Preparation method of aluminum-based composite material and aluminum-based composite material

Abstract

The embodiment of the invention provides a preparation method of an aluminum-based composite and the aluminum-based composite.The preparation method of the aluminum-based composite comprises the steps that target powder at least comprising aluminum-based alloy powder is put into a plasma generation cavity, and the plasma generation cavity is vacuumized; discharging gas is introduced into the vacuumized plasma generation cavity; carrying out plasma discharge treatment on the target powder in the plasma generation cavity, and carrying out surface modification on the target powder by utilizing discharge plasma generated by discharge gas in the plasma discharge treatment process to obtain modified powder; and the modified powder is subjected to selective laser melting layer-by-layer melting forming through the selective laser melting technology, and the aluminum-based composite material is obtained. According to the embodiment of the invention, the mechanical property, the wear resistance and the corrosion resistance of the aluminum-based composite material are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing, and in particular to a preparation method of an aluminum-based composite material and the aluminum-based composite material. Background Art

[0002] As one of the most widely used aluminum alloys, AlSi10Mg alloy has a small tendency to hot cracking and shrinkage, and has excellent casting performance, welding performance and good cutting performance. It is widely used in aircraft and spacecraft parts (for example, main engine casing, pump cover, etc.). Commonly used aluminum alloy parts manufacturing methods, such as casting, forging and welding, can be mass-produced, but there are problems such as limited processing feasibility and difficulty in processing complex parts.

[0003] At present, AlSi10Mg alloy powder obtained by atomization is usually used for additive manufacturing to prepare aluminum-based composite materials through selective laser melting technology, so as to achieve the preparation of precise and complex aluminum-based composite parts.

[0004] However, the AlSi10Mg alloy powder obtained by atomization has poor fluidity and low surface wettability, and the pore filling effect is poor during the selective laser melting process, resulting in low density and severe grain coarsening of the prepared aluminum-based composite material. The low density and severe grain coarsening of the aluminum-based composite material will further lead to reduced mechanical properties, corrosion resistance and wear resistance of the aluminum-based composite material, which cannot meet the high performance requirements of the relatively harsh service environment in the aerospace field. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method for preparing an aluminum-based composite material and an aluminum-based composite material, so as to solve the problem that the aluminum-based composite material prepared by the relevant technology has reduced mechanical properties, corrosion resistance and wear resistance, and cannot meet the high performance requirements of the aerospace field.

[0006] In order to solve the above problems, the present invention is achieved through the following technical solutions:

[0007] The present invention provides a method for preparing an aluminum-based composite material, the method comprising:

[0008] Putting target powder into a plasma generating chamber and performing vacuum treatment on the plasma generating chamber; the target powder at least includes aluminum-based alloy powder;

[0009] Introducing discharge gas into the vacuum-treated plasma generating chamber;

[0010] Performing plasma discharge treatment on the target powder in the plasma generating chamber, so as to modify the surface of the target powder by utilizing the discharge plasma generated by the discharge gas during the plasma discharge treatment to obtain modified powder;

[0011] The modified powder is subjected to laser selective melting and consolidation layer by layer by adopting selective laser melting technology to obtain an aluminum-based composite material.

[0012] Furthermore, in the method, the gas pressure of the plasma discharge treatment is 0.01 MPa to 0.1 MPa; the peak-to-peak value of the discharge voltage of the plasma discharge treatment is 20 kV to 30 kV; and the duration of the plasma discharge treatment is 1 h to 6 h.

[0013] Furthermore, in the method, during the plasma discharge treatment of the target powder in the plasma generating chamber, the amplitude of the plasma generating chamber is 8 mm to 15 mm.

[0014] Further, in the method, the target powder also includes a reinforcement phase;

[0015] The weight percentage of the reinforcement phase in the target powder is 0.5% to 3%.

[0016] Furthermore, in the method, the particle size of the reinforcement phase is 50 nm to 200 nm.

[0017] Furthermore, in the method, the duration of the plasma discharge treatment is 1 hour to 3 hours.

[0018] Furthermore, in the method, the target powder also includes a reinforcement phase, and the discharge gas is any one of NH3, N2 and Ar.

[0019] Furthermore, in the method, the target powder does not include a reinforcement phase, and the discharge gas is any one of NH3 and N2.

[0020] Furthermore, in the method described above, the particle size of the aluminum-based alloy powder is 20 μm to 50 μm.

[0021] The present invention also provides an aluminum-based composite material, wherein the aluminum-based composite material is prepared by the method for preparing the aluminum-based composite material as described in any one of the above items.

[0022] Compared with the related art, the embodiments of the present invention have the following advantages:

[0023] The preparation method of the aluminum-based composite material provided by the embodiment of the present invention comprises the following steps: performing plasma discharge treatment on the target powder including the aluminum-based alloy powder in the plasma generating chamber, bombarding the surface of the target powder with the discharge plasma generated by the breakdown of the discharge gas during the plasma discharge treatment, cleaning and etching the surface of the target powder, achieving physical modification of the surface of the target powder, and improving the fluidity and surface wettability of the modified powder obtained by the plasma discharge treatment; in the process of performing selective laser melting and layer-by-layer melting and forming of the modified powder by the selective laser melting technology, the higher fluidity and surface wettability of the modified powder are conducive to the heat transfer and the filling of the pores, thereby improving the density of the aluminum-based composite material; by improving the density of the aluminum-based composite material, the mechanical properties of the aluminum-based composite material can be improved, the generation of spalling wear during the friction and wear process can be reduced, and the wear resistance of the aluminum-based composite material can be improved; in addition, the aluminum-based composite material with a higher density can also reduce the contact area between the corrosive medium and the aluminum-based composite material, and improve the corrosion resistance of the aluminum-based composite material, so that the aluminum-based composite material prepared by the embodiment of the present invention has higher mechanical properties, wear resistance and corrosion resistance, and can meet the needs of more application scenarios.

[0024] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0026] Figure 1 It is a flow chart of steps of a method for preparing an aluminum-based composite material provided by the present invention;

[0027] Figure 2 is a backscattered SEM image of the cross section of the modified powder obtained in Comparative Example 1 provided by the present invention;

[0028] Figure 3 is a backscattered SEM image of the cross section of the modified powder obtained in Example 1 provided by the present invention;

[0029] Figure 4 is a SEM image of the aluminum-based composite material prepared in Comparative Example 1 provided by the present invention;

[0030] Figure 5 is a SEM image of the aluminum-based composite material prepared in Example 1 provided by the present invention;

[0031] Figure 6 is a SEM image of the aluminum-based composite material prepared in Comparative Example 2 provided by the present invention;

[0032] Figure 7 This is a SEM image of the aluminum-based composite material prepared in Example 15 provided by the present invention. DETAILED DESCRIPTION

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

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Aluminum alloys are favored for their excellent properties such as low density, good conductivity, high ductility and high recovery rate. Among them, AlSi10Mg, as one of the most widely used alloys in aluminum alloys, has a small tendency to hot cracking and shrinkage, and has excellent casting performance, welding performance and good cutting performance. It is widely used in aircraft and spacecraft parts, such as main engine casings, pump covers, etc. Commonly used methods for manufacturing aluminum alloy parts include casting, forging and welding. Although casting, forging and welding can produce aluminum alloy parts in large quantities, there are problems such as limited processing feasibility and difficulty in processing complex parts. In recent years, the emerging selective laser melting (SLM) forming technology has high forming accuracy and simple process flow, which is convenient for preparing small and medium-sized precision and complex aluminum-based composite parts, and has opened up a new direction for the manufacture of complex-shaped aluminum alloy parts. In the process of preparing aluminum-based composites using SLM forming technology, the AlSi10Mg alloy powder obtained by atomization is usually selected to prepare aluminum-based composites by additive manufacturing through selective laser melting technology; however, the aluminum-based alloy powders such as AlSi10Mg obtained by atomization have poor fluidity and low surface wettability, and the pore filling effect is poor during the selective laser melting forming process, resulting in poor density of the prepared aluminum-based composite materials. The low density will further lead to reduced mechanical properties, corrosion resistance and wear resistance of the aluminum-based composite materials, which cannot meet the high performance requirements of the relatively harsh service environment in the aerospace field.

[0036] In order to solve the above problems, the present invention provides a method for preparing an aluminum-based composite material. Figure 1, shows a flow chart of steps of a method for preparing an aluminum-based composite material provided by an embodiment of the present invention, the method comprising steps S101 to S104:

[0037] Step S101, placing target powder into a plasma generating chamber, and evacuating the plasma generating chamber; the target powder includes at least aluminum-based alloy powder.

[0038] Step S102, introducing discharge gas into the plasma generating chamber after vacuum treatment.

[0039] Step S103 , performing plasma discharge treatment on the target powder in the plasma generating chamber, so as to modify the surface of the target powder by utilizing the discharge plasma generated by the discharge gas during the plasma discharge treatment to obtain modified powder.

[0040] Step S104: using a selective laser melting technique to perform laser selective melting and consolidation forming on the modified powder layer by layer to obtain an aluminum-based composite material.

[0041] In an embodiment of the present invention, the target powder may be an aluminum-based alloy powder, or a mixed powder of an aluminum-based alloy powder and a reinforcement phase, that is, the target powder includes at least an aluminum-based alloy powder, and the target powder may or may not include a reinforcement phase.

[0042] Aluminum-based alloy powders may include, but are not limited to, AlSi10Mg alloy powder, 60 series aluminum alloy powder, 70 series aluminum alloy powder, etc. Among them, AlSi10Mg alloy is mainly composed of aluminum (Al), silicon (Si), magnesium (Mg) and other elements, and the weight proportion of silicon in AlSi10Mg alloy is 10%, the weight proportion of magnesium is 0.3% to 0.6%, and the sum of the weight proportion of aluminum, silicon and magnesium is 100%. 60 series aluminum alloy refers to 6000 series aluminum alloy, which is mainly composed of aluminum, magnesium, silicon and other elements; among them, 6060 and 6061 are more common models in 60 series aluminum alloy. 70 series aluminum alloy refers to 7000 series aluminum alloy, which is mainly composed of aluminum, zinc (Zn) and other elements, among which 7075 is a more common model in 70 series aluminum alloy.

[0043] It should be noted that, in the embodiment of the present invention, the aluminum-based alloy powder in the target powder is a powder prepared by using an atomization technology, and the atomization technology includes a water atomization technology and a gas atomization technology.

[0044] The reinforcement phase is nano-scale ceramic particles, and the reinforcement phase may include but is not limited to: TiC, SiC, TiN, Al2O3, etc.

[0045] The method for preparing an aluminum-based composite material provided in an embodiment of the present invention comprises first performing plasma discharge treatment on a target powder including at least an aluminum-based alloy powder through steps S101 to S103 before preparing the aluminum-based composite material by using the selective laser melting technology, so as to modify the physical properties of the surface of the target powder and obtain a modified powder; and finally preparing the aluminum-based composite material through step S104, thereby improving the mechanical properties, corrosion resistance and wear resistance of the aluminum-based composite material.

[0046] Specifically, before step S101, the aluminum-based alloy powder obtained by atomization can be used as the target powder, or a preset ratio of reinforcing phase can be added to the aluminum-based alloy powder obtained by atomization, and a mixed powder consisting of the aluminum-based alloy powder and the reinforcing phase can be determined as the target powder. The preset ratio can be determined according to the actual demand for introducing the reinforcing phase into the aluminum matrix, and the embodiment of the present invention does not specifically limit the value of the preset ratio.

[0047] In step S101, the acquired target powder can be placed in a plasma generating chamber, and the plasma generating chamber can be evacuated to exhaust the air in the plasma generating chamber, which is conducive to introducing discharge gas into the vacuum plasma generating chamber in step S102. At the same time, it can also prevent oxygen in the air from contacting with the aluminum-based alloy powder and causing oxidation of the aluminum-based alloy powder.

[0048] The plasma generating chamber is a sealed container for containing the discharge gas, electrodes and target powder in the plasma generating process, wherein the number of electrodes is 2. The main function of the plasma generating chamber is to provide a stable electric field environment through the electrodes so that the discharge gas molecules are broken down under the action of the electric field to form a discharge plasma.

[0049] In step S102, the discharge gas introduced into the vacuum-processed plasma generating chamber may include, but is not limited to, argon (Ar), nitrogen (N2), helium (He), hydrogen (H2), and ammonia (NH3), etc. The discharge gas is used to be broken down under the action of the electric field in the plasma generating chamber to form a discharge plasma.

[0050] In step S103, when discharge gas is introduced into the plasma generating chamber after the vacuum treatment in step S102, plasma discharge treatment can be performed on the target powder in the plasma generating chamber, so as to modify the surface of the target powder by utilizing the discharge plasma generated by the discharge gas during the plasma discharge treatment to obtain modified powder.

[0051] Specifically, a discharge voltage is applied between two electrodes in a plasma generating chamber, and as the discharge voltage applied between the two electrodes increases, an electric field is formed between the two electrodes.

[0052] Furthermore, as the electric field strength increases, the strong electric field formed between the electrodes will accelerate the electrons and collide with the discharge gas molecules in the plasma generating chamber, causing the discharge gas molecules to be ionized; as the ionization area expands, the density of ions and electrons in the discharge gas reaches a certain threshold, so that the entire area is filled with charged particles, the discharge gas is completely broken down, and a discharge plasma is generated.

[0053] In an embodiment of the present invention, when the discharge gas generates a discharge plasma, the high-speed moving discharge plasma in the plasma generating chamber bombards the surface of the target powder, cleans and etches the surface of the target powder, thereby achieving physical modification of the surface of the target powder and improving the fluidity and surface wettability of the modified powder obtained by plasma discharge treatment.

[0054] After the modified powder is obtained, the modified powder can be subjected to laser selective melting and consolidation layer by layer using a selective laser melting technique in step S104 to obtain an aluminum-based composite material.

[0055] In the embodiment of the present invention, during the process of executing step S104, the modified powder may be subjected to laser selective melting and consolidation layer by layer to obtain the aluminum-based composite material by using a selective laser melting technique known to those skilled in the art.

[0056] Specifically, in the process of laser selective melting and solidification of the modified powder layer by layer, the scanning speed can be 1000mm / s to 2000mm / s, the laser power can be 300W to 500W, the powder thickness can be 30μm, and the scanning spacing can be 120μm to 130μm.

[0057] The preparation method of the aluminum-based composite material provided by the embodiment of the present invention comprises the following steps: performing plasma discharge treatment on the target powder including the aluminum-based alloy powder in the plasma generating chamber, bombarding the surface of the target powder with the discharge plasma generated by the breakdown of the discharge gas during the plasma discharge treatment, cleaning and etching the surface of the target powder, achieving physical modification of the surface of the target powder, and improving the fluidity and surface wettability of the modified powder obtained by the plasma discharge treatment; in the process of performing selective laser melting and layer-by-layer melting and forming of the modified powder by the selective laser melting technology, the higher fluidity and surface wettability of the modified powder are conducive to the heat transfer and the filling of the pores, thereby improving the density of the aluminum-based composite material; by improving the density of the aluminum-based composite material, the mechanical properties of the aluminum-based composite material can be improved, the generation of spalling wear during the friction and wear process can be reduced, and the wear resistance of the aluminum-based composite material can be improved; in addition, the aluminum-based composite material with a higher density can also reduce the contact area between the corrosive medium and the aluminum-based composite material, and improve the corrosion resistance of the aluminum-based composite material, so that the aluminum-based composite material prepared by the embodiment of the present invention has higher mechanical properties, wear resistance and corrosion resistance, and can meet the needs of more application scenarios.

[0058] The aluminum-based composite material prepared by the method for preparing the aluminum-based composite material provided in the embodiment of the present invention can be applied to fields such as aerospace, and specifically, the aluminum-based composite material can be aircraft parts and spacecraft parts.

[0059] Optionally, during the plasma discharge treatment of the target powder in the plasma generating chamber, the gas pressure of the plasma discharge treatment is 0.01MPa to 0.1MPa; the peak-to-peak value of the discharge voltage of the plasma discharge treatment is 20kV to 30kV; and the duration of the plasma discharge treatment is 1h to 6h.

[0060] Among them, gas pressure refers to the pressure of the discharge gas inside the plasma generating chamber; the size of the gas pressure will affect the density, temperature and electron energy distribution of the discharge plasma. Specifically, a lower gas pressure is conducive to the formation of a high-density, low-temperature discharge plasma, which is suitable for fine processing of the material surface; a higher gas pressure may increase the temperature and collision frequency of the discharge plasma, which is suitable for processing processes requiring strong chemical reactions. In some embodiments, the gas pressure of the plasma discharge treatment can be a range of one or any two of 0.01MPa, 0.02MPa, 0.03MPa, 0.04MPa, 0.05MPa, 0.06MPa, 0.07MPa, 0.08MPa, 0.09MPa and 0.1MPa.

[0061] The peak-to-peak value of the discharge voltage refers to the difference between the positive peak value and the negative peak value in the waveform of the discharge voltage applied to the two electrodes in the plasma generating chamber during the plasma discharge process. The peak-to-peak value of the discharge voltage determines the electric field strength in the plasma generating chamber, thereby affecting the acceleration and collision process of the discharge plasma. In some embodiments, the peak-to-peak value of the discharge voltage of the plasma discharge process can be a range of one or any two of 20kV, 21kV, 22kV, 23kV, 24kV, 25kV, 26kV, 27kV, 28kV, 29kV and 30kV.

[0062] The duration of the plasma discharge treatment refers to the duration of the discharge plasma continuously acting on the surface of the target powder; the duration of the plasma discharge treatment directly affects the degree and depth of surface modification of the target powder. In some embodiments, the duration of the plasma discharge treatment can be a range of one or any two of 1 h, 2 h, 3 h, 4 h, 5 h and 6 h.

[0063] The method for preparing an aluminum-based composite material provided in an embodiment of the present invention controls the gas pressure of plasma discharge treatment within the range of 0.01MPa to 0.1MPa, controls the peak-to-peak value of the discharge voltage of plasma discharge treatment within the range of 20kV to 30kV, and controls the duration of plasma discharge treatment within the range of 1h to 6h, so that the discharge plasma generated by the discharge gas in the plasma generating chamber can fully clean and etch the target powder, thereby improving the fluidity and surface wettability of the modified powder obtained by the plasma discharge treatment.

[0064] Optionally, during the plasma discharge treatment of the target powder in the plasma generating chamber, the amplitude of the plasma generating chamber is 8 mm to 15 mm. In some embodiments, the amplitude of the plasma generating chamber can be in the range of one or any two of 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm and 15 mm.

[0065] The preparation method of the aluminum-based composite material provided by an embodiment of the present invention controls the amplitude of the plasma generating chamber within the range of 8 mm to 15 mm, so that the discharge plasma can fully contact the powder surface of the target powder, thereby improving the uniformity and comprehensiveness of the surface modification of the target powder, and further improving the fluidity and surface wettability of the modified powder.

[0066] Optionally, the target powder further includes a reinforcement phase, wherein the weight proportion of the reinforcement phase in the target powder is 0.5% to 3%. In some embodiments, the weight proportion of the reinforcement phase in the target powder can be in the range of one or any two of 0.5%, 1%, 1.5%, 2%, 2.5% and 3%.

[0067] It is understandable that in some relatively harsh service environments, a small amount of ceramic particle reinforcement phase, such as TiC, SiC, TiN, etc., will be introduced into the AlSi10Mg alloy to further improve the strength and corrosion resistance of the AlSi10Mg alloy. However, the aluminum-based composite materials prepared by commonly used powder metallurgy methods, such as ball milling and mechanical mixing, have problems such as poor wettability between the reinforcement phase and the aluminum matrix, poor interface bonding, and easy brittle phases, which cannot meet the high performance requirements of harsh service environments.

[0068] Related Technology In the process of preparing aluminum-based composite materials containing TiC reinforcement phase, AlSi10Mg powder and TiC powder are usually mixed by low-energy ball milling in a ball mill, and then additive manufacturing is achieved layer by layer through selective laser melting technology to obtain TiC-reinforced AlSi10Mg alloy. Although this method can mix AlSi10Mg powder and TiC powder to a certain extent, there are still problems such as uneven distribution of TiC particles in the AlSi10Mg matrix and defects in the interface bonding between TiC and AlSi10Mg; in addition, the ball milling process will also introduce new impurities into the powder, and the introduction of impurities will lead to further deterioration of the performance of the aluminum-based composite material.

[0069] Furthermore, in order to improve the interface bonding performance between the reinforcement phase and the aluminum matrix, the related technology also uses a molten salt method to deposit zirconium on the surface of the boron powder to form zirconium-coated boron reinforcement phase particles, and then mixes AlSi10Mg powder and zirconium-coated boron powder under the protection of argon gas through a ball milling process to obtain aluminum-based alloy powder, and uses selective laser melting technology to form it. During the laser melting forming process, Zr reacts with B to form ZrB2, and Zr reacts with Al to form Al3Zr, obtaining an in-situ Al3Zr+ZrB2 reinforced aluminum-based composite material, wherein Al3Zr can enhance the interface bonding performance between ZrB2 and the aluminum matrix and reduce interface defects. Although this solution can improve the interface bonding performance between the reinforcement phase and the aluminum matrix to a certain extent, the use of a molten salt method to uniformly plate zirconium elements on the surface of the boron powder to obtain zirconium-coated boron reinforcement particles is not only cumbersome, but the residual molten salt elements will also lead to the introduction of impurities.

[0070] It can be seen that the current relevant technologies are unable to improve the distribution uniformity of the reinforcement phase in the aluminum matrix and the interface bonding performance between the reinforcement phase and the aluminum matrix without introducing new impurities during the preparation of aluminum-based composite materials containing a reinforcement phase, resulting in the aluminum-based composite materials containing a reinforcement phase having low mechanical properties, corrosion resistance and wear resistance, which cannot reach the expected level in actual application scenarios.

[0071] In an embodiment of the present invention, in the process of preparing an aluminum-based composite material containing a reinforcing phase, the reinforcing phase is added to the aluminum-based alloy powder obtained after atomization according to the weight proportion of the reinforcing phase in the target powder being 0.5% to 3%, to obtain a mixed powder, and the mixed powder is determined as the target powder; thereafter, the aluminum-based composite material containing the reinforcing phase is prepared through operations corresponding to steps S101 to S104.

[0072] Among them, through the operations corresponding to step S101 to step S103, the discharge plasma generated by the discharge gas is used to bombard the surface of the target powder, the surface of the target powder is cleaned and etched, and the fluidity and surface wettability of the modified powder obtained by the plasma discharge treatment are improved. At the same time, under the action of the electric field in the plasma generating chamber during the plasma discharge treatment, based on the large difference in dielectric constant between the reinforcement phase and the aluminum-based alloy powder, a distorted electric field is induced, so that the reinforcement phase particles are evenly distributed on the surface of the aluminum-based alloy powder, thereby improving the uniformity of the distribution of the reinforcement phase in the modified powder in the aluminum-based alloy powder, and further improving the uniformity of the distribution of the reinforcement phase in the aluminum matrix in the aluminum-based composite material prepared based on the modified powder.

[0073] Furthermore, through the operations corresponding to step S101 to step S103, the discharge plasma generated by the discharge gas is used to clean and etch the surface of the target powder to achieve physical modification of the surface of the target powder, thereby improving the wettability of the modified powder, and also improving the wettability between the aluminum-based alloy powder and the reinforcement phase particles. In the process of laser selectively melting and solidifying the modified powder layer by layer using the selective laser melting technology, the wettability of the melt corresponding to the aluminum-based alloy powder to the reinforcement phase particles is also improved accordingly, thereby improving the interface bonding effect between the reinforcement phase and the aluminum matrix in the aluminum-based composite material, reducing interface bonding defects, and reducing the adverse effects caused by the interface bonding defects between the reinforcement phase and the aluminum matrix, so that the dispersion strengthening effect of the reinforcement phase in the aluminum-based composite material is fully exerted, and the mechanical properties, corrosion resistance and wear resistance of the aluminum-based composite material containing the reinforcement phase are further improved.

[0074] The preparation method of the aluminum-based composite material provided in an embodiment of the present invention, when the target powder includes a reinforcing phase and an aluminum-based alloy powder, uses the operations corresponding to steps S101 to S103 to perform surface modification on the target powder, thereby improving the distribution uniformity of the reinforcing phase in the aluminum matrix and the interface bonding performance between the reinforcing phase and the aluminum matrix. Not only is the operation process simple, but the plasma discharge treatment process does not introduce new impurities, and the weight proportion of the reinforcing phase in the target powder is controlled in the range of 0.5% to 3%, which can further enable the dispersion strengthening effect of the reinforcing phase in the aluminum matrix to be fully exerted, thereby improving the mechanical properties, corrosion resistance and wear resistance of the aluminum-based composite material.

[0075] Optionally, the particle size of the reinforcement phase is 50 nm to 200 nm. In some embodiments, the particle size of the reinforcement phase can be in the range of one or any two of 50 nm, 80 nm, 110 nm, 130 nm, 150 nm, 180 nm and 200 nm.

[0076] The particle size of the reinforcement phase may be the average particle size of the reinforcement phase particles or the Dv50 particle size of the reinforcement phase particles. It is understood that Dv50 represents the particle size corresponding to when the volume cumulative distribution percentage of the reinforcement phase particles is equal to 50%.

[0077] Optionally, when the target powder includes a reinforcement phase and an aluminum-based alloy powder, the duration of the plasma discharge treatment is 1 to 3 hours. In some embodiments, when the target powder includes a reinforcement phase and an aluminum-based alloy powder, the duration of the plasma discharge treatment can be a range of one or any two of 1 hour, 1.2 hours, 1.4 hours, 1.6 hours, 1.8 hours, 2 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours and 3 hours.

[0078] Optionally, the target powder includes a reinforcement phase and an aluminum-based alloy powder, and the discharge gas is any one of NH 3 , N 2 and Ar.

[0079] Optionally, the target powder does not include a reinforcement phase, that is, the target powder includes only an aluminum-based alloy powder, and the discharge gas is any one of NH 3 and N 2 .

[0080] In an embodiment of the present invention, in the process of surface modification of the target powder by using the discharge plasma generated by the discharge gas, the surface of the target powder is bombarded by the discharge plasma moving at high speed in the plasma generating chamber, which also induces a chemical reaction on the surface of the aluminum-based alloy powder in the target powder, so that the aluminum-based alloy powder combines with the free radicals in the discharge space to generate a new compound phase in situ on the surface of the aluminum-based alloy powder, thereby changing the physical phase composition of the surface of the aluminum-based alloy powder. Based on the compound phase generated in situ on the surface of the aluminum-based alloy powder, the fluidity and surface wettability of the modified powder obtained by plasma discharge treatment can be further improved.

[0081] Specifically, when the discharge gas is any one of NH3 and N2, the surface of the target powder is bombarded by the high-speed discharge plasma in the plasma generating cavity, inducing a chemical reaction on the surface of the aluminum-based alloy powder in the target powder, so that the aluminum-based alloy powder combines with the N-containing free radicals generated by NH3 or N2 in the discharge space, and an AlN phase is generated in situ on the surface of the aluminum-based alloy powder. The presence of the AlN phase can not only further modify the fluidity and surface wettability of the powder to improve the density of the aluminum-based composite material, but the AlN phase can also be used as a heterogeneous nucleation particle in the process of laser selective layer-by-layer melting and forming of the modified powder using the selective laser melting technology, thereby increasing the nucleation rate of aluminum grains, and the pinning of the AlN phase at the grain boundary can also inhibit the further growth of the eutectic phase and aluminum grains, thereby playing a role in refining the grains. The embodiment of the present invention can further improve the mechanical properties and wear resistance of the aluminum-based composite material based on the fine grain strengthening effect by improving the degree of grain refinement of the aluminum-based composite material, and the refined grains can also reduce the diffusion rate of corrosion particles in the aluminum-based composite material during corrosion, thereby further improving the corrosion resistance of the aluminum-based composite material.

[0082] It can be understood that, when the target powder only includes aluminum-based alloy powder, in order to further improve the mechanical properties, wear resistance and corrosion resistance of the aluminum-based composite material, any one of NH3 and N2 can be selected as the discharge gas, and the aluminum-based alloy powder is combined with the N-containing free radicals in the discharge space to generate AlN phase in situ on the surface of the aluminum-based alloy powder to refine the grain size in the aluminum-based composite material, thereby further improving the mechanical properties, wear resistance and corrosion resistance of the aluminum-based composite material through grain refinement strengthening.

[0083] In the case where the target powder includes both the reinforcing phase and the aluminum-based alloy powder, the discharge gas can be selected from any one of NH3, N2 and Ar because the dispersion strengthening effect of the reinforcing phase can further improve the mechanical properties, wear resistance and corrosion resistance of the aluminum-based composite material. When the discharge gas is Ar, the surface modification of the target powder is mainly used to improve the fluidity and surface wettability of the modified powder, as well as the uniformity of the distribution of the reinforcing phase in the aluminum matrix and the interface bonding performance between the reinforcing phase and the aluminum matrix, thereby improving the mechanical properties, wear resistance and corrosion resistance of the aluminum-based composite material based on the dispersion strengthening effect of the reinforcing phase and the density of the aluminum-based composite material. When the discharge gas is NH3 or N2, the mechanical properties, wear resistance and corrosion resistance of the aluminum-based composite material can be improved based on the dispersion strengthening effect of the reinforcing phase, the density of the aluminum-based composite material and the fine grain strengthening effect.

[0084] Optionally, the particle size of the aluminum-based alloy powder is 20 μm to 50 μm. Specifically, in some embodiments, the particle size of the aluminum-based alloy powder can be in the range of one or any two of 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm and 50 μm.

[0085] The particle size of the aluminum-based alloy powder can be the average particle size of the aluminum-based alloy powder or the Dv50 particle size of the aluminum-based alloy powder. It is understood that Dv50 represents the particle size corresponding to when the volume cumulative distribution percentage of the aluminum-based alloy powder is equal to 50%.

[0086] The method for preparing an aluminum-based composite material provided in an embodiment of the present invention controls the particle size of the aluminum-based alloy powder within the range of 20 μm to 50 μm, thereby improving the laser absorption rate of the modified powder and the powder filling density in step S104, while ensuring the fluidity of the modified powder and reducing the agglomeration problem of the modified powder, thereby facilitating improving the mechanical properties, corrosion resistance and wear resistance of the aluminum-based composite material.

[0087] The present invention also provides an aluminum-based composite material, wherein the aluminum-based composite material is prepared by the method for preparing the aluminum-based composite material as described in any one of the above items.

[0088] The present invention is described in detail below by way of examples.

[0089] Example 1

[0090] (1) Obtaining the target powder

[0091] The original atomized spherical AlSi10Mg alloy powder with a particle size of 30 μm was determined as the target powder.

[0092] (2) Obtaining modified powder

[0093] First, the target powder obtained in step (1) is placed in a plasma generating chamber, and the plasma generating chamber is evacuated; then, NH3 is introduced into the evacuated plasma generating chamber; finally, the target powder in the plasma generating chamber is subjected to plasma discharge treatment, so as to modify the surface of the target powder by utilizing the discharge plasma generated by the discharge gas during the plasma discharge treatment to obtain a modified powder; wherein the gas pressure of the plasma discharge treatment is 0.05 MPa, the peak-to-peak value of the discharge voltage of the plasma discharge treatment is 28 kV, and the duration of the plasma discharge treatment is 3 hours; and the amplitude of the plasma generating chamber is 8 mm.

[0094] (3) Preparation of aluminum-based composite materials

[0095] First, use the SLM-150 selective laser melting equipment to load the aluminum substrate into the forming chamber, and load the modified powder obtained in step (2) into the powder chamber; then, introduce high-purity argon as a protective gas and ensure that the oxygen partial pressure in the selective laser melting equipment is less than 50ppm; then, establish a printing task, and set the powder thickness to 30μm, the laser power to 300W, the scanning speed to 1200mm / s, the scanning spacing to 130μm, and the scanning strategy to partitioned island scanning; finally, the powder spreading system spreads a layer of powder into the forming chamber, and the laser beam selectively melts and solidifies a layer of powder according to the slice data of the three-dimensional model, and obtains the aluminum-based composite material by layer-by-layer melting and solidification.

[0096] Embodiment 2-3

[0097] The difference between Examples 2 to 3 and Example 1 is that in step (2), the gas pressures of the plasma discharge treatment are 0.01 MPa and 0.1 MPa, respectively.

[0098] Embodiment 4-5

[0099] The difference between Examples 4 to 5 and Example 1 is that in step (2), the peak-to-peak values ​​of the discharge voltage of the plasma discharge treatment are 20 kV and 30 kV, respectively.

[0100] Embodiment 6-7

[0101] The difference between Examples 6 to 7 and Example 1 is that in step (2), the duration of the plasma discharge treatment is 1 h and 6 h, respectively.

[0102] Embodiment 8-9

[0103] The difference between Examples 8 to 9 and Example 1 is that in step (2), the amplitude of the plasma generating chamber is 11 mm and 15 mm respectively.

[0104] Example 10

[0105] The difference between Example 10 and Example 1 is that in step (2), N2 is introduced into the plasma generating chamber after the vacuum treatment.

[0106] Examples 11-12

[0107] The difference between Examples 11 to 12 and Example 1 is that in step (1), the particle sizes of the AlSi10Mg alloy powder are 20 μm and 50 μm, respectively.

[0108] Embodiment 13

[0109] The difference between Example 13 and Example 1 is that in step (2), the peak-to-peak value of the discharge voltage of the plasma discharge treatment is 20 kV, and the duration of the plasma discharge treatment is 1 hour.

[0110] Embodiment 14

[0111] The difference between Example 14 and Example 1 is that in step (2), the peak-to-peak value of the discharge voltage of the plasma discharge treatment is 25 kV, and the duration of the plasma discharge treatment is 6 hours.

[0112] Embodiment 15

[0113] The difference between Example 15 and Example 1 is that:

[0114] In step (1), TiC ceramic particles with a particle size of 50 nm are added to the original atomized spherical AlSi10Mg alloy powder with a particle size of 30 μm to obtain a target powder; wherein the weight proportion of the TiC ceramic particles in the target powder is 1%;

[0115] In step (3), the scanning speed is 1000 mm / s and the scanning interval is 120 μm.

[0116] Embodiments 16 to 17

[0117] The difference between Examples 16 to 17 and Example 15 is that in step (1), the particle sizes of the TiC ceramic particles are 100 nm and 200 nm, respectively.

[0118] Embodiments 18 to 19

[0119] The difference between Examples 18 to 19 and Example 15 is that in step (1), the weight proportion of TiC ceramic particles in the target powder is 0.5% and 3%, respectively.

[0120] Embodiment 20-21

[0121] The difference between Examples 20 to 21 and Example 15 is that in step (1), the particle sizes of the AlSi10Mg alloy powder are 20 μm and 50 μm, respectively.

[0122] Embodiments 22-23

[0123] The difference between Examples 22 to 23 and Example 15 is that in step (2), N2 and Ar are introduced into the vacuum-treated plasma generating chamber.

[0124] Embodiments 24 to 25

[0125] The difference between Examples 24 to 25 and Example 15 is that in step (2), the duration of the plasma discharge treatment is 1 h and 2 h, respectively.

[0126] Embodiments 26 to 27

[0127] The difference between Examples 26 to 27 and Example 15 is that in step (2), the gas pressures of the plasma discharge treatment are 0.01 MPa and 0.1 MPa, respectively.

[0128] Embodiments 28 to 29

[0129] The difference between Examples 28 to 29 and Example 15 is that in step (2), the peak-to-peak values ​​of the discharge voltage of the plasma discharge treatment are 20 kV and 30 kV, respectively.

[0130] Embodiment 30-31

[0131] The difference between Examples 30 to 31 and Example 15 is that in step (2), the amplitude of the plasma generating chamber is 11 mm and 15 mm respectively.

[0132] Embodiment 32

[0133] The difference between Example 32 and Example 15 is that:

[0134] In step (1), the weight percentage of TiC ceramic particles in the target powder is 0.5%;

[0135] In step (2), N2 is introduced into the vacuum-treated plasma generating chamber; the duration of the plasma discharge treatment is 1 hour.

[0136] Embodiment 33

[0137] The difference between Example 33 and Example 15 is that:

[0138] In step (1), the weight percentage of TiC ceramic particles in the target powder is 3%;

[0139] In step (2), the duration of the plasma discharge treatment is 1 hour.

[0140] Embodiment 34

[0141] The difference between Example 34 and Example 15 is that:

[0142] In step (1), the weight percentage of TiC ceramic particles in the target powder is 0.5%;

[0143] In step (2), Ar is introduced into the vacuum-treated plasma generating chamber; the duration of the plasma discharge treatment is 1 hour.

[0144] Comparative Example 1

[0145] The difference between Comparative Example 1 and Example 1 is that in step (2), the peak-to-peak value of the discharge voltage of the plasma discharge treatment is 0 kV.

[0146] Comparative Example 2

[0147] The difference between Comparative Example 2 and Example 15 is that in step (2), the peak-to-peak value of the discharge voltage of the plasma discharge treatment is 0 kV.

[0148] The components and parameters of the aluminum-based composite materials prepared in various embodiments and comparative examples are shown in Table 1.

[0149] Table 1

[0150]

[0151] Test method:

[0152] (1) Mechanical properties test:

[0153] ①Hardness test: First, the surface of the aluminum-based composite material sample was polished with 800#, 1000#, 1200#, 1500#, 2000#, and 2500# sandpaper in turn; then, the polished surface was polished to a mirror surface by mechanical polishing; finally, the aluminum-based composite material sample with a mirror surface polished was tested for microhardness by using a HVS-1000 Vickers hardness tester. During the test, the instrument was first calibrated, and then the aluminum-based composite material samples were tested in turn. The test parameters included: load 2.94N, holding time 15s. To ensure the reliability of the experimental data, each aluminum-based composite material sample was measured at 9 points (excluding the maximum and minimum values) and the average value was taken as the final hardness test result.

[0154] ②Tensile strength test:

[0155] The tensile strength test of the tensile specimens of aluminum-based composite materials was carried out using an Instron 5980 electronic universal material testing machine. The size of the tensile specimens was determined according to the ISO6892-1:2019 metal material tensile test standard. First, the tensile specimens were polished with 800# sandpaper until the surface was smooth before the test; then, the tensile strength test of the tensile specimens was carried out. To ensure the test accuracy, the range sensor was selected to be 5KN, and the tensile rate was set to 0.5mm / min. After entering the specified parameters in the Bluehill3 software, data points can be automatically collected and tensile curves can be generated. According to the tensile curve, the software can automatically calculate the tensile strength and elongation of the tensile specimens.

[0156] (2) Wear resistance test: The SFT-2M pin-on-disc friction and wear tester was used to test the friction and wear of the disc specimens of the aluminum-based composite material. Before the test, the disc specimens of the aluminum-based composite material were ground and polished, and the test equipment was zeroed and calibrated. The test parameters were set in the DTM-friction tester: speed 500r / min, load 3N, rotation radius 5mm, grinding ball diameter 3mm, grinding ball made of stainless steel, its hardness is 60HRC, and the test time is 15min. After the test, the time-friction coefficient curve can be derived. Each group of aluminum-based composite materials was tested three times to ensure the accuracy of the test data.

[0157] (3) Corrosion resistance test: The potentiodynamic polarization curve of the aluminum-based composite material sample was tested using an electrochemical workstation, and the model of the electrochemical workstation was GAMRY Reference 3000. A three-electrode system was used in the test, in which the working electrode was the aluminum-based composite material sample, the reference electrode was a saturated calomel electrode, and the auxiliary counter electrode was a platinum electrode. The potentiodynamic polarization curve of the aluminum-based composite material sample was mainly measured to obtain the self-corrosion current density and self-corrosion voltage data of the aluminum-based composite material sample. The program parameters of the potentiodynamic polarization curve were set as follows: scanning speed of 1mV / s, scanning range of -0.4V to -1.1V, and test time of 30min. The specific operations are as follows: prepare an effective area of ​​1cm 3 The aluminum-based composite disc sample is fixed with a knob, and the surface other than the test surface is sealed with epoxy resin. This electrode is used as the working electrode. Before the test, the aluminum-based composite disc sample is polished with 800#, 1000#, 1500#, 2000# and 2500# sandpaper, and then the aluminum-based composite disc sample is placed in anhydrous ethanol for ultrasonic cleaning of the surface. The aluminum-based composite disc sample to be tested is exposed to the air for at least 48 hours. Each group of aluminum-based composite materials is tested 3 times to ensure the stability of the test data.

[0158] (4) Backscattering SEM test of modified powder: A Supra40 field emission scanning electron microscope was used. During the test, secondary electrons (SE2) and backscattered electrons (BSE) were used to analyze the microscopic morphology of the surface of the aluminum-based composite material sample. The INCA energy dispersive spectrometer (EDS) was used to analyze the surface micro-area of ​​the aluminum-based composite material sample to obtain the content and specific distribution of each element in the micro-area.

[0159] (5) SEM test of aluminum-based composite materials: In order to study the influence of heat flow during the forming process of aluminum-based composite materials, the growth, size and texture orientation of the internal grains of aluminum-based composite materials were scanned and tested by backscatter diffraction. The detection equipment model was Zeiss GMINI300+symmetry S2. First, the surface of the aluminum-based composite material sample was mechanically polished, then ion-etched with an ion etcher, and SEM test was performed after stress relief treatment.

[0160] The aluminum-based composite materials prepared in each embodiment and comparative example were subjected to the above test, and the test data are shown in Table 2.

[0161] Table 2

[0162]

[0163] Reference Figure 2 , shows a backscattered SEM image of the cross section of the modified powder obtained in Comparative Example 1; Figure 3 , shows a backscattered SEM image of the cross section of the modified powder obtained in Example 1; compared with Comparative Example 1, in the cross section of the modified powder obtained by the plasma discharge treatment in step (2) of Example 1 of the present invention, the Al-Si eutectic phase is significantly refined.

[0164] Reference Figure 4 , shows the SEM image of the aluminum-based composite material prepared in Comparative Example 1; Figure 5 , shows the SEM image of the aluminum-based composite material prepared in Example 1; compared with Comparative Example 1, the grain sizes of the welding heat affected zone (HAZ), coarse grain zone (Coarse Zone) and fine grain zone (Fine Zone) in the aluminum-based composite material obtained by step (3) of Example 1 of the present invention are significantly refined.

[0165] Reference Figure 6 , shows the SEM image of the aluminum-based composite material prepared in Comparative Example 2; Figure 7 , shows the SEM image of the aluminum-based composite material prepared in Example 15; compared with Comparative Example 2, the grain sizes of the welding heat affected zone, coarse grain zone and fine grain zone in the aluminum-based composite material obtained by step (3) of Example 15 of the present invention are significantly refined.

[0166] According to the test data in Table 2, under the same conditions, compared with Comparative Example 1, Example 1 provided by the present invention performs plasma discharge treatment on a target powder including an AlSi10Mg alloy powder in a plasma generating chamber, and uses a discharge plasma generated by the breakdown of a discharge gas during the plasma discharge treatment process to bombard the surface of the target powder, cleans and etches the surface of the target powder to achieve physical modification of the surface of the target powder, and induces a chemical reaction on the surface of the AlSi10Mg alloy powder in the target powder, so that the AlSi10Mg alloy powder combines with the N-containing free radicals generated by NH3 or N2 in the discharge space, and in-situ generates an AlN phase on the surface of the AlSi10Mg alloy powder. The modified AlN phase is formed in situ on the surface of the AlSi10Mg alloy powder, which improves the fluidity and surface wettability of the modified powder obtained by plasma discharge treatment; in the process of selective laser melting and layer-by-layer melting of the modified powder by the selective laser melting technology, the higher fluidity and surface wettability of the modified powder are conducive to the transfer of heat and the filling of pores, and the density of the aluminum-based composite material is increased from 92% in the comparative example 1 to 96%; in addition, the AlN phase can also be used as a heterogeneous nucleation point in the process of laser selective layer-by-layer melting and forming of the modified powder by the selective laser melting technology, thereby improving the nucleation rate of aluminum grains, and the pinning of the AlN phase at the grain boundary can also inhibit the further growth of the eutectic phase and the aluminum grains, thereby playing a role in refining the grains (refer to Figure 5 ), by increasing the density of the aluminum-based composite material and reducing the grain size of the aluminum-based composite material, the mechanical properties of the aluminum-based composite material can be improved, the generation of spalling wear during friction and wear can be reduced, and the wear resistance of the aluminum-based composite material can be improved; further, the aluminum-based composite material with a higher density can also reduce the contact area between the corrosive medium and the aluminum-based composite material, and the refined grains can also reduce the diffusion rate of the corrosive particles in the aluminum-based composite material during the corrosion process, thereby improving the corrosion resistance of the aluminum-based composite material, so that the hardness of the aluminum-based composite material prepared in Example 1 of the present invention is increased from 118HV of Comparative Example 1 to 129HV, the tensile strength is increased from 350Mpa of Comparative Example 1 to 400Mpa, the elongation is increased from 3.5% of Comparative Example 1 to 5.5%, the friction coefficient is reduced from 0.42 of Comparative Example 1 to 0.38, and the wear rate is reduced from 1.74×10 -4 mm 3 N -1 m -1 Reduced to 1.24×10 -4 mm 3 N -1 m -1 The self-corrosion potential increased from -0.6066V in comparative example 1 to -0.5516V, and the self-corrosion current increased from 9.8690×10 -8A / cm 2 Reduced to 9.6947×10 -8 A / cm 2 , to meet the needs of more application scenarios.

[0167] Under the same conditions, compared with Comparative Example 2, in Example 15 provided by the present invention, the discharge plasma generated by the discharge gas is used to bombard the surface of the target powder, the surface of the target powder is cleaned and etched, and AlN phase is generated in situ on the surface of the AlSi10Mg alloy powder, so as to improve the fluidity and surface wettability of the modified powder obtained by the plasma discharge treatment. At the same time, under the action of the electric field in the plasma generating chamber during the plasma discharge treatment, based on the large difference in dielectric constant between the TiC particles and the AlSi10Mg alloy powder, a distorted electric field is induced, so that the TiC particles are evenly distributed on the surface of the AlSi10Mg alloy powder, thereby improving the uniformity of the distribution of the TiC particles in the modified powder in the AlSi10Mg alloy powder, and further improving the uniformity of the distribution of the TiC particles in the aluminum matrix in the aluminum-based composite material prepared based on the modified powder; further, the discharge plasma generated by the discharge gas is used to clean and etch the surface of the target powder to achieve The physical modification of the target powder surface also improves the wettability between the AlSi10Mg alloy powder and the TiC particles. In the process of laser selectively melting and solidifying the modified powder layer by layer using the selective laser melting technology, the wettability of the melt corresponding to the AlSi10Mg alloy powder to the TiC particles is also improved accordingly, thereby improving the interface bonding effect between the TiC particles and the aluminum matrix in the aluminum-based composite material, reducing the interface bonding defects, and giving full play to the dispersion strengthening effect of the TiC particles in the aluminum-based composite material, so that the density of the aluminum-based composite material prepared in the embodiment of the present invention is increased from 92.4% of the comparative example 2 to 96%, the hardness is increased from 120HV of the comparative example 2 to 124HV, the tensile strength is increased from 409Mpa of the comparative example 2 to 451Mpa, the elongation is increased from 5.8% of the comparative example 2 to 7.9%, the friction coefficient is reduced from 0.39 of the comparative example 2 to 0.35, and the wear rate is reduced from 1.55×10 -4 mm 3 N -1 m -1 Reduced to 1.24×10 -5 mm3N -1 m -1 The self-corrosion potential increased from -0.5934 V in comparative example 2 to -0.5434 V; the self-corrosion current increased from 9.7979×10 -8 A / cm 2 Reduced to 9.6747×10 - 8 A / cm 2 .

[0168] To summarize, the embodiments of the present invention obtain modified powder by subjecting target powder including aluminum-based alloy powder in a plasma generating chamber to plasma discharge treatment, so that the mechanical properties, wear resistance and corrosion resistance of the aluminum-based composite material obtained by selective laser melting the modified powder layer by layer using the selective laser melting technology are significantly improved, thereby solving the problem that the aluminum-based composite material prepared in the related technology has reduced mechanical properties, corrosion resistance and wear resistance, and cannot meet the high performance requirements of the aerospace field.

[0169] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic creative concept. Therefore, the claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0170] The above is a detailed introduction to the preparation method of an aluminum-based composite material and the aluminum-based composite material provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for general technicians in this field, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A method for preparing an aluminum-based composite material, characterized in that: The method comprises: Putting target powder into a plasma generating chamber and performing vacuum treatment on the plasma generating chamber; the target powder at least includes aluminum-based alloy powder; Introducing discharge gas into the vacuum-treated plasma generating chamber; Performing plasma discharge treatment on the target powder in the plasma generating chamber, so as to modify the surface of the target powder by utilizing the discharge plasma generated by the discharge gas during the plasma discharge treatment to obtain modified powder; The modified powder is subjected to laser selective melting and consolidation layer by layer by adopting selective laser melting technology to obtain an aluminum-based composite material.

2. The method according to claim 1, characterized in that: The gas pressure of the plasma discharge treatment is 0.01 MPa to 0.1 MPa; the peak-to-peak value of the discharge voltage of the plasma discharge treatment is 20 kV to 30 kV; and the duration of the plasma discharge treatment is 1 h to 6 h.

3. The method according to claim 1, characterized in that During the plasma discharge treatment of the target powder in the plasma generating chamber, the amplitude of the plasma generating chamber is 8 mm to 15 mm.

4. The method according to claim 1, characterized in that The target powder also includes a reinforcement phase; The weight percentage of the reinforcement phase in the target powder is 0.5% to 3%.

5. The method according to claim 4, characterized in that The particle size of the reinforcement phase is 50nm to 200nm.

6. The method according to claim 4, characterized in that The duration of the plasma discharge treatment is 1 hour to 3 hours.

7. The method according to claim 1, characterized in that The target powder further includes a reinforcement phase, and the discharge gas is any one of NH 3 , N 2 and Ar.

8. The method according to claim 1, characterized in that The target powder does not include a reinforcement phase, and the discharge gas is any one of NH 3 and N 2 .

9. The method according to any one of claims 1 to 8, characterized in that: The particle size of the aluminum-based alloy powder is 20 μm to 50 μm.

10. An aluminum-based composite material, characterized in that: The aluminum-based composite material is prepared by the method for preparing an aluminum-based composite material according to any one of claims 1 to 9.

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