Preparation method of Al2O3 dispersion strengthened copper composite material ingot blank

Abstract

The invention relates to the technical field of metal composite material preparation, in particular to a preparation method of an Al2O3 dispersion strengthened copper composite material ingot blank, which comprises the following specific steps: S1, preparing gas atomized Cu powder; s2, oxygen distribution; s3, carrying out internal oxidation to obtain Cu / gamma-Al2O3 dispersed copper powder; s4, carrying out CIP processing; s5, reduction is conducted, specifically, the ingot blank is placed in high-purity hydrogen to be reduced; and S6, hot pressed sintering. The high-purity oxygen-free electrolytic copper and the copper-aluminum intermediate alloy are smelted, oxygen is added to obtain oxygen-added powder, then the oxygen-added powder is subjected to internal oxidation to obtain Cu / gamma-Al2O3 powder, the fluidity and the filling property are good, the density and the structural uniformity of a green body are improved, meanwhile, treatment is conducted under the high CIP pressure, the density of the green body is further improved, and after hot pressing sintering, the quality of the green body is improved. And the process is simple, and the cost is low.

Description

Technical Field

[0001] The present invention relates to the technical field of metal composite material preparation, and in particular to an Al 2 O 3 A method for preparing a dispersion-strengthened copper composite material ingot. Background Art

[0002] Dispersion strengthening is a method of strengthening materials by adding uniform, fine oxide particles into the metal matrix to pin dislocations, grain boundaries, and subgrain boundaries, hindering the movement of dislocations. 2 O 3 Dispersion-strengthened copper is a type of copper that is uniformly dispersed and contains fine Al 2 O 3 Particles have high strength and high softening temperature, while maintaining their excellent electrical and thermal conductivity.

[0003] Dispersion-strengthened copper alloys are considered to be new functional materials with great development potential and application prospects due to their excellent high-temperature resistance, high strength and high conductivity. They have been widely used in many high-tech fields such as high-power microwave tubes, ultra-large-scale integrated circuit lead frames, overhead and wire high-pulse magnetic field conductors for high-speed rail transit, continuous casting machine crystallizers and resistance welding electrodes.

[0004] Al 2 O 3 There are many methods for preparing dispersed copper composite materials, including mechanical alloying, powder metallurgy, composite electrodeposition, vacuum mixed casting, co-precipitation, reactive spray deposition, sol-gel and internal oxidation. These methods are suitable for preparing small-sized dispersed copper materials. With the continuous expansion of the application scope of dispersed copper materials, the original small-sized bars cannot meet the market demand, and the preparation method of large-sized dispersed copper materials has not been reported.

[0005] Publication No.: CN108057732B A method for preparing a dispersion-strengthened copper and oxygen-free copper composite rod, using powder metallurgy and pressure processing technology to 2 O 3 Nano-dispersion-strengthened copper and oxygen-free copper are compounded to prepare Cu-Al 2 O 3 Nano-dispersion strengthened copper and oxygen-free copper composite rods. However, this solution forms a composite structure through powder metallurgy combined with extrusion to generate a rod with dispersed copper inside and oxygen-free copper outside. It uses cold isostatic pressing + extrusion + finishing, peeling + composite copper ingot preparation + secondary extrusion + stretching, and the process is complicated. In addition, the atmospheric smelting method will mix in charcoal, P and other inclusions, affecting the purity of the material and reducing the mechanical properties of the material. It also requires oxygen source preparation and powder mixing, which is complicated and has the phenomenon of uneven powder mixing.

[0006] Therefore, it is urgent to design new Al 2 O 3 The preparation method of dispersion-strengthened copper composite ingot solves the problem that the existing technology is difficult to prepare large-scale high-performance Al 2 O 3 Problems with dispersion-strengthened copper composites. Summary of the invention

[0007] In view of this, the present invention aims to provide an Al 2 O 3 The preparation method of dispersion-strengthened copper composite ingot solves the problem that the existing technology is difficult to prepare large-scale high-performance Al 2 O 3 Problems with dispersion-strengthened copper composites.

[0008] In order to solve the above problems, the present invention adopts CPI processing + reduction + hot pressing sintering in three steps to achieve high density and high performance of the material, and the oxygen distribution is uniform, with only one process, simple process and low cost. By introducing high-purity nitrogen atomization to prepare CuAl alloy powder, and combining a series of steps such as oxygen distribution, internal oxidation, cold isostatic pressing (CIP) processing, an integrated and efficient production process from raw materials to finished products is realized, the process is simplified, and the quality and consistency of the product are improved. By controlling the temperature of 400-500℃ during the internal oxidation and reduction process, Al 2 O 3 The abnormal growth of particles makes the dispersed phase particles small and evenly distributed, ensuring the high strength and good electrical conductivity of the material. After testing, the relative density of the ingots prepared by this method exceeds 98%, the tensile strength is 500-650MPa, the yield strength is 450-600MPa, the hardness (HRB) is 80.0-83.9, and the electrical conductivity is 79-82%IACS. At the same time, the processing method at this temperature is significantly better than the traditional method, which often requires higher temperature treatment and may cause the particle size to increase or uneven distribution. Due to the generated Cu / γ-Al 2 O 3 The powder has good fluidity and the pressing process under higher pressure can produce large-sized ingots such as Ф400mm, which can meet the market demand for large-sized high-performance dispersed copper materials.

[0009] The technical solution of the present invention is achieved in this way:

[0010] The invention discloses an Al 2 O 3 The method for preparing a dispersion-strengthened copper composite material ingot comprises the following specific steps:

[0011] S1: Preparation of gas atomized CuAl powder, using a vacuum medium frequency melting furnace for melting, adding high-purity oxygen-free electrolytic copper and copper-aluminum master alloy into the vacuum medium frequency furnace for melting, and then using high-purity nitrogen for atomization and powdering, drying and sieving the CuAl powder for standby use;

[0012] S2: oxygen matching, putting the copper and aluminum powders into an oxygen matching furnace, heating them to a set temperature for oxygen matching, and obtaining oxygen matching powder;

[0013] S3: Internal oxidation to obtain Cu / γ-Al 2 O 3 Dispersed copper powder;

[0014] S4: CIP processing, Cu / γ-Al 2 O 3 The powder is placed in an isostatic pressing bag to form a denser ingot;

[0015] S5: reduction, placing the ingot in high-purity hydrogen for reduction;

[0016] S6: hot pressing and sintering.

[0017] Furthermore, in step S1, high-purity nitrogen gas with a pressure of 0.1-1.2 MPa is used for atomization and powdering, and 400-mesh CuAl powder is dried and sieved for standby use.

[0018] Further, in step S1, high-purity oxygen-free electrolytic copper and copper-aluminum master alloy are smelted in a vacuum medium frequency furnace at 10 -3 50 to 90 minutes under Pa conditions.

[0019] Furthermore, in step S2, the temperature in the oxygen distribution furnace is heated to 180-200°C for oxygen distribution.

[0020] Further, in step S3, the oxygen-matched powder is placed in a vacuum sintering furnace with a vacuum degree of ≤10 -3 Pa conditions for internal oxidation, the heating temperature is 400℃~500℃, and the holding time is 5~10h.

[0021] Furthermore, in step S4, the CIP pressing process is as follows: the pressure increasing speed is 1 to 5 MPa / minute, the maximum pressure is 350 to 450 MPa, and the pressure holding time is 10 to 15 minutes.

[0022] Furthermore, in step S5, the reduction temperature is 400-500° C., and the reduction time is 2-6 hours.

[0023] Furthermore, in step S6, the pressure in the hot pressing sintering furnace is controlled at 30-60 MPa, the hot pressing temperature is 700-1000° C., and the sintering time is 1-10 h.

[0024] Furthermore, in step S6, the diameter of the dispersed copper material is obtained to be no greater than 400 mm.

[0025] Compared with the prior art, an Al 2 O 3 The preparation method of dispersion strengthened copper composite ingot has the following advantages:

[0026] 1. The present invention obtains Cu / γ-Al by smelting high-purity oxygen-free electrolytic copper and copper-aluminum master alloy and performing oxygen matching and internal oxidation processes. 2 O 3 Powder, then internally oxidized to obtain Cu / γ-Al 2 O 3 The powder has good fluidity and filling properties, which is beneficial to improving the green body density and its structural uniformity. At the same time, processing under higher CIP pressure further improves the green body density. Finally, through the hot pressing and sintering process, the ingot reaches a higher density level, with a relative density of more than 98%, a tensile strength of 500-650MPa, a yield strength of 450-600MPa, a hardness (HRB) of 80.0-83.9, and a conductivity of 79-82%IACS.

[0027] 2. In the present invention, the ingot is oxidized at a temperature of 400-500°C under vacuum and reduced in high-purity hydrogen within the same temperature range, which effectively prevents the dispersed phase Al 2 O 3 The abnormal growth of particles ensures that the particle size is small and evenly distributed, making the dispersed phase Al 2 O 3 The average distance between particles is less than 50nm, and the size is all below 10nm, which improves the overall strength of the material and maintains excellent conductive properties.

[0028] 3. The process flow adopted by the present invention is simple and efficient, including the steps of gas atomization powder making, oxygen addition, internal oxidation, cold isostatic pressing, reduction and hot pressing sintering, etc. It is easy to operate, reduces production costs, and ensures the high quality and consistency of the materials.

[0029] 4. The present invention generates Cu / γ-Al 2 O 3 The good powder fluidity and the pressing process under higher pressure make it possible to produce large-sized ingots such as Ф400mm, which can meet the market demand for large-sized high-performance dispersed copper materials and is suitable for the preparation of large-sized dispersed copper materials. DETAILED DESCRIPTION

[0030] In order to make the technical means, objectives and effects of the present invention easy to understand, the embodiments of the present invention are described in detail below.

[0031] It should be noted that all the terms used in the present invention to indicate directionality and positionality, such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "inside", "outside", "top", "lower", "lateral", "longitudinal", "center", etc., are only used to explain the relative positional relationship and connection status between the components in a certain state, and are only for the convenience of describing the present invention, rather than requiring the present invention to be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features.

[0032] In the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0034] CIP processing refers to cold isostatic pressing (CIP). This is a molding technology that applies uniform pressure to material powder through a liquid medium at room temperature or near room temperature. Cold isostatic pressing is mainly used to manufacture ceramic, metal and composite parts with high density and good mechanical properties.

[0035] Oxygen addition is a step in the material preparation process. Its main purpose is to introduce an appropriate amount of oxygen into the material so that the required oxide can be formed during subsequent processing. 2 O 3 In the preparation of dispersed copper composite materials, oxygen addition mainly refers to heating the copper-aluminum alloy powder to a specific temperature to partially oxidize the aluminum therein to generate a certain amount of aluminum oxide or provide sufficient oxygen source for subsequent internal oxidation.

[0036] Internal oxidation is a special oxidation process that is mainly used to generate fine and evenly distributed oxide particles in the metal matrix. 2 O 3 For dispersed copper composite materials, internal oxidation is to further heat the copper-aluminum alloy powder that has been treated with oxygen in a vacuum environment, so that the aluminum atoms react with the pre-adsorbed or introduced oxygen to form nano-scale Al 2 O 3 Particles.

[0037] The invention discloses an Al 2 O 3 The method for preparing a dispersion-strengthened copper composite material ingot comprises the following specific steps:

[0038] S1: Preparation of gas atomized Cu powder, using a vacuum medium frequency melting furnace for melting, adding high-purity oxygen-free electrolytic copper and copper-aluminum master alloy into the vacuum medium frequency furnace for melting, and then using high-purity nitrogen for atomization and powdering, drying and sieving the CuAl powder for standby use;

[0039] By smelting high-purity oxygen-free electrolytic copper and copper-aluminum master alloy and using high-purity nitrogen for atomization powder making to obtain CuAl powder, a powder with high purity and narrow particle size distribution can be obtained, which helps to improve the performance of the final product and provides a basis for the subsequent formation of uniformly distributed Al 2 O 3 The particles provide the foundation.

[0040] S2: oxygen matching, putting the copper and aluminum powders into an oxygen matching furnace, heating them to a set temperature for oxygen matching, and obtaining oxygen matching powder;

[0041] Heating the CuAl powder at a specific temperature promotes the oxidation reaction, thus preparing for the subsequent internal oxidation process. By controlling the degree of oxidation, the content of oxides in the final product can be precisely adjusted, thereby affecting the mechanical properties and thermal stability of the material.

[0042] S3: Internal oxidation to obtain Cu / γ-Al 2 O 3 Dispersed copper powder;

[0043] The oxygen-doped powder is further processed under vacuum conditions to combine aluminum atoms with oxygen to form nanoscale Al 2 O 3 The particles are evenly dispersed in the copper matrix, which can achieve effective dispersion of nano-scale oxide particles without damaging the copper matrix, thereby significantly improving the strength, hardness and wear resistance of the material.

[0044] S4: CIP processing, Cu / γ-Al 2 O 3The powder is placed in an isostatic pressing bag to form a denser ingot;

[0045] Cu / γ-Al 2 O 3 The powder is compressed into a dense ingot. By applying high pressure, the powder particles are in close contact, the porosity is reduced, and parts with complex shapes and high density can be manufactured. At the same time, the directional problems that may occur in the traditional pressing process are avoided, ensuring the consistency and reliability of the material.

[0046] S5: reduction, placing the ingot in high-purity hydrogen for reduction;

[0047] The CIP-treated ingots are subjected to a reduction treatment in a hydrogen atmosphere to remove any possible oxide impurities, effectively reducing the oxygen content, improving the conductivity and mechanical properties of the material, and ensuring the purity and quality of the final product.

[0048] S6: hot pressing sintering;

[0049] The ingot is sintered under high temperature and high pressure conditions to further increase the density of the material, improve its microstructure, and enhance the mechanical properties. By optimizing the sintering parameters, the ideal grain size and phase composition can be obtained, thus giving the material excellent comprehensive properties, such as high strength, good conductivity and heat resistance, and obtaining a large-sized product with a diameter of 400mm and a length of no more than 450mm, meeting the market demand for large-sized products.

[0050] This setup not only produces Al with excellent properties 2 O 3 Dispersion-strengthened copper composite materials can ensure the consistency and stability of product quality through fine control of each step, and are suitable for high-end application fields such as electronic packaging, aerospace, etc.

[0051] Specifically, in step S1, high-purity nitrogen gas with a pressure of 0.1-1.2 MPa is used for atomization and powdering, and 400-mesh CuAl powder is dried and sieved for standby use.

[0052] Using high-purity nitrogen as the atomizing medium can avoid the introduction of impurities and ensure that the generated CuAl alloy powder has a high purity. By adjusting the nitrogen pressure (0.1~1.2Mpa), the degree of droplet breakage during the atomization process can be effectively controlled to obtain a powder with a relatively uniform particle size distribution. The 400-mesh CuAl powder obtained after screening has good fluidity and filling properties, which can ensure uniform powder filling during the pressing process, and is conducive to achieving more uniform internal oxidation and reduction reactions in the subsequent heat treatment process, thereby generating a finer and more uniform dispersed phase Al 2 O 3 particle.

[0053] This setting can increase the density of the green body and its structural uniformity, significantly improve the strength and high temperature resistance of the final product, and simplify the impurity removal steps in the preparation process, reducing production costs while improving production efficiency.

[0054] Specifically, in step S1, high-purity oxygen-free electrolytic copper and copper-aluminum master alloy are smelted in a vacuum medium frequency furnace for 50 to 90 minutes.

[0055] By heating, high-purity oxygen-free electrolytic copper and copper-aluminum master alloy are fully melted and mixed to ensure that the final alloy composition is uniform. Appropriate smelting time ensures that all added elements are completely dissolved in the copper matrix, and helps to reduce or eliminate possible microscopic inhomogeneities or local enrichment phenomena, thereby improving the overall quality and performance of the material.

[0056] The long melting time of this setting helps to achieve the best mixing state of raw materials, effectively control the chemical composition and remove impurities, and better control the microstructure of the product, such as grain size, phase distribution, etc., to meet different application requirements.

[0057] Specifically, in step S2, the temperature in the oxygen distribution furnace is heated to 180-200° C. for oxygen distribution.

[0058] In a specific temperature range (180~200℃), heating can accelerate the reaction between aluminum and oxygen in copper-aluminum powder to generate Al 2 O 3 , to prepare for the subsequent internal oxidation process and ensure that there is enough oxygen source to form a dispersed Al 2 O 3 By precisely controlling the temperature and time, the degree of oxidation reaction can be adjusted to avoid excessive oxidation that may lead to a decrease in material properties or the generation of unnecessary by-products. Proper pre-oxidation helps achieve a more uniform Al 2 O 3 particle distribution, thereby improving the overall performance of the composite material.

[0059] This setting helps to significantly improve the hardness, wear resistance and heat resistance of the material, and can effectively improve the mechanical properties of the material, such as increasing strength and hardness, while maintaining good conductivity and toughness, and helps to reduce internal defects of the material caused by incomplete oxidation or excessive oxidation.

[0060] Specifically, in step S3, the oxygen-containing powder is placed in a vacuum sintering furnace and heated under vacuum for internal oxidation.

[0061] Heating in a vacuum environment ensures that the previously adsorbed or introduced oxygen reacts with the aluminum in the copper-aluminum powder to generate fine and evenly distributed Al2 O 3 Particles. Since it is carried out under vacuum conditions, it helps to avoid the introduction of external impurities and ensure the purity of the reaction environment. By controlling the temperature and time, the oxidation reaction can be carried out more gently and evenly, thereby preventing Al 2 O 3 Excessive particle growth or aggregation. Internal oxidation under vacuum conditions helps to reduce the porosity inside the material and increase the density, thereby further enhancing the overall performance of the material.

[0062] This setting effectively enhances the hardness and wear resistance of the copper matrix without significantly reducing its electrical conductivity. 2 O 3 The particles can provide excellent thermal stability at high temperatures, allowing the material to maintain good mechanical properties even in high temperature environments.

[0063] Specifically, in step S3, the vacuum degree is ≤10 -3 Pa conditions for internal oxidation, the heating temperature is 400℃~500℃, and the holding time is 5~10h.

[0064] Processing under high vacuum conditions can effectively remove oxygen and other impurity gases in the air, avoiding contamination or oxidation of CuAl alloy powder by these impurities, thus ensuring the generated Al 2 O 3 To ensure the purity and uniformity of the dispersed phase, the heating temperature is selected in the range of 400℃~500℃. This temperature range can ensure that the aluminum element in the CuAl alloy is fully converted into Al 2 O 3 The dispersed phase does not cause abnormal growth or aggregation of particles, keeping the particle size small and uniform. Lower pressure is conducive to reducing the oxidation reaction rate and can achieve effective internal oxidation without causing overoxidation. The holding time is set to 5~10 hours, which is long enough for the internal oxidation reaction to proceed fully and ensure that all CuAl alloy particles are uniformly distributed with Al 2 O 3 Diffuse phase.

[0065] The holding time of this setting is set to 5~10 hours, which is long enough for the internal oxidation reaction to proceed fully and ensure that all CuAl alloy particles are evenly distributed with Al 2 O 3 Dispersed phase, prevent Al 2 O 3 The particles grow abnormally at high temperatures, ensuring that the particle size is within the ideal range, improving the mechanical properties of the material and maintaining good electrical conductivity.

[0066] Specifically, in step S4, the CIP pressing process is: pressure increasing speed: 1-5 MPa / min, maximum pressure 350-450 MPa, and pressure holding time 10-15 minutes.

[0067] A pressurization rate of 1 to 5 MPa / min is important to ensure proper contact and densification between powder particles. An appropriate pressurization rate can avoid internal stress concentration or particle rupture caused by too rapid pressure increase.

[0068] The high pressure of 350-450 MPa is the core of the CIP process, which promotes the plastic deformation of powder particles, reduces the gaps between particles, and thus improves the density and uniformity of the material. This pressure range is sufficient to form a dense ingot from the powder, but not too high to cause unnecessary equipment wear or other problems.

[0069] Maintaining high pressure for 10-15 minutes helps to further compact the material, ensuring that all areas reach the desired density level. This step helps to eliminate any micro-porosity that may exist and enhances the mechanical strength and consistency of the final product.

[0070] This setting can obtain ingots with high density and uniform distribution by precisely controlling the pressure increase speed, maximum pressure and holding time. It can effectively reduce porosity and other defects in the finished product, such as cracks or delamination, thereby improving the overall quality and reliability of the material.

[0071] Specifically, in step S5, the ingot is placed in high-purity hydrogen at 400-500°C for reduction for 2-6 hours.

[0072] During the previous processing, some oxides may be formed on the surface or inside the material, such as copper oxide CuO or cuprous oxide Cu 2 O, these oxides will affect the conductivity and mechanical properties of the material. Through high-temperature reduction treatment in a hydrogen atmosphere, these oxides can be converted into metallic copper and water vapor, thereby being removed. In addition to removing oxides, hydrogen reduction can also help remove other possible impurities, further purify the material, ensure its purity, and help adjust the material's microstructure, such as grain size, phase distribution, etc.

[0073] This setting significantly improves the conductivity of the material by removing the oxide layer and other impurities. The purified material has better mechanical strength and toughness, and reduces the risk of brittle fracture due to the presence of impurities. After reduction treatment, the material is more suitable for subsequent hot pressing sintering or other forming processes because the material is purer and the structure is more stable. By adjusting the temperature to 400-500℃ and the time to 2-6 hours, the degree of reduction can be precisely controlled according to the specific alloy composition and the requirements of the target product to avoid over-reduction or under-reduction.

[0074] Specifically, in step S6, the treated ingot is placed in a hot pressing sintering furnace and sintered at 30-60 MPa and 700-1000°C for 1-10 hours.

[0075] The pressure applied during hot pressing sintering helps to overcome the contact resistance between particles and promotes the diffusion and rearrangement between particles, thereby significantly improving the density of the material and reducing the porosity. By controlling the sintering temperature and time, the grain growth, phase distribution and second phase (such as Al 2 O 3 The dispersion of metal particles can be checked to ensure that they are evenly distributed in the matrix. Appropriate temperature conditions can promote the diffusion between metal atoms, further improve the alloy structure, and enhance the consistency and stability of the material.

[0076] By precisely controlling the pressure and temperature parameters, this setting can obtain a material with a density close to the theoretical density, significantly improving its tensile strength, hardness and wear resistance, reducing the presence of pores and impurities, and significantly improving the electrical and thermal conductivity of the material.

[0077] Cu-0.6%Al 2 O 3 As an example, the dispersed copper ingot obtained was tested. The average distance between dispersed phase Al2O3 particles was less than 50nm, and the dispersion distribution was uniform. 2 O 3 The particle size is below 10nm, the relative density exceeds 98%, the tensile strength is 500-650MPa, the yield strength is 450-600MPa, the hardness HRB is 80.0-83.9, the conductivity is 79-82%IACS, and the comprehensive performance is good.

[0078] Specifically, in step S6, the diameter of the dispersed copper material is obtained to be no greater than 400 mm.

[0079] Example 1

[0080] Cu-0.6%Al 2 O 3 , take the Ф315×400mm ingot as an example.

[0081] The powder is atomized with high-purity nitrogen and smelted in a medium-frequency smelting furnace. High-purity oxygen-free electrolytic copper and copper-aluminum intermediate alloy are added into the medium-frequency furnace and smelted for 50 minutes. Then, high-purity nitrogen is atomized to make powder, and the CuAl alloy powder is dried and sieved for standby use.

[0082] The CuAl powder was placed in an oxygen-matching furnace and oxygenated at 200°C to obtain oxygen-matched powder. The oxygen-matched powder was placed in a vacuum sintering furnace and sintered at 500°C to obtain Cu / γ-Al2 O 3 Composite powder. Cu / γ-Al 2 O 3 The powder is placed in an isostatic pressing bag, and the pressing process is: pressure increase speed: 15Mpa / minute, maximum pressure 350Mpa, holding time 20 minutes, to form a denser ingot. The CIP-treated ingot is placed in high-purity hydrogen and reduced at 400℃ for 4h to obtain a reduced ingot. The reduced ingot is placed in a hot pressing sintering furnace and sintered at 950℃ and 45MPa for 5h to obtain a dense ingot.

[0083] After testing, the relative density of the ingot is 98.8%, the tensile strength is 570MPa, the yield strength is 532MPa, the hardness (HRB) is 80.8, and the conductivity is 80.6%IACS, with ideal comprehensive performance.

[0084] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing an Al2O3 dispersion-strengthened copper composite material ingot, characterized in that: The specific steps include: S1: vacuum gas atomization CuAl powder preparation, using vacuum medium frequency melting furnace for melting, adding high purity oxygen-free electrolytic copper and copper-aluminum master alloy into the vacuum medium frequency furnace for melting, and then using high purity nitrogen for atomization powder making, drying and sieving the CuAl powder for standby use; S2: oxygen matching, putting the copper and aluminum powders into an oxygen matching furnace, heating them to a set temperature for oxygen matching, and obtaining oxygen matching powder; S3: internal oxidation to obtain Cu / γ- Al2O3 dispersed copper powder; S4: CIP processing, placing the Cu / γ-Al2O3 powder in an isostatic pressing package to form a denser ingot; S5: reduction, placing the ingot in high-purity hydrogen for reduction; S6: hot pressing and sintering.

2. The method for preparing the Al2O3 dispersion-strengthened copper composite material ingot according to claim 1, characterized in that: In step S1, high-purity nitrogen gas with a pressure of 0.1-1.2 MPa is used for atomization and powdering, and 400-mesh CuAl powder is dried and sieved for standby use.

3. The method for preparing the Al2O3 dispersion-strengthened copper composite material ingot according to claim 1, characterized in that: In step S1, in a vacuum medium frequency furnace, high-purity oxygen-free electrolytic copper and copper-aluminum master alloy are heated at 10 -3 Smelting under Pa conditions for 50 to 90 minutes.

4. The method for preparing the Al2O3 dispersion-strengthened copper composite material ingot according to claim 1, characterized in that: In step S2, in the oxygen distribution furnace, the temperature is heated to 180-200°C for oxygen distribution.

5. The method for preparing the Al2O3 dispersion-strengthened copper composite material ingot according to claim 1, characterized in that: In step S3, the oxygen-matched powder is placed in a vacuum sintering furnace and heated under vacuum for internal oxidation, with a vacuum degree of ≤10 -3 Pa, heating temperature is 400℃~500℃, and holding time is 5~10h.

6. The method for preparing the Al2O3 dispersion strengthened copper composite material ingot according to claim 1, characterized in that: In step S4, the CIP pressing process is as follows: the pressure increasing speed is 1-5 MPa / min, the maximum pressure is 350-450 MPa, and the pressure holding time is 10-15 minutes.

7. The method for preparing an Al2O3 dispersion-strengthened copper composite material ingot according to claim 1, characterized in that: In step S5, the reduction temperature is 400-500°C, and the reduction time is 2-6h.

8. The method for preparing an Al2O3 dispersion-strengthened copper composite material ingot according to claim 1, characterized in that: In step S6, the pressure in the hot pressing sintering furnace is controlled at 30-60 MPa, the hot pressing temperature is 700-1000° C., and the sintering time is 1-10 h.

9. The method for preparing an Al2O3 dispersion-strengthened copper composite material ingot according to claim 1, characterized in that: In step S6, the diameter of the dispersed copper material is obtained to be no greater than 400 mm.