Mo-containing ultrahigh-strength aluminum alloy wire as well as preparation method and application thereof

Abstract

The invention relates to the field of preparation of aluminum alloy materials, and discloses a Mo-containing ultrahigh-strength aluminum alloy wire and a preparation method and application thereof. By optimizing the alloy ratio and the preparation process, the Mo-containing ultrahigh-strength aluminum alloy wire is prepared, and the Mo-containing ultrahigh-strength aluminum alloy wire has the following performance characteristics that (1) the tensile strength is larger than or equal to 440 MPa, and the yield strength is larger than or equal to 400 MPa; the aluminum alloy wire is mainly used for manufacturing ultrahigh-strength 7-series material welding structural parts, has good corrosion resistance and excellent welding performance and machining performance, and can effectively solve the problem that in the prior art, the welding performance, yield strength and corrosion resistance of aluminum alloy cannot be considered at the same time.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy material preparation, specifically to a Mo-containing ultra-high strength aluminum alloy wire, its preparation method, and its application. Background Technology

[0002] 7-series aluminum alloys are widely used as lightweight structural materials in aerospace, transportation, and military fields due to their high strength and low density. However, while meeting the high strength requirements, existing 7-series aluminum alloys often have some problems, such as insufficient yield strength, reduced corrosion resistance, and poor anodizing effect.

[0003] To improve the strength of aluminum alloys, the content of alloying elements is usually increased or more complex heat treatment processes are employed. However, these methods often lead to increased deformation resistance of the material, making it difficult to produce thin-walled profiles and resulting in a situation where high-strength materials are difficult to lighten. This is especially true for 7-series aluminum alloys, which have high Zn and Mg solid solution content, resulting in a large number of precipitated phases after aging, and are prone to grain growth during processing, leading to performance degradation.

[0004] Furthermore, in welding applications, existing aluminum alloy materials often face the tendency for corrosion at weld joints and the risk of cracking due to differences in cooling deformation between the weld and the substrate. These problems severely restrict the promotion and use of 7-series aluminum alloys in ultra-high strength applications, necessitating the development of a new type of ultra-high strength aluminum alloy material to meet the growing high-strength demands of aerospace, 3C electronics, and other fields. Summary of the Invention

[0005] The purpose of this invention is to provide a Mo-containing aluminum alloy wire that can simultaneously satisfy high strength, good corrosion resistance and excellent processing performance, and a method for preparing the same, thereby providing at least a beneficial option or creating conditions for solving one or more technical problems existing in the prior art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution.

[0007] A method for preparing Mo-containing ultra-high strength aluminum alloy wire, comprising the following steps: 1) Casting ingots, wherein the aluminum alloy is configured according to the following mass percentages: Mg content 4.5%-5.0%, Mn content 0.5%-0.7%, Cr content 0.2%-0.3%, Fe content not exceeding 0.2%, Cu content 0.1%-0.2%, Si content not exceeding 0.1%, Mo content 0.2%-0.3%, La content 0.1%-0.2%, Zn content 0.3%-0.4%, Zr content 0.1%-0.2%, with the balance being Al; 2) A two-stage homogenization process is adopted to perform the first stage of homogenization on the cast aluminum ingots. The process involves two stages of homogenization: first-stage homogenization at 400℃-440℃ for 10-20 hours, and second-stage homogenization at 480℃-520℃ for 2-4 hours; 3) extrusion molding to extrude the homogenized aluminum rods into round rods with a diameter of 5mm-10mm, with an extrusion ratio controlled between 10-30 and an extrusion temperature controlled between 350℃-450℃; 4) multi-stage drawing to draw the extruded round rods, with each drawing deformation controlled between 30%-60%, followed by annealing at 400℃-450℃ for 1-3 hours after each drawing, resulting in a final material diameter of 0.6mm-2mm.

[0008] This invention increases the recrystallization temperature of aluminum alloys by adding trace elements such as Mn, Cr, Mo, Zr, and La to form fine and dispersed precipitates, thereby preventing grain growth during processing and welding. The pre-addition of Zn content reduces the tendency of corrosion at weld joints, decreases the difference in cooling deformation between the weld and the substrate, and increases the weld coefficient to no less than 96%.

[0009] The Mo-containing ultra-high strength aluminum alloy wire obtained by this invention has the following performance characteristics: 1) tensile strength ≥440MPa, yield strength ≥400MPa; 2) elongation ≥8%; 3) intergranular corrosion level reaches level 3; 4) excellent corrosion resistance, and can be surface anodized; 5) weldability ≥96%.

[0010] The Mo-containing ultra-high strength aluminum alloy wire obtained by this invention is mainly used for the manufacture of welded structural parts made of ultra-high strength 7-series materials. It has good corrosion resistance, excellent welding performance and processing performance, and can effectively solve the problems of poor welding performance, insufficient yield strength and decreased corrosion resistance of 7-series aluminum alloys in the prior art.

[0011] The present invention adopts the above technical solution and has at least the following advantages and beneficial effects.

[0012] First, by pre-adding Zn content, the tendency for corrosion to occur at the weld joint is significantly reduced, effectively solving the problem of easy corrosion in the welding application of existing 7-series aluminum alloy materials and improving the corrosion resistance of the material.

[0013] Second, the composite addition of Mn, Cr, Mo, Zr, and La significantly increases the recrystallization temperature of the material, effectively preventing performance degradation caused by grain growth during processing and welding, thus improving the overall performance and service life of the material.

[0014] Third, a two-stage homogenization process is adopted to homogenize the cast aluminum rods in two stages, which significantly improves the uniformity of the internal structure of the material, improves the processing performance of the material, and effectively solves the problem that the single-stage homogenization process in the existing technology is difficult to achieve the internal uniformity of the material.

[0015] Fourth, by using the extrusion molding process and a combination of two-stage homogenization temperature and holding time, the material is homogenized and densified, which greatly improves the density of the material and enhances its tensile strength and yield strength.

[0016] Fifth, by adopting a multi-stage drawing process and controlling the amount of drawing deformation and annealing temperature, the difference in material cooling deformation is effectively reduced, the risk of cracks between the welding position and the substrate is lowered, and the welding coefficient is improved.

[0017] Some other beneficial effects of the present invention will become more apparent in the following description or may be learned by practice. Detailed Implementation

[0018] The specific embodiments of the present invention will be further described below to make the technical solution and its beneficial effects clearer and more explicit. The embodiments described below are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0019] Additional aspects and advantages of the invention will become apparent in the following description or may be learned by practice of the invention.

[0020] Example 1.

[0021] A method for preparing Mo-containing ultra-high strength aluminum alloy wire includes the following steps:

[0022] 1) Casting: Prepare the alloy composition according to the specified ratio and cast it into an aluminum rod. The alloy composition is: Mg 4.6wt%, Mn 0.55wt%, Cr 0.23wt%, Fe 0.11wt%, Cu 0.13wt%, Si 0.07wt%, Mo 0.22wt%, La 0.12wt%, Zn 0.33wt%, Zr 0.11wt%, with the balance being aluminum. This proper ratio of elements also serves to strengthen the rod. The cast aluminum rod has a diameter of 100mm.

[0023] 2) Two-stage homogenization treatment: The cast aluminum rod undergoes a first-stage homogenization treatment at 410℃ for 18 hours; followed by a second-stage homogenization treatment at 490℃ for 3 hours. This two-stage homogenization process effectively improves the uniformity of the material and prevents localized enrichment.

[0024] 3) Extrusion Molding: The homogenized aluminum rods are hot-extruded to produce round rods with a diameter of 10mm. A 4-hole die is used, the extrusion ratio is 22, and the extrusion temperature is controlled between 410℃ and 430℃. The hot extrusion process can improve the density of the material and enhance the uniformity of its internal structure.

[0025] 4) Multi-stage drawing process: The extruded round bar is drawn three times, with the deformation controlled at 50% each time. After each drawing, it is annealed at 420℃ for 2 hours. The diameter of the final formed material is controlled at 1.2mm.

[0026] The Mo-containing ultra-high strength aluminum alloy wire prepared in this embodiment forms a fine, dispersed precipitate phase through the synergistic effect of trace elements such as Mn, Cr, Mo, Zr, and La. This significantly increases the recrystallization temperature of the material and prevents grain growth during processing. Simultaneously, the pre-addition of Zn effectively reduces the tendency for corrosion at weld joints, minimizes the difference in cooling deformation between the weld and the substrate, and achieves a weld coefficient of no less than 96%.

[0027] Example 2.

[0028] A method for preparing Mo-containing ultra-high strength aluminum alloy wire includes the following steps:

[0029] 1) Casting: Prepare the alloy composition according to the specified ratio and cast it into an aluminum rod. The alloy composition is: Mg 4.9wt%, Mn 0.65wt%, Cr 0.27wt%, Fe 0.16wt%, Cu 0.17wt%, Si 0.07wt%, Mo 0.27wt%, La 0.17wt%, Zn 0.34wt%, Zr 0.17wt%, with the balance being Al. Through the reasonable proportion of these elements, which also serve to strengthen the rod, an aluminum rod with a diameter of 80mm is cast.

[0030] 2) Two-stage homogenization treatment: The cast aluminum rod undergoes a first-stage homogenization treatment at 430℃ for 14 hours; followed by a second-stage homogenization treatment at 510℃ for 2.5 hours. This two-stage homogenization process effectively improves the uniformity of the material and prevents localized enrichment.

[0031] 3) Extrusion molding: The homogenized aluminum rod is hot-extruded to produce round rods with a diameter of 7mm. The extrusion ratio is controlled at 25, and the extrusion temperature is controlled at 390℃-410℃. The hot extrusion process can improve the density of the material and improve the uniformity of the internal structure.

[0032] 4) Multi-stage drawing process: The extruded round bar is drawn three times, with the deformation controlled at 40% each time. After each drawing, it is annealed at 430℃ for 2 hours. The diameter of the final formed material is controlled at 1.5mm.

[0033] The Mo-containing ultra-high strength aluminum alloy wire prepared in this embodiment forms a fine, dispersed precipitate phase through the synergistic effect of trace elements such as Mn, Cr, Mo, Zr, and La. This significantly increases the recrystallization temperature of the material and prevents grain growth during processing. Simultaneously, the pre-addition of Zn effectively reduces the tendency for corrosion at weld joints, minimizes the difference in cooling deformation between the weld and the substrate, and achieves a weld coefficient of no less than 96%.

[0034] Comparative Example 1.

[0035] A method for preparing aluminum alloy wire includes the following steps:

[0036] 1) Casting: Prepare the alloy composition according to the specified ratio and cast it into an aluminum rod. The alloy composition is: Mg 4.6wt%, Mn 0.55wt%, Cr 0.23wt%, Fe 0.11wt%, Cu 0.13wt%, Si 0.07wt%, La 0.12wt%, Zn 0.33wt%, Zr 0.11wt%, with the balance being aluminum. The cast aluminum rod has a diameter of 100mm.

[0037] 2) Two-stage homogenization treatment: The cast aluminum rods undergo a first-stage homogenization treatment at a temperature of 410℃ for 18 hours; then a second-stage homogenization treatment is performed at a temperature of 490℃ for 3 hours.

[0038] 3) Extrusion molding: The homogenized aluminum rod is hot extruded to produce round rods with a diameter of 10mm. A 4-hole die is used, the extrusion ratio is 22, and the temperature of the extruded aluminum rod is controlled at 410℃-430℃.

[0039] 4) Multi-stage drawing process: The extruded round bar is drawn three times, with the deformation controlled at 50% each time. After each drawing, it is annealed at 420℃ for 2 hours. The diameter of the final formed material is controlled at 1.2mm.

[0040] Comparative Example 2.

[0041] A method for preparing aluminum alloy wire includes the following steps:

[0042] 1) Casting: Prepare the alloy composition according to the specified ratio and cast it into an aluminum rod. The alloy composition is: Mg 4.6wt%, Mn 0.55wt%, Cr 0.23wt%, Fe 0.11wt%, Si 0.07wt%, Mo 0.22wt%, La 0.12wt%, Zn 0.33wt%, with the balance being aluminum. The cast aluminum rod has a diameter of 100mm.

[0043] 2) Two-stage homogenization treatment: The cast aluminum rods undergo a first-stage homogenization treatment at a temperature of 410℃ for 18 hours; then a second-stage homogenization treatment is performed at a temperature of 490℃ for 3 hours.

[0044] 3) Extrusion molding: The homogenized aluminum rod is hot extruded to produce round rods with a diameter of 10mm. A 4-hole die is used, the extrusion ratio is 22, and the temperature of the extruded aluminum rod is controlled at 410℃-430℃.

[0045] 4) Multi-stage drawing process: The extruded round bar is drawn three times, with the deformation controlled at 50% each time. After each drawing, it is annealed at 420℃ for 2 hours. The diameter of the final formed material is controlled at 1.2mm.

[0046] Comparative Example 3.

[0047] A method for preparing aluminum alloy wire includes the following steps:

[0048] 1) Casting: Prepare the alloy composition according to the specified ratio and cast it into an aluminum rod. The alloy composition is: Mg 4.6wt%, Mn 0.55wt%, Cr 0.23wt%, Fe 0.11wt%, Cu 0.13wt%, Si 0.07wt%, Mo 0.22wt%, La 0.12wt%, Zn 0.33wt%, Zr 0.11wt%, with the balance being aluminum. This proper ratio of elements also serves to strengthen the rod. The cast aluminum rod has a diameter of 100mm.

[0049] 2) Homogenization treatment: The cast aluminum rods are subjected to primary homogenization treatment at a temperature of 410℃ for 18 hours.

[0050] 3) Extrusion Molding: The homogenized aluminum rods are hot-extruded to produce round rods with a diameter of 10mm. A 4-hole die is used, the extrusion ratio is 22, and the extrusion temperature is controlled between 410℃ and 430℃. The hot extrusion process can improve the density of the material and enhance the uniformity of its internal structure.

[0051] 4) Multi-stage drawing process: The extruded round bar is drawn three times, with the deformation controlled at 50% each time. After each drawing, it is annealed at 420℃ for 2 hours. The diameter of the final formed material is controlled at 1.2mm.

[0052] Comparative Example 4.

[0053] A method for preparing aluminum alloy wire includes the following steps:

[0054] 1) Casting: Prepare the alloy composition according to the specified ratio and cast it into an aluminum rod. The alloy composition is: Mg 4.6wt%, Mn 0.55wt%, Cr 0.23wt%, Fe 0.11wt%, Cu 0.13wt%, Si 0.07wt%, Mo 0.22wt%, La 0.12wt%, Zn 0.33wt%, Zr 0.11wt%, with the balance being aluminum. The cast aluminum rod has a diameter of 100mm.

[0055] 2) Two-stage homogenization treatment: The cast aluminum rods undergo a first-stage homogenization treatment at a temperature of 410℃ for 18 hours; then a second-stage homogenization treatment is performed at a temperature of 490℃ for 3 hours.

[0056] 3) Extrusion Molding: The homogenized aluminum rods are hot-extruded to produce round rods with a diameter of 10mm. A 4-hole die is used, the extrusion ratio is 4:4, and the extrusion temperature is controlled between 410℃ and 430℃. The hot extrusion process can improve the density of the material and enhance the uniformity of its internal structure.

[0057] 4) Multi-stage drawing process: The extruded round bar is drawn three times, with the deformation amount controlled at 50% each time. The diameter of the final formed material is controlled at 1.2mm.

[0058] Performance testing.

[0059] Ten samples were prepared according to the preparation methods of each embodiment and comparative example, and their tensile strength, yield strength, elongation, intergranular corrosion level and weldability were tested. The results are shown in Table 1.

[0060] Table 1. Performance test comparison of each embodiment and comparative example.

[0061]

[0062] As shown in Table 1, when Mo is not added (Comparative Example 1), the tensile strength, yield strength, and elongation of the resulting aluminum alloy wire all decrease significantly, and the welding coefficient is less than 96%. When Cu and Zr are not added (Comparative Example 2), the tensile strength of the resulting aluminum alloy wire decreases significantly, and the upper and lower limits of the yield strength and elongation also decrease significantly, and the welding coefficient is less than 96%. When the two-stage homogenization treatment is changed to a single-stage homogenization treatment (Comparative Example 3), the tensile strength and elongation of the resulting aluminum alloy wire decrease significantly, and the upper and lower limits of the yield strength also decrease significantly. When a larger extrusion ratio is used and no annealing treatment is performed (Comparative Example 4), the tensile strength, yield strength, and elongation of the resulting aluminum alloy wire all decrease significantly, and the welding coefficient is less than 96%.

[0063] Therefore, it can be seen that the technical effect of this invention is the result of the combined effect of alloy ratio and corresponding process, and the two have a synergistic effect.

[0064] Example 3.

[0065] The Mo-containing ultra-high strength aluminum alloy wire obtained by this invention is used in the manufacture of welded structural components made of ultra-high strength 7-series materials. Table 2 shows a performance comparison between the welding wire obtained by this invention and traditional 7075 and 5356 welding wires.

[0066] Table 2. Performance comparison of the welding wire prepared using the present invention with traditional 7075 welding wire and 5356 welding wire.

[0067]

[0068] As shown in Table 2, compared with the traditional 7075 welding wire, the welding wire prepared using the present invention has lower tensile strength and yield strength, but significantly improved elongation, especially in terms of intergranular corrosion level, corrosion resistance, and weldability. Compared with the traditional 5356 welding wire, the present invention has a significant strength advantage. Therefore, the present invention can balance strength, corrosion resistance, and processing performance, effectively addressing the shortcomings of existing technologies.

[0069] It should be noted that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0070] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Parts not described in the specific embodiments are all prior art or common knowledge.

[0071] It should also be noted that, in this invention, the term "prepared from" is synonymous with "comprising". The terms "comprising", "including", "having", "containing", or any other variations thereof, as used in this invention, are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus comprising the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such a composition, step, method, article, or apparatus.

Claims

1. A method for preparing Mo-containing ultra-high strength aluminum alloy wire, comprising the following steps: 1) Casting rods: Prepare the alloy composition according to the following weight percentages and cast them into aluminum rods. The alloy composition is: Mg 4.5%-5.0%, Mn 0.5%-0.7%, Cr 0.2%-0.3%, Fe≤0.2%, Cu 0.1%-0.2%, Si≤0.1%, Mo 0.2%-0.3%, La 0.1%-0.2%, Zn 0.3%-0.4%, Zr 0.1%-0.2%, with the balance being Al; 2) Two-stage homogenization treatment: The first-stage homogenization temperature is 400℃-440℃, and the holding time is 10h-20h; the second-stage homogenization temperature is 480℃-520℃, and the holding time is 2h-4h. 3) Extrusion molding: The homogenized aluminum rod is extruded into a round rod, with the extrusion ratio controlled between 10 and 30 and the extrusion temperature controlled between 350℃ and 450℃. 4) Multi-stage drawing process: The extruded round bar is drawn using a multi-stage drawing process. The deformation amount of each drawing is controlled at 30%-60%. After each drawing, the bar is annealed at 400℃-450℃ for 1-3 hours. The diameter of the final formed material is controlled at 0.6mm-2mm.

2. The method for preparing a Mo-containing ultra-high strength aluminum alloy wire according to claim 1, characterized in that, When casting the rod, prepare the alloy composition according to the following weight percentages and cast it into an aluminum rod: Mg 4.6wt%, Mn 0.55wt%, Cr 0.23wt%, Fe 0.11wt%, Cu 0.13wt%, Si 0.07wt%, Mo 0.22wt%, La 0.12wt%, Zn 0.33wt%, Zr 0.11wt%, with the balance being aluminum.

3. The method for preparing a Mo-containing ultra-high strength aluminum alloy wire according to claim 1, characterized in that, When casting the rods, prepare the alloy composition according to the following weight percentages and cast them into aluminum rods: Mg 4.9wt%, Mn 0.65wt%, Cr 0.27wt%, Fe 0.16wt%, Cu 0.17wt%, Si 0.07wt%, Mo 0.27wt%, La 0.17wt%, Zn 0.34wt%, Zr 0.17wt%, with the balance being Al.

4. The method for preparing a Mo-containing ultra-high strength aluminum alloy wire according to claim 1, characterized in that, The diameter of the aluminum rods obtained by casting is 50-100mm, and the diameter of the round rods obtained by extrusion is 5-10mm.

5. The method for preparing a Mo-containing ultra-high strength aluminum alloy wire according to claim 1, characterized in that, The drawing process is repeated three times, with the deformation amount controlled at 40%-50% for each drawing.

6. A Mo-containing ultra-high strength aluminum alloy wire, characterized in that, It is prepared using the method for preparing a Mo-containing ultra-high strength aluminum alloy wire as described in any one of claims 1-5.

7. The Mo-containing ultra-high strength aluminum alloy wire as described in claim 6, characterized in that, It has the following performance characteristics: 1) Tensile strength ≥ 440 MPa, yield strength ≥ 400 MPa; 2) Elongation ≥ 8%; 3) Intergranular corrosion grade reaches level 3; 4) Weldability coefficient ≥ 96%.

8. The application of the Mo-containing ultra-high strength aluminum alloy wire as described in claim 6 in the preparation of welding wire.

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