Aluminum alloy wire with heat-resistant phase and method for manufacturing the same

Abstract

The application discloses an aluminum alloy wire added with a heat-resistant phase and a preparation method thereof. 12 An aluminum base intermediate alloy powder containing an (Fe, V) 3 Si phase is added into aluminum liquid to smelt an aluminum alloy melt, the aluminum alloy melt is cast to obtain an aluminum alloy ingot, and the aluminum alloy ingot is hot extruded to obtain an aluminum alloy wire rod, and the aluminum alloy wire rod is water-quenched to obtain the aluminum alloy wire. 12 The preparation method adds the (Fe, V) 3 Si phase with a low diffusion coefficient into the aluminum base to prepare the aluminum alloy wire with excellent electric conductivity, heat resistance and mechanical properties. The heat-resistant phase added in the application does not contain rare earth elements, but the heat resistance of the aluminum alloy can be equivalent to or even better than that of the rare earth alloy phase formed by adding the rare earth elements. The process is simple, the process flow is short, and the preparation cost of the aluminum alloy wire is greatly reduced.

Description

Technical Field

[0001] This invention belongs to the field of high conductivity aluminum alloy material preparation and application technology, specifically relating to an aluminum alloy wire with added heat-resistant phase and its preparation method. Background Technology

[0002] When aluminum alloys are used in conductive cables and other fields, in addition to excellent conductivity, special attention must be paid to the mechanical and electrical properties of the aluminum alloy cables at temperatures above 100℃. Conventional aluminum alloy conductors are required to operate at a long-term temperature of ≤90℃, and during occasional short-term short circuits lasting less than 5 seconds, the temperature should be ≤250℃. However, the long-term operating temperature requirement for normal heat-resistant aluminum alloy conductors is 100℃~125℃, at which point conventional pure aluminum and aluminum alloy conductors have already softened significantly and their conductivity has rapidly decreased. Overhead heat-resistant aluminum alloy conductors are divided into three operating temperature levels: 150℃, 210℃, and 230℃, requiring the aluminum alloy conductors to maintain excellent mechanical and electrical properties at these temperatures. However, the conductivity, heat resistance, and mechanical strength of aluminum alloys are contradictory; to simultaneously meet the requirements of all three properties, alloy design and manufacturing process optimization are necessary.

[0003] The key to improving the heat resistance of aluminum alloys lies in the presence of thermally stable phases in the aluminum matrix. These phases do not grow at high temperatures and remain in a fine, dispersed state, thus preserving the alloy's mechanical strength from room temperature to high temperatures. Conventional alloying methods involve adding Cu and Mg to form the S phase with a temperature resistance of 200℃, and adding Cu, Mg, and Ag to form the Ω phase with a temperature resistance of 250℃. In addition, a common method to simultaneously improve the heat resistance of aluminum alloys is to add rare earth elements to the aluminum matrix, such as cerium, scandium, and zirconium. For example, this can form the Al3Sc phase with a temperature resistance of up to 300℃. 11 Adding elements like Ce3 significantly improves the strength and heat resistance of the aluminum matrix. Patent publication number CN108893660A discloses the addition of three rare earth elements (Y, Ce, and La) to aluminum; patent publication number CN118553476A adds Y and Zr; and patent publication number CN120866697A adds Er and Sc. The aim is to enhance the heat resistance of aluminum alloys while maintaining their original strength. However, adding Cu, Mg, Ag, or rare earth elements creates a large number of dispersed alloying strengthening phases in the aluminum matrix. While this increases the alloy's strength, it reduces the electrical conductivity of the aluminum matrix. Furthermore, the addition of rare earth elements increases the price of aluminum alloys.

[0004] Some patents also improve the electrical conductivity and heat resistance of aluminum alloys by improving and enhancing the processing technology for aluminum alloys without added strengthening alloying elements. For example, the patent with publication number CN118291823A optimizes the alloy phase by using five artificial aging methods to improve the electrical conductivity and strength of aluminum alloys. However, the process is long and not conducive to industrial application. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the first objective of this invention is to provide a method for preparing aluminum alloy wires with added heat-resistant phases. This method involves adding Al with a low diffusion coefficient to an aluminum matrix. 12 The (Fe,V)3Si phase is used to prepare aluminum alloy wires with excellent conductivity, heat resistance and mechanical properties. The heat-resistant phase added in this invention does not contain rare earth elements, but it can obtain aluminum alloy heat resistance that is comparable to or even better than that of rare earth alloy phases formed by adding rare earth elements. Moreover, the process is simple and the process flow is short, which greatly reduces the preparation cost of aluminum alloy wires.

[0006] The second objective of this invention is to provide a heat-resistant conductive aluminum alloy wire prepared by the above-described preparation method.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] This invention provides a method for preparing aluminum alloy wires with added heat-resistant phases, wherein Al-containing... 12 (Fe,V)3Si phase aluminum-based master alloy powder is added to molten aluminum to obtain aluminum alloy melt, aluminum alloy melt is cast to obtain aluminum alloy ingot, aluminum alloy ingot is hot extruded to obtain aluminum alloy wire, aluminum alloy wire is water-cooled and quenched to obtain aluminum alloy conductor.

[0009] The Al-containing 12 The process for obtaining aluminum-based master alloy powder of (Fe,V)3Si phase is as follows: according to the original ratio, Al∶Fe∶V∶Si=12∶1.5∶1.5∶1, iron powder, vanadium powder, and silicon powder are prepared in the theoretical proportion, and aluminum powder is prepared in the theoretical proportion of 1 to 1.1 times. The mixture is first mixed for 15 to 30 minutes to obtain a mixture, and then the mixture is mechanically alloyed by high-energy ball milling. During the hot extrusion process, the extrusion ratio is controlled to be ≥35.

[0010] The preparation method of the present invention uses Al-rich materials. 12 Aluminum-based master alloy powder containing the (Fe,V)3Si phase was added to molten aluminum to ultimately prepare an alloy containing Al. 12 (Fe,V)3Si phase aluminum alloy wire, Al 12The (Fe,V)3Si phase has a body-centered cubic crystal structure, exhibiting an icosahedral structure with a lattice constant a = 1.256 nm, three times that of the aluminum matrix. This forms a low-interfacial-energy coherent interface. Due to its specific crystal structure and interfacial properties with the aluminum matrix, this phase has a very low diffusion coefficient in the aluminum matrix. At high temperatures, compared with other heat-resistant strengthening phases in aluminum alloys, its coarsening rate is 2 to 4 orders of magnitude lower, comparable to compounds formed by rare earth elements such as Al3Sc, a typical heat-resistant alloy phase. It becomes a very good heat-resistant stabilizing phase in the aluminum matrix, maintaining the strengthening effect.

[0011] In addition, Al 12 The aluminum-based master alloy powder block containing the (Fe,V)3Si phase contains elements such as Fe, V, and Si. Fe and Si are the two most prevalent impurity elements in pure aluminum. Due to the principle of heterogeneous nucleation, these impurity elements can further adhere to the Al during the preparation process. 12 Nucleation on the (Fe,V)3Si phase allows impurity elements in the aluminum matrix to form effective alloying strengthening phases, thereby mitigating the adverse effects of impurity elements and enabling aluminum alloy materials to possess Al... 12 The (Fe,V)3Si phase exhibits excellent heat resistance, while also giving the aluminum matrix high electrical conductivity and high strength.

[0012] However, experiments have shown that only by using Al-containing... 12 The aluminum-based master alloy powder containing (Fe,V)3Si phase is finally obtained by adding it to molten aluminum and smelting it. 12 Aluminum alloy wires containing (Fe,V)3Si phase and no other alloying phases, because if smelting is used, the temperature <10 3 Al cannot be formed under conventional solidification cooling rates of ℃ / s. 12 The (Fe,V)3Si phase requires a cooling rate of 10 molten aluminum alloy. 5 ~10 6 This phase can only be obtained under rapid solidification conditions of ℃ / s, but even under rapid solidification conditions of aluminum alloy melt, elements such as Al, Fe, V, and Si can still form Al. 13 Fe4, Al6Fe, Al8Fe2Si, Al 21 Other alloy phases, such as V2, not only fail to improve heat resistance but also deplete alloying elements and generate unnecessary other phases. Therefore, this invention utilizes Al-containing... 12 Aluminum-based master alloy powder with (Fe,V)3Si phase was used as a raw material and added to molten aluminum. However, to ensure the Al... 12The (Fe,V)3Si phase in the aluminum matrix offers advantages in terms of thermal stability and improving the heat resistance of the aluminum matrix. To minimize the impact of repeated heating and annealing softening processes during the drawing and plastic deformation of aluminum wires, this invention employs a high extrusion ratio to directly extrude aluminum alloy wires from aluminum alloy ingots. The extruded wires are then rapidly water-quenched to stabilize the microstructure of the aluminum matrix after extrusion and plastic deformation, thus enhancing the Al... 12 The (Fe,V)3Si phase is uniformly and diffused at the nanoscale within the aluminum alloy matrix, enabling the processing of the heat-resistant Al phase in aluminum alloy wires. 12 The adverse effects of (Fe,V)3Si are minimized while improving the strength, heat resistance and conductivity of aluminum conductors.

[0013] Experiments have shown that mechanical alloying via high-energy ball milling can ensure the acquisition of Al alloys with a large volume fraction. 12 Aluminum-based master alloy powder with (Fe,V)3Si phase was obtained through mechanical alloying, but experiments showed that obtaining Al-containing master alloy powder was difficult. 12 For aluminum-based master alloy powders with (Fe,V)3Si phase, only iron powder, vanadium powder, and silicon powder must be mixed according to the theoretical atomic ratio, while aluminum powder can be mixed according to the theoretical ratio or slightly in excess (generally, the excess should not exceed 10%).

[0014] In this invention, the purity of the aluminum powder, iron powder, vanadium powder, and silicon powder used is ≥99.9%.

[0015] In a preferred embodiment, the high-energy ball milling speed is 100~800 rpm, preferably 600~800 rpm, and the high-energy ball milling time is 1~24h, preferably 12~24h.

[0016] In a further preferred embodiment, the high-energy ball milling is performed under argon protection.

[0017] In a further preferred embodiment, the grinding balls used in the high-energy ball mill are steel balls with a diameter of 8-12 mm; the ball-to-material mass ratio is 8-10:1.

[0018] The preferred solution is to include Al 12 The aluminum-based master alloy powder with the (Fe,V)3Si phase was first wrapped in pure aluminum foil, then compacted into a block, and then added to molten aluminum for melting. Experiments showed that wrapping the aluminum-based master alloy powder in pure aluminum foil and then compacting it into a block prevented it from dispersing in the high-temperature melt during melting. Dispersal would lead to the formation of Al-containing... 12 (Fe,V)3Si phase aluminum-based master alloy powder is difficult to alloy with molten aluminum due to surface tension, and is prone to oxidation. However, Al-containing master alloy powder... 12Aluminum-based master alloy powder with the (Fe,V)3Si phase is first wrapped in pure aluminum foil, then compacted into a block. It can then be easily immersed in molten aluminum to react with the melt, thereby obtaining an Al-containing alloy through smelting and casting. 12 Aluminum alloy ingots with (Fe,V)3Si phase.

[0019] In a further preferred embodiment, the pressure used for compaction is 2–10 MPa. Compaction ensures that the powder is completely and tightly wrapped by the aluminum foil.

[0020] In actual operation, a graphite bell jar is used to press the powder block into the bottom of the molten aluminum and leave it for 5 to 15 minutes to allow the alloy powder block to completely melt into the molten aluminum. Depending on the quality of the molten aluminum and the aluminum block, this step can be performed by pressing the powder block into the molten aluminum in one go or by pressing it into the molten aluminum in batches.

[0021] In a preferred embodiment, the process of obtaining the molten aluminum is as follows: heating the aluminum ingot to 730℃~750℃ and melting it to obtain molten aluminum.

[0022] Further preferably, the purity of the aluminum ingot is ≥99.6%.

[0023] In a preferred embodiment, the Al-containing 12 The amount of aluminum-based master alloy powder with the (Fe,V)3Si phase added is 1.0% to 4.0% of the mass of the molten aluminum. Experiments have shown that controlling the Al content... 12 The optimal performance of the aluminum alloy conductor is achieved when the amount of (Fe,V)3Si phase aluminum-based master alloy powder added is in the range of 1.0% to 4.0%. If too much is added, the strength and heat resistance will be improved, but the conductivity of the aluminum matrix will decrease.

[0024] In a preferred embodiment, the smelting process is as follows: [The process involves] melting Al-containing materials... 12 Aluminum-based master alloy powder with (Fe,V)3Si phase was added to molten aluminum, and the Al content was increased. 12 After melting the aluminum-based master alloy powder of (Fe,V)3Si phase, stir for 5 to 15 minutes, maintaining the melt temperature at 700℃ to 730℃ during stirring. Then add refining agent, degas and slag, remove slag and let stand for 10 to 20 minutes to obtain the final product.

[0025] In a further preferred embodiment, the stirring is carried out at a depth of 2 / 3 of the melt, and the stirring method is mechanical stirring.

[0026] In a further preferred embodiment, the refining agent is hexachloroethane powder, and the amount of the refining agent added is 1 to 3 wt% of the total mass of the melt.

[0027] In a preferred embodiment, the casting temperature is 700℃~720℃.

[0028] In a preferred embodiment, the aluminum alloy ingot obtained from the casting of molten aluminum alloy is water-cooled using flowing cooling water until the surface temperature of the aluminum alloy ingot is ≤50℃. Water cooling not only increases the cooling rate and improves casting process efficiency, but also avoids Al... 12 Coarsening of the (Fe,V)3Si phase at high temperatures.

[0029] In actual operation, the surface oxide layer of the aluminum alloy ingot is removed by turning, and then hot extrusion plastic deformation is performed.

[0030] In a preferred embodiment, the aluminum alloy ingot is preheated at 360℃~400℃ for 1~2 hours before hot extrusion.

[0031] In a preferred embodiment, during hot extrusion, the extrusion ratio is controlled to be 35~90, preferably 37.5~90.

[0032] Experiments have shown that the aluminum alloy ingots obtained by this invention can be used to obtain aluminum alloy wires with the target diameter through high extrusion heat extrusion without the need for drawing plastic deformation. This not only greatly simplifies the process, but also results in aluminum alloy wires with superior performance.

[0033] In a preferred embodiment, the aluminum alloy wire is completely immersed in a water tank and water-cooled to below 100°C, with flowing cooling water circulating in the water tank.

[0034] In actual operation, the length of the aluminum wire immersed in the water tank should be 3 to 10 meters, depending on the diameter of the aluminum wire, to ensure that the aluminum alloy wire is completely submerged in the water tank. Flowing cooling water into the tank ensures the cooling rate of the aluminum alloy wire, thereby reducing the temperature and humidity of the aluminum alloy wire. 12 The microstructure of the (Fe,V)3Si phase is stabilized, ultimately enabling Al 12 The (Fe,V)3Si phase is fine and uniformly dispersed in the aluminum matrix.

[0035] In actual operation, after the aluminum alloy wire is processed in the water tank, it is quickly wound into a coil by the winding machine, while a high-power fan is used to dry the water stains remaining on the surface of the aluminum wire.

[0036] In a preferred embodiment, the aluminum alloy wire obtained after water quenching is annealed at 50℃~250℃ for 30~120min. Depending on certain application requirements, the aluminum alloy can be further subjected to stabilization annealing treatment. The annealing temperature and time can be adjusted according to specific needs. After cooling to room temperature, the finished aluminum alloy wire is obtained.

[0037] In a preferred embodiment, the diameter of the aluminum alloy wire is 1mm to 6mm.

[0038] The present invention also provides an aluminum alloy wire prepared by the above-described preparation method.

[0039] In a preferred embodiment, the aluminum alloy conductor, by mass percentage, comprises: Fe 0.2%–0.75%; V 0.2%–0.75%; Si 0.08%–0.3%, with the balance being Al.

[0040] In a preferred embodiment, the aluminum alloy wire comprises an aluminum matrix and Al dispersed in the aluminum matrix. 12 The Al phase is composed of (Fe,V)3Si. 12 The (Fe,V)3Si phase is nanoscale.

[0041] The beneficial effects of the aluminum alloy wire prepared by this invention are as follows:

[0042] (1) Al-rich powder prepared in advance by atomic percentage Al-Fe-V-Si powder is produced by mechanical alloying high-energy ball milling. 12 (Fe,V)3Si phase alloy powder can effectively serve as the basis for the heat-resistant phase in the subsequent melting and casting process of aluminum alloy wire materials. This phase forms a low interfacial energy coherent interface with the aluminum matrix, having little impact on the conductivity of the aluminum matrix. Simultaneously, this phase has a very low diffusion coefficient in the aluminum matrix, and its coarsening rate at high temperatures is 2-4 orders of magnitude lower than other alloy phases, comparable to compounds formed by rare earth elements such as Al3Sc, a typical heat-resistant alloy phase, making it an excellent heat-resistant stabilizing phase in the aluminum matrix.

[0043] (2) Al 12 The (Fe,V)3Si phase is nanoscale in size, and even at high temperatures, it maintains a low coarsening growth rate over a long period. In this invention, the phase was kept at 200℃, 400℃, and 600℃ for 240 hours. Although the phase coarsens somewhat, it still maintains the nanoscale and has a good strengthening effect and thermal stability. It can effectively improve the strength and heat resistance of the aluminum matrix. This phase becomes an important reinforcing phase for obtaining high-strength, high-conductivity, and heat-resistant aluminum alloy wires.

[0044] (3) Added Al 12 The (Fe,V)3Si phase exhibits excellent heat resistance, effectively reducing the need for subsequent heat treatment processes in aluminum alloy wires to obtain the heat-resistant stable phase. Aluminum alloy conductive wires can be obtained by directly hot-extruded the cast ingot followed by rapid water cooling, reducing the multiple "drawing + heat treatment" processes required for conventional aluminum wires after extrusion. The heat-resistant Al phase in the alloy... 12 (Fe,V)3Si directly acts as a heat-resistant and strengthening agent in the aluminum matrix, with minimal impact on electrical conductivity.

[0045] (4) Added Al 12The (Fe,V)3Si phase is rich in Fe and Si, which are the two most abundant and influential impurity elements in the aluminum matrix. If these two impurity elements exist in the aluminum matrix as conventional impurity phases, they will adversely affect the electrical conductivity, corrosion resistance, and mechanical properties of aluminum. Introducing Al... 12 The (Fe,V)3Si phase involves Fe and Si impurities in aluminum that adhere to the Al phase during the smelting and casting process due to heterogeneous nucleation. 12 The precipitation on the (Fe,V)3Si phase reduces the adverse effects of impurity elements in the aluminum matrix and also improves the conductivity of the aluminum matrix.

[0046] (5) Adding Al through alloy design 12 The (Fe,V)3Si phase is used to improve the heat resistance of aluminum conductors, eliminating the need to introduce rare earth elements to enhance their heat resistance and thus effectively reducing the material cost of aluminum conductors. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments and comparative examples of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 The Al-containing material prepared by mechanical alloying in Example 2 12 Electron micrographs and diffraction patterns of aluminum-based master alloy powder with (Fe,V)3Si phase.

[0049] Figure 2 Al-containing sample obtained in Example 2 12 X-ray spectra of aluminum-based master alloy powder with (Fe,V)3Si phase after exposure at different temperatures for 12 hours.

[0050] Figure 3 Al-containing sample obtained in Example 2 12 The particle coarsening of aluminum-based master alloy powder with (Fe,V)3Si phase after holding at different temperatures for 240 h, among which Figure 3 In the text, (a) is 200℃. Figure 3 (b) in the text is 400℃. Figure 3 (c) in the figure is 600℃.

[0051] Figure 4 Electron microscope images and structural analysis diffraction patterns of the aluminum alloy ingot in Example 3.

[0052] Figure 5For each embodiment containing Al 12 The hardness variation of aluminum-based master alloy powder with (Fe,V)3Si phase after being pressed into blocks at different temperatures. Detailed Implementation

[0053] To enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention, and to make the above-mentioned objectives, features and advantages of the present invention more readily apparent, the specific embodiments of the present invention will be further described below.

[0054] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0055] The following detailed embodiments illustrate the preparation method of the high-strength, high-conductivity, and creep-resistant aluminum alloy wire of the present invention.

[0056] Example 1

[0057] S1: Design a high-conductivity, high-strength aluminum alloy wire with excellent heat resistance. Only three alloying elements, Fe, V, and Si, are added to the aluminum matrix. These three elements are added through a special intermediate alloying method. After addition, the aluminum alloy contains 0.2% Fe, 0.2% V, and 0.08% Si, with the remainder being aluminum.

[0058] S2: For the designed aluminum alloy conductor material, an Al-rich material is first prepared using a mechanical alloying high-energy ball milling method. 12 (Fe,V)3Si phase alloy powder. The preparation method involves mixing 99.9% aluminum powder, 99.9% iron powder, 99.9% vanadium powder, and 99.9% silicon powder in a three-dimensional mixer at an atomic ratio of Al:Fe:V:Si = 12:1.5:1.5:1 for 15 minutes. The mixture is then placed in a stainless steel ball mill jar using 10mm diameter steel balls at a ball-to-powder mass ratio of 10:1. Argon gas is introduced into the ball mill jar, and the mixture is ball-milled in a planetary ball mill at a speed of 100 rpm for 1 hour. After milling, an Al-rich alloy powder is obtained. 12 Alloy powder of (Fe,V)3Si phase.

[0059] S3: Wrap the obtained alloy powder in pure aluminum foil and compact it into a block under a pressure of 2MPa to ensure that the powder is completely and tightly wrapped by the aluminum foil.

[0060] S4: Heat aluminum ingots with a purity of ≥99.6% to 730℃ in a resistance furnace to melt them and obtain liquid aluminum.

[0061] S5: Add aluminum foil-wrapped, Al-rich material to the molten aluminum at a mass ratio of 1.0%. 12 The alloy powder block of (Fe,V)3Si phase was pressed into the bottom of the aluminum liquid using a graphite bell jar and left for 5 minutes until the alloy powder block was completely melted in the aluminum liquid.

[0062] S6: Mechanically stir the aluminum alloy melt after the powder block is melted at 2 / 3 depth of the melt for 5 minutes, and maintain the melt temperature at 700℃ during the stirring process.

[0063] S7: Prepare hexachloroethane powder at 1% of the total weight of the molten aluminum. Press it into the bottom of the molten aluminum alloy using a graphite bell jar to vent and slag. After the venting reaction is complete, slowly remove the bell jar and skim off the slag generated on the surface of the molten aluminum alloy. After skimming, close the furnace door and allow the molten aluminum alloy to stand for 10 minutes. Adjust the furnace temperature to 700℃ and wait for the molten alloy to reach the desired temperature.

[0064] S8: After settling, open the furnace cover and remove the slag from the surface of the molten aluminum. Then, cast the molten aluminum alloy (ensure the casting temperature is 700℃). After casting, wait for the aluminum alloy ingot to be cooled with water. Use flowing cold water to continuously pour on the surface of the ingot to cool it down until it is below 50℃.

[0065] S9: The surface oxide layer of the aluminum alloy ingot is removed by turning. The ingot diameter is 30mm. Hot extrusion plastic deformation is performed. The ingot is preheated at 400℃ for 1 hour and then hot extruded to form 10 aluminum alloy wires with a diameter of 1mm. The extrusion ratio is 90.

[0066] S10: After extrusion, the aluminum wire is directly placed into a water tank of flowing cold water for rapid cooling. The length of the aluminum wire immersed in the water tank is 3 meters according to the diameter of the aluminum wire and cooled to below 100°C.

[0067] S11: After being processed in the water tank, the aluminum wire is quickly wound into a coil by a winding machine, while a high-power fan is used to dry the water stains remaining on the surface of the aluminum wire.

[0068] S12: The wound aluminum wire can be placed in a heat treatment furnace at 50°C for annealing for 30 minutes to perform stabilization annealing. The annealing temperature and time are determined according to the different properties of the final aluminum alloy wire. After cooling to room temperature, the finished aluminum alloy wire is obtained.

[0069] Example 2

[0070] S1: Design a high-conductivity, high-strength aluminum alloy wire with excellent heat resistance. Only three alloying elements, Fe, V, and Si, are added to the aluminum matrix. These three elements are added through a special intermediate alloying method. After addition, the Fe content in the aluminum alloy is 0.75%, the V content is 0.75%, the Si content is 0.3%, and the remainder is aluminum.

[0071] S2: For the designed aluminum alloy conductor material, an Al-rich material is first prepared using a mechanical alloying high-energy ball milling method. 12 (Fe,V)3Si phase alloy powder. The preparation method involves mixing 99.9% aluminum powder, 99.9% iron powder, 99.9% vanadium powder, and 99.9% silicon powder in a three-dimensional mixer at an atomic ratio of Al:Fe:V:Si = 12:1.5:1.5:1 for 30 minutes. The mixture is then placed in a stainless steel ball mill jar using 10mm diameter steel balls at a ball-to-powder mass ratio of 10:1. Argon gas is introduced into the ball mill jar, and the mixture is ball-milled in a planetary ball mill at 800 rpm for 24 hours. After milling, an Al-rich alloy powder is obtained. 12 Alloy powder of (Fe,V)3Si phase.

[0072] S3: Wrap the obtained alloy powder in pure aluminum foil and compact it into a block under a pressure of 10MPa to ensure that the powder is completely and tightly wrapped by the aluminum foil.

[0073] S4: Heat aluminum ingots with a purity of ≥99.6% to 750℃ in a resistance furnace to melt them and obtain liquid aluminum.

[0074] S5: Add aluminum foil-wrapped, Al-rich material to the molten aluminum at a ratio of 4.0% by mass. 12 The alloy powder block of (Fe,V)3Si phase was pressed into the bottom of the molten aluminum using a graphite bell jar and left for 15 minutes until the alloy powder block was completely melted in the molten aluminum.

[0075] S6: Mechanically stir the aluminum alloy melt after the powder block is melted at 2 / 3 depth of the melt for 15 minutes, and maintain the melt temperature at 730℃ during the stirring process.

[0076] S7: Prepare hexachloroethane powder at 3% of the total weight of the molten aluminum. Press it into the bottom of the molten aluminum alloy using a graphite bell jar to vent and slag. After the venting reaction is complete, slowly remove the bell jar and skim off the slag generated on the surface of the molten aluminum alloy. After skimming, close the furnace door and allow the molten aluminum alloy to stand for about 20 minutes. Adjust the furnace temperature to 720℃ and wait for the molten alloy to reach the desired temperature.

[0077] S8: After settling, open the furnace cover and remove the slag from the surface of the molten aluminum. Then, cast the molten aluminum alloy (ensure the casting temperature is above 700℃). After casting, wait for the aluminum alloy ingot to be cooled with water. Use flowing cold water to continuously pour on the surface of the ingot to cool it down until it is below 50℃.

[0078] S9: The surface oxide layer of the aluminum alloy ingot is removed by turning. The ingot diameter is 90mm. Hot extrusion plastic deformation is performed. The ingot is preheated at 400℃ for 1 hour and then hot extruded to form 6 aluminum alloy wires with a diameter of 6mm. The extrusion ratio is 37.5.

[0079] S10: After extrusion, the aluminum wire is directly placed into a water tank of flowing cold water for rapid cooling. The length of the aluminum wire immersed in the water tank is 10 meters, and the temperature is cooled to below 100°C, according to the diameter of the aluminum wire.

[0080] S11: After being processed in the water tank, the aluminum wire is quickly wound into a coil by a winding machine, while a high-power fan is used to dry the water stains remaining on the surface of the aluminum wire.

[0081] S12: The wound aluminum wire can be placed in a heat treatment furnace at a temperature of 250°C for annealing for 120 minutes to perform stabilization annealing. The annealing temperature and time are determined according to the different properties of the final aluminum alloy wire. After cooling to room temperature, the finished aluminum alloy wire is obtained.

[0082] Example 3

[0083] S1: Design a high-conductivity, high-strength aluminum alloy wire with excellent heat resistance. Only three alloying elements, Fe, V, and Si, are added to the aluminum matrix. These three elements are added through a special intermediate alloying method. After addition, the Fe content in the aluminum alloy is 0.5%, the V content is 0.5%, the Si content is 0.15%, and the remainder is aluminum.

[0084] S2: For the designed aluminum alloy conductor material, an Al-rich material is first prepared using a mechanical alloying high-energy ball milling method. 12 (Fe,V)3Si phase alloy powder. The preparation method involves mixing 99.9% aluminum powder, 99.9% iron powder, 99.9% vanadium powder, and 99.9% silicon powder in a three-dimensional mixer at an atomic ratio of Al:Fe:V:Si = 12:1.5:1.5:1 for 25 minutes. The mixture is then placed in a stainless steel ball mill jar using 10mm diameter steel balls at a ball-to-powder mass ratio of 10:1. Argon gas is introduced into the ball mill jar, and the mixture is ball-milled in a planetary ball mill at a speed of 600 rpm for 12 hours. After milling, an Al-rich alloy powder is obtained. 12 Alloy powder of (Fe,V)3Si phase.

[0085] S3: Wrap the obtained alloy powder in pure aluminum foil and compact it into a block under a pressure of 5MPa to ensure that the powder is completely and tightly wrapped by the aluminum foil.

[0086] S4: Heat aluminum ingots with a purity of ≥99.6% to 740℃ in a resistance furnace to melt them and obtain liquid aluminum.

[0087] S5: Add aluminum foil-wrapped, Al-rich material to the molten aluminum at a ratio of 3.0% by mass. 12 The alloy powder block of (Fe,V)3Si phase was pressed into the bottom of the molten aluminum using a graphite bell jar and left for 10 minutes until the alloy powder block was completely melted in the molten aluminum.

[0088] S6: Mechanically stir the aluminum alloy melt after the powder block is melted at 2 / 3 depth of the melt for 10 minutes, and maintain the melt temperature at 720℃ during the stirring process.

[0089] S7: Prepare hexachloroethane powder at 2% of the total weight of the molten aluminum. Press it into the bottom of the molten aluminum alloy using a graphite bell jar to vent and slag. After the venting reaction is complete, slowly remove the bell jar and skim off the slag generated on the surface of the molten aluminum alloy. After skimming, close the furnace door and allow the molten aluminum alloy to stand for 15 minutes. Adjust the furnace temperature to 710℃ and wait for the molten alloy to reach the desired temperature.

[0090] S8: After settling, open the furnace cover and remove the slag from the surface of the molten aluminum. Then, cast the molten aluminum alloy (ensure the casting temperature is above 700℃). After casting, wait for the aluminum alloy ingot to be cooled with water. Use flowing cold water to continuously pour on the surface of the ingot to cool it down until it is below 50℃.

[0091] S9: The surface oxide layer of the aluminum alloy ingot is removed by turning. The ingot diameter is 90mm. Hot extrusion plastic deformation is performed. The ingot is preheated at 400℃ for 1 hour and then hot extruded to form 12 aluminum alloy wires with a diameter of 3mm. The extrusion ratio is 75.

[0092] S10: After extrusion, the aluminum wire is directly placed into a water tank of flowing cold water for rapid cooling. The length of the aluminum wire immersed in the water tank is 5 meters according to the diameter of the aluminum wire and cooled to below 100°C.

[0093] S11: After being processed in the water tank, the aluminum wire is quickly wound into a coil by a winding machine, while a high-power fan is used to dry the water stains remaining on the surface of the aluminum wire.

[0094] S12: The wound aluminum wire can be placed in a heat treatment furnace at 150°C for annealing for 60 minutes to perform stabilization annealing. The annealing temperature and time are determined according to the different properties of the final aluminum alloy wire. After cooling to room temperature, the finished aluminum alloy wire is obtained.

[0095] Comparative Example 1

[0096] Al powder, Fe powder, V powder, and Si powder were prepared according to the proportions in Example 1 and mixed using a three-dimensional mixer for 100 hours. Testing revealed that the various metal powders remained elemental powders, indicating that alloying had not been achieved, and Al was not obtained. 12 (Fe,V)3Si phase alloy powder.

[0097] Comparative Example 2

[0098] Al powder, Fe powder, V powder, and Si powder were prepared according to the proportions in Example 1, added to molten aluminum, and smelted. The resulting ingot, after testing, yielded Al... 13 Fe4, Al6Fe, Al8Fe2Si, Al 21 V2 and other alloy phases were not obtained from Al. 12 The (Fe,V)3Si phase cannot improve the heat resistance in the Al matrix, and it will also reduce the strength and conductivity of the alloy.

[0099] Comparative Example 3

[0100] The other conditions were the same as in Example 1, except that the hot-extruded aluminum alloy wire was not water-cooled but naturally cooled at room temperature. The results showed that the wire strength decreased significantly and the conductivity was also low.

[0101] Performance Tests and Results

[0102] Figure 1 Al prepared by mechanical alloying in Example 2 12 Electron micrographs and structural analysis of the diffraction pattern of the (Fe,V)3Si phase confirm that Al 12 Morphology and crystal structure characteristics of the (Fe,V)3Si phase, including Al 12 The (Fe,V)3Si phase is small in size and appears as nano-sized particles.

[0103] Figure 2 Al obtained in Example 2 12 The X-ray spectra of (Fe,V)3Si phase powder exposed at different temperatures for 12 hours show that the phase has clear peaks and stable high-temperature performance. The phase remains stable even at the melting temperature of Al alloy (640℃). Therefore, it can be added to molten aluminum to become an intermediate alloy phase for preparing highly conductive aluminum alloys.

[0104] Figure 3 Al obtained in Example 2 12 The particle coarsening of (Fe,V)3Si phase powder after being held at 200℃ (a), 400℃ (b), and 600℃ (c) for 240 hours shows that Al 12Although the (Fe,V)3Si phase exhibits slight coarsening under prolonged high-temperature conditions, the size of the phase particles remains at the nanometer level after high-temperature coarsening, and it still possesses very low thermal diffusivity and excellent thermal stability.

[0105] Figure 4 The electron microscope images and diffraction patterns of the aluminum alloy ingot in Example 3 show that the Al matrix and Al can be observed simultaneously. 12 Crystal structure pattern of (Fe,V)3Si phase.

[0106] Figure 5 In the three embodiments, the mechanically alloyed high-energy ball-milled Al 12 The hardness change of (Fe,V)3Si phase powder after being pressed into blocks and heated at different temperatures for 1 hour is evident in the Al... 12 The hardness of the (Fe,V)3Si phase powder compact remains almost unchanged at high temperatures, even above 500℃, indicating that this alloy phase has high thermal stability.

[0107] Furthermore, the performance of each embodiment and Comparative Example 3 at different temperatures is shown in Table 1:

[0108] Table 1. Performance comparison of pure aluminum and aluminum alloy wires in Examples and Comparative Example 3 at different temperatures.

[0109]

[0110] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any form or substance. It should be noted that those skilled in the art can make various improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention. Any modifications, alterations, and equivalent changes made by those skilled in the art based on the above-disclosed technical content without departing from the spirit and scope of the present invention are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and evolutions made to the above embodiments based on the essential technology of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing an aluminum alloy wire with an added heat-resistant phase, characterized in that: Al 12 (Fe,V)3Si phase aluminum-based master alloy powder is added to molten aluminum to obtain aluminum alloy melt, aluminum alloy melt is cast to obtain aluminum alloy ingot, aluminum alloy ingot is hot extruded to obtain aluminum alloy wire, aluminum alloy wire is water-cooled and quenched to obtain aluminum alloy conductor. The Al-containing 12 The process for obtaining aluminum-based master alloy powder of (Fe,V)3Si phase is as follows: according to the atomic ratio Al∶Fe∶V∶Si=12∶1.5∶1.5∶1, iron powder, vanadium powder, and silicon powder in theoretical proportions are prepared, and aluminum powder in theoretical proportions of 1 to 1.1 times is prepared at the same time. The mixture is first mixed for 15 to 30 minutes to obtain a mixture, and then the mixture is mechanically alloyed by high-energy ball milling. During the hot extrusion process, the extrusion ratio is controlled to be ≥35.

2. The method for preparing an aluminum alloy wire with an added heat-resistant phase according to claim 1, characterized in that: The high-energy ball mill operates at a speed of 100-800 rpm and a milling time of 1-24 hours. The high-energy ball milling was carried out under argon protection; In the high-energy ball milling process, the grinding balls used are steel balls with a diameter of 8-12 mm; the ball-to-material mass ratio is 8-10:

1.

3. The method for preparing an aluminum alloy wire with an added heat-resistant phase according to claim 1, characterized in that: Al 12 The aluminum-based master alloy powder of (Fe,V)3Si phase is first wrapped in pure aluminum foil, then compacted into a block, and then added to molten aluminum for smelting. The pressure used for compaction into blocks is 2–10 MPa; The process of obtaining the molten aluminum is as follows: heating the aluminum ingot to 730℃~750℃ and melting it to obtain molten aluminum; The purity of the aluminum ingot is ≥99.6%.

4. The method for preparing an aluminum alloy wire with an added heat-resistant phase according to claim 1, characterized in that: The Al-containing 12 The amount of aluminum-based master alloy powder with (Fe,V)3Si phase added is 1.0% to 4.0% of the mass of aluminum liquid.

5. The method for preparing an aluminum alloy wire with an added heat-resistant phase according to claim 1, characterized in that: The smelting process is as follows: Al-containing... 12 Aluminum-based master alloy powder with (Fe,V)3Si phase was added to molten aluminum, and the Al content was increased. 12 After melting the aluminum-based master alloy powder of (Fe,V)3Si phase, stir for 5 to 15 minutes, keeping the melt temperature at 700℃ to 730℃ during stirring. Then add refining agent, degas and slag, remove slag and let stand for 10 to 20 minutes to obtain the final product. The stirring is carried out at a depth of 2 / 3 of the melt, and the stirring method is mechanical stirring; The refining agent is hexachloroethane powder, and the amount of the refining agent added is 1 to 3 wt% of the total mass of the melt.

6. The method for preparing an aluminum alloy wire with an added heat-resistant phase according to claim 1, characterized in that: The casting temperature is 700℃~720℃; The aluminum alloy ingots obtained by casting the molten aluminum alloy are water-cooled using flowing cooling water until the surface temperature of the aluminum alloy ingots is ≤50℃.

7. The method for preparing an aluminum alloy wire with an added heat-resistant phase according to claim 1, characterized in that: Before hot extrusion, the aluminum alloy ingot is preheated at 360℃~400℃ for 1~2 hours; During the hot extrusion, the extrusion ratio is controlled to be 35-90.

8. The method for preparing an aluminum alloy wire with an added heat-resistant phase according to claim 1, characterized in that: The aluminum alloy wire is directly immersed in a water tank for water cooling and quenching to below 100°C, and flowing cooling water is circulated in the water tank.

9. A method for preparing an aluminum alloy wire with an added heat-resistant phase according to any one of claims 1-8, characterized in that: The aluminum alloy wire obtained after water quenching is annealed at 50℃~250℃ for 30~120min.

10. An aluminum alloy wire with added heat-resistant phase prepared by the preparation method according to any one of claims 1-8, characterized in that: The aluminum alloy conductor, by mass percentage, has the following composition: Fe 0.2%–0.75%; V 0.2%–0.75%; Si 0.08%–0.3%, with the balance being Al; The aluminum alloy wire consists of an aluminum matrix and Al dispersed in the aluminum matrix. 12 The Al phase is composed of (Fe,V)3Si. 12 The (Fe,V)3Si phase is nanoscale.

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