High-strength heat-resistant aluminum alloy conductor and preparation method thereof

Abstract

The invention discloses a high-strength heat-resistant aluminum alloy conductor which comprises the following components in percentage by mass: less than or equal to 0.15% of Fe, less than or equal to 0.15% of Si, 0.03-0.2% of Mo, 0.03-0.2% of Ta, 0.03-0.2% of Nb, 0.03-0.2% of Yb, 0.03-0.2% of Dy, 0.001-0.008% of B, less than or equal to 0.03% of other inevitable single impurity elements, less than or equal to 0.003% of the total amount of Mn, Cr and V, less than or equal to 0.15% of the total amount of the impurity elements and the balance of aluminum. The high-strength heat-resistant aluminum alloy conductor has high conductivity and excellent high-temperature mechanical properties, the tensile strength at the room temperature is larger than or equal to 160 MPa, the elongation at break is larger than or equal to 16%, the conductivity at the temperature of 20 DEG C is larger than or equal to 62% IACS, and the high-strength heat-resistant aluminum alloy conductor has high compressive creep resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of aluminum alloys and processing thereof, and particularly relates to a high-strength heat-resistant aluminum alloy wire and a preparation method thereof. Background Art

[0002] Aluminum alloy conductors are the main structure and function of aluminum alloy cables. They can be used not only in the traditional field of power transportation, but also have good application prospects in other fields. For example, in the field of photovoltaic power generation, under the condition of meeting electrical performance, the cost of low-voltage aluminum alloy cables is low, and combined with the strong corrosion resistance of aluminum alloy materials, lighter and more flexible characteristics, it can make up for the shortcomings of traditional copper core cables such as memory effect and high rebound. In the field of wind power generation, because aluminum alloy cables are mainly used for fixed laying sections, the cables are arranged regularly and have good heat dissipation performance. After docking with copper cables, the temperature rise is smaller than that of copper cables in the torsion section, the transmission loss is also smaller, and the power generation efficiency of the wind turbine is higher. In addition, aluminum alloy cables also have great competitive advantages in railways, buildings, ships, etc.

[0003] However, since the performance of traditional aluminum alloy products in my country, such as tensile strength, conductivity, creep resistance, etc., needs to be improved, there are few high-performance and high-quality aluminum alloy conductor products, which affects the promotion and application of aluminum alloy conductors. For example, in urban power grid systems, the application volume of cables in 35 kV and below distribution lines is large, with an annual increase of more than 100,000 kilometers, but the proportion of aluminum core cables is less than 5%, and the aluminum alloy cables used in medium-voltage distribution are even less.

[0004] In order to improve the performance of aluminum alloy wires, researchers hope to obtain aluminum alloy wires with excellent mechanical properties and heat resistance by adding different alloying elements. For example, Chinese patent application No. 201911121270.7 discloses an aluminum alloy wire and its preparation method by adding Co, Zr, Cu, Ag, Au and other transition metal elements; Chinese patent application No. 202210324020.9 discloses an aluminum alloy wire and its preparation method mainly adding Co and Zr elements. The above-mentioned reported technology improves the tensile strength and elongation of aluminum alloy wires and makes them have higher heat resistance, but does not pay attention to the improvement of room temperature conductivity. It can be seen that how to comprehensively improve the mechanical properties, heat resistance and conductivity of aluminum alloy wires is the focus and difficulty of current research. Summary of the invention

[0005] In view of the above shortcomings, the present invention discloses a high-strength heat-resistant aluminum alloy wire and a preparation method thereof, which improves the mechanical properties, heat resistance and electrical conductivity of the aluminum alloy wire by rationally optimizing the aluminum alloy elements and adding an appropriate amount of rare earth elements for micro-alloying.

[0006] The present invention is achieved by adopting the following technical solutions: A high-strength heat-resistant aluminum alloy wire, comprising the following components in percentage by mass: Fe≤0.15%, Si≤0.15%, 0.03~0.2% Mo, 0.03~0.2% Ta, 0.03~0.2% Nb, 0.03~0.2% Yb, 0.03~0.2% Dy, 0.001~0.008% B, other unavoidable single impurity elements ≤0.03% and the total amount of Mn, Cr and V ≤0.003%, the total amount of impurity elements ≤0.15%, and the balance is aluminum.

[0007] Furthermore, the high-strength heat-resistant aluminum alloy wire comprises the following components in percentage by mass: Fe≤0.1%, Si≤0.1%, 0.05-0.16% Mo, 0.05-0.14% Ta, 0.03-0.14% Nb, 0.05-0.18% Yb, 0.05-0.18% Dy, 0.001-0.005% B, other unavoidable single impurity elements ≤0.03% and the total amount of Mn, Cr and V ≤0.003%, the total amount of impurity elements ≤0.15%, and the balance is aluminum; the total content of Mo, Ta and Nb is 0.18-0.40%; the total content of Yb and Dy is 0.15-0.30%, and the ratio of their contents Yb:Dy is (1-3):1.

[0008] A method for preparing a high-strength heat-resistant aluminum alloy wire comprises the following steps: (1) According to the composition of the above-mentioned high-strength heat-resistant aluminum alloy wire, aluminum ingots, aluminum-iron master alloys, aluminum-molybdenum master alloys, aluminum-tantalum master alloys, aluminum-niobium master alloys, aluminum-ytterbium master alloys and aluminum-dysprosium master alloys are selected and loaded into a melting furnace, heated to 720-800° C., and then kept warm for melting to obtain melt I; (2) adding an aluminum-boron master alloy to the melt I obtained in step (1), and when the aluminum-boron master alloy is completely melted, smelting at 720 to 760° C. to obtain a melt II; (3) Sampling the melt II obtained in step (2) to detect the composition. If the composition is unqualified, adjusting according to the result, adding the corresponding intermediate alloy to the melt II until the composition is qualified; when the composition is qualified, refining the melt II, that is, introducing argon gas into the melt II and refining at 720-760° C., after the refining is completed, letting it stand and removing the slag on the surface to obtain aluminum liquid; (4) The aluminum liquid obtained in step (3) is discharged and subjected to double-stage filtration treatment in a filter box, and then transferred to a heat preservation furnace for heat preservation, and then the aluminum liquid is horizontally continuously cast and continuously drawn into a round rod with a diameter of 8 to 10 mm, and the round rod is collected into a coil by a wire take-up machine to obtain a wire I, wherein the tensile strength of the wire I is ≥120 MPa and the electrical conductivity is ≥58% IACS; (5) placing the wire material I obtained in step (4) into an annealing furnace for homogenization annealing, and after the annealing is completed, taking the wire material out of the furnace and cooling it to obtain the wire material II; (6) Drawing the wire II obtained in step (5) for 8 to 12 times, performing an intermediate annealing on the wire II during the drawing process, and finally annealing the wire II after drawing it to a diameter of 1.35 to 1.40 mm, and then removing the cooling to obtain the wire III; (7) The wire III obtained in step (6) is subjected to final drawing and sizing processing to obtain a wire with a diameter of 1.18 to 1.22 mm, and the surface oil is removed and dried to obtain a high-strength heat-resistant aluminum alloy conductor.

[0009] Furthermore, in step (1), the heat preservation and smelting time is 1 to 2 hours.

[0010] Furthermore, in step (2), the heat preservation and smelting time is 1 to 2 hours.

[0011] Furthermore, in step (3), the refining time is 45 to 60 minutes, and the argon gas introduced is 99.99% high-purity argon gas.

[0012] Furthermore, in step (4), the double-stage filtration treatment is to use a 60-mesh ceramic filter plate for the first stage filtration and then use an 80-mesh ceramic filter plate for the second stage filtration.

[0013] Furthermore, in step (4), the temperature of the aluminum liquid in the insulation furnace is controlled at 680-720°C.

[0014] Furthermore, in step (4), the casting speed of the round rod is 200 to 500 mm / min.

[0015] Furthermore, in step (5), the homogenization annealing is performed by placing the wire material I into an annealing furnace and keeping the temperature at 540-600° C. for 8-24 hours, and the cooling method is water cooling.

[0016] Furthermore, in step (6), the temperatures of the intermediate annealing and the final annealing are both 380-480° C., the holding times of the intermediate annealing and the final annealing are both 1.5-4 hours, and the cooling method is air cooling.

[0017] Compared with the prior art, this technical solution has the following beneficial effects: 1. The present invention improves the mechanical properties of aluminum alloy wires by adding appropriate amounts of rare earth elements Yb and Dy, while strictly controlling the amount of rare earth elements added to ensure that the aluminum alloy wires have high electrical conductivity. Rare earth elements Yb and Dy have multiple functions: on the one hand, Yb and Dy can effectively purify and remove hydrogen elements and inclusions in the aluminum liquid during the smelting process to ensure the cleanliness of the aluminum liquid; on the other hand, Yb and Dy can effectively refine the grain size of the cast aluminum alloy during the casting process to obtain a fine grain structure; on the other hand, Yb and Dy can undergo solid-state phase transformation during the subsequent homogenization process, precipitate in the form of nanoscale compounds, and hinder the migration of dislocations and grain boundaries. These multiple functions can simultaneously improve the room temperature mechanical properties and heat resistance of aluminum alloy wires.

[0018] (2) The present invention improves the mechanical properties of aluminum alloy wires by adding appropriate amounts of refractory metal elements Mo, Ta, and Nb, while strictly controlling the amount of added elements to ensure that the aluminum alloy wires have high electrical conductivity. Refractory metal elements Mo, Ta, and Nb also have multiple functions: on the one hand, Mo, Ta, and Nb can generate intermetallic compounds in aluminum alloys, and act as seeds to increase the nucleation rate of crystallization during solidification and crystallization, and refine the cast grain size of aluminum alloys; on the other hand, Mo, Ta, and Nb have low diffusion coefficients in aluminum alloys, and the intermetallic compounds generated by them are highly stable at higher temperatures, and can hinder dislocation and grain boundary migration at high temperatures; on the other hand, Mo, Ta, and Nb have the possibility of interacting with rare earth elements Yb and Dy, and generating complex intermetallic compounds. Such complex intermetallic compounds have higher heat resistance and can further improve the mechanical properties and heat resistance of aluminum alloy wires. The main purpose of adding Mo, Ta, and Nb elements is to improve the heat resistance of aluminum alloy wires.

[0019] (3) The present invention strictly controls the content of impurity elements, wherein the content of Fe and Si is required to be no higher than 0.1%, and strictly controls the total content of transition metal elements Cr, Mn, and V, to ensure that the aluminum alloy wire has a high electrical conductivity. In addition, compared with the prior art, the aluminum alloy wire material of the present invention does not add alloy elements such as Cu, Mg, and Zn, which have a high solid solubility in aluminum alloys and have a greater impact on electrical conductivity, further ensuring that the aluminum alloy wire has a high electrical conductivity. DETAILED DESCRIPTION

[0020] The present invention is further described by the following examples, but is not intended to be limiting of the present invention. Specific experimental conditions and methods not specified in the following examples are conventional methods commonly known to those skilled in the art.

[0021] Embodiment 1: A high-strength heat-resistant aluminum alloy wire, comprising the following components in percentage by mass: Fe: 0.06%, Si: 0.04%, Mo: 0.11%, Ta: 0.12%, Nb: 0.09%, Yb: 0.16%, Dy: 0.14%, B: 0.003%, other unavoidable single impurity elements ≤ 0.03%, of which the total amount of Mn, Cr, and V is 0.0008%, the total amount of impurity elements ≤ 0.15%, and the balance is aluminum; the total content of Mo, Ta and Nb is 0.32%; the total content of Yb and Dy is 0.30%, and the content ratio of the two, Yb:Dy, is 1.14:1.

[0022] The method for preparing the high-strength heat-resistant aluminum alloy wire described in this embodiment comprises the following steps: (1) According to the composition of the high-strength heat-resistant aluminum alloy wire described in this embodiment, aluminum ingots, aluminum-iron master alloys, aluminum-molybdenum master alloys, aluminum-tantalum master alloys, aluminum-niobium master alloys, aluminum-ytterbium master alloys and aluminum-dysprosium master alloys are selected and loaded into a melting furnace, heated to 760° C., and then kept warm for melting to obtain melt I, and the time for the kept warm melting is 1.5 hours; (2) adding an aluminum-boron master alloy to the melt I obtained in step (1), and when the aluminum-boron master alloy is completely melted, smelting the melt at 745° C. for 1.5 hours to obtain a melt II; (3) Sampling the melt II obtained in step (2) to detect the composition. If the composition is unqualified, adjusting according to the result, adding the corresponding intermediate alloy to the melt II until the composition is qualified; when the composition is qualified, refining the melt II, that is, introducing argon gas into the melt II and refining it at 745° C. After the refining is completed, the melt II is allowed to stand and the slag on the surface is removed to obtain aluminum liquid; the refining time is 50 minutes, and the introduced argon gas is 99.99% high-purity argon gas; (4) The aluminum liquid obtained in step (3) is discharged and subjected to double-stage filtration treatment in a filter box, and then transferred to a heat preservation furnace for heat preservation. The temperature of the aluminum liquid in the heat preservation furnace is controlled at 717° C., and then the aluminum liquid is horizontally continuously cast and drawn into a round rod with a diameter of 8.6 mm, and then collected into a coil by a wire take-up machine to obtain wire I. The casting speed of the round rod is 400 mm / min. The double-stage filtration treatment adopts a 60-mesh ceramic filter plate for the first stage filtration, and then adopts an 80-mesh ceramic filter plate for the second stage filtration. The tensile strength and conductivity of the wire I are tested, and the wire I with a tensile strength ≥120 MPa and a conductivity ≥58% IACS is reserved; (5) placing the wire material I obtained in step (4) into an annealing furnace for homogenization annealing, and after the annealing is completed, taking the wire material out of the furnace and cooling it to obtain the wire material II; the homogenization annealing is performed by placing the wire material I into the annealing furnace and keeping it at a temperature of 560° C. for 16 hours, and the cooling method is water cooling; (6) subjecting the wire II obtained in step (5) to 8 to 12 drawing processes, during which the wire II is subjected to one intermediate annealing, and after the wire II is drawn to a diameter of 1.35 to 1.40 mm, it is subjected to a final annealing, and then removed and cooled to obtain the wire III; the temperature of the intermediate annealing and the final annealing are both 400° C., the holding time of the intermediate annealing and the final annealing are both 2 hours, and the cooling method is air cooling; (7) The wire III obtained in step (6) is subjected to final drawing and sizing processing to obtain a wire with a diameter of 1.18 to 1.22 mm, and the surface oil is removed and dried to obtain a high-strength heat-resistant aluminum alloy conductor.

[0023] Embodiment 2: A high-strength heat-resistant aluminum alloy wire, comprising the following components in percentage by mass: Fe: 0.04%, Si: 0.04%, Mo: 0.08%, Ta: 0.08%, Nb: 0.09%, Yb: 0.12%, Dy: 0.07%, B: 0.002%, other unavoidable single impurity elements ≤ 0.03%, of which the total amount of Mn, Cr, and V is 0.0009%, the total amount of impurity elements is ≤ 0.15%, and the balance is aluminum; the total content of Mo, Ta and Nb is 0.25%; the total content of Yb and Dy is 0.19, and the content ratio of the two, Yb:Dy, is 1.71:1.

[0024] The method for preparing the high-strength heat-resistant aluminum alloy wire described in this embodiment comprises the following steps: (1) According to the composition of the high-strength heat-resistant aluminum alloy wire described in this embodiment, aluminum ingots, aluminum-iron master alloys, aluminum-molybdenum master alloys, aluminum-tantalum master alloys, aluminum-niobium master alloys, aluminum-ytterbium master alloys and aluminum-dysprosium master alloys are selected and loaded into a melting furnace, heated to 780° C., and then kept warm for melting to obtain melt I. The time for the kept warm melting is 1.5 hours; (2) adding an aluminum-boron master alloy to the melt I obtained in step (1), and when the aluminum-boron master alloy is completely melted, smelting the melt II at 750° C. for 1.5 hours; (3) Sampling the melt II obtained in step (2) to detect the composition. If the composition is unqualified, adjusting according to the result, adding the corresponding intermediate alloy to the melt II until the composition is qualified; when the composition is qualified, refining the melt II, that is, introducing argon gas into the melt II and refining it at 750° C. After the refining is completed, the melt II is allowed to stand and the slag on the surface is removed to obtain aluminum liquid; the refining time is 50 minutes, and the introduced argon gas is 99.99% high-purity argon gas; (4) The aluminum liquid obtained in step (3) is discharged and subjected to double-stage filtration treatment in a filter box, and then transferred to a heat preservation furnace for heat preservation. The temperature of the aluminum liquid in the heat preservation furnace is controlled at 710° C., and then the aluminum liquid is horizontally continuously cast and drawn into a round rod with a diameter of 8.2 mm, and then collected into a coil by a wire take-up machine to obtain wire I. The casting speed of the round rod is 450 mm / min. The double-stage filtration treatment adopts a 60-mesh ceramic filter plate for the first stage filtration, and then adopts an 80-mesh ceramic filter plate for the second stage filtration. The tensile strength and conductivity of the wire I are tested, and the wire I with a tensile strength ≥120 MPa and a conductivity ≥58% IACS is reserved; (5) placing the wire material I obtained in step (4) into an annealing furnace for homogenization annealing, and after the annealing is completed, taking the wire material out of the furnace and cooling it to obtain the wire material II; the homogenization annealing is performed by placing the wire material I into the annealing furnace and keeping it at a temperature of 570° C. for 12 hours, and the cooling method is water cooling; (6) The wire II obtained in step (5) is subjected to 8 to 12 drawing processes, during which the wire II is subjected to one intermediate annealing, and the wire II is drawn to a diameter of 1.35 to 1.40 mm and then subjected to final annealing, followed by removal and cooling to obtain the wire III; the intermediate annealing and final annealing temperatures are both 420° C., the intermediate annealing and final annealing holding times are both 2 hours, and the cooling method is air cooling; (7) The wire III obtained in step (6) is subjected to final drawing and sizing processing to obtain a wire with a diameter of 1.18 to 1.22 mm, and the surface oil is removed and dried to obtain a high-strength heat-resistant aluminum alloy conductor.

[0025] Embodiment 3: A high-strength heat-resistant aluminum alloy wire, comprising the following components in percentage by mass: Fe: 0.05%, Si: 0.06%, Mo: 0.15%, Ta: 0.12%, Nb: 0.10%, Yb: 0.18%, Dy: 0.07%, B: 0.003%, other unavoidable single impurity elements ≤ 0.03%, of which the total amount of Mn, Cr, and V is 0.0008%, the total amount of impurity elements is ≤ 0.15%, and the balance is aluminum; the total content of Mo, Ta and Nb is 0.37%; the total content of Yb and Dy is 0.25%, and the content ratio of the two, Yb:Dy, is 2.57:1.

[0026] The method for preparing the high-strength heat-resistant aluminum alloy wire described in this embodiment comprises the following steps: (1) According to the composition of the high-strength heat-resistant aluminum alloy wire described in this embodiment, aluminum ingots, aluminum-iron master alloys, aluminum-molybdenum master alloys, aluminum-tantalum master alloys, aluminum-niobium master alloys, aluminum-ytterbium master alloys and aluminum-dysprosium master alloys are selected and loaded into a melting furnace, heated to 760° C., and then kept warm for melting to obtain melt I, and the time for the kept warm melting is 1.5 hours; (2) adding an aluminum-boron master alloy to the melt I obtained in step (1), and when the aluminum-boron master alloy is completely melted, smelting the melt at 745° C. for 1.5 hours to obtain a melt II; (3) Sampling the melt II obtained in step (2) to detect the composition. If the composition is unqualified, adjusting according to the result, adding the corresponding intermediate alloy to the melt II until the composition is qualified; when the composition is qualified, refining the melt II, that is, introducing argon gas into the melt II and refining it at 745° C. After the refining is completed, the melt II is allowed to stand and the slag on the surface is removed to obtain aluminum liquid; the refining time is 50 minutes, and the introduced argon gas is 99.99% high-purity argon gas; (4) The aluminum liquid obtained in step (3) is discharged and subjected to double-stage filtration treatment in a filter box, and then transferred to a heat preservation furnace for heat preservation. The temperature of the aluminum liquid in the heat preservation furnace is controlled at 717° C., and then the aluminum liquid is horizontally continuously cast and drawn into a round rod with a diameter of 8.6 mm, and then collected into a coil by a wire take-up machine to obtain wire I. The casting speed of the round rod is 400 mm / min. The double-stage filtration treatment adopts a 60-mesh ceramic filter plate for the first stage filtration, and then adopts an 80-mesh ceramic filter plate for the second stage filtration. The tensile strength and conductivity of the wire I are tested, and the wire I with a tensile strength ≥120 MPa and a conductivity ≥58% IACS is reserved; (5) placing the wire material I obtained in step (4) into an annealing furnace for homogenization annealing, and after the annealing is completed, taking the wire material out of the furnace and cooling it to obtain the wire material II; the homogenization annealing is performed by placing the wire material I into the annealing furnace and keeping it at a temperature of 560° C. for 16 hours, and the cooling method is water cooling; (6) subjecting the wire II obtained in step (5) to 8 to 12 drawing processes, during which the wire II is subjected to one intermediate annealing, and after the wire II is drawn to a diameter of 1.35 to 1.40 mm, it is subjected to a final annealing, and then removed and cooled to obtain the wire III; the temperature of the intermediate annealing and the final annealing are both 400° C., the holding time of the intermediate annealing and the final annealing are both 2 hours, and the cooling method is air cooling; (7) The wire III obtained in step (6) is subjected to final drawing and sizing processing to obtain a wire with a diameter of 1.18 to 1.22 mm, and the surface oil is removed and dried to obtain a high-strength heat-resistant aluminum alloy conductor.

[0027] Embodiment 4: A high-strength heat-resistant aluminum alloy wire comprising the following components in percentage by mass: Fe: 0.04%, Si: 0.04%, Mo: 0.03%, Ta: 0.03%, Nb: 0.03%, Yb: 0.2%, Dy: 0.2%, B: 0.001%, other unavoidable single impurity elements ≤ 0.03%, of which the total content of Mn, Cr and V is 0.0007%, the total amount of impurity elements is ≤ 0.15%, and the balance is aluminum; the total content of Mo, Ta and Nb is 0.09%; the total content of Yb and Dy is 0.40%, and the ratio of their contents Yb:Dy is 1:1.

[0028] The method for preparing the high-strength heat-resistant aluminum alloy wire described in this embodiment comprises the following steps: (1) According to the composition of the high-strength heat-resistant aluminum alloy wire described in this embodiment, aluminum ingots, aluminum-iron master alloys, aluminum-molybdenum master alloys, aluminum-tantalum master alloys, aluminum-niobium master alloys, aluminum-ytterbium master alloys and aluminum-dysprosium master alloys are selected and loaded into a melting furnace, heated to 720° C., and then kept warm for melting to obtain melt I, and the time for the kept warm melting is 1 hour; (2) adding an aluminum-boron master alloy to the melt I obtained in step (1), and when the aluminum-boron master alloy is completely melted, smelting at 720° C. to obtain a melt II, wherein the smelting time is 1 hour; (3) Sampling the melt II obtained in step (2) to detect the composition. If the composition is unqualified, adjusting according to the result, adding the corresponding intermediate alloy to the melt II until the composition is qualified; when the composition is qualified, refining the melt II, that is, introducing argon gas into the melt II and refining at 720° C., after the refining is completed, standing and removing the slag on the surface to obtain aluminum liquid; the refining time is 45 minutes, and the introduced argon gas is 99.99% high-purity argon gas; (4) The aluminum liquid obtained in step (3) is discharged and subjected to double-stage filtration treatment in a filter box, and then transferred to a heat preservation furnace for heat preservation. The temperature of the aluminum liquid in the heat preservation furnace is controlled at 680° C., and then the aluminum liquid is horizontally continuously cast and drawn into a round rod with a diameter of 8 mm, and is collected into a coil by a wire take-up machine to obtain wire I. The casting speed of the round rod is 200 mm / min. The double-stage filtration treatment adopts a 60-mesh ceramic filter plate for the first stage filtration, and then adopts an 80-mesh ceramic filter plate for the second stage filtration. The tensile strength and conductivity of the wire I are tested, and the wire I with a tensile strength ≥120 MPa and a conductivity ≥58% IACS is reserved; (5) placing the wire material I obtained in step (4) into an annealing furnace for homogenization annealing, and after the annealing is completed, taking the wire material out of the furnace and cooling it to obtain the wire material II; the homogenization annealing is performed by placing the wire material I into the annealing furnace and keeping it at a temperature of 540° C. for 24 hours, and the cooling method is water cooling; (6) subjecting the wire II obtained in step (5) to 8 to 12 drawing processes, during which the wire II is subjected to one intermediate annealing, and after the wire II is drawn to a diameter of 1.35 to 1.40 mm, it is subjected to a final annealing, and then removed and cooled to obtain the wire III; the temperature of the intermediate annealing and the final annealing are both 380° C., the holding time of the intermediate annealing and the final annealing are both 4 hours, and the cooling method is air cooling; (7) The wire III obtained in step (6) is subjected to final drawing and sizing processing to obtain a wire with a diameter of 1.18 to 1.22 mm, and the surface oil is removed and dried to obtain a high-strength heat-resistant aluminum alloy conductor.

[0029] Embodiment 5: A high-strength heat-resistant aluminum alloy wire comprising the following components in percentage by mass: Fe: 0.05%, Si: 0.05%, Mo: 0.12%, Ta: 0.12%, Nb: 0.11%, Yb: 0.03%, Dy: 0.03%, B: 0.003%, other inevitable single impurity elements ≤ 0.03%, of which the total amount of Mn, Cr, and V is 0.0008%, the total amount of impurity elements ≤ 0.15%, and the balance is aluminum; the total content of Mo, Ta and Nb is 0.33%; the total content of Yb and Dy is 0.06%, and the ratio of their contents Yb:Dy is 1:1.

[0030] The method for preparing the high-strength heat-resistant aluminum alloy wire described in this embodiment comprises the following steps: (1) According to the composition of the high-strength heat-resistant aluminum alloy wire described in this embodiment, aluminum ingots, aluminum-iron master alloys, aluminum-molybdenum master alloys, aluminum-tantalum master alloys, aluminum-niobium master alloys, aluminum-ytterbium master alloys and aluminum-dysprosium master alloys are selected and loaded into a melting furnace, heated to 760° C., and then kept warm for melting to obtain melt I, and the time for the kept warm melting is 1.5 hours; (2) adding an aluminum-boron master alloy to the melt I obtained in step (1), and when the aluminum-boron master alloy is completely melted, smelting the melt at 745° C. for 1.5 hours to obtain a melt II; (3) Sampling the melt II obtained in step (2) to detect the composition. If the composition is unqualified, adjusting according to the result, adding the corresponding intermediate alloy to the melt II until the composition is qualified; when the composition is qualified, refining the melt II, that is, introducing argon gas into the melt II and refining it at 745° C. After the refining is completed, the melt II is allowed to stand and the slag on the surface is removed to obtain aluminum liquid; the refining time is 50 minutes, and the introduced argon gas is 99.99% high-purity argon gas; (4) The aluminum liquid obtained in step (3) is discharged and subjected to double-stage filtration treatment in a filter box, and then transferred to a heat preservation furnace for heat preservation. The temperature of the aluminum liquid in the heat preservation furnace is controlled at 717° C., and then the aluminum liquid is horizontally continuously cast and drawn into a round rod with a diameter of 8.6 mm, and then collected into a coil by a wire take-up machine to obtain wire I. The casting speed of the round rod is 400 mm / min. The double-stage filtration treatment adopts a 60-mesh ceramic filter plate for the first stage filtration, and then adopts an 80-mesh ceramic filter plate for the second stage filtration. The tensile strength and conductivity of the wire I are tested, and the wire I with a tensile strength ≥120 MPa and a conductivity ≥58% IACS is reserved; (5) placing the wire material I obtained in step (4) into an annealing furnace for homogenization annealing, and after the annealing is completed, taking the wire material out of the furnace and cooling it to obtain the wire material II; the homogenization annealing is performed by placing the wire material I into the annealing furnace and keeping it at a temperature of 560° C. for 16 hours, and the cooling method is water cooling; (6) subjecting the wire II obtained in step (5) to 8 to 12 drawing processes, during which the wire II is subjected to one intermediate annealing, and after the wire II is drawn to a diameter of 1.35 to 1.40 mm, it is subjected to a final annealing, and then removed and cooled to obtain the wire III; the temperature of the intermediate annealing and the final annealing are both 400° C., the holding time of the intermediate annealing and the final annealing are both 2 hours, and the cooling method is air cooling; (7) The wire III obtained in step (6) is subjected to final drawing and sizing processing to obtain a wire with a diameter of 1.18 to 1.22 mm, and the surface oil is removed and dried to obtain a high-strength heat-resistant aluminum alloy conductor.

[0031] Embodiment 6: A high-strength heat-resistant aluminum alloy wire comprising the following components in percentage by mass: Fe: 0.06%, Si: 0.04%, Mo: 0.2%, Ta: 0.2%, Nb: 0.2%, Yb: 0.2%, Dy: 0.05%, B: 0.008%, other unavoidable single impurity elements ≤ 0.03%, of which the total amount of Mn, Cr and V is 0.003%, the total amount of impurity elements ≤ 0.15%, and the balance is aluminum; the total content of Mo, Ta and Nb is 0.6%; the total content of Yb and Dy is 0.25%, and the content ratio of the two, Yb:Dy, is 4:1.

[0032] The method for preparing the high-strength heat-resistant aluminum alloy wire described in this embodiment comprises the following steps: (1) According to the composition of the high-strength heat-resistant aluminum alloy wire described in this embodiment, aluminum ingots, aluminum-iron master alloys, aluminum-molybdenum master alloys, aluminum-tantalum master alloys, aluminum-niobium master alloys, aluminum-ytterbium master alloys and aluminum-dysprosium master alloys are selected and loaded into a melting furnace, heated to 800° C., and then kept warm for melting to obtain melt I, and the time for the kept warm melting is 2 hours; (2) adding an aluminum-boron master alloy to the melt I obtained in step (1), and when the aluminum-boron master alloy is completely melted, smelting the melt at 760° C. for 2 hours to obtain a melt II; (3) Sampling the melt II obtained in step (2) to detect the composition. If the composition is unqualified, adjusting according to the result, adding the corresponding intermediate alloy to the melt II until the composition is qualified; when the composition is qualified, refining the melt II, that is, introducing argon gas into the melt II and refining at 760° C., after the refining is completed, standing and removing the slag on the surface to obtain aluminum liquid; the refining time is 60 minutes, and the introduced argon gas is 99.99% high-purity argon gas; (4) The aluminum liquid obtained in step (3) is discharged and subjected to double-stage filtration treatment in a filter box, and then transferred to a heat preservation furnace for heat preservation. The temperature of the aluminum liquid in the heat preservation furnace is controlled at 720° C., and then the aluminum liquid is horizontally continuously cast and drawn into a round rod with a diameter of 10 mm, and then collected into a coil by a wire take-up machine to obtain wire I. The casting speed of the round rod is 500 mm / min. The double-stage filtration treatment adopts a 60-mesh ceramic filter plate for the first stage filtration, and then adopts an 80-mesh ceramic filter plate for the second stage filtration. The tensile strength and conductivity of the wire I are tested, and the wire I with a tensile strength ≥120 MPa and a conductivity ≥58% IACS is reserved; (5) placing the wire material I obtained in step (4) into an annealing furnace for homogenization annealing, and after the annealing is completed, taking the wire material out of the furnace and cooling it to obtain the wire material II; the homogenization annealing is performed by placing the wire material I into the annealing furnace and keeping it at a temperature of 600° C. for 8 hours, and the cooling method is water cooling; (6) The wire II obtained in step (5) is subjected to 8 to 12 drawing processes, during which the wire II is subjected to one intermediate annealing, and the wire II is drawn to a diameter of 1.35 to 1.40 mm and then subjected to final annealing, followed by removal and cooling to obtain the wire III; the intermediate annealing and final annealing temperatures are both 480° C., the intermediate annealing and final annealing holding times are both 1.5 hours, and the cooling method is air cooling; (7) The wire III obtained in step (6) is subjected to final drawing and sizing processing to obtain a wire with a diameter of 1.18 to 1.22 mm, and the surface oil is removed and dried to obtain a high-strength heat-resistant aluminum alloy conductor.

[0033] Comparative Example 1: After conventional 8030 aluminum alloy sold on the market was melted, an aluminum alloy wire was prepared according to the method described in steps (4) to (7) in Example 1. The main components of the 8030 aluminum alloy are: Fe: 0.52%, Si≤0.1%, Cu: 0.21%, Mg≤0.05%, Zn≤0.05%, and B: 0.016%.

[0034] Experimental Example: Aluminum alloy wires were prepared according to the methods described in Examples 1 to 6 and Comparative Example 1, and then subjected to room temperature mechanical tests and room temperature electrical conductivity testing machine compressive creep tests, wherein the compressive creep test conditions were a temperature of 130° C. and a test time of 100 hours. Specific test results are shown in Table 1.

[0035] Table 1 Performance test results of aluminum alloy wires prepared by different methods

[0036] It can be seen from Table 1 that the aluminum alloy wire obtained by the method of the present invention not only has better room temperature mechanical properties and elongation than the commonly used 8030 aluminum alloy wire, but also has better compressive creep performance than the 8030 aluminum alloy wire.

[0037] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A high-strength heat-resistant aluminum alloy conductor, characterized in that: The following components are included in mass percentage: Fe≤0.15%, Si≤0.15%, 0.03~0.2% Mo, 0.03~0.2% Ta, 0.03~0.2% Nb, 0.03~0.2% Yb, 0.03~0.2% Dy, 0.001~0.008% B, other unavoidable single impurity elements ≤0.03% and the total amount of Mn, Cr and V ≤0.003%, the total amount of impurity elements ≤0.15%, and the balance is aluminum.

2. The high-strength heat-resistant aluminum alloy conductor according to claim 1, characterized in that: The high-strength heat-resistant aluminum alloy wire comprises the following components in percentage by mass: Fe≤0.1%, Si≤0.1%, 0.05-0.16% Mo, 0.05-0.14% Ta, 0.03-0.14% Nb, 0.05-0.18% Yb, 0.05-0.18% Dy, 0.001-0.005% B, other unavoidable single impurity elements ≤0.03% and the total amount of Mn, Cr and V ≤0.003%, the total amount of impurity elements ≤0.15%, and the balance is aluminum; the total content of Mo, Ta and Nb is 0.18-0.40%; the total content of Yb and Dy is 0.15-0.30%, and the ratio of their contents Yb:Dy is (1-3):

1.

3. A method for preparing a high-strength heat-resistant aluminum alloy wire as claimed in claim 1 or 2, characterized in that: The following steps are involved: (1) According to the composition of the high-strength heat-resistant aluminum alloy wire, aluminum ingots, aluminum-iron master alloys, aluminum-molybdenum master alloys, aluminum-tantalum master alloys, aluminum-niobium master alloys, aluminum-ytterbium master alloys and aluminum-dysprosium master alloys are selected and loaded into a melting furnace, heated to 720-800° C., and then kept warm for melting to obtain melt I; (2) adding an aluminum-boron master alloy to the melt I obtained in step (1), and when the aluminum-boron master alloy is completely melted, smelting at 720 to 760° C. to obtain a melt II; (3) Sampling the melt II obtained in step (2) to detect the composition. If the composition is unqualified, adjusting according to the result, adding the corresponding intermediate alloy to the melt II until the composition is qualified; when the composition is qualified, refining the melt II, that is, introducing argon gas into the melt II and refining at 720-760° C., after the refining is completed, letting it stand and removing the slag on the surface to obtain aluminum liquid; (4) The aluminum liquid obtained in step (3) is discharged and subjected to double-stage filtration treatment in a filter box, and then transferred to a heat preservation furnace for heat preservation, and then the aluminum liquid is horizontally continuously cast and continuously drawn into a round rod with a diameter of 8 to 10 mm, and the round rod is collected into a coil by a wire take-up machine to obtain a wire I, wherein the tensile strength of the wire I is ≥120 MPa and the electrical conductivity is ≥58% IACS; (5) placing the wire material I obtained in step (4) into an annealing furnace for homogenization annealing, and after the annealing is completed, taking the wire material out of the furnace and cooling it to obtain the wire material II; (6) Drawing the wire II obtained in step (5) for 8 to 12 times, performing an intermediate annealing on the wire II during the drawing process, and finally annealing the wire II after drawing it to a diameter of 1.35 to 1.40 mm, and then removing the cooling to obtain the wire III; (7) The wire III obtained in step (6) is subjected to final drawing and sizing processing to obtain a wire with a diameter of 1.18 to 1.22 mm, and the surface oil is removed and dried to obtain a high-strength heat-resistant aluminum alloy conductor.

4. The preparation method according to claim 3, characterized in that: In step (1), the heat preservation and melting time is 1 to 2 hours; in step (2), the heat preservation and melting time is 1 to 2 hours.

5. The preparation method according to claim 3, characterized in that: In step (3), the refining time is 45 to 60 minutes, and the argon gas introduced is 99.99% high-purity argon gas.

6. The preparation method according to claim 3, characterized in that: In step (4), the double-stage filtration treatment is to use a 60-mesh ceramic filter plate for the first stage filtration and then use an 80-mesh ceramic filter plate for the second stage filtration.

7. The preparation method according to claim 3, characterized in that: In step (4), the temperature of the aluminum liquid in the insulation furnace is controlled at 680-720°C.

8. The preparation method according to claim 3, characterized in that: In step (4), the casting speed of the round rod is 200 to 500 mm / min.

9. The preparation method according to claim 3, characterized in that: In step (5), the homogenization annealing is to place the wire material I into an annealing furnace and keep it at a temperature of 540-600° C. for 8-24 hours, and the cooling method is water cooling.

10. The preparation method according to claim 3, characterized in that: In step (6), the temperatures of the intermediate annealing and the final annealing are both 380-480° C., the holding times of the intermediate annealing and the final annealing are both 1.5-4 hours, and the cooling method is air cooling.

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