Preparation method of high-conductivity and high-toughness Al-Fe alloy ultrafine wire

Abstract

The present application belongs to the field of preparation and processing of conductive aluminum alloy, and particularly relates to a preparation method of high-conductivity and high-toughness Al-Fe alloy ultrafine electronic wire. The Al-Fe alloy material is composed of the following elements by weight percentage: 0.3-0.6% of iron, 0-0.04% of rare earth element lanthanum, 0-0.04% of rare earth element cerium, ≤0.1% of total amount of impurity elements, and the balance of aluminum. The Al-Fe alloy ingot is subjected to homogenization treatment, hot extrusion and continuous extrusion to prepare an alloy round rod. The Al-Fe alloy rod is sequentially subjected to one-time drawing, one-time annealing, two-time drawing and two-time annealing to prepare the ultrafine Al-Fe alloy electronic wire with high conductivity and high elongation. In the future, the high-conductivity and high-toughness Al-Fe alloy ultrafine electronic wire prepared by the present application is applied to the electronic wire harness of new energy vehicles, which can significantly improve the endurance mileage of new energy vehicles and greatly reduce the overall cost of new energy vehicles.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of preparation and processing of conductive aluminum alloy, and particularly relates to a preparation method of high-conductivity and high-toughness Al-Fe alloy ultrafine electronic wire. BACKGROUND

[0002] Electronic wire harness is called the nerve and blood vessel of new energy vehicles. Under the trend of intelligent development of vehicles, the number of sensors of a vehicle increases rapidly, and the data transmission of sensors needs electronic wire harness as a carrier. Therefore, the development of intelligent vehicles greatly promotes the rapid growth of the demand for electronic wire harness. Ultrafine metal electronic wire is an important part of electronic wire harness and plays a role in power and signal transmission. Copper is currently commonly used in electronic wire harness of new energy vehicles due to its good electrical and mechanical properties. However, copper is a strategic resource, and its price increases year by year, so the continued use of copper electronic wire will increase the cost of the vehicle. In addition to copper, aluminum also has good electrical conductivity and is often used as a conductor material. In addition, the density of aluminum is one-third of that of copper, and the use of aluminum electronic wire instead of copper electronic wire will greatly reduce the weight of the vehicle, thereby improving the cruising range of new energy vehicles. In addition, the price of aluminum is relatively lower, and the use of aluminum electronic wire in new energy vehicles can reduce the cost of the vehicle. Therefore, aluminum electronic wire has a good application prospect instead of copper electronic wire, and currently foreign vehicle enterprises have adopted aluminum electronic wire as the vehicle harness and achieved good expected results. Therefore, domestic vehicle enterprises will adopt aluminum electronic wire. However, the research on aluminum alloy electronic wire started late, and the preparation technology of aluminum alloy electronic wire is relatively lacking, so it is urgent to develop aluminum alloy electronic wire. For electronic wire for new energy vehicles, electrical conductivity and elongation are important performance indicators. High electrical conductivity can reduce the line loss of electrical energy, and high elongation can avoid breakage when the electronic wire harness is bent. In summary, it is urgent to develop aluminum alloy electronic wire with high conductivity and high toughness. SUMMARY

[0003] The purpose of the application is to provide a preparation method of high-conductivity and high-toughness Al-Fe alloy ultrafine electronic wire to meet the demand for high-conductivity and high-toughness electronic wire in the transportation field.

[0004] The technical scheme of the application is as follows:

[0005] A preparation method of high-conductivity and high-toughness Al-Fe alloy ultrafine electronic wire comprises the following process steps:

[0006] (1) The Al-Fe melt is micro-alloyed by a rare earth element, and the melt is sufficiently purified by using an inert gas or a refining agent, and then the melt is cast into an Al-Fe alloy ingot;

[0007] (2) the Al-Fe alloy ingot is subjected to homogenization treatment, hot extrusion and continuous extrusion to prepare an Al-Fe alloy round rod;

[0008] (3) the Al-Fe alloy round rod is subjected to primary drawing, primary annealing, secondary drawing and secondary annealing to obtain an Al-Fe alloy ultra-fine electronic wire;

[0009] the primary drawing pass is 15-20, and the Al-Fe alloy thin wire with a diameter of 1.5-2.5 mm is drawn; the primary annealing temperature is 300-400℃, and the Al-Fe alloy thin wire is annealed for 5-60 min and then air-cooled to room temperature; the secondary drawing pass is 20-25, and the Al-Fe alloy ultra-fine wire with a diameter of 0.2-0.4 mm is drawn; the secondary annealing temperature is 350-450℃, and the Al-Fe alloy ultra-fine wire is annealed for 0.5-30 min and then air-cooled to room temperature.

[0010] The Al-Fe alloy material comprises, by weight percentage, 0.3-0.6% of iron, 0-0.04% of rare earth element lanthanum, 0-0.04% of rare earth element cerium, ≤0.1% of impurity elements, and the balance of aluminum.

[0011] The preparation method of the high-conductivity and high-toughness Al-Fe alloy ultra-fine electronic wire comprises the following steps:

[0012] (1) pure aluminum is placed in a melting furnace and melted, and a covering agent is added to the surface of the melt, and the temperature of the melt is adjusted to 740-770℃, wherein the covering agent is a mixture of sodium chloride, potassium chloride and cryolite;

[0013] (2) iron is added to the melt in the form of pure iron or Al-Fe intermediate alloy, the melt is fully stirred and kept for 30 min;

[0014] (3) the composition of the melt is tested and adjusted so that the content of each element is as follows: 0.3-0.6% of iron, ≤0.1% of impurity elements, and the balance of aluminum;

[0015] (4) the melt is purified by using inert gas or 0.2% of refining agent based on the weight of the melt;

[0016] (5) the temperature of the melt is reduced to 700-720℃;

[0017] (6) rare earth element cerium is added to the melt in the form of high-purity rare earth element cerium or Al-Ce intermediate alloy, and rare earth element lanthanum is added to the melt in the form of high-purity rare earth element lanthanum or Al-La intermediate alloy, and then the melt is stirred and kept for 10 min;

[0018] (7) control the temperature at 700-720℃, and let the slag or inclusions float to the surface of the Al-Fe alloy melt, and remove the dross on the surface of the melt;

[0019] (8) pour the Al-Fe alloy melt into a mold to obtain a high-conductivity Al-Fe alloy ingot.

[0020] In the preparation method of the high-conductivity and high-toughness Al-Fe alloy ultrafine electronic wire, inert gas is filled into the smelting furnace to protect the Al-Fe alloy during heating, melting and holding, so as to weaken the absorption and oxidation of the melt.

[0021] In the preparation method of the high-conductivity and high-toughness Al-Fe alloy ultrafine electronic wire, the hydrogen content in the Al-Fe alloy melt is strictly controlled, and the hydrogen content in the melt is less than 0.15 ml / 100g Al before the rare earth element cerium is added into the Al-Fe alloy melt.

[0022] In the preparation method of the high-conductivity and high-toughness Al-Fe alloy ultrafine electronic wire, when the rare earth elements cerium and lanthanum are added in the form of pure metals, the purity is greater than or equal to 99.9wt%; when the rare earth elements cerium and lanthanum are added in the form of Al-Ce intermediate alloy and Al-La intermediate alloy, the impurity element content of the Al-Ce intermediate alloy and the Al-La intermediate alloy used is less than 0.1wt%.

[0023] In the preparation method of the high-conductivity and high-toughness Al-Fe alloy ultrafine electronic wire, the preparation method of the Al-Fe alloy round rod in step (2) includes the following steps:

[0024] (1) homogenizing annealing the Al-Fe alloy ingot at 520-540℃ for 8-12h;

[0025] (2) extruding the Al-Fe alloy ingot into a rough round rod by using a horizontal extruder, and the extrusion temperature is 400-420℃;

[0026] (3) processing the rough round rod into an Al-Fe alloy round rod with a diameter of 8.5-10.5mm by continuous extrusion.

[0027] In the preparation method of the high-conductivity and high-toughness Al-Fe alloy ultrafine electronic wire, continuous extrusion is carried out by using a continuous extruder, and the rotating speed of the continuous extruder is 12-16r / min.

[0028] In the preparation method of the high-conductivity and high-toughness Al-Fe alloy ultrafine electronic wire, in step (3), the primary drawing process is cold drawing, and the wire drawing speed is 30-50m / min.

[0029] The preparation method of the high-conductivity and high-toughness Al-Fe alloy ultra-fine electronic wire comprises the following steps: (1) preparing an Al-Fe alloy round bar; (2) performing continuous extrusion on the Al-Fe alloy round bar; (3) performing secondary drawing on the Al-Fe alloy wire after the Al-Fe alloy wire is annealed once; and (4) performing secondary annealing on the Al-Fe alloy wire after the Al-Fe alloy wire is drawn twice.

[0030] The design principle and beneficial effects of the application are as follows:

[0031] 1. In the drawing process, as the drawing deformation increases, the strength of the Al-Fe alloy wire increases, and the elongation decreases. When the elongation cannot meet the requirement of plastic deformation in the drawing process, a wire breaking accident occurs, which leads to discontinuous drawing. Therefore, the Al-Fe alloy wire needs to maintain a certain elongation to meet the requirement of plastic deformation in the drawing process. Therefore, the application firstly improves the uniformity of the alloy round bar and reduces the gas content in the alloy through liquid aluminum refining and continuous extrusion process, so as to ensure that the alloy has excellent plastic deformation capacity. Secondly, the Al-Fe alloy wire is annealed once after being drawn once, so that the grains in the Al-Fe alloy wire are recrystallized, the elongation is restored, and the elongation requirement of the secondary drawing is met. After the secondary drawing, the grains in the Al-Fe alloy ultra-fine wire are severely refined, and a large number of dislocations and vacancies and other defects exist, which leads to a large decrease in the electrical conductivity. In addition, the microstructure defects in the drawn Al-Fe alloy ultra-fine wire lead to a significant decrease in the work hardening capacity, which leads to a low elongation. Therefore, after the secondary drawing, the purpose of the secondary annealing is to improve the electrical conductivity and the elongation of the Al-Fe alloy wire, to realize the regulation of the electrical conductivity and the elongation of the Al-Fe alloy ultra-fine electronic wire, and to prepare the high-conductivity and high-toughness Al-Fe alloy ultra-fine electronic wire.

[0032] 2. Beneficial effects: the application can prepare the Al-Fe alloy ultra-fine electronic wire with high conductivity and high toughness through the matching design of the whole process preparation process of the Al-Fe alloy wire. In the future, the high-conductivity and high-toughness Al-Fe alloy ultra-fine electronic wire prepared by the application can be applied to the electronic wire harness of new energy vehicles. On the one hand, the application can significantly improve the endurance mileage of the new energy vehicles. On the other hand, the application can greatly reduce the overall cost of the new energy vehicles. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 The drawing-annealing process flow chart of the high-conductivity and high-toughness Al-Fe alloy ultra-fine electronic wire is shown in the figure. DETAILED DESCRIPTION

[0034] In the specific implementation process, the high-conductivity and high-toughness Al-Fe alloy ultra-fine electronic wire is composed of the following elements by weight percentage: 0.3-0.6% of iron, 0-0.04% of rare earth element lanthanum, 0-0.04% of rare earth element cerium, ≤0.1% of impurity elements, and the balance of aluminum.

[0035] The high-conductivity and high-toughness Al-Fe alloy ultrafine wire preparation method comprises the following steps:

[0036] (1) Put pure aluminum into a smelting furnace to melt and add a covering agent (a mixture of sodium chloride, potassium chloride and cryolite) on the surface of the melt, and adjust the melt temperature to 740-770°C;

[0037] (2) Add iron to the melt in the form of pure iron or Al-Fe intermediate alloy, fully stir the melt, and after heat preservation for about 30 min, purify the melt by using inert gas or refining agent;

[0038] (3) Test and analyze the melt composition and adjust it so that the weight percentage of each element is: iron 0.3-0.6%, total impurity elements ≤0.1%, and the balance is aluminum;

[0039] (4) Purify the melt by using high-purity argon gas (volume purity 99.999%) or refining agent accounting for about 0.2% of the weight of the melt;

[0040] (5) Reduce the melt temperature to 700-720°C;

[0041] (6) Add rare earth element cerium to the melt in the form of high-purity rare earth element cerium (purity ≥99.9wt%) or Al-Ce intermediate alloy, and add rare earth element lanthanum to the melt in the form of high-purity rare earth element lanthanum (purity ≥99.9wt%) or Al-La intermediate alloy, then stir the melt and heat preserve for about 10 min;

[0042] (7) Control the temperature at 700-720°C, stand for about 10 min, let the slag or inclusions float to the surface of the Al-Fe alloy melt, and remove the scum on the surface of the melt;

[0043] (8) Pour the Al-Fe alloy melt into a mold to obtain a high-conductivity Al-Fe alloy ingot.

[0044] (9) Homogenize anneal the Al-Fe alloy ingot at 520-540°C for 8-12 h;

[0045] (10) Use a horizontal extruder to extrude the ingot into a round rod, and the extrusion temperature is 400-420°C;

[0046] (11) Process the aluminum round rod into a round rod with a diameter of 8.5-10.5 mm by continuous extrusion, and the rotation speed of the continuous extruder is 12-16 rpm.

[0047] (12) The Al-Fe alloy round rod is drawn once to obtain Al-Fe alloy fine wire with a diameter of 1.5-2.5 mm, the drawing process is cold drawing, the drawing pass is 15-20, and the wire drawing speed is 30-50 m / min.

[0048] (13) The Al-Fe alloy fine wire after the first drawing is annealed once, the annealing temperature is 300-400℃, the holding time is 5-60 min, and then the temperature is cooled to room temperature, and the cooling mode is air cooling.

[0049] (14) The Al-Fe alloy fine wire after the first annealing is drawn twice to obtain Al-Fe alloy ultra-fine wire with a diameter of 0.2-0.4 mm, the drawing pass is 20-25, and the wire drawing speed is 30-60 m / min.

[0050] (15) The Al-Fe alloy ultra-fine wire after the second drawing is annealed twice, the temperature is 350-450℃, the holding time is 0.5-30 min, and then the temperature is cooled to room temperature, and the cooling mode is air cooling.

[0051] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other examples improved or decorated by those skilled in the art belong to the scope of protection of the present application. It should be understood that the embodiments of the present application are only used to illustrate the technical effects of the present application, and are not used to limit the protection scope of the present application. In the embodiments, the methods used are conventional methods unless otherwise specified.

[0052] Embodiment 1

[0053] In this embodiment, the Al-Fe alloy used in the high-conductivity and high-toughness Al-Fe alloy ultra-fine electronic wire has the following chemical composition: Fe 0.6 wt.%, Ce 0.04 wt.%, total amount of impurity elements 0.02 wt.%, and the balance of Al.

[0054] In this embodiment, the preparation method of the high-conductivity and high-toughness Al-Fe alloy ultra-fine electronic wire is as follows:

[0055] (1) Put pure aluminum into a smelting furnace and melt it, and add a covering agent to the surface of the melt, the covering agent being a mixture of sodium chloride, potassium chloride and cryolite in a weight ratio of 2:2:1 → adjust the melt temperature to 760°C → add iron to the melt in the form of pure iron or Al-Fe intermediate alloy, thoroughly stir the melt and keep it for about 30 min, and then purify the melt using high-purity argon (volume purity 99.999%) or a commonly used aluminum alloy refining agent accounting for 0.2% of the weight of the melt → reduce the melt temperature to 710°C → add the rare earth element cerium to the melt in the form of an Al-Ce intermediate alloy → stir the melt and keep it for about 10 min → control the temperature at 710°C and let it stand for 10 min to allow the slag or inclusions to float to the surface of the aluminum alloy melt, and remove the scum on the surface of the melt → pour the alloy melt into a mold to obtain a high-conductivity Al-Fe alloy ingot.

[0056] (2) Homogenize the Al-Fe alloy ingot at 540°C for 8h;

[0057] (3) Use a horizontal extruder to extrude the ingot into a round rod, with an extrusion temperature of 400°C;

[0058] (4) Process the round rod into a round rod with a diameter of 8.5-10.5mm by continuous extrusion, with a continuous extruder speed of 12 revolutions / min.

[0059] As shown in Figure 1 , further adopting a drawing-annealing process flow as follows:

[0060] (5) First drawing, drawing the Al-Fe alloy rod with a diameter of 9.5mm, the drawing process being cold drawing, with 18 drawing passes, and the die diameters being 8.5mm→7.6mm→6.7mm→5.9mm→5.2mm→4.8mm→4.4mm→4.0mm→3.7mm→3.4mm→3.1mm→2.9mm→2.7mm→2.5mm→2.4mm→2.3mm→2.2mm→2.1mm in sequence, with a wire drawing speed of 40m / min, and obtaining an Al-Fe alloy fine wire with a diameter of 2.1mm by drawing;

[0061] (6) First annealing, annealing the Al-Fe alloy fine wire with a diameter of 2.1mm after first drawing at 380°C for 60min, with air cooling;

[0062] (7) Secondary drawing, the Al-Fe alloy fine wire after the first annealing is drawn, the drawing process is cold drawing, the drawing pass is 22, the die diameter is 2.0 mm→1.8 mm→1.6 mm→1.4 mm→1.2 mm→1.1 mm→1.0 mm→0.9 mm→0.8 mm→0.75 mm→0.7 mm→0.65 mm→0.6 mm→0.55 mm→0.5 mm→0.45 mm→0.4 mm→0.36 mm→0.32 mm→0.28 mm→0.24 mm→0.20 mm in turn, the wire drawing speed is 50 m / min, and the Al-Fe alloy ultrafine wire with a diameter of 0.20 mm is drawn;

[0063] (8) Secondary annealing, the Al-Fe alloy ultrafine wire with a diameter of 0.20 mm obtained by the secondary drawing is annealed at 400 ℃ for 5 min, and the cooling mode is air cooling, and the preparation of the high-conductivity and high-toughness Al-Fe alloy ultrafine electronic wire is completed.

[0064] Example 2

[0065] Different from example 1, as shown in the drawing, the drawing-annealing process flow is as follows: Figure 1

[0066] (1) Primary drawing, the Al-Fe alloy rod with a diameter of 9.0 mm is drawn, the drawing process is cold drawing, the drawing pass is 17, the die diameter is 8.0 mm→7.0 mm→6.5 mm→6.0 mm→5.5 mm→5.0 mm→4.5 mm→4.0 mm→3.5 mm→3.1 mm→2.8 mm→2.5 mm→2.3 mm→2.2 mm→2.1 mm→2.0 mm→1.9 mm in turn, the wire drawing speed is 35 m / min, and the Al-Fe alloy fine wire with a diameter of 1.9 mm is drawn;

[0067] (2) Primary annealing, the Al-Fe alloy fine wire with a diameter of 1.9 mm after the primary drawing is annealed at 400 ℃ for 40 min, and the cooling mode is air cooling;

[0068] ​(3) secondary drawing, drawing the Al-Fe alloy wire after the first annealing, the drawing process is cold drawing, the drawing pass is 21, the die diameter of each pass is 1.7 mm→1.5 mm→1.3 mm→1.2 mm→1.1 mm→1.0 mm→0.9 mm→0.8 mm→0.75 mm→0.7 mm→0.65 mm→0.6 mm→0.55 mm→0.5 mm→0.45 mm→0.4 mm→0.36 mm→0.32 mm→0.28 mm→0.24 mm→0.20 mm, the wire drawing speed is 60 m / min, and the Al-Fe alloy ultrafine wire with a diameter of 0.20 mm is obtained by drawing;

[0069] (4) secondary annealing, the Al-Fe alloy ultrafine electronic wire with a diameter of 0.20 mm obtained by secondary drawing is subjected to annealing treatment at 450 °C for 3 min, and the cooling mode is air cooling, thereby completing the preparation of the high-conductivity and high-toughness Al-Fe alloy ultrafine electronic wire.

[0070] Comparative Example 1

[0071] The difference from Example 1 is that:

[0072] (1) the designed Al-Fe alloy composition is, in terms of element weight percentage, Fe 0.58 wt.%, La 0.02 wt.%, total amount of impurity elements 0.01 wt.%, and the balance is Al;

[0073] (2) the hot extruded round rod is not subjected to continuous extrusion treatment before subsequent drawing-annealing process.

[0074] Comparative Example 2

[0075] Steps (1)-(4) are the same as Example 1, and the difference from Example 1 is that:

[0076] (1) the designed Al-Fe alloy composition is, in terms of element weight percentage, Fe 0.58 wt.%, La 0.02 wt.%, total amount of impurity elements 0.01 wt.%, and the balance is Al;

[0077] The Al-Fe alloy thin wire with a diameter of 1.6 mm after once drawing is annealed at 380 DEG C for 60 min, and the cooling mode is air cooling.

[0078] Comparative Example 3

[0079] The difference from Comparative Example 2 is that the Al-Fe alloy thin wire with a diameter of 1.6 mm prepared by once drawing is not annealed.

[0080] Comparative Example 4

[0081] Steps (1)-(7) are the same as those in Example 1, and the Al-Fe alloy ultra-thin wire with a diameter of 0.2 mm is prepared, and the difference is that the second annealing is not performed.

[0082] The Al-Fe alloy ultra-thin electronic wire prepared in Example 1, Example 2 and Comparative Example 1 is tested for mechanical properties and electrical conductivity, and the results are shown in Table 1. As shown in Table 1, the Al-Fe alloy ultra-thin electronic wire prepared by the present application has good electrical conductivity and elongation, and the elongation of Comparative Example 1 is significantly lower. The performance test results of Example 1 and Comparative Examples 2 and 3 show that the Al-Fe alloy ultra-thin wire cannot be prepared by once drawing without intermediate annealing process. Moreover, the performance test results of Comparative Example 3 show that the strength of the Al-Fe alloy thin wire without second annealing is high, but the elongation is greatly reduced, which cannot meet the performance requirements of elongation during assembly and service of the ultra-thin electronic wire; the test results of Example 1 and Comparative Example 4 show that the Al-Fe alloy ultra-thin wire with a diameter of 0.2 mm can be prepared by once drawing, once annealing and twice drawing, but without second annealing, which results in low elongation of the Al-Fe alloy ultra-thin wire, which cannot meet the requirements of elongation during assembly and service of the ultra-thin electronic wire.

[0083] Table 1 Performance test results of Al-Fe alloy ultra-thin electronic wire of Example 1, Example 2 and Comparative Example 1

[0084] Al-Fe alloy wire Wire diameter / mm Tensile strength / MPa Electrical conductivity / IACS % Elongation / % Example 1 0.2 126.3 62.23 16.7 Example 2 0.2 109.7 62.38 22.4 Comparative Example 1 0.2 115.2 61.53 14.2 Comparative Example 2 1.6 120.5 62.03 13.7 Comparative Example 3 1.6 198.5 61.85 2.5 Comparative Example 4 0.2 210.5 61.77 3.1

[0085] The implementation results show that the Al-Fe alloy ingot is uniformly treated, hot extruded and continuously extruded to prepare an Al-Fe alloy round rod, the Al-Fe alloy round rod is once drawn, once annealed, twice drawn and twice annealed to prepare an ultra-thin Al-Fe alloy electronic wire with high electrical conductivity and high elongation.

Claims

1. A method for preparing high-conductivity, high-toughness Al-Fe alloy ultrafine electronic wires, characterized in that, The process includes the following steps: (1) The Al-Fe melt is micro-alloyed by rare earth elements and the melt is fully purified by inert gas or refining agent before being cast into Al-Fe alloy ingots. The elemental composition of the Al-Fe alloy material by weight percentage is as follows: iron 0.3-0.6%, the Al-Fe alloy material contains rare earth elements lanthanum and / or cerium, rare earth elements lanthanum 0-0.04%, rare earth elements cerium 0-0.04%, total impurity elements ≤0.1%, and the balance is aluminum. (2) The Al-Fe alloy ingot is homogenized, hot-extruded and continuously extruded to prepare Al-Fe alloy round rods; In step (2), the preparation method of the Al-Fe alloy round rod includes the following steps: (1) The Al-Fe alloy ingot was homogenized and annealed at 520-540℃ for 8-12 hours; (2) Use a horizontal extrusion press to extrude Al-Fe alloy ingots into coarse round rods at an extrusion temperature of 400-420℃; (3) The above-mentioned rough round rod is continuously extruded into an Al-Fe alloy round rod with a diameter of 8.5 to 10.5 mm; Continuous extrusion processing is carried out using a continuous extruder with a rotation speed of 12–16 rpm; (3) The Al-Fe alloy round rod is subjected to one drawing, one annealing, two drawing and two annealing to obtain Al-Fe alloy ultrafine electronic wire; The first drawing pass consists of 15 to 20 passes, drawing Al-Fe alloy fine wires with a diameter of 1.5 to 2.5 mm; the first annealing temperature is 300 to 400°C, held for 5 to 60 minutes, and then air-cooled to room temperature; the second drawing pass consists of 20 to 25 passes, drawing Al-Fe alloy ultrafine wires with a diameter of 0.2 to 0.4 mm; the second annealing temperature is 350 to 450°C, held for 0.5 to 30 minutes, and then air-cooled to room temperature.

2. The method for preparing high-conductivity, high-toughness Al-Fe alloy ultrafine electronic wires according to claim 1, characterized in that, In step (1), the preparation process of the Al-Fe alloy ingot is as follows: (1) Pure aluminum is placed in a smelting furnace to melt and a covering agent is added to the surface of the melt. The temperature of the melt is adjusted to 740℃~770℃. The covering agent is a mixture of sodium chloride, potassium chloride and cryolite. (2) Add iron to the melt in the form of pure iron or Al-Fe master alloy, stir the melt thoroughly and keep it at a temperature for 30 minutes; (3) The composition of the melt is tested, analyzed and adjusted so that the content of each element is: iron 0.3-0.6%, total impurity elements ≤0.1%, and the balance is aluminum; (4) Purify the melt using inert gas or a refining agent accounting for 0.2% of the melt weight; (5) Reduce the melt temperature to 700℃~720℃; (6) Add rare earth element cerium to the melt in the form of high-purity rare earth element cerium or Al-Ce master alloy, add rare earth element lanthanum to the melt in the form of high-purity rare earth element lanthanum or Al-La master alloy, then stir the melt and keep it warm for 10 min. (7) Control the temperature at 700℃~720℃, let it stand for 10 minutes, allow the slag or inclusions to float to the surface of the Al-Fe alloy melt, and remove the slag from the surface of the melt. (8) Pour the Al-Fe alloy melt into a mold to obtain a highly conductive Al-Fe alloy ingot.

3. The method for preparing high-conductivity, high-toughness Al-Fe alloy ultrafine electronic wires according to claim 2, characterized in that, During the heating, melting, and holding process of Al-Fe alloys, the melting furnace is filled with inert gas for protection to reduce gas absorption and oxidation of the melt.

4. The method for preparing high-conductivity, high-toughness Al-Fe alloy ultrafine electronic wires according to claim 2, characterized in that, During the Al-Fe alloy smelting process, the hydrogen content in the Al-Fe alloy melt is strictly controlled. Before adding the rare earth element cerium to the Al-Fe alloy melt, the hydrogen content in the melt is less than 0.15 ml / 100g Al.

5. The method for preparing high-conductivity, high-toughness Al-Fe alloy ultrafine electronic wires according to claim 2, characterized in that, When rare earth elements cerium and lanthanum are added in pure metal form, their purity is ≥99.9wt%; when rare earth elements cerium and lanthanum are added in the form of Al-Ce master alloy and Al-La master alloy, the impurity element content in the Al-Ce master alloy and Al-La master alloy used is less than 0.1wt%.

6. The method for preparing high-conductivity, high-toughness Al-Fe alloy ultrafine electronic wires according to claim 1, characterized in that, In step (3), the single drawing process used is cold drawing, and the wire drawing speed is 30-50 m / min.

7. The method for preparing high-conductivity, high-toughness Al-Fe alloy ultrafine electronic wires according to claim 1, characterized in that, In step (3), the secondary drawing feed material is Al-Fe alloy wire that has undergone one annealing process, and the wire drawing speed is 30-60 m / min.

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