A micro-nano hybrid SiC p Reinforced aluminum-based composite material cylindrical part and preparation method thereof

Abstract

This application discloses a micro-nano hybrid SiC p The invention relates to a reinforced aluminum-based composite cylindrical component and a preparation method thereof, and belongs to the technical field of plastic processing of aluminum alloy materials. p , nano-SiC p After mixing with aluminum powder, high-energy ball milling is performed, and after high-temperature dissolution and ultrasonic treatment with aluminum alloy, die casting and homogenization are performed, and then continuous forging + reverse extrusion and T6 heat treatment are performed to obtain micro-nano hybrid SiC p Reinforced aluminum-based composite cylindrical piece, micro-nano hybrid SiC prepared by the preparation method provided in this application p Reinforced aluminum matrix composite cylindrical parts can make nano-scale SiC p , micron SiC p It is interlocked with aluminum powder to increase the strength and hardness of the crystal, thereby improving the mechanical properties of the aluminum-based composite material; through continuous forging and reverse extrusion thermal deformation, it can eliminate casting defects such as shrinkage and pores to achieve grain refinement and improve the distribution of reinforcement, thereby giving the cylindrical part excellent mechanical properties.

Description

Technical Field

[0001] This application belongs to the technical field of aluminum alloy material processing, and in particular to a micro-nano hybrid SiC p Reinforced aluminum-based composite material cylindrical component and preparation method thereof. Background Art

[0002] Aluminum matrix composites (AMCs) have higher specific strength, specific stiffness, good high temperature stability, low linear expansion coefficient and excellent wear resistance, and have broad application prospects in aerospace, automobile transportation and electronic 3C fields. In order to further improve the mechanical properties of aluminum matrix composites, the addition of particle reinforced metal matrix composites is usually used to effectively balance the contradiction between the strength and plasticity of traditional AMCs. Silicon carbide particles (SiC p ) has comprehensive properties such as high strength, high modulus, high hardness and low density, and is widely used as a reinforcement phase in various aluminum-based composite materials to improve the strength and modulus of aluminum-based composite materials. However, existing nano-scale SiC p The addition of materials, due to their large surface energy, is very easy to agglomerate. p The wettability of aluminum-based composite materials is poor, making it difficult to add them to aluminum-based melts. Therefore, it is necessary to develop an optimized preparation process to prepare aluminum-based composite materials with excellent comprehensive performance and thus achieve the overall mechanical properties of the cylinder.

[0003] However, the existing preparation methods of cylinders made of aluminum-based composite materials have the following problems: first, only physical compounding is performed, which fails to affect the essence of the aluminum-based composite materials, resulting in poor mechanical properties of the cylinders; second, the preparation process is complicated and costly, which is not conducive to large-scale production. Summary of the Invention

[0004] The purpose of this application is to disclose a micro-nano hybrid SiC p Reinforced aluminum matrix composite cylindrical parts and preparation methods thereof are intended to solve the existing problems based on micro-nano hybrid SiC p The preparation method of cylindrical parts made of reinforced aluminum-based composite materials has technical problems such as poor mechanical properties, complicated preparation process and high cost.

[0005] In order to achieve the above objectives, the technical solution of this application is:

[0006] The first aspect of the present application provides a micro-nano hybrid SiC p A method for preparing a reinforced aluminum-based composite material cylindrical member, the method comprising:

[0007] Micron SiC p , nano-SiC p After mixing with aluminum powder, high-energy ball milling is performed to obtain SiC-Al composite particles;

[0008] The SiC-Al composite particles and aluminum alloy are dissolved at high temperature and ultrasonically treated, and then die-cast and homogenized to obtain cast SiC p Reinforced aluminum matrix composites;

[0009] The cast SiC p After the reinforced aluminum matrix composite material is forged, reversely extruded and subjected to T6 heat treatment, the micro-nano hybrid SiC is obtained. p Reinforced aluminum matrix composite cylindrical parts.

[0010] In combination with the first aspect, preferably, the micron SiC p The particle size is 0-5 μm, and the added mass fraction is 2.5 wt%.

[0011] In combination with the first aspect, preferably, the nano-SiC p The particle size is 0-50 nm, and the added mass fraction is 1.5 wt%.

[0012] In combination with the first aspect, preferably, the micron SiC p , nano-SiC p The mass ratio of aluminum powder to aluminum powder is 1:10.

[0013] In combination with the first aspect, preferably, the micron SiC p , nano-SiC p When the high-energy ball milling treatment is carried out after mixing with aluminum powder, it is carried out in three stages: the first stage is at 150 rpm for 4 hours, the second stage is at 220 rpm for 10 hours, and the third stage is at 330 rpm for 6 hours.

[0014] In combination with the first aspect, preferably, the aluminum alloy is an Al-Mg-Si alloy, with a mass fraction of 97.6% Al, 1.6% Mg, and 0.8% Si.

[0015] In combination with the first aspect, preferably, when the SiC-Al composite particles and the aluminum alloy are dissolved at a high temperature and ultrasonically treated, the ultrasonic frequency is 20 kHz, the power is 3000 W, and the treatment time is 20 min.

[0016] In combination with the first aspect, preferably, after the SiC-Al composite particles and the aluminum alloy are dissolved at high temperature and ultrasonically treated, the die casting is performed at a temperature of 500° C., a pressure of 400 MPa, and a time of 3 minutes.

[0017] In combination with the first aspect, preferably, the cast SiC p When the reinforced aluminum matrix composite material is forged, the temperature is 400°C;

[0018] And / or, during the T6 heat treatment, the solution treatment is performed at 550° C. for 2 h, and the aging treatment is performed at 180° C. for 12 h.

[0019] The second aspect of the present application provides a micro-nano hybrid SiC prepared by the preparation method described in the first aspect. p Reinforced aluminum matrix composite cylindrical parts.

[0020] Compared with the prior art, the advantages or beneficial effects of the embodiments of the present application include at least:

[0021] The preparation method provided by the application is to p , nano-SiC p After mixing with aluminum powder, high-energy ball milling is performed, and after die-casting with aluminum alloy, continuous forging, reverse extrusion and T6 heat treatment are performed to obtain micro-nano hybrid SiC p Reinforced aluminum matrix composite cylindrical parts. On the one hand, it can make nano-scale SiC p , micron SiC p By intercalating with aluminum powder, the recrystallization degree of the composite material is improved, the strength and hardness of the crystal are increased, and at the same time, a density close to that of the aluminum alloy matrix can be achieved, thereby improving the mechanical properties of the aluminum-based composite material. On the other hand, the wetting and dispersion of the SiC-Al composite particle reinforcement in the aluminum alloy melt matrix can be improved simultaneously in a short time, thereby achieving its uniform distribution. Thirdly, it can eliminate casting defects such as shrinkage and pores to achieve grain refinement, improve reinforcement distribution, and thereby prepare cylindrical parts with excellent mechanical properties. At the same time, the preparation process provided by this application is simple and easy to repeat, which significantly improves the strength and plasticity of the aluminum-based composite cylindrical parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some of the embodiments described in this application. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0023] Figure 1 The micro-nano hybrid SiC provided in the embodiment of the present application p Flow chart of the preparation process of reinforced aluminum matrix composite cylindrical parts;

[0024] Figure 2 A schematic diagram of an angled casting mold used in a die-casting process according to an embodiment of the present application;

[0025] Figure 3 Schematic diagram of the continuous forging + reverse extrusion device provided in an embodiment of the present application;

[0026] Figure 4 A macroscopic photograph of SiC-Al composite particles provided in an embodiment of the present application;

[0027] Figure 5 The cast Al-1.6Mg-0.8Si, 5μm-4wt% SiC provided in the embodiment of this application p / Al-1.6Mg-0.8Si, 50nm-1.5wt%SiC p / Al-1.6Mg-0.8Si, (5μm-2.5wt%+50nm-1.5wt%)SiC p Scanning electron microscope image of / Al-1.6Mg-0.8Si reinforced aluminum matrix composite;

[0028] Among them, (a) Al-1.6Mg-0.8Si; (b) 5μm-4wt% SiC p / Al-1.6Mg-0.8Si; (c) 50nm-1.5wt%SiC p / Al-1.6Mg-0.8Si; (d) (5μm-2.5wt%+50nm-1.5wt%)SiC p / Al-1.6Mg-0.8Si;

[0029] Figure 6 Al-1.6Mg-0.8Si, 5μm-4wt% SiC provided in the embodiment of this application p / Al-1.6Mg-0.8Si, 50nm-1.5wt%SiC p / Al-1.6Mg-0.8Si, (5μm-2.5wt%+50nm-1.5wt%)SiC p Scanning electron microscope image of a cylindrical component of aluminum-based composite material reinforced with Al-1.6Mg-0.8Si;

[0030] Among them, (a) Al-1.6Mg-0.8Si; (b) 5μm-4wt% SiC p / Al-1.6Mg-0.8Si; (c) 50nm-1.5wt%SiC p / Al-1.6Mg-0.8Si; (d) (5μm-2.5wt%+50nm-1.5wt%)SiC p / Al-1.6Mg-0.8Si;

[0031] Figure 7 The cast Al-1.6Mg-0.8Si, 5μm-4wt% SiC provided in the embodiment of this application p / Al-1.6Mg-0.8Si, 50nm-1.5wt%SiC p / Al-1.6Mg-0.8Si, (5μm-2.5wt%+50nm-1.5wt%)SiC p / Stress-strain curve of Al-1.6Mg-0.8Si reinforced aluminum matrix composites;

[0032] Figure 8 Al-1.6Mg-0.8Si, 5μm-4wt% SiC provided in the embodiment of this application p / Al-1.6Mg-0.8Si, 50nm-1.5wt%SiC p / Al-1.6Mg-0.8Si, (5μm-2.5wt%+50nm-1.5wt%)SiC p Stress-strain curve of cylindrical parts of / Al-1.6Mg-0.8Si reinforced aluminum matrix composite materials. DETAILED DESCRIPTION

[0033] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0034] In the following description of this embodiment, the term "and / or" is used to describe the association relationship between associated objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, B exists alone, and both A and B exist. A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0035] In the following description of this embodiment, the term "at least one" refers to one or more, and "plurality" refers to two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all represent: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0036] Those skilled in the art should understand that in the following description of the embodiments of the present application, the order of serial numbers does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0037] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0038] It should be noted that all raw materials and reagents in the examples of this application were purchased on the market or prepared according to conventional methods well known to those skilled in the art. p , nano-SiC p The aluminum powder and the like are all purchased from the market or prepared according to conventional methods well known to those skilled in the art.

[0039] In the first aspect, the embodiment of the present application provides a micro-nano hybrid SiC p A method for preparing a reinforced aluminum-based composite material cylindrical member, the method comprising:

[0040] Micron SiC p , nano-SiC p After mixing with aluminum powder, high-energy ball milling is performed to obtain SiC-Al composite particles;

[0041] The SiC-Al composite particles and aluminum alloy are dissolved at high temperature and ultrasonically treated, and then die-cast and homogenized to obtain cast SiC p Reinforced aluminum matrix composites;

[0042] The cast SiC p After the reinforced aluminum matrix composite material is subjected to continuous forging, reverse extrusion and T6 heat treatment, the micro-nano hybrid SiC p Reinforced aluminum matrix composite cylindrical parts.

[0043] Among them, on the one hand, it can make nano-scale SiC p , micron SiC pBy intercalating with aluminum powder, the recrystallization degree of the composite material is improved through the grain boundary pinning effect, Orowan strengthening effect and promotion of nucleation mechanism, thereby increasing the strength and hardness of the crystal, and thus improving the mechanical properties of the aluminum-based composite material; on the other hand, it can simultaneously improve the wetting and dispersion of the SiC-Al composite particle reinforcement in the aluminum alloy melt matrix in a very short time, achieving its uniform distribution; thirdly, it can eliminate casting defects such as shrinkage and pores to achieve grain refinement, improve reinforcement distribution, and prepare cylindrical parts with excellent mechanical properties. At the same time, the preparation process of this application is simple and easy to repeat, which significantly improves the strength and plasticity of the aluminum-based composite cylindrical parts.

[0044] In the embodiment of the present application, the micron SiC p The particle size of the nano-SiC is preferably 0-5 μm, and the added mass fraction is preferably 2.5 wt%. p The particle size is 0-50nm, and the added mass fraction is preferably 1.5wt%, micron SiC p , nano-SiC p The mass ratio of nano-SiC to aluminum powder is preferably 1:10. p Reinforcement, can pin the grain boundary, inhibit grain growth, and provide Orowan strengthening effect, while adding micron SiC p The degree of recrystallization of the aluminum matrix can be improved through the thermal mismatch strengthening mechanism and the particle stimulated nucleation mechanism. By controlling the addition amount of the two, the synergistic improvement of the strength and plasticity of the aluminum-based composite cylindrical parts can be achieved.

[0045] In the embodiment of the present application, the micron SiC p , nano-SiC p After mixing with aluminum powder, high energy ball milling was carried out in three stages: the first stage was at 150rpm for 4 hours, the second stage was at 220rpm for 10 hours, and the third stage was at 330rpm for 6 hours. p The process of high-energy ball milling with aluminum powder is as follows: the first stage is material mixing (150rpm, 4h), the second stage is material embedding (220rpm, 10h), and the third stage is material welding (330rpm, 6h). Clockwise rotation and counterclockwise rotation are alternated every hour, with a 30min break in between. p The mass ratio of aluminum powder to micro-SiC is 1:10, and high-energy ball milling is performed under argon protective atmosphere. p Get effective dispersion, while SiC p The millimeter-sized SiC-Al composite particles are obtained by high-energy ball milling. pIf the mass ratio of aluminum powder to aluminum powder is lower than 1:10, it is difficult to ball-mill into millimeter-sized composite particles.

[0046] In the embodiment of the present application, the aluminum alloy is preferably an Al-Mg-Si alloy. The Al-Mg-Si alloy has good corrosion resistance and excellent machinability, but its strength and modulus are relatively low. SiC ceramic particles (SiC p ) has excellent properties such as high strength, high hardness, high wear resistance, oxidation resistance, high thermal conductivity, low thermal expansion rate and is not corroded by most acid and alkali solutions. It is a good reinforcing phase. Based on this, the present application adopts Al-Mg-Si alloy as the base alloy, by adding SiC p , improve the mechanical properties of Al-Mg-Si alloy and expand its application. Among them, the mass fraction of Al-Mg-Si alloy is preferably Al 97.6%, Mg 1.6%, Si 0.8%. Through the selection of this aluminum alloy, magnesium and silicon elements can form Mg2Si phase, which has a good strengthening effect in aluminum alloy. In addition, SiC p The introduction of reinforcement phase can improve the strength of the material on the one hand, and promote the precipitation of Mg2Si phase on the other hand. p The synergistic effect of the reinforcement phase and the Mg2Si phase can effectively improve the strength and hardness of the aluminum-based composite material.

[0047] In the embodiment of the present application, when the SiC-Al composite particles and the aluminum alloy are dissolved at high temperature and ultrasonically treated, the ultrasonic frequency is preferably 20kHz, the power is preferably 3000w, and the treatment time is preferably 20min. p It is evenly distributed in the aluminum melt, and ultrasonic treatment has a degassing effect.

[0048] In the embodiment of the present application, the cast SiC p When continuously forging the reinforced aluminum-based composite material, the temperature is preferably 400°C. During the T6 heat treatment, the solution treatment is preferably performed at 550°C for 2 hours, and the aging treatment is preferably performed at 180°C for 12 hours. Controlling the T6 heat treatment can eliminate some stress in the aluminum alloy, thereby improving its plasticity and ductility, resulting in improved deformation capabilities. It can also significantly increase the hardness of the aluminum alloy, giving it better wear resistance and impact resistance. It can also enhance the aluminum alloy's corrosion resistance, making it more durable in humid or corrosive environments and extending its service life.

[0049] It should be noted that, with SiC p -Al mixed powder is wrapped in aluminum foil to form a 1cm 3The purpose is to facilitate the addition of the reinforcement to the aluminum-based melt. When the aluminum-based alloy melt is controlled to be semi-solid, the reinforcement is added by mechanically stirring clockwise for preferably 10 minutes. The temperature is then increased and counterclockwise stirring is preferably performed for 10 minutes. The mechanical stirring speed is preferably ~600 rpm. After the temperature is increased to a liquid state, an ultrasonic horn is added. The ultrasonic horn is positioned 2 cm below the liquid surface. The ultrasonic frequency is preferably 20 kHz, the power is preferably ~3000 W, and the treatment time is preferably ~20 minutes.

[0050] It should be noted that the prepared as-cast composite material is first homogenized and then wire-cut and polished according to dimensional requirements. The homogenization temperature is preferably 500°C and the time is preferably 12 hours. The mold and as-cast composite material are then preheated to 400°C. At 150°C, the inner wall of the mold is coated with graphite oil and forged. The forging speed is preferably 0.5 mm / s. When the forging reaches the specified height, the upper mold is replaced for back extrusion. The back extrusion speed is preferably 0.5 mm / s. The ratio of the mold inner diameter to the upper mold diameter is preferably 4:3.

[0051] In the second aspect, the present application also provides a micro-nano hybrid SiC prepared by the preparation method described in the first aspect. p Reinforced aluminum matrix composite cylindrical parts. p The reinforced aluminum-based composite cylindrical component maintains the elongation of the matrix while giving it excellent yield strength and tensile strength, and has excellent mechanical properties.

[0052] The technical solution of the present application will be further described below in conjunction with specific embodiments.

[0053] Example 1

[0054] This embodiment provides a micro-nano hybrid SiC p The preparation method of the reinforced aluminum-based composite cylindrical member specifically comprises:

[0055] according to Figure 1 The preparation process is shown in the preparation process flow chart:

[0056] S101: Micronized SiC with a mass fraction of 2.5wt% p , nano-SiC with a mass fraction of 1.5wt% p Mixed with aluminum powder, micron SiC p , nano-SiC pThe mass ratio of SiC to aluminum powder is 1:10, and high-energy ball milling is carried out under argon protective atmosphere. The process is as follows: the first stage is material mixing (150 rpm, 4 hours), the second stage is material embedding (220 rpm, 10 hours), and the third stage is material welding (330 rpm, 6 hours). Clockwise rotation and counterclockwise rotation are alternated every hour, with a 30-minute rest in between, to obtain SiC-Al composite particles.

[0057] according to Figure 3 As we know, the appearance of the prepared SiC-Al composite particles can be p intercalated with aluminum powder to obtain millimeter-sized SiC-Al composite particles;

[0058] S102: Under an argon protective atmosphere, SiC-Al composite particles and aluminum alloy are added to the melting furnace and the temperature is adjusted to 740°C. After the aluminum alloy is melted, the temperature is lowered to 620°C (semi-solid temperature), and the mixture is added to the semi-solid aluminum alloy melt by clockwise mechanical stirring. After about 10 minutes, counterclockwise stirring is used for 10 minutes and the melting furnace temperature is increased to 690°C, wherein the stirring speed is about 500-800r / min. Subsequently, the aluminum-based composite material melt is subjected to high-power ultrasonic treatment, the ultrasonic amplitude rod is positioned 2 cm below the liquid surface, the ultrasonic frequency is 20kHz, the power is 3000w, and the treatment time is 20 minutes. The treated aluminum-based composite material melt is cast into a mold preheated to 500°C, and the pressure is maintained at 400MPa for 3 minutes, and homogenized at a temperature of 500°C for 12 hours to obtain cast SiC p Reinforced aluminum matrix composites;

[0059] Among them, according to Figure 2 The casting mold shown is a split-half casting mold with an angle, comprising a mold base 1, a cover mold 2, and a split mold 3. The purpose of the tilt of the cover mold 2 and the split mold 3 is to facilitate demolding. After the die-casting is completed, the casting mold base 1 is removed, the mold is turned 180 degrees, and the middle split mold 3 is pressed out with a press, and then broken into two halves to obtain the cast aluminum-based composite material.

[0060] S103: Cast SiC p The reinforced aluminum matrix composite material is placed in a preheated 400℃ casting mold. At 150℃, the inner wall of the mold is coated with graphite oil and forged at a speed of 0.5mm / s. When the forging reaches the specified height, it is kept at 400℃ for 30 minutes, and the upper mold is replaced for reverse extrusion at a speed of 0.5mm / s. Then, T6 heat treatment is performed, with a solution process at 550℃ for 2 hours and an aging process at 180℃ for 12 hours to obtain micro-nano hybrid SiC. pReinforced aluminum matrix composite cylindrical parts ((5μm-2.5wt%+50nm-1.5wt%)SiC p / Al-1.6Mg-0.8Si composite cylindrical parts).

[0061] according to Figure 3 The schematic diagram of the continuous hot forging heated reverse extrusion device shown in the figure includes a forging upper die 4, a sleeve die 5, an iron block 6 in the die, a push rod 7, and a reverse extrusion upper die 8. The forging upper die 4 can transfer the load to the blank to implement the blank forging operation; the sleeve die 5 is fixed to the press base with screws and places the blank therein; the iron block 6 is used to limit the downward flow of the cast blank during high-temperature forging and reverse extrusion; the push rod 7 is used to eject the cylinder and the iron block from the die together after the high-temperature forging and reverse extrusion are completed; after the hot forging is completed, the forging upper die 4 is replaced by the reverse extrusion upper die 8, which is used to implement hot reverse extrusion to form the cylindrical part. First, the homogenized cast billet is placed in the sleeve mold 5 (it should be noted that the size and height of the billet should be consistent with the sleeve mold), and then the obtained cast material is forged, and then the back-extrusion operation is carried out. After the back-extrusion is completed, the rising push rod 7 pushes the iron pad 6 and the composite material cylindrical part out of the sleeve mold 5, thereby obtaining an aluminum-based composite material cylindrical part.

[0062] At the same time, in order to verify the micro-nano hybrid SiC prepared in the above embodiment p To enhance the comprehensive performance of the aluminum-based composite cylindrical member, the present application provides the following comparative examples for detailed description.

[0063] Comparative Example 1

[0064] The component proportions, preparation operation and process parameters of the B1-aluminum-based composite cylindrical member prepared in the comparative example provided in this application are basically the same as those in Example 1. The difference is that only micron SiC is added to the prepared material in this comparative example. p The aluminum alloy was reinforced to obtain a B1-aluminum composite cylindrical piece (5μm-4wt% SiC p / Al-1.6Mg-0.8Si composite cylindrical parts).

[0065] Comparative Example 2

[0066] The component proportions, preparation operation and process parameters of the B2-aluminum-based composite cylindrical member prepared in the comparative example provided in this application are basically the same as those in Example 1. The difference is that only nano-SiC is added to the preparation material in this comparative example. p The aluminum alloy was reinforced by the reinforcement material to obtain a B2-aluminum matrix composite cylindrical piece (50nm-1.5wt% SiC p / Al-1.6Mg-0.8Si composite cylindrical parts).

[0067] Comparative Example 3

[0068] The component proportions, preparation operation and process parameters of the B2-aluminum-based composite cylindrical member prepared in the comparative example of this application are basically the same as those in Example 1. The difference is that the micron SiC is not added in this comparative example. p and nano-SiC p Reinforced materials are used to produce B3-aluminum-based composite cylindrical parts (Al-1.6Mg-0.8Si material cylindrical parts).

[0069] In order to verify the appearance of the reinforced aluminum-based composite cylindrical member prepared in the embodiment of the present application, the aluminum-based composite material prepared in the embodiment was tested, and the results were as follows: Figures 5 and 6 As shown. Among them, Figure 5 As-cast Al-1.6Mg-0.8Si, 5μm-4wt%SiC p / Al-1.6Mg-0.8Si, 50nm-1.5wt%SiC p / Al-1.6Mg-0.8Si, (5μm-2.5wt%+50nm-1.5wt%)SiC p Scanning electron microscope image of / Al-1.6Mg-0.8Si reinforced aluminum matrix composite; Figure 6 Al-1.6Mg-0.8Si, 5μm-4wt%SiC p / Al-1.6Mg-0.8Si, 50nm-1.5wt%SiC p / Al-1.6Mg-0.8Si, (5μm-2.5wt%+50nm-1.5wt%)SiC p Scanning electron microscope image of a cylindrical part made of / Al-1.6Mg-0.8Si reinforced aluminum matrix composite material.

[0070] according to Figure 5 It can be seen that the microstructure of the Al-1.6Mg-0.8Si alloy material is dense, no micropores are observed, and the particle distribution is relatively uniform. Figure 5 (a) shows that the grain boundaries of the Al-1.6Mg-0.8Si alloy are discontinuous and the grain size is large. In Figures (bd), it can be seen that the reinforcement particles are mainly distributed along the grain boundaries in the matrix and are relatively uniform, indicating that the early ultrasonic treatment has played a certain effect on promoting the uniform distribution of reinforcement particles, and the grain size of the composite material has been significantly refined. p The particles have the most obvious effect on the refinement of matrix grains. This may be due to the fact that during the solidification process, SiC p Particles can act as nucleation sites for grains and promote the nucleation of crystals. On the other hand, during the crystallization process, SiC pParticles can pin grain boundaries, limiting grain growth. Furthermore, the acoustic cavitation and acoustic streaming effects generated during ultrasonic treatment can further refine grains. On the one hand, changes in acoustic wave pressure during ultrasonic treatment can form cavitation bubbles in the metal melt. These bubbles expand and burst, causing drastic changes in the temperature and pressure in the local melt. This not only changes the equilibrium melting point of the material but also increases the degree of undercooling in certain areas of the melt, promoting nucleation. On the other hand, the vibration of the ultrasonic wave can form microscopic eddies and flow layers in the melt. This acoustic streaming effect can strongly agitate the melt and hinder grain growth, leading to grain movement and rearrangement, increasing the number of nuclei and further enhancing grain refinement.

[0071] according to Figure 6 It can be seen that compared with Al-1.6Mg-0.8Si alloy and 5μm-4wt%SiC p / Al-1.6Mg-0.8Si, 50nm-1.5wt%SiC p / Al-1.6Mg-0.8Si, (5μm-2.5wt%+50nm-1.5wt%)SiC p The microstructure of the cylindrical parts of / Al-1.6Mg-0.8Si composite materials was found to be p There are many nano-scale precipitates evenly distributed near the particles, and the number of precipitates in the area without particle distribution is small. The size of the precipitates in the composite material is much smaller than that of the Al-1.6Mg-0.8Si alloy and is dispersed. This phenomenon is found in (5μm-2.5wt%+50nm-1.5wt%)SiC p / Al-1.6Mg-0.8Si composite materials are more obvious, such as Figure 6 (ad) This may be due to the fact that SiC p The presence of particles leads to an increase in the dislocation density in the composite material. Its high-density dislocation structure provides channels for the diffusion of solute atoms, which is beneficial to the diffusion of solute atoms. In addition, high-density dislocations can serve as nucleation sites for precipitated phases, thereby accelerating precipitation and forming a large number of areas enriched with Mg2Si phase precipitation phases.

[0072] In order to verify the micro-nano hybrid SiC prepared in this application example p Enhance the mechanical properties of aluminum matrix composite cylindrical parts, the micro-nano hybrid SiC p The reinforced aluminum matrix composite cylindrical parts were tested and the results were Figures 7 and 8 As shown. Among them, Figure 7 As-cast Al-1.6Mg-0.8Si, 5μm-4wt%SiC p / Al-1.6Mg-0.8Si, 50nm-1.5wt%SiC p / Al-1.6Mg-0.8Si, (5μm-2.5wt%+50nm-1.5wt%)SiC p Stress-strain curve of / Al-1.6Mg-0.8Si composite material; Figure 8 Al-1.6Mg-0.8Si, 5μm-4wt%SiC p / Al-1.6Mg-0.8Si, 50nm-1.5wt%SiC p / Al-1.6Mg-0.8Si, (5μm-2.5wt%+50nm-1.5wt%)SiC p Engineering stress-strain curve of cylindrical parts of / Al-1.6Mg-0.8Si reinforced aluminum matrix composite materials.

[0073] according to Figure 7 It can be seen that the cast Al-1.6Mg-0.8Si, 5μm-4wt%SiC p / Al-1.6Mg-0.8Si, 50nm-1.5wt%SiC p / Al-1.6Mg-0.8Si, (5μm-2.5wt%+50nm-1.5wt%)SiC p Engineering stress-strain curve of / Al-1.6Mg-0.8Si composite material. As can be seen from the figure, micro-nano hybrid SiC p The introduction of reinforcement phase has a significant improvement on the performance of the composite material. Compared with Al-1.6Mg-0.8Si alloy, SiC p / Al-Mg-Si composite materials have significantly improved strength, among which the micro-nano hybrid SiC p The strengthening effect caused by the particles is significantly higher than that of single-scale micron or nano SiC particles. This is because the micro-nano mixed SiC p The introduction of particles refines the grain size and at the same time, SiC p The particles are hard particles, the deformation of the particles and the matrix is ​​not coordinated, and the micro-nano mixed SiC p The introduction of particles will lead to dislocation accumulation in the material during the tensile process, resulting in an increase in strength. In addition, it can be found that micron SiC p and nano-SiC p The introduction of reinforcement phase can not only significantly improve the strength, but also maintain the toughness of the composite material to the greatest extent.

[0074] according to Figure 8 It can be seen that Al-1.6Mg-0.8Si, 5μm-4wt%SiC p / Al-1.6Mg-0.8Si, 50nm-1.5wt%SiC p / Al-1.6Mg-0.8Si, (5μm-2.5wt%+50nm-1.5wt%)SiC p The tensile strength of the cylindrical parts reinforced with Al-1.6Mg-0.8Si composite materials are 168.9MPa, 278.2MPa, 285.3MPa and 305.3MPa respectively, and the yield strength are 78.6MPa, 213.4MPa, 216.8MPa and 229.4MPa respectively. Compared with Al-1.6Mg-0.8Si alloy, SiC p The tensile strength of the Mg / Al-Mg-Si composites increased by 64.7%, 68.9%, and 80.8%, respectively, and the yield strength increased by 171.5%, 175.8%, and 189.8%, respectively. This is due to the presence of reinforcing particles, which act as nucleation sites and promote the dynamic precipitation of nanophases. The presence of a large number of nanophases in the aged aluminum matrix hinders dislocation motion, effectively increasing the matrix strength. At the same time, the elongation of the composites can be maintained at 12%-15%.

[0075] The test results of the mechanical properties of the aluminum-based composite cylindrical parts prepared in the examples and comparative examples of the present application are shown in Table 1.

[0076] Table 1 Test results of mechanical properties of aluminum matrix composite cylindrical parts

[0077]

[0078] Therefore, the preparation method provided by the present application is to p , nano-SiC p After mixing with aluminum powder, high-energy ball milling is performed, and after die-casting with aluminum alloy, continuous forging + reverse extrusion treatment is performed, and then solution aging heat treatment is performed to obtain micro-nano hybrid SiC p Reinforced aluminum-based composite cylindrical parts can improve the dispersion of reinforcements and produce cylindrical parts with excellent mechanical properties.

[0079] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0080] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A micro-nano hybrid SiC p The method for preparing a reinforced aluminum-based composite cylindrical member is characterized in that: The method comprises: Micron SiC p , nano-SiC p After mixing with aluminum powder, high-energy ball milling is performed to obtain SiC-Al composite particles; The SiC-Al composite particles and aluminum alloy are dissolved at high temperature and ultrasonically treated, and then die-cast and homogenized to obtain cast SiC p Reinforced aluminum matrix composites; The cast SiC p After the reinforced aluminum matrix composite material is subjected to continuous forging, reverse extrusion and T6 heat treatment, the micro-nano hybrid SiC p Reinforced aluminum matrix composite cylindrical parts; The micron SiC p The particle size is 0-5 μm, and the added mass fraction is 2.5 wt%; The nano SiC p The particle size is 0-50 nm, and the added mass fraction is 1.5 wt%; The micron SiC p , nano-SiC p The mass ratio of aluminum powder to aluminum powder is 1:10; The aluminum alloy is an Al-Mg-Si alloy, with a mass fraction of Al 97.6%, Mg 1.6%, and Si 0.8%; The SiC-Al composite particles and the aluminum alloy were dissolved at high temperature and ultrasonically treated, and then die-casting was performed with a mold preheating temperature of 500°C, a pressure of 400 MPa, and a time of 3 minutes; The cast SiC p When the reinforced aluminum matrix composite material is continuously forged, the temperature is 400 °C; During the T6 heat treatment, the solution treatment is performed at 550°C for 2 h, and the aging treatment is performed at 180°C for 12 h.

2. The micro-nano hybrid SiC according to claim 1 p The method for preparing a reinforced aluminum-based composite cylindrical member is characterized in that: The micron SiC p , nano-SiC p When mixed with aluminum powder and then subjected to high-energy ball milling, the process was carried out in three stages: the first stage was at 150 rpm for 4 h, the second stage was at 220 rpm for 10 h, and the third stage was at 330 rpm for 6 h.

3. The micro-nano hybrid SiC according to claim 1 p The method for preparing a reinforced aluminum-based composite cylindrical member is characterized in that: When the SiC-Al composite particles and the aluminum alloy are dissolved at high temperature and ultrasonically treated, the ultrasonic frequency is 20 kHz, the power is 3000 W, and the treatment time is 20 min.

4. A micro-nano hybrid SiC prepared by the preparation method according to any one of claims 1 to 3 p Reinforced aluminum matrix composite cylindrical parts.

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