A ZrO2@diamond / 2024 aluminum alloy composite material based on the isolation effect of ZrO2 coating

Abstract

The application discloses a ZrO2@diamond / 2024 aluminum alloy composite material based on the isolation of a ZrO2 coating, and belongs to the field of metal matrix composites. The preparation process of the ZrO2@diamond / 2024 aluminum alloy composite material comprises the following steps: coating diamond powder with ZrO2, 2024 aluminum alloy, mixing, cold pressing and atmosphere hot pressing. The ZrO2 coating plays a role in isolating the direct contact between the diamond and the aluminum matrix. In the atmosphere hot pressing process, the ZrO2 does not react with the diamond and the Al melt, forming an effective mechanical barrier layer, avoiding the formation of the harmful Al4C3 phase at the interface of the composite material, and improving the wettability between the diamond and the Al melt. The thickness of the ZrO2 coating is 0.1-10 microns, the plating rate is higher than 98%, and the ZrO2 coating is uniformly distributed. The tensile strength of the ZrO2@diamond / 2024 aluminum alloy composite material is improved by 10%-40% compared with that of the diamond / 2024 aluminum alloy composite material without the ZrO2 coating. The application has the characteristics of simple process and low cost, and can realize industrial application.

Description

Technical Field

[0001] This invention relates to a ZrO2@diamond / 2024 aluminum alloy composite material based on the isolation effect of ZrO2 coating, belonging to the field of metal matrix composites. Background Technology

[0002] Diamond particles possess advantages such as high elastic modulus, high hardness, high strength, and low density. In particular, diamond's high elastic modulus allows it to significantly improve the stiffness of composite materials when used as a reinforcing phase. Furthermore, diamond has high thermal conductivity. Therefore, diamond particle-reinforced metal matrix composites exhibit remarkable thermophysical properties, making them excellent heat dissipation materials for electronic packaging.

[0003] Currently, the common preparation processes for diamond / 2024 aluminum alloy composites mainly include powder metallurgy (e.g., spark plasma sintering, vacuum or atmospheric hot pressing) and melt infiltration. The preparation temperature is mostly within the semi-solid state of aluminum (505.3℃~623.5℃) or above the melting point, which makes it easy to form the Al4C3 brittle phase at the interface between diamond particles and aluminum matrix. In addition, the poor wettability between diamond particles and aluminum matrix makes interfacial bonding difficult.

[0004] To address the interface issues in diamond / aluminum matrix composites, improvements are typically made through matrix alloying and surface treatment. Matrix element control involves adding other alloying elements to the aluminum matrix to increase the wettability between diamond and aluminum while suppressing the formation of the brittle Al4C3 phase. Commonly used alloying elements include silicon, titanium, and copper. However, excessive amounts of these elements added to the matrix can negatively impact the composite's elastic modulus and thermal conductivity, hindering the full realization of diamond's high elastic modulus and thermal conductivity. Surface treatment involves coating the diamond surface to prevent contact between diamond and aluminum, thereby controlling the interface. Common coating elements include W, Ti, and Li, with W having the highest density at 19.35 g / cm³. 3 Contrary to the concept of weight reduction in electronic packaging materials, Ti is difficult to control in the process of depositing oxides on the diamond surface, and the oxides formed by Li react with Al. Therefore, none of these elements are suitable for diamond oxide isolation films. Zr has a low density, and zirconium nitrate pentahydrate can easily form a zirconium oxide film on the diamond surface without reacting with Al, which can effectively isolate diamond from aluminum. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a ZrO2@diamond / 2024 aluminum alloy composite material based on the isolating effect of a ZrO2 coating. The ZrO2@diamond / 2024 aluminum alloy composite material comprises 2024 aluminum alloy and diamond coated with a ZrO2 coating. The 2024 aluminum alloy, the ZrO2 coating, and the diamond are mechanically bonded together. The ZrO2 coating thickness is 0.1-10 μm, and the coating coverage is greater than or equal to 98%.

[0006] Preferably, the composite material is obtained by mixing 2024 aluminum alloy powder and diamond powder coated with ZrO2, followed by cold pressing and atmospheric hot pressing. During the atmospheric hot pressing preparation of ZrO2@diamond / 2024 aluminum alloy composite material, the ZrO2 coating acts as a mechanical barrier layer, isolating the diamond from direct contact with the aluminum melt. ZrO2 does not react with either the diamond or the aluminum melt, thus avoiding the formation of harmful Al4C3 phases at the interface of the composite material.

[0007] Preferably, the diamond powder without ZrO2 coating has a particle size of 1-100 μm, and the 2024 aluminum alloy powder has a particle size of 1-100 μm.

[0008] Preferably, the volume fraction of the diamond powder coated with ZrO2 is 1-60% of the total volume of the diamond powder coated with ZrO2 and the 2024 aluminum alloy powder.

[0009] Preferably, the cold pressing conditions of the present invention are 300-600 MPa, and pressure holding at room temperature for 10-30 min.

[0010] Preferably, the atmospheric hot pressing treatment conditions of the present invention are: under argon atmosphere, 500-600℃, pressure 10-120MPa, and pressure holding for 1-5h.

[0011] Preferably, the specific process of depositing a ZrO2 coating on the surface of diamond powder is as follows:

[0012] (1) The diamond powder is acid-washed until neutral and then dried for later use.

[0013] (2) Dissolve zirconium nitrate pentahydrate in ethanol, then add the diamond powder obtained in step (1), heat and stir continuously until the ethanol evaporates completely, and obtain diamond with zirconium nitrate pentahydrate crystals on the surface.

[0014] (3) Heat-treat the diamond obtained in step (2) to obtain a diamond with a zirconium oxide coating.

[0015] Preferably, in step (1), the diamond powder is acid-washed with a 2 mol / L HNO3 solution for 20 min and stirred with a magnetic stirrer, and then washed with deionized water. The particle size of the diamond powder is 1-100 μm.

[0016] Preferably, the heat treatment temperature in step (3) is 600℃ and the treatment time is 180min.

[0017] The principle of this invention:

[0018] 1. The formation and isolation principle of zirconium oxide coating

[0019] When diamond comes into direct contact with the aluminum matrix, a brittle Al4C3 phase forms at the interface. The low mechanical properties of the diamond / 2024 aluminum alloy composite are mainly due to this phase. A uniform layer of zirconium nitrate pentahydrate crystallizes on the surface of the diamond. At 100℃, zirconium nitrate pentahydrate begins to lose its water of crystallization. When the temperature is raised to 600℃, zirconium nitrate pentahydrate completely decomposes into zirconium oxide. To obtain zirconium oxide-coated diamond powder, heat treatment at 600℃ for 180 min decomposes zirconium nitrate pentahydrate into zirconium oxide.

[0020] Zr(NO3)4·5H2O→ZrO2+NO2+H2O

[0021] A homogeneous zirconium oxide film is formed to coat the diamond surface. The ZrO2 coating acts as an isolation layer between the diamond and the aluminum substrate. During the semi-solid hot pressing process, ZrO2 does not react with the diamond or the aluminum melt, forming an effective mechanical barrier layer. This avoids the formation of the harmful Al4C3 phase at the composite material interface and improves the wettability between the diamond and the Al melt.

[0022] 2. Principle of Zirconia Isolation Coating Thickness Control

[0023] Prepare materials according to the following ratio: diamond powder mass: zirconium nitrate pentahydrate mass: ethanol mass = (30-40):(68-84):100. Dissolve zirconium nitrate pentahydrate in ethanol and then add diamond powder. Heat to 65°C and stir continuously until the ethanol evaporates completely. The zirconium nitrate pentahydrate crystallizes on the diamond surface. Heat treat at 600°C for 180 minutes to decompose the zirconium nitrate pentahydrate into zirconium oxide, forming a zirconium oxide coating.

[0024] Calculate the surface area of ​​the diamond particle:

[0025]

[0026] (1) In the formula, S—the surface area of ​​diamond powder, cm² 2 ρ1—density of diamond powder, ρ1=3.52g / cm³ 3m1—mass of diamond powder, g; r—particle size of diamond powder, μm.

[0027] Calculate the relationship between coating thickness and required zirconium oxide mass:

[0028]

[0029] (2) Where δ—average thickness of ZrO2 coating, μm; S—surface area of ​​diamond powder, cm 2 m2—Mass of ZrO2 precipitated on the surface of diamond powder, g; ρ2—Density of ZrO2, ρ2=5.85g / cm³ 3 S—Surface area of ​​diamond powder, cm² 2 .

[0030] Calculate the mass relationship between zirconium nitrate pentahydrate and zirconium oxide:

[0031]

[0032] (3) In the formula, m2 is the mass of zirconium oxide, g; m3 is the mass of zirconium nitrate pentahydrate, g; M1 is the relative molecular mass of zirconium oxide, 123.22; M2 is the relative molecular mass of zirconium nitrate pentahydrate, 429.301.

[0033] According to equations (1), (2), and (3), the coating thickness is related to the amount of zirconium nitrate pentahydrate added and the diamond particle size, as shown in equation (4).

[0034]

[0035] In formula (4), δ—average thickness of ZrO2 coating, μm; r—diamond powder particle size, μm; m3—mass of zirconium nitrate pentahydrate, g; m1—mass of diamond powder; M1—relative molecular mass of zirconium oxide, 123.22; M2—relative molecular mass of zirconium nitrate pentahydrate, 429.301; ρ1—density of diamond powder, ρ1=3.52g / cm³ 3 ρ2—The density of ZrO2, ρ2=5.85g / cm³ 3 .

[0036] Beneficial effects of the present invention

[0037] (1) In the atmosphere hot pressing preparation process of ZrO2@diamond / 2024 aluminum alloy composite material, the ZrO2 coating isolates the direct contact between diamond and aluminum melt. ZrO2 does not react with diamond and aluminum melt, forming an effective mechanical barrier layer, avoiding the formation of harmful Al4C3 phase at the interface of composite material, and improving the wettability between diamond and Al melt.

[0038] (2) The interface characteristics of ZrO2@diamond / 2024 aluminum alloy composite material are: uniform distribution, coating rate of more than 98%, mechanical bonding between 2024 aluminum alloy-ZrO2-diamond, relatively tight interface bonding, and fewer interface pores and grooves compared with diamond / 2024 aluminum alloy composite material without ZrO2 coating.

[0039] (3) The tensile strength of ZrO2@diamond / 2024 aluminum alloy composite material is increased by 10%-40% compared with diamond / 2024 aluminum alloy composite material without ZrO2 coating.

[0040] (4) The prepared composite material can be used in electronic packaging materials.

[0041] (5) In this invention, the thickness of the zirconium oxide coating can be determined according to actual needs, and the mass ratio of diamond powder to zirconium nitrate pentahydrate can be calculated according to the required coating thickness, saving time and cost and avoiding waste of raw materials.

[0042] (6) Using zirconium nitrate pentahydrate as raw material for coating is simpler and cheaper than direct coating of zirconium oxide. Furthermore, zirconium nitrate pentahydrate crystallizes directly on the diamond surface, which can fill the defects on the diamond surface. After coating, the diamond surface is smoother and flatter. However, the processing defects on the diamond surface are not filled when directly coating zirconium oxide, and the surface has defects and the edges are too sharp, resulting in more defects at the interface of the composite material. Attached Figure Description

[0043] Figure 1 This is a process flow diagram for preparing ZrO2@diamond / 2024 aluminum alloy composite material.

[0044] Figure 2 For the comparison of tensile strength of composite materials, the preparation process of diamond / 2024 aluminum alloy composite material without ZrO2 coating is the same as that of ZrO2@diamond / 2024 aluminum alloy composite material, except that ZrO2 coating treatment is not performed. Detailed Implementation

[0045] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the following embodiments are merely simple examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0046] Example 1

[0047] A ZrO2@diamond / 2024 aluminum alloy composite material based on the isolating effect of ZrO2 coating was prepared. In this embodiment, the average thickness of the ZrO2 coating was 0.1 μm, and the diamond particle size used was 1 μm. The composite material was prepared using the formula... Calculated In the formula, δ—average thickness of ZrO2 coating, μm; r—diamond powder particle size, μm; m1—mass of diamond powder, g; m3—mass of zirconium nitrate pentahydrate, g; M1—relative molecular mass of zirconium oxide, 123.22; M2—relative molecular mass of zirconium nitrate pentahydrate, 429.301; ρ1—density of diamond powder, ρ1=3.52g / cm³ 3 ρ2—the density of ZrO2, ρ2=5.85g / cm3. Therefore, in this embodiment, the materials are prepared according to the ratio of diamond powder mass: zirconium nitrate pentahydrate mass: alcohol mass = 40∶68∶100, and the specific preparation method is as follows:

[0048] (1) Add commercially available diamond powder with a particle size of 1 μm to a 2 mol / L HNO3 solution and stir magnetically for 20 min. Then wash repeatedly with deionized water until neutral and place in a drying oven to dry for later use.

[0049] (2) Dissolve zirconium nitrate pentahydrate in ethanol and then add the diamond powder obtained in step (1). Heat to 65°C and stir continuously until the ethanol evaporates completely to obtain diamond with zirconium nitrate pentahydrate crystals on the surface.

[0050] (3) The diamond obtained in step (2) is heat-treated at 600°C for 180 min to decompose zirconium nitrate pentahydrate into zirconium oxide, thereby obtaining diamond with a zirconium oxide coating.

[0051] (4) The diamond with zirconium oxide coating obtained in step (3) is mixed with 2024 aluminum alloy powder with a particle size of 1μm. The amount of diamond with zirconium oxide coating added is 60% of the total volume of the mixed powder. The mixture is dried in a drying oven at 100℃ for 60min and then mixed in a three-dimensional mixer for 8h to obtain the mixed powder.

[0052] (5) Place the mixed powder obtained in step (4) into a mold, hold it under pressure of 600 MPa at room temperature for 10 minutes for cold pressing, and then demold to obtain a cold-pressed sample.

[0053] (6) The cold-pressed sample obtained in step (5) is placed into a hot-pressing mold and subjected to heat treatment at a temperature of 500℃, a pressure of 120MPa and a holding time of 5h under an argon atmosphere to obtain ZrO2@diamond / 2024 aluminum alloy composite material.

[0054] In the composite material prepared in this embodiment, ZrO2 does not react with diamond or aluminum melt. ZrO2 forms an effective mechanical barrier layer, preventing the formation of harmful Al4C3 phases at the composite material interface. At the same time, it improves the wettability between diamond and Al melt, resulting in a tighter interfacial bond. The interfacial porosity and groove phenomena are reduced compared to the diamond / 2024 aluminum alloy composite material without ZrO2 coating. The tensile strength is increased by 10.00% compared to the diamond / 2024 aluminum alloy composite material without ZrO2 coating.

[0055] Example 2

[0056] A ZrO2@diamond / 2024 aluminum alloy composite material based on the isolating effect of a ZrO2 coating was prepared. In this embodiment, the average thickness of the ZrO2 coating was 4 μm, and the diamond particle size used was 25 μm. The composite material was prepared using the formula... Calculated In the formula, δ—average thickness of ZrO2 coating, μm; r—diamond powder particle size, μm; m1—mass of diamond powder, g; m3—mass of zirconium nitrate pentahydrate, g; M1—relative molecular mass of zirconium oxide, 123.22; M2—relative molecular mass of zirconium nitrate pentahydrate, 429.301; ρ1—density of diamond powder, ρ1=3.52g / cm³ 3 ρ2—The density of ZrO2, ρ2=5.85g / cm3. Therefore, in this embodiment, the materials are prepared according to the ratio of diamond powder mass: zirconium nitrate pentahydrate mass: alcohol mass = 30∶84∶100, and the specific preparation method is as follows:

[0057] (1) Add commercially available diamond powder with a particle size of 1 μm to a 2 mol / L HNO3 solution and stir magnetically for 20 min. Then wash repeatedly with deionized water until neutral and place in a drying oven to dry for later use.

[0058] (2) Dissolve zirconium nitrate pentahydrate in ethanol and then add the diamond powder obtained in step (1). Heat to 65°C and stir continuously until the ethanol evaporates completely to obtain diamond with zirconium nitrate pentahydrate crystals on the surface.

[0059] (3) The diamond obtained in step (2) is heat-treated at 600°C for 180 min to decompose zirconium nitrate pentahydrate into zirconium oxide, thereby obtaining diamond with a zirconium oxide coating.

[0060] (4) The diamond with zirconium oxide coating obtained in step (3) is mixed with 2024 aluminum alloy powder with a particle size of 25 μm. The amount of diamond with zirconium oxide coating added is 35% of the total volume of the mixed powder. The mixture is dried in a drying oven at 100°C for 60 min and then mixed in a three-dimensional mixer for 8 h to obtain the mixed powder.

[0061] (5) Place the mixed powder obtained in step (4) into a mold, hold it under pressure of 500 MPa at room temperature for 15 minutes for cold pressing, and then demold to obtain a cold-pressed sample.

[0062] (6) The cold-pressed sample obtained in step (5) is placed into a hot-pressing mold and subjected to heat treatment at a temperature of 530°C, a pressure of 90MPa and a holding time of 3.5h under an argon atmosphere to obtain ZrO2@diamond / 2024 aluminum alloy composite material.

[0063] In the composite material prepared in this embodiment, ZrO2 does not react with diamond or aluminum melt. ZrO2 forms an effective mechanical barrier layer, preventing the formation of harmful Al4C3 phases at the composite material interface. At the same time, it improves the wettability between diamond and Al melt, resulting in a tighter interfacial bond. The interfacial porosity and groove phenomena are reduced compared to the diamond / 2024 aluminum alloy composite material without ZrO2 coating. The tensile strength is increased by 16.33% compared to the diamond / 2024 aluminum alloy composite material without ZrO2 coating.

[0064] Example 3

[0065] A ZrO2@diamond / 2024 aluminum alloy composite material based on the isolating effect of a ZrO2 coating was prepared. In this embodiment, the average thickness of the ZrO2 coating was 6 μm, and the diamond particle size used was 43 μm. The composite material was prepared using the formula... Calculated In the formula, δ—average thickness of ZrO2 coating, μm; r—diamond powder particle size, μm; m1—mass of diamond powder, g; m3—mass of zirconium nitrate pentahydrate, g; M1—relative molecular mass of zirconium oxide, 123.22; M2—relative molecular mass of zirconium nitrate pentahydrate, 429.301; ρ1—density of diamond powder, ρ1=3.52g / cm³ 3 ρ2—The density of ZrO2, ρ2=5.85g / cm3. Therefore, in this embodiment, the materials are prepared according to the ratio of diamond powder mass: zirconium nitrate pentahydrate mass: alcohol mass = 33∶79.2∶100, and the specific preparation method is as follows:

[0066] (1) Add commercially available diamond powder with a particle size of 43 μm to a 2 mol / L HNO3 solution and stir magnetically for 20 min. Then wash repeatedly with deionized water until neutral and place in a drying oven to dry for later use.

[0067] (2) Dissolve zirconium nitrate pentahydrate in ethanol and then add the diamond powder obtained in step (1). Heat to 65°C and stir continuously until the ethanol evaporates completely to obtain diamond with zirconium nitrate pentahydrate crystals on the surface.

[0068] (3) The diamond obtained in step (2) is heat-treated at 600°C for 180 min to decompose zirconium nitrate pentahydrate into zirconium oxide, and a diamond with zirconium oxide coating is obtained with a coating rate of 99.00%.

[0069] (4) The diamond with zirconium oxide coating obtained in step (3) is mixed with 2024 aluminum alloy powder with a particle size of 55 μm. The amount of diamond with zirconium oxide coating added is 25% of the total volume of the mixed powder. The mixture is dried in a drying oven at 100°C for 60 min and then mixed in a three-dimensional mixer for 8 h to obtain the mixed powder.

[0070] (5) Place the mixed powder obtained in step (4) into a mold, hold it under pressure of 400 MPa for 25 minutes at room temperature for cold pressing, and then demold to obtain a cold-pressed sample.

[0071] (6) The cold-pressed sample obtained in step (5) is placed into a hot-pressing mold and subjected to heat treatment at a temperature of 560℃, a pressure of 50MPa and a holding time of 2.5h under an argon atmosphere to obtain ZrO2@diamond / 2024 aluminum alloy composite material.

[0072] In the composite material prepared in this embodiment, ZrO2 does not react with diamond or aluminum melt. ZrO2 forms an effective mechanical barrier layer, preventing the formation of harmful Al4C3 phases at the composite material interface. At the same time, it improves the wettability between diamond and Al melt, resulting in a tighter interfacial bond. The interfacial porosity and groove phenomena are reduced compared to the diamond / 2024 aluminum alloy composite material without ZrO2 coating. The tensile strength is increased by 40.00% compared to the diamond / 2024 aluminum alloy composite material without ZrO2 coating.

[0073] Example 4

[0074] A ZrO2@diamond / 2024 aluminum alloy composite material based on the isolating effect of a ZrO2 coating was prepared. In this embodiment, the average thickness of the ZrO2 coating was 10 μm, and the diamond particle size used was 100 μm. The composite material was prepared using the formula... Calculated In the formula, δ—average thickness of ZrO2 coating, μm; r—diamond powder particle size, μm; m1—mass of diamond powder, g; m3—mass of zirconium nitrate pentahydrate, g; M1—relative molecular mass of zirconium oxide, 123.22; M2—relative molecular mass of zirconium nitrate pentahydrate, 429.301; ρ1—density of diamond powder, ρ1=3.52g / cm³ 3ρ2—the density of ZrO2, ρ2=5.85g / cm3. Therefore, in this embodiment, the materials are prepared according to the ratio of diamond powder mass: zirconium nitrate pentahydrate mass: alcohol mass = 40∶68∶100, and the specific preparation method is as follows:

[0075] (1) Add commercially available diamond powder with a particle size of 100 μm to a 2 mol / L HNO3 solution and stir magnetically for 20 min. Then wash repeatedly with deionized water until neutral and place in a drying oven to dry for later use.

[0076] (2) Dissolve zirconium nitrate pentahydrate in ethanol and then add the diamond powder obtained in step (1). Heat to 65°C and stir continuously until the ethanol evaporates completely to obtain diamond with zirconium nitrate pentahydrate crystals on the surface.

[0077] (3) The diamond obtained in step (2) is heat-treated at 600℃ for 180 min to decompose zirconium nitrate pentahydrate into zirconium oxide, and a diamond with zirconium oxide coating is obtained with a coating rate of 99.53%.

[0078] (4) The diamond with zirconium oxide coating obtained in step (3) is mixed with 2024 aluminum alloy powder with a particle size of 100 μm. The amount of diamond with zirconium oxide coating added is 1% of the total volume of the mixed powder. The mixture is dried in a drying oven at 100°C for 60 min and then mixed in a three-dimensional mixer for 8 h to obtain the mixed powder.

[0079] (5) Place the mixed powder obtained in step (4) into a mold, hold it under pressure of 300 MPa at room temperature for 30 min for cold pressing, and then demold to obtain a cold-pressed sample.

[0080] (6) The cold-pressed sample obtained in step (5) is placed into a hot-pressing mold and subjected to heat treatment at a temperature of 600℃, a pressure of 10MPa and a holding time of 1h under an argon atmosphere to obtain ZrO2@diamond / 2024 aluminum alloy composite material.

[0081] In the composite material prepared in this embodiment, ZrO2 does not react with diamond or aluminum melt. ZrO2 forms an effective mechanical barrier layer, which avoids the formation of harmful Al4C3 phase at the composite material interface. At the same time, it improves the wettability between diamond and Al melt, resulting in a tighter interfacial bond. The interfacial porosity and groove phenomenon are reduced compared with diamond / 2024 aluminum alloy composite material without ZrO2 coating. The tensile strength is increased by 11.77% compared with diamond / 2024 aluminum alloy composite material without ZrO2 coating.

[0082] from Figure 2It can be seen that the tensile strength of the diamond / 2024 aluminum alloy composite material coated with ZrO2 is stronger than that of the diamond / 2024 aluminum alloy composite material without ZrO2 coating.

Claims

1. A method for preparing ZrO2@diamond / 2024 aluminum alloy composite material based on the isolating effect of ZrO2 coating, characterized in that: The composite material is obtained by mixing 2024 aluminum alloy powder and diamond powder coated with ZrO2, followed by cold pressing and atmospheric hot pressing. During the atmospheric hot pressing preparation of ZrO2@diamond / 2024 aluminum alloy composite material, the ZrO2 coating acts as a mechanical barrier layer, isolating the diamond from direct contact with the aluminum melt. ZrO2 does not react with either the diamond or the aluminum melt, thus avoiding the formation of the harmful Al4C3 phase at the interface of the composite material. The specific process of depositing a ZrO2 coating on the surface of diamond powder is as follows: (1) The diamond powder is acid-washed, washed until neutral, and dried for later use; (2) Dissolve zirconium nitrate pentahydrate in ethanol, then add the diamond powder obtained in step (1), heat and stir continuously until the ethanol evaporates completely, and obtain diamond with zirconium nitrate pentahydrate crystals on the surface. (3) Heat-treat the diamond obtained in step (2) to obtain a diamond with a zirconium oxide coating.

2. The preparation method of ZrO2@diamond / 2024 aluminum alloy composite material based on the isolation effect of ZrO2 coating according to claim 1, characterized in that: The cold pressing process is performed at 300-600 MPa, with pressure held at room temperature for 10-30 minutes.

3. The preparation method of ZrO2@diamond / 2024 aluminum alloy composite material based on the isolation effect of ZrO2 coating according to claim 1, characterized in that: The hot pressing conditions are as follows: under an argon atmosphere, 500-600℃, pressure 10-120MPa, and pressure holding for 1-5 hours.

4. The preparation method of ZrO2@diamond / 2024 aluminum alloy composite material based on the isolation effect of ZrO2 coating according to claim 1, characterized in that: In step (1), acid washing is performed with a 2 mol / L HNO3 solution for 20 min and the mixture is stirred with a magnetic stirrer. Then, deionized water is used for washing.

5. The preparation method of ZrO2@diamond / 2024 aluminum alloy composite material based on the isolation effect of ZrO2 coating according to claim 1, characterized in that: In step (3), the heat treatment temperature is 600℃ and the treatment time is 180min.

6. The method for preparing ZrO2@diamond / 2024 aluminum alloy composite material based on the isolation effect of ZrO2 coating according to claim 1, characterized in that: The volume fraction of diamond powder coated with ZrO2 is 1-60% of the total volume of diamond powder coated with ZrO2 and 2024 aluminum alloy powder.

7. The method for preparing ZrO2@diamond / 2024 aluminum alloy composite material based on the isolation effect of ZrO2 coating according to claim 1, characterized in that: Before being coated with ZrO2, the particle size of diamond powder is 1-100μm, and the particle size of 2024 aluminum alloy powder is 1-100μm.

8. The ZrO2@diamond / 2024 aluminum alloy composite material prepared by the method according to any one of claims 1 to 7, characterized in that: The ZrO2@diamond / 2024 aluminum alloy composite material includes: 2024 aluminum alloy and diamond coated with ZrO2. The 2024 aluminum alloy, ZrO2 coating and diamond are mechanically bonded together. The thickness of ZrO2 coating is 0.1-10μm and the coating coverage is greater than or equal to 98%.

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