Preparation process of ultra-fine copper conductor for new energy vehicles

Abstract

The present application relates to copper conductor preparation technical field, especially a kind of super fine micro copper conductor preparation process for new energy vehicles.The super fine micro copper conductor preparation process for new energy vehicles is as follows: first, copper alloy rod blank is prepared, then copper alloy rod blank is used to melt casting, solid solution, cooling deformation, aging treatment to obtain copper alloy rod embryo, then the first wire drawing treatment, the first intermediate annealing treatment, the second wire drawing treatment, the second intermediate annealing treatment, the third wire drawing treatment, the third intermediate annealing treatment, the final annealing treatment of copper alloy rod embryo are carried out to obtain finished product copper alloy super fine single strand wire, and the finished product copper alloy super fine single strand wire is used for multi-strand stranding to obtain super fine micro copper stranded conductor.The super fine micro copper conductor prepared in the present application has the advantages of high electrical conductivity, high strength and high flexibility, which is comparable to imported products, and can realize domestic substitution of imported products.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of copper conductor preparation, in particular to a super-fine copper conductor preparation process for new energy vehicles. BACKGROUND

[0002] With the publication of the New Energy Vehicle Industry Development Plan, the new energy vehicle industry is developing rapidly. Copper alloy material refers to an alloy obtained by adding one or more other elements to pure copper, which has excellent electrical conductivity, thermal conductivity, corrosion resistance, wear resistance, high strength, fatigue resistance, and can be used to make high-voltage cables in new energy vehicles. High-voltage cables are mainly used for electric vehicle wiring harnesses, and the voltage they carry is about 600V.

[0003] Automotive wiring harness is the main carrier for controlling the functions of automotive electrical and electronic components, and is the blood vessels and nerves of the vehicle, providing power, signal transmission and feedback for various electronic components. A high-conductivity, high-strength, and high-flexibility copper alloy high-voltage cable can improve the driving safety performance of new energy vehicles. Such high-value-added copper alloy high-voltage cables are mainly dependent on imports, such as Sumitomo Electric, Hitachi Cable, Mitsubishi, and Furukawa. At present, China has become a major consumer of high-strength and high-conductivity special copper conductors, but due to the late start of research in the field of high-strength and high-conductivity special copper conductors, high-strength and high-conductivity special copper conductors have to rely on imports. Therefore, the present application provides a super-fine copper conductor preparation process for new energy vehicles. SUMMARY

[0004] In order to solve the above-mentioned problem that the high-strength and high-conductivity special copper conductor is highly dependent on imports, the present application provides a super-fine copper conductor preparation process for new energy vehicles.

[0005] The super-fine copper conductor preparation process for new energy vehicles provided by the present application is realized by the following scheme:

[0006] A super-fine copper conductor preparation process for new energy vehicles, comprising the following steps:

[0007] Step 1: Preparation of copper alloy rod blank: mix copper alloy powder and surface-modified carbon nanotubes uniformly to obtain mixed alloy powder, the content of surface-modified carbon nanotubes in the mixed alloy powder is 0.2-1.0wt%;

[0008] The mass percentage of elements in the copper alloy powder is as follows: 0.05%-0.15% Ag, 0.05%-0.50% Nb, 0.01%-0.10% In, 0.02%-0.08% Si, 0.30%-0.80% Cr, 0.003%-0.008% Ti, 0.002%-0.06% Hf, 0.004%-0.016% Sc, unavoidable impurities total content <0.15%, and the balance is Cu.

[0009] Step two, melt and cast the mixed alloy powder in step two into copper alloy rod blanks with a diameter of 8-12mm, and the copper alloy rod blanks are subjected to solid solution and aging treatment to obtain copper alloy rod billets;

[0010] Step three, the copper alloy rod billets with a diameter of 8-12mm in step three are subjected to first drawing treatment and first intermediate annealing treatment to obtain copper alloy coarse wires with a diameter of 3-6mm;

[0011] Step four, the copper alloy coarse wires with a diameter of 3-6mm are subjected to second drawing treatment and second intermediate annealing treatment to obtain copper alloy primary fine wires with a diameter of 0.3-0.6mm;

[0012] Step five, the copper alloy primary fine wires with a diameter of 0.3-0.6mm are subjected to third drawing treatment and third intermediate annealing treatment to obtain semi-finished copper alloy ultra-fine single-strand wires with a diameter of 0.80-1.08mm;

[0013] Step six, the semi-finished copper alloy ultra-fine wires are subjected to final annealing treatment to obtain finished copper alloy ultra-fine single-strand wires, and the finished copper alloy ultra-fine single-strand wires are used for multi-strand twisting to obtain ultra-fine copper twisted conductor wires.

[0014] The carbon nanotubes are modified by surface monatomic copper in the application, the compatibility of the carbon nanotubes and the copper alloy matrix is improved, the carbon nanotubes can be uniformly dispersed in the copper alloy melt under the melting condition, and the conductivity, mechanical strength and bending resistance of the copper alloy rod billets are improved, the copper alloy rod billets are comparable to imported high-strength and high-conductivity special copper conductors; in combination with the multiple drawing and multiple intermediate annealing treatment + final annealing provided in the application, the problem of wire breakage can be effectively avoided, and finally the ultra-fine copper twisted conductor wires with high conductivity, high strength and high bending resistance can be obtained by multi-strand twisting, which meets the demand of high-voltage cables for new energy vehicles.

[0015] The ultra-fine copper conductor prepared in the application has the advantages of high conductivity, high strength and high bending resistance, and is comparable to imported products, which can realize domestic substitution of imported products.

[0016] Preferably, the content of the surface-modified carbon nanotubes in the mixed alloy powder is 0.5-0.6wt%.

[0017] By optimizing the content of the surface-modified carbon nanotubes, the overall conductivity of the ultra-fine copper conductor can be improved while ensuring that it has better drawing strength and bending resistance.

[0018] Preferably, the surface-modified carbon nanotubes are monatomic copper-modified carbon nanotubes, the monatomic copper loading rate is 5-10wt%, the tube diameter of the carbon nanotubes is 5-40nm, the length is 0.5-20nm, and the hydroxyl content is 2-3wt%.

[0019] By adopting the technical scheme, the overall ultra-fine copper conductor can have excellent conductivity.

[0020] Preferably, the solution treatment parameters in step two are: heating to 980-1060 DEG C and holding for 15-45 min.

[0021] Preferably, the solution treatment parameters in step two are: heating to 1020-1040 DEG C and holding for 25-30 min.

[0022] Preferably, the aging treatment parameters in step two are: heating to 420-480 DEG C and holding for 120-160 min.

[0023] By adopting the technical scheme, the tensile strength and the bending performance of the copper alloy rod blank can be ensured.

[0024] Preferably, the angle of the extrusion die used in the first drawing process in step three is 25-30 DEG, and the processing deformation rate is 8+ / -0.5%; the first intermediate annealing parameters are: heating to 840-860 DEG C and holding for 15-30 min.

[0025] Preferably, the angle of the extrusion die used in the second drawing process in step four is 25-30 DEG, and the processing deformation rate is 5+ / -0.5%; the second intermediate annealing parameters are: heating to 840-860 DEG C and holding for 15-30 min.

[0026] Preferably, the angle of the extrusion die used in the third drawing process in step five is 25-30 DEG, and the processing deformation rate is 2+ / -0.5%; the third intermediate annealing parameters are: heating to 840-860 DEG C and holding for 15-30 min.

[0027] Preferably, the final annealing treatment parameters are: heating to 900-960 DEG C and holding for 0.4-0.6 s.

[0028] By adopting the technical scheme, the ultra-fine copper conductor for new energy vehicles with high conductivity, high strength and high bending resistance can be obtained, and the performance requirements of the high-voltage cable for new energy vehicles can be met.

[0029] In summary, the present application has the following advantages:

[0030] 1、The ultra-fine copper conductor for new energy vehicles prepared in the present application has the advantages of high conductivity, high strength and high bending resistance, which is comparable to imported products, and can realize domestic substitution of imported products.

[0031] 2. The present invention modifies the surface of carbon nanotubes with single-atom copper, thereby improving the compatibility of carbon nanotubes and the copper alloy matrix. The carbon nanotubes can be evenly dispersed in the copper alloy melt under molten conditions, thereby improving the conductivity, mechanical strength and flexural resistance of the copper alloy rod embryo. The copper alloy rod embryo is comparable to the high-strength and high-conductivity special copper conductors imported from abroad. Combined with the multiple wire drawing and multiple intermediate annealing treatments + final annealing provided by the present invention, the problem of wire breakage during wire drawing can be effectively avoided. Finally, multiple strands can be twisted to produce ultra-fine copper stranded conductor wires with high conductivity, high strength and high flexural resistance, meeting the needs of high-voltage cables for new energy vehicles.

[0032] 3. The preparation process of the present invention is relatively simple, which facilitates mass production and market promotion. DETAILED DESCRIPTION

[0033] In order to further understand the present invention, the technology of the present invention is described below in conjunction with embodiments and comparative examples.

[0034] Example

[0035] A process for preparing ultra-fine copper conductors for new energy vehicles comprises the following steps:

[0036] Step 1, preparation of copper alloy rod blank: copper alloy powder and surface-modified carbon nanotubes are mixed at high speed to obtain mixed alloy powder, wherein the content of surface-modified carbon nanotubes in the mixed alloy powder is 0.2-1.0 wt%; preferably, the content of surface-modified carbon nanotubes in the mixed alloy powder is 0.5-0.6 wt%;

[0037] The surface-modified carbon nanotubes are single-atom copper-modified carbon nanotubes, with a single-atom copper loading rate of 5-10wt%, a diameter of 5-40nm, a length of 0.5-20nm, and a hydroxyl content of 2-3wt%;

[0038] The mass percentages of the copper alloy powder are as follows: 0.05% to 0.15% Ag, 0.05% to 0.50% Nb, 0.01% to 0.10% In, 0.02% to 0.08% Si, 0.30% to 0.80% Cr, 0.003% to 0.008% Ti, 0.002% to 0.06% Hf, 0.004% to 0.016% Sc, the total content of unavoidable impurities is <0.15%, and the balance is Cu;

[0039] Step 2: The mixed alloy powder in step 2 is melt-casted into a copper alloy rod blank with a diameter of 8-12 mm. The obtained copper alloy rod blank is subjected to a solution treatment: heating to 980-1060° C. at a rate of 5-10° C. / min and holding for 15-45 minutes, and then subjected to an aging treatment: heating to 420-480° C. at a rate of 1-3° C. / min and holding for 120-160 minutes to obtain a copper alloy rod blank;

[0040] Step 3: The copper alloy rod blank with a diameter of 8-12 mm in step 3 is subjected to a first wire drawing process, wherein the angle α of the extrusion die used in the first wire drawing process is 25-30°, and the processing deformation rate is 8±0.5%. After the first wire drawing process is completed, an online first intermediate annealing process is performed, wherein the first intermediate annealing parameters are heating to 840-860° C. at a rate of 5-10° C. / min and holding for 15-30 minutes to obtain a copper alloy thick wire with a diameter of 3-6 mm;

[0041] Step 4: The copper alloy thick wire with a diameter of 3-6 mm is subjected to a second wire drawing process. The angle α of the extrusion die used in the second wire drawing process is 25-30 degrees, and the processing deformation rate is 5±0.5%. After the second wire drawing process is completed, an online second intermediate annealing process is performed. The second intermediate annealing parameters are heating to 840-860°C at 5-10°C / min and holding for 15-30 minutes to obtain a copper alloy primary filament with a diameter of 0.3-0.6 mm;

[0042] Step 5: The copper alloy primary filament with a diameter of 0.3-0.6 mm is subjected to a third wire drawing process. The angle α of the extrusion die used in the third wire drawing process is 25-30 degrees, and the processing deformation rate is 2±0.5%. After the third wire drawing process is completed, an online third intermediate annealing process is performed. The third intermediate annealing parameters are heating to 840-860°C at 5-10°C / min and holding for 15-30 minutes, thereby obtaining a semi-finished copper alloy ultrafine single strand wire with a diameter of 0.80-1.08 mm.

[0043] Step six, the semi-finished copper alloy ultrafine wire is subjected to final annealing treatment, heating the temperature to 900-960°C at a rate of 5-10°C / min and keeping the temperature for 0.4-0.6s to obtain the finished copper alloy ultrafine single strand wire. The finished copper alloy ultrafine single strand wire is twisted into multiple strands to produce an ultrafine copper stranded conductor wire.

[0044] Preparation Example

[0045] The element formula of the copper alloy powder in mass percentage is shown in Table 1-3.

[0046] Table 1: Elemental formula of copper alloy powder in mass percentage in preparation examples 1-7

[0047]

[0048] Table 2: Elemental formula of copper alloy powder in mass percentage in preparation examples 8-14

[0049]

[0050] Table 3: Elemental formula of copper alloy powder in mass percentage in Preparation Examples 15-20

[0051]

[0052] Preparation method of copper alloy powder: high-purity cathode electrolytic copper ingot (99.99%), copper-silver alloy (Ag-10Cu, 99.99%, Beijing Ruichi High-tech Co., Ltd.), copper-niobium alloy (CuNb5, 99.99%, Tianjin Hejifeng Metal Materials Co., Ltd.), copper-indium alloy (CuIn5, 4N, Beijing Zhongke Yannuo Technology Co., Ltd.), copper-silicon alloy (CuSi20 copper-silicon alloy, 99.9%, Jiangsu Xitike Metal Products Co., Ltd.), copper-chromium alloy (CuCr10 copper-chromium alloy, 99.99%, Suzhou Rongqian Rare Metal Products Co., Ltd.), copper-titanium alloy (CuTi20 copper-titanium alloy, 99.99%, Tianjin Hejifeng Metal Materials Co., Ltd.), copper-hafnium alloy (CuHf2, 99.99%, customized by Hebei Ruichi New Materials Co., Ltd.), copper-scandium alloy (Cu Sc, 99.99%, customized by Hebei Ruichi New Materials Co., Ltd.) is placed in a smelting furnace at 1090℃. After all the raw materials are completely melted, they are refined, degassed, and deslaged to obtain a copper alloy melt. Copper alloy powder is obtained by spraying. The particle size is D 50 =12-16μm.

[0053] Example 1: A process for preparing ultrafine copper conductors for new energy vehicles, comprising the following steps:

[0054] Step 1, preparation of copper alloy rod blank: prepare copper alloy powder according to the element formula of mass percentage of copper alloy powder provided in Preparation Example 1: place high-purity cathode electrolytic copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, and copper-scandium alloy in a smelting furnace at 1090°C, and after all raw materials are completely melted, refine, degas, and remove slag to obtain a copper alloy melt, and prepare the particle size D by spraying. 50 = 14.8 μm copper alloy powder, 998 g of copper alloy powder and 2 g of surface-modified carbon nanotubes (single-atom copper-modified carbon nanotubes customized by Beijing Graphene Technology Research Institute Co., Ltd., with a single-atom copper loading of 5.13 wt%, and industrial-grade multi-walled carbon nanotubes TNNF-6 as the carrier, produced by Chengdu Organic Chemistry Co., Ltd., Chinese Academy of Sciences) were placed in a high-speed stirring kettle and mixed at 600 rpm for 1.0 h under argon protection to obtain a mixed alloy powder;

[0055] The preparation method of the surface-modified carbon nanotube is as follows: 0.50 g of industrial multi-walled carbon nanotube TNNF-6 (provided by Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, OD: 10-20 nm, length 5-20 microns, SSA > 120 m 2 / g) is dispersed in 1.0 L distilled water to obtain a graphene dispersion liquid by magnetic stirring at 200 rpm, and then 4.0 g of potassium hydroxide is dissolved in 1.0 L distilled water to obtain a potassium hydroxide aqueous solution; under magnetic stirring at 200 rpm, the prepared potassium hydroxide aqueous solution is added to the graphene dispersion liquid at a dropwise adding speed of 2 drops / s, and after the dropwise adding is completed, stirring is continued for 5 min, the water bath is warmed to 80℃, and magnetic stirring is carried out at 200 rpm for 1 h, the temperature is raised to 100℃ to remove the water in the solution, and then a multi-walled carbon nanotube TNNF-6 / KOH dry powder is obtained; 13.1 g of copper chloride CuCl2 is placed in one crucible (labeled as crucible A), and 4.5 g of multi-walled carbon nanotube TNNF-6 / KOH dry powder is placed in another crucible (labeled as crucible B), crucible A is placed in the upstream zone of the tube furnace, and crucible B is placed in the downstream zone of the tube furnace, then the tube furnace is sealed, argon gas (purity 99.9%) is introduced into the tube furnace, under the argon atmosphere, the upstream temperature zone of the tube furnace is heated from room temperature to 550℃ at a speed of 10℃ / min, and maintained at 550℃ for 1.0 h, and at the same time, under the argon atmosphere, the downstream temperature zone of the tube furnace is heated from room temperature to 550℃ at a speed of 10℃ / min, and also maintained at 550℃ for 1.0 h, and then a metal single-atom copper-doped industrial multi-walled carbon nanotube TNNF-6 precursor is obtained; the obtained industrial multi-walled carbon nanotube TNNF-6 precursor is added to 400 ml of dilute hydrochloric acid with a concentration of 1.0 ml / L, and stirred at 200 rpm for 1 h, then vacuum filtration is carried out, and the obtained solid powder is washed with distilled water for three times, the obtained solid powder is placed in a vacuum drying box, the vacuum degree is adjusted to 100 Pa, the drying temperature is 125℃, and vacuum drying treatment is carried out for 60 min, then the obtained solid material is placed in a planetary ball mill, the grinding ball is zirconia, the inner wall of the tank body of the planetary ball mill is polytetrafluoroethylene, argon gas (purity 99.9%) is introduced into the planetary ball mill, and under the argon atmosphere, stirring is carried out at 60 rpm for 10 min, at 200 rpm for 5 min, at 400 rpm for 5 min, at 10 min, and at 60 rpm for 10 min, and then a metal single-atom copper-doped industrial multi-walled carbon nanotube TNNF-6 powder with an average particle size of 180-250 nm is obtained for structure characterization, and the atoms exist on the graphene surface in the form of copper single atoms; inductively coupled plasma emission spectrum analysis shows that the copper single atom doping amount is about 5.13 wt%;

[0056] Step 2: placing the mixed alloy powder in step 1 into a smelting furnace at 1090° C., and after all raw materials are completely melted, refining, degassing, and deslagging are performed to obtain a copper alloy melt, which is then melt-cast into a copper alloy rod blank with a diameter of 8 mm. The obtained copper alloy rod blank is subjected to a solution treatment: heating at 10° C. / min to 1015° C. and holding for 25 min, and then an aging treatment: heating at 2° C. / min to 465° C. and holding for 2.0 h to obtain a copper alloy rod blank;

[0057] Step 3: The copper alloy rod blank with a diameter of 8 mm in step 3 is subjected to a first wire drawing process. The angle α of the extrusion die used in the first wire drawing process is 30°, and the processing deformation rate is 8%. After the first wire drawing process is completed, an online first intermediate annealing process is performed. The first intermediate annealing parameters are heating to 860° C. at a rate of 10° C. / min and holding for 20 minutes to obtain a copper alloy thick wire with a diameter of 3.0 mm;

[0058] Step 4: The copper alloy thick wire with a diameter of 3.0 mm is subjected to a second wire drawing process. The angle α of the extrusion die used in the second wire drawing process is 30°, and the processing deformation rate is 4.5%. After the second wire drawing process, an online second intermediate annealing process is performed. The second intermediate annealing parameters are heating to 850° C. at 8° C. / min and holding for 25 minutes, to obtain a copper alloy primary filament with a diameter of 0.40 mm;

[0059] Step 5: The copper alloy primary filament with a diameter of 0.40 mm was subjected to a third wire drawing process. The angle α of the extrusion die used in the third wire drawing process was 30°, and the processing deformation rate was 1.5%. After the third wire drawing process, an online third intermediate annealing process was performed. The third intermediate annealing parameters were: heating to 840° C. at a rate of 5° C. / min and holding for 30 minutes, thereby obtaining a semi-finished copper alloy ultrafine single strand filament with a diameter of 0.106 mm.

[0060] Step 6: Perform a final annealing treatment on the semi-finished copper alloy ultrafine wire with a diameter of 0.106 mm, heating it to 948°C at a rate of 10°C / min and keeping it warm for 0.6s to obtain a finished copper alloy ultrafine single-strand wire. The finished copper alloy ultrafine single-strand wire is twisted into multiple strands to produce 42 ultrafine copper stranded conductor wires.

[0061] The difference between Example 2 and Example 1 is that: Step 1, preparation of copper alloy rod blank: Copper alloy powder is prepared according to the element formula of mass percentage of copper alloy powder provided in Preparation Example 2: high-purity cathode electrolytic copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, and copper-scandium alloy are placed in a smelting furnace at 1090°C, and after all raw materials are completely melted, they are refined, degassed, and deslagging to obtain a copper alloy melt, and a particle size of D is obtained by spraying. 50= 14.6 μm copper alloy powder, 998 g of the copper alloy powder and 2 g of the surface-modified carbon nanotubes were placed in a high-speed stirring kettle and mixed at 600 rpm for 1.0 h under argon protection to obtain the mixed alloy powder.

[0062] Example 3 differs from Example 1 in that in Step 1, preparation of the copper alloy rod blank: the copper alloy powder was prepared according to the elemental formula provided in Preparation Example 3 in terms of mass percentage: high-purity cathode electrolytic copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, and copper-scandium alloy were placed in a smelting furnace at 1090°C, and after complete melting of all raw materials, the copper alloy melt was refined, degassed, and deslagged, and a copper alloy powder with a particle size D 50 = 14.6 μm copper alloy powder, 998 g of the copper alloy powder and 2 g of the surface-modified carbon nanotubes were placed in a high-speed stirring kettle and mixed at 600 rpm for 1.0 h under argon protection to obtain the mixed alloy powder.

[0063] Example 4 differs from Example 1 in that in Step 1, preparation of the copper alloy rod blank: the copper alloy powder was prepared according to the elemental formula provided in Preparation Example 4 in terms of mass percentage: high-purity cathode electrolytic copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, and copper-scandium alloy were placed in a smelting furnace at 1090°C, and after complete melting of all raw materials, the copper alloy melt was refined, degassed, and deslagged, and a copper alloy powder with a particle size D 50 = 14.6 μm copper alloy powder, 998 g of the copper alloy powder and 2 g of the surface-modified carbon nanotubes were placed in a high-speed stirring kettle and mixed at 600 rpm for 1.0 h under argon protection to obtain the mixed alloy powder.

[0064] Example 5 differs from Example 1 in that in Step 1, preparation of the copper alloy rod blank: the copper alloy powder was prepared according to the elemental formula provided in Preparation Example 5 in terms of mass percentage: high-purity cathode electrolytic copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, and copper-scandium alloy were placed in a smelting furnace at 1090°C, and after complete melting of all raw materials, the copper alloy melt was refined, degassed, and deslagged, and a copper alloy powder with a particle size D 50 = 14.6 μm copper alloy powder, 998 g of the copper alloy powder and 2 g of the surface-modified carbon nanotubes were placed in a high-speed stirring kettle and mixed at 600 rpm for 1.0 h under argon protection to obtain the mixed alloy powder.

[0065] Example 6 differs from Example 1 in that in Step 1, the preparation of the copper alloy rod blank: the copper alloy powder is prepared according to the elemental formula of the mass percentage of the copper alloy powder provided in Preparation Example 6: high-purity cathode copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, copper-scandium alloy are placed in a smelting furnace at 1090°C, after all the raw materials are completely melted, the copper alloy melt is refined, degassed, and deslagged, and a copper alloy powder with a particle size D 50 = 14.8 μm is prepared by a spray method, 998 g of the copper alloy powder and 2 g of surface-modified carbon nanotubes are placed in a high-speed stirred tank, mixed at 600 rpm under argon protection for 1.0 h, and the mixed alloy powder is obtained.

[0066] Example 7 differs from Example 1 in that in Step 1, the preparation of the copper alloy rod blank: the copper alloy powder is prepared according to the elemental formula of the mass percentage of the copper alloy powder provided in Preparation Example 7: high-purity cathode copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, copper-scandium alloy are placed in a smelting furnace at 1090°C, after all the raw materials are completely melted, the copper alloy melt is refined, degassed, and deslagged, and a copper alloy powder with a particle size D 50 = 14.7 μm is prepared by a spray method, 998 g of the copper alloy powder and 2 g of surface-modified carbon nanotubes are placed in a high-speed stirred tank, mixed at 600 rpm under argon protection for 1.0 h, and the mixed alloy powder is obtained.

[0067] Example 8 differs from Example 1 in that in Step 1, the preparation of the copper alloy rod blank: the copper alloy powder is prepared according to the elemental formula of the mass percentage of the copper alloy powder provided in Preparation Example 1: high-purity cathode copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, copper-scandium alloy are placed in a smelting furnace at 1090°C, after all the raw materials are completely melted, the copper alloy melt is refined, degassed, and deslagged, and a copper alloy powder with a particle size D 50 = 14.6 μm is prepared by a spray method, 996 g of the copper alloy powder and 4 g of surface-modified carbon nanotubes are placed in a high-speed stirred tank, mixed at 600 rpm under argon protection for 1.0 h, and the mixed alloy powder is obtained.

[0068] Example 9 differs from Example 1 in that in Step 1, the preparation of the copper alloy rod blank: the copper alloy powder is prepared according to the elemental formula of the mass percentage of the copper alloy powder provided in Preparation Example 1: high-purity cathode copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, copper-scandium alloy are placed in a smelting furnace at 1090°C, after all the raw materials are completely melted, the copper alloy melt is refined, degassed, and deslagged, and a copper alloy powder with a particle size D 50= 14.6 μm, 995 copper alloy powder and 5.5 g of surface-modified carbon nanotubes were placed in a high-speed stirred tank and mixed at 600 rpm for 1.0 h under argon protection to obtain the mixed alloy powder.

[0069] Example 10 differs from Example 1 in that in Step 1, the preparation of the copper alloy rod blank: the copper alloy powder was prepared according to the elemental formula provided in Preparation Example 1 in terms of mass percentage: high-purity cathode copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, copper-scandium alloy were placed in a smelting furnace at 1090°C, and after all the raw materials were completely melted, the copper alloy melt was refined, degassed, and deslagged, and a copper alloy rod blank with a diameter of 8 mm was obtained by smelting and casting the copper alloy melt. 50 = 14.6 μm, 995 copper alloy powder and 5.5 g of surface-modified carbon nanotubes were placed in a high-speed stirred tank and mixed at 600 rpm for 1.0 h under argon protection to obtain the mixed alloy powder.

[0070] Example 11 differs from Example 1 in that in Step 1, the preparation of the copper alloy rod blank: the copper alloy powder was prepared according to the elemental formula provided in Preparation Example 1 in terms of mass percentage: high-purity cathode copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, copper-scandium alloy were placed in a smelting furnace at 1090°C, and after all the raw materials were completely melted, the copper alloy melt was refined, degassed, and deslagged, and a copper alloy rod blank with a diameter of 8 mm was obtained by smelting and casting the copper alloy melt. 50 = 14.6 μm, 995 copper alloy powder and 5.5 g of surface-modified carbon nanotubes were placed in a high-speed stirred tank and mixed at 600 rpm for 1.0 h under argon protection to obtain the mixed alloy powder.

[0071] Example 12 differs from Example 1 in that in Step 2, the mixed alloy powder in Step 2 was placed in a smelting furnace at 1090°C, and after all the raw materials were completely melted, the copper alloy melt was refined, degassed, and deslagged, and a copper alloy rod blank with a diameter of 8 mm was obtained by smelting and casting the copper alloy melt, and the obtained copper alloy rod blank was subjected to solid solution treatment: heating at 10°C / min to 980°C and holding for 30 min, followed by cooling deformation: the cooling deformation amount was 80%, and then aging treatment: heating at 2°C / min to 480°C and holding for 2 h to obtain the copper alloy rod blank.

[0072] Example 13 differs from Example 1 in that in Step 2, the mixed alloy powder in Step 2 is placed in a smelting furnace at 1090°C, and after all raw materials are completely melted, the copper alloy melt is obtained by refining, degassing and slagging, the copper alloy melt is used to melt and cast a copper alloy rod blank with a diameter of 8 mm, the obtained copper alloy rod blank is subjected to solid solution treatment: increasing to 1055°C at 10°C / min and keeping for 20 min, then cold deformation: the cold deformation amount is 80%, and then aging treatment: increasing to 450°C at 2°C / min and keeping for 2 h to obtain a copper alloy rod blank.

[0073] Example 14 differs from Example 1 in that in Step 2, the mixed alloy powder in Step 2 is placed in a smelting furnace at 1090°C, and after all raw materials are completely melted, the copper alloy melt is obtained by refining, degassing and slagging, the copper alloy melt is used to melt and cast a copper alloy rod blank with a diameter of 8 mm, the obtained copper alloy rod blank is subjected to solid solution treatment: increasing to 1025°C at 10°C / min and keeping for 25 min, then cold deformation: the cold deformation amount is 80%, and then aging treatment: increasing to 475°C at 2°C / min and keeping for 3 h to obtain a copper alloy rod blank.

[0074] Example 15 differs from Example 1 in that in Step 2, the mixed alloy powder in Step 2 is placed in a smelting furnace at 1090°C, and after all raw materials are completely melted, the copper alloy melt is obtained by refining, degassing and slagging, the copper alloy melt is used to melt and cast a copper alloy rod blank with a diameter of 8 mm, the obtained copper alloy rod blank is subjected to solid solution treatment: increasing to 1025°C at 10°C / min and keeping for 25 min, then cold deformation: the cold deformation amount is 80%, and then aging treatment: increasing to 470°C at 2°C / min and keeping for 4 h to obtain a copper alloy rod blank.

[0075] Example 16 differs from Example 1 in that in Step 3, the copper alloy rod blank with a diameter of 8 mm in Step 3 is subjected to first drawing treatment, the angle α of the extrusion die used in the first drawing treatment is 30°, and the processing deformation rate is 7.5%, after the first drawing treatment, online first intermediate annealing treatment is carried out, the first intermediate annealing parameters are increasing to 840°C at 8°C / min and keeping for 30 min to obtain a copper alloy coarse wire with a diameter of 3.0 mm;

[0076] In Step 4, the copper alloy coarse wire with a diameter of 3.0 mm is subjected to second drawing treatment, the angle α of the extrusion die used in the second drawing treatment is 30°, and the processing deformation rate is 5.0%, after the second drawing treatment, online second intermediate annealing treatment is carried out, the second intermediate annealing parameters are increasing to 840°C at 8°C / min and keeping for 30 min to obtain a copper alloy primary fine wire with a diameter of 0.40 mm;

[0077] Step 5: The copper alloy primary filament with a diameter of 0.40 mm is subjected to a third wire drawing process. The angle α of the extrusion mold used in the third wire drawing process is 30°, and the processing deformation rate is 2.5%. After the third wire drawing process is completed, an online third intermediate annealing process is performed. The third intermediate annealing parameters are to increase the temperature to 860°C at 6°C / min and keep warm for 30 minutes to obtain a semi-finished copper alloy ultrafine single strand wire with a diameter of 0.107 mm.

[0078] The difference between Comparative Example 1 and Example 1 is as follows: Step 1, preparation of copper alloy rod blank: Copper alloy powder is prepared according to the element formula of mass percentage of copper alloy powder provided in Preparation Example 8: high-purity cathode electrolytic copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, and copper-scandium alloy are placed in a smelting furnace at 1090°C, and after all raw materials are completely melted, they are refined, degassed, and deslagging to obtain a copper alloy melt, and a particle size of D is obtained by spraying. 50 =14.7μm copper alloy powder, 998 copper alloy powder and 2g of surface-modified carbon nanotubes were placed in a high-speed stirring kettle and mixed at 600rpm for 1.0h under argon protection to obtain a mixed alloy powder.

[0079] The difference between Comparative Example 2 and Example 1 is as follows: Step 1, preparation of copper alloy rod blank: Copper alloy powder is prepared according to the element formula of the copper alloy powder in mass percentage provided in Preparation Example 9: high-purity cathode electrolytic copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, and copper-scandium alloy are placed in a smelting furnace at 1090°C, and after all raw materials are completely melted, they are refined, degassed, and deslaged to obtain a copper alloy melt, and a particle size of D is obtained by spraying. 50 =14.6μm copper alloy powder, 998 copper alloy powder and 2g of surface-modified carbon nanotubes were placed in a high-speed stirring kettle and mixed at 600rpm for 1.0h under argon protection to obtain a mixed alloy powder.

[0080] The difference between Comparative Example 3 and Example 1 is as follows: Step 1, preparation of copper alloy rod blank: Copper alloy powder is prepared according to the element formula of the copper alloy powder in mass percentage provided in Preparation Example 10: high-purity cathode electrolytic copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, and copper-scandium alloy are placed in a smelting furnace at 1090°C, and after all raw materials are completely melted, they are refined, degassed, and deslagging to obtain a copper alloy melt, and a particle size of D is obtained by spraying. 50 =14.8μm copper alloy powder, 998 copper alloy powder and 2g of surface-modified carbon nanotubes were placed in a high-speed stirring kettle and mixed at 600rpm for 1.0h under argon protection to obtain a mixed alloy powder.

[0081] The difference between Comparative Example 4 and Example 1 is as follows: Step 1, preparation of copper alloy rod blank: Copper alloy powder is prepared according to the element formula of the copper alloy powder in mass percentage provided in Preparation Example 11: high-purity cathode electrolytic copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, and copper-scandium alloy are placed in a smelting furnace at 1090°C, and after all raw materials are completely melted, they are refined, degassed, and deslagging to obtain a copper alloy melt, and a particle size of D is obtained by spraying. 50 =14.7μm copper alloy powder, 998 copper alloy powder and 2g of surface-modified carbon nanotubes were placed in a high-speed stirring kettle and mixed at 600rpm for 1.0h under argon protection to obtain a mixed alloy powder.

[0082] The difference between Comparative Example 5 and Example 1 is as follows: Step 1, preparation of copper alloy rod blank: Copper alloy powder is prepared according to the element formula of the copper alloy powder in mass percentage provided in Preparation Example 12: high-purity cathode electrolytic copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, and copper-scandium alloy are placed in a smelting furnace at 1090°C, and after all raw materials are completely melted, they are refined, degassed, and deslagging to obtain a copper alloy melt, and a particle size of D is obtained by spraying. 50 =14.6μm copper alloy powder, 998 copper alloy powder and 2g of surface-modified carbon nanotubes were placed in a high-speed stirring kettle and mixed at 600rpm for 1.0h under argon protection to obtain a mixed alloy powder.

[0083] The difference between Comparative Example 6 and Example 1 is as follows: Step 1, preparation of copper alloy rod blank: Copper alloy powder is prepared according to the element formula of the copper alloy powder in mass percentage provided in Preparation Example 13: high-purity cathode electrolytic copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, and copper-scandium alloy are placed in a smelting furnace at 1090°C, and after all raw materials are completely melted, they are refined, degassed, and deslagging to obtain a copper alloy melt, and a particle size of D is obtained by spraying. 50 =14.6μm copper alloy powder, 998 copper alloy powder and 2g of surface-modified carbon nanotubes were placed in a high-speed stirring kettle and mixed at 600rpm for 1.0h under argon protection to obtain a mixed alloy powder.

[0084] The difference between Comparative Example 7 and Example 1 is as follows: Step 1, preparation of copper alloy rod blank: Copper alloy powder is prepared according to the element formula of the copper alloy powder in mass percentage provided in Preparation Example 14: high-purity cathode electrolytic copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, and copper-scandium alloy are placed in a smelting furnace at 1090°C, and after all raw materials are completely melted, they are refined, degassed, and deslagging to obtain a copper alloy melt, and a particle size of D is obtained by spraying. 50=14.8μm copper alloy powder, 998 copper alloy powder and 2g of surface-modified carbon nanotubes were placed in a high-speed stirring kettle and mixed at 600rpm for 1.0h under argon protection to obtain a mixed alloy powder.

[0085] The difference between Comparative Example 8 and Example 1 is as follows: Step 1, preparation of copper alloy rod blank: Copper alloy powder is prepared according to the element formula of the copper alloy powder in mass percentage provided in Preparation Example 15: high-purity cathode electrolytic copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, and copper-scandium alloy are placed in a smelting furnace at 1090°C, and after all raw materials are completely melted, they are refined, degassed, and deslagging to obtain a copper alloy melt, and a particle size of D is obtained by spraying. 50 =14.6μm copper alloy powder, 998 copper alloy powder and 2g of surface-modified carbon nanotubes were placed in a high-speed stirring kettle and mixed at 600rpm for 1.0h under argon protection to obtain a mixed alloy powder.

[0086] The difference between Comparative Example 9 and Example 1 is as follows: Step 1, preparation of copper alloy rod blank: Copper alloy powder is prepared according to the element formula of the copper alloy powder in mass percentage provided in Preparation Example 16: high-purity cathode electrolytic copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, and copper-scandium alloy are placed in a smelting furnace at 1090°C, and after all raw materials are completely melted, they are refined, degassed, and deslagging to obtain a copper alloy melt, and a particle size of D is obtained by spraying. 50 =14.8μm copper alloy powder, 998 copper alloy powder and 2g of surface-modified carbon nanotubes were placed in a high-speed stirring kettle and mixed at 600rpm for 1.0h under argon protection to obtain a mixed alloy powder.

[0087] The difference between Comparative Example 10 and Example 1 is as follows: Step 1, preparation of copper alloy rod blank: Copper alloy powder is prepared according to the element formula of the copper alloy powder in mass percentage provided in Preparation Example 17: high-purity cathode electrolytic copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, and copper-scandium alloy are placed in a smelting furnace at 1090°C, and after all raw materials are completely melted, they are refined, degassed, and deslagging to obtain a copper alloy melt, and a particle size of D is obtained by spraying. 50 =14.7μm copper alloy powder, 998 copper alloy powder and 2g of surface-modified carbon nanotubes (single-atom copper-modified carbon nanotubes customized by Beijing Graphene Technology Research Institute Co., Ltd.) were placed in a high-speed stirring kettle and mixed at 600rpm for 1.0h under argon protection to obtain a mixed alloy powder.

[0088] The difference between Comparative Example 11 and Example 1 is as follows: Step 1, preparation of copper alloy rod blank: Copper alloy powder is prepared according to the element formula of the copper alloy powder in mass percentage provided in Preparation Example 18: high-purity cathode electrolytic copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, and copper-scandium alloy are placed in a smelting furnace at 1090°C, and after all raw materials are completely melted, they are refined, degassed, and deslagging to obtain a copper alloy melt, and a particle size of D is obtained by spraying. 50 =14.6μm copper alloy powder, 998 copper alloy powder and 2g of surface-modified carbon nanotubes (single-atom copper-modified carbon nanotubes customized by Beijing Graphene Technology Research Institute Co., Ltd.) were placed in a high-speed stirring kettle and mixed at 600rpm for 1.0h under argon protection to obtain a mixed alloy powder.

[0089] The difference between Comparative Example 12 and Example 1 is as follows: Step 1, preparation of copper alloy rod blank: Copper alloy powder is prepared according to the element formula of the copper alloy powder in mass percentage provided in Preparation Example 19: high-purity cathode electrolytic copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, and copper-scandium alloy are placed in a smelting furnace at 1090°C, and after all raw materials are completely melted, they are refined, degassed, and deslagging to obtain a copper alloy melt, and a particle size of D is obtained by spraying. 50 =14.7μm copper alloy powder, 998 copper alloy powder and 2g of surface-modified carbon nanotubes (single-atom copper-modified carbon nanotubes customized by Beijing Graphene Technology Research Institute Co., Ltd.) were placed in a high-speed stirring kettle and mixed at 600rpm for 1.0h under argon protection to obtain a mixed alloy powder.

[0090] The difference between Comparative Example 13 and Example 1 is as follows: Step 1, preparation of copper alloy rod blank: Copper alloy powder is prepared according to the element formula of the copper alloy powder in mass percentage provided in Preparation Example 20: high-purity cathode electrolytic copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, and copper-scandium alloy are placed in a smelting furnace at 1090°C, and after all raw materials are completely melted, they are refined, degassed, and deslagging to obtain a copper alloy melt, and a particle size of D is obtained by spraying. 50 =14.7μm copper alloy powder, 998 copper alloy powder and 2g of surface-modified carbon nanotubes (single-atom copper-modified carbon nanotubes customized by Beijing Graphene Technology Research Institute Co., Ltd.) were placed in a high-speed stirring kettle and mixed at 600rpm for 1.0h under argon protection to obtain a mixed alloy powder.

[0091] The difference between Comparative Example 14 and Example 1 is as follows: Step 1, preparation of copper alloy rod blank: Copper alloy powder is prepared according to the element formula of the copper alloy powder in mass percentage provided in Preparation Example 1: high-purity cathode electrolytic copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, and copper-scandium alloy are placed in a smelting furnace at 1090°C, and after all raw materials are completely melted, they are refined, degassed, and deslagging to obtain a copper alloy melt, and a particle size of D is obtained by spraying. 50 =15.2μm copper alloy powder, 998 copper alloy powder and 2g of unsurface-modified carbon nanotubes (industrial-grade multi-walled carbon nanotubes TNNF-6, Chengdu Organic Chemistry Co., Ltd., Chinese Academy of Sciences) were placed in a high-speed stirring kettle and mixed at 600rpm for 1.0h under argon protection to obtain a mixed alloy powder.

[0092] The difference between Comparative Example 15 and Example 1 is as follows: Step 1, preparation of copper alloy rod blank: Copper alloy powder is prepared according to the element formula of mass percentage of copper alloy powder provided in Preparation Example 1: high-purity cathode electrolytic copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, and copper-scandium alloy are placed in a smelting furnace at 1090°C, and after all raw materials are completely melted, they are refined, degassed, and deslagging to obtain a copper alloy melt, and a particle size of D is obtained by spraying. 50 =14.7μm copper alloy powder, 999.5g copper alloy powder and 0.5g surface-modified carbon nanotubes (single-atom copper-modified carbon nanotubes customized by Beijing Graphene Technology Research Institute Co., Ltd.) were placed in a high-speed stirring kettle and mixed at 600rpm for 1.0h under argon protection to obtain a mixed alloy powder.

[0093] The difference between Comparative Example 16 and Example 1 is as follows: Step 1, preparation of copper alloy rod blank: Copper alloy powder is prepared according to the element formula of the copper alloy powder in mass percentage provided in Preparation Example 1: high-purity cathode electrolytic copper ingot, copper-silver alloy, copper-niobium alloy, copper-indium alloy, copper-silicon alloy, copper-chromium alloy, copper-titanium alloy, copper-hafnium alloy, and copper-scandium alloy are placed in a smelting furnace at 1090°C, and after all raw materials are completely melted, they are refined, degassed, and deslagging to obtain a copper alloy melt, and a particle size of D is obtained by spraying. 50 =14.6μm copper alloy powder, 998 copper alloy powder and 12g of surface-modified carbon nanotubes (single-atom copper-modified carbon nanotubes customized by Beijing Graphene Technology Research Institute Co., Ltd.) were placed in a high-speed stirring kettle and mixed at 600rpm for 1.0h under argon protection to obtain a mixed alloy powder.

[0094] Performance Testing: 1. Mechanical Properties: The tensile strength and elongation at break of the copper alloy rod blank were measured using an HH11013YZUFY universal tensile testing machine in accordance with GB / T228.1-2010. 2. Conductivity: The volume resistivity (conductivity) of a single wire was measured using a QJ-36 digital bridge and supporting bracket in accordance with GB / T3048.7-2008. 3. Bending performance test: A TH-8506 wire bending tester is used to conduct repeated bending tests on finished cables. The test is carried out in accordance with EN50396:2005+A1:2011(E). The cable transmission performance requirements refer to IEC61156-5:2020. The relevant test conditions and requirements are implemented in accordance with the PI Association. The repeated bending radius is 7 times the outer diameter of the cable, and the hanging weight is 300g. The transmission performance is tested online when the repeated bending test reaches the set number of times. The number of bends that pass the transmission performance for the last time is the test result. When the number of bends of the sample is ≥3.5 million times, it is qualified, and when the number of bends is <3.5 million times, it is unqualified.

[0095] Table 4: Physical properties of copper alloy rod embryos in Examples 1-16 and bending resistance of cables made from stranded ultra-fine copper conductor wires prepared using the copper alloy rod embryos

[0096]

[0097] Table 5: Physical properties test table of copper alloy rod embryos in comparative examples 1-16 and bending resistance performance table of cables made of stranded ultra-fine copper stranded conductor wires prepared using copper alloy rod embryos

[0098]

[0099] From Examples 1-7 and Comparative Examples 8-13 and Tables 4-5, it can be seen that the copper alloy prepared using the copper alloy formula provided in the present invention and the copper alloy rod embryos prepared using single-atom copper modified carbon nanotubes have excellent electrical conductivity, mechanical strength, and high flexural resistance.

[0100] Combining Example 1, Examples 8-11 and Comparative Example 14 and Tables 4-5, it can be seen that single-atom copper modified carbon nanotubes can be uniformly dispersed in the copper alloy matrix, effectively improving the conductivity, mechanical strength and high flexural resistance of the copper alloy rod embryo.

[0101] Combining Example 1, Examples 8-11 and Comparative Examples 15-16 and Tables 4-5, it can be seen that the addition amount of the single-atom copper modified carbon nanotubes is preferably controlled to be 0.2-1.0 wt %, and preferably in the range of 0.5-0.7 wt %.

[0102] Combining Example 1 with Examples 12-16 and Table 4, it can be seen that the copper alloy rod blanks prepared by the solution treatment parameters: heating to 980-1060°C and holding for 15-45 minutes and the aging treatment parameters: heating to 420-480°C and holding for 120-160 minutes, have excellent electrical conductivity, mechanical strength, and high flexural resistance.

[0103] In summary, the present invention modifies the surface of carbon nanotubes with single-atom copper, thereby improving the compatibility of carbon nanotubes and the copper alloy matrix. The carbon nanotubes are uniformly dispersed in the copper alloy melt under molten conditions, thereby improving the conductivity, mechanical strength and flexural resistance of the copper alloy rod embryo. The copper alloy rod embryo is comparable to the high-strength and high-conductivity special copper conductors imported from abroad. Combined with the multiple wire drawing and multiple intermediate annealing treatments + final annealing provided by the present invention, the problem of wire breakage during wire drawing can be effectively avoided. Finally, multiple strands can be twisted to produce an ultra-fine copper stranded conductor wire with high conductivity, high strength and high flexural resistance, which meets the needs of high-voltage cables for new energy vehicles.

[0104] This specific embodiment is merely an explanation of the present invention and is not intended to limit the present invention. After reading this specification, those skilled in the art may make non-creative modifications to this embodiment as needed. However, as long as such modifications are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A process for preparing ultrafine copper conductors for new energy vehicles, characterized by: The following steps are involved: Step 1, preparation of copper alloy rod blank: copper alloy powder and surface-modified carbon nanotubes are uniformly mixed to obtain mixed alloy powder, wherein the content of surface-modified carbon nanotubes in the mixed alloy powder is 0.2-1.0 wt%; The mass percentages of the copper alloy powder are as follows: 0.05% to 0.15% Ag, 0.05% to 0.50% Nb, 0.05% to 0.10% In, 0.02% to 0.08% Si, 0.30% to 0.80% Cr, 0.003% to 0.008% Ti, 0.002% to 0.06% Hf, 0.004% to 0.016% Sc, the total content of unavoidable impurities is <0.15%, and the balance is Cu; Step 2: Melt and cast the mixed alloy powder in step 2 into a copper alloy rod embryo with a diameter of 8-12 mm, and subject the obtained copper alloy rod embryo to solid solution and aging treatment to obtain a copper alloy rod embryo; Step 3: performing a first wire drawing process and a first intermediate annealing process on the copper alloy rod blank with a diameter of 8-12 mm in step 3 to obtain a copper alloy thick wire with a diameter of 3-6 mm; Step 4: The copper alloy thick wire with a diameter of 3-6 mm is subjected to a second wire drawing process and a second intermediate annealing process to obtain a copper alloy primary filament with a diameter of 0.3-0.6 mm; Step 5: subjecting the primary copper alloy filaments with a diameter of 0.3-0.6 mm to a third drawing process and a third intermediate annealing process to obtain semi-finished copper alloy ultrafine single strand filaments with a diameter of 0.80-1.08 mm; Step 6: Final annealing is performed on the semi-finished copper alloy ultrafine wire to obtain a finished copper alloy ultrafine single strand wire, and the finished copper alloy ultrafine single strand wire is twisted into multiple strands to obtain an ultrafine copper stranded conductor wire; The surface-modified carbon nanotubes are single-atom copper-modified carbon nanotubes, with a single-atom copper loading rate of 5-10 wt %, a diameter of 5-40 nm, a length of 0.5-20 nm, and a hydroxyl content of 2-3 wt %. Solution treatment parameters in step 2: heating to 980-1060°C and keeping warm for 15-45 minutes; The aging treatment parameters in step 2 are as follows: heating to 420-480° C. and holding for 120-160 minutes.

2. The process for preparing ultrafine copper conductors for new energy vehicles according to claim 1, characterized in that: The content of surface-modified carbon nanotubes in the mixed alloy powder is 0.5-0.6 wt %.

3. The process for preparing ultrafine copper conductors for new energy vehicles according to claim 1, characterized in that: Solution treatment parameters in step 2: heating to 1020-1040° C. and keeping the temperature for 25-30 minutes.

4. The process for preparing ultrafine copper conductors for new energy vehicles according to claim 1, characterized in that: The angle α of the extrusion die used in the first wire drawing process in step three is 25-30°, and the processing deformation rate is 8±0.5%; the parameters of the first intermediate annealing process are heating to 840-860°C and keeping warm for 15-30 minutes.

5. The process for preparing ultrafine copper conductors for new energy vehicles according to claim 1, characterized in that: The angle α of the extrusion die used in the second wire drawing process in step 4 is 25-30°, and the processing deformation rate is 5±0.5%; the parameters of the second intermediate annealing process are heating to 840-860°C and keeping warm for 15-30 minutes.

6. The process for preparing ultrafine copper conductors for new energy vehicles according to claim 1, characterized in that: The angle α of the extrusion die used in the third wire drawing process in step five is 25-30°, and the processing deformation rate is 2±0.5%. The parameters of the third intermediate annealing process are heating to 840-860° C. and keeping warm for 15-30 minutes.

7. The process for preparing ultrafine copper conductors for new energy vehicles according to claim 1, characterized in that: Final annealing parameters: heat to 900-960°C and hold for 0.4-0.6s.

8. An ultra-fine copper conductor for new energy vehicles prepared by the preparation process according to any one of claims 1 to 7.

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