CN114606414B

CN114606414B - High-conductivity regenerated aluminum alloy conductor and preparation method thereof

Info

Publication number: CN114606414B
Application number: CN202210243019.3A
Authority: CN
Inventors: 王俊升; 李全; 王兵; 刘鑫秀; 关绍康; 赵红亮
Original assignee: Zhengzhou University; Beijing Institute of Technology BIT
Current assignee: Zhengzhou University; Beijing Institute of Technology BIT
Priority date: 2022-03-11
Filing date: 2022-03-11
Publication date: 2022-12-02
Anticipated expiration: 2042-03-11
Also published as: CN114606414A

Abstract

The invention provides a high-conductivity regenerated aluminum alloy conductor and a preparation method thereof, belonging to the technical field of aluminum alloy conductors; the paint consists of the following chemical components: the alloy comprises, by mass, 0.10-0.20% of Si, 0.40-0.70% of Fe, 0-0.20% of Cu, 0-0.30% of Mn, 0-0.10% of Mg, 0-0.30% of Cr, 0.01-0.10% of Zn, 0.02-0.10% of Ti, and the balance of Al and inevitable impurities, wherein the total amount of the inevitable impurities is less than 0.05%. The method comprises the following steps: melting the aluminum block, adding the intermediate alloy to meet the component requirement, refining and preserving heat; casting the smelted alloy liquid to obtain a secondary aluminum alloy cast ingot; homogenizing, hot rolling, solution treatment, cold rolling and aging treatment are carried out on the cast ingot. The regenerated aluminum alloy wire has high conductivity and higher strength, and the line loss is obviously reduced.

Description

High-conductivity regenerated aluminum alloy conductor and preparation method thereof

Technical Field

The invention relates to the technical field of aluminum alloy wires, in particular to a high-conductivity regenerated aluminum alloy wire and a preparation method thereof.

Background

Along with the progress of China's society and economy, the demand and the use amount of aluminum and aluminum alloy are increased year by year, the electrolytic aluminum yield of China reaches the first world, and along with the continuous exploitation of aluminum resources, the residual aluminum resources of China are not abundant enough. With the rapid increase of the production and consumption, the available aluminum scrap resources in China are gradually increased, and the application potential of the aluminum scrap is continuously shown. From industrial waste, e.g. discarded drinks cansThe recycled and produced recycled aluminum alloy such as waste electric wires and 3C electronic products has the advantages of energy conservation, environmental protection and low cost. From the aluminum smelting point of view, the electricity consumption for producing one ton of electrolytic aluminum is 12000-13000 kW/h; the production of the secondary aluminum alloy by using the waste aluminum only needs to be carried out by remelting, thereby avoiding the high energy consumption in the smelting and extracting process, the production energy consumption is only 5 percent of that of electrolytic aluminum, and simultaneously, CO is discharged ₂ Etc. are less contaminated. Therefore, in the production process of the aluminum alloy, partial aluminum scrap is adopted to replace an electrolytic aluminum ingot, even all aluminum scrap is used for remelting for producing secondary aluminum, so that the production cost of an enterprise can be greatly reduced, the alloy with the best standard specification can be obtained at the lowest cost, and the method has wide economic and social application values.

Aluminum and its alloys are considered as one of the most important engineering materials due to their characteristics of good electrical conductivity, low density, high strength, good plasticity, corrosion resistance, etc., and are widely used as main materials of industrial overhead power lines, and the usage amount thereof is steadily increasing in recent years. At present, steel-cored aluminum stranded wires are commonly used for high-voltage, ultrahigh-voltage and extra-high-voltage overhead transmission lines in China, the production and application technology of the wire is basically mature, but the transmission line loss is high, the corrosion resistance is poor, and the current-carrying capacity is low. Compared with the conventional aluminum conductor reinforced by steel (ACSR), the adoption of the all-aluminum alloy conductor (AAAC) on the transmission line has the following advantages: the line has the characteristics of small loss, large draw-weight ratio, good sag characteristic, scratch resistance of the surface, simple and convenient construction, good corrosion resistance, long service life of the line, particularly in coastal areas or heavy industrial polluted areas and the like.

Therefore, the reasonable application of the regenerated aluminum alloy is realized, and the regenerated aluminum alloy has wide industrial application prospect when being used for the environment-friendly production of the power transmission line. The method is specifically implemented by recycling waste aluminum impurities for manufacturing the regenerated all-aluminum alloy conductor (AAAC) for the transmission line, and can effectively improve the mechanical property and the conductivity of the regenerated aluminum alloy conductor by matching with a proper processing technology and a proper heat treatment method, so that the service performance of the regenerated aluminum alloy conductor serving as the overhead transmission conductor is met. Therefore, the recycling of scrap aluminum and the manufacturing and production of the recycled aluminum alloy wire are one flight in the application and development history of aluminum alloy.

Alwan et al (Alwan H A, al-Jubouri H A H, saffar N L A. Use of water for the manufacturing of Electric Power Transmission wire [ J ]. Int J Eng Technol,2013,3: 906-913.) studied the mechanical properties and conductivity of recycled aluminum alloy wire manufactured using scrap aluminum. The smelted and cast scrap aluminum is composed of 50% of waste beverage cans and 50% of waste aluminum alloy wires, and comprises the following chemical components in percentage by mass: 0.195% of Si, 0.418% of Fe, 0.122% of Cu, 0.588% of Mn, 1.12% of Mg, 0.016% of Cr, 0.004% of Ni, 0.050% of Zn, 0.013% of Ti, 0.002% of B, 0.008% of V, 0.001% of Zr and the balance of Al. And carrying out the following heat treatments on the cast secondary aluminum alloy cast ingot: 1) Homogenization treatment: homogenizing at 500 deg.C for 10 hr; 2) Solution treatment: solution treatment is carried out for 1 hour at 500 ℃; 3) Aging treatment: isothermal artificial aging treatment is carried out at 175 ℃ for different time (1-5-10-20-30-50 hours), and then mechanical property, hardness and conductivity tests and microstructure observation are carried out on the sample. The results show that: the hardness and the conductivity of the sample are highest when the aging time is 20 hours, 85.6HV and 40.4% IACS, respectively. The tensile strength, yield strength and elongation of the sample under these conditions were 285MPa, 141MPa and 14%, respectively.

The effects of artificial aging and cold rolling on the electrical and tensile properties of graphene reinforced Recycled aluminum alloy wire were studied by Chyada et al (Chyada F A, jabur AR, alwan H A. Effect addition of graphene on electrical conductivity and tensile strain for Recycled electrical power transmission wires [ J ]. Energy Process, 2017, 119.. The base alloy (aluminum alloy waste wire) comprises the following chemical components in percentage by mass: 0.107% of Si, 0.423% of Fe, 0.010% of Cu, 0.005% of Mn, 0.001% of Mg, 0.003% of Cr, 0.001% of Ni, 0.008% of Zn, 0.002% of Ti, 0.0009% of Pb, 0.001% of V and the balance of Al. 0.5% of graphene nano powder is added into the molten aluminum wire (waste wire), and a graphene reinforced base alloy (aluminum wire) bar is cast. And then, carrying out solid solution for 45min at 490 ℃, then carrying out water quenching and 90% cold rolling, and finally carrying out artificial aging (1, 2, 4, 6, 8 and 10 hours) at 200 ℃ to prepare the graphene reinforced regenerated aluminum alloy wire. The result shows that the addition of the graphene improves the conductivity and the tensile strength of the wire, and the wire yield and the tensile strength of the Al-0.5% graphene reinforced regenerated aluminum alloy wire are highest under the aging condition of 1h at 200 ℃, and are respectively 36.8% IACS and 180MPa.

Krolo et al (Krolo J, lela B, vagelj Z, et al, adaptive nerve-fusing and regression models for predicting micro-and electric conductivity of solid-state recycled EN AW 6082J. The International Journal of Advanced Manufacturing Technology,2019,100 (9): 2981-2993.) compared The ability of Adaptive Neural Fuzzy Interference System (ANFIS) and regression models to predict The micro-hardness and electric conductivity of solid-state recycled EN AW6082 alloy based on no-reflow recycling of aluminum, so-called Solid State Recycling (SSR) or direct recycling. The regenerated EN AW6082 alloy comprises the following chemical components in percentage by mass: (Si 0.7-1.3%, fe 0-0.5%, cu 0-0.1%, mn 0.1-0.4%, mg 0.6-1.2%, zn 0-0.2%, ti 0-0.1%, cr 0-0.25%, others 0-0.15%, and the rest of Al). The effect of Direct Extrusion (DE) temperature, ECAP temperature, number of passes of material through ECAP on microhardness and electrical conductivity of the recovered samples was studied with emphasis. The change ranges of DE temperature, ECAP temperature and ECAP channel frequency are 400-500 ℃, 20-300 ℃ and 1-4 respectively. The results show that: the average microhardness of the ECAP-treated SSR samples was 72HV and 63.5HV, respectively, and the average conductivity was 45.9% IACS and 47.4% IACS, respectively, at 160 ℃ and 300 ℃.

Kim et al (Kim J Y, kim S J, song I K, et al. Aging characteristics of recycled ACSR wires for distribution lines [ C]Procedures electric Insulation Conference and electric Manufacturing and Coil Winding Conference. IEEE,1997: 585-588) investigated the aging characteristics of ACSR recycled conductors for distribution lines, comparing regenerated and new ACSR160mm ² Mechanical, electrical and oxidation properties of the wire after 7.5 years of service life. The results show that: the structure of the regenerated aluminum is close to that of the new aluminum, and in the long-time service process, the volume resistivity, the conductivity and the tensile strength of the regenerated aluminum alloy conductor and the new conductor are similar to each other in the change characteristics and the aging characteristics, and no special difference exists, so that the stability of the regenerated aluminum alloy conductor in the service process is shown.

In the case of aluminum alloys, the electrical conductivity is closely related to the chemical composition, impurity content, crystalline state of aluminum, processing technique, and the like. The high-strength all-aluminum alloy wire has low conductivity and large line loss due to more added alloy elements; the medium-strength all-aluminum alloy wire has lower strength than the high-strength all-aluminum alloy wire due to the reduction of the addition of alloy elements, but the conductivity is obviously improved, and the strength is within an acceptable proper range. However, the regenerated aluminum alloy conductor prepared by the method has low conductivity and few varieties, and cannot meet the requirement of practical use, so that the large-scale use of the conductor in a power transmission line is limited, and the development of a regenerated aluminum alloy conductor with high conductivity and medium strength and a preparation method thereof are still needed.

Disclosure of Invention

The invention aims to solve the technical problem of providing a high-conductivity regenerated aluminum alloy conductor and a preparation method thereof, and solves the problems that the existing reported regenerated aluminum alloy conductor is low in conductivity and few in variety and cannot meet the actual power transmission requirement.

In order to solve the technical problems, the invention provides the following technical scheme:

a high-conductivity regenerated aluminum alloy wire comprises the following chemical components: according to the mass percentage, 0.10-0.20% of Si, 0.40-0.70% of Fe, 0-0.20% of Cu, 0-0.30% of Mn, 0-0.10% of Mg, 0-0.30% of Cr, 0.01-0.10% of Zn, 0.02-0.10% of Ti, and the balance of Al and inevitable impurities, wherein the total amount of the inevitable impurities is less than 0.05%.

Wherein, preferably, the Cr content in the composition is 0.

Wherein, preferably, the content of at least one element of Cu, mn and Mg in the composition is 0.

Wherein, preferably, the chemical composition comprises the following chemical components: 0.10 to 0.15 percent of Si, 0.60 to 0.70 percent of Fe, 0 to 0.2 percent of Cu, 0 to 0.30 percent of Mn, 0 to 0.05 percent of Mg, 0 to 0.30 percent of Cr, 0.01 to 0.05 percent of Zn, 0.02 to 0.05 percent of Ti, and the balance of Al and inevitable impurities, wherein the total amount of the inevitable impurities is less than 0.05 percent.

The invention also provides a preparation method of the high-conductivity regenerated aluminum alloy conductor, which comprises the following steps:

s1, proportioning raw materials according to required raw materials, wherein the raw materials comprise secondary aluminum and intermediate alloy of other required elements;

s2, smelting the regenerated aluminum, introducing the intermediate alloy except the aluminum-titanium-boron intermediate alloy and the optional aluminum-magnesium intermediate alloy, and stirring and melting to obtain an alloy liquid;

s3, refining the alloy liquid, removing gas and slag, adding an aluminum-titanium-boron intermediate alloy and an optional aluminum-magnesium intermediate alloy, preserving heat for 20-40min after all the intermediate alloys are completely melted, and then casting and optionally cooling to obtain a regenerated aluminum alloy cast ingot;

s4, homogenizing the secondary aluminum alloy cast ingot at 490-530 ℃;

s5, carrying out hot rolling on the homogenized regenerated aluminum alloy cast ingot, wherein the rolling temperature is 520-530 ℃, and the rolling temperature is 140-160 ℃ to obtain a regenerated aluminum alloy plate;

s6, performing double-stage solution treatment on the regenerated aluminum alloy plate at 490-530 ℃, and then performing water quenching;

and S7, cold rolling the water-quenched plate, and then performing aging treatment to obtain the regenerated aluminum alloy wire.

Wherein, preferably, the preparation method further comprises: in S1, preheating raw materials and required equipment at 150-250 ℃ for 0.5-1h.

Wherein, preferably, in S3, the casting conditions include: the temperature is 730-740 ℃, and the casting speed is 80-100 mm/min.

Preferably, in S4, the homogenizing process includes: the temperature is firstly preserved for 3 to 5 hours at 490 to 500 ℃, and then preserved for 5 to 7 hours at 520 to 530 ℃.

Wherein, preferably, the hot rolling in S5 leads the rolling deformation to be 20-40%; and/or the rolling speed of hot rolling is 1-1.5m/s.

Preferably, in S6, the double-stage solution treatment process includes: the temperature is kept at 490-500 ℃ for 1-3h, and then at 520-530 ℃ for 4-6h.

Among them, in S7, the cold rolling is preferably performed so that the cold rolling deformation is 20 to 40%, and is preferably the same as the hot rolling deformation.

Wherein, preferably, the aging treatment conditions comprise: treating at 170-180 deg.C for 2-32h, preferably 4-8h.

The inventor of the invention researches and discovers that the section size of the engineering lead is usually larger, and in order to ensure that the aluminum conductor has higher conductivity and high strength during engineering construction, micro-alloying is often adopted to improve the strength and the elongation of the aluminum conductor. The waste mixed aluminum contains more trace elements after remelting and regeneration, and the alloy components of the waste mixed aluminum are mainly adjusted by adding pure aluminum and various aluminum intermediate alloys into aluminum melt in the current industrial production of the regenerated aluminum. The common micro-alloy elements in the regenerated aluminum alloy comprise Cu, mg, si, mn, cr, zn and the like, and the solid solubility of the alloy elements in the aluminum alloy is large along with the temperature change, so that the alloy elements are separated out from a saturated solid solution to form various strengthening phases to play a role in precipitation strengthening. Meanwhile, various elements contained in the aluminum alloy reduce the conductivity of the aluminum alloy, and in order to improve the conductivity of the regenerated aluminum alloy, the content of the elements (including alloying elements and impurity elements) contained in the aluminum alloy needs to be reduced, and the reduction of the content of the alloying elements causes the reduction of the performance of the aluminum alloy, thereby affecting the power transmission efficiency of the lead. Therefore, when alloying elements are added into the aluminum alloy, the conductive capability of the aluminum alloy wire is not obviously affected, and the formation of finer and more dispersed particles in the aluminum alloy is promoted, so that the necessary mechanical property is ensured. At present, the aluminum alloy wire is mainly produced based on 6XXX series Al-Mg-Si alloy, the inventor designs the main components of the regenerated aluminum alloy wire by carrying out statistical research and research on the components of various regenerated aluminum alloys and considering the contents of main impurity elements Fe and Cu enriched in the recovery of the regenerated aluminum alloy and the conductivity of the regenerated aluminum alloy wire, and provides the invention based on the main components.

The technical scheme of the invention has the following beneficial effects:

based on the technical scheme, the invention provides the regenerated aluminum alloy wire and the preparation method thereof, and the prepared regenerated aluminum alloy wire has higher conductivity and medium strength. Secondly, the preparation method of the regenerated aluminum alloy conductor is simple, low in cost and energy-saving, the regenerated aluminum alloy conductor with higher conductivity and strength matching can be obtained without special equipment, the conductivity of the regenerated aluminum alloy conductor is superior to that of the currently reported regenerated aluminum alloy conductor, the practicability is high, the popularization is easy, the price is low, the energy is saved, and the application requirement can be met. The beneficial effects are divided into the following three aspects:

1. the prepared regenerated aluminum alloy wire has high conductivity and moderate strength, and can reduce the line loss

The regenerated aluminum alloy lead wire has higher conductivity and moderate strength, can effectively increase the power transmission capacity of the lead wire, obviously reduces the line loss, and is beneficial to energy conservation and emission reduction. As shown in Table 1, the overall performance of each of the recycled aluminum alloy wires is shown to be that the electrical conductivity of the recycled aluminum alloy wire of the present invention is 37.64-59.20% IACS, which is better than the reported electrical conductivity of the recycled aluminum alloy wire of 36.8-47.4% IACS. And the high conductivity can improve the power transmission efficiency and reduce the line loss. Meanwhile, the hardness of the wire is 41.60-52.25 HV, the tensile strength is 130 MPa-230 MPa, and the wire has medium strength.

2. Reasonably regulating and controlling alloy components, and further expanding the application range of the regenerated aluminum alloy wire

In consideration of the characteristic that Fe and Cu elements are continuously enriched in the actual recycling production link, the content of Fe and Cu is particularly increased to be consistent with the actual recycling production link of the secondary aluminum and to be cooperated with other alloy elements, so that the secondary aluminum alloy wire with higher conductivity and strength can be obtained by adopting a simple preparation method under the condition of adding a small amount of alloy elements, the conductivity of the secondary aluminum alloy wire is superior to that of the reported secondary aluminum alloy wire, the secondary aluminum alloy wire is strong in practicability, easy to popularize, low in price and energy-saving, and the application requirement can be met.

3. The preparation process of the regenerated aluminum alloy conductor is simple, efficient and low in cost

The preparation process of the wire is simplified, and the regenerated aluminum alloy wire with higher conductivity and medium strength can be obtained only by one-time hot rolling and one-time cold rolling and combining a proper heat treatment process.

Therefore, the regenerated aluminum alloy conductor has the characteristics of high efficiency and low cost, can be further applied to meet the preparation and use requirements of the regenerated aluminum alloy conductor for the overhead transmission line, and has practical industrial guidance significance and potential economic and commercial values.

Detailed Description

With the rapid development of national economy and the continuous improvement of the living standard of people, the demand on electric power is rapidly increased, and the power transmission line is gradually developed towards a large capacity direction, so that the transmission capacity of the lead is required to be increased. The aluminum alloy conductor can meet the use requirements as a special conductor with good performance. In the process of power transmission, the conductivity of the aluminum alloy conductor material has a great determining effect on the use of the manufactured conductor. Therefore, in order to further satisfy the requirement of the transmission line on the transmission capacity, the conductivity of the aluminum alloy conductor needs to be improved, so that the transmission loss is reduced, and the transmission efficiency is improved.

In contrast, the invention provides a high-conductivity regenerated aluminum alloy conductor which comprises the following chemical components: according to the mass percentage, 0.10-0.20% of Si, 0.40-0.70% of Fe, 0-0.20% of Cu, 0-0.30% of Mn, 0-0.10% of Mg, 0-0.30% of Cr, 0.01-0.10% of Zn, 0.02-0.10% of Ti, and the balance of Al and inevitable impurities, wherein the total amount of the inevitable impurities is less than 0.05%.

In the above-mentioned embodiment of the present invention, the regenerated aluminum alloy component is subjected to the batch melting using a large amount of Fe and Cu as the main impurity elements, and omitting the inevitable amounts of Ni, B, V and Pb as the trace impurity elements (the sum of the total amounts is less than 0.014%, which is negligible). Mainly considering that the continuous enrichment of Fe and Cu elements in the aluminum alloy recovery process can increase the casting hot cracking tendency in the remelting process and reduce the performance. Meanwhile, fe is a main impurity element in the regenerated aluminum alloy, and the increase of Fe can generate a series of adverse effects on the mechanical property, the conductivity and the like of the alloy. Therefore, in consideration of the characteristic that Fe and Cu elements are continuously enriched in the actual recovery production link, the contents of main impurities Fe and Cu elements in the embodiment of the invention are respectively improved by about 40% and 50% compared with the reported components of the secondary aluminum alloy wire. So as to conform to the actual recycling production link of the secondary aluminum and further expand the components and application range of the secondary aluminum alloy wire. Meanwhile, no technology for effectively removing and purifying impurity Fe exists at present, and controlling the Fe content and the Fe-rich phase morphology is very key to the performance improvement and quality improvement of the secondary aluminum. The invention fully utilizes the Fe and Cu with high content, does not need to remove and purify the impurity elements, and can obtain the regenerated aluminum alloy wire with higher conductivity and strength matching by cooperating with other alloy elements with proper amount, the conductivity of the regenerated aluminum alloy wire is superior to that of the currently reported regenerated aluminum alloy wire, the practicability is strong, and the popularization is easy.

Meanwhile, the alloy element components added in the aluminum alloy wire are generally not more than 2%, otherwise, the conductivity can be greatly influenced. The regenerated aluminum alloy achieves the effects of improving the conductivity and having the strength by adding the minimum alloy elements. The total addition amount of alloy elements in the regenerated aluminum alloy wire is preferably controlled within 1.4 percent, the addition amount of the alloy elements in the regenerated aluminum alloy wire reported in the prior art is within 3 percent, the addition of micro alloy elements is greatly reduced, and meanwhile, the performance requirements of the conductivity and the strength of the regenerated aluminum alloy wire are met by adjusting the addition amounts of different micro alloy elements through optimized combination, so that the components of the high-conductivity medium-strength regenerated aluminum alloy wire under the appropriate addition amount are obtained, and a theoretical basis is provided for further expanding the production application range of the regenerated aluminum alloy wire. Wherein, the added synergistic effect of part of microalloy elements is as follows:

mn and Cr elements: mn and Cr elements can modify the Fe-rich phase, and part of Fe atoms in the Fe-rich phase are replaced, so that the appearance of the Fe-rich phase can be effectively improved. For example: mn element enters into the Fe-rich phase to generate Al ₁₅ (Fe Mn) ₃ Si ₂ So as to refine the Fe-rich phase and improve the mechanical property of the alloy.

Mg element is 6061 regenerated aluminium alloyOne of the important strengthening elements in gold, mg and Si, forms Mg mainly in Al-Mg-Si alloys ₂ The Si strengthening phase and the Mg element can not only strengthen the alloy, but also improve the corrosion resistance.

The Mn element can neutralize redundant Fe in the regenerated aluminum alloy, and the melt quality is improved.

Cu is one of important strengthening elements of 6061 regenerated aluminum alloy, and Cu and Al can form Al ₂ The Cu phase is an important age-hardening phase, and the Cu element can improve the heat resistance of the alloy.

Zn is also an aging strengthening element, has larger solid solubility in aluminum and can play a role in solid solution strengthening, and the solid solubility is larger along with the temperature change, is separated out from a saturated solid solution and plays a role in precipitation strengthening.

Wherein, preferably, the Cr content in the composition is 0. Under the preferred scheme, the addition of Cr element is lacked, the addition amount of alloy elements is reduced, and the conductivity of the lead is improved.

Wherein, preferably, the content of at least one element of Cu, mn and Mg in the composition is 0. Under the preferred scheme, the optimal comprehensive proportion of the conductivity and the strength is more favorably obtained, and on the basis, the comprehensive performance of the strength and the conductivity is met, and meanwhile, the addition amount of alloy elements is reduced.

In some embodiments, consists of the following chemical components: 0.10 to 0.15 percent of Si, 0.60 to 0.70 percent of Fe, 0 to 0.2 percent of Cu, 0 to 0.30 percent of Mn, 0 to 0.05 percent of Mg, 0 to 0.30 percent of Cr, 0.01 to 0.05 percent of Zn, 0.02 to 0.05 percent of Ti, and the balance of Al and inevitable impurities, wherein the total amount of the inevitable impurities is less than 0.05 percent.

Wherein, preferably, the chemical composition comprises the following chemical components: 0.10% of Si, 0.70% of Fe, 0-0.2% of Cu, 0-0.30% of Mn, 0-0.05% of Mg, 0-0.30% of Cr, 0.05% of Zn, 0.02% of Ti, and the balance of Al and inevitable impurities, wherein the total amount of the inevitable impurities is less than 0.05%.

Wherein, preferably, the chemical composition comprises the following chemical components: 0.10% of Si, 0.70% of Fe, 0.2% of Cu, 0.05% of Mg, 0.05% of Zn, 0.02% of Ti, the balance of Al and inevitable impurities, wherein the total amount of the inevitable impurities is less than 0.05%.

at present, the recovered waste aluminum is available from two types, one is the residual waste aluminum material or scrap material in the aluminum material processing; the other type is a waste aluminum material recovered in the market, but the waste aluminum material has serious mixed material, extremely complex components and excessive individual impurity elements and can only be remelted to be used as a raw material of a regenerated aluminum ingot.

The invention selects the recycled aluminum as the residual aluminum scrap or leftover scrap during the aluminum processing, the scrap can be better stacked in a classification way, the impurities are less, the chemical components are stable and clear, and the recycled aluminum can be directly returned together with the original aluminum to prepare a new alloy.

S2, smelting the regenerated aluminum, introducing an intermediate alloy except the aluminum-titanium-boron intermediate alloy and the optional aluminum-magnesium intermediate alloy, and stirring and melting to obtain an alloy liquid;

s4, homogenizing the secondary aluminum alloy cast ingot at 490-530 ℃;

s5, carrying out hot rolling on the homogenized recycled aluminum alloy cast ingot, wherein the rolling temperature is 520-530 ℃, and the rolling temperature is 140-160 ℃, so as to obtain a recycled aluminum alloy plate;

In the S1, the components of the secondary aluminum alloy are proportioned, and the raw material is intermediate aluminum alloy of secondary aluminum and other raw materials; the intermediate aluminum alloy of other raw materials includes Al-Cu intermediate alloy, al-Mn intermediate alloy, etc., and is preferably selected from Al-50Cu, al-20Mn, al-20Mg, al-10Cr, al-20Zn, al-5Ti-B, for example. Wherein, mg element needs to consider 10% of burning loss to carry out the proportioning of the aluminum-magnesium intermediate alloy, and Fe element needs to consider the existence of impurities.

Wherein, preferably, the preparation method further comprises: in S1, preheating raw materials and required equipment at 150-250 ℃ for 0.5-1h. The equipment needed is such as mould and crucible.

Wherein, in S2, the smelting is carried out in an environment of 730-740 ℃.

In S2, preferably, the secondary aluminum and the intermediate alloy selected from aluminum silicon, aluminum iron, aluminum copper, aluminum manganese, aluminum chromium, and aluminum zinc are sequentially added in this order.

Preferably, in S3, the refining, degassing and slag-removing process includes: adding a deslagging agent accounting for 0.6-0.9wt% of the mass of the alloy liquid and a refining agent accounting for 0.1-0.3 wt% of the mass of the alloy liquid into the alloy liquid, refining for 10-20min, then removing floating slag, standing for 20-30min, and then introducing the aluminum-titanium-boron intermediate alloy and the optional aluminum-magnesium intermediate alloy.

The deslagging agent and refining agent can be conventional ones, for example, the deslagging agent can be selected from Na ₃ AlF ₆ 、 K ₃ SiF ₆ 、Na ₂ SiF ₆ At least one of (a); the refining agent may be selected from solid refining agents: hexachloroethane, liquid refining agent: carbon tetrachloride, gas refining agent: at least one of nitrogen, argon and mixed gas formed by mixing the nitrogen, the argon and chlorine.

Wherein, preferably, in S3, the casting conditions include: the temperature is 730-740 ℃, and the casting speed is 80-100 mm/min. Under the preferred scheme, because the casting temperature is lower, the growth of high-temperature grains is avoided, and the casting speed is moderate, the uniform, rapid and balanced filling of the mold cavity by the molten aluminum is facilitated, and the regenerated aluminum alloy ingot with good quality is obtained.

Preferably, cooling is performed after the casting, preferably natural cooling in air.

Preferably, in S4, the homogenization process includes: the temperature is firstly preserved for 3-5h at 490-500 ℃ and then preserved for 5-7h at 520-530 ℃. Under the preferred scheme, because of homogenization treatment before rolling, the problem of uneven components of cast alloy can be improved, dendrite segregation is eliminated, alloy elements are fully dissolved and uniformly distributed, the thermoplasticity and the aging strengthening potential of the alloy are improved, and the subsequent rolling processing performance and the final use performance of the alloy can be improved to the maximum extent.

Wherein, preferably, the hot rolling in S5 leads the rolling deformation to be 20-40%; and/or the rolling speed of hot rolling is 1-1.5m/s. Under the preferred scheme, the rolling deformation is small, so that the uniform deformation of the alloy is facilitated, and meanwhile, the crystal grains of the alloy can be refined by proper hot rolling, and the defect of a casting structure is further eliminated, so that the alloy structure is compact, and the mechanical property is improved; the reason is that dynamic recovery occurs in the hot rolling process, dislocation can be eliminated, the work hardening effect is weakened, and the number of precipitated phases is obviously increased under the action of higher temperature and large deformation amount, which can also cause the increase of electric conductivity.

Preferably, in S6, the double-stage solution treatment process includes: the temperature is kept at 490-500 ℃ for 1-3h, and then at 520-530 ℃ for 4-6h. In this preferred embodiment, the eutectic phase, such as Al, is due to the low melting point of the alloy ₂ Cu (theta phase), al ₅ Cu ₂ Mg ₈ Si ₆ The (Q phase) and the like are difficult to completely eliminate in the traditional single-stage solid solution process, the non-equilibrium solidification path of the alloy is calculated and analyzed by using Pandat thermodynamic calculation software to obtain the eutectic temperature of the low-melting-point phase (theta phase, Q phase and the like), and on the basis, a proper two-stage solid solution method is adopted, so that the residual excess phase is more favorably and effectively dissolved, the coarsening phenomenon of Jin Jingli synthesized at high temperature can be effectively relieved, and the over-burning temperature of the alloy can be improved.

Among them, in S7, the cold rolling is preferably performed so that the cold rolling deformation is 20 to 40%, and is preferably the same as the hot rolling deformation. Under the optimized scheme, the cold rolling before aging is favorable for increasing the density of defects such as dislocation, vacancy and the like, and is more favorable for nucleation and precipitation of fine dispersed precipitation strengthening phases at the defects during aging, so that the aging hardening effect is enhanced, and the strength of the alloy is improved.

Wherein, preferably, the aging treatment conditions include: treating at 170-180 deg.C for 2-32h, preferably 4-8h. Under the preferred scheme, due to the fact that the aging temperature is low, the growth of the precipitated second phase can be effectively avoided, meanwhile, the optimal aging time is determined preferably, and the aging heat treatment process is more beneficial to being efficiently developed.

In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following detailed description is given with reference to specific embodiments. In the following examples, pure aluminum as a raw material is secondary aluminum, i.e., a waste aluminum material or scrap remaining during aluminum material processing.

Example 1

The regenerated aluminum alloy wire described in this embodiment is composed of the following components in percentage by mass: 0.1wt% of Si, 0.7wt% of Fe, 0.05wt% of Zn, 0.02wt% of Ti, and the balance of Al and inevitable impurities.

A preparation method of a recycled aluminum alloy wire comprises the following steps:

s1, selecting raw materials: proportioning the components of the regenerated aluminum alloy, wherein the raw material is intermediate aluminum alloy of the regenerated aluminum and other raw materials;

s2, preprocessing: preheating the raw material and the die for 1h at 200 ℃;

s3, smelting: sequentially adding the raw materials pretreated in the step S2, the secondary aluminum, aluminum silicon, aluminum iron and aluminum zinc intermediate alloy into a furnace in sequence, heating the temperature in the furnace to 730 ℃, and preserving the heat for 30min to obtain a melt;

s4, aluminum liquid treatment: fully stirring the melt in the step S3, adding a deslagging agent and a refining agent in an amount which is 0.8wt% of the mass of the melt and 0.3wt% of the mass of the melt, refining for 13min, then skimming scum, and then standing for 25min;

s5, adding an intermediate alloy: adding an aluminum-titanium-boron intermediate alloy into the melt with the scum removed in the step S4, and fully stirring;

s6, casting: keeping the temperature for 30min until the intermediate alloy added in the step S5 is completely melted, then casting at the casting temperature of 730 ℃ and the casting speed of 90mm/min, and taking out the secondary aluminum alloy cast ingot after cooling;

s7, carrying out homogenization treatment on the regenerated aluminum alloy cast ingot by firstly preserving heat at 490 ℃ for 4h and then preserving heat at 530 ℃ for 6 h;

s8, carrying out hot rolling on the homogenized recycled aluminum alloy cast ingot, wherein the rolling temperature is 530 ℃, the rolling temperature is 150 ℃, the rolling speed is 1m/S, and a plate is obtained, and the hot deformation is 30%;

s9, performing double-stage solution treatment on the hot-rolled plate by insulating at 490 ℃ for 2h and then insulating at 530 ℃ for 6h, and then performing water quenching;

s10, cold rolling the water-quenched plate, wherein the cold rolling deformation is 30%;

s11, carrying out aging treatment on the cold-rolled plate at 175 ℃ for 2-32h (the specific treatment time is shown in Table 2) to obtain the regenerated aluminum alloy wire.

The prepared regenerated aluminum alloy wire has an electric conductivity of 59.20% IACS, a hardness of 41.60HV, a yield strength of 120MPa, a tensile strength of 150MPa, and an elongation of 9%.

Example 2

A secondary aluminum alloy wire described in this example is different from example 1 in that: the aluminum alloy conductor comprises the following components in percentage by mass: 0.1wt% of Si, 0.7wt% of Fe, 0.05wt% of Mg, 0.05wt% of Zn, 0.02wt% of Ti, and the balance of Al and inevitable impurities.

s1, selecting raw materials: proportioning the components of the regenerated aluminum alloy, wherein the raw material is intermediate aluminum alloy of the regenerated aluminum and other raw materials; wherein, mg element needs to consider 10% of burning loss to select the aluminum-magnesium intermediate alloy;

s2, preprocessing: preheating the raw material and the die for 1h at 200 ℃;

s3, smelting: sequentially adding the raw materials pretreated in the step S2, namely secondary aluminum and aluminum-silicon, aluminum-iron and aluminum-zinc intermediate alloy into a furnace in sequence, heating the temperature in the furnace to 730 ℃, and preserving the heat for 30min to obtain a melt;

s4, aluminum liquid treatment: fully stirring the melt in the step S3, adding a deslagging agent and a refining agent (which are respectively the same as the embodiment 1), refining for 13min, then removing floating slag, and then standing for 25min;

s5, adding an intermediate alloy: adding an aluminum-magnesium intermediate alloy and an aluminum-titanium-boron intermediate alloy into the melt with the scum removed in the step S4, and fully stirring;

s6, casting: keeping the temperature for 30min until the intermediate alloy added in the step S5 is completely melted, then casting, and taking out the regenerated aluminum alloy ingot after cooling;

s7, carrying out homogenization treatment on the regenerated aluminum alloy ingot at 490 ℃, 4h +530 ℃ and 6 h;

s8, heating the homogenized recycled aluminum alloy cast ingot at the rolling temperature of 530 ℃ to obtain a plate, wherein the heat deformation is 30%;

s9, performing double-stage solution treatment on the hot-rolled plate at 490 ℃ for heat preservation of 2h +530 ℃ for heat preservation of 6h, and then performing water quenching;

s11, carrying out aging treatment on the cold-rolled plate at 175 ℃ for 2-32h (the specific treatment time is shown in Table 2) to obtain the regenerated aluminum alloy wire. Other process conditions were the same as in example 1.

The conductivity of the prepared regenerated aluminum alloy wire can reach 58.04 percent IACS, the hardness can reach 43.50HV, the yield strength can reach 130MPa, the tensile strength can reach 165MPa, and the elongation can reach 7.8 percent.

Example 3

A secondary aluminum alloy wire described in this example is different from example 1 in that: the aluminum alloy conductor comprises the following components in percentage by mass: 0.1wt% of Si, 0.7wt% of Fe, 0.2wt% of Cu, 0.05wt% of Mg, 0.05wt% of Zn, 0.02wt% of Ti, and the balance of Al and inevitable impurities.

s1, selecting raw materials: proportioning the components of the regenerated aluminum alloy, wherein the raw materials are intermediate aluminum alloy of the regenerated aluminum and other raw materials; wherein, mg element needs to consider 10% of burning loss to select the aluminum-magnesium intermediate alloy;

s2, preprocessing: preheating the raw material and the die for 1h at 200 ℃;

s3, smelting: sequentially adding the raw materials pretreated in the step S2, secondary aluminum, aluminum silicon, aluminum iron, aluminum copper and aluminum zinc intermediate alloy into a furnace in sequence, heating the temperature in the furnace to 730 ℃, and preserving the heat for 30min to obtain a melt;

s4, aluminum liquid treatment: fully stirring the melt in the step S3, adding a deslagging agent and a refining agent (which are respectively the same as in the embodiment 1), refining for 13min, then skimming dross, and then standing for 25min;

The conductivity of the prepared regenerated aluminum alloy wire can reach 57.17 percent IACS, the hardness can reach 50.75HV, the yield strength can reach 150MPa, the tensile strength can reach 203MPa, and the elongation can reach 6 percent.

Example 4

A secondary aluminum alloy wire described in this example is different from example 1 in that: the aluminum alloy conductor comprises the following components in percentage by mass: 0.1wt% of Si, 0.7wt% of Fe, 0.2wt% of Cu, 0.3wt% of Mn, 0.05wt% of Mg, 0.05wt% of Zn, 0.02wt% of Ti, and the balance of Al and inevitable impurities.

s2, preprocessing: preheating the raw material and the die for 1h at 200 ℃;

s3, smelting: sequentially adding the raw materials pretreated in the step S2, namely secondary aluminum, aluminum silicon, aluminum iron, aluminum copper, aluminum manganese and aluminum zinc intermediate alloy into a furnace in sequence, heating the temperature in the furnace to 730 ℃, and preserving the heat for 30min to obtain a melt;

s10, cold rolling the water-quenched sheet, wherein the cold rolling deformation is 30%;

The conductivity of the prepared regenerated aluminum alloy wire can reach 49.27 percent IACS, the hardness can reach 49.25HV, the yield strength can reach 143MPa, the tensile strength can reach 187MPa, and the elongation can reach 6.8 percent.

Example 5

A secondary aluminum alloy wire described in this example is different from example 1 in that: the aluminum alloy conductor comprises the following components in percentage by mass: 0.1wt% of Si, 0.7wt% of Fe, 0.2wt% of Cu, 0.3wt% of Mn, 0.05wt% of Mg, 0.3wt% of Cr, 0.05wt% of Zn, 0.02wt% of Ti, and the balance of Al and unavoidable impurities.

s2, preprocessing: preheating the raw material and the die for 1h at 200 ℃;

s3, smelting: sequentially adding the raw materials pretreated in the step S2, namely secondary aluminum, aluminum silicon, aluminum iron, aluminum copper, aluminum manganese, aluminum chromium and aluminum zinc intermediate alloy into a furnace in sequence, heating the temperature in the furnace to 730 ℃, and preserving the heat for 30min to obtain a melt;

The prepared regenerated aluminum alloy wire has an electric conductivity of 37.64% IACS, a hardness of 52.25HV, a yield strength of 180MPa, a tensile strength of 230MPa, and an elongation of 5.8%.

Test example

The tensile strength, elongation, electrical conductivity and hardness of the recycled aluminum alloy wires of examples 1 to 5 were measured and compared with the electrical conductivity and strength of the recycled aluminum alloy wires reported in the prior art. Wherein, table 1 shows the measurement results of the conductivity properties of the secondary aluminum alloys of examples 1 to 5; table 2 shows the results of measuring the electrical conductivity and hardness of the secondary aluminum alloy wires of examples 1 to 5 with respect to aging time, based on which the optimum aging time of the alloy in the example was determined to be 4 to 8 hours; table 3 shows the properties of the currently reported recycled aluminum alloy wire.

Table 1 shows the comprehensive properties of each of the regenerated aluminum alloy conductors

Examples	YTS(MPa)	UTS(MPa)	EL％	HV	％IACS
						1	120	150	9	41.60	59.20
2	130	165	7.8	43.50	58.04
						3	150	203	6	50.75	57.17
4	143	187	6.8	49.25	49.27
						5	180	230	5.8	52.25	37.64

TABLE 2 age hardening results for each of the secondary aluminum alloy wires in the examples

Table 3 shows the comprehensive properties of the recycled aluminum alloy wire

Compared with the reported results of the conductivity and the mechanical properties of the regenerated aluminum alloy conductor in the test example, the conductor has higher conductivity and strength, simple preparation process and low manufacturing cost, and the regenerated aluminum alloy conductor and the preparation method thereof can better meet the preparation and use requirements of the regenerated aluminum alloy conductor for the overhead transmission line.

The comprehensive comparison of the conductivity and strength of the examples 1 to 4 without the addition of the Cr element and the example 5 with the addition of the Cr element shows that the comprehensive effect of the addition of the Cr element on the conductivity and strength of the alloy Jin Daoxian has a great influence, and the scheme without the Cr element is more beneficial to obtaining the alloy wire with good conductivity and medium strength.

As can be seen from the age hardening results of the regenerated aluminum alloy wires in the test example table 2, the optimal aging time of the regenerated aluminum alloy wire obtained by the invention is 4-8h, and the good matching of the conductivity and the strength of the wire can be ensured. Further, in example 5, the electric conductivity was lower than 37.64% IACS (strength 230 MPa) at this aging time, but was also higher than 36.8% IACS (strength 180 MPa), which was reported to be the lowest, and the wire strength was also higher. The other 4 groups of examples all had significantly higher ranges of electrical conductivity (49.27-59.20% IACS) than the reported range of electrical conductivity of the secondary aluminum alloy wire (36.8-47.4% IACS), with a minimum electrical conductivity of 49.27% IACS being higher than the highest electrical conductivity of 47.4% IACS. Through comprehensive comparison, the electric conductivity of the lead wire is superior to that of the reported regenerated aluminum alloy lead wire, and the line loss can be obviously reduced.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A high-conductivity regenerated aluminum alloy wire is characterized by comprising the following chemical components: according to mass percentage, 0.10 to 0.20 percent of Si, 0.40 to 0.70 percent of Fe, 0 to 0.20 percent of Cu, 0 to 0.30 percent of Mn, 0 to 0.10 percent of Mg, 0 to 0.30 percent of Cr, 0.01 to 0.10 percent of Zn, 0.02 to 0.10 percent of Ti, the balance of Al and inevitable impurities, wherein the total amount of the inevitable impurities is less than 0.05 percent;

the total adding amount of alloy elements in the regenerated aluminum alloy wire is controlled within 1.4 percent;

the preparation method of the regenerated aluminum alloy wire comprises the following steps: smelting alloy raw materials; casting the smelted alloy liquid to obtain a secondary aluminum alloy cast ingot; carrying out homogenization treatment, hot rolling, solution treatment, cold rolling and aging treatment on the cast ingot;

the preparation method of the regenerated aluminum alloy wire specifically comprises the following steps:

s2, smelting the regenerated aluminum, introducing an intermediate alloy except the aluminum-titanium-boron intermediate alloy and the aluminum-magnesium intermediate alloy, and stirring and melting to obtain an alloy liquid;

s3, refining the alloy liquid, removing gas and slag, adding an aluminum-titanium-boron intermediate alloy and an aluminum-magnesium intermediate alloy, preserving heat for 20-40min after all the intermediate alloys are completely melted, and then casting and cooling to obtain a regenerated aluminum alloy cast ingot;

s4, homogenizing the secondary aluminum alloy cast ingot at 490-530 ℃;

s7, cold rolling the water-quenched plate, and then performing aging treatment to obtain a regenerated aluminum alloy wire;

the electrical conductivity of the recycled aluminum alloy wire is 37.64-59.20% IACS, the hardness of the recycled aluminum alloy wire is 41.60-52.25HV, and the tensile strength of the recycled aluminum alloy wire is 130 MPa-230 MPa.

2. The high-conductivity recycled aluminum alloy wire as recited in claim 1, wherein the content of at least one element selected from the group consisting of Cu, mn, and Mg in the composition is 0.

3. The high-conductivity recycled aluminum alloy wire as recited in claim 1, wherein the wire is composed of the following chemical components: 0.10 to 0.15 percent of Si, 0.60 to 0.70 percent of Fe, 0 to 0.2 percent of Cu, 0 to 0.30 percent of Mn, 0 to 0.05 percent of Mg, 0 to 0.30 percent of Cr, 0.01 to 0.05 percent of Zn, 0.02 to 0.05 percent of Ti, and the balance of Al and inevitable impurities, wherein the total amount of the inevitable impurities is less than 0.05 percent.

4. The method for producing a high-conductivity regenerated aluminum alloy wire as set forth in any one of claims 1 to 3, characterized by comprising the steps of:

s4, homogenizing the secondary aluminum alloy cast ingot at 490-530 ℃;

5. The method of claim 4, further comprising: in S1, preheating raw materials and required equipment at 150-250 ℃ for 0.5-1h.

6. The method according to claim 4, wherein in S4, the homogenizing process comprises: the temperature is firstly preserved for 3 to 5 hours at 490 to 500 ℃, and then preserved for 5 to 7 hours at 520 to 530 ℃.

7. The production method according to claim 4, wherein the hot rolling in S5 is performed so that the rolling deformation amount is 20-40%; and/or the rolling speed of hot rolling is 1-1.5m/s.

8. The method according to claim 4, wherein in S6, the double-stage solution treatment process comprises: the temperature is kept at 490-500 ℃ for 1-3h, and then at 520-530 ℃ for 4-6h.

9. The method according to claim 4, wherein in S7, the cold rolling is performed to achieve a cold rolling deformation of 20-40%; the aging treatment conditions comprise: treating at 170-180 deg.C for 2-32h.