Steel-cored high-conductivity rare-earth aluminum stranded wire and preparation method thereof

Abstract

The present application belongs to the technical field of aluminum stranded wire, and particularly relates to a steel-cored high-conductivity rare earth aluminum stranded wire and a preparation method thereof. The steel-cored high-conductivity rare earth aluminum stranded wire is composed of a steel core and hard aluminum wires stranded on the outer layer of the steel core. The hard aluminum wire comprises the following raw materials by weight percentage: Fe 0.11-0.18 wt%, Si 0.15-0.24 wt%, B 0.04-0.15 wt%, Cu 0.22-0.35 wt%, Sm 0.04-0.08 wt%, gadolinium carbide 0.05-0.12 wt%, modified MXene 0.18-0.25 wt%, and the balance of Al. The modified MXene is prepared by the following process: Ti3C2T X , copper chloride, ammonium chloride, ascorbic acid and thiourea are added into water, and the modified MXene is obtained after ultrasonic dispersion under heating. The hard aluminum wire of the present application has excellent conductivity and excellent mechanical properties.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of aluminum stranded wire, and particularly relates to a steel core high-conductivity rare earth aluminum stranded wire and a preparation method thereof. BACKGROUND

[0002] The power generation resources in China are mainly concentrated in the western region, and the power consumption areas are mainly located in the eastern region. In order to meet the power demand, long-distance and large-capacity power transmission is required. Due to the long transmission line and large line loss, a large amount of electric energy is lost on the transmission line every year. Under the industry opportunity of the upgrading of the State Grid and the surge demand for renewable energy grid connection, the market demand for high-performance power transmission wire is increasing. The steel core aluminum stranded wire has the advantages of high conductivity and tensile strength, simple structure, convenient erection and maintenance, low line cost, etc., and is widely used in the power transmission line at the present stage. However, the traditional steel core aluminum stranded wire has the industry problem that the conductivity and tensile strength cannot be compatible, resulting in high transmission loss (5%~8%), limited transmission capacity, and increased operation and maintenance cost.

[0003] In order to break through the mutual restriction between the strength and the electrical conductivity of the power transmission wire, and adapt to the development demand of the power grid, various new wires have become a research hotspot in recent years, such as carbon fiber composite core stranded wire, heat-resistant aluminum alloy wire, and aluminum-based ceramic fiber core aluminum stranded wire. However, these wires are not suitable or economical in actual line application, and have not yet achieved key technical breakthroughs. Based on the traditional steel core aluminum stranded wire, the aluminum alloy material is optimized and improved through the composite addition of micro-alloying elements, the modification of nano materials, the design of multi-layer stranded structure, the improvement of stranded technology, the gradient heat treatment process, etc. The high tensile strength and conductivity of the aluminum alloy material are synergistically improved, and the standard deviation of the strength fluctuation of the aluminum wire is reduced, the life and stability of the aluminum stranded wire are improved, and the application prospect and obvious progress are wide. SUMMARY

[0004] The first object of the application is to provide a steel core high-conductivity rare earth aluminum stranded wire, which has excellent conductivity and excellent mechanical properties.

[0005] The second object of the application is to provide a preparation method of the above-mentioned steel core high-conductivity rare earth aluminum stranded wire.

[0006] In order to achieve the above-mentioned objects, the technical scheme adopted by the application is:

[0007] A high-conductivity rare-earth aluminum stranded wire with a steel core is composed of a steel core and hard aluminum wire stranded on the outer layer of the steel core. The hard aluminum wire comprises the following raw materials in weight percentage: Fe 0.11-0.18 wt%, Si 0.15-0.24 wt%, B 0.04-0.15 wt%, Cu 0.22-0.35 wt%, Sm 0.04-0.08 wt%, gadolinium carbide 0.05-0.12 wt%, modified MXene 0.18-0.25 wt%, with the balance being Al.

[0008] The modified MXene was prepared by the following process:

[0009] Ti3C2T X Modified MXene was obtained by adding copper chloride, ammonium chloride, ascorbic acid and thiourea to water and ultrasonically dispersing them for 40-50 minutes under heating conditions.

[0010] Furthermore, the Ti3C2T X The ratio of copper chloride, ammonium chloride, ascorbic acid, thiourea and water is 10 g: (2.5-3.0) g: (0.5-0.7) g: (1.5-2.5) g: (0.01-0.03) g: (80-100) mL; the heating temperature is 80-90 ℃.

[0011] Furthermore, the gadolinium carbide is prepared by the following process:

[0012] Gadolinium and carbon powder are mixed and heated to 850-950 ℃ under an argon atmosphere for 2-3 hours. The temperature is then raised to 1300-1450 ℃ and held for 1-2 hours. After standing and cooling, washing, filtering, and drying, gadolinium carbide is obtained.

[0013] Furthermore, the mass ratio of gadolinium to carbon powder is (5-8):1.

[0014] Furthermore, the Ti3C2T X It is prepared by the following process:

[0015] Ti3AlC2 and lithium fluoride were added to a hydrochloric acid solution and stirred to obtain Ti3C2T. X .

[0016] Furthermore, the ratio of Ti3AlC2, lithium fluoride, and hydrochloric acid is 1 g: (1.5-2.0) g: (12-15) mL; the mass concentration of the hydrochloric acid is 36-38%.

[0017] Further, the steel core comprises the following raw materials by weight percentage: Mn 0.12-0.18 wt%, Ti 0.03-0.08 wt%, Si 0.014-0.022 wt%, C ≤0.01 wt%, P ≤0.008 wt%, with the balance being Fe.

[0018] The above-mentioned method for preparing high-conductivity rare-earth aluminum stranded wire with steel core includes the following steps:

[0019] (a) Weigh all the raw materials for the steel core, melt, refine, cast, roll and draw to obtain steel wire, and arrange the steel wire in a regular 1+6 pattern to obtain the steel core;

[0020] (b) Weigh all the raw materials for hard aluminum wire, melt, refine, cast, roll, draw and anneal to obtain hard aluminum wire;

[0021] (c) The steel core and hard aluminum wire are stranded together and subjected to gradient heat treatment to obtain aluminum stranded wire.

[0022] Further, the annealing temperature in step (b) is 180-220 °C, and the time is 12 h.

[0023] Further, the gradient heat treatment in step (c) is as follows: first heat treatment at 180-200 ℃ for 1-3 h, then heat treatment at 260-280 ℃ for 2-5 h, and finally heat treatment at 140-160 ℃ for 1-2 h.

[0024] The beneficial technical effects of this invention are as follows:

[0025] 1. This invention incorporates rare earth elements samarium and gadolinium carbide into hard aluminum wire. Samarium accumulates at grain boundaries, inhibiting grain growth and purifying the melt, reducing electron scattering by impurities and optimizing the conductivity of the aluminum wire. Gadolinium carbide possesses high hardness and high-temperature stability, and its dispersed distribution in the matrix forms pinning, hindering grain boundary and dislocation movement, thus enhancing the strength and heat resistance of the aluminum wire. The composite addition of rare earth elements allows for precise control of the microstructure of the hard aluminum wire, achieving a synergistic improvement in the conductivity and overall strength of the aluminum stranded wire.

[0026] 2. This invention adds modified MXene to hard aluminum wire. MXene has a two-dimensional layered structure and its intrinsic conductivity is better than that of aluminum. Copper plating on the surface of MXene can form a conductive network. Adding it to aluminum wire can effectively improve the conductivity of aluminum stranded wire. At the same time, copper plating can improve the dispersion of MXene in the matrix and its interfacial bonding performance with the matrix, regulate the microstructure of the matrix, and improve the strength of aluminum stranded wire.

[0027] 3. This invention employs a gradient heat treatment process to regulate the microstructure of the stranded wire, optimize its mechanical properties, and improve its lifespan and stability. Attached Figure Description

[0028] Figure 1 A scanning electron microscope image of gadolinium carbide prepared in Example 1 of this invention;

[0029] Figure 2 Scanning electron microscope image of the modified MXene prepared in Example 4 of this invention. Detailed Implementation

[0030] The following is a further detailed description of the present invention in conjunction with specific preferred embodiments, and it should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention. Specific conditions not specified in the embodiments are performed according to conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, all reagents or instruments used are conventional products obtained through commercial channels.

[0031] (a) Preparation example

[0032] Preparation Example 1

[0033] Preparation Example 1 provides a gadolinium carbide prepared by the following process:

[0034] Gadolinium and carbon powder were mixed at a mass ratio of 6:1 and placed in a tube furnace under argon gas. The mixture was heated to 900 °C and held for 3 h, then heated to 1400 °C and held for 2 h. After heating was stopped, the mixture was allowed to cool, washed, filtered, and dried to obtain gadolinium carbide. The scanning electron microscope image of the gadolinium carbide obtained in this preparation example is shown below. Figure 1 As shown.

[0035] Preparation Example 2

[0036] Preparation Example 2 provides a gadolinium carbide prepared by the following process:

[0037] The gadolinium and carbon powder were mixed at a mass ratio of 5:1 and placed in a tube furnace with argon gas introduced. The mixture was heated to 850 °C and held for 2 hours, then heated to 1300 °C and held for 1 hour. After heating was stopped, the mixture was allowed to cool, washed, filtered, and dried to obtain gadolinium carbide.

[0038] Preparation Example 3

[0039] Preparation Example 3 provides a gadolinium carbide prepared by the following process:

[0040] The gadolinium and carbon powder were mixed at a mass ratio of 8:1 and placed in a tube furnace with argon gas introduced. The mixture was heated to 950 °C and held for 3 hours, then heated to 1450 °C and held for 2 hours. After heating was stopped, the mixture was allowed to cool, washed, filtered, and dried to obtain gadolinium carbide.

[0041] Preparation Example 4

[0042] Preparation Example 4 provides a modified MXene prepared by the following process:

[0043] Ti3AlC2, lithium fluoride, and 38% hydrochloric acid solution were added to the hydrochloric acid solution at a ratio of 1 g: 1.8 g: 12 mL. The mixture was etched by stirring at 30 °C for 12 h. After filtration, washing, and drying, Ti3C2T was obtained. X According to Ti3C2T X The ratio of copper chloride, ammonium chloride, ascorbic acid, thiourea, and water is 10 g: 2.8 g: 0.6 g: 2 g: 0.02 g: 90 mL. Add Ti3C2T X Copper chloride, ammonium chloride, ascorbic acid, and thiourea were added to water and ultrasonically dispersed at 80 °C for 40 min. After filtration, washing, and drying, modified MXene was obtained. The scanning electron microscope image of the modified MXene obtained in this preparation example is shown below. Figure 2 As shown.

[0044] Preparation Example 5

[0045] Preparation Example 5 provides a modified MXene prepared by the following process:

[0046] Ti3AlC2, lithium fluoride, and 36% hydrochloric acid solution were added to the hydrochloric acid solution at a ratio of 1 g: 1.5 g: 12 mL. The mixture was etched by stirring at 30 °C for 10 h. After filtration, washing, and drying, Ti3C2T was obtained. X According to Ti3C2T x The ratio of copper chloride, ammonium chloride, ascorbic acid, thiourea, and water is 10 g: 2.5 g: 0.5 g: 1.5 g: 0.01 g: 80 mL. Add Ti3C2T X Copper chloride, ammonium chloride, ascorbic acid, and thiourea were added to water and ultrasonically dispersed at 80 °C for 40 min. After filtration, washing, and drying, modified MXene was obtained.

[0047] Preparation Example 6

[0048] Preparation Example 6 provides a modified MXene prepared by the following process:

[0049] Ti3AlC2, lithium fluoride, and 38% hydrochloric acid solution were added to the hydrochloric acid solution at a ratio of 1 g: 2.0 g: 15 mL. The mixture was etched by stirring at 40 °C for 15 h. After filtration, washing, and drying, Ti3C2T was obtained. X According to Ti3C2TX The ratio of copper chloride, ammonium chloride, ascorbic acid, thiourea, and water is 10 g: 3.0 g: 0.7 g: 2.5 g: 0.03 g: 100 mL. Add Ti3C2T X Copper chloride, ammonium chloride, ascorbic acid, and thiourea were added to water and ultrasonically dispersed at 90 °C for 50 min. After filtration, washing, and drying, modified MXene was obtained.

[0050] (II) Implementation Examples

[0051] Example 1

[0052] Example 1 provides a steel-core high-conductivity rare-earth aluminum stranded wire, which consists of a steel core and hard aluminum wire stranded on the outer layer of the steel core; the hard aluminum wire comprises the following raw materials by weight percentage: Fe 0.15 wt%, Si 0.21 wt%, B 0.11 wt%, Cu 0.29 wt%, Sm 0.06 wt%, gadolinium carbide of Preparation Example 1 0.09 wt%, modified MXene of Preparation Example 4 0.21 wt%, with the balance being Al; the steel wire comprises the following raw materials by weight percentage: Mn 0.16 wt%, Ti 0.05 wt%, Si 0.019 wt%, C ≤0.01 wt%, P ≤0.008 wt%, with the balance being Fe.

[0053] This embodiment also provides a method for preparing the above-mentioned steel-core high-conductivity rare-earth aluminum stranded wire, the specific steps of which are as follows:

[0054] (a) Weigh the above raw materials for the steel core, melt, refine, cast, roll and draw to obtain steel wire, and arrange the steel wire in a regular 1+6 pattern to obtain the steel core;

[0055] (b) Weigh the above raw materials for hard aluminum wire, melt, refine, cast, roll, draw and then anneal at 200 °C for 12 h to obtain hard aluminum wire;

[0056] (c) Arrange the hard aluminum wires in a regular 12+18 pattern to form the outer layer of the steel core. Twist the steel core and hard aluminum wires together, then heat treat at 200 ℃ for 2 h, then heat treat at 280 ℃ for 4 h, and finally heat treat at 150 ℃ for 2 h to obtain aluminum stranded wire.

[0057] Example 2

[0058] Example 2 provides a steel-core high-conductivity rare-earth aluminum stranded wire, which is composed of a steel core and hard aluminum wire stranded on the outer layer of the steel core; the hard aluminum wire comprises the following raw materials by weight percentage: Fe 0.11 wt%, Si 0.15 wt%, B 0.04 wt%, Cu 0.22 wt%, Sm 0.04 wt%, gadolinium carbide of Preparation Example 2 0.05 wt%, modified MXene of Preparation Example 5 0.18 wt%, with the balance being Al; the steel wire comprises the following raw materials by weight percentage: Mn 0.12 wt%, Ti 0.03 wt%, Si 0.014 wt%, C ≤0.01 wt%, P ≤0.008 wt%, with the balance being Fe.

[0059] This embodiment also provides a method for preparing the above-mentioned steel-core high-conductivity rare-earth aluminum stranded wire, the specific steps of which are as follows:

[0060] (a) Weigh the above raw materials for the steel core, melt, refine, cast, roll and draw to obtain steel wire, and arrange the steel wire in a regular 1+6 pattern to obtain the steel core;

[0061] (b) Weigh the above raw materials for hard aluminum wire, melt, refine, cast, roll, draw and then anneal at 180 °C for 12 h to obtain hard aluminum wire;

[0062] (c) Arrange the hard aluminum wires in a regular 12+18 pattern to form the outer layer of the steel core. Twist the steel core and hard aluminum wires together, then heat treat at 180 ℃ for 1 h, then heat treat at 260 ℃ for 2 h, and finally heat treat at 140 ℃ for 1 h to obtain aluminum stranded wire.

[0063] Example 3

[0064] Example 3 provides a steel-core high-conductivity rare-earth aluminum stranded wire, which consists of a steel core and hard aluminum wire stranded on the outer layer of the steel core; the hard aluminum wire comprises the following raw materials by weight percentage: Fe 0.18 wt%, Si 0.24 wt%, B 0.15 wt%, Cu 0.35 wt%, Sm 0.08 wt%, gadolinium carbide from Preparation Example 3 0.12 wt%, modified MXene from Preparation Example 6 0.25 wt%, with the balance being Al; the steel wire comprises the following raw materials by weight percentage: Mn 0.18 wt%, Ti 0.08 wt%, Si 0.022 wt%, C ≤0.01 wt%, P ≤0.008 wt%, with the balance being Fe.

[0065] This embodiment also provides a method for preparing the above-mentioned steel-core high-conductivity rare-earth aluminum stranded wire, the specific steps of which are as follows:

[0066] (a) Weigh the above raw materials for the steel core, melt, refine, cast, roll and draw to obtain steel wire, and arrange the steel wire in a regular 1+6 pattern to obtain the steel core;

[0067] (b) Weigh the above raw materials for hard aluminum wire, melt, refine, cast, roll, draw and then anneal at 220 °C for 12 h to obtain hard aluminum wire;

[0068] (c) Arrange the hard aluminum wires in a regular 12+18 pattern to form the outer layer of the steel core. Twist the steel core and hard aluminum wires together, then heat treat at 200 ℃ for 3 h, then heat treat at 280 ℃ for 5 h, and finally heat treat at 160 ℃ for 2 h to obtain aluminum stranded wire.

[0069] (III) Comparative Example

[0070] Comparative Example 1

[0071] Comparative Example 1 is basically the same as Example 1, except that gadolinium carbide in the hard aluminum wire of Example 1 is replaced with gadolinium.

[0072] Comparative Example 2

[0073] Comparative Example 2 is basically the same as Example 1, except that the modified MXene in Example 1 is omitted.

[0074] Comparative Example 3

[0075] Comparative Example 3 is basically the same as Example 1, except that the modified MXene in Example 1 is replaced with MXene material Ti3C2T. X .

[0076] (iv) Test Examples

[0077] The hard aluminum wires prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests.

[0078] Mechanical property testing: The mechanical properties of the hard aluminum wires in Examples 1-3 and Comparative Examples 1-3 were tested in accordance with GB / T 4909.3-2009 "Test methods for bare wires - Part 3: Tensile test". The results are shown in Table 1.

[0079] Conductivity test: The conductivity of the hard aluminum wires in Examples 1-3 and Comparative Examples 1-3 was tested according to GB / T 3048.2-2007 "Test methods for electrical properties of wires and cables - Part 2: Test for resistivity of metallic materials". The results are shown in Table 1.

[0080] Table 1. Test results of mechanical properties and conductivity of hard aluminum wire

[0081]

[0082] As shown in Table 1, the hard aluminum wires obtained in Examples 1-3 of this invention possess excellent mechanical properties and good electrical conductivity. Compared to Example 1, Comparative Example 1 replaces gadolinium carbide with gadolinium, Comparative Example 2 omits the modified MXene in Example 1, and Comparative Example 3 replaces the modified MXene in Example 1 with the MXene material Ti3C2T. X The mechanical and electrical properties of the samples in Comparative Examples 1-3 all decreased to varying degrees. Specific analysis reveals two main points: First, the present invention incorporates rare earth elements samarium and gadolinium carbide into the hard aluminum wire. Samarium accumulates at grain boundaries, inhibiting grain growth and purifying the melt, reducing electron scattering by impurities and optimizing the electrical conductivity of the aluminum wire. Gadolinium carbide possesses high hardness and high-temperature stability, dispersing throughout the matrix to form pinning structures, hindering grain boundary and dislocation movement, thus enhancing the strength and heat resistance of the aluminum wire. The composite addition of rare earth elements allows for precise control of the microstructure of the hard aluminum wire, achieving a synergistic improvement in both conductivity and overall strength. Second, the present invention adds modified MXene to the hard aluminum wire. MXene has a two-dimensional layered structure and intrinsic conductivity superior to aluminum. Copper plating on the surface of MXene forms a conductive network, effectively improving the conductivity of the aluminum stranded wire. Simultaneously, copper plating improves the dispersion of MXene in the matrix and its interfacial bonding with the matrix, controlling the microstructure of the matrix and enhancing the strength of the aluminum stranded wire.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. The basic principles and main features of the present invention have been described above with specific implementation schemes. Based on the present invention, some modifications or substitutions can be made, but these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of protection claimed by the present invention.

Claims

1. A steel-core high-conductivity rare-earth aluminum stranded wire, comprising a steel core and hard aluminum wire stranded on the outer layer of the steel core, characterized in that, The hard aluminum wire comprises the following raw materials by weight percentage: Fe 0.11-0.18 wt%, Si 0.15-0.24 wt%, B 0.04-0.15 wt%, Cu 0.22-0.35 wt%, Sm 0.04-0.08 wt%, gadolinium carbide 0.05-0.12 wt%, modified MXene 0.18-0.25 wt%, with the balance being Al; The modified MXene was prepared by the following process: Ti3C2T X Modified MXene was obtained by adding copper chloride, ammonium chloride, ascorbic acid and thiourea to water and ultrasonically dispersing them for 40-50 minutes under heating conditions. The Ti3C2T X The ratio of copper chloride, ammonium chloride, ascorbic acid, thiourea, and water is 10 g : (2.5-3.0) g : (0.5-0.7) g : (1.5-2.5) g : (0.01-0.03) g : (80-100) mL; the heating temperature is 80-90 ℃. The Ti3C2T X It is prepared by the following process: Ti3AlC2 and lithium fluoride were added to a hydrochloric acid solution and stirred at 30-40℃ for 10-15 h to obtain Ti3C2T. X ; The ratio of Ti3AlC2, lithium fluoride, and hydrochloric acid is 1 g : (1.5-2.0) g : (12-15) mL; the mass concentration of the hydrochloric acid is 36-38%.

2. The steel-cored, high-conductivity rare-earth aluminum stranded wire according to claim 1, characterized in that, The gadolinium carbide is prepared by the following process: Gadolinium and carbon powder are mixed and heated to 850-950 ℃ under an argon atmosphere for 2-3 hours. The temperature is then raised to 1300-1450 ℃ and held for 1-2 hours. After standing and cooling, washing, filtering, and drying, gadolinium carbide is obtained.

3. The steel-cored, high-conductivity rare-earth aluminum stranded wire according to claim 2, characterized in that, The mass ratio of gadolinium to carbon powder is (5-8):

1.

4. The steel-cored high-conductivity rare-earth aluminum stranded wire according to claim 1, characterized in that, The steel core comprises the following raw materials by weight percentage: Mn 0.12-0.18 wt%, Ti 0.03-0.08 wt%, Si 0.014-0.022 wt%, C ≤0.01 wt%, P ≤0.008 wt%, with the balance being Fe.

5. A method for preparing the steel-core high-conductivity rare-earth aluminum stranded wire according to claim 4, characterized in that, Includes the following steps: (a) Weigh all the raw materials for the steel core, melt, refine, cast, roll and draw to obtain steel wire, and arrange the steel wire in a regular 1+6 pattern to obtain the steel core; (b) Weigh all the raw materials for hard aluminum wire, melt, refine, cast, roll, draw and anneal to obtain hard aluminum wire; (c) The steel core and hard aluminum wire are stranded together and subjected to gradient heat treatment to obtain aluminum stranded wire.

6. The method for preparing steel-cored high-conductivity rare-earth aluminum stranded wire according to claim 5, characterized in that, The annealing temperature in step (b) is 180-220 °C, and the time is 12 h.

7. The method for preparing steel-cored high-conductivity rare-earth aluminum stranded wire according to claim 5, characterized in that, The gradient heat treatment steps described in step (c) are as follows: first heat treatment at 180-200 ℃ for 1-3 h, then heat treatment at 260-280 ℃ for 2-5 h, and finally heat treatment at 140-160 ℃ for 1-2 h.

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