Carbon nanotube reinforced aluminum matrix composite material and method for manufacturing the same

Abstract

The application provides a carbon nanotube reinforced aluminum matrix composite material and a preparation method thereof, and the preparation method comprises the following steps: step 1) under the atmosphere of inert gas and oxygen, CNT powder and aluminum raw material powder are subjected to ball milling mixing, so that the surface of at least part of the aluminum powder is formed into aluminum oxide, the surface of at least part of the CNT is formed into suspended carbon, and the aluminum oxide and the suspended carbon are chemically combined; after the ball milling, a composite material powder is obtained; step 2) the composite material powder is subjected to sintering treatment, so that a blank ingot is obtained; a composite core-shell structure is formed in the blank ingot; step 3) the blank ingot is subjected to plastic processing treatment, solid solution treatment and aging treatment, so that the carbon nanotube reinforced aluminum matrix composite material is obtained. In the ball milling stage, the oxygen source is introduced, the aluminum oxide is formed with the CNT to form a composite core-shell structure, the generation of Al4C3 phase is reduced, the composite core-shell structure can be applied to a humid environment, and the composite core-shell structure can promote the interface combination and improve the mechanical properties of the material.

Description

Technical Field

[0001] This invention relates to the field of metal matrix composites, and in particular to a carbon nanotube-reinforced aluminum matrix composite and its preparation method. Background Technology

[0002] Carbon nanotubes (CNTs) possess extremely high mechanical properties (tensile strength >10 GPa, elastic modulus ~1 GPa), and are considered ideal reinforcements for composite materials. Adding a small amount of CNTs to an aluminum alloy matrix promises to produce high-strength, high-modulus aluminum-based composites, thus offering broad application prospects in the aerospace field.

[0003] However, due to the poor wettability between carbon nanotubes (CNTs) and the aluminum matrix, existing technologies often require synthesizing CNTs and the aluminum matrix at higher temperatures to promote interfacial bonding and induce partial interfacial reactions. Compared to low-temperature sintered CNT / Al composites, the formation of the interfacial reaction product Al4C3 phase helps improve the strength and toughness of the material [Carbon, 2017; 114P 198-208]. However, since Al4C3 is an easily hydrolyzed phase, CNT / Al composites containing a large amount of Al4C3 are prone to vaporization in humid environments, resulting in numerous pores and defects at the initial sites of the Al4C3 phase. This reduces the strength and elongation of the CNT / Al composite, making it difficult to use in humid environments. Therefore, improving the interfacial bonding of CNT / Al composites and minimizing the formation of easily hydrolyzed Al4C3 phase has become a key factor determining the overall performance of CNT / Al composites.

[0004] In summary, existing CNT / Al composite materials have at least the following technical problems:

[0005] When existing CNT / Al composites are used in humid environments, a large number of Al4C3 phases form pores at their initial locations, resulting in a decrease in the strength and elongation of the CNT / Al composites. Summary of the Invention

[0006] In view of this, the present invention provides a carbon nanotube reinforced aluminum matrix composite material and its preparation method, which can solve the problem that when existing CNT / Al composite materials are used in humid environments, a large number of Al4C3 phases form pore defects at their initial locations, resulting in a decrease in the strength and elongation of the CNT / Al composite material.

[0007] To address the aforementioned problems, this invention provides a carbon nanotube-reinforced aluminum-based composite material and its preparation method, the preparation method comprising the following steps:

[0008] Step 1) Under an atmosphere of inert gas and oxygen, CNT powder and aluminum raw material powder are ball-milled and mixed so that at least some of the aluminum powder surface forms alumina and at least some of the CNT surface forms suspended carbon, while the alumina and suspended carbon are chemically bonded; after the ball milling and mixing is completed, composite material powder is obtained.

[0009] Step 2) The composite material powder is sintered to obtain a billet; wherein at least a portion of the alumina and at least a portion of the CNTs in the billet form a composite core-shell structure of alumina-coated CNTs;

[0010] Step 3) After performing plastic processing, solution treatment and aging treatment on the billet in sequence, carbon nanotube reinforced aluminum matrix composite material is obtained.

[0011] In the aforementioned method for preparing a carbon nanotube-reinforced aluminum-based composite material, in step 1), CNT powder and aluminum raw material powder are placed in a high-energy ball mill, and a mixture of inert gas and oxygen is introduced into the high-energy ball mill. After ball milling and mixing, composite material powder is obtained; wherein:

[0012] Aluminum raw material powder is one or more of pure aluminum powder and aluminum alloy powder;

[0013] Preferably, the aluminum content in the aluminum raw material powder is greater than 85 wt%.

[0014] Preferably, the aluminum raw material powder includes one or more of 2-series aluminum alloy powder, 6-series aluminum alloy powder, and 7-series aluminum alloy powder.

[0015] In the aforementioned method for preparing a carbon nanotube-reinforced aluminum matrix composite material, in step 1), the average radial dimension of the CNT powder is 10-100 nm, and / or the average particle size of the aluminum matrix powder is 0.1-200 μm.

[0016] In the aforementioned method for preparing a carbon nanotube-reinforced aluminum matrix composite material, in step 1), the mass ratio of the ball to the material is controlled to be 5:1-30:1; and / or the ball milling time is controlled to be 1-20 hours.

[0017] The total mass of aluminum raw material powder and CNT powder is a, and the mass of CNT powder is b, wherein the mass fraction of b in a is 0.2-8 wt.%.

[0018] In the aforementioned method for preparing a carbon nanotube-reinforced aluminum matrix composite material, in step 1), the flow rate of the mixed gas is controlled to be 100-2000 ml / min, and / or the mass ratio of inert gas to oxygen is controlled to be 8:1-100:1.

[0019] In the aforementioned method for preparing a carbon nanotube-reinforced aluminum matrix composite material, step 2) includes a sintering process comprising one of hot pressing sintering, hot isostatic pressing sintering, and spark plasma sintering.

[0020] In the aforementioned method for preparing a carbon nanotube-reinforced aluminum matrix composite material, in step 2), when the sintering treatment is performed under pressure sintering, the temperature is controlled at 350-660℃, the holding time is controlled at 0-4 hours, and the pressure is controlled at 20-100MPa.

[0021] In the aforementioned method for preparing a carbon nanotube-reinforced aluminum matrix composite material, in step 2), when the spark plasma sintering treatment is performed using pressureless sintering, the pressureless sintering temperature is controlled at 600-700℃, and the sintering holding time is controlled at 0-4 hours.

[0022] In the aforementioned method for preparing a carbon nanotube-reinforced aluminum matrix composite material, in step 3), the temperature for plastic processing is controlled at 350-550℃.

[0023] In the aforementioned method for preparing a carbon nanotube-reinforced aluminum matrix composite material, step 3) includes plastic processing, which includes one of extrusion, forging, and rolling.

[0024] Preferred: Nominal extrusion ratio not less than 7:1;

[0025] Preferred: Nominal rolling ratio not less than 60%.

[0026] In the aforementioned method for preparing a carbon nanotube-reinforced aluminum matrix composite material, in step 3), the solution treatment temperature is controlled at 450-550℃ and the time is controlled at 1-4 hours; and / or the aging treatment time is controlled at 5-120 hours.

[0027] Preferably, time-sensitivity processing includes natural time-sensitivity or artificial time-sensitivity;

[0028] Preferably, the temperature for artificial aging is controlled at 100-200℃.

[0029] On the other hand, the present invention also provides a carbon nanotube reinforced aluminum matrix composite material, which includes an aluminum matrix and a reinforcement, wherein the reinforcement includes a composite core-shell structure of alumina-coated carbon nanotubes.

[0030] The carbon nanotube reinforced aluminum matrix composite material is prepared by any of the above preparation methods.

[0031] Compared with the prior art, the carbon nanotube-reinforced aluminum matrix composite material and its preparation method provided by the present invention have at least the following beneficial effects.

[0032] On one hand, this invention provides a method for preparing carbon nanotube-reinforced aluminum-based composite materials. Step 1) Under an inert gas and oxygen atmosphere, CNT powder and aluminum raw material powder are ball-milled and mixed to form alumina on the surface of at least a portion of the aluminum powder and suspended carbon on the surface of at least a portion of the CNTs, while simultaneously allowing the alumina and suspended carbon to chemically bond. After ball milling, composite material powder is obtained. Step 2) The composite material powder is sintered to obtain an ingot; wherein at least a portion of the alumina and at least a portion of the CNTs in the ingot form a composite core-shell structure of alumina-coated CNTs. Step 3) The ingot is sequentially subjected to plastic processing, solution treatment, and aging treatment to obtain the carbon nanotube-reinforced aluminum-based composite material. Based on this, this invention introduces an appropriate amount of oxygen during the high-energy ball milling process of CNT powder and aluminum raw material powder. The oxygen can react in situ with the aluminum powder surface during the high-energy ball milling process to form alumina. During the ball milling process, some CNT powder will form a significant amount of suspended carbon on the CNT surface due to structural damage. Under the mechanical activation effect of a high-energy ball mill, the temperature of CNT powder and aluminum raw material powder is significantly increased, promoting the chemical bonding between alumina and suspended carbon on the surface of carbon nanotubes. This results in the formation of a composite core-shell structure of alumina-coated carbon nanotubes during subsequent high-temperature sintering. This composite core-shell structure can significantly reduce the amount of easily hydrolyzable Al4C3 phase generated by the direct reaction between aluminum and suspended carbon, thus enabling the carbon nanotube-reinforced aluminum matrix composite to operate in humid environments. Furthermore, the in-situ reaction between suspended carbon and alumina forms bonds at the interface between the aluminum alloy matrix and the reinforcing phase, thereby enhancing the bonding strength at the interface between CNTs and the aluminum matrix alloy, and improving the mechanical properties of the carbon nanotube-reinforced aluminum matrix composite. In summary, the carbon nanotube-reinforced aluminum matrix composite prepared by this invention can be used in humid environments and exhibits superior mechanical properties.

[0033] In some embodiments, step 1 of this invention specifically involves placing CNT powder and aluminum raw material powder into a high-energy ball mill, and introducing a mixture of inert gas and oxygen into the high-energy ball mill. After ball milling and mixing, a composite material powder is obtained. The average radial dimension of the CNT powder is 10-100 nm, and / or the average particle size of the aluminum matrix powder is 0.1-200 μm. This invention, by mixing CNT powder and aluminum raw material powder in a high-energy ball mill while simultaneously introducing a mixture of inert gas and oxygen, results in the formation of more alumina and more suspended carbon on the CNT surface during high-energy ball milling. This facilitates the formation of a composite core-shell structure during subsequent high-temperature sintering. Furthermore, this invention controls the particle size of the CNT powder and the aluminum matrix powder, increasing the ball milling efficiency and enhancing the formation of alumina and CNT suspended carbon.

[0034] In some embodiments, the ball-to-powder mass ratio of the present invention is controlled at 5:1-30:1; and / or the ball milling time is controlled at 1-20 hours; the total mass of aluminum raw material powder and CNT powder is a, and the mass of CNT powder is b, wherein the mass fraction of b in a is 0.2-8 wt.%. The present invention improves the ball milling efficiency by controlling the ball-to-powder ratio added to the high-energy ball mill. Furthermore, by controlling the proportion of CNT powder in the mixed powder, the present invention ensures that the CNT powder is fully dispersed in the aluminum raw material powder, thereby improving the chemical bonding efficiency between alumina and the suspended carbon on the CNT surface.

[0035] In some embodiments, the flow rate of the mixed gas introduced into the present invention is controlled at 100-2000 ml / min, and / or the mass ratio of inert gas to oxygen is controlled at 8:1-100:1. By controlling the flow rate of the mixed gas introduced into the high-energy ball mill and the oxygen content, the present invention ensures sufficient oxidation efficiency of the mixed powder, allowing oxygen to react with aluminum powder to form more alumina, while also reducing the risk of explosions and other dangerous accidents caused by accelerated oxidation of aluminum powder, thus improving the safety factor.

[0036] In some embodiments, the sintering process of the present invention includes one of hot pressing sintering, hot isostatic pressing sintering, and spark plasma sintering. The present invention employs hot pressing or hot isostatic pressing sintering, which can further promote the bonding of suspended carbon bonds between alumina and the surface of carbon nanotubes. Both of these sintering processes are pressure sintering, which can improve the density of the ingot with the assistance of pressure. Furthermore, the present invention can employ pressureless sintering in the spark plasma sintering process. Pressureless sintering relies entirely on thermal diffusion to achieve interfacial bonding between powders. Although its densification degree is slightly lower than that of pressure sintering, this method can prepare multiple ingots in a single sintering process, resulting in higher production efficiency in large-scale material production.

[0037] In some embodiments, the present invention, based on the characteristics of different aluminum alloy sintering processes, controls the temperature of pressure sintering to 350-660℃ and the temperature of pressureless sintering to 600-700℃ to meet the sintering requirements of the present invention. Furthermore, to prevent excessive grain growth during sintering, the sintering holding time is controlled to 0-4 hours, and the pressure is controlled to 20-100 MPa.

[0038] In some embodiments, the temperature of the plastic processing of the present invention is controlled at 350-550°C. The present invention eliminates initial porosity defects in the billet through large plastic deformation and refines the grains, thereby improving the mechanical properties of carbon nanotube-reinforced aluminum matrix composites. The plastic processing of the present invention includes one of extrusion, forging, and rolling. When plastic processing is performed by extrusion, the nominal extrusion ratio is not less than 7:1; when plastic processing is performed by rolling, the nominal rolling rate is not less than 60%. By controlling the temperature of the plastic processing above the recrystallization temperature of the aluminum alloy and by controlling the deformation ratio, the present invention further improves the density of the bulk billet, improves the microstructure of the material, and ultimately obtains a carbon nanotube-reinforced aluminum matrix composite with superior performance.

[0039] On the other hand, this invention provides a carbon nanotube-reinforced aluminum matrix composite material. Because this composite material includes an aluminum matrix and a reinforcement, with the reinforcement comprising a composite core-shell structure of carbon nanotubes coated with alumina, this invention significantly reduces the amount of easily hydrolyzable Al4C3 phase formed by the direct reaction of aluminum with suspended carbon. Consequently, when the carbon nanotube-reinforced aluminum matrix composite material is used in humid environments, there will be fewer pores and defects at the initial sites of the Al4C3 phase, thus ensuring the strength and elongation of the composite material. Furthermore, it enhances the interfacial bonding of the composite material, resulting in superior mechanical properties. Attached Figure Description

[0040] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0041] Figure 1 This is a schematic diagram of the micro-region structure of a carbon nanotube-reinforced aluminum matrix composite material prepared by the present invention and its preparation method.

[0042] Figure 2 middle: Figure 2 a is a schematic diagram of the microstructure of the carbon nanotube-reinforced aluminum matrix composite material prepared in Example 1 according to the carbon nanotube-reinforced aluminum matrix composite material and its preparation method of the present invention; Figure 2 b is a schematic diagram of the microstructure of the ordinary carbon nanotube reinforced aluminum matrix composite material prepared in Comparative Example 1.

[0043] Figure 3 middle: Figure 3a is a schematic diagram of the microstructure of the carbon nanotube-reinforced aluminum matrix composite material prepared in Example 2 according to the carbon nanotube-reinforced aluminum matrix composite material and its preparation method of the present invention; Figure 3 b is a schematic diagram of the microstructure of the ordinary carbon nanotube-reinforced aluminum matrix composite material prepared in Comparative Example 2.

[0044] Figure 4 middle: Figure 4 a is a schematic diagram of the microstructure of the carbon nanotube-reinforced aluminum matrix composite material prepared in Example 3 according to the present invention and its preparation method. Figure 4 b is a schematic diagram of the microstructure of the ordinary carbon nanotube-reinforced aluminum matrix composite material prepared in Comparative Example 3. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. 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.

[0046] How to prepare carbon nanotube-reinforced aluminum matrix composites that can be used in humid environments and have excellent mechanical properties.

[0047] The main solution of this invention is as follows:

[0048] This invention provides a method for preparing carbon nanotube-reinforced aluminum-based composite materials, the method comprising the following steps:

[0049] Step 1) Under an atmosphere of inert gas and oxygen, CNT powder and aluminum raw material powder are ball-milled and mixed so that at least some of the aluminum powder surface forms alumina and at least some of the CNT surface forms suspended carbon, while the alumina and suspended carbon are chemically bonded; after the ball milling and mixing is completed, composite material powder is obtained.

[0050] Step 2) The composite material powder is sintered to obtain a billet; wherein at least a portion of the alumina and at least a portion of the CNTs in the billet form a composite core-shell structure of alumina-coated CNTs;

[0051] Step 3) After performing plastic processing, solution treatment and aging treatment on the billet in sequence, carbon nanotube reinforced aluminum matrix composite material is obtained.

[0052] Based on the above preparation method, the main inventive concept of this invention is as follows: This invention provides a method for preparing carbon nanotube-reinforced aluminum-based composite materials. During the ball milling mixing stage, an appropriate amount of a mixture of oxygen and inert gas is introduced into the ball mill jar. The powder in the ball mill jar can react in situ with the oxygen in the mixed gas during the ball milling process to generate alumina. The alumina can be dispersed and distributed within and on the surface of the aluminum powder under repeated crushing and cold welding. The ball milling process causes structural damage to the carbon nanotubes, generating more suspended carbon.

[0053] In industrial production, the carbon nanotube (CNT) wall layers produced cannot guarantee that all carbon atoms form a perfect six-membered ring structure. Some carbon chains extend out and hang on the surface of the CNTs in a suspended form. This invention enables the formation of more suspended carbon on the CNT surface during ball milling due to structural damage. This promotes the chemical bonding between alumina and the suspended carbon on the CNT surface, resulting in a composite core-shell structure of alumina-coated carbon nanotubes during subsequent high-temperature sintering. This composite core-shell structure can significantly reduce the amount of easily hydrolyzed Al4C3 generated by the in-situ reaction between aluminum and carbon, thus allowing the carbon nanotube-reinforced aluminum matrix composite material prepared by this invention to be used in humid environments. Furthermore, the composite core-shell structure formed by this invention can improve the interfacial bonding characteristics between carbon nanotubes and the aluminum alloy matrix, increasing the interfacial bonding strength. This results in the carbon nanotube-reinforced aluminum matrix composite material prepared by this invention having higher strength and toughness than ordinary carbon nanotube-reinforced aluminum matrix composite materials, and is expected to be applied in the aerospace field where lightweight and high strength are required.

[0054] Further, in step 1) of this invention, CNT powder and aluminum raw material powder are placed in a high-energy ball mill, and a mixture of inert gas and oxygen is introduced into the high-energy ball mill. After ball milling and mixing, composite material powder is obtained. This invention controls the average radial dimension of the CNT powder to be 10-100 nm, and / or the average particle size of the aluminum matrix powder to be 0.1-200 μm. Through the method in step 1 and the aforementioned particle size, this invention improves the mixing and reaction effect of this step, promoting the formation of more alumina between oxygen and aluminum powder during high-energy ball milling, and the formation of more suspended carbon on the CNT surface, providing support for subsequent reactions.

[0055] In the aluminum raw material powder of the present invention, the aluminum raw material powder is one or more of pure aluminum powder and aluminum alloy powder; preferably, the aluminum content in the aluminum raw material powder is greater than 85 wt%; preferably, the aluminum raw material powder includes one or more of 2-series aluminum alloy powder, 6-series aluminum alloy powder and 7-series aluminum alloy powder. The present invention can select different aluminum powders or aluminum alloy powders according to actual needs, and has a wide range of applicability.

[0056] Further, in step 1), the present invention improves the mixing efficiency of the ball milling process by controlling the mass ratio of the ball powder to the material in the high-energy ball mill to be 5:1-30:1, and / or controlling the ball milling time to be 1-20 hours. The total mass of the aluminum raw material powder and CNT powder in the present invention is a, and the mass of the CNT powder is b, wherein the mass fraction of b in a is 0.2-8 wt.%. The proportion of CNT powder in the total powder (aluminum raw material powder + CNT powder) of the present invention shall not exceed 8 wt%, thereby ensuring that the CNT powder is fully dispersed in the aluminum powder and improving the chemical bonding efficiency between alumina and the suspended carbon on the CNT surface.

[0057] Further, in step 1), the flow rate of the mixed gas is controlled at 100-2000 ml / min, and / or the mass ratio of inert gas to oxygen is controlled at 8:1-100:1. This invention controls the amount of inert gas added to be much higher than that of oxygen. Experimental verification shows that when the ratio of inert gas to oxygen is controlled at 8:1-100:1 and the flow rate of the mixed gas is controlled at 100-2000 ml / min, it ensures sufficient oxidation efficiency of the mixed powder to form more alumina, while also reducing the safety hazard of excessive oxidation and potential explosion.

[0058] It should be noted that the inert gas can be selected reasonably according to actual needs. For example, high-energy ball mills such as argon can be selected, but are not limited to stirred ball mills or planetary ball mills. In order to increase the ball milling efficiency, a reasonable high-energy ball mill can be selected according to actual needs.

[0059] Further, in step 2, the sintering treatment of the present invention includes one of hot pressing sintering, hot isostatic pressing sintering, and spark plasma sintering. Under reasonable conditions, any sintering method can theoretically significantly reduce the amount of easily hydrolyzable Al4C3 generated from the in-situ reaction between aluminum and carbon, and promote the interfacial bonding between carbon nanotubes and the aluminum matrix. The present invention, through reasonable selection, uses one of hot pressing sintering, hot isostatic pressing sintering, and spark plasma sintering for sintering treatment, thereby further promoting the suspended carbon bond bonding between alumina and the surface of carbon nanotubes. Both of these sintering treatments are pressure sintering, which can increase the density of the ingot under pressure, thus obtaining a dense ingot in this step.

[0060] It should be noted that both hot pressing sintering and hot isostatic pressing sintering are pressure sintering processes. Pressure sintering can also be used when employing spark plasma sintering. Pressure sintering can improve the density of the ingot under pressure assistance. Based on the sintering process characteristics of different aluminum alloy grades, this invention selects a pressure sintering temperature of 350-660℃, a post-sintering holding time of 0-4 hours, and a pressure of 20-100MPa. Furthermore, pressureless sintering can also be used when employing spark plasma sintering. In pressureless sintering, interfacial bonding between powders is achieved entirely through thermal diffusion, resulting in a slightly lower degree of densification than the pressure method. However, this method can prepare multiple ingots in a single sintering process, leading to higher production efficiency in large-scale material production. The pressureless sintering temperature should be slightly higher than the liquidus line of the base alloy. Depending on the characteristics of different aluminum alloy grades, the pressureless sintering temperature is controlled at 600-700℃, and the sintering holding time is controlled at 0-4 hours. This invention controls the holding time after sintering to 0-4 hours to prevent excessive grain growth during sintering. Therefore, the sintering holding time should not be too long and can be controlled between 0-4 hours; preferably, 1 hour is selected.

[0061] Furthermore, in step 2) of this invention, the plastic processing temperature is above the recrystallization temperature of the aluminum alloy, generally selected as 350-550℃. Plastic processing can be performed using extrusion, forging, or rolling. The main purpose of plastic processing is to eliminate initial porosity defects in the billet through large plastic deformation and to refine the grains to improve the mechanical properties of the material. Plastic processing requires a large deformation ratio to effectively improve the density of the billet. When extrusion is used, the nominal extrusion ratio is not less than 7:1; when rolling is used, the nominal rolling rate is not less than 60%. This invention, through the control of plastic processing temperature and parameters such as the nominal extrusion ratio and nominal rolling rate, combined with the aforementioned ball milling and sintering processes, further improves the density of the bulk billet, improves the microstructure of the material, and ultimately obtains a carbon nanotube-reinforced aluminum matrix composite material with better mechanical properties that can be applied in humid environments.

[0062] This invention further optimizes and improves the ductility and toughness of carbon nanotube-reinforced aluminum matrix composites by controlling the solution treatment temperature to 450-550℃ and the time to 1-4 hours; and / or controlling the aging treatment time to 5-120 hours; preferably, the aging treatment includes natural aging or artificial aging; preferably, the temperature of artificial aging is controlled to 100-200℃. By controlling the parameters of solution treatment and aging treatment, this invention further optimizes and improves the ductility and toughness of carbon nanotube-reinforced aluminum matrix composites.

[0063] This invention discloses a method for preparing carbon nanotube-reinforced aluminum-based composite materials. The method employs a convenient and easily controllable process, enabling large-scale production. During ball milling, an oxygen source is introduced. The alumina formed in situ by the oxygen and aluminum powder is dispersed throughout the aluminum powder under repeated crushing and cold welding (the initial formation of alumina occurs when oxygen contacts the aluminum powder surface; initially, alumina exists only on the powder surface. During cold welding, the original powder surface is encapsulated within the powder. Repeated crushing then creates a new surface, resulting in alumina distribution both inside and on the surface of the aluminum powder). This dispersion, combined with subsequent sintering, forms an alumina-encapsulated carbon nanotube composite core-shell structure (e.g., ...). Figure 1 As shown in the diagram, this minimizes the amount of easily hydrolyzed Al4C3 formed by the in-situ reaction of aluminum and carbon, allowing it to operate in humid environments. Furthermore, the aforementioned composite core-shell structure improves the interfacial bonding strength between carbon nanotubes and the aluminum matrix, enhancing the strength and toughness of carbon nanotube-reinforced aluminum matrix composites.

[0064] The present invention also provides a carbon nanotube reinforced aluminum matrix composite material, which has a composite core-shell structure of alumina-coated carbon nanotubes, thereby enabling the carbon nanotube reinforced aluminum matrix composite material to be used in humid environments, and the carbon nanotube reinforced aluminum matrix composite material has good interfacial bonding strength, resulting in better mechanical properties.

[0065] The following detailed description of a carbon nanotube-reinforced aluminum matrix composite material and its preparation method, through specific embodiments and comparative examples, further illustrates the present invention.

[0066] Example 1

[0067] This embodiment prepares a carbon nanotube-reinforced aluminum-based composite material, mainly including the following steps:

[0068] Step 1) Select 2024Al powder with an average particle size of 13μm and carbon nanotube powder with an average diameter of 15nm and mix them using a high-energy ball mill. The carbon nanotube powder accounts for 2wt% of the mixed powder (2024Al powder and carbon nanotube powder), the ball-to-powder weight ratio is 20:1, and the speed of the high-energy ball mill is controlled at 350rpm, with a maximum linear velocity of 4.4m / s. During ball milling, a mixture of oxygen and argon gas was introduced, with oxygen comprising 10 wt% of the mixture. The flow rate of the mixed gas was 1000 ml / min, and the total ball milling time was 8 hours, yielding composite material powder. The composition of the 2024Al powder was as follows: Cu 3.8–4.9 wt%, Mg 1.2–1.8 wt%, Mn 0.3–0.9 wt%, Zn <0.25 wt.%, Cr <0.1 wt.%, Ti <0.15 wt.%, Si <0.5 wt.%, Fe <0.5 wt.%, with the balance being Al.

[0069] Step 2) The composite material powder is hot-pressed and vacuum sintered for 2 hours at 580℃ and 80MPa to obtain a sintered ingot.

[0070] Step 3) The sintered billet is extruded at 450°C with an extrusion ratio of 9:1 to obtain the extruded material. Figure 2 As shown in Figure a, the extruded material has a core-shell structure of alumina-coated carbon nanotubes and lacks the Al4C3 phase. The extruded material was solution-treated at 500℃ for 2 hours and then naturally aged for 96 hours to obtain a carbon nanotube-reinforced aluminum-based composite material. Testing revealed that this carbon nanotube-reinforced aluminum-based composite material exhibited a yield strength of 660 MPa, a tensile strength of 750 MPa, and an elongation of 7%.

[0071] Example 2

[0072] This embodiment prepares a carbon nanotube-reinforced aluminum-based composite material, mainly including the following steps:

[0073] Step 1) 7055Al powder with an average particle size of 10 μm and carbon nanotube powder with an average diameter of 15 nm were mixed using a high-energy ball mill. The carbon nanotube powder accounted for 1 wt% of the mixed powder (7055Al powder and carbon nanotube powder), with a ball-to-powder weight ratio of 20:1. The high-energy ball mill was operated at 350 rpm with a maximum linear velocity of 4.4 m / s. During the ball milling process, a mixture of oxygen and argon was introduced, with oxygen comprising 10 wt% of the mixture at a flow rate of 1000 ml / min. The total ball milling time was 8 hours, yielding the composite material powder. The 7055Al powder composition was: Zn 7.6–8.4 wt%, Cu 2.0–2.6 wt%, Mg 1.8–2.3 wt%, Zr 0.05–0.25 wt%, Mn <0.05 wt%.

[0074] Cr < 0.04 wt.%, Ti < 0.06 wt.%, Si < 0.1 wt.%, Fe < 0.15 wt.%, balance Al;

[0075] Step 2) The composite material powder is hot-pressed and vacuum sintered for 2 hours at 540℃ and 80MPa to obtain a sintered ingot; Step 3) The sintered ingot is extruded at 420℃ with an extrusion ratio of 9:1 to obtain the extruded material, such as... Figure 3 As shown, in Figure 3As shown in Figure a, the extruded material has a core-shell structure of alumina-coated carbon nanotubes and lacks the Al4C3 phase. The extruded material was solution-treated at 470℃ for 1 hour and then artificially aged at 120℃ for 24 hours to obtain a carbon nanotube-reinforced aluminum-based composite material. Testing revealed that this carbon nanotube-reinforced aluminum-based composite material exhibited a yield strength of 710 MPa, a tensile strength of 795 MPa, and an elongation of 5%.

[0076] Example 3

[0077] This embodiment prepares a carbon nanotube-reinforced aluminum-based composite material, mainly including the following steps:

[0078] Step 1) 6092Al powder with an average particle size of 20 μm and carbon nanotube powder with an average diameter of 15 nm were mixed using a high-energy ball mill. The carbon nanotube powder accounted for 2 wt% of the mixed powder (6092Al powder and carbon nanotube powder), and the ball-to-powder weight ratio was 20:1. The high-energy ball mill was controlled at a speed of 350 rpm and a maximum linear velocity of 4.4 m / s. During the ball milling process, a mixture of oxygen and argon was introduced, with oxygen accounting for 10 wt% of the mixture. The flow rate of the mixed gas was 1000 ml / min, and the total ball milling time was 6 hours, yielding a composite material powder. The composition of the 6092Al powder was: Mg 0.8–1.2 wt%, Cu 0.7–1.0 wt%, Si 0.4–0.8 wt.%, Fe <0.15 wt.%, Zn <0.25 wt.%, Ti <0.15 wt.%, with the balance being Al.

[0079] Step 2) The composite material powder is hot-pressed and vacuum sintered for 2 hours at 540℃ and 80MPa to obtain a sintered ingot.

[0080] Step 3) The sintered billet is rolled at 470°C with a rolling reduction of 80% to obtain the rolled material, such as... Figure 4 As shown, in Figure 4 As shown in Figure a, the rolled material has a core-shell structure of alumina-coated carbon nanotubes and does not contain the Al4C3 phase. The rolled material was solution-treated at 540℃ for 2 hours and then artificially aged at 175℃ for 12 hours to obtain a carbon nanotube-reinforced aluminum matrix composite. Testing revealed that this carbon nanotube-reinforced aluminum matrix composite exhibited a yield strength of 480 MPa, a tensile strength of 550 MPa, and an elongation of 10%.

[0081] Comparative Example 1

[0082] This comparative example prepares a carbon nanotube-reinforced aluminum-based composite material, mainly including the following steps:

[0083] Step 1) 2024Al powder with an average particle size of 13 μm and carbon nanotube powder with an average diameter of 15 nm were mixed using a high-energy ball mill. The carbon nanotube powder accounted for 2 wt% of the mixed powder (2024Al powder and carbon nanotube powder), with a ball-to-powder weight ratio of 20:1. The high-energy ball mill was controlled at a rotation speed of 350 rpm and a maximum linear velocity of 4.4 m / s. Argon gas was introduced as a protective gas during the ball milling process at a flow rate of 1000 ml / min. The total ball milling time was 8 hours to obtain the composite material powder. The composition of the 2024Al powder was Cu 3.8–4.9 wt%, Mg 1.2–1.8 wt%, Mn 0.3–0.9 wt%, Zn <0.25 wt.%, Cr <0.1 wt.%, Ti <0.15 wt.%, Si <0.5 wt.%, Fe <0.5 wt.%, with the balance being Al.

[0084] Step 2) The composite material powder is hot-pressed and vacuum sintered for 2 hours at 580℃ and 80MPa to obtain a sintered ingot.

[0085] Step 3) The sintered billet is extruded at 450°C with an extrusion ratio of 9:1 to obtain the extruded material. Figure 2 As can be seen from b, the extruded material contains a certain amount of Al₄C₃. The extruded material is then solution-treated at 500℃ for 2 hours and naturally aged for 96 hours to finally obtain a carbon nanotube-reinforced aluminum-based composite material.

[0086] In Comparative Example 1, only argon gas was introduced as a protective gas during the ball milling stage. After testing, the carbon nanotube-reinforced aluminum matrix composite material obtained in Comparative Example 1 showed a yield strength of 640 MPa, a tensile strength of 690 MPa, and an elongation of 3%. Compared to Example 1, the yield strength, tensile strength, and elongation of the carbon nanotube-reinforced aluminum matrix composite material in Comparative Example 1 were all lower than those in Example 1. Furthermore, the carbon nanotube-reinforced aluminum matrix composite material in Comparative Example 1 contained a relatively large amount of Al4C3. With a high content of Al4C3 phase, it is prone to vaporization in humid environments, resulting in numerous pore defects at the initial sites of the Al4C3 phase in the carbon nanotube-reinforced aluminum matrix composite material. This reduces the strength and elongation of the carbon nanotube-reinforced aluminum matrix composite material, making it difficult to apply in humid environments.

[0087] Comparative Example 2

[0088] This comparative example prepares a carbon nanotube-reinforced aluminum-based composite material, mainly including the following steps:

[0089] Step 1) Select 7055Al powder with an average particle size of 10μm and carbon nanotube powder with an average diameter of 15nm and mix them using a high-energy ball mill. The carbon nanotube powder accounts for 1wt% of the mixed powder (7055Al powder and carbon nanotube powder), the ball-to-powder weight ratio is 20:1, and the speed of the high-energy ball mill is controlled at 350rpm, with a maximum linear velocity of 4.4m / s. Argon gas was introduced as a protective gas during the ball milling process at a flow rate of 1000 ml / min, and the total ball milling time was 8 hours to obtain composite material powder. The composition of the 7055Al powder was as follows: Zn 7.6–8.4 wt%, Cu 2.0–2.6 wt%, Mg 1.8–2.3 wt%, Zr 0.05–0.25 wt%, Mn <0.05 wt%, Cr <0.04 wt.%, Ti <0.06 wt.%, Si <0.1 wt.%, Fe <0.15 wt.%, with the balance being Al.

[0090] Step 2) The composite material powder is hot-pressed and vacuum sintered for 2 hours at 540℃ and 80MPa to obtain a sintered ingot.

[0091] Step 3) The sintered billet is extruded at 420°C with an extrusion ratio of 9:1 to obtain the extruded material, such as... Figure 3 As shown, in Figure 3 As can be seen from b, the extruded material contains a certain amount of Al4C3. The extruded material was solution-treated at 470℃ for 1 hour and artificially aged at 120℃ for 24 hours to finally obtain a carbon nanotube-reinforced aluminum matrix composite material.

[0092] In Comparative Example 2, only argon gas was introduced as a protective gas during the ball milling stage. After testing, the carbon nanotube-reinforced aluminum matrix composite material obtained in Comparative Example 2 showed a yield strength of 670 MPa, a tensile strength of 764 MPa, and an elongation of 2%. Compared to Example 2, the yield strength, tensile strength, and elongation of the carbon nanotube-reinforced aluminum matrix composite material obtained in Comparative Example 2 were all lower than those of the carbon nanotube-reinforced aluminum matrix composite material in Example 2.

[0093] Comparative Example 3

[0094] This comparative example prepares a carbon nanotube-reinforced aluminum-based composite material, mainly including the following steps:

[0095] Step 1) 6092Al powder with an average particle size of 20 μm and carbon nanotube powder with an average diameter of 15 nm were mixed using a high-energy ball mill. The carbon nanotube powder accounted for 2 wt% of the mixed powder (6092Al powder and carbon nanotube powder), with a ball-to-powder weight ratio of 20:1. The high-energy ball mill was operated at 350 rpm with a maximum linear velocity of 4.4 m / s. Argon gas was introduced as a protective gas during the ball milling process at a flow rate of 1000 ml / min. The total ball milling time was 6 hours, yielding a composite material powder. The composition of the 6092Al powder was 0.8–1.2 wt% Mg, 0.7–1.0 wt% Cu, and 0.4–0.8 wt%.

[0096] Fe < 0.15 wt.%, Zn < 0.25 wt.%, Ti < 0.15 wt.%, balance Al;

[0097] Step 2) The composite material powder is hot-pressed and vacuum sintered for 2 hours at 540℃ and 80MPa to obtain a sintered ingot.

[0098] Step 3) The sintered billet is rolled at 470°C with a rolling reduction of 80% to obtain the rolled material, such as... Figure 4 As shown, in Figure 4 As can be seen from b, the extruded material contains a certain amount of Al4C3. The rolled material was solution-treated at 540℃ for 2 hours and then artificially aged at 175℃ for 12 hours to finally obtain a carbon nanotube-reinforced aluminum matrix composite material.

[0099] In Comparative Example 3, only argon gas was introduced as a protective gas during the ball milling stage. After testing, the carbon nanotube-reinforced aluminum matrix composite material obtained in Comparative Example 3 showed a yield strength of 450 MPa, a tensile strength of 512 MPa, and an elongation of 7%. Compared to Example 3, the yield strength, tensile strength, and elongation of the carbon nanotube-reinforced aluminum matrix composite material in Comparative Example 3 were all lower than those of the carbon nanotube-reinforced aluminum matrix composite material in Example 3.

[0100] Comparative Example 4

[0101] Step 1) 2024Al powder with an average particle size of 13 μm and carbon nanotube powder with an average diameter of 15 nm were mixed using a high-energy ball mill. The carbon nanotube powder accounted for 2 wt% of the mixed powder (2024Al powder and carbon nanotube powder), and the ball-to-powder weight ratio was 20:1. The high-energy ball mill was controlled at a rotation speed of 350 rpm and a maximum linear velocity of 4.4 m / s. During the ball milling process, a mixture of oxygen and argon was introduced, with oxygen accounting for 10 wt% of the mixture. The flow rate of the mixed gas was 50 ml / min, and the total ball milling time was 8 hours to obtain the composite material powder. The composition of the 2024Al powder was Cu 3.8–4.9 wt%, Mg 1.2–1.8 wt%, Mn 0.3–0.9 wt%, Zn <0.25 wt.%, Cr <0.1 wt.%, Ti <0.15 wt.%, Si <0.5 wt.%, Fe <0.5 wt.%, with the balance being Al.

[0102] Step 2) The composite material powder is hot-pressed and vacuum sintered for 2 hours at 580℃ and 80MPa to obtain a sintered ingot.

[0103] Step 3) The sintered ingot was extruded at 450°C with an extrusion ratio of 9:1 to obtain the extruded material. The extruded material was then solution-treated at 500°C for 2 hours and naturally aged for 96 hours to finally obtain a carbon nanotube-reinforced aluminum matrix composite material. After testing, the yield strength of this carbon nanotube-reinforced aluminum matrix composite material reached 648 MPa, the tensile strength was 698 MPa, and the elongation was 4%. The flow rate of the mixed gas in Comparative Example 4 was less than that of the mixed gas in this invention. Compared with Example 1, the yield strength, tensile strength, and elongation of the carbon nanotube-reinforced aluminum matrix composite material in Comparative Example 4 were all lower than those of the carbon nanotube-reinforced aluminum matrix composite material in Example 1.

[0104] Comparative Example 5

[0105] Step 1) 2024Al powder with an average particle size of 13 μm and carbon nanotube powder with an average diameter of 15 nm were mixed using a high-energy ball mill. The carbon nanotube powder accounted for 2 wt% of the mixed powder (2024Al powder and carbon nanotube powder), with a ball-to-powder weight ratio of 20:1. The high-energy ball mill was operated at 350 rpm with a maximum linear velocity of 4.4 m / s. During the ball milling process, a mixture of oxygen and argon was introduced, with oxygen comprising 10 wt% of the mixture at a flow rate of 3000 ml / min. The total ball milling time was 8 hours, yielding the composite material powder. The 2024Al powder composition was: Cu 3.8–4.9 wt%, Mg 1.2–1.8 wt%, Mn 0.3–0.9 wt%, Zn <0.25 wt.%, Cr <0.1 wt.%, Ti <0.15 wt.%.

[0106] Si < 0.5 wt.%, Fe < 0.5 wt.%, balance Al;

[0107] Step 2) The composite material powder is hot-pressed and vacuum sintered for 2 hours at 580℃ and 80MPa to obtain a sintered ingot.

[0108] Step 3) The sintered ingot is extruded at 450°C with an extrusion ratio of 9:1 to obtain the extruded material. The extruded material is then solution-treated at 500°C for 2 hours and naturally aged for 96 hours to finally obtain a carbon nanotube-reinforced aluminum matrix composite material. After testing, the yield strength of this carbon nanotube-reinforced aluminum matrix composite material reached 651 MPa, the tensile strength was 710 MPa, and the elongation was 3%. The flow rate of the mixed gas in Comparative Example 5 was greater than that of the mixed gas in this invention. Compared with Example 1, the yield strength, tensile strength, and elongation of the carbon nanotube-reinforced aluminum matrix composite material in Comparative Example 5 were all lower than those of the carbon nanotube-reinforced aluminum matrix composite material in Example 1.

[0109] Comparative Example 6

[0110] Step 1) 2024Al powder with an average particle size of 13 μm and carbon nanotube powder with an average diameter of 15 nm were mixed using a high-energy ball mill. The carbon nanotube powder accounted for 2 wt% of the mixed powder (2024Al powder and carbon nanotube powder), with a ball-to-powder weight ratio of 4:1. The high-energy ball mill was operated at 350 rpm with a maximum linear velocity of 4.4 m / s. During the ball milling process, a mixture of oxygen and argon was introduced, with oxygen comprising 10 wt% of the mixture at a flow rate of 50 ml / min. The total ball milling time was 8 hours, yielding the composite material powder. The 2024Al powder composition was: Cu 3.8–4.9 wt%, Mg 1.2–1.8 wt%, Mn 0.3–0.9 wt%, Zn <0.25 wt.%, Cr <0.1 wt.%, Ti <0.15 wt.%.

[0111] Si < 0.5 wt.%, Fe < 0.5 wt.%, balance Al;

[0112] Step 2) The composite material powder is hot-pressed and vacuum sintered for 2 hours at 580℃ and 80MPa to obtain a sintered ingot.

[0113] Step 3) The sintered ingot is extruded at 450°C with an extrusion ratio of 9:1 to obtain the extruded material. The extruded material is then solution-treated at 500°C for 2 hours and naturally aged for 96 hours to finally obtain a carbon nanotube-reinforced aluminum matrix composite material. After testing, the yield strength of this carbon nanotube-reinforced aluminum matrix composite material reached 568 MPa, the tensile strength was 621 MPa, and the elongation was 6%. The ball-to-material weight ratio of Comparative Example 6 is lower than that of the present invention. Compared with Example 1, the yield strength, tensile strength, and elongation of the carbon nanotube-reinforced aluminum matrix composite material of Comparative Example 6 are all lower than those of the carbon nanotube-reinforced aluminum matrix composite material of Example 1.

[0114] In summary, this invention provides a carbon nanotube-reinforced aluminum matrix composite material and its preparation method. The method involves dispersing carbon nanotube powder and aluminum raw material powder using high-energy ball milling. During ball milling, a certain amount of oxygen is introduced, allowing the oxygen source to react in situ with the aluminum powder surface. This results in the formation of more suspended carbon on the carbon nanotube surface. Under the mechanical activation effect of ball milling, the oxidation reaction product, alumina, chemically bonds with the suspended carbon bonds on the aluminum powder surface. In the subsequent high-temperature sintering process, a composite core-shell structure of alumina-coated carbon nanotubes is formed. This composite core-shell structure significantly reduces the amount of easily hydrolyzed Al4C3 generated from the in-situ reaction between aluminum and carbon, thus enabling the carbon nanotube-reinforced aluminum matrix composite material to operate in humid environments. Furthermore, the composite core-shell structure improves the interfacial bonding characteristics between the carbon nanotubes and the aluminum matrix, promoting interfacial bonding and effectively enhancing the strength, toughness, and overall mechanical properties of the carbon nanotube-reinforced aluminum matrix composite material.

[0115] The 2-series aluminum alloy powders used in this invention include, but are not limited to, 2024-series aluminum alloy powders; the 6-series aluminum alloy powders include, but are not limited to, 6092-series aluminum alloy powders; and the 7-series aluminum alloy powders include, but are not limited to, 7055-series aluminum alloy powders. ， Other 2-series aluminum alloy powders, 6-series aluminum alloy powders, and 7-series aluminum alloy powders can all be used in the invention.

[0116] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a carbon nanotube-reinforced aluminum-based composite material, characterized in that, The preparation method includes the following steps: Step 1) Place carbon nanotube powder and aluminum raw material powder into a high-energy ball mill, and introduce a mixture of inert gas and oxygen into the high-energy ball mill. Under the atmosphere of inert gas and oxygen, the carbon nanotube powder and aluminum raw material powder are mixed by high-energy ball milling, so that at least some of the aluminum powder surface forms alumina and at least some of the carbon nanotube surface forms suspended carbon, while the alumina and suspended carbon are chemically bonded. The mass ratio of inert gas to oxygen is controlled at 8:1-100:1, the flow rate of the mixed gas is controlled at 100-2000 ml / min, the ball-to-material ratio is controlled at 5:1-30:1, and the ball milling time is controlled at 1-20 hours. After ball milling and mixing, composite material powder is obtained; Step 2) The composite material powder is sintered to obtain a billet; wherein at least a portion of the alumina and at least a portion of the carbon nanotubes in the billet form a composite core-shell structure of alumina-coated carbon nanotubes. Step 3) After performing plastic processing, solution treatment and aging treatment on the billet in sequence, carbon nanotube reinforced aluminum matrix composite material is obtained. The carbon nanotube reinforced aluminum matrix composite material includes a composite core-shell structure phase of alumina-coated carbon nanotubes.

2. The method for preparing a carbon nanotube-reinforced aluminum-based composite material according to claim 1, characterized in that, The aluminum raw material powder is one or more of pure aluminum powder and aluminum alloy powder.

3. The method for preparing a carbon nanotube-reinforced aluminum-based composite material according to claim 2, characterized in that, The aluminum alloy powder contains more than 85 wt% aluminum.

4. The method for preparing a carbon nanotube-reinforced aluminum-based composite material according to claim 2, characterized in that, The aluminum alloy powder includes one or more of 2-series aluminum alloy powder, 6-series aluminum alloy powder, and 7-series aluminum alloy powder.

5. The method for preparing a carbon nanotube-reinforced aluminum-based composite material according to claim 1, characterized in that, In step 1), the average radial dimension of the carbon nanotube powder is 10-100 nm, and / or the average particle size of the aluminum raw material powder is 0.1-200 μm.

6. The method for preparing a carbon nanotube-reinforced aluminum-based composite material according to claim 1, characterized in that, The total mass of aluminum raw material powder and carbon nanotube powder is a, and the mass of carbon nanotube powder is b, wherein the mass fraction of b in a is 0.2-8 wt.%.

7. The method for preparing a carbon nanotube-reinforced aluminum-based composite material according to claim 1, characterized in that, In step 2), the sintering process is one of hot pressing sintering, hot isostatic pressing sintering, and spark plasma sintering.

8. The method for preparing a carbon nanotube-reinforced aluminum-based composite material according to claim 7, characterized in that, In step 2), when the sintering process is pressure sintering, the temperature is controlled at 350-660℃, the holding time is controlled at 0-4 hours and not 0, and the pressure is controlled at 20-100MPa.

9. The method for preparing a carbon nanotube-reinforced aluminum-based composite material according to claim 7, characterized in that, In step 2), when the discharge plasma sintering process is performed under pressureless sintering, the temperature of the pressureless sintering is controlled at 600-700℃, and the sintering holding time is controlled at 0-4 hours and not 0.

10. The method for preparing a carbon nanotube-reinforced aluminum-based composite material according to claim 1, characterized in that, In step 3), the temperature of plastic processing is controlled at 350-550℃.

11. The method for preparing a carbon nanotube-reinforced aluminum-based composite material according to claim 10, characterized in that, In step 3), plastic processing includes one of extrusion, forging, and rolling.

12. The method for preparing a carbon nanotube-reinforced aluminum-based composite material according to claim 11, characterized in that, When plastic processing is performed by extrusion, the nominal extrusion ratio shall not be less than 7:

1.

13. The method for preparing a carbon nanotube-reinforced aluminum-based composite material according to claim 11, characterized in that, When plastic processing is performed by rolling, the nominal rolling rate shall not be less than 60%.

14. The method for preparing a carbon nanotube-reinforced aluminum-based composite material according to claim 1, characterized in that, In step 3), The solution treatment temperature is controlled at 450-550℃, and the time is controlled at 1-4 hours; and / or the aging treatment time is controlled at 5-120 hours.

15. The method for preparing a carbon nanotube-reinforced aluminum-based composite material according to claim 14, characterized in that, The timeliness processing includes natural timeliness or artificial timeliness.

16. The method for preparing a carbon nanotube-reinforced aluminum-based composite material according to claim 15, characterized in that, When performing artificial aging, the temperature should be controlled between 100-200℃.

17. A carbon nanotube-reinforced aluminum-based composite material, characterized in that, The carbon nanotube-reinforced aluminum matrix composite material includes an aluminum matrix and a reinforcement, wherein the reinforcement includes a composite core-shell structure of carbon nanotubes coated with alumina. The carbon nanotube-reinforced aluminum matrix composite material is prepared by the preparation method of any one of claims 1-16.

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