A high-conductivity rare earth aluminum alloy plate and preparation method thereof

Abstract

A high-conductivity rare earth aluminum alloy plate and a preparation method thereof, which relates to an aluminum alloy plate and a preparation method thereof. The purpose of the invention is to solve the technical problem that the existing aluminum alloy sacrifices its conductivity when adding other alloy elements to improve the mechanical properties of the alloy. A high-conductivity rare earth aluminum alloy plate comprises the following components by weight percentage: Fe: 0.30-0.8%, Si≤0.1%, Cu: 0.15-0.30%, B: 0.001-0.04%, Zn≤0.05%, Mn≤0.0031%, Ti≤0.0017%, Er: 0.7%, La: 0.15-0.55%, the total amount of impurities is less than 0.1% and the balance Al. Method: 1. Prepare aluminum alloy ingot; 2. Heat treatment; 3. Rolling. The invention allows the aluminum alloy plate to have both high conductivity and enhanced mechanical properties.

Description

Technical Field

[0001] The invention relates to an aluminum alloy plate and a preparation method thereof. Background Art

[0002] With the continuous development of modern industrial society, the development and utilization of copper resources have intensified. my country has also followed the trend and proposed a policy of "replacing copper with aluminum". As a traditional metal conductive material, the price of copper is increasing day by day. People urgently need to develop a new type of aluminum alloy conductive material to replace copper, so that the performance in all aspects is improved compared with copper conductive materials. In this context, how to develop this new type of aluminum alloy conductive material is the focus of current attention. For conductive aluminum alloys, both the mechanical properties of the alloy and the conductivity of the material must be considered to achieve a good match between the material properties.

[0003] 8030 aluminum alloy is the most widely used Al-Fe-Cu alloy at present. It has the advantages of high temperature resistance, wear resistance, corrosion resistance and good creep resistance. It is the most commercialized alloy conductor material used in low-voltage distribution lines for industrial and civil buildings. The addition of rare earth elements is easy to combine with impurity elements, thereby reducing impurities and purifying the aluminum alloy matrix, achieving the effect of grain refinement, so that the aluminum alloy improves its mechanical properties and conductivity.

[0004] Most existing technologies improve the mechanical properties of aluminum alloy conductors at the expense of the conductivity of aluminum alloy conductors, which is not conducive to the comprehensive performance of aluminum alloy conductors. Generally speaking, the amount of rare earth elements added will affect the performance of aluminum alloys. Too little rare earth element addition will result in insignificant grain refinement effect of rare earth elements, while too much rare earth element addition will cause dislocation entanglement on the grain boundaries of aluminum alloys, increase defects, increase the electron scattering effect, and reduce the conductivity. How to improve the strength without affecting the conductivity of aluminum alloys requires a reasonable selection of the type and amount of rare earth elements added. Summary of the invention

[0005] The purpose of the present invention is to solve the technical problem that the electrical conductivity of the existing aluminum alloy will be sacrificed when other alloy elements are added to improve the mechanical properties of the alloy, and to provide a high-conductivity rare earth aluminum alloy plate and a preparation method thereof.

[0006] A high-conductivity rare earth aluminum alloy plate comprises the following components by weight percentage: Fe: 0.30-0.8%, Si≤0.1%, Cu: 0.15-0.30%, B: 0.001-0.04%, Zn≤0.05%, Mn≤0.0031%, Ti≤0.0017%, Er: 0.7%, La: 0.15-0.55%, the total amount of impurities is less than 0.1% and the balance is Al.

[0007] A method for preparing a high-conductivity rare earth aluminum alloy plate is specifically completed by the following steps:

[0008] 1. Preparation of aluminum alloy ingots:

[0009] ①. Weigh 8030 aluminum alloy, Al-20Er master alloy and Al-20La master alloy according to the following weight percentages: Fe: 0.30-0.8%, Si≤0.1%, Cu: 0.15-0.30%, B: 0.001-0.04%, Zn≤0.05%, Mn≤0.0031%, Ti≤0.0017%, Er: 0.7%, La: 0.15-0.55%, the total amount of impurities is less than 0.1% and the balance is Al to obtain raw materials;

[0010] ②, put 8030 aluminum alloy into a crucible, and heat it in a furnace with electricity. The furnace temperature is controlled at 750℃~760℃. After the 8030 aluminum alloy is completely melted, remove the scum, add Al-20Er master alloy and Al-20La master alloy into the crucible, and keep the temperature at 750℃~760℃. After all the raw materials are melted, obtain aluminum alloy liquid; add a refining agent to the aluminum alloy liquid at a temperature of 730℃~750℃ for refining, degas and remove slag, and then cast at 720℃~730℃ to obtain an aluminum alloy ingot;

[0011] 2. Heat treatment:

[0012] The aluminum alloy ingot is homogenized to obtain a heat-treated aluminum alloy ingot;

[0013] 3. Rolling:

[0014] ① Cutting the aluminum alloy ingot after heat treatment to obtain rolling billets;

[0015] ②. The rolled billet is heated and kept warm, and then hot-rolled and cold-rolled to obtain a highly conductive rare earth aluminum alloy sheet.

[0016] Principle of the present invention:

[0017] 1. The addition of rare earth elements Er and La in the present invention can further refine the grains, purify the melt, and improve its mechanical properties; rare earth elements have a large affinity for hydrogen, can absorb and dissolve hydrogen in the melt, and rare earth elements can refine the grains and thus increase the nucleation rate. Rare earth elements are deposited at the front of the solid-liquid interface, increase the concentration gradient of other elements, produce a component supercooling zone, and increase the component supercooling. When it is greater than the critical supercooling required for nucleation, the nucleation rate increases; rare earth elements are chemically active, and the compounds formed with other elements can become the core of heterogeneous nucleation, thereby increasing the nucleation rate; rare earth elements exist in the aluminum alloy matrix in the form of substitutional solid solution, which can fill the surface defects of the alloy phase, thereby increasing the nucleation rate, thereby improving the electrical conductivity;

[0018] 2. The present invention uses a rolling process, and the grains and the second phase are crushed and refined along the rolling direction under the action of a strong rolling force, thereby eliminating defects such as bubbles, cracks and looseness formed during casting, and effectively improving the organization and mechanical properties of the material.

[0019] Advantages of the present invention:

[0020] The high-conductivity rare earth aluminum alloy plate prepared by the present invention has an electrical conductivity of more than 60% IACS, a hardness of more than 58HV, and a tensile strength of more than 117MPa, so that the aluminum alloy plate has both high electrical conductivity and enhanced mechanical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a digital photo of the high-conductivity rare earth aluminum alloy plate prepared in Example 1;

[0022] Figure 2 This is the metallographic image of the high-conductivity rare earth aluminum alloy plate prepared in Example 1. DETAILED DESCRIPTION

[0023] Specific implementation method 1: This implementation method is a high conductive rare earth aluminum alloy plate, which includes the following components by weight percentage: Fe: 0.30-0.8%, Si≤0.1%, Cu: 0.15-0.30%, B: 0.001-0.04%, Zn≤0.05%, Mn≤0.0031%, Ti≤0.0017%, Er: 0.7%, La: 0.15-0.55%, the total amount of impurities is less than 0.1% and the balance is Al.

[0024] Specific implementation method 2: This implementation method is different from specific implementation method 1 in that: the content of a single impurity in the impurities is less than 0.03%; the thickness of the high-conductivity rare earth aluminum alloy plate is 2.5-3 mm. The other steps are the same as those in specific implementation method 1.

[0025] Specific embodiment 3: This embodiment differs from specific embodiment 1 or 2 in that: the high-conductivity rare earth aluminum alloy plate comprises the following components by weight percentage: Fe: 0.316%, Si: 0.065%, Cu: 0.181%, B: 0.003%, Zn: 0.0114%, Mn: 0.0031%, Ti: 0.0017%, Er: 0.7%, La: 0.55%, the total amount of impurities is less than 0.1% and the balance is Al. The other steps are the same as those of specific embodiment 1 or 2.

[0026] Specific embodiment 4: This embodiment differs from specific embodiments 1 to 3 in that the high-conductivity rare earth aluminum alloy plate comprises the following components by weight percentage: Fe: 0.316%, Si: 0.065%, Cu: 0.181%, B: 0.003%, Zn: 0.0114%, Mn: 0.0031%, Ti: 0.0017%, Er: 0.7%, La: 0.45%, the total amount of impurities is less than 0.1% and the balance is Al. The other steps are the same as those of specific embodiments 1 to 3.

[0027] Specific embodiment 5: This embodiment differs from specific embodiments 1 to 4 in that the high-conductivity rare earth aluminum alloy plate comprises the following components by weight percentage: Fe: 0.316%, Si: 0.065%, Cu: 0.181%, B: 0.003%, Zn: 0.0114%, Mn: 0.0031%, Ti: 0.0017%, Er: 0.7%, La: 0.35%, the total amount of impurities is less than 0.1% and the balance is Al. The other steps are the same as those of specific embodiments 1 to 4.

[0028] Specific embodiment 6: This embodiment differs from specific embodiments 1 to 5 in that the high-conductivity rare earth aluminum alloy plate comprises the following components by weight percentage: Fe: 0.316%, Si: 0.065%, Cu: 0.181%, B: 0.003%, Zn: 0.0114%, Mn: 0.0031%, Ti: 0.0017%, Er: 0.7%, La: 0.25%, the total amount of impurities is less than 0.1% and the balance is Al. The other steps are the same as those of specific embodiments 1 to 5.

[0029] Specific embodiment 7: This embodiment differs from specific embodiments 1 to 6 in that the high-conductivity rare earth aluminum alloy plate comprises the following components by weight percentage: Fe: 0.316%, Si: 0.065%, Cu: 0.181%, B: 0.003%, Zn: 0.0114%, Mn: 0.0031%, Ti: 0.0017%, Er: 0.7%, La: 0.15%, the total amount of impurities is less than 0.1% and the balance is Al. The other steps are the same as those of specific embodiments 1 to 6.

[0030] Specific embodiment 8: This embodiment differs from specific embodiments 1 to 7 in that: a method for preparing a high-conductivity rare earth aluminum alloy plate is specifically completed in the following steps:

[0031] 1. Preparation of aluminum alloy ingots:

[0032] ①. Weigh 8030 aluminum alloy, Al-20Er master alloy and Al-20La master alloy according to the following weight percentages: Fe: 0.30-0.8%, Si≤0.1%, Cu: 0.15-0.30%, B: 0.001-0.04%, Zn≤0.05%, Mn≤0.0031%, Ti≤0.0017%, Er: 0.7%, La: 0.15-0.55%, the total amount of impurities is less than 0.1% and the balance is Al to obtain raw materials;

[0033] ②, put 8030 aluminum alloy into a crucible, and heat it in a furnace with electricity. The furnace temperature is controlled at 750℃~760℃. After the 8030 aluminum alloy is completely melted, remove the scum, add Al-20Er master alloy and Al-20La master alloy into the crucible, and keep the temperature at 750℃~760℃. After all the raw materials are melted, obtain aluminum alloy liquid; add a refining agent to the aluminum alloy liquid at a temperature of 730℃~750℃ for refining, degas and remove slag, and then cast at 720℃~730℃ to obtain an aluminum alloy ingot;

[0034] 2. Heat treatment:

[0035] The aluminum alloy ingot is homogenized to obtain a heat-treated aluminum alloy ingot;

[0036] 3. Rolling:

[0037] ① Cutting the aluminum alloy ingot after heat treatment to obtain rolling billets;

[0038] ②, heating and heat preservation of the rolled blank, and then hot rolling and cold rolling to obtain a high-conductivity rare earth aluminum alloy plate. The other steps are the same as those of the first to seventh embodiments.

[0039] Specific embodiment 9: This embodiment differs from specific embodiments 1 to 8 in that: in step 1②, Al-20Er master alloy and Al-20La master alloy are added into a crucible, kept at 750℃~760℃ for 20min~30min, and aluminum alloy liquid is obtained after all raw materials are melted; refining agent is added into the aluminum alloy liquid at a temperature of 730℃~750℃ for refining for 10min~15min; the refining agent is hexachloroethane; the amount of refining agent added is 0.1% of the weight of the raw materials weighed in step 1. The other steps are the same as those of specific embodiments 1 to 8.

[0040] Specific embodiment 10: The difference between this embodiment and specific embodiments 1 to 9 is that the method of homogenization treatment described in step 2 is: placing the aluminum alloy ingot in a heating furnace, heating it to 510℃~515℃ and then keeping it warm for 24h~25h, the heating rate is 8℃ / min~10℃ / min, and air cooling after it is taken out of the furnace; the thickness of the rolled billet described in step 3① is 10mm; before keeping the rolled billet warm in step 3②, use sandpaper to clean the surface oxide layer and impurities of the rolled billet, and keep the surface Clean; the temperature of heating and heat preservation described in step 3② is 470℃~480℃, and the heating and heat preservation time is 30min~40min; the hot rolling described in step 3② is 2-3 passes, the reduction rate of each pass is 20%~25%, the hot rolling temperature is 470℃~480℃, and the heat preservation between hot rolling passes is 5min~10min; the cold rolling described in step 3② is 1-2 passes, the reduction rate of each pass is 20%~30%, and the cold rolling temperature is 20℃~25℃. The other steps are the same as the specific embodiments one to nine.

[0041] The following examples are used to verify the beneficial effects of the present invention:

[0042] Embodiment 1: A method for preparing a high-conductivity rare earth aluminum alloy plate is completed by the following steps:

[0043] 1. Preparation of aluminum alloy ingots:

[0044] ①, weigh 8030 aluminum alloy, Al-20Er master alloy and Al-20La master alloy according to the following weight percentages: Fe: 0.316%, Si: 0.065%, Cu: 0.181%, B: 0.003%, Zn: 0.0114%, Mn: 0.0031%, Ti: 0.0017%, Er: 0.7%, La: 0.55%, the total amount of impurities is less than 0.1% and the balance is Al to obtain raw materials;

[0045] The content of a single impurity in the impurities in step 1① is less than 0.03%;

[0046] ②, put 8030 aluminum alloy into a crucible, heat it in a furnace, control the furnace temperature at 750°C, and after the 8030 aluminum alloy is completely melted, remove the scum, add Al-20Er master alloy and Al-20La master alloy into the crucible, keep the temperature at 750°C for 30 minutes, and after all the raw materials are melted, obtain aluminum alloy liquid; add a refining agent to the aluminum alloy liquid at a temperature of 740°C for refining for 15 minutes, degas and remove slag, and then cast at 730°C to obtain an aluminum alloy ingot;

[0047] The refining agent described in step 1② is hexachloroethane; the amount of the refining agent added is 0.1% of the weight of the raw material weighed in step 1;

[0048] 2. Heat treatment:

[0049] The aluminum alloy ingot is homogenized to obtain a heat-treated aluminum alloy ingot;

[0050] The homogenization treatment method described in step 2 is: placing the aluminum alloy ingot in a heating furnace, heating it to 510°C and then keeping it warm for 24 hours at a heating rate of 10°C / min, and air cooling it out of the furnace;

[0051] 3. Rolling:

[0052] ①. Cut the aluminum alloy ingot after heat treatment to obtain a rolled billet with a thickness of 10 mm; use sandpaper to clean the surface oxide layer and impurities to keep the surface clean;

[0053] ②, heating and keeping the rolled billet warm, and then hot rolling and cold rolling to obtain an aluminum alloy rolled sheet;

[0054] The heating and heat preservation temperature in step 3② is 480°C, and the heating and heat preservation time is 30 minutes;

[0055] The hot rolling described in step 3② is performed by 3 passes, with a reduction rate of 25% for each pass, a hot rolling temperature of 480°C, and a heat preservation of 10 minutes between hot rolling passes;

[0056] The cold rolling described in step 3② is performed by one pass rolling, with a pass reduction rate of 30% and a cold rolling temperature of 20° C. to obtain a high conductive rare earth aluminum alloy sheet.

[0057] Embodiment 2: The difference between this embodiment and embodiment 1 is that in step 1①, 8030 aluminum alloy, Al-20Er master alloy and Al-20La master alloy are weighed according to weight percentage of Fe: 0.316%, Si: 0.065%, Cu: 0.181%, B: 0.003%, Zn: 0.0114%, Mn: 0.0031%, Ti: 0.0017%, Er: 0.7%, La: 0.45%, the total amount of impurities is less than 0.1% and the balance Al. Other steps and parameters are the same as those in embodiment 1.

[0058] Embodiment 3: The difference between this embodiment and embodiment 1 is that in step 1①, 8030 aluminum alloy, Al-20Er master alloy and Al-20La master alloy are weighed according to weight percentage of Fe: 0.316%, Si: 0.065%, Cu: 0.181%, B: 0.003%, Zn: 0.0114%, Mn: 0.0031%, Ti: 0.0017%, Er: 0.7%, La: 0.35%, the total amount of impurities is less than 0.1% and the balance Al. Other steps and parameters are the same as those in embodiment 1.

[0059] Embodiment 4: The difference between this embodiment and embodiment 1 is that in step 1①, 8030 aluminum alloy, Al-20Er master alloy and Al-20La master alloy are weighed according to weight percentage of Fe: 0.316%, Si: 0.065%, Cu: 0.181%, B: 0.003%, Zn: 0.0114%, Mn: 0.0031%, Ti: 0.0017%, Er: 0.7%, La: 0.25%, the total of impurities is less than 0.1% and the balance Al. Other steps and parameters are the same as those in embodiment 1.

[0060] Embodiment 5: The difference between this embodiment and embodiment 1 is that in step 1①, 8030 aluminum alloy, Al-20Er master alloy and Al-20La master alloy are weighed according to weight percentage of Fe: 0.316%, Si: 0.065%, Cu: 0.181%, B: 0.003%, Zn: 0.0114%, Mn: 0.0031%, Ti: 0.0017%, Er: 0.7%, La: 0.15%, the total amount of impurities is less than 0.1% and the balance Al. Other steps and parameters are the same as those in embodiment 1.

[0061] Comparative Example 1: The difference between this embodiment and embodiment 1 is that in step 1①, 8030 aluminum alloy and Al-20Er master alloy are weighed according to the weight percentage of Fe: 0.316%, Si: 0.065%, Cu: 0.181%, B: 0.003%, Zn: 0.0114%, Mn: 0.0031%, Ti: 0.0017%, Er: 0.7%, the total amount of impurities is less than 0.1% and the balance Al. The other steps and parameters are the same as those in embodiment 1.

[0062] Comparative Example 2: The difference between this embodiment and embodiment 1 is that in step 1①, 8030 aluminum alloy and Al-20La master alloy are weighed according to the weight percentage of Fe: 0.316%, Si: 0.065%, Cu: 0.181%, B: 0.003%, Zn: 0.0114%, Mn: 0.0031%, Ti: 0.0017%, La: 0.55%, the total amount of impurities is less than 0.1% and the balance Al. The other steps and parameters are the same as those in embodiment 1.

[0063] Comparative Example 3: The difference between this embodiment and embodiment 1 is that in step 1①, 8030 aluminum alloy is weighed according to the weight percentage of Fe: 0.316%, Si: 0.065%, Cu: 0.181%, B: 0.003%, Zn: 0.0114%, the total impurities less than 0.1% and the balance Al. The other steps and parameters are the same as those in embodiment 1.

[0064] Mechanical properties and electrical conductivity tests:

[0065] 1. In order to test the mechanical properties of aluminum alloy plates, the Vickers hardness and room temperature tensile properties of aluminum alloy plates were tested: the Vickers hardness adopted a test force of 0.1kgf, a loading time of 15s, and the measured value was the average of three measurements, with a spacing of 1mm between the three sampling points; for the room temperature tensile properties test, samples were taken along the rolling direction of the plates, and processed into tensile specimens in accordance with the provisions of GB / T228.1-2021 "Room Temperature Tensile Test of Metal Materials". The tensile test was carried out on an electronic universal testing machine, and the strain rate was 1mm / min, and the value was the average of three measurements.

[0066] 2. Conductivity test: SIGMATEST 2.070 conductivity tester is used for conductivity measurement. The sample size is 25mm*25mm*3mm. The value is calibrated first and then measured. The measured value is the average of three measurements.

[0067] The relevant performance test data of the high conductive rare earth aluminum alloy plates prepared in Examples 1 to 5 and the aluminum alloy plates prepared in Comparative Examples 1 to 3 are shown in Table 1;

[0068] Table 1

[0069]

[0070]

[0071] It can be seen from the composition, process flow and material performance data of Examples 1-5 and Comparative Examples 1 to 3 in Table 1 that the embodiments of the present invention simultaneously add appropriate contents of Er and La elements to the 8030 aluminum alloy and a reasonable processing technology so that the aluminum alloy plate of the present invention has significantly higher electrical conductivity than other aluminum alloy plates, thereby improving the electrical conductivity and mechanical properties of the material.

[0072] Figure 1 This is a digital photo of the high-conductivity rare earth aluminum alloy plate prepared in Example 1;

[0073] from Figure 1 It can be seen that the prepared high-conductivity rare earth aluminum alloy plates have consistent specifications and sizes, bright and shiny appearance, and are suitable for large-scale production in factories.

[0074] Figure 2 This is the metallographic image of the high-conductivity rare earth aluminum alloy plate prepared in Example 1.

[0075] from Figure 2 It can be seen that the grains in the metallographic structure of the prepared high-conductivity rare earth aluminum alloy plate are elongated along the rolling direction, and the precipitated phase is fine and evenly distributed, thereby improving the mechanical and electrical properties of the high-conductivity rare earth aluminum alloy plate.

Claims

1. A method for preparing a high-conductivity rare earth aluminum alloy plate, characterized in that The high-conductivity rare earth aluminum alloy plate prepared by the preparation method has an electrical conductivity of 61.1% IACS, a hardness of 61.6 HV, and a tensile strength of 123 MPa. The preparation method is specifically completed according to the following steps:

1. Preparation of aluminum alloy ingots: ①, weigh 8030 aluminum alloy, Al-20Er master alloy and Al-20La master alloy according to the following weight percentages: Fe: 0.316%, Si: 0.065%, Cu: 0.181%, B: 0.003%, Zn: 0.0114%, Mn: 0.0031%, Ti: 0.0017%, Er: 0.7%, La: 0.55%, the total amount of impurities is less than 0.1% and the balance is Al to obtain raw materials; The content of a single impurity in the impurities in step 1① is less than 0.03%; ②, put 8030 aluminum alloy into a crucible, heat it in a furnace, control the furnace temperature at 750°C, and after the 8030 aluminum alloy is completely melted, remove the scum, add Al-20Er master alloy and Al-20La master alloy into the crucible, keep the temperature at 750°C for 30 minutes, and after all the raw materials are melted, obtain aluminum alloy liquid; add a refining agent to the aluminum alloy liquid at a temperature of 740°C for refining for 15 minutes, degas and remove slag, and then cast at 730°C to obtain an aluminum alloy ingot; The refining agent described in step 1② is hexachloroethane; the amount of the refining agent added is 0.1% of the weight of the raw material weighed in step 1; 2. Heat treatment: The aluminum alloy ingot is homogenized to obtain a heat-treated aluminum alloy ingot; The homogenization treatment method described in step 2 is: placing the aluminum alloy ingot in a heating furnace, heating it to 510°C and then keeping it warm for 24 hours at a heating rate of 10°C / min, and air cooling it out of the furnace; 3. Rolling: ①. Cut the aluminum alloy ingot after heat treatment to obtain a rolled billet with a thickness of 10 mm; use sandpaper to clean the surface oxide layer and impurities to keep the surface clean; ②, heating and keeping the rolled billet warm, and then hot rolling and cold rolling to obtain an aluminum alloy rolled sheet; The heating and heat preservation temperature in step 3② is 480°C, and the heating and heat preservation time is 30 minutes; The hot rolling described in step 3② is performed by 3 passes, with a reduction rate of 25% for each pass, a hot rolling temperature of 480°C, and a heat preservation of 10 minutes between hot rolling passes; The cold rolling described in step 3② is performed by one pass rolling, with a pass reduction rate of 30% and a cold rolling temperature of 20° C. to obtain a high conductive rare earth aluminum alloy sheet.

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