Preparation method of high-performance multi-scale silicon carbide reinforced aluminum-based composite material

Abstract

The invention discloses a preparation method of a high-performance multi-scale silicon carbide reinforced aluminum-based composite material, and relates to a preparation method of an aluminum-based composite material. The invention aims to solve the problem that the performance of the composite material is influenced by aluminum oxide impurities generated by oxidation of the aluminum-based composite material. According to the preparation method, the reagent a is added into the silicon carbide-aluminum composite powder to coat the aluminum powder, so that oxidation of the aluminum powder is reduced; the reagent a and the reagent b can generate reducing substances after being heated to react with oxygen and aluminum oxide introduced in subsequent operation, the content of aluminum oxide in the composite material is reduced, the degree of secondary oxidation of aluminum is reduced, and compared with a composite material with aluminum oxide impurities not treated, the strength and plasticity of the composite material are greatly improved, and the service life of the composite material is prolonged. Physical properties such as electric conduction and heat conduction are also improved. The content of aluminum oxide impurities in the silicon carbide-aluminum composite material is reduced by adopting a chemical method, operation under inert atmosphere protection is not needed, and the method is simple in process, convenient to operate, energy-saving, environment-friendly, low in cost and suitable for large-scale industrial production.

Description

Technical Field

[0001] The invention relates to a method for preparing an aluminum-based composite material. Background Art

[0002] Aluminum-based composites, due to their exceptional properties, including high specific strength, high specific modulus, good wear resistance, and dimensional stability, have shown great potential for application in aerospace, automotive manufacturing, electronic communications, and other fields. As modern industry continues to demand higher performance from materials, the research and development of aluminum-based composites is gaining increasing attention.

[0003] Currently, the main performance indicators for aluminum-based composites include strength, hardness, wear resistance, thermal conductivity, electrical conductivity, and high-temperature performance. Strength and hardness are key factors in determining the material's load-bearing capacity, while wear resistance directly affects its service life. Furthermore, good thermal and electrical conductivity are crucial for heat dissipation and signal transmission in electronic devices, while excellent high-temperature performance is essential for applications in aerospace and other fields.

[0004] However, aluminum-based composites inevitably oxidize during their preparation, resulting in the presence of aluminum oxide (Al2O3) impurities in the composites. This aluminum oxide primarily originates from impurities in the raw materials, oxidation during the smelting process, and interfacial reactions during composite preparation. The presence of aluminum oxide can have a number of adverse effects on the performance of aluminum-based composites, including:

[0005] ① Reduce mechanical properties: Alumina particles are hard and brittle, which can easily cause stress concentration in the matrix and become a source of cracks, resulting in a decrease in material strength and toughness.

[0006] ② Deterioration of processing performance: Alumina particles will aggravate tool wear, increase processing difficulty and reduce processing efficiency.

[0007] ③Affect thermal conductivity and electrical conductivity: Aluminum oxide is an insulator. Its presence will hinder the transmission of electrons and phonons, reducing the thermal conductivity and electrical conductivity of the material.

[0008] ④ Reduce high-temperature performance: Alumina easily reacts with the matrix at high temperatures to form a brittle phase, reducing the high-temperature strength and oxidation resistance of the material.

[0009] In order to reduce the alumina content in aluminum-based composite materials and improve material properties, the following methods are currently used:

[0010] Raw material purification: impurities in the raw materials are removed through refining, filtration, and other means to reduce the introduction of alumina. However, this method is costly and it is difficult to completely remove fine alumina particles.

[0011] Melt protection: Inert gas protection, flux covering and other methods are used to reduce the oxidation of aluminum liquid during the smelting process. However, this method has high requirements for equipment and the protection effect is limited, and it is difficult to completely avoid the formation of aluminum oxide.

[0012] Interface modification: By adding alloying elements and performing surface treatments, the interface between the reinforcement and the matrix is ​​improved, suppressing the interfacial reaction that produces aluminum oxide. However, the interface modification process is complex and may introduce other impurities, affecting material properties.

[0013] Post-processing: Heat treatment, mechanical processing and other methods are used to remove the surface oxide layer of the material and reduce the aluminum oxide content. However, this method is difficult to completely remove the aluminum oxide inside the material and may cause damage to the surface of the material.

[0014] In summary, existing methods for inhibiting oxidation in aluminum-based composites have certain limitations and are unable to meet the development needs of high-performance aluminum-based composites. Therefore, it is of great significance to develop an efficient, low-cost, and industrially scalable method for reducing the aluminum oxide content in aluminum-based composites. Summary of the Invention

[0015] The purpose of the present invention is to solve the problem of the influence of aluminum oxide impurities generated by oxidation of aluminum-based composite materials on the performance of the composite materials, and to reduce the content of aluminum oxide impurities in the aluminum-based composite materials by chemical methods, thereby obtaining high-performance aluminum-based composite materials.

[0016] The preparation method of the high-performance multi-scale silicon carbide reinforced aluminum-based composite material of the present invention is carried out by the following steps:

[0017] 1. Weighing

[0018] Weigh 2-6% of nano-SiC particles, 8-24% of micron-SiC particles, and the balance of aluminum powder as raw materials by volume; then weigh reagents a and b, with the mass of each being 20-30% of the total mass of SiC and aluminum powder; finally weigh a process control agent, with the mass of the process control agent being 1-3% of the total mass of the nano-SiC particles, micron-SiC particles, and aluminum powder;

[0019] The reagent a is glycerol or fatty alcohol polyoxyethylene ether carboxylic acid;

[0020] The reagent b is acetic acid or propionic acid;

[0021] 2. Mixed powder

[0022] First, the nano-silicon carbide particles, aluminum metal powder, and process control agent weighed in step 1 are placed in a planetary ball mill and subjected to high-speed ball milling, so that the nano-silicon carbide particles are embedded in the aluminum metal powder particles; then, micron silicon carbide particles and reagent a are added to the powder after high-speed ball milling, and low-speed ball milling is performed to coat the surface of the aluminum metal powder with reagent a, thereby inhibiting direct contact between aluminum and air; finally, reagent b is added and low-speed ball milling is continued. During the low-speed ball milling process, reagent b reacts with aluminum oxide on the surface of the aluminum metal particles to obtain a composite material slurry;

[0023] 3. Drying

[0024] The composite material slurry obtained in step 2 is placed in a drying oven for drying to obtain composite material powder; in order to remove impurities such as water generated during the powder mixing reaction in step 2;

[0025] 4. Moulding

[0026] The composite material powder obtained by drying in step 3 is placed in a steel mold, and the mold is placed in a press to apply pressure for compaction to obtain a silicon carbide-aluminum composite material precursor;

[0027] 5. Preparation of Silicon Carbide-Aluminum Composite Materials by Liquid Phase Method

[0028] First, the silicon carbide-aluminum composite precursor and the steel mold are preheated; the aluminum metal matrix is ​​taken and prepared into an aluminum metal melt, and then the aluminum metal melt is infiltrated into the preheated silicon carbide-aluminum precursor under mechanical pressure; finally, the aluminum matrix is ​​cooled and solidified in air to obtain an aluminum matrix composite material;

[0029] The composition of the aluminum metal matrix is ​​the same as that of the aluminum metal powder in step one.

[0030] Principles and beneficial effects of the present invention:

[0031] 1. The present invention adopts a chemical method to reduce the content of aluminum oxide impurities in the silicon carbide-aluminum composite material, does not need to be operated under the protection of an inert atmosphere, has a simple process, is easy to operate, is energy-saving and environmentally friendly, has a low cost, and is suitable for large-scale industrial production.

[0032] 2. The present invention reduces the oxidation of the aluminum powder by adding reagent a to the silicon carbide-aluminum composite powder to coat the aluminum powder; at the same time, reagent b is added to the composite powder to react with aluminum oxide, thereby reducing the aluminum oxide content in the composite material.

[0033] 3. Reagents a and b added to the silicon carbide-aluminum composite material powder of the present invention can generate reducing substances such as hydrogen and carbon monoxide after heating. These reducing substances can react with oxygen and aluminum oxide introduced in subsequent operations, thereby reducing the degree of secondary oxidation of aluminum.

[0034] 4. The silicon carbide-aluminum composite material prepared by the present invention has an extremely low aluminum oxide content. Compared with the composite material without treated aluminum oxide impurities, its strength and plasticity are greatly improved, and its physical properties such as electrical conductivity and thermal conductivity are also improved.

[0035] 5. The multi-scale silicon carbide-reinforced aluminum-based composite prepared by the present invention has nano-silicon carbide particles distributed within the aluminum matrix particles, ensuring the material's strength and good plasticity; micron-sized silicon carbide particles are distributed at the grain boundaries of the aluminum matrix particles, ensuring the material's strength and stiffness. This non-uniformly distributed microstructure can produce a composite material with a coordinated improvement in strength and plasticity. 6. The present invention is also applicable to the preparation of other ceramic-reinforced aluminum-based composites, reducing the content of harmful alumina impurities therein and improving the performance of the aluminum-based composite.

[0036] 7. The present invention does not generate harmful gases during the preparation process, and is environmentally friendly, green and healthy. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The SEM and element distribution (EDS) images of the silicon carbide-aluminum composite material prepared in Example 1;

[0038] Figure 2 SEM and element distribution (EDS) images of the silicon carbide-aluminum composite material prepared in the comparative example (without addition of glycerol and acetic acid). DETAILED DESCRIPTION

[0039] The technical solution of the present invention is not limited to the specific implementation methods listed below, but also includes any reasonable combination of the specific implementation methods.

[0040] Specific embodiment 1: The preparation method of the high-performance multi-scale silicon carbide reinforced aluminum-based composite material of this embodiment is carried out according to the following steps:

[0041] 1. Weighing

[0042] Weigh 2-6% of nano-SiC particles, 8-24% of micron-SiC particles, and the balance of aluminum powder as raw materials by volume; then weigh reagents a and b, with the mass of each being 20-30% of the total mass of SiC and aluminum powder; finally weigh a process control agent, with the mass of the process control agent being 1-3% of the total mass of the nano-SiC particles, micron-SiC particles, and aluminum powder;

[0043] The reagent a is glycerol or fatty alcohol polyoxyethylene ether carboxylic acid;

[0044] The reagent b is acetic acid or propionic acid;

[0045] 2. Mixed powder

[0046] First, the nano-silicon carbide particles, aluminum metal powder, and process control agent weighed in step 1 are placed in a planetary ball mill and subjected to high-speed ball milling, so that the nano-silicon carbide particles are embedded in the aluminum metal powder particles; then, micron silicon carbide particles and reagent a are added to the powder after high-speed ball milling, and low-speed ball milling is performed to coat the surface of the aluminum metal powder with reagent a, thereby inhibiting direct contact between aluminum and air; finally, reagent b is added and low-speed ball milling is continued. During the low-speed ball milling process, reagent b reacts with aluminum oxide on the surface of the aluminum metal particles to obtain a composite material slurry;

[0047] 3. Drying

[0048] The composite material slurry obtained in step 2 is placed in a drying oven for drying to obtain composite material powder; in order to remove impurities such as water generated during the powder mixing reaction in step 2;

[0049] 4. Moulding

[0050] The composite material powder obtained by drying in step 3 is placed in a steel mold, and the mold is placed in a press to apply pressure for compaction to obtain a silicon carbide-aluminum composite material precursor;

[0051] 5. Preparation of Silicon Carbide-Aluminum Composite Materials by Liquid Phase Method

[0052] First, the silicon carbide-aluminum composite material precursor is preheated together with the steel mold. The preheating causes the reagents a and b in the precursor to decompose and produce hydrogen and carbon monoxide. An aluminum metal substrate is taken and prepared into an aluminum metal melt. The aluminum metal melt is then infiltrated into the preheated silicon carbide-aluminum precursor under mechanical pressure.

[0053] The hydrogen and carbon monoxide produced by the decomposition react with the aluminum oxide in the aluminum metal melt and the oxygen in the gaps of the silicon carbide-aluminum composite material precursor, inhibiting the oxidation of aluminum and reducing the content of aluminum oxide; finally, the aluminum matrix composite material is obtained by cooling and solidifying in air;

[0054] The composition of the aluminum metal matrix is ​​the same as that of the aluminum metal powder in step one.

[0055] This embodiment has the following beneficial effects:

[0056] 1. This embodiment adopts a chemical method to reduce the content of aluminum oxide impurities in the silicon carbide-aluminum composite material. It does not need to be operated under the protection of an inert atmosphere. The process is simple, easy to operate, energy-saving and environmentally friendly, and low in cost, making it suitable for large-scale industrial production.

[0057] 2. In this embodiment, reagent a is added to the silicon carbide-aluminum composite powder to coat the aluminum powder, thereby reducing the oxidation of the aluminum powder; and reagent b is added to the composite powder to react with aluminum oxide, thereby reducing the aluminum oxide content in the composite material.

[0058] 3. In this embodiment, reagents a and b added to the silicon carbide-aluminum composite material powder can generate reducing substances such as hydrogen and carbon monoxide after heating. These reducing substances can react with oxygen and aluminum oxide introduced in subsequent operations, thereby reducing the degree of secondary oxidation of aluminum.

[0059] 4. The silicon carbide-aluminum composite material prepared in this embodiment has an extremely low aluminum oxide content. Compared with the composite material without aluminum oxide impurities, its strength and plasticity are greatly improved, and its physical properties such as electrical conductivity and thermal conductivity are also improved.

[0060] 5. In the multi-scale silicon carbide reinforced aluminum-based composite material prepared in this embodiment, nano-silicon carbide particles are distributed inside the aluminum matrix particles to ensure the strength and good plasticity of the material; micron silicon carbide particles are distributed at the grain boundaries of the aluminum matrix particles to ensure the strength and stiffness of the material; this non-uniformly distributed microstructure can obtain a composite material with coordinated improvement in strength and plasticity.

[0061] 6. This embodiment is also applicable to the preparation of other ceramic phase reinforced aluminum-based composite materials, which can reduce the content of harmful impurities of aluminum oxide and improve the performance of the aluminum-based composite materials.

[0062] 7. This embodiment does not generate any harmful gases during the preparation process, and is eco-friendly, environmentally friendly, and healthy.

[0063] Specific embodiment 2: This embodiment differs from specific embodiment 1 in that: the average particle size of the nano-silicon carbide particles in step 1 is 1-150 nm; the average particle size of the micron silicon carbide particles is 1-10 μm; and the average particle size of the aluminum metal powder particles is 30-50 μm.

[0064] Specific embodiment three: This embodiment differs from specific embodiment one or two in that: the purity of reagent a and reagent b described in step one is both above 99%.

[0065] Specific embodiment 4: This embodiment differs from any one of specific embodiments 1 to 3 in that: the process control agent in step 1 is polysilazane.

[0066] Specific embodiment five: This embodiment differs from any one of specific embodiments one to four in that the aluminum metal powder described in step one is pure aluminum, Al-Si alloy, Al-Si-Cu alloy, Al-Mg-Si alloy, Al-Cu-Mg alloy, Al-Zn-Cu alloy, Al-Zn-Mg-Cu alloy, Al-Si-Cu-Mg alloy, or a combination of several of them.

[0067] Specific embodiment 6: This embodiment differs from any one of specific embodiments 1 to 5 in that: the rotation speed of the high-speed ball mill in step 2 is 150-300 rpm, and the time is 4-8 hours.

[0068] Specific embodiment seven: This embodiment differs from any one of specific embodiments one to six in that: the rotation speed of the low-speed ball milling in step two is 40-50 rpm, and the time is 6-10 h.

[0069] Specific embodiment eight: This embodiment differs from any one of specific embodiments one to seven in that: the drying temperature in step three is 50-80° C., and the drying time is 6-12 hours.

[0070] Specific embodiment 9: This embodiment differs from any one of specific embodiments 1 to 8 in that the mechanical pressure applied in the press molding described in step 4 is 50-100 kN, and the holding time is 10-20 min.

[0071] Specific embodiment ten: This embodiment differs from any one of specific embodiments one to nine in that the mechanical pressure applied during the infiltration in step five is 10-15 MPa.

[0072] Example 1

[0073] The preparation method of the high-performance multi-scale silicon carbide reinforced aluminum-based composite material of this embodiment is carried out by the following steps:

[0074] 1. Weighing

[0075] 2% of nano-SiC particles, 8% of micron-SiC particles, and the balance of aluminum powder are weighed as raw materials by volume; glycerol and acetic acid are weighed, with the mass of each being 20% ​​of the total mass of SiC and aluminum powder; and finally, a process control agent is weighed, with the mass of the process control agent being 3% of the total mass of the nano-SiC particles, micron-SiC particles, and aluminum powder.

[0076] The average particle size of the nano-silicon carbide particles is 150 nm; the average particle size of the micron silicon carbide particles is 5 μm; and the average particle size of the aluminum metal powder particles is 50 μm.

[0077] The purity of the glycerol and acetic acid is above 99%;

[0078] The process control agent is polysilazane;

[0079] The aluminum metal powder is pure aluminum;

[0080] 2. Mixed powder

[0081] First, the nano-silicon carbide particles, aluminum metal powder, and process control agent weighed in step 1 are placed in a planetary ball mill and subjected to high-speed ball milling, so that the nano-silicon carbide particles are embedded in the aluminum metal powder particles; then, micronized silicon carbide particles and glycerol are added to the powder after high-speed ball milling, and low-speed ball milling is performed to coat the surface of the aluminum metal powder with glycerol, thereby inhibiting direct contact between aluminum and air; finally, acetic acid is added and low-speed ball milling is continued. During the low-speed ball milling process, the acetic acid reacts with aluminum oxide on the surface of the aluminum metal particles to obtain a composite material slurry;

[0082] The high-speed ball milling speed is 200 rpm and the time is 6 h;

[0083] The low-speed ball milling was performed at a speed of 50 rpm for 6 h.

[0084] 3. Drying

[0085] The composite material slurry obtained in step 2 is placed in a drying oven for drying to obtain composite material powder; in order to remove impurities such as water generated during the powder mixing reaction in step 2;

[0086] The drying temperature is 80°C and the drying time is 6;

[0087] 4. Moulding

[0088] The composite material powder obtained by drying in step 3 is placed in a steel mold, and the mold is placed in a press to apply pressure for compaction to obtain a silicon carbide-aluminum composite material precursor;

[0089] The mechanical pressure applied during the compression molding is 100 kN, and the holding time is 10 min;

[0090] 5. Preparation of Silicon Carbide-Aluminum Composite Materials by Liquid Phase Method

[0091] First, the silicon carbide-aluminum composite material precursor is preheated together with the steel mold. The preheating causes the glycerol and acetic acid in the precursor to decompose and produce hydrogen and carbon monoxide. An aluminum metal substrate is taken and prepared into an aluminum metal melt. The aluminum metal melt is then infiltrated into the preheated silicon carbide-aluminum precursor under mechanical pressure.

[0092] The hydrogen and carbon monoxide produced by the decomposition react with the aluminum oxide in the aluminum metal melt and the oxygen in the gaps of the silicon carbide-aluminum composite material precursor, inhibiting the oxidation of aluminum and reducing the content of aluminum oxide; finally, the aluminum matrix composite material is obtained by cooling and solidifying in air;

[0093] The composition of the aluminum metal matrix is ​​the same as that of the aluminum metal powder in step 1;

[0094] The mechanical pressure applied during the impregnation was 10 MPa.

[0095] At the same time, a comparative example 1 is set up: the preparation method of the silicon carbide reinforced aluminum-based composite material of comparative example 1 is carried out according to the following steps:

[0096] 1. Weighing

[0097] 2% of nano-SiC particles, 8% of micron-SiC particles, and the balance of aluminum powder are weighed as raw materials by volume; finally, a process control agent is weighed, the mass of which is 3% of the total mass of the nano-SiC particles, micron-SiC particles, and aluminum powder;

[0098] The average particle size of the nano-silicon carbide particles is 150 nm; the average particle size of the micron silicon carbide particles is 5 μm; and the average particle size of the aluminum metal powder particles is 50 μm.

[0099] The process control agent is polysilazane;

[0100] The aluminum metal powder is pure aluminum;

[0101] 2. Mixed powder

[0102] First, the nano-silicon carbide particles, aluminum metal powder and process control agent weighed in step 1 are placed in a planetary ball mill and ball milled at high speed so that the nano-silicon carbide particles are embedded in the aluminum metal powder particles; then, micron silicon carbide particles are added to the powder after high-speed ball milling, and low-speed ball milling is performed to obtain a mixed powder;

[0103] The high-speed ball milling speed is 200 rpm and the time is 6 h;

[0104] The low-speed ball milling was performed at a speed of 50 rpm for 6 h.

[0105] 3. Drying

[0106] The mixed powder obtained in step 2 is placed in a drying oven for drying to obtain composite material powder; in order to remove impurities such as water generated during the powder mixing process in step 2;

[0107] The drying temperature is 80°C and the drying time is 6;

[0108] 4. Moulding

[0109] The composite material powder obtained by drying in step 3 is placed in a steel mold, and the mold is placed in a press to apply pressure for compaction to obtain a silicon carbide-aluminum composite material precursor;

[0110] The mechanical pressure applied during the compression molding is 100 kN, and the holding time is 10 min;

[0111] 5. Preparation of Silicon Carbide-Aluminum Composite Materials by Liquid Phase Method

[0112] The silicon carbide-aluminum composite precursor and the steel mold are preheated together; an aluminum metal matrix is ​​taken and prepared into an aluminum metal melt, and then the aluminum metal melt is infiltrated into the preheated silicon carbide-aluminum precursor under mechanical pressure to obtain an aluminum-based composite material;

[0113] The composition of the aluminum metal matrix is ​​the same as that of the aluminum metal powder in step 1;

[0114] The mechanical pressure applied during the impregnation was 10 MPa.

[0115] Figure 1 The SEM and element distribution (EDS) images of the silicon carbide-aluminum composite material prepared in Example 1; Figure 2 The SEM and element distribution (EDS) images of the silicon carbide-aluminum composite material prepared in the comparative example (without adding glycerol and acetic acid). Figure 1 、 2 It can be found that the oxygen content in the composite material prepared in Example 1 is lower than that in the comparative composite material. The preparation method of the present invention can effectively inhibit the oxidation of the aluminum-based composite material during the preparation process.

[0116] Figure 1 It can also be seen that silicon is non-uniformly distributed in the aluminum matrix. This non-uniformly distributed microstructure can obtain a composite material with coordinated improvement in strength and plasticity.

[0117] The multi-scale silicon carbide reinforced aluminum-based composite material prepared in Example 1 has a tensile strength of 743 MPa, an elastic modulus of 93 GPa, and an elongation of 15.8%.

[0118] Example 2

[0119] The preparation method of the high-performance multi-scale silicon carbide reinforced aluminum-based composite material of this embodiment is carried out by the following steps:

[0120] 1. Weighing

[0121] 2% of nano-SiC particles, 8% of micron-SiC particles, and the balance of aluminum powder are weighed as raw materials by volume; glycerol and acetic acid are weighed, with the mass of each being 20% ​​of the total mass of SiC and aluminum powder; and finally, a process control agent is weighed, with the mass of the process control agent being 3% of the total mass of the nano-SiC particles, micron-SiC particles, and aluminum powder.

[0122] The average particle size of the nano-silicon carbide particles is 50 nm; the average particle size of the micron silicon carbide particles is 5 μm; and the average particle size of the aluminum metal powder particles is 30 μm.

[0123] The purity of the glycerol and acetic acid is above 99%;

[0124] The process control agent is polysilazane;

[0125] The aluminum metal powder is 6061Al;

[0126] 2. Mixed powder

[0127] First, the nano-silicon carbide particles, aluminum metal powder, and process control agent weighed in step 1 are placed in a planetary ball mill and subjected to high-speed ball milling, so that the nano-silicon carbide particles are embedded in the aluminum metal powder particles; then, micronized silicon carbide particles and glycerol are added to the powder after high-speed ball milling, and low-speed ball milling is performed to coat the surface of the aluminum metal powder with glycerol, thereby inhibiting direct contact between aluminum and air; finally, acetic acid is added and low-speed ball milling is continued. During the low-speed ball milling process, the acetic acid reacts with aluminum oxide on the surface of the aluminum metal particles to obtain a composite material slurry;

[0128] The high-speed ball milling speed is 200 rpm and the time is 6 h;

[0129] The low-speed ball milling was performed at a speed of 50 rpm for 6 h.

[0130] 3. Drying

[0131] The composite material slurry obtained in step 2 is placed in a drying oven for drying to obtain composite material powder; in order to remove impurities such as water generated during the powder mixing reaction in step 2;

[0132] The drying temperature is 80°C and the drying time is 6 hours;

[0133] 4. Moulding

[0134] The composite material powder obtained by drying in step 3 is placed in a steel mold, and the mold is placed in a press to apply pressure for compaction to obtain a silicon carbide-aluminum composite material precursor;

[0135] The mechanical pressure applied during the compression molding is 90 kN, and the holding time is 15 min;

[0136] 5. Preparation of Silicon Carbide-Aluminum Composite Materials by Liquid Phase Method

[0137] First, the silicon carbide-aluminum composite material precursor is preheated together with the steel mold. The preheating causes the glycerol and acetic acid in the precursor to decompose and produce hydrogen and carbon monoxide. An aluminum metal substrate is taken and prepared into an aluminum metal melt. The aluminum metal melt is then infiltrated into the preheated silicon carbide-aluminum precursor under mechanical pressure.

[0138] The hydrogen and carbon monoxide produced by the decomposition react with the aluminum oxide in the aluminum metal melt and the oxygen in the gaps of the silicon carbide-aluminum composite material precursor, inhibiting the oxidation of aluminum and reducing the content of aluminum oxide; finally, the aluminum matrix composite material is obtained by cooling and solidifying in air;

[0139] The composition of the aluminum metal matrix is ​​the same as that of the aluminum metal powder in step 1;

[0140] The mechanical pressure applied during the impregnation was 10 MPa.

[0141] The multi-scale silicon carbide reinforced aluminum-based composite material prepared in Example 2 has a tensile strength of 774 MPa, an elastic modulus of 102 GPa, and an elongation of 14.3%.

[0142] Example 3

[0143] The preparation method of the high-performance multi-scale silicon carbide reinforced aluminum-based composite material of this embodiment is carried out by the following steps:

[0144] 1. Weighing

[0145] 2% of nano-SiC particles, 8% of micron-SiC particles, and the balance of aluminum powder are weighed as raw materials by volume; glycerol and acetic acid are weighed, with the mass of each being 20% ​​of the total mass of SiC and aluminum powder; and finally, a process control agent is weighed, with the mass of the process control agent being 3% of the total mass of the nano-SiC particles, micron-SiC particles, and aluminum powder.

[0146] The average particle size of the nano-silicon carbide particles is 150 nm; the average particle size of the micron silicon carbide particles is 5 μm; and the average particle size of the aluminum metal powder particles is 50 μm.

[0147] The purity of the glycerol and acetic acid is above 99%;

[0148] The process control agent is polysilazane;

[0149] The aluminum metal powder is pure aluminum;

[0150] 2. Mixed powder

[0151] First, the nano-silicon carbide particles, aluminum metal powder, and process control agent weighed in step 1 are placed in a planetary ball mill and subjected to high-speed ball milling, so that the nano-silicon carbide particles are embedded in the aluminum metal powder particles; then, micronized silicon carbide particles and glycerol are added to the powder after high-speed ball milling, and low-speed ball milling is performed to coat the surface of the aluminum metal powder with glycerol, thereby inhibiting direct contact between aluminum and air; finally, acetic acid is added and low-speed ball milling is continued. During the low-speed ball milling process, the acetic acid reacts with aluminum oxide on the surface of the aluminum metal particles to obtain a composite material slurry;

[0152] The high-speed ball milling was performed at a speed of 150 rpm for 8 h.

[0153] The low-speed ball milling was performed at a speed of 50 rpm for 6 h.

[0154] 3. Drying

[0155] The composite material slurry obtained in step 2 is placed in a drying oven for drying to obtain composite material powder; in order to remove impurities such as water generated during the powder mixing reaction in step 2;

[0156] The drying temperature is 80°C and the drying time is 6 hours;

[0157] 4. Moulding

[0158] The composite material powder obtained by drying in step 3 is placed in a steel mold, and the mold is placed in a press to apply pressure for compaction to obtain a silicon carbide-aluminum composite material precursor;

[0159] The mechanical pressure applied during the compression molding is 100 kN, and the holding time is 15 min;

[0160] 5. Preparation of Silicon Carbide-Aluminum Composite Materials by Liquid Phase Method

[0161] First, the silicon carbide-aluminum composite material precursor is preheated together with the steel mold. The preheating causes the glycerol and acetic acid in the precursor to decompose and produce hydrogen and carbon monoxide. An aluminum metal substrate is taken and prepared into an aluminum metal melt. The aluminum metal melt is then infiltrated into the preheated silicon carbide-aluminum precursor under mechanical pressure.

[0162] The hydrogen and carbon monoxide produced by the decomposition react with the aluminum oxide in the aluminum metal melt and the oxygen in the gaps of the silicon carbide-aluminum composite material precursor, inhibiting the oxidation of aluminum and reducing the content of aluminum oxide; finally, the aluminum matrix composite material is obtained by cooling and solidifying in air;

[0163] The composition of the aluminum metal matrix is ​​the same as that of the aluminum metal powder in step 1;

[0164] The mechanical pressure applied during the impregnation was 10 MPa.

[0165] The multi-scale silicon carbide reinforced aluminum-based composite material prepared in Example 3 has a tensile strength of 717 MPa, an elastic modulus of 92 GPa, and an elongation of 16.3%.

Claims

1. A method for preparing a high-performance multi-scale silicon carbide reinforced aluminum-based composite material, characterized by: The preparation method of high-performance multi-scale silicon carbide reinforced aluminum matrix composite material is carried out in the following steps:

1. Weighing Weigh 2-6% of nano-SiC particles, 8-24% of micron-SiC particles, and the balance of aluminum powder as raw materials by volume; then weigh reagents a and b, with the mass of each being 20-30% of the total mass of SiC and aluminum powder; finally weigh a process control agent, with the mass of the process control agent being 1-3% of the total mass of the nano-SiC particles, micron-SiC particles, and aluminum powder; The reagent a is glycerol or fatty alcohol polyoxyethylene ether carboxylic acid; The reagent b is acetic acid or propionic acid; 2. Mixed powder First, the nano-silicon carbide particles, aluminum metal powder, and process control agent weighed in step 1 are placed in a planetary ball mill and subjected to high-speed ball milling, so that the nano-silicon carbide particles are embedded in the aluminum metal powder particles; then, micron silicon carbide particles and reagent a are added to the powder after high-speed ball milling, and low-speed ball milling is performed to coat the surface of the aluminum metal powder with reagent a, thereby inhibiting direct contact between aluminum and air; finally, reagent b is added and low-speed ball milling is continued. During the low-speed ball milling process, reagent b reacts with aluminum oxide on the surface of the aluminum metal particles to obtain a composite material slurry; 3. Drying The composite material slurry obtained in step 2 is placed in a drying oven for drying to obtain composite material powder; in order to remove impurities such as water generated during the powder mixing reaction in step 2; 4. Moulding The composite material powder obtained by drying in step 3 is placed in a steel mold, and the mold is placed in a press to apply pressure for compaction to obtain a silicon carbide-aluminum composite material precursor; 5. Preparation of Silicon Carbide-Aluminum Composite Materials by Liquid Phase Method First, the silicon carbide-aluminum composite precursor and the steel mold are preheated; the aluminum metal matrix is ​​taken and prepared into an aluminum metal melt, and then the aluminum metal melt is infiltrated into the preheated silicon carbide-aluminum precursor under mechanical pressure; finally, the aluminum matrix is ​​cooled and solidified in air to obtain an aluminum matrix composite material; The composition of the aluminum metal matrix is ​​the same as that of the aluminum metal powder in step one.

2. The method for preparing a high-performance multi-scale silicon carbide reinforced aluminum-based composite material according to claim 1, characterized in that: The average particle size of the nano-silicon carbide particles in step 1 is 1-150 nm; the average particle size of the micron silicon carbide particles is 1-10 μm; and the average particle size of the aluminum metal powder particles is 30-50 μm.

3. The method for preparing a high-performance multi-scale silicon carbide reinforced aluminum-based composite material according to claim 1, characterized in that: The purity of reagent a and reagent b described in step 1 is both above 99%.

4. The method for preparing a high-performance multi-scale silicon carbide reinforced aluminum-based composite material according to claim 1, characterized in that: The process control agent in step 1 is polysilazane.

5. The method for preparing a high-performance multi-scale silicon carbide reinforced aluminum-based composite material according to claim 1, characterized in that: The aluminum metal powder described in step 1 is one of pure aluminum, Al-Si alloy, Al-Si-Cu alloy, Al-Mg-Si alloy, Al-Cu-Mg alloy, Al-Zn-Cu alloy, Al-Zn-Mg-Cu alloy, Al-Si-Cu-Mg alloy, or a combination of several thereof.

6. The method for preparing a high-performance multi-scale silicon carbide reinforced aluminum-based composite material according to claim 1, characterized in that: The speed of the high-speed ball mill in step 2 is 150-300 rpm, and the time is 4-8 hours.

7. The method for preparing a high-performance multi-scale silicon carbide reinforced aluminum-based composite material according to claim 1, characterized in that: The rotation speed of the low-speed ball mill in step 2 is 40-50 rpm, and the time is 6-10 h.

8. The method for preparing a high-performance multi-scale silicon carbide reinforced aluminum-based composite material according to claim 1, characterized in that: The drying temperature in step 3 is 50-80°C and the drying time is 6-12 hours.

9. The method for preparing a high-performance multi-scale silicon carbide reinforced aluminum-based composite material according to claim 1, characterized in that: The mechanical pressure applied in the compression molding described in step 4 is 50-100 kN, and the holding time is 10-20 minutes.

10. The method for preparing a high-performance multi-scale silicon carbide reinforced aluminum-based composite material according to claim 1, characterized in that: The mechanical pressure applied during the infiltration in step 5 is 10-15 MPa.

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