High-strength heat-resistant and corrosion-resistant 8-series aluminum alloy wire and preparation method thereof

Abstract

The application discloses a high-strength heat-resistant corrosion-resistant 8-series aluminum alloy conductor wire, which is mainly composed of Al, Fe, Cu, Sc, Zr, B, Er, Y and inevitable impurity elements. The aluminum alloy conductor wire has small grain size, high strength, heat resistance and good corrosion resistance through the synergistic effect of the process and components. The conductivity of the high-strength heat-resistant corrosion-resistant 8-series aluminum alloy conductor wire is greater than or equal to 61% IACS, the tensile strength is greater than or equal to 240 MPa, the strength residual rate at 240 DEG C / 1h is greater than 90%, the long-term heat-resistant temperature is as high as 220 DEG C, no obvious change is found in the corrosion resistance test for 120h, and the application requirement of the increasingly improved electric wire and cable in the coastal industrial city can be met.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aluminum alloy manufacturing, in particular to a high-strength heat-resistant and corrosion-resistant 8-series aluminum alloy wire and a preparation method thereof. BACKGROUND

[0002] Electric wires and cables are widely used in electrical, communication, transportation and energy industries, and are known as the "blood vessels" and "nerves" of the national economy. Electric wires and cables are mostly made of copper, but copper is expensive and is greatly affected by international futures fluctuations. Aluminum alloy wires have obvious cost advantages, high cost performance, and small price fluctuations. With the development of aluminum alloy wire technology, it is inevitable to replace copper with aluminum in the field of electric wires and cables. However, in industrialized coastal cities, the demand for electricity is strong, and the requirements for aluminum alloy wires are higher, especially excellent corrosion resistance to cope with industrial pollution and high salt and humid environments.

[0003] A high-conductivity heat-resistant and corrosion-resistant aluminum alloy wire and a preparation process have been disclosed, which has a conductivity of 61.8% IACS, a long-term operating temperature of 210℃, a strength residual rate of more than 90% at 230℃ / 1h, and excellent corrosion resistance, but its tensile strength is only about 190MPa. Another patent discloses a high-strength heat-resistant aluminum alloy wire and a preparation method thereof, which has a room temperature tensile strength of >320MPa, a tensile strength of >290MPa after 250℃ heat preservation for 1 hour, and a tensile strength residual rate of >91%, but the electrical conductivity is only 56% IACS, and it does not involve corrosion resistance.

[0004] In summary, after the applicant's extensive search, no product has been found that can have high strength, high heat resistance, corrosion resistance and good electrical conductivity. The 8-series aluminum alloy with Al, Fe and Cu as the main elements has good heat resistance, electrical conductivity and medium strength, which can ensure the safe use of aluminum alloy wires under high power transmission capacity. On this basis, through the addition of trace elements, optimization of preparation process and surface treatment, it is expected to develop a high-strength heat-resistant and corrosion-resistant aluminum alloy wire to meet the increasing application requirements of electric wires and cables in coastal industrial cities. SUMMARY

[0005] Therefore, in order to solve the problem that the strength, heat resistance and corrosion resistance of the aluminum alloy wire used in coastal areas cannot be balanced, the present application provides a high-strength heat-resistant and corrosion-resistant 8-series aluminum alloy wire and a preparation method thereof, and the specific technical solutions are as follows:

[0006] The application discloses a high-strength heat-resistant and corrosion-resistant 8-series aluminum alloy wire, which comprises the following components in percentage by mass: Fe: 0.6-0.7%, Cu: 0.15-0.2%, B: 0.03-0.06%, Sc: 0.03-0.07%, Zr: 0.07-0.12%, (Er+Y): 0.05-0.1%, and the balance of Al.

[0007] Further, the application also comprises other impurities, and the total amount of the other impurities is less than or equal to 0.1%.

[0008] Further, the high-strength heat-resistant and corrosion-resistant 8-series aluminum alloy wire has an electrical conductivity greater than or equal to 61% IACS, a tensile strength greater than or equal to 240 MPa, a strength residual rate of 240 DEG C / 1h greater than 90%, a long-term heat-resistant temperature up to 220 DEG C, and no obvious change after corrosion for 120h in a salt mist test.

[0009] In addition, the application also provides a preparation method of the high-strength heat-resistant and corrosion-resistant 8-series aluminum alloy wire.

[0010] S1: selecting Al-20Fe alloy, Al-20Cu alloy, Al-10Er alloy, Al-10Y alloy, Al-2Sc alloy, Al-4B alloy, Al-10Zr alloy and aluminum ingot with a purity of 99.8% as raw materials;

[0011] S2: placing the aluminum ingot under the condition of heating and melting at 720 DEG C-750 DEG C, then sequentially adding the remaining raw materials, and stirring and melting into an aluminum alloy melt;

[0012] S3: performing spray refining on the aluminum alloy melt by using sodium-free refining agent and argon, the spray refining temperature is 720 DEG C-750 DEG C, the spray refining is performed for several times, and slagging is performed after the spray refining is completed;

[0013] S4: performing ultrasonic treatment on the aluminum alloy melt by using an ultrasonic metal melt treatment device;

[0014] S5: sequentially performing online degassing and filtering treatment on the aluminum alloy melt;

[0015] S6: semi-continuously casting the aluminum alloy melt into an aluminum alloy ingot under the condition that the casting temperature is 710 DEG C-740 DEG C, the casting speed is 90 mm / min-120 mm / min, and the cooling water pressure is 0.1 MPa-0.2 MPa;

[0016] S7: uniformly heating the aluminum alloy ingot to 490 DEG C-530 DEG C for 20h-28h, and then performing water mist forced cooling to room temperature;

[0017] S8: the homogenization treated aluminum alloy ingot is heated to 410-450 DEG C, extrusion forming is carried out under the condition that the extrusion speed is 1-3 mm / s to obtain an extruded aluminum alloy rod, and then water cooling is carried out to room temperature;

[0018] S9: the extruded rod is drawn into an aluminum alloy wire with a diameter of 2-5 mm by using a wire drawing machine, and then annealing treatment is carried out on the aluminum alloy wire to obtain an aluminum alloy conductor.

[0019] Further, in S3, the addition amount of the sodium-free refining agent is 3 kg of refining agent per ton of aluminum alloy melt.

[0020] Further, in S3, the blowing refining time is 25-40 min, and after skimming, it needs to be placed for 25-35 min.

[0021] Further, in S4, the power of the ultrasonic treatment is 100-200 W, and the vibration time is 1-15 min.

[0022] Further, in S4, the in-line degassing filtration treatment is that the aluminum alloy melt flows through a degassing tank with a rotation speed of 200-300 rpm and an argon flow rate of 4-5 m3 / h and a double-layer foam ceramic filter plate with a porosity of 40 ppi+60 ppi.

[0023] Further, in S8, the die temperature of extrusion is 420-460 DEG C, and the extrusion cylinder temperature is 400-450 DEG C.

[0024] Further, in S9, the annealing treatment is 330-370 DEG C for 1-3 h.

[0025] The conductivity of the high-strength heat-resistant and corrosion-resistant 8-series aluminum alloy conductor of the application is greater than or equal to 61% IACS, the tensile strength is greater than or equal to 240 MPa, the strength retention rate at 240 DEG C / 1 h is greater than 90%, the long-term heat-resistant temperature is as high as 220 DEG C, and there is no obvious change after corrosion for 120 h in the salt spray test. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the application more clear and explicit, the application is further described in detail below in combination with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the application, and do not limit the protection scope of the application.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0028] The high-strength heat-resistant corrosion-resistant 8-series aluminum alloy wire according to an embodiment of the application comprises the following components in percentage by mass: Fe: 0.6% to 0.7%, Cu: 0.15% to 0.2%, B: 0.03% to 0.06%, Sc: 0.03% to 0.07%, Zr: 0.07% to 0.12%, (Er+Y) 0.05% to 0.1%, and the balance being Al.

[0029] In one embodiment, the application further comprises other impurities, and the total amount of the other impurities is less than or equal to 0.1%.

[0030] In one embodiment, the high-strength heat-resistant corrosion-resistant 8-series aluminum alloy wire has an electrical conductivity greater than or equal to 61% IACS, a tensile strength greater than or equal to 240 MPa, a strength retention rate of 240 ℃ / 1 h greater than 90%, a long-term heat-resistant temperature up to 220 ℃, and no obvious change after corrosion for 120 h in a salt spray test.

[0031] In one embodiment, the application further provides a preparation method of the high-strength heat-resistant corrosion-resistant 8-series aluminum alloy wire, and the preparation method comprises the following steps:

[0032] S1: selecting Al-20Fe alloy, Al-20Cu alloy, Al-10Er alloy, Al-10Y alloy, Al-2Sc alloy, Al-4B alloy, Al-10Zr alloy, and aluminum ingots with a purity of 99.8% as raw materials;

[0033] S2: placing the aluminum ingots in a condition of 720 ℃ to 750 ℃ for heating and melting, and then sequentially adding the remaining raw materials to stir and melt into an aluminum alloy melt;

[0034] S3: performing spray refining on the aluminum alloy melt with sodium-free refining agent and argon, the spray refining temperature is 720 ℃ to 750 ℃, the spray refining is performed for several times, and slagging is performed after the spray refining is completed;

[0035] S4: performing ultrasonic treatment on the aluminum alloy melt using an ultrasonic metal melt treatment device;

[0036] S5: sequentially performing online degassing and filtration treatment on the aluminum alloy melt;

[0037] S6: the aluminum alloy melt is semi-continuously cast into an aluminum alloy ingot under the conditions of a casting temperature of 710 DEG C to 740 DEG C, a casting speed of 90 mm / min to 120 mm / min, and a cooling water pressure of 0.1 MPa to 0.2 MPa;

[0038] S7: the aluminum alloy ingot is heated to 490 DEG C to 530 DEG C for homogenization treatment for 20 h to 28 h, and then is forcedly cooled to room temperature by water mist;

[0039] S8: the aluminum alloy ingot after the homogenization treatment is heated to 410 DEG C to 450 DEG C, is extruded to form an extruded aluminum alloy rod under the condition of an extrusion speed of 1 m / s to 3 mm / s, and then is cooled to room temperature by water;

[0040] S9: the extruded rod is drawn into an aluminum alloy wire with a diameter of 2 mm to 5 mm by using a wire drawing machine, and then the aluminum alloy wire is annealed to obtain an aluminum alloy conductor.

[0041] In one of the embodiments, in S3, the amount of the sodium-free refining agent added is 3 kg of the refining agent per ton of the aluminum alloy melt.

[0042] In one of the embodiments, in S3, the time for the blowing refining is 25 min to 40 min, and after the slagging, the aluminum alloy melt needs to be placed for 25 min to 35 min.

[0043] In one of the embodiments, in S4, the power for the ultrasonic treatment is 100 W to 200 W, and the vibration time is 1 min to 15 min.

[0044] In one of the embodiments, in S4, the in-line degassing filtration treatment is that the aluminum alloy melt flows through a degassing box with a rotating speed of 200 to 300 revolutions per minute and an argon flow of 4 to 5 cubic meters per hour, and a double-layer foam ceramic filter plate with a porosity of 40 ppi+60 ppi.

[0045] In one of the embodiments, in S8, the temperature of the mold for the extrusion is 420 DEG C to 460 DEG C, and the temperature of the extrusion cylinder is 400 DEG C to 450 DEG C.

[0046] In one of the embodiments, in S9, the annealing treatment is at 330 DEG C to 370 DEG C for 1 h to 3 h.

[0047] The high-strength heat-resistant and corrosion-resistant 8-series aluminum alloy conductor has an electrical conductivity of greater than or equal to 61% IACS, a tensile strength of greater than or equal to 240 MPa, a strength residual rate of 240 DEG C / 1 h of greater than 90%, a long-term heat-resistant temperature of up to 220 DEG C, and no obvious change after corrosion for 120 h in a salt mist test.

[0048] Embodiments of the present application will be described in detail below with specific examples.

[0049] Example 1

[0050] The aluminum alloy wire is composed of the following components in mass percentage: Fe: 0.6%, Cu: 0.15%, B: 0.03%, Sc: 0.03%, Zr: 0.07%, (Er+Y): 0.05%, the balance being Al and unavoidable other impurities, the total amount of impurities ≤0.1%.

[0051] The preparation method of the aluminum alloy wire comprises the following steps:

[0052] S1: selecting Al-20Fe alloy, Al-20Cu alloy, Al-10Er alloy, Al-10Y alloy, Al-2Sc alloy, Al-4B alloy, Al-10Zr alloy and aluminum ingot with a purity of 99.8% as raw materials;

[0053] S2: heating and melting the aluminum ingot at 720℃, then adding the remaining raw materials, and stirring to form an aluminum alloy melt;

[0054] S3: using sodium-free refining agent and argon to spray and refine the aluminum alloy melt at a ratio of 3 kg of refining agent per ton of aluminum alloy melt, the spray refining temperature is 720℃, the spray refining is performed twice, each time for 40 min; after spray refining, slagging is performed, and after slagging, it is placed for 35 min;

[0055] S4: using an ultrasonic metal melt treatment device to perform ultrasonic treatment on the aluminum alloy melt, the power of the ultrasonic treatment is 120W, and the vibration time is 10 min;

[0056] S5: the aluminum alloy liquid sequentially flows through a degassing box with a rotation speed of 300 revolutions per minute and an argon flow rate of 5 cubic meters per hour and a double-layer foam ceramic filter plate with a porosity of 40 ppi+60 ppi, and is subjected to online degassing and filtration treatment;

[0057] S6: the aluminum alloy liquid is semi-continuously cast into an aluminum alloy ingot under the conditions of a casting temperature of 710℃, a casting speed of 90mm / min, and a cooling water pressure of 0.1MPa;

[0058] S7: the aluminum alloy ingot is heated to 490℃ for homogenization treatment for 28h, and then is forcedly cooled to room temperature by water mist;

[0059] S8: the aluminum alloy ingot after homogenization treatment is heated to 410℃, and is subjected to extrusion forming under the conditions of a mold temperature of 420℃, an extrusion cylinder temperature of 400℃, and an extrusion speed of 3m / s, and then is cooled to room temperature by water;

[0060] S9: The extruded bar is drawn into an aluminum alloy wire with a diameter of 2 mm by using a wire drawing machine, and then the aluminum alloy wire is annealed at 330 ℃ for 3 h to obtain an aluminum alloy wire.

[0061] Example 2:

[0062] The aluminum alloy wire is composed of the following components by mass percentage: Fe: 0.7%, Cu: 0.2%, B: 0.06%, Sc: 0.07%, Zr: 0.12%, (Er+Y): 0.1%, and the balance of Al and unavoidable other impurities, with the total amount of impurities ≤0.1%.

[0063] The aluminum alloy wire preparation method comprises the following steps:

[0064] S1: Al-20Fe alloy, Al-20Cu alloy, Al-10Er alloy, Al-10Y alloy, Al-2Sc alloy, Al-4B alloy, Al-10Zr alloy, and aluminum ingot with a purity of 99.8% are selected as raw materials;

[0065] S2: The aluminum ingot is heated and melted at 750 ℃, and then the remaining raw materials are added and stirred to form an aluminum alloy melt;

[0066] S3: The aluminum alloy melt is subjected to spray refining with sodium-free refining agent and argon at a ratio of 3 kg of refining agent per ton of aluminum alloy melt, the spray refining temperature is 750 ℃, the spray refining is performed twice, each time for 25 min; after spray refining, the slag is removed, and the aluminum alloy melt is left to stand for 25 min;

[0067] S4: The aluminum alloy melt is subjected to ultrasonic treatment using an ultrasonic metal melt treatment device, the power of the ultrasonic treatment is 150 W, and the vibration time is 5 min;

[0068] S5: The aluminum alloy liquid is sequentially flowed through a degassing tank with a rotation speed of 200 revolutions per minute and an argon flow rate of 4 cubic meters per hour and a double-layer foam ceramic filter plate with a porosity of 40 ppi+60 ppi for online degassing and filtration treatment;

[0069] S6: The aluminum alloy liquid is semi-continuously cast into an aluminum alloy ingot under the conditions of a casting temperature of 740 ℃, a casting speed of 120 mm / min, and a cooling water pressure of 0.2 MPa;

[0070] S7: The aluminum alloy ingot is heated to 530 ℃ for homogenization treatment for 20 h, and then water mist forced cooling is performed to room temperature;

[0071] S8: The homogenized aluminum alloy ingot is heated to 450 ℃, and is subjected to extrusion forming under the conditions of a mold temperature of 460 ℃, an extrusion cylinder temperature of 420 ℃, and an extrusion speed of 1 m / s, and then is water cooled to room temperature.

[0072] S9: The extruded bar is drawn into aluminum alloy wire with a diameter of 5 mm by using a wire drawing machine, and then the aluminum alloy wire is annealed at 370℃ for 1 h to obtain the aluminum alloy wire.

[0073] Example 3:

[0074] The aluminum alloy wire is composed of the following components by mass percentage: Fe: 0.65%, Cu: 0.18%, B: 0.05%, Sc: 0.05%, Zr: 0.1%, (Er+Y): 0.08%, and the balance of Al and unavoidable other impurities, with the total amount of impurities ≤0.1%.

[0075] The preparation method of the aluminum alloy wire comprises the following steps:

[0076] S1: Al-20Fe alloy, Al-20Cu alloy, Al-10Er alloy, Al-10Y alloy, Al-2Sc alloy, Al-4B alloy, Al-10Zr alloy, and aluminum ingot with a purity of 99.8% are selected as raw materials;

[0077] S2: The aluminum ingot is heated and melted at 730℃, and then the remaining raw materials are added and stirred to form an aluminum alloy melt;

[0078] S3: The aluminum alloy melt is subjected to spray refining with sodium-free refining agent and argon at a ratio of 3 kg of refining agent per ton of aluminum alloy melt, the spray refining temperature is 730℃, the spray refining is performed twice, each time for 30 min, and after spray refining, the slag is removed, and after slag removal, the aluminum alloy melt is allowed to stand for 30 min;

[0079] S4: The aluminum alloy melt is subjected to ultrasonic treatment using an ultrasonic metal melt treatment device, the power is 140W, and the vibration time is 8min;

[0080] S5: The aluminum alloy liquid is sequentially flowed through a degassing tank with a rotation speed of 250 revolutions per minute and an argon flow rate of 4.5 cubic meters per hour and a double-layer foam ceramic filter plate with a porosity of 40ppi+60ppi for online degassing and filtration treatment;

[0081] S6: The aluminum alloy liquid is semi-continuously cast into an aluminum alloy ingot at a casting temperature of 720℃, a casting speed of 110mm / min, and a cooling water pressure of 0.15MPa;

[0082] S7: The aluminum alloy ingot is heated to 510℃ for homogenization treatment for 24h, and then water mist forced cooling to room temperature;

[0083] S8: The aluminum alloy ingot after homogenization treatment was heated to 430°C, and extrusion forming was performed under the conditions of a die temperature of 440°C, an extrusion cylinder temperature of 410°C, and an extrusion speed of 2 m / s, and then water cooling was performed to room temperature;

[0084] S9: The extruded bar was drawn into an aluminum alloy wire with a diameter of 4 mm using a wire drawing machine, and then the aluminum alloy wire was annealed at 350°C for 1.5 h, thereby obtaining an aluminum alloy wire.

[0085] Comparative Example 1:

[0086] Comparative Example 1 differs from Example 3 in that the aluminum alloy wire is composed of the following components in mass percent: Fe: 0.5%, Cu: 0.10%, B: 0.05%, Sc: 0.05%, Zr: 0.1%, (Er+Y): 0.08%, with the balance being Al and unavoidable other impurities, with the total amount of impurities being ≤0.1%.

[0087] The other preparation processes are the same as those of Example 3.

[0088] Comparative Example 2:

[0089] Comparative Example 2 differs from Example 3 in that the aluminum alloy wire is composed of the following components in mass percent: Fe: 0.8%, Cu: 0.25%, B: 0.05%, Sc: 0.05%, Zr: 0.1%, (Er+Y): 0.08%, with the balance being Al and unavoidable other impurities, with the total amount of impurities being ≤0.1%.

[0090] The other preparation processes are the same as those of Example 3.

[0091] Comparative Example 3:

[0092] Comparative Example 3 differs from Example 3 in that the aluminum alloy wire is composed of the following components in mass percent: Fe: 0.65%, Cu: 0.18%, Sc: 0.05%, Zr: 0.1%, (Er+Y): 0.08%, with the balance being Al and unavoidable other impurities, with the total amount of impurities being ≤0.1%.

[0093] The other preparation processes are the same as those of Example 3.

[0094] Comparative Example 4:

[0095] Comparative Example 4 differs from Example 3 in that the aluminum alloy wire is composed of the following components in mass percent: Fe: 0.65%, Cu: 0.18%, B: 0.05%, Sc: 0.05%, Zr: 0.1%, with the balance being Al and unavoidable other impurities, with the total amount of impurities being ≤0.1%.

[0096] The other preparation processes are the same as those of Example 3.

[0097] Comparative Example 5:

[0098] Comparative Example 5 differs from Example 3 in that the aluminum alloy wire is composed of the following mass percentages of components: Fe: 0.65%, Cu: 0.18%, B: 0.05%, Zr: 0.1%, (Er+Y): 0.08%, with the balance being Al and unavoidable other impurities, with the total amount of impurities ≤ 0.1%.

[0099] The other preparation processes are the same as those of Example 3.

[0100] Comparative Example 6:

[0101] Comparative Example 6 differs from Example 3 in that the aluminum alloy wire is composed of the following mass percentages of components: Fe: 0.65%, Cu: 0.18%, B: 0.05%, Sc: 0.05%, (Er+Y): 0.08%, with the balance being Al and unavoidable other impurities, with the total amount of impurities ≤ 0.1%.

[0102] The other preparation processes are the same as those of Example 3.

[0103] Comparative Example 7:

[0104] Comparative Example 7 differs from Example 3 in that the ultrasonic treatment described in S4 is not performed.

[0105] The other preparation processes are the same as those of Example 3.

[0106] Comparative Example 8:

[0107] Comparative Example 8 differs from Example 3 in that after the extruded rod is drawn into an aluminum alloy wire, no annealing treatment is performed.

[0108] The other preparation processes are the same as those of Example 3.

[0109] The aluminum alloy wires prepared in Examples 1-3 and Comparative Examples 1-10 are subjected to relevant performance tests, and the results are shown in Table 1 below. Among them, the mechanical properties of the products are tested according to GB / T 228.1-2021 “Metallic Materials Tensile Test Part 1: Room Temperature Test Method”; the electrical conductivity of the products is tested according to GB / T 12966-2022 Aluminum and Aluminum Alloy Electrical Conductivity Eddy Current Test Method, and the salt spray resistance is tested using a salt spray test chamber according to GB / T 2423.17.2008 / IEC 60068-2-11:1981 “Electrical and Electronic Products Environmental Test-Salt Spray”.

[0110] Table 1:

[0111]

[0112] The difference between Examples 1-3 is that the amount of raw materials added to the aluminum alloy conductor wire is different. As shown in Table 1, the electrical conductivity of the aluminum alloy conductor wire prepared in Examples 1-3 is greater than or equal to 61% IACS, the tensile strength is greater than or equal to 240 MPa, the strength retention rate at 240℃ / 1h is greater than 90%, the long-term heat resistance temperature is as high as 220℃, and in the salt spray test, there is no obvious change after corrosion for 120h;

[0113] Comparative Example 1 and Example 3 differ in that the Fe content of the added raw materials is 0.5% and the Cu content is 0.1%. Fe and Cu are the main alloying elements in this series of aluminum alloys. Fe can form Al3Fe in the alloy, which has excellent thermal stability, thereby improving the strength and heat resistance of the alloy. Cu mainly improves the strength of the alloy through solid solution strengthening and precipitation strengthening, i.e., forming CuAl2 phase with obvious strengthening effect. As shown in Table 1, the tensile strength and heat resistance of Comparative Example 1 are lower than those of Example 3. In combination with Examples 1-3, it is known that when the Fe content is less than 0.6% and the Cu content is less than 0.15%, the tensile strength of the aluminum alloy conductor wire cannot reach 240 MPa, and the strength retention rate at 240℃ / 1h and the strength retention rate at 220℃ / 400h cannot reach more than 90%;

[0114] Comparative Example 2 and Example 3 differ in that the Fe content of the added raw materials is 0.8% and the Cu content is 0.25%. Fe and Cu are the main alloying elements in this series of aluminum alloys, but too high Fe content can reduce the electrical conductivity and corrosion resistance of the material. Too high Cu content can increase the tendency of pitting corrosion. As shown in Table 1, the electrical conductivity and salt spray resistance time of Comparative Example 2 are lower than those of Example 3. In combination with Examples 1-3, it is known that when the Fe content is greater than 0.7% and the Cu content is greater than 0.2%, the electrical conductivity of the aluminum alloy conductor wire cannot reach 61% IACS, and the salt spray resistance time cannot reach 120h;

[0115] Comparative Example 3 and Example 3 differ in that a certain amount of B element is not added. A certain amount of B element can purify the alloy matrix, so that the solid solution atoms in the alloy change from solid solution state to precipitation state, reduce the lattice distortion caused by solid solution atoms, reduce the scattering of electrons, and thus improve the electrical conductivity of the alloy. At the same time, B can refine the alloy grains, so that the tensile strength of the alloy is improved. Furthermore, B can also purify the grain boundary, thereby improving the corrosion resistance of the alloy. As shown in Table 1, the tensile strength, electrical conductivity and salt spray resistance of Comparative Example 3 are lower than those of Example 3, and cannot achieve the performance effect of the aluminum alloy conductor wire prepared in Example 3, i.e., the tensile strength is greater than or equal to 240 MPa, the electrical conductivity is greater than or equal to 61% IACS, and the salt spray resistance time is greater than or equal to 120h;

[0116] The difference between Comparative Example 4 and Example 3 is that a certain amount of Er and Y elements are not added. Er and Y can form a special thermal stable phase Al3(Zr, Er / Y) with Zr, which improves the heat resistance and strength of the alloy. Meanwhile, Er and Y can also react with Fe element to form fine and dispersed compounds. On the one hand, the Fe in Al is displaced, which makes Fe precipitate and reduces the resistivity. On the other hand, the precipitated phase is fine and uniformly distributed, which can play a role in refining the grain. Further, Er and Y can both purify the grain boundary and reduce the aggregation of impurity atoms such as Si at the grain boundary, which is beneficial to the improvement of corrosion resistance. As can be seen from the data in Table 1, compared with Example 3, the tensile strength, electrical conductivity, heat resistance and salt spray resistance of Comparative Example 4 all decrease, and the performance effects of the aluminum alloy conductor prepared in Example 3 cannot be achieved, i.e., the tensile strength is greater than or equal to 240 Mpa, the electrical conductivity is greater than or equal to 61% IACS, the strength residual rate at 240℃ / 1h and the strength residual rate at 220℃ / 400h are greater than 90%, and the salt spray resistance time is greater than or equal to 120h;

[0117] The difference between Comparative Example 5 and Example 3 is that a certain amount of Sc element is not added. Sc element can significantly improve the strength, high temperature performance and recrystallization temperature of the alloy. This is because Sc can form a stable Al3Sc phase with Al, which has a small mismatch with the aluminum matrix, can effectively inhibit grain growth, improve alloy strength and high temperature performance, can pin dislocations and grain boundaries, hinder recrystallization, improve recrystallization temperature, inhibit recrystallization behavior, and improve the corrosion resistance of the alloy. As can be seen from the data in Table 1, compared with Example 3, the tensile strength, heat resistance and salt spray resistance of Comparative Example 5 all decrease, and the performance effects of the aluminum alloy conductor prepared in Example 3 cannot be achieved, i.e., the tensile strength is greater than or equal to 240 Mpa, the strength residual rate at 240℃ / 1h and the strength residual rate at 220℃ / 400h are greater than 90%, and the salt spray resistance time is greater than or equal to 120h;

[0118] The difference between Comparative Example 6 and Example 3 is that a certain amount of Zr element is not added. A certain amount of Zr can form an Al3(Sc, Zr) phase with a core-shell structure and good thermal stability with Sc, which has a better strengthening effect than adding Sc or Zr alone. The core-shell structure changes the dynamics of the precipitation phase enrichment in nature, increases the stability of the microstructure, and prevents the coarsening of the second phase, thus having better high temperature performance. Its beneficial effect on corrosion resistance is similar to that of Sc. As can be seen from the data in Table 1, compared with Example 3, the tensile strength, heat resistance and salt spray resistance of Comparative Example 6 all decrease, and the performance effects of the aluminum alloy conductor prepared in Example 3 cannot be achieved, i.e., the tensile strength is greater than or equal to 240 Mpa, the strength residual rate at 240℃ / 1h and the strength residual rate at 220℃ / 400h are greater than 90%, and the salt spray resistance time is greater than or equal to 120h;

[0119] Comparative Example 7 differs from Example 3 in that no ultrasonic treatment is performed, and the alloy is cast using ultrasonic casting technology, and the melt is treated with ultrasonic waves of optimal frequency to promote grain nucleation and break up grains through "cavitation effect" to refine grains and improve the tensile strength of the alloy. As can be seen from the data in Table 1, the tensile strength of Comparative Example 7 is lower than that of Example 3, and cannot achieve the performance effect of the aluminum alloy wire prepared in Example 3, which has a tensile strength greater than or equal to 240 MPa;

[0120] Comparative Example 8 differs from Example 3 in that no annealing treatment is performed after the aluminum alloy wire is drawn, and the annealing treatment causes the strengthening phases to dissolve, the solid solution atoms in the alloy to decrease, and the electrical conductivity of the material to improve. As can be seen from the data in Table 1, the electrical conductivity of Comparative Example 8 is lower than that of Example 3, and cannot achieve the performance effect of the aluminum alloy wire prepared in Example 3, which has an electrical conductivity greater than or equal to 61% IACS;

[0121] In the present application, Fe and Cu are the main alloying elements of the series of aluminum alloys. Fe can form Al3Fe in the alloy, which has excellent thermal stability, and improves the strength and heat resistance of the alloy. However, too high Fe content can reduce the electrical conductivity and corrosion resistance of the material. Therefore, the Fe content is controlled at 0.6%-0.7%. Cu mainly improves the strength of the alloy through solid solution strengthening and precipitation strengthening, i.e., forming CuAl2 phase with obvious strengthening effect. Meanwhile, Cu is beneficial to the electrical conductivity of the alloy. However, the addition of Cu element tends to cause pitting. Therefore, the Cu content is controlled at 0.15%-0.2%. Zr and Sc are the main added elements, which can greatly improve the heat resistance of the material. Sc element can significantly improve the strength, high temperature performance and recrystallization temperature of the alloy. This is because Sc can form Al3Sc phase with aluminum, which has small mismatch degree with the aluminum matrix, can effectively inhibit grain growth, improve the strength and high temperature performance of the alloy, and can pin dislocations and grain boundaries, hinder recrystallization, improve the recrystallization temperature, inhibit the recrystallization behavior, and improve the corrosion resistance of the alloy. However, Sc is relatively expensive, and generally Sc and Zr are added together to form Al3(Sc, Zr) phase with core-shell structure and better thermal stability. The strengthening effect of the Al3(Sc, Zr) phase is better than that of Sc or Zr alone. The core-shell structure changes the dynamic behavior of the second phase enrichment in essence, increases the stability of the microstructure, and prevents the second phase from coarsening. Therefore, the core-shell structure has better high temperature performance, and has similar beneficial effects on corrosion resistance as Sc. However, the addition of Zr can cause lattice distortion of the aluminum matrix, increase electron scattering and thus reduce electrical conductivity. Therefore, the Sc content is controlled at 0.03%-0.07%, and the Zr content is controlled at 0.07%-0.12%. A certain amount of B element can purify the alloy matrix, so that the solid solution atoms in the alloy change from solid solution state to precipitation state, reduce the lattice distortion caused by solid solution atoms, reduce the scattering of electrons, and thus improve the electrical conductivity of the alloy. At the same time, the alloy grain can be refined, so that the tensile strength of the alloy is improved. However, too high B element is not conducive to the electrical conductivity of the alloy. Therefore, the B content is controlled at 0.03%-0.06%. Er and Y can form a similar thermal stable phase Al3(Zr, Er / Y) with Zr, like Sc, to improve the heat resistance and strength of the alloy. Meanwhile, Er and Y can also react with Fe element to form fine and dispersed compounds. On the one hand, the Fe in Al is displaced, which makes Fe precipitate and reduces the resistivity. On the other hand, the precipitated phase is fine and uniformly distributed, which can refine the grain. Furthermore, B, Er and Y can all purify the grain boundary, reduce the aggregation of impurity atoms such as Si at the grain boundary, and are beneficial to the improvement of corrosion resistance. However, grain refinement and increase of grain boundary area are not conducive to the electrical conductivity of the alloy. Therefore, too much grain refining element should not be added. Considering the effects of Zr, Sc, Er and Y, it is found that, under a certain Zr and Sc content, controlling the Er+Y content at 0.05%-0.1% can balance the strength and electrical conductivity.

[0122] The purity of the aluminum alloy is improved, and the mechanical property and the corrosion resistance of the aluminum alloy are improved.

[0123] The grain refinement of the ingot is realized by the synergistic effect of the added elements and the ultrasonic treatment. When the ultrasonic wave penetrates the melt, a certain cavitation region is formed in the melt, a large number of cavities are formed in the region, and heat is absorbed from the nearby melt, resulting in a large amount of local supercooling of the melt, and a large number of nucleation, thereby realizing grain refinement. On the other hand, the local high temperature and high pressure generated by the breaking of unstable bubbles can also cause secondary grain breakage and refinement. The ultrasonic power is controlled at 120W-150W, and the vibration time is 5min-10min, and the casting grain size of 120-150 microns can be obtained.

[0124] The homogenization treatment can improve the element segregation in the alloy, improve the composition uniformity and extrudability, and has a certain improvement effect on the final mechanical property of the alloy. After a large number of experimental researches, the inventors find that the ideal homogenization temperature and time of the aluminum alloy are 490-530℃ and 20-28h, which can completely eliminate the macro and micro segregation of elements in the ingot, and make the elements and coarse intermetallic compounds fully solid solution.

[0125] The water cooling after extrusion can shorten the residence time of the extruded rod at high temperature, reduce the occurrence of static recrystallization, and more stay in the dynamic recovery stage, so that the alloy has more subgrains, and has higher dislocation density after drawing. In the subsequent annealing heat treatment, the grain growth is not obvious. At the same time, the annealing treatment makes the strengthening phase fully precipitated, the solid solution atoms in the alloy are reduced, and the electrical conductivity of the material is improved. Through the annealing process research of the aluminum alloy wire, the inventors find that the best annealing process is 330-370℃ for 1-3h. If the annealing temperature is lower than 330℃ or the holding time is less than 1h, the strengthening phase is not fully precipitated, and the electrical conductivity of the material is insufficient. If the annealing temperature is higher than 330℃ or the holding time is more than 3h, the grain growth is obvious, and the strength decreases significantly.

[0126] The technical features of the above-mentioned embodiments can be combined arbitrarily, and in order to make the description simple, all possible combinations of the technical features in the above-mentioned embodiments are not described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application.

[0127] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are within the scope of protection of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A high-strength heat-resistant corrosion-resistant 8-series aluminum alloy wire, characterized by, Comprise the following ingredients by mass percentage: Fe: 0.6%~0.7%, Cu: 0.15%~0.2%, B: 0.03%~0.06%, Sc: 0.03%~0.07%, Zr: 0.07%~0.12%, (Er+Y) 0.05%~0.1%, the balance of Al; The preparation method of the high-strength heat-resistant and corrosion-resistant 8-series aluminum alloy wire, Comprise the following steps: S1: select Al-20Fe alloy, Al-20Cu alloy, Al-10Er alloy, Al-10Y alloy, Al-2Sc alloy, Al-4B alloy, Al-10Zr alloy and aluminum ingot with a purity of 99.8% as raw materials; S2: place the aluminum ingot in a condition of heating and melting at 720~750 DEG C, then sequentially add the remaining raw materials, and stir and melt into an aluminum alloy melt; S3: spray refining of the aluminum alloy melt with sodium-free refining agent and argon, the spray refining temperature is 720~750 DEG C, spray refining for several times, and after spray refining, slagging is carried out; S4: ultrasonic treatment of the aluminum alloy melt is carried out using ultrasonic metal melt treatment equipment, and the power of the ultrasonic treatment is 100~200 W, and the vibration time is 1~15 min; S5: the aluminum alloy melt is sequentially subjected to online degassing and filtration treatment; S6: the aluminum alloy melt is semi-continuously cast into an aluminum alloy ingot under the conditions of a casting temperature of 710~740 DEG C, a casting speed of 90~120 mm / min, and a cooling water pressure of 0.1~0.2 MPa; S7: the aluminum alloy ingot is heated to 490~530 DEG C for homogenization treatment for 20~28 h, and then water mist forced cooling is carried out to room temperature; S8: the aluminum alloy ingot after homogenization treatment is heated to 410~450 DEG C, and is subjected to extrusion forming under the condition of an extrusion speed of 1~3 m / s to obtain an extruded aluminum alloy rod, and then water cooling is carried out to room temperature; S9: the extruded rod is drawn into an aluminum alloy wire with a diameter of 2~5 mm using a wire drawing machine, and then annealing treatment is carried out on the aluminum alloy wire to obtain an aluminum alloy wire.

2. The high-strength heat-resistant corrosion-resistant 8-series aluminum alloy wire of claim 1, wherein, Still include other impurities, the total amount of other impurities is ≤0.1%.

3. The high-strength, heat-resistant, corrosion-resistant, Series 8 aluminum alloy wire of claim 1, wherein, The high-strength heat-resistant and corrosion-resistant 8-series aluminum alloy wire has an electrical conductivity of greater than or equal to 61% IACS, a tensile strength of greater than or equal to 240 MPa, a strength residual rate of greater than 90% at 240 DEG C / 1 h, a long-term heat-resistant temperature of up to 220 DEG C, and no obvious change after corrosion for 120 h in a salt spray test.

4. A method for preparing high-strength heat-resistant and corrosion-resistant 8-series aluminum alloy wire, characterized by, The preparation method is used for preparing the 8-series aluminum alloy wire as claimed in any one of claims 1~3, and comprises the following steps: S1: select Al-20Fe alloy, Al-20Cu alloy, Al-10Er alloy, Al-10Y alloy, Al-2Sc alloy, Al-4B alloy, Al-10Zr alloy and aluminum ingot with a purity of 99.8% as raw materials; S2: place the aluminum ingot in a condition of heating and melting at 720~750 DEG C, then sequentially add the remaining raw materials, and stir and melt into an aluminum alloy melt; S3: Spraying refining the aluminum alloy melt with sodium-free refining agent and argon, the spraying refining temperature is 720℃-750℃, spraying refining several times, and then performing slagging after the spraying refining is completed; S4: Using ultrasonic metal melt processing equipment to perform ultrasonic treatment on the aluminum alloy melt; S5: The aluminum alloy melt is sequentially subjected to online degassing and filtration treatment; S6: The aluminum alloy melt is semi-continuously cast into an aluminum alloy ingot under the conditions of a casting temperature of 710℃-740℃, a casting speed of 90 mm / min-120 mm / min, and a cooling water pressure of 0.1 MPa-0.2 MPa; S7: The aluminum alloy ingot is heated to 490℃-530℃ for homogenization treatment for 20h-28h, and then forcedly cooled to room temperature by water mist; S8: The homogenized aluminum alloy ingot is heated to 410℃-450℃, and extruded under the condition of an extrusion speed of 1m / s-3m / s to obtain an extruded aluminum alloy rod, and then cooled to room temperature by water; S9: The extruded rod is drawn into an aluminum alloy wire with a diameter of 2mm-5mm using a wire drawing machine, and then the aluminum alloy wire is annealed at 330℃-370℃ for 1h-3h, thereby obtaining an aluminum alloy wire.

5. The method of claim 4, wherein the high-strength heat-resistant corrosion-resistant 8-series aluminum alloy wire is prepared by the steps of: preparing a 8-series aluminum alloy wire; and performing a heat treatment on the 8-series aluminum alloy wire. In S3, the addition amount of sodium-free refining agent is 3kg of refining agent per ton of aluminum alloy melt.

6. The method of claim 4, wherein the high-strength heat-resistant corrosion-resistant 8-series aluminum alloy wire is prepared by the steps of: preparing a 8-series aluminum alloy wire; and performing a heat treatment on the 8-series aluminum alloy wire. In S3, the spraying refining time is 25min-40min, and after slagging, it needs to be stationary for 25min-35min.

7. The method of claim 4, wherein the high-strength heat-resistant corrosion-resistant 8-series aluminum alloy wire is prepared by the steps of: preparing a 8-series aluminum alloy wire; and performing a heat treatment on the 8-series aluminum alloy wire. In S4, the online degassing and filtration treatment is that the aluminum alloy melt flows through a degassing box with a rotational speed of 200-300 revolutions / minute and an argon flow rate of 4-5 cubic meters / hour, and a double-layer foam ceramic filter plate with a porosity of 40ppi+60ppi.

8. The method of claim 4, wherein the high-strength heat-resistant corrosion-resistant 8-series aluminum alloy wire is prepared by the steps of: preparing a 8-series aluminum alloy wire; and performing a heat treatment on the 8-series aluminum alloy wire. In S8, the mold temperature for extrusion is 420℃-460℃, and the extrusion cylinder temperature is 400℃-450℃.

Images