A method for preparing TiB2-Al2O3 / Cu composite material

Abstract

The application discloses a preparation method of TiB2-Al2O3 / Cu composite material, which comprises the following steps: step 1, Al2O3 / Cu composite material powder, TiH2 powder and B powder are mixed and placed in a ball mill tank, and ball milling is carried out under the protection of an inert atmosphere to obtain TiH2-B-Al2O3 / Cu mixed powder; step 2, the TiH2-B-Al2O3 / Cu mixed powder is poured into a cold pressing mold and cold pressed into a shape under a four-column hydraulic machine to obtain TiH2-B-Al2O3 / Cu mixed powder cold pressing blank; and step 3, the TiH2-B-Al2O3 / Cu mixed powder cold pressing blank is placed in a graphite mold and sintered in a hot pressing furnace to obtain TiB2-Al2O3 / Cu composite material; the material prepared by the method solves the problems of poor processability and low conductivity of the Al2O3 / Cu composite material, and the comprehensive performance of the Al2O3 / Cu composite material is improved.

Description

Technical Field

[0001] This invention belongs to the field of copper-based composite material preparation technology, specifically relating to a method for preparing TiB2-Al2O3 / Cu composite material. Background Technology

[0002] Al2O3 / Cu composite materials are widely used in electronics, new energy vehicles, and spot welding electrodes due to their excellent high-temperature strength, good resistance to high-temperature softening and arc erosion.

[0003] Numerous studies have been conducted on Al2O3 / Cu composite materials. Patent CN102943185A describes a mechanical alloying method that ball-mills copper powder and alumina powder together. The composite powder is then mixed with a binder, granulated, and injection molded. After debinding and sintering, a dispersed copper product is prepared. Patent CN117399613A describes a method using gas atomization and sol-gel methods to prepare Cu / γ-Al2O3 composite powder, which is then isostatically pressed, reduced, and hot-extruded to obtain high-performance dispersed copper. Patent CN114045411A provides a method for preparing alumina dispersed copper using external oxidation, which enhances the structural strength of the dispersed aluminum-copper billet and yields alumina dispersed copper with fully oxidized doped phases and uniformly controlled composition.

[0004] Currently, numerous techniques for preparing alumina-dispersed copper are available, but powder metallurgy methods are predominant, especially internal oxidation (e.g., patents CN103938018A and CN105132736A). Due to limitations in preparation technology, the volume fraction of Al2O3 reinforcing phase in Al2O3 / Cu composites prepared by internal oxidation is relatively low, resulting in limitations in the overall performance of Al2O3 / Cu composites. Patent CN109207766A provides a preparation technique involving ball milling activation and two-stage internal oxidation, which can prepare a high-alumina-content Cu-Al2O3 nano-dispersed copper alloy with controllable microstructure. However, high-energy ball milling easily introduces impurities, and the process is relatively complex and costly. Therefore, further improving the overall performance of Al2O3 / Cu composites faces significant challenges.

[0005] The design concept of hybrid reinforced metal matrix composites based on in-situ self-generated technology points the way to optimizing the comprehensive performance of Al2O3 / Cu composites. In the preparation process of Al2O3 / Cu composites, adding some auxiliary components can improve the performance of the composite to a certain extent. Patents with publication numbers CN101290838A, CN105132736A, and CN103993196A respectively prepared multi-component reinforced dispersion-strengthened copper materials using Cr doping, Y doping, and SiC doping methods. TiB2 particles possess high melting point (3253℃), high hardness (30GPa), and low resistivity (10... -4 The advantage of (Ω.cm) allows for a synergistic improvement in the strength and conductivity of copper-based composite materials. In-situ introduction of TiB2 particles to reinforce Al2O3 / Cu composites holds promise for enhancing their overall performance. Summary of the Invention

[0006] The purpose of this invention is to provide a method for preparing TiB2-Al2O3 / Cu composite materials. This method utilizes a two-phase hybrid reinforcement approach to improve the strength of copper-based composite materials while ensuring high conductivity, providing a new approach to breaking the inverse relationship between strength and conductivity of copper-based composite materials.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A method for preparing a TiB2-Al2O3 / Cu composite material, specifically implemented according to the following steps:

[0009] Step 1, ball milling: Al2O3 / Cu composite powder, TiH2 powder, and B powder are mixed and placed in a ball mill jar. A process control agent is added, and ball milling is carried out under an inert atmosphere to obtain TiH2-B-Al2O3 / Cu mixed powder.

[0010] Step 2, pressing and molding: The TiH2-B-Al2O3 / Cu mixed powder obtained in Step 1 is poured into a cold pressing mold and cold pressed under a four-column hydraulic press to obtain a TiH2-B-Al2O3 / Cu mixed powder cold pressing blank;

[0011] Step 3, hot pressing sintering: The TiH2-B-Al2O3 / Cu mixed powder cold pressing blank obtained in step 2 is placed in a graphite mold, and the graphite mold containing the cold pressing blank is placed in a hot pressing furnace for sintering to obtain TiB2-Al2O3 / Cu composite material.

[0012] Furthermore, in step 1, the particle size of the Al2O3 / Cu composite powder is 5–30 μm, the purity of the TiH2 powder is 99.9%, the particle size of the TiH2 powder is 0.5–3 μm, the purity of the B powder is 99.9%, and the particle size of the B powder is 300–800 nm.

[0013] Furthermore, in step 1, the mass fraction of Al2O3 in the Al2O3 / Cu composite powder is 0.1–0.6 wt.%.

[0014] Further, the method is characterized in that the amount of anhydrous ethanol process control agent added in step 1 is 0.5-3 wt%.

[0015] Further, in step 1, the Al2O3 / Cu composite powder, TiH2 powder, and B powder are weighed with zirconia grinding beads at a ball-to-material ratio of 10:1 to 20:1, the ball milling speed is 250 to 450 r / min, and the ball milling time is 2 to 30 h.

[0016] Furthermore, the conditions for cold pressing in step 2 are: pressure of 50-300 MPa and holding time of 20-60 s.

[0017] Furthermore, the specific sintering procedure in step 3 is as follows: the sintering environment is a vacuum or inert gas protection, the temperature is raised from room temperature to 800℃ at a rate of 20℃ / min, and held at 800℃ for 30min. After the holding period, the temperature is raised from 800℃ to 850℃-1060℃ at a rate of 10℃ / min, and held at 850℃-1060℃ for 1h. After the holding period, the sample is cooled to room temperature with the furnace.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] This invention achieves in-situ introduction of TiB2 particles into Al2O3 / Cu composite materials through mechanical ball milling, cold pressing, and hot pressing sintering. The content of the TiB2 reinforcing phase can be freely controlled, resulting in a dual-phase reinforcement of the copper-based composite material and improving its overall performance. The in-situ generated Al2O3 and TiB2 dual-phase particles possess high elastic modulus, high melting point, and high hardness and strength. They also exhibit good bonding with the matrix, hindering dislocation movement during plastic deformation and improving the mechanical properties of the composite material. The small, uniform, and dispersed size of the reinforcing phase reduces the impact of lattice distortion within the matrix on the electron mean free path, minimizing damage to conductivity. The combined effect of the Al2O3 and TiB2 dual-phase particles enhances the strength of the copper-based composite material while maintaining excellent conductivity. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating a method for preparing a TiB2-Al2O3 / Cu composite material according to the present invention;

[0021] Figure 2 This is a microstructure diagram of the TiB2-Al2O3 / Cu composite material prepared in Example 2 of the present invention. Figure 2(a) is a low-magnification microstructure diagram of the TiB2-Al2O3 / Cu composite material. Figure 2 (b) is a high-magnification microstructure diagram of the TiB2-Al2O3 / Cu composite material;

[0022] Figure 3 The microstructure of the TiH2-B-Al2O3 / Cu composite powder obtained by ball milling in Example 3 of this invention is shown. Detailed Implementation

[0023] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0024] like Figure 1 As shown, a method for preparing a TiB2-Al2O3 / Cu composite material is implemented according to the following steps.

[0025] Step 1, ball milling:

[0026] Al2O3 / Cu composite powder with a particle size of 5–30 μm was taken. The Al2O3 / Cu composite powder contained 0.1–0.6 wt.% Al2O3, 99.9% purity, and 300–800 nm particle size B powder, and 99.9% purity and 0.5–3 μm particle size TiH2 powder. Zirconia grinding beads were weighed according to a ball-to-particle ratio of 10:1–20:1. 0.5–3 wt% anhydrous ethanol process control agent was added, and the mixture was placed in a planetary ball mill. Ball milling was carried out under an inert atmosphere (nitrogen, argon, hydrogen) at a speed of 250–450 r / min for 2–30 h to obtain TiH2-B-Al2O3 / Cu composite powder. During the subsequent hot pressing and sintering process, TiH2 powder and B powder undergo an in-situ reaction TiH2 + 2B → TiB2 + H2 to generate TiB2. The required amount of TiH2 powder and B powder for the reaction is calculated based on the mass fraction of titanium diboride generated being 1-3 wt.%.

[0027] Step 2, pressing and molding:

[0028] The TiH2-B-Al2O3 / Cu mixed powder obtained in step 1 is poured into a cold pressing mold and cold pressed under a four-column hydraulic press. The pressing pressure is 50-300 MPa and the holding time is 20-60 s to obtain a cold-pressed blank of TiH2-B-Al2O3 / Cu mixed powder.

[0029] Step 3, hot pressing and sintering:

[0030] The TiH2-B-Al2O3 / Cu mixed powder cold-pressed preform obtained in step 2 was placed in a graphite mold, and the graphite mold containing the cold-pressed preform was placed in a hot press furnace for sintering. The specific sintering process was as follows: the sintering environment was a vacuum or inert gas protection, the temperature was raised from room temperature to 800℃ at a heating rate of 20℃ / min, held for 30min, and then raised from 800℃ to 850℃~1060℃ at a heating rate of 10℃ / min, and held for 1h to obtain the TiB2-Al2O3 / Cu composite material.

[0031] Example 1

[0032] Step 1: Take 29.69g of Al2O3 / Cu composite powder with a particle size of 5-30μm (Al2O3 mass fraction in Al2O3 / Cu composite powder is 0.1wt.%), 0.09g of B powder with a particle size of 300-800nm, and 0.22g of TiH2 powder with a particle size of 0.5-3μm, and place them in a ball mill jar. Add 600g of zirconia grinding beads (ball-to-material ratio 20:1) and 3wt.% anhydrous ethanol process control agent. Then place it in a planetary ball mill and ball mill at 400r / min for 20h under argon atmosphere to complete the mechanical alloying process, obtaining TiH2-B-Al2O3 / Cu mixed powder. Among them, TiH2 powder and B powder undergo an in-situ reaction TiH2+2B→TiB2+H2 during the subsequent hot pressing sintering process to generate 1wt.% TiB2.

[0033] Step 2: Pour the TiH2-B-Al2O3 / Cu mixed powder obtained in Step 1 into a cold press mold and cold press it under a four-column hydraulic press. The pressing pressure is 300MPa and the holding time is 30s to obtain the TiH2-B-Al2O3 / Cu mixed powder cold press blank.

[0034] Step 3: Place the cold-pressed TiH2-B-Al2O3 / Cu mixed powder obtained in Step 2 into a graphite mold, and raise the temperature stepwise in a vertical nitrogen atmosphere hot press furnace under microcomputer program control. The temperature is raised from room temperature to 800℃ at a heating rate of 20℃ / min and held for 30min. Then, the temperature is raised from 800℃ to 1050℃ at a heating rate of 10℃ / min and held for 1h to obtain a 1wt.%TiB2-0.6wt.%Al2O3 / Cu composite material.

[0035] Example 2

[0036] Step 1: Take 29.38g of Al2O3 / Cu composite powder with a particle size of 5-30μm (Al2O3 mass fraction in Al2O3 / Cu composite powder is 0.3wt.%), 0.19g of B powder with a particle size of 300-800nm, and 0.43g of TiH2 powder with a particle size of 0.5-3μm, and place them in a ball mill jar. Add 300g of grinding beads (ball-to-particle ratio 10:1) and 0.5wt.% of anhydrous ethanol process control agent. Then place it in a planetary ball mill under argon atmosphere and ball mill at 450r / min for 2h to complete the mechanical alloying process, obtaining TiH2-B-Al2O3 / Cu mixed powder. Among them, TiH2 powder and B powder undergo an in-situ reaction TiH2+2B→TiB2+H2 during the subsequent hot pressing sintering process to generate 2wt.% TiB2.

[0037] Step 2: Pour the TiH2-B-Al2O3 / Cu mixed powder obtained in Step 1 into a cold press mold and cold press it under a four-column hydraulic press. The pressing pressure is 280MPa and the holding time is 20s to obtain the TiH2-B-Al2O3 / Cu mixed powder cold press blank.

[0038] Step 3: Place the TiH2-B-Al2O3 / Cu cold-pressed preform obtained in Step 2 into a graphite mold, and raise the temperature stepwise in a vertical nitrogen atmosphere hot press furnace under microcomputer program control. The temperature is raised from room temperature to 800℃ at a heating rate of 20℃ / min and held for 30min. Then, the temperature is raised from 800℃ to 1060℃ at a heating rate of 10℃ / min and held for 1h to obtain a 2wt.% TiB2-0.6wt.% Al2O3 / Cu composite material.

[0039] like Figure 2 The image shows the microstructure of the in-situ TiB2-Al2O3 / Cu composite material prepared in Example 2. Figure 2 (a) is a low-magnification microstructure diagram of the TiB2-Al2O3 / Cu composite material. Figure 2 (b) is a high-magnification microstructure diagram of the TiB2-Al2O3 / Cu composite material; from the attached... Figure 2 It can be seen that the TiB2 and Al2O3 reinforcing phases are uniformly dispersed in the matrix with clear boundaries.

[0040] Example 3

[0041] Step 1: Take 29.07g of Al2O3 / Cu composite powder with a particle size of 5-30μm (Al2O3 mass fraction in Al2O3 / Cu composite powder is 0.6wt.%), 0.28g of B powder with a particle size of 300-800nm, and 0.65g of TiH2 powder with a particle size of 0.5-3μm, respectively, and place them in a ball mill jar. Add 450g of grinding balls (ball-to-powder ratio 15:1) and 2wt.% process control agent. The ball milling process is carried out under an argon atmosphere. Subsequently, place it in a planetary ball mill under a hydrogen atmosphere at a speed of 250r / min for 30h to complete the mechanical alloying process, obtaining TiH2-B-Al2O3 / Cu mixed powder. Among them, TiH2 powder and B powder undergo an in-situ reaction TiH2 + 2B → TiB2 + H2 during the subsequent hot pressing sintering process to generate 3wt.% TiB2.

[0042] Step 2: Pour the TiH2-B-Al2O3 / Cu mixed powder obtained in Step 1 into a cold press mold and cold press it under a four-column hydraulic press. The pressing pressure is 50MPa and the holding time is 60s to obtain the TiH2-B-Al2O3 / Cu mixed powder cold press blank.

[0043] Step 3: Place the cold-pressed TiH2-B-Al2O3 / Cu mixed powder obtained in Step 2 into a graphite mold, and raise the temperature stepwise in a vertical vacuum atmosphere hot press furnace under microcomputer program control. The temperature is raised from room temperature to 800℃ at a heating rate of 20℃ / min and held for 30min. Then, the temperature is raised from 800℃ to 850℃ at a heating rate of 10℃ / min and held for 1h to obtain a 3wt.% TiB2-0.6wt.% Al2O3 / Cu composite material.

[0044] like Figure 3 The image shows the microstructure of the TiH2-B-Al2O3 / Cu composite powder obtained by ball milling in Example 3 of this invention. (From the attached image...) Figure 3 It can be seen that after high-energy ball milling, the powder is broken, deformed, and welded together, exhibiting a sheet-like morphology.

[0045] Table 1 compares the electrical conductivity and mechanical properties of the in-situ self-generated TiB2-Al2O3 / Cu composite materials prepared in Examples 1-3.

[0046] Table 1

[0047]

[0048] As shown in Table 1, the 1wt.% TiB2-0.6wt.% Al2O3 / Cu composite material finally prepared in Example 1 achieved a hardness of 138 HV, a conductivity of 75.3% IACS, and a tensile strength of 405 MPa. The 2wt.% TiB2-0.6wt.% Al2O3 / Cu composite material finally prepared in Example 2 achieved a hardness of 160 HV, a conductivity of 75% IACS, and a tensile strength of 447 MPa. The 3wt.% TiB2-0.6wt.% Al2O3 / Cu composite material finally prepared in Example 3 achieved a hardness of 156 HV, a conductivity of 70.4% IACS, and a tensile strength of 349 MPa.

[0049] The embodiments described above merely illustrate specific implementations of the present invention, and while the descriptions are detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for preparing a TiB2-Al2O3 / Cu composite material, characterized in that, The specific steps are as follows: Step 1, ball milling: Al2O3 / Cu composite powder, TiH2 powder, and B powder are mixed and placed in a ball mill jar. A process control agent is added, and ball milling is carried out under an inert atmosphere to obtain TiH2-B-Al2O3 / Cu mixed powder. Step 2, pressing and molding: The TiH2-B-Al2O3 / Cu mixed powder obtained in Step 1 is poured into a cold pressing mold and cold pressed under a four-column hydraulic press to obtain a TiH2-B-Al2O3 / Cu mixed powder cold pressing blank; Step 3, hot pressing sintering: The TiH2-B-Al2O3 / Cu mixed powder cold pressing blank obtained in step 2 is placed in a graphite mold, and the graphite mold containing the cold pressing blank is placed in a hot pressing furnace for sintering to obtain TiB2-Al2O3 / Cu composite material. The specific sintering process is as follows: the sintering environment is a vacuum or inert gas protection, the temperature is raised from room temperature to 800 ℃ at a rate of 20 ℃ / min, and held at 800 ℃ for 30 min. After the holding period, the temperature is raised from 800 ℃ to 850 ℃-1060 ℃ at a rate of 10 ℃ / min, and held at 850 ℃-1060 ℃ for 1 h. After the holding period, the sample is cooled to room temperature with the furnace.

2. The method for preparing a TiB2-Al2O3 / Cu composite material according to claim 1, characterized in that, In step 1, the particle size of the Al2O3 / Cu composite powder is 5~30μm, the purity of the TiH2 powder is 99.9%, the particle size of the TiH2 powder is 0.5~3μm, the purity of the B powder is 99.9%, and the particle size of the B powder is 300~800nm.

3. The method for preparing a TiB2-Al2O3 / Cu composite material according to claim 1, characterized in that, In step 1, the mass fraction of Al2O3 in the Al2O3 / Cu composite powder is 0.1~0.6 wt.%.

4. The method for preparing a TiB2-Al2O3 / Cu composite material according to claim 1, characterized in that, The amount of anhydrous ethanol process control agent added in step 1 is 0.5 ~ 3 wt.

5. The method for preparing a TiB2-Al2O3 / Cu composite material according to claim 1, characterized in that, In step 1, the Al2O3 / Cu composite powder, TiH2 powder, and B powder are weighed according to a ball-to-material ratio of 10:1 to 20:

1. Zirconia grinding beads are used, the ball milling speed is 250 to 450 r / min, and the ball milling time is 2 to 30 h.

6. The method for preparing a TiB2-Al2O3 / Cu composite material according to claim 1, characterized in that, The conditions for cold pressing in step 2 are: pressure of 50~300 MPa and holding time of 20~60s.

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