Aluminum alloy wire and preparation method thereof

Abstract

The invention belongs to the field of alloy materials, and particularly relates to an aluminum alloy wire and a preparation method thereof. The aluminum alloy wire provided by the invention comprises the following components in percentage by weight: 0.05-0.15% of Fe, 0.05-0.1% of Si, 0.08-0.15% of Sc, less than or equal to 0.3% of Mg, less than or equal to 0.3% of Cu, less than or equal to 0.3% of Mn, less than or equal to 0.1% of Cr, less than or equal to 0.1% of Zn, less than or equal to 0.2% of Ti and the balance of Al. The mass ratio of Fe to Si is 1-2. The content of Fe and Si in the aluminum alloy wire is controlled to be 0.05-0.15 wt% and 0.05-0.1 wt%, 0.08-0.15 wt% of Sc element is added, and the upper limit content of other elements is controlled, so that the aluminum alloy wire has excellent conductivity, strength, plasticity and welding performance.

Description

Technical Field

[0001] The present invention belongs to the field of alloy materials, and particularly relates to an aluminum alloy wire and a preparation method thereof. Background Art

[0002] In recent years, with the rapid growth of the new energy vehicle market, the demand for new energy motors has increased significantly. As the core component of new energy vehicles, the motor is responsible for converting electrical energy in the battery system into mechanical energy, directly determining the safety, stability and economy of the vehicle. The stator winding of the motor is an important part of the motor, usually composed of multiple coils or coil groups, and traditionally copper wires are mostly used. However, copper wires have high costs and high densities, which limit the lightweight and cost optimization of motors.

[0003] In contrast, aluminum alloys have the characteristics of low density and low cost, and are particularly suitable for the application of high torque density motors. By using aluminum alloys to replace copper wires, the cost can be reduced by 80%, and at the same time, the weight of the motor can be significantly reduced and the performance can be improved. However, existing aluminum alloy wires have obvious deficiencies in elongation, welding performance and electrical conductivity compared with copper wires, and it is difficult to meet the high-performance requirements of motor stator windings. In addition, high electrical conductivity requires high purity aluminum alloys, but high purity aluminum alloys have low strength and are prone to splash during the welding process. Therefore, it is of great practical significance to develop an aluminum alloy wire with high electrical conductivity, high strength and good welding performance. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide an aluminum alloy wire and a preparation method thereof. The aluminum alloy wire provided by the present invention has high electrical conductivity, high strength and good welding performance.

[0005] The present invention provides an aluminum alloy wire. By weight percentage, the composition of the aluminum alloy wire includes: Fe 0.05 - 0.15%, Si 0.05 - 0.1%, Sc 0.08 - 0.15%, Mg ≤ 0.3%, Cu ≤ 0.3%, Mn ≤ 0.3%, Cr ≤ 0.1%, Zn ≤ 0.1%, Ti ≤ 0.2%, and the rest is Al; the mass ratio of Fe to Si is 1 - 2.

[0006] Preferably, by weight percentage, the composition of the aluminum alloy wire includes: Fe 0.08 - 0.1%, Si 0.05 - 0.08%, Sc 0.12 - 0.15%, Mg 0.05 - 0.1%, Cu 0.001 - 0.005%, Mn 0.0005 - 0.001%, Cr 0.0005 - 0.001%, Zn 0.0005 - 0.001%, Ti 0.01 - 0.02%, and the rest is Al.

[0007] Preferably, in the metallographic structure of the aluminum alloy wire rod, the diameter of the Al3Sc particles is ≤20 nm.

[0008] The present invention provides a method for preparing the aluminum alloy wire rod described in the above technical solution, comprising the following steps:

[0009] S1: Using aluminum ingots and master alloys, preparing an aluminum alloy casting rod by a semi-continuous casting process;

[0010] S2: Performing a homogenization treatment on the aluminum alloy casting rod, and the specific treatment process includes: at a heating rate of 5-15 °C / min, heating the aluminum alloy casting rod to 400-430 °C and holding for 10-20 h, then heating to 560-600 °C and holding for 4-12 h, and then cooling;

[0011] S3: Turning the aluminum alloy casting rod after the homogenization treatment to remove the oxide scale;

[0012] S4: Heating the aluminum alloy casting rod after the treatment in step S3 to 450-550 °C and holding for 2-4 h, and then performing hot rough rolling, with the final rolling temperature controlled at 300-360 °C, to obtain a hot rough rolling billet;

[0013] S5: Heating the hot rough rolling billet to 400-500 °C, and then performing hot finish rolling, with the final rolling temperature controlled at 260-320 °C, to obtain a hot finish rolling billet;

[0014] S6: Performing cold rolling on the hot finish rolling billet, with the cold rolling deformation amount ≥10%;

[0015] S7: Performing cold drawing on the billet after the cold rolling, with the cold drawing deformation amount ≥25%, to obtain a cold drawn wire rod;

[0016] S8: Performing annealing treatment on the cold drawn wire rod in a protective gas atmosphere, with the annealing temperature being 280-380 °C, holding for 1-4 h, and then cooling, to obtain the aluminum alloy wire rod.

[0017] Preferably, in step S2, the specific treatment process includes: at a heating rate of 5-10 °C / min, heating the aluminum alloy casting rod to 400-420 °C and holding for 12-16 h, then heating to 560-580 °C and holding for 10-12 h, and then cooling.

[0018] Preferably, in step S4, the aluminum alloy casting rod is heated to 460-480 °C; the final rolling temperature is controlled at 320-350 °C; the total deformation amount of the hot rough rolling ≥95%, the pass deformation amount is 10-30%, and the hot rolling speed is 0.4-2 m / s.

[0019] Preferably, in step S5, the hot rough rolling billet is heated to 400-420 °C; the final rolling temperature is controlled at 280-300 °C.

[0020] Preferably, in step S6, the cold rolling deformation is 20-30%.

[0021] Preferably, in step S8, the annealing temperature is 280-320 °C; the heat preservation time is 2-4 h; the cooling rate is 0.5-1 °C / min.

[0022] The present invention provides an aluminum alloy wire product, including a core material and an insulating coating coated on the surface of the core material, and the core material is the aluminum alloy wire described in the above technical solution or the aluminum alloy wire prepared by the preparation method described in the above technical solution.

[0023] Compared with the prior art, the present invention provides an aluminum alloy wire and a preparation method thereof. By weight percentage, the composition of the aluminum alloy wire provided by the present invention includes: Fe 0.05-0.15%, Si 0.05-0.1%, Sc 0.08-0.15%, Mg≤0.3%, Cu≤0.3%, Mn≤0.3%, Cr≤0.1%, Zn≤0.1%, Ti≤0.2%, and the rest is Al; the mass ratio of Fe to Si is 1-2. By controlling the contents of Fe and Si in the aluminum alloy wire within the ranges of 0.05-0.15 wt% and 0.05-0.1 wt%, adding 0.08-0.15 wt% of Sc element, and controlling the upper limit contents of other elements, the aluminum alloy wire has excellent electrical conductivity, strength, plasticity and welding performance. On this basis, the present invention further optimizes the preparation process of the aluminum alloy wire, especially the optimization of the homogenization treatment, rolling and post-rolling treatment processes, further improving the performance of the aluminum alloy wire. The experimental results show that: the conductivity of the aluminum alloy wire provided by the present invention is ≥60% IACS, the yield strength is ≥100 MPa, the elongation is ≥30%; there is no splash during laser welding, and the tensile strength after welding is ≥150 MPa. Specific Embodiments

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0025] The present invention provides an aluminum alloy wire, and by weight percentage, its composition includes: Fe 0.05-0.15%, Si 0.05-0.1%, Sc 0.08-0.15%, Mg≤0.3%, Cu≤0.3%, Mn≤0.3%, Cr≤0.1%, Zn≤0.1%, Ti≤0.2%, and the rest is Al.

[0026] In the aluminum alloy wire provided by the present invention, Fe is the main impurity element, which forms intermetallic compounds (such as Al5FeSi) with Al and Si. These compounds can play a certain strengthening role and improve the hardness and strength of the aluminum alloy. An appropriate amount of Fe can refine the grains and improve the processing properties of the aluminum alloy, especially during rolling and extrusion. Excessive Fe will form coarse intermetallic compounds, reducing the ductility and plasticity of the aluminum alloy. Its presence will reduce the electrical conductivity of the aluminum alloy, which is not conducive to the motor stator flat wire that requires high conductivity. Therefore, the content of Fe in the aluminum alloy wire needs to be controlled to 0.05-0.15wt%, preferably 0.08-0.1wt%.

[0027] In the aluminum alloy wire provided by the present invention, an appropriate amount of Si can refine the grain structure of the aluminum alloy and improve the strength and toughness of the material. Excessive Si will form a brittle phase and reduce the ductility and plasticity of the aluminum alloy. Si is an impurity element, and its presence will reduce the conductivity of the aluminum alloy, which is not conducive to high conductivity applications. Therefore, the content of Si in the aluminum alloy wire needs to be controlled to 0.05-0.1wt%, preferably 0.05-0.08wt%.

[0028] In the aluminum alloy wire provided by the present invention, the mass ratio of Fe to Si is 1 to 2, preferably 1.25 to 1.6.

[0029] In the aluminum alloy wire provided by the present invention, Sc is a rare earth element, which has a significant optimization effect on the microstructure and mechanical properties of the aluminum alloy. Sc and Al form fine Al3Sc phases, which can act as heterogeneous nucleation points during the solidification process, significantly refining the grain structure of the aluminum alloy. The Al3Sc phase plays a role of dispersion strengthening in the aluminum alloy, and the Sc element can also inhibit recrystallization, increase the dislocation density of the material, and thus enhance the strength. After adding Sc, the yield strength and tensile strength of the aluminum alloy are significantly improved while maintaining good plasticity. Al3Sc particles have high thermal stability, can maintain a fine and uniform distribution at high temperatures, and inhibit grain growth. The most important Sc element can refine the grain structure of the welding area, reduce the grain growth of the welding heat-affected zone, and inhibit the generation of welding cracks, which is crucial to improving the welding performance of flat wires for motor stators. In the present invention, the content of Sc in the aluminum alloy wire is 0.08-0.15wt%, preferably 0.12-0.15wt%.

[0030] In the aluminum alloy wire provided by the present invention, the content of Mg is ≤0.3wt%, and can further be 0.05-0.1wt%.

[0031] In the aluminum alloy wire provided by the present invention, the content of Cu is ≤0.3wt%, and can further be 0.001-0.005wt%.

[0032] In the aluminum alloy wire provided by the present invention, the content of Mn is ≤ 0.3 wt%, and further can be 0.0005 - 0.001 wt%.

[0033] In the aluminum alloy wire provided by the present invention, the content of Cr is ≤ 0.1 wt%, and further can be 0.0005 - 0.001 wt%.

[0034] In the aluminum alloy wire provided by the present invention, the content of Zn is ≤ 0.1 wt%, and further can be 0.0005 - 0.001 wt%.

[0035] In the aluminum alloy wire provided by the present invention, the content of Ti is ≤ 0.2 wt%, and further can be 0.01 - 0.02 wt%.

[0036] In the aluminum alloy wire provided by the present invention, the diameter of Al3Sc particles in its metallographic structure is preferably ≤ 20 nm.

[0037] By optimizing the alloying elements and their contents in the aluminum alloy wire provided by the present invention, the material has excellent electrical conductivity, strength, plasticity and welding performance at the same time.

[0038] The present invention also provides a preparation method of the aluminum alloy wire described in the above technical solution, including the following steps:

[0039] S1: Using aluminum ingots and master alloys, preparing an aluminum alloy cast rod by a semi-continuous casting process;

[0040] S2: Performing homogenization treatment on the aluminum alloy cast rod. The specific treatment process includes: heating the aluminum alloy cast rod to 400 - 430 °C at a heating rate of 5 - 15 °C / min and holding for 10 - 20 h (the first-stage homogenization treatment), then heating to 560 - 600 °C and holding for 4 - 12 h (the second-stage homogenization treatment), and then cooling;

[0041] S3: Turning the aluminum alloy cast rod after the homogenization treatment to remove the oxide scale;

[0042] S4: Heating the aluminum alloy cast rod after the treatment in step S3 to 450 - 550 °C (rolling starting temperature), holding for 2 - 4 h, and then performing hot rough rolling, controlling the final rolling temperature at 300 - 360 °C to obtain a hot rough rolling blank;

[0043] S5: Heating the hot rough rolling blank to 400 - 500 °C (rolling starting temperature), and then performing hot finish rolling, controlling the final rolling temperature at 260 - 320 °C to obtain a hot finish rolling blank;

[0044] S6: Performing cold rolling on the hot finish rolling blank, and the cold rolling deformation amount ≥ 10%;

[0045] S7: Cold draw the billet after the cold rolling. The cold drawing deformation is ≥25%, and cold drawn wire is obtained.

[0046] S8: Anneal the cold drawn wire in a protective gas atmosphere. The annealing temperature is 280 - 380°C, hold for 1 - 4 h, and then cool to obtain aluminum alloy wire.

[0047] In the preparation method provided by the present invention, in step S2, in order to promote the massive precipitation of Al3Sc particles, the temperature and time of the homogenization treatment need to be precisely controlled. By using the two-stage homogenization treatment in step S2, the first-stage homogenization treatment uses slow heating to nucleate Al3Sc particles and holds for a sufficient time to ensure the full diffusion of Sc element and the uniform precipitation of Al3Sc particles; the second-stage homogenization treatment uses high-temperature annealing to transform the needle-shaped β-Fe(Al5FeSi) phase into a massive or granular α-Fe(Al9Fe2Si 12 ) phase, improving the hot working performance and plasticity of the alloy.

[0048] In the preparation method provided by the present invention, in step S2, the heating rate of the homogenization treatment is preferably 5 - 10°C / min; the first-stage homogenization temperature of the homogenization treatment is preferably 400 - 420°C, and the holding time is preferably 12 - 16 h; the second-stage homogenization temperature of the homogenization treatment is preferably 560 - 580°C, and the holding time is preferably 10 - 12 h; the cooling method of the homogenization treatment is preferably air cooling.

[0049] In the preparation method provided by the present invention, in step S4, controlling the starting rolling temperature is beneficial to plastic deformation and controlling the final rolling temperature of the material. If the starting rolling temperature is too low, it will reduce the hot working performance of the alloy and easily lead to uneven deformation and edge cracking during rolling; and too low a final rolling temperature is not conducive to improving the subsequent sheet forming performance. In view of this, the starting rolling temperature in step S4 is set to 450 - 550°C, and the final rolling temperature is set to 300 - 360°C, which is beneficial to the deformation process and the smooth progress of the subsequent heat treatment process.

[0050] In the preparation method provided by the present invention, in step S4, the starting rolling temperature is preferably 460 - 480°C; the holding time after heating to the starting rolling temperature can be specifically 3 h; the final rolling temperature is preferably 320 - 350°C.

[0051] In the preparation method provided by the present invention, in step S4, the total deformation of the hot rough rolling is preferably ≥95%, more preferably 96 - 97%; the pass deformation of the hot rough rolling is preferably 10 - 30%, more preferably 20 - 25%; the hot rolling speed of the hot rough rolling is preferably 0.4 - 2 m / s, more preferably 1.2 - 1.5 m / s.

[0052] In the preparation method provided by the present invention, in step S5, the starting rolling temperature is preferably 400 - 420 °C; the finishing rolling temperature is preferably 280 - 300 °C.

[0053] In the preparation method provided by the present invention, in step S6, the cold rolling deformation amount is preferably 20 - 30%.

[0054] In the preparation method provided by the present invention, in step S7, controlling the cold drawing amount is beneficial to controlling the grain size and strength of the wire after annealing. Too small a deformation amount is likely to cause coarse grains, reducing the plasticity and strength of the wire. Therefore, the cold drawing deformation amount is controlled at ≥25%, preferably 35 - 40%.

[0055] In the preparation method provided by the present invention, in step S8, the purpose of the annealing treatment is to eliminate the internal stress generated during the drawing process and improve the plasticity and conductivity of the wire. The temperature of the annealing treatment is set at 280 - 380 °C to ensure that the alloy undergoes recrystallization and the grains do not grow excessively.

[0056] In the preparation method provided by the present invention, in step S8, the protective gas is preferably nitrogen; the temperature of the annealing treatment is preferably 280 - 320 °C, more preferably 300 - 320 °C; the heat preservation time of the annealing treatment is preferably 2 - 4 h, more preferably 2 - 3 h; the cooling rate of the cooling is preferably 0.5 - 1 °C / min.

[0057] On the basis of optimizing the composition design of the aluminum alloy wire, the preparation method provided by the present invention further improves the performance of the aluminum alloy wire by further optimizing the preparation process, especially the homogenization treatment, rolling and post-rolling treatment processes.

[0058] The present invention also provides an aluminum alloy wire product, including a core material and an insulating coating coated on the surface of the core material, wherein the core material is the aluminum alloy wire described in the above technical solution or the aluminum alloy wire prepared by the preparation method described in the above technical solution.

[0059] For the sake of clarity, the following will be described in detail through the following examples and comparative examples.

[0060] Example 1

[0061] S1: Using aluminum ingots and master alloys, an aluminum alloy casting rod is prepared by a semi-continuous casting process; the aluminum alloy casting rod includes the following components by weight percentage: Fe 0.1%, Si 0.08%, Sc 0.12%, Mg 0.10%, Cu 0.005%, Mn 0.001%, Cr 0.001%, Zn 0.001%, Ti 0.02%, and the rest is Al, and the Fe / Si mass ratio = 1.25;

[0062] S2: Perform double-stage homogenization treatment on the aluminum alloy ingot. The specific treatment process includes: heating the aluminum alloy ingot to 400 °C at a heating rate of 10 °C / min and holding for 16 h, then heating to 580 °C and holding for 10 h, and air-cooling to room temperature;

[0063] S3: Turn and remove the oxide scale from the aluminum alloy ingot after the homogenization treatment is completed;

[0064] S4: Heat the aluminum alloy ingot after the treatment in step S3 to 460 °C (rolling start temperature), hold for 3 h, and then perform hot rough rolling; among them, the total deformation amount of hot rough rolling is 96%, the pass deformation amount is 25%, the hot rolling speed is 1.5 m / s, and the final rolling temperature is controlled at 350 °C; after the hot rough rolling treatment, a hot rough rolling blank is obtained;

[0065] S5: Heat the hot rough rolling blank to 420 °C (rolling start temperature), and then perform hot finish rolling, with the final rolling temperature controlled at 300 °C to obtain a hot finish rolling blank;

[0066] S6: Perform cold rolling on the hot finish rolling blank, and the cold rolling deformation amount is 20%;

[0067] S7: Perform cold drawing on the blank after the cold rolling is completed, and the cold drawing deformation amount is 35% to obtain cold drawn wire;

[0068] S8: Anneal the cold drawn wire under nitrogen protection, with the annealing temperature being 320 °C, holding for 2 h, and then cooling to room temperature at a rate of 1 °C / min to obtain aluminum alloy wire;

[0069] S9: Clean the aluminum alloy wire, and then coat and cure an insulating paint on the surface to obtain an aluminum alloy wire product.

[0070] Example 2

[0071] Referring to Example 1, the difference is only that in step S1, the aluminum alloy ingot includes the following components by weight percentage: Fe 0.08%, Si 0.05%, Sc 0.15%, Mg 0.05%, Cu 0.005%, Mn 0.001%, Cr 0.001%, Zn 0.001%, Ti 0.02%, and the rest is Al, and the Fe / Si mass ratio = 1.6.

[0072] Example 3

[0073] Referring to Example 1, the difference is only that in step S2, the specific treatment process includes: heating the aluminum alloy ingot to 420 °C at a heating rate of 5 °C / min and holding for 12 h, then heating to 560 °C and holding for 12 h, and air-cooling to room temperature.

[0074] Example 4

[0075] Referring to Example 1, the difference is only that in step S4, the starting rolling temperature of hot rough rolling is 480 °C.

[0076] Example 5

[0077] Referring to Example 1, the difference is only that in step S5, the starting rolling temperature of hot finish rolling is 400 °C.

[0078] Example 6

[0079] Referring to Example 1, the difference is only that in step S7, the cold drawing deformation amount is 40%.

[0080] Example 7

[0081] Referring to Example 1, the difference is only that in step S8, the annealing temperature is 300 °C, the holding time is 3 h, and the cooling rate is 0.5 °C / min.

[0082] Example 8

[0083] Referring to Example 1, the difference is only that in step S8, the annealing temperature is 280 °C and the holding time is 4 h.

[0084] Comparative Example 1

[0085] Referring to Example 1, the difference is only that in step S1, the Fe content in the aluminum alloy ingot is adjusted to 0.5 wt% and the Si content is adjusted to 0.5 wt%.

[0086] Comparative Example 2

[0087] Referring to Example 1, the difference is only that in step S2, single-stage homogenization treatment is adopted. The specific treatment process includes: heating the aluminum alloy ingot to 570 °C at a heating rate of 30 °C / h, holding for 10 h, and then air-cooling to room temperature.

[0088] Comparative Example 3

[0089] Referring to Example 1, the difference is only that in step S7, the cold drawing deformation amount is 8%.

[0090] Comparative Example 4

[0091] Referring to Example 1, the difference is only that in step S8, the annealing treatment is carried out without atmosphere protection and the annealing temperature is 400 °C.

[0092] Performance test

[0093] The performance tests were carried out on the aluminum alloy wires prepared in Examples 1-8 and Comparative Examples 1-4. Among them, the mechanical property test standard was GB / T 228-2010; the conductivity test standard was GB / T 12966-2008; the welding process corresponding to the performance after welding was laser welding, with a power of 800-1200 W (pulse width 4 ms, frequency 50 Hz), defocus amount: +0.1 mm (spot diameter 0.15 mm), and shielding gas: He+Ar mixed gas (volume ratio He:Ar = 3:1, flow rate 20 L / min). The test results are shown in Table 1.

[0094] Table 1 Performance and microstructure test results of the materials prepared in Examples 1-8 and Comparative Examples 1-4

[0095]

[0096] As can be seen from Table 1, compared with the comparative examples, the examples of the present invention have been improved in terms of alloy composition, controlling the Fe and Si elements that have a significant impact on the conductivity, strength and elongation of the alloy, and the Sc element that has a significant impact on the welding performance and strength of the alloy. A large number of fine and dispersed Al3Sc particles are precipitated through the homogenization process, and through the adjustment and cooperation of the preparation process, the prepared aluminum alloy wire has a conductivity ≥ 60% IACS, a yield strength ≥ 100 MPa, and an elongation ≥ 30%; there is no spatter during laser welding, and the tensile strength after welding ≥ 150 MPa.

[0097] The above is only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. An aluminum alloy wire, characterized in that, By weight percentage, the composition of the aluminum alloy wire rod includes: Fe 0.05 - 0.15%, Si 0.05 - 0.1%, Sc 0.08 - 0.15%, Mg ≤ 0.3%, Cu ≤ 0.3%, Mn ≤ 0.3%, Cr ≤ 0.1%, Zn ≤ 0.1%, Ti ≤ 0.2%, and the balance is Al; the mass ratio of Fe to Si is 1 - 2.

2. The aluminum alloy wire according to claim 1, wherein, By weight percentage, the composition of the aluminum alloy wire rod includes: Fe 0.08 - 0.1%, Si 0.05 - 0.08%, Sc 0.12 - 0.15%, Mg 0.05 - 0.1%, Cu 0.001 - 0.005%, Mn 0.0005 - 0.001%, Cr 0.0005 - 0.001%, Zn 0.0005 - 0.001%, Ti 0.01 - 0.02%, and the balance is Al.

3. The aluminum alloy wire according to claim 1, characterized in that In the metallographic structure of the aluminum alloy wire rod, the diameter of Al3Sc particles ≤ 20 nm.

4. A method for preparing an aluminum alloy wire according to any one of claims 1 to 3, characterized in that, It includes the following steps: S1: Using aluminum ingots and master alloys, prepare aluminum alloy cast rods by semi - continuous casting process. S2: Carry out homogenization treatment on the aluminum alloy cast rods. The specific treatment process includes: at a heating rate of 5 - 15 °C / min, heat the aluminum alloy cast rods to 400 - 430 °C and hold for 10 - 20 h, then heat to 560 - 600 °C and hold for 4 - 12 h, and then cool. S3: Turn and remove the oxide scale from the aluminum alloy cast rods that have completed the homogenization treatment. S4: Heat the aluminum alloy cast rods that have completed step S3 to 450 - 550 °C and hold for 2 - 4 h, then carry out hot rough rolling, and control the final rolling temperature at 300 - 360 °C to obtain hot - rolled rough blanks. S5: Heat the hot - rolled rough blanks to 400 - 500 °C, then carry out hot finish rolling, and control the final rolling temperature at 260 - 320 °C to obtain hot - rolled finished blanks. S6: Carry out cold rolling on the hot - rolled finished blanks, and the cold rolling deformation amount ≥ 10%. S7: Carry out cold drawing on the blanks that have completed the cold rolling, and the cold drawing deformation amount ≥ 25% to obtain cold - drawn wire rods. S8: Anneal the cold - drawn wire rods in a protective gas atmosphere, with the annealing temperature being 280 - 380 °C, holding for 1 - 4 h, and then cooling to obtain aluminum alloy wire rods.

5. The preparation method according to claim 4, characterized in that, In step S2, the specific treatment process includes: at a heating rate of 5 - 10 °C / min, heat the aluminum alloy cast rods to 400 - 420 °C and hold for 12 - 16 h, then heat to 560 - 580 °C and hold for 10 - 12 h, and then cool.

6. The preparation method according to claim 4, wherein In step S4, the aluminum alloy cast rods are heated to 460 - 480 °C; the final rolling temperature is controlled at 320 - 350 °C; the total deformation amount of the hot rough rolling ≥ 95%, the pass deformation amount is 10 - 30%, and the hot rolling speed is 0.4 - 2 m / s.

7. The preparation method according to claim 4, characterized in that, In step S5, the hot - rolled rough blanks are heated to 400 - 420 °C; the final rolling temperature is controlled at 280 - 300 °C.

8. The preparation method according to claim 4, characterized in that, In step S6, the cold rolling deformation amount is 20 - 30%.

9. The preparation method according to claim 4, wherein In step S8, the annealing temperature is 280 to 320 °C; the heat preservation time is 2 to 4 h; the cooling rate of the cooling is 0.5 to 1 °C / min.

10. An aluminum alloy wire product, characterized in that, It includes a core material and an insulating coating coated on the surface of the core material, and the core material is the aluminum alloy wire according to any one of claims 1 to 3 or the aluminum alloy wire prepared by the preparation method according to any one of claims 4 to 9.

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