High-conductivity aluminum alloy busbar and preparation method thereof

Abstract

The present application relates to the technical field of aluminum alloy conductive bar, and discloses a high-conductivity aluminum alloy conductive bar and a preparation method thereof.The present application precisely controls the content of alloy components, adopts specific homogenization temperature and cooling speed requirements of aluminum rods, adopts specific extrusion temperature and speed, respectively carries out cold deformation before and after aging, adopts a two-stage aging process, so that the aluminum alloy conductive bar has the comprehensive performance of high conductivity (≥62% IACS), high thermal conductivity (≥220 W / (mK), high strength (tensile strength ≥110 MPa, yield strength ≥110 MPa) and good toughness (elongation ≥12%, hardness ≥30 HV), meets the demand of the electrical material field for high-conductivity aluminum alloy, solves the problems of the prior art, such as the decline of material strength, complex process and high cost caused by the improvement of conductivity, and has remarkable superiority and broad application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aluminum alloy busbar, and particularly relates to a high-conductivity aluminum alloy busbar and a preparation method thereof. BACKGROUND

[0002] In the field of metal materials, aluminum alloy is widely used in the field of electrical materials due to its excellent electrical conductivity and lightweight characteristics. In particular, in the manufacture of cables, busbars, electrical components and other products, high-conductivity aluminum alloy is an essential material. However, the electrical conductivity of aluminum alloy is closely related to its internal crystal structure, distribution and quantity of precipitated phases, so how to prepare aluminum alloy with high electrical conductivity and high strength is an important technical challenge.

[0003] In the prior art, the addition of certain alloying elements is usually used to improve the electrical conductivity of aluminum alloy. For example, the addition of magnesium, silicon, iron and other elements can form Mg2Si phase, which can improve the electrical conductivity of aluminum alloy. In addition, heat treatment and cold deformation can be used to change the crystal structure and distribution of precipitated phases of aluminum alloy, thereby improving its electrical conductivity. For example, through aging treatment, the precipitated phase can be refined and uniformly distributed, thereby improving the electrical conductivity; through cold deformation, dislocations and other defects can be introduced, increasing electron scattering, thereby improving the electrical conductivity.

[0004] Although the prior art can improve the electrical conductivity of aluminum alloy to some extent, there are still some problems and limitations. First, the prior art often leads to a decrease in the strength of the material while improving the electrical conductivity, thereby limiting its application range. Second, the prior art often requires complex process flow and high cost in the preparation of high-conductivity aluminum alloy, which is not conducive to large-scale production. In addition, the prior art still has certain difficulties in controlling the distribution and quantity of precipitated phases, which will affect the stability and consistency of the electrical properties of aluminum alloy. SUMMARY

[0005] The purpose of the present application is to provide an aluminum alloy busbar with high electrical conductivity, high strength, and good stability and consistency of electrical properties, and a preparation method thereof, to solve one or more technical problems in the prior art and at least provide a beneficial choice or create conditions.

[0006] To achieve the above purpose, the technical scheme adopted by the present application is as follows.

[0007] A preparation method of a high-conductivity aluminum alloy busbar, the preparation steps of which are as follows: 1) casting bar, preparing alloy components in proportion and casting into aluminum bar, the alloy components being: Mg 0.25wt%-0.35wt%, Si 0.25wt%-0.35wt%, Fe 0.05wt%-0.15wt%, Si-Fe difference Si-Fe 0.15wt%-0.25wt%, the ratio of Mg / (Si-Fe) being 1.5-2.0, B 0.02wt%-0.04wt%, Sr 0.01wt%-0.03wt%, and the balance being aluminum; 2) homogenization treatment, sending the cast aluminum bar into a homogenization furnace for homogenization heat treatment, heating the aluminum bar to 530-560℃ and keeping for 5-10h, after the keeping, first cooling to 250-300℃ at normal temperature, and then rapidly cooling at an environmental temperature below 5℃; 3) extrusion, rapidly heating the aluminum bar to 450-500℃, and then extruding into a required shape, rapidly cooling the profile after extrusion at a cooling speed >200℃ / min; 4) first cold deformation, after extrusion, performing cold deformation on the profile by a straightening machine at a stretching amount of 10%-15%; 5) aging, adopting a two-stage aging process, the first-stage aging temperature being 230-250℃, the first-stage aging keeping time being 4-10h, the second-stage aging temperature being 160-170℃, and the second-stage aging keeping time being 18-36h; and 6) second cold deformation, performing second cold deformation on the profile after aging, and using a straightening machine to perform cold deformation on the profile at a stretching amount of 5%-10%.

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

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

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

[0011] More preferably, in the step 1) of the casting rod step, the alloy composition is: Mg 0.32wt%, Si 0.28wt%, Fe 0.12wt%, Si-Fe difference Si-Fe is 0.16wt%, the ratio of Mg / (Si-Fe) 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 the step 2) of the homogenization treatment step, if the room temperature is greater than 5℃, the aluminum rod is air-cooled after the end of the heat preservation, and the aluminum rod is cooled to below 250℃ and then enters the cooling chamber for air cooling or water spraying rapid cooling.

[0013] More preferably, in the step 2) of the homogenization treatment step, if the room temperature is less than 5℃, the aluminum rod is first furnace-cooled to 300℃ after the end of the heat preservation, and then air-cooled or enters the cooling chamber for air cooling or water spraying rapid cooling.

[0014] More preferably, in the step 3) of the extrusion step, the rapid heating of the aluminum rod is realized by a power frequency furnace or a permanent magnet heating furnace.

[0015] In another aspect, the application also provides a high-conductivity aluminum alloy busbar prepared by the preparation method.

[0016] Compared with the prior art, the application mainly solves the following technical problems: 1) improving the conductivity of the aluminum alloy while maintaining the strength and stability of the material and expanding its application range; 2) simplifying the process flow, reducing the cost, and realizing large-scale production in the process of preparing the high-conductivity aluminum alloy; 3) precisely controlling the distribution and quantity of precipitated phases, and improving the stability and consistency of the conductivity of the aluminum alloy; and 4) optimizing the crystal structure of the aluminum alloy and the distribution of the precipitated phases through reasonable heat treatment and cold deformation processes, so as to obtain the aluminum alloy with high conductivity and high strength.

[0017] Compared with the prior art, the application at least has the following advantages and beneficial effects.

[0018] By precisely controlling the content of the alloy composition, especially the ratio of Mg, Si, Fe, B and Sr elements, the specific ratio helps to improve the conductivity. At the same time, by adding appropriate amounts of B and Sr elements, the distribution and quantity of the precipitated phases can be further optimized, thereby improving the balance of the conductivity and the strength.

[0019] The application adopts specific aluminum rod homogenization temperature and cooling speed requirements, so that the Mg2Si precipitates in the material after homogenization, and does not completely solid-solute in the extrusion process, which does not affect the conductivity on the basis of providing certain material performance.

[0020] The specific extrusion temperature and speed and water cooling mode adopted by the application make the crystal structure in the alloy more compact, which is beneficial to improve the conductivity.

[0021] The cold deformation before and after aging is carried out in the application, which can introduce a large number of dislocations and other defects, increase electron scattering, and thus improve the 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, the conductivity can be improved while avoiding excessive plastic deformation of the material, thereby maintaining the strength of the material.

[0022] The double-stage aging process is adopted in the application, which refines and uniformly distributes the precipitated phase through the first-stage aging, and further improves the compactness and uniformity of the precipitated phase through the second-stage aging, 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 conductivity.

[0023] The aluminum alloy conducting bar of the application has the comprehensive performance of high conductivity (≥62% IACS), high thermal conductivity (≥220 W / (mK), high strength (tensile strength ≥110 MPa, yield strength ≥110 MPa) and good toughness (elongation ≥12%, hardness ≥30 HV), which meets the demand of the electrical material field for high conductivity aluminum alloy and has broad application prospects. In general, compared with the prior art, the application optimizes the alloy composition, improves the process parameters, and controls the distribution and quantity of the precipitated phase to prepare an aluminum alloy conducting bar with excellent comprehensive performance, solves the problems of the prior art, such as the decrease in material strength, complex process and high cost when improving the conductivity, and has significant advantages.

[0024] Due to the advanced technology of the present application, it can be widely applied in the fields of metal materials, material preparation, and electrical materials, etc. In the field of metal materials, the present application provides a method for preparing high-conductivity aluminum alloy busbars, which controls the alloy composition accurately and adopts special extrusion, aging, and cold deformation processes, so that the prepared aluminum alloy busbars have high conductivity and high strength, meeting 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 application is simple, the process flow is easy to control, and the cost is relatively low, which is very suitable for large-scale production, which will greatly promote the application of high-conductivity aluminum alloy busbars in the field of material preparation. In the field of electrical materials, the application of high-conductivity aluminum alloy busbars can greatly improve the performance of electrical products, for example, in the manufacture of cables, busbars, electrical components, etc., high-conductivity aluminum alloy can reduce power loss and improve the efficiency and reliability of electrical products, which will greatly promote the development of electrical materials. In general, the application prospect of the present application is broad, the market demand is large, and it is expected to play an important role in the fields of metal materials, material preparation, and electrical materials, etc. DETAILED DESCRIPTION

[0025] The specific embodiments of the present application are further described below to make the technical solutions and beneficial effects of the present application more clear and explicit. The following description of the embodiments is exemplary and is intended to explain the present application, but cannot be understood as a limitation of the present application.

[0026] Additional aspects and advantages of the present application will become apparent in the description that follows, or can be learned by practice of the present application.

[0027] A method for preparing high-conductivity aluminum alloy busbars includes the following control processes.

[0028] 1) Alloy composition control: by accurately controlling the content of Mg, Si, Fe, B, Sr, etc. in the aluminum alloy, it is within a certain range, so as to optimize the crystal structure and distribution of precipitated phase of the aluminum alloy, and improve the electrical conductivity of the aluminum alloy. Among them, the Mg content is controlled in 0.25wt%-0.35wt%, the Si content is controlled in 0.25wt%-0.35wt%, the Fe content is controlled in 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 in 0.02wt%-0.04wt%, and the Sr content is controlled in 0.01wt%-0.03wt%. The aluminum ingot raw material used needs to be an aluminum ingot with V content less than 0.01wt% to ensure the purity and performance of the final product.

[0029] 2) Aluminum bar homogenization process optimization: A special homogenization post-cooling process is adopted, i.e., the aluminum bar is heated to 530-560°C and held for 5-10h, if the room temperature is greater than 5°C, the aluminum bar is discharged and air-cooled after holding, and the aluminum bar is cooled to below 250°C and then enters the cooling chamber for air cooling or water spraying rapid cooling; if the room temperature is lower than 5°C, the aluminum bar is first furnace-cooled to 300°C after holding, and then discharged for air cooling or enters the cooling chamber for air cooling or water spraying rapid cooling. Through this process, the cooling speed is ensured to promote the precipitation and coarsening of a large amount of Mg2Si, so as to provide certain material performance without affecting the electrical conductivity.

[0030] 3) Extrusion process optimization: By optimizing the extrusion temperature, speed and cooling method, the aluminum alloy can form a more uniform crystal structure and precipitate phase distribution during extrusion, thereby improving the electrical conductivity of the aluminum alloy. Specifically, the aluminum bar is rapidly heated to 450-500°C by a power frequency furnace or a permanent magnet heating furnace, and then extruded into the required shape. The profile is rapidly cooled after extrusion, and the cooling speed is ensured to be >200°C / min.

[0031] 4) Cold deformation process control: After extrusion, the profile is cold deformed by 10%-15% by a straightening machine, so that the aluminum alloy can form a more uniform precipitate phase distribution before and after aging, greatly accelerating the material aging treatment speed, reducing the precipitation temperature, and thereby greatly improving the electrical conductivity of the aluminum alloy.

[0032] 5) Aging process optimization: A two-stage aging process is adopted, so that the aluminum alloy can form a more uniform precipitate phase distribution during aging, thereby improving the electrical conductivity and strength of the aluminum alloy. The first stage aging temperature is 230-250°C, the first stage aging holding time is 4-10h, the second stage aging temperature is 160-170°C, and the second stage aging holding time is 18-36h.

[0033] 6) Secondary cold deformation process: After aging, secondary cold deformation is performed, and the profile is cold deformed by 5%-10% by 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 combining a large number of dislocations with the original internal strengthening precipitates to improve the creep resistance of the material.

[0034] Example 1.

[0035] The embodiment provides a preparation method of a high-conductivity aluminum alloy conductor bar, and the specific steps are as follows.

[0036] Step one: first, prepare alloy components in a specific ratio and cast into aluminum rods, the alloy components are: Mg 0.27wt%, Si 0.27wt%, Fe 0.10wt%, Si-Fe difference Si-Fe 0.17wt%, the ratio of Mg / (Si-Fe) is 1.59, B 0.02wt%, Sr 0.01wt%, and the V content in the aluminum ingot used is 0.008wt%.

[0037] Step two: send the cast aluminum rods into a homogenizing furnace for homogenizing heat treatment, heat the aluminum rods to 550℃ and keep for 6h, room temperature 15℃, after the aluminum rods are kept for heat treatment, take out the furnace and air cool, and after the aluminum rods are cooled to 250℃ or below, enter the cooling room for air cooling.

[0038] Step three: heat the prepared aluminum rods to 475℃ quickly through a power frequency furnace or a permanent magnet heating furnace, then extrude into the required shape, and cool the profile quickly after extrusion, with a cooling speed of >200℃ / min.

[0039] Step three: after extrusion, perform cold deformation on the profile through a straightening machine with a stretching amount of 12%.

[0040] Step four: adopt a two-stage aging process for the extruded profile, the first-stage aging temperature is 240℃, the first-stage aging holding time is 6 hours, the second-stage aging temperature is 160℃, and the second-stage aging holding time is 36 hours.

[0041] Step five: perform secondary cold deformation offline stretching on the aged profile, and perform cold deformation on the profile through a straightening machine with a stretching amount of 7%.

[0042] Through the above steps, the electrical conductivity of the aluminum alloy conductor bar obtained finally 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.

[0043] Example 2.

[0044] The embodiment provides a preparation method of a high-conductivity aluminum alloy conductor bar, and the specific steps are as follows.

[0045] Step one: first, prepare alloy components in a specific ratio and cast into aluminum rods, the alloy components are: Mg 0.27wt%, Si 0.27wt%, Fe 0.10wt%, Si-Fe difference Si-Fe 0.17wt%, the ratio of Mg / (Si-Fe) is 1.59, B 0.02wt%, Sr 0.01wt%, and the V content in the aluminum ingot used is 0.008wt%.

[0046] Step two: the cast aluminum bar is sent into a homogenizing furnace for homogenizing heat treatment, the aluminum bar is heated to 560℃ and kept for 6h, the room temperature is 15℃, after the aluminum bar is kept for 6h, it is taken out of the furnace and air cooled, and after the aluminum bar is cooled to 250℃ or below, it is sent into a cooling chamber for air cooling.

[0047] Step three: the prepared aluminum bar is quickly heated to 490℃ by a power frequency furnace or a permanent magnet heating furnace, and then extruded into a required shape, and the profile is quickly cooled after extrusion, and the cooling speed is ensured to be >200℃ / min.

[0048] Step three: after extrusion, the profile is cold deformed by 14% stretching amount through a straightening machine.

[0049] Step four: the extruded profile is subjected to a two-stage aging process, the first stage aging temperature is 250℃, the first stage aging holding time is 5h, the second stage aging temperature is 170℃, and the second stage aging holding time is 18h.

[0050] Step five: the aged profile is subjected to secondary cold deformation offline stretching, and the profile is cold deformed by 5% stretching amount through a straightening machine.

[0051] Through the above steps, the conductivity of the final aluminum alloy conductive bar 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.

[0052] Example 3.

[0053] The embodiment provides a preparation method of a high-conductivity aluminum alloy conductive bar, and the specific steps are as follows.

[0054] Step one: first, alloy components are prepared according to a specific proportion and cast into an aluminum bar, the alloy components are as follows: Mg 0.32wt%, Si 0.28wt%, Fe 0.12wt%, silicon-iron difference (Si-Fe) is 0.16wt%, the ratio of Mg / (Si-Fe) is 2.0, B 0.04wt%, Sr 0.02wt%, and the V content of the aluminum ingot used is 0.008wt%.

[0055] Step two: the cast aluminum bar is sent into a homogenizing furnace for homogenizing heat treatment, the aluminum bar is heated to 540℃ and kept for 8h, the room temperature is 15℃, after the aluminum bar is kept for 8h, it is taken out of the furnace and air cooled, and after the aluminum bar is cooled to 250℃ or below, it is sent into a cooling chamber for air cooling.

[0056] Step three: the prepared aluminum bar is quickly heated to 455℃ by a power frequency furnace or a permanent magnet heating furnace, and then extruded into a required shape, and the profile is quickly cooled after extrusion, and the cooling speed is ensured to be >200℃ / min.

[0057] Step three: after extrusion, the profile is cold deformed by 10% elongation through a straightening machine.

[0058] Step four: a two-stage aging process is used for the extruded profile, the first stage aging temperature is 250°C, the first stage aging holding time is 4 hours, the second stage aging temperature is 165°C, and the second stage aging holding time is 24 hours.

[0059] Step five: the profile after aging is subjected to secondary cold deformation offline stretching, and the profile is cold deformed by 10% elongation through a straightening machine.

[0060] Through the above steps, the electrical conductivity of the final aluminum alloy conducting bar can reach 62.2% IACS, the tensile strength can reach 120 MPa, the yield strength can reach 114 MPa, the elongation can reach 10%, and the hardness can reach 36 HV.

[0061] Example 4.

[0062] The embodiment provides a preparation method of a high-conductivity aluminum alloy conducting bar, and the specific steps are as follows.

[0063] Step one: first, prepare alloy components in a specific proportion and cast into aluminum rods, the alloy components are: Mg 0.27wt%, Si 0.27wt%, Fe 0.10wt%, Si-Fe difference Si-Fe 0.17wt%, the ratio of Mg / (Si-Fe) is 1.59, B 0.02wt%, Sr 0.01wt%, and the V content in the aluminum ingot used is 0.008wt%.

[0064] Step two: the cast aluminum rod is sent into a homogenizing furnace for homogenizing heat treatment, the aluminum rod is heated to 550°C and held for 6h, and then cooled to 300°C at room temperature 4°C, and then taken out of the furnace for air cooling.

[0065] Step three: the prepared aluminum rod is quickly heated to 475°C through a power frequency furnace or a permanent magnet heating furnace, and then extruded into the required shape, and the profile is quickly cooled after extrusion, and the cooling speed is ensured to be >200°C / min.

[0066] Step three: after extrusion, the profile is cold deformed by 12% elongation through a straightening machine.

[0067] Step four: a two-stage aging process is used for the extruded profile, the first stage aging temperature is 240°C, the first stage aging holding time is 6 hours, the second stage aging temperature is 160°C, and the second stage aging holding time is 36 hours.

[0068] Step five: the profile after aging is subjected to secondary cold deformation offline stretching, and the profile is cold deformed by 7% elongation through a straightening machine.

[0069] Through the above steps, the conductivity of the final aluminum alloy busbar 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.

[0070] Comparative Example 1.

[0071] A preparation method of an aluminum alloy busbar, the specific steps are as follows.

[0072] Step one: first, prepare alloy components in a specific ratio and cast into aluminum rods, the alloy components are: Mg 0.57wt%, Si 0.57wt%, Fe 0.17wt%, silicon-iron difference (Si-Fe) is 0.40wt%, the ratio of Mg / (Si-Fe) is 1.43, B 0.02wt%, Sr 0.01wt%, and the V content of the aluminum ingot used is 0.008wt%.

[0073] Step two: send the cast aluminum rod into a homogenizing furnace for homogenizing heat treatment, heat the aluminum rod to 550℃ and keep for 6h, room temperature 15℃, after the aluminum rod is kept, take out the furnace and air cool, after the aluminum rod is cooled to 250℃ or less, enter the cooling room for air cooling.

[0074] Step three: heat the prepared aluminum rod to 475℃ quickly through a power frequency furnace or a permanent magnet heating furnace, then extrude into the required shape, and cool the profile quickly after extrusion, the cooling speed is ensured to be >200℃ / min.

[0075] Step three: after extrusion, the profile is cold deformed by 10% elongation through a straightening machine.

[0076] Step four: the extruded profile is subjected to a two-stage aging process, the first stage aging temperature is 240℃, the first stage aging holding time is 6 hours, the second stage aging temperature is 160℃, and the second stage aging holding time is 36 hours.

[0077] Step five: the aged profile is subjected to secondary cold deformation offline stretching, and the profile is cold deformed by 5% elongation through a straightening machine.

[0078] Through the above steps, the conductivity of the final aluminum alloy busbar 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.

[0079] Comparative Example 2.

[0080] A preparation method of an aluminum alloy busbar, the specific steps are as follows.

[0081] Step one: first, prepare alloy components in a specific ratio and cast into aluminum rods, the alloy components are: Mg 0.10wt%, Si 0.15wt%, Fe 0.10wt%, silicon-iron difference (Si-Fe) is 0.05wt%, the ratio of Mg / (Si-Fe) is 2, B 0.01wt%, Sr 0.01wt%, the V content of the aluminum ingot used is 0.008wt%.

[0082] Step two: send the cast aluminum rods into a homogenizing furnace for homogenizing heat treatment, heat the aluminum rods to 560℃ and keep for 6h, room temperature 15℃, after the aluminum rods are kept for 6h, take them out of the furnace and air cool, after the temperature of the aluminum rods is reduced to 250℃ or below, put them into a cooling room for air cooling.

[0083] Step three: heat the prepared aluminum rods to 490℃ quickly through a power frequency furnace or a permanent magnet heating furnace, then extrude them into the required shape, and cool the profile quickly after extrusion, the cooling speed is ensured to be >200℃ / min.

[0084] Step three: after extrusion, perform cold deformation on the profile through a straightening machine with a stretching amount of 15%.

[0085] Step four: adopt a two-stage aging process for the extruded profile, the first-stage aging temperature is 250℃, the first-stage aging holding time is 5h, the second-stage aging temperature is 170℃, and the second-stage aging holding time is 18h.

[0086] Step five: perform secondary cold deformation offline stretching on the aged profile, and perform cold deformation on the profile through a straightening machine with a stretching amount of 7%.

[0087] Through the above steps, the final aluminum alloy busbar has an electrical conductivity of 62.5%IACS, a tensile strength of 72MPa, a yield strength of 62MPa, an elongation of 12%, and a hardness of 30HV.

[0088] Comparative example 3.

[0089] A preparation method of an aluminum alloy busbar, the specific steps are as follows.

[0090] Step one: first, prepare alloy components in a specific ratio and cast into aluminum rods, the alloy components are: Mg 0.10wt%, Si 0.15wt%, Fe 0.10wt%, silicon-iron difference (Si-Fe) is 0.05wt%, the ratio of Mg / (Si-Fe) is 2, B 0.01wt%, Sr 0.01wt%, the V content of the aluminum ingot used is 0.008wt%.

[0091] Step two: the cast aluminum bar is sent into a homogenizing furnace for homogenizing heat treatment, the aluminum bar is heated to 540℃ and kept for 8h, the room temperature is 15℃, after the aluminum bar is kept for 8h, it is taken out of the furnace and air cooled, and after the aluminum bar is cooled to 250℃ or below, it is sent into a cooling chamber for air cooling.

[0092] Step three: the prepared aluminum bar is quickly heated to 455℃ by a power frequency furnace or a permanent magnet heating furnace, and then extruded into a required shape, and the profile is quickly cooled after extrusion, and the cooling speed is ensured to be >200℃ / min.

[0093] Step three: after extrusion, the profile is cold deformed by a stretcher for 1% stretching amount.

[0094] Step four: a two-stage aging process is adopted for the profile after extrusion, the first-stage aging temperature is 250℃, the first-stage aging keeping time is 4h, the second-stage aging temperature is 165℃, and the second-stage aging keeping time is 24h.

[0095] Step five: the profile after aging is subjected to secondary cold deformation offline stretching, and the profile is cold deformed by a stretcher for 10% stretching amount.

[0096] Through the above steps, the electrical conductivity of the aluminum alloy electrically 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.

[0097] Comparative example 4.

[0098] A preparation method of an aluminum alloy electrically conductive bar, and the specific steps are as follows.

[0099] Step one: first, alloy components are prepared according to specific proportions and cast into aluminum bars, the alloy components are: 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%.

[0100] Step two: the cast aluminum bar is sent into a homogenizing furnace for homogenizing heat treatment, the aluminum bar is heated to 540℃ and kept for 8h, the room temperature is 15℃, after the aluminum bar is kept for 8h, it is taken out of the furnace and air cooled, and after the aluminum bar is cooled to 250℃ or below, it is sent into a cooling chamber for air cooling.

[0101] Step three: the prepared aluminum bar is quickly heated to 455℃ by a power frequency furnace or a permanent magnet heating furnace, and then extruded into a required shape, and the profile is quickly cooled after extrusion, and the cooling speed is ensured to be >200℃ / min.

[0102] Step three: after extrusion, the profile is cold deformed by a stretcher for 10% stretching amount.

[0103] Step four: the profile after extrusion adopts double-stage aging process, the first stage aging temperature is 250℃, the first stage aging holding time is 4 hours, the second stage aging temperature is 165℃, and the second stage aging holding time is 24 hours.

[0104] Step five: the profile after aging is subjected to secondary cold deformation offline stretching, and the profile is subjected to 1% stretching amount of cold deformation through a straightening machine.

[0105] Through the above steps, the conductivity of the finally obtained aluminum alloy conducting bar can reach 62.3% IACS, the tensile strength is 102 MPa, the yield strength is 86 MPa, the elongation is 14%, and the hardness is 32 HV.

[0106] Comparative example 5.

[0107] A preparation method of an aluminum alloy conducting bar, and the specific steps are as follows.

[0108] Step one: first, prepare alloy components according to a specific proportion and cast into aluminum rods, the alloy components are: 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%.

[0109] Step two: send the cast aluminum rod into a homogenizing furnace for homogenizing heat treatment, heat the aluminum rod to 540℃ and keep for 8h, and then take out the aluminum rod after heat preservation and air cool at room temperature 15℃, and then enter the cooling room for air cooling after the aluminum rod is cooled to 250℃ or below.

[0110] Step three: the prepared aluminum rod is quickly heated to 455℃ through a power frequency furnace or a permanent magnet heating furnace, and then extruded into the required shape, and the profile is quickly cooled after extrusion, and the cooling speed is ensured to be >200℃ / min.

[0111] Step three: after extrusion, the profile is subjected to 1% stretching amount of cold deformation through a straightening machine.

[0112] Step four: the profile after extrusion adopts double-stage aging process, the first stage aging temperature is 250℃, the first stage aging holding time is 4 hours, the second stage aging temperature is 165℃, and the second stage aging holding time is 24 hours.

[0113] Step five: the profile after aging is subjected to secondary cold deformation offline stretching, and the profile is subjected to 1% stretching amount of cold deformation through a straightening machine.

[0114] Through the above steps, the conductivity of the final aluminum alloy bus bar can reach 62.0% IACS, the tensile strength is 88 MPa, the yield strength is 72 MPa, the elongation is 15%, and the hardness is 30 HV.

[0115] It should be noted that any combination of the technical features in the above embodiments can be made, and in order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the description.

[0116] The above embodiments only express several implementation manners of the present application, the description is more specific and detailed, but it should not be understood as the limitation of the scope of the patent. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of variations and improvements can be made, which are within the protection scope of the present application. The parts not described in the specific embodiments are all prior art or common knowledge.

[0117] In addition, it should be noted that in the description of the present application, the preferred embodiment of the present application is described in detail and the embodiments included can more easily understand the content of the present application. Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as generally understood by those skilled in the art to which the present application belongs. When there is a contradiction, the definition in the specification shall prevail.

[0118] In the present application, the term "prepared from" is synonymous with "comprising". The terms "comprising", "including", "having" "with" or any other variation thereof, used in the present application are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or device comprising the listed elements does not necessarily limit to only those elements, but can include other elements not explicitly listed or inherent to such composition, step, method, article, or device.

[0119] In the present application, when the equivalent, concentration, or other value or parameter is expressed in a range, a preferred range, or a range defined by a series of upper preferred values and lower preferred values, it should be understood that all ranges formed by any pair of range upper limit or preferred value and any range lower limit or preferred value are specifically disclosed, regardless of whether the range is disclosed separately. For example, when the range "1 to 5" is disclosed, the described range should be interpreted as including the range "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 application, unless otherwise stated, the range is intended to include its end value and all integers and fractions within the range.

[0120] Also, the indefinite articles "a" and "an" preceding an element or component of the application are intended to be non-limiting regarding the number of elements or components. Therefore "a" or "an" should be read to include one or at least one, and the singular word form of an element or component also includes the plural unless the number is clearly specified.

Claims

1. A method of making a high conductivity aluminum alloy busbar, characterized by, The preparation steps are as follows: 1) Casting bar, prepare alloy components in proportion and cast into aluminum bar, 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%, the ratio of Mg / (Si-Fe) is 1.5-2.0, B 0.02wt%-0.04wt%, Sr 0.01wt%-0.03wt%, and the balance is aluminum; 2) Homogenization treatment, the cast aluminum bar is sent into a homogenization furnace for homogenization heat treatment, the aluminum bar is heated to 530℃-560℃ and then is kept for 5h-10h, after the keeping, the aluminum bar is first cooled to 250-300℃ at normal temperature, and then is rapidly cooled at an environmental temperature below 5℃; 3) Extrusion, the aluminum bar is rapidly heated to 450℃-500℃, and then is extruded into a required shape, and the profile is rapidly cooled after the extrusion at a cooling speed of >200℃ / min; 4) First cold deformation, after the extrusion, the profile is subjected to cold deformation by a stretcher for a stretching amount of 10%-15%; 5) Aging, a two-stage aging process is adopted, the first-stage aging temperature is 230℃-250℃, the first-stage aging keeping time is 4-10 hours, the second-stage aging temperature is 160℃-170℃, and the second-stage aging keeping time is 18-36 hours; 6) Second cold deformation, the profile is subjected to second cold deformation after the aging, and is subjected to cold deformation by the stretcher for a stretching amount of 5%-10%.

2. The method of claim 1, wherein the high conductivity aluminum alloy conductor rail is prepared by the steps of: In the step 1) casting bar step, the V content in the aluminum ingot raw material used is lower than 0.01wt%.

3. A method of producing a high conductivity aluminium alloy busbar according to claim 1 or 2, characterised in that, In the step 1) casting bar step, the alloy components are: Mg 0.27wt%, Si 0.27wt%, Fe 0.10wt%, Si-Fe difference Si-Fe 0.17wt%, the ratio of Mg / (Si-Fe) 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 busbar according to claim 1 or 2, characterized in that, In the step 1) casting bar step, the alloy components are: Mg 0.33wt%, Si 0.33wt%, Fe 0.15wt%, Si-Fe difference Si-Fe 0.18wt%, the ratio of Mg / (Si-Fe) is 1.83, B 0.03wt%, Sr content 0.02wt%, and the V content in the aluminum ingot used is 0.009wt%.

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

6. The method of claim 1, wherein the high conductivity aluminum alloy conductor rail is prepared by the steps of: In the step 2) homogenization treatment step, if the room temperature is greater than 5℃, the aluminum bar is taken out of the furnace and air-cooled after the keeping, and the aluminum bar is cooled to 250℃ or below and then is rapidly cooled in a cooling room by air cooling or water spraying.

7. The method of claim 1, wherein the high conductivity aluminum alloy conductor rail is prepared by the steps of: In the homogenizing step 2), if the room temperature is lower than 5℃, the aluminum bar is first furnace-cooled to 300℃ after the heat preservation is over, and then air-cooled or rapidly cooled by air or water in the cooling room.

8. The method of claim 1, wherein the high conductivity aluminum alloy conductor rail is prepared by the steps of: In the extruding step 3), the rapid heating of the aluminum bar is realized by a power frequency furnace or a permanent magnet heating furnace.

9. A high-conductivity aluminum alloy busbar prepared by the preparation method in any one of claims 1-8.