High-strength heat-resistant aluminum alloy wire material and method for manufacturing the same

Abstract

This invention belongs to the field of alloys, specifically disclosing a high-strength, heat-resistant aluminum alloy wire material and its preparation method. The aluminum alloy wire material is composed of the following components by mass percentage: Fe 0.5–1.2%, Zr 0.10–0.15%, B 0.01–0.03%, RE 0.01–0.04%, Sr 0.005–0.01%, unavoidable impurities ≤0.15%, and the balance being Al; RE is selected from at least one of La and Ce. The aluminum alloy wire material of this invention has a high iron content. By introducing lower amounts of Sr and RE elements, the type, morphology, and distribution of the iron-rich phase in the aluminum alloy are improved, resulting in high room-temperature tensile strength, excellent conductivity, and good high-temperature resistance.

Description

A high-strength heat-resistant aluminum alloy conductor material and its preparation method Technical Field

[0001] This invention belongs to the field of alloys, specifically relating to a high-strength heat-resistant aluminum alloy conductor material and its preparation method. Background Technology

[0002] Heat-resistant aluminum alloy conductors are a key material for high-capacity transmission lines due to their excellent conductivity, high-temperature mechanical properties, and creep resistance. Traditional aluminum conductors soften easily at high temperatures, limiting their current-carrying capacity. To improve the heat resistance of aluminum alloy conductors, domestic and international researchers have added trace alloying elements, such as Zr, Fe, and rare earth elements, to form high-melting-point dispersed phases, significantly enhancing their heat resistance and strength. Adding appropriate amounts of Zr can form metastable Al3Zr nanoprecipitates, which are beneficial for improving the alloy's strength and thermal stability, showing promising application prospects. However, Zr has a certain solubility in aluminum alloys, leading to a decrease in the alloy's conductivity. Furthermore, as aluminum alloy conductors enter the recycling process, steel cores and other materials are inevitably introduced, increasing the Fe content. The resulting coarse, iron-rich phases significantly reduce the conductor's plasticity and conductivity, making it impossible to achieve grade retention.

[0003] CN115798778A discloses a high-conductivity heat-resistant aluminum alloy wire and its preparation method. The wire mainly contains 0.08-0.12% Zr, 0.1-0.15% Si, 0.12-0.17% Fe, and 0.05-0.1% RE. It utilizes a mixture of La and Ce rare earth elements to promote the precipitation and stabilization of the heat-resistant Al3Zr particles, and to refine the Fe-rich phase and disperse it at the grain boundaries, thereby improving the heat resistance of the aluminum alloy wire. The prepared aluminum alloy wire exhibits a conductivity greater than 62% IACS and a strength retention rate greater than 94% after heating at 230℃ for 1 hour, demonstrating excellent comprehensive mechanical properties. CN118957364A discloses a high-conductivity, heat-resistant aluminum alloy wire and its preparation method. The wire mainly contains Zr 0.03-0.1%, Er 0.05-0.15%, B 0.01-0.04%, Fe 0.05-0.13%, Si 0.03-0.06%, and (V+Ti+Cr+Mn) 0.005-0.02%. The prepared wire has a conductivity ≥61.5% IACS, a tensile strength ≥160MPa, and a strength retention rate greater than 90% after heating at 230℃ for 1 hour.

[0004] Among the aforementioned patent documents, CN115798778A discloses a conductor with a high RE content and a low Fe content, which is not conducive to recycling. CN118957364A contains a high Er content, resulting in high cost and making it unsuitable for industrial applications. Summary of the Invention

[0005] In order to overcome at least one of the technical problems existing in the prior art, one of the objectives of the present invention is to provide an aluminum alloy wire material containing a high iron content, in which Fe, Zr and Al form a high volume fraction of high-temperature phase, thereby improving the heat resistance of the aluminum alloy wire material. Furthermore, the introduction of Sr and RE rare earth elements improves the morphology and distribution of the iron-rich phase and improves the plasticity of the aluminum alloy wire material.

[0006] The second objective of this invention is to provide a method for preparing aluminum alloy conductor materials.

[0007] The third objective of this invention is to provide a product.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] The first aspect of the present invention provides an aluminum alloy conductor material composed of the following components by mass percentage: Fe 0.5-1.2%, Zr 0.10-0.15%, B 0.01-0.03%, RE 0.01-0.04%, Sr 0.005-0.01%, unavoidable impurities ≤0.15%, and the balance being Al;

[0010] RE is selected from at least one of La and Ce.

[0011] In some embodiments of the present invention, the mass percentage of Fe can be selected from any value or a range formed by any two of 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, and 1.2%. If the iron content is high, Fe easily forms a coarse iron-rich phase in the aluminum alloy, thereby significantly reducing the plasticity and conductivity of the conductor. Therefore, the iron content of aluminum alloy conductor materials in the prior art is generally controlled below 0.2%. Even if the iron content is below 0.2%, the prior art uses rare earth elements to refine the iron-rich phase, thereby reducing the adverse effects of Fe on the performance of the aluminum alloy. The aluminum alloy conductor material of the present invention has a very high iron content, ranging from 0.5% to 1.2%. To avoid the formation of a coarse iron-rich phase, the present invention introduces Sr and RE elements to improve the morphology of the iron-rich phase, achieving excellent mechanical and electrical properties of the aluminum alloy conductor material even with a high Fe content.

[0012] Furthermore, the iron content in existing aluminum alloy wire materials is low, making it impossible to use waste aluminum alloy wire materials as raw materials, which is not conducive to the recycling of aluminum alloy wires.

[0013] In some embodiments of the present invention, the mass percentage of Zr can be selected from any value of 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, or a range formed by any combination of both. Zr is a common heat-resistant phase, and through high-temperature annealing, a high-density nanophase can be formed, improving the room temperature and high-temperature strength of aluminum alloy wire materials.

[0014] In some embodiments of the present invention, the mass percentage of B may be selected from any value of 0.01%, 0.015%, 0.02%, 0.025%, 0.03%, or a range formed by any two of these values.

[0015] In some embodiments of the present invention, the mass percentage of RE can be selected from any value or a range formed by any combination of 0.01%, 0.015%, 0.02%, 0.025%, 0.03%, 0.035%, and 0.04%. The present invention uses relatively small amounts of RE and Sr elements to modify Fe up to 0.5-1.2%, improving the morphology and refining the iron-rich phase, thereby avoiding the presence of coarse iron-rich phases. Furthermore, the RE elements used in the present invention are all relatively inexpensive rare earth elements, and the amount used is small, which can significantly reduce the manufacturing cost of aluminum alloys.

[0016] In some embodiments of the present invention, the mass percentage of Sr may be selected from any value of 0.005%, 0.006%, 0.007%, 0.008%, 0.009%, 0.01%, or a range formed by any two of these values.

[0017] In some embodiments of the present invention, RE and Sr are added in the form of an Al-Sr-RE master alloy. The Al-Sr-RE master alloy is used as a composite modifier to modify the aluminum alloy. The Al-Sr-RE master alloy is used as a composite modifier to improve the morphology of the iron-rich phase. The Al3Fe phase formed by Al and Fe is mainly needle-shaped and becomes coarser with increasing Fe content, which adversely affects the plasticity and thermal conductivity of the aluminum alloy conductor. The present invention utilizes the improving effect of the Al-Sr-RE modifier on the iron-rich phase to improve the strength, plasticity, and thermal conductivity of the conductor. The principle is that the Al-Sr-RE modifier mainly consists of Al4(SrRE) and Al, which are mutually dissolved by Sr and RE. 11When (RESr)3 is added to the melt, some Sr and RE elements remain in a clustered state. Since both Sr and Ce are highly reactive, they readily adsorb onto the nucleation sites and surfaces of the iron-rich phase, hindering its nucleation and growth, and improving its morphology and distribution. The synergistic adsorption effect of Sr and RE is even better. Simultaneously, some Sr and RE elements dissolve into the iron-rich phase, altering its type and morphology. Under the synergistic effect of Sr and RE, the coarse needle-like iron-rich phase gradually transforms into granular particles with a particle size of 2-6 μm.

[0018] In some embodiments of the present invention, the content of a single impurity element in the unavoidable impurities is ≤0.05%.

[0019] The second aspect of the present invention provides a method for preparing the aluminum alloy conductor material described in the first aspect of the present invention, comprising the following steps:

[0020] S1: Smelt aluminum-containing raw materials, then melt and mix them with Al-B master alloy, and then melt and mix them with Al-Sr-RE master alloy to obtain aluminum alloy melt;

[0021] S2: Cast and roll the aluminum alloy melt to obtain aluminum alloy rods;

[0022] S3: Anneal and draw the aluminum alloy rod to obtain the aluminum alloy conductor material. This invention improves the heat resistance, strength, and plasticity of the aluminum alloy conductor by adding an Al-B master alloy for "boronization" and introducing an Al-Sr-RE master alloy for composite modification treatment, thereby changing the type, morphology, and distribution of the iron-rich phase in the recycled aluminum alloy.

[0023] In some embodiments of the present invention, step S1 is as follows: heating the aluminum-containing raw material to 750-800°C to melt the aluminum-containing raw material, and then passing in a mixture of refining agent and inert gas for refining; then melting and mixing with Al-B master alloy, letting it stand, transferring the melt, and then melting and mixing with Al-Sr-RE master alloy to obtain an aluminum alloy melt.

[0024] In some embodiments of the present invention, step S1 specifically includes:

[0025] Aluminum-containing raw materials are added to a smelting furnace and heated to 750-800°C to melt them. Then, a mixture of refining agent and inert gas is introduced for refining.

[0026] Then, add Al-B master alloy and boronize it under an electromagnetic stirring system. After holding it at a constant temperature for 20-30 minutes, transfer the melt to a holding furnace for refining.

[0027] Then, an Al-Sr-RE master alloy was added and modified under an electromagnetic stirring system. After removing the surface slag, a covering agent was added to obtain an aluminum alloy melt.

[0028] This invention removes transition elements through a boronizing process using an Al-B master alloy. The invention uses aluminum-containing waste materials such as discarded aluminum alloy wires as raw materials, inevitably introducing V and Ti elements into the resulting recycled aluminum alloy. Since transition elements have high solubility in aluminum alloys and significant differences in element radii, they easily cause lattice distortion, which is detrimental to the conductivity of the aluminum alloy wire material. B has a high affinity for both Ti and V, and the resulting high-temperature particles MB2 can be removed through natural sedimentation; M is either Ti or V. To improve removal efficiency, the melt undergoes a static holding and liquid-transfer treatment to reduce the introduction of MB2 into the next stage.

[0029] In some embodiments of the present invention, the aluminum-containing raw material is selected from at least one of waste aluminum alloy wires and waste pure aluminum materials.

[0030] In some embodiments of the present invention, the waste pure aluminum material is selected from at least one of aluminum ceilings, aerosol cans, and aluminum foil.

[0031] This invention uses a high proportion of waste aluminum wires and industrial pure aluminum scrap as raw materials, with the scrap proportion reaching over 90%. These raw materials contain a high content of Fe. Since Fe has extremely low solubility in aluminum alloys and mainly exists in the form of an iron-rich phase, it has little impact on the conductivity of the aluminum alloy. Utilizing the low solid solubility of Fe and the high heat resistance of the iron-rich phase, increasing the Fe content effectively increases the volume fraction of the heat-resistant phase in the alloy, thereby improving the room temperature and high temperature strength of the wires.

[0032] In some embodiments of the present invention, the smelting step in step S1 includes melting and refining steps. Melting is to melt aluminum-containing raw materials at 750-800°C, and refining refers to refining the melt with a refining agent to remove impurities from the melt.

[0033] In some embodiments of the present invention, the melting temperature in step S1 is 750-800°C; in some embodiments of the present invention, the melting temperature in step S1 is any value of 750°C, 760°C, 770°C, 780°C, 790°C, 800°C, or a range formed by any two of these values.

[0034] In some embodiments of the present invention, the melt mixing step in step S1 is performed by using an electromagnetic stirring device.

[0035] In some embodiments of the present invention, the preparation method further includes the step of adding a covering agent; the step of adding the covering agent is located after step S1 and before step S2.

[0036] In some embodiments of the present invention, the casting step is as follows: after removing air bubbles from the aluminum alloy melt, it is filtered and then poured into a wheel crystallizer for continuous casting.

[0037] In some embodiments of the present invention, the drawing speed in step S3 is 8 to 12 m / s; in some embodiments of the present invention, the drawing speed in step S3 is any value of 8 m / s, 8.5 m / s, 9 m / s, 9.5 m / s, 10 m / s, 10.5 m / s, 11 m / s, 11.5 m / s, 12 m / s, or a range formed by any two of these values.

[0038] In some embodiments of the present invention, the drawing temperature in step S3 is 20-25°C.

[0039] In some embodiments of the present invention, in step S3, the deformation of the drawn aluminum alloy rod is not less than 80%.

[0040] In some embodiments of the present invention, the entry temperature during rolling is 500–520°C; in some embodiments of the present invention, the entry temperature during rolling is any value or a range formed by any combination of 500°C, 502°C, 504°C, 506°C, 508°C, 510°C, 512°C, 514°C, 516°C, 518°C, and 520°C. The entry temperature refers to the temperature at which the casting, after being cast from the aluminum alloy melt, enters the continuous rolling mill.

[0041] In some embodiments of the present invention, the rolling temperature is 300–400°C; in other embodiments, the rolling temperature is any value or a range formed by any combination of 300°C, 310°C, 320°C, 330°C, 340°C, 350°C, 360°C, 370°C, 380°C, 390°C, and 400°C. The rolling temperature refers to the temperature at which the casting is rolled in a continuous rolling mill.

[0042] In some embodiments of the present invention, the exit temperature during rolling is 200–250°C; in other embodiments, the exit temperature during rolling is any value or a range formed by any combination of 200°C, 210°C, 220°C, 230°C, 240°C, and 250°C. The exit temperature refers to the temperature of the rolled aluminum alloy bar when it exits the continuous rolling mill.

[0043] In some embodiments of the present invention, the annealing temperature is 360–400°C; in some embodiments of the present invention, the annealing temperature is any value of 360°C, 365°C, 370°C, 375°C, 380°C, 385°C, 390°C, 395°C, 400°C, or a range formed by any two of these values.

[0044] In some embodiments of the present invention, the annealing time is 2 to 4 hours; in some embodiments of the present invention, the annealing time is any value or a range formed by any two of the following: 2 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours, 3 hours, 3.2 hours, 3.4 hours, 3.6 hours, 3.8 hours, and 4 hours.

[0045] In some embodiments of the present invention, the number of annealing cycles is 1 to 5; in some embodiments of the present invention, the number of annealing cycles is any value of 1, 2, 3, 4, or 5, or a range formed by any two of them.

[0046] In some embodiments of the present invention, the number of pulls is 1 to 5 times; in some embodiments of the present invention, the number of pulls is any value of 1, 2, 3, 4, or 5 times, or a range formed by any two of them.

[0047] A third aspect of the present invention provides a product comprising the aluminum alloy conductor material described in the first aspect of the present invention, the product being selected from wires and cables or power fittings.

[0048] The beneficial effects of this invention are as follows: The aluminum alloy wire material of this invention has a high iron content. By introducing a low content of Sr and RE elements, the type, morphology and distribution of the iron-rich phase in the aluminum alloy are improved, so that the aluminum alloy wire material has high room temperature tensile strength, excellent conductivity and good high temperature resistance. Specifically, the room temperature tensile strength is 230-250 MPa, the conductivity is 61-62% IACS, and the residual strength retention rate after being placed at 230°C for 1 hour is 94-98%. Attached Figure Description

[0049] Figure 1 is a high-magnification scanning electron microscope image of the cast-rolled aluminum alloy in Example 1.

[0050] Figure 2 shows the energy spectrum and elemental analysis results at point A in Figure 1.

[0051] Figure 3 shows the energy spectrum and elemental analysis results at point B in Figure 1.

[0052] Figure 4 shows the energy spectrum and elemental analysis results at point C in Figure 1. Detailed Implementation

[0053] The specific implementation of the present invention will be further described in detail below with reference to the accompanying drawings and examples, but the implementation and protection of the present invention are not limited thereto. It should be noted that any processes not specifically described in detail below are those that can be implemented or understood by those skilled in the art by referring to the prior art. Reagents or instruments used without specified manufacturers are all conventional products that can be purchased commercially.

[0054] In the following embodiments, the total deformation is calculated as: (Cross-sectional area of ​​the conductor after drawing / Cross-sectional area of ​​the rod before drawing) * 100%.

[0055] Example 1

[0056] This example provides a high-strength, heat-resistant aluminum alloy conductor material, which is composed of the following components by mass percentage: Fe 1.2%, Zr 0.15%, B 0.02%, Sr 0.01%, La 0.03%, with unavoidable impurities totaling ≤0.15%, and the balance being Al. The content of any single impurity element among the unavoidable impurities does not exceed 0.05%.

[0057] This example also provides a method for preparing the above-mentioned aluminum alloy conductor material, including the following steps:

[0058] (1) Smelting: Remove the outer sheath of the waste aluminum alloy wires and then add them together with waste aluminum materials of industrial pure aluminum, such as pure aluminum ceilings, aerosol cans, aluminum foil, etc., into the smelting furnace and heat them to 800℃.

[0059] (2) Composition adjustment: Using high-purity argon gas (purity ≥99.9%) as a carrier, commercially available aluminum alloy refining agent is uniformly blown into the melt. After holding at this temperature for 30 minutes, samples are taken to test the composition, and the content of Zr, Fe and impurity elements in the melt is adjusted to the designed composition.

[0060] (3) Boration treatment and liquid transfer: Add Al-B master alloy, start the electromagnetic stirring system to promote melt flow, ensure that Al-B master alloy is completely dissolved, and then hold at the temperature for 30 minutes. After the holding time is completed, transfer the liquid to the holding furnace, and use high-purity argon gas as a carrier to introduce commercially available aluminum alloy refining agent to purify the melt.

[0061] (4) Al-Sr-RE composite modification: Add 0.3% Al-5Sr-10La composite modifier by mass of the melt and start the electromagnetic stirring device; after the Al-5Sr-10La composite modifier melts, remove the surface scum and add an appropriate amount of commercially available covering agent to protect the melt. In the Al-5Sr-10La composite modifier, the mass percentage of Sr is 5%, the mass percentage of La is 10%, and Al is the balance.

[0062] (5) Continuous casting and rolling: The aluminum alloy melt is degassed and filtered online and poured into a wheel crystallizer for continuous casting to obtain a billet.

[0063] (6) Continuous rolling: The billet is transferred to a continuous rolling mill for continuous rolling. The inlet temperature is 520℃, the rolling temperature is 400℃, and the outlet temperature is 230℃ to obtain aluminum alloy rods.

[0064] (7) Drawing: The aluminum alloy rod is annealed at 380℃ for 4 hours and then drawn at 8m / s using a wire drawing machine after cooling to room temperature. Then, multiple annealing and drawing processes are performed, with a total deformation of 80%, and finally the aluminum alloy wire material in this example is obtained.

[0065] Performance of aluminum alloy conductor material: room temperature strength 245MPa; conductivity 61.2% IACS; residual strength ratio reaches 97% at 230℃ / 1h.

[0066] The second phase of the cast-rolled aluminum alloy in Example 1 was analyzed using a high-magnification scanning electron microscope (SEM), as shown in Figure 1. Then, the energy dispersive spectroscopy (EDS) was used to analyze the energy dispersive spectroscopy (EDS) and composition at points A, B, and C in Figure 1, as shown in Figures 2-4. Figures 1-4 show that the iron-rich phase in the aluminum alloy conductor material is mainly granular and fibrous, with particle sizes of 2-6 μm and fiber lengths of 2-15 μm. The iron-rich phase mainly consists of three types: Al-Fe-RE (point A in Figure 1), Al-Fe (point B in Figure 1), and Al-Fe-Sr-RE-Si phase (point C in Figure 1). Si is an unavoidable impurity element, while RE and Sr exist as solid-solution elements in the iron-rich phase, thus altering its morphology and distribution.

[0067] Example 2

[0068] This example provides a high-strength, heat-resistant aluminum alloy conductor material, which is composed of the following components by mass percentage: Fe 0.5%, Zr 0.10%, B 0.01%, Sr 0.005%, Ce 0.01%, with unavoidable impurities totaling ≤0.15%, and the balance being Al. The content of any single impurity element among the unavoidable impurities does not exceed 0.05%.

[0069] This example also provides a method for preparing aluminum alloy conductor material, including the following steps:

[0070] (1) Smelting: Remove the outer sheath of the waste aluminum alloy wires and then add them together with waste aluminum materials of industrial pure aluminum, such as pure aluminum ceilings, aerosol cans, aluminum foil, etc., into the smelting furnace and heat them to 750℃.

[0071] (2) Composition adjustment: Using high-purity nitrogen (purity ≥99.9%) as a carrier, commercially available aluminum alloy refining agent is uniformly blown into the melt. After holding at this temperature for 15 minutes, samples are taken to test the composition, and the content of Zr, Fe and impurity elements in the melt is adjusted to the designed composition.

[0072] (3) Boration treatment and liquid transfer: Add Al-B master alloy, start the electromagnetic stirring system to promote melt flow, ensure that Al-B master alloy is completely dissolved, and then hold at the temperature for 20 minutes. After the holding time is completed, transfer the liquid to the holding furnace, and use high-purity nitrogen as a carrier to introduce commercially available aluminum alloy refining agent to purify the melt.

[0073] (4) Al-Sr-RE composite modification: Add 0.1% (based on the total mass of the melt) of Al-9Sr-10Ce composite modifier and start the electromagnetic stirring device; after the Al-9Sr-10Ce composite modifier melts, remove the surface slag and sprinkle an appropriate amount of commercially available aluminum alloy covering agent to protect the melt. In the Al-9Sr-10Ce composite modifier, the mass percentage of Sr is 9%, the mass percentage of Ce is 10%, and Al is the balance.

[0074] (5) Continuous casting and rolling: The aluminum alloy melt is degassed and filtered online and poured into a wheel crystallizer for continuous casting to obtain a billet.

[0075] (6) Continuous rolling: The billet is transferred to a continuous rolling mill for continuous rolling. The inlet temperature is 500℃, the rolling temperature is 300℃, and the outlet temperature is 220℃ to obtain aluminum alloy rods.

[0076] (7) Drawing: The aluminum alloy rod is annealed at 400℃ for 2 hours and then drawn at 9m / s using a wire drawing machine after cooling to room temperature. The annealing and drawing are then repeated multiple times, with a total deformation of 90%, and finally the aluminum alloy wire material in this example is obtained.

[0077] Properties of aluminum alloy conductor material: room temperature strength 230MPa; conductivity 61.8% IACS; residual strength ratio at 230℃ / 1h 95%.

[0078] Example 3

[0079] This example provides a high-strength, heat-resistant aluminum alloy conductor material, which is composed of the following components by mass percentage: Fe 0.8%, Zr 0.12%, B 0.03%, Sr 0.008%, Ce 0.012%, La 0.018%, with unavoidable impurities totaling ≤0.15%, and the balance being Al. The content of any single impurity element among the unavoidable impurities does not exceed 0.05%.

[0080] This example also provides a method for preparing aluminum alloy conductor material, including the following steps:

[0081] (1) Smelting: Remove the outer sheath of the waste aluminum alloy wires and then add them together with waste aluminum materials of industrial pure aluminum, such as pure aluminum ceilings, aerosol cans, aluminum foil, etc., into the smelting furnace and heat them to 780℃.

[0082] (2) Composition adjustment: Using high-purity nitrogen (purity ≥99.9%) as a carrier, commercially available aluminum alloy refining agent is uniformly blown into the melt. After holding at this temperature for 15 minutes, samples are taken to test the composition, and the content of Zr, Fe and impurity elements in the melt is adjusted to the designed composition.

[0083] (3) Boration treatment and liquid transfer: Add Al-B master alloy, start the electromagnetic stirring system to promote melt flow, ensure that Al-B master alloy is completely dissolved, and then hold at the temperature for 20 minutes. After the holding time is completed, transfer the liquid to the holding furnace, and use high-purity argon gas as a carrier to introduce commercially available aluminum alloy refining agent to purify the melt.

[0084] (4) Al-Sr-RE composite modification: Add 0.3% (based on the total mass of the melt) of Al-5Sr-4Ce-6La composite modifier and start the electromagnetic stirring device; after the modifier melts, remove the surface scum and sprinkle an appropriate amount of covering agent to protect the melt. In the Al-5Sr-4Ce-6La composite modifier, the mass percentage of Sr is 5%, the mass percentage of Ce is 4%, the mass percentage of La is 6%, and Al is the balance.

[0085] (5) Continuous casting and rolling: The aluminum alloy melt is degassed and filtered online and poured into a wheel crystallizer for continuous casting to obtain a billet.

[0086] (6) Continuous rolling: The billet is transferred to a continuous rolling mill for continuous rolling. The inlet temperature is 510℃, the rolling temperature is 350℃, and the outlet temperature is 210℃ to obtain aluminum alloy rods.

[0087] (7) Drawing: The aluminum alloy rod is annealed at 380℃ for 3 hours and then cooled to room temperature. It is then drawn at a speed of 10m / s using a wire drawing machine. After multiple annealing and drawing processes, the total deformation is 85%, and the aluminum alloy wire material in this example is finally obtained.

[0088] Performance of aluminum alloy conductor material: room temperature strength 240MPa; conductivity 61.4% IACS; residual strength ratio at 230℃ / 1h 96%.

[0089] Example 4

[0090] This example provides a high-strength, heat-resistant aluminum alloy conductor material, which is composed of the following components by mass percentage: Fe 1.0%, Zr 0.13%, B 0.025%, Sr 0.007%, Ce 0.012%, La 0.012%, with unavoidable impurities totaling ≤0.15%, and the balance being Al. The content of any single impurity element among the unavoidable impurities does not exceed 0.05%.

[0091] This example also provides a method for preparing aluminum alloy conductor material, including the following steps:

[0092] (1) Smelting: Remove the outer sheath of the waste aluminum alloy wires and then add them together with waste aluminum materials of industrial pure aluminum, such as pure aluminum ceilings, aerosol cans, aluminum foil, etc., into the smelting furnace and heat them to 770℃.

[0093] (2) Composition adjustment: Using high-purity argon gas (purity ≥99.9%) as a carrier, commercially available aluminum alloy refining agent is uniformly blown into the melt. After holding at this temperature for 25 minutes, samples are taken to test the composition, and the content of Zr, Fe and impurity elements in the melt is adjusted to the designed composition.

[0094] (3) Boration treatment and liquid transfer: Add Al-B master alloy, start the electromagnetic stirring system to promote melt flow, ensure that Al-B master alloy is completely dissolved, and then hold at the temperature for 30 minutes. After the holding time is completed, transfer the liquid to the holding furnace, and use high-purity argon gas as a carrier to introduce commercially available refining agent to purify the melt.

[0095] (4) Al-Sr-RE composite modification: Add 0.2% (based on the total mass of the melt) of Al-7Sr-6Ce-6La composite modifier and start the electromagnetic stirring device; after the modifier melts, remove the surface scum and add 0.02% of covering agent to protect the melt. In the Al-7Sr-6Ce-6La composite modifier, the mass percentage of Sr is 7%, the mass percentage of Ce is 6%, the mass percentage of La is 6%, and Al is the balance.

[0096] (5) Continuous casting and rolling: The aluminum alloy melt is degassed and filtered online and poured into a wheel crystallizer for continuous casting to obtain a billet.

[0097] (6) Continuous rolling: The billet is transferred to a continuous rolling mill for continuous rolling. The inlet temperature is 515℃, the rolling temperature is 370℃, and the outlet temperature is 230℃ to obtain aluminum alloy rods.

[0098] (7) Drawing: The aluminum alloy rod is annealed at 360°C for 3.5 hours and then drawn at 9 m / s using a wire drawing machine after cooling to room temperature. Subsequently, multiple annealing and drawing processes are performed, with a total deformation of 82%, and finally the aluminum alloy wire material in this example is obtained.

[0099] Performance of aluminum alloy conductor material: room temperature strength 238 MPa; conductivity 61.3% IACS; residual strength ratio at 230℃ / 1h 96%.

[0100] Comparative Example 1

[0101] Compared to Example 1, the Fe content in this example reaches 1.5%.

[0102] Comparative Example 2

[0103] Compared to Example 2, no "boration" treatment is performed in this example, that is, step (3) in Example 2 is not performed.

[0104] Comparative Example 3

[0105] Compared with Example 3, this example does not perform step (4) of Example 3, that is, Al-Sr-RE composite modifier is not added in this example.

[0106] Comparative Example 4

[0107] Compared to Example 4, the Fe content in this example is reduced to 0.15%.

[0108] Performance testing:

[0109] Samples of the aluminum alloy wire materials from Examples 1-4 and Comparative Examples 1-4 were taken respectively, and their tensile strength, conductivity, and residual strength were tested. The specific test methods are as follows:

[0110] Room temperature tensile strength: The test was conducted according to the test method described in HB 5177-1996 Tensile testing method for metallic wires;

[0111] Elongation: The test shall be conducted in accordance with the test method described in HB 5177-1996 Tensile Test Method for Metal Wires;

[0112] Conductivity: The test shall be conducted in accordance with the test method described in GB / T 3048.2-2007 "Test methods for electrical properties of wires and cables - Part 2: Test for resistivity of metallic materials";

[0113] Residual strength: The aluminum alloy wire is placed at 230℃ for 1 hour, and then its tensile strength is tested and compared with its room temperature tensile strength to obtain the residual strength, that is, residual strength = tensile strength at 230℃ / 1 hour / room temperature tensile strength * 100%;

[0114] The performance data of the aluminum alloy conductor material obtained according to the above test method are shown in Table 1 below:

[0115] Table 1 Performance data of aluminum alloy conductor materials

[0116]

[0117] Table 1 shows that the range of Fe content, the presence or absence of boriding treatment and Al-Sr-RE composite modification treatment in the preparation method significantly affect the properties of the conductor. Fe content and Al-Sr-RE composite modification treatment affect the strength, plasticity, conductivity, and high-temperature residual strength ratio of the conductor material, while boriding treatment mainly affects the conductivity. With increasing Fe content, the room-temperature tensile strength and residual strength ratio of the alloy slightly increase, but the elongation and conductivity slightly decrease. However, excessively high Fe content leads to a significant decrease in plasticity and strength, while excessively low Fe content leads to a decrease in strength and residual strength ratio. Al-Sr-RE composite modification significantly improves the mechanical properties and conductivity of the conductor.

[0118] The embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. An aluminum alloy conductor material, characterized in that: It is composed of the following components by mass percentage: Fe 0.5~1.2%, Zr 0.10~0.15%, B 0.01~0.03%, RE 0.01~0.04%, Sr 0.005~0.01%, unavoidable impurities ≤0.15%, and the balance being Al; RE is selected from at least one of La and Ce; RE and Sr are added in the form of an Al-Sr-RE master alloy; the room temperature tensile strength of the aluminum alloy conductor material is 230-250 MPa.

2. The aluminum alloy conductor material according to claim 1, characterized in that: Of the unavoidable impurities, the content of a single impurity element is ≤0.05%.

3. The method for preparing the aluminum alloy conductor material according to any one of claims 1 to 2, characterized in that: Includes the following steps: S1: Melt aluminum-containing raw materials, then melt and mix them with Al-B master alloy, and then melt and mix them with Al-Sr-RE master alloy to obtain an aluminum alloy melt; S2: Cast and roll the aluminum alloy melt to obtain an aluminum alloy rod; S3: Anneal and draw the aluminum alloy rod to obtain the aluminum alloy wire material.

4. The method for preparing aluminum alloy conductor material according to claim 3, characterized in that: The aluminum-containing raw material is selected from at least one of waste aluminum alloy wires and waste pure aluminum materials.

5. The method for preparing aluminum alloy conductor material according to claim 4, characterized in that: The waste pure aluminum material is selected from at least one of aluminum ceilings, aerosol cans, and aluminum foil.

6. The method for preparing aluminum alloy conductor material according to claim 3, characterized in that: In step S1, the melting temperature is 750~800℃; and / or, in step S3, the drawing speed is 8~12m / s.

7. The method for preparing aluminum alloy conductor material according to claim 3, characterized in that: In step S2, the rolling process has at least one of the following characteristics: (a1) the infeed temperature during rolling is 500~520℃; (a2) the rolling temperature is 300~400℃; (a3) ​​the rolling outlet temperature is 200~250℃.

8. The method for preparing aluminum alloy conductor material according to claim 3, characterized in that: The annealing process has at least one of the following characteristics: (b1) the annealing temperature is 360~400℃; (b2) the annealing time is 2~4h; (b3) the annealing is performed 1~5 times.

9. A product, characterized in that: The product includes the aluminum alloy conductor material as described in any one of claims 1 to 2, wherein the product is selected from wires and cables or power fittings.

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