Layered gradient copper-silver alloy composite material and preparation method and application thereof

Abstract

The invention provides a layered gradient copper-silver alloy composite material and a preparation method and application thereof. The preparation method comprises the following steps that silver powder and copper powder are mixed according to different mass ratios to prepare AgCu alloy powder; and then silver powder, AgCu alloy powder and copper powder are sequentially loaded into a mold to obtain layered powder, the layered powder is subjected to forming treatment through a cold isostatic pressing process to obtain a green body, the green body is subjected to pressure sintering under inert gas to obtain a sintered blank, and the sintered blank is subjected to hot isostatic pressing treatment to obtain the layered gradient copper-silver alloy composite material. According to the layered gradient copper-silver alloy composite material and the preparation method thereof, through the gradually-decreased gradient distribution design of the mass content of the silver powder from inside to outside, the overall strength of the layered gradient copper-silver alloy composite material is improved through the outer-layer copper powder while the high conductivity of the inner layer is guaranteed, then the layered gradient copper-silver alloy composite material is accurately matched with all technologies, synergistic improvement of the conductivity and the mechanical property is achieved, and meanwhile the interface bonding strength is improved.

Description

Technical Field

[0001] This invention belongs to the field of metal matrix composite technology, specifically relating to a layered gradient copper-silver alloy composite material, its preparation method, and its application. Background Technology

[0002] In the fields of modern electronic information and high-end equipment manufacturing, the performance optimization of metal matrix composites has always been a key driving force for technological development. Copper-silver alloys, with their excellent electrical conductivity, good thermal conductivity, and machinability, are widely used in high-frequency electronic devices, aerospace wires, and high-reliability electrical connection components. For example, in the signal transmission system of 5G communication base stations, wire materials must simultaneously meet the requirements of low resistance loss and high mechanical strength; while in aerospace equipment, electrical connection components require good and stable conductivity.

[0003] However, traditional copper-silver alloys are mostly homogeneous or simple layered composite structures, making it difficult to meet the diverse performance requirements under complex working conditions. On the one hand, homogeneous copper-silver alloys suffer from the problem of balancing conductivity and strength: while increasing the silver content can enhance conductivity, it reduces the tensile strength and processing plasticity of the material. On the other hand, simple layered composite materials, due to abrupt changes in composition between layers, are prone to stress concentration at the interface. Under thermal cycling or mechanical vibration, defects such as cracks and delamination are likely to occur at the interface, seriously affecting the reliability and service life of the material.

[0004] Existing preparation processes, such as traditional powder metallurgy, electrodeposition, and hot rolling composite technology, also have significant limitations. Traditional powder metallurgy-prepared copper-silver alloys require high-temperature and high-pressure treatment to achieve densification due to weak interparticle bonding; however, high temperatures can lead to uneven silver diffusion, disrupting the gradient structure. While electrodeposition allows for precise composition control, its low production efficiency and high cost make it difficult to meet the demands of large-scale industrial production. Hot rolling composite technology is limited by material deformation and interfacial diffusion, making it difficult to form a continuous and stable composition gradient. Therefore, developing a copper-silver alloy composite material and its preparation method that combines excellent conductivity, high strength, good interfacial bonding performance, and suitability for industrial production has become a pressing technical challenge in the field of metal matrix composites. Summary of the Invention

[0005] The technical problem to be solved by this invention is how to improve the electrical conductivity, mechanical strength and interfacial bonding strength of copper-silver alloy composite materials.

[0006] The present invention solves the above-mentioned technical problems through the following technical means:

[0007] The first aspect of this invention provides a method for preparing a layered gradient copper-silver alloy composite material, comprising the following steps: S1 mixes silver powder and copper powder in different mass ratios to prepare AgCu alloy powder; then the silver powder, AgCu alloy powder and copper powder are sequentially loaded into a mold to obtain layered powder, which includes a silver powder layer, an AgCu alloy powder layer and a copper powder layer, wherein the mass of silver powder in the AgCu alloy powder layer decreases in the direction away from the silver powder layer. S2 uses a cold isostatic pressing process to form a green body from layered powder. The pressure of the cold isostatic pressing is 60MPa~80MPa, and the time of the cold isostatic pressing is 5min~10min. S3 involves pressurizing and sintering the green billet under inert gas to obtain a sintered billet. The pressurization and sintering temperature is 800℃~1000℃, the pressurization and sintering pressure is 40MPa~80MPa, and the pressure of the inert gas is 0.1MPa~0.3MPa. S4 obtains a layered gradient copper-silver alloy composite material by hot isostatic pressing of sintered billets. The hot isostatic pressing temperature is 850℃~950℃ and the hot isostatic pressing pressure is 100MPa~150MPa.

[0008] Beneficial effects: This invention, through a gradient distribution design of silver powder content decreasing from the inside out, ensures high conductivity in the inner layer while enhancing the overall strength of the layered gradient copper-silver alloy composite material with copper powder in the outer layer. This overcomes the technical bottleneck of traditional copper-silver alloys where conductivity and mechanical strength are difficult to balance. The layered powder, through the gradient transition of AgCu alloy powder, effectively suppresses the difference in thermal expansion coefficient and stress concentration at the interface caused by abrupt changes in composition, significantly improving the stability and reliability of the layered gradient copper-silver alloy composite material under complex working conditions such as thermal cycling and mechanical vibration. Subsequently, precise matching with various processes achieves synergistic improvement in conductivity and mechanical properties, while also increasing interfacial bonding strength.

[0009] Preferably, the purity of both silver powder and copper powder is ≥99.9%.

[0010] Preferably, the particle size of both silver powder and copper powder is 10μm~45μm.

[0011] Preferably, the mixing method is mechanical mixing or ball milling mixing.

[0012] Preferably, the mass ratio of silver powder to copper powder is 17~16:3~4, 6~5:5~4, or 3~2:8~7.

[0013] Preferably, the silver powder layer accounts for 20% to 25% of the layered powder.

[0014] Preferably, the pressure sintering time is 1h to 3h.

[0015] Preferably, the hot isostatic pressing time is 1h to 2h.

[0016] The second aspect of the present invention provides a method for preparing the above-mentioned layered gradient copper-silver alloy composite material.

[0017] Beneficial effects: The layered gradient copper-silver alloy composite material of the present invention has high electrical conductivity (≥95% IACS), excellent tensile strength (≥405MPa) and good coefficient of thermal expansion (≤18×10). -6 ( / K), which significantly reduces the risk of cracking caused by interfacial thermal stress, and is particularly suitable for high-frequency electronic devices, aerospace wires and electrical connection components.

[0018] The third aspect of the present invention provides a method for preparing the above-mentioned layered gradient copper-silver alloy composite material, and its application in high-frequency electronic devices, aerospace wires, or electrical connection components. Attached Figure Description

[0019] Figure 1 These are cross-sectional views of the layered powders obtained in Examples 1-4 of this invention; Figure 2 These are performance diagrams of the layered gradient copper-silver alloy composite materials prepared in Examples 1-3 of this invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Unless otherwise specified, all test materials and reagents used in the following examples are commercially available.

[0022] Unless otherwise specified in the embodiments, the techniques or conditions described in the literature in this field or in accordance with the product manual may be followed.

[0023] Example 1 This embodiment provides a method for preparing a layered gradient copper-silver alloy composite material, specifically including the following steps: S1 Raw Material Preparation: Silver powder and copper powder with a purity of 99.9% and a particle size of 20μm~35μm are selected. Silver powder and copper powder are mechanically mixed at a mass ratio of 4:1 to obtain Ag4Cu1 alloy powder, silver powder and copper powder are mechanically mixed at a mass ratio of 1:1 to obtain AgCu alloy powder, and silver powder and copper powder are mechanically mixed at a mass ratio of 1:4 to obtain Ag1Cu4 alloy powder.

[0024] S2 Layered Filling: Silver powder, Ag4Cu1 alloy powder, AgCu alloy powder, Ag1Cu4 alloy powder, and copper powder are sequentially filled into a mold to obtain layered powder. The cross-section of the layered powder is shown below. Figure 1 As shown, the layered powder consists of, from the inside out, a silver powder layer, an Ag4Cu1 alloy powder layer, an AgCu alloy powder layer, an Ag1Cu4 alloy powder layer, and a copper powder layer. The layered powder is formed with the silver powder content decreasing from the inside out, and the silver powder layer accounts for 20% of the layered powder. Figure 1 In the process, the radius R of the layered powder is 5 mm, and the ratio of the radius R1 of the silver powder layer, the thickness R2 of the Ag4Cu1 alloy powder layer, the thickness R3 of the AgCu alloy powder layer, the thickness R4 of the Ag1Cu4 alloy powder layer, and the thickness R5 of the copper powder layer is 20:5:10:15:50.

[0025] S3 Cold Isostatic Pressing: Layered powder is formed into a green compact using a cold isostatic pressing process. Specifically, the compact is pressed at 70 MPa for 8 minutes, achieving a density of over 95% and a density of 8.4 g / cm³. 3 .

[0026] S4 pressure sintering: The green blank is placed in an argon protective atmosphere (argon pressure is 0.2MPa) and pressure sintered at 950°C and 60MPa for 2 hours. Through the action of high temperature and high pressure, a strong metallurgical bond is formed between the powder particles, which further densifies the powder and thus obtains the sintered blank.

[0027] S5 Hot Isostatic Pressing Treatment: The sintered billet is subjected to hot isostatic pressing treatment at 900°C and 120MPa pressure, and held for 1.5h to finally obtain a layered gradient copper-silver alloy composite material.

[0028] Example 2 This embodiment provides a method for preparing a layered gradient copper-silver alloy composite material, specifically including the following steps: S1 Raw Material Preparation: Silver powder and copper powder with a purity of 99.9% and a particle size of 10μm~25μm are selected. Silver powder and copper powder are ball-milled and mixed at a mass ratio of 4:1 to obtain Ag4Cu1 alloy powder. Silver powder and copper powder are ball-milled and mixed at a mass ratio of 1:1 to obtain AgCu alloy powder. Silver powder and copper powder are ball-milled and mixed at a mass ratio of 1:4 to obtain Ag1Cu4 alloy powder.

[0029] S2 Layered Filling: Silver powder, Ag4Cu1 alloy powder, AgCu alloy powder, Ag1Cu4 alloy powder, and copper powder are sequentially filled into a mold to obtain layered powder. The cross-section of the layered powder is shown below. Figure 1As shown, the layered powder consists of, from the inside out, a silver powder layer, an Ag4Cu1 alloy powder layer, an AgCu alloy powder layer, an Ag1Cu4 alloy powder layer, and a copper powder layer. The layered powder is formed with the silver powder content decreasing from the inside out, and the silver powder layer accounts for 20% of the layered powder. Figure 1 In the process, the radius R of the layered powder is 7.5 mm, and the ratio of the radius R1 of the silver powder layer, the thickness R2 of the Ag4Cu1 alloy powder layer, the thickness R3 of the AgCu alloy powder layer, the thickness R4 of the Ag1Cu4 alloy powder layer, and the thickness R5 of the copper powder layer is 20:5:10:15:50.

[0030] S3 Cold Isostatic Pressing: Layered powder is formed into a green compact using a cold isostatic pressing process. Specifically, the compact is pressed at 65 MPa for 6 minutes, achieving a density of over 95% and a density of 8.3 g / cm³. 3 .

[0031] S4 pressure sintering: The green blank is placed in an argon protective atmosphere (argon pressure is 0.1MPa) and pressure sintered at 900°C and 50MPa for 1.5h. Through the action of high temperature and high pressure, a strong metallurgical bond is formed between the powder particles, which further densifies the powder and obtains the sintered blank.

[0032] S5 Hot Isostatic Pressing Treatment: The sintered billet is subjected to hot isostatic pressing treatment at 850°C and 110MPa pressure, and held for 1 hour to finally obtain a layered gradient copper-silver alloy composite material.

[0033] Example 3 This embodiment provides a method for preparing a layered gradient copper-silver alloy composite material, specifically including the following steps: S1 Raw Material Preparation: Silver powder and copper powder with a purity of 99.9% and a particle size of 30μm~45μm are selected. Silver powder and copper powder are mechanically mixed at a mass ratio of 4:1 to obtain Ag4Cu1 alloy powder, silver powder and copper powder are mechanically mixed at a mass ratio of 1:1 to obtain AgCu alloy powder, and silver powder and copper powder are mechanically mixed at a mass ratio of 1:4 to obtain Ag1Cu4 alloy powder.

[0034] S2 Layered Filling: Silver powder, Ag4Cu1 alloy powder, AgCu alloy powder, Ag1Cu4 alloy powder, and copper powder are sequentially filled into a mold to obtain layered powder. The cross-section of the layered powder is shown below. Figure 1 As shown, the layered powder consists of, from the inside out, a silver powder layer, an Ag4Cu1 alloy powder layer, an AgCu alloy powder layer, an Ag1Cu4 alloy powder layer, and a copper powder layer. The layered powder is formed with the silver powder content decreasing from the inside out, and the silver powder layer accounts for 20% of the layered powder. Figure 1In the process, the radius R of the layered powder is 10 mm, and the ratio of the radius R1 of the silver powder layer, the thickness R2 of the Ag4Cu1 alloy powder layer, the thickness R3 of the AgCu alloy powder layer, the thickness R4 of the Ag1Cu4 alloy powder layer, and the thickness R5 of the copper powder layer is 20:5:10:15:50.

[0035] S3 Cold Isostatic Pressing: Layered powder is formed into a green compact using a cold isostatic pressing process. Specifically, the compact is pressed at 80 MPa for 10 minutes, achieving a density of over 95% and a density of 8.5 g / cm³. 3 .

[0036] S4 pressure sintering: The green blank is placed in an argon protective atmosphere (argon pressure is 0.3MPa) and pressure sintered at 1000°C and 80MPa for 3 hours. Through the action of high temperature and high pressure, a strong metallurgical bond is formed between the powder particles, which further densifies the powder and thus obtains the sintered blank.

[0037] S5 Hot Isostatic Pressing Treatment: The sintered billet is subjected to hot isostatic pressing treatment at 950°C and 150MPa pressure, and held for 2 hours to finally obtain a layered gradient copper-silver alloy composite material.

[0038] according to Figure 2 It can be seen that the tensile strength of the layered gradient copper-silver alloy composite material prepared in Example 1 is 425 MPa and the conductivity is 96.5% IACS; the tensile strength of the layered gradient copper-silver alloy composite material prepared in Example 2 is 410 MPa and the conductivity is 95.8% IACS; and the tensile strength of the layered gradient copper-silver alloy composite material prepared in Example 3 is 440 MPa and the conductivity is 97.2% IACS.

[0039] Example 4 This embodiment provides a method for preparing a layered gradient copper-silver alloy composite material, specifically including the following steps: S1 Raw Material Preparation: Silver powder and copper powder with a purity of 99.95% and a particle size of 15μm~30μm were selected. The silver powder and copper powder were mechanically mixed at a mass ratio of 17:3 to obtain Ag. 17 Cu3 alloy powder, silver powder and copper powder are mechanically mixed at a mass ratio of 3:2 to obtain Ag3Cu2 alloy powder, and silver powder and copper powder are mechanically mixed at a mass ratio of 3:7 to obtain Ag3Cu7 alloy powder.

[0040] S2 Layered Filling: Silver powder, Ag 17 Cu3 alloy powder, Ag3Cu2 alloy powder, Ag3Cu7 alloy powder, and copper powder are sequentially loaded into a mold to obtain layered powder. The cross-section of the layered powder is shown below. Figure 1 As shown, the layered powder consists of a silver powder layer, an Ag layer, and an Ag layer, from the inside out. 17The layered powder consists of Cu3 alloy powder, Ag3Cu2 alloy powder, Ag3Cu7 alloy powder, and copper powder. The silver powder content decreases from the inside out, with the silver powder layer comprising 25% of the layered powder. Figure 1 In the middle, the radius R of the layered powder is 4 mm, and the radius R1 of the silver powder layer is Ag. 17 The ratio of the thicknesses of the Cu3 alloy powder layer (R2), Ag3Cu2 alloy powder layer (R3), Ag3Cu7 alloy powder layer (R4), and copper powder layer (R5) is 25:8:12:15:40.

[0041] S3 Cold Isostatic Pressing: Layered powder is formed into a green compact using a cold isostatic pressing process. Specifically, the compact is pressed at 75 MPa for 9 minutes, achieving a density of over 96% and a density of 8.45 g / cm³. 3 .

[0042] S4 pressure sintering: The green blank is placed in an argon protective atmosphere (argon pressure is 0.25MPa) and pressure sintered at 920°C and 55MPa for 2.5h. Through the action of high temperature and high pressure, a strong metallurgical bond is formed between the powder particles, which further realizes densification and thus obtains the sintered blank.

[0043] S5 Hot Isostatic Pressing Treatment: The sintered billet was subjected to hot isostatic pressing treatment at 880°C and 130MPa pressure, and held for 1.8h to finally obtain a layered gradient copper-silver alloy composite material.

[0044] Comparative Example 1 This comparative example provides a method for preparing a layered gradient copper-silver alloy composite material. The difference between this comparative example and Example 1 is that in S2, silver powder, Ag4Cu1 alloy powder, AgCu alloy powder, Ag1Cu4 alloy powder and copper powder are loaded into a mold to form layered powder. The layered powder is not formed in a manner where the mass content of silver powder decreases from the inside to the outside. The layered powder is formed from the inside to the outside in the following order: Ag4Cu1 alloy powder layer, silver powder layer, AgCu alloy powder layer, copper powder layer, and Ag1Cu4 alloy powder layer. Everything else is the same as in Example 1.

[0045] Comparative Example 2 This comparative example provides a method for preparing a layered gradient copper-silver alloy composite material. The difference between this comparative example and Example 2 is that the S5 hot isostatic pressing treatment was not performed, while all other aspects are the same as in Example 2.

[0046] Comparative Example 3 This comparative example provides a method for preparing a layered gradient copper-silver alloy composite material. The difference between this comparative example and Example 3 is that in S3, the green billet is pressed under 50 MPa pressure for 5 minutes, resulting in a green billet density of over 90% and a density of 7.8 g / cm³. 3 Everything else is the same as in Example 3.

[0047] Comparative Example 4 This comparative example provides a method for preparing a layered gradient copper-silver alloy composite material. The difference between this comparative example and Example 1 is that in step S3, 8 min is replaced with 2 min, and the density of the green compact is 7.7 g / cm³. 3 Everything else is the same as in Example 1.

[0048] Comparative Example 5 This comparative example provides a method for preparing a layered gradient copper-silver alloy composite material. The difference between this comparative example and Example 1 is that in S4, 60MPa is replaced with 20MPa, while the rest is the same as in Example 1.

[0049] Comparative Example 6 This comparative example provides a method for preparing a layered gradient copper-silver alloy composite material. The difference between this comparative example and Example 1 is that in S5, 900°C is replaced with 1050°C, while the rest is the same as in Example 1.

[0050] Comparative Example 7 This comparative example provides a method for preparing a layered gradient copper-silver alloy composite material. The difference between this comparative example and Example 1 is that in S3, 70MPa is replaced with 100MPa, while the rest is the same as in Example 1.

[0051] Comparative Example 8 This comparative example provides a method for preparing a layered gradient copper-silver alloy composite material. The difference between this comparative example and Example 1 is that in S4, 950°C is replaced with 700°C, while the rest is the same as in Example 1.

[0052] Comparative Example 9 This comparative example provides a method for preparing a layered gradient copper-silver alloy composite material. The difference between this comparative example and Example 1 is that in S4, 950°C is replaced with 1050°C, while the rest is the same as in Example 1.

[0053] Comparative Example 10 This comparative example provides a method for preparing a layered gradient copper-silver alloy composite material. The difference between this comparative example and Example 1 is that in S4, 60MPa is replaced with 90MPa, while the rest is the same as in Example 1.

[0054] Comparative Example 11 This comparative example provides a method for preparing a layered gradient copper-silver alloy composite material. The difference between this comparative example and Example 1 is that in S5, 900°C is replaced with 800°C, while the rest is the same as in Example 1.

[0055] Comparative Example 12 This comparative example provides a method for preparing a layered gradient copper-silver alloy composite material. The difference between this comparative example and Example 1 is that in S5, 120MPa is replaced with 90MPa, while the rest is the same as in Example 1.

[0056] Comparative Example 13 This comparative example provides a method for preparing a layered gradient copper-silver alloy composite material. The difference between this comparative example and Example 1 is that in S5, 120MPa is replaced with 160MPa, while the rest is the same as in Example 1.

[0057] Comparative Example 14 This comparative example provides a method for preparing a layered gradient copper-silver alloy composite material. The difference between this comparative example and Example 1 is that in S3, the pressure of argon gas is replaced by 0.4 MPa instead of 0.2 MPa, while the rest is the same as in Example 1.

[0058] Comparative Example 15 This comparative example provides a method for preparing a layered gradient copper-silver alloy composite material. The difference between this comparative example and Example 1 is that in S3, pressure sintering is carried out directly in air, while the rest is the same as in Example 1.

[0059] Experimental Example The layered gradient copper-silver alloy composite materials prepared in Examples 1-4 and Comparative Examples 1-15 were subjected to performance tests, the specific items of which are as follows: 1. Porosity testing: Porosity was tested using metallographic microscopy, referring to the GB / T 19587-2017 standard. The specific results are shown in Table 1.

[0060] 2. Tensile strength test: The tensile strength was tested using an electronic universal testing machine, referring to the GB / T 228.1-2010 standard. The specific results are shown in Table 1.

[0061] 3. Test of thermal expansion coefficient: The thermal expansion coefficient was tested using a thermal expansion meter, referring to the GB / T 4339-2008 standard. The specific results are shown in Table 1.

[0062] 4. Conductivity test: The conductivity was tested using an eddy current conductivity meter, with IACS as the evaluation standard. The specific results are shown in Table 1.

[0063] 5. The breakage rate of the layered gradient copper-silver alloy composite materials prepared in Example 1 and Comparative Example 1 was tested. The breakage rate simulated the actual working conditions of high-frequency electronic devices (temperature 25±5℃, relative humidity 45%~65%). The breakage rate was tested within a specified time (500h). The breakage rate of Example 1 was ≤0.5%; the breakage rate of Comparative Example 1 was ≥1.2%.

[0064] 6. The thermal cycling stability of the layered gradient copper-silver alloy composite materials prepared in Example 2 and Comparative Example 2 was tested. The cycling stability was tested using a high and low temperature test chamber (high temperature: 150℃; low temperature: -55℃). The number of stable cycles was recorded in accordance with GB / T 2423.1-2008 standard. The number of cycles in Example 2 was ≥500; the number of cycles in Comparative Example 2 was ≤300.

[0065] 7. The service life of the layered gradient copper-silver alloy composite materials prepared in Example 3 and Comparative Example 3 was tested. The service life simulated the actual service environment of aerospace wires and electrical connection components (temperature -60℃~120℃, humidity 5%~30%). The stable working time was tested. The working time of Example 3 was ≥1000 hours; the working time of Comparative Example 3 was ≤500 hours.

[0066] Table 1 Performance Test Results

[0067] As shown in Table 1, the layered gradient copper-silver alloy composite materials prepared in Examples 1-4 exhibit excellent comprehensive performance and can be applied to high-frequency electronic devices, aerospace wires, and electrical connection components. In contrast, the layered gradient copper-silver alloy composite materials prepared in Comparative Examples 1-15 all show a significant decrease in performance. The core reasons for the difference between the two are as follows: The layered gradient copper-silver alloy composite materials prepared in Examples 1-4 exhibit excellent performance due to the precise matching of the gradient silver powder mass content layered setting with various process parameters. The cold isostatic pressing process lays a dense foundation for atomic diffusion. The pressure sintering under inert gas protection at 0.1MPa~0.3MPa effectively inhibits oxidation and promotes the full diffusion of silver and copper atoms to form a strong metallurgical bond. Hot isostatic pressing further eliminates porosity and optimizes interlayer bonding. The transition layer with the gradient silver powder mass content can reduce interfacial stress, ultimately achieving a synergistic improvement in conductivity and mechanical properties.

[0068] The poor overall performance of the layered gradient copper-silver alloy composites prepared in Comparative Examples 1-15 is essentially due to abnormalities in key reaction processes such as atomic diffusion and metallurgical bonding. This is caused by the failure to set a gradient in the mass content of silver powder, the absence of key processes, deviation of process parameters from reasonable ranges, or abnormal inert gas protection, resulting in problems such as disordered atomic diffusion, insufficient metallurgical bonding, residual pores, or oxide inclusions, which in turn affect the overall performance of the layered gradient copper-silver alloy composites.

[0069] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention 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 of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a layered gradient copper-silver alloy composite material, characterized in that, Includes the following steps: S1 mixes silver powder and copper powder in different mass ratios to prepare AgCu alloy powder; then the silver powder, AgCu alloy powder and copper powder are sequentially loaded into a mold to obtain layered powder, which includes a silver powder layer, an AgCu alloy powder layer and a copper powder layer, wherein the mass of silver powder in the AgCu alloy powder layer decreases in the direction away from the silver powder layer. S2 uses a cold isostatic pressing process to form a green body from layered powder. The pressure of the cold isostatic pressing is 60MPa~80MPa, and the time of the cold isostatic pressing is 5min~10min. S3 involves pressurizing and sintering the green billet under inert gas to obtain a sintered billet. The pressurization and sintering temperature is 800℃~1000℃, the pressurization and sintering pressure is 40MPa~80MPa, and the pressure of the inert gas is 0.1MPa~0.3MPa. S4 obtains a layered gradient copper-silver alloy composite material by hot isostatic pressing of sintered billets. The hot isostatic pressing temperature is 850℃~950℃ and the hot isostatic pressing pressure is 100MPa~150MPa.

2. The method for preparing the layered gradient copper-silver alloy composite material according to claim 1, characterized in that, The purity of both silver powder and copper powder is ≥99.9%.

3. The method for preparing the layered gradient copper-silver alloy composite material according to claim 1, characterized in that, The particle size of both silver and copper powder is 10μm~45μm.

4. The method for preparing the layered gradient copper-silver alloy composite material according to claim 1, characterized in that, The mixing method is mechanical mixing or ball milling mixing.

5. The method for preparing the layered gradient copper-silver alloy composite material according to claim 1, characterized in that, Three types of AgCu alloy powder with different silver powder mass contents were prepared by mixing silver powder and copper powder. The mass ratios of silver powder to copper powder in the three AgCu alloy powders were 17~16:3~4, 6~5:5~4, and 3~2:8~7, respectively.

6. The method for preparing the layered gradient copper-silver alloy composite material according to claim 1, characterized in that, The silver powder layer accounts for 20% to 25% of the layered powder.

7. The method for preparing the layered gradient copper-silver alloy composite material according to claim 1, characterized in that, The pressure sintering time is 1h to 3h.

8. The method for preparing the layered gradient copper-silver alloy composite material according to claim 1, characterized in that, The hot isostatic pressing time is 1 to 2 hours.

9. A method for preparing a layered gradient copper-silver alloy composite material according to any one of claims 1-8.

10. The application of a method for preparing a layered gradient copper-silver alloy composite material as described in any one of claims 1-8 in high-frequency electronic devices, aerospace wires, or electrical connection components.

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