High-strength heat-resistant high-conductivity aluminum alloy conductor and method of manufacturing the same

Abstract

This invention relates to a high-strength, heat-resistant, and highly conductive aluminum alloy conductor and its preparation method. The high-strength, heat-resistant aluminum alloy conductor material, by weight percentage, comprises the following components: Zr 0.05–0.30%, Fe 0.05–0.35%, Si 0.05–0.25%, B 0.02–0.05%, Al 99.05% to 99.83%, and the content of other individual impurity elements is less than 0.03%, with a total impurity element content of less than 0.1%. The microstructure of the conductor material contains a Zr-containing nanoscale dispersed reinforcing phase precipitated in situ during processing. The method includes: S1. Batching and smelting: preparing raw materials according to the chemical composition ratio and smelting to obtain an aluminum alloy melt; S2. Continuous casting: continuously casting the aluminum alloy melt to obtain an aluminum alloy rod blank; S3. Continuous large deformation processing: continuously rolling and / or drawing the aluminum alloy rod blank to obtain an aluminum alloy monofilament; S4. Controlled cooling: controlling the cooling of the aluminum alloy monofilament obtained in step S3; the Zr nanoscale dispersed strengthening phase precipitates in situ during the continuous large deformation processing and / or controlled cooling process.

Description

Technical Field

[0001] This invention belongs to the field of conductive metal materials technology, specifically relating to a high-strength heat-resistant aluminum alloy conductor material suitable for high-temperature environments such as automotive high-voltage cables and power battery harnesses, as well as composite conductors containing this material, stranded wires, and their preparation methods. Background Technology

[0002] In the fields of power transmission, rail transportation, new energy vehicles, and special electrical equipment, comprehensive performance requirements for conductor materials have been put forward, including high strength, high conductivity, and heat resistance. Although pure aluminum conductors have excellent conductivity and are lightweight, their strength, especially high-temperature strength, is insufficient, which limits their widespread application in high-temperature areas such as engine compartments and high-voltage cables.

[0003] To improve the strength of aluminum alloys, existing technologies often add copper (Cu), magnesium (Mg), and rare earth elements (RE) to enhance mechanical properties through solid solution strengthening or precipitation strengthening. However, while these elements improve strength, they often significantly impair electrical conductivity, and their reliance on expensive elements leads to increased costs and complex processes. Another strengthening approach is to add zirconium (Zr) to the aluminum matrix, achieving dispersion strengthening by forming Al3Zr nanoprecipitates. This improves both strength and recrystallization temperature, giving the material good heat resistance. However, the addition of Zr presents two technical contradictions: Firstly, while the Al3Zr precipitate hinders dislocation movement and increases strength, it also hinders the directional movement of electrons, leading to increased resistivity and decreased conductivity. Secondly, in order to promote the full diffusion of Zr and the formation of fine and dispersed reinforcing phases, traditional processes rely on long-term high-temperature solid solution and aging treatment. This high heat input process is not only energy-intensive and has a long process, but it is also prone to induce grain coarsening and harmful phase aggregation, which in turn damages the final performance of the material.

[0004] Furthermore, while existing technologies such as the high-strength aluminum alloy disclosed in CN202010270750 exhibit high strength, they do not address heat resistance and rely on expensive elements such as Cu, Mg, and RE. Although CN202210299626 introduces Zr to improve heat resistance, it still requires the addition of rare earth elements, resulting in poor synergy, high cost, and poor process compatibility. Therefore, how to achieve a synergistic optimization of high strength, high conductivity, and excellent heat resistance without the need for precious metals, while simplifying the manufacturing process and reducing energy consumption, has become a pressing technical challenge in this field. Summary of the Invention

[0005] This invention aims to solve the problems of significant strength decay of existing aluminum alloy conductor materials under high temperature environment, dependence on precious metal elements, difficulty in achieving both high strength and high conductivity, and long process flow and high energy consumption. It provides a high-strength heat-resistant aluminum alloy conductor material without Cu, Mg and rare earth elements and a short process preparation method, achieving synergistic optimization of strength, conductivity and heat resistance.

[0006] The first technical solution of this invention is the high-strength, heat-resistant, and high-conductivity aluminum alloy conductor, characterized in that, by weight percentage, its chemical composition consists of the following components: Zr 0.05–0.30%, Fe 0.05–0.35%, Si 0.05–0.25%, B 0.02–0.05%, Al 99.05% to 99.83%, and the content of other individual impurity elements is less than 0.03%, with a total impurity element content of less than 0.1%. The microstructure of the conductor material contains a Zr-containing nanoscale dispersed strengthening phase precipitated in situ during processing. By explicitly limiting the aluminum content to 99.05% to 99.83%, and combining this with specific ranges for Zr, Fe, Si, and B, as well as strict impurity control, this invention ensures that the total alloy composition is 100%, thereby guaranteeing the feasibility and industrial reproducibility of the technical solution.

[0007] Preferably, its chemical composition by weight percentage is: Zr 0.10-0.25%, Fe 0.10-0.25%, Si 0.08-0.20%, B 0.02-0.05%, and Al 99.25% to 99.70%; the Zr-containing nanoscale dispersed reinforcing phase is the Al3Zr phase.

[0008] Preferably, the conductor material is in the form of a single filament with a functional composite layer on its surface; the functional composite layer is an Al2O3 ceramic layer generated in situ on the surface of the single filament by micro-arc oxidation or anodic oxidation.

[0009] The second technical solution of the present invention is the composite conductor, characterized in that it comprises: a conductor core made of a high-conductivity aluminum alloy; and a high-strength heat-resistant layer covering the outer periphery of the conductor core, wherein the material of the high-strength heat-resistant layer is the aforementioned high-strength heat-resistant aluminum alloy conductor material; the conductor core and the high-strength heat-resistant layer are integrally bonded by co-extrusion molding. The conductor material is in the form of a monofilament, and its surface has a functional composite layer; the functional composite layer is preferably an Al2O3 ceramic layer generated in situ on the surface of the monofilament by micro-arc oxidation or anodizing.

[0010] Preferably, the high conductivity aluminum alloy is a microalloyed aluminum alloy, and its Fe and Si contents are lower than those in the high strength heat-resistant layer material.

[0011] The third technical solution of the present invention is the method for preparing a high-strength, heat-resistant, and highly conductive aluminum alloy conductor as described in any of the preceding claims, characterized in that the method comprises the following steps in sequence: S1. Batching and smelting: Prepare raw materials according to the aforementioned chemical composition ratio, and smelt to obtain aluminum alloy melt; S2. Continuous casting: The aluminum alloy melt is continuously cast to obtain an aluminum alloy rod billet; S3. Continuous large deformation processing: The aluminum alloy rod blank is continuously rolled and / or drawn to obtain aluminum alloy single wire; S4. Controlled cooling: The aluminum alloy monofilament obtained in step S3 is subjected to controlled cooling; The method does not include a separate solution treatment process and a separate aging treatment process. The Zr-containing nanoscale dispersed strengthening phase is precipitated in situ during the continuous large deformation processing and / or the controlled cooling process.

[0012] Preferably, during the continuous large deformation processing described in step S3, the strain field exhibits periodic changes; the periodic changes in the strain field are achieved by employing at least one of asynchronous rolling or periodic reversing drawing.

[0013] Preferably, the continuous large deformation processing described in step S3 is carried out in a temperature gradient field; the processing includes deformation in a first temperature range of 300°C to 350°C during a first time period, and short-term heat preservation for a duration of seconds in a second temperature range of 400°C to 450°C during a subsequent second time period.

[0014] Preferably, the controlled cooling in step S4 adopts a staged cooling method, including: first cooling the aluminum alloy monofilament to a first temperature at a first cooling rate; then holding it at a temperature range of 200°C to 300°C for a short time to induce the fine dispersion precipitation of Fe-rich phase and / or Si-rich phase; and then cooling it to room temperature at a second cooling rate.

[0015] The fourth technical solution of the present invention is the high-strength heat-resistant aluminum alloy stranded wire, which is special in that it is made of multiple single wires made of the aforementioned high-strength heat-resistant aluminum alloy conductor material twisted together; the twisting process is carried out in an environment filled with a pressure medium, which is an inert gas or liquid.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) This invention creatively employs a gradient composite structure, dividing the conductor into a core and an outer layer with distinct functions. The core uses a high-purity, low-alloy composition with very few internal defects and solute atoms, providing a low-scattering environment for electron transport and thus ensuring excellent conductivity of the entire conductor. The outer layer is specifically responsible for bearing mechanical loads and meeting heat resistance requirements. The zirconium element contained within it forms an Al3Zr dispersed phase during subsequent processing, which effectively pins dislocations and grain boundaries, significantly improving the material's strength and high-temperature stability. This locally optimal design of "conductive core and tough outer layer" resolves the contradiction between increased strength and decreased conductivity at the structural root, achieving an excellent balance between high conductivity (≥57% IACS) and high strength (≥135 MPa).

[0017] (2) This invention abandons the traditional long-duration high-temperature solution treatment and aging process, and instead adopts a short-process thermo-mechanical coupling process. By completing the main deformation in the low-temperature range (300℃~350℃), the initial grains are effectively refined and a large amount of deformation energy is accumulated. The subsequent instantaneous high-temperature (400℃~450℃) dynamic aging treatment utilizes the additional driving force provided by this deformation energy for atomic diffusion, promoting the rapid diffusion of zirconium atoms and forming a fine, dispersed Al3Zr strengthening phase. The process requires an extremely short time (on the order of seconds), which not only significantly reduces energy consumption and simplifies the process, but also avoids the grain coarsening problem caused by prolonged high-temperature exposure, achieving efficient strengthening under low heat input. Tests show that the strength retention rate of the material of this invention can reach more than 89% after holding at 150℃ for 1000 hours, which is significantly better than the traditional process.

[0018] (3) Introducing a periodically varying strain field can more effectively break up coarse grains with lower cumulative deformation, promote dislocation reorganization, and form a more uniform deformation texture. This periodic strain mode is conducive to the uniform diffusion of Zr atoms in the matrix, thereby promoting the precipitation of finer and more uniform Al3Zr phases, further optimizing the strength and toughness matching of the material. At the same time, by using a staged cooling process to hold the material at a temperature range of 200℃ to 300℃ for a short time, fine and dispersed precipitation of Fe-rich and / or Si-rich phases is induced, which serves as an effective supplement to the dispersion strengthening of Al3Zr, further improving the strength of the material at room temperature and medium temperature without significantly impairing its conductivity.

[0019] (4) A dense alumina ceramic layer is generated in situ on the conductor surface, which serves as a robust protective shell. This significantly improves the conductor's resistance to oxidation and insulation under high temperature, high humidity, or corrosive environments, extending its service life. At the same time, this surface treatment hardly damages the conductor's internal conductivity and mechanical properties, achieving a functional composite upgrade.

[0020] (5) This invention eliminates expensive elements such as Cu, Mg, and RE throughout the entire process and uses common alloying elements, which significantly reduces the cost of raw materials; it also eliminates the independent solid solution aging process, shortens the process flow by more than 30%, and greatly reduces energy consumption, thus having good economic benefits and industrial promotion value.

[0021] (6) The beneficial effects of this solution compared with existing technologies:

[0022] (7) This invention exhibits excellent heat resistance. Compared with prior art document D1 (CN202511104951), the heat-resistant aluminum alloy wire prepared by this invention retains over 90% of its high-temperature tensile strength after heating at 230℃ for 24 hours, and the strength loss after cooling to room temperature is less than 0.5%, showing almost no loss. In contrast, prior art document D1 shows a strength retention loss between 3.7% and 16.9% after high-temperature cooling. This indicates that this invention, through the synergistic effect of composition and process, significantly improves the microstructure stability and mechanical property retention of the material under high-temperature service and thermal cycling conditions. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the cross-sectional structure of a high-strength heat-resistant aluminum alloy composite conductor provided in an embodiment of the present invention; the reference numerals in the figure are: 1-core; 2-outer layer; 3-functional composite layer; Figure 2 This is a schematic diagram of the conductor arrangement 3.9.15 of the present invention; Figures 3 to 5 The test report issued by Cablewise Testing Agency (Report No.: TN25-5314); Figures 6 to 8 Test report issued for China Steel Group Zhengzhou Metal Products Research Institute Co., Ltd. (Report No.: JCBG(01)250900833); Figures 9 to 11 Test report issued for China Steel Group Zhengzhou Metal Products Research Institute Co., Ltd. (Report No.: JCBG(01)250900834); Figures 12 to 14 Test report issued for China Steel Group Zhengzhou Metal Products Research Institute Co., Ltd. (Report No.: JCBG(01)250903536); Figures 15 to 17 Test report issued for China Steel Group Zhengzhou Metal Products Research Institute Co., Ltd. (Report No.: JCBG(01)250903537); Figures 18 to 20 Test report issued by China Steel Group Zhengzhou Metal Products Research Institute Co., Ltd. (Report No.: JCBG(01)250903538). Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments: Example 1

[0025] This embodiment provides a high-strength, heat-resistant, and highly conductive aluminum alloy conductor and its preparation method.

[0026] 1. Alloy composition (by weight %): Zr: 0.15%, Fe: 0.18%, Si: 0.12%, B: 0.03%, individual impurities <0.03%, total impurities <0.1%, Al: 99.52%.

[0027] 2. Preparation method: S1. Batching and smelting: High-purity aluminum ingots are put into a smelting furnace and heated to 750℃ to melt. Al-Si, Al-Fe, Al-B and Al-Zr master alloys are added according to the above ratio. Argon gas is introduced and stirred for 18 minutes to remove slag from the melt. S2. Continuous casting: The purified melt is continuously cast at 730℃ to obtain aluminum alloy rod blanks; S3. Continuous large deformation processing: The rod blank is continuously rolled at 420℃ using an asynchronous rolling mode with a 10% speed difference between the upper and lower rolls to achieve periodic changes in the strain field; the rolled wire is then drawn at 250℃. S4. Controlled cooling: Staged cooling is adopted. The extruded monofilament is first rapidly cooled to 250°C, held at this temperature for 60 seconds, and then cooled to room temperature. S5. Surface Treatment: The monofilament is placed in an electrolyte for micro-arc oxidation treatment at a voltage of 400V and a current density of 10A / dm². 2 The processing time is 10 minutes, and a dense Al2O3 ceramic layer with a thickness of about 10 micrometers is generated in situ on the surface of the monofilament. S6. Stranding: Multiple surface-treated monofilaments are stranded in a 0.5MPa nitrogen atmosphere to obtain the finished conductor.

[0028] Performance testing: Tensile strength: 135 MPa Elongation: 18.5% Conductivity: 57.2% IACS Heat resistance: Tested at 230℃ for 24 hours, the high-temperature tensile strength is 123.66 MPa, with a strength retention rate of 91.6%; the room-temperature tensile strength after cooling is 134.56 MPa, with a strength retention rate of 99.7%.

[0029] Strength retention rate after 1000 hours of heat treatment at 150℃: 89% Example 2

[0030] This embodiment is basically the same as Embodiment 1, except that the alloy composition has been adjusted.

[0031] The conductor's composition by weight % is as follows: Zr: 0.30%, Fe: 0.05%, Si: 0.05%, B: 0.02%, the content of each individual impurity element is less than 0.03%, the total content of impurity elements is less than 0.1%, and Al is 99.58%.

[0032] The preparation method is the same as in Example 1.

[0033] The properties of the aluminum alloy conductor prepared in this embodiment were tested and are as follows: Tensile strength: 142 MPa Elongation: 16% Conductivity: 56.0% IACS Heat resistance: Tested at 230℃ for 24 hours, the high-temperature tensile strength is 124.34 MPa, with a strength retention rate of 92.1%; the room-temperature tensile strength after cooling is 134.87 MPa, with a strength retention rate of 99.9%.

[0034] After being kept at 150℃ for 1000 hours, the tensile strength retention rate was 91%. Example 3

[0035] This embodiment is basically the same as Embodiment 1, except that the alloy composition has been adjusted.

[0036] The conductor's composition by weight % is as follows: Zr: 0.05%, Fe: 0.35%, Si: 0.25%, B: 0.05%, the content of each individual impurity element is less than 0.03%, the total content of impurity elements is less than 0.1%, and Al is 99.30%.

[0037] The preparation method is the same as in Example 1.

[0038] The properties of the aluminum alloy conductor prepared in this embodiment were tested and are as follows: Tensile strength: 122 MPa Elongation: 20% Conductivity: 58.5% IACS Heat resistance: Tested at 230℃ for 24 hours, the high-temperature tensile strength is 122.72 MPa, with a strength retention rate of 90.9%; the room-temperature tensile strength after cooling is 134.19 MPa, with a strength retention rate of 99.4%.

[0039] After being kept at 150℃ for 1000 hours, the tensile strength retention rate was 87%.

[0040] Comparative Example 1 Using the composition and process disclosed in CN202010270750, containing Cu and Mg, and subjected to solution aging treatment. Properties are as follows: Tensile strength: 140 MPa Elongation: 6% Conductivity: 55% IACS Strength retention rate at 150℃: 82% Comparative Example 2 An aluminum alloy conductor was prepared using the patented technology disclosed in CN114657403A. Its composition includes Zr and RE elements. Testing showed that its elongation was approximately 16.5 parts per 100 mm², its conductivity was approximately 60.5 parts per 100 mm², and the relative material cost was approximately 1.2–1.5.

[0041] Comparative Example 2 It uses conventional pure aluminum conductors, with a composition of Fe + Si < 0.1%, and the remainder being Al. Its properties are as follows: Tensile strength: 115 MPa Elongation: 25% Conductivity: 64% IACS Strength retention rate at 150℃: 65% Comparative Example 3 This comparative example provides an aluminum alloy conductor with only Zr added, but no B, and with impurities not strictly controlled; the remaining components are the same as in Example 1. Its preparation method is basically the same as in Example 1.

[0042] Testing revealed that the conductor structure prepared in this comparative example exhibited significant Zr segregation and coarse precipitates, resulting in lower mechanical properties (especially plasticity) and conductivity compared to Example 1. Specifically, the elongation was approximately 12 parts, the conductivity was approximately 54 parts IACS, and the high-temperature strength retention was approximately 80 parts.

[0043] The preparation method of this invention adopts a fully continuous, short-process technology, organically combining smelting, deep purification, continuous casting, continuous hot rolling, wire drawing deformation, and final annealing. In particular, by removing harmful impurities through online deep purification, combined with the large deformation of continuous hot rolling and the medium-temperature deformation in the subsequent wire drawing process, and utilizing a strain-induced precipitation mechanism, Zr can uniformly and dispersedly precipitate to form the Al3Zr strengthening phase without the need for traditional high-temperature solution treatment and separate aging processes. This not only simplifies the process and reduces energy consumption but also effectively ensures the stability and consistency of product performance.

[0044] A comparison of Examples 1-3 with Comparative Examples 1-3 shows that, without adding Cu, Mg, or RE elements, the embodiments of the present invention, through the synergistic effect of Si, Fe, Zr, and B elements in a specific ratio and matched with a dedicated short-process continuous preparation process, successfully obtained an aluminum alloy conductor with high strength, high conductivity, high elongation, and excellent heat resistance without adding expensive elements. Moreover, the cost is significantly lower than that of existing technical solutions, and the overall performance is excellent, making it highly competitive in the market.

[0045] Heat resistance performance comparison test To further verify the excellent heat resistance of the material of the present invention, the aluminum alloy wires prepared in Examples 1 to 3 of the present invention were subjected to a high-temperature test of 230℃ for 24h, referring to the comparison method between the present invention and D1CN202511104951. The results are shown in the table below.

[0046]

[0047] As shown in the table above, the heat-resistant aluminum alloy wire prepared by this invention exhibits a strength loss rate of less than 10% at 230℃, and almost no strength loss after cooling to room temperature (loss rate less than 0.6%), which is significantly better than the strength retention rate disclosed in prior art document D1 (CN202511104951) (loss of 3.7% to 16.9% after high-temperature cooling). This indicates that the technical solution of this invention has achieved unexpected technical effects in improving the high-temperature service stability and resistance to thermal cycling degradation of aluminum alloy conductor materials.

[0048] Inventive step description regarding the overall technical solution of this invention: This invention possesses outstanding substantive features and significant progress compared to the prior art, for the following reasons: A breakthrough approach to addressing core technical issues: Existing technologies (such as CN202010270750) often solve the strength problem of aluminum alloys by adding elements such as Cu, Mg, and RE for composite strengthening, but this brings new problems such as high cost, insufficient heat resistance, or complex processes. Another type of technology (such as CN202210299626) recognizes the heat resistance effect of Zr, but still relies on RE for assistance, failing to break free from dependence on expensive / rare elements. This invention takes a different approach, solving the long-standing technical contradiction of "high strength, high heat resistance, and high conductivity" through the synergistic effect of four elements: Si, Fe, Zr, and B, without adding any Cu, Mg, or RE elements. This technical concept itself is highly innovative.

[0049] Non-obviousness of ingredient selection: Zr-based strengthening: It is well known in the art that the Al3Zr phase formed by Zr is an effective way to strengthen Zr at high temperatures, but its addition alone can easily lead to segregation and the formation of coarse phases, which deteriorates performance. Therefore, existing technologies often use Zr in combination with other elements (such as RE). This invention abandons this conventional approach.

[0050] The key synergistic effect of boron: This invention creatively discovers a non-obvious synergistic effect between boron in a specific content range (0.02 parts to 0.05 parts) and zirconium in a specific content range (0.02 parts to 0.3 parts). Boron not only refines grains, but more importantly, it effectively suppresses zirconium segregation, promoting its uniform precipitation as a fine, dispersed Al3Zr phase. This "Boron-driven zirconium precipitation" mechanism solves the core process challenges of using zirconium alone, making it possible to achieve zirconium dispersion strengthening without refractive index (RE) assistance.

[0051] A Deeper Understanding of Extreme Impurity Control: This invention strictly controls the total amount of impurities to below 0.1 parts, far exceeding the requirements for conventional industrial pure aluminum or aluminum alloys. Its underlying purpose is to prevent trace impurities (especially elements that can form compounds with Zr) from adversely reacting with Zr, thereby ensuring that the limited Zr element can be used to the maximum extent to form an effective Al3Zr strengthening phase. This profound insight and precise control over the interaction between impurities and trace alloying elements is not a conventional approach for those skilled in the art.

[0052] Process innovation and synergy in preparation methods: Adaptability of the Short-Process Technology: The continuous process of "continuous casting-continuous rolling-drawing-stranding-annealing" adopted in this invention is not a simple application of existing production lines. Its core lies in replacing the traditional "high-temperature solution treatment + aging" process required for Zr-strengthened aluminum alloys by coupling the large deformation and heat energy during continuous rolling and subsequent drawing. This process path is specifically designed for the Cu-, Mg-, and RE-free composition system described in this invention, aiming to utilize deformation heat and deformation energy storage to drive the uniform dispersion precipitation of Zr, achieving a high degree of matching between "composition-process-microstructure-properties". This technological transformation simplifies the process, reduces energy consumption, and complements the composition design, jointly ensuring the achievement of the final performance. For those skilled in the art, without the compositional inspiration of this invention, it would be difficult to conceive of activating the strengthening potential of Zr in a RE-free system through such a simplified process.

[0053] In summary, the conclusion is as follows: Creative discussion of the overall technical solution (i) The syllogistic argument of technical problem—technical features—beneficial effects

[0054] (ii) Synergistic effects and system effects among features This invention is not an improvement on a single technical feature, but rather achieves a systemic effect of "1+1>2" through multi-dimensional synergy of composition, process, and structure: 1. Synergistic effect of composition: B and Zr work together. B refines grains and purifies grain boundaries, while promoting uniform distribution of Zr and preventing Zr segregation and coarsening of Al3Zr. Fe and Si provide basic solid solution strengthening and have no adverse interaction with Zr. Through hierarchical cooling, they are transformed into fine dispersed phases to form a multi-level strengthening system.

[0055] 2. Process Synergy: Continuous large deformation (rolling + extrusion) and online thermo-mechanical coupling replace traditional solution aging, using deformation energy storage to drive Zr precipitation, realizing the integration of "deformation + aging"; the synergistic effect of periodic strain field and temperature gradient field results in a more uniform microstructure with lower cumulative deformation.

[0056] 3. Structural Synergy: The gradient composite structure achieves functional zoning of "conductive core and tough outer layer"; the surface ceramic layer and the internal highly conductive substrate form a composite functional structure of "internal conduction and external protection", which do not interfere with each other and synergistically enhance each other's effectiveness.

[0057] 4. Full-process collaboration: From composition design, smelting and purification, continuous casting, large deformation processing, controlled cooling to surface treatment and stranding, each link is closely connected and matched with each other to form a complete short-process technology system, ensuring the stability and consistency of the final product performance.

[0058] (iii) Creativity of the overall technical solution This invention, compared to the prior art, possesses outstanding substantive features and significant progress, and meets the requirements of Article 22, Paragraph 3 of the Patent Law regarding inventiveness: 1. Non-obvious compositional system reconstruction: In existing technologies, to simultaneously obtain high strength, high conductivity, and heat resistance, multi-element composite strengthening such as Cu, Mg, and RE is usually employed, or the synergistic effect of Zr and RE is relied upon. This invention abandons Cu, Mg, and RE, and only uses a quaternary system of Si, Fe, B, and Zr. By utilizing the "guiding effect" of B on Zr and the "conversion and utilization" of Fe and Si, a unified approach to dispersion strengthening, grain refinement, and conductivity protection is achieved. This compositional reconstruction is not obvious to those skilled in the art.

[0059] 2. Breakthrough in Traditional Process Paradigm: For a long time, the dispersion strengthening of aluminum alloys has relied on independent solution treatment and aging treatment, which is the established technical approach in this field. This invention breaks this paradigm by using a short-process thermo-mechanical coupling process of "low-temperature large deformation energy storage + instantaneous high-temperature dynamic aging" to achieve uniform dispersion precipitation of Zr in situ during continuous processing. This innovative process path is groundbreaking.

[0060] 3. Unified resolution of multiple technical contradictions: This invention simultaneously resolves multiple technical contradictions such as "high strength vs. high conductivity," "high heat input vs. low heat input," and "structural stability vs. deformability," demonstrating systematic technological innovation. The organic combination of multiple technical means, including gradient composite structure, periodic strain field, temperature gradient control, staged cooling, and surface ceramic layer, is not a simple superposition, but rather mutually supportive and synergistic, constituting a complete technical solution.

[0061] 4. Significant technological advancements: Compared with existing technologies, this invention achieves comprehensive performance with tensile strength ≥135 MPa, conductivity ≥57% IACS, and strength retention rate ≥89% at 150℃ without the use of precious metals. At the same time, the process flow is shortened by more than 30% and the cost is significantly reduced, demonstrating significant technological advancements and industrial application value.

[0062] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should be covered by the claims of the present invention.

Claims

1. A high-strength, heat-resistant aluminum alloy conductor material, characterized in that, By weight percentage, its chemical composition consists of the following components: Zr 0.05-0.30%, Fe 0.05-0.35%, Si 0.05-0.25%, B 0.02-0.05%, Al 99.05% to 99.83%, and the content of other individual impurity elements is less than 0.03%, and the total content of impurity elements is less than 0.1%; the microstructure of the conductor material contains a Zr-containing nanoscale dispersed reinforcing phase precipitated in situ during processing.

2. The high-strength heat-resistant aluminum alloy conductor material according to claim 1, characterized in that, By weight percentage, its chemical composition satisfies: Zr 0.10-0.25%, Fe 0.10-0.25%, Si 0.08-0.20%, B 0.02-0.05%, and Al 99.25% to 99.70%; the Zr-containing nanoscale dispersed reinforcing phase is the Al3Zr phase.

3. The high-strength heat-resistant aluminum alloy conductor material according to claim 1 or 2, characterized in that, The conductor material is in the form of a single filament with a functional composite layer on its surface; the functional composite layer is an Al2O3 ceramic layer generated in situ on the surface of the single filament by micro-arc oxidation or anodic oxidation.

4. A composite conductor, characterized in that, include: Conductor core made of high conductivity aluminum alloy; The conductor core is covered with a high-strength heat-resistant layer, the material of which is the high-strength heat-resistant aluminum alloy conductor material as described in claim 1 or 2; the conductor core and the high-strength heat-resistant layer are integrally bonded by co-extrusion molding.

5. The composite conductor according to claim 4, characterized in that, The high conductivity aluminum alloy is a microalloyed aluminum alloy, and its Fe and Si contents are lower than those in the high strength heat-resistant layer material.

6. A method for preparing the high-strength heat-resistant aluminum alloy conductor material as described in claim 1 or 2, characterized in that, The method includes the following steps in sequence: S1. Batching and smelting: Prepare raw materials according to the chemical composition ratio described in claim 1 or 2, and smelt to obtain aluminum alloy melt; S2. Continuous casting: The aluminum alloy melt is continuously cast to obtain an aluminum alloy rod billet; S3. Continuous large deformation processing: The aluminum alloy rod blank is continuously rolled and / or drawn to obtain aluminum alloy single wire; S4. Controlled cooling: The aluminum alloy monofilament obtained in step S3 is subjected to controlled cooling; The method does not include a separate solution treatment process and a separate aging treatment process. The Zr-containing nanoscale dispersed strengthening phase is precipitated in situ during the continuous large deformation processing and / or the controlled cooling process.

7. The method for preparing the high-strength heat-resistant aluminum alloy conductor material according to claim 6, characterized in that, During the continuous large deformation processing described in step S3, the strain field exhibits periodic changes; the periodic changes in the strain field are achieved by employing at least one of asynchronous rolling or periodic reversing drawing.

8. The method for preparing the high-strength heat-resistant aluminum alloy conductor material according to claim 6, characterized in that, The continuous large deformation processing described in step S3 is carried out in a temperature gradient field; the processing includes deformation in a first temperature range of 300℃ to 350℃ in a first time period, and short-term heat preservation for a duration of seconds in a second temperature range of 400℃ to 450℃ in a subsequent second time period.

9. The method for preparing the high-strength heat-resistant aluminum alloy conductor material according to claim 6, characterized in that, The controlled cooling described in step S4 adopts a staged cooling method, including: first cooling the aluminum alloy monofilament to a first temperature at a first cooling rate; then holding it at a temperature range of 200℃ to 300℃ for a short time to induce the fine dispersion precipitation of Fe-rich phase and / or Si-rich phase; and then cooling it to room temperature at a second cooling rate.

10. A high-strength, heat-resistant aluminum alloy stranded wire, characterized in that, It is formed by stranding multiple monofilaments made of the high-strength heat-resistant aluminum alloy conductor material as described in claim 3; the stranding process is carried out in an environment filled with a pressure medium, which is an inert gas or liquid.

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