A high-performance modified aluminum alloy material and its processing method

Abstract

This application discloses a high-performance modified aluminum alloy material comprising the following components by mass percentage: Mg (0.95–1.03)%; Si (0.63–0.68)%; Cu (0.28–0.30)%; Cr (0.15–0.25)%; Mn (0.08–0.15)%; Ti (0.08–0.15)%; Zr (0.04–0.10)%; La + Ce (0.04–0.10)%; and unavoidable impurities: Fe < 0.30%; Zn < 0.20%, with the balance being Al. To address the need for improved performance of 6061 aluminum alloy, this study breaks through the limitations of traditional single-element modification by innovatively adopting a composite microalloying scheme of Ti, Cr, Mn, Zr and La & Ce rare earth elements, along with a customized preparation process. Through the synergistic effect of multiple elements, a multiplier effect of 1+1>2 is achieved in key aspects such as grain refinement, recrystallization inhibition, melt purification, dispersion strengthening and microstructure modification, significantly improving the alloy's comprehensive mechanical properties and service stability.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy materials technology, and in particular to a high-performance modified aluminum alloy material and its processing method. Background Technology

[0002] 6061 aluminum alloy, as the most widely used 6-series medium-strength alloy, occupies an important position in transportation, machinery, and sporting goods due to its good formability, corrosion resistance, and comprehensive mechanical properties. However, with the increasing urgency of industrial upgrading and lightweighting, the performance bottlenecks of traditional 6061 aluminum alloy are becoming increasingly prominent, mainly reflected in:

[0003] Strength-toughness contradiction: The tensile strength of 6061 aluminum alloy strengthened by conventional heat treatment processes is usually difficult to exceed 360MPa, and while the strength is improved, the plasticity and toughness are often reduced.

[0004] Insufficient fatigue performance: For components subjected to cyclic loads, such as bicycle cranks and automobile suspension links, the fatigue resistance of materials is crucial. Traditional 6061 alloy is relatively sensitive to microscopic defects (such as coarse iron-rich phases, oxide inclusions, and porosity), which become fatigue crack initiation points, limiting its application in high-reliability applications.

[0005] Extrusion processability issues: The coarse, brittle β-AlFeSi phase present in the alloy easily leads to defects such as scratches and orange peel on the product surface during extrusion. To alleviate this problem, a conservative process of increasing extrusion temperature and reducing extrusion speed is often adopted in production, which severely restricts production efficiency.

[0006] Chinese invention patent CN118904959A discloses an extrusion process for 6061 aluminum alloy bars used in automotive probe housings. The aluminum alloy material is composed of the following mass percentages: 0.5~0.7wt% Si, 0.2~0.3wt% Cu, 0.9~1.0wt% Mg, 0.04~0.07wt% Cr, and Mn ≤0.05%, with other components added according to national standards. The 6061 extruded bars prepared using this process achieve a tensile strength of up to 340MPa, a specified plastic elongation strength of up to 310MPa, and an elongation at break ≥13% after aging.

[0007] Analysis of enterprise production practice records and results from the invention embodiments shows that improving the strength of 6061 aluminum alloy bars remains quite difficult. Currently, 6061 aluminum alloy extruded bars are widely used in sporting goods, aerospace, and transportation fields, such as bicycle cranks, requiring both high strength and high fatigue resistance. Therefore, improving these bars and developing a high-strength, fatigue-resistant aluminum alloy material has become an urgent problem for the industry. Summary of the Invention

[0008] The present invention aims to solve one of the technical problems existing in the prior art.

[0009] This application provides a high-performance modified aluminum alloy material comprising the following components by mass percentage: Mg (0.95–1.03)%; Si (0.63–0.68)%; Cu (0.28–0.30)%; Cr (0.15–0.25)%; Mn (0.08–0.15)%; Ti (0.08–0.15)%; Zr (0.04–0.10)%; La + Ce (0.04–0.10)%; and unavoidable impurities: Fe < 0.30%; Zn < 0.20%, with the balance being Al.

[0010] Preferably, the mass percentage of Mg and Si elements is set to 1.35 ≤ Mg / Si ≤ 1.73.

[0011] Preferably, the mass percentage of the Mg, Si, and Cu elements is set to 1.90% ≤ wt.%Si + wt.%Mg + wt.%Cu ≤ 2.05%.

[0012] Preferably, the mass percentage of Zr and Ti elements is set to wt.%Zr ≤ wt.%Ti.

[0013] Preferably, the Fe content in the unavoidable impurities, by mass percentage, satisfies wt.%Fe ≤ wt.%Mn + wt.%Cr.

[0014] Preferably, the content of Ti + Zr is 0.15% ≤ wt.% Ti + wt.% Zr ≤ 0.25% by mass percentage.

[0015] A processing method suitable for the above-described high-performance modified aluminum alloy material includes the following steps:

[0016] S1: Smelting and refining: According to the mass percentage of each chemical element in the alloy, preheated Al-Mn, Al-Cr, Al-Ti, Al-Zr and La&Ce master alloys are added sequentially to the aluminum liquid at (730~750)℃. After one refining, pure Mg ingots and copper wires are added. The melting is assisted by electromagnetic stirring. Liquid refining and powder spraying refining are combined. Slag is removed and the mixture is allowed to stand.

[0017] S2: Casting: The aluminum liquid is cast at a temperature of (720~730)℃ and a DC casting (i.e. direct water-cooled casting) traction speed of (80~90) mm / min to produce aluminum alloy cast rods for extrusion.

[0018] S3: Homogenization treatment: The aluminum alloy casting rod is rapidly heated and held at (560~580)℃ for (6~10)h to carry out homogenization treatment, with a cooling rate ≥250℃ / h;

[0019] S4: Extrusion processing: After surface treatment of aluminum alloy cast rods, they are heated to (460~480)℃ and extruded at an extrusion speed of (4~5)mm / s, and air-cooled to obtain rod-shaped rods;

[0020] S5: Heat treatment: The bar is subjected to T6 heat treatment, with a solution temperature of (530~545)℃ and a holding time of (1.5~2.5)h; an aging temperature of (175~190)℃ and a holding time of (4~7)h; after solution treatment, it is water quenched, with the water temperature controlled at (20~40)℃ before quenching and a transfer time ≤15s, to obtain the final aluminum bar product.

[0021] Preferably, in step S1, the material is thoroughly refined twice with a refining agent, each time for (25-35) min.

[0022] Preferably, in step S3, the homogenization process employs a two-stage heating method: the first stage heats the temperature to 450°C at a rate of (50-100)°C / h, and the second stage heats the temperature to (560-580)°C at a rate of (100-150)°C / h.

[0023] Preferably, in step S4, the preheating temperature of the extrusion die is 430-450℃, and the temperature of the extrusion cylinder is 420-440℃.

[0024] This high-performance modified 6061 aluminum alloy material addresses the performance enhancement needs of 6061 aluminum alloy by breaking through the limitations of traditional single-element modification. It innovatively employs a Ti, Cr, Mn, Zr, and La & Ce rare earth composite microalloying scheme, coupled with a customized preparation process. Through the synergistic effect of multiple elements, a multiplier effect (1+1>2) is achieved in key areas such as grain refinement, recrystallization inhibition, melt purification, dispersion strengthening, and microstructure modification, significantly improving the alloy's comprehensive mechanical properties and service stability. The core innovation lies in the synergistic regulation of multiple elements, constructing a comprehensive microstructure optimization mechanism.

[0025] (1) Grain refinement: Multi-dimensional nucleation enhancement, inhibiting grain coarsening

[0026] During the nucleation stage, Al combines with Zr to form the Al3Zr phase. Due to its good crystal structure compatibility with the Al matrix lattice, it can serve as a heterogeneous nucleation core, promoting nucleation. However, Zr has a potential "poisoning" effect on traditional grain refiners, while Ti-rich modifiers (such as Al-Ti-B systems) can weaken the "poisoning" effect of Zr. Therefore, an appropriate amount of Ti is added to the material. The benefits of adding Ti are not limited to this. The Al3Ti phase formed by the reaction of Ti and Al participates in the peritectic reaction during the solidification stage, becoming a highly efficient heterogeneous nucleation substrate. Furthermore, it can form a stable Al3Ti / TiB two-dimensional composite layer on the surface of TiB2 particles, forming a "Al3Ti+Al3Zr" dual heterogeneous nucleation system with Al3Ti as the dominant element and Al3Zr as the auxiliary element. This enriches the nucleation core types, increases the total amount of nucleation, significantly increases the nucleus density, and significantly refines the grains.

[0027] In addition to promoting nucleation, Zr can significantly increase the number of crystal nuclei and shorten the grain growth time window by enhancing chemical composition undercooling, thereby expanding the effective nucleation range, reducing the critical nucleation radius and nucleation work, and thus strengthening the refinement of the as-cast microstructure. Mn, as an auxiliary element, can synergistically work with Zr to enhance composition undercooling.

[0028] During the grain growth stage, La and Ce rare earth elements act as core growth inhibitors, forming an active adsorption film at grain boundaries to hinder the preferential growth of columnar crystals and secondary dendrites, and promote the formation of fine equiaxed crystals; La and Ce rare earth elements can form fine dispersed phases (Al... 11 Ce3, Al 11 La3 and Al3(La,Ce) work together with Al6Mn and Al7Cr phases to pin grain boundaries, inhibit grain growth, and optimize grain morphology and second phase distribution from the source.

[0029] (2) Recrystallization inhibition: Multi-dispersed phase synergistic pinning to construct high-strength tissue

[0030] Suppressing recrystallization during extrusion processing can preserve some high dislocation density structures, significantly improving the tensile strength, specified ductile elongation strength, and hardness of the alloy, while avoiding plasticity loss and improving the fatigue life of the material.

[0031] Cr, Mn, and Zr are all highly efficient elements in aluminum alloys for inhibiting recrystallization. They can significantly increase the recrystallization temperature and form dispersed phases (such as Al6Mn, (Cr,Mn)Al). 12The material exhibits extremely high thermal stability, meaning that these dispersed phases (Cr,Fe)Al7 and Al3Zr) remain stable even after high-temperature deformation. The micron-sized dispersed phases formed by Cr and Mn elements, in particular, have a stronger pinning effect on dislocations and grain boundaries. Simultaneously, the dispersed phases Al3Ti and Al3(La,Ce) in the material also work synergistically to enhance the pinning effect on dislocations and grain boundaries. Furthermore, the increased number of grain boundaries generated by grain refinement results in greater migration resistance, further suppressing recrystallization.

[0032] (3) Dispersion strengthening: Multiphase synergistic load bearing, improving the upper limit of mechanical properties

[0033] Ti and Zr form fine Al3Ti and Al3Zr phases, respectively; Mn and Cr form larger Al6Mn and Al7Cr phases; La and Ce rare earth elements form Al3(La,Ce) and Al3(Ce) phases when their content is close to 0.1%. 11 The (La,Ce)3 phase combines with Fe / Si to form small-sized Al8La2Si and Al6CeFe dispersed phases, replacing the traditional coarse, lamellar Al3Fe and β-AlFeSi phases. These dispersed phases are widely distributed in the matrix, serving as nucleation cores to refine grains and, through synergistic effects, effectively pinning dislocations, significantly improving the alloy's strength and hardness. The ultrafine coherent particles formed by the composite addition of Zr / La&Ce can synergistically work with the Al7Cr phase to hinder the formation and propagation of slip bands, becoming a key barrier to suppress fatigue crack initiation. In particular, Cr can significantly improve the resistance to stress corrosion cracking (SCC)—at the same addition amount, Cr can increase the SCC life by tens to hundreds of times compared to an equal amount of Mn, directly enhancing the fatigue durability of the material under complex working conditions.

[0034] (4) Melt purification and deterioration: Eliminating defects at the source and optimizing matrix quality

[0035] As a crucial pre-process in aluminum alloy production, melt purification and modification optimize the state of the molten aluminum from the source, becoming a core guarantee for controlling the quality of the final product. La & Ce mixed rare earth elements can effectively reduce hydrogen content through composition control. Due to their strong hydrogen capture ability, they can generate stable refractory compounds such as CeH2 and LaH2, significantly reducing the hydrogen content and porosity of the alloy. Simultaneously, the mixed rare earth elements combine with trace amounts of low-melting-point metals such as Pb, Bi, and Sn in the melt, forming refractory rare earth intermetallic compounds (such as LaPb2 and CeBi), which can be removed with the slag, greatly improving melt purity. They also work synergistically with Mn to combine with the Fe / Si impurities commonly present in the melt to generate small-sized Al atoms. 12 The (Fe,Mn)3Si, Al8La2Si, and Al6CeFe phases reduce the brittle Al-Fe-Si phase in the matrix and suppress the adverse effects of Si segregation on the extrusion process.

[0036] Through the above-mentioned processing method for high-performance modified 6061 aluminum alloy materials, the innovative composite microalloying and process optimization, the T6 state properties of the 6-series aluminum alloy prepared by this invention have achieved a leapfrog improvement:

[0037] Significantly improved strength: tensile strength stably reaches over 415MPa, and specified plastic elongation strength exceeds 385MPa, far exceeding the tensile strength level of 320MPa of ordinary 6061 bars;

[0038] Balance of toughness and plasticity: The elongation after fracture is maintained above 12.5% ​​to avoid embrittlement under high strength;

[0039] Excellent fatigue performance: Rare earth purification eliminates crack sources such as porosity and inclusions, and coherent particles such as Al3Zr hinder slip bands and crack propagation, greatly improving the fatigue limit of the alloy;

[0040] Good high-temperature stability: Thermally stable dispersed phases such as Al3(La,Ce), Al6Mn, and Al7Cr ensure that the alloy maintains good performance under long-term complex working conditions.

[0041] The beneficial effects of the present invention will be described in detail in the embodiments, thereby making the beneficial effects more obvious. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of a scanning electron microscope image from Embodiment 5 of this application. Detailed Implementation

[0043] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0044] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0045] The embodiments of this application will be described in detail below with reference to the accompanying drawings and specific examples and application scenarios.

[0046] Example 1:

[0047] This embodiment of the invention discloses a high-performance modified aluminum alloy material and its processing method. In a specific embodiment of the invention, the composition and mass percentage of each component are as follows: Mg 1.01%; Si 0.64%; Cu 0.28%; Cr 0.24%; Mn 0.12%; Ti 0.12%; Zr 0.08%; La & Ce 0.09%; other unavoidable impurities: Fe < 0.30%; Zn < 0.20%, etc., with the balance being Al.

[0048] (1) Weigh the required raw materials according to the alloy composition design requirements. Al, Mg and Cu are added in the form of pure metals with a purity greater than 99.7%, while Si, Mn, Cr, Zr, Ti and La / Ce are added in the form of intermediate alloys.

[0049] (2) When all the raw materials have melted and the melt temperature is 735°C, the refining process is carried out. After removing the surface slag, the melt is allowed to settle and stand for 30 minutes so that the aluminum liquid inclusions can be separated and the aluminum melt can be further purified.

[0050] (3) When the melt temperature is 720℃, the aluminum liquid enters the casting pan after online degassing and filtration, and the casting speed is 85mm / min, and aluminum alloy rods with a diameter of 254mm are cast.

[0051] (4) Homogenize the casting rod at a temperature of 560℃ for 8 hours and cool it to room temperature with strong air.

[0052] (5) Heat the aluminum alloy cast rod to 480°C and feed it into the extrusion press. The extrusion speed is (4-5) mm / s. The rod is then cooled by air.

[0053] (6) The obtained bar is subjected to solution treatment at a temperature of 535°C for 2.5 hours, an aging temperature of 175°C for 6 hours, and then cooled to obtain the 6061 bar.

[0054] The performance of the aluminum alloy bar in this embodiment was tested, and the results are shown in Table 1.

[0055] Table 1 Alloy properties of Example 1

[0056]

[0057] Example 2:

[0058] This embodiment of the invention discloses a high-performance modified aluminum alloy material and its processing method. In a specific embodiment of the invention, the composition and mass percentage of each component are as follows: Mg 0.97%; Si 0.68%; Cu 0.29%; Cr 0.18%; Mn 0.12%; Ti 0.12%; Zr 0.07%; La & Ce 0.07%; other unavoidable impurities: Fe < 0.30%; Zn < 0.20%, etc., with the balance being Al.

[0059] (1) Weigh the required raw materials according to the alloy composition design requirements. Al, Mg and Cu are added in the form of pure metals with a purity greater than 99.7%, while Si, Mn, Cr, Zr, Ti and La / Ce are added in the form of intermediate alloys.

[0060] (2) When all the raw materials have melted and the melt temperature is 735°C, the refining process is carried out. After removing the surface slag, the melt is allowed to settle and stand for 30 minutes so that the aluminum liquid inclusions can be separated and the aluminum melt can be further purified.

[0061] (3) When the melt temperature is 720℃, the aluminum liquid enters the casting pan after online degassing and filtration, and the casting speed is 85mm / min, and aluminum alloy rods with a diameter of 254mm are cast.

[0062] (4) Homogenize the casting rod at a temperature of 565℃ for 8 hours and cool it to room temperature with strong air.

[0063] (5) Heat the aluminum alloy cast rod to 480°C and feed it into the extruder. The extrusion speed is (4-5) mm / s. Use air cooling to obtain the rod-shaped bar.

[0064] (6) The obtained bar is subjected to solution treatment at a temperature of 535°C for 2.5 hours, an aging temperature of 175°C for 6 hours, and then cooled to obtain the 6061 bar.

[0065] The performance of the aluminum alloy bar in this embodiment was tested, and the results are shown in Table 2.

[0066] Table 2 Alloy properties of Example 2

[0067]

[0068] Example 3:

[0069] This embodiment of the invention discloses a high-performance modified aluminum alloy material and its processing method. In a specific embodiment of the invention, the composition and mass percentage of each component are as follows: Mg 0.96%; Si 0.68%; Cu 0.30%; Cr 0.19%; Mn 0.14%; Ti 0.13%; Zr 0.06%; La & Ce 0.07%; other unavoidable impurities: Fe < 0.30%; Zn < 0.20%, etc., with the balance being Al.

[0070] (1) Weigh the required raw materials according to the alloy composition design requirements. Al, Mg and Cu are added in the form of pure metals with a purity greater than 99.7%, while Si, Mn, Cr, Zr, Ti and La / Ce are added in the form of intermediate alloys.

[0071] (2) When all the raw materials have melted and the melt temperature is 735°C, the refining process is carried out. After removing the surface slag, the melt is allowed to settle and stand for 30 minutes so that the aluminum liquid inclusions can be separated and the aluminum melt can be further purified.

[0072] (3) When the melt temperature is 720℃, the aluminum liquid enters the casting pan after online degassing and filtration, and the casting speed is 85mm / min, and aluminum alloy rods with a diameter of 254mm are cast.

[0073] (4) Homogenize the casting rod at a temperature of 565℃ for 8 hours and cool it to room temperature with strong air.

[0074] (5) Heat the aluminum alloy cast rod to 485°C and feed it into the extruder. The extrusion speed is (4-5) mm / s. Use air cooling to obtain the rod-shaped bar.

[0075] (6) The obtained bar is subjected to solution treatment at a temperature of 535°C for 2.5 hours, an aging temperature of 175°C for 6 hours, and then cooled to obtain the 6061 bar.

[0076] The performance of the aluminum alloy bar in this embodiment was tested, and the results are shown in Table 3.

[0077] Table 3 Alloy properties of Example 3

[0078]

[0079] Example 4:

[0080] This embodiment of the invention discloses a high-performance modified aluminum alloy material and its processing method. In a specific embodiment of the invention, the composition and mass percentage of each component are as follows: Mg 0.98%; Si 0.68%; Cu 0.30%; Cr 0.19%; Mn 0.12%; Ti 0.12%; Zr 0.05%; La & Ce 0.07%; other unavoidable impurities: Fe < 0.30%; Zn < 0.20%, etc., with the balance being Al.

[0081] (1) Weigh the required raw materials according to the alloy composition design requirements. Al, Mg and Cu are added in the form of pure metals with a purity greater than 99.7%, while Si, Mn, Cr, Zr, Ti and La / Ce are added in the form of intermediate alloys.

[0082] (2) When all the raw materials have melted and the melt temperature is 735°C, the refining process is carried out. After removing the surface slag, the melt is allowed to settle and stand for 30 minutes so that the aluminum liquid inclusions can be separated and the aluminum melt can be further purified.

[0083] (3) When the melt temperature is 720℃, the aluminum liquid enters the casting pan after online degassing and filtration, and the casting speed is 85mm / min, and aluminum alloy rods with a diameter of 254mm are cast.

[0084] (4) Homogenize the casting rod at a temperature of 560℃ for 8 hours and cool it to room temperature with strong air.

[0085] (5) Heat the aluminum alloy cast rod to 485°C and feed it into the extruder. The extrusion speed is (4-5) mm / s. Use air cooling to obtain the rod-shaped bar.

[0086] (6) The obtained bar is subjected to solution treatment at a temperature of 535°C for 2.5 hours, an aging temperature of 175°C for 6 hours, and then cooled to obtain the 6061 bar.

[0087] The performance of the aluminum alloy bar in this embodiment was tested, and the results are shown in Table 4.

[0088] Table 4 Alloy properties of Example 4

[0089]

[0090] Example 5:

[0091] This embodiment of the invention discloses a high-performance modified aluminum alloy material and its processing method. In a specific embodiment of the invention, the composition and mass percentage of each component are as follows: Mg 0.97%; Si 0.66%; Cu 0.30%; Cr 0.20%; Mn 0.11%; Ti 0.13%; Zr 0.06%; La & Ce 0.06%; and other unavoidable impurities: Fe < 0.30%; Zn < 0.20%, etc., with the balance being Al.

[0092] (1) Weigh the required raw materials according to the alloy composition design requirements. Al, Mg and Cu are added in the form of pure metals with a purity greater than 99.7%, while Si, Mn, Cr, Zr, Ti and La / Ce are added in the form of intermediate alloys.

[0093] (2) When all the raw materials have melted and the melt temperature is 730°C, the refining process is carried out. After removing the surface slag, the melt is allowed to settle and stand for 30 minutes so that the aluminum liquid inclusions can be separated and the aluminum melt can be further purified.

[0094] (3) When the melt temperature is 720℃, the aluminum liquid enters the casting pan after online degassing and filtration, and the casting speed is 85mm / min, and aluminum alloy rods with a diameter of 254mm are cast.

[0095] (4) Homogenize the casting rod at a temperature of 565℃ for 8 hours and cool it to room temperature with strong air.

[0096] (5) Heat the aluminum alloy cast rod to 485°C and feed it into the extruder. The extrusion speed is (4-5) mm / s. Use air cooling to obtain the rod-shaped bar.

[0097] (6) The obtained bar is subjected to solution treatment at a temperature of 535°C for 2.5 hours, an aging temperature of 175°C for 6 hours, and then cooled to obtain the 6061 bar.

[0098] The performance of the aluminum alloy bar in this embodiment was tested, and the results are shown in Table 5.

[0099] Table 5 Alloy properties of Example 5

[0100]

[0101] Comparative Example 1:

[0102] This comparative example describes a high-performance modified aluminum alloy material and its processing method. The composition and mass percentage of each component are as follows: Mg 0.94%; Si 0.65%; Cu 0.30%; Cr 0.15%; Mn 0.08%; Ti 0.13%; Zr 0.05%; other unavoidable impurities: Fe <0.30%; Zn <0.20%, etc., with the balance being Al.

[0103] (1) Weigh the required raw materials according to the alloy composition design requirements. Al, Mg and Cu are added in the form of pure metals with a purity greater than 99.7%, while Si, Mn, Cr, Zr and Ti are added in the form of intermediate alloys.

[0104] (2) When all the raw materials have melted and the melt temperature is 735°C, the refining process is carried out. After removing the surface slag, the melt is allowed to settle and stand for 30 minutes so that the aluminum liquid inclusions can be separated and the aluminum melt can be further purified.

[0105] (3) When the melt temperature is 720℃, the aluminum liquid enters the casting pan after online degassing and filtration, and the casting speed is 85mm / min, and aluminum alloy rods with a diameter of 254mm are cast.

[0106] (4) Homogenize the casting rod at a temperature of 565℃ for 8 hours and cool it to room temperature with strong air.

[0107] (5) Heat the aluminum alloy cast rod to 480°C and feed it into the extruder. The extrusion speed is 4-5 mm / s. Use air cooling to obtain the rod-shaped bar.

[0108] (6) The obtained bar is subjected to solution treatment at a temperature of 535°C for 2.5 hours, an aging temperature of 175°C for 6 hours, and then cooled to obtain the 6061 bar.

[0109] The performance of the aluminum alloy bars in this comparative example was tested, and the results are shown in Table 6.

[0110] Table 6. Alloy properties of Comparative Example 1

[0111]

[0112] Comparative Example 2:

[0113] This comparative example describes a high-performance modified aluminum alloy material and its processing method. The composition and mass percentage of each component are as follows: Mg 0.95%; Si 0.60%; Cu 0.30%; Cr 0.15%; Mn 0.08%; Ti 0.12%; La & Ce 0.06%; other unavoidable impurities: Fe <0.30%; Zn <0.20%, etc., with the balance being Al.

[0114] (1) Weigh the required raw materials according to the alloy composition design requirements. Al, Mg and Cu are added in the form of pure metals with a purity greater than 99.7%, while Si, Mn, Cr, Zr and Ti are added in the form of intermediate alloys.

[0115] (2) When all the raw materials have melted and the melt temperature is 730°C, the refining process is carried out. After removing the surface slag, the melt is allowed to settle and stand for 30 minutes so that the aluminum liquid inclusions can be separated and the aluminum melt can be further purified.

[0116] (3) When the melt temperature is 720℃, the aluminum liquid enters the casting pan after online degassing and filtration, and the casting speed is 85mm / min, and aluminum alloy rods with a diameter of 254mm are cast.

[0117] (4) Homogenize the casting rod at a temperature of 565℃ for 8 hours and cool it to room temperature with strong air.

[0118] (5) Heat the aluminum alloy cast rod to 485°C and feed it into the extruder. The extrusion speed is (4-5) mm / s. Use air cooling to obtain the rod-shaped bar.

[0119] (6) The obtained bar is subjected to solution treatment at a temperature of 535°C for 2.5 hours, an aging temperature of 175°C for 6 hours, and then cooled to obtain the 6061 bar.

[0120] The performance of the aluminum alloy bars in this comparative example was tested, and the results are shown in Table 7.

[0121] Table 7. Alloy properties of Comparative Example 2

[0122]

[0123] Comparative Example 3:

[0124] This comparative example describes a high-performance modified aluminum alloy material and its processing method. The composition and mass percentage of each component are as follows: Mg 0.90%; Si 0.70%; Cu 0.30%; Cr 0.20%; Mn 0.15%; Ti 0.12%; Zr 0.03%; La & Ce 0.04%; other unavoidable impurities: Fe < 0.30%; Zn < 0.20%, etc., with the balance being Al.

[0125] (1) Weigh the required raw materials according to the alloy composition design requirements. Al, Mg and Cu are added in the form of pure metals with a purity greater than 99.7%, while Si, Mn, Cr, Zr and Ti are added in the form of intermediate alloys.

[0126] (2) When all the raw materials have melted and the melt temperature is 730°C, the refining process is carried out. After removing the surface slag, the melt is allowed to settle and stand for 30 minutes so that the aluminum liquid inclusions can be separated and the aluminum melt can be further purified.

[0127] (3) When the melt temperature is 720℃, the aluminum liquid enters the casting pan after online degassing and filtration, and the casting speed is 85mm / min, and aluminum alloy rods with a diameter of 254mm are cast.

[0128] (4) Homogenize the casting rod at a temperature of 565℃ for 8 hours and cool it to room temperature with strong air.

[0129] (5) Heat the aluminum alloy cast rod to 485°C and feed it into the extruder. The extrusion speed is (4-5) mm / s. Use air cooling to obtain the rod-shaped bar.

[0130] (6) The obtained bar is subjected to solution treatment at a temperature of 535°C for 2.5 hours, an aging temperature of 175°C for 6 hours, and then cooled to obtain the 6061 bar.

[0131] The performance of the aluminum alloy bars in this comparative example was tested, and the results are shown in Table 8.

[0132] Table 8. Properties of alloys in Comparative Example 3

[0133]

[0134] Comparative Example 4:

[0135] This comparative example describes a high-performance modified aluminum alloy material and its processing method. The composition and mass percentage of each component are as follows: Mg 1.10%; Si 0.58%; Cu 0.30%; Cr 0.13%; Mn 0.07%; Ti 0.12%; Zr 0.03%; La & Ce 0.03%; other unavoidable impurities: Fe < 0.30%; Zn < 0.20%, etc., with the balance being Al.

[0136] (1) Weigh the required raw materials according to the alloy composition design requirements. Al, Mg and Cu are added in the form of pure metals with a purity greater than 99.7%, while Si, Mn, Cr, Zr and Ti are added in the form of intermediate alloys.

[0137] (2) When all the raw materials have melted and the melt temperature is 730°C, the refining process is carried out. After removing the surface slag, the melt is allowed to settle and stand for 30 minutes so that the aluminum liquid inclusions can be separated and the aluminum melt can be further purified.

[0138] (3) When the melt temperature is 720℃, the aluminum liquid enters the casting pan after online degassing and filtration, and the casting speed is 85mm / min, and aluminum alloy rods with a diameter of 254mm are cast.

[0139] (4) Homogenize the casting rod at a temperature of 565℃ for 8 hours and cool it to room temperature with strong air.

[0140] (5) Heat the aluminum alloy cast rod to 485°C and feed it into the extruder. The extrusion speed is (4-5) mm / s. Use air cooling to obtain the rod-shaped bar.

[0141] (6) The obtained bar is subjected to solution treatment at a temperature of 535°C for 2.5 hours, an aging temperature of 175°C for 6 hours, and then cooled to obtain the 6061 bar.

[0142] The performance of the aluminum alloy bars in this comparative example was tested, and the results are shown in Table 9.

[0143] Table 9. Alloy Properties of Comparative Example 4

[0144]

[0145] Tensile strength of alloy properties in Examples 1-5 and Comparative Examples 1-4 R m Specified plastic elongation strength R p0.2 Elongation after fracture A Measured using a universal tensile testing machine.

[0146] Comparing the alloy properties of Examples 1-5 and Comparative Examples 1-4, it can be seen that the alloy materials in Examples 1-5 all meet the tensile strength requirement. R m ≥390MPa, specified plastic elongation strength R p0.2 ≥340 MPa, elongation after fracture A ≥12.5%. Compared to Comparative Examples 1-4, the strength of Examples 1-5 is significantly improved, and the plasticity does not decrease due to the increase in strength. This indicates that the composite addition of reinforcing elements can play a synergistic role in improving performance, meeting the performance requirements of high-performance sports equipment and transportation. On the other hand, this 6061 aluminum alloy material of the present invention has excellent fatigue resistance in extruded products. After customer processing and testing, the fatigue resistance of the products is improved by 100%, making it suitable for the material requirements of more industries.

[0147] Example 1 is a preferred embodiment of the present invention, and its chemical composition and processing technology meet the requirements of the present invention.

[0148] Compared with Comparative Example 1, the tensile strength of the material in Example 1 is significantly higher than that in Comparative Example 1. The difference lies in the addition of 0.09% La+Ce mixed rare earth element in Example 1. Compared with Comparative Example 2, the tensile strength of the material in Example 1 is significantly higher than that in Comparative Example 2. The difference lies in the addition of 0.08% Zr in Example 1. This indicates that the composite addition of Zr and La&Ce mixed rare earth element has a significant synergistic effect on enhancing the material's properties.

[0149] Compared with Comparative Example 3, Examples 1 and 2 show significant differences in material properties. The difference lies in the higher content of the composite addition of Cr, Ti, Zr, La & Ce mixed rare earth elements, and the fact that the Mg / Si ratio in Comparative Example 3 does not satisfy 1.35 ≤ Mg / Si ≤ 1.73. A small amount of excess silicon can participate in the synergistic strengthening process of elements in the material, thereby improving the performance of the aluminum alloy material.

[0150] Compared with Comparative Example 4, Examples 1 and 4 show that the content of Cr and Mn elements in Comparative Example 4 is too low, failing to meet the requirement of wt.%Fe ≤ wt.%Mn + wt.%Cr, and the Mg / Si ratio does not meet the requirement of 1.35 ≤ Mg / Si ≤ 1.73. In contrast, Examples 1 and 4 contain more Cr, Ti, Zr, La & Ce mixed rare earth elements. The Cr and Mn elements in the material can not only increase the recrystallization temperature and refine the grain structure, but also play a role in spheroidizing the iron phase, reducing the needle-like iron phase that may exist in the structure due to excessive Fe impurities, improving the microstructure, and enhancing the strength and toughness of the structure.

[0151] Figure 1 The image shows the scanning electron microscope (SEM) results of the tensile fracture surface of Example 1. The image reveals a uniformly distributed, finely dispersed strengthening phase. Due to the addition of alloying elements such as Cr 0.24%, Mn 0.12%, Ti 0.12%, Zr 0.08%, and La & Ce 0.09% in Example 1, through innovative composite microalloying of Ti, Cr, Mn, Zr, and La & Ce rare earth elements, in addition to the original Mg2Si, Ti and Zr respectively form Al3Ti and Al3Zr phases. When the La & Ce rare earth content is close to 0.1%, it forms a fine Al3(La,Ce) phase, while Mn and Cr form Al6Mn and Al7Cr phases. These dispersed phases, combined with the Mg2Si phase, increase the multiphase synergistic strengthening effect of the material, thereby improving the upper limit of its mechanical properties.

[0152] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0153] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A processing method for a high-performance modified aluminum alloy material, characterized in that, High-performance modified aluminum alloy materials comprise the following components by mass percentage: Mg (0.95–1.03)%; Si (0.63–0.68)%; Cu (0.28–0.30)%; Cr (0.15–0.25)%; Mn (0.08–0.15)%; Ti (0.08–0.15)%; Zr (0.04–0.10)%; La + Ce (0.04–0.10)%; and unavoidable impurities: Fe < 0.30%; Zn < 0.20%, with the balance being Al. Includes the following steps: S1: Smelting and refining: According to the mass percentage of each chemical element in the alloy, preheated Al-Mn, Al-Cr, Al-Ti, Al-Zr and La&Ce master alloys are added sequentially to the aluminum liquid at (730~750)℃. After one refining, pure Mg ingots and copper wires are added. The smelting is assisted by stirring, and liquid refining and powder spraying refining are combined. The slag is removed and the mixture is allowed to stand. S2: Casting: The aluminum liquid is cast at a temperature of (720~730)℃ and a DC casting traction speed of (80~90)mm / min to produce aluminum alloy cast rods for extrusion. S3: Homogenization treatment: The aluminum alloy casting rod is rapidly heated and held at (560~580)℃ for (6~10)h to carry out homogenization treatment, with a cooling rate ≥250℃ / h; S4: Extrusion processing: After surface treatment of aluminum alloy cast rods, they are heated to (460~480)℃ and extruded at an extrusion speed of (4~5)mm / s, and air-cooled to obtain rod-shaped rods; S5: Heat treatment: The bar is subjected to T6 heat treatment, with a solution temperature of (530~545)℃ and a holding time of (1.5~2.5)h; an aging temperature of (175~190)℃ and a holding time of (4~7)h; after solution treatment, it is water quenched, with the water temperature controlled at (20~40)℃ before quenching and a transfer time ≤15s, to obtain the final aluminum bar product.

2. The processing method for a high-performance modified aluminum alloy material according to claim 1, characterized in that, The mass percentage of Mg and Si elements is set to 1.35 ≤ Mg / Si ≤ 1.

73.

3. The processing method for a high-performance modified aluminum alloy material according to claim 1, characterized in that, The mass percentages of Mg, Si, and Cu elements are set to 1.90% ≤ wt.%Si + wt.%Mg + wt.%Cu ≤ 2.05%.

4. The processing method for a high-performance modified aluminum alloy material according to claim 1, characterized in that, The mass percentages of Zr and Ti elements are set to wt.%Zr ≤ wt.%Ti.

5. The processing method for a high-performance modified aluminum alloy material according to claim 1, characterized in that, The Fe content in the unavoidable impurities, by mass percentage, satisfies wt.%Fe ≤ wt.%Mn + wt.%Cr.

6. The processing method for a high-performance modified aluminum alloy material according to claim 1, characterized in that, By mass percentage, it satisfies 0.15% ≤ wt.%Ti + wt.%Zr ≤ 0.25%.

7. The processing method for a high-performance modified aluminum alloy material according to claim 1, characterized in that, In step S1, the mixture is thoroughly refined twice with a refining agent, each time for (25-35) min.

8. The processing method for a high-performance modified aluminum alloy material according to claim 1, characterized in that, In step S3, the homogenization process employs a two-stage heating process: the first stage heats the temperature to 450°C at a rate of (50-100)°C / h, and the second stage heats the temperature to (560-580)°C at a rate of (100-150)°C / h.

9. The processing method for a high-performance modified aluminum alloy material according to claim 1, characterized in that, In step S4, the preheating temperature of the extrusion die is (430~450)℃, and the temperature of the extrusion cylinder is (420~440)℃.

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