Preparation method of high-heat-resistance and high-wear-resistance aluminum-based composite material

Abstract

The invention provides a preparation method of a high-heat-resistance and high-wear-resistance aluminum-based composite material, which comprises the following steps: carrying out high-temperature oxidation treatment on MAX-phase ceramic particles to form oxides on the surfaces of the MAX-phase ceramic particles and obtain composite particles with MAX phases as cores and oxides as shells; mixing the composite particles, SiC ceramic particles and aluminum powder to obtain mixed powder; and the mixed powder is sequentially subjected to cold press molding treatment and powder metallurgy sintering treatment, and the aluminum-based composite material is obtained. According to the method, an oxide layer is formed on the surface of the MAX phase ceramic particles through high-temperature oxidation treatment, in the subsequent powder metallurgy sintering treatment process, the MAX phase reacts with Al to generate A13Ti, oxide enters A13Ti crystals, and oxide compounded A13Ti particles are formed; in addition, in-situ A13Ti generated by reaction of MAX and Al can form a low-energy interface with a coherent relationship with an Al matrix, an Al grain boundary can be effectively pinned, grain coarsening and interface degradation caused by high temperature are avoided, and therefore the composite material has high heat resistance.

Description

Technical Field

[0001] This invention belongs to the field of aluminum-based composite material technology, specifically relating to a method for preparing a high heat-resistant and high wear-resistant aluminum-based composite material. Background Technology

[0002] With the continuous increase in rail transit speeds and the ongoing breakthroughs in aerospace vehicle performance, high-performance braking systems face increasingly stringent operating conditions. SiC / Al composite materials (SiC-reinforced aluminum matrix composites) have become the preferred material for next-generation brake discs due to their superior lightweight properties and excellent thermal conductivity. However, traditional SiC / Al composite materials exhibit significant performance degradation (i.e., poor heat resistance) under high-temperature conditions, and this high-temperature failure problem is particularly prominent in applications requiring frequent braking.

[0003] Under high-temperature conditions, SiC cannot effectively pin Al grain boundaries, resulting in significant grain coarsening in the composite material. Simultaneously, the degree of SiC-Al interfacial mismatch (thermal mismatch, modulus mismatch, etc.) further increases at high temperatures. This high-temperature grain coarsening and interfacial degradation lead to a substantial decrease in the wear resistance of SiC / Al composites, severely impacting their service life and safety, and directly hindering their widespread application in critical fields.

[0004] Therefore, it is necessary to provide a method for preparing aluminum-based composite materials with high heat resistance and high wear resistance. Summary of the Invention

[0005] Therefore, the present invention provides a method for preparing a high heat-resistant and high wear-resistant aluminum-based composite material, which can solve the problem of poor heat resistance and wear resistance of SiC / Al composite materials in the prior art.

[0006] To address the above problems, this invention provides a method for preparing a high heat-resistant and high wear-resistant aluminum-based composite material, comprising the following steps:

[0007] Step 1): The MAX phase ceramic particles are subjected to high-temperature oxidation treatment to form oxides on the surface of the MAX phase ceramic particles, and a composite particle with the MAX phase as the core and the oxide as the shell is obtained.

[0008] Step 2): The composite particles, SiC ceramic particles and aluminum powder are mixed to obtain a mixed powder;

[0009] Step 3): The mixed powder is subjected to cold pressing and powder metallurgy sintering in sequence to obtain an aluminum-based composite material reinforced with Al3Ti and SiC.

[0010] In the powder metallurgy sintering process, the MAX phase in the composite particles reacts with Al to form Al3Ti, and the oxide on the surface of the composite particles enters the Al3Ti crystal.

[0011] Furthermore, in step 1):

[0012] The high-temperature oxidation treatment is performed at a temperature of 800-1200℃ for 3-8 hours; and / or

[0013] The oxide shell in the composite particles has a thickness of less than 80 nm, and the thickness is uniformly covered on the surface of the MAX phase ceramic particles.

[0014] Furthermore, the MAX phase ceramic particles are ball-milled MAX phase ceramic particles; the ball-milled MAX phase ceramic particles are plate-shaped, with an aspect ratio of 2-6 and an average particle size of less than 1 μm;

[0015] Preferably, the MAX phase ceramic particles are Ti2AlC ceramic particles or Ti3AlC2 ceramic particles, and the average particle size of the MAX phase ceramic particles before ball milling is 1-30 μm.

[0016] Preferably, the ball milling process is performed using high-energy ball milling.

[0017] The ball-to-material weight ratio is 5-30:1, the rotation speed is 220-600 rpm, and the ball milling time is 5-30 hours.

[0018] Furthermore, in step 2), a mixer is used to perform the mixing process;

[0019] The ball weight ratio in the mixer is 1-3:1, the mixer speed is 50-100 rpm, and the mixing time is 6 hours.

[0020] Furthermore, by mass percentage, the content of the composite particles in the mixed powder is 1-10 wt.%, the content of the SiC ceramic particles is 10-30 wt.%, and the average particle size is 10-50 μm; the aluminum powder includes aluminum powder, aluminum alloy powder, or a mixed powder of aluminum powder and alloy element powder, with an average particle size of 1-50 μm.

[0021] Furthermore, in step 3), the pressure used in the cold pressing process is 60-120 MPa.

[0022] Furthermore, in step 3), the powder metallurgy sintering treatment employs one of the following: vacuum hot pressing sintering, hot isostatic pressing, or discharge ion beam sintering; and / or

[0023] The powder metallurgy sintering treatment is carried out at a temperature of 580-650℃ and a sintering pressure of 50-200MPa; the powder metallurgy sintering treatment time is 1-3h.

[0024] Furthermore, after the powder metallurgy sintering process in step 3), the process further includes: plastic deformation processing.

[0025] Preferably, the temperature for the plastic deformation processing is 400-630℃;

[0026] Preferably, the plastic deformation processing method is one of forging, rolling, or extrusion.

[0027] On the other hand, the present invention provides a high heat-resistant and high wear-resistant aluminum-based composite material, wherein the high heat-resistant and high wear-resistant aluminum-based composite material is an aluminum-based composite material reinforced with Al3Ti and SiC; wherein Al3Ti and SiC are dispersedly distributed in the aluminum matrix; the average particle size of Al3Ti is less than 1μm, and Al3Ti crystals are encapsulated with oxides.

[0028] Furthermore, the high heat-resistant and high wear-resistant aluminum-based composite material has a tensile strength of 180 MPa or higher at 350°C; preferably, the high heat-resistant and high wear-resistant aluminum-based composite material is obtained by any of the preparation methods described above.

[0029] The method for preparing a high heat-resistant and high wear-resistant aluminum-based composite material provided by this invention has the following beneficial effects:

[0030] 1. On one hand, the present invention provides a method for preparing a high heat-resistant and high wear-resistant aluminum-based composite material, comprising the following steps: subjecting MAX phase ceramic particles to high-temperature oxidation treatment to form oxides on the surface of the MAX phase ceramic particles, and obtaining composite particles with MAX phase as the core and oxide as the shell; mixing the composite particles, SiC ceramic particles and aluminum powder to obtain a mixed powder; subjecting the mixed powder to cold pressing and powder metallurgy sintering treatment in sequence to obtain an aluminum-based composite material reinforced with Al3Ti and SiC; in the powder metallurgy sintering treatment, the MAX phase in the composite particles reacts with Al to form Al3Ti, and the oxide on the surface of the composite particles enters the Al3Ti crystal. It should be noted that this invention uses high-temperature oxidation to form an oxide layer on the surface of MAX phase ceramic particles, followed by cold pressing to obtain a basic green body. In the subsequent powder metallurgy sintering process, the MAX phase reacts with Al to produce Al3Ti. The oxide on the surface of the MAX phase enters the Al3Ti grains through the subgrain merging process of Al3Ti, forming oxide-composite Al3Ti particles. On the one hand, SiC is dispersed in the aluminum matrix, ensuring that the composite material has good wear resistance. On the other hand, the in-situ Al3Ti produced by the reaction of MAX and Al can form a low-energy interface with a coherent relationship with the Al matrix, which can effectively pin the Al grain boundaries and avoid grain coarsening and interface degradation caused by high temperature, thereby giving the composite material high heat resistance. At the same time, the oxide inside Al3Ti can strengthen Al3Ti through dislocation pinning and other methods, increasing the hardness of Al3Ti. The dispersed distribution of Al3Ti particles in the aluminum matrix can reduce the particle-free areas in the composite material, thereby improving the uniformity of the microstructure and giving the composite material high wear resistance.

[0031] 2. Further, MAX phase ceramic particles are crushed using a high-energy ball milling process to obtain plate-like particles with an aspect ratio of 2-6. During high-energy ball milling, the intense collisions and shearing between the milling balls and the particles cause significant deformation and crushing of the MAX phase ceramic particles. Simultaneously, due to the intrinsic lamellar structure of the MAX phase ceramic particles, the milled particles exhibit a typical plate-like shape with a high specific surface area, thus promoting the nucleation of oxides in the MAX phase during subsequent high-temperature oxidation and increasing the oxide content. Furthermore, the crushed MAX phase particles can provide more nucleation sites for Al3Ti particles, promoting the reaction between MAX and Al to form dispersed submicron-sized equiaxed Al3Ti particles. This avoids incomplete MAX phase reaction, which leads to Al3Ti agglomeration, coarseness (average particle size of several to tens of micrometers), and uneven distribution.

[0032] 3. Furthermore, by controlling the temperature and time during the high-temperature oxidation process, a nano-oxide layer is formed on the surface of the MAX phase particles. This nano-oxide layer has a thickness of less than 80 nm and uniformly covers the surface of the MAX phase ceramic particles. The MAX phase (Ti2AlC or Ti3AlC2) reacts with oxygen at high temperatures to generate Al2O3 and TiO2. After ball milling, the average particle size of the MAX phase particles is less than 1 μm, avoiding the problem of excessively coarse particle size (too small specific surface area) leading to excessively low surface oxide content. Only the Al3Ti nucleated on the initial surface can effectively undergo oxide recombination. At the same time, the high-temperature, short-time oxidation process can effectively avoid the coarsening of the MAX phase surface oxide, allowing the nano-oxide to be encapsulated within the submicron Al3Ti crystals, while retaining the high reactivity of the MAX phase and Al.

[0033] 4. On the other hand, the present invention provides a high heat-resistant and high wear-resistant aluminum-based composite material, which is obtained by the above preparation method. The high heat-resistant and high wear-resistant aluminum-based composite material is an aluminum-based composite material reinforced with Al3Ti and SiC. Al3Ti and SiC are dispersed in the aluminum matrix. The average particle size of Al3Ti is less than 1 μm, and Al3Ti crystals are encapsulated with oxides. Based on the above characteristics, the obtained high heat-resistant and high wear-resistant aluminum-based composite material has a tensile strength of more than 180 MPa at 350°C. Attached Figure Description

[0034] 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.

[0035] Figure 1 These are transmission electron microscope images of Al3Ti in the high heat-resistant and high wear-resistant aluminum matrix composite material in Example 3;

[0036] Figure 2 This is a transmission electron microscope image of Al3Ti in the high heat-resistant and high wear-resistant aluminum matrix composite material in Comparative Example 2;

[0037] Figure 3 This is a transmission electron microscope (TEM) image of Al3Ti in the high heat-resistant and high wear-resistant aluminum matrix composite material in Comparative Example 4. Detailed Implementation

[0038] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the specific embodiments, structures, features, and effects according to the present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments. In the following description, different "an embodiment" or "an embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0039] Studies have shown that nanophases can effectively pin grain boundaries, significantly improving the heat resistance of composite materials. Existing technologies have attempted to improve the high-temperature performance of composite materials by adding nano-reinforcing phases, but practical application faces numerous challenges. For example, the strong van der Waals forces between nanoparticles make them prone to agglomeration during mixing, making uniform dispersion difficult and resulting in numerous particle-free regions within the composite material. On the one hand, agglomerated regions easily induce stress concentration, leading to premature failure of the composite material; on the other hand, the Al grains in particle-free regions, lacking particle pinning, are prone to Al grain boundary migration at high temperatures, resulting in rapid grain coarsening and reduced heat resistance, thus limiting the application of nano-reinforcing phases in SiC / Al composites.

[0040] The applicant discovered that Al3Ti has high thermal stability and a small difference in thermal expansion coefficient with Al. Using MAX phase ceramic particles as a precursor, submicron-sized Al3Ti is introduced in situ through the reaction of MAX-Al, avoiding the problem of difficult dispersion of added nanoparticles. At the same time, it can also form a low-energy Al3Ti-Al interface with coherent relationship, thereby suppressing grain coarsening and interface degradation caused by high temperature.

[0041] However, Al3Ti itself has relatively low hardness, which limits its performance in high-wear-resistance applications to some extent. Therefore, in order to fully utilize the strengthening effect of Al3Ti, it is necessary to further strengthen it to improve its hardness and wear resistance. The specific solution of the present invention is as follows:

[0042] This invention provides a method for preparing a high heat-resistant and high wear-resistant aluminum-based composite material, comprising the following steps:

[0043] Step 1): The MAX phase ceramic particles are subjected to high-temperature oxidation treatment to form oxides on the surface of the MAX phase ceramic particles, and a composite particle with the MAX phase as the core and the oxide as the shell is obtained.

[0044] Step 2): After mixing the composite particles, SiC ceramic particles and aluminum powder, a mixed powder is obtained;

[0045] Step 3): The mixed powder is subjected to cold pressing, powder metallurgy sintering and plastic deformation processing in sequence to obtain an aluminum matrix composite material reinforced with Al3Ti and SiC.

[0046] In the powder metallurgy sintering process, the MAX phase in the composite particles reacts with Al to form Al3Ti, and the oxides in the composite particles enter the Al3Ti crystal.

[0047] It should be noted that a high-temperature oxidation treatment forms an oxide layer on the surface of the MAX phase ceramic particles. After cold pressing, a basic green body is obtained. During subsequent powder metallurgy sintering, the MAX phase reacts with Al to produce Al3Ti. The oxide on the MAX phase surface enters the Al3Ti grains through the subgrain merging process, forming oxide-composite Al3Ti particles. On one hand, SiC is dispersed within the aluminum matrix, ensuring the composite material has good wear resistance. On the other hand, the reaction of MAX with Al produces in-situ Al3Ti, which has high thermal stability and a relatively different coefficient of thermal expansion compared to Al. The small size of Al3Ti allows it to form a low-energy interface with a coherent relationship with the Al matrix, effectively pinning Al grain boundaries and preventing grain coarsening and interface degradation caused by high temperatures, thus giving the composite material high heat resistance. At the same time, the oxides inside Al3Ti can strengthen Al3Ti through dislocation pinning and other methods, increasing the hardness of Al3Ti. The dispersed distribution of Al3Ti particles in the aluminum matrix can reduce the particle-free areas in the composite material, thereby improving the uniformity of the microstructure and giving the composite material high wear resistance. In addition, the dispersed distribution of SiC in the aluminum matrix gives the resulting aluminum-based composite metamaterial lightweight properties and good thermal conductivity.

[0048] In step 1) above: a high-temperature oxidation treatment is performed in a tube furnace at a temperature of 800-1200℃ for 3-8 hours, so that the thickness of the oxide layer formed on the surface of the MAX phase ceramic particles (the thickness of the oxide shell in the composite particles) is less than 80 nm. The MAX phase (Ti2AlC or Ti3AlC2) reacts with oxygen at high temperature to generate Al2O3 and TiO2. The average particle size of the MAX phase particles is less than 1 μm, avoiding the problem of excessively coarse particles (too small specific surface area) leading to insufficient surface oxide content, where only the initially nucleated Al3Ti can undergo oxide composite formation. Simultaneously, the high-temperature, short-time oxidation process effectively avoids the coarsening of the MAX phase surface oxide, allowing the nano-oxide to be encapsulated within the submicron Al3Ti crystals, while retaining the high reactivity of the MAX phase and Al.

[0049] In some embodiments, the MAX phase ceramic particles are MAX phase ceramic particles after high-energy ball milling; the MAX phase ceramic particles after high-energy ball milling are plate-shaped with an aspect ratio of 2-6 and an average particle size of less than 1 μm; the MAX phase ceramic particles are Ti2AlC ceramic particles or Ti3AlC2 ceramic particles, and the average particle size of the MAX phase ceramic particles before high-energy ball milling is 1-30 μm; wherein, high-energy ball milling is carried out under an argon atmosphere, the ball-to-material weight ratio is 5-30:1, the rotation speed is 220-600 rpm, and the ball milling time is 5-30 h. The flaky MAX phase ceramic particles after high-energy ball milling have a high specific surface area, which can promote the nucleation of oxides in the MAX phase during subsequent high-temperature oxidation and increase the oxide content. In addition, the broken MAX phase particles can provide more nucleation sites for Al3Ti particles, promote the reaction of MAX with Al to form dispersed submicron-sized equiaxed Al3Ti particles, thereby avoiding the problems of incomplete MAX phase reaction, which leads to Al3Ti agglomeration, coarse size (average particle size of several to tens of micrometers) and uneven distribution.

[0050] In step 2): a mixer is used for mixing in an air atmosphere; the ball-to-particle weight ratio in the mixer is 1-3:1, the mixer speed is 50-100 rpm, and the mixing time is 6 hours. By mass percentage, the composite particle content in the mixed powder is 1-10 wt.%, the SiC ceramic particle content is 10-30 wt.%, and the average particle size is 10-50 μm; the aluminum powder includes aluminum powder, aluminum alloy powder, or a mixture of aluminum powder and alloy element powder, with an average particle size of 1-50 μm. Using the above mixing method, the collision energy between the grinding balls and the oxidized MAX phase ceramic particles is low, and the oxide on the MAX phase surface remains attached to the MAX phase surface, avoiding oxide layer breakage and dispersion caused by high-energy collisions, thus ensuring the content of oxides entering the Al3Ti crystal. The above mixing process has the advantages of short process flow, high preparation efficiency, and simple equipment, enabling low-cost batch preparation.

[0051] In step 3): the cold pressing process uses a pressure of 60-120 MPa; the powder metallurgy sintering process uses one of the following: vacuum hot pressing, hot isostatic pressing, or discharge ion beam sintering; the powder metallurgy sintering temperature is 580-650℃, the sintering pressure is 50-200 MPa, and the time is 1-3 hours. The plastic deformation processing temperature is 400-630℃; the plastic deformation processing method is one of forging, rolling, or extrusion. Specifically, the powder metallurgy sintering process causes the MAX phase to react with aluminum to form Al3Ti, which is uniformly distributed in the aluminum matrix with an average particle size of less than 1 μm. Nano-oxides are encapsulated within Al3Ti; SiC is uniformly distributed in the aluminum matrix; and the plastic deformation processing further improves the density of the composite material.

[0052] On the other hand, the present invention provides a high heat-resistant and high wear-resistant aluminum-based composite material, which is obtained by the above preparation method. The high heat-resistant and high wear-resistant aluminum-based composite material is an aluminum-based composite material reinforced with Al3Ti and SiC. Al3Ti and SiC are dispersed in the aluminum matrix. The average particle size of Al3Ti is less than 1 μm, and Al3Ti crystals are encapsulated with oxides. Based on the above characteristics, the obtained high heat-resistant and high wear-resistant aluminum-based composite material has a tensile strength of more than 180 MPa at 350°C.

[0053] The present invention will be further described below with reference to specific embodiments and comparative examples.

[0054] Example 1

[0055] This embodiment provides a method for preparing a high heat-resistant and high wear-resistant aluminum-based composite material, including the following steps:

[0056] Step 1): High-energy ball milling was performed on Ti2AlC ceramic particles with an average particle size of 5μm to obtain (broken) Ti2AlC ceramic particles after ball milling; then, the broken MAX phase particles were subjected to high-temperature oxidation treatment in a tube furnace at a temperature of 800℃ for 8h to form oxides on the surface of Ti2AlC ceramic particles, and composite particles with Ti2AlC phase as core and oxide as shell were obtained.

[0057] The ball-to-material weight ratio during high-energy ball milling was 5:1, the rotation speed was 600 rpm, and the milling time was 8 hours, resulting in broken MAX phase particles; the thickness of the oxide layer on the surface of the MAX particles was approximately 50 nm.

[0058] Step 2): Weigh 50g of the above composite particles, 100g of SiC ceramic particles with an average particle size of 10μm and 850g of aluminum powder with an average particle size of 30μm, and mix them in an air atmosphere using a mixer to obtain a mixed powder.

[0059] During the mixing process, the weight ratio of balls in the mixer is 1:1, the rotation speed is 50 rpm, and the time is 6 hours.

[0060] Step 3): The above mixed powder is cold-pressed at 80 MPa, and then sintered at 580℃ and 100 MPa for 2 hours in a vacuum hot press furnace to obtain a composite material billet. The composite material billet is then hot-extruded at 500℃ at an extrusion ratio of 7:1 to obtain an aluminum-based composite material reinforced with Al3Ti and SiC.

[0061] In the powder metallurgy sintering process, the MAX phase in the composite particles reacts with Al to form Al3Ti with an average particle size of about 150 nm, and the oxides in the composite particles enter the Al3Ti crystal.

[0062] The aluminum-based composite material obtained in this embodiment has a uniform microstructure, with SiC and Al3Ti particles evenly distributed in the aluminum matrix and nano-oxides evenly distributed in the Al3Ti. On the one hand, the dispersed SiC and Al3Ti particles reinforced by nano-oxides ensure good wear resistance of the composite material; on the other hand, the dispersed Al3Ti particles effectively pin the Al grain boundaries, improving the heat resistance of the composite material. The tensile strength of this composite material at 350℃ is approximately 180 MPa.

[0063] Example 2

[0064] This embodiment provides a method for preparing a high heat-resistant and high wear-resistant aluminum-based composite material, including the following steps:

[0065] Step 1): High-energy ball milling was performed on Ti2AlC ceramic particles with an average particle size of 10 μm to obtain (broken) Ti2AlC ceramic particles after ball milling; then, the broken MAX phase particles were subjected to high-temperature oxidation treatment in a tube furnace at a temperature of 1000℃ for 5 h to form oxides on the surface of the Ti2AlC ceramic particles, and composite particles with Ti2AlC phase as core and oxide as shell were obtained.

[0066] The ball-to-material weight ratio during high-energy ball milling was 15:1, the rotation speed was 350 rpm, and the milling time was 15 h, resulting in broken MAX phase particles; the thickness of the oxide layer on the surface of the MAX particles was approximately 60 nm.

[0067] Step 2): Weigh 80g of the above composite particles, 200g of SiC ceramic particles with an average particle size of 30μm and 720g of aluminum powder with an average particle size of 10μm, and mix them in an air atmosphere using a mixer to obtain a mixed powder.

[0068] During the mixing process, the weight ratio of balls in the mixer is 2:1, the rotation speed is 80 rpm, and the time is 6 hours.

[0069] Step 3): The above mixed powder is cold-pressed at 80 MPa, and then sintered at 610°C and 100 MPa for 2 hours in a vacuum hot press furnace to obtain a composite material billet. The composite material billet is then hot-extruded at 500°C at an extrusion ratio of 7:1 to obtain an aluminum-based composite material reinforced with Al3Ti and SiC.

[0070] In the powder metallurgy sintering process, the MAX phase in the composite particles reacts with Al to form Al3Ti with an average particle size of about 200 nm, and the oxides in the composite particles enter the Al3Ti crystal.

[0071] The aluminum-based composite material obtained in this embodiment has a uniform microstructure, with SiC and Al3Ti particles evenly distributed in the aluminum matrix and nano-oxides evenly distributed in the Al3Ti. On the one hand, the dispersed SiC and Al3Ti particles reinforced by nano-oxides ensure good wear resistance of the composite material; on the other hand, the dispersed Al3Ti particles effectively pin the Al grain boundaries, improving the heat resistance of the composite material. The tensile strength of this composite material at 350℃ is approximately 190 MPa.

[0072] Example 3

[0073] This embodiment provides a method for preparing a high heat-resistant and high wear-resistant aluminum-based composite material, including the following steps:

[0074] Step 1): High-energy ball milling was performed on Ti3AlC2 ceramic particles with an average particle size of 30μm to obtain (broken) Ti3AlC2 ceramic particles after ball milling; then, the broken Ti3AlC2 phase particles were subjected to high-temperature oxidation treatment in a tube furnace at a temperature of 1200℃ for 3h to form oxides on the surface of the Ti3AlC2 ceramic particles, and composite particles with Ti2AlC phase as core and oxide as shell were obtained.

[0075] The ball-to-material weight ratio during high-energy ball milling was 30:1, the rotation speed was 220 rpm, and the milling time was 30 h, resulting in broken Ti3AlC2 phase particles; the thickness of the oxide layer on the surface of the Ti3AlC2 particles was approximately 80 nm.

[0076] Step 2): Weigh 100g of the above composite particles, 300g of SiC ceramic particles with an average particle size of 50μm and 600g of aluminum powder with an average particle size of 1μm, and mix them in an air atmosphere using a mixer to obtain a mixed powder.

[0077] During the mixing process, the weight ratio of balls in the mixer is 3:1, the rotation speed is 100 rpm, and the time is 6 hours.

[0078] Step 3): The above mixed powder is cold-pressed at 80 MPa, and then sintered at 650℃ and 100 MPa for 2 hours in a vacuum hot press furnace to obtain a composite material billet. The composite material billet is then hot-extruded at 500℃ at an extrusion ratio of 7:1 to obtain an aluminum-based composite material reinforced with Al3Ti and SiC.

[0079] In the powder metallurgy sintering process, the MAX phase in the composite particles reacts with Al to form Al3Ti with an average particle size of about 300 nm, and the oxides in the composite particles enter the Al3Ti crystal.

[0080] The aluminum-based composite material obtained in this embodiment has a uniform microstructure and its morphology is as follows: Figure 1 As shown, Al3Ti particles are uniformly distributed in the aluminum matrix, and nano-oxides are uniformly distributed within the Al3Ti. On one hand, the dispersed SiC and Al3Ti particles reinforced by nano-oxides ensure good wear resistance of the composite material; on the other hand, the dispersed Al3Ti particles effectively pin the Al grain boundaries, improving the heat resistance of the composite material. The tensile strength of this composite material at 350℃ is approximately 200 MPa.

[0081] Comparative Example 1

[0082] This comparative example provides a method for preparing an aluminum-based composite material, comprising the following steps:

[0083] Step 1): Ti3AlC2 ceramic particles with a uniform particle size of 30μm are subjected to high-temperature oxidation treatment using a tube furnace at a temperature of 1200℃ for 3 hours, so that oxides are formed on the surface of the Ti3AlC2 ceramic particles, and composite particles with Ti2AlC phase as core and oxide as shell are obtained.

[0084] The oxide layer on the surface of the Ti3AlC2 particles is approximately 70 nm thick.

[0085] Step 2): Weigh 100g of the above composite particles, 300g of SiC ceramic particles with an average particle size of 50μm and 600g of aluminum powder with an average particle size of 1μm, and mix them in an air atmosphere using a mixer to obtain a mixed powder.

[0086] During the mixing process, the weight ratio of balls in the mixer is 3:1, the rotation speed is 100 rpm, and the time is 6 hours.

[0087] Step 3): The above mixed powder is cold-pressed at 80 MPa, and then sintered at 650℃ and 100 MPa for 2 hours in a vacuum hot press furnace to obtain a composite material ingot. The composite material ingot is then hot-extruded at 500℃ at an extrusion ratio of 7:1 to obtain an aluminum-based composite material reinforced with Ti3AlC2, Al3Ti and SiC.

[0088] In this comparative example, since the MAX phase (Ti3AlC2 ceramic particles) was not subjected to high-energy ball milling, most of the MAX phase existed in the form of polycrystalline clusters within the aluminum matrix. The Al3Ti obtained from the reaction of the MAX phase and Al existed as a reaction layer on the surface of the MAX phase particles, with a thickness of approximately 10 μm. Some Al3Ti particles contained nano-oxide distributions, but the content was low, and the strengthening effect of the nano-oxides on the Al3Ti particles was weak. The composite material contained a significant amount of unreacted MAX phase particles, with an unreacted MAX phase particle content exceeding 5%. This uneven microstructure and the relatively weak Al3Ti particles resulted in poor heat resistance and wear resistance of the composite material, with a tensile strength of approximately 80 MPa at 350 °C.

[0089] Comparative Example 2

[0090] This comparative example provides a method for preparing an aluminum-based composite material, comprising the following steps:

[0091] Step 1): High-energy ball milling was performed on Ti2AlC ceramic particles with an average particle size of 5 μm to obtain ball-milled (broken) Ti2AlC ceramic particles.

[0092] The ball-to-material weight ratio during high-energy ball milling was 5:1, the rotation speed was 600 rpm, and the milling time was 8 hours, resulting in broken MAX phase particles.

[0093] Step 2): Weigh 50g of the above-mentioned crushed MAX phase particles, 100g of SiC ceramic particles with an average particle size of 10μm and 850g of aluminum powder with an average particle size of 30μm, and mix them in an air atmosphere using a mixer to obtain a mixed powder.

[0094] During the mixing process, the weight ratio of balls in the mixer is 1:1, the rotation speed is 50 rpm, and the time is 6 hours.

[0095] Step 3): The above mixed powder is cold-pressed at 80 MPa, and then sintered at 580℃ and 100 MPa for 2 hours in a vacuum hot press furnace to obtain a composite material billet. The composite material billet is then hot-extruded at 500℃ at an extrusion ratio of 7:1 to obtain an aluminum-based composite material reinforced with Al3Ti and SiC.

[0096] In the powder metallurgy sintering process, the MAX phase in the composite particles reacts with Al to form Al3Ti with an average particle size of about 300 nm.

[0097] The morphology of the aluminum-based composite material obtained in this comparative example is as follows: Figure 2As shown, the A13Ti particles are uniformly distributed in the aluminum matrix. Because this comparative example did not undergo high-temperature oxidation of the broken MAX phase particles, there is a lack of internal oxides to strengthen the A13Ti particles. Therefore, the tensile strength of this aluminum matrix composite at 350°C is approximately 150 MPa, lower than the strength in the examples.

[0098] Comparative Example 3

[0099] This comparative example provides a method for preparing an aluminum-based composite material, comprising the following steps:

[0100] Step 1): High-energy ball milling was performed on Ti2AlC ceramic particles with an average particle size of 5 μm to obtain (broken) Ti2AlC ceramic particles after ball milling; then, the broken MAX phase particles were subjected to high-temperature oxidation treatment in a tube furnace at a temperature of 1800℃ for 8 hours to form oxides on the surface of the Ti2AlC ceramic particles, and composite particles with Ti2AlC phase as core and oxide as shell were obtained.

[0101] The ball-to-material weight ratio during high-energy ball milling was 5:1, the rotation speed was 600 rpm, and the milling time was 8 hours, resulting in broken MAX phase particles; the thickness of the oxide layer on the surface of the MAX particles was approximately 400 nm.

[0102] Step 2): Weigh 50g of the above composite particles, 100g of SiC ceramic particles with an average particle size of 10μm and 850g of aluminum powder with an average particle size of 30μm, and mix them in an air atmosphere using a mixer to obtain a mixed powder.

[0103] During the mixing process, the weight ratio of balls in the mixer is 1:1, the rotation speed is 50 rpm, and the time is 6 hours.

[0104] Step 3): The above mixed powder is cold-pressed at 80 MPa, and then sintered at 580℃ and 100 MPa for 2 hours in a vacuum hot press furnace to obtain a composite material billet. The composite material billet is then hot-extruded at 500℃ at an extrusion ratio of 7:1 to obtain an aluminum-based composite material reinforced with Al3Ti and SiC.

[0105] In the powder metallurgy sintering process, the MAX phase in the composite particles reacts with Al to form Al3Ti with an average particle size of about 150 nm, and the oxides in the composite particles enter the Al3Ti crystal.

[0106] In this comparative example, due to the excessively high temperature of the oxidation treatment of the broken MAX phase particles, the oxide layer thickness on the surface is about 400 nm. The excessively thick oxide layer on the surface of the MAX phase particles reduces the reactivity, so that the MAX phase and Al hardly react during the sintering process. The tensile strength of this aluminum-based composite material at 350 °C is about 100 MPa.

[0107] Comparative Example 4

[0108] This comparative example provides a method for preparing an aluminum-based composite material, comprising the following steps:

[0109] Step 1): High-energy ball milling was performed on Ti2AlC ceramic particles with an average particle size of 5 μm to obtain (broken) Ti2AlC ceramic particles after ball milling; then, the broken MAX phase particles were subjected to high-temperature oxidation treatment in a tube furnace at a temperature of 800℃ for 1 h to form oxides on the surface of the Ti2AlC ceramic particles, and composite particles with Ti2AlC phase as core and oxide as shell were obtained.

[0110] The ball-to-material weight ratio during high-energy ball milling was 5:1, the rotation speed was 600 rpm, and the milling time was 8 hours, resulting in broken MAX phase particles; the thickness of the oxide layer on the surface of the MAX particles was approximately 50 nm.

[0111] Step 2): Weigh 50g of the above composite particles, 100g of SiC ceramic particles with an average particle size of 10μm and 850g of aluminum powder with an average particle size of 30μm, and mix them in an air atmosphere using a mixer to obtain a mixed powder.

[0112] During the mixing process, the weight ratio of balls in the mixer is 1:1, the rotation speed is 50 rpm, and the time is 6 hours.

[0113] Step 3): The above mixed powder is cold-pressed at 80 MPa, and then sintered at 580℃ and 100 MPa for 2 hours in a vacuum hot press furnace to obtain a composite material billet. The composite material billet is then hot-extruded at 500℃ at an extrusion ratio of 7:1 to obtain an aluminum-based composite material reinforced with Al3Ti and SiC.

[0114] In the powder metallurgy sintering process, the MAX phase in the composite particles reacts with Al to form Al3Ti with an average particle size of about 150 nm, and the oxides in the composite particles enter the Al3Ti crystal.

[0115] In this comparative example, due to the insufficient high-temperature oxidation time of the broken MAX phase particles, the oxides on the surface were discontinuous, distributed in an island-like pattern on the surface of the MAX particles, failing to form a uniform oxide layer. The nano-oxides were distributed inside the Al3Ti particles, but in low concentrations, and their morphology was as follows: Figure 3 As shown, Al3Ti particles are uniformly distributed in the aluminum matrix. Due to the lack of sufficient oxide to strengthen the Al3Ti particles, the tensile strength of this composite material at 350°C is approximately 110 MPa.

[0116] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0117] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A method for preparing a high heat-resistant and high wear-resistant aluminum-based composite material, characterized in that, Includes the following steps: Step 1): The MAX phase ceramic particles are subjected to high-temperature oxidation treatment to form oxides on the surface of the MAX phase ceramic particles, and a composite particle with the MAX phase as the core and the oxide as the shell is obtained. Step 2): The composite particles, SiC ceramic particles and aluminum powder are mixed to obtain a mixed powder; Step 3): The mixed powder is subjected to cold pressing and powder metallurgy sintering in sequence to obtain an aluminum-based composite material reinforced with Al3Ti and SiC. In the powder metallurgy sintering process, the MAX phase in the composite particles reacts with Al to form Al3Ti, and the oxide on the surface of the composite particles enters the Al3Ti crystal.

2. The method for preparing the high heat-resistant and high wear-resistant aluminum-based composite material according to claim 1, characterized in that, In step 1): The high-temperature oxidation treatment is performed at a temperature of 800-1200℃ for 3-8 hours; and / or The thickness of the oxide shell in the composite particles is less than 80 nm.

3. The method for preparing the high heat-resistant and high wear-resistant aluminum-based composite material according to claim 1 or 2, characterized in that, The MAX phase ceramic particles are ball-milled MAX phase ceramic particles; the ball-milled MAX phase ceramic particles are plate-shaped with an aspect ratio of 2-6 and an average particle size of less than 1 μm. Preferably, the MAX phase ceramic particles are Ti2AlC ceramic particles or Ti3AlC2 ceramic particles, and the average particle size of the MAX phase ceramic particles before ball milling is 1-30 μm. Preferably, the ball milling process is performed using high-energy ball milling. The ball-to-material weight ratio is 5-30:1, the rotation speed is 220-600 rpm, and the ball milling time is 5-30 hours.

4. The method for preparing the high heat-resistant and high wear-resistant aluminum-based composite material according to claim 1, characterized in that, In step 2): a mixer is used to perform the mixing process; The ball weight ratio in the mixer is 1-3:1, the mixer speed is 50-100 rpm, and the mixing time is 6 hours.

5. The method for preparing the high heat-resistant and high wear-resistant aluminum-based composite material according to any one of claims 1-4, characterized in that, In the mixed powder, by mass percentage, the content of the composite particles is 1-10 wt.%, the content of the SiC ceramic particles is 10-30 wt.%, and the average particle size is 10-50 μm; the aluminum powder includes aluminum powder, aluminum alloy powder, or a mixed powder of aluminum powder and alloy element powder, with an average particle size of 1-50 μm.

6. The method for preparing the aluminum-based composite material according to claim 1, characterized in that, In step 3), the pressure used in the cold pressing process is 60-120 MPa.

7. The method for preparing the high heat-resistant and high wear-resistant aluminum-based composite material according to claim 1, characterized in that, In step 3), the powder metallurgy sintering treatment employs one of the following: vacuum hot pressing sintering, hot isostatic pressing, or discharge ion beam sintering; and / or The powder metallurgy sintering treatment is carried out at a temperature of 580-650℃ and a sintering pressure of 50-200MPa; the powder metallurgy sintering treatment time is 1-3h.

8. The method for preparing the high heat-resistant and high wear-resistant aluminum-based composite material according to claim 1, characterized in that, After the powder metallurgy sintering process in step 3), the process further includes: plastic deformation processing. Preferably, the temperature for the plastic deformation processing is 400-630℃; Preferably, the plastic deformation processing method is one of forging, rolling, or extrusion.

9. A high heat-resistant and high wear-resistant aluminum-based composite material, characterized in that, The high heat-resistant and high wear-resistant aluminum matrix composite material is an aluminum matrix composite material reinforced with Al3Ti and SiC; wherein Al3Ti and SiC are dispersedly distributed in the aluminum matrix; the average particle size of Al3Ti is less than 1μm, and Al3Ti crystals are encapsulated with oxides.

10. The high heat resistance and high wear resistance aluminum-based composite material according to claim 9, characterized in that, The high heat-resistant and high wear-resistant aluminum-based composite material has a tensile strength of over 180 MPa at 350°C. Preferably, the high heat-resistant and high wear-resistant aluminum-based composite material is obtained by the preparation method described in any one of claims 1-8.

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