An alumina dispersion-strengthened copper alloy, its preparation method and application

Abstract

This application discloses an alumina dispersion-strengthened copper alloy, its preparation method, and its application, belonging to the field of metal matrix composite technology. The preparation method of the alumina dispersion-strengthened copper alloy provided in this application includes: melting copper, aluminum, and silver, and preparing alloy powder by water atomization; the alloy powder comprises components in the following mass percentages: aluminum 0.1%-0.4%, silver 0.1%-0.4%, oxygen content less than 0.03%, and the balance being copper; mixing the alloy powder with an oxidant and then performing cold isostatic pressing to obtain a preliminary billet; subjecting the preliminary billet to internal oxidation, reduction, hot isostatic pressing, and hot extrusion to obtain an alloy rod; and subjecting the alloy rod to hot deformation treatment to obtain the alumina dispersion-strengthened copper alloy. The alumina dispersion-strengthened copper alloy prepared by the method provided in this application significantly improves the bending performance and overall plasticity of the material while maintaining high strength.

Description

Technical Field

[0001] This application belongs to the field of metal matrix composite technology, and particularly relates to an alumina dispersion-reinforced copper alloy, its preparation method and application. Background Technology

[0002] Alumina dispersion-reinforced copper (Al2O3 / Cu) materials are widely used in key areas such as lead frames for electronic devices, resistance welding electrodes, and high-temperature wires due to their excellent strength, conductivity, high-temperature resistance, and resistance to softening. However, due to the interfacial bonding problem between the dispersed alumina particles and the copper matrix, microcracks are easily nucleated and rapidly propagated during bending, leading to brittle fracture and a small bending angle, which severely limits their application in precision electronic devices that require frequent bending.

[0003] Existing methods typically involve adjusting the composition ratio of materials or optimizing preparation process parameters. For example, prior art with publication number CN 114959342 A discloses a method for improving the processing performance of alumina dispersion-reinforced copper-based composite materials. This method reduces the Al content in the raw materials to decrease the amount of hard phase Al2O3 formed, while adding copper-chromium alloy powder. It utilizes the re-dissolution and precipitation of chromium during hot deformation to achieve dynamic strengthening and improve the plasticity of the material.

[0004] Although the above-mentioned treatment methods can improve the processing performance to a certain extent, the following problems still exist: they improve the processing performance by sacrificing certain indicators such as hardness and conductivity of copper-based composite materials through alumina dispersion reinforcement, but fail to significantly improve the overall performance of the material.

[0005] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of protection of this application. Summary of the Invention

[0006] This application discloses an alumina dispersion-strengthened copper alloy, its preparation method, and its application, aiming to solve the technical problem that it is difficult to balance the comprehensive properties of existing alumina dispersion-strengthened copper materials, such as hardness, conductivity, plasticity, and bending performance.

[0007] To achieve the above objectives, the technical solution of this application is: The first aspect of this application provides a method for preparing an alumina dispersion-strengthened copper alloy, the method comprising: Copper, aluminum and silver are smelted together, and alloy powder is prepared by water atomization. The alloy powder is mixed with an oxidant and then subjected to cold isostatic pressing to obtain a preliminary billet. The initial billet is subjected to internal oxidation, reduction, hot isostatic pressing, and hot extrusion to obtain alloy bars; The alloy bar is subjected to hot deformation treatment to obtain an alumina dispersion-strengthened copper alloy.

[0008] Preferably, in conjunction with the first aspect, the alloy powder comprises the following components by mass percentage: aluminum 0.1% 0.4%, silver 0.1%-0.4%, oxygen content less than 0.03%, balance is copper.

[0009] Preferably, in conjunction with the first aspect, the hot deformation treatment is hot rolling or hot forging.

[0010] Preferably, in conjunction with the first aspect, the conditions for the heat deformation treatment are: temperature 600-900 ℃, holding time 15-60 min, deformation per pass 1-2 mm, and total deformation 20-60%.

[0011] Preferably, in conjunction with the first aspect, the oxidant is cuprous oxide with a powder particle size of less than 300 mesh; The mass ratio of the alloy powder to the oxidant is (50-200):1; The mixing time is 1-3 hours.

[0012] Preferably, in conjunction with the first aspect, the cold isostatic pressing employs a polyurethane mold, and the pressure is 100. 300 MPa, holding time 5-20 min; and / or The reaction conditions for the internal oxidation are: under a nitrogen or argon atmosphere, at a temperature of 800-900 °C for 1-5 h.

[0013] Preferably, in conjunction with the first aspect, the reduction reaction conditions are: under a hydrogen atmosphere, at 850-950 °C for 2-6 h; and / or The conditions for hot isostatic pressing are: a temperature of 750-950 ℃, a pressure of 100-200 MPa, and a holding time of 1-6 h.

[0014] In conjunction with the first aspect, preferably, the conditions for hot extrusion are: temperature 800-900 ℃, holding time 1-2 h, and extrusion ratio 15-50.

[0015] The second aspect of this application provides an alumina dispersion-strengthened copper alloy prepared by the preparation method described in the first aspect; The tensile strength of the alumina dispersion-strengthened copper alloy is ≥405 MPa; The conductivity of the alumina dispersion-strengthened copper alloy is ≥83.4% IACS.

[0016] The third aspect of this application provides the application of the alumina dispersion-strengthened copper alloy described in the second aspect in the fields of new energy vehicles, ultra-high voltage power transmission and transformation, aerospace, or high-speed rail transportation.

[0017] Compared with the prior art, the advantages or beneficial effects of the embodiments of this application include at least the following: The method for preparing alumina dispersion-strengthened copper alloy provided in this application involves adding silver to alumina dispersion-strengthened copper material and then subjecting the resulting alloy rods to hot deformation treatment. On the one hand, this method strengthens interfacial bonding, reduces crack initiation sites, and improves interfacial debonding resistance. Furthermore, the Ag segregation at grain boundaries promotes grain boundary slip and coordinated deformation, reducing grain boundary stress concentration. This significantly improves the bending performance and overall plasticity of the material while maintaining high strength. On the other hand, it also eliminates some dislocations, reduces lattice distortion, refines and elongates grains to form a fibrous structure, significantly improving the material's plasticity and resistance to bending deformation. Additionally, it promotes the uniform distribution of alumina particles in the copper matrix, reducing agglomeration and thus enhancing the dispersion strengthening effect. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A flowchart illustrating a method for improving the bending properties of alumina dispersion-reinforced copper materials provided in this application embodiment. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0021] In the following description of this embodiment, the term "and / or" is used to describe the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, B existing alone, and A and B existing simultaneously. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0022] In the following description of this embodiment, the term "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0023] Those skilled in the art should understand that, in the following description of the embodiments of this application, the sequence of numbers does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0024] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms "a" and "the" as used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0025] It should be noted that all raw materials and / or reagents in the embodiments of this application were purchased on the market or prepared according to conventional methods known to those skilled in the art.

[0026] In a first aspect, this application provides a method for preparing an alumina dispersion-strengthened copper alloy, the method comprising: Copper, aluminum and silver are smelted together, and alloy powder is prepared by water atomization. The alloy powder is mixed with an oxidant and then subjected to cold isostatic pressing to obtain a preliminary billet. The initial billet is subjected to internal oxidation, reduction, hot isostatic pressing, and hot extrusion to obtain alloy bars; The alloy bar is subjected to hot deformation treatment to obtain an alumina dispersion-strengthened copper alloy.

[0027] It should be noted that this application uses a water atomization method to prepare alloy powder after melting copper, aluminum, and silver. This rapid cooling allows for uniform mixing of aluminum and silver within the copper matrix. The resulting powder has fine grains, uniform composition, and controllable oxygen content, providing a stable raw material basis for subsequent internal oxidation reactions and ensuring the uniform and fine formation of the alumina dispersed phase. After mixing the alloy powder with the oxidant, it is cold isostatically pressed, resulting in a dense and uniform initial blank. This facilitates sufficient contact between the oxidant and uniform diffusion of oxygen, ensuring controllable internal oxidation reactions and improving product performance consistency. The synergistic effect of internal oxidation and reduction transforms aluminum into a dispersed Al2O3 strengthening phase, removing excess oxygen. This improves the alloy's high-temperature strength, softening resistance, and wear resistance while retaining the excellent electrical and thermal conductivity of the copper matrix. Hot isostatic pressing and hot extrusion combined densification can eliminate internal defects and enhance interfacial bonding. Subsequent hot deformation further optimizes the microstructure, refines the grains, and reduces particle agglomeration, ultimately giving the alloy high strength, high electrical conductivity, high heat resistance, and good plasticity, significantly improving the alloy's bending resistance.

[0028] In this embodiment, the alloy powder preferably comprises the following components by mass percentage: aluminum 0.1%. 0.4%, silver 0.1% 0.4%, oxygen content less than 0.03%, balance being copper; the alloy powder more preferably comprises the following components by mass percentage: aluminum 0.2%. The aluminum content is 0.3%, and the silver content is 0.2%-0.3%. By controlling the aluminum content, sufficient, fine, and uniformly dispersed Al2O3 dispersion strengthening phases are generated during the subsequent internal oxidation process, providing the alloy with excellent high-temperature strength, softening resistance, and wear resistance. At the same time, excessive aluminum content avoids damaging the excellent electrical and thermal conductivity of the copper matrix itself, achieving a balance between strength and conductivity. By controlling the silver content, without significantly reducing the alloy's conductivity, the alloy's plasticity, bending resistance, and processing performance are synergistically optimized. Combined with the alumina dispersion strengthening phase, this further enhances the material's comprehensive mechanical properties and improves its toughness. By controlling the oxygen content, uncontrolled oxidation of the alloy powder during powder preparation and early processes can be avoided, ensuring a stable and uniform subsequent internal oxidation reaction.

[0029] It should be noted that after melting copper, aluminum, and silver in a specific ratio, the alloy powder is prepared using a water atomization method, which allows aluminum and silver to be uniformly mixed within the copper matrix. The water atomization powder preparation process has a rapid cooling rate, resulting in powder with fine grains, uniform composition, and controllable oxygen content. This provides a stable and uniform raw material basis for subsequent internal oxidation reactions, ensuring that the alumina dispersed phase can be uniformly, finely, and dispersedly generated in subsequent processes, thereby improving the overall performance of the alloy.

[0030] In this embodiment, the oxidant is preferably cuprous oxide with a powder particle size of less than 300 mesh; the preferred mass ratio of the alloy powder to the oxidant is (50-200):1; and the preferred mixing time is 1-3 hours. The cold isostatic pressing is performed using a polyurethane mold at a pressure of 100... The pressure is 300 MPa, and the holding time is 5-20 min; the preferred reaction conditions for the internal oxidation are: under a nitrogen or argon atmosphere, at 800-900 ℃ for 1-5 h.

[0031] Specifically, after uniformly mixing the alloy powder and oxidant, cold isostatic pressing is performed. This allows for the application of uniform pressure in all directions to the powder without heating, resulting in close contact between particles within the billet, and fine, uniformly distributed pores. The uniform and dense billet facilitates sufficient contact between the oxidant and the alloy powder, ensuring consistent oxygen diffusion channels during subsequent internal oxidation. This allows the internal oxidation reaction to proceed uniformly along the entire billet, making the degree of oxidation and reaction depth more controllable and improving the uniformity and consistency of product performance.

[0032] It should be noted that through the synergistic process of internal oxidation and reduction, the aluminum element in the alloy is transformed into a nano-sized alumina dispersion strengthening phase, while the reduction process removes excess oxygen and avoids excessive oxidation of the matrix. Under the action of internal oxidation, the aluminum element reacts with oxygen in situ to generate fine and stable Al2O3 particles, which are uniformly anchored in the grain boundaries and grain interior of the copper matrix, significantly improving the high-temperature strength, softening resistance, and wear resistance of the alloy; at the same time, the nano-dispersion phase has little impact on electron scattering, and can retain the excellent electrical and thermal conductivity of the copper matrix to the greatest extent.

[0033] In this embodiment, the preferred conditions for hot isostatic pressing are: a temperature of 750-950 ℃, a pressure of 100-200 MPa, and a holding time of 1-6 h; the preferred conditions for hot extrusion are: a temperature of 800-900 ℃, a holding time of 1-2 h, and an extrusion ratio of 15-50. Through combined densification via hot isostatic pressing and hot extrusion, the preform after oxidation-reduction treatment, which eliminates porosity and interfacial bonding, further eliminates internal micropores and porosity defects under high temperature and high pressure, significantly increasing the material density to near a fully dense state. Then, hot extrusion causes intense plastic deformation between the matrix and the dispersed phase, breaking up coarse structures, refining grains, and enhancing the interfacial bonding strength between the copper matrix and the Al2O3 dispersed phase, significantly improving the structural stability and mechanical properties of the alloy.

[0034] In this embodiment, the hot deformation treatment is preferably hot rolling or hot forging. The preferred conditions for the hot deformation treatment are: temperature 600-900 ℃, holding time 15-60 min, deformation per pass 1-2 mm, and total deformation 20%-60%. The hot deformation treatment further optimizes the microstructure, eliminates some dislocations, reduces lattice distortion, refines and elongates grains to form a fibrous structure, significantly improves the material's plasticity and resistance to bending deformation, and promotes the uniform distribution of alumina particles in the copper matrix, reducing agglomeration and thus enhancing the dispersion strengthening effect. The resulting alumina dispersion-strengthened copper alloy possesses high strength, high conductivity, high heat resistance, and good plasticity, resulting in a significant improvement in its bending resistance.

[0035] Specifically, by controlling the aluminum content, at low content, there are fewer alumina particles with larger spacing. Although dislocations encounter obstacles during movement, they still have space to move freely, allowing the material to undergo significant plastic deformation and exhibiting good bending properties. At high content, the number of alumina particles increases dramatically, and the interparticle spacing decreases sharply. The free path for dislocation movement is severely compressed, and the material's deformation ability is severely suppressed. This manifests as increased yield strength but significantly decreased plasticity and toughness, making it extremely prone to fracture during bending. The added Ag element can strengthen interfacial bonding, reduce crack initiation sources, and improve interfacial debonding resistance. Furthermore, Ag segregates at grain boundaries, promoting grain boundary slip and coordinated deformation, reducing grain boundary stress concentration. Thus, while maintaining high strength, it significantly improves the material's bending properties and overall plasticity. Hot deformation treatment further optimizes the microstructure, eliminating some dislocations, reducing lattice distortion, refining and elongating grains to form a fibrous structure, and significantly improving the material's plasticity and resistance to bending deformation.

[0036] Secondly, this application provides an alumina dispersion-strengthened copper alloy, which is prepared according to the preparation method described in the first aspect; the alumina dispersion-strengthened copper alloy has a bending performance of ≥5 cycles; the alumina dispersion-strengthened copper alloy has a conductivity of ≥83.4% IACS; the alumina dispersion-strengthened copper alloy has a tensile strength of ≥405 MPa; the alumina dispersion-strengthened copper alloy has an elongation of ≥20.4%; the obtained alumina dispersion-strengthened copper alloy simultaneously possesses high strength, high conductivity and good plasticity, thus significantly improving its bending resistance.

[0037] Thirdly, this application also provides the application of the alumina dispersion-strengthened copper alloy described in the second aspect in the fields of new energy vehicles, ultra-high voltage power transmission and transformation, aerospace, or high-speed rail transportation. Based on the excellent comprehensive performance of the aforementioned alumina dispersion-strengthened copper alloy, which combines high strength, high conductivity, high heat resistance, and excellent bending resistance, it can meet the requirements of these high-end fields for key conductive structural components under harsh conditions such as high temperature, high load, and frequent bending. It can be widely used in components such as motor conductors, high-voltage contacts, aviation connectors, and high-speed train contact networks.

[0038] The technical solution of this application will be further described below with reference to specific embodiments, but the scope of protection of this application is not limited to the following embodiments.

[0039] Example 1 The method for improving the bending performance of alumina dispersion-reinforced copper materials provided in this embodiment is illustrated in the flowchart below. Figure 1 As shown, it specifically includes: S101: Electrolytic copper, aluminum ingots and silver granules are added to a medium-frequency induction furnace in proportion for smelting at a temperature of 1150 ℃. A mixture (a mixture of water and copper alloy powder) is obtained by high-pressure water jet spraying with an atomization pressure of 20 MPa. After precipitation, pressure filtration and drying, the mixture is used to obtain alloy powder (0.2% aluminum and 0.2% silver).

[0040] S102: After passing the alloy powder through a 100-mesh sieve, mix it with 300-mesh cuprous oxide powder at a ratio of 100:1 and add it to a V-type mixer to mix for 2 hours. Then, put it into a polyurethane mold, plug both ends, reinforce it with iron wire, and put it into a cold isostatic press for pressing. Apply a pressure of 200 MPa for 10 minutes to obtain a copper alloy billet.

[0041] S103: The copper alloy billet is placed in a heating furnace and internally oxidized in a nitrogen atmosphere at 850 °C for 4 hours. After internal oxidation, reduction is performed in a hydrogen atmosphere at 900 °C for 5 hours. The copper alloy billet is then placed in a sleeve, vacuum-evacuated, and subjected to hot isostatic pressing at 880 °C for 4 hours and 150 MPa. After unpacking, a copper alloy ingot is obtained. The ingot is then heated to 920 °C and held for 1 hour at an extrusion ratio of 30 to obtain extruded bars.

[0042] S104: The above extruded bar is subjected to hot rotary forging treatment. The heating temperature is 800 ℃, the holding time is 30 min, the single-pass deformation is 1 mm, and the total deformation is 50%, to obtain Al-alumina dispersion-strengthened copper alloy bar.

[0043] Example 2 The method for improving the bending properties of alumina-dispersed copper material in this embodiment differs from that in Example 1 in that, in step S101, the silver content of the alloy powder is reduced. The alloy powder comprises the following components by mass percentage: 0.2% aluminum, 0.1% silver, 250 ppm oxygen content, and the balance being copper. For any items not mentioned, refer to the steps in Example 1.

[0044] Example 3 The method for improving the bending properties of alumina-dispersed copper material in this embodiment differs from that in Example 1 in that, in step S101, the silver content of the alloy powder is increased. The alloy powder comprises the following components by mass percentage: 0.2% aluminum, 0.4% silver, 250 ppm oxygen content, and the balance being copper. For any items not mentioned, refer to the steps in Example 1.

[0045] Example 4 The method for improving the bending properties of alumina-dispersed copper material in this embodiment differs from that in Example 1 in that, in step S101, the aluminum content of the alloy powder is reduced. The alloy powder comprises the following components by mass percentage: 0.1% aluminum, 0.2% silver, 250 ppm oxygen content, and the balance being copper. For any items not mentioned, refer to the steps in Example 1.

[0046] Example 5 The method for improving the bending properties of alumina-dispersed copper material in this embodiment differs from that in Example 1 in that, in step S101, the aluminum content of the alloy powder is increased. The alloy powder comprises the following components by mass percentage: 0.4% aluminum, 0.2% silver, 250 ppm oxygen content, and the balance being copper. For any items not mentioned, refer to the steps in Example 1.

[0047] Example 6 The method for improving the bending properties of alumina-dispersed copper material in this embodiment differs from that in Example 1 in that the heating temperature in step S104 is 600°C. For any details not mentioned, refer to the steps in Example 1.

[0048] Example 7 The method for improving the bending properties of alumina-dispersed copper material in this embodiment differs from that in Embodiment 1 in that hot rotary forging is performed in step S104, with a total deformation of 30%. For any details not mentioned, refer to the steps in Embodiment 1.

[0049] Meanwhile, to verify the comprehensive performance of the alumina dispersion-strengthened copper alloy preparation method provided in the above embodiments, this application provides the following comparative examples for detailed illustration.

[0050] Comparative Example 1 This comparative example provides a preparation method for B1-alumina dispersion-strengthened copper alloy. The component ratio, preparation operation, and process parameters are basically the same as those in Example 1. The difference is that in step S101 of this comparative example, the alloy powder includes the following components by mass percentage: aluminum 0.2%, no silver is added, and the final step S104 is not performed, that is, no hot deformation treatment is performed, in order to prepare B1-alumina dispersion-strengthened copper alloy.

[0051] Comparative Example 2 This comparative example provides a preparation method for B2-alumina dispersion-strengthened copper alloy. The component ratio, preparation operation, and process parameters are basically the same as those in Example 1. The difference is that in step S101 of this comparative example, the alloy powder includes the following components by mass percentage: aluminum 0.2%, without adding silver, to prepare B2-alumina dispersion-strengthened copper alloy.

[0052] Comparative Example 3 This comparative example provides a preparation method for B3-alumina dispersion-strengthened copper alloy. The component ratios, preparation operations, and process parameters are basically the same as those in Example 1. The difference is that the final step S104 is not performed in this comparative example, i.e., no hot deformation treatment is performed, in order to obtain B3-alumina dispersion-strengthened copper alloy.

[0053] This application conducted performance tests on samples of the alumina-dispersed copper alloy rods prepared in the examples and comparative examples. The test results are shown in Table 3. The test methods are as follows: Tensile strength and elongation were tested according to the methods in the current national standard GB / T 228.1-2021 "Metallic materials, tensile testing - Part 1: Test at room temperature". The bending performance was tested using the methods specified in the current national standard GB / T 232-2024, "Metallic Materials - Bending Test Method". Conductivity was determined using the method specified in the current national standard GB / T 32791-2016, "Eddy Current Test Method for Conductivity of Copper and Copper Alloys".

[0054] The comprehensive performance comparison of the alloys prepared in the embodiments and comparative examples of this application is shown in Table 1: Table 1. Overall Performance Comparison

[0055] As shown in Table 1, the changes in conditions in each embodiment of this application have different effects on the performance of the alloys. The dispersed copper prepared using the methods of Examples 1, 2, and 3 of this application, compared to the comparative example, has different amounts of Ag element added and undergoes hot forging treatment. While maintaining a basically unchanged conductivity, its tensile strength and elongation are improved, especially its bending performance, which is significantly enhanced. The material strength, plasticity, and toughness are also significantly improved. The dispersed copper prepared using the methods of Examples 4 and 5 of this application, compared to Example 1, has an adjusted aluminum content, resulting in significant changes in various material indicators. This indicates that the added aluminum content is one of the key factors affecting the various properties of alumina dispersed copper. The dispersed copper prepared using the method of Example 6 of this application, compared to Example 1, has a slightly improved tensile strength, while its elongation and bending performance are slightly decreased. This indicates that the hot working deformation temperature is also a factor affecting the material properties of dispersed copper; the higher the deformation temperature, the weaker the work hardening effect, and the more significant the improvement in plasticity and toughness. The dispersed copper prepared by the method of Example 7 of this application showed little change in tensile strength and elongation compared with Example 1, but its bending performance decreased slightly. This indicates that the greater the amount of deformation during hot deformation processing, the better the effect on improving bending deformation capacity.

[0056] Therefore, the alumina dispersion-reinforced copper alloy prepared by the method provided in this application significantly improves the bending performance and overall plasticity of the material while maintaining high strength. It can meet the requirements of the aforementioned high-end fields for the use of key conductive structural components under harsh conditions such as high temperature, high load, and frequent bending, and can be widely used in components such as motor conductors, high-voltage contacts, aviation connectors, and high-speed train overhead contact lines.

[0057] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0058] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of this application.

Claims

1. A method for preparing an alumina dispersion-strengthened copper alloy, characterized in that, The preparation method includes: Copper, aluminum and silver are smelted together, and alloy powder is prepared by water atomization. The alloy powder is mixed with an oxidant and then subjected to cold isostatic pressing to obtain a preliminary billet. The initial billet is subjected to internal oxidation, reduction, hot isostatic pressing, and hot extrusion to obtain alloy bars; The alloy bar is subjected to hot deformation treatment to obtain an alumina dispersion-strengthened copper alloy.

2. The preparation method according to claim 1, characterized in that, The alloy powder comprises the following components by mass percentage: aluminum 0.1% 0.4%, silver 0.1%-0.4%, oxygen content less than 0.03%, balance is copper.

3. The preparation method according to claim 1, characterized in that, The hot deformation treatment is hot rolling or hot forging.

4. The preparation method according to claim 3, characterized in that, The conditions for the heat deformation treatment are: temperature 600-900 ℃, holding time 15-60 min, deformation per pass 1-2 mm, and total deformation 20-60%.

5. The preparation method according to claim 1, characterized in that, The oxidant is cuprous oxide, and the powder particle size is less than 300 mesh; The mass ratio of the alloy powder to the oxidant is (50-200):1; The mixing time is 1-3 hours.

6. The preparation method according to claim 1, characterized in that, The cold isostatic pressing is performed using a polyurethane mold at a pressure of 100. 300 MPa, holding time 5-20 min; and / or The reaction conditions for the internal oxidation are: under a nitrogen or argon atmosphere, at a temperature of 800-900 °C for 1-5 h.

7. The preparation method according to claim 1, characterized in that, The reduction reaction conditions are: under a hydrogen atmosphere, at 850-950 °C for 2-6 h; The conditions for hot isostatic pressing are: a temperature of 750-950 ℃ and a pressure of 100-200 MPa, and a holding time of 1-6 hours.

8. The preparation method according to claim 1, characterized in that, The conditions for hot extrusion are: temperature 800-900℃, holding time 1-2 h, and extrusion ratio 15-50.

9. An alumina dispersion-strengthened copper alloy, characterized in that, The alumina dispersion-strengthened copper alloy is prepared according to any one of the preparation methods described in claims 1-8; The tensile strength of the alumina dispersion-strengthened copper alloy is ≥405 MPa; The conductivity of the alumina dispersion-strengthened copper alloy is ≥83.4% IACS.

10. The application of the alumina dispersion-strengthened copper alloy according to any one of claims 9 in the fields of new energy vehicles, ultra-high voltage power transmission and transformation, aerospace or high-speed rail transportation.

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