High-strength high-conductivity copper alloy rod and method for manufacturing the same

Abstract

The application relates to a high-strength high-conductivity copper alloy rod and a preparation method thereof. The preparation method of the high-strength high-conductivity copper alloy rod comprises the steps of batching, smelting, casting, homogenizing heat treatment, removing a surface oxide skin, room-temperature electromagnetic pulse partial back pressure type isometric angular extrusion and annealing treatment, and a high-strength high-conductivity copper alloy rod with a composition of Cu-xSn is obtained, wherein x=0.2wt%-1.0wt%. The preparation method is synergistically optimized through alloy composition design and a processing technology, the grain size and dislocation density are regulated, the unification of high strength and high conductivity of the copper alloy rod is realized, and the application requirement of high-strength high-conductivity copper alloy in the high-performance electrical and advanced manufacturing fields can be met.

Description

Technical Field

[0001] This invention relates to the field of high-performance copper alloy technology, specifically to a high-strength, high-conductivity copper alloy rod and its preparation method. Background Technology

[0002] Copper and copper alloys, due to their excellent electrical and thermal conductivity and good formability, are widely used in technical fields such as rail transportation, machinery manufacturing, electronic information, shipbuilding, and aerospace. With the continuous development of high-tech industries, especially the rapid advancement of microelectronics, new energy vehicles, and high-speed railways, more stringent requirements have been placed on the comprehensive performance of copper alloy materials. Taking contact wire materials for high-speed railways as an example, they must simultaneously meet multiple technical indicators during service, including high strength, low linear density, good electrical conductivity, wear resistance, and corrosion resistance. Among these, material strength and electrical conductivity are key parameters affecting their performance. However, in existing copper alloy systems, an increase in material strength is usually accompanied by a decrease in electrical conductivity, indicating a certain constraint between the two. Traditional room-temperature back-pressure equal-diameter angular extrusion processing of copper alloys suffers from high deformation resistance, uneven dislocation density distribution, and susceptibility to defects, making it difficult to balance strength and electrical conductivity. Therefore, improvements to existing technologies are urgently needed. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a high-strength and high-conductivity copper alloy rod and its preparation method. The preparation method of the present invention controls the grain size and dislocation density of the copper alloy rod by synergistic optimization of alloy composition design and processing technology, thereby achieving a balance between high strength and high conductivity of the copper alloy rod, which can meet the application requirements of high-strength and high-conductivity copper alloys in the fields of high-performance electrical engineering and advanced manufacturing.

[0004] The technical solution adopted by the present invention to solve the above problems is as follows: On one hand, the present invention provides a method for preparing a high-strength, high-conductivity copper alloy rod, comprising the following steps: 1) A Cu-xSn bar stock is obtained through batching, smelting, and casting; wherein x = 0.2wt%~1.0wt%; 2) The bar stock obtained in step 1) is subjected to homogenization heat treatment and the surface oxide scale is removed; 3) Perform multi-pass room temperature electromagnetic pulse partial back pressure equal diameter angular extrusion on the bar stock after step 2). 4) Anneal the bar material after step 3) to obtain the high-strength, high-conductivity copper alloy bar material.

[0005] The Sn content in this invention is 0.2% to 1.0% by mass, for example, 0.2%, 0.27%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.74%, 0.8%, 0.9%, 1.0%, etc., but is not limited to the listed values; other unlisted values ​​within this range are also applicable. When the Sn content is below 0.2%, the solid solution strengthening effect is limited, making it difficult to significantly improve tensile strength and yield strength; when the Sn content is above 1.0%, the electron scattering effect of solid solution atoms is enhanced, the electrical conductivity decreases significantly, and the risk of work hardening and uneven deformation may increase. Therefore, controlling the Sn content between 0.2% and 1.0% is more conducive to achieving a good match between alloy strength and electrical conductivity.

[0006] The main purpose of homogenization heat treatment is to eliminate dendritic segregation generated during casting, significantly improve the hot plasticity of the alloy, and prevent cracking due to stress concentration at coarse dendrites during subsequent large deformation processing.

[0007] Among them, electromagnetic pulse partial back pressure equal diameter angular extrusion refers to the use of electromagnetic pulse forming technology in conjunction with an extrusion die that can provide partial back pressure to the material to be processed to perform equal diameter angular extrusion forming. The structure of the loading device used in electromagnetic pulse forming in this invention can be found in "Ding Liangcheng, Research on Electromagnetic Pulse-Equal Diameter Angular Extrusion Composite Deformation of Cu-Cr-Zr Copper Alloy [D]. Inner Mongolia University of Technology, 2025". In addition, the extrusion die used in this invention is a die that is modified based on the conventional equal diameter angular extrusion die. Its exit section channel diameter is slightly smaller, which can apply controllable local back pressure to the extruded sample. The introduction of back pressure makes the material adhere tightly to the inner wall of the die, so that the shear deformation is more complete and evenly distributed, effectively closes the original micropores inside the material and inhibits the propagation of new microcracks, increases the accumulation of deformation energy, makes the grain breakage more thorough, and gives the alloy better performance.

[0008] The purpose of annealing is to utilize thermal activation energy to drive recovery and recrystallization within the alloy, thereby regulating the physical properties of the material after processing. At the microscopic level, annealing first induces the rearrangement and annihilation of high-density dislocations in the extruded microstructure, releasing residual distortion energy. Subsequently, distortion-free new grains are formed on the existing fine-grained matrix, significantly reducing the probability of electron scattering and allowing electrical conductivity to recover. Simultaneously, the solute pinning effect of Sn atoms restricts excessive grain boundary migration, ensuring that the alloy maintains the refined equiaxed microstructure characteristics during stress relief and plasticity recovery, ultimately achieving a combination of high strength, high conductivity, and good plasticity.

[0009] The method for preparing high-strength, high-conductivity copper alloy rods of this invention first eliminates dendritic segregation generated during casting through homogenization treatment, significantly improving the alloy's thermoplasticity. Then, multi-pass room-temperature electromagnetic pulse partial back-pressure equal-diameter angular extrusion introduces high cumulative plastic strain into the material, promoting dislocation proliferation and entanglement, forming high-density dislocation cells and subgrain structures. As the deformation degree increases, subgrain boundaries gradually evolve into large-angle grain boundaries, ultimately obtaining a stable fine-grained structure. The grain boundary strengthening effect significantly enhances the alloy's yield strength and tensile strength. Simultaneously, Sn, dissolved in a low concentration in the Cu matrix, effectively pinns dislocation movement, forming a synergistic effect with grain refinement and dislocation strengthening, achieving efficient strengthening without introducing a brittle second phase. Finally, annealing treatment achieves a controllable reduction in dislocation density and a stable, perfected fine-grained structure. Furthermore, the low Sn content in solid solution has minimal impact on electron scattering, thus maintaining high strength while preserving high electrical conductivity. In summary, the preparation method of the present invention achieves a balance between high strength and high conductivity of copper alloy rods through the synergistic optimization of alloy composition design and processing technology, which can meet the application requirements of high-strength and high-conductivity copper alloys in the fields of high-performance electrical engineering and advanced manufacturing.

[0010] The preparation environment of the present invention is atmospheric environment and room temperature, and the equipment and process used are simple with no other special requirements, which can meet the conditions for large-scale production.

[0011] Preferably, in step 1), the bar stock is made from elemental metals Cu and Sn.

[0012] It is understood that the purity of the elemental Cu and Sn is greater than or equal to 99.99%, and the elemental Cu can be copper granules or copper foil, and the elemental Sn can be tin granules, but is not limited to these.

[0013] Preferably, in step 1), the melting is performed in a non-vacuum environment at a temperature of 1200℃~1210℃.

[0014] In one specific implementation, the non-vacuum melting process may include: adding elemental copper to a graphite crucible and adding graphite powder as a covering agent; using a medium-frequency induction melting furnace, heating the furnace to 1200℃~1210℃ at a rate of 50℃ / min~100℃ / min under atmospheric conditions, and holding at that temperature until it is completely melted; then, adding tin granules wrapped in copper foil, waiting for them to melt, and stirring with a graphite rod to obtain a uniformly mixed molten metal. However, the melting process is not limited to this.

[0015] Preferably, in step 1), the casting adopts the near-liquid phase casting method, uses a graphite mold with a temperature of 310℃~330℃, and a casting temperature of 1120℃~1140℃.

[0016] Preferably, in step 2), the homogenization heat treatment involves heat-treating the bar stock at 930°C to 950°C for 55 min to 65 min, and then air-cooling it to room temperature.

[0017] Preferably, the pulse loading voltage of the electromagnetic pulse device used in step 3) is 11-13kV, the pulse loading time is 1600μs-1800μs, and the pulse frequency is 3.255kHz-3.281kHz.

[0018] Preferably, the extrusion channel of the extrusion die used in step 3) includes a constant diameter corner section, a connecting transition section, and a reduced diameter back pressure section arranged coaxially in sequence; the outer end angle of the constant diameter corner section is 20° and the inner end angle is 90°, the diameter ratio of the reduced diameter back pressure section to the constant diameter corner section is 0.85-0.92:1, and the connecting transition section is a 45° constricted conical channel.

[0019] Among them, the constant diameter corner section is the core shear deformation zone of the mold and the main area where the specimen undergoes pure shear deformation; the connecting transition section is used to connect the constant diameter corner section and the reduced diameter back pressure section, which is the surface deformation zone of the specimen and mainly realizes the initial reduction of the specimen's cross-section in one direction; the reduced diameter back pressure section is a unidirectional cross-section reduction channel section, which is the back pressure generation zone of the mold. It applies a controllable portion of back pressure to the specimen through linear reduction of the cross-section, thereby increasing the hydrostatic pressure in the deformation zone.

[0020] Preferably, in step 3), the extrusion passes are 4. During extrusion, after any one pass, the bar is rotated 90° in a single direction before the next extrusion pass.

[0021] In this invention, the extrusion passes are preferably four times because the strength of the sample obtained by three extrusion passes is not as high as that obtained by four extrusion passes, while the sample obtained by five extrusion passes is prone to surface cracking and internal cracking due to stress concentration, which affects the overall performance of the alloy.

[0022] It is understandable that a single rotation direction refers to clockwise or counterclockwise. For example, after the bar stock undergoes the first extrusion, it rotates 90° clockwise for the second extrusion. After the second extrusion, it rotates 90° clockwise again for the third extrusion, and so on, until the fourth extrusion is completed.

[0023] Preferably, in step 4), the annealing temperature is 440℃~460℃, the time is 15min~25min, and then the mixture is air-cooled to room temperature.

[0024] It should be noted that the room temperature described in this application is 22℃~26℃.

[0025] On the other hand, the present invention provides a high-strength, high-conductivity copper alloy rod, which is prepared by the above-described method for preparing high-strength, high-conductivity copper alloy rods.

[0026] The high-strength, high-conductivity copper alloy rod of this invention has a fine grain size and suitable dislocation density with uniform dislocation distribution. This copper alloy rod uses a low content of Sn as the main strengthening element. Sn exists primarily in solid solution form within the copper matrix. Sn effectively pins dislocation movement, forming a synergistic effect with grain refinement and dislocation strengthening, achieving efficient strengthening without introducing a brittle second phase. Furthermore, since the Sn content in solid solution form is controlled and has minimal impact on electron scattering, the copper alloy rod maintains high electrical conductivity while significantly improving strength.

[0027] The copper alloy rod of this invention has a tensile strength of over 560 MPa, a yield strength of over 460 MPa, an elongation after fracture of over 5%, and a relative conductivity of over 60% IACS. It achieves a balance between high strength and high conductivity in copper alloy rods, which can meet the application requirements of high-strength and high-conductivity copper alloys in high-performance electrical engineering and advanced manufacturing fields (such as contact wires for electrified railways, conductive components in new energy vehicles, lead frames for integrated circuits, and precision devices in aerospace equipment).

[0028] The present invention has the following beneficial effects: The method for preparing high-strength, high-conductivity copper alloy rods of the present invention innovatively combines electromagnetic pulse forming with partial back-pressure equal-diameter angular extrusion, processing the copper alloy at room temperature. This not only solves the problem of high deformation resistance in traditional room-temperature back-pressure equal-diameter angular extrusion, but also promotes dislocation rearrangement, making the dislocation distribution more uniform, and controlling the dislocation density within a suitable range that is conducive to the balance between strength and conductivity, thereby achieving the synergistic effect of fine grain strengthening and uniform dislocation strengthening.

[0029] The method for preparing high-strength, high-conductivity copper alloy rods of the present invention, through the synergistic optimization of alloy composition design and processing technology, controls the grain size and dislocation density of the copper alloy rods. The prepared copper alloy rods have a tensile strength of over 560 MPa, a yield strength of over 460 MPa, an elongation after fracture of over 5%, and a relative conductivity of over 60% IACS. This method achieves a balance between high strength and high conductivity in copper alloy rods, which can meet the application requirements of high-strength, high-conductivity copper alloys in high-performance electrical engineering and advanced manufacturing fields.

[0030] The preparation environment of the present invention is atmospheric environment and room temperature, and the equipment and process used are simple with no other special requirements, which can meet the conditions for large-scale production. Attached Figure Description

[0031] Figure 1 This is a process flow diagram of the preparation method of high-strength and high-conductivity copper alloy rods in an embodiment of the present invention; Figure 2 This is a schematic diagram of electromagnetic pulse partial back pressure equal diameter angular extrusion according to an embodiment of the present invention; Figure 3 The images show the IPF (inverse pole figures) of the copper alloy rods prepared in Examples 1-3 and Comparative Examples 1-3 of this invention; where (a)-(c) are the IPF images of Examples 1-3, and (d)-(f) are the IPF images of Comparative Examples 1-3, respectively. Figure 4 The images show the grain size distribution of the copper alloy rods prepared in Examples 1-3 and Comparative Examples 1-3 of this invention; where (a)-(c) are the grain size distribution of Examples 1-3, and (d)-(f) are the grain size distribution of Comparative Examples 1-3, respectively. Figure 5 The GND diagrams (geometrically necessary dislocation distribution diagrams) of the copper alloy rods prepared in Examples 1-3 and Comparative Examples 1-3 of this invention are shown; wherein, (a)-(c) are the GND diagrams of Examples 1-3, and (d)-(f) are the GND diagrams of Comparative Examples 1-3, respectively. Figure 6 The engineering stress-strain curves of the high-strength, high-conductivity copper alloy rods prepared in Examples 1-3 of this invention are shown. Figure 7 The engineering stress-strain curves of the copper alloy rods prepared for comparative examples 1 to 3. Detailed Implementation

[0032] To make the technical problems, solutions, and advantages of this invention clearer, a detailed description will be provided below with reference to specific examples. However, the scope of protection of this invention is not limited to the following specific embodiments. The described embodiments are merely some, not all, of the embodiments of this invention, and are not intended to limit the invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0033] This invention relates to high-strength, high-conductivity copper alloy rods and their preparation methods, and includes Examples 1-3 and Comparative Examples 1-3. Example 1:

[0034] A high-strength, high-conductivity copper alloy rod and its preparation method are disclosed. The high-strength, high-conductivity copper alloy rod contains, by mass percentage: 0.27% Sn, with the balance being Cu and unavoidable impurities. The process flow of the preparation method is as follows: Figure 1 As shown, it includes the following steps: 1) Bar stock is obtained through batching, smelting, and casting: Specifically, each alloying element is weighed according to the composition ratio of the copper alloy rod. Cu is added as 99.99% pure cathode electrolytic copper granules and copper foil, and Sn is added as 99.99% pure tin granules. The rod is prepared using a non-vacuum melting + near-liquid phase casting method. Specifically, 99.99% pure copper granules are added to a graphite crucible and covered with graphite powder. Then, the crucible is heated in an atmospheric environment using a medium-frequency induction melting furnace at a heating rate of 80℃ / min, reaching 1205℃. The temperature is held until completely melted. Tin granules wrapped in copper foil are then added (because tin granules are light, direct addition would cause some to float on the surface graphite powder, preventing uniform mixing with the copper melt and reducing the tin content of the alloy; the weight of the copper foil is included in the total copper addition during batching). After melting, the mixture is stirred with a graphite rod to obtain a uniformly mixed molten metal. Then, using a graphite mold at a temperature of 320℃, casting was performed at 1130℃ to obtain a cylindrical bar with a diameter of 12 mm × 80 mm.

[0035] 2) The bar stock obtained in step 1) is subjected to homogenization heat treatment, and the surface oxide scale is removed: Specifically, the bar stock is loaded into a heat treatment furnace and heated to 940°C at a rate of 10°C / min. After holding at that temperature for 60 minutes, it is air-cooled to room temperature (26°C) and then the surface oxide scale is removed.

[0036] 3) Perform multi-pass room temperature electromagnetic pulse partial back pressure equal diameter angular extrusion on the bar stock processed in step 2): Specifically, the pulse loading voltage of the electromagnetic pulse device used in step 3) is 11 to 13 kV, the pulse loading time is 1600 μs to 1800 μs, and the pulse frequency is 3.255 kHz to 3.281 kHz.

[0037] like Figure 2 As shown, the extrusion channel of the extrusion die used in step 3) includes a constant diameter corner section, a connecting transition section, and a reduced diameter back pressure section arranged coaxially in sequence; the outer end angle ψ of the constant diameter corner section is 20°, the inner end angle θ is 90°, the diameter of the constant diameter corner section is 12mm, the diameter of the reduced diameter back pressure section is 11mm, and the connecting transition section is a 45° constricted conical channel.

[0038] In step 3), the extrusion passes are 4; after any extrusion pass, the bar is rotated 90° clockwise before the next extrusion pass.

[0039] 4) Anneal the extruded bar to obtain the high-strength, high-conductivity copper alloy bar: Specifically, the extruded bar is loaded into a heat treatment furnace and heated to 450°C at a rate of 8°C / min. After holding at this temperature for 20 minutes, it is air-cooled to room temperature (26°C). Then, the surface oxide scale is removed to obtain the high-strength, high-conductivity copper alloy bar. Example 2:

[0040] The only difference from Example 1 is the composition ratio of the copper alloy rod. This high-strength, high-conductivity copper alloy rod contains, by mass percentage: 0.52% Sn, with the balance being Cu and unavoidable impurities. Example 3:

[0041] The only difference from Example 1 is the composition ratio of the copper alloy rod. This high-strength, high-conductivity copper alloy rod contains, by mass percentage: 0.74% Sn, with the balance being Cu and unavoidable impurities.

[0042] Comparative Example 1: The only difference from Example 1 is that a conventional press is used for extrusion, and the extrusion rate is 30 mm / min.

[0043] Comparative Example 2: The only difference from Example 2 is that a conventional press is used for extrusion, and the extrusion rate is 30 mm / min.

[0044] Comparative Example 3: The only difference from Example 3 is that a conventional press is used for extrusion, and the extrusion rate is 30 mm / min. Microscopic tissue testing and observation:

[0045] The copper alloy rods prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to wire cutting, sandpaper grinding, mechanical polishing, electrolytic polishing, alcohol rinsing, and drying to obtain samples. The electrolytic polishing solution used was a mixture of phosphoric acid, alcohol, and deionized water in a 1:1:2 ratio. The polishing voltage was set to 5V, and the polishing time was 120-180 s. During electrolytic polishing, an appropriate amount of liquid nitrogen was added to the electrolyte to control the polishing temperature, which was maintained at approximately -20℃. EBSD testing was performed on the samples using a Thermo Fisher Scientific Apreo2S scanning electron microscope. The scanning step size was set to 0.78 μm-0.88 μm based on the sample microstructure characteristics, and the accelerating voltage was 20 kV. The final data were further processed and analyzed using Aztec Crystal software to obtain IPF maps, grain size distribution maps, and GND maps. The test results are shown below. Figures 3-5 .

[0046] from Figure 3It can be seen that the copper alloy rods prepared in Examples 1-3 of this invention all have fine and uniform equiaxed grain structures, with concentrated grain size distribution and good microstructure uniformity. This indicates that the preparation method of this invention can effectively achieve grain refinement and improve microstructure uniformity under the same extrusion passes. Compared with the examples of this invention, the samples prepared in Comparative Examples 1-3 have poorer grain refinement effects and lower microstructure uniformity. Therefore, the preparation method of this invention can significantly improve the microstructure of copper alloy rods, providing favorable conditions for obtaining good overall performance.

[0047] from Figure 4 It can be seen that the average grain size of the alloys in Examples 1-3 is between 3.78 μm and 4.32 μm, while the average grain size of the alloys in Comparative Examples 1-3 is between 4.41 μm and 4.57 μm. This is consistent with... Figure 3 The IPF figures (a) to (c) show characteristics of finer grains and more uniform structure, which is consistent with the features shown.

[0048] from Figure 5 It can be seen that the dislocation density of the alloys in Examples 1-3 is mainly concentrated in the low blue region, indicating that the dislocation distribution under this processing technology is relatively uniform overall, with an average dislocation density of [missing value]. Comparative examples 1-3 show a high-value green dislocation density cluster, indicating that the dislocation distribution under this processing technique is not uniform overall, with an average dislocation density of [missing value]. . Performance testing:

[0049] The copper alloy rods prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests.

[0050] 1. Tensile property test: The sample was cut into I-shaped flat specimens using an electrical discharge wire cutter. The dimensions were as follows: specimen thickness 1 mm, gauge length 10 mm, width 4 mm, clamping section length 7 mm, width 10 mm, and the fillet radius of the transition section connecting the gauge length and clamping section was 3 mm. The total specimen length was 30 mm. The flat specimens were ground until smooth, and burrs and other macroscopic defects were removed to obtain tensile specimens. The clamping sections at both ends of the tensile specimens were held in place by a universal testing machine, and tensile testing was performed at a tensile speed of 0.6 mm / min. The tensile results of three specimens for each type of sample were averaged to obtain the tensile strength, yield strength, and elongation after fracture values ​​for that type of sample.

[0051] 2. Conductivity test: The samples were cut into cylindrical specimens with dimensions of Φ11 mm × 4 mm using an electrical discharge wire cutter. The specimens were then polished until smooth, free of oxide scale and macroscopic defects. The relative conductivity data of the specimens was measured and recorded using an FD-102 eddy current conductivity meter. For each type of sample, the relative conductivity results of three specimens were selected, and the average value was taken as the relative conductivity of that type of sample.

[0052] The performance test results are shown in Table 1 and Figures 6-7 .

[0053] Table 1. Alloy composition and performance test results of the examples and comparative examples.

[0054] By comparing the performance test data of Examples 1-3 and Comparative Examples 1-3, it can be seen that the copper alloy rods prepared in the embodiments of the present invention have significantly improved tensile strength and yield strength, with tensile strength exceeding 560 MPa, yield strength exceeding 460 MPa, and elongation after fracture exceeding 5%. At the same time, the relative conductivity is maintained at a high level of 63.53% IACS to 79.9% IACS, achieving a good match between the comprehensive mechanical properties and electrical conductivity of the alloy.

[0055] The above-mentioned differences in structure and properties are due to the fact that in the preparation method of the present invention, the electromagnetic pulse partial back pressure equal diameter angular extrusion can promote dislocation rearrangement, make the dislocation distribution more uniform, and control the dislocation density within a suitable range that is conducive to the balance of strength and conductivity. This achieves the refinement of structure, the homogenization of dislocations, and the appropriate control of dislocation density, thereby obtaining a better strength-conductivity match while maintaining a fine-grained structure.

[0056] The method for preparing high-strength, high-conductivity copper alloy rods of the present invention, through the synergistic optimization of alloy composition design and processing technology, controls the grain size and dislocation density of the copper alloy rods. The prepared copper alloy rods have a tensile strength of over 560 MPa, a yield strength of over 460 MPa, an elongation after fracture of over 5%, and a relative conductivity of over 60% IACS. This method achieves a balance between high strength and high conductivity in copper alloy rods, which can meet the application requirements of high-strength, high-conductivity copper alloys in high-performance electrical engineering and advanced manufacturing fields.

[0057] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0058] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0059] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for preparing a high-strength, high-conductivity copper alloy rod, characterized in that, It includes the following steps: 1) A Cu-xSn bar stock is obtained through batching, smelting, and casting; wherein x = 0.2wt%~1.0wt%; 2) The bar stock obtained in step 1) is subjected to homogenization heat treatment and the surface oxide scale is removed; 3) Perform multi-pass room temperature electromagnetic pulse partial back pressure equal diameter angular extrusion on the bar stock after step 2). 4) Anneal the bar material after step 3) to obtain the high-strength, high-conductivity copper alloy bar material.

2. The preparation method according to claim 1, characterized in that, In step 1), the bar stock is made from elemental metals Cu and Sn.

3. The preparation method according to claim 1 or 2, characterized in that, In step 1), the melting is carried out in a non-vacuum manner, and the melting temperature is 1200℃~1210℃.

4. The preparation method according to claim 1 or 2, characterized in that, In step 1), the casting adopts the near-liquid phase casting method, uses a graphite mold with a temperature of 310℃~330℃, and a casting temperature of 1120℃~1140℃.

5. The preparation method according to claim 1, characterized in that, In step 2), the homogenization heat treatment involves heat-treating the bar stock at 930℃~950℃ for 55min~65min and then air-cooling it to room temperature.

6. The preparation method according to claim 1, characterized in that, The pulse loading voltage of the electromagnetic pulse device used in step 3) is 11-13kV, the pulse loading time is 1600μs-1800μs, and the pulse frequency is 3.255kHz-3.281kHz.

7. The preparation method according to claim 1, characterized in that, The extrusion channel of the extrusion die used in step 3) includes a constant diameter corner section, a connecting transition section, and a diameter reduction back pressure section arranged coaxially in sequence; the outer end angle of the constant diameter corner section is 20° and the inner end angle is 90°, the diameter ratio of the diameter reduction back pressure section to the constant diameter corner section is 0.85-0.92:1, and the connecting transition section is a 45° constricted conical channel; in step 3), the extrusion passes are 4; during extrusion, after any extrusion pass, the bar is rotated 90° in a single direction of rotation before the next extrusion pass.

8. The preparation method according to claim 1, characterized in that, The annealing process is carried out at a temperature of 440℃~460℃ for 15min~25min, followed by air cooling to room temperature.

9. A high-strength, high-conductivity copper alloy rod, characterized in that, The high-strength, high-conductivity copper alloy rod is prepared by the preparation method of high-strength, high-conductivity copper alloy rod as described in any one of claims 1 to 8.

10. The high-strength, high-conductivity copper alloy rod according to claim 9, characterized in that, The copper alloy rod has a tensile strength of over 560 MPa, a yield strength of over 460 MPa, an elongation after fracture of over 5%, and a relative electrical conductivity of over 60% IACS.

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