Al-Si-Mg-based aluminum alloy conductor and preparation method thereof

Abstract

The invention discloses an Al-Si-Mg-based aluminum alloy conductor and a preparation method thereof, and belongs to the field of metal material processing and manufacturing, the conductor is a silicon-rich low-magnesium aluminum alloy, the component of the conductor is Al-xSi-yMg-zFe-mCu-n rare earth RE, 0.2 < = x < = 1.2, 0.05 < = y < = 0.3, 0.05 < = z < = 0.15, m < = 0.1, n < = 0.5, and x > = y. According to the preparation method, a smelting-refining-casting-solid solution-aging process method matched with a new alloy formula is adopted, so that high conductivity (greater than or equal to 58% IACS) is obtained while high mechanical strength (greater than or equal to 80 MPa) of an aluminum alloy conductor casting blank is obtained. The method is short in technological process, easy to operate, low in preparation cost and convenient to industrialize, and the prepared alloy material belongs to an aluminum alloy conductor with great application potential; good application and popularization prospects are realized.

Description

Technical Field

[0001] The invention relates to the field of metal material processing and manufacturing, and in particular to an Al-Si-Mg based aluminum alloy conductor and a preparation method thereof. Background Art

[0002] At present, the conductors produced and used in my country are still mainly copper. Under the current background of global energy transformation and sustainable development, China is facing a situation of shortage of copper resources and dependence on imports. According to data, as a major copper consumer, China is extremely short of copper resources, and nearly 90% of its copper relies on foreign imports. Although China's copper reserves rank sixth in the world, its external dependence exceeds 70%, which is heavily dependent on imports. In addition, with the continuous development of the economy and high-quality transformation, the demand for copper will continue to increase, and the import volume and import value are expected to continue to rise. At the same time, as a resource-rich and low-cost material, aluminum has gradually received attention in the fields of power transmission, electrical equipment, and electronic communications. In recent years, China's electrolytic aluminum industry has increased dramatically, and some places have even experienced overcapacity. Therefore, the development of high-conductivity aluminum alloy conductors can not only alleviate the problem of aluminum overcapacity, but also respond to the national development strategy of "saving copper with aluminum", which is particularly important for the development of the power industry.

[0003] Aluminum alloy conductors have many advantages in performance, such as lightness, cost-effectiveness and corrosion resistance. Although its electrical conductivity is only about half of that of copper, under the same power transmission conditions, the cross-sectional area of ​​aluminum alloy conductors is 1.6 times that of copper conductors. However, since the density of aluminum is less than 1 / 3 of that of copper, the required mass is only half of that of copper. In addition, the price of aluminum alloy is much lower than that of copper, so aluminum alloy cables have obvious advantages in terms of cost of use. The practical experience of using aluminum alloy cables in Europe and the United States for decades has also fully demonstrated the quality, safety and stability of aluminum alloy conductors used in wires and cables. In addition, aluminum alloy cables have significant advantages in the application of UHV power transmission, smart grids and microgrid construction, which not only improves the intelligence level and operation efficiency of the power grid, but also makes them more flexible in deployment due to their light weight and high flexibility, and adapts to different installation environments and needs.

[0004] Aluminum alloy conductor materials have broad application prospects. With the advancement of material synthesis and processing technology, the conductivity and high temperature resistance of aluminum alloy cables have been significantly improved. For example, Huadong aluminum alloy cables use AA-8000 series aluminum alloy conductors, which greatly improves the conductivity and high temperature resistance of aluminum alloy cables.

[0005] In summary, the development and application of aluminum alloy conductor materials have important strategic significance for the development of the power industry. Among aluminum alloy materials, 1xxx series aluminum alloys mainly refer to pure aluminum or aluminum alloys with an aluminum content of more than 99%, which are characterized by good plasticity and high electrical conductivity, but their mechanical properties are relatively low, and their tensile strength is generally less than 70MPa. 6xxx series aluminum alloys, with Mg and Si as the main alloying elements, are characterized by high strength, but poor performance in electrical properties, and their electrical conductivity is generally lower than 55%IACS. For aluminum alloy conductors (cast embryos) with electrical conductivity higher than 58%IACS and tensile strength higher than 80MPa, it is still to be developed to meet the needs of users for aluminum alloy conductors with both mechanical properties and electrical properties. The present invention adds excess Si elements to the alloy through the "excess Si" theory to form a nano-scale excess silicon dispersed phase different from the common 6xxx series aluminum alloy β phase, which reduces the solid solubility of the alloy elements and reduces the alloy lattice distortion, thereby significantly improving the alloy conductivity. The prepared new aluminum alloy conductor (such as Example 1: Al-1Si-0.2Mg-0.05Fe-0.025Cu) has an electrical conductivity of up to 58.9% IACS and a tensile strength of up to 132 MPa. Therefore, the aluminum alloy conductor can be used as a product with relatively balanced mechanical and electrical properties to fill the market gap. The aluminum alloy conductor designed by the present invention can obtain high mechanical properties while preparing aluminum alloy materials with high conductivity by using a simple "melting-refining-casting-solid solution-aging" process, providing an important conductor material for the development of a new generation of aluminum alloy cables and tooling equipment. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art, and to provide an Al-Si-Mg-based aluminum alloy conductor and a preparation method thereof, which belongs to the field of metal material processing and manufacturing. The conductor is a "silicon-rich and low-magnesium" aluminum alloy, and its composition is Al-xSi-yMg-zFe-mCu-n rare earth RE, wherein 0.2≤x≤1.2, 0.05≤y≤0.3, 0.05≤z≤0.15, m≤0.1, n≤0.5, x≥y. The preparation method adopts a "melting-refining-casting-solid solution-aging" process method that matches the new alloy formula, and obtains a higher aluminum alloy conductor casting embryo mechanical strength (≥80MPa) while obtaining a higher conductivity (≥58%IACS). The method has a short process flow, is easy to operate, has a low preparation cost, is easy to industrialize, and the prepared alloy material is a kind of aluminum alloy conductor with great application potential; it has an excellent application and promotion prospect.

[0007] In order to achieve the above technical effects, the following technical solutions are adopted:

[0008] An Al-Si-Mg based aluminum alloy conductor is an Al-Si-Mg based aluminum alloy, wherein the nominal composition is Al-xSi-yMg-zFe-mCu-n rare earth RE, wherein the coefficients x, y, z, m, and n are respectively the mass percentages of Si, Mg, Fe, Cu, and rare earth RE in the alloy, 0.2≤x≤1.2, 0.05≤y≤0.3, 0.05≤z≤0.15, m≤0.1, n≤0.5, and x≥y.

[0009] A method for preparing an Al-Si-Mg-based aluminum alloy conductor is a "melting-refining-casting-solid solution-aging" processing method adapted to a "silicon-rich and low-magnesium" formula; specifically comprising the following steps:

[0010] Step S1: Weighing

[0011] Pure Al is weighed as aluminum alloy parent material, Si, Mg, Fe, Cu, rare earth RE single substance or its aluminum-based master alloy is weighed as alloying agent, and hexachloroethane is weighed as refining agent according to mass ratio;

[0012] Step S2: Melting

[0013] The pure Al in step S1 is heated to 730-770°C in a reaction vessel to melt the aluminum completely, and then kept warm for 10 minutes. Then, alloying agents of Si, Mg, Fe, Cu, and rare earth RE are added in sequence. Each time an alloying agent is added, it is stirred for 5 minutes and allowed to stand for 5 minutes.

[0014] Step S3: Refining

[0015] The hexachloroethane in step S1 is placed in a reaction vessel, stirred for 5 minutes, allowed to stand for 5 minutes, then slag is removed, and the mixture is kept at 730-770°C for 10 minutes before casting;

[0016] Step S4: Casting

[0017] The melt obtained in step S3 is poured into a mold preheated to 200-400° C., and naturally cooled to room temperature in air to form an aluminum alloy casting embryo;

[0018] Step S5: Solid solution strengthening treatment

[0019] The aluminum alloy ingot after heat treatment obtained in step S4 is placed in a heat treatment furnace and kept at 480-560° C. for 4-6 hours, and then the sample is quickly taken out for water quenching to obtain the aluminum alloy ingot after solid solution treatment;

[0020] Step S6: Aging annealing treatment

[0021] The aluminum alloy ingot obtained in step S5 after solid solution is placed in a heat treatment furnace, and after being kept at a temperature of 180-260° C. for 2-24 hours, the sample is cooled to room temperature along with the furnace to obtain an Al-Si-Mg based aluminum alloy conductor.

[0022] Furthermore, the rare earth RE is Ce or Er; the pure Al in step S2 is solid metal or aluminum liquid; when the pure Al is aluminum liquid, it does not need to be melted, but still needs to be heated and kept warm.

[0023] Furthermore, the grade of pure Al is industrial pure aluminum or above; when the pure Al is solid metal, it is aluminum ingot, aluminum particles or powder.

[0024] Furthermore, the aluminum-based master alloy in step S1 is Al-Si, Al-Mg, Al-Fe, Al-Cu, Al-RE of any composition or an aluminum-based ternary alloy of any composition.

[0025] Furthermore, the aluminum-based master alloy is in the form of blocks, particles or powder.

[0026] Furthermore, the amount of hexachloroethane added in step S1 is 0.4-1.2 wt % of the total mass of the alloy.

[0027] Furthermore, the reaction container in step S2 is graphite, silicon carbide, other high temperature resistant and oxidation resistant metals or a ceramic crucible.

[0028] Furthermore, in step S4, the mold is a high-strength graphite, ceramic or steel mold.

[0029] Furthermore, the Al-Si-Mg based aluminum alloy conductor simultaneously satisfies the requirements of room temperature electrical conductivity ≥ 58% IACS and tensile strength ≥ 80 MPa.

[0030] The beneficial effects of the present invention are:

[0031] (1) The present invention adopts a new formula of "rich in silicon and high in magnesium" and combines it with the process method of "smelting-refining-casting-solid solution-aging". Through the synergistic effect of melting-refining-casting-solid solution-aging, under suitable process parameter conditions, a uniformly distributed nano-scale excess silicon dispersion phase is formed in the prepared aluminum alloy conductor matrix, thereby achieving a simultaneous improvement in tensile strength and electrical conductivity.

[0032] (2) The equipment, process method and process parameters adopted by the present invention match the modern aluminum alloy industrial production technology, which is convenient for future industrial application. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. The drawings in the following description are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0034] Figure 1 This is a process flow chart of preparing an Al-Si-Mg based aluminum alloy conductor according to an embodiment of the present invention;

[0035] Figure 2 This is a field emission scanning electron microscope image of the high-conductivity aluminum alloy conductor material prepared in Example 1 of the present invention;

[0036] Figure 3 The stress-strain curve diagram of the high-conductivity aluminum alloy conductor material prepared in Examples 1 to 10 of the present invention;

[0037] Figure 4 The electrical conductivity diagram of the high-conductivity aluminum alloy conductor material prepared in Examples 1 to 10 of the present invention. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0039] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0040] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations and / or combinations thereof.

[0041] Embodiment 1:

[0042] like Figure 1 As shown: Al-1.2Si-0.2Mg-0.05Fe-0.025Cu aluminum alloy conductor preparation:

[0043] The raw materials are prepared according to the mass percentage of each element in the Al-1.2Si-0.2Mg-0.05Fe-0.025Cu aluminum alloy conductor: This example is used to illustrate the influence of alloy composition on conductor performance. The preparation steps of the conductor are as follows:

[0044] S1: Ingredients: weigh 137.10 g pure aluminum, 9.00 g Al-20Si master alloy, 3.00 g Al-10Mg master alloy, 0.75 g Al-10Fe master alloy, 0.075 g Al-50Cu master alloy, and 1.5 g hexachloroethane.

[0045] S2: Melting: melt the prepared pure aluminum and heat it to 750°C for 10 minutes, then add Al-20Si master alloy, Al-10Mg master alloy, Al-10Fe master alloy and Al-50Cu master alloy to the melt in sequence, stir mechanically and evenly after adding the alloying agent each time, and then heat it for 5 minutes to form an alloy melt.

[0046] S3: refining, adding hexachloroethane to the alloy melt obtained in step S2, mechanically stirring and then keeping warm for 10 minutes, and using a special slag removal tool to remove slag on the surface of the melt.

[0047] S4: Casting: pour the melt obtained in S3 into a preheated mold, and after natural cooling, obtain a cylindrical cast rod with a diameter of 22 mm and a height of 120 mm.

[0048] S5: solution treatment, placing the aluminum alloy ingot sample obtained in step S4 into a heat treatment furnace, keeping the temperature at 520° C. for 5 hours, and then quenching with water.

[0049] S6: Aging annealing: placing the aluminum alloy ingot sample obtained in step S5 after solid solution strengthening into a heat treatment furnace and annealing at 220° C. for 12 hours to optimize its electrical properties.

[0050] The aluminum alloy conductor prepared by the above steps has a tensile strength of 132MPa, an elongation of 10.2%, and a conductivity of 58.9% IACS. The field emission scanning electron microscope image is shown in FIG. Figure 2 shown.

[0051] Example 2

[0052] Al-1Si-0.05Mg-0.05Fe-0.025Cu-0.5Ce aluminum alloy conductor preparation:

[0053] The raw materials are prepared according to the mass percentage of each element in the Al-1Si-0.05Mg-0.05Fe-0.025Cu-0.5Ce aluminum alloy conductor: This example is used to illustrate the influence of alloy composition and solution temperature on conductor performance. The preparation steps of the conductor are as follows:

[0054] S1: Ingredients: weigh 133.40 g pure aluminum, 7.49 g Al-20Si master alloy, 0.75 g Al-10Mg master alloy, 0.75 g Al-10Fe master alloy, 0.075 g Al-50Cu master alloy, 7.50 g Al-Ce master alloy, and 1.5 g hexachloroethane.

[0055] S2: Melting: melt the prepared pure aluminum and heat it to 750°C for 10 minutes, then add Al-20Si master alloy, Al-10Mg master alloy, Al-10Fe master alloy and Al-50Cu master alloy to the melt in sequence, stir mechanically and evenly after adding the alloying agent each time, and then heat it for 5 minutes to form an alloy melt.

[0056] S3: Refining, adding hexachloroethane to the alloy melt obtained in step S2, mechanically stirring and then keeping warm for 10 minutes, and using a special slag removal tool to remove slag on the surface of the melt.

[0057] S4: Casting: pour the melt obtained in S3 into a preheated mold, and after natural cooling, obtain a cylindrical cast rod with a diameter of 22 mm and a height of 120 mm.

[0058] S5: Solution treatment: the aluminum alloy ingot sample obtained in step S4 is placed in a heat treatment furnace at 560° C. for 4 hours, and then water quenched.

[0059] S6: Aging annealing: placing the aluminum alloy ingot sample obtained in step S5 after solid solution strengthening into a heat treatment furnace and annealing at 220° C. for 12 hours to optimize its electrical properties.

[0060] The aluminum alloy conductor prepared through the above steps has a tensile strength of 120 MPa, an elongation of 13.4%, and an electrical conductivity of 58.5% IACS.

[0061] Example 3

[0062] Al-1Si-0.2Mg-0.05Fe-0.025Cu aluminum alloy conductor preparation:

[0063] The raw materials are prepared according to the mass percentage of each element in the Al-1Si-0.2Mg-0.05Fe-0.025Cu aluminum alloy conductor: This example is used to illustrate the effect of solution temperature on conductor performance. The preparation steps of the conductor are as follows:

[0064] S1: Ingredients: weigh 138.60 g pure aluminum, 7.50 g Al-20Si master alloy, 3.01 g Al-10Mg master alloy, 0.75 g Al-10Fe master alloy, 0.076 g Al-50Cu master alloy, and 1.5 g hexachloroethane.

[0065] S2: Melting: melt the prepared pure aluminum and heat it to 750°C for 10 minutes, then add Al-20Si master alloy, Al-10Mg master alloy, Al-10Fe master alloy and Al-50Cu master alloy to the melt in sequence, stir mechanically and evenly after adding the alloying agent each time, and then heat it for 5 minutes to form an alloy melt.

[0066] S3: refining, adding hexachloroethane to the alloy melt obtained in step S2, mechanically stirring and then keeping warm for 10 minutes, and using a special slag removal tool to remove slag on the surface of the melt.

[0067] S4: Casting: pour the melt obtained in S3 into a preheated mold, and after natural cooling, obtain a cylindrical cast rod with a diameter of 22 mm and a height of 120 mm.

[0068] S5: Solution treatment: the aluminum alloy ingot sample obtained in step S4 is placed in a heat treatment furnace at 480° C. for 6 hours, and then water quenched.

[0069] S6: Aging annealing: placing the aluminum alloy ingot sample after the solution treatment obtained in step S5 into a heat treatment furnace and annealing at 220° C. for 12 hours to optimize its electrical properties.

[0070] The aluminum alloy conductor prepared through the above steps has a tensile strength of 125 MPa, an elongation of 9.1%, and an electrical conductivity of 58.8% IACS.

[0071] Example 4

[0072] Al-1Si-0.2Mg-0.05Fe-0.025Cu aluminum alloy conductor preparation:

[0073] The raw materials are prepared according to the mass percentage of each element in the Al-1Si-0.2Mg-0.05Fe-0.025Cu aluminum alloy conductor: This example is used to illustrate the effect of aging temperature on conductor performance. The preparation steps of the conductor are as follows:

[0074] S1: Ingredients: weigh 138.61 g pure aluminum, 7.50 g Al-20Si master alloy, 3.00 g Al-10Mg master alloy, 0.75 g Al-10Fe master alloy, 0.075 g Al-50Cu master alloy, and 1.5 g hexachloroethane.

[0075] S2: Melting: melt the prepared pure aluminum and heat it to 750°C for 10 minutes, then add Al-20Si master alloy, Al-10Mg master alloy, Al-10Fe master alloy and Al-50Cu master alloy to the melt in sequence, stir mechanically and evenly after adding the alloying agent each time, and then heat it for 5 minutes to form an alloy melt.

[0076] S3: Refining, adding hexachloroethane to the alloy melt obtained in step S2, mechanically stirring and then keeping warm for 10 minutes, and using a special slag removal tool to remove slag on the surface of the melt.

[0077] S4: Casting: pour the melt obtained in S3 into a preheated mold, and after natural cooling, obtain a cylindrical cast rod with a diameter of 22 mm and a height of 120 mm.

[0078] S5: Solution treatment: the aluminum alloy ingot sample obtained in step S4 is placed in a heat treatment furnace at 520° C. for 5 hours, and then water quenched.

[0079] S6: Aging annealing: placing the aluminum alloy ingot sample after the solution treatment obtained in step S5 into a heat treatment furnace and annealing at 260° C. for 2 hours to optimize its electrical properties.

[0080] The aluminum alloy conductor prepared through the above steps has a tensile strength of 117 MPa, an elongation of 14.4%, and an electrical conductivity of 58.2% IACS.

[0081] Example 5

[0082] Al-1Si-0.2Mg-0.05Fe-0.3Ce aluminum alloy conductor preparation:

[0083] The raw materials are prepared according to the mass percentage of each element in the Al-1Si-0.2Mg-0.05Fe-0.3Ce aluminum alloy conductor: This example is used to illustrate the influence of alloy composition and aging temperature on conductor performance. The preparation steps of the conductor are as follows:

[0084] S1: Ingredients: weigh 134.24 g pure aluminum, 7.50 g Al-20Si master alloy, 3.00 g Al-10Mg master alloy, 0.75 g Al-10Fe master alloy, 4.50 g Al-10Ce master alloy, and 1.5 g hexachloroethane.

[0085] S2: Melting: melt the prepared pure aluminum and heat it to 750°C for 10 minutes, then add Al-20Si master alloy, Al-10Mg master alloy, Al-10Fe master alloy and Al-50Cu master alloy to the melt in sequence, stir mechanically and evenly after adding the alloying agent each time, and then heat it for 5 minutes to form an alloy melt.

[0086] S3: Refining, adding hexachloroethane to the alloy melt obtained in step S2, mechanically stirring and then keeping warm for 10 minutes, and using a special slag removal tool to remove slag on the surface of the melt.

[0087] S4: Casting: pour the melt obtained in S3 into a preheated mold, and after natural cooling, obtain a cylindrical cast rod with a diameter of 22 mm and a height of 120 mm.

[0088] S5: solution treatment, placing the aluminum alloy ingot sample obtained in step S5 into a heat treatment furnace, keeping the temperature at 520° C. for 5 hours, and then quenching with water.

[0089] S6: Aging annealing: placing the aluminum alloy ingot sample after the solution treatment obtained in step S6 into a heat treatment furnace and annealing at 180° C. for 12 hours to optimize its electrical properties.

[0090] The aluminum alloy conductor prepared through the above steps has a tensile strength of 118 MPa, an elongation of 9.2%, and an electrical conductivity of 58.1% IACS.

[0091] Example 6

[0092] Al-1Si-0.2Mg-0.05Fe-0.025Cu-0.3Ce aluminum alloy conductor preparation:

[0093] The raw materials are prepared according to the mass percentage of each element in the Al-1Si-0.2Mg-0.05Fe-0.025Cu-0.3Ce aluminum alloy conductor: This example is used to illustrate the influence of alloy composition and aging temperature on conductor performance. The preparation steps of the conductor are as follows:

[0094] S1: Ingredients: weigh 134.10 g pure aluminum, 7.49 g Al-20Si master alloy, 3.00 g Al-10Mg master alloy, 0.75 g Al-10Fe master alloy, 0.075 g Al-50Cu master alloy, 4.50 g Al-10Ce master alloy, and 1.5 g hexachloroethane.

[0095] S2: Melting: melt the prepared pure aluminum and heat it to 750°C for 10 minutes, then add Al-20Si master alloy, Al-10Mg master alloy, Al-10Fe master alloy, Al-50Cu master alloy and Al-10Ce master alloy to the melt in sequence, stir mechanically after each addition and keep the mixture warm for 5 minutes to form an alloy melt.

[0096] S3: Refining, adding hexachloroethane to the alloy melt obtained in step S2, mechanically stirring and keeping warm for 10 minutes, and then using a special slag removal tool to remove slag on the surface of the melt.

[0097] S4: Casting: pour the melt obtained in S3 into a preheated mold, and after natural cooling, obtain a cylindrical cast rod with a diameter of 22 mm and a height of 120 mm.

[0098] S5: solution treatment, placing the aluminum alloy ingot sample obtained in step S4 into a heat treatment furnace, keeping the temperature at 520° C. for 5 hours, and then quenching with water.

[0099] S6: Aging annealing: placing the aluminum alloy ingot sample after the solid solution treatment obtained in step S5 into a heat treatment furnace and annealing at 240° C. for 8 hours to optimize its electrical properties.

[0100] The aluminum alloy conductor prepared through the above steps has a tensile strength of 128 MPa, an elongation of 11.2%, and an electrical conductivity of 59.2% IACS.

[0101] Example 7

[0102] Al-1Si-0.2Mg-0.05Fe-0.025Cu-0.3Er aluminum alloy conductor preparation:

[0103] The raw materials are prepared according to the mass percentage of each element in the Al-1Si-0.2Mg-0.05Fe-0.025Cu-0.3Er aluminum alloy conductor: This example is used to illustrate the influence of alloy composition on conductor performance. The preparation steps of the conductor are as follows:

[0104] S1: Ingredients: weigh 134.10 g pure aluminum, 7.50 g Al-20Si master alloy, 3.00 g Al-10Mg master alloy, 0.75 g Al-10Fe master alloy, 0.075 g Al-50Cu master alloy, 4.50 g Al-10Er master alloy, and 1.5 g hexachloroethane.

[0105] S2: Melting: melt the prepared pure aluminum and heat it to 750°C for 10 minutes, then add Al-20Si master alloy, Al-10Mg master alloy, Al-10Fe master alloy, Al-50Cu master alloy and Al-10Er master alloy to the melt in sequence, stir mechanically after each addition and keep the mixture warm for 5 minutes to form an alloy melt.

[0106] S3: Refining, adding hexachloroethane to the alloy melt obtained in step S2, mechanically stirring and keeping warm for 10 minutes, and then using a special slag removal tool to remove slag on the surface of the melt.

[0107] S4: Casting: pour the melt obtained in S3 into a preheated mold, and after natural cooling, obtain a cylindrical cast rod with a diameter of 22 mm and a height of 120 mm.

[0108] S5: solution treatment, placing the aluminum alloy ingot sample obtained in step S4 into a heat treatment furnace, keeping the temperature at 520° C. for 5 hours, and then quenching with water.

[0109] S6: Aging annealing: placing the aluminum alloy ingot sample after the solution treatment obtained in step S5 into a heat treatment furnace and annealing at 220° C. for 12 hours to optimize its electrical properties.

[0110] The aluminum alloy conductor prepared through the above steps has a tensile strength of 131 MPa, an elongation of 12.2%, and an electrical conductivity of 59.5% IACS.

[0111] Example 8

[0112] Al-0.8Si-0.2Mg-0.05Fe-0.025Cu aluminum alloy conductor preparation:

[0113] The raw materials are prepared according to the mass percentage of each element in the Al-0.8Si-0.2Mg-0.05Fe-0.025Cu aluminum alloy conductor: This example is used to illustrate the influence of alloy composition and aging temperature on conductor performance. The preparation steps of the conductor are as follows:

[0114] S1: Ingredients: weigh 140.13 g pure aluminum, 6.02 g Al-20Si master alloy, 3.01 g Al-10Mg master alloy, 0.75 g Al-10Fe master alloy, 0.075 g Al-50Cu master alloy, and 1.5 g hexachloroethane.

[0115] S2: Melting: Melt the prepared pure aluminum and heat it to 750°C for 10 minutes, then add Al-20Si master alloy, Al-10Mg master alloy, Al-10Fe master alloy and Al-50Cu master alloy to the melt in sequence according to the composition ratio, stir mechanically after each addition and keep the mixture warm for 5 minutes to form an alloy melt.

[0116] S3: refining, adding hexachloroethane to the alloy melt obtained in step S2, mechanically stirring and then keeping warm for 10 minutes, and using a special slag removal tool to remove slag on the surface of the melt.

[0117] S4: Casting: pour the melt obtained in S3 into a preheated mold, and after natural cooling, obtain a cylindrical cast rod with a diameter of 22 mm and a height of 118 mm.

[0118] S5: solution treatment, placing the aluminum alloy ingot sample obtained in step S4 into a heat treatment furnace, keeping the temperature at 520° C. for 5 hours, and then quenching with water.

[0119] S6: Aging annealing: placing the aluminum alloy ingot sample after the solid solution treatment obtained in step S5 into a heat treatment furnace and annealing at 240° C. for 6 hours to optimize its electrical properties.

[0120] The aluminum alloy conductor prepared through the above steps has a tensile strength of 116 MPa, an elongation of 14.8%, and an electrical conductivity of 58.5% IACS.

[0121] Example 9

[0122] Al-0.5Si-0.3Mg-0.1Fe-0.1Cu aluminum alloy conductor preparation:

[0123] The raw materials are prepared according to the mass percentage of each element in the Al-0.5Si-0.3Mg-0.1Fe-0.1Cu aluminum alloy conductor: This example is used to illustrate the influence of alloy composition on conductor performance. The preparation steps of the conductor are as follows:

[0124] S1: Ingredients: weigh 140.30 g pure aluminum, 3.75 g Al-20Si master alloy, 4.50 g Al-10Mg master alloy, 1.50 g Al-10Fe master alloy, 0.30 g Al-50Cu master alloy, and 1.50 g hexachloroethane.

[0125] S2: Melting: Melt the prepared pure aluminum and heat it to 750°C for 10 minutes, then add Al-20Si master alloy, Al-10Mg master alloy, Al-10Fe master alloy and Al-50Cu master alloy to the melt in sequence according to the composition ratio, stir mechanically after each addition and keep the mixture warm for 5 minutes to form an alloy melt.

[0126] S3: Refining, adding hexachloroethane to the alloy melt obtained in step S2, mechanically stirring and then keeping warm for 10 minutes, and using a special slag removal tool to remove slag on the surface of the melt.

[0127] S4: Casting: pour the melt obtained in S3 into a preheated mold, and after natural cooling, obtain a cylindrical cast rod with a diameter of 22 mm and a height of 115 mm.

[0128] S5: Solution treatment: the aluminum alloy ingot sample obtained in step S4 is placed in a heat treatment furnace at 520° C. for 5 hours, and then water quenched.

[0129] S6: Aging annealing: placing the aluminum alloy ingot sample after the solution treatment obtained in step S5 into a heat treatment furnace and annealing at 220° C. for 12 hours to optimize its electrical properties.

[0130] The aluminum alloy conductor prepared through the above steps has a tensile strength of 89 MPa, an elongation of 18.0%, and an electrical conductivity of 58.7% IACS.

[0131] Example 10

[0132] Al-0.2Si-0.2Mg-0.15Fe-0.05Cu aluminum alloy conductor preparation:

[0133] The raw materials are prepared according to the mass percentage of each element in the Al-0.2Si-0.2Mg-0.15Fe-0.05Cu aluminum alloy conductor: This example is used to illustrate the influence of alloy composition on conductor performance. The preparation steps of the conductor are as follows:

[0134] S1: Ingredients: weigh 143.10 g pure aluminum, 1.50 g Al-20Si master alloy, 3.00 g Al-10Mg master alloy, 2.25 g Al-10Fe master alloy, 0.15 g Al-50Cu master alloy, and 1.5 g hexachloroethane.

[0135] S2: Melting: Melt the prepared pure aluminum and heat it to 750°C for 10 minutes, then add Al-20Si master alloy, Al-10Mg master alloy, Al-10Fe master alloy and Al-50Cu master alloy to the melt in sequence according to the composition ratio, stir mechanically after each addition and keep the mixture warm for 5 minutes to form an alloy melt.

[0136] S3: Refining, adding hexachloroethane to the alloy melt obtained in step S2, mechanically stirring and then keeping warm for 10 minutes, and using a special slag removal tool to remove slag on the surface of the melt.

[0137] S4: Casting: pour the melt obtained in S3 into a preheated mold, and after natural cooling, obtain a cylindrical cast rod with a diameter of 22 mm and a height of 115 mm.

[0138] S5: Solution treatment: the aluminum alloy ingot sample obtained in step S4 is placed in a heat treatment furnace at 520° C. for 5 hours, and then water quenched.

[0139] S6: Aging annealing: placing the aluminum alloy ingot sample after the solution treatment obtained in step S5 into a heat treatment furnace and annealing at 220° C. for 12 hours to optimize its electrical properties.

[0140] The aluminum alloy conductor prepared through the above steps has a tensile strength of 81 MPa, an elongation of 17.8%, and an electrical conductivity of 59.8% IACS.

[0141] Comparative Example 1

[0142] Al-1Si-0.2Mg-0.05Fe-0.025Cu aluminum alloy conductor preparation:

[0143] This comparative example is intended to examine the effect of melting temperature on alloy properties. Under the same alloy formulation as in Example 3, the melting temperature is 850° C. Compared with Example 3, except for the melting temperature in step S2, the other preparation process conditions are exactly the same.

[0144] The aluminum alloy conductor prepared through the above steps has a tensile strength of 98 MPa, an elongation of 7.8%, and an electrical conductivity of 56.5% IACS.

[0145] Comparative Example 2

[0146] Al-0.5Si-0.3Mg-0.1Fe-0.1Cu aluminum alloy conductor preparation:

[0147] This comparative example is intended to examine the effect of aging annealing temperature on alloy properties. Under the same alloy formulation as in Example 9, the aging annealing temperature is 160°C. Compared with Example 9, except for the aging annealing temperature in step S7, the other preparation process conditions are exactly the same.

[0148] The aluminum alloy conductor prepared through the above steps has a tensile strength of 93 MPa, an elongation of 10.0%, and an electrical conductivity of 55.6% IACS.

[0149] Comparative Example 3

[0150] Al-0.2Si-0.8Mg-0.05Fe-0.025Cu aluminum alloy conductor preparation:

[0151] This comparative example is intended to examine the influence of the relative content of Mg and Si elements on the mechanical properties and electrical properties of aluminum alloy conductors. Under the same conditions as in Example 8, the Mg content is 0.8wt% and the Si content is 0.2wt%. Compared with Example 8, except for the different Mg and Si content in step S1, the other preparation process conditions are exactly the same.

[0152] S1: Ingredients: weigh 134.82 g pure aluminum, 1.50 g Al-20Si master alloy, 12 g Al-10Mg master alloy, 0.75 g Al-10Fe master alloy, 0.075 g Al-50Cu master alloy, and 1.5 g hexachloroethane.

[0153] The aluminum alloy conductor prepared through the above steps has a tensile strength of 139 MPa, an elongation of 4.5%, and an electrical conductivity of 53.2% IACS.

[0154] Comparative Example 4

[0155] Al-0.2Si-0.2Mg-0.15Fe-0.05Cu aluminum alloy conductor preparation:

[0156] This comparative example is intended to examine the effect of refining agents on alloy properties. Under the same alloy formulation as in Example 10, no refining agent is added. Compared with Example 10, except for eliminating the refining step S3, the other preparation process conditions are exactly the same.

[0157] The aluminum alloy conductor prepared through the above steps has a tensile strength of 69 MPa, an elongation of 10.0%, and an electrical conductivity of 55.6% IACS.

[0158] Comparative Example 5

[0159] Al-0.2Si-0.2Mg-0.15Fe-0.05Cu aluminum alloy conductor preparation:

[0160] This comparative example is intended to examine the effect of solution temperature on alloy properties. Under the same alloy formulation as in Example 10, the solution treatment temperature is 400° C. Compared with Example 10, except for the different temperature in step S5 solution treatment, the other preparation process conditions are exactly the same.

[0161] The aluminum alloy conductor prepared through the above steps has a tensile strength of 72 MPa, an elongation of 12.1%, and an electrical conductivity of 56.1% IACS.

[0162] The data of the embodiments and comparative examples are summarized in Table 1:

[0163] Table 1 Example and Comparative Example Preparation Ingredients (g)

[0164]

[0165]

[0166] In Table 1, “-” represents that the master alloy is not doped.

[0167] For the convenience of comparison, the main mechanical properties and conductivity indicators obtained in the above embodiments and comparative examples are listed in Table 2, as follows:

[0168] Table 2 Performance test data of high conductivity aluminum alloy conductor at room temperature (20℃)

[0169]

[0170]

[0171] like Figure 2 As shown in the figure, it can be seen that a uniformly distributed nano-scale dispersed phase is formed in the aluminum alloy conductor matrix, thereby achieving a simultaneous improvement in tensile strength and electrical conductivity. Figure 3 and Figure 4As shown, the room temperature ultimate tensile strength of the high-conductivity aluminum alloy conductors in Examples 1 to 10 is ≥80MPa, and the conductivity is ≥58.0%IACS. The aluminum alloy conductors in this composition range have great potential in high-precision fields such as wires and cables, and electrical equipment. Comparative Example 1 may have a low room temperature ultimate tensile strength of the wire due to overburning; Comparative Example 2 has a low aging annealing temperature and high alloy solid solubility, which makes the tensile strength too high and the conductivity low; and Comparative Example 3 has a high tensile strength and low conductivity due to the high Mg content; Comparative Example 4 has a large number of solid phase inclusions in the alloy due to the cancellation of refining and slag removal, resulting in low tensile strength and conductivity; Comparative Example 5 has a low solution treatment temperature, the alloy cast second phase is coarse, and the dissolution is not complete, resulting in low tensile strength and conductivity. In short, the tensile strength and conductivity of the alloy conductor materials prepared in all embodiments have good data, and are aluminum alloy conductor materials with great potential.

[0172] Comprehensive analysis shows that the Al-xSi-yMg-zFe-mCu-nRE high-conductivity aluminum alloy conductor prepared by the present invention, within the scope of the rights protection, is a new practical high-conductivity aluminum alloy conductor material with better electrical properties than 6xxx series aluminum alloys and better mechanical properties than 1xxx series aluminum alloys, and has great potential in high-precision fields such as wires and cables, and electrical equipment.

[0173] In summary, the present invention discloses an Al-Si-Mg-based aluminum alloy conductor and a preparation method thereof, which belongs to the field of metal material processing and manufacturing. The conductor is a "silicon-rich and low-magnesium" aluminum alloy, and its composition is Al-xSi-yMg-zFe-mCu-nRE, wherein 0.2≤x≤1.2, 0.05≤y≤0.3, 0.05≤z≤0.15, m≤0.1, n≤0.5, x≥y. The preparation method adopts a "melting-refining-casting-solid solution-aging" process method that matches the new alloy formula, and obtains a higher aluminum alloy conductor casting embryo mechanical strength (≥80MPa) while obtaining a higher conductivity (≥58% IACS). The method has a short process flow, is easy to operate, has a low preparation cost, and is easy to industrialize. The prepared alloy material is an aluminum alloy conductor with great application potential; it has an excellent application and promotion prospect.

[0174] At this point, those skilled in the art recognize that, although the embodiments of the present invention have been shown and described in detail herein, many other variations or modifications that conform to the principles of the present invention can still be directly determined or derived based on the contents disclosed in the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and recognized as covering all such other variations or modifications.

Claims

1. An Al-Si-Mg based aluminum alloy conductor, characterized in that: The aluminum alloy conductor is an Al-Si-Mg based aluminum alloy, and its nominal composition is Al-xSi-yMg-zFe-mCu-n rare earth RE, wherein coefficients x, y, z, m, and n are respectively the mass percentages of Si, Mg, Fe, Cu, and rare earth RE in the alloy, 0.2≤x≤1.2, 0.05≤y≤0.3, 0.05≤z≤0.15, m≤0.1, n≤0.5, and x≥y.

2. The method for preparing an Al-Si-Mg based aluminum alloy conductor as claimed in claim 1, characterized in that: The preparation method is a "melting-refining-casting-solid solution-aging" processing method that is compatible with the "silicon-rich and low-magnesium" formula; The specific steps include: Step S1: Weighing Pure Al is weighed as aluminum alloy parent material, Si, Mg, Fe, Cu, rare earth RE single substance or its aluminum-based master alloy is weighed as alloying agent, and hexachloroethane is weighed as refining agent according to mass ratio; Step S2: Melting The pure Al in step S1 is heated to 730-770°C in a reaction vessel to melt the aluminum completely, and then kept warm for 10 minutes. Then, alloying agents of Si, Mg, Fe, Cu, and rare earth RE are added in sequence. Each time an alloying agent is added, it is stirred for 5 minutes and allowed to stand for 5 minutes. Step S3: Refining The hexachloroethane in step S1 is placed in a reaction vessel, stirred for 5 minutes, allowed to stand for 5 minutes, then slag is removed, and the mixture is kept at 730-770°C for 10 minutes before casting; Step S4: Casting The melt obtained in step S3 is poured into a mold preheated to 200-400° C., and naturally cooled to room temperature in air to form an aluminum alloy casting embryo; Step S5: Solid solution strengthening treatment The aluminum alloy ingot after heat treatment obtained in step S4 is placed in a heat treatment furnace and kept at 480-560° C. for 4-6 hours, and then the sample is quickly taken out for water quenching to obtain the aluminum alloy ingot after solid solution treatment; Step S6: Aging annealing treatment The aluminum alloy ingot obtained in step S5 after solid solution is placed in a heat treatment furnace, and after being kept at a temperature of 180-260° C. for 2-24 hours, the sample is cooled to room temperature along with the furnace to obtain an Al-Si-Mg based aluminum alloy conductor.

3. A method for preparing an Al-Si-Mg based aluminum alloy conductor as claimed in claim 2, characterized in that: The rare earth RE is Ce or Er; the pure Al in step S2 is solid metal or aluminum liquid; when the pure Al is aluminum liquid, it does not need to be melted, but still needs to be heated and kept warm.

4. A method for preparing an Al-Si-Mg based aluminum alloy conductor as claimed in claim 3, characterized in that: The pure Al grade is industrial pure aluminum or above; when the pure Al is solid metal, it is aluminum ingot, aluminum particles or powder.

5. The method for preparing an Al-Si-Mg based aluminum alloy conductor as claimed in claim 2, characterized in that: The aluminum-based master alloy in step S1 is any composition of Al-Si, Al-Mg, Al-Fe, Al-Cu, Al-rare earth RE or any composition of aluminum-based ternary alloy.

6. A method for preparing an Al-Si-Mg based aluminum alloy conductor as claimed in claim 5, characterized in that: The aluminum-based master alloy is in the form of blocks, particles or powder.

7. A method for preparing an Al-Si-Mg based aluminum alloy conductor as claimed in claim 2, characterized in that: The amount of hexachloroethane added in step S1 is 0.4-1.2 wt % of the total mass of the alloy.

8. The method for preparing an Al-Si-Mg based aluminum alloy conductor as claimed in claim 2, characterized in that: The reaction container in step S2 is graphite, silicon carbide, other high temperature resistant and oxidation resistant metals or a ceramic crucible.

9. A method for preparing an Al-Si-Mg based aluminum alloy conductor as claimed in claim 2, characterized in that: The mold in step S4 is a high-strength graphite, ceramic or steel mold.

10. The method for preparing an Al-Si-Mg based aluminum alloy conductor as claimed in claim 2, characterized in that: The Al-Si-Mg based aluminum alloy conductor simultaneously satisfies room temperature electrical conductivity ≥58% IACS and tensile strength ≥80 MPa.

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