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

Abstract

The application relates to the technical field of aluminum alloy wire manufacturing, and particularly discloses a high-strength heat-resistant aluminum alloy wire and a preparation method thereof; the high-strength heat-resistant aluminum alloy wire is composed of the following components in percentage by mass: Zr 0.1-0.2%, Fe 0.05-0.1%, Zn 0.01-0.03%, Si 0.06-0.1%, a doping substance 0.18-0.25%, the rest impurities 0.01-0.05%, and the rest is Al; the doping substance is composed of W2B and MoB2; the high-strength heat-resistant aluminum alloy wire provided by the application is optimized in the elements of zirconium (Zr), iron (Fe), zinc (Zn) and silicon (Si) and the doping substances W2B and MoB2; on the basis of maintaining good conductivity of the aluminum alloy wire, the heat resistance and tensile strength of the aluminum alloy wire are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy wire manufacturing technology, specifically to a high-strength heat-resistant aluminum alloy wire and its preparation method. Background Technology

[0002] Aluminum alloy conductors, as a core material in modern power transmission systems, play an irreplaceable role in power grid construction due to their excellent comprehensive performance. Compared to pure aluminum conductors, aluminum alloy materials, by introducing trace alloying elements, significantly improve mechanical strength and corrosion resistance while maintaining high conductivity, effectively solving the technical bottlenecks of low tensile strength and easy creep and sag in pure aluminum conductors. These conductors are widely used in high-voltage transmission lines, rail transit contact networks, and urban power grid renovation projects. Their lightweight characteristics reduce the structural load on towers, while their good weather resistance meets the long-term service requirements in complex environments, making them a key material foundation for improving the efficiency and economy of power transmission.

[0003] Despite significant improvements in the performance of traditional aluminum alloy conductors, bottlenecks in high-temperature operation continue to hinder power system upgrades. Existing heat-resistant aluminum alloy conductors generally operate within a range of 90-150℃. When transmission lines experience instantaneous high temperatures due to overload or short-circuit current surges, the material is prone to recrystallization, softening, and grain boundary slippage, leading to a sharp drop in tensile strength of over 30%, exacerbating conductor sag and posing safety hazards. Conventional strengthening methods, such as excessive addition of zirconium and titanium, severely compromise conductivity, failing to meet the increased conductivity requirements of high-capacity power transmission.

[0004] Chinese patent document CN112853162A discloses a high-conductivity and heat-resistant aluminum alloy and its preparation method. The aluminum alloy comprises the following components by mass percentage: Zr 0.01-0.2%, Er 0.01-0.2%, Si 0.01-0.1%, Fe≤0.20%, B 0.01-0.04%, (V+Ti+Cr+Mn)≤0.01%, with the balance being aluminum. The aluminum alloy achieves a conductivity of up to 61.8% IACS and a hardness of up to 30HV, but its tensile strength is only up to 100MPa, requiring further improvement. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a high-strength heat-resistant aluminum alloy wire and its preparation method. By optimizing the alloy composition, the present invention effectively improves the heat resistance and tensile strength of the aluminum alloy wire.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A high-strength heat-resistant aluminum alloy wire, wherein the high-strength heat-resistant aluminum alloy wire is composed of the following components in mass percentage: Zr 0.1-0.2%, Fe 0.05-0.1%, Zn 0.01-0.03%, Si 0.06-0.1%, dopant 0.18-0.25%, other impurities 0.01-0.05%, and the balance being Al, wherein the dopant is composed of W2B and MoB2.

[0008] In the technical solution disclosed in this invention, Zr can form fine and highly dispersed nanoscale precipitates in the aluminum matrix. These precipitates have strong stability even at high temperatures, effectively pinning grain boundaries and dislocations, hindering grain growth and material softening at high temperatures, thereby improving the alloy's resistance to high-temperature creep and ensuring that the conductor is not prone to elongation and sagging during continuous high-temperature operation.

[0009] The amount of Zr added can be selected as 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, or 0.2%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0010] In the technical solution disclosed in this invention, Fe mainly plays the role of solid solution strengthening and improving strength. A certain amount of iron can refine the grain structure and form tiny intermetallic compound particles with elements such as aluminum. These particles help to enhance the overall hardness and strength of the material, especially under high temperature conditions, and can provide a certain long-term load-bearing capacity.

[0011] The amount of Fe added can be selected as 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, or 0.1%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0012] In the technical solution disclosed in this invention, Zn can be dissolved in the aluminum matrix, hindering dislocation movement and improving tensile strength. At the same time, zinc can also inhibit grain growth at high temperature and maintain the mechanical stability of aluminum alloy wires when working at high temperature.

[0013] The amount of Zn added can be selected as 0.01%, 0.015%, 0.02%, 0.025%, or 0.03%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0014] In the technical solution disclosed in this invention, Si can significantly improve the casting performance of the alloy, making it easier to process and form. At the same time, silicon can form a solid solution in the alloy to produce a strengthening effect, and may also combine with elements such as iron to form fine silicon-iron compound particles. These particles are dispersed in the matrix as hard points, providing an effective dispersion strengthening effect and improving the room temperature and high temperature tensile strength of the material.

[0015] The amount of Si added can be selected as 0.06%, 0.07%, 0.08%, 0.09%, or 0.1%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0016] In the technical solution disclosed in this invention, the total amount of iron (Fe) and silicon (Si) added is strictly limited to less than 0.2%, which can minimize the scattering of free electrons by Fe / Si atoms, ensuring that the aluminum alloy wire has high conductivity. At the same time, it can also reduce the number and size of coarse and brittle phases, so that the aluminum alloy wire has high tensile strength.

[0017] In the technical solution disclosed in this invention, the dopant is composed of W2B and MoB2. W2B and MoB2 work together to significantly improve the mechanical and heat resistance properties of the aluminum alloy wire. W2B possesses high hardness and thermal stability, serving as the main anti-deformation skeleton. MoB2 exhibits excellent matrix compatibility, filling the anti-deformation skeleton structure and strengthening the network structure, preventing excessive elongation and sagging of the aluminum alloy wire due to long-term heat softening. This invention adds W2B and MoB2 raw materials to the refined and impurity-removed aluminum alloy liquid, making it easier to achieve mechanical dispersion through vigorous stirring. The resulting continuously cast billet is then formed under ultrasonic treatment, ensuring that W2B and MoB2, as beneficial reinforcing phases, are uniformly distributed in the aluminum matrix, effectively avoiding the uneven dispersion problems caused by W2B and MoB2 agglomeration and sedimentation.

[0018] Specifically, this invention also limits the amount of dopant added. If the amount of dopant added is too low, the total amount of strengthening phase formed will be insufficient, the density of dispersed particles will not be high enough, and the spacing will be too large, which will greatly weaken its effect of pinning grain boundaries and hindering dislocation movement, and it will be unable to effectively resist creep deformation at high temperatures. If the amount of dopant added is too high, the introduction of excessive particles will significantly increase the number of interfaces inside the alloy, severely hindering the directional flow of electrons, resulting in an excessive decrease in the conductivity of aluminum alloy wires. Excessive particles may also lead to local agglomeration or the formation of large particle aggregation areas, which become stress concentration points and damage the mechanical properties of the material.

[0019] The amount of dopant added can be selected from 0.18%, 0.19%, 0.20%, 0.21%, 0.22%, 0.23%, 0.24%, and 0.25%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0020] The mass ratio of W2B to MoB2 in the dopant is 1-1.5:1, for example, 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1 can be selected, but it is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0021] This invention also provides a method for preparing the above-mentioned high-strength heat-resistant aluminum alloy wire, comprising the following steps:

[0022] S1. Add aluminum ingots to a resistance furnace and heat to melt them to obtain molten aluminum;

[0023] S2. Add Zr-containing raw materials, Fe-containing raw materials, Zn-containing raw materials and Si-containing raw materials to the aluminum liquid in sequence, stir evenly to obtain aluminum alloy liquid;

[0024] S3. Under an inert atmosphere, a refining agent is added to the molten aluminum alloy for refining and impurity removal.

[0025] S4. Add W2B raw material and MoB2 raw material to the refined and impurity-removed aluminum alloy liquid, stir evenly to obtain a mixture, and then continuously cast the mixture into a continuous casting billet under ultrasonic action. After straightening, the continuous casting billet is rolled into an aluminum alloy round rod by a continuous rolling mill.

[0026] S5. Heat treat the rolled aluminum alloy round rod.

[0027] S6. The heat-treated aluminum alloy round rod is then drawn to obtain a high-strength heat-resistant aluminum alloy wire.

[0028] In the technical solution disclosed in this invention, in step S1, the heating and melting temperature is 750-760℃.

[0029] In the technical solution disclosed in this invention, in step S3, the amount of refining agent used is 0.1-0.2% of the weight of the aluminum alloy liquid.

[0030] In the technical solution disclosed in this invention, in step S3, the refining time is 15-30 minutes and the refining temperature is 720-740℃.

[0031] In the technical solution disclosed in this invention, in step S4, the ultrasonic output frequency is 20-40kHz and the power is 400-600W.

[0032] In the technical solution disclosed in this invention, in step S5, the heat treatment temperature is 400-450℃ and the treatment time is 100-150h.

[0033] In the technical solution disclosed in this invention, in step S6, the wire drawing speed is 15-20m / s, and the wire is drawn into an aluminum alloy wire with a diameter of 1-5mm.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] (1) The heat-resistant aluminum alloy wire provided by the present invention significantly improves the heat resistance and tensile strength of the aluminum alloy wire while maintaining the good conductivity of the aluminum alloy wire through the optimized design of zirconium (Zr), iron (Fe), zinc (Zn), silicon (Si) elements and dopants W2B and MoB.

[0036] (2) The dopant provided by this invention is composed of W2B and MoB. W2B and MoB work together to significantly improve the mechanical properties and heat resistance of aluminum alloy wires. Among them, W2B has high hardness and thermal stability, and serves as the main anti-deformation skeleton. MoB has excellent matrix compatibility and fills the anti-deformation skeleton structure, strengthening the network structure and preventing the aluminum alloy wires from excessively elongating and sagging due to long-term heat softening. This invention adds W2B and MoB2 raw materials to the refined and impurity-removed aluminum alloy liquid, making it easier to achieve mechanical dispersion distribution through strong stirring, and then casting it into a continuous casting billet under ultrasonic action. This allows W2B and MoB2 to be uniformly distributed in the aluminum matrix as beneficial strengthening phases, effectively avoiding the problem of uneven dispersion caused by the agglomeration and sedimentation of W2B and MoB2. Attached Figure Description

[0037] Figure 1 This is an electron microscope image of the aluminum alloy wire provided in Embodiment 1 of the present invention. Detailed Implementation

[0038] The present invention will be further described in detail below through specific preferred embodiments, but the present invention is not limited to the following embodiments.

[0039] It should be noted that, unless otherwise specified, all chemical reagents involved in this invention were purchased through commercial channels.

[0040] In the embodiments of this invention, the Zr-containing raw material is an aluminum-zirconium alloy, the Fe-containing raw material is an aluminum-iron alloy, the Zn-containing raw material is an aluminum-zinc alloy, the Si-containing raw material is an aluminum-silicon alloy, the W2B powder has a particle size of 120 nm, and the MoB2 powder has a particle size of 50 nm.

[0041] The refining agent used in the refining and impurity removal embodiments of this invention is model XW-8871, purchased from Dongying Xinwang Chemical Co., Ltd.

[0042] Example 1

[0043] A high-strength heat-resistant aluminum alloy wire, wherein the high-strength heat-resistant aluminum alloy wire is composed of the following components in mass percentage: Zr 0.16%, Fe 0.08%, Zn 0.015%, Si 0.08%, W2B 0.12%, MoB2 0.12%, other impurities 0.034%, and the balance being Al.

[0044] A method for preparing a high-strength heat-resistant aluminum alloy wire includes the following steps:

[0045] S1. Add aluminum ingots to a resistance furnace and heat to 755℃ to melt them, obtaining molten aluminum;

[0046] S2. Add Zr-containing raw materials, Fe-containing raw materials, Zn-containing raw materials and Si-containing raw materials to the aluminum liquid in sequence, stir evenly, and keep the temperature at 730℃ to obtain aluminum alloy liquid;

[0047] S3. Under an argon atmosphere, a refining agent is added to the molten aluminum alloy for refining and impurity removal. The refining temperature is 730℃, the refining time is 20 minutes, and the amount of refining agent used is 0.15% of the weight of the molten aluminum alloy.

[0048] S4. Add W2B and MoB2 raw materials to the refined and impurity-removed aluminum alloy liquid, stir evenly to obtain a mixture, control the temperature of the mixture at 700℃, and then inject the mixture into a continuous casting machine equipped with an ultrasonic vibrating rod. Under the action of ultrasound, the mixture is continuously cast into a continuous casting billet, wherein the ultrasonic output frequency is 30kHz and the output power is 500W. After straightening, the continuous casting billet enters the continuous rolling mill, the temperature is controlled at 500℃, the final rolling speed of the continuous rolling mill is 8m / s, and it is rolled into an aluminum alloy round rod with a diameter of 9.5mm.

[0049] S5. The rolled aluminum alloy round bar is heat-treated at a temperature of 420℃ for 120 hours.

[0050] S6. The heat-treated aluminum alloy round rod is drawn into an aluminum alloy wire with a diameter of 3mm by drawing at a speed of 15m / s.

[0051] Example 2

[0052] A high-strength heat-resistant aluminum alloy wire, wherein the high-strength heat-resistant aluminum alloy wire is composed of the following components in mass percentage: Zr 0.18%, Fe 0.05%, Zn 0.02%, Si 0.1%, W2B 0.15%, MoB2 0.10%, other impurities 0.047%, and the balance being Al.

[0053] A method for preparing a high-strength heat-resistant aluminum alloy wire includes the following steps:

[0054] S1. Add aluminum ingots to a resistance furnace and heat to 755℃ to melt them, obtaining molten aluminum;

[0055] S2. Add Zr-containing raw materials, Fe-containing raw materials, Zn-containing raw materials and Si-containing raw materials to the aluminum liquid in sequence, stir evenly, and keep the temperature at 730℃ to obtain aluminum alloy liquid;

[0056] S3. Under an argon atmosphere, a refining agent is added to the molten aluminum alloy for refining and impurity removal. The refining temperature is 730℃, the refining time is 20 minutes, and the amount of refining agent used is 0.15% of the weight of the molten aluminum alloy.

[0057] S4. Add W2B and MoB2 raw materials to the refined and impurity-removed aluminum alloy liquid, stir evenly to obtain a mixture, control the temperature of the mixture at 700℃, and then inject the mixture into a continuous casting machine equipped with an ultrasonic vibrating rod. Under the action of ultrasound, the mixture is continuously cast into a continuous casting billet, wherein the ultrasonic output frequency is 30kHz and the output power is 500W. After straightening, the continuous casting billet enters the continuous rolling mill, the temperature is controlled at 500℃, the final rolling speed of the continuous rolling mill is 8m / s, and it is rolled into an aluminum alloy round rod with a diameter of 9.5mm.

[0058] S5. The rolled aluminum alloy round bar is heat-treated at a temperature of 420℃ for 120 hours.

[0059] S6. The heat-treated aluminum alloy round rod is drawn into an aluminum alloy wire with a diameter of 3mm by drawing at a speed of 15m / s.

[0060] Example 3

[0061] A high-strength heat-resistant aluminum alloy wire, wherein the high-strength heat-resistant aluminum alloy wire is composed of the following components in mass percentage: Zr 0.10%, Fe 0.07%, Zn 0.01%, Si 0.06%, W2B 0.12%, MoB2 0.10%, other impurities 0.041%, and the balance being Al.

[0062] A method for preparing a high-strength heat-resistant aluminum alloy wire includes the following steps:

[0063] S1. Add aluminum ingots to a resistance furnace and heat to 755℃ to melt them, obtaining molten aluminum;

[0064] S2. Add Zr-containing raw materials, Fe-containing raw materials, Zn-containing raw materials and Si-containing raw materials to the aluminum liquid in sequence, stir evenly, and keep the temperature at 730℃ to obtain aluminum alloy liquid;

[0065] S3. Under an argon atmosphere, a refining agent is added to the molten aluminum alloy for refining and impurity removal. The refining temperature is 730℃, the refining time is 20 minutes, and the amount of refining agent used is 0.15% of the weight of the molten aluminum alloy.

[0066] S4. Add W2B and MoB2 raw materials to the refined and impurity-removed aluminum alloy liquid, stir evenly to obtain a mixture, control the temperature of the mixture at 700℃, and then inject the mixture into a continuous casting machine equipped with an ultrasonic vibrating rod. Under the action of ultrasound, the mixture is continuously cast into a continuous casting billet, wherein the ultrasonic output frequency is 30kHz and the output power is 500W. After straightening, the continuous casting billet enters the continuous rolling mill, the temperature is controlled at 500℃, the final rolling speed of the continuous rolling mill is 8m / s, and it is rolled into an aluminum alloy round rod with a diameter of 9.5mm.

[0067] S5. The rolled aluminum alloy round bar is heat-treated at a temperature of 420℃ for 120 hours.

[0068] S6. The heat-treated aluminum alloy round rod is drawn into an aluminum alloy wire with a diameter of 3mm by drawing at a speed of 15m / s.

[0069] Example 4

[0070] A high-strength heat-resistant aluminum alloy wire, wherein the high-strength heat-resistant aluminum alloy wire is composed of the following components in mass percentage: Zr 0.20%, Fe 0.01%, Zn 0.03%, Si 0.1%, W2B 0.12%, MoB2 0.12%, other impurities 0.039%, and the balance being Al.

[0071] A method for preparing a high-strength heat-resistant aluminum alloy wire includes the following steps:

[0072] S1. Add aluminum ingots to a resistance furnace and heat to 755℃ to melt them, obtaining molten aluminum;

[0073] S2. Add Zr-containing raw materials, Fe-containing raw materials, Zn-containing raw materials and Si-containing raw materials to the aluminum liquid in sequence, stir evenly, and keep the temperature at 730℃ to obtain aluminum alloy liquid;

[0074] S3. Under an argon atmosphere, a refining agent is added to the molten aluminum alloy for refining and impurity removal. The refining temperature is 730℃, the refining time is 20 minutes, and the amount of refining agent used is 0.15% of the weight of the molten aluminum alloy.

[0075] S4. Add W2B and MoB2 raw materials to the refined and impurity-removed aluminum alloy liquid, stir evenly to obtain a mixture, control the temperature of the mixture at 700℃, and then inject the mixture into a continuous casting machine equipped with an ultrasonic vibrating rod. Under the action of ultrasound, the mixture is continuously cast into a continuous casting billet, wherein the ultrasonic output frequency is 30kHz and the output power is 500W. After straightening, the continuous casting billet enters the continuous rolling mill, the temperature is controlled at 500℃, the final rolling speed of the continuous rolling mill is 8m / s, and it is rolled into an aluminum alloy round rod with a diameter of 9.5mm.

[0076] S5. The rolled aluminum alloy round bar is heat-treated at a temperature of 420℃ for 120 hours.

[0077] S6. The heat-treated aluminum alloy round rod is drawn into an aluminum alloy wire with a diameter of 3mm by drawing at a speed of 15m / s.

[0078] Comparative Example 1

[0079] A high-strength heat-resistant aluminum alloy wire, wherein the high-strength heat-resistant aluminum alloy wire is composed of the following components by mass percentage: Zr 0.16%, Fe 0.08%, Zn 0.015%, Si 0.08%, W2B 0.24%, other impurities 0.034%, and the balance being Al.

[0080] A method for preparing a high-strength heat-resistant aluminum alloy wire includes the following steps:

[0081] S1. Add aluminum ingots to a resistance furnace and heat to 755℃ to melt them, obtaining molten aluminum;

[0082] S2. Add Zr-containing raw materials, Fe-containing raw materials, Zn-containing raw materials and Si-containing raw materials to the aluminum liquid in sequence, stir evenly, and keep the temperature at 730℃ to obtain aluminum alloy liquid;

[0083] S3. Under an argon atmosphere, a refining agent is added to the molten aluminum alloy for refining and impurity removal. The refining temperature is 730℃, the refining time is 20 minutes, and the amount of refining agent used is 0.15% of the weight of the molten aluminum alloy.

[0084] S4. Add W2B and MoB2 raw materials to the refined and impurity-removed aluminum alloy liquid, stir evenly to obtain a mixture, control the temperature of the mixture at 700℃, and then inject the mixture into a continuous casting machine equipped with an ultrasonic vibrating rod. Under the action of ultrasound, the mixture is continuously cast into a continuous casting billet, wherein the ultrasonic output frequency is 30kHz and the output power is 500W. After straightening, the continuous casting billet enters the continuous rolling mill, the temperature is controlled at 500℃, the final rolling speed of the continuous rolling mill is 8m / s, and it is rolled into an aluminum alloy round rod with a diameter of 9.5mm.

[0085] S5. The rolled aluminum alloy round bar is heat-treated at a temperature of 420℃ for 120 hours.

[0086] S6. The heat-treated aluminum alloy round rod is drawn into an aluminum alloy wire with a diameter of 3mm by drawing at a speed of 15m / s.

[0087] Compared with Comparative Example 1 and Example 1, MoB2 was replaced with W2B, while other conditions remained unchanged.

[0088] Comparative Example 2

[0089] A high-strength heat-resistant aluminum alloy wire, wherein the high-strength heat-resistant aluminum alloy wire is composed of the following components in mass percentage: Zr 0.16%, Fe 0.08%, Zn 0.015%, Si 0.08%, MoB2 0.24%, other impurities 0.034%, and the balance being Al.

[0090] A method for preparing a high-strength heat-resistant aluminum alloy wire includes the following steps:

[0091] S1. Add aluminum ingots to a resistance furnace and heat to 755℃ to melt them, obtaining molten aluminum;

[0092] S2. Add Zr-containing raw materials, Fe-containing raw materials, Zn-containing raw materials and Si-containing raw materials to the aluminum liquid in sequence, stir evenly, and keep the temperature at 730℃ to obtain aluminum alloy liquid;

[0093] S3. Under an argon atmosphere, a refining agent is added to the molten aluminum alloy for refining and impurity removal. The refining temperature is 730℃, the refining time is 20 minutes, and the amount of refining agent used is 0.15% of the weight of the molten aluminum alloy.

[0094] S4. Add W2B and MoB2 raw materials to the refined and impurity-removed aluminum alloy liquid, stir evenly to obtain a mixture, control the temperature of the mixture at 700℃, and then inject the mixture into a continuous casting machine equipped with an ultrasonic vibrating rod. Under the action of ultrasound, the mixture is continuously cast into a continuous casting billet, wherein the ultrasonic output frequency is 30kHz and the output power is 500W. After straightening, the continuous casting billet enters the continuous rolling mill, the temperature is controlled at 500℃, the final rolling speed of the continuous rolling mill is 8m / s, and it is rolled into an aluminum alloy round rod with a diameter of 9.5mm.

[0095] S5. The rolled aluminum alloy round bar is heat-treated at a temperature of 420℃ for 120 hours.

[0096] S6. The heat-treated aluminum alloy round rod is drawn into an aluminum alloy wire with a diameter of 3mm by drawing at a speed of 15m / s.

[0097] Compared with Comparative Example 2 and Example 1, W2B was replaced with MoB2, while other conditions remained unchanged.

[0098] Comparative Example 3

[0099] A high-strength heat-resistant aluminum alloy wire, wherein the high-strength heat-resistant aluminum alloy wire is composed of the following components in mass percentage: Zr 0.16%, Fe 0.08%, Zn 0.015%, Si 0.08%, W2B 0.05%, MoB2 0.05%, other impurities 0.034%, and the balance being Al.

[0100] A method for preparing a high-strength heat-resistant aluminum alloy wire includes the following steps:

[0101] S1. Add aluminum ingots to a resistance furnace and heat to 755℃ to melt them, obtaining molten aluminum;

[0102] S2. Add Zr-containing raw materials, Fe-containing raw materials, Zn-containing raw materials and Si-containing raw materials to the aluminum liquid in sequence, stir evenly, and keep the temperature at 730℃ to obtain aluminum alloy liquid;

[0103] S3. Under an argon atmosphere, a refining agent is added to the molten aluminum alloy for refining and impurity removal. The refining temperature is 730℃, the refining time is 20 minutes, and the amount of refining agent used is 0.15% of the weight of the molten aluminum alloy.

[0104] S4. Add W2B and MoB2 raw materials to the refined and impurity-removed aluminum alloy liquid, stir evenly to obtain a mixture, control the temperature of the mixture at 700℃, and then inject the mixture into a continuous casting machine equipped with an ultrasonic vibrating rod. Under the action of ultrasound, the mixture is continuously cast into a continuous casting billet, wherein the ultrasonic output frequency is 30kHz and the output power is 500W. After straightening, the continuous casting billet enters the continuous rolling mill, the temperature is controlled at 500℃, the final rolling speed of the continuous rolling mill is 8m / s, and it is rolled into an aluminum alloy round rod with a diameter of 9.5mm.

[0105] S5. The rolled aluminum alloy round bar is heat-treated at a temperature of 420℃ for 120 hours.

[0106] S6. The heat-treated aluminum alloy round rod is drawn into an aluminum alloy wire with a diameter of 3mm by drawing at a speed of 15m / s.

[0107] Compared with Comparative Example 3 and Example 1, the sum of the amounts of W2B and MoB2 added was 0.1%.

[0108] Comparative Example 4

[0109] A high-strength heat-resistant aluminum alloy wire, wherein the high-strength heat-resistant aluminum alloy wire is composed of the following components by mass percentage: Zr 0.16%, Fe 0.08%, Zn 0.015%, Si 0.08%, W2B 0.20%, MoB2 0.20%, other impurities 0.034%, and the balance being Al.

[0110] A method for preparing a high-strength heat-resistant aluminum alloy wire includes the following steps:

[0111] S1. Add aluminum ingots to a resistance furnace and heat to 755℃ to melt them, obtaining molten aluminum;

[0112] S2. Add Zr-containing raw materials, Fe-containing raw materials, Zn-containing raw materials and Si-containing raw materials to the aluminum liquid in sequence, stir evenly, and keep the temperature at 730℃ to obtain aluminum alloy liquid;

[0113] S3. Under an argon atmosphere, a refining agent is added to the molten aluminum alloy for refining and impurity removal. The refining temperature is 730℃, the refining time is 20 minutes, and the amount of refining agent used is 0.15% of the weight of the molten aluminum alloy.

[0114] S4. Add W2B and MoB2 raw materials to the refined and impurity-removed aluminum alloy liquid, stir evenly to obtain a mixture, control the temperature of the mixture at 700℃, and then inject the mixture into a continuous casting machine equipped with an ultrasonic vibrating rod. Under the action of ultrasound, the mixture is continuously cast into a continuous casting billet, wherein the ultrasonic output frequency is 30kHz and the output power is 500W. After straightening, the continuous casting billet enters the continuous rolling mill, the temperature is controlled at 500℃, the final rolling speed of the continuous rolling mill is 8m / s, and it is rolled into an aluminum alloy round rod with a diameter of 9.5mm.

[0115] S5. The rolled aluminum alloy round bar is heat-treated at a temperature of 420℃ for 120 hours.

[0116] S6. The heat-treated aluminum alloy round rod is drawn into an aluminum alloy wire with a diameter of 3mm by drawing at a speed of 15m / s.

[0117] Compared with Comparative Example 4 and Example 1, the sum of the amounts of W2B and MoB2 added was 0.4%.

[0118] The aluminum alloy wires prepared in Examples 1-2 and Comparative Examples 1-4 were subjected to performance tests, as detailed below:

[0119] Conductivity test: The test was conducted in accordance with standard GB 3048.2-2007 "Test methods for electrical properties of wires and cables - Part 2: Test for resistivity of metallic materials", and the resistance value was measured and then converted into the conductivity value.

[0120] Tensile strength test: The test was conducted in accordance with the standard GB / T 228-2002 "Metallic materials - tensile test at room temperature". The test was performed 3 times and the average value of the results was taken.

[0121] Heat resistance test: The aluminum alloy wires prepared in Examples 1-2 and Comparative Examples 1-4 were heated at 280°C for 24 hours and cooled to room temperature. The tensile strength of the aluminum alloy wires was then tested. The tensile strength was divided by the tensile strength of the aluminum alloy wire before heating to obtain the strength retention rate. The results are shown in Table 1.

[0122] Table 1 Performance Test Results

[0123] Electrical conductivity (IACS) Tensile strength (MPa) Strength retention rate (%) Example 1 57.6 307 96.3 Example 2 58.1 302 95.8 Comparative Example 1 56.9 256 85.4 Comparative Example 2 57.2 225 83.1 Comparative Example 3 58.4 201 89.7 Comparative Example 4 56.3 279 91.6

[0124] Finally, it should be noted that the above embodiments do not limit the present invention in any way. Those skilled in the art can make modifications and improvements based on the present invention. Therefore, any modifications or improvements made without departing from the spirit of the present invention are within the scope of protection claimed by the present invention.

Claims

1. A high-strength heat-resistant aluminum alloy wire, characterized in that, The high-strength heat-resistant aluminum alloy wire is composed of the following components by mass percentage: Zr 0.1-0.2%, Fe 0.05-0.1%, Zn 0.01-0.03%, Si 0.06-0.1%, dopant 0.18-0.25%, other impurities 0.01-0.05%, and the balance being Al. The dopant is composed of W2B and MoB2.

2. The high-strength heat-resistant aluminum alloy wire according to claim 1, characterized in that, The mass ratio of W2B to MoB2 in the doped material is 1-1.5:

1.

3. The method for preparing high-strength heat-resistant aluminum alloy wire according to any one of claims 1-2, characterized in that, Includes the following steps: S1. Add aluminum ingots to a resistance furnace and heat to melt them to obtain molten aluminum; S2. Add Zr-containing raw materials, Fe-containing raw materials, Zn-containing raw materials and Si-containing raw materials to the aluminum liquid in sequence, stir evenly to obtain aluminum alloy liquid; S3. Under an inert atmosphere, a refining agent is added to the molten aluminum alloy for refining and impurity removal. S4. Add W2B raw material and MoB2 raw material to the refined and impurity-removed aluminum alloy liquid, stir evenly to obtain a mixture, and then continuously cast the mixture into a continuous casting billet under ultrasonic action. After straightening, the continuous casting billet is rolled into an aluminum alloy round rod by a continuous rolling mill. S5. Heat treat the rolled aluminum alloy round rod. S6. The heat-treated aluminum alloy round rod is then drawn to obtain a high-strength heat-resistant aluminum alloy wire.

4. The preparation method according to claim 3, characterized in that, In step S1, the heating and melting temperature is 750-760℃.

5. The preparation method according to claim 3, characterized in that, In step S3, the amount of refining agent used is 0.1-0.2% of the weight of the aluminum alloy liquid.

6. The preparation method according to claim 3, characterized in that, In step S3, the refining time is 15-30 minutes, and the refining temperature is 720-740℃.

7. The preparation method according to claim 3, characterized in that, In step S4, the ultrasonic output frequency is 20-40kHz and the power is 400-600W.

8. The preparation method according to claim 3, characterized in that, In step S5, the heat treatment temperature is 400-450℃ and the treatment time is 100-150h.

9. The preparation method according to claim 3, characterized in that, In step S6, the drawing speed is 15-20m / s, and the wire is drawn into an aluminum alloy wire with a diameter of 1-5mm.

Images