Preparation method of high-strength and high-conductivity 6101 aluminum alloy through rolling and heat treatment

Abstract

This invention discloses a method for preparing high-strength, high-conductivity 6101 aluminum alloy through rolling and heat treatment, belonging to the field of aluminum alloy material processing and heat treatment technology. The steps include: preparing an ingot by melting raw materials containing 0.37-0.42% Si and 0.42-0.52% Mg according to a specific ratio; homogenizing the ingot at 520-540℃ for 7-8 hours; hot-rolling and cold-rolling the ingot sequentially, with the total deformation during cold rolling strictly controlled to 50%; performing flash solution treatment at 510-520℃ for only 30 seconds to 1 minute, followed by room temperature water quenching; and finally aging at 190℃ for 10-14 hours. This invention overcomes the defect of traditional long-term solution treatment leading to recrystallization and softening of the deformed structure. It utilizes large deformation energy storage to drive rapid solute re-dissolution during flash solution treatment, while avoiding complete recrystallization, preserving the strengthening effect of the deformed substructure, and combining this with long-term aging to purify the matrix lattice, breaking the seesaw effect between strength and conductivity. The resulting sheet has a tensile strength ≥140.4MPa and a conductivity ≥61.4%IACS, making it suitable for conductive components in new energy vehicles, photovoltaic and energy storage systems.

Description

Technical Field

[0001] This invention belongs to the field of aluminum alloy material processing and heat treatment technology, specifically relating to a method for preparing high-strength, high-conductivity 6101 aluminum alloy by rolling and heat treatment, which is particularly suitable for manufacturing high-performance aluminum alloy materials for electrical connection busbars of new energy vehicles, conductive frames of photovoltaic solar panels, and conductive components of battery energy storage systems. Background Technology

[0002] 6101 aluminum alloy, an Al-Mg-Si system, possesses low density, good electrical conductivity, excellent formability, and moderate production cost, making it a high-conductivity, medium-strength electrical aluminum material specifically designed for the power and new energy industries. In recent years, the rapid development of green energy industries such as new energy vehicles, large-capacity battery storage, and solar photovoltaics has placed extremely stringent demands on the comprehensive performance of high-current transmission networks and electrical connection components. Due to the global shortage of copper resources and the need for lightweight design, replacing copper with aluminum has become an inevitable trend in the field of conductive materials.

[0003] However, in the physical metallurgy of aluminum alloys, electrical conductivity and mechanical strength have always been a difficult contradiction to reconcile. According to the classic Matheson's rule, although microscopic defects such as solid solution atoms, grain boundaries, dislocations, and precipitates in the alloy can significantly hinder dislocation movement and thus improve the alloy's strength (i.e., the strengthening effect), they also produce strong electron scattering, leading to a shortening of the electron mean free path and consequently a significant reduction in the material's electrical conductivity.

[0004] In existing technologies, traditional 6101 aluminum alloys typically employ a process route of homogenization, extrusion or hot rolling, cold rolling, solution treatment, and artificial aging. To achieve high conductivity, solution treatment and aging are necessary to induce the complete precipitation of Mg and Si elements; while to obtain high strength, it is usually necessary to rely on cold deformation such as cold rolling to introduce a large number of dislocations for strengthening, or to achieve solid solution strengthening by adding trace alloying elements. However, in actual industrial production, existing technologies generally suffer from the following fatal defects and shortcomings: First, traditional solution treatment processes completely eliminate the work-hardening effect, limiting the upper limit of strength. In existing heat treatment systems, to ensure that alloy phases such as Mg and Si fully dissolve back into the aluminum matrix, those skilled in the art generally agree that a sufficiently long solution treatment holding time is necessary. For example, in the published Chinese invention patent CN117265348B, the solution temperature is 545℃ and the solution treatment holding time is as long as 45 minutes; similarly, in conventional 6000 series aluminum alloy processing, the solution treatment time often ranges from tens of minutes to several hours. While this long holding time achieves sufficient solution of alloying elements, it inevitably leads to complete recrystallization and severe growth of matrix grains. This results in the complete elimination of the high-density dislocation network and subgrain boundaries accumulated through dozens of cold rolling passes, such as large deformation cold rolling, i.e., static recovery and recrystallization. This causes the material to lose the deformation strengthening increment brought about by cold deformation, ultimately making it difficult to break through the bottleneck in overall strength after aging.

[0005] Second, strength and conductivity are caught in a seesaw effect, making it impossible to achieve a high level of both. Due to the limitations of the aforementioned microscopic mechanisms, existing technologies often compromise one aspect for the other. For example, in Chinese invention patent CN116356184A, after hot rolling deformation and conventional solution aging heat treatment, when the tensile strength of 6101 aluminum alloy in the T62 state barely reaches 200 MPa, its conductivity drops sharply to only 58.1% IACS; while when its conductivity is aimed at 60.5% IACS, its tensile strength drops significantly to 126 MPa. Similarly, in Chinese invention patent CN119753447A, after ingot extrusion and solution aging treatment, when the tensile strength reaches 246 MPa, the conductivity is only 55.8% IACS. These existing technologies have failed to break the technical curse that high strength inevitably leads to low conductivity, and high conductivity inevitably leads to low strength.

[0006] In summary, existing 6101 aluminum alloy manufacturing processes suffer from severe physical metallurgical limitations in matching heat treatment parameters. They cannot simultaneously preserve the dislocation-strengthened structure from large deformation cold rolling while effectively controlling the Mg2Si nano-precipitates. Therefore, there is an urgent need in this field to develop a novel rolling and heat treatment synergistic process to overcome the recrystallization softening defects caused by traditional long-term solid solution treatment. This process should achieve a significant leap in tensile strength while maintaining or exceeding the existing conductivity level of ≥61% IACS, thereby meeting the urgent demand of the modern new energy industry for high-strength, high-conductivity aluminum alloy materials. Summary of the Invention

[0007] The problem this invention aims to solve is that in the existing 6101 aluminum alloy preparation process, traditional long-term solution treatment leads to complete recrystallization and softening of the cold-rolled deformation structure, causing the alloy's mechanical strength and electrical conductivity to inevitably fall into an inherent defect of a seesaw effect where one increases while the other decreases. This invention aims to provide a method for preparing high-strength, high-conductivity 6101 aluminum alloy by rolling and heat treatment. By constructing a non-equilibrium heat treatment regime, it achieves effective precipitation of alloying elements while retaining the deformation dislocation strengthening structure, thereby fundamentally breaking through the bottleneck of traditional physical metallurgy and achieving a high-level balance between tensile strength and electrical conductivity.

[0008] To address the aforementioned problems, this invention provides a method for preparing high-strength, high-conductivity 6101 aluminum alloy by rolling and heat treatment, comprising the following steps: S1. Provide alloy raw materials according to the following mass percentages and smelt them: Si 0.37-0.42%, Mg 0.42-0.52%, Cu≤0.01%, Mn≤0.01%, Cr≤0.01%, Fe≤0.15%, Zn≤0.03%, with the balance being Al and unavoidable impurities, and satisfying 1.13≤Mg / Si≤1.23, to prepare 6101 aluminum alloy ingots and cut off the head and tail milled surfaces; S2. Homogenization treatment: The billet is placed in a box furnace for homogenization treatment. The heating temperature is 520℃~540℃ and the holding time is 7h~8h. S3. Deformation and Short-Time Solution Treatment and Aging: The homogenized aluminum alloy ingot is subjected to hot rolling and cold rolling deformation in sequence, followed by solution treatment and aging treatment. The hot rolling deformation temperature is 520℃~530℃, the total hot rolling deformation is 69%~71%, and the reduction in pressure per pass accounts for 9.8%~10.2% of the total deformation. The total cold rolling deformation is strictly controlled at 50%, and the reduction in pressure per pass accounts for 15%~17% of the total deformation. The solution treatment is a short-time solution treatment, with a solution temperature of 510℃~520℃ and a solution holding time of 30s~1min, followed by room temperature water quenching. The aging treatment has an aging temperature of 190℃ and a holding time of 10h~14h, resulting in the high-strength, high-conductivity 6101 aluminum alloy rolled sheet.

[0009] Preferably, in step S3, the solution treatment time is 1 minute and the aging treatment time is 14 hours.

[0010] Preferably, in step S3, during the hot rolling deformation, the hot rolling passes are kept warm for 10 minutes; and immediately after hot rolling, the plate is placed in water to cool to room temperature before the cold rolling deformation is carried out.

[0011] Preferably, the smelting step in step S1 specifically includes: placing pure aluminum ingots in a smelting furnace and heating them to 720°C to 730°C while maintaining a constant temperature; after complete melting, adding Al-20Si master alloy to the melt under stirring and letting it stand for 10 to 15 minutes; adding Al-50Cu, Al-15Mn, Al-10Cr master alloys and pure Zn under stirring and letting it stand for 10 to 15 minutes; adding Al-10Mg master alloy to the melt under stirring and letting it stand for 10 to 15 minutes; after the above materials are completely melted, adding a degassing agent for degassing and refining, skimming off the reaction byproducts on the surface of the melt, letting it stand, and finally pouring it into a mold preheated to 250°C to cool into a billet.

[0012] Preferably, in step S2, the process parameters for the homogenization treatment are: heating temperature 530℃ and holding time 8h.

[0013] Preferably, the high-strength, high-conductivity aluminum alloy material prepared has a room temperature tensile strength ≥140.4MPa and a conductivity ≥61.4%IACS.

[0014] Preferably, the high-strength, high-conductivity aluminum alloy material is used in electrical connection components of new energy vehicles, conductive frames of photovoltaic solar panels, conductive connectors of battery energy storage systems, or conductive components of wind power generation devices.

[0015] Compared with the prior art, the present invention achieves the following beneficial technical effects: This invention overcomes the technical bottleneck of softening caused by traditional long-term solid solution treatment, achieving a perfect synergy between deformation dislocation retention and alloy element solid solution. Existing technologies generally suffer from a technical bias, believing that 6000 series aluminum alloys must undergo solid solution treatment and holding for tens of minutes or even hours to allow strengthening elements such as Mg and Si to fully dissolve. However, this invention creatively discovers that after cold rolling with a large deformation of up to 50%, an extremely high-density dislocation network and deformation energy storage accumulate within the aluminum matrix; these dense dislocations act as high-speed channels for atomic diffusion. Therefore, only a very short flash solid solution treatment of 510℃ to 520℃ (30 seconds to 1 minute) is needed to instantly and fully dissolve Mg and Si atoms using high deformation distortion energy. More importantly, due to the extremely short solid solution time, the aluminum matrix does not have time to undergo static recovery and complete recrystallization, thus perfectly preserving the subgrain boundaries and high-density dislocations generated during cold rolling. This invention cleverly utilizes the time difference between diffusion kinetics and recrystallization thermodynamics to achieve a microstructure that is unattainable by traditional processes. By coupling a non-equilibrium process involving 50% large cold rolling deformation, 30s-1min flash solution treatment, and 190℃ aging, a high-performance 6101 aluminum alloy sheet with a room temperature tensile strength ≥140.4MPa and an electrical conductivity ≥61.4%IACS was successfully prepared. This performance combination represents a qualitative leap compared to existing technologies. First, compared to the complete solution treatment path, the existing 45-minute long solution treatment process, while achieving high strength, suppresses the conductivity to a low 53.2%IACS. This invention, with only a fraction of the solution treatment time, improves the conductivity by more than 8 percentage points while maintaining comparable strength. Second, compared to the heat-free treatment path, the existing process that completely abandons solution aging, while achieving a conductivity of 61.4%IACS, cannot provide any phase transformation strengthening gain, and the strength is inevitably far inferior. This invention, while achieving the same ultra-high conductivity, still ensures a considerable tensile strength of 140.4-197.8MPa. Next, comparing with other parameter ranges of this patent, the strictly defined process window of this invention has an indisputable critical effect. As shown in Comparative Example 5, when the solution time is extended to 1 hour, although the strength soars to 257.2 MPa, the conductivity drops sharply to 58.7% IACS, indicating the failure of the technical target. As shown in Comparative Example 3, when the solution time is the same at 30 seconds but the aging time is less than 10 hours, the strength is only 197.8 MPa. However, Example 2, under the conditions of 1 minute solution treatment and 14 hours of aging, achieved the same high conductivity plateau of 61.4% IACS with a tensile strength of 179.4 MPa, proving the unique advantage of this scheme in the optimization of strength and conductivity balance.

[0016] This invention successfully breaks the seesaw effect between strength and conductivity, achieving an ultimate balance between high strength and high conductivity. The extremely short-time solution treatment combined with a long-term aging process at a specific temperature and pressure of 190℃ / 10-14h allows for heterogeneous nucleation of the supersaturated solid solution on the preserved high-density dislocation network. Numerous fine and dispersed Mg2Si nano-precipitates preferentially precipitate along the dislocation lines, providing not only extremely strong precipitation strengthening effects, superimposed with the retained dislocation strengthening, but also thoroughly purifying the aluminum matrix and greatly reducing the scattering of electrons by the matrix lattice. Experimental data conclusively confirm this unexpected effect: as shown in Example 2, the 6101 aluminum alloy prepared using the preferred process of this invention exhibits a room-temperature tensile strength as high as 179.4 MPa, while simultaneously achieving an astonishing conductivity of 61.4% IACS. In contrast, if the solution treatment time is too long, such as 20 minutes in Comparative Example 4, recrystallization leads to the loss of dislocation strengthening, causing the tensile strength to drop sharply to 158.6 MPa and the conductivity to drop to 60.1% IACS. If conventional short-time heat treatment is used without large-deformation cold rolling, such as 17% cold rolling and 1 minute solution treatment in Comparative Example 1, the tensile strength is only 129.1 MPa and the conductivity is only 59.7% IACS. This invention precisely anchors the parameter singularity, completely solving the century-old problem in the industry that high strength inevitably leads to low conductivity and high conductivity inevitably leads to low strength.

[0017] This invention, based on a non-equilibrium microstructure regulation mechanism, fundamentally resolves the contradiction between achieving both matrix purity and strengthening phase precipitation. The core innovation lies in breaking through the traditional thermodynamic equilibrium concept of complete solid solution recrystallization and employing a non-equilibrium flash solution treatment strategy. The physical metallurgical essence of its technical effect lies in: cold rolling with large deformation stores distortion energy; 50% reduction in cold rolling introduces extremely high density dislocations and substructures into the matrix, which is not only the microstructure basis for subsequent strengthening but also the driving force for the dramatic phase transformation during the flash solution stage. Flash solution achieves a precise competition between incomplete solid solution and incomplete recrystallization; within an extremely short solution window of 30s-1min at 510℃-520℃, only some coarse equilibrium phases undergo re-dissolution, providing a moderate solute supersaturation; simultaneously, the energy stored in cold rolling is only sufficient to drive recovery and limited local recrystallization, allowing a large number of subgrain boundaries and dislocation cells to be retained. This semi-finished microstructure is key to achieving balanced performance subsequently. Synergistic gains from long-term aging: During subsequent aging at 190℃ for 10-14 hours, the retained substructures act as preferred nucleation sites for precipitated phases, inducing the dispersion precipitation of strengthening phases and ensuring mechanical strength; and since the matrix never undergoes complete solid solution, its concentration of solid solution atoms is much lower than that of the quenched state in traditional processes, and the aluminum lattice maintains a relatively pure state, fundamentally suppressing the scattering of conduction electrons by solute atoms, thereby preserving an ultra-high conductivity of up to 61.4% IACS. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. Wherein: Figure 1 This is a tensile fracture diagram of Comparative Example 1; Figure 2 This is a tensile fracture diagram of Comparative Example 2; Figure 3 This is a tensile fracture diagram of Comparative Example 3; Figure 4 This is a tensile fracture diagram of Comparative Example 4; Figure 5 This is a tensile fracture diagram of Comparative Example 5; Figure 6 This is a tensile fracture diagram of Comparative Example 6; Figure 7 This is a tensile fracture diagram of Comparative Example 7; Figure 8 This is a tensile fracture diagram of Example 1; Figure 9 This is a tensile fracture diagram of Example 2; Figure 10 This is a tensile fracture diagram of Example 3; Figure 11 This is a metallographic diagram of the T62 state in Example 2; Figure 12 This is a schematic diagram of a conductivity test. Detailed Implementation

[0019] The present invention will be further explained and described below with reference to the accompanying drawings and embodiments.

[0020] In all embodiments and comparative examples of this invention, the measured composition of the 6101 aluminum alloy raw material used, by mass percentage, is as follows: Si content is 0.392%; Mg content is 0.495%; Cu content is 0.006%; Mn content is 0.005%; Cr content is 0.004%; Fe content is 0.131%; Zn content is 0.011%, with the balance being Al. This composition meets the ratio requirement of 1.13 ≤ Mg / Si ≤ 1.23.

[0021] Comparative Example 1: The above-mentioned 6101 aluminum alloy rough billet was placed in an electric resistance furnace and melted at 720℃-730℃ to obtain 6101 aluminum alloy melt. A dried impurity remover was added to the melt for degassing and refining. After removing reaction byproducts from the surface of the melt, it was allowed to stand and then poured into a mold preheated to 250℃ to form a billet. The billet was homogenized at 530℃ for 8 hours. The homogenized material was then hot-rolled at 520℃ with a total deformation of 70%, 10% deformation per pass, and a 10-minute holding time between passes. Immediately after hot rolling, the plate was water-cooled to room temperature. Cold rolling followed, with a total deformation of only 17% in a single pass. The material was then solution-aged at 520℃ for 1 minute, followed by water quenching at room temperature. The aging temperature was 190℃ for 10 hours.

[0022] A tensile sample with a thickness of 2 mm was prepared and measured. Figure 1 The tensile fracture surface diagram is shown. The mechanical properties and electrical conductivity were determined at room temperature. The tensile strength was 129.1 MPa, the elongation was 14.1%, and the electrical conductivity was 59.7% IACS.

[0023] Comparative Example 2: A rough 6101 aluminum alloy billet was melted in an electric resistance furnace at 720℃-730℃ to obtain a 6101 aluminum alloy melt. A dried impurity remover was added to the melt for degassing and refining. After removing reaction byproducts from the surface of the melt, it was allowed to stand, then poured into a mold and preheated to 250℃ to form a cast billet. The cast billet was homogenized at 530℃ for 8 hours. The homogenized material was then hot-rolled at 520℃ with a deformation rate of 70%, 10% deformation per pass, and a 10-minute holding time between passes. Immediately after hot rolling, the plate was placed in water and cooled to room temperature, followed by cold rolling with a total deformation rate of 35%, 17% deformation per pass. The material was then solution-aged at 520℃ for 1 minute, followed by water quenching at room temperature. The aging temperature was 190℃, and the holding time was 10 hours.

[0024] Tensile samples with a thickness of 2 mm were prepared using the above method and measured. (See attached image) Figure 2 The tensile fracture surface diagram is shown. The mechanical properties and electrical conductivity were measured at room temperature, and the results are as follows: tensile strength is 138.2 MPa, elongation is 13.9%, and electrical conductivity is 60.8% IACS.

[0025] Comparative Example 3: A rough 6101 aluminum alloy billet was melted in an electric resistance furnace at 720℃-730℃ to obtain a 6101 aluminum alloy melt. A dried impurity remover was added to the melt for degassing and refining. After removing reaction byproducts from the surface of the melt, it was allowed to stand, then poured into a mold and preheated to 250℃ to form a cast billet. The cast billet was homogenized at 530℃ for 8 hours. The homogenized material was then hot-rolled at 520℃ with a deformation rate of 70%, 10% deformation per pass, and a 10-minute holding time between passes. Immediately after hot rolling, the plate was placed in water and cooled to room temperature, followed by cold rolling with a total deformation rate of 50%, 17% deformation per pass. The material was then solution-aged at 520℃ for 30 seconds, followed by water quenching at room temperature. The aging temperature was 190℃, and the holding time was 10 hours.

[0026] Tensile samples with a thickness of 2 mm were prepared using the above method and measured. (See attached image) Figure 3 The tensile fracture surface diagram is shown. The mechanical properties and electrical conductivity were measured at room temperature, and the results are as follows: tensile strength is 197.8 MPa, elongation is 10.2%, and electrical conductivity is 61.1% IACS.

[0027] Comparative Example 4: A rough 6101 aluminum alloy billet was melted in an electric resistance furnace at 720℃-730℃ to obtain a 6101 aluminum alloy melt. A dried impurity remover was added to the melt for degassing and refining. After removing reaction byproducts from the surface of the melt, it was allowed to stand, then poured into a mold and preheated to 250℃ to form a cast billet. The cast billet was homogenized at 530℃ for 8 hours. The homogenized material was then hot-rolled at 520℃ with a deformation rate of 70%, 10% deformation per pass, and a 10-minute holding time between passes. Immediately after hot rolling, the plate was placed in water and cooled to room temperature, followed by cold rolling with a total deformation rate of 50%, 17% deformation per pass. The material was then solution-aged at 520℃ for 20 minutes, followed by water quenching at room temperature. The aging temperature was 190℃, and the holding time was 10 hours.

[0028] Tensile samples with a thickness of 2 mm were prepared using the above method and measured. (See attached image) Figure 4 The tensile fracture surface diagram is shown. The mechanical properties and electrical conductivity were measured at room temperature, and the results are as follows: tensile strength is 158.6 MPa, elongation is 13.1%, and electrical conductivity is 60.1% IACS.

[0029] Comparative Example 5: A rough 6101 aluminum alloy billet was melted in an electric resistance furnace at 720℃-730℃ to obtain a 6101 aluminum alloy melt. A dried impurity remover was added to the melt for degassing and refining. After removing reaction byproducts from the surface of the melt, it was allowed to stand, then poured into a mold and preheated to 250℃ to form a cast billet. The cast billet was homogenized at 530℃ for 8 hours. The homogenized material was then hot-rolled at 520℃ with a deformation rate of 70%, 10% deformation per pass, and a 10-minute holding time between passes. Immediately after hot rolling, the plate was placed in water and cooled to room temperature, followed by cold rolling with a total deformation rate of 50%, 17% deformation per pass. The material was then solution-treated and aged at 520℃ for 1 hour, followed by water quenching at room temperature. The aging temperature was 190℃, and the holding time was 8 hours.

[0030] Tensile samples with a thickness of 2 mm were prepared using the above method and measured. (See attached image) Figure 5 The tensile fracture surface diagram is shown. The mechanical properties and electrical conductivity were measured at room temperature, and the results are as follows: tensile strength is 257.2 MPa, elongation is 9.9%, and electrical conductivity is 58.7% IACS.

[0031] Comparative Example 6: A rough 6101 aluminum alloy billet was melted in an electric resistance furnace at 720℃-730℃ to obtain a 6101 aluminum alloy melt. A dried impurity remover was added to the melt for degassing and refining. After removing reaction byproducts from the surface of the melt, it was allowed to stand, then poured into a mold and preheated to 250℃ to form a cast billet. The cast billet was homogenized at 530℃ for 8 hours. The homogenized material was then hot-rolled at 520℃ with a deformation rate of 70%, 10% deformation per pass, and a 10-minute holding time between passes. Immediately after hot rolling, the plate was placed in water and cooled to room temperature, followed by cold rolling with a total deformation rate of 50%, 17% deformation per pass. The material was then solution-treated and aged at 520℃ for 1 minute, followed by water quenching at room temperature. The aging temperature was 190℃, and the holding time was 8 hours.

[0032] Tensile samples with a thickness of 2 mm were prepared using the above method and measured. (See attached image) Figure 6 The tensile fracture surface diagram is shown. The mechanical properties and electrical conductivity were measured at room temperature, and the results are as follows: tensile strength is 143.6 MPa, elongation is 13.5%, and electrical conductivity is 61.4% IACS.

[0033] Comparative Example 7: A rough 6101 aluminum alloy billet was melted in an electric resistance furnace at 720℃-730℃ to obtain a 6101 aluminum alloy melt. A dried impurity remover was added to the melt for degassing and refining. After removing reaction byproducts from the surface of the melt, it was allowed to stand, then poured into a mold and preheated to 250℃ to form a cast billet. The cast billet was homogenized at 530℃ for 8 hours. The homogenized material was then hot-rolled at 520℃ with a deformation rate of 70%, 10% deformation per pass, and a 10-minute holding time between passes. Immediately after hot rolling, the plate was placed in water and cooled to room temperature, followed by cold rolling with a total deformation rate of 50%, 17% deformation per pass. The material was then solution-aged at 520℃ for 1 minute, followed by water quenching at room temperature. The aging temperature was 230℃ for 10 hours.

[0034] Tensile samples with a thickness of 2 mm were prepared using the above method and measured. (See attached image) Figure 7 The tensile fracture surface diagram is shown. The mechanical properties and electrical conductivity were measured at room temperature, and the results are as follows: tensile strength is 139.1 MPa, elongation is 13.8%, and electrical conductivity is 60.9% IACS.

[0035] Example 1: A rough 6101 aluminum alloy billet was melted in a resistance furnace at 720℃-730℃ to obtain a 6101 aluminum alloy melt. A dried impurity remover was added to the melt for degassing and refining. After removing reaction byproducts from the surface of the melt, it was allowed to stand, then poured into a mold and preheated to 250℃ to form a cast billet. The cast billet was homogenized at 530℃ for 8 hours. The homogenized material was then hot-rolled at 520℃ with a deformation rate of 70%, 10% deformation per pass, and a 10-minute holding time between passes. Immediately after hot rolling, the plate was placed in water and cooled to room temperature, followed by cold rolling with a total deformation rate of 50%, 17% deformation per pass. The material was then solution-aged at 520℃ for 1 minute, followed by water quenching at room temperature. The aging temperature was 190℃, and the holding time was 10 hours.

[0036] Tensile samples with a thickness of 2 mm were prepared using the above method and measured. (See attached image) Figure 8 The tensile fracture surface diagram is shown. The mechanical properties and electrical conductivity were measured at room temperature, and the results are as follows: tensile strength is 140.4 MPa, elongation is 13.2%, and electrical conductivity is 61.4% IACS.

[0037] Example 2: A rough 6101 aluminum alloy billet was melted in a resistance furnace at 720℃-730℃ to obtain a 6101 aluminum alloy melt. A dried impurity remover was added to the melt for degassing and refining. After removing reaction byproducts from the surface of the melt, it was allowed to stand, then poured into a mold and preheated to 250℃ to form a cast billet. The cast billet was homogenized at 530℃ for 8 hours. The homogenized material was then hot-rolled at 520℃ with a deformation rate of 70%, 10% deformation per pass, and a 10-minute holding time between passes. Immediately after hot rolling, the plate was placed in water and cooled to room temperature, followed by cold rolling with a total deformation rate of 50%, 17% deformation per pass. The material was then solution-aged at 520℃ for 1 minute, followed by water quenching at room temperature. The aging temperature was 190℃, and the holding time was 14 hours.

[0038] Tensile samples with a thickness of 2 mm were prepared using the above method and measured. (See attached image) Figure 9 The tensile fracture surface diagram is shown. The mechanical properties and electrical conductivity were measured at room temperature, and the results are as follows: tensile strength is 179.4 MPa, elongation is 10.5%, and electrical conductivity is 61.4% IACS.

[0039] Example 3: A rough 6101 aluminum alloy billet was melted in a resistance furnace at 720℃-730℃ to obtain a 6101 aluminum alloy melt. A dried impurity remover was added to the melt for degassing and refining. After removing reaction byproducts from the surface of the melt, it was allowed to stand, then poured into a mold and preheated to 250℃ to form a cast billet. The cast billet was homogenized at 530℃ for 8 hours. The homogenized material was then hot-rolled at 520℃ with a deformation rate of 70%, 10% deformation per pass, and a 10-minute holding time between passes. Immediately after hot rolling, the plate was placed in water and cooled to room temperature, followed by cold rolling with a total deformation rate of 50%, 17% deformation per pass. The material was then solution-aged at 520℃ for 1 minute, followed by water quenching at room temperature. The aging temperature was 210℃ for 10 hours.

[0040] Tensile samples with a thickness of 2 mm were prepared using the above method and measured. (See attached image) Figure 10 The tensile fracture surface diagram is shown. The mechanical properties and electrical conductivity were measured at room temperature, and the results are as follows: tensile strength is 168.6 MPa, elongation is 10.7%, and electrical conductivity is 60.6% IACS.

[0041] As can be seen from Comparative Examples 1-7 and Examples 1-3, the preferred rolling and heat treatment process is as follows: hot rolling temperature 520℃, deformation amount 70%, deformation per pass 10%, holding time 10 min between passes; cold rolling total deformation amount 50%, deformation per pass 17%, solution treatment temperature 520℃, holding time 1 min; aging temperature 190℃, holding time 14 h. The 6101 aluminum alloy treated by this rolling and heat treatment process has a tensile strength of 179.4 MPa, an elongation of 10.5%, and an electrical conductivity of 61.4% IACS, showing a relatively good balance between strength and electrical conductivity.

[0042] Table 1. Effects of different rolling and heat treatment processes on the mechanical properties and electrical conductivity of 6101 aluminum alloy. Comparative Example 1 129.1 14.1 59.7 Comparative Example 2 138.2 13.9 60.8 Comparative Example 3 197.8 10.2 61.1 Comparative Example 4 158.6 13.1 60.1 Comparative Example 5 257.2 9.9 58.7 Comparative Example 6 143.6 13.5 61.4 Comparative Example 7 139.1 13.8 60.9 Example 1 140.4 13.2 61.4 Example 2 179.4 10.5 61.4 Example 3 168.6 10.7 60.6 The data in Table 1 clearly and irrefutably demonstrate the criticality of the process parameter combination of 50% cold rolling deformation, 30s-1min short-time solution treatment, and 190℃ long-time aging as defined in this invention, and the unexpected technical effects it brings: The critical effect of solution treatment time and the decisive role of the flash solution window: When the cold rolling deformation is fixed at 50% and the aging regime is fixed at 190℃×10h, the alloy properties change drastically simply by changing the solution treatment holding time. Comparative Example 3 achieved a high strength of 197.8MPa and a high conductivity of 61.1% IACS after 30s of solution treatment; Example 1 maintained a high conductivity of 61.4% IACS while also possessing good strength after 1min of solution treatment. However, once the solution time exceeds the 1-minute limit set by this invention, the performance deteriorates rapidly: in Comparative Example 4, when the solution time was extended to 20 minutes, the tensile strength plummeted to 158.6 MPa due to significant recrystallization and softening, and the conductivity also dropped to 60.1% IACS; in Comparative Example 5, when the solution time was further extended to 1 hour, although the alloy achieved an extremely high strength of 257.2 MPa due to sufficient solution and subsequent aging precipitation, its conductivity collapsed to 58.7% IACS, indicating that the goal of achieving both high strength and high conductivity pursued by this invention has completely failed.

[0043] The fundamental role of cold rolling deformation: Comparing Comparative Example 1 (17%), Comparative Example 2 (35%), and Example 1 (50%) cold rolling, it is evident that, under the condition that the solution treatment time is 1 minute, only a large deformation of 50% can provide sufficient deformation energy for flash solution treatment, thereby completing the re-dissolution of necessary solute atoms in an ultra-short time and preserving sufficient substructure to support subsequent mechanical properties. Insufficient deformation will result in excessively low final strength, failing to achieve the performance objectives of this invention.

[0044] Optimization and Synergy of Aging Systems: Under the conditions of a fixed solution treatment time of 1 minute and a fixed cold rolling deformation of 50%, a comparison between Comparative Example 6 (190℃×8h) and Examples 1 (190℃×10h) and 2 (190℃×14h) shows that using a lower temperature of 190℃ combined with a longer holding time of 10h-14h is the preferred path to achieve a high level of balance between strength and conductivity. Comparative Example 7 (230℃×10h), due to its excessively high aging temperature, tends to coarsen the precipitated phase, weakening the strengthening effect and resulting in poor strength performance.

[0045] In summary, the technical solution protected by this invention is precisely anchored on the singularity of physical metallurgical parameters that can break the traditional inverse relationship between strength and conductivity, namely 50% cold rolling deformation, 30s-1min flash solution treatment, and 190℃ / 10h-14h aging. The resulting comprehensive performance with tensile strength ≥140.4MPa and conductivity ≥61.4%IACS is something that no prior art prior to the application date has taught, suggested, or achieved.

[0046] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing high-strength, high-conductivity 6101 aluminum alloy by rolling and heat treatment, characterized in that, Includes the following steps: S1. Provide alloy raw materials according to the following mass percentages and smelt them: Si 0.37-0.42%, Mg 0.42-0.52%, Cu≤0.01%, Mn≤0.01%, Cr≤0.01%, Fe≤0.15%, Zn≤0.03%, with the balance being Al and unavoidable impurities, and satisfying 1.13≤Mg / Si≤1.23, to prepare 6101 aluminum alloy ingots and cut off the head and tail milled surfaces; S2. Homogenization treatment: The billet is placed in a box furnace for homogenization treatment. The heating temperature is 520℃~540℃ and the holding time is 7h~8h. S3. Deformation and Short-Time Solution Treatment and Aging: The homogenized aluminum alloy ingot is subjected to hot rolling and cold rolling deformation in sequence, followed by solution treatment and aging treatment. The hot rolling deformation temperature is 520℃~530℃, the total hot rolling deformation is 69%~71%, and the reduction in pressure per pass accounts for 9.8%~10.2% of the total deformation. The total cold rolling deformation is strictly controlled at 50%, and the reduction in pressure per pass accounts for 15%~17% of the total deformation. The solution treatment is a short-time solution treatment, with a solution temperature of 510℃~520℃ and a solution holding time of 30s~1min, followed by room temperature water quenching. The aging treatment has an aging temperature of 190℃ and a holding time of 10h~14h, resulting in the high-strength, high-conductivity 6101 aluminum alloy rolled sheet.

2. The preparation method of high-strength, high-conductivity 6101 aluminum alloy by rolling and heat treatment according to claim 1, characterized in that, In step S3, the solution treatment time is 1 minute and the aging treatment time is 14 hours.

3. The method for preparing high-strength, high-conductivity 6101 aluminum alloy by rolling and heat treatment according to claim 1 or 2, characterized in that, In step S3, during the hot rolling deformation, the hot rolling passes are kept warm for 10 minutes; and immediately after hot rolling, the plate is placed in water to cool to room temperature before the cold rolling deformation is carried out.

4. The preparation method of high-strength, high-conductivity 6101 aluminum alloy by rolling and heat treatment according to claim 1, characterized in that, The smelting steps described in step S1 specifically include: placing pure aluminum ingots in a smelting furnace and heating them to 720℃~730℃ while maintaining a constant temperature. After complete melting, Al-20Si master alloy is added to the melt under stirring and allowed to stand for 10~15 minutes; under stirring, Al-50Cu, Al-15Mn, Al-10Cr master alloys and pure Zn are added and allowed to stand for 10~15 minutes; under stirring, Al-10Mg master alloy is added to the melt and allowed to stand for 10~15 minutes; after the above materials are completely melted, a degassing agent is added for degassing and refining, and after removing the reaction byproducts from the surface of the melt, it is allowed to stand. Finally, it is poured into a mold preheated to 250℃ and cooled to form a billet.

5. The method for preparing high-strength, high-conductivity 6101 aluminum alloy by rolling and heat treatment according to claim 1, characterized in that, In step S2, the process parameters for the homogenization treatment are: heating temperature 530℃ and holding time 8h.

6. The method for preparing high-strength, high-conductivity 6101 aluminum alloy by rolling and heat treatment according to any one of claims 1 to 5, characterized in that, The high-strength, high-conductivity aluminum alloy material prepared has a room temperature tensile strength ≥140.4MPa and a conductivity ≥61.4%IACS.

7. The application of the high-strength, high-conductivity 6101 aluminum alloy rolled sheet according to claim 6 in electrical connection components, characterized in that, The high-strength, high-conductivity aluminum alloy material is used in electrical connection components of new energy vehicles, conductive frames of photovoltaic solar panels, conductive connectors of battery energy storage systems, or conductive components of wind power generation devices.

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