Graphene-aluminum alloy wire, preparation method thereof and application thereof in cable field
By combining rare earth purification and low-frequency electromagnetic stirring with heat preservation continuous rolling technology, graphene aluminum alloy conductors were prepared, solving the problems of uniform dispersion and orientation of graphene in aluminum alloys, improving conductivity and mechanical properties, and making them suitable for the cable industry.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- AEROSPACE ELECTRIC GRP CO LTD
- Filing Date
- 2026-03-18
- Publication Date
- 2026-06-05
AI Technical Summary
Existing technologies make it difficult to achieve uniform dispersion and high orientation of graphene in aluminum alloys without destroying the graphene lattice structure, resulting in a decrease in the electrical conductivity and mechanical properties of graphene-aluminum composites.
Rare earth elements and multi-stage purification treatment are used to process the aluminum alloy melt. Combined with low-frequency electromagnetic stirring and heat preservation continuous rolling technology, graphene is introduced and continuously annealed and drawn into wires to make it uniformly dispersed in the aluminum alloy matrix and highly oriented along the wire.
The graphene-aluminum alloy conductor achieves high conductivity, high strength, and high creep resistance, making it suitable for use in the cable industry.
Smart Images
Figure CN122147111A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of composite material technology, and in particular to a graphene aluminum alloy conductor, its preparation method, and its application in the field of cables. Background Technology
[0002] 8000 series aluminum alloys, represented by 8030 aluminum alloy, are prepared by adding alloying elements such as iron and copper to pure aluminum. They possess conductivity comparable to pure aluminum and largely solve the problem of poor creep resistance in pure aluminum, making them widely used as cable conductors. With the continuous upgrading of power transmission and transformation technology, the industry has put forward new requirements for the performance of 8000 series aluminum alloy conductors, especially for their conductivity, strength, and creep resistance, which are now more stringent. Traditional methods such as alloy purification, micro-alloying, and processing technology optimization are no longer sufficient to meet these requirements.
[0003] Graphene is a type of graphene produced by sp 2 Carbon atoms in a honeycomb lattice structure are novel nanomaterials with excellent mechanical, electrical and thermal conductivity properties. They are considered ideal reinforcing phases for composite materials. Introducing graphene into aluminum alloys is an effective way to achieve a breakthrough in their performance.
[0004] In recent years, articles have reported methods for preparing graphene-aluminum composites, mainly powder metallurgy and melt stirring casting. Compared with powder metallurgy, melt stirring casting has significant advantages in cost and efficiency, and is conducive to large-scale production. However, graphene and aluminum have significantly different densities and are non-wetting, and are prone to reaction at high temperatures, which can destroy the lattice structure of graphene. Therefore, achieving uniform dispersion of graphene without severely damaging its lattice structure has long been an unsolved problem in this field.
[0005] Furthermore, graphene, as a typical two-dimensional nanomaterial, exhibits significant anisotropy, with its in-plane properties far superior to its out-of-plane properties. The oriented arrangement of graphene sheets along lines is also key to improving the performance of graphene-aluminum composites. However, the aforementioned methods inevitably involve a mixing process to achieve uniform graphene dispersion, resulting in a disordered arrangement of graphene sheets. This reduces the continuity of electron transport and affects load transfer, ultimately leading to a decrease in the electrical and mechanical properties of the graphene-aluminum composite. Summary of the Invention
[0006] In view of this, the present invention provides a graphene aluminum alloy conductor, a method for preparing the conductor, and its application in the field of cables. The preparation method provided by the present invention can maintain the graphene lattice structure, and the graphene is uniformly dispersed and highly oriented.
[0007] This invention provides a method for preparing graphene-aluminum alloy wires, comprising the following steps: 1) Aluminum alloy and rare earth are mixed and then smelted, refined, degassed and filtered in sequence to obtain aluminum alloy melt; 2) Under an inert atmosphere, graphene is introduced into the aluminum alloy melt to obtain a mixture; 3) The mixture is subjected to continuous casting and heat-insulating continuous rolling in sequence to obtain a graphene aluminum alloy rod; 4) The graphene aluminum alloy rod is continuously annealed and drawn to obtain a graphene aluminum alloy wire.
[0008] Preferably, the rare earth element includes one or more of erbium, lanthanum, cerium, scandium, and yttrium; the mass ratio of the rare earth element to the aluminum alloy is 0.05~0.5:98.7~99.75.
[0009] Preferably, the refining temperature is 720~770℃, and the refining time is 8~20 minutes; the refining agent used is an inorganic salt refining agent; the amount of the refining agent added is 1.0~1.5 kg / ton of aluminum alloy melt; the refining method is injection refining; the carrier used for injection refining is argon or nitrogen; and the flow rate of the carrier is 1~2 m³ / ton. 3 / h.
[0010] Preferably, the method for introducing graphene includes the following steps: adding a graphene master alloy to the aluminum alloy melt and performing low-frequency electromagnetic stirring; the frequency of the low-frequency electromagnetic stirring is 2~10Hz, and the stirring time is 5~10 minutes.
[0011] Preferably, the continuous casting equipment includes a crystallizing wheel casting machine; the continuous casting temperature is 700~730℃, and the crystallizing wheel speed is 12~16m / s.
[0012] Preferably, the equipment for the heat-insulating continuous rolling includes a heat-insulating cover; the heat-insulating layer of the heat-insulating cover is made of aluminum silicate heat-resistant fiber material (commercially available); the inlet temperature of the heat-insulating continuous rolling is 490~520℃, and the outlet temperature is 380~430℃; the total deformation of the heat-insulating continuous rolling is 97%~98.5%.
[0013] Preferably, the annealing temperature of the continuous annealing and drawing process is 350~400℃, and the total deformation of the drawing process is 72.3~95.6%.
[0014] The present invention also provides a graphene aluminum alloy wire, which is obtained by the preparation method of the graphene aluminum alloy wire described above.
[0015] Preferably, the graphene-aluminum alloy wire comprises the following components: 0.3-0.8 wt.% iron, 0.15-0.3 wt.% copper, 0.02-0.15 wt.% silicon, 0.01-0.2 wt.% manganese, 0.01-0.04 wt.% boron, 0.02-0.05 wt.% zirconium, 0.05-0.5 wt.% rare earth elements, 0.2-0.8 wt.% graphene, and the balance aluminum.
[0016] The present invention also provides an application of graphene aluminum alloy conductor in the field of cables, wherein the graphene aluminum alloy conductor is the graphene aluminum alloy conductor described in the above-mentioned scheme.
[0017] This invention provides a method for preparing graphene-aluminum alloy wires. The invention reduces the hydrogen and impurity content of the aluminum alloy melt through rare earth elements and multi-stage purification, resulting in a pure aluminum alloy melt. Graphene is then introduced, and the graphene is macroscopically homogenized using strong low-frequency electromagnetic stirring. Further, continuous rolling and annealing drawing ensure that the aluminum alloy matrix maintains high plasticity throughout the plastic deformation process, reducing the resistance to graphene orientation and micro-dispersion. This achieves uniform dispersion and high orientation of the graphene sheets along the wire while minimizing lattice structure damage. The resulting graphene-aluminum alloy wire possesses the advantages of high conductivity, high strength, and high creep resistance. The preparation method provided by this invention is highly controllable, low-cost, and suitable for large-scale industrial production.
[0018] This invention also provides a graphene-aluminum alloy wire, obtained using the preparation method described above. The graphene-aluminum alloy wire provided by this invention possesses high conductivity, high strength, and high creep resistance, exhibiting excellent overall performance.
[0019] This invention also provides an application of graphene-aluminum alloy wire in the cable field, wherein the graphene-aluminum alloy wire is the same as described in the above-mentioned solution. The graphene-aluminum alloy wire provided by this invention possesses high conductivity, high strength, and high creep resistance, making it suitable for use in the cable field. Attached Figure Description
[0020] To more clearly illustrate the technical solutions of this invention, the accompanying drawings used in the embodiments of this invention or in the prior art are briefly described below. For those skilled in the art, other drawings can be derived from the following drawings without creative effort, and all such drawings are within the protection scope of this invention.
[0021] Figure 1 This is a process flow diagram for preparing graphene-aluminum alloy wires according to the present invention; Figure 2The images show the scanning electron microscope (SEM) image and Raman spectrum of the graphene-aluminum alloy wire prepared in Example 1 of this invention; wherein, (a) is the SEM image of the graphene-aluminum alloy wire of Example 1 on a 1 μm scale, and (b) is the Raman spectrum of the graphene-aluminum alloy wire of Example 1. Figure 3 The images show the Raman spectra of the graphene-aluminum alloy wires prepared in Comparative Examples 2 and 3 of this invention; wherein, (a) is the Raman spectrum of the graphene-aluminum alloy wire in Comparative Example 2, and (b) is the Raman spectrum of the graphene-aluminum alloy wire in Comparative Example 3. Detailed Implementation
[0022] This invention provides a method for preparing graphene-aluminum alloy wires, comprising the following steps: 1) Aluminum alloy and rare earth are mixed and then smelted, refined, degassed and filtered in sequence to obtain aluminum alloy melt; 2) Under an inert atmosphere, graphene is introduced into the aluminum alloy melt to obtain a mixture; 3) The mixture is subjected to continuous casting and heat-insulating continuous rolling in sequence to obtain a graphene aluminum alloy rod; 4) The graphene aluminum alloy rod is continuously annealed and drawn to obtain a graphene aluminum alloy wire.
[0023] The process flow for preparing graphene-aluminum alloy wires according to this invention is as follows: Figure 1 As shown. This invention involves mixing aluminum alloy and rare earth elements, then sequentially smelting, refining, degassing, and filtering to obtain an aluminum alloy melt. In this invention, the aluminum alloy is preferably an 8000 series aluminum alloy, more preferably an 8030 aluminum alloy, and specifically preferably comprises the following components: iron 0.3~0.8 wt.%, copper 0.15~0.3 wt.%, silicon 0.02~0.15 wt.%, manganese 0.01~0.2 wt.%, boron 0.01~0.04 wt.%, zirconium 0.02~0.05 wt.%, and the balance aluminum.
[0024] In this invention, the rare earth elements preferably include one or more of erbium, lanthanum, cerium, scandium, and yttrium.
[0025] In this invention, the mass ratio of rare earth to aluminum alloy is preferably 0.05~0.5:98.7~99.75, more preferably 0.1~0.4:99.
[0026] In this invention, the melting temperature is preferably 730~780℃, more preferably 740~770℃, and even more preferably 750~760℃. The holding time is preferably determined according to the melting amount and the type of melting furnace, specifically preferably 20~120 minutes, more preferably 40~100 minutes, and even more preferably 60~80 minutes.
[0027] In this invention, the refining temperature is preferably 720~770℃, more preferably 740~750℃, and the refining time is preferably 8~20 minutes, more preferably 12~16 minutes; the refining agent used in the refining is preferably an inorganic salt refining agent; the inorganic salt refining agent is preferably the 6RF type refining agent produced by Evans (Jiaozuo) New Materials Co., Ltd.; the amount of the refining agent added is preferably 1.0~1.5 kg / ton of aluminum alloy melt, more preferably 1.2~1.3 kg / ton of aluminum alloy melt.
[0028] In this invention, the refining method is preferably jet refining; the carrier used in the jet refining is preferably argon or nitrogen; and the flow rate of the carrier is preferably 1-2 m³ / s. 3 / h, more preferably 1.5~1.8m 3 / h. In this invention, the refining agent during the refining process is blown into the molten aluminum alloy via a carrier.
[0029] In this invention, the degassing is preferably online; the online degassing is preferably off-furnace online degassing; the degassing equipment preferably includes a degassing box; the degassing box is preferably disposed in a flow channel; the degassing box is preferably provided with a graphite rotor; the rotational speed of the graphite rotor is preferably 200~500 rpm, more preferably 300~400 rpm.
[0030] In this invention, the gas used for degassing is preferably a mixed gas; the mixed gas is preferably chlorine and a carrier gas; the carrier gas is preferably argon or nitrogen; the volume fraction of chlorine in the mixed gas is preferably 2-5%, more preferably 3-4%.
[0031] In this invention, the filtration is preferably online filtration; the filtration device preferably includes a filter box; the filter box is preferably disposed in a flow channel; and the filter box is preferably provided with a ceramic filter tube.
[0032] After obtaining the aluminum alloy melt, the present invention introduces graphene into the aluminum alloy melt under an inert atmosphere to obtain a mixture. In the present invention, the inert atmosphere is preferably argon or nitrogen.
[0033] In this invention, the method for introducing graphene preferably includes the following steps: adding a graphene master alloy to the aluminum alloy melt and performing low-frequency electromagnetic stirring.
[0034] In this invention, the preferred method for preparing the graphene master alloy includes the following steps: ball milling and mixing graphene with aluminum powder, followed by cold pressing.
[0035] In this invention, the graphene is preferably obtained by physical exfoliation or chemical vapor deposition; the graphene sheet diameter is preferably not less than 0.5 μm, more preferably 2~8 μm, and the number of layers is preferably not more than 20 layers, more preferably 1~5 layers.
[0036] In this invention, the average particle size of the aluminum powder is preferably 30~50μm, more preferably 40μm.
[0037] In this invention, the mass ratio of graphene to aluminum powder is preferably 1.8~2.1:100, more preferably 2:100.
[0038] In this invention, the grinding balls used in the ball mill are preferably stainless steel grinding balls; the ball-to-material ratio of the ball mill is preferably 4.8~5.2:1, more preferably 5:1; the ball milling is preferably carried out in an inert atmosphere; the inert atmosphere is preferably argon; the ball milling speed is preferably 180~220 rpm, more preferably 200 rpm; and the ball milling time is preferably 1.8~2.2 hours, more preferably 2 hours.
[0039] In this invention, the preferred temperature for cold pressing is room temperature (20~35℃), the preferred pressure is 150~250MPa, more preferably 170~220MPa, even more preferably 195MPa, and the preferred holding time is 15~20 minutes, more preferably 18 minutes.
[0040] In this invention, the mass ratio of graphene to aluminum alloy melt in the graphene master alloy is preferably 0.2~0.8:99.2~99.8, more preferably 0.4~0.6:99.4~99.6, and even more preferably 0.5:99.5.
[0041] In this invention, the frequency of the low-frequency electromagnetic stirring is preferably 2~10Hz, more preferably 6Hz, and the stirring time is preferably 5~10 minutes, more preferably 7 minutes.
[0042] After obtaining the mixture, the present invention sequentially performs continuous casting and heat-holding continuous rolling on the mixture to obtain a graphene aluminum alloy rod. In the present invention, the equipment for continuous casting preferably includes a crystallizing wheel casting machine; the temperature of continuous casting is preferably 700~730℃, more preferably 710~720℃, and the speed of the crystallizing wheel is preferably 12~16m / s, more preferably 13m / s.
[0043] In this invention, the equipment for continuous heat insulation rolling preferably includes a heat insulation cover; the heat insulation layer of the heat insulation cover is preferably made of aluminum silicate heat-resistant fiber material (commercially available); the inlet temperature of the continuous heat insulation rolling is preferably 490~520℃, more preferably 500℃, and the outlet temperature is preferably 380~430℃, more preferably 400℃; the total deformation of the continuous heat insulation rolling is preferably 97%~98.5%, more preferably 98%.
[0044] After obtaining the graphene-aluminum alloy rod, the present invention continuously anneals and draws the graphene-aluminum alloy rod to obtain a graphene-aluminum alloy wire. In the present invention, the annealing temperature for continuous annealing and drawing is preferably 350~400℃, more preferably 370~380℃, and the total deformation of the wire is preferably 72.3~95.6%, more preferably 80~90%.
[0045] The present invention also provides a graphene aluminum alloy wire, which is obtained by the preparation method of the graphene aluminum alloy wire described above.
[0046] In this invention, the graphene-aluminum alloy wire preferably comprises the following components: 0.3-0.8 wt.% iron, 0.15-0.3 wt.% copper, 0.02-0.15 wt.% silicon, 0.01-0.2 wt.% manganese, 0.01-0.04 wt.% boron, 0.02-0.05 wt.% zirconium, 0.05-0.5 wt.% rare earth elements, 0.2-0.8 wt.% graphene, and the balance aluminum.
[0047] The present invention also provides an application of graphene aluminum alloy conductor in the field of cables, wherein the graphene aluminum alloy conductor is the graphene aluminum alloy conductor described in the above-mentioned scheme.
[0048] To further illustrate the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments.
[0049] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.
[0050] In this invention, unless otherwise specified, the test materials and instruments are all conventional test materials in the field and can be purchased through commercial channels.
[0051] Example 1: This embodiment prepares a graphene-aluminum alloy wire with the following composition: 0.5 wt.% iron, 0.12 wt.% copper, 0.05 wt.% silicon, 0.02 wt.% manganese, 0.02 wt.% boron, 0.02 wt.% zirconium, 0.04 wt.% cerium, 0.02 wt.% lanthanum, 0.7 wt.% graphene, and the balance aluminum.
[0052] The specific steps for preparing the graphene-aluminum alloy wire in this embodiment are as follows: (1) The aluminum alloy and rare earth elements (cerium and lanthanum) are put into a melting furnace, heated to 750°C, and held at that temperature for 40 minutes until completely melted. The temperature is then maintained within the range of 730~750°C, and argon gas is used as the carrier gas at a speed of 1.2m. 3A 6RF refining agent (Avans (Jiaozuo) New Materials Co., Ltd.) of 1.2 kg / ton of aluminum alloy melt is injected into the melting furnace at a flow rate of / h. After refining for 15 minutes, the slag is removed. After the slag is removed, the flow channel is opened, the graphite rotor of the degassing box is started (the speed of the graphite rotor is set to 400 rpm), and a chlorine / argon mixed gas with a chlorine gas fraction of 2% is blown into the degassing box for online degassing. After online degassing, the mixture is filtered online through the ceramic filter tube of the filter box to obtain pure aluminum alloy melt.
[0053] (2) Physically exfoliated graphene with a sheet diameter of 2-8 μm and 1-5 layers was weighed with spherical aluminum powder with an average particle size of 45 μm at a mass ratio of 2:100 and put into a ball mill. Stainless steel grinding balls were used, and the material ratio was 5:1. The mixture was ball-milled under argon protection at a speed of 200 rpm for 2 hours. After the ball milling was completed, the mixture was cold-pressed at room temperature at a pressure of 195 MPa for 15 minutes to obtain an intermediate alloy. After the pure aluminum alloy melt was injected into the stirring tank, the prepared intermediate alloy was added under argon protection to make the graphene content in the aluminum alloy 0.7 wt.%. Low-frequency electromagnetic stirring was started with the following parameters: stirring frequency of 5 Hz and stirring time of 8 minutes.
[0054] (3) A heat insulation cover with a heat insulation layer of aluminum silicate heat-resistant fiber material (thickness 50mm) is used. After low-frequency electromagnetic stirring, continuous casting and heat insulation continuous rolling are carried out. Casting is carried out using a crystallizing wheel casting machine with a casting temperature of 720℃, a crystallizing wheel speed of 12m / s, a total deformation of 97% in heat insulation continuous rolling, an in-rolling temperature of 510℃, and an out-rolling temperature of 420℃ to obtain a graphene aluminum alloy rod with a diameter of 9.5mm.
[0055] (4) The graphene aluminum alloy rod was continuously annealed and drawn at a temperature of 380°C. The total deformation of the drawing was 82.3%, resulting in a graphene aluminum alloy wire with a diameter of 4 mm.
[0056] Example 2: This embodiment prepares a graphene-aluminum alloy wire with the following composition: 0.5 wt.% iron, 0.12 wt.% copper, 0.05 wt.% silicon, 0.02 wt.% manganese, 0.02 wt.% boron, 0.02 wt.% zirconium, 0.04 wt.% cerium, 0.02 wt.% lanthanum, 0.2 wt.% graphene, and the balance aluminum.
[0057] The specific steps for preparing the graphene-aluminum alloy wire in this embodiment are as follows: (1) The aluminum alloy and rare earth (cerium or lanthanum) are put into a melting furnace, heated to 730°C, held for 40 minutes until completely melted, and then the temperature is maintained in the range of 715~730°C. Argon gas is used as the carrier gas and the melting process is carried out at a speed of 1.2m. 3A 6RF type refining agent (Avans (Jiaozuo) New Materials Co., Ltd.) of 1.3 kg / ton of aluminum alloy melt is injected into the melting furnace at a flow rate of / h. After refining for 15 minutes, the slag is removed. After the slag is removed, the flow channel is opened, the graphite rotor of the degassing box is started (speed 400 rpm), and a chlorine / argon mixed gas with a chlorine gas fraction of 2% is blown into the degassing box for online degassing. After online degassing, the mixture is filtered online through the ceramic filter tube of the filter box to obtain pure aluminum alloy melt.
[0058] (2) Physically exfoliated graphene with a diameter of 0.5~1μm and 1~2 layers was weighed with spherical aluminum powder with an average particle size of 45μm at a mass ratio of 2:100 and put into a ball mill. Stainless steel grinding balls were used, and the material ratio was 5:1. The mixture was ball-milled under argon protection at a speed of 200rpm for 2 hours. After ball milling, the mixture was cold-pressed at room temperature at a pressure of 195MPa for 15 minutes to obtain an intermediate alloy. After injecting the pure aluminum alloy melt into a stirring tank, the prepared intermediate alloy was added under argon protection to make the graphene content in the aluminum alloy 0.2wt.%. Low-frequency electromagnetic stirring was started with the following parameters: stirring frequency 5Hz and stirring time 6 minutes.
[0059] (3) A heat insulation cover with a heat insulation layer of aluminum silicate heat-resistant fiber material (thickness 50mm) is used. After the low frequency electromagnetic stirring treatment, continuous casting and heat insulation continuous rolling are carried out. Casting is carried out using a crystallizing wheel casting machine with a casting temperature of 710℃, a crystallizing wheel speed of 12m / s, a total deformation of 97% in heat insulation continuous rolling, an in-rolling temperature of 500℃, and an out-rolling temperature of 400℃ to obtain a graphene aluminum alloy rod with a diameter of 9.5mm.
[0060] (4) The graphene aluminum alloy rod was continuously annealed and drawn at a temperature of 380°C. The total deformation of the drawing was 82.3%, resulting in a graphene aluminum alloy wire with a diameter of 4 mm.
[0061] Comparative Example 1: The preparation method of this comparative example is the same as that of Example 1, except that graphene is not added.
[0062] Comparative Example 2: The preparation method of this comparative example is the same as that of Example 1, except that in step (3), ordinary continuous rolling without heat insulation cover is used, with an entry temperature of 510°C and an exit temperature of 275°C.
[0063] Comparative Example 3: The preparation method of this comparative example is the same as that of Example 1, except that in step (4), after cold drawing, it is annealed at 380°C for 2 hours.
[0064] Comparative Example 4: The preparation method of this comparative example is the same as that of Example 1, except that: in step (3), ordinary continuous rolling without heat preservation cover is used; in step (4), after cold drawing, it is annealed at 380°C for 2 hours, the entry temperature is 500°C, and the exit temperature is 270°C.
[0065] Test Example 1: The graphene-aluminum alloy wires prepared in Example 1 were characterized using scanning electron microscopy (SEM) and Raman spectroscopy, and the results are as follows: Figure 2 As shown.
[0066] according to Figure 2 As can be seen, in the graphene-aluminum alloy wire prepared in Example 1, graphene is uniformly dispersed in the aluminum alloy matrix and exhibits a highly oriented morphology along the wire.
[0067] The graphene-aluminum alloy wires prepared in Comparative Examples 2 and 3 were characterized by Raman spectroscopy, and the results are as follows: Figure 3 As shown.
[0068] The ratio of the diffraction intensity of the D peak to the G peak in the Raman spectrum, I D / I G , is often used to characterize the degree of disruption to the lattice structure of graphene. According to Figure 2 and Figure 3 It can be seen that the graphene-aluminum alloy wire prepared in Example 1 has a significantly lower degree of damage to the graphene lattice structure than that in Comparative Example 2 and Comparative Example 3.
[0069] Test Example 2: The graphene-aluminum alloy wires prepared in Examples 1-2 and Comparative Examples 1-4 were tested for conductivity, room temperature tensile strength, and creep resistance. Conductivity testing was performed according to GB / T3048.2-2007 "Electrical Properties Test Methods for Wires and Cables - Part 2: Resistivity Test of Metallic Materials" using a QJ57 DC bridge resistance meter. Room temperature tensile testing was performed according to GB / T4908.3-2009 "Test Methods for Bare Wires - Part 3: Tensile Test" using a WDS-100 electronic universal testing machine at a tensile rate of 1 mm / min. Creep resistance testing was performed according to GB / T31840.1-2025 "Rated Voltage 1kV (U m =1.2kV) to 35kV (U m =40.5kV) Aluminum alloy core extruded insulated power cable Part 1: Rated voltage 1kV (U m =1.2kV) and 3kV (U m=3.6kV) Cable Appendix G Aluminum Alloy Conductor Pressure Creep Test Method was used. The instrument was a WDL-600 creep testing machine, the test temperature was 130℃, and the test time was 100 hours. The creep resistance was evaluated by the ratio of the stable pressure value to the initial pressure value. The results are shown in Table 1.
[0070] Table 1. Performance of graphene-aluminum alloy wires in Examples 1-2 and Comparative Examples 1-4:
[0071] As shown in Table 1, the conductivity, tensile strength, and creep resistance of the graphene-aluminum alloy wire prepared in Example 1 are significantly higher than those of Comparative Examples 1-3. Compared to Example 1, the graphene-aluminum alloy wire prepared in Comparative Example 1 does not contain graphene. Comparative Examples 2 and 3, which employed conventional continuous rolling and cold drawing followed by annealing without an insulation cover, respectively, resulted in significant damage to the lattice structure of graphene, deteriorating its intrinsic properties and thus reducing the conductivity, tensile strength, and creep resistance of the graphene-aluminum alloy wire. The conductivity, tensile strength, and creep resistance of the graphene-aluminum alloy wire prepared in Example 2 are significantly higher than those of Comparative Example 4. Compared to Example 2, Comparative Example 4 employed conventional continuous rolling and cold drawing followed by annealing without an insulation cover.
[0072] As can be seen from the above embodiments, the preparation method provided by the present invention, based on the addition of rare earth elements and multi-stage purification to obtain a pure aluminum alloy melt, introduces graphene and uses low-frequency electromagnetic stirring combined with heat preservation rolling and continuous annealing and wire drawing to ensure that the graphene in the aluminum alloy is uniformly dispersed and highly oriented along the line, while the lattice structure is less damaged. The resulting graphene aluminum alloy wire has the advantages of high conductivity, high strength and high creep resistance.
[0073] The embodiments of the present invention have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. All other embodiments obtained by those skilled in the art based on the above embodiments of the present invention without inventive effort are within the protection scope of the present invention.
Claims
1. A method for preparing a graphene-aluminum alloy wire, characterized in that, Includes the following steps: 1) Aluminum alloy and rare earth are mixed and then smelted, refined, degassed and filtered in sequence to obtain aluminum alloy melt; 2) Under an inert atmosphere, graphene is introduced into the aluminum alloy melt to obtain a mixture; 3) The mixture is subjected to continuous casting and heat-insulating continuous rolling in sequence to obtain a graphene aluminum alloy rod; 4) The graphene aluminum alloy rod is continuously annealed and drawn to obtain a graphene aluminum alloy wire.
2. The preparation method according to claim 1, characterized in that, The rare earth elements include one or more of erbium, lanthanum, cerium, scandium, and yttrium.
3. The preparation method according to claim 1, characterized in that, The refining temperature is 720~770℃, and the refining time is 8~20 minutes; The refining agent used in the refining process is an inorganic salt refining agent, and the amount of the refining agent added is 1.0~1.5 kg / ton of aluminum alloy melt; The refining method is jet refining.
4. The preparation method according to claim 1, characterized in that, The method for introducing graphene includes the following steps: A graphene master alloy was added to the aluminum alloy melt and then subjected to low-frequency electromagnetic stirring. The low-frequency electromagnetic stirring has a frequency of 2~10Hz and a stirring time of 5~10 minutes.
5. The preparation method according to claim 1, characterized in that, The continuous casting equipment includes a crystallizing wheel casting machine; The continuous casting temperature is 700~730℃, and the crystallizing wheel speed is 12~16m / s.
6. The preparation method according to claim 1, characterized in that, The equipment for continuous heat preservation rolling includes a heat preservation cover; The insulation layer of the insulation cover is made of aluminum silicate heat-resistant fiber material; The inlet temperature of the heat-insulating continuous rolling mill is 490~520℃, and the outlet temperature is 380~430℃. The total deformation of the heat-insulating continuous rolling mill is 97%~98.5%.
7. The preparation method according to claim 1, characterized in that, The annealing temperature for the continuous annealing and drawing process is 350~400℃, and the total deformation during drawing is 72.3~95.6%.
8. A graphene-aluminum alloy wire, characterized in that, The graphene-aluminum alloy wire is obtained by the preparation method described in any one of claims 1 to 7.
9. The graphene-aluminum alloy wire according to claim 8, characterized in that, It comprises the following components: iron 0.3~0.8 wt.%, copper 0.15~0.3 wt.%, silicon 0.02~0.15 wt.%, manganese 0.01~0.2 wt.%, boron 0.01~0.04 wt.%, zirconium 0.02~0.05 wt.%, rare earth 0.05~0.5 wt.%, graphene 0.2~0.8 wt.%, and the balance aluminum.
10. An application of graphene-aluminum alloy conductor in the field of cables, characterized in that, The graphene aluminum alloy wire is the graphene aluminum alloy wire according to any one of claims 8 to 9.