High-conductivity and high-tensile-strength aluminum alloy conductor and preparation method and application thereof

Abstract

The invention discloses a high-conductivity and high-tensile-strength aluminum alloy conductor and a preparation method and application thereof, and relates to the technical field of conductor materials. The aluminum alloy conductor comprises the following components in percentage by mass: 0.5 to 0.8 percent of Fe, 0.2 to 0.5 percent of Cu, 0.05 to 0.1 percent of B, 0.001 to 0.003 percent of Ti, 0.001 to 0.003 percent of C and the balance of aluminum and inevitable impurities; the preparation method comprises the following steps: melting industrial pure aluminum, adding an Al-Fe intermediate alloy, an Al-Cu intermediate alloy and an Al-B intermediate alloy, then adding a refining agent, slagging off, adding a grain refiner, casting and cooling to obtain an aluminum alloy rod material; the aluminum alloy rod material is subjected to pre-aging treatment, machining and two-stage aging treatment, and the aluminum alloy conductor with high conductivity and high strength is obtained. The electric conductivity, the tensile strength and the elongation of the prepared aluminum alloy conductor can reach 63.1% IACS, 129.6 MPa and 21.3% respectively, and the problem that the electric conductivity and the tensile strength restrict each other urgently in the industry is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of conductor materials, and particularly to a high-conductivity and high-tensile-strength aluminum alloy conductor and its preparation method and application. Background Art

[0002] With the continuous growth of China's power demand and the progress of power grid transmission technology, the requirements for transmission cable conductor materials are increasing day by day. Traditional aluminum alloys have problems such as low conductivity, poor strength, and inability to balance these two properties. At the same time, China's copper resources are limited, the price of copper materials fluctuates greatly and is expensive, and the import dependence is high, which restricts its wide application. China is rich in aluminum resources, and China's electrolytic aluminum industry has developed rapidly. Developing aluminum alloy conductors can not only alleviate the problem of overcapacity of aluminum, but also effectively reduce the cost of conductor materials. In addition, promoting aluminum alloy conductors conforms to the national strategic policy of "saving copper with aluminum", helps to reduce the consumption of copper, and promotes the sustainable development of the power industry. Therefore, developing aluminum alloy conductors with high conductivity and high tensile strength has important practical significance and broad application prospects.

[0003] At present, the application of aluminum alloy conductor materials in the field of power transmission is restricted by their insufficient conductivity and tensile strength, and it is difficult to meet the high requirements for conductor materials in the fields of high voltage and large-capacity transmission in new power systems. Summary of the Invention

[0004] In view of the above deficiencies, the present invention provides a high-conductivity and high-tensile-strength aluminum alloy conductor and its preparation method and application, which solves the industry problem that it is difficult to simultaneously meet conductivity and tensile strength. The specific technical solutions are as follows:

[0005] A high-conductivity and high-tensile-strength aluminum alloy conductor, the aluminum alloy conductor comprises the following components by mass percentage: Fe: 0.5 - 0.8%, Cu: 0.2 - 0.5%, B: 0.05 - 0.1%, Ti: 0.001 - 0.003%, C: 0.001 - 0.003%, and the balance is aluminum and inevitable impurities.

[0006] The present invention also provides a preparation method for the above high-conductivity and high-tensile-strength aluminum alloy conductor, comprising the following steps:

[0007] S1. Heat industrial pure aluminum to 720 - 750 °C. After the pure aluminum is completely melted, add Al-Fe master alloy, Al-Cu master alloy, and Al-B master alloy in sequence, and stir for 5 - 10 minutes after adding each master alloy to obtain an aluminum alloy liquid;

[0008] S2. Add a refining agent to the aluminum alloy liquid, stir for 5 - 10 minutes to make it react fully, and skim the slag to obtain a high-purity aluminum alloy liquid;

[0009] S3. Add a grain refiner to the high-purity aluminum alloy liquid, stir for 5 - 10 min to make it react fully, and keep warm for 10 - 30 min;

[0010] S4. Pour the aluminum alloy liquid after heat preservation in step S3 into a preheated mold, and naturally cool it in the air to obtain an aluminum alloy rod;

[0011] S5. Perform pre-aging treatment on the aluminum alloy rod, and perform machining after naturally cooling to room temperature to obtain an aluminum alloy wire;

[0012] S6. Perform two-stage aging treatment on the aluminum alloy wire to obtain an aluminum alloy conductor with both high conductivity and high strength.

[0013] Preferably, in step S1, the Al-Fe master alloy is Al-10Fe; the Al-Cu master alloy is Al-10Cu; the Al-B master alloy is Al-3B.

[0014] Preferably, in step S2, the component of the refining agent is C2Cl6, and the content is 0.5 - 1.5% of the mass of the aluminum alloy liquid.

[0015] Preferably, in step S3, the component of the grain refiner is Al-5Ti-0.8B-0.2C, and the content is 0.5 - 1% of the total mass of the high-purity aluminum alloy liquid.

[0016] Preferably, in step S4, the material of the mold is graphite or pure copper, and the preheating temperature is 180 - 250 °C.

[0017] Preferably, in step S5, the pre-aging treatment temperature is 150 - 200 °C, and the treatment time is 8 - 10 h.

[0018] Preferably, in step S5, the machining is to use a cold rolling mill and a wire drawing machine to process the aluminum alloy rod into an aluminum alloy wire, and the deformation amount reaches 96 - 97.5%.

[0019] Preferably, in step S6, the two-stage aging treatment is to first treat at 180 - 220 °C for 3 - 5 h, and then raise the temperature to 280 - 330 °C and treat for 7 - 9 h.

[0020] The present invention also provides the application of the above high-conductivity and high-tensile strength aluminum alloy conductor in the field of wire and cable.

[0021] Through unique composition design and process optimization, the aluminum alloy conductor of the present invention achieves a tensile strength of 120 MPa level while maintaining a conductivity of more than 62% IACS, and is particularly suitable for medium and high voltage and large-capacity power transmission scenarios.

[0022] The reasons why the pre-aging treatment and bipolar aging treatment process of the present invention can improve the conductivity and strength properties of the aluminum alloy conductor are as follows:

[0023] The precipitation of nanometer-scale iron phase during the pre-aging process strengthens the matrix, reduces the hardness difference with the primary iron phase, and improves their coordinated deformation ability during the rolling process; the submicron iron phase precipitated during the pre-aging process can inhibit the growth of recrystallized grains during the final double-stage aging process, thereby playing a role in refining the grains; a large amount of nanometer-scale precipitation during the pre-aging process can serve as nucleation points for dislocations during deformation, promote the formation of dislocations, thereby increasing the dislocation density of the deformed sample and improving the work hardening effect; based on the pinning effect of nanoparticles on dislocations, the dynamic recrystallization of the matrix during the rolling process can be effectively inhibited; the pre-aging process promotes the initial precipitation of iron, copper and silicon atoms in the matrix, and the double-stage aging treatment allows the solute atoms to precipitate more thoroughly, so that the aluminum alloy wire provided by the present invention has higher conductivity.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The present invention adds elements such as iron, copper, boron, titanium and carbon to industrial pure aluminum to achieve the effect of solid solution strengthening, and cooperates with the strengthening effect of excess copper and iron phase, Al2Cu and Al8Fe2Si phase, as well as fine grain strengthening and improvement of microstructure uniformity of boron, titanium and carbon, so that the aluminum alloy conductor has both high conductivity and high tensile strength. In the preparation method, the aging process is improved, and a pre-aging treatment before mechanical processing and a double-stage aging treatment after mechanical processing are proposed, so that the conductivity, tensile strength and elongation of the prepared aluminum alloy conductor can reach 63.1% IACS, 129.6 MPa and 21.3% respectively, thereby solving the problem of mutual restriction between conductivity and tensile strength that needs to be broken through in industry.

[0026] 2. The present invention uses cheap and common industrial pure aluminum, aluminum iron, aluminum copper and aluminum boron master alloy as raw materials, and after refining, adds grain refiner and heat preservation casting to obtain raw materials with excellent performance. After pre-aging treatment, mechanical processing, double-stage aging and other process steps, aluminum alloy wires with both high conductivity and high tensile strength can be obtained, which saves a lot of costs compared to hot processing. In general, the raw materials, equipment, process methods and process parameters used in the present invention are not difficult to implement in industrial production, which is convenient for future industrial applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments are briefly introduced below.

[0028] Figure 1 The present invention is a process flow chart for preparing a high-conductivity, high-tensile-strength aluminum alloy conductor. Detailed Embodiments

[0029] The following is a detailed description of the specific embodiments of the present invention, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0030] Example 1

[0031] This example provides a high-conductivity, high-tensile-strength aluminum alloy conductor and its preparation method. The preparation method includes raw material preparation, aluminum alloy conductor preparation, and aging process treatment:

[0032] (1) Raw material preparation: Prepare Al-0.8Fe-0.2Cu-0.05B by weight percentage, and weigh corresponding raw materials such as Al-10Fe, Al-10Cu, Al-3B master alloys and the remaining industrial pure aluminum, totaling 200 g. Weigh 1 g of grain refiner Al-5Ti-0.8B-0.2C and 1 g of refining agent C2Cl6.

[0033] (2) The process of preparing the aluminum alloy conductor includes: placing industrial pure aluminum in a quartz crucible in a melting furnace, heating to 720 °C, waiting for the pure aluminum to completely melt, and sequentially adding Al-Fe, Al-Cu, and Al-B master alloys, stirring for 5 minutes after each addition of a master alloy to obtain an aluminum alloy liquid; adding 1 g of refining agent C2Cl6 to the aluminum alloy liquid, stirring for 5 minutes to make it react fully, and skimming the slag to obtain a high-purity aluminum alloy liquid; adding 1 g of grain refiner Al-5Ti-0.8B-0.2C to the refined aluminum alloy liquid, stirring for 5 minutes to make it react fully, and keeping warm for 20 minutes; pouring the aluminum alloy liquid into a circular graphite mold preheated at 200 °C, and allowing it to cool naturally in the air to obtain an aluminum alloy electrical round rod. Perform pre-aging treatment on the aluminum alloy electrical round rod. After naturally cooling to room temperature, use a cold rolling mill and a wire drawing machine to perform mechanical processing on the aluminum alloy electrical round rod to obtain an aluminum alloy wire with a diameter of 2 mm, with a deformation amount reaching 97.2%. Perform double-stage aging treatment on the aluminum alloy wire to obtain an aluminum alloy conductor that takes into account both high conductivity and high strength.

[0034] That is, the aging process treatment of this example includes: casting an electrical round rod → Pre-aging (200 °C / 8 h) → machining into a Φ2 mm aluminum alloy wire → double-stage aging treatment (200 °C / 4 h + 300 °C / 8 h) → high-conductivity and high-strength aluminum alloy wire.

[0035] Example 2

[0036] This example provides a high-conductivity, high-tensile-strength aluminum alloy conductor and its preparation method. The preparation method includes raw material preparation, aluminum alloy conductor preparation, and aging process treatment:

[0037] (1) Raw material preparation: Prepare Al-0.8Fe-0.2Cu-0.05B according to weight percentage, and weigh a total of 200 g of raw materials such as the corresponding Al-10Fe, Al-10Cu, Al-3B master alloys and the remaining industrial pure aluminum. Weigh 1 g of grain refiner Al-5Ti-0.8B-0.2C and 1 g of refining agent C2Cl6.

[0038] (2) The preparation process of the aluminum alloy conductor includes: placing industrial pure aluminum in a graphite crucible in a melting furnace, heating to 750 °C, waiting for the pure aluminum to completely melt, and sequentially adding Al-Fe, Al-Cu, and Al-B master alloys. Stir for 10 min after adding each master alloy to obtain aluminum alloy liquid; add 1 g of refining agent C2Cl6 to the aluminum alloy liquid, stir for 10 min to make it react fully, and obtain high-purity aluminum alloy liquid after skimming the slag; add 1 g of grain refiner Al-5Ti-0.8B-0.2C to the refined aluminum alloy liquid, stir for 10 min to make it react fully, and keep warm for 20 min; pour the aluminum alloy liquid into a circular pure copper mold preheated at 180 °C, and let it cool naturally in the air to obtain an aluminum alloy electrician's round bar. Perform pre-aging treatment on the aluminum alloy electrician's round bar. After naturally cooling to room temperature, use a cold rolling mill and a wire drawing machine to perform machining on the aluminum alloy electrician's round bar to obtain an aluminum alloy wire with a diameter of 2 mm, and the deformation amount reaches 97.2%. Perform double-stage aging treatment on the aluminum alloy wire to obtain an aluminum alloy conductor with both high conductivity and high strength.

[0039] That is, the aging process treatment of this embodiment includes: casting an electrician's round bar → Pre-aging (150 °C / 10 h) → machining into a Φ2 mm aluminum alloy wire → double-stage aging treatment (180 °C / 5 h + 280 °C / 9 h) → high-conductivity and high-strength aluminum alloy wire.

[0040] Example 3

[0041] This embodiment provides a high-conductivity and high-tensile-strength aluminum alloy conductor and its preparation method. The preparation method includes raw material preparation, aluminum alloy conductor preparation, and aging process treatment:

[0042] (1) Raw material preparation: Prepare Al-0.8Fe-0.2Cu-0.05B according to weight percentage, and weigh a total of 200 g of raw materials such as the corresponding Al-10Fe, Al-10Cu, Al-3B master alloys and the remaining industrial pure aluminum. Weigh 1 g of grain refiner Al-5Ti-0.8B-0.2C and 1 g of refining agent C2Cl6.

[0043] (2) The preparation process of the aluminum alloy conductor includes: placing industrial pure aluminum in a quartz crucible in a melting furnace, heating it to 740 °C, waiting for the pure aluminum to completely melt, and successively adding Al-Fe, Al-Cu, and Al-B master alloys. Stir for 8 minutes after adding each master alloy to obtain aluminum alloy liquid; add 1 g of refining agent C2Cl6 to the aluminum alloy liquid, stir for 8 minutes to make it fully react, and obtain high-purity aluminum alloy liquid after skimming the slag; add 1 g of grain refiner Al-5Ti-0.8B-0.2C to the refined aluminum alloy liquid, stir for 8 minutes to make it fully react, and keep it warm for 20 minutes; pour the aluminum alloy liquid into a circular graphite mold preheated at 250 °C, and let it cool naturally in the air to obtain an aluminum alloy electrician round bar. Perform pre-aging treatment on the aluminum alloy electrician round bar. After naturally cooling to room temperature, use a cold rolling mill and a wire drawing machine to perform mechanical processing on the aluminum alloy electrician round bar to obtain an aluminum alloy wire with a diameter of 2 mm and a deformation amount of 97.2%. Perform double-stage aging treatment on the aluminum alloy wire to obtain an aluminum alloy conductor with both high conductivity and high strength.

[0044] That is, the aging process treatment of this embodiment includes: casting an electrician round bar → Pre-aging (180 °C / 8 h) → machining into a Φ2 mm aluminum alloy wire → double-stage aging treatment (220 °C / 3 h + 330 °C / 7 h) → high-conductivity and high-strength aluminum alloy wire.

[0045] Comparative Example 1

[0046] This comparative example provides a high-conductivity and high-tensile-strength aluminum alloy conductor and its preparation method. The preparation method includes raw material preparation, aluminum alloy conductor preparation, and aging process treatment:

[0047] (1) Raw material preparation: The same as in Example 1.

[0048] (2) The preparation process of the aluminum alloy conductor includes: placing industrial pure aluminum in a quartz crucible in a melting furnace, heating it to 720 °C, waiting for the pure aluminum to completely melt, and sequentially adding Al-Fe, Al-Cu, and Al-B master alloys. Stir for 5 minutes after adding each master alloy to obtain aluminum alloy liquid; add 1 g of refining agent C2Cl6 to the aluminum alloy liquid, stir for 5 minutes to make it fully react, and obtain high-purity aluminum alloy liquid after skimming the slag; add 1 g of grain refiner Al-5Ti-0.8B-0.2C to the refined aluminum alloy liquid, stir for 5 minutes to make it fully react, and keep it warm for 20 minutes; pour the aluminum alloy liquid into a circular graphite mold preheated at 200 °C and let it cool naturally in the air to obtain an aluminum alloy electrician's round rod. Perform pre-aging treatment on the aluminum alloy electrician's round rod. After naturally cooling to room temperature, use a cold rolling mill and a wire drawing machine to perform machining on the aluminum alloy electrician's round rod to obtain an aluminum alloy wire with a diameter of 2 mm and a deformation amount of 97.2%. Perform aging treatment on the aluminum alloy wire to obtain an aluminum alloy conductor.

[0049] That is, the aging process treatment of this comparative example includes: the aging process treatment includes: casting an electrician's round rod → Pre-aging (200 °C / 8 h) → machining into a Φ2 mm aluminum alloy wire → aging treatment (200 °C / 12 h) → aluminum alloy wire.

[0050] That is, compared with Example 1 in the preparation process of this comparative example, aging treatment (200 °C / 12 h) is used instead of double-stage aging treatment.

[0051] Comparative Example 2

[0052] This comparative example provides a high-conductivity and high-tensile-strength aluminum alloy conductor and its preparation method. The preparation method includes raw material preparation, aluminum alloy conductor preparation, and aging process treatment:

[0053] (1) Raw material preparation: The same as in Example 1.

[0054] (2) The preparation process of the aluminum alloy conductor includes: placing industrial pure aluminum in a quartz crucible in a melting furnace, heating it to 720 °C, waiting for the pure aluminum to completely melt, and sequentially adding Al-Fe, Al-Cu, and Al-B master alloys. Stir for 5 minutes after adding each master alloy to obtain aluminum alloy liquid; add 1 g of refining agent C2Cl6 to the aluminum alloy liquid, stir for 5 minutes to make it react fully, and obtain high-purity aluminum alloy liquid after skimming the slag; add 1 g of grain refiner Al-5Ti-0.8B-0.2C to the refined aluminum alloy liquid, stir for 5 minutes to make it react fully, and keep it warm for 20 minutes; pour the aluminum alloy liquid into a circular graphite mold preheated at 200 °C, and let it cool naturally in the air to obtain an aluminum alloy electrician's round bar. Perform pre-aging treatment on the aluminum alloy electrician's round bar. After naturally cooling to room temperature, use a cold rolling mill and a wire drawing machine to perform machining on the aluminum alloy electrician's round bar to obtain an aluminum alloy wire with a diameter of 2 mm and a deformation amount of 97.2%. Perform aging treatment on the aluminum alloy wire to obtain an aluminum alloy conductor.

[0055] That is, the aging process treatment of this comparative example includes: casting an electrician's round bar → Pre-aging (200 °C / 8 h) → machining into a Φ2 mm aluminum alloy wire → aging treatment (300 °C / 12 h) → aluminum alloy wire.

[0056] That is, compared with Example 1 in the preparation process of this comparative example, aging treatment (300 °C / 12 h) is used instead of double-stage aging treatment.

[0057] Comparative Example 3

[0058] This comparative example provides a high-conductivity and high-tensile-strength aluminum alloy conductor and its preparation method. The preparation method includes raw material preparation, aluminum alloy conductor preparation, and aging process treatment:

[0059] (1) Raw material preparation: The same as in Example 1.

[0060] (2) The preparation process of the aluminum alloy conductor includes: placing industrial pure aluminum in a quartz crucible in a melting furnace, heating it to 720 °C, waiting for the pure aluminum to completely melt, and then successively adding Al-Fe, Al-Cu, and Al-B master alloys. Stir for 5 minutes after adding each master alloy to obtain aluminum alloy liquid; add 1 g of refining agent C2Cl6 to the aluminum alloy liquid, stir for 5 minutes to make it fully react, and obtain high-purity aluminum alloy liquid after skimming the slag; add 1 g of grain refiner Al-5Ti-0.8B-0.2C to the refined aluminum alloy liquid, stir for 5 minutes to make it fully react, and keep it warm for 20 minutes; pour the aluminum alloy liquid into a circular graphite mold preheated at 200 °C and let it cool naturally in the air to obtain an aluminum alloy electrician's round bar. Use a cold rolling mill and a wire drawing machine to machine the aluminum alloy electrician's round bar to obtain an aluminum alloy wire with a diameter of 2 mm and a deformation amount reaching 97.2%. Perform double-stage aging treatment on the aluminum alloy wire to obtain an aluminum alloy conductor.

[0061] That is, the aging process treatment of this comparative example includes: casting an electrician's round bar → machining into a Φ2 mm aluminum alloy wire → double-stage aging treatment (200 °C / 4 h + 300 °C / 8 h) → aluminum alloy wire.

[0062] That is, compared with Example 1 in the preparation process of this comparative example, there is no pre-aging treatment.

[0063] Comparative Example 4

[0064] This comparative example provides a high-conductivity and high-tensile-strength aluminum alloy conductor and its preparation method. The preparation method includes raw material preparation, aluminum alloy conductor preparation, and aging process treatment:

[0065] (1) Raw material preparation: The same as in Example 1.

[0066] (2) The preparation process of the aluminum alloy conductor includes: placing industrial pure aluminum in a quartz crucible in a melting furnace, heating it to 720 °C, waiting for the pure aluminum to completely melt, and then successively adding Al-Fe, Al-Cu, and Al-B master alloys. Stir for 5 minutes after adding each master alloy to obtain aluminum alloy liquid; add 1 g of refining agent C2Cl6 to the aluminum alloy liquid, stir for 5 minutes to make it fully react, and obtain high-purity aluminum alloy liquid after skimming the slag; add 1 g of grain refiner Al-5Ti-0.8B-0.2C to the refined aluminum alloy liquid, stir for 5 minutes to make it fully react, and keep it warm for 20 minutes; pour the aluminum alloy liquid into a circular graphite mold preheated at 200 °C and let it cool naturally in the air to obtain an aluminum alloy electrician's round bar. Use a cold rolling mill and a wire drawing machine to machine the aluminum alloy electrician's round bar to obtain an aluminum alloy wire with a diameter of 2 mm. Perform aging treatment on the aluminum alloy wire to obtain an aluminum alloy conductor.

[0067] That is, the aging process treatment of this comparative example includes: casting electrical round bars → machining into Φ2mm aluminum alloy wires → aging treatment (200°C / 12h) → aluminum alloy wires.

[0068] That is, compared with Example 1 in the preparation process of this comparative example, there is no pre-aging treatment, and the aging treatment (200°C / 12h) is used instead of the two-stage aging treatment.

[0069] Comparative Example 5

[0070] This comparative example provides a high-conductivity and high-tensile-strength aluminum alloy conductor and its preparation method. The preparation method includes raw material preparation, aluminum alloy conductor preparation, and aging process treatment:

[0071] (1) Raw material preparation: The same as in Example 1.

[0072] (2) The aluminum alloy conductor preparation process includes: placing industrial pure aluminum in a quartz crucible in a melting furnace, heating to 720°C, waiting for the pure aluminum to completely melt, and sequentially adding Al-Fe, Al-Cu, and Al-B master alloys. Stir for 5 minutes after adding each master alloy to obtain aluminum alloy liquid; add 1g of refining agent C2Cl6 to the aluminum alloy liquid, stir for 5 minutes to make it react fully, and skim the slag to obtain high-purity aluminum alloy liquid; add 1g of grain refiner Al-5Ti-0.8B-0.2C to the refined aluminum alloy liquid, stir for 5 minutes to make it react fully, and keep warm for 20 minutes; pour the aluminum alloy liquid into a circular graphite mold preheated at 200°C, and let it cool naturally in the air to obtain aluminum alloy electrical round bars. Use a cold rolling mill and a wire drawing machine to machine the aluminum alloy electrical round bars to obtain aluminum alloy wires with a diameter of 2mm, with a deformation amount reaching 97.2%. Perform aging treatment on the aluminum alloy wires to obtain aluminum alloy conductors.

[0073] That is, the aging process treatment of this comparative example includes: casting electrical round bars → machining into Φ2mm aluminum alloy wires → aging treatment (300°C / 12h) → aluminum alloy wires.

[0074] That is, compared with Example 1 in the preparation process of this comparative example, there is no pre-aging treatment, and the aging treatment (300°C / 12h) is used instead of the two-stage aging treatment.

[0075] Comparative Example 6

[0076] This comparative example provides a high-conductivity and high-tensile-strength aluminum alloy conductor and its preparation method. The preparation method includes raw material preparation, aluminum alloy conductor preparation, and aging process treatment:

[0077] (1) Raw material preparation: The same as in Example 1.

[0078] (2) The preparation process of the aluminum alloy conductor includes: placing industrial pure aluminum in a quartz crucible in a melting furnace, heating it to 720 °C, waiting for the pure aluminum to completely melt, and then adding Al-Fe, Al-Cu, and Al-B master alloys in sequence. Stir for 5 minutes after adding each master alloy to obtain aluminum alloy liquid; add 1 g of refining agent C2Cl6 to the aluminum alloy liquid, stir for 5 minutes to make it react fully, and obtain high-purity aluminum alloy liquid after skimming the slag; add 1 g of grain refiner Al-5Ti-0.8B-0.2C to the refined aluminum alloy liquid, stir for 5 minutes to make it react fully, and keep it warm for 20 minutes; pour the aluminum alloy liquid into a circular graphite mold preheated to 200 °C, and let it cool naturally in the air to obtain an aluminum alloy electrician's round rod. Use a cold rolling mill and a wire drawing machine to machine the aluminum alloy electrician's round rod to obtain an aluminum alloy wire with a diameter of 2 mm, with a deformation amount reaching 97.2%, and obtain the aluminum alloy conductor.

[0079] That is, the aging process treatment of this comparative example includes: casting the electrician's round rod → machining it into a Φ2 mm aluminum alloy wire,

[0080] That is, compared with Example 1 in the preparation process of this comparative example, there is no pre-aging treatment, nor aging treatment or two-stage aging treatment.

[0081] Comparative Example 7

[0082] This comparative example provides a high-conductivity and high-tensile-strength aluminum alloy conductor and its preparation method. The preparation method includes raw material preparation, aluminum alloy conductor preparation, and aging process treatment:

[0083] (1) Raw material preparation: Prepare Al-0.8Fe-0.2Cu according to weight percentage, weigh the corresponding Al-10Fe, Al-10Cu master alloys and the remaining industrial pure aluminum and other raw materials for a total of 200 g. Weigh 1 g of refining agent C2Cl6.

[0084] (2) Aluminum alloy conductor preparation: The same as in Example 1.

[0085] That is, the raw materials in this comparative example do not contain B and grain refiner.

[0086] Performance test:

[0087] Perform performance tests on the aluminum alloy conductors prepared in each example and comparative example respectively. Use a QJ84 digital DC double-arm bridge to test the conductivity of the wire in each implementation case. Use a Shimadzu (China) AGS-X 100KN universal testing machine to test the tensile strength and elongation of the wire in each example. The test results are shown in Table 1:

[0088] Table 2 Performance of Aluminum Alloy Conductors Prepared in Each Example and Comparative Example

[0089] Group Conductivity / %IACS Tensile strength / MPa Elongation / % Example 1 63.1 129.6 21.3 Example 2 63.0 129.1 20.6 Example 3 63.0 129.4 20.9 Comparative Example 1 62.4 194.2 6.2 Comparative Example 2 62.8 110.2 19.3 Comparative Example 3 61.8 122.4 16.3 Comparative Example 4 61.2 176.3 4.2 Comparative Example 5 61.5 103.2 18.4 Comparative Example 6 57.6 247.5 1.2 Comparative Example 7 60.8 106.7 15.6

[0090] From the comparison of the performance test results of the aluminum alloy wires provided by Example 1 and Comparative Examples 1 and 2, it can be seen that the double-stage aging can comprehensively improve the conductivity, tensile strength and elongation rate of the conductor compared with low-temperature or medium-temperature single-stage aging. Moreover, the conductivity of 63.1% IACS is better than 62.4% IACS and 62.8% IACS of single-stage aging, which indicates that the double-stage aging process of the present invention application can coordinate the balance among the three properties of the aluminum alloy conductor.

[0091] At the same time, comparing Example 1 with Comparative Example 3; Comparative Example 1 with Comparative Example 4; and Comparative Example 2 with Comparative Example 5 for the performance test results of the aluminum alloy wires provided, it can be seen that the pre-aging treatment before machining can significantly improve the conductivity of the aluminum alloy conductor: 61.8 → 63.1, 61.2 → 62.4, and 61.5 → 62.8; and it can also improve the tensile strength and elongation rate simultaneously, which shows that the pre-aging process of the present invention application can significantly improve the performance of the aluminum alloy conductor.

[0092] From the performance test results of the aluminum alloy wires provided by Example 1 and Comparative Example 7, it can be seen that boron removal by impurity and fine grain strengthening are very necessary.

[0093] In summary, compared with the traditional processing route, the pre-aging treatment increases dislocation proliferation through the pinning of primary iron phase to dislocations, reduces the growth of recrystallized grains to improve the work hardening effect, and promotes the precipitation of the second-phase particles in the alloy. The process parameters of the pre-aging treatment of the present invention can further improve the tensile strength, elongation rate and electrical conductivity of the aluminum alloy wire; and the tensile strength and electrical conductivity of the aluminum alloy after pre-aging treatment and double-stage temperature-increasing aging treatment are significantly higher than those of the aluminum alloy only subjected to single-stage temperature aging treatment, and also higher than the tensile strength and electrical conductivity of the aluminum alloy only subjected to double-stage temperature-increasing aging treatment. The process improvement of the present invention synergistically improves the tensile strength and electrical conductivity of the aluminum alloy wire through pre-aging and double-stage temperature-increasing aging treatment. Therefore, the pre-aging treatment before rolling and the double-stage aging after machining can effectively achieve the double improvement of the electrical conductivity and mechanical properties of the material.

[0094] The foregoing description of specific exemplary embodiments of the present invention is for the purposes of illustration and exemplification. These descriptions are not intended to limit the invention to the precise forms disclosed, and obviously, many changes and variations are possible in light of the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical applications, so that those skilled in the art can implement and utilize the various different exemplary embodiments of the present invention, as well as various different selections and changes. The scope of the present invention is intended to be defined by the claims and their equivalents.

Claims

1. A high conductivity, high tensile strength aluminum alloy conductor, characterized in that: The aluminum alloy conductor comprises the following components by mass percentage: Fe: 0.5-0.8%, Cu: 0.2-0.5%, B: 0.05-0.1%, Ti: 0.001-0.003%, C: 0.001-0.003%, and the balance is aluminum and inevitable impurities.

2. A method for preparing the high conductivity and high tensile strength aluminum alloy conductor as claimed in claim 1, characterized in that: The following steps are involved: S1, heating industrial pure aluminum to 720-750° C., and after the pure aluminum is completely melted, sequentially adding Al-Fe master alloy, Al-Cu master alloy, and Al-B master alloy to obtain aluminum alloy liquid; S2, adding a refining agent to the aluminum alloy liquid, stirring, and skimming to obtain a high-purity aluminum alloy liquid; S3, adding a grain refiner to the high-purity aluminum alloy liquid, stirring, and keeping warm for 10 to 30 minutes; S4, casting the aluminum alloy liquid after the insulation in step S3 into a preheated mold, and cooling it naturally in the air to obtain an aluminum alloy rod; S5, performing a pre-aging treatment on the aluminum alloy rod material, cooling it naturally to room temperature, and then performing mechanical processing to obtain an aluminum alloy wire material; S6. Performing a double-stage aging treatment on the aluminum alloy wire in sequence to obtain an aluminum alloy conductor with both high conductivity and high strength.

3. The method for preparing a high-conductivity, high-tensile-strength aluminum alloy conductor according to claim 2, characterized in that: In step S1, the Al-Fe master alloy is Al-10Fe; the Al-Cu master alloy is Al-10Cu; and the Al-B master alloy is Al-3B.

4. The method for preparing a high-conductivity, high-tensile-strength aluminum alloy conductor according to claim 2, characterized in that: In step S2, the refining agent comprises C2Cl6, and its content is 0.5-1.5% of the mass of the aluminum alloy liquid.

5. The method for preparing a high-conductivity, high-tensile-strength aluminum alloy conductor according to claim 2, characterized in that: In step S3, the grain refiner has a composition of Al-5Ti-0.8B-0.2C, and its content is 0.5-1% of the total mass of the high-purity aluminum alloy liquid.

6. The method for preparing a high-conductivity, high-tensile-strength aluminum alloy conductor according to claim 2, characterized in that: In step S4, the material of the mold is graphite or pure copper, and the preheating temperature is 180-250°C.

7. The method for preparing a high-conductivity, high-tensile-strength aluminum alloy conductor according to claim 2, characterized in that: In step S5, the pre-aging treatment temperature is 150-200° C., and the treatment time is 8-10 hours.

8. The method for preparing a high-conductivity, high-tensile-strength aluminum alloy conductor according to claim 2, characterized in that: In step S5, the mechanical processing is to use a cold rolling mill and a wire drawing machine to process the aluminum alloy rod material into an aluminum alloy wire, and the deformation amount reaches 96-97.5%.

9. The method for preparing a high-conductivity, high-tensile-strength aluminum alloy conductor according to claim 2, characterized in that: In step S6, the double-stage aging treatment is firstly treated at 180-220°C for 3-5h, and then the temperature is raised to 280-330°C for 7-9h.

10. Application of the high conductivity and high tensile strength aluminum alloy conductor according to any one of claims 1 to 9 in the field of wires and cables.

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