High-conductivity aluminum alloy conducting bar and preparation method thereof

Abstract

The invention relates to the technical field of aluminum alloy conducting bars, and discloses a high-conductivity aluminum alloy conducting bar and a preparation method thereof. According to the method, the content of alloy components is accurately controlled, specific aluminum bar homogenizing temperature and cooling speed requirements are adopted, specific extrusion temperature and speed are adopted, cold deformation is performed before and after aging, and a two-stage aging process is adopted; the aluminum alloy conducting bar has the comprehensive performance of high conductivity (greater than or equal to 62% IACS), high thermal conductivity (greater than or equal to 220W / (mK)), high strength (tensile strength greater than or equal to 110MPa and yield strength greater than or equal to 110MPa) and good toughness (ductility greater than or equal to 12% and hardness greater than or equal to 30HV), meets the requirements of the field of electrical materials for high-conductivity aluminum alloy, and has wide application prospects. The problems that the material strength is reduced, the process is complex, the cost is high and the like when the electric conductivity is improved in the prior art are solved, and the method has remarkable superiority and wide application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum alloy conductive bars, and in particular to a high-conductivity aluminum alloy conductive bar and a preparation method thereof. Background Art

[0002] In the field of metal materials, aluminum alloys are widely used in the field of electrical materials due to their excellent electrical conductivity and lightweight characteristics. In particular, when manufacturing products such as cables, busbars, and electrical components, aluminum alloys with high conductivity are indispensable materials. However, the electrical conductivity of aluminum alloys is closely related to their internal crystal structure, the distribution and quantity of precipitated phases, so how to prepare aluminum alloys with high conductivity and high strength is an important technical challenge.

[0003] In the prior art, the conductivity of aluminum alloys is usually improved by adding certain alloying elements. For example, adding elements such as magnesium, silicon, and iron can form a Mg2Si phase, which can improve the conductivity of aluminum alloys. In addition, the crystal structure and distribution of the precipitated phase of the aluminum alloy can be changed by heat treatment and cold deformation, thereby improving its conductivity. For example, through aging treatment, the precipitated phase can be refined and evenly distributed, thereby improving the conductivity; through cold deformation, defects such as dislocations can be introduced to increase electron scattering, thereby improving the conductivity.

[0004] Although the existing technology can improve the conductivity of aluminum alloys to a certain extent, there are still some problems and limitations. First, while improving the conductivity, the existing technology often leads to a decrease in the strength of the material, thereby limiting its scope of application. Secondly, in the process of preparing high-conductivity aluminum alloys, the existing technology often requires complex process flows and high costs, which is not conducive to large-scale production. In addition, the existing technology still has certain difficulties in controlling the distribution and amount of the precipitated phase, which will affect the stability and consistency of the conductive properties of the aluminum alloy. Summary of the invention

[0005] The object of the present invention is to provide an aluminum alloy conductive bar with high conductivity, high strength, good stability and consistency of conductive performance and a preparation method thereof, so as to at least provide a beneficial choice or create conditions for solving one or more technical problems existing in the prior art.

[0006] To achieve the above objectives, the present invention adopts the following technical solutions.

[0007] A method for preparing a high-conductivity aluminum alloy electric busbar, the preparation steps of which are as follows: 1) casting a rod, preparing alloy components in proportion and casting into an aluminum rod, the alloy components are: Mg 0.25wt%-0.35wt%, Si 0.25wt%-0.35wt%, Fe 0.05wt%-0.15wt%, Si-Fe difference Si-Fe is 0.15wt%-0.25wt%, Mg / (Si-Fe) ratio is 1.5-2.0, B 0.02wt%-0.04wt%, Sr 0.01wt%-0.03wt%, the remainder is aluminum; 2) Homogenization treatment, the cast aluminum rod is sent to the homogenization furnace for homogenization heat treatment, the aluminum rod is heated to 530℃-560℃ and then kept warm for 5h-10h. After the insulation is completed, it is first cooled to 250-300℃ at room temperature, and then quickly cooled to an ambient temperature below 5℃; 3) Extrusion, the aluminum rod is quickly heated to 450℃-500℃, and then extruded into the required shape. After extrusion, the profile is quickly cooled, and the cooling rate is >200℃ / min ; 4) The first cold deformation, after extrusion, the profile is cold deformed by 10%-15% stretching through a straightening machine; 5) Aging, a two-stage aging process is adopted, the first stage aging temperature is 230℃-250℃, the first stage aging insulation time is 4-10 hours, the second stage aging temperature is 160℃-170℃, and the second stage aging insulation time is 18-36 hours; 6) The second cold deformation, after aging, the secondary cold deformation is carried out, and the profile is cold deformed by 5%-10% stretching using a straightening machine.

[0008] More preferably, in step 1) the rod casting step, the V content in the aluminum ingot raw material used is less than 0.01wt%.

[0009] More preferably, in step 1) the rod casting step, the alloy composition is: Mg 0.27wt%, Si 0.27wt%, Fe 0.10wt%, ferrosilicon Si-Fe 0.17wt%, Mg / (Si-Fe) ratio is 1.59, B 0.02wt%, Sr 0.01wt%, and the V content in the aluminum ingot used is 0.008wt%.

[0010] More preferably, in step 1) the rod casting step, the alloy composition is: Mg 0.33wt%, Si 0.33wt%, Fe 0.15wt%, ferrosilicon Si-Fe 0.18wt%, Mg / (Si-Fe) ratio is 1.83, B 0.03wt%, Sr content 0.02wt%, and the V content of the aluminum ingot used is 0.009wt%.

[0011] More preferably, in step 1) the rod casting step, the alloy composition is: Mg 0.32wt%, Si 0.28wt%, Fe 0.12wt%, ferrosilicon Si-Fe difference is 0.16wt%, Mg / (Si-Fe) ratio is 2.0, B 0.04wt%, Sr 0.02wt%, and the V content of the aluminum ingot used is 0.008wt%.

[0012] More preferably, in step 2) the homogenization step, if the room temperature is greater than 5°C, the aluminum rod is taken out of the furnace for air cooling after the insulation is completed, and the aluminum rod is cooled to less than 250°C and then enters the cooling chamber for rapid cooling by air cooling or water spraying.

[0013] More preferably, in step 2) of the homogenization step, if the room temperature is below 5°C, the aluminum bar is first cooled to 300°C after the insulation is completed, and then taken out of the furnace for air cooling or put into a cooling chamber for rapid cooling by air cooling or water spraying. More preferably, in step 3) the extrusion step, the rapid heating of the aluminum rod is achieved by an industrial frequency furnace or a permanent magnet heating furnace.

[0014] On the other hand, the present invention also provides a high conductivity aluminum alloy busbar prepared by the preparation method as described above.

[0015] Compared with the prior art, the present invention mainly solves the following technical problems: 1) While improving the electrical conductivity of aluminum alloy, the strength and stability of the material are maintained, and its application range is expanded. 2) In the process of preparing high-conductivity aluminum alloy, the process flow is simplified, the cost is reduced, and large-scale production is achieved. 3) The distribution and amount of the precipitated phase are accurately controlled to improve the stability and consistency of the conductive properties of the aluminum alloy. 4) Through reasonable heat treatment and cold deformation processes, the crystal structure of the aluminum alloy and the distribution of the precipitated phase are optimized, thereby obtaining an aluminum alloy with high conductivity and high strength.

[0016] Compared with the prior art, the present invention has at least the following advantages and beneficial effects.

[0017] The present invention precisely controls the content of alloy components, especially the ratio of elements such as Mg, Si, Fe, B and Sr, and this specific ratio helps to improve the electrical conductivity. At the same time, by adding appropriate amounts of B and Sr elements, the distribution and amount of the precipitated phase can be further optimized, thereby improving the balance between electrical conductivity and strength.

[0018] The present invention adopts specific aluminum rod homogenization temperature and cooling rate requirements, so that Mg2Si inside the material is fully precipitated after homogenization, and no complete solid solution occurs during the extrusion process, and the conductivity is not affected on the basis of providing certain material properties.

[0019] The present invention adopts a specific extrusion temperature and speed, and a water-penetrating cooling method, so that the crystal structure inside the alloy is more compact, which is conducive to improving the conductivity. At the same time, the optimization of such process parameters can reduce the generation of internal defects, thereby improving the strength and toughness of the material.

[0020] The present invention performs cold deformation before and after aging. This process can introduce a large number of defects such as dislocations, increase electron scattering, and thus improve electrical conductivity. At the same time, cold deformation can also eliminate internal stress and improve the creep resistance of the material. In addition, by controlling the stretching amount of cold deformation, while improving electrical conductivity, excessive plastic deformation of the material can be avoided, thereby maintaining the strength of the material.

[0021] The present invention adopts a double-stage aging process, wherein the first stage aging refines and evenly distributes the precipitated phase, and the second stage aging further improves the compactness and uniformity of the precipitated phase, thereby improving the conductivity. The adoption of this double-stage aging process can better control the distribution and quantity of the precipitated phase, thereby improving the stability and consistency of the conductive performance.

[0022] The aluminum alloy conductive bar of the present invention has the comprehensive properties of high electrical conductivity (≥62% IACS), high thermal conductivity (≥220W / (mK), high strength (tensile strength ≥110MPa, yield strength ≥110MPa) and good toughness (elongation ≥12%, hardness ≥30HV), which meets the demand for high electrical conductivity aluminum alloy in the field of electrical materials and has broad application prospects. In general, compared with the prior art, the present invention prepares an aluminum alloy conductive bar with excellent comprehensive performance by optimizing alloy composition, improving process parameters and controlling the distribution and amount of precipitated phases, and solves the problems of the prior art that the material strength decreases, the process is complicated and the cost is high while the electrical conductivity is improved, and has significant advantages.

[0023] Due to the technical advancement of the present invention, it can be widely used in the application fields such as the field of metal materials, the field of material preparation and the field of electrical materials. In the field of metal materials, the present invention provides a method for preparing a high-conductivity aluminum alloy conductive bar. By precisely controlling the alloy composition and adopting special extrusion, aging and cold deformation processes, the prepared aluminum alloy conductive bar has high conductivity and high strength, which meets the demand for high-performance aluminum alloys in the field of metal materials. In the field of material preparation, the preparation method of the present invention is simple, the process flow is easy to control, and the cost is low, which is very suitable for large-scale production, which will greatly promote the application of high-conductivity aluminum alloy conductive bars in the field of material preparation. In the field of electrical materials, the application of high-conductivity aluminum alloy conductive bars can greatly improve the performance of electrical products. For example, when manufacturing products such as cables, busbars, and electrical components, high-conductivity aluminum alloys can reduce power loss and improve the efficiency and reliability of electrical products, which will greatly promote the development of the field of electrical materials. In general, the present invention has broad application prospects and large market demand, and is expected to play an important role in multiple fields such as the field of metal materials, the field of material preparation and the field of electrical materials. DETAILED DESCRIPTION

[0024] The specific implementation of the present invention is further described below to make the technical solution and beneficial effects of the present invention clearer and more specific. The following embodiments are exemplary and intended to explain the present invention, but cannot be construed as limiting the present invention.

[0025] Additional aspects and advantages of the present invention will become apparent from the following description or may be learned by practice of the present invention.

[0026] A method for preparing a high-conductivity aluminum alloy conductive bar includes the following control processes.

[0027] 1) Alloy composition control: By precisely controlling the content of elements such as Mg, Si, Fe, B, Sr in the aluminum alloy so that they are within a specific range, the crystal structure and distribution of the precipitated phase of the aluminum alloy are optimized, and the electrical conductivity of the aluminum alloy is improved. Among them, the Mg content is controlled at 0.25wt%-0.35wt%, the Si content is controlled at 0.25wt%-0.35wt%, the Fe content is controlled at 0.05wt%-0.15wt%, the (Si-Fe) content range is 0.15wt%-0.25wt%, the Mg / (Si-Fe) content ratio is 1.5-2.0, the B content is controlled at 0.02wt%-0.04wt%, and the Sr content is controlled at 0.01wt%-0.03wt%. The aluminum ingot raw material used needs to be an aluminum ingot with a V content of less than 0.01wt% to ensure the purity and performance of the final product.

[0028] 2) Optimization of aluminum bar homogenization process: A special cooling process after homogenization is adopted, that is, the aluminum bar is heated to 530℃-560℃ and then kept warm for 5h-10h. If the room temperature is greater than 5℃, the aluminum bar is taken out of the furnace for air cooling after the insulation is completed. The aluminum bar is cooled to less than 250℃ and then enters the cooling room for rapid cooling by air cooling or water spraying; if the room temperature is lower than 5℃, the aluminum bar is first cooled to 300℃ after the insulation is completed, and then taken out of the furnace for air cooling or enters the cooling room for rapid cooling by air cooling or water spraying. Through this process, the cooling speed is guaranteed to promote the large-scale precipitation and coarsening of Mg2Si, so that it provides certain material properties but does not affect the conductivity.

[0029] 3) Extrusion process optimization: By optimizing the extrusion temperature, speed and cooling method, the aluminum alloy can form a more uniform crystal structure and precipitation phase distribution during the extrusion process, thereby improving the electrical conductivity of the aluminum alloy. Specifically: the aluminum bar is quickly heated to 450℃-500℃ through an industrial frequency furnace or a permanent magnet heating furnace, and then extruded into the required shape. After extrusion, the profile is quickly cooled, and the cooling rate is guaranteed to be >200℃ / min.

[0030] 4) Cold deformation process control: After extrusion, the profile is cold deformed by a straightening machine with a stretching amount of 10%-15%. This allows the aluminum alloy to form a more uniform precipitation phase distribution before and after aging, greatly speeding up the material aging treatment speed and reducing the precipitation temperature, thereby greatly improving the electrical conductivity of the aluminum alloy.

[0031] 5) Aging process optimization: The two-stage aging process is adopted to enable the aluminum alloy to form a more uniform distribution of precipitation phases during the aging process, thereby improving the electrical conductivity and strength of the aluminum alloy. The first-stage aging temperature is 230℃-250℃, the first-stage aging holding time is 4-10 hours, the second-stage aging temperature is 160℃-170℃, and the second-stage aging holding time is 18-36 hours.

[0032] 6) Secondary cold deformation process: Secondary cold deformation is performed after aging, and the profile is cold deformed by 5%-10% stretching using a straightening machine. Precise control of the cold deformation amount can greatly improve the strength of the aluminum alloy, while eliminating internal stress through cold deformation, and using a large number of dislocations combined with the original internal strengthening precipitation phase to improve the creep resistance of the material. Example 1.

[0033] This embodiment provides a method for preparing a high-conductivity aluminum alloy conductive bar, and the specific steps are as follows.

[0034] Step 1: First, prepare the alloy composition according to a specific ratio and cast it into an aluminum rod. The alloy composition is: Mg 0.27wt%, Si 0.27wt%, Fe 0.10wt%, ferrosilicon Si-Fe 0.17wt%, Mg / (Si-Fe) ratio is 1.59, B 0.02wt%, Sr 0.01wt%, and the V content in the aluminum ingot used is 0.008wt%.

[0035] Step 2: Send the cast aluminum rod into the homogenizing furnace for homogenizing heat treatment. After the aluminum rod is heated to 550℃, it is kept warm for 6 hours, and the room temperature is 15℃. After the aluminum rod is kept warm, it is taken out of the furnace and air-cooled. After the aluminum rod is cooled to less than 250℃, it enters the cooling room for air cooling.

[0036] Step 3: The prepared aluminum rod is quickly heated to 475°C by an industrial frequency furnace or a permanent magnet heating furnace, and then extruded into the required shape. After extrusion, the profile is quickly cooled, and the cooling rate is guaranteed to be >200°C / min.

[0037] Step 3: After extrusion, the profile is cold deformed by a straightening machine with a 12% stretching amount.

[0038] Step 4: A double-stage aging process is adopted for the extruded profile, the first-stage aging temperature is 240°C, the first-stage aging insulation time is 6 hours, the second-stage aging temperature is 160°C, and the second-stage aging insulation time is 36 hours.

[0039] Step 5: Perform secondary cold deformation and offline stretching on the aged profile, and use a straightening machine to perform cold deformation of the profile with a stretching amount of 7%.

[0040] Through the above steps, the conductivity of the aluminum alloy conductive bar finally obtained can reach 62.3%IACS, the tensile strength can reach 116MPa, the yield strength can reach 111MPa, the elongation can reach 11%, and the hardness can reach 34HV. Example 2.

[0041] This embodiment provides a method for preparing a high-conductivity aluminum alloy conductive bar, and the specific steps are as follows.

[0042] Step 1: First, prepare the alloy composition according to a specific ratio and cast it into an aluminum rod. The alloy composition is: Mg 0.33wt%, Si 0.33wt%, Fe 0.15wt%, ferrosilicon Si-Fe 0.18wt%, Mg / (Si-Fe) ratio is 1.83, B 0.03wt%, Sr content 0.02wt%, and the V content of the aluminum ingot used is 0.009wt%.

[0043] Step 2: Send the cast aluminum rod into the homogenizing furnace for homogenizing heat treatment. After the aluminum rod is heated to 560℃, it is kept warm for 6 hours, and the room temperature is 15℃. After the aluminum rod is kept warm, it is taken out of the furnace and air-cooled. After the aluminum rod is cooled to less than 250℃, it enters the cooling room for air cooling.

[0044] Step 3: The prepared aluminum rod is quickly heated to 490°C by an industrial frequency furnace or a permanent magnet heating furnace, and then extruded into the required shape. After extrusion, the profile is quickly cooled, and the cooling rate is guaranteed to be >200°C / min.

[0045] Step 3: After extrusion, the profile is cold deformed with a 14% stretching amount through a straightening machine.

[0046] Step 4: A double-stage aging process is adopted for the extruded profile, the first-stage aging temperature is 250°C, the first-stage aging insulation time is 5 hours, the second-stage aging temperature is 170°C, and the second-stage aging insulation time is 18 hours.

[0047] Step 5: Perform secondary cold deformation and offline stretching on the aged profile, and use a straightening machine to perform cold deformation of the profile with a stretching amount of 5%.

[0048] Through the above steps, the conductivity of the aluminum alloy conductive bar finally obtained can reach 62.1%IACS, the tensile strength can reach 118MPa, the yield strength can reach 112MPa, the elongation can reach 10%, and the hardness can reach 36HV. Example 3.

[0049] This embodiment provides a method for preparing a high-conductivity aluminum alloy conductive bar, and the specific steps are as follows.

[0050] Step 1: First, prepare the alloy composition according to a specific ratio and cast it into an aluminum rod. The alloy composition is: Mg 0.32wt%, Si 0.28wt%, Fe 0.12wt%, silicon-iron difference (Si-Fe) is 0.16wt%, Mg / (Si-Fe) ratio is 2.0, B 0.04wt%, Sr 0.02wt%, and the V content of the aluminum ingot used is 0.008wt%.

[0051] Step 2: Send the cast aluminum rod into the homogenizing furnace for homogenizing heat treatment. After the aluminum rod is heated to 540℃, it is kept warm for 8 hours, and the room temperature is 15℃. After the aluminum rod is kept warm, it is taken out of the furnace and air-cooled. After the aluminum rod is cooled to less than 250℃, it enters the cooling room for air cooling.

[0052] Step 3: The prepared aluminum rod is quickly heated to 455°C by an industrial frequency furnace or a permanent magnet heating furnace, and then extruded into the required shape. After extrusion, the profile is quickly cooled, and the cooling rate is guaranteed to be >200°C / min.

[0053] Step 3: After extrusion, the profile is cold deformed by a straightening machine with a 10% stretching amount.

[0054] Step 4: A double-stage aging process is adopted for the extruded profile, the first-stage aging temperature is 250°C, the first-stage aging insulation time is 4 hours, the second-stage aging temperature is 165°C, and the second-stage aging insulation time is 24 hours.

[0055] Step 5: Perform secondary cold deformation and offline stretching on the aged profile, and use a straightening machine to perform cold deformation of the profile with a stretching amount of 10%.

[0056] Through the above steps, the conductivity of the aluminum alloy conductive bar finally obtained can reach 62.2%IACS, the tensile strength can reach 120MPa, the yield strength can reach 114MPa, the elongation can reach 10%, and the hardness can reach 36HV. Example 4.

[0057] This embodiment provides a method for preparing a high-conductivity aluminum alloy conductive bar, and the specific steps are as follows.

[0058] Step 1: First, prepare the alloy composition according to a specific ratio and cast it into an aluminum rod. The alloy composition is: Mg 0.27wt%, Si 0.27wt%, Fe 0.10wt%, ferrosilicon Si-Fe 0.17wt%, Mg / (Si-Fe) ratio is 1.59, B 0.02wt%, Sr 0.01wt%, and the V content in the aluminum ingot used is 0.008wt%.

[0059] Step 2: Send the cast aluminum rod into the homogenizing furnace for homogenizing heat treatment. The aluminum rod is heated to 550℃ and then kept warm for 6 hours. The room temperature is 4℃. After the aluminum rod is kept warm, it is first cooled to 300℃ in the furnace and then taken out of the furnace for air cooling.

[0060] Step 3: The prepared aluminum rod is quickly heated to 475°C by an industrial frequency furnace or a permanent magnet heating furnace, and then extruded into the required shape. After extrusion, the profile is quickly cooled, and the cooling rate is guaranteed to be >200°C / min.

[0061] Step 3: After extrusion, the profile is cold deformed by a straightening machine with a 12% stretching amount.

[0062] Step 4: A double-stage aging process is adopted for the extruded profile, the first-stage aging temperature is 240°C, the first-stage aging insulation time is 6 hours, the second-stage aging temperature is 160°C, and the second-stage aging insulation time is 36 hours.

[0063] Step 5: Perform secondary cold deformation and offline stretching on the aged profile, and use a straightening machine to perform cold deformation of the profile with a stretching amount of 7%.

[0064] Through the above steps, the conductivity of the aluminum alloy conductive bar finally obtained can reach 62.2%IACS, the tensile strength can reach 118MPa, the yield strength can reach 112MPa, the elongation can reach 11%, and the hardness can reach 34HV.

[0065] Comparative example 1.

[0066] A method for preparing an aluminum alloy conductive bar, the specific steps are as follows.

[0067] Step 1: First, prepare the alloy composition according to a specific ratio and cast it into an aluminum rod. The alloy composition is: Mg 0.57wt%, Si 0.57wt%, Fe 0.17wt%, silicon-iron difference (Si-Fe) is 0.40wt%, Mg / (Si-Fe) ratio is 1.43, B 0.02wt%, Sr 0.01wt%, and the V content of the aluminum ingot used is 0.008wt%.

[0068] Step 2: Send the cast aluminum rod into the homogenizing furnace for homogenizing heat treatment. After the aluminum rod is heated to 550℃, it is kept warm for 6 hours, and the room temperature is 15℃. After the aluminum rod is kept warm, it is taken out of the furnace and air-cooled. After the aluminum rod is cooled to less than 250℃, it enters the cooling room for air cooling.

[0069] Step 3: The prepared aluminum rod is quickly heated to 475°C by an industrial frequency furnace or a permanent magnet heating furnace, and then extruded into the required shape. After extrusion, the profile is quickly cooled, and the cooling rate is guaranteed to be >200°C / min.

[0070] Step 3: After extrusion, the profile is cold deformed by a straightening machine with a 10% stretching amount.

[0071] Step 4: A double-stage aging process is adopted for the extruded profile, the first-stage aging temperature is 240°C, the first-stage aging insulation time is 6 hours, the second-stage aging temperature is 160°C, and the second-stage aging insulation time is 36 hours.

[0072] Step 5: Perform secondary cold deformation and offline stretching on the aged profile, and use a straightening machine to perform cold deformation of the profile with a stretching amount of 5%.

[0073] Through the above steps, the conductivity of the aluminum alloy conductive bar finally obtained is 58.7% IACS, the tensile strength is 242 MPa, the yield strength is 232 MPa, the elongation is 4%, and the hardness is 85 HV.

[0074] Comparative example 2.

[0075] A method for preparing an aluminum alloy conductive bar, the specific steps are as follows.

[0076] Step 1: First, prepare the alloy composition according to a specific ratio and cast it into an aluminum rod. The alloy composition is: Mg 0.10wt%, Si 0.15wt%, Fe 0.10wt%, silicon-iron difference (Si-Fe) is 0.05wt%, Mg / (Si-Fe) ratio is 2, B 0.01wt%, Sr 0.01wt%, and the V content of the aluminum ingot used is 0.008wt%.

[0077] Step 2: Send the cast aluminum rod into the homogenizing furnace for homogenizing heat treatment. After the aluminum rod is heated to 560℃, it is kept warm for 6 hours, and the room temperature is 15℃. After the aluminum rod is kept warm, it is taken out of the furnace and air-cooled. After the aluminum rod is cooled to less than 250℃, it enters the cooling room for air cooling.

[0078] Step 3: The prepared aluminum rod is quickly heated to 490°C by an industrial frequency furnace or a permanent magnet heating furnace, and then extruded into the required shape. After extrusion, the profile is quickly cooled, and the cooling rate is guaranteed to be >200°C / min.

[0079] Step 3: After extrusion, the profile is cold deformed by a straightening machine with a 15% stretching amount.

[0080] Step 4: A double-stage aging process is adopted for the extruded profile, the first-stage aging temperature is 250°C, the first-stage aging insulation time is 5 hours, the second-stage aging temperature is 170°C, and the second-stage aging insulation time is 18 hours.

[0081] Step 5: Perform secondary cold deformation and offline stretching on the aged profile, and use a straightening machine to perform cold deformation of the profile with a stretching amount of 7%.

[0082] Through the above steps, the conductivity of the aluminum alloy conductive bar finally obtained is 62.5% IACS, the tensile strength is 72 MPa, the yield strength is 62 MPa, the elongation is 12%, and the hardness is 30 HV.

[0083] Comparative example 3.

[0084] A method for preparing an aluminum alloy conductive bar, the specific steps are as follows.

[0085] Step 1: First, prepare the alloy composition according to a specific ratio and cast it into an aluminum rod. The alloy composition is: Mg 0.32wt%, Si 0.28wt%, Fe 0.12wt%, silicon-iron difference (Si-Fe) is 0.16wt%, Mg / (Si-Fe) ratio is 2.0, B 0.04wt%, Sr 0.02wt%, and the V content of the aluminum ingot used is 0.008wt%.

[0086] Step 2: Send the cast aluminum rod into the homogenizing furnace for homogenizing heat treatment. After the aluminum rod is heated to 540℃, it is kept warm for 8 hours, and the room temperature is 15℃. After the aluminum rod is kept warm, it is taken out of the furnace and air-cooled. After the aluminum rod is cooled to less than 250℃, it enters the cooling room for air cooling.

[0087] Step 3: The prepared aluminum rod is quickly heated to 455°C by an industrial frequency furnace or a permanent magnet heating furnace, and then extruded into the required shape. After extrusion, the profile is quickly cooled, and the cooling rate is guaranteed to be >200°C / min.

[0088] Step 3: After extrusion, the profile is cold deformed by 1% stretching through a straightening machine.

[0089] Step 4: A double-stage aging process is adopted for the extruded profile, the first-stage aging temperature is 250°C, the first-stage aging insulation time is 4 hours, the second-stage aging temperature is 165°C, and the second-stage aging insulation time is 24 hours.

[0090] Step 5: Perform secondary cold deformation and offline stretching on the aged profile, and use a straightening machine to perform cold deformation of the profile with a stretching amount of 10%.

[0091] Through the above steps, the conductivity of the aluminum alloy conductive bar finally obtained can reach 61.5%IACS, the tensile strength is 102MPa, the yield strength is 93MPa, the elongation is 11%, and the hardness is 34HV.

[0092] Comparative example 4.

[0093] A method for preparing an aluminum alloy conductive bar, the specific steps are as follows.

[0094] Step 1: First, prepare the alloy composition according to a specific ratio and cast it into an aluminum rod. The alloy composition is: Mg 0.32wt%, Si 0.28wt%, Fe 0.12wt%, silicon-iron difference (Si-Fe) is 0.16wt%, Mg / (Si-Fe) ratio is 2.0, B 0.04wt%, Sr 0.02wt%, and the V content of the aluminum ingot used is 0.008wt%.

[0095] Step 2: Send the cast aluminum rod into the homogenizing furnace for homogenizing heat treatment. After the aluminum rod is heated to 540℃, it is kept warm for 8 hours, and the room temperature is 15℃. After the aluminum rod is kept warm, it is taken out of the furnace and air-cooled. After the aluminum rod is cooled to less than 250℃, it enters the cooling room for air cooling.

[0096] Step 3: The prepared aluminum rod is quickly heated to 455°C by an industrial frequency furnace or a permanent magnet heating furnace, and then extruded into the required shape. After extrusion, the profile is quickly cooled, and the cooling rate is guaranteed to be >200°C / min.

[0097] Step 3: After extrusion, the profile is cold deformed by a straightening machine with a 10% stretching amount.

[0098] Step 4: A double-stage aging process is adopted for the extruded profile, the first-stage aging temperature is 250°C, the first-stage aging insulation time is 4 hours, the second-stage aging temperature is 165°C, and the second-stage aging insulation time is 24 hours.

[0099] Step 5: Perform secondary cold deformation and offline stretching on the aged profile, and use a straightening machine to perform cold deformation of the profile with a stretching amount of 1%.

[0100] Through the above steps, the conductivity of the aluminum alloy conductive bar finally obtained can reach 62.3%IACS, the tensile strength is 102MPa, the yield strength is 86MPa, the elongation is 14%, and the hardness is 32HV.

[0101] Comparative example 5.

[0102] A method for preparing an aluminum alloy conductive bar, the specific steps are as follows.

[0103] Step 1: First, prepare the alloy composition according to a specific ratio and cast it into an aluminum rod. The alloy composition is: Mg 0.32wt%, Si 0.28wt%, Fe 0.12wt%, silicon-iron difference (Si-Fe) is 0.16wt%, Mg / (Si-Fe) ratio is 2.0, B 0.04wt%, Sr 0.02wt%, and the V content of the aluminum ingot used is 0.008wt%.

[0104] Step 2: Send the cast aluminum rod into the homogenizing furnace for homogenizing heat treatment. After the aluminum rod is heated to 540℃, it is kept warm for 8 hours, and the room temperature is 15℃. After the aluminum rod is kept warm, it is taken out of the furnace and air-cooled. After the aluminum rod is cooled to less than 250℃, it enters the cooling room for air cooling.

[0105] Step 3: The prepared aluminum rod is quickly heated to 455°C by an industrial frequency furnace or a permanent magnet heating furnace, and then extruded into the required shape. After extrusion, the profile is quickly cooled, and the cooling rate is guaranteed to be >200°C / min.

[0106] Step 3: After extrusion, the profile is cold deformed by 1% stretching through a straightening machine.

[0107] Step 4: A double-stage aging process is adopted for the extruded profile, the first-stage aging temperature is 250°C, the first-stage aging insulation time is 4 hours, the second-stage aging temperature is 165°C, and the second-stage aging insulation time is 24 hours.

[0108] Step 5: Perform secondary cold deformation and offline stretching on the aged profile, and use a straightening machine to perform cold deformation of the profile with a stretching amount of 1%.

[0109] Through the above steps, the conductivity of the aluminum alloy conductive bar finally obtained can reach 62.0%IACS, the tensile strength is 88MPa, the yield strength is 72MPa, the elongation is 15%, and the hardness is 30HV.

[0110] It should be noted that the technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0111] The above embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. The parts not described in the specific embodiments are all prior art or common knowledge.

[0112] It should be noted that, in the description of the present invention, the content of the present invention can be more easily understood by referring to the detailed description of the preferred implementation method of the present invention above and the embodiments included. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those of ordinary skill in the art to which the present invention belongs. When there is a conflict, the definitions in this specification shall prevail.

[0113] In the present invention, the term "prepared from..." is used synonymously with "comprising". The terms "comprising", "including", "having", "containing" or any other variation thereof, as used in the present invention, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus comprising the listed elements is not necessarily limited to only those elements, but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0114] In the present invention, when an amount, concentration, or other value or parameter is expressed as a range, a preferred range, or a range limited by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including a range of "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5" etc. When a numerical range is described in the present invention, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range.

[0115] In addition, the indefinite articles "a" and "an" before the elements or components of the present invention have no restrictions on the quantity requirements (i.e. the number of occurrences) of the elements or components. Therefore, "a" or "an" should be interpreted as including one or at least one, and the elements or components in the singular form also include the plural form, unless the number is obviously intended to be in the singular form.

Claims

1. A method for preparing a high conductivity aluminum alloy conductive bar, characterized in that: The preparation steps are as follows: 1) Casting rods, preparing alloy components in proportion and casting into aluminum rods, the alloy components are: Mg 0.25wt%-0.35wt%, Si 0.25wt%-0.35wt%, Fe 0.05wt%-0.15wt%, ferrosilicon Si-Fe difference is 0.15wt%-0.25wt%, Mg / (Si-Fe) ratio is 1.5-2.0, B 0.02wt%-0.04wt%, Sr 0.01wt%-0.03wt%, and the balance is aluminum; 2) Homogenization treatment: send the cast aluminum rod into the homogenization furnace for homogenization heat treatment. The aluminum rod is heated to 530℃-560℃ and then kept warm for 5h-10h. After the insulation is completed, it is first cooled to 250-300℃ at room temperature, and then quickly cooled to an ambient temperature below 5℃; 3) Extrusion: quickly heat the aluminum bar to 450℃-500℃, and then extrude it into the required shape. After extrusion, the profile is quickly cooled, and the cooling rate is >200℃ / min; 4) The first cold deformation: after extrusion, the profile is cold deformed by 10%-15% stretching through a straightening machine; 5) Aging: a two-stage aging process is adopted, the first-stage aging temperature is 230℃-250℃, the first-stage aging insulation time is 4-10 hours, the second-stage aging temperature is 160℃-170℃, and the second-stage aging insulation time is 18-36 hours; 6) Second cold deformation: After aging, the second cold deformation is carried out, and the profile is cold deformed with a stretching amount of 5%-10% using a straightening machine.

2. The method for preparing a high conductivity aluminum alloy conductive bar according to claim 1, characterized in that: In step 1) the rod casting step, the V content in the aluminum ingot raw material used is less than 0.01wt%.

3. The method for preparing a high conductivity aluminum alloy conductive bar according to claim 1 or 2, characterized in that: In step 1) the rod casting step, the alloy composition is: Mg 0.27wt%, Si 0.27wt%, Fe 0.10wt%, ferrosilicon Si-Fe 0.17wt%, Mg / (Si-Fe) ratio is 1.59, B 0.02wt%, Sr 0.01wt%, and the V content in the aluminum ingot used is 0.008wt%.

4. The method for preparing a high conductivity aluminum alloy conductive bar according to claim 1 or 2, characterized in that: In step 1) the rod casting step, the alloy composition is: Mg 0.33wt%, Si 0.33wt%, Fe 0.15wt%, ferrosilicon Si-Fe 0.18wt%, Mg / (Si-Fe) ratio is 1.83, B 0.03wt%, Sr content 0.02wt%, and the V content of the aluminum ingot used is 0.009wt%.

5. The method for preparing a high conductivity aluminum alloy conductive bar according to claim 1 or 2, characterized in that: In step 1) the rod casting step, the alloy composition is: Mg 0.32wt%, Si 0.28wt%, Fe 0.12wt%, ferrosilicon Si-Fe difference is 0.16wt%, Mg / (Si-Fe) ratio is 2.0, B 0.04wt%, Sr 0.02wt%, and the V content of the aluminum ingot used is 0.008wt%.

6. The method for preparing a high conductivity aluminum alloy conductive bar according to claim 1, characterized in that: In step 2) of the homogenization step, if the room temperature is greater than 5°C, the aluminum rod is taken out of the furnace for air cooling after the insulation is completed. After the aluminum rod is cooled to less than 250°C, it enters the cooling room for rapid cooling by air cooling or water spraying.

7. The method for preparing a high conductivity aluminum alloy conductive bar according to claim 1, characterized in that: In step 2) of homogenization, if the room temperature is below 5°C, the aluminum bar is first cooled to 300°C in a furnace after the insulation is completed, and then taken out of the furnace for air cooling or put into a cooling room for rapid cooling by air cooling or water spraying.

8. The method for preparing a high conductivity aluminum alloy conductive bar according to claim 1, characterized in that: In step 3) the extrusion step, the rapid heating of the aluminum rod is achieved by an industrial frequency furnace or a permanent magnet heating furnace.

9. A high conductivity aluminum alloy conductive bar prepared by the preparation method according to any one of claims 1 to 8.