wire scraping, thereby synergistically promoting the aluminum alloy welding wire to have excellent tensile strength, for example, greater than 400 MPa.

[0063] To further fully melt the various elements and optimize the melting temperature, in some specific embodiments, the melting temperature in step S1 is 795~820℃. Using this melting temperature allows for the complete melting of the Al-Re master alloy, maximizing the solidification of rare earth elements in the alloy matrix and preventing the precipitation of primary Al3Re coarse phases during the cooling process.

[0064] Purifying the melt before casting aims to obtain high-purity aluminum alloy materials. Specifically, the preferred purification method is as follows: the melt is sequentially refined with a refining agent (a mixture of sodium nitrate, potassium chloride, aluminum chloride, and magnesium fluoride), slag is removed, and the melt is allowed to stand for 40-80 minutes to degas, resulting in a purified melt. The homogenization heat treatment is then performed at 468-474℃ for 28-42 hours. This multi-stage purification improves melt purity and, under the aforementioned homogenization heat treatment conditions, helps the various elements in the melt to dissolve uniformly and stably in the aluminum matrix, which is beneficial for subsequent processing and ultimately promotes the tensile strength of the final aluminum alloy material.

[0065] To reduce the precipitation of alloy phases, refine grains, and improve material strength, the casting process is further optimized in some specific embodiments. In step S2, when the first initial casting length is 200-220 mm, the first casting speed is 7-12 mm / min, and the first cooling water pressure is 0.05-0.12 MPa; when the second casting length is 220-380 mm, the second casting speed is 20-22 mm / min, and the second cooling water pressure is 0.17-0.19 MPa; when the third casting length is 380-2300 mm, the third casting speed is 32-38 mm / min, and the third cooling water pressure is 0.20-0.22 MPa. Using these segmented casting conditions can reduce the precipitation of Mg2Si phase, MgZn2 phase, and rare earth alloy second phases, refine the as-cast grains, and help improve the tensile strength, yield strength, and appropriate elongation of the material.

[0066] In some specific embodiments, in step S2, when the melt sequentially passes through the aforementioned casting process conditions, extrusion process conditions, rolling process conditions, cold drawing process conditions, and wire scraping process conditions, the diameter of the cast rod obtained by casting is 280~320mm; in S3, the diameter of the extruded billet is 132~148mm; in S4, the diameter of the rolled billet is 6~10mm; in S5, the diameter of the cold-drawn billet is 1.8~2.0mm; and in S6, the diameter of the aluminum alloy welding wire material is 1.2~1.6mm. Controlling the diameter of the rod at each stage to match it with the corresponding process conditions results in aluminum alloy welding wire material with excellent tensile strength, which helps the tensile strength of the printed parts reach over 400MPa.

[0067] To better hot roll the extruded billet and obtain longer and thinner bars, in some specific embodiments, in step S4, the extruded billet is held at a temperature of 423~453℃ for 2.5~8 hours before hot rolling; for example, the holding temperature is any value or a range between any two of 423℃, 425℃, 428℃, 430℃, 435℃, 440℃, 445℃, 450℃, and 453℃; and the holding time is any value or a range between any two of 2.5, 3, 4, 5, 6, 7, and 8 hours. The range of values; the initial rolling temperature for hot rolling is 415~450℃, for example, any value or a range between any two of the following initial rolling temperatures: 415℃, 420℃, 425℃, 430℃, 435℃, 440℃, 445℃, 450℃; the final rolling temperature is 235~350℃, for example, any value or a range between any two of the following final rolling temperatures: 235℃, 250℃, 280℃, 300℃, 320℃, 350℃; the exit speed is 3~9m / s; for example, 3, 4, 5, 6, 7, 8, 9. The water pressure used for water cooling is 0.5~3.5MPa, for example, any value or a range between 0.5, 1, 1.5, 2, 2.5, 3, 3.5MPa; the air pressure used for the second air cooling is 2~9 bar; for example, any value or a range between 2, 3, 4, 5, 6, 7, 8, 9 bar. Further, the extruded billet is held at 435~450℃ for 6.5~8h before hot rolling; the initial rolling temperature is 435~450℃, the final rolling temperature is 260~320℃, and the exit speed is 6~8m / s; the water pressure used for water cooling is 0.5~2.0MPa, and the air pressure used for the second air cooling is 3~5 bar, for example, to obtain a φ8mm billet. Using the above-mentioned hot rolling temperature, exit speed and cooling conditions, high-pressure water cooling is first used to avoid the precipitation of the second phase and grain growth caused by slow cooling; then high-pressure air cooling is used to compensate for the insufficient water cooling effect caused by the excessive winding speed, and to dry the line body to avoid the problem of large pores in the additive printed parts caused by residual moisture.

[0068] In order to refine the grain size of the billet and further improve the subsequent deformation effect, in some specific embodiments, the intermediate annealing in step S5 includes: heating at a rate of 40~100℃ / h, heating to 420~465℃, holding at that temperature for 2~4h, cooling to 320~360℃ for 1~3h, and then cooling to 15~35℃ for 7~10h. The heating rate can be any value from 40, 50, 60, 70, 80, 90, 100℃ / h or any range between two; the heating temperature can be any value from 420℃, 430℃, 440℃, 450℃, 460℃, 465℃ or any range between two; for example, the heating rate is 60~80℃ / h, heating to 430~460℃, holding at that temperature for 2.5~3.5h, cooling to 330~350℃ after 1.5~2.5h, and then cooling to 20~30℃ (room temperature) after 8~9h. The deformation per pass in cold drawing is 10~37%, the total number of passes is 8~12, the drawing speed is 35~70m / min, and the temperature of the drawing lubricant is 5~20℃. The deformation amount can be any value from 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, 37%, or any range between two; the drawing speed can be any value from 35, 40, 45, 50, 55, 60, 65, 70 m / min or any range between two. For example, the deformation amount per pass in cold drawing is 15~35%, and the drawing speed is 40~60 m / min. In step S5, intermediate annealing and cold drawing are repeated sequentially to obtain a cold-drawn billet. Intermediate annealing uses a segmented cooling method, first rapidly cooling from 420~465℃ to 320~360℃ to reduce the precipitation of the second phase and avoid grain growth above the recrystallization temperature; then cooling to room temperature for 7~10 hours fully eliminates the work hardening from the previous cold deformation, which is beneficial for subsequent deformation. The intermediate annealing and cold drawing process can be repeated several times, for example, 7~11 times, depending on the actual situation.

[0069] In some specific embodiments, in step S6, the number of scraping passes is 3 to 5, preferably 3 to 4, for example 3. The scraping amount per pass is 0.08 to 0.12 mm, for example 0.10 mm; the total scraping amount is 0.20 to 0.30 mm, for example 0.30 mm. Under the above scraping conditions, the surface oxide layer, oil layer, stress layer, and coarse grain layer can be sufficiently removed.

[0070] According to a second aspect of this application, an aluminum alloy welding wire material is provided, which is prepared by the above-described preparation method; wherein the tensile strength of the aluminum alloy welding wire material is >340MPa.

[0071] According to a third aspect of this application, an aluminum alloy additive manufacturing article is provided, which is obtained by using the above-mentioned aluminum alloy welding wire material preparation method or by additive manufacturing of the above-mentioned aluminum alloy welding wire material; wherein, the additively manufactured aluminum alloy part has a tensile strength > 400 MPa, a yield strength > 280 MPa, and an elongation > 8%.

[0072] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.

[0073] The raw materials used in the embodiments of this application are all existing technologies and are commercially available.

[0074] Example 1

[0075] A method for preparing a high-strength weldable wire includes the following steps:

[0076] Step S1: Prepare raw materials according to the proportion of each element; by weight percentage, Mg 3.2%, Zn 2.2%, Zr 0.06%, Ti 0.02%, Re 0.06%, Si 0.01%, Fe 0.15%, with the balance being Al; among which, Re is Sc 0.02%, La 0.02%, Ce 0.02%, totaling 100%; see Table 1 for details; pure magnesium, pure zinc, aluminum-zirconium master alloy, aluminum-titanium master alloy, Re aluminum master alloy, and pure aluminum ingot are smelted at 780℃ to obtain aluminum alloy melt.

[0077] Step S2: The above aluminum alloy melt is sequentially refined (using a mixture of 20% sodium nitrate, 40% potassium chloride, 20% aluminum chloride, and 20% magnesium fluoride), slag is removed, the melt is allowed to stand for 40 minutes, and degassing is performed to obtain a purified melt. The purified melt is then cast. Initially, when the casting length reaches 150 mm, the casting speed is 5 mm / min and the cooling water pressure is 0.07 MPa; when the casting length reaches 220 mm, the casting speed is 19 mm / min and the cooling water pressure is 0.17 MPa; when the casting length reaches 380 mm, the casting speed is 32 mm / min and the cooling water pressure is 0.19 MPa. An aluminum alloy ingot with a diameter φ of 280 mm is obtained, and its microstructure is as follows: Figure 1 As shown, the aluminum alloy casting rod was subjected to homogenization heat treatment at 474℃ for 28 hours to obtain a homogenized rod billet.

[0078] Step S3: The above-mentioned hot-soaked bar billet is extruded at a temperature of 435℃ to obtain a φ132mm ingot (extruded bar billet), the microstructure of which is as follows. Figure 2 As shown, the extrusion ratio is 4.4, and the extruded material is air-cooled with a cooling air pressure of 8 bar.

[0079] Step S4: Hot rough rolling is performed on the above extruded bar billet. Before hot rolling, the billet is held at 423℃ for 2.5h. The initial rolling temperature is controlled at 415℃ and the final rolling temperature is controlled at 235℃. The exit speed is 3m / s. After hot rolling, the billet is first cooled by water at a pressure of 0.5MPa and then cooled by air at a pressure of 2bar to obtain a φ6mm rolled billet.

[0080] Step S5: The rolled billet is subjected to intermediate annealing at a heating rate of 40℃ / h, reaching 420℃, holding for 2h, cooling to 320℃ for 1h, and then cooling to room temperature for 7h to obtain the annealed billet; the annealed billet is subjected to cold drawing at a deformation rate of 10% per pass, a drawing speed of 35m / min, and the temperature of the drawing lubricant is controlled at 5℃ to obtain the cold-drawn billet; the intermediate annealing and cold drawing process is repeated 8 times to finally obtain the φ1.8mm cold-drawn billet.

[0081] Step S6: Perform three wire scraping passes on the above cold-drawn billet, with each pass scraping by 0.05 mm, for a total scraping amount of 0.15 mm, to obtain a high-strength weldable aluminum alloy wire, the microstructure of which is as follows. Figure 3 As shown in the figure; specific process conditions are shown in Table 2.

[0082] The high-strength weldable aluminum alloy wire was additively manufactured using the Austrian Fröhne TPS4000 CMT advanced equipment to obtain aluminum alloy additive manufacturing parts. The tensile strength of the printed aluminum alloy parts was 418 MPa, the yield strength was 296 MPa, and the elongation was 8.6%, as shown in Table 3.

[0083] Example 2

[0084] The difference between Example 2 and Example 1 is that the aluminum alloy formula in step S1 is replaced with: Mg 6.8%, Zn 4.6%, Zr 0.28%, Ti 0.08%, Re 0.38%, Si 0.10%, Fe 0.20%, with the remainder being Al, and Re being Er 0.08%, Sc 0.16%, Yb 0.05%, and Y 0.09%; see Table 1 for details; see Table 2 for process conditions; see Table 3 for the mechanical property test results of the aluminum alloy additive manufacturing part.

[0085] Example 3

[0086] The difference between Example 3 and Example 1 is that the aluminum alloy formula in step S1 is replaced with: Mg 4.5%, Zn 3.5%, Zr 0.15%, Ti 0.05%, Re 0.13%, Si 0.05%, Fe 0.18%, with the remainder being Al, and Re being Sc 0.05%, Er 0.03%, and Yb 0.05%; see Table 1 for details; see Table 2 for process conditions; see Table 3 for the mechanical property test results of the aluminum alloy additive manufacturing part.

[0087] Example 4

[0088] The difference between Example 4 and Example 1 is that the melting temperature in step S1 is replaced with 820°C, the extrusion ratio in step S3 is 5.8, and the casting process in step S2 is replaced; the mechanical property test results of the additively manufactured aluminum alloy parts are shown in Table 3.

[0089] Specifically, in step S2, the casting process is as follows: when the initial casting length reaches 220mm, the casting speed is 12mm / min and the cooling water pressure is 0.15MPa; when the casting length reaches 580mm, the casting speed is 26mm / min and the cooling water pressure is 0.22MPa; when the casting length is greater than 580mm, the casting speed is 44mm / min and the cooling water pressure is 0.28MPa; thus, a φ320mm aluminum alloy casting rod is obtained.

[0090] Example 5

[0091] The difference between Example 5 and Example 1 is that the melting temperature in step S1 is replaced with 800℃; the extrusion ratio in step S3 is 5.0; the casting process in step S2 is replaced; the mechanical property test results of the additively manufactured aluminum alloy parts are shown in Table 3.

[0092] Specifically, in step S2, the casting process is as follows: when the initial casting length reaches 180mm, the casting speed is 9mm / min and the cooling water pressure is 0.11MPa; when the casting length reaches 380mm, the casting speed is 22mm / min and the cooling water pressure is 0.20MPa; when the casting length reaches 580mm, the casting speed is 38mm / min and the cooling water pressure is 0.23MPa; thus, a φ320mm aluminum alloy casting rod is obtained.

[0093] Example 6

[0094] The difference between Example 6 and Example 1 is that the extrusion temperature in step S3 was replaced with 455℃, resulting in a φ148mm ingot with an extrusion ratio of 3.5. The extruded material was air-cooled with a cooling air pressure of 10 bar. The mechanical property test results of the aluminum alloy additive manufacturing parts are shown in Table 3.

[0095] Example 7

[0096] The difference between Example 7 and Example 1 is that the extrusion temperature in step S3 was replaced with 445℃, resulting in a φ142mm ingot with an extrusion ratio of 3.8. The extruded material was air-cooled with a cooling air pressure of 9 bar. The mechanical property test results of the aluminum alloy additive manufacturing parts are shown in Table 3.

[0097] Example 8

[0098] The difference between Example 8 and Example 1 is that the pretreatment conditions of the extruded bar billet in step S4 before hot rough rolling were replaced with holding at 453℃ for 6.5 hours; the initial hot rolling temperature was controlled at 450℃, the final rolling temperature was controlled at 350℃, the exit speed was 9m / s, and after hot rolling, the billet was first water-cooled at a water pressure of 3.5MPa, and then air-cooled at an air pressure of 9bar to obtain a φ10mm billet. The mechanical property test results of the aluminum alloy additive manufacturing parts are shown in Table 3.

[0099] Example 9

[0100] The difference between Example 9 and Example 1 is that the pretreatment conditions of the extruded bar billet in step S4 before hot rough rolling were replaced with holding at 435℃ for 8.0h; the initial hot rolling temperature was controlled at 435℃, the final rolling temperature was controlled at 320℃, the exit speed was 6m / s, and after hot rolling, the billet was first water-cooled at a water pressure of 2.0MPa, and then air-cooled at an air pressure of 5bar to obtain a φ10mm billet. The mechanical property test results of the aluminum alloy additive manufacturing parts are shown in Table 3.

[0101] Example 10

[0102] The difference between Example 10 and Example 1 is that the intermediate annealing heating rate in step S5 is replaced with 100℃ / h, heating to 465℃, holding at that temperature for 4 hours, cooling to 360℃ for 3 hours, and then cooling to room temperature for another 10 hours to obtain the annealed billet. The mechanical property test results of the aluminum alloy additive manufacturing parts are shown in Table 3.

[0103] Example 11

[0104] The difference between Example 11 and Example 1 is that the intermediate annealing heating rate in step S5 is replaced with 80℃ / h, heating to 445℃, holding at that temperature for 3 hours, cooling to 340℃ for 2 hours, and then cooling to room temperature for another 8 hours to obtain the annealed billet. The mechanical property test results of the additively manufactured aluminum alloy parts are shown in Table 3.

[0105] Example 12

[0106] The difference between Example 12 and Example 1 is that the deformation amount per cold drawing pass in step S5 is replaced with 25%, the drawing speed is 50 m / min, and the temperature of the drawing lubricant is controlled at 15°C to obtain a cold-drawn billet. The mechanical property test results of the aluminum alloy additive manufacturing parts are shown in Table 3.

[0107] Example 13

[0108] The difference between Example 13 and Example 1 is that the deformation amount of the cold drawing pass in step S5 is replaced with 37%, the drawing speed is 70 m / min, and the temperature of the drawing lubricant is controlled at 20°C to obtain the cold-drawn billet. The mechanical property test results of the aluminum alloy additive manufacturing parts are shown in Table 3.

[0109] Example 14

[0110] The difference between Example 14 and Example 1 is that the cold-drawn billet from step S6 is subjected to four wire scraping passes, with each pass scraping by 0.15 mm and a total scraping amount of 0.6 mm, to obtain high-strength weldable aluminum alloy wire. The mechanical property test results of the aluminum alloy additive manufacturing parts are shown in Table 3.

[0111] Example 15

[0112] The difference between Example 15 and Example 1 is that the cold-drawn billet from step S6 is subjected to five scraping passes, with each pass involving a scraping amount of 0.10 mm and a total scraping amount of 0.50 mm, to obtain a high-strength weldable aluminum alloy wire. The mechanical property test results of the aluminum alloy additive manufacturing parts are shown in Table 3.

[0113] Comparative Example 1

[0114] The difference between Comparative Example 1 and Example 1 is that the melting temperature in step S1 is replaced with 750°C, and the casting process in step S2 is replaced.

[0115] Specifically, in step S2: when the initial casting length reaches 150mm, the casting speed is 18mm / min and the cooling water pressure is 0.05MPa; when the casting length reaches 200mm, the casting speed is 32mm / min and the cooling water pressure is 0.15MPa; when the casting length reaches 300mm, the casting speed is 48mm / min and the cooling water pressure is 0.18MPa; thus, a φ260mm aluminum alloy ingot is obtained; the microstructure of the ingot is as follows... Figure 4 As shown in Table 3, the performance test results of the aluminum alloy additively manufactured parts are presented.

[0116] Comparative Example 2

[0117] The difference between Comparative Example 2 and Example 1 is that the extrusion temperature in step S3 was replaced with 420℃, resulting in a φ155mm ingot with an extrusion ratio of 3.2. The extruded material was air-cooled at a cooling air pressure of 5 bar. The microstructure of the extruded bar is as follows: Figure 5 As shown in Table 3, the performance test results of the aluminum alloy additive manufacturing parts are presented.

[0118] Comparative Example 3

[0119] The difference between Comparative Example 3 and Example 1 is that the scraping conditions in step S6 are replaced with: one scraping pass on the cold-drawn billet, with a scraping amount of 0.02 mm per pass; aluminum alloy welding wire is obtained; the coarse grain morphology of the wire edge is as follows. Figure 6 As shown in Table 3, the performance test results of the aluminum alloy additively manufactured parts are presented.

[0120] Comparative Example 4

[0121] The difference between Comparative Example 4 and Example 1 is that the scraping conditions in step S6 are replaced with: two scraping passes are performed on the cold-drawn billet, with a single scraping amount of 0.02 mm and a total scraping amount of 0.04 mm; thus, aluminum alloy welding wire is obtained. The performance test results of the aluminum alloy additive manufacturing parts are shown in Table 3.

[0122] Performance testing:

[0123] The tensile strength, yield strength, and elongation of the additive manufacturing parts printed with aluminum alloy welding wires prepared in each embodiment and comparative example were tested using an Instron tensile testing machine in accordance with GB / T 228.1-2021; the test results are shown in Table 3.

[0124] Table 1

[0125]

[0126] Table 2

[0127]

[0128] Table 3

[0129]

[0130] As shown in Table 3, the tensile strength of the aluminum alloy additively manufactured parts prepared in Examples 1-15 of this application is all >400 MPa, specifically between 402 and 425 MPa; the yield strength is between 296 and 302 MPa; and the elongation is between 8.2 and 9.1. In contrast, the tensile strength of the aluminum alloy welding wire printed parts prepared in Comparative Examples 1-4 did not reach 400 MPa, specifically between 346 and 385 MPa; the yield strength was between 252 and 269 MPa; and the elongation was between 4.2 and 5.2. Clearly, the aluminum alloy welding wire printed parts prepared in this application have superior overall mechanical properties.

[0131] Depend on Figure 1 and Figure 4 It can be seen that the grain size of the cast rod in Example 1 is about 128 μm; the grain size of the cast rod in Comparative Example 1 is about 346 μm. This shows that by using the specific graded casting process conditions of this application, the grain size in the as-cast state can be refined, thereby increasing the tensile strength of the wire to more than 400 MPa.

[0132] Depend on Figure 2 and Figure 5 It can be seen that the Type I cracks in the extrusion bar of Example 1 were effectively welded into Type II cracks; in Comparative Example 2, due to insufficient extrusion ratio, a large number of Type I cracks still could not be welded; this shows that by using the specific extrusion temperature and extrusion ratio of this application, the structural defects of the bar can be effectively improved; thereby increasing the tensile strength of the wire to over 400 MPa.

[0133] Depend on Figure 3 and Figure 6 It can be seen that the aluminum alloy weldable wire of Example 1 did not show obvious coarse grains at the edges; the aluminum alloy weldable wire of Comparative Example 3 still had a large number of coarse grains at the edges; indicating that by using the scraping process of this application, the surface coarse grains can be fully scraped off, and the fine grain strengthening effect can be utilized to improve the tensile strength of the wire to more than 400 MPa.

[0134] This application achieves comprehensive control over the wire melting and casting temperature, ingot cooling rate, extrusion and hot rolling cooling rate and method, intermediate annealing regime, and wire scraping amount. This reduces moisture ingress, reduces coarse phase formation, fully dissolves soluble phases, and refines wire grain size throughout the entire processing flow. This effectively avoids the formation of internal pores and the negative mechanical properties caused by coarse phases due to moisture residue during wire printing, thereby maximizing the quality of the finished product. After arc additive printing, the tensile strength in the printed state is >400MPa, yield strength >280MPa, and elongation >8%.

[0135] It should be noted that the terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented, for example, in a sequence other than those described herein.

[0136] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method of making an aluminum alloy welding wire material characterized by, The preparation method comprises the following steps: Step S1: melting each raw material according to element content to obtain a melt; wherein, the element content comprises, in terms of weight percentage: Mg 3.2-6.8%, Zn 2.2-4.6%, Zr 0.06-0.28%, Ti 0.02-0.08%, Re 0.06-0.38%, Si 0.01-0.10%, Fe 0.15-0.20%, and the balance being Al; Re is at least one of Er, Sc, Y, Yb, La and Ce; the melting temperature is 780-820℃; Step S2: sequentially performing purification, casting and homogenization heat treatment on the melt to obtain a soaking blank; wherein, the casting comprises sequentially performing first casting, second casting and third casting; the first casting comprises: an initial casting length of 150-220mm, a casting speed of 5-12mm / min, and a cooling water pressure of 0.05-0.15MPa; the second casting comprises: a casting length of 220-580mm, a casting speed of 19-26mm / min, and a cooling water pressure of 0.17-0.22MPa; the third casting comprises: a casting length of 580-2800mm, a casting speed of 32-44mm / min, and a cooling water pressure of 0.19-0.28MPa; the homogenization heat treatment temperature is 468-474℃, and the holding time is 28-42h; Step S3: sequentially performing extrusion and first air cooling on the soaking blank to obtain an extruded blank; wherein, the extrusion comprises: an extrusion temperature of 435-455℃, and an extrusion ratio of 3.5-5.8; the first air cooling cooling air pressure is 8-10bar; Step S4: sequentially performing hot rolling, water cooling and second air cooling on the extruded blank to obtain a rolled blank; wherein, the hot rolling starting temperature is 415-450℃, the hot rolling final temperature is 235-350℃, the hot rolling exit speed is 3-9m / s; the water cooling cooling water pressure is 0.5-3.5MPa; the second air cooling cooling air pressure is 2-9bar; Step S5: sequentially performing intermediate annealing and cold drawing on the rolled blank to obtain a cold drawn blank; wherein, the intermediate annealing comprises: heating to 420-465℃ at a heating rate of 40-100℃ / h, and holding for 2-4h, then cooling to 320-360℃ over 1-3h, and further cooling to 15-35℃ over 7-10h; the single pass deformation of the cold drawing is 10-37%, the total pass number is 8-12, the drawing speed is 35-70m / min, and the drawing lubricating oil temperature is 5-20℃; Step S6: scraping the cold drawn blank to obtain the aluminum alloy welding wire material; wherein, the scraping comprises: 3-5 scraping passes, a scraping amount of each pass is 0.05-0.15mm, and the total scraping amount is 0.15-0.30mm.

2. The method of making an aluminum alloy wire material of claim 1, wherein, The melting temperature is 795-820℃.

3. The method of producing an aluminum alloy wire material according to claim 1, characterized by, In the step S4, the extruded blank is kept at a temperature of 423-453℃ for 2.5-8h before the hot rolling.

4. The method of producing an aluminum alloy wire material according to claim 3, characterized by, In the step S4, the extruded blank is kept at a temperature of 435-450℃ for 6.5-8h before the hot rolling. In the step S4, the hot rolling is performed at a starting temperature of 435-450℃, a finishing temperature of 260-320℃, and a speed of 6-8m / s. In the step S4, the water cooling is performed at a water pressure of 0.5-2.0MPa, and the second air cooling is performed at an air pressure of 3-5bar.

5. The method of producing an aluminum alloy wire material according to any one of claims 1 to 3, characterized by, In the step S5, the intermediate annealing and the cold drawing are repeatedly performed to obtain the cold drawn blank, wherein the number of repetitions is 7-11.

6. The method of making an aluminum alloy wire material of any of claims 1-3, wherein, In the step S2, the first casting is performed at a length of 200-220mm, a speed of 7-12mm / min, and a water pressure of 0.05-0.12MPa. In the step S2, the second casting is performed at a length of 220-380mm, a speed of 20-22mm / min, and a water pressure of 0.17-0.19MPa. In the step S2, the third casting is performed at a length of 380-2300mm, a speed of 32-38mm / min, and a water pressure of 0.20-0.22MPa.

7. The method of making an aluminum alloy wire material of any of claims 1-3, wherein, In the step S2, the diameter of the cast blank is 280-320mm. In the step S3, the diameter of the extruded blank is 132-148mm. In the step S4, the diameter of the rolled blank is 6-10mm. In the step S5, the diameter of the cold drawn blank is 1.8-2.0mm. In the step S6, the diameter of the aluminum alloy welding wire material is 1.2-1.6mm. In the step S2, the purification is performed by sequentially refining, skimming, standing, and degassing the melt to obtain a purified melt.

8. An aluminum alloy welding wire material characterized by, The aluminum alloy welding wire material is prepared by the method of any one of claims 1-7, and has a tensile strength >340MPa.

9. An aluminum alloy additively manufactured article characterized by, The aluminum alloy welding wire material is prepared by the method of any one of claims 1-7 or the aluminum alloy welding wire material of claim 8 is obtained by additive manufacturing, and has a tensile strength >400MPa, a yield strength >280MPa, and an elongation >8%.

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