Aluminum-based composite material synergistically enhanced by nano ceramic particles and copper-plated flake graphite as well as preparation method and application of aluminum-based composite material

Abstract

The invention discloses an aluminum-based composite material synergistically reinforced by nano ceramic particles and copper-plated flake graphite as well as a preparation method and application of the aluminum-based composite material, and belongs to the technical field of new materials and preparation. The aluminum-based composite material is prepared from 1-3 wt.% of nano ceramic particles, 2-6 wt.% of copper-plated flake graphite and the balance of spherical aluminum powder through cold press molding and rapid hot press sintering. Wherein the crystalline flake graphite is obtained by plating a metal copper layer on the surface of the crystalline flake graphite by adopting a chemical plating method. According to the nano ceramic particle and copper-plated flake graphite hybrid reinforced aluminum-based composite material, the flaky aluminum powder prepared through a high-energy ball milling method has a larger specific surface area, adhesion of SiC ceramic particles is better facilitated, and the mechanical property of the aluminum-based composite material is improved; the surface of the crystalline flake graphite is plated with copper, so that the bonding strength of the crystalline flake graphite and the aluminum matrix can be improved, and the frictional wear resistance of the aluminum matrix composite is improved.

Description

Technical Field

[0001] The invention relates to the field of new materials and preparation technology, and in particular to an aluminum-based composite material synergistically reinforced with nano-ceramic particles and copper-plated flake graphite, and a preparation method and application thereof. Background Art

[0002] Aluminum-based composite materials have the characteristics of high specific strength, high specific modulus, corrosion resistance, strong designability, simple processing and molding technology, and low development cost. They are widely used in industrial fields such as aerospace, aviation, weapons and equipment, and automobiles to meet the needs of light weight and high performance. At present, the reinforcement of aluminum-based composite materials is mainly divided into continuous fiber reinforcement and discontinuous fiber reinforcement (including particles, short fibers, whiskers, etc.). Among them, the preparation and molding of particle-reinforced aluminum-based composite materials are the most studied, with the widest range of engineering applications and the highest technical maturity. By evenly distributing nano-scale reinforcement particles in the matrix, the dislocation accumulation caused by the obstruction of dislocation movement can produce a dispersion strengthening effect on the metal material, so that when a small amount of nano-reinforcement particles are added, the composite material still has a high strength while maintaining the original plasticity of the Al matrix as much as possible.

[0003] Traditional aluminum-based composite materials reinforced with micron SiC particles have large surface roughness of SiC particles, and the distribution of SiC hard points is uneven, resulting in poor surface quality after processing. Micron-sized SiC particles are more likely to agglomerate in the aluminum matrix and are difficult to disperse evenly, which can easily lead to stress concentration and affect the mechanical properties of the composite material. When flake graphite is used as a reinforcement for aluminum-based composite materials, the interfacial bonding force between the two is weak, resulting in easy interfacial debonding between the reinforcement and the matrix when subjected to external force, which reduces the mechanical properties of the composite material. At the same time, the aluminum matrix is ​​prone to interfacial reaction with flake graphite to generate Al2C3, which is a brittle phase itself, thereby reducing the mechanical properties of the composite material. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide an aluminum-based composite material synergistically reinforced with nano-ceramic particles and copper-plated flake graphite, and a preparation method and application thereof. By subjecting nano-SiC and other ceramic particles to high-energy ball milling with spherical aluminum powder to obtain flaky aluminum powder with a larger specific surface area, the distribution of SiC and other particles is facilitated, and the mechanical properties of the aluminum-based composite material are improved; at the same time, the use of copper-plated flake graphite greatly improves the bonding strength between the flake graphite and the aluminum matrix, and the Cu plating layer of appropriate thickness further increases the interface bonding strength between the flake graphite and the aluminum-based composite material; and the friction and wear performance of the aluminum-based composite material is greatly improved.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] The invention discloses an aluminum-based composite material synergistically reinforced by nano-ceramic particles and copper-plated flake graphite. The matrix of the aluminum-based composite material is aluminum metal, and the reinforcing phase is nano-ceramic particles and copper-plated flake graphite, wherein the content of the nano-ceramic particles is 1-3wt.%, and the content of the copper-plated flake graphite is 2-6wt.%.

[0007] Furthermore, the nano-ceramic particles are one or more of SiC particles, B4C particles, A12O3 particles, SiO2 particles, Si3N4 particles and AlN particles, and the particle size is nanometer scale.

[0008] Furthermore, the copper layer thickness of the copper-plated flake graphite is 1-3 μm.

[0009] Furthermore, the preparation method of the aluminum-based composite material synergistically reinforced by nano-ceramic particles and copper-plated flake graphite is to mix the nano-ceramic particles, copper-plated flake graphite and spherical aluminum powder in proportion and cold-press them, and then quickly hot-press and sinter them to obtain the aluminum-based composite material synergistically reinforced by nano-ceramic particles and copper-plated flake graphite.

[0010] Furthermore, the method specifically comprises the following steps:

[0011] (1) preparing copper-plated flake graphite by chemical plating;

[0012] (2) weighing the amounts of nano-ceramic particles, copper-plated flake graphite and spherical aluminum powder according to the composition of the aluminum-based composite material to be prepared;

[0013] (3) placing spherical aluminum powder and nano-ceramic particles into a ball mill and subjecting them to high-energy ball milling to obtain mixed powder I (spherical aluminum powder is transformed into flaky aluminum powder with a larger specific surface area after high-energy ball milling);

[0014] (4) adding the copper-plated flake graphite prepared in step (1) to the mixed powder I obtained in step (3), and then placing the mixed powder in a ball mill, and mixing the mixed powder II by high-energy ball milling;

[0015] (5) The mixed powder II obtained in step (4) is cold pressed into shape using a cold press machine, and then the green body obtained after cold pressing is sintered using rapid hot pressing sintering, and the green body is taken out after the temperature in the furnace cools to room temperature, thereby obtaining the aluminum-based composite material synergistically reinforced by the nano-ceramic particles and copper-plated flake graphite.

[0016] Furthermore, in step (2), the size of the spherical aluminum powder is 40-45 μm, and the size of the nano-ceramic particles is 20-80 nm.

[0017] Furthermore, when high-energy ball milling is performed in step (3), the ball-to-material ratio is (15-25):1, the ball milling speed is 200-300 rpm, and the ball milling time is 8-12 h; when high-energy ball milling is performed in step (4), the ball milling speed is 200-300 rpm, and the ball milling time is 1.5-3 h.

[0018] Furthermore, in step (1), the preparation process of copper-plated flake graphite is as follows: natural flake graphite is subjected to sensitization and activation treatment in sequence and then subjected to chemical copper plating, the chemical copper plating is carried out at 35-45° C. and under stirring conditions, the natural flake graphite is placed in a copper plating solution, and formaldehyde is uniformly added dropwise to the copper plating solution at a rate of 2 mL / min (according to a ratio of natural flake graphite to formaldehyde of 3 g:(5-10) mL), the copper plating reaction time is 20-30 min, and copper-plated natural flake graphite is obtained after chemical copper plating.

[0019] Furthermore, in the process of preparing the copper-plated flake graphite, the particle size of the natural flake graphite is 50-100 μm;

[0020] The sensitization treatment is to add natural flake graphite into the sensitization solution and stir for 10-20 minutes, and then filter out the sensitized flake graphite; the sensitizer composition is: SnCl2·2H2O is 20-25g / L, HCl is 40-50mL / L, and the rest is deionized water;

[0021] The activation treatment is to add the sensitized natural flake graphite into the sensitizing solution and stir for 10-20 minutes, and then filter out the activated flake graphite; the composition of the activator is: PdCl2 is 0.25-0.4g / L, HCl is 2.5-3.5mL / L, and the rest is deionized water;

[0022] The copper plating solution comprises: 16-20 g / L CuSO4·5H2O, 20-25 g / L potassium sodium tartrate (NaKC4H4O6), 25-30 g / L ethylenediaminetetraacetic acid (Na2EDTA), 14-16 g / L NaOH, and the rest is deionized water.

[0023] Furthermore, in step (5), the pressure applied during the cold pressing is 1.5-3 MPa, the pressing time is 5-15 min, and when the rapid hot pressing sintering is performed, the vacuum degree of the sintering is 13 -2 -10 -2 Pa, the sintering pressure is 50-60MPa, the sintering temperature is 560-580℃, and the sintering time is 8-15min.

[0024] The design mechanism and beneficial effects of the present invention are as follows:

[0025] 1. Adding nano-SiC particles to the aluminum-based composite material of the present invention can transfer the load from the aluminum matrix to the nano-SiC particles with higher strength and modulus when the aluminum matrix is ​​subjected to external force, thereby improving the load-bearing capacity of the composite material and effectively enhancing the strength and hardness of the material.

[0026] 2. When the present invention uses a high-energy ball milling process to mix silicon carbide particles with spherical aluminum powder, the spherical aluminum powder is transformed into flaky aluminum powder with a larger specific surface area after high-energy ball milling, which can make the silicon carbide particles evenly distributed in the aluminum matrix, which can hinder the movement and migration of dislocations. When dislocations move near particles, they need to bypass or cut through the particles, which increases the resistance to dislocation movement, thereby improving the tensile strength of the material.

[0027] 3. Copper-plated flake graphite is added to the aluminum-based composite material of the present invention. The copper layer with appropriate thickness on its surface improves the interfacial bonding performance between the reinforcement phase and the aluminum matrix and inhibits the formation of the brittle phase Al2C3, so that the load can be more effectively transferred from the aluminum matrix to the reinforcement, giving full play to the self-lubricating properties of the flake graphite.

[0028] 4. The copper-plated flake graphite added to the aluminum-based composite material of the present invention has a layered structure that can reduce friction during the friction process, reduce the friction coefficient of the composite material, reduce wear, and greatly improve the wear resistance and service life of the material.

[0029] 5. The copper-plated flake graphite added to the aluminum-based composite material of the present invention improves the interface bonding and improves the interface bonding strength by controlling the thickness of the copper-plated layer. Specifically, the Cu-plated layer of appropriate thickness increases the interface bonding strength between the flake graphite and the aluminum-based composite material. Too thin a coating cannot effectively improve the wettability of the interface between aluminum and graphite, thereby affecting the load transfer, and easily generating defects and cracks at the interface when the material is subjected to external force. The appropriate thickness can make the graphite and aluminum closely connected and better transfer stress. Too thick a coating will cause the interface bonding between graphite and the aluminum matrix to deteriorate because the density of copper is much greater than the density of graphite, and cracks will be generated at the interface when subjected to external force, reducing the mechanical properties of the material.

[0030] 6. The aluminum-based composite material synergistically reinforced by nano-ceramic particles and copper-plated flake graphite prepared by the present invention selects 1-3wt.% of nano-ceramic particles and 2-6wt.% of copper-plated flake graphite, and the copper layer thickness of the copper-plated flake graphite is 1-3μm, which can improve the mechanical properties and wear resistance while ensuring the plastic strength of the original aluminum matrix. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1The metallographic structure of the aluminum-based composite material of the present invention prepared by high-energy ball milling and the aluminum-based composite material prepared without ball milling is compared; wherein: (a) the aluminum-based composite material of the present invention; (b) the aluminum-based composite material prepared without ball milling.

[0032] Figure 2 The XRD spectrum of the aluminum-based composite material of the present invention is shown in FIG.

[0033] Figure 3 The SEM morphology of the tensile fracture of the aluminum-based composite material of the present invention; wherein: (a) the fracture morphology; (b) the energy spectrum at the arrow point in Figure (a). DETAILED DESCRIPTION

[0034] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0035] In the following examples, the sensitizer composition is: SnCl2·2H2O is 20 g / L, HCl is 40 mL / L, and the rest is deionized water; the ratio of natural flake graphite to sensitizer is 3 g: (100-500) mL;

[0036] The composition of the activator is: 0.25 g / L PdCl2, 2.5 mL / L HCl, and the rest is deionized water; the ratio of natural flake graphite to the activator is 3 g: (100-500) mL.

[0037] The copper plating solution comprises 16 g / L CuSO4·5H2O, 20 g / L potassium sodium tartrate (NaKC4H4O6), 25 g / L ethylenediaminetetraacetic acid (Na2EDTA), 14 g / L NaOH, and the rest is deionized water.

[0038] The particle size of the flake graphite used in the following examples and comparative examples is about 75 μm, and the size of the spherical aluminum powder is 40-45 μm; the particle size of the SiC particles in each example and comparative example 1 and comparative example 3 is about 50 nm.

[0039] In the following examples, when preparing copper-plated flake graphite, the ratio of flake graphite to formaldehyde is 3g:7mL.

[0040] Example 1

[0041] This embodiment is a method for preparing an aluminum-based composite material reinforced by hybridization of nano-SiC ceramic particles and copper-plated flake graphite, and the specific process is as follows:

[0042] 1. Preparation of copper-plated flake graphite:

[0043] At room temperature, add flake graphite to the sensitizer and stir for 15 minutes for sensitization treatment, filter out the sensitized flake graphite, and then add it to the prepared activator and stir for 15 minutes for activation treatment. Add the sensitized and activated natural flake graphite to the copper plating solution, stir evenly at 35-45°C, add formaldehyde at a rate of 2mL / min for 20-30 minutes, and chemically plate copper to obtain copper-plated flake graphite, with a copper film thickness of about 2μm.

[0044] 2. Preparation of mixed powder of nano-SiC ceramic particles and aluminum powder Ⅰ:

[0045] SiC ceramic particles and spherical aluminum powder were placed in a ball mill at a mass ratio of 2:96 and a ball-to-material ratio of 20:1. The ball mill was placed in a planetary ball mill and subjected to high-energy ball milling at a rotation speed of 200 rpm for 10 hours to obtain a mixed powder of nano-SiC ceramic particles and flaky aluminum powder, namely, mixed powder I.

[0046] 3. Preparation of mixed powder (mixed powder II) of copper-plated flake graphite, nano-SiC ceramic particles and aluminum powder:

[0047] The copper-plated flake graphite prepared in step 1 and the mixed powder I obtained in step 2 are placed in a ball mill at a mass ratio of 2:98, and ball milled at a speed of 200 rpm for 2 hours to obtain a mixed powder of copper-plated flake graphite, nano-SiC ceramic particles and aluminum powder, i.e., mixed powder II;

[0048] 4. Preparation of aluminum matrix composites reinforced by nano-SiC ceramic particles and copper-plated flake graphite

[0049] The mixed powder II was pre-compressed at a pressure of 2 MPa for 10 min using a cold press. The cold pressed green body was subjected to spark plasma sintering. The sintering process parameters were: vacuum degree of 1.3×10 -1 Pa, increase the pressure to 56 MPa at a pressure increase rate of 10 MPa / min, and maintain the pressure at this pressure for 5 minutes; then increase the temperature to 580°C, a sintering temperature, at a heating rate of 100°C / min, and maintain at 56 MPa and 580°C for 10 minutes; when the temperature in the furnace cools to below 150°C, release the hydraulic pressure, and then cool to room temperature to obtain the aluminum-based composite material.

[0050] The metallographic morphology of the aluminum-based composite material prepared in this embodiment is as follows Figure 1 (a) shows the XRD diffraction pattern of the aluminum-based composite material. Figure 2 As shown in the figure, it can be seen that there is no impurity phase Al2C3 in the composite material. The fracture morphology of the aluminum-based composite material is as follows Figure 3 As shown, it can be seen that the flake graphite is not pulled out at the dimple, indicating that the reinforcement phase is well bonded to the matrix.

[0051] Example 2

[0052] This embodiment is a method for preparing an aluminum-based composite material reinforced by hybridization of nano-SiC ceramic particles and copper-plated flake graphite, and the specific process is as follows:

[0053] 1. Preparation of copper-plated flake graphite:

[0054] At room temperature, natural flake graphite is added to the sensitizer and stirred for 15 minutes for sensitization treatment, the sensitized flake graphite is filtered out, and then added to the prepared activator and stirred for 15 minutes for activation treatment. The sensitized and activated natural flake graphite is added to the copper plating solution, stirred evenly at 35-45°C, and formaldehyde is added dropwise at a rate of 2mL / min for 20-30 minutes to react, and chemical copper plating is performed to obtain copper-plated flake graphite, and the copper film thickness is about 2μm.

[0055] 2. Preparation of mixed powder of nano-SiC ceramic particles and aluminum powder Ⅰ:

[0056] SiC ceramic particles and spherical aluminum powder were placed in a ball mill at a mass ratio of 2:94 and a ball-to-material ratio of 20:1. The ball mill was placed in a planetary ball mill and subjected to high-energy ball milling at a rotation speed of 200 rpm for 10 hours to obtain a mixed powder of nano-SiC ceramic particles and flaky aluminum powder, namely, mixed powder I.

[0057] 3. Preparation of mixed powder (mixed powder II) of copper-plated flake graphite, nano-SiC ceramic particles and aluminum powder:

[0058] The copper-plated flake graphite prepared in step 1 and the mixed powder I obtained in step 2 are placed in a ball mill at a mass ratio of 4:96, and ball milled at a speed of 200 rpm for 2 hours to obtain a mixed powder of copper-plated flake graphite, nano-SiC ceramic particles and aluminum powder, i.e., mixed powder II;

[0059] 4. Preparation of aluminum matrix composites reinforced by nano-SiC ceramic particles and copper-plated flake graphite

[0060] The mixed powder II was pre-compressed at a pressure of 2 MPa for 10 min using a cold press. The cold pressed green body was subjected to spark plasma sintering. The sintering process parameters were: vacuum degree of 1.3×10 -1 Pa, increase the pressure to 56 MPa at a pressure increase rate of 10 MPa / min, and maintain the pressure at this pressure for 5 minutes; then increase the temperature to 580°C, a sintering temperature, at a heating rate of 100°C / min, and maintain at 56 MPa and 580°C for 10 minutes; when the temperature in the furnace cools to below 150°C, release the hydraulic pressure, and then cool to room temperature to obtain the aluminum-based composite material.

[0061] The microscopic morphology of the aluminum-based composite material prepared in this embodiment is the same as that in Example 1. The XRD diffraction pattern of the aluminum-based composite material is as follows: Figure 2 As shown, it can be seen that there is no impure phase Al2C3 produced in the composite material; the flake graphite is not pulled out at the dimple, indicating that the reinforcement phase is well bonded with the matrix.

[0062] Example 3

[0063] This embodiment discloses a method for preparing an aluminum-based composite material reinforced by hybridization of nano-SiC ceramic particles and copper-plated flake graphite, comprising the following steps:

[0064] 1. Preparation of copper-plated flake graphite:

[0065] At room temperature, add flake graphite to the sensitizer and stir for 15 minutes for sensitization treatment, filter out the sensitized flake graphite, and then add it to the prepared activator and stir for 15 minutes for activation treatment. Add the sensitized and activated natural flake graphite to the copper plating solution, stir evenly at 35-45°C, add formaldehyde at a rate of 2mL / min for 20-30 minutes, and chemically plate copper to obtain copper-plated flake graphite, with a copper film thickness of about 2μm.

[0066] 2. Preparation of mixed powder of nano-SiC ceramic particles and aluminum powder Ⅰ:

[0067] SiC ceramic particles and spherical aluminum powder were placed in a ball mill at a mass ratio of 2:92 and a ball-to-material ratio of 20:1. The ball mill was placed in a planetary ball mill and subjected to high-energy ball milling at a rotation speed of 200 rpm for 10 hours to obtain a mixed powder of nano-SiC ceramic particles and flaky aluminum powder, namely, mixed powder I.

[0068] 3. Preparation of mixed powder (mixed powder II) of copper-plated flake graphite, nano-SiC ceramic particles and aluminum powder:

[0069] The copper-plated flake graphite prepared in step 1 and the mixed powder I obtained in step 2 are placed in a ball mill at a mass ratio of 6:94, and ball milled at a speed of 200 rpm for 2 hours to obtain a mixed powder of copper-plated flake graphite, nano-SiC ceramic particles and aluminum powder, i.e., mixed powder II;

[0070] 4. Preparation of aluminum matrix composites reinforced by nano-SiC ceramic particles and copper-plated flake graphite

[0071] The mixed powder II was pre-compressed at a pressure of 2 MPa for 10 min using a cold press. The cold pressed green body was subjected to spark plasma sintering. The sintering process parameters were: vacuum degree of 1.3×10 -1Pa, increase the pressure to 56 MPa at a pressure increase rate of 10 MPa / min, and maintain the pressure at this pressure for 5 minutes; then increase the temperature to 580°C, a sintering temperature, at a heating rate of 100°C / min, and maintain at 56 MPa and 580°C for 10 minutes; when the temperature in the furnace cools to below 150°C, release the hydraulic pressure, and then cool to room temperature to obtain the aluminum-based composite material.

[0072] The microscopic morphology of the aluminum-based composite material prepared in this embodiment is the same as that in Example 1. The XRD diffraction pattern of the aluminum-based composite material is as follows: Figure 2 As shown, it can be seen that there is no impure phase Al2C3 produced in the composite material; the flake graphite is not pulled out at the dimple, indicating that the reinforcement phase is well bonded with the matrix.

[0073] Comparative Example 1

[0074] This comparative example discloses a method for preparing an aluminum-based composite material reinforced by hybridization of nano-SiC ceramic particles and flake graphite. Compared with the embodiment, this example uses non-copper-plated flake graphite, and comprises the following steps:

[0075] 1. Preparation of mixed powder of nano-SiC ceramic particles and aluminum powder Ⅰ:

[0076] SiC ceramic particles and spherical aluminum powder were placed in a ball mill at a mass ratio of 2:96 and a ball-to-material ratio of 20:1. The ball mill was placed in a planetary ball mill and subjected to high-energy ball milling at a rotation speed of 200 rpm for 10 hours to obtain a mixed powder of nano-SiC ceramic particles and flaky aluminum powder, namely, mixed powder I.

[0077] 2. Preparation of mixed powder (mixed powder II) of flake graphite, nano-SiC ceramic particles and aluminum powder:

[0078] The flake graphite and the mixed powder I obtained in step 1 are placed in a ball mill at a mass ratio of 2:98, and ball milled at a speed of 200 rpm for 2 hours to obtain a mixed powder of copper-plated flake graphite, nano-SiC ceramic particles and aluminum powder, i.e., mixed powder II;

[0079] 3. Preparation of aluminum matrix composites reinforced by nano-SiC ceramic particles and flake graphite

[0080] The mixed powder II was pre-compressed at a pressure of 2 MPa for 10 min using a cold press. The cold pressed green body was subjected to spark plasma sintering. The sintering process parameters were: vacuum degree of 1.3×10 -1Pa, increase the pressure to 56 MPa at a pressure increase rate of 10 MPa / min, and maintain the pressure at this pressure for 5 minutes; then increase the temperature to 580°C, a sintering temperature, at a heating rate of 100°C / min, and maintain at 56 MPa and 580°C for 10 minutes; when the temperature in the furnace cools to below 150°C, release the hydraulic pressure, and then cool to room temperature to obtain the aluminum-based composite material.

[0081] Comparative Example 2

[0082] This comparative example discloses a method for preparing a hybrid reinforced aluminum-based composite material of micron SiC ceramic particles and copper-plated flake graphite. Compared with the embodiment, this example uses micron-sized SiC particles and includes the following steps:

[0083] 1. Preparation of copper-plated flake graphite:

[0084] At room temperature, add flake graphite to the sensitizer and stir for 15 minutes for sensitization treatment, filter out the sensitized flake graphite, and then add it to the prepared activator and stir for 15 minutes for activation treatment. Add the sensitized and activated natural flake graphite to the copper plating solution, stir evenly at 35-45°C, add formaldehyde at a rate of 2mL / min for 20-30 minutes, and chemically plate copper to obtain copper-plated flake graphite, with a copper film thickness of about 2μm.

[0085] In this comparative example, the sensitizer composition is: SnCl2·2H2O is 20g / L, HCl is 40mL / L, and the rest is deionized water; the ratio of natural flake graphite to sensitizer is 3g: (100-500)mL;

[0086] The composition of the activator is: 0.25 g / L PdCl2, 2.5 mL / L HCl, and the rest is deionized water; the ratio of natural flake graphite to the activator is 3 g: (100-500) mL.

[0087] The copper plating solution comprises 16 g / L CuSO4·5H2O, 20 g / L potassium sodium tartrate (NaKC4H4O6), 25 g / L ethylenediaminetetraacetic acid (Na2EDTA), 14 g / L NaOH, and the rest is deionized water.

[0088] 2. Preparation of mixed powder of micron SiC ceramic particles and aluminum powder Ⅰ:

[0089] SiC ceramic particles (50 μm) and spherical aluminum powder were placed in a ball mill at a mass ratio of 2:92 and a ball-to-material ratio of 20:1. The ball mill was placed in a planetary ball mill and subjected to high-energy ball milling at a rotation speed of 200 rpm for 10 hours to obtain a mixed powder of nano-SiC ceramic particles and flaky aluminum powder, namely, mixed powder I.

[0090] 3. Preparation of mixed powder (mixed powder II) of copper-plated flake graphite, nano-SiC ceramic particles and aluminum powder:

[0091] The copper-plated flake graphite prepared in step 1 and the mixed powder I obtained in step 2 are placed in a ball mill at a mass ratio of 2:98, and ball milled at a speed of 200 rpm for 2 hours to obtain a mixed powder of copper-plated flake graphite, nano-SiC ceramic particles and aluminum powder, i.e., mixed powder II;

[0092] 4. Preparation of aluminum matrix composites reinforced by nano-SiC ceramic particles and copper-plated flake graphite

[0093] The mixed powder II was pre-compressed at a pressure of 2 MPa for 10 min using a cold press. The cold pressed green body was subjected to spark plasma sintering. The sintering process parameters were: vacuum degree of 1.3×10 -1 Pa, increase the pressure to 56 MPa at a pressure increase rate of 10 MPa / min, and maintain the pressure at this pressure for 5 minutes; then increase the temperature to 580°C, a sintering temperature, at a heating rate of 100°C / min, and maintain at 56 MPa and 580°C for 10 minutes; when the temperature in the furnace cools to below 150°C, release the hydraulic pressure, and then cool to room temperature to obtain the aluminum-based composite material.

[0094] Comparative Example 3

[0095] This comparative example discloses a method for preparing a nano-SiC ceramic particle reinforced aluminum-based composite material. Compared with the embodiment, this example only uses nano-SiC particles, and includes the following steps:

[0096] 1. Preparation of mixed powder of nano-SiC ceramic particles and aluminum powder Ⅰ:

[0097] SiC ceramic particles and spherical aluminum powder were placed in a ball mill at a mass ratio of 2:96 and a ball-to-material ratio of 20:1. The ball mill was placed in a planetary ball mill and subjected to high-energy ball milling at a rotation speed of 200 rpm for 10 hours to obtain a mixed powder of nano-SiC ceramic particles and flaky aluminum powder, namely, mixed powder I.

[0098] 2. Preparation of aluminum matrix composites reinforced with nano-SiC ceramic particles

[0099] The mixed powder I was pre-compressed for 10 min at a pressure of 2 MPa using a cold press. The cold pressed green body was subjected to spark plasma sintering. The sintering process parameters were: vacuum degree of 1.3×10 -1Pa, increase the pressure to 56 MPa at a pressure increase rate of 10 MPa / min, and maintain the pressure at this pressure for 5 minutes; then increase the temperature to 580°C, a sintering temperature, at a heating rate of 100°C / min, and maintain at 56 MPa and 580°C for 10 minutes; when the temperature in the furnace cools to below 150°C, release the hydraulic pressure, and then cool to room temperature to obtain the aluminum-based composite material.

[0100] Comparative Example 4

[0101] This comparative example discloses a method for preparing a copper-plated flake graphite reinforced aluminum-based composite material. Compared with the embodiment, this example only uses copper-plated flake graphite, and includes the following steps:

[0102] 1. Preparation of copper-plated flake graphite:

[0103] At room temperature, add flake graphite to the sensitizer and stir for 15 minutes for sensitization treatment, filter out the sensitized flake graphite, and then add it to the prepared activator and stir for 15 minutes for activation treatment. Add the sensitized and activated natural flake graphite to the copper plating solution, stir evenly at 35-45°C, add formaldehyde at a rate of 2mL / min for 20-30 minutes, and chemically plate copper to obtain copper-plated flake graphite, with a copper film thickness of about 2μm.

[0104] In this comparative example, the sensitizer composition is: SnCl2·2H2O is 20g / L, HCl is 40mL / L, and the rest is deionized water; the ratio of natural flake graphite to sensitizer is 3g: (100-500)mL;

[0105] The composition of the activator is: 0.25 g / L PdCl2, 2.5 mL / L HCl, and the rest is deionized water; the ratio of natural flake graphite to the activator is 3 g: (100-500) mL.

[0106] The copper plating solution comprises 16 g / L CuSO4·5H2O, 20 g / L potassium sodium tartrate (NaKC4H4O6), 25 g / L ethylenediaminetetraacetic acid (Na2EDTA), 14 g / L NaOH, and the rest is deionized water.

[0107] 2. Preparation of mixed powder of copper-plated flake graphite and aluminum powder (mixed powder I):

[0108] The copper-plated flake graphite and spherical aluminum powder prepared in step 1 are placed in a ball mill at a mass ratio of 2:98, and ball milled at a speed of 200 rpm for 2 hours to obtain a mixed powder of copper-plated flake graphite, nano-SiC ceramic particles and aluminum powder, i.e., mixed powder I;

[0109] 3. Preparation of copper-plated flake graphite reinforced aluminum matrix composites

[0110] The mixed powder I was pre-compressed for 10 min at a pressure of 2 MPa using a cold press. The cold pressed green body was subjected to spark plasma sintering. The sintering process parameters were: vacuum degree of 1.3×10 -1 Pa, increase the pressure to 56 MPa at a pressure increase rate of 10 MPa / min, and maintain the pressure at this pressure for 5 minutes; then increase the temperature to 580°C, a sintering temperature, at a heating rate of 100°C / min, and maintain at 56 MPa and 580°C for 10 minutes; when the temperature in the furnace cools to below 150°C, release the hydraulic pressure, and then cool to room temperature to obtain the aluminum-based composite material.

[0111] Comparative Example 5

[0112] This comparative example discloses a method for preparing an aluminum-based composite material reinforced by hybridization of nano-SiC ceramic particles and copper-plated flake graphite. In this example, different copper plating formulas are used to prepare copper-plated flake graphite with a thinner copper plating layer, comprising the following steps:

[0113] 1. Preparation of copper-plated flake graphite:

[0114] At room temperature, add flake graphite to the sensitizer and stir for 15 minutes for sensitization treatment, filter out the sensitized flake graphite, and then add it to the prepared activator and stir for 15 minutes for activation treatment. Add the sensitized and activated natural flake graphite to the copper plating solution, stir evenly at 35-45°C, add formaldehyde at a rate of 2mL / min for 20-30 minutes, and chemically plate copper to obtain copper-plated flake graphite, with a copper film thickness of about 0.5μm.

[0115] In this comparative example, the sensitizer composition is: SnCl2·2H2O is 20g / L, HCl is 40mL / L, and the rest is deionized water; the ratio of natural flake graphite to sensitizer is 3g: (100-500)mL;

[0116] The composition of the activator is: 0.25 g / L PdCl2, 2.5 mL / L HCl, and the rest is deionized water; the ratio of natural flake graphite to the activator is 3 g: (100-500) mL.

[0117] The copper plating solution comprises: 12 g / L CuSO4·5H2O, 20 g / L potassium sodium tartrate (NaKC4H4O6), 25 g / L ethylenediaminetetraacetic acid (Na2EDTA), 14 g / L NaOH, and the rest is deionized water.

[0118] 2. Preparation of mixed powder of nano-SiC ceramic particles and aluminum powder Ⅰ:

[0119] SiC ceramic particles and spherical aluminum powder were placed in a ball mill at a mass ratio of 2:96 and a ball-to-material ratio of 20:1. The ball mill was placed in a planetary ball mill and subjected to high-energy ball milling at a rotation speed of 200 rpm for 10 hours to obtain a mixed powder of nano-SiC ceramic particles and flaky aluminum powder, namely, mixed powder I.

[0120] 3. Preparation of mixed powder (mixed powder II) of copper-plated flake graphite, nano-SiC ceramic particles and aluminum powder:

[0121] The copper-plated flake graphite prepared in step 1 and the mixed powder I obtained in step 2 are placed in a ball mill at a mass ratio of 2:98, and ball milled at a speed of 200 rpm for 2 hours to obtain a mixed powder of copper-plated flake graphite, nano-SiC ceramic particles and aluminum powder, i.e., mixed powder II;

[0122] 4. Preparation of aluminum matrix composites reinforced by nano-SiC ceramic particles and copper-plated flake graphite

[0123] The mixed powder II was pre-compressed at a pressure of 2 MPa for 10 min using a cold press. The cold pressed green body was subjected to spark plasma sintering. The sintering process parameters were: vacuum degree of 1.3×10 -1 Pa, increase the pressure to 56 MPa at a pressure increase rate of 10 MPa / min, and maintain the pressure at this pressure for 5 minutes; then increase the temperature to 580°C, a sintering temperature, at a heating rate of 100°C / min, and maintain at 56 MPa and 580°C for 10 minutes; when the temperature in the furnace cools to below 150°C, release the hydraulic pressure, and then cool to room temperature to obtain the aluminum-based composite material.

[0124] Comparative Example 6

[0125] This comparative example discloses a method for preparing an aluminum-based composite material reinforced by hybridization of nano-SiC ceramic particles and copper-plated flake graphite. In this example, different copper plating formulas are used to prepare copper-plated flake graphite with a thicker copper plating layer, comprising the following steps:

[0126] 1. Preparation of copper-plated flake graphite:

[0127] At room temperature, add flake graphite to the sensitizer and stir for 15 minutes for sensitization treatment, filter out the sensitized flake graphite, and then add it to the prepared activator and stir for 15 minutes for activation treatment. Add the sensitized and activated natural flake graphite to the copper plating solution, stir evenly at 35-45°C, add 7mL of formaldehyde at a rate of 2mL / min for 20-30 minutes, and chemically plate copper to obtain copper-plated flake graphite, with a copper film thickness of about 6μm.

[0128] In this comparative example, the sensitizer composition is: SnCl2·2H2O is 20g / L, HCl is 40mL / L, and the rest is deionized water; the ratio of natural flake graphite to sensitizer is 3g: (100-500)mL;

[0129] The composition of the activator is: 0.25 g / L PdCl2, 2.5 mL / L HCl, and the rest is deionized water; the ratio of natural flake graphite to the activator is 3 g: (100-500) mL.

[0130] The copper plating solution comprises 25 g / L CuSO4·5H2O, 20 g / L potassium sodium tartrate (NaKC4H4O6), 25 g / L ethylenediaminetetraacetic acid (Na2EDTA), 14 g / L NaOH, and the rest is deionized water.

[0131] 2. Preparation of mixed powder of nano-SiC ceramic particles and aluminum powder Ⅰ:

[0132] SiC ceramic particles and spherical aluminum powder were placed in a ball mill at a mass ratio of 2:96 and a ball-to-material ratio of 20:1. The ball mill was placed in a planetary ball mill and subjected to high-energy ball milling at a rotation speed of 200 rpm for 10 hours to obtain a mixed powder of nano-SiC ceramic particles and flaky aluminum powder, namely, mixed powder I.

[0133] 3. Preparation of mixed powder (mixed powder II) of copper-plated flake graphite, nano-SiC ceramic particles and aluminum powder:

[0134] The copper-plated flake graphite prepared in step 1 and the mixed powder I obtained in step 2 are placed in a ball mill at a mass ratio of 2:98, and ball milled at a speed of 200 rpm for 2 hours to obtain a mixed powder of copper-plated flake graphite, nano-SiC ceramic particles and aluminum powder, i.e., mixed powder II;

[0135] 4. Preparation of aluminum matrix composites reinforced by nano-SiC ceramic particles and copper-plated flake graphite

[0136] The mixed powder II was pre-compressed at a pressure of 2 MPa for 10 min using a cold press. The cold pressed green body was subjected to spark plasma sintering. The sintering process parameters were: vacuum degree of 1.3×10 -1 Pa, increase the pressure to 56 MPa at a pressure increase rate of 10 MPa / min, and maintain the pressure at this pressure for 5 minutes; then increase the temperature to 580°C, a sintering temperature, at a heating rate of 100°C / min, and maintain at 56 MPa and 580°C for 10 minutes; when the temperature in the furnace cools to below 150°C, release the hydraulic pressure, and then cool to room temperature to obtain the aluminum-based composite material.

[0137] Performance Testing

[0138] The composite materials prepared in the above examples and comparative examples were tested for relative density, Brinell hardness, tensile strength, average friction coefficient and wear loss, wherein:

[0139] Relative density: that is, density, which is the ratio of actual density to theoretical density;

[0140] Brinell hardness test: using HB-3000B Brinell hardness tester, the loading force is 125N, the holding time is 15s, and the indenter diameter is 10mm;

[0141] Tensile strength test: using Instron 5982 electronic universal material testing machine, the tensile speed is 0.1mm / min;

[0142] Average friction coefficient test: measured using Rtec-MFT-5000-H multifunctional friction and wear testing machine;

[0143] Wear test: measured using JJ223BC high-precision electronic balance;

[0144] The test results are summarized in Table 1

[0145]

[0146]

Claims

1. An aluminum-based composite material synergistically reinforced by nano-ceramic particles and copper-plated flake graphite, characterized in that: The matrix of the aluminum-based composite material is aluminum metal, and the reinforcing phase is nano-ceramic particles and copper-plated flake graphite, wherein the content of the nano-ceramic particles is 1-3wt.%, and the content of the copper-plated flake graphite is 2-6wt.%.

2. The aluminum-based composite material synergistically reinforced by nano-ceramic particles and copper-plated flake graphite according to claim 1, characterized in that: The nano ceramic particles are one or more of SiC particles, B4C particles, A12O3 particles, SiO2 particles, Si3N4 particles and AlN particles, and the particle size is nanometer level.

3. The aluminum-based composite material synergistically reinforced by nano-ceramic particles and copper-plated flake graphite according to claim 1, characterized in that: The copper layer thickness of the copper-plated flake graphite is 1-3 μm.

4. The method for preparing the aluminum-based composite material synergistically reinforced by nano-ceramic particles and copper-plated flake graphite according to any one of claims 1 to 3, characterized in that: The method comprises the following steps: mixing the nano ceramic particles, copper-plated flake graphite and spherical aluminum powder in proportion and cold pressing them into shape, and then rapidly hot pressing and sintering them to obtain an aluminum-based composite material synergistically reinforced by the nano ceramic particles and copper-plated flake graphite.

5. The method for preparing the aluminum-based composite material synergistically reinforced by nano-ceramic particles and copper-plated flake graphite according to claim 4, characterized in that: The method specifically comprises the following steps: (1) preparing copper-plated flake graphite by chemical plating; (2) weighing the amounts of nano-ceramic particles, copper-plated flake graphite and spherical aluminum powder according to the composition of the aluminum-based composite material to be prepared; (3) placing spherical aluminum powder and nano-ceramic particles into a ball mill and subjecting them to high-energy ball milling to obtain a mixed powder I; (4) adding the copper-plated flake graphite prepared in step (1) to the mixed powder I obtained in step (3), and then placing the mixed powder in a ball mill, and mixing the mixed powder II by high-energy ball milling; (5) The mixed powder II obtained in step (4) is cold pressed into shape using a cold press machine, and then the green body obtained after cold pressing is sintered using rapid hot pressing sintering, and the green body is taken out after the temperature in the furnace cools to room temperature, thereby obtaining the aluminum-based composite material synergistically reinforced by the nano-ceramic particles and copper-plated flake graphite.

6. The method for preparing the aluminum-based composite material synergistically reinforced by nano-ceramic particles and copper-plated flake graphite according to claim 5, characterized in that: In step (2), the size of the spherical aluminum powder is 40-45 μm, and the size of the nano-ceramic particles is 20-80 nm.

7. The method for preparing the aluminum-based composite material synergistically reinforced by nano-ceramic particles and copper-plated flake graphite according to claim 5, characterized in that: When high-energy ball milling is performed in step (3), the ball-to-material ratio is (15-25):1, the ball milling speed is 200-300 rpm, and the ball milling time is 8-12 h; when high-energy ball milling is performed in step (4), the ball milling speed is 200-300 rpm, and the ball milling time is 1.5-3 h.

8. The method for preparing the aluminum-based composite material synergistically reinforced by nano-ceramic particles and copper-plated flake graphite according to claim 5, characterized in that: In step (1), the copper-plated flake graphite preparation process is: natural flake graphite is subjected to sensitization and activation treatment in sequence and then subjected to chemical copper plating, the chemical copper plating is carried out at 35-45° C. and under stirring conditions, the natural flake graphite is placed in a copper plating solution, and formaldehyde is uniformly added dropwise to the copper plating solution at a rate of 2 mL / min (according to the ratio of natural flake graphite to formaldehyde being 3 g:(5-10) mL), the copper plating reaction time is 20-30 min, and copper-plated natural flake graphite is obtained after chemical copper plating.

9. The method for preparing the aluminum-based composite material synergistically reinforced by nano-ceramic particles and copper-plated flake graphite according to claim 8, characterized in that: In the process of preparing copper-plated flake graphite, the particle size of the natural flake graphite is 50-100 μm; The sensitization treatment is to add natural flake graphite into the sensitization solution and stir for 10-20 minutes, and then filter out the sensitized flake graphite; the sensitizer composition is: SnCl2·2H2O is 20-25g / L, HCl is 40-50mL / L, and the rest is deionized water; The activation treatment is to add the sensitized natural flake graphite into the sensitizing solution and stir for 10-20 minutes, and then filter out the activated flake graphite; the composition of the activator is: PdCl2 is 0.25-0.4g / L, HCl is 2.5-3.5mL / L, and the rest is deionized water; The copper plating solution comprises: 16-20 g / L CuSO4·5H2O, 20-25 g / L potassium sodium tartrate (NaKC4H4O6), 25-30 g / L ethylenediaminetetraacetic acid (Na2EDTA), 14-16 g / L NaOH, and the rest is deionized water.

10. The method for preparing the aluminum-based composite material synergistically reinforced by nano-ceramic particles and copper-plated flake graphite according to claim 8, characterized in that: In step (5), the pressure applied during the cold pressing is 1.5-3 MPa, the pressing time is 5-15 min, and when the rapid hot pressing sintering is performed, the vacuum degree of the sintering is 13 -2 -10 -2 Pa, the sintering pressure is 50-60MPa, the sintering temperature is 560-580℃, and the sintering time is 8-15min.

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