A method for interfacial coating of aluminum alloy wires modified with nano-high conductivity particles

Abstract

This invention provides a method for interfacial coating of aluminum alloy wires modified with nano-high conductivity particles, belonging to the field of wire processing technology. The method includes: firstly, pretreating solid nano-high conductivity particles sequentially, followed by mechanical dispersion, ultrasonic dispersion, and vacuum drying under an inert atmosphere to obtain uniformly dispersed particle powder; then, inorganically coating the powder under stirring and densifying it through annealing to obtain coated modified nano-high conductivity particles; quantitatively adding the coated particles to an aluminum alloy melt, and obtaining a composite melt through electromagnetic stirring and ultrasonic dispersion; finally, forming the composite melt into a billet, which is then rolled and drawn sequentially to obtain the finished modified aluminum alloy wire. This invention effectively improves the problems of easy agglomeration of nano-high conductivity particles and poor interfacial bonding with the aluminum alloy matrix, enhancing the overall conductivity and mechanical properties of the wire while improving the density of the particle coating layer and the uniform dispersion of particles in the matrix.

Description

Technical Field

[0001] This invention relates to the field of wire processing technology, and in particular to an interface coating treatment method for aluminum alloy wires modified with nano-high conductivity particles. Background Technology

[0002] Currently, methods to improve the performance of aluminum alloy conductors mainly involve adjusting the alloy composition or optimizing the heat treatment process. For example, adding small amounts of alloying elements or precisely controlling the temperature and time of heat treatment can improve conductivity and heat resistance. However, these methods are limited by the inherent metallic properties of aluminum alloys, limiting the potential for improved conductivity and making it difficult to meet the demands of efficient and low-loss power transmission. Furthermore, some modification methods can lead to a conflict between conductivity and mechanical properties, making it difficult to simultaneously improve both. Other processes are time-consuming and energy-intensive, unsuitable for large-scale production and application. While some studies have attempted modification using highly conductive particles, the particle coating structures in these studies are typically loose and lack density, making uniform distribution within the matrix difficult. This not only reduces the conductivity of the highly conductive particles but also weakens the conductor's mechanical properties due to interface defects, ultimately affecting the overall performance.

[0003] With the large-scale integration of new energy sources such as photovoltaics and wind power into the power grid, grid operation has become more complex. Transmission lines face challenges such as increased short-term current carrying capacity and fluctuations in ambient temperature, which places higher demands on the overall performance and service reliability of the lines. Current aluminum alloy conductor modification technologies have failed to overcome the performance bottlenecks caused by matrix composition control, and have not solved key problems such as particle aggregation, poor interfacial bonding, and incomplete coating when modifying with foreign highly conductive particles. As a result, the conductivity of the conductors is prone to fluctuation under complex operating conditions, mechanical properties are prone to decline, and long-term stability cannot be guaranteed. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, the purpose of this invention is to provide an interface coating treatment method for aluminum alloy conductors modified with nano-high conductivity particles. This method effectively improves the problems of easy agglomeration of nano-high conductivity particles and poor interfacial bonding with the aluminum alloy matrix. While improving the overall conductivity and mechanical properties of the conductor, it enhances the density of the particle coating layer and the uniform dispersion of particles in the matrix, thereby reducing the energy loss of the transmission line and ensuring the long-term stable service performance of the conductor under complex outdoor conditions.

[0005] To achieve the above objectives, the present invention provides the following solution: A method for interfacial coating of aluminum alloy wires modified with nano-high conductivity particles includes the following steps: S1. Select solid nano-high conductivity particles, and perform pretreatment, mechanical dispersion, ultrasonic dispersion and vacuum drying under inert atmosphere protection in sequence to obtain uniformly dispersed solid nano-high conductivity particle powder. S2. Under the stirring and dispersion state, the solid nano-high conductivity particle powder is subjected to inorganic interface coating treatment to deposit a coating layer on the particle surface, and then subjected to annealing and densification treatment to obtain coated and modified nano-high conductivity particles. S3. The coated and modified nano-high conductivity particles are quantitatively added to the aluminum alloy melt, and electromagnetic stirring and ultrasonic dispersion are performed in sequence to obtain an aluminum alloy composite melt with uniformly dispersed particles. S4. The aluminum alloy composite melt is prepared into a billet, and then rolled and drawn in sequence to obtain a nano-high conductivity particle modified aluminum alloy wire.

[0006] Preferably, in S1, the solid nano-high conductivity particles are one or more of nano-copper, nano-silver, and nano-copper-silver alloy; the particle size of the solid nano-high conductivity particles is 80nm-180nm.

[0007] Preferably, in step S1, the solid nano-high conductivity particles are subjected to pretreatment, mechanical dispersion, ultrasonic dispersion, and vacuum drying under an inert atmosphere in sequence, specifically including the following steps: S11. Solid high-conductivity nanoparticles are mixed with anhydrous ethanol at a mass ratio of 1:190-1:210 and placed in a ball mill jar for segmented mechanical ball milling. The ball-to-material mass ratio is 4:1, the ball milling speed is 220 r / min-280 r / min, and the mill is stopped for 11 min-14 min after each 22 min-28 min of ball milling. The total ball milling time is 1.8 h-2.2 h, and a particle suspension is obtained. S12. The particle suspension is ultrasonically dispersed with an ultrasonic power of 230W-270W and a dispersion time of 32min-38min. The temperature of the suspension is controlled below 50℃ during the ultrasonic process to obtain an ultrasonically dispersed particle suspension. S13. Place the ultrasonically dispersed particle suspension in an argon protective atmosphere and vacuum dry it at 85℃-95℃ for 6.5h-7.5h to obtain solid nano-high conductivity particle powder.

[0008] Preferably, in S2, the inorganic interface coating treatment is carried out by chemical liquid phase deposition under stirring, and the coating layer is one or more of Al2O3-SiO2 composite layer and Al-Ti-O amorphous layer; the thickness of the coating layer is 25nm-45nm.

[0009] Preferably, the mass fraction of Ti in the coating layer is 4%-7%, and the mass fraction of Si is 3%-5%.

[0010] Preferably, in S2, the annealing densification process is as follows: under an inert atmosphere, the coated high-conductivity nanoparticles are heated to 300℃-330℃ and held for 1.8h-2.2h to obtain densified coated modified high-conductivity nanoparticles.

[0011] Preferably, in S3, the aluminum alloy melt is obtained by melting wrought aluminum alloy ingots at a melting temperature of 720℃-735℃, and the oxygen content of the melt during the melting process is ≤0.001%.

[0012] Preferably, in S3, the addition rate of the coated and modified nano-high conductivity particles is 1.5 g / min-2.5 g / min, and the melt temperature during addition is 715℃-725℃; the electromagnetic stirring speed is 350 r / min-450 r / min, the ultrasonic dispersion power is 320 W-380 W, and the dispersion time is 18 min-22 min.

[0013] Preferably, in step S3, after the particles are dispersed, a fluorine-free refining agent is added to the melt, followed by heat preservation and settling. The fluorine-free refining agent is one or more of calcium carbonate, magnesium oxide, and aluminum oxide, and the amount added is 0.12%-0.18% of the melt mass. The heat preservation time is 11-14 minutes, and the settling time is 6-7 minutes.

[0014] Preferably, in step S4, the billet is prepared using a continuous casting process, with a casting temperature of 705℃-715℃ and a casting speed of 1.2m / min-1.8m / min; the rolling temperature is 340℃-360℃ and the rolling reduction rate is 35%-45%; the drawing speed is 3.5m / min-5.5m / min, and after drawing, a nano-high conductivity particle modified aluminum alloy wire with a diameter of 2.5mm-3.5mm is obtained.

[0015] Compared with the prior art, the present invention discloses at least the following technical effects: This invention effectively solves the technical problems of easy agglomeration of high-conductivity nanoparticles, poor interfacial bonding with the aluminum alloy matrix, and insufficient density of the coating layer in existing technologies by pretreatment of solid high-conductivity nanoparticles, mechanical ultrasonic stepwise dispersion, and inert atmosphere-protected drying, combined with chemical liquid-phase deposition inorganic interface coating and annealing densification treatment under stirring, and further combined with electromagnetic ultrasonic synergistic dispersion in aluminum alloy melt. It not only achieves uniform dispersion of high-conductivity nanoparticles in the aluminum alloy matrix and strengthens the interfacial bonding strength between particles and matrix, avoiding the problem of brittle phase formation by interfacial reaction, but also significantly improves the overall conductivity of aluminum alloy conductors, reduces energy loss of transmission lines, and optimizes the tensile strength and other mechanical properties of conductors. It achieves synergistic improvement of conductivity and mechanical properties, enhances the structural stability of modified conductors, and ensures long-term stable service of conductors under complex working conditions such as current carrying capacity fluctuations and ambient temperature changes. It provides reliable technical support for the large-scale industrial application of high-conductivity nanoparticle-modified aluminum alloy conductors in long-distance, high-capacity power transmission scenarios. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a flowchart of an interface coating treatment method for aluminum alloy wires modified with nano-high conductivity particles according to the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] like Figure 1 As shown, this invention provides an interface coating treatment method for aluminum alloy wires modified with nano-high conductivity particles, comprising the following steps: S1. Select solid nano-high conductivity particles, and perform pretreatment, mechanical dispersion, ultrasonic dispersion and vacuum drying under inert atmosphere protection in sequence to obtain uniformly dispersed solid nano-high conductivity particle powder.

[0021] Specifically, solid high-conductivity nanoparticles are selected from one or more of nano-copper, nano-silver, and nano-copper-silver alloys, with a particle size of 80nm-180nm. This particle size range ensures that the particles themselves have high conductivity.

[0022] In addition, the pretreatment and multi-stage dispersion are carried out in steps according to the sequence of segmented mechanical ball milling, ultrasonic dispersion, and inert atmosphere vacuum drying. The segmented mechanical ball milling involves mixing solid nano-high conductivity particles with anhydrous ethanol at a mass ratio of 1:190-1:210 in a ball mill jar, and processing at a ball-to-particle mass ratio of 4:1 and a rotation speed of 220-280 rpm. Each ball milling cycle lasts 22-28 minutes, with a 11-14 minute stop, for a total milling time of 1.8-2.2 hours. This process achieves primary dispersion while preventing particle agglomeration, resulting in... The particle suspension was then ultrasonically dispersed at an ultrasonic power of 230W-270W for 32-38 minutes, with the suspension temperature controlled below 50℃ throughout the process. The ultrasonic cavitation effect broke up the micro-agglomerates, achieving deep dispersion of the particles. Finally, the ultrasonically dispersed particle suspension was placed in an argon protective atmosphere and vacuum dried at 85℃-95℃ for 6.5-7.5 hours. This rapidly removed the dispersion medium while effectively inhibiting oxidation on the particle surface, ultimately yielding uniformly dispersed, clean, solid nano-high conductivity particle powder.

[0023] The above-mentioned process addresses the problem of easy agglomeration of high-conductivity nanoparticles through a multi-stage mechanical-ultrasonic dispersion step. Combined with a vacuum drying process protected by argon gas, it reduces the degree of particle oxidation, providing uniform particle size and impurity-free particle raw materials for interface coating, thus ensuring the continuous deposition of the coating layer.

[0024] S2. Under a stirred and dispersed state, the solid nano-high conductivity particle powder is subjected to an inorganic interface coating treatment to deposit a coating layer on the particle surface, and then subjected to an annealing and densification treatment to obtain the coated and modified nano-high conductivity particles.

[0025] Specifically, the inorganic interface coating treatment adopts a chemical liquid phase deposition method under stirred dispersion. This process can be adapted to the coating requirements of nanoparticles and achieve uniform deposition on the particle surface. The coating layer is selected from one or more of Al2O3-SiO2 composite layer and Al-Ti-O amorphous layer. The coating layer thickness is controlled at 25nm-45nm. If it is Al-Ti-O amorphous layer, the mass fraction of Ti element is 4%-7%. If it is Al2O3-SiO2 composite layer, the mass fraction of Si element is 3%-5%. This thickness and element ratio range can ensure the compactness of the coating layer without affecting the conductivity of the particles due to excessive coating layer thickness.

[0026] After coating, the particles undergo annealing and densification treatment. Under an inert atmosphere, the coated high-conductivity nanoparticles are heated to 300℃-330℃ and held for 1.8h-2.2h, isolating them from air throughout the process to prevent oxidation. Simultaneously, a gentle annealing process eliminates micropores within the coating layer, strengthening the bond between the coating layer and the particle surface. This inorganic coating layer, constructed using chemical liquid phase deposition, effectively prevents direct contact between the high-conductivity nanoparticles and the aluminum alloy matrix during subsequent melt composite processes, avoiding interfacial reactions that generate brittle phases. The annealing and densification treatment further enhances the stability of the coating structure, ensuring the stable existence of the particles in the molten aluminum alloy.

[0027] S3. The coated and modified nano-high conductivity particles are quantitatively added to the aluminum alloy melt, and electromagnetic stirring and ultrasonic dispersion are performed sequentially to obtain an aluminum alloy composite melt with uniformly dispersed particles.

[0028] Specifically, the aluminum alloy melt is obtained by melting wrought aluminum alloy ingots. The melting temperature is controlled at 720℃-735℃. This temperature range can ensure that the wrought aluminum alloy ingots are completely melted, while avoiding the high temperature that would cause the melt to oxidize more. At the same time, the oxygen content of the melt is strictly controlled to be ≤0.001% during the melting process to create a low-oxygen melt environment and reduce the oxidation loss of nano-high conductivity particles.

[0029] Then, when quantitatively adding the modified nano-high conductivity particles to the aluminum alloy melt, the addition rate is controlled at 1.5 g / min-2.5 g / min, and the melt temperature is maintained at 715℃-725℃ during addition. Low-speed addition can avoid local enrichment of particles and formation of agglomerates, and the appropriate melt temperature ensures that the coating layer does not undergo thermal decomposition. After the particles are added, electromagnetic stirring and ultrasonic dispersion are performed sequentially. First, electromagnetic stirring is performed at a speed of 350 r / min-450 r / min to achieve initial uniform distribution of particles in the melt. Then, ultrasonic power of 320W-380W is used for continuous dispersion for 18min-22min. The strong shearing effect of ultrasound breaks up the micro-agglomerates of particles in the melt, achieving deep dispersion.

[0030] After particle dispersion, a fluorine-free refining agent, one or more of calcium carbonate, magnesium oxide, and aluminum oxide, is added to the melt at a rate of 0.12%-0.18% of the melt mass. After addition, the mixture is held at a temperature of 11-14 minutes and then allowed to stand for 6-7 minutes. The fluorine-free refining agent effectively removes impurities and gases from the melt without reacting with the nano-conductive particles, thus avoiding particle loss and melt contamination. This step, through a combination of low-speed addition and electromagnetic-ultrasonic synergistic dispersion, achieves uniform dispersion of the nano-conductive particles in the aluminum alloy melt. Combined with low-oxygen melting and fluorine-free refining processes, this ensures both the cleanliness of the melt and the structural integrity of the nano-conductive particles and the coating layer, preventing particle failure.

[0031] S4. The aluminum alloy composite melt is prepared into a billet, and then rolled and drawn in sequence to obtain a nano-high conductivity particle modified aluminum alloy wire.

[0032] Specifically, the aluminum alloy composite melt is prepared into a billet using a continuous casting process. The casting temperature is controlled at 705℃-715℃, and the casting speed is 1.2m / min-1.8m / min. These process parameters are compatible with the performance of the nano-composite aluminum alloy melt, avoiding defects such as shrinkage cavities and porosity in the billet due to excessively high temperature or casting speed, and ensuring the density and structural integrity of the billet.

[0033] After the billet is prepared, it undergoes rolling at a temperature of 340℃-360℃ and a reduction rate of 35%-45%. This gentle rolling temperature and moderate reduction rate effectively prevent rolling cracks in the nano-composite aluminum alloy due to plastic deformation. Simultaneously, rolling refines and densifies the grains of the billet, improving the mechanical properties of the conductor. Following rolling, a drawing process is performed at a speed controlled at 3.5m / min-5.5m / min. Through multi-stage drawing, a nano-high conductivity particle-modified aluminum alloy conductor with a diameter of 2.5mm-3.5mm is finally obtained. Low-speed drawing avoids problems such as necking and breakage, ensuring the dimensional accuracy and surface quality of the finished conductor.

[0034] Therefore, this step not only ensures the dimensional accuracy and structural integrity of the conductor, but also achieves a synergistic improvement in the conductivity and mechanical properties of the conductor through the grain refinement effect of rolling, ultimately obtaining a high-performance nano-conductivity particle modified aluminum alloy conductor.

[0035] The interface coating treatment method for modified aluminum alloy wires with nano-high conductivity particles according to the present invention will be described in detail below with reference to embodiments and comparative examples. It should be noted that the embodiments provided by the present invention are only some examples.

[0036] Example 1 This embodiment aims to provide an interface coating treatment method for modified aluminum alloy wires using nano-high conductivity particles. The method involves preparing modified aluminum alloy wires with a diameter of 3.0 mm using nano-copper powder as the high conductivity particles and an Al2O3-SiO2 composite layer as the coating layer. Specifically, the method includes: Step 1: Select 120nm copper nanoparticles as solid high-conductivity nanoparticles. Mix them with anhydrous ethanol at a mass ratio of 1:200 and place them in a ball mill jar. Perform segmented mechanical ball milling at a ball-to-particle mass ratio of 4:1 and a rotation speed of 250r / min. After each 25min ball milling, stop for 12min, for a total ball milling time of 2.0h, to obtain a particle suspension. Disperse the suspension using 250W ultrasonic power for 35min, controlling the suspension temperature at 45℃ throughout the process, to obtain an ultrasonically dispersed suspension. Place it in an argon protective atmosphere and vacuum dry at 90℃ for 7.0h to obtain uniformly dispersed solid copper nanoparticles.

[0037] Step 2: Under stirred and dispersed conditions, the nano-copper powder is subjected to inorganic interface coating treatment by chemical liquid phase deposition to deposit an Al2O3-SiO2 composite coating layer with a Si element mass fraction of 4% and a coating layer thickness of 35nm. Subsequently, under argon protection, the coated nano-copper powder is heated to 320℃ and held at that temperature for 2.0h to complete the annealing and densification treatment, and a densified coated modified nano-copper powder is obtained.

[0038] Step 3: Place the deformed aluminum alloy ingot in a melting furnace and heat it to 730℃ for melting. Control the oxygen content of the melt to ≤0.001% to obtain an aluminum alloy melt. Add the coated modified nano copper powder to the aluminum alloy melt at 720℃ at a feeding rate of 2.0g / min. First, electromagnetically stir at 400r / min for 5min, and then disperse it with 350W ultrasonic power for 20min. After the particles are dispersed, add 0.15% of the melt mass of magnesium oxide fluorine-free refining agent to the melt, keep it at the temperature for 12min, and let it stand for 6min to obtain an aluminum alloy composite melt with uniformly dispersed particles.

[0039] Step 4: Prepare a billet from the aluminum alloy composite melt using a continuous casting process at a casting temperature of 710℃ and a casting speed of 1.5m / min. Roll the billet at 350℃ with a rolling reduction rate of 40%, and then draw it at a drawing speed of 4.5m / min to finally obtain a 3.0mm diameter nano-high conductivity particle modified aluminum alloy wire.

[0040] Example 2 This embodiment provides an interface coating treatment method for modified aluminum alloy wires using nano-high conductivity particles. Modified aluminum alloy wires with a diameter of 2.5 mm are prepared using nano-silver powder as the high conductivity particles and an Al2O3-SiO2 composite layer as the coating layer. Specifically, the method includes: Step 1: Select 100nm nano-silver powder as solid high-conductivity nanoparticles, mix them with anhydrous ethanol at a mass ratio of 1:190 and place them in a ball mill jar. Perform segmented mechanical ball milling at a ball-to-particle mass ratio of 4:1 and a rotation speed of 220r / min, with each ball milling session lasting 22min and a 11min stop, for a total ball milling time of 1.8h, to obtain a particle suspension. Disperse the suspension using 230W ultrasonic power for 32min, maintaining the suspension temperature at 40℃ throughout the process. Then, vacuum dry the suspension at 85℃ for 6.5h under argon protection to obtain uniformly dispersed solid nano-silver powder.

[0041] Step 2: Under the stirring and dispersion state, an Al2O3-SiO2 composite coating layer with a mass fraction of 3% Si element and a thickness of 25nm is deposited by chemical liquid phase deposition; under argon protection, the coated nano-silver powder is heated to 300℃ and held for 1.8h to complete the annealing and densification, and the coated modified nano-silver powder is obtained.

[0042] Step 3: Melt the deformed aluminum alloy ingot at 720℃, controlling the oxygen content of the melt to ≤0.001%; ​​add the coated modified nano silver powder to the aluminum alloy melt at 715℃ at a feeding rate of 1.5g / min, stir electromagnetically at 350r / min for 5min, and then disperse with ultrasonic power at 320W for 18min; add 0.12% of the melt mass of calcium carbonate refining agent, hold at the temperature for 11min, and let stand for 6min to obtain the aluminum alloy composite melt.

[0043] Step 4: The composite melt is continuously cast into a billet at 705℃ and 1.2m / min; it is then rolled at 340℃ with a rolling reduction rate of 35%, and then drawn at a drawing speed of 3.5m / min to obtain a 2.5mm diameter nano-high conductivity particle modified aluminum alloy wire.

[0044] Example 3 This embodiment provides an interface coating treatment method for modified aluminum alloy wires using nano-high conductivity particles. Modified aluminum alloy wires with a diameter of 3.5 mm are prepared using nano-copper-silver alloy powder as the high conductivity particles and an Al-Ti-O amorphous layer as the coating layer. Specifically, the method includes: Step 1: Select 150nm copper-silver alloy nanoparticles as solid high-conductivity nanoparticles. Mix them with anhydrous ethanol at a mass ratio of 1:210 and place them in a ball mill jar. Perform segmented mechanical ball milling at a ball-to-particle mass ratio of 4:1 and a rotation speed of 280r / min. After each 28min ball milling, stop the machine for 14min, for a total ball milling time of 2.2h, to obtain a particle suspension. Disperse the suspension using 270W ultrasonic power for 38min while controlling the temperature at 48℃. Vacuum dry at 95℃ for 7.5h under argon protection to obtain uniformly dispersed solid copper-silver alloy nanoparticles.

[0045] Step 2: Under stirred and dispersed conditions, an Al-Ti-O amorphous coating layer with a Ti element mass fraction of 5% and a thickness of 45 nm was deposited by chemical liquid phase deposition. The coated particles were heated to 330℃ and held for 2.2 h under argon protection to complete the annealing and densification, and the coated modified nano copper-silver alloy powder was obtained.

[0046] Step 3: Melt the deformed aluminum alloy ingot at 735℃, controlling the oxygen content of the melt to ≤0.001%; ​​add the coated modified particles to the aluminum alloy melt at 725℃ at a feeding rate of 2.5g / min, stir electromagnetically at 450r / min for 5min, and then disperse with ultrasonic power of 380W for 22min; add 0.18% of the melt mass of alumina refining agent, hold at the temperature for 14min, and let stand for 7min to obtain the aluminum alloy composite melt.

[0047] Step 4: The composite melt is continuously cast into a billet at 715℃ and 1.8m / min; it is then rolled at 360℃ with a rolling reduction rate of 45%, and then drawn at a drawing speed of 5.5m / min to obtain a 3.5mm diameter nano-high conductivity particle modified aluminum alloy wire.

[0048] Example 4 This embodiment provides an interface coating treatment method for modified aluminum alloy wires with nano-high conductivity particles. Modified aluminum alloy wires with a diameter of 3.5 mm are prepared by using nano-copper powder as high conductivity particles and a high Ti-content Al-Ti-O amorphous layer as the coating layer. The specific parameters are basically the same as those in Example 3, except that the mass fraction of Ti element in the coating layer is adjusted to 7% and the drawing speed is reduced to 5.0 m / min. The remaining steps and process parameters are the same as those in Example 3.

[0049] Example 5 This embodiment provides an interface coating treatment method for aluminum alloy wires modified with nano-high conductivity particles. It is a compound particle modification scheme. Nano-copper powder with a particle size of 120nm and nano-silver powder are selected and compounded at a mass ratio of 1:1 to form solid nano-high conductivity particles. The process is carried out according to the process steps and parameters of Example 1, and finally a compound particle modified aluminum alloy wire with a diameter of 3.0mm is obtained.

[0050] Comparative Example 1 The interface coating treatment method in this comparative example is exactly the same as that in Example 1. The multi-stage dispersion treatment step of solid nano-high conductivity particles in S1 is omitted. The original nano-copper powder that has not undergone pretreatment, mechanical dispersion, ultrasonic dispersion and vacuum drying under inert atmosphere protection is directly selected. The remaining steps and process parameters are the same as those in Example 1.

[0051] Comparative Example 2 The interface coating treatment method in this comparative example is exactly the same as that in Example 1. The inorganic interface coating and annealing densification steps in S2 are omitted. The uniformly dispersed nano-copper powder obtained in S1 is directly added to the aluminum alloy melt. No coating layer deposition and annealing densification are performed. The remaining steps and process parameters are the same as those in Example 1.

[0052] Comparative Example 3 The interface coating treatment method in this comparative example is exactly the same as that in Example 1. The synergistic dispersion process of electromagnetic stirring and ultrasonic dispersion in S3 is omitted, and the addition and refining treatment of fluorine-free refining agent are cancelled. The coated modified nano copper powder is directly added to the aluminum alloy melt without any dispersion treatment or refining of the melt. The remaining steps and process parameters are the same as those in Example 1.

[0053] Comparative Example 4 The interface coating treatment method in this comparative example is exactly the same as that in Example 1. The casting, rolling and drawing process in S4 is omitted. The casting, rolling and drawing process parameters of conventional aluminum alloy wires (casting temperature 730℃, casting speed 3m / min; rolling temperature 450℃, reduction rate 60%; drawing speed 8m / min) are used for forming. The remaining steps and process parameters are the same as those in Example 1.

[0054] The aluminum alloy wires prepared according to Examples 1-5 and Comparative Examples 1-4 were subjected to performance tests in accordance with national standards and industry specifications. The specific test criteria are as follows: Conductivity: Tested in accordance with GB / T3048.2-2007 "Test Methods for Electrical Properties of Wires and Cables - Part 2: Test for Resistivity of Metallic Materials"; Tensile strength: Tested in accordance with GB / T4909.3-2009 "Test methods for bare wires - Part 3: Tensile test"; Elongation: Refer to the tensile test in GB / T4909.2-2009 "Test Methods for Bare Wires Part 2: Dimensional Measurement".

[0055] Current standard performance indicators: The current standard performance indicators of aluminum alloy conductors are conductivity 58.0~61.0% IACS, tensile strength 160~170MPa, and elongation 1.5~2.0%.

[0056] The results of all tests are summarized in Table 1: Table 1 Comparison of Performance Test Results

[0057] As can be seen from the performance test data in Table 1, the performance indicators of the nano-high conductivity particle-modified aluminum alloy wires prepared in Examples 1-5 of this invention are all superior to the conventional levels of existing technologies. Specifically, the conductivity reaches 61.3%-62.0% IACS, the tensile strength is 170-178 MPa, and the elongation is 2.0%-2.3%, achieving improvements in both conductivity and mechanical properties.

[0058] The performance of the finished wires obtained in each comparative example showed a significant decline. Comparative example 1 omitted the multi-level dispersion treatment of nanoparticles, resulting in particle agglomeration, discontinuous conductive pathways, and a sharp drop in mechanical properties. Comparative example 2 omitted the inorganic interface coating and annealing densification treatment, causing the nanoparticles to react with the aluminum alloy melt to form a brittle phase, resulting in the loss of high conductivity of the particles and a significant decline in the mechanical properties of the wire. Comparative example 3 omitted the synergistic dispersion and fluorine-free refining process, causing a large amount of particle agglomeration, residual impurity gas in the melt, and the formation of a large number of structural defects. Comparative example 4 resulted in a loose billet and microcracks during the rolling and drawing process, which reduced the density and structural integrity of the wire, and the performance of each example was far lower than that of example 1.

[0059] Therefore, the above-mentioned interface coating treatment method for modified aluminum alloy conductors with nano-high conductivity particles effectively improves the problems of easy agglomeration of nano-high conductivity particles and poor interfacial bonding with aluminum alloy matrix. While improving the overall conductivity and tensile strength of the conductor, it enhances the density of the particle coating layer and the uniform dispersion of particles in the matrix, thereby reducing the energy loss of transmission lines and ensuring the long-term stable service performance of the conductor under complex outdoor conditions.

[0060] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0061] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for interface coating treatment of a nanometer high-conductivity particle modified aluminum alloy wire, characterized in that, Includes the following steps: S1. Select solid nano-high conductivity particles, and perform pretreatment, mechanical dispersion, ultrasonic dispersion and vacuum drying under inert atmosphere protection in sequence to obtain uniformly dispersed solid nano-high conductivity particle powder. S2. Under the stirring and dispersion state, the solid nano-high conductivity particle powder is subjected to inorganic interface coating treatment to deposit a coating layer on the particle surface, and then subjected to annealing and densification treatment to obtain coated and modified nano-high conductivity particles. S3. The coated and modified nano-high conductivity particles are quantitatively added to the aluminum alloy melt, and electromagnetic stirring and ultrasonic dispersion are performed sequentially to obtain an aluminum alloy composite melt with uniformly dispersed particles. S4. The aluminum alloy composite melt is prepared into a billet, and then rolled and drawn in sequence to obtain a nano-high conductivity particle modified aluminum alloy wire.

2. The method of claim 1, wherein, In S1, the solid nano-high conductivity particles are one or more of nano-copper, nano-silver, and nano-copper-silver alloy; the particle size of the solid nano-high conductivity particles is 80nm-180nm.

3. The method according to claim 1, characterized in that, In S1, the solid nano-high conductivity particles are subjected to pretreatment, mechanical dispersion, ultrasonic dispersion, and vacuum drying under an inert atmosphere in sequence, specifically including the following steps: S11. Solid high-conductivity nanoparticles are mixed with anhydrous ethanol at a mass ratio of 1:190-1:210 and placed in a ball mill jar for segmented mechanical ball milling. The ball-to-material mass ratio is 4:1, the ball milling speed is 220 r / min-280 r / min, and the mill is stopped for 11 min-14 min after each 22 min-28 min of ball milling. The total ball milling time is 1.8 h-2.2 h, and a particle suspension is obtained. S12. The particle suspension is ultrasonically dispersed with an ultrasonic power of 230W-270W and a dispersion time of 32min-38min. The temperature of the suspension is controlled below 50℃ during the ultrasonic process to obtain an ultrasonically dispersed particle suspension. S13. Place the ultrasonically dispersed particle suspension in an argon protective atmosphere and vacuum dry it at 85℃-95℃ for 6.5h-7.5h to obtain solid nano-high conductivity particle powder.

4. The method according to claim 1, characterized in that, In S2, the inorganic interface coating treatment adopts a chemical liquid phase deposition method under stirring state, and the coating layer is one or more of Al2O3-SiO2 composite layer and Al-Ti-O amorphous layer; the thickness of the coating layer is 25nm-45nm.

5. The method of claim 4, wherein, The coating layer contains 4%-7% Ti and 3%-5% Si by mass.

6. The method of claim 1, wherein, In S2, the annealing densification process is as follows: under an inert atmosphere, the coated high-conductivity nanoparticles are heated to 300℃-330℃ and held for 1.8h-2.2h to obtain densified coated modified high-conductivity nanoparticles.

7. The method of claim 1, wherein, In S3, the aluminum alloy melt is obtained by melting wrought aluminum alloy ingots at a melting temperature of 720℃-735℃, and the oxygen content of the melt during the melting process is ≤0.001%.

8. The method of claim 1, wherein, In S3, the addition rate of the coated and modified nano-high conductivity particles is 1.5 g / min-2.5 g / min, and the melt temperature during addition is 715℃-725℃; the electromagnetic stirring speed is 350 r / min-450 r / min, the ultrasonic dispersion power is 320 W-380 W, and the dispersion time is 18 min-22 min.

9. The method of claim 1, wherein, In step S3, after the particles are dispersed, a fluorine-free refining agent is added to the melt, followed by heat preservation and settling. The fluorine-free refining agent is one or more of calcium carbonate, magnesium oxide, and aluminum oxide, and the amount added is 0.12%-0.18% of the melt mass. The heat preservation time is 11-14 minutes, and the settling time is 6-7 minutes.

10. The method of claim 1, wherein, In S4, the billet is prepared using a continuous casting process at a casting temperature of 705℃-715℃ and a casting speed of 1.2m / min-1.8m / min; the rolling temperature is 340℃-360℃ and the rolling reduction rate is 35%-45%; the drawing speed is 3.5m / min-5.5m / min, and after drawing, a nano-high conductivity particle modified aluminum alloy wire with a diameter of 2.5mm-3.5mm is obtained.

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