High-toughness and high-modulus aluminum matrix composite material and preparation method thereof

Abstract

This invention relates to the field of special aluminum-based composite materials, and discloses a high-strength, high-toughness, and high-modulus aluminum-based composite material and its preparation method. The method includes: mixing SiC ceramic particles with aluminum powder, ball milling in a vacuum ball mill jar, followed by cold pressing and vacuum sintering to prepare an aluminum-based composite material precursor; melting the aluminum-based composite material precursor with 6061 aluminum alloy ingots and materials containing Cu, Mg, Re (La / Ce = 3 / 2), and Zr elements in a melting furnace, cooling to a semi-solid temperature range after reaching a molten state and stirring; then heating to 740-760℃, and after reaching a molten state, ultrasonically vibrating; finally, casting and die-casting to obtain the high-strength, high-toughness, and high-modulus aluminum-based composite material. This invention introduces semi-solid stirring and high-power ultrasonic treatment during melting to achieve SiC… p Uniformly distributed in the melt, by comprehensively considering alloying elements and SiC p The mechanism of the influence of content and size on mechanical properties was investigated, enabling the mass production of high-strength, high-toughness, and high-modulus aluminum-based materials.

Description

A high-strength, high-toughness, high-modulus aluminum-based composite material and its preparation method Technical Field

[0001] This invention relates to the field of special aluminum-based composite materials, specifically to a high-strength, high-toughness, high-modulus aluminum-based composite material and its preparation method. Background Technology

[0002] High-strength aluminum-based materials are key lightweight components in the rapid development of rockets, spacecraft, and other aerospace vehicles. However, conventional commercial aluminum alloys are prone to failure in complex service environments due to issues such as the mismatch between strength and toughness, low modulus, and severe softening at high temperatures. Research has shown that by incorporating other alloying elements into the aluminum matrix and adding high-strength, high-modulus ceramic particles to form advanced special aluminum-based composite materials with complementary advantages, the performance of the aluminum alloy matrix can be significantly improved. Based on this, this invention proposes to develop an excellent method for preparing aluminum-based composite materials through alloying and compositing, in order to achieve the preparation of special aluminum-based composite materials with high strength, toughness, and high modulus, thereby solving the problem of insufficient aluminum alloy performance under complex and harsh environments.

[0003] In terms of alloying, to improve material performance, it is necessary to reduce the coarsening tendency of the second phase. The composition design considers the L phase (AlMg4Si3Cu) and L12 phase, which have good heat resistance, as the main precipitates. Therefore, commercially available 6061 aluminum ingots are used as the matrix alloy, and appropriate addition of Cu significantly promotes the formation of the L phase, changes the type of precipitates, and significantly improves the mechanical properties of the material. Mg has a high binding energy with vacancies, and the presence of Mg at grain boundaries can capture dislocations, promote grain boundary nucleation, and to some extent weaken the formation of precipitate-free zones, thereby improving the material strength. Furthermore, Mg readily combines with SiC... p The grains are near-segregated, therefore an additional amount of Mg is required. To achieve significant grain refinement while preventing thermal cracking, Re (La, Ce) is chosen as a nucleating agent, which can also form a thermodynamically stable L12 ordered phase (Al3Re). Considering the relatively high diffusion rate of Re in Al, Al3Re may coarsen at high temperatures (e.g., 300-400 °C), while Zr has a low diffusion rate in Al. Therefore, adding Zr to Al can resist the coarsening tendency by forming an in-situ L12 ordered Re / Zr-rich phase Al3(Re,Zr).

[0004] In terms of composite materials, the development of aluminum matrix composites (AMCs) has effectively solved the shortcomings of poor mechanical properties of aluminum compared with traditional aluminum. At the same time, AMCs have higher specific strength and specific stiffness, good high-temperature stability, low coefficient of linear expansion and excellent wear resistance, and have broad application prospects in aerospace, automotive transportation and electronics 3C fields. pWith its high modulus (400 GPa), high hardness (3400 HV), high wear resistance, low density, good thermal stability, resistance to cracking, and non-reaction with the aluminum matrix, SiC is an extremely superior reinforcing material. Furthermore, the introduction of nano-reinforcing materials not only exhibits excellent strengthening effects but also maintains the initial toughness of the matrix, effectively balancing the contradiction between strength and plasticity inherent in traditional aluminum composite materials (AMCs). Based on considerations of improving the comprehensive mechanical properties of composites, micron-sized SiC... p With nano SiC p Composite materials are prepared by incorporating hybrids as reinforcements into aluminum alloy matrices, aiming to improve their strength and modulus without compromising their plasticity, thereby achieving excellent comprehensive mechanical properties. Summary of the Invention

[0005] Based on the specific requirements of the composite material itself, and starting from the current research status of aluminum alloy matrix, raw materials were selected, taking into account alloying elements and SiC. p The influence of SiC content and size on mechanical properties aims to achieve mass production of high-strength, high-toughness, and high-modulus materials. Stir casting is widely used due to its advantages such as fewer process steps, simpler equipment, ease of molding, lower cost, and ability to achieve mass production of ingots. However, conventional stir casting methods struggle to produce high-content SiC materials. p On the one hand, it is difficult to disperse uniformly in aluminum melt; on the other hand, it is difficult to disperse nano-sized SiC. p Added to molten aluminum. Based on this, the present invention provides a hot-pressing sintering-assisted semi-solid stirring casting method for preparing high-strength, high-toughness, and high-modulus aluminum-based composite materials. The present invention utilizes SiC ceramic particles (SiC... p High-energy ball milling with aluminum powder to initially disperse SiC p And a composite material preform was prepared, achieving SiC p It exhibits excellent interfacial bonding with Al while maintaining a density close to that of aluminum-based melt during smelting. High-speed semi-solid stirring and high-power ultrasonic treatment are introduced during smelting to achieve SiC... p It is evenly distributed in the melt.

[0006] To achieve the above objectives, the present invention provides a method for preparing a high-strength, high-toughness, high-modulus aluminum-based composite material, comprising the following steps:

[0007] S1. SiC ceramic particles are mixed with aluminum powder and ball-milled in a vacuum ball mill under an argon protective atmosphere. The mixture is then cold-pressed and vacuum sintered to prepare an aluminum-based composite precursor.

[0008] The mass ratio of SiC ceramic particles to aluminum powder is 1:4 to 1:5, and the SiC ceramic particles are micron-sized SiC with a mass ratio of 5:1. p With nano SiC p ;

[0009] S2. Under an argon protective atmosphere, the aluminum-based composite precursor obtained in step S1, 6061 aluminum alloy ingot, and materials containing Cu, Mg, Re (La / Ce=3 / 2), and Zr elements are smelted in a melting furnace at a furnace temperature of 800 ℃. After reaching the molten state, the temperature is lowered to the semi-solid temperature range of 600~630 ℃ to obtain a semi-solid melt, which is then stirred to ensure that the SiC ceramic particles are fully and uniformly dispersed. The temperature is then raised to 740~760 ℃, and after the semi-solid melt transforms into the molten state, ultrasonic vibration is used to uniformly distribute the SiC ceramic particles in the aluminum melt. Finally, the mixture is cast and die-cast to obtain a high-strength, high-toughness, and high-modulus aluminum-based composite material.

[0010] Among them, the added micron-sized SiC p With nano SiC p The added Cu, Mg, Re (La / Ce=3 / 2), and Zr elements account for 5 wt% and 1 wt% of the 6061 aluminum alloy ingot, respectively. The added Cu, Mg, Re (La / Ce=3 / 2), and Zr elements account for 4 wt%, 1 wt%, 0.5 wt%, and 0.2 wt% of the 6061 aluminum alloy ingot, respectively. The Cu element is selected from Al-50Cu master alloy, the Mg element is selected from pure magnesium ingot, the Re element is selected from Al-10Re master alloy, and the Zr element is selected from Al-10Zr master alloy.

[0011] The present invention uses conventional 6061 aluminum alloy ingots, the main components of which are shown in Table 1:

[0012] Table 1

[0013]

[0014] As a further preferred technical solution of the present invention, in step S1, micron-sized SiC p The particle size is 3-8 μm, nano SiC p The particle size is 40-80 nm.

[0015] As a further preferred technical solution of the present invention, in step S1, the parameters for ball milling SiC ceramic particles and aluminum powder are: rotation speed 220 rpm, time 15 h, and alternating clockwise and counterclockwise rotation every hour with a 30 min interval in between.

[0016] As a further preferred technical solution of the present invention, in step S1, the cold pressing pressure is 60 MPa and the vacuum sintering temperature is 540 ℃.

[0017] As a further preferred technical solution of the present invention, in step S2, the aluminum-based composite material precursor is placed at the bottom of the 6061 aluminum alloy ingot.

[0018] As a further preferred technical solution of the present invention, in step S2, the stirring speed is 400~700 rpm.

[0019] As a further preferred embodiment of the present invention, in step S2, an ultrasonic amplitude transformer is used for ultrasonic vibration. The ultrasonic amplitude transformer is positioned 2-5 cm below the liquid surface, the ultrasonic frequency is 18-20 kHz, the power is 3000 W, and the processing time is 5-10 min.

[0020] As a further preferred technical solution of the present invention, in step S2, the pressure of the die casting process is 400 kN and the holding time is 2~5 min.

[0021] According to another aspect of the present invention, the present invention also provides a high-strength, high-toughness, high-modulus aluminum-based composite material, which is prepared by the above-described method.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] This invention utilizes early SiC p High-energy ball milling with aluminum powder to initially disperse SiC p Then, composite material preforms are prepared to achieve SiC p It exhibits excellent interfacial bonding with Al while maintaining a density close to that of aluminum-based melt during smelting. Semi-solid stirring and high-power ultrasonic treatment are introduced during smelting to achieve SiC... p It is uniformly distributed in the melt. This is achieved by comprehensively considering the alloying elements and SiC. p The mechanism of the influence of content and size on mechanical properties was investigated, enabling the mass production of high-strength, high-toughness, and high-modulus aluminum-based materials. Attached Figure Description

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0025] Figure 1 is a schematic diagram of the extrusion casting principle used in Example 1.

[0026] Figure 2 is a macroscopic photograph of the aluminum-based composite material ingot prepared in Example 1.

[0027] Figure 3 is a metallographic microstructure of the aluminum-based composite material prepared in Example 1 and the original composition of 6061 aluminum alloy prepared in Comparative Example 1 at 200x magnification.

[0028] Figure 4 shows the engineering stress-strain curves and modulus fitting curves of the aluminum alloy material samples prepared in Example 1 and Comparative Example 1.

[0029] Figure 5 shows the engineering stress-strain curves of the 6 wt% SiC-increased aluminum matrix composite and the 10 wt% SiC-reinforced aluminum matrix composite in Comparative Example 2.

[0030] Figure 6 shows the experimental results of preparing aluminum-based composite materials using the conventional stir casting method in Comparative Example 3.

[0031] Figure 7 is a 200x metallographic microstructure of the aluminum-based composite materials prepared in Example 1, Comparative Example 2 and Comparative Example 4.

[0032] Figure 8 shows the engineering stress-strain curves of the aluminum-based composite materials prepared in Example 1, Comparative Example 2, and Comparative Example 4.

[0033] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0034] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0035] Unless otherwise defined, the technical terms used in the following embodiments have the same meanings as commonly understood by those skilled in the art to which this invention pertains. Unless otherwise specified, the experimental reagents used in the following embodiments are conventional biochemical reagents; and the experimental methods described are conventional methods.

[0036] The following examples and comparative examples include the addition of Cu, Mg, Re (La / Ce=3 / 2), Zr elements, and micron-sized SiC. p Nano SiC p The quantities are all percentages of the mass of 6061 aluminum alloy ingots. The 6061 aluminum alloy ingots used were purchased from Southwest Aluminum Industry Co., Ltd.; the product type was 6061 aluminum extruded bars; the applicable standards were GJB2504, GJB2920, and GJB3539.

[0037] The aluminum-based composite materials with added SiC ceramic particles prepared in the following examples and comparative examples are also known as SiC-reinforced aluminum-based composite materials. The SiC ceramic particles used were purchased from Hefei Duoyile Trading Co., Ltd.

[0038] Example 1:

[0039] This embodiment provides a method for preparing a high-strength, high-toughness, and high-modulus aluminum-based composite material. It uses a 6061 aluminum alloy ingot as the matrix aluminum alloy composition, and adds 4wt% Cu, 1wt% Mg, 0.5wt% Re (La / Ce=3 / 2), and 0.2wt% Zr elements, and composites it with 5wt% micron-sized SiC. p With 1 wt% nano SiC p The specific preparation method is as follows:

[0040] Step 1: Preparation of SiC p Composite preform with aluminum powder

[0041] SiC p The aluminum powder was subjected to high-energy ball milling in a zirconia ball mill jar under an argon protective atmosphere, wherein SiC p The mass ratio of SiC to aluminum powder is 1:4. p Micron-sized SiC with a mass ratio of 5:1 p (Average particle size 5 μm) and nano-SiC p (Average particle size 50nm), the total volume of the material and grinding balls in the ball mill jar occupies 2 / 3 of the jar's volume. The high-energy ball milling process is: 220 rpm, 15 h, alternating between clockwise and counterclockwise rotation every hour, with a 30 min interval in between. Subsequently, it will be mixed with the ball-milled SiC... p Al mixed powder was pressed into columnar blocks under 60 MPa, and then sintered in a vacuum furnace at 540℃ for 3 h to obtain an aluminum-based composite material preform. This step allows for the fabrication of micro and nano SiC... p Effective dispersion can be achieved, and SiC can be realized. p It effectively interfaces with aluminum powder to facilitate its smooth addition to the molten aluminum in subsequent operations.

[0042] Step 2: Preparation of aluminum-based composite material ingots

[0043] Under an argon-protected atmosphere, SiC at micrometer levels p Nano SiC p The mass fractions of the prepared aluminum-based composite preforms were 5 wt% and 1 wt%. These preforms were inserted into the bottom of a 6061 aluminum alloy ingot (composition shown in Table 2) and placed in a melting furnace. Al-50Cu master alloy, pure Mg, Al-10Re master alloy, and Al-10Zr master alloy were added at the following amounts: 4 wt% Cu, 1 wt% Mg, 0.5 wt% Re (La / Ce=3 / 2), and 0.2 wt% Zr, respectively. The melting furnace temperature was adjusted to 800 ℃, and the material was allowed to molten for 10 minutes. Subsequently, the temperature was lowered to the semi-solid range of 740-760 ℃, and the semi-solid melt was stirred to ensure uniform dispersion of the added SiC particles. The stirring speed was 600 rpm, and the stirring time was 10 minutes. The temperature was then raised to 750℃, and the aluminum-based composite melt was subjected to high-power ultrasonic vibration. The ultrasonic amplitude transformer was positioned 2 cm below the liquid surface, the ultrasonic frequency was 20 kHz, the power was 3000 W, and the processing time was 10 min, thus achieving the external addition of SiC. p The aluminum matrix composite material is evenly distributed in the molten aluminum. Finally, the treated aluminum matrix composite melt is poured into a mold preheated to 500 °C for extrusion casting. After demolding, a high-strength, high-toughness, high-modulus aluminum matrix composite ingot is obtained.

[0044] Squeeze casting is a conventional technique. A schematic diagram of squeeze casting is shown in Figure 1, which includes an upper punch 1, a tilted, split-part mold 2, a graphite pad 3, an iron pad 4, and a billet 5. The upper punch transfers the load to the billet, applying the pressure required for die casting. The tilted, split mold 2 supports the pouring of molten aluminum, and its tilt and split design facilitate demolding. The graphite pad 3 serves two purposes: firstly, to expel gas during the die casting process, and secondly, to prevent direct contact between the molten aluminum and the mold, which could lead to demolding difficulties and contamination of the billet and mold. The iron pad 4 restricts the upward flow of the billet during squeeze casting. First, a graphite pad is placed at the bottom of the casting mold 2, and a high-temperature release agent is sprayed onto the inner wall of the mold. The mold is preheated at 500 °C. Then, the treated aluminum-based composite material melt is poured into the mold 2. Next, the graphite pad and iron pad 4 are placed in sequence. The punch 1 is moved downwards at a speed of 200 mm / min. When the punch contacts the iron pad, the die-casting speed is changed to 20 kN / s, the pressure is set to 400 kN, and the holding time is 3 min. After die-casting, the mold is rotated 180°, and the mold 2 with the inclined sleeve in the middle is pressed out using a press. The mold is then broken in half to obtain the aluminum-based composite material ingot. Figure 2 shows a macroscopic photograph of the prepared aluminum-based composite material ingot.

[0045] The components (excluding SiC ceramic particles) with an actual matrix alloy content greater than 0.1 wt% in the aluminum matrix composite ingot prepared in Example 1 were tested by ICP-MS, and the results are shown in Table 2.

[0046] Table 2

[0047]

[0048] To further demonstrate the beneficial technical effects of the present invention, the following comparative experiments were conducted, wherein the 6061 aluminum alloy ingot raw material used had the same composition as that in Example 1.

[0049] Comparative Example 1:

[0050] As a control experiment for Example 1, the difference from Example 1 is that Cu, Mg, Re (La / Ce=3 / 2), Zr, and SiCp were not added to the 6061 aluminum alloy composition. The specific preparation process of Comparative Example 1 was as follows: Under an argon-protected atmosphere, a 6061 aluminum alloy ingot was melted in a melting furnace at 800 °C. After melting, the ingot was allowed to stand for 10 minutes. Subsequently, the temperature was lowered to 740-760 °C, and the aluminum alloy melt was subjected to high-power ultrasonic vibration. The ultrasonic amplitude transformer was positioned 2 cm below the liquid surface, the ultrasonic frequency was 20 kHz, the power was 3000 W, and the treatment time was 10 minutes. Finally, the treated aluminum alloy melt was poured into a mold preheated to 500 °C for extrusion casting. After demolding, a 6061 aluminum alloy ingot was obtained. The extrusion casting process was the same as that of Example 1.

[0051] Comparative Example 2:

[0052] As a control experiment for Example 1, this comparative example used essentially the same preparation method as Example 1. The only difference from Example 1 was the change in the content of added SiCp, and only micron-sized SiCp was added. p (Average particle size 5 μm) and two groups of samples were prepared with contents of 6 wt% and 10 wt%, respectively. The remaining processes were the same as in Example 1.

[0053] Comparative Example 3:

[0054] As a control experiment for Example 1, compared to Example 1, an aluminum-based composite material was prepared using a conventional stirred casting method, with all material compositions and amounts remaining consistent with Example 1. The specific process was as follows: Under an argon-protected atmosphere, a 6061 aluminum alloy ingot and a master alloy of Cu, Mg, Re (La / Ce=3 / 2), and Zr elements were placed in a melting furnace at 800 °C. After complete melting, the mixture was allowed to stand for 10 minutes. Subsequently, the temperature was lowered to 740-760 °C, and aluminum powder and micron-sized SiC were added in the same amounts as in Example 1 under mechanical stirring. p (Average particle size 5 μm) and nano-SiC p (Average particle size 50nm). Finally, the aluminum-based composite material melt was poured into a mold preheated to 500°C for extrusion casting. After demolding, an aluminum-based composite material ingot was obtained. The extrusion casting process was the same as that in Example 1.

[0055] Comparative Example 4:

[0056] Compared to Comparative Example 3, this comparative example differed only in the content of added SiCp. The comparative example included 10 wt% SiC particles with an average particle size of 5 μm, while the rest of the process remained the same as Comparative Example 3.

[0057] Figure 3 shows the 200x metallographic microstructure of the 6061 aluminum alloy and aluminum-based composite material prepared in Comparative Example 1 and Example 1, respectively. As can be seen from the figure, compared to the 6061 aluminum alloy, the aluminum-based composite material prepared in this invention exhibits significantly refined grain size and significantly improved microstructure uniformity. This is because: firstly, the introduction of micron-sized SiC particles can serve as nucleation sites for grains and the second phase, leading to a significant reduction in grain size; and second-phase nucleation occurs around the SiC particles, reducing the segregation of the second phase at grain boundaries. Secondly, the nano-sized SiC particles segregated at grain boundaries have a certain grain-pinning effect, hindering grain growth. Furthermore, the added Zr and Re (La, Ce) elements are effective grain refiners, effectively segregating at grain boundaries to hinder grain expansion.

[0058] Figure 4 shows the engineering stress-strain curves and modulus fitting curves of the 6061 aluminum alloy and aluminum-based composite material prepared in Comparative Example 1 and Example 1, respectively. As shown in Figure 4(a), the tensile strengths of the aluminum-based composite material and the 6061 aluminum alloy prepared in this invention are 230.5 MPa and 152.8 MPa, respectively; the yield strengths are 115.8 MPa and 80.7 MPa, respectively; and the elongation at break is 22.1% and 4.8%, respectively. Compared with the 6061 aluminum alloy, the tensile strength, yield strength, and elongation at break of the composite material prepared in this invention are increased by 50.8%, 43.5%, and 360.4%, respectively, achieving a synergistic improvement in strength and plasticity. As shown in Figure 4(b), the elastic modulus of the aluminum-based composite material prepared in this invention is as high as ~116 GPa, which is ~71% higher than the ~68 GPa elastic modulus of commercial 6061 aluminum alloy.

[0059] Whether from the grain size and microstructure uniformity in Figure 3, or the engineering stress-strain curve and modulus in Figure 4, the aluminum-based composite material prepared by this invention exhibits a high level, reflecting the advanced nature of the composition design.

[0060] Figure 5 shows the engineering stress-strain curves of the 6 wt% micron SiC-reinforced aluminum matrix composite and the 10 wt% micron SiC-reinforced aluminum matrix composite in Comparative Example 2. It can be seen that the strength of the composite increases with the increase of the micron SiC content. Therefore, in subsequent comparative examples, only the 10 wt% micron SiC-reinforced aluminum matrix composite is used for comparison.

[0061] Figure 6 shows the experimental results of preparing aluminum-based composite materials using the conventional stir casting method in Comparative Example 3. As can be seen from the figure, it is difficult to incorporate nano-sized SiCp into the aluminum melt using the conventional stir casting method. This is because nano-sized SiCp floats on top of the aluminum melt during the melting process, forming impurities.

[0062] Figure 7 shows the metallographic microstructure of the aluminum matrix composites prepared in Examples 1, 2, and 4 at 200x magnification. Figures 7(a) and (b) are metallographic schematic diagrams of the (5µm-5wt%+50nm-1wt%) SiC reinforced aluminum matrix composite (Example 1) and (5µm-10wt%) SiC reinforced aluminum matrix composite (Comparative Example 2), both prepared using the optimized stir casting method. It can be seen from the figures that the (5µm-5wt%+50nm-1wt%) SiC reinforced aluminum matrix composite has a finer grain size and a more uniform SiC distribution. Figure 7(c) is a metallographic schematic diagram of the (5µm-10wt%) SiC reinforced aluminum matrix composite (Comparative Example 4) prepared using the conventional stir casting method. It can be seen from the figure that the aluminum matrix composite prepared by the optimized stir casting method exhibits significantly enhanced particle dispersion, while the aluminum matrix composite prepared by the conventional stir casting method shows more agglomeration.

[0063] Figure 8 shows the engineering stress-strain curves of the aluminum matrix composites prepared in Examples 1, 2, and 4. As can be seen from the figure, the (5µm-5wt%+50nm-1wt%) SiC reinforced aluminum matrix composite prepared by the optimized stirred casting method has similar yield strength, tensile strength, and modulus to the (5µm-10wt%) SiC reinforced aluminum matrix composite, but exhibits superior elongation. This is mainly because the (5µm-5wt%+50nm-1wt%) SiC reinforced aluminum matrix composite has better microstructure uniformity. Compared with the (5µm-10wt%) SiC reinforced aluminum matrix composite prepared by the conventional casting method, the optimized aluminum matrix composite exhibits higher mechanical properties.

[0064] From the microstructure and mechanical properties of the aluminum matrix composites, it can be seen that the (5µm-5wt%+50nm-1wt%) SiC-reinforced aluminum matrix composite exhibits the best microstructure uniformity and performance, demonstrating the effectiveness of the SiC particle addition strategy of this invention. Furthermore, compared with conventional stir casting, the optimized stir casting method proposed in this invention not only solves the problem of adding nanoscale SiC particles but also achieves effective dispersion of SiC particles in the aluminum melt, strongly proving the superiority of the optimized stir casting method for aluminum matrix composites proposed in this invention.

[0065] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and various changes or modifications can be made to these embodiments without departing from the principles and essence of the present invention. The scope of protection of the present invention is defined only by the appended claims.

Claims

1. A method for preparing a high-strength, high-toughness, high-modulus aluminum-based composite material, characterized in that, Includes the following steps: S1. SiC ceramic particles are mixed with aluminum powder and ball-milled in a vacuum ball mill under an argon protective atmosphere. The mixture is then cold-pressed and vacuum-sintered to prepare an aluminum-based composite precursor. The mass ratio of SiC ceramic particles to aluminum powder is 1:4 to 1:5, and the SiC ceramic particles are micron-sized SiC with a mass ratio of 5:

1. p With nano SiC p S2. Under an argon protective atmosphere, the aluminum-based composite precursor obtained in step S1, 6061 aluminum alloy ingot, and materials containing Cu, Mg, RE, and Zr elements are smelted in a melting furnace at a temperature of 800 ℃. After it becomes molten, it is cooled to the semi-solid temperature range of 600~630 ℃ to obtain a semi-solid melt, which is then stirred to ensure that the SiC ceramic particles are fully and uniformly dispersed. The temperature was then raised to 740-760℃. After the semi-solid melt transformed into a molten state, ultrasonic vibration was used to uniformly distribute SiC ceramic particles in the molten aluminum. Finally, through casting and die casting, a high-strength, high-toughness, high-modulus aluminum-based composite material was obtained. The added micron-sized SiC particles... p With nano SiC p The added Cu, Mg, RE, and Zr elements account for 5 wt% and 1 wt% of the 6061 aluminum alloy ingot, respectively, and account for 4 wt%, 1 wt%, 0.5 wt%, and 0.2 wt% of the 6061 aluminum alloy ingot, respectively. The RE element is specifically La / Ce=3 / 2. The materials containing Cu, Mg, RE, and Zr elements are as follows: Cu element is selected from Al-50Cu master alloy, Mg element is selected from pure magnesium ingot, RE element is selected from Al-10Re master alloy, and Zr element is selected from Al-10Zr master alloy. In step S1, the cold pressing pressure is 60 MPa and the vacuum sintering temperature is 540 ℃. In step S2, the aluminum-based composite material precursor is placed at the bottom of the 6061 aluminum alloy ingot. In step S2, the die casting pressure is 400 kN.

2. The method for preparing high-strength, high-toughness, high-modulus aluminum-based composite materials according to claim 1, characterized in that, In step S1, micron-sized SiC p The particle size is 3-8 μm, nano SiC p The particle size is 40-80 nm.

3. The method for preparing high-strength, high-toughness, high-modulus aluminum-based composite materials according to claim 1, characterized in that, In step S1, the parameters for ball milling SiC ceramic particles and aluminum powder are: rotation speed 220 rpm, time 15 h, with clockwise and counterclockwise rotations alternating every hour, with a 30 min interval in between.

4. The method for preparing high-strength, high-toughness, high-modulus aluminum-based composite materials according to claim 1, characterized in that, In step S2, the stirring speed is 400~700 rpm.

5. The method for preparing high-strength, high-toughness, high-modulus aluminum-based composite materials according to claim 1, characterized in that, In step S2, an ultrasonic amplitude transformer is used to perform ultrasonic vibration.

6. The method for preparing high-strength, high-toughness, high-modulus aluminum-based composite materials according to claim 5, characterized in that, The ultrasonic amplitude transformer is positioned 2-5 cm below the liquid surface, with an ultrasonic frequency of 18-20 kHz, a power of 3000 W, and a processing time of 5-10 min.

7. The method for preparing high-strength, high-toughness, high-modulus aluminum-based composite materials according to claim 1, characterized in that, In step S2, the pressure of the die casting process is 400 kN, and the holding time is 2~5 min.

8. A high-strength, high-toughness, high-modulus aluminum-based composite material, characterized in that, It is prepared by the method described in any one of claims 1-7.

Images