A high-strength and high-plasticity Cu-Al2O3 / Cu composite rod, its preparation method and application

Abstract

This invention discloses a high-strength, high-plasticity Cu-Al2O3 / Cu composite rod, its preparation method, and its application, belonging to the field of materials technology. The rod has a mixed-crystal structure, wherein the fine Al2O3-dispersed Cu grains have a particle size ≤1.5μm, and the coarse pure Cu grains have a particle size ≥2μm; the content of fine grains in the rod is 40-90wt%, with the remainder being coarse grains. The aforementioned fine Al2O3-dispersed Cu grains provide the rod with high strength, while the coarse pure Cu grains provide high plasticity. Through this mixed-crystal ratio, the inverted relationship of "high strength-high plasticity" in the Cu-Al2O3 / Cu composite material can be effectively improved, enhancing the overall performance of the rod. The preparation of the rod includes: mixing the raw materials to form an ingot, followed by internal oxidation treatment, reduction treatment, and hot extrusion. This preparation process is simple to operate, has low production cost, and is highly feasible.

Description

Technical Field

[0001] This invention relates to the field of materials technology, and more specifically, to a high-strength, high-plasticity Cu-Al2O3 / Cu composite rod, its preparation method, and its application. Background Technology

[0002] Cu-Al2O3 dispersion-strengthened copper alloy composites possess excellent properties such as high strength, high electrical conductivity, and high softening temperature, making them a research hotspot in the field of copper-based composite materials. After years of research and development, Cu-Al2O3 dispersion-strengthened copper alloys have been widely used in resistance welding electrodes, integrated circuit lead frames, transmitter grid support rods, traveling wave tube slow-wave lines, continuous casting steel crystallizers, high-strength power lines, and microwave tube structures. Because the Al2O3 particles are dispersed in the copper matrix, they effectively pin dislocation movement and hinder grain boundary slip, resulting in high strength and high hardness. However, with increasing Al2O3 content, the strength of Cu-Al2O3 dispersion-strengthened copper alloys increases significantly, while their plasticity decreases significantly. This indicates an inverted relationship between "high strength" and "high plasticity" in Cu-Al2O3 alloy composites, which greatly limits their further application.

[0003] In view of this, the present invention is proposed. Summary of the Invention

[0004] The purpose of this invention is to provide a high-strength, high-plasticity Cu-Al2O3 / Cu composite rod, its preparation method, and its application, so as to solve or improve the above-mentioned technical problems.

[0005] This application can be implemented as follows:

[0006] In a first aspect, this application provides a high-strength and high-plasticity Cu-Al2O3 / Cu composite rod, which has a mixed crystal structure, the mixed crystals including fine Al2O3-dispersed Cu grains and coarse pure Cu grains;

[0007] Among them, the particle size of Al2O3-dispersed Cu grains is ≤1.5μm, and the content in high-strength and high-plasticity Cu-Al2O3 / Cu composite rods is 40-90wt%; the particle size of coarse pure Cu grains is ≥2μm, and the content in high-strength and high-plasticity Cu-Al2O3 / Cu composite rods is 10-60wt%.

[0008] In an optional embodiment, the raw materials for preparing the high-strength and high-plasticity Cu-Al2O3 / Cu composite rods include CuAl powder, Cu2O powder, and pure Cu powder.

[0009] The content of pure Cu powder in the raw materials shall not exceed 50 wt%; the oxygen content in Cu2O powder shall not be lower than the oxygen content theoretically required to oxidize aluminum in CuAl powder;

[0010] The Al content in CuAl powder is 0.4-1 wt%.

[0011] In an optional embodiment, the Al content in the CuAl powder is 0.6 wt%.

[0012] In optional embodiments, the particle size of CuAl powder is ≤150 μm; and / or, the particle size of Cu2O powder is ≤0.1 μm; and / or, the particle size of pure Cu powder is ≤100 μm.

[0013] In an optional embodiment, the high-strength, high-plasticity Cu-Al2O3 / Cu composite rod has at least one of the following characteristics:

[0014] Feature 1: The diameter of the high-strength and high-plasticity Cu-Al2O3 / Cu composite rod is 10-30mm, preferably 18-20mm;

[0015] Feature 2: The tensile strength of the high-strength and high-plasticity Cu-Al2O3 / Cu composite rod is not less than 392 MPa;

[0016] Feature 3: The elongation of the high-strength and high-plasticity Cu-Al2O3 / Cu composite rod is not less than 27%;

[0017] Feature 4: The conductivity of the high-strength and high-plasticity Cu-Al2O3 / Cu composite rod is not less than 79%.

[0018] Secondly, this application provides a method for preparing high-strength and high-plasticity Cu-Al2O3 / Cu composite rods as described in any of the foregoing embodiments, comprising the following steps: mixing the raw materials for preparing high-strength and high-plasticity Cu-Al2O3 / Cu composite rods to prepare Cu-Al2O3 / Cu composite ingots, and then subjecting the Cu-Al2O3 / Cu composite ingots to internal oxidation treatment, reduction treatment and hot extrusion.

[0019] In an optional embodiment, the raw materials are prepared by cold pressing to form Cu-Al2O3 / Cu composite material ingots.

[0020] In an optional embodiment, the cold pressing pressure is 150-200 MPa, and the holding time is 5-10 min.

[0021] In an optional embodiment, the internal oxidation treatment includes at least one of the following features:

[0022] Feature 1: Internal oxidation treatment is carried out in a non-oxidizing environment;

[0023] Feature 2: The internal oxidation treatment temperature is 850-900℃;

[0024] Feature 3: The internal oxidation treatment time is 4-6 hours.

[0025] In an optional implementation, the reduction process includes at least one of the following features:

[0026] Feature 1: The reduction process is carried out in a reducing environment;

[0027] Feature 2: The reduction treatment temperature is 800-850℃;

[0028] Feature 3: The reduction process takes 6-8 hours.

[0029] In an optional embodiment, hot extrusion includes at least one of the following features:

[0030] Feature 1: The hot extrusion temperature is 950-980℃;

[0031] Feature 2: The hot extrusion time is 5-15 seconds;

[0032] Feature 3: The extrusion ratio of hot extrusion is 25:1-30:1.

[0033] Thirdly, this application provides an application of a high-strength, high-plasticity Cu-Al2O3 / Cu composite rod as described in any of the foregoing embodiments, for example, it can be used to prepare resistance welding electrodes, integrated circuit lead frames, transmitter grid support rods, traveling wave tube slow wave lines, continuous casting steel crystallizers, high-strength power lines, or microwave tube structures.

[0034] The beneficial effects of this application include:

[0035] The Cu-Al2O3 / Cu composite rods provided in this application have a mixed-crystal structure, wherein fine Al2O3-dispersed Cu grains provide high strength to the rods, while coarse pure Cu grains provide high plasticity. By using a specific mixed-crystal ratio, the inverse relationship of "high strength-high plasticity" in Cu-Al2O3 / Cu composite materials can be effectively improved, thereby enhancing the overall performance of the rods.

[0036] The preparation process of this Cu-Al2O3 / Cu composite rod is simple, low-cost, and highly feasible, making it suitable for mass production. The resulting high-strength and high-plasticity Cu-Al2O3 / Cu composite rod can be used to prepare resistance welding electrodes, integrated circuit lead frames, transmitter grid support rods, traveling wave tube slow wave lines, continuous casting steel crystallizers, high-strength power lines, or microwave tube structures, etc. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a microstructure diagram of the Cu-Al2O3 / Cu composite rod obtained during the preparation process of Example 1 of this application, where the arrows indicate nano-Al2O3 particles;

[0039] Figure 2 The EBSD-inverse pole figure and grain boundary cloud figure of the transverse cross section microstructure of the Cu-Al2O3 / Cu composite rod prepared in Example 1 of this application are shown.

[0040] Figure 3 The EBSD pole figure and grain boundary cloud diagram of the longitudinal section microstructure of the Cu-Al2O3 / Cu composite rod prepared in Example 1 of this application are shown.

[0041] Figure 4 This is a physical image of the Cu-Al2O3 / Cu composite rod prepared in Example 1 of this application. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0043] The following provides a detailed description of the high-strength, high-plasticity Cu-Al2O3 / Cu composite rods provided in this application, their preparation methods, and applications.

[0044] This application proposes a high-strength and high-plasticity Cu-Al2O3 / Cu composite rod, which has a mixed crystal structure, comprising fine Al2O3-dispersed Cu grains and coarse pure Cu grains.

[0045] The Al₂O₃-dispersed Cu grains have a particle size ≤1.5μm and constitute 40-90wt% (e.g., 40wt%, 50wt%, 60wt%, 70wt%, 80wt%, or 90wt%) of the high-strength, high-plasticity Cu-Al₂O₃ / Cu composite rods. The coarse pure Cu grains have a particle size ≥2μm and constitute 10-60wt% of the high-strength, high-plasticity Cu-Al₂O₃ / Cu composite rods. The total content of the fine Al₂O₃-dispersed Cu grains and the coarse pure Cu grains is 100wt%.

[0046] The fine Al2O3-dispersed Cu grains provide high strength to the rods, while the coarse pure Cu grains provide high plasticity. By adjusting the above-mentioned mixed crystal ratio, the inverse relationship between "high strength" and "high plasticity" in Cu-Al2O3 / Cu composite materials can be effectively improved, thereby enhancing the overall performance of the rods.

[0047] In this application, the raw materials for preparing the high-strength and high-plasticity Cu-Al2O3 / Cu composite rods include CuAl powder, Cu2O powder, and pure Cu powder.

[0048] After the CuAl powder reacts with Cu2O powder, the oxygen in the Cu2O powder reacts with the aluminum in the CuAl powder to form Al2O3, which is dispersed in the remaining Cu. In other words, CuAl powder and Cu2O powder can jointly form fine Al2O3-dispersed Cu grains. Furthermore, the reaction of CuAl powder with Cu2O powder can also form some pure Cu grains. Pure Cu powder is mainly used to form coarse pure Cu grains.

[0049] For reference, the content of pure Cu powder in the raw materials shall not exceed 50 wt%, for example, it may be 50 wt%, 45 wt%, 40 wt%, 35 wt%, 30 wt%, 25 wt%, 20 wt%, 15 wt%, 5 wt%, etc., or any other value within the range not exceeding 50 wt%.

[0050] The oxygen content in the Cu2O powder is not less than the oxygen content theoretically required to oxidize the aluminum in the CuAl powder. That is, the amount of Cu2O powder used in the preparation raw materials must be sufficient to completely oxidize the aluminum in the CuAl powder to Al2O3. In some optional embodiments, the amount of oxygen required for the complete oxidation of the aluminum in the CuAl powder is m, and the oxygen provided by the cuprous oxide powder is 1.2m. In other words, the cuprous oxide powder is added at 120% of the theoretical oxygen content.

[0051] The Al content in the CuAl powder can be 0.4-1 wt%. In some typical embodiments, the Al content in the CuAl powder is 0.6 wt%.

[0052] For reference, the particle size of CuAl powder is ≤150μm, such as 150μm, 120μm, 100μm, 80μm, or 50μm. The particle size of Cu2O powder is ≤0.1μm, such as 0.1μm, 0.05μm, or 0.01μm. The particle size of pure Cu powder is ≤100μm, such as 100μm, 80μm, 50μm, or 10μm, and the purity of the pure Cu powder is preferably not less than 99%.

[0053] In some embodiments, the CuAl powder has a particle size of 120 μm, the Cu2O powder has a particle size of 0.05 μm, and the pure Cu powder has a particle size of 5 μm.

[0054] For reference, the diameter of the high-strength, high-plasticity Cu-Al2O3 / Cu composite rods provided in this application can be 10-30 mm, such as 10 mm, 15 mm, 20 mm, 25 mm, or 30 mm, or any other value within the range of 10-30 mm. In some typical embodiments, the diameter of the high-strength, high-plasticity Cu-Al2O3 / Cu composite rods is 18-20 mm.

[0055] In this application, the tensile strength of the high-strength and high-plasticity Cu-Al2O3 / Cu composite rod is not less than 392 MPa, the elongation is not less than 27%, and the conductivity is not less than 79%.

[0056] Accordingly, this application also provides a method for preparing the above-mentioned high-strength and high-plasticity Cu-Al2O3 / Cu composite rod, which may include the following steps: mixing the raw materials for preparing the high-strength and high-plasticity Cu-Al2O3 / Cu composite rod to prepare Cu-Al2O3 / Cu composite ingot, and then subjecting the Cu-Al2O3 / Cu composite ingot to internal oxidation treatment, reduction treatment and hot extrusion.

[0057] For reference, after the raw materials are mechanically mixed, Cu-Al2O3 / Cu composite material ingots can be formed by cold pressing.

[0058] Cold pressing can be performed on a cold press. The pressure for cold pressing can be 150-200 MPa, such as 150 MPa, 160 MPa, 170 MPa, 180 MPa, 190 MPa, or 200 MPa, or any other value within the range of 150-200 MPa. The holding time can be 5-10 minutes, such as 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, or 10 minutes, or any other value within the range of 5-10 minutes. The temperature for cold pressing is room temperature.

[0059] Internal oxidation is performed in a non-oxidizing environment, such as an argon atmosphere.

[0060] The internal oxidation treatment temperature can be 850-900℃, such as 850℃, 860℃, 870℃, 880℃, 890℃ or 900℃, or any other value within the range of 850-900℃.

[0061] The internal oxidation treatment time can be 4-6 hours, such as 4 hours, 4.5 hours, 5 hours, 5.5 hours or 6 hours, or any other value within the range of 4-6 hours.

[0062] If the internal oxidation temperature is below 850℃, it is not conducive to the formation of diffusely distributed Al2O3 particles through sufficient internal oxidation; if the internal oxidation temperature is above 900℃, it is not conducive to the formation of fine, diffusely distributed Al2O3 particles. If the internal oxidation time is less than 4 hours, the internal oxidation is insufficient, which is not conducive to obtaining Al2O3 particles formed by complete internal oxidation reaction; if the internal oxidation time is longer than 6 hours, the Al2O3 particles tend to grow larger, which is not conducive to the formation of fine, diffusely distributed Al2O3 particles.

[0063] Through internal oxidation treatment, a finely sized Al2O3 particle-reinforced phase with diffuse distribution can be obtained.

[0064] The reduction process is carried out in a reducing environment, such as in a hydrogen atmosphere.

[0065] The reduction treatment temperature can be 800-850℃, such as 800℃, 810℃, 820℃, 830℃, 840℃ or 850℃, or any other value within the range of 800-850℃.

[0066] The restoration process can take 6-8 hours, such as 6h, 6.5h, 7h, 7.5h or 8h, or any other value within the range of 6-8 hours.

[0067] The desired Cu grains can be obtained through reduction treatment.

[0068] Hot extrusion can be performed in an extruder.

[0069] The temperature for hot extrusion can be 950-980℃, such as 950℃, 955℃, 960℃, 965℃, 970℃, 975℃ or 980℃, or any other value within the range of 950-980℃.

[0070] The hot extrusion time can be 5-15 seconds, such as 5 seconds, 10 seconds, or 15 seconds, or any other value within the range of 5-15 seconds.

[0071] The extrusion ratio for hot extrusion can be 25:1-30:1, such as 25:1, 26:1, 27:1, 28:1, 29:1 or 30:1, or any other value within the range of 25:1-30:1.

[0072] The hot extrusion process described above not only improves the density of the bar stock but also promotes uniform grain distribution.

[0073] If the hot extrusion temperature is below 950℃, it is not conducive to the smooth progress of the extrusion process; if the hot extrusion temperature is above 980℃, it is not conducive to obtaining a bar with a bright surface; if the hot extrusion time is less than 5s, it is not conducive to the process; if the hot extrusion time is longer than 5s, the billet will cool down easily, which is not conducive to the smooth progress of the extrusion process; if the extrusion ratio of hot extrusion is less than 25:1 (such as 20:1), it is not conducive to obtaining a bar with a dense structure; if the extrusion ratio of hot extrusion is higher than 30:1 (such as 35:1), it is not conducive to the smooth progress of the extrusion process.

[0074] As mentioned above, the preparation process of the high-strength and high-plasticity Cu-Al2O3 / Cu composite rods provided in this application is simple to operate, has low production cost, and is highly feasible, making it suitable for mass production of Cu-Al2O3 / Cu composite materials.

[0075] In addition, this application also provides applications of the above-mentioned high-strength and high-plasticity Cu-Al2O3 / Cu composite rods, such as their use in the preparation of resistance welding electrodes, integrated circuit lead frames, transmitter grid support rods, traveling wave tube slow wave lines, continuous casting steel crystallizers, high-strength power lines or microwave tube structures, etc.

[0076] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0077] Example 1

[0078] This embodiment provides a high-strength, high-plasticity Cu-Al2O3 / Cu composite rod with a diameter of 20 mm. Its preparation method is as follows:

[0079] S1: Mixing

[0080] CuAl powder, Cu2O powder, and pure Cu powder were mechanically mixed together to obtain the raw materials. The content of pure Cu powder in the above raw materials was 5 wt%, Cu2O powder was added at 120% of the theoretical oxygen content, and the Al content in CuAl powder was 0.6 wt%.

[0081] The particle size of CuAl powder is 150 μm, the particle size of Cu2O powder is 0.1 μm, and the particle size of pure Cu powder is 100 μm.

[0082] S2: Cold pressing

[0083] The mechanically mixed powder is cold-pressed on a cold press at a pressure of 150 MPa for 10 minutes to produce a billet with dimensions of φ100mm×300mm.

[0084] S3: Internal oxidation treatment

[0085] The Cu-Al2O3 / Cu composite ingot was subjected to internal oxidation treatment in an argon atmosphere at a temperature of 850℃ for 6 hours.

[0086] S4: Reduction Processing

[0087] Cu-Al2O3 / Cu composite ingots were reduced in a hydrogen environment at a temperature of 800℃ for 8 hours.

[0088] S5: Hot Extrusion

[0089] The Cu-Al2O3 / Cu composite billet was extruded on an extruder at a temperature of 950℃ for 5 seconds and an extrusion ratio of 25:1.

[0090] In the finished bar product, the Al2O3-dispersed Cu grains have a particle size of 1.5 μm and a content of 40 wt%; the coarse pure Cu grains have a particle size of 2 μm and a content of 60 wt%.

[0091] The microstructure of the Cu-Al2O3 / Cu composite rod obtained in this embodiment is shown in the figure below. Figure 1 As shown, the EBSD-inverse pole figure contour map and grain boundary contour map of the transverse cross-section structure are as follows: Figure 2 As shown, the EBSD pole figure contour map and grain boundary contour map of the longitudinal section structure are as follows: Figure 3 As shown in the picture, the actual product is as follows. Figure 4 As shown.

[0092] Example 2

[0093] This embodiment provides a high-strength, high-plasticity Cu-Al2O3 / Cu composite rod with a diameter of 18 mm. Its preparation method is as follows:

[0094] S1: Mixing

[0095] CuAl powder, Cu2O powder, and pure Cu powder were mechanically mixed together to obtain the raw materials. The content of pure Cu powder in the above raw materials was 50 wt%, Cu2O powder was added at 120% of the theoretical oxygen content, and the Al content in CuAl powder was 0.6 wt%.

[0096] The particle size of CuAl powder is 150 μm, the particle size of Cu2O powder is 0.1 μm, and the particle size of pure Cu powder is 100 μm.

[0097] S2: Cold pressing

[0098] The mechanically mixed powder is cold-pressed on a cold press at a pressure of 200 MPa for 5 minutes to produce a billet with a size of φ100mm×300mm.

[0099] S3: Internal oxidation treatment

[0100] The Cu-Al2O3 / Cu composite ingot was subjected to internal oxidation treatment in an argon atmosphere at a temperature of 900℃ for 4 hours.

[0101] S4: Reduction Processing

[0102] Cu-Al2O3 / Cu composite ingots were reduced in a hydrogen environment at a temperature of 850℃ for 6 hours.

[0103] S5: Hot Extrusion

[0104] The Cu-Al2O3 / Cu composite billet was extruded on an extruder at a temperature of 980℃ for 10 seconds and an extrusion ratio of 30:1.

[0105] In this finished bar, the Al2O3-dispersed Cu grains have a particle size of 0.5 μm and a content of 90 wt%; the coarse pure Cu grains have a particle size of 10 μm and a content of 10 wt%.

[0106] Example 3

[0107] This embodiment provides a high-strength, high-plasticity Cu-Al2O3 / Cu composite rod with a diameter of 10 mm. Its preparation method is as follows:

[0108] S1: Mixing

[0109] CuAl powder, Cu2O powder, and pure Cu powder were mechanically mixed together to obtain the raw materials. The content of pure Cu powder in the above raw materials was 25 wt%, Cu2O powder was added at 110% of the theoretical oxygen content, and the Al content in CuAl powder was 0.4 wt%.

[0110] The particle size of CuAl powder is 150 μm, the particle size of Cu2O powder is 0.1 μm, and the particle size of pure Cu powder is 100 μm.

[0111] S2: Cold pressing

[0112] The mechanically mixed powder is cold-pressed on a cold press at a pressure of 180 MPa for 7 minutes to produce a billet with dimensions of φ100mm×300mm.

[0113] S3: Internal oxidation treatment

[0114] The Cu-Al2O3 / Cu composite ingot was subjected to internal oxidation treatment in an argon atmosphere at a temperature of 880℃ for 5.5 hours.

[0115] S4: Reduction Processing

[0116] Cu-Al2O3 / Cu composite ingots were reduced in a hydrogen environment at a temperature of 800℃ for 8 hours.

[0117] S5: Hot Extrusion

[0118] The Cu-Al2O3 / Cu composite billet was extruded on an extruder at a temperature of 960℃ for 15 seconds and an extrusion ratio of 28:1.

[0119] In this finished bar, the particle size of Al2O3-dispersed Cu grains is 1 μm and the content is 50 wt%; the particle size of coarse pure Cu grains is 5 μm and the content is 50 wt%.

[0120] Example 4

[0121] This embodiment provides a high-strength, high-plasticity Cu-Al2O3 / Cu composite rod with a diameter of 30 mm. Its preparation method is as follows:

[0122] S1: Mixing

[0123] CuAl powder, Cu2O powder, and pure Cu powder were mechanically mixed together to obtain the raw materials. The content of pure Cu powder in the above raw materials was 30 wt%, Cu2O powder was added at 130% of the theoretical oxygen content, and the Al content in CuAl powder was 1 wt%.

[0124] The particle size of CuAl powder is 150 μm, the particle size of Cu2O powder is 0.1 μm, and the particle size of pure Cu powder is 100 μm.

[0125] S2: Cold pressing

[0126] The mechanically mixed powder is cold-pressed on a cold press at a pressure of 200 MPa for 5 minutes to produce a billet with a size of φ100mm×300mm.

[0127] S3: Internal oxidation treatment

[0128] The Cu-Al2O3 / Cu composite ingot was subjected to internal oxidation treatment in an argon atmosphere at a temperature of 870℃ for 4.5 hours.

[0129] S4: Reduction Processing

[0130] Cu-Al2O3 / Cu composite ingots were reduced in a hydrogen environment at a temperature of 820℃ for 7 hours.

[0131] S5: Hot Extrusion

[0132] The Cu-Al2O3 / Cu composite billet was extruded on an extruder at a temperature of 970℃ for 8 seconds and an extrusion ratio of 26:1.

[0133] In the finished bar product, the particle size of Al2O3-dispersed Cu grains is 0.8μm and the content is 55wt%; the particle size of coarse pure Cu grains is 9μm and the content is 45wt%.

[0134] Comparative Example 1

[0135] The difference between this comparative example and Example 1 is that the internal oxidation treatment temperature is 800°C.

[0136] Comparative Example 2

[0137] The difference between this comparative example and Example 1 is that the internal oxidation treatment temperature is 950°C.

[0138] Comparative Example 3

[0139] The difference between this comparative example and Example 1 is that the internal oxidation treatment time is 2 hours.

[0140] Comparative Example 4

[0141] The difference between this comparative example and Example 1 is that the internal oxidation treatment time is 8 hours.

[0142] Comparative Example 5

[0143] The difference between this comparative example and Example 1 is that: after the internal oxidation treatment, no reduction treatment was performed, and hot extrusion was performed directly.

[0144] Comparative Example 6

[0145] The difference between this comparative example and Example 1 is that the hot extrusion temperature is 900°C.

[0146] Comparative Example 7

[0147] The difference between this comparative example and Example 1 is that the hot extrusion temperature is 1000°C.

[0148] Comparative Example 8

[0149] The difference between this comparative example and Example 1 is that the extrusion ratio is 20:1.

[0150] Comparative Example 9

[0151] The difference between this comparative example and Example 1 is that the extrusion ratio is 35:1.

[0152] Test case

[0153] The performance of the bars prepared in Examples 1-4 and Comparative Examples 1-9 was tested at room temperature. Tensile specimens were prepared in accordance with GB / T228.1-2010 and tensile tests were conducted. The conductivity was determined in accordance with GB / T3048.2-2007. The results are shown in Table 1.

[0154] Table 1 Test Results

[0155]

[0156]

[0157] As can be seen from Table 1, the Cu-Al2O3 / Cu composite rods prepared in the embodiments of this application have better tensile strength, elongation and electrical conductivity, and can simultaneously have high strength and plasticity, thus exhibiting excellent comprehensive performance.

[0158] In summary, the Cu-Al2O3 / Cu composite rods provided in this application possess high strength and ductility, effectively mitigating the inverse relationship between high strength and high ductility in Cu-Al2O3 / Cu composite materials. The preparation process is simple, cost-effective, and highly feasible, making it suitable for mass production. The resulting high-strength, high-ductility Cu-Al2O3 / Cu composite rods can be used to fabricate resistance welding electrodes, integrated circuit lead frames, transmitter grid support rods, traveling wave tube slow-wave lines, continuously cast steel crystallizers, high-strength power lines, or microwave tube structures, etc.

[0159] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-strength, high-plasticity Cu-Al2O3 / Cu composite rod, characterized in that, The high-strength and high-plasticity Cu-Al2O3 / Cu composite rod has a mixed crystal structure, which includes fine Al2O3-dispersed Cu grains and coarse pure Cu grains; The Al2O3-dispersed Cu grains have a particle size ≤1.5μm and a content of 40-90wt% in the high-strength, high-plasticity Cu-Al2O3 / Cu composite rods; the coarse pure Cu grains have a particle size ≥2μm and a content of 10-60wt% in the high-strength, high-plasticity Cu-Al2O3 / Cu composite rods. The raw materials for preparing the high-strength, high-plasticity Cu-Al2O3 / Cu composite rods include CuAl powder, Cu2O powder, and pure Cu powder; wherein, the content of pure Cu powder in the raw materials does not exceed 50 wt%; the oxygen content in the Cu2O powder is not less than the oxygen content theoretically required for oxidizing aluminum in the CuAl powder; and the Al content in the CuAl powder is 0.4-1 wt%. The CuAl powder has a particle size ≤150μm; the Cu2O powder has a particle size ≤0.1μm; the pure Cu powder has a particle size ≤100μm. The preparation of the high-strength and high-plasticity Cu-Al2O3 / Cu composite rod includes the following steps: mixing the raw materials for the preparation of the high-strength and high-plasticity Cu-Al2O3 / Cu composite rod to prepare Cu-Al2O3 / Cu composite ingots, and then subjecting the Cu-Al2O3 / Cu composite ingots to internal oxidation treatment, reduction treatment and hot extrusion. The raw materials are used to form the Cu-Al2O3 / Cu composite material ingot by cold pressing; the cold pressing pressure is 150-200MPa and the holding time is 5-10min. The internal oxidation treatment is carried out in a non-oxidizing environment; the temperature of the internal oxidation treatment is 850-900℃; and the time of the internal oxidation treatment is 4-6 hours. The reduction treatment is carried out in a reducing environment; the temperature of the reduction treatment is 800-850℃; and the time of the reduction treatment is 6-8 hours. The hot extrusion temperature is 950-980℃; the hot extrusion time is 5-15s; and the hot extrusion ratio is 25:1-30:

1.

2. The high-strength, high-plasticity Cu-Al2O3 / Cu composite rod according to claim 1, characterized in that, The CuAl powder contains 0.6 wt% Al.

3. The high-strength, high-plasticity Cu-Al2O3 / Cu composite rod according to claim 1 or 2, characterized in that, The high-strength, high-plasticity Cu-Al2O3 / Cu composite rod has at least one of the following characteristics: Feature 1: The diameter of the high-strength, high-plasticity Cu-Al2O3 / Cu composite rod is 10-30mm. Feature 2: The tensile strength of the high-strength, high-plasticity Cu-Al2O3 / Cu composite rod is not less than 392 MPa; Feature 3: The elongation of the high-strength, high-plasticity Cu-Al2O3 / Cu composite rod is not less than 27%; Feature 4: The conductivity of the high-strength and high-plasticity Cu-Al2O3 / Cu composite rod is not less than 79%.

4. A method for preparing a high-strength, high-plasticity Cu-Al2O3 / Cu composite rod as described in any one of claims 1-3, characterized in that, Includes the following steps: The raw materials for preparing the high-strength and high-plasticity Cu-Al2O3 / Cu composite rods are mixed to prepare Cu-Al2O3 / Cu composite ingots. Subsequently, the Cu-Al2O3 / Cu composite ingots are subjected to internal oxidation treatment, reduction treatment and hot extrusion. The raw materials are used to form the Cu-Al2O3 / Cu composite material ingot by cold pressing; the cold pressing pressure is 150-200MPa and the holding time is 5-10min. The internal oxidation treatment is carried out in a non-oxidizing environment; the temperature of the internal oxidation treatment is 850-900℃; and the time of the internal oxidation treatment is 4-6 hours. The reduction treatment is carried out in a reducing environment; the temperature of the reduction treatment is 800-850℃; and the time of the reduction treatment is 6-8 hours. The hot extrusion temperature is 950-980℃; the hot extrusion time is 5-15s; and the hot extrusion ratio is 25:1-30:

1.

5. An application of the high-strength, high-plasticity Cu-Al2O3 / Cu composite rod as described in claim 1 or 2, characterized in that, The high-strength, high-plasticity Cu-Al2O3 / Cu composite rods are used to prepare resistance welding electrodes, integrated circuit lead frames, transmitter grid support rods, traveling wave tube slow wave lines, continuous casting steel crystallizers, high-strength power lines, or microwave tube structures.

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