A Conductive Al-Cu-Sn-Er Rare Earth Aluminum Alloy and Its Processing Method

Abstract

The present invention discloses a conductive Al-Cu-Sn-Er rare earth aluminum alloy and a processing method thereof, wherein the content of copper element in the rare earth aluminum alloy is 0.2-1.0wt%, the content of tin element is 0.1-0.8wt%, the sum of the content of tin element and erbium element is less than or equal to 1.0wt%, and the remainder is aluminum. The processing method is as follows: pure aluminum is smelted in an atmospheric environment by a medium frequency induction smelting furnace to obtain a pure aluminum melt; aluminum-copper master alloy, aluminum-tin master alloy and aluminum-erbium master alloy are sequentially added to the pure aluminum melt to obtain a mixed melt by smelting; the mixed melt is cast by a near-liquidus casting method to obtain an alloy ingot; the alloy ingot is subjected to a solid solution treatment to obtain an alloy billet; the alloy billet is subjected to alternating treatments of three rollings and three-stage aging. The present invention can solve the problem that the electrical conductivity and mechanical strength of the existing aluminum alloy cannot be combined.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum alloy processing, in particular to a conductive Al-Cu-Sn-Er rare earth aluminum alloy and a processing method thereof. Background Art

[0002] my country's nonferrous metal material resources are short of copper and rich in aluminum, and most of the copper resources are used in low-end industries such as wires and cables, resulting in a huge waste of scarce resources. Aluminum conductors and aluminum cables can replace copper conductors and copper cables, so aluminum replacing copper is the development trend of my country's cable industry and an effective measure to save copper resources. Shenyang University of Technology has developed a conductive aluminum alloy conductor with a conductivity of 62% IACS and a strength of 220MPa; Wuxi Huaneng Cable Co., Ltd. has developed an aluminum alloy conductor with a conductivity of 60% IACS; Far East Cable Co., Ltd. has produced an aluminum alloy conductor with a conductivity of 57.5% IACS and a strength of 260-300MPa; State Grid Smart Grid Research Institute has developed an aluminum alloy wire with a conductivity of 60% IACS and a tensile strength of 243MPa; Jiangsu Hengtong Electric Power Special Conductor Company has developed an aluminum alloy conductor with a conductivity of 59.2% IACS and a tensile strength of 240-255MPa.

[0003] However, since the performance indicators of aluminum conductors and cables are still not ideal, the research and development of new high-strength conductive aluminum alloys has become a research hotspot in the cable industry. As a carrier for transmitting electrical energy, aluminum alloy conductors and cables are required to have high conductivity while taking into account certain mechanical properties. However, there is a contradictory relationship between conductivity and mechanical properties (strength). How to improve the strength under the premise of good conductivity of aluminum alloy is the key issue of whether "aluminum can replace copper". Summary of the invention

[0004] To this end, the technical problem to be solved by the present invention is to provide a conductive Al-Cu-Sn-Er rare earth aluminum alloy and a processing method thereof to solve the problem that the existing aluminum alloy cannot have both electrical conductivity and mechanical strength.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] A conductive Al-Cu-Sn-Er rare earth aluminum alloy, wherein the content of copper element is 0.2-1.0wt%, the content of tin element is 0.1-0.8wt%, the sum of the content of tin element and erbium element is less than or equal to 1.0wt%, and the balance is aluminum.

[0007] The processing method of the conductive Al-Cu-Sn-Er rare earth aluminum alloy comprises the following steps:

[0008] Step (1): Pure aluminum is melted in an intermediate frequency induction melting furnace under atmospheric environment to obtain a pure aluminum melt;

[0009] Step (2): An aluminum-copper master alloy, an aluminum-tin master alloy and an aluminum- erbium master alloy are sequentially added to the pure aluminum melt, and melted to obtain a mixed melt;

[0010] Step (3): The mixed melt is cast by the near liquidus casting method to obtain an alloy ingot;

[0011] Step (4): The alloy ingot is solution treated to obtain an alloy blank;

[0012] Step (5): The alloy blank is alternately treated by three rolling passes and three-stage aging. After the treatment is completed, the above-mentioned conductive Al-Cu-Sn-Er rare earth aluminum alloy is obtained.

[0013] Since the crystal structure of Er is a close-packed hexagonal structure and Al is a face-centered cubic structure, the addition reduces the stacking fault energy of the alloy and the critical nucleation thickness of twins, making it easier to form twins during plastic deformation. Twins can improve the strength of the alloy while having little effect on the electrical conductivity; Er 3+ has 21 unfilled valence orbitals in its electronic structure, and the special 4f orbitals can accommodate 12 electrons, which is beneficial to the propagation of electrons; in addition, the solid solubility of Er at room temperature is <0.05%, and solute atoms will precipitate in the form of the second phase at room temperature, avoiding the reduction of electrical conductivity caused by lattice distortion due to solid solution strengthening. Al3Er belongs to the Pm3m space group and has an L12-type crystal structure. Its lattice constant (0.4215 nm) is very close to that of the Al matrix (0.4049 nm). Therefore, the Al3Er phase decomposed from the supersaturated solid solution has good interface coherency with the matrix.

[0014] After adding Cu element to Al, the existing form of Cu element is the intermetallic compound Al2Cu phase, which is an important strengthening phase in the Al-Cu-Sn-Er alloy; when adding Sn element, rich Sn particles are formed during the precipitation strengthening process of the Al-Cu-Sn-Er alloy, and the rich Sn particles act as modifiers to limit the growth of the Al2Cu phase; Er mainly exists in the form of Al3Er in the alloy, and the shape of Al3Er in the alloy is massive and punctiform, and part of Al3Er is coherent with the aluminum alloy matrix. The fine Al3Er can be used as the core for heterogeneous nucleation of the Al2Cu phase and promote the formation of the Al2Cu phase at the same time. If the content of copper element is less than 0.2wt%, its strengthening effect on the alloy is not obvious. If its content is higher than 1.0wt%, the casting is prone to cracking during subsequent plastic deformation and affects the electrical conductivity of the alloy; since the tin element exists in the form of elemental particles in the Al-Cu-Sn-Er alloy, it can be used as the nucleation substrate for strengthening phases such as Al2Cu and can limit the growth of its size at the same time. If the content of tin element is less than 0.1wt%, it cannot play a role in inhibiting the size growth of strengthening phases such as Al2Cu, but if the content is higher than 0.8wt%, it will increase the electron diffuse scattering and affect the electrical conductivity of the alloy. In addition, the addition of erbium element has the effects of purifying the matrix, modifying, and microalloying, etc. When the content of erbium element is too low (such as less than 0.1wt.%), it mainly plays the roles of fine grain strengthening and limited solid solution strengthening, while conductor materials generally need to avoid lattice distortion caused by solid solution strengthening; when the erbium element is 0.1 - 0.3wt.%, the erbium element can form spherical intermetallic compound Al3Er with aluminum element, and the influence on the electrical conductivity is relatively small when improving the strength of the aluminum alloy; when the erbium element > 0.3wt.%, it forms a large number of needle-shaped and rod-shaped intermetallic compounds with aluminum element, which are distributed at the grain boundaries or in the grains, and has a greater influence on the electrical conductivity while improving the strength.

[0015] The present invention controls the contents and ratios of three alloying elements, namely erbium, copper, and tin, in the aluminum alloy within a specific range, which is beneficial to strengthening the synergistic effect among erbium, tin, and copper. Under the processing conditions of the present invention, more twins can be formed during plastic deformation, and better interfacial coherency can be generated between the formed strengthening phase and the matrix, and finally an aluminum alloy with both ideal electrical conductivity and alloy strength can be obtained.

[0016] For the processing method of the above-mentioned conductive Al-Cu-Sn-Er rare earth aluminum alloy, in step (5), the alternating treatment process of three-roll rolling and three-stage aging is as follows: First, perform a first room-temperature rolling on the alloy blank at room temperature with a deformation amount of 75-85%, and perform a first-stage aging treatment on the alloy blank after the first room-temperature rolling at 150°C for 14 h; then perform a second room-temperature rolling on the alloy blank after the first-stage aging treatment with a deformation amount of 55-65%, and perform a second-stage aging treatment on the alloy after the second room-temperature rolling at 140°C for 10 h; finally, perform a third room-temperature rolling on the alloy blank after the second-stage aging treatment with a deformation amount of 35-45%, and perform a third-stage aging treatment on the alloy after the third room-temperature rolling at 130°C for 6 h. After the treatment is completed, the conductive Al-Cu-Sn-Er rare earth aluminum alloy is obtained.

[0017] For the processing method of the above-mentioned conductive Al-Cu-Sn-Er rare earth aluminum alloy, in step (5), the alternating treatment process of three-roll rolling and three-stage aging is as follows: First, perform a first room-temperature rolling on the alloy blank at room temperature with a deformation amount of 80%, and perform a first-stage aging treatment on the alloy blank after the first room-temperature rolling at 150°C for 14 h; then perform a second room-temperature rolling on the alloy blank after the first-stage aging treatment with a deformation amount of 60%, and perform a second-stage aging treatment on the alloy after the second room-temperature rolling at 140°C for 10 h; finally, perform a third room-temperature rolling on the alloy blank after the second-stage aging treatment with a deformation amount of 40%, and perform a third-stage aging treatment on the alloy after the third room-temperature rolling at 130°C for 6 h. After the treatment is completed, the conductive Al-Cu-Sn-Er rare earth aluminum alloy is obtained.

[0018] For the processing method of the above-mentioned conductive Al-Cu-Sn-Er rare earth aluminum alloy, in step (1), the purity of pure aluminum is greater than or equal to 99.997 wt.%, and the melting temperature is 670-720°C.

[0019] For the processing method of the above-mentioned conductive Al-Cu-Sn-Er rare earth aluminum alloy, in step (2), the copper content in the aluminum-copper master alloy is 50 wt.%; the tin content in the aluminum-tin master alloy is 50 wt.%; the erbium content in the aluminum-erbium master alloy is 10 wt.%; control the addition amounts of the aluminum-copper master alloy, the aluminum-tin master alloy, and the aluminum-erbium master alloy so that the copper element content in the finally prepared conductive Al-Cu-Sn-Er rare earth aluminum alloy is 1.0 wt.%, the tin element content is 0.1 wt.%, and the erbium element content is 0.1-0.3 wt.%.

[0020] For the processing method of the above-mentioned conductive Al-Cu-Sn-Er rare earth aluminum alloy, in step (2), when adding the aluminum-copper master alloy to the pure aluminum melt, raise the temperature of the pure aluminum melt to 750-770°C, and keep it at 750-770°C for 15-20 min after the aluminum-copper master alloy, the aluminum-tin master alloy, and the aluminum-erbium master alloy are all added.

[0021] For the processing method of the above-mentioned conductive Al-Cu-Sn-Er rare earth aluminum alloy, in step (3), when casting, the temperature of the molten mixture is controlled at 660-670 °C. Before casting, the mold is preheated to 150-180 °C first.

[0022] For the processing method of the above-mentioned conductive Al-Cu-Sn-Er rare earth aluminum alloy, in step (4), the solution treatment method is: placing the alloy ingot in a heat treatment furnace, heating it to 380-400 °C at a heating rate of 5-10 °C / min and holding for 1-1.5 h, and then quenching with normal temperature water.

[0023] For the processing method of the above-mentioned conductive Al-Cu-Sn-Er rare earth aluminum alloy, in step (1), the purity of pure aluminum is greater than or equal to 99.997 wt.%, and the melting temperature is 720 °C;

[0024] In step (2), the copper content in the aluminum-copper master alloy is 50 wt.%; the tin content in the aluminum-tin master alloy is 50 wt.%; the erbium content in the aluminum-erbium master alloy is 10 wt.%; controlling the addition amounts of the aluminum-copper master alloy, the aluminum-tin master alloy and the aluminum-erbium master alloy makes the copper element content in the finally prepared conductive Al-Cu-Sn-Er rare earth aluminum alloy 1.0 wt.%, the tin element content 0.1 wt.%, and the erbium element content 0.2 wt.%; when adding the aluminum-copper master alloy to the pure aluminum melt, the temperature of the pure aluminum melt is raised to 750 °C, and after the aluminum-copper master alloy, the aluminum-tin master alloy and the aluminum-erbium master alloy are all added, it is held at 750 °C for 20 min;

[0025] In step (3), when casting, the temperature of the molten mixture is controlled at 670 °C. Before casting, the mold is preheated to 150 °C first.

[0026] In step (4), the solution treatment method is: placing the alloy ingot in a heat treatment furnace, heating it to 390 °C at a heating rate of 10 °C / min and holding for 1 h, and then quenching with normal temperature water; since the solidus temperature of the Al-Cu-Sn-Er alloy in the present invention is 400 °C, overburning will occur if the solution temperature is too high, while if the solution temperature is too low, solute atoms cannot fully dissolve back into the lattice of the solvent. Therefore, the solution temperature used in the present invention is slightly lower than the solidus temperature, which is 390 °C. If the solution treatment time is too short, the solute cannot completely dissolve back into the lattice of the solvent, and if the solution treatment time is too long, the structure in the alloy such as grain coarsening will occur, affecting the strength and conductivity of the alloy; using normal temperature water quenching in the present invention can make the alloy have a fast cooling rate in the high temperature zone and obtain an alloy with higher strength.

[0027] In step (5), the alternating process of three - stage rolling and three - stage aging is as follows: First, the alloy billet is subjected to a first room - temperature rolling at room temperature with a deformation amount of 80%, and then the alloy billet after the first room - temperature rolling is subjected to a first - stage aging treatment at 150 °C for 14 h; Then, the alloy billet after the first - stage aging treatment is subjected to a second room - temperature rolling with a deformation amount of 60%, and the alloy after the second room - temperature rolling is subjected to a second - stage aging treatment at 140 °C for 10 h; Finally, the alloy billet after the second - stage aging treatment is subjected to a third room - temperature rolling with a deformation amount of 40%, and the alloy after the third room - temperature rolling is subjected to a third - stage aging treatment at 130 °C for 6 h. After the treatment, a conductive Al - Cu - Sn - Er rare - earth aluminum alloy is obtained. Compared with the conventional processing method of first completing rolling and then performing aging treatment, by adopting the alternating treatment of three - stage rolling and three - stage aging in the present invention, through controlling the deformation amount of the three - stage rolling, the treatment temperature and time of the three - stage aging, the rolling deformation amount, the aging treatment temperature and the aging treatment time of the alternating treatment of three - stage rolling and three - stage aging all show a decreasing trend. This not only can effectively avoid alloy cracking caused by incomplete stress elimination, but also can effectively reduce the size of the second phase during the aging treatment process (in the first - stage aging Al - Cu - Sn - Er alloy, the Al2Cu phase exists as GPⅠ zones (pre - θ″), in the second - stage aging as θ″ zones (Al3Cu, GPⅡ zones), and in the third - stage aging as θ′ (Al2Cu)), so that the strengthening phase generated after treatment has a better interfacial relationship (coherent relationship or semi - coherent relationship) with the matrix.

[0028] The technical solution of the present invention has achieved the following beneficial technical effects:

[0029] 1. The present invention prepares an alloy ingot by adding specific contents of three elements, namely copper, tin, and erbium, to aluminum, and adopts an alternating treatment process combining three - stage room - temperature rolling and three - stage low - temperature aging after the solution treatment of the alloy ingot, obtaining nano - scale precipitated phases, so that the strength of the prepared conductive rare - earth aluminum alloy is ≥320 MPa and the conductivity is ≥59% IACS, which can meet the use requirements of the electric power industry for high - strength conductive aluminum alloy stranded wires. This is mainly because at room temperature, the room - temperature solubility of erbium, copper, and tin in aluminum alloy is very low. After being processed by the processing method of the present invention, the excessive copper and tin atoms in the alloy will precipitate from the supersaturated solid solution, thereby strengthening the matrix alloy strength and improving its conductivity.

[0030] 2. The present invention adds tin element and rare - earth erbium element to the aluminum - copper alloy. After being processed by the present invention, it can effectively enhance the effect of copper, tin, and erbium in refining grains, and at the same time, the rare - earth element can also react with impurities to purify the matrix. Under the processing conditions of the present invention, the tin element can better promote the precipitation of the Al2Cu phase during the aging process, and the Al2Cu phase can effectively inhibit the growth of the Sn phase, thereby effectively improving the comprehensive performance of the aluminum - copper alloy.

[0031] 3. The novel rare earth aluminum alloy is prepared by using the processing method of the present invention. While ensuring the good electrical conductivity of the aluminum alloy material, its tensile strength can be greatly improved. This is due to the fact that after the alloy blank after solution treatment of the present invention is alternately processed by three times of room temperature rolling and three levels of low temperature aging, nano-scale twins and nano-scale precipitation phases are generated in the alloy structure. The strengthening effect of these crystal phases solves the contradiction that it is difficult to coexist the strength and electrical conductivity of the aluminum alloy. Brief Description of the Drawings

[0032] Figure 1 The process flow chart of the alternate treatment of three times of rolling and three levels of aging in the embodiment and comparative example of the present invention;

[0033] Figure 2 The microstructure of the Al-Cu-Sn alloy ingot in the comparative example of the present invention;

[0034] Figure 3 The microstructure of the Al-Cu-Sn-Er alloy ingot in the embodiment of the present invention;

[0035] Figure 4 The microstructure of the Al-Cu-Sn alloy after rolling (40% at room temperature) in the comparative example of the present invention;

[0036] Figure 5 The microstructure of the Al-Cu-Sn alloy after aging (130°C × 6h) in the comparative example of the present invention;

[0037] Figure 6 The microstructure of the Al-Cu-Sn-Er alloy after rolling (40% at room temperature) in the embodiment of the present invention;

[0038] Figure 7 The microstructure of the Al-Cu-Sn-Er alloy after aging (130°C × 6h) in the embodiment of the present invention;

[0039] Figure 8 The change rule of the tensile strength of the Al-Cu-Sn (-Er) alloy in the embodiment and comparative example of the present invention;

[0040] Figure 9 The change rule of the elongation after fracture of the Al-Cu-Sn (-Er) alloy in the embodiment and comparative example of the present invention;

[0041] Figure 10 The change rule of the relative electrical conductivity of the Al-Cu-Sn (-Er) alloy in the embodiment and comparative example of the present invention. Detailed Description of the Invention

[0042] Embodiment

[0043] The processing method of the conductive Al-Cu-Sn-Er rare earth aluminum alloy in this embodiment includes the following steps:

[0044] Step (1): Pure aluminum (purity ≥ 99.997 wt.%) is melted in an intermediate frequency induction melting furnace under atmospheric environment. The melting temperature is 720 °C. Wait until all the pure aluminum is melted to obtain a pure aluminum melt.

[0045] Step (2): When the temperature of the pure aluminum melt rises to 750 °C, add aluminum-copper master alloy (Al-50 wt.% Cu, copper content is 50 wt.%), aluminum-tin master alloy (Al-50 wt.% Sn, tin content is 50 wt.%) and aluminum- erbium master alloy (Al-10 wt.% Er, erbium content is 10 wt.%) in sequence. After the addition of the aluminum- erbium master alloy is completed, control the temperature at 750 °C and keep it warm for 20 min for melting to obtain a mixed melt.

[0046] Step (3): Cool the mixed melt to 670 °C and carry out casting by the near liquidus casting method to obtain an alloy ingot; preheat the mold to 150 °C before casting.

[0047] Step (4): Carry out solution treatment on the alloy ingot to obtain an alloy billet; the method of solution treatment is: place the alloy ingot in a heat treatment furnace, raise the temperature to 390 °C at a heating rate of 10 °C / min and keep it warm for 1 h, and then perform water quenching with normal temperature water.

[0048] Step (5): Carry out an alternating treatment of three rolling passes and three-stage aging on the alloy billet. The process of the alternating treatment of three rolling passes and three-stage aging is shown in Figure 1 : First, carry out a first room temperature rolling on the alloy billet at room temperature with a deformation amount of 80%, and carry out a first-stage aging treatment of 150 °C × 14 h on the alloy billet after the first room temperature rolling; then carry out a second room temperature rolling on the alloy billet after the first-stage aging treatment with a deformation amount of 60%, and carry out a second-stage aging treatment of 140 °C × 10 h on the alloy after the second room temperature rolling; finally, carry out a third room temperature rolling on the alloy billet after the second-stage aging treatment with a deformation amount of 40%, and carry out a third-stage aging treatment of 130 °C × 6 h on the alloy after the third room temperature rolling. After the treatment is completed, a conductive Al-Cu-Sn-Er rare earth aluminum alloy is obtained.

[0049] In this embodiment, by controlling the addition amounts of the aluminum-copper master alloy, aluminum-tin master alloy and aluminum- erbium master alloy in the pure aluminum melt, in the finally prepared conductive Al-Cu-Sn-Er rare earth aluminum alloy, the content of copper element is 1.0 wt.%, the content of tin element is 0.1 wt.%, the content of erbium element is 0.2 wt.%, and the total content of the three elements is less than 2 wt.%.

[0050] Comparative example

[0051] The difference between this comparative example and the example lies only in that: in step (2), no Al-Er master alloy was added, and other operation methods and process parameters are exactly the same as those in Example 1.

[0052] In the conductive Al-Cu-Sn aluminum alloy finally prepared in this comparative example by controlling the addition amounts of Al-Cu master alloy and Al-Sn master alloy in the pure aluminum melt, the content of copper element is 1.0 wt.%, and the content of tin element is 0.1 wt.%.

[0053] Figure 2 and Figure 3 are respectively the micrographs of the alloy ingots during the processing of the conductive Al-Cu-Sn(-Er) aluminum alloy in the comparative example and the example. By comparing Figure 2 and Figure 3 it can be found that after adding rare earth Er element, the as-cast structure of the alloy is refined; Figure 4 and Figure 5 as well as Figure 6 and Figure 7 are respectively the micrographs of the conductive Al-Cu-Sn(-Er) aluminum alloy after three rolling and three-stage aging alternating treatment during the processing of the conductive Al-Cu-Sn(-Er) aluminum alloy in the comparative example and the example. It can be seen from the figures that after three-stage rolling deformation, the grains become strip-shaped, and after three-stage aging, the precipitates are deposited at the grain boundaries, inhibiting the grain growth and making the structure more uniform; in the example, rare earth elements are added, and the structure is finer than that in the comparative example.

[0054] From Figures 8 to 10 it can be seen that the conductive Al-Cu-Sn-Er alloy prepared in the example has good comprehensive properties, with a room temperature tensile strength of 327 MPa, a room temperature elongation of 23.3%, and a room temperature relative conductivity of 59.8% IACS; while the conductive Al-Cu-Sn alloy prepared in the comparative example has a room temperature tensile strength of 303 MPa, a room temperature elongation of 21.6%, and a room temperature relative conductivity of 61.7% IACS. It can be seen that the room temperature tensile strength of the aluminum alloy prepared in the comparative example is significantly lower than that of the example, and the room temperature elongation is also lower than that of the example, while the relative conductivity is slightly higher than that of the example but there is no significant difference; overall, the comprehensive properties of the conductive Al-Cu-Sn alloy prepared in the comparative example are not as good as those of the conductive Al-Cu-Sn-Er alloy prepared in the example.

[0055] Obviously, the above examples are only illustrations given clearly and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the claims of this patent application.

Claims

1. A processing method for a conductive Al-Cu-Sn-Er rare earth aluminum alloy, characterized in that, It includes the following steps: Step (1): Melting pure aluminum using an intermediate frequency induction melting furnace in an atmospheric environment to obtain a pure aluminum melt; the purity of the pure aluminum is greater than or equal to 99.997 wt.%, and the melting temperature is 670 - 720 °C; Step (2): Sequentially adding aluminum - copper master alloy, aluminum - tin master alloy, and aluminum - erbium master alloy to the pure aluminum melt and melting to obtain a mixed melt; when adding the aluminum - copper master alloy to the pure aluminum melt, raise the temperature of the pure aluminum melt to 750 - 770 °C. After the aluminum - copper master alloy, aluminum - tin master alloy, and aluminum - erbium master alloy are all added, hold at 750 - 770 °C for 15 - 20 min; Step (3): Casting the mixed melt using the near - liquidus casting method to obtain an alloy ingot; during casting, control the temperature of the mixed melt at 660 - 670 °C. Before casting, pre - heat the mold to 150 - 180 °C; Step (4): Performing solution treatment on the alloy ingot to obtain an alloy billet; the method of solution treatment is: placing the alloy ingot in a heat treatment furnace, heating it to 380 - 400 °C at a heating rate of 5 - 10 °C / min and holding for 1 - 1.5 h, and then quenching with normal temperature water; Step (5): Alternately processing the alloy billet through three - stage rolling and three - stage aging. The process of three - stage rolling and three - stage aging is as follows: First, perform one - time room - temperature rolling on the alloy billet at room temperature with a deformation amount of 75 - 85%, and perform primary aging treatment on the alloy billet after one - time room - temperature rolling at 150 °C for 14 h; then perform secondary room - temperature rolling on the alloy billet after primary aging treatment with a deformation amount of 55 - 65%, and perform secondary aging treatment on the alloy after secondary room - temperature rolling at 140 °C for 10 h; finally, perform tertiary room - temperature rolling on the alloy billet after secondary aging treatment with a deformation amount of 35 - 45%, and perform tertiary aging treatment on the alloy after tertiary room - temperature rolling at 130 °C for 6 h. After the treatment is completed, the conductive Al - Cu - Sn - Er rare - earth aluminum alloy is obtained; In the conductive Al - Cu - Sn - Er rare - earth aluminum alloy, the content of copper element is 0.2 - 1.0 wt%, the content of tin element is 0.1 - 0.8 wt%, the sum of the contents of tin element and erbium element is less than or equal to 1.0 wt%, and the balance is aluminum.

2. The processing method of the conductive Al-Cu-Sn-Er rare earth aluminum alloy according to claim 1, wherein, In step (5), the process of three - stage rolling and three - stage aging is as follows: First, perform one - time room - temperature rolling on the alloy billet at room temperature with a deformation amount of 80%, and perform primary aging treatment on the alloy billet after one - time room - temperature rolling at 150 °C for 14 h; then perform secondary room - temperature rolling on the alloy billet after primary aging treatment with a deformation amount of 60%, and perform secondary aging treatment on the alloy after secondary room - temperature rolling at 140 °C for 10 h; finally, perform tertiary room - temperature rolling on the alloy billet after secondary aging treatment with a deformation amount of 40%, and perform tertiary aging treatment on the alloy after tertiary room - temperature rolling at 130 °C for 6 h. After the treatment is completed, the conductive Al - Cu - Sn - Er rare - earth aluminum alloy is obtained.

3. The processing method of the conductive Al-Cu-Sn-Er rare earth aluminum alloy according to claim 1, characterized in that, In step (2), the copper content in the aluminum-copper master alloy is 50 wt.%; the tin content in the aluminum-tin master alloy is 50 wt.%; the erbium content in the aluminum-erbium master alloy is 10 wt.%; control the addition amounts of the aluminum-copper master alloy, the aluminum-tin master alloy, and the aluminum-erbium master alloy so that the copper element content in the finally prepared conductive Al-Cu-Sn-Er rare earth aluminum alloy is 1.0 wt.%, the tin element content is 0.1 wt.%, and the erbium element content is 0.1 - 0.3 wt.%.

4. The processing method of the conductive Al-Cu-Sn-Er rare earth aluminum alloy according to claim 1, characterized in that, In step (1), the purity of the pure aluminum is greater than or equal to 99.997 wt.%, and the melting temperature is 720 °C; In step (2), the copper content in the aluminum-copper master alloy is 50 wt.%; the tin content in the aluminum-tin master alloy is 50 wt.%; the erbium content in the aluminum-erbium master alloy is 10 wt.%; control the addition amounts of the aluminum-copper master alloy, the aluminum-tin master alloy, and the aluminum-erbium master alloy so that the copper element content in the finally prepared conductive Al-Cu-Sn-Er rare earth aluminum alloy is 1.0 wt.%, the tin element content is 0.1 wt.%, and the erbium element content is 0.2 wt.%; when adding the aluminum-copper master alloy to the pure aluminum melt, raise the temperature of the pure aluminum melt to 750 °C, and keep it at 750 °C for 20 min after the aluminum-copper master alloy, the aluminum-tin master alloy, and the aluminum-erbium master alloy are all added; In step (3), control the temperature of the mixed melt during casting to be 670 °C. Before casting, preheat the mold to 150 °C; In step (4), the solution treatment method is: place the alloy ingot in a heat treatment furnace, raise the temperature to 390 °C at a heating rate of 10 °C / min and hold for 1 h, and then perform water quenching with normal temperature water; In step (5), the alternating treatment process of three times of rolling and three-stage aging is: first perform one-time room temperature rolling on the alloy billet at room temperature with a deformation amount of 80%, and perform first-stage aging treatment on the alloy billet after one-time room temperature rolling at 150 °C × 14 h; then perform secondary room temperature rolling on the alloy billet after first-stage aging treatment with a deformation amount of 60%, and perform second-stage aging treatment on the alloy after secondary room temperature rolling at 140 °C × 10 h; finally perform three-time room temperature rolling on the alloy billet after second-stage aging treatment with a deformation amount of 40%, and perform third-stage aging treatment on the alloy after three-time room temperature rolling at 130 °C × 6 h. After the treatment is completed, the conductive Al-Cu-Sn-Er rare earth aluminum alloy is obtained.

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