High-strength high-conductivity heat-resistant aluminum alloy energy-saving wire, preparation method and application thereof

Abstract

This invention relates to the field of overhead conductors for power transmission lines, specifically to a high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire, its preparation method, and its application. This invention provides a high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire, comprising, by weight percentage: 0.03–0.06% Zr; 0.05–0.15% Er; 0.002–0.02% B; Fe ≤ 0.1%; Si ≤ 0.05%; (Cr + Mn + V + Ti) ≤ 0.005%, with the balance being aluminum and unavoidable trace impurities. This invention optimizes the addition of alloying elements such as Zr, Er, and B to the aluminum alloy, and by controlling the content of each alloying element, enables the aluminum alloy wire to possess high electrical conductivity, high strength, and high heat resistance.

Description

Technical Field

[0001] This invention relates to the field of overhead conductors for power transmission lines, specifically to a high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire, its preparation method, and its application. Background Technology

[0002] With the construction of new power systems and the large-scale grid connection, transmission and consumption of clean energy, higher requirements are placed on the safe and efficient transmission capacity of transmission lines. Existing technologies need new energy-saving conductors that can transmit large currents and operate at high temperatures to support the improvement of grid quality and efficiency and ensure the grid connection and consumption of new energy.

[0003] Heat-resistant aluminum alloy conductors are characterized by high heat resistance and large transmission capacity. The maximum allowable operating temperature can reach over 150℃. Without replacing the towers, only the conductors can be replaced, increasing the transmission capacity by 40%-60% compared to steel-cored aluminum stranded wire of the same specification. This can effectively reduce the cost of line renovation and can be applied to new transmission lines, capacity expansion and renovation lines, and ultra-high voltage lines. Currently, the mature heat-resistant aluminum alloy conductors in China are mainly of the following types: NRLH1 [heat resistance temperature 150℃, conductivity ≥60% IACS, tensile strength ≥(159~169)MPa], NRLH2 [heat resistance temperature 150℃, conductivity ≥55% IACS, tensile strength ≥(225~248)MPa], and NRLH3 [heat resistance temperature 210℃, conductivity 60% IACS, tensile strength ≥(159~176)MPa]. For ultra-heat resistant aluminum alloy wires with a heat resistance temperature of up to 210℃, the conductivity of related products at home and abroad is only 60% IACS, which is 1% lower than that of ordinary steel-cored aluminum stranded wire. The high transmission loss severely restricts the promotion and application of ultra-heat resistant aluminum alloy conductors in overhead transmission lines.

[0004] Currently, Al-Zr alloys are commonly used as conductor materials in heat-resistant aluminum alloy wires. Zr, as the main alloying element, can form Al3Zr precipitates with the aluminum matrix, exhibiting good high-temperature stability and improving the alloy's heat resistance. However, the slow diffusion rate and uneven precipitation of Zr in the aluminum matrix limit the precipitation strengthening effect and the optimization of heat resistance. In summary, aluminum alloy wires prepared from existing Al-Zr alloys struggle to simultaneously achieve high electrical conductivity, high strength, and high heat resistance. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the shortcomings of existing Al-Zr alloy-based aluminum alloy wires, which are difficult to achieve high electrical conductivity, high strength and high heat resistance, and thus provide a high-strength, high-conductivity and heat-resistant aluminum alloy energy-saving wire, its preparation method and application.

[0006] This invention provides a high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire, comprising, by weight percentage: 0.03-0.06% Zr; 0.05-0.15% Er; 0.002-0.02% B; Fe≤0.1%; Si≤0.05%; (Cr+Mn+V+Ti)≤0.005%, with the balance being aluminum and unavoidable trace impurities.

[0007] Preferably, the Zr content is 0.045–0.050%;

[0008] Preferably, the Er content is 0.05% to 0.1%.

[0009] Preferably, the high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire has a conductivity ≥61.5% IACS, a tensile strength ≥169MPa, and a maximum allowable continuous operating temperature of 210℃.

[0010] The roles and mechanisms of each alloying element are as follows:

[0011] 1) Zr: Zirconium is one of the main alloying elements, significantly affecting the microstructure and properties of alloys. Zirconium can form an Al3Zr phase with an aluminum matrix, exhibiting good thermal stability, coherence with the aluminum matrix, and low lattice mismatch. However, the low diffusion rate of Zr results in slow and uneven precipitation of the Al3Zr phase. While Zr is beneficial for improving the heat resistance of alloys, excessive Zr addition can negatively impact electrical conductivity. Therefore, accelerating the precipitation kinetics of Al3Zr, promoting the age-dependent precipitation of Zr atoms, and improving the size and distribution of the Al3Zr precipitate phase are key to improving the performance of high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wires.

[0012] 2) Er: Rare earth elements have purification, modification, refinement, and microalloying effects. Due to their low solubility in the aluminum matrix, rare earth elements improve the conductivity of the alloy. Simultaneously, the intermetallic compounds formed through eutectic reactions can increase the alloy's strength and thermal stability. Er, with its rapid diffusion rate, can first form the Al3Er phase as a nucleation site for Zr, accelerating the precipitation kinetics of zirconium. On the other hand, the addition of Er increases the distribution of the second phase in the aluminum alloy, achieving grain refinement and increasing precipitation strengthening, which is beneficial for improving the mechanical properties of high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wires.

[0013] 3)B: Reducing impurity elements helps improve the conductivity of aluminum conductors. Boring is an effective method to reduce impurity content. Reasonable boring can cause transitional impurity elements in the ingot to form borides and settle to the bottom of the furnace, reducing the content of Mn, Cr, V and Ti impurity elements in the aluminum liquid, achieving the purpose of purification, and helping to improve the conductivity of high-strength, high-conductivity and heat-resistant aluminum alloy energy-saving wire.

[0014] 4) Fe and Si: Fe and Si are major impurities in high-purity aluminum, and they usually form the AlFeSi impurity phase. Adding appropriate amounts of Fe and Si can effectively refine the grains, significantly increase the primary phase, and exhibit a continuous irregular morphology at the grain boundaries. However, the content of iron and silicon needs to be strictly controlled.

[0015] 5) V, Mn, Cr, and Ti: These four elements are impurities in electrical-grade pure aluminum. When Cr, Mn, V, and Ti impurities exist in a solid solution state in aluminum, they easily absorb free electrons from the material and fill their incomplete electron layers. The reduced number of free electrons that contribute to conductivity leads to an increase in the resistivity of the aluminum. Studies have shown that 1% (Cr+Mn+V+Ti) of impurities has a five times greater detrimental effect on the conductivity of aluminum conductors than 1% of Si. Therefore, strictly controlling the content of Cr, Mn, V, and Ti impurities plays a crucial role in the conductivity of high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wires.

[0016] The present invention also provides a method for preparing the above-mentioned high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire, comprising the following steps:

[0017] 1) Melt the raw materials according to the formula ratio to obtain an aluminum alloy solution;

[0018] 2) The aluminum alloy solution is refined, allowed to stand, and then cast to obtain aluminum alloy ingots;

[0019] 3) The aluminum alloy ingot is heat-treated and then rolled to obtain an aluminum alloy round rod;

[0020] 4) The aluminum alloy round rod is drawn and aged to obtain the high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire;

[0021] The heat treatment process for aluminum alloy ingots includes sequentially performing a first heat treatment, a second heat treatment, and a third heat treatment; the temperature for the first heat treatment is 300℃~320℃; the temperature for the second heat treatment is 480℃~500℃; and the temperature for the third heat treatment is 500℃~600℃.

[0022] Preferably, the first heat treatment lasts for 8–10 hours, the second heat treatment lasts for 8–10 hours, and the third heat treatment lasts for 3–15 hours; and / or,

[0023] The temperature during the rolling process is 400-450℃; and / or,

[0024] The diameter of the rolled aluminum alloy round bar is 8-12 mm; and / or,

[0025] In the wire drawing step, the wire drawing rate is 6–8 m / s, the wire drawing temperature is 40–50°C, the single-pass deformation is 5–8%, and the diameter of the aluminum alloy wire obtained after drawing is 3.5–4 mm; and / or,

[0026] The aging temperature in the aging process is 200℃~220℃, and the aging time is 4~6h.

[0027] Preferably, the smelting process in step 1) includes the following steps: smelting industrial aluminum ingots at 730℃~750℃, then adding Al-B master alloy at 720-730℃, stirring, and letting it stand for 20-30 minutes, then adding Al-Zr master alloy and Al-Er master alloy at 720~730℃, stirring, and after all alloy materials have melted, stirring 2-3 times, each stirring time being 10-15 minutes, with an interval of 10-15 minutes between each stirring.

[0028] Preferably, the industrial aluminum ingot contains 99.7-99.8 wt% Al, ≤0.085 wt% Fe, ≤0.036 wt% Si, and ≤0.009 wt% Cr, Mn, V and Ti.

[0029] The Al-B master alloy contains 2-3 wt% B, the Al-Zr master alloy contains 4-6 wt% Zr, and the Al-Er master alloy contains 8-12 wt% Er.

[0030] Preferably, the refining step in step 2) includes: controlling the aluminum alloy solution at 740–760°C, then introducing nitrogen and a refining agent into the solution, aerating for 10–15 minutes, stirring for 15–20 minutes, then allowing it to stand for 20–30 minutes, and finally removing the slag to obtain the refined aluminum alloy solution; and / or,

[0031] The casting process involves pouring molten aluminum alloy into a ceramic mold; and / or,

[0032] The process also includes a preheating step of the ceramic mold before casting, wherein the preheating temperature is 750-760℃; and / or,

[0033] The process of filtering the refined aluminum alloy solution before the casting step also includes a step of filtering the solution.

[0034] Preferably, the purity of the nitrogen gas is not less than 99.99%, and the amount of the refining agent added is 0.25% to 0.30% of the weight of the aluminum alloy solution.

[0035] Preferably, the refining agent comprises, by mass percentage: 25-30% NaCl, 10-15% KCl, 40-50% NaF, and 5-15% Na3AlF6.

[0036] Preferably, the heat treatment steps for the aluminum alloy ingot include: after the first heat treatment, heating to the second heat treatment temperature at a heating rate of 40-60℃ / h for the second heat treatment; and after the second heat treatment, heating to the third heat treatment temperature at a heating rate of 40-60℃ / h for the third heat treatment.

[0037] The present invention also provides a power transmission conductor, which includes the high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire described above or the high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire prepared by the preparation method described above.

[0038] The technical solution of this invention has the following advantages:

[0039] 1. The high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire provided by the present invention comprises, by weight percentage: 0.03-0.06% Zr; 0.05-0.15% Er; 0.002-0.02% B; Fe≤0.1%; Si≤0.05%; (Cr+Mn+V+Ti)≤0.005%, with the balance being aluminum and unavoidable trace impurities.

[0040] This invention optimizes the addition of alloying elements such as Zr, Er, and B to aluminum alloys, and by controlling the content of each alloying element, aluminum alloy wires can possess high electrical conductivity, high strength, and high heat resistance.

[0041] 2. The preparation method of the high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire provided by the present invention includes the following steps: 1) melting the raw materials according to the formula ratio to obtain an aluminum alloy solution; 2) refining, settling, and casting the aluminum alloy solution to obtain an aluminum alloy ingot; 3) heat-treating the aluminum alloy ingot and then rolling it to obtain an aluminum alloy round rod; 4) drawing and aging the aluminum alloy round rod to obtain the high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire; wherein, the heat treatment step of the aluminum alloy ingot includes a first heat treatment, a second heat treatment, and a third heat treatment; the temperature of the first heat treatment is 300℃~320℃; the temperature of the second heat treatment is 480℃~500℃; and the temperature of the third heat treatment is 500℃~600℃.

[0042] The aluminum alloy solution obtained by smelting raw materials according to the formula ratio is refined, allowed to stand, cast, and rolled to obtain aluminum alloy round rods. After a first heat treatment at 300℃~320℃, the rapidly diffusing Er element is precipitated to form the Al3Er phase, thus providing nucleation sites for Zr in the matrix. Then, a second heat treatment is carried out at 480℃~500℃, which causes Zr to precipitate from the matrix and react with the Al3Er phase, and combine with the Si element in the matrix to form the (Al,Si)3(Er,Zr) composite phase. This phase is small in size and uniformly distributed. Then, a third heat treatment is carried out at 500℃~600℃ to further promote the precipitation, desolvation and strengthening of Zr, forming the Al3Zr phase. This constitutes a coherent thermally stable phase and a strengthening phase composite microstructure, so that the overall heat resistance of the alloy reaches the level of ultra-heat resistance, while also ensuring the high strength and conductivity of the aluminum alloy. Finally, the aluminum alloy round rod is drawn and aged to obtain aluminum alloy wire with high strength, high conductivity and heat resistance. Detailed Implementation

[0043] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0044] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0045] The industrial aluminum ingots used in the examples and comparative examples have the following composition: Al content is 99.7 wt%, Fe content is ≤0.085 wt%, Si content is ≤0.036 wt%, and the total content of Cr, Mn, V and Ti is ≤0.009 wt%.

[0046] The B content in the Al-B master alloy is 2 wt%.

[0047] The Zr content in the Al-Zr master alloy is 5 wt%.

[0048] The Er content in the Al-Er master alloy is 10 wt%.

[0049] Example 1

[0050] This embodiment provides a high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wire. By mass percentage, the composition of the high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wire includes: 0.045% Zr; 0.10% Er; 0.020% B; 0.010% Fe; 0.043% Si; 0.004% (Cr+Mn+V+Ti), with the balance being aluminum and unavoidable trace impurities.

[0051] This embodiment also provides a method for preparing the above-mentioned high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wire, including the following steps: preparing industrial aluminum ingots, Al-B master alloys, Al-Zr master alloys, and Al-Er master alloys according to the composition of the high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wire; placing the industrial aluminum ingots in a melting furnace and melting them at 730°C; after the industrial aluminum ingots are completely melted, adding the Al-B master alloy for boronizing treatment and stirring evenly; then adding the Al-Zr master alloy and Al-Er master alloy at 720°C and stirring. Stir until all raw materials are completely melted, then stir three times, each time for 10 minutes, with a 10-minute interval between each stirring, to obtain an aluminum alloy solution. Control the temperature of the aluminum alloy solution to 740℃, and introduce high-purity nitrogen gas (99.99% purity) and a refining agent (0.3% of the aluminum alloy solution volume, comprising 30% NaCl, 15% KCl, 40% NaF, and 15% Na3AlF6) into the bottom of the aluminum alloy solution for 15 minutes. After stirring for 20 minutes, the mixture was allowed to stand for 30 minutes, followed by slag removal. The aluminum alloy solution after slag removal was filtered to remove impurities. The filtered aluminum alloy solution was then cast into a ceramic mold preheated to 750℃ to prepare an aluminum alloy ingot with dimensions of 25×25×400mm. The aluminum alloy ingot was then heat-treated at 310℃ for 9 hours, followed by a heating rate of 50℃ / h to 490℃, and heat-treated at this temperature for 9 hours. Finally, the temperature was raised to 550℃ at a heating rate of 50℃ / h for 12 hours. After heat treatment, the temperature is lowered to 400℃ and continuously rolled into an aluminum alloy round rod with a diameter of 9.5mm. The aluminum alloy round rod is then drawn multiple times on a wire drawing machine at a speed of 6m / s at 40℃, with a deformation of 8% per drawing pass, until the aluminum alloy round rod becomes an aluminum alloy round single wire with a diameter of 3.84mm. The aluminum alloy round single wire is then aged in a box-type heat treatment furnace at a temperature of 210℃ for 5 hours. After aging, the aluminum alloy round single wire is air-cooled to room temperature to obtain the high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire.

[0052] Example 2

[0053] This embodiment provides a high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wire. By mass percentage, the composition of the high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wire includes: 0.045% Zr; 0.05% Er; 0.015% B; 0.093% Fe; 0.046% Si; 0.004% (Cr+Mn+V+Ti), with the balance being aluminum and unavoidable trace impurities.

[0054] This embodiment also provides a method for preparing the above-mentioned high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wire, including the following steps: preparing industrial aluminum ingots, Al-B master alloys, Al-Zr master alloys, and Al-Er master alloys according to the composition of the high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wire; placing the industrial aluminum ingots in a melting furnace and melting them at 730°C; after the industrial aluminum ingots are completely melted, adding the Al-B master alloy for boronizing treatment and stirring evenly; then adding the Al-Zr master alloy and Al-Er master alloy at 720°C and stirring. Stir until all raw materials are completely melted, then stir three times, each time for 10 minutes, with a 10-minute interval between each stirring, to obtain an aluminum alloy solution. Control the temperature of the aluminum alloy solution to 740℃, and introduce high-purity nitrogen gas (99.99% purity) and a refining agent (0.3% of the aluminum alloy solution volume, comprising 30% NaCl, 15% KCl, 40% NaF, and 15% Na3AlF6) into the bottom of the aluminum alloy solution for 15 minutes. After stirring for 20 minutes, the mixture was allowed to stand for 30 minutes, followed by slag removal. The aluminum alloy solution after slag removal was filtered to remove impurities. The filtered aluminum alloy solution was then cast into a ceramic mold preheated to 750℃ to prepare an aluminum alloy ingot with dimensions of 25×25×400mm. The aluminum alloy ingot was then heat-treated at 310℃ for 9 hours, followed by a heating rate of 50℃ / h to 490℃, and heat-treated at this temperature for 9 hours. Finally, the temperature was raised to 550℃ at a heating rate of 50℃ / h for 12 hours. After heat treatment, the temperature is lowered to 400℃ and continuously rolled into an aluminum alloy round rod with a diameter of 9.5mm. The aluminum alloy round rod is then drawn multiple times on a wire drawing machine at a speed of 6m / s at 40℃, with a deformation of 8% per drawing pass, until the aluminum alloy round rod becomes an aluminum alloy round single wire with a diameter of 3.84mm. The aluminum alloy round single wire is then aged in a box-type heat treatment furnace at a temperature of 210℃ for 5 hours. After aging, the aluminum alloy round single wire is air-cooled to room temperature to obtain the high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire.

[0055] Example 3

[0056] This embodiment provides a high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wire. By mass percentage, the composition of the high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wire includes: 0.05% Zr; 0.10% Er; 0.015% B; 0.080% Fe; 0.040% Si; 0.003% (Cr+Mn+V+Ti), with the balance being aluminum and unavoidable trace impurities.

[0057] This embodiment also provides a method for preparing the above-mentioned high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wire, including the following steps: preparing industrial aluminum ingots, Al-B master alloys, Al-Zr master alloys, and Al-Er master alloys according to the composition of the high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wire; placing the industrial aluminum ingots in a melting furnace and melting them at 730°C; after the industrial aluminum ingots are completely melted, adding the Al-B master alloy for boronizing treatment and stirring evenly; then adding the Al-Zr master alloy and Al-Er master alloy at 720°C and stirring. Stir until all raw materials are completely melted, then stir three times, each time for 10 minutes, with a 10-minute interval between each stirring, to obtain an aluminum alloy solution. Control the temperature of the aluminum alloy solution to 740℃, and introduce high-purity nitrogen gas (99.99% purity) and a refining agent (0.3% of the aluminum alloy solution volume, comprising 30% NaCl, 15% KCl, 40% NaF, and 15% Na3AlF6) into the bottom of the aluminum alloy solution for 15 minutes. After stirring for 20 minutes, the mixture was allowed to stand for 30 minutes, followed by slag removal. The aluminum alloy solution after slag removal was filtered to remove impurities. The filtered aluminum alloy solution was then cast into a ceramic mold preheated to 750℃ to prepare an aluminum alloy ingot with dimensions of 25×25×400mm. The aluminum alloy ingot was then heat-treated at 310℃ for 9 hours, followed by a heating rate of 50℃ / h to 490℃, and heat-treated at this temperature for 9 hours. Finally, the temperature was raised to 550℃ at a heating rate of 50℃ / h for 12 hours. After heat treatment, the temperature is lowered to 400℃ and continuously rolled into an aluminum alloy round rod with a diameter of 9.5mm. The aluminum alloy round rod is then drawn multiple times on a wire drawing machine at a speed of 6m / s at 40℃, with a deformation of 8% per drawing pass, until the aluminum alloy round rod becomes an aluminum alloy round single wire with a diameter of 3.84mm. The aluminum alloy round single wire is then aged in a box-type heat treatment furnace at a temperature of 210℃ for 5 hours. After aging, the aluminum alloy round single wire is air-cooled to room temperature to obtain the high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire.

[0058] Example 4

[0059] This embodiment provides a high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wire. By mass percentage, the composition of the high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wire includes: 0.05% Zr; 0.15% Er; 0.016% B; 0.092% Fe; 0.040% Si; 0.003% (Cr+Mn+V+Ti), with the balance being aluminum and unavoidable trace impurities.

[0060] This embodiment also provides a method for preparing the above-mentioned high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wire, including the following steps: preparing industrial aluminum ingots, Al-B master alloys, Al-Zr master alloys, and Al-Er master alloys according to the composition of the high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wire; placing the industrial aluminum ingots in a melting furnace and melting them at 730°C; after the industrial aluminum ingots are completely melted, adding the Al-B master alloy for boronizing treatment and stirring evenly; then adding the Al-Zr master alloy and Al-Er master alloy at 720°C and stirring. Stir until all raw materials are completely melted, then stir three times, each time for 10 minutes, with a 10-minute interval between each stirring, to obtain an aluminum alloy solution. Control the temperature of the aluminum alloy solution to 740℃, and introduce high-purity nitrogen gas (99.99% purity) and a refining agent (0.3% of the aluminum alloy solution volume, comprising 30% NaCl, 15% KCl, 40% NaF, and 15% Na3AlF6) into the bottom of the aluminum alloy solution for 15 minutes. After stirring for 20 minutes, the mixture was allowed to stand for 30 minutes, followed by slag removal. The aluminum alloy solution after slag removal was filtered to remove impurities. The filtered aluminum alloy solution was then cast into a ceramic mold preheated to 750℃ to prepare an aluminum alloy ingot with dimensions of 25×25×400mm. The aluminum alloy ingot was then heat-treated at 310℃ for 9 hours, followed by a heating rate of 50℃ / h to 490℃, and heat-treated at this temperature for 9 hours. Finally, the temperature was raised to 550℃ at a heating rate of 50℃ / h for 12 hours. After heat treatment, the temperature is lowered to 400℃ and continuously rolled into an aluminum alloy round rod with a diameter of 9.5mm. The aluminum alloy round rod is then drawn multiple times on a wire drawing machine at a speed of 6m / s at 40℃, with a deformation of 8% per drawing pass, until the aluminum alloy round rod becomes an aluminum alloy round single wire with a diameter of 3.84mm. The aluminum alloy round single wire is then aged in a box-type heat treatment furnace at a temperature of 210℃ for 5 hours. After aging, the aluminum alloy round single wire is air-cooled to room temperature to obtain the high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire.

[0061] Example 5

[0062] This embodiment provides a high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wire. By mass percentage, the composition of the high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wire includes: 0.06% Zr; 0.15% Er; 0.010% B; 0.095% Fe; 0.043% Si; 0.004% (Cr+Mn+V+Ti), with the balance being aluminum and unavoidable trace impurities.

[0063] This embodiment also provides a method for preparing the above-mentioned high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wire, including the following steps: preparing industrial aluminum ingots, Al-B master alloys, Al-Zr master alloys, and Al-Er master alloys according to the composition of the high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wire; placing the industrial aluminum ingots in a melting furnace and melting them at 730°C; after the industrial aluminum ingots are completely melted, adding the Al-B master alloy for boronizing treatment and stirring evenly; then adding the Al-Zr master alloy and Al-Er master alloy at 720°C and stirring. Stir until all raw materials are completely melted, then stir three times, each time for 10 minutes, with a 10-minute interval between each stirring, to obtain an aluminum alloy solution. Control the temperature of the aluminum alloy solution to 740℃, and introduce high-purity nitrogen gas (99.99% purity) and a refining agent (0.3% of the aluminum alloy solution volume, comprising 30% NaCl, 15% KCl, 40% NaF, and 15% Na3AlF6) into the bottom of the aluminum alloy solution for 15 minutes. After stirring for 20 minutes, the mixture was allowed to stand for 30 minutes, followed by slag removal. The aluminum alloy solution after slag removal was filtered to remove impurities. The filtered aluminum alloy solution was then cast into a ceramic mold preheated to 750℃ to prepare an aluminum alloy ingot with dimensions of 25×25×400mm. The aluminum alloy ingot was then heat-treated at 310℃ for 9 hours, followed by a heating rate of 50℃ / h to 490℃, and heat-treated at this temperature for 9 hours. Finally, the temperature was raised to 550℃ at a heating rate of 50℃ / h for 12 hours. After heat treatment, the temperature is lowered to 400℃ and continuously rolled into an aluminum alloy round rod with a diameter of 9.5mm. The aluminum alloy round rod is then drawn multiple times on a wire drawing machine at a speed of 6m / s at 40℃, with a deformation of 8% per drawing pass, until the aluminum alloy round rod becomes an aluminum alloy round single wire with a diameter of 3.84mm. The aluminum alloy round single wire is then aged in a box-type heat treatment furnace at a temperature of 210℃ for 5 hours. After aging, the aluminum alloy round single wire is air-cooled to room temperature to obtain the high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire.

[0064] Example 6

[0065] This embodiment provides a high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wire. By mass percentage, the composition of the high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wire includes: 0.045% Zr; 0.05% Er; 0.015% B; 0.093% Fe; 0.046% Si; 0.004% (Cr+Mn+V+Ti), with the balance being aluminum and unavoidable trace impurities.

[0066] This embodiment also provides a method for preparing the above-mentioned high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire, including the following steps: Prepare industrial aluminum ingots, Al-B master alloy, Al-Zr master alloy, and Al-Er master alloy according to the composition of the high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire; place the industrial aluminum ingot in a melting furnace and melt it at 730°C; after the industrial aluminum ingot is completely melted, add the Al-B master alloy for boronizing treatment and stir evenly; add the Al-Zr master alloy and Al-Er master alloy at 720°C and stir; after all raw materials are completely melted, stir three times, each time for 10 minutes, with a 10-minute interval between each stirring, to obtain an aluminum alloy solution; control the temperature of the aluminum alloy solution to 740°C; introduce high-purity nitrogen gas (99.99% purity) and a refining agent (the amount of the refining agent is 0.3% of the aluminum alloy solution, wherein the refining agent includes the following components: 30% NaCl, 15% KCl, 40% NaF, and 15% Na3) into the bottom of the aluminum alloy solution. AlF6 was used, with an aeration time of 15 min, stirring for 20 min, and then allowed to stand for 30 min. The slag was then removed. The aluminum alloy solution after slag removal was filtered to remove impurities. The filtered aluminum alloy solution was then cast into a ceramic mold preheated to 750℃ to prepare an aluminum alloy ingot with dimensions of 25×25×400mm. The aluminum alloy ingot was then heat-treated at 310℃ for 9 h, followed by a heating rate of 50℃ / h to 490℃, and heat-treated at this temperature for 21 h. After cooling to 400℃, the aluminum alloy round rod is continuously rolled into a Φ9.5mm aluminum alloy round rod. The aluminum alloy round rod is then drawn multiple times on a wire drawing machine at 40℃ and a speed of 6m / s, with a deformation of 8% per drawing pass, until the aluminum alloy round rod becomes an aluminum alloy round single wire with a diameter of 3.84mm. The aluminum alloy round single wire is then aged in a box-type heat treatment furnace at 210℃ for 5 hours. After aging, the aluminum alloy round single wire is air-cooled to room temperature to obtain the high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire.

[0067] Test case

[0068] The high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wires obtained in Examples 1-7 were tested for room temperature conductivity, room temperature tensile strength, and high-temperature strength retention.

[0069] The room temperature conductivity was tested at 20℃ according to GB / T 3048.2-2007 standard;

[0070] The room temperature tensile strength was tested at 20℃ according to GB / T 4909.3-2009 standard;

[0071] The high-temperature strength retention rate test was conducted at 280℃, according to the GB / T 30551-2014 standard.

[0072] The test results of room temperature conductivity, room temperature tensile strength and high temperature strength retention are shown in Table 1.

[0073] Table 1

[0074]

[0075]

[0076] As shown in Table 1, the high conductivity and ultra-heat resistant aluminum alloy wire material of the present invention has obvious advantages in comprehensive performance. In particular, the room temperature (20℃) conductivity can reach 61.5% IACS, the room temperature tensile strength can reach 169MPa, the strength retention rate after 1 hour of heat preservation at 280℃ can reach 95.8%, and the heat resistance temperature can reach 210℃.

[0077] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A high-strength high-conductivity heat-resistant aluminum alloy energy-saving wire, characterized by, By mass percentage, it includes: 0.03~0.06% Zr; 0.05~0.15% Er; 0.002~0.02% B; Fe≤0.1%; Si≤0.05%; (Cr+Mn+V+Ti)≤0.005%, with the balance being aluminum and unavoidable trace impurities; The preparation method of the high-strength, high-conductivity, and heat-resistant aluminum alloy energy-saving wire includes the following steps: 1) Melt the raw materials according to the formula ratio to obtain an aluminum alloy solution; 2) The aluminum alloy solution is refined, allowed to stand, and then cast to obtain aluminum alloy ingots; 3) The aluminum alloy ingot is heat-treated and then rolled to obtain an aluminum alloy round rod; 4) The aluminum alloy round rod is drawn and aged to obtain the high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire; The heat treatment process for aluminum alloy ingots includes sequentially performing a first heat treatment, a second heat treatment, and a third heat treatment; the temperature for the first heat treatment is 300℃~320℃; the temperature for the second heat treatment is 480℃~500℃; the temperature for the third heat treatment is 500℃~600℃; the duration for the first heat treatment is 8~10 hours, the duration for the second heat treatment is 8~10 hours, and the duration for the third heat treatment is 3 hours~15 hours.

2. The method of producing the high-strength high-conductivity heat-resistant aluminum alloy energy-saving wire rod of claim 1, characterized by, Includes the following steps: 1) Melt the raw materials according to the formula ratio to obtain an aluminum alloy solution; 2) The aluminum alloy solution is refined, allowed to stand, and then cast to obtain aluminum alloy ingots; 3) The aluminum alloy ingot is heat-treated and then rolled to obtain an aluminum alloy round rod; 4) The aluminum alloy round rod is drawn and aged to obtain the high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire; The heat treatment process for aluminum alloy ingots includes sequentially performing a first heat treatment, a second heat treatment, and a third heat treatment; the temperature for the first heat treatment is 300℃~320℃; the temperature for the second heat treatment is 480℃~500℃; and the temperature for the third heat treatment is 500℃~600℃.

3. The method for preparing high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire according to claim 2, characterized in that, The temperature during the rolling process is 400-450℃; and / or, The diameter of the rolled aluminum alloy round bar is 8-12 mm; and / or, In the wire drawing step, the wire drawing rate is 6~8 m / s, the wire drawing temperature is 40~50℃, the single-pass deformation is 5~8%, and the diameter of the aluminum alloy wire obtained after drawing is 3.5-4 mm; and / or, The aging temperature in the aging process is 200℃~220℃, and the aging time is 4~6 hours.

4. The method for preparing high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire according to claim 2, characterized in that, The smelting process in step 1) includes the following steps: smelting industrial aluminum ingots at 730℃~750℃, then adding Al-B master alloy at 720-730℃, stirring, and letting it stand for 20-30 minutes. Then adding Al-Zr master alloy and Al-Er master alloy at 720~730℃, stirring, and stirring 2~3 times after all alloy materials have melted, with each stirring time being 10~15 minutes and the interval between each stirring being 10~15 minutes.

5. The method for preparing high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire according to claim 4, characterized in that, The industrial aluminum ingot contains 99.7-99.8 wt% Al, ≤0.085 wt% Fe, ≤0.036 wt% Si, and ≤0.009 wt% Cr, Mn, V, and Ti. The Al-B master alloy contains 2-3 wt% B, the Al-Zr master alloy contains 4-6 wt% Zr, and the Al-Er master alloy contains 8-12 wt% Er.

6. The method for preparing high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire according to claim 2, characterized in that, The refining step described in step 2) includes: controlling the aluminum alloy solution at 740~760℃, then introducing nitrogen and refining agent into the solution, stirring for 15~20 minutes after purging, then letting it stand for 20~30 minutes before removing the slag to obtain the refined aluminum alloy solution; and / or, The casting process involves pouring molten aluminum alloy into a ceramic mold; and / or, The process also includes a preheating step of the ceramic mold before casting, wherein the preheating temperature is 750-760℃; and / or, The process of filtering the refined aluminum alloy solution before the casting step also includes a step of filtering the solution.

7. The method for preparing high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire according to claim 6, characterized in that, The purity of the nitrogen gas is not less than 99.99%, and the amount of the refining agent added is 0.25% to 0.30% of the weight of the aluminum alloy solution.

8. The method for preparing high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire according to claim 7, characterized in that, The refining agent comprises, by mass percentage, the following components: 25-30% NaCl, 10-15% KCl, 40-50% NaF, and 5-15% Na3AlF6.

9. The method for preparing high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire according to any one of claims 2-8, characterized in that, The heat treatment process for aluminum alloy ingots includes the following steps: after the first heat treatment, the temperature is increased to the second heat treatment temperature at a rate of 40-60℃ / h for the second heat treatment; after the second heat treatment, the temperature is increased to the third heat treatment temperature at a rate of 40-60℃ / h for the third heat treatment.

10. A power transmission conductor, characterized in that, The power transmission conductor includes the high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire as described in claim 1, or the high-strength, high-conductivity, heat-resistant aluminum alloy energy-saving wire prepared by any one of the preparation methods described in claims 2-9.

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