In-situ aluminum nitride and intermetallic compound particle hybrid reinforced aluminum-based composite material and preparation method thereof

Abstract

The invention relates to the technical field of preparation of aluminum-based composite materials, in particular to an in-situ aluminum nitride and intermetallic compound particle hybrid reinforced aluminum-based composite material and a preparation method of the in-situ aluminum nitride and intermetallic compound particle hybrid reinforced aluminum-based composite material. S2, surface treatment of the base body, wherein sand blasting roughening treatment is conducted on the surface of the base body; s3, cold spraying solid deposition molding; s4, performing heat treatment in-situ synthesis; and S5, stirring friction processing treatment is conducted, and the in-situ aluminum nitride and intermetallic compound particle dispersed and mixed reinforced compact aluminum-based composite material with an aluminum matrix of a uniform ultra-fine grain structure is obtained. According to the preparation method, grain size refinement of the aluminum nitride and the M-Al intermetallic compound and uniform dispersion distribution of the aluminum nitride and the M-Al intermetallic compound in an aluminum matrix are achieved, meanwhile grain refinement and tissue densification of the aluminum matrix material are achieved, and therefore the aluminum matrix composite high in abrasion resistance and density is obtained.

Description

Technical Field

[0001] This invention relates to the field of aluminum-based composite material preparation technology, and in particular to an in-situ aluminum nitride and intermetallic compound particles hybrid reinforced aluminum-based composite material and its preparation method. Background Technology

[0002] Aluminum matrix composites are among the most widely used lightweight metal matrix composites, finding extensive applications in defense, aerospace, transportation, information products, and civilian machinery. Particulate-reinforced aluminum matrix composites, in particular, have garnered significant attention due to their numerous advantages, including light weight, high specific strength and stiffness, good fatigue resistance and wear resistance, low coefficient of thermal expansion, and excellent dimensional stability. Currently, the preparation processes for particulate-reinforced aluminum matrix composites include stirred casting, extrusion casting, infiltration casting, powder metallurgy, and spray deposition. However, in these methods, the reinforcing particles are introduced into the aluminum alloy matrix externally. For example, in stirred casting, the aluminum alloy matrix is ​​first heated above the liquidus line, then the molten aluminum is stirred, and the particles are poured into the molten aluminum, dispersing them through the stirring of the melt. However, the wettability between these reinforcing particles and the aluminum alloy matrix is ​​poor, making effective bonding difficult, and the reinforcing particles are not easily uniformly distributed within the aluminum alloy matrix. Furthermore, most aluminum matrix composites currently use single-particle reinforcing particles, such as ceramic particles, metal particles, intermetallic compound particles, and high-entropy alloy particles. For example, while ceramic particle-reinforced aluminum matrix composites exhibit high hardness and elastic modulus, they lack sufficient plasticity and toughness. Conversely, aluminum matrix composites reinforced with metal particles or intermetallic compounds show better plasticity but insufficient strength. This necessitates improvements to current methods, requiring the reinforcing phase to wet well with the aluminum alloy matrix and the reinforcing particles to be uniformly distributed within the matrix, in order to prepare aluminum matrix composites with both high strength and good plasticity.

[0003] Traditional aluminum-based composite material preparation processes, such as powder metallurgy, casting, and hot pressing sintering, suffer from drawbacks that significantly limit their engineering applications. These include complex processes, the risk of material performance degradation due to high-temperature heat sources, difficulty in significantly increasing the volume fraction of reinforcing phases, and high costs. Therefore, the development of novel aluminum-based composite material preparation technologies has attracted widespread attention. Cold spraying, as an emerging solid-state additive manufacturing method, achieves deposition through localized metallurgical bonding and mechanical interlocking between raw material particles. The raw material powder remains solid throughout the deposition process, effectively avoiding the thermal effects of high temperatures on the matrix material and raw material particles, as well as defects such as oxidation phase transformations. This makes it a highly promising method for preparing aluminum-based composite materials. Furthermore, aluminum-based composites prepared using cold spraying technology exhibit a wide range of strength-toughness control and good machinability, effectively avoiding the problem of poor surface quality in aluminum-based composite processing.

[0004] Studies have shown that aluminum-based composites reinforced with in-situ ceramic / intermetallic compound composite particles exhibit excellent interfacial bonding between the in-situ intermetallic compound reinforcing phase and the matrix alloy, playing a significant reinforcing role. Compared to the matrix aluminum alloy, these composites possess superior mechanical properties. Furthermore, the in-situ ceramic particles, often distributed at smaller sizes within the matrix metal, provide dispersion reinforcement, resulting in higher wear resistance and high-temperature resistance. Friction stir treatment (FSP) is a novel solid-state treatment method used in recent years for synthesizing intermetallic compounds or altering the microstructure of materials. During FSP, a rotating stirring head contacts the material and moves in a specific direction. Under the high heat generated by friction, the material undergoes significant plastic deformation, producing a very fine microstructure and refining the grains, thereby significantly improving its toughness and strength. Research has found that after FSP post-treatment, the hardness of cold-sprayed Al-Al2O3 composite coatings increases due to the redistribution and refinement of Al2O3 particles.

[0005] Based on the above premises, we provide an in-situ aluminum nitride and intermetallic compound particles hybrid reinforced aluminum matrix composite material and its preparation method, which can solve the defect of insufficient strength of aluminum matrix composite materials in the prior art. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide an in-situ aluminum nitride and intermetallic compound mixed reinforced aluminum matrix composite material and its preparation method, which not only achieves the refinement of the particle size of aluminum nitride and M-Al intermetallic compound and its uniform dispersion distribution in the aluminum matrix, but also achieves the refinement of the grain size and the densification of the aluminum matrix material, thereby obtaining a high wear resistance and high density aluminum matrix composite material.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] A method for preparing an in-situ aluminum nitride and intermetallic compound particle hybrid reinforced aluminum matrix composite material includes the following steps:

[0009] S1, Raw material preparation: Spherical pure aluminum powder or aluminum alloy powder is mechanically mixed with pure metal powder M that can form intermetallic compounds with it according to the ratio to obtain M / Al mixed powder for cold spraying.

[0010] S2, Surface treatment of the substrate: The surface of the substrate is roughened by sandblasting;

[0011] S3, Cold spray solid deposition molding: The M / Al mixed powder prepared in step S1 is cold sprayed and deposited onto the substrate surface treated in step S2 to form an aluminum matrix composite precursor with uniformly distributed M metal particles.

[0012] S4, In-situ synthesis by heat treatment: The aluminum-based composite material precursor prepared in step S3 is subjected to heat diffusion treatment in a high-purity nitrogen environment, which promotes the in-situ reaction of the highly active outer surface of aluminum particles in the composite material with nitrogen to form an aluminum nitride ceramic phase. At the same time, metal particles M undergo in-situ solid-state diffusion reaction with the surrounding aluminum matrix to form M-Al intermetallic compound phase particles, thereby obtaining an aluminum-based composite material reinforced by an in-situ aluminum nitride ceramic phase and an intermetallic compound phase.

[0013] S5, Friction Stir Processing: The in-situ aluminum nitride ceramic phase and intermetallic compound phase reinforced aluminum matrix composite material obtained in step S4 is placed on a friction stir machine. The stirring tool head is adjusted to be aligned with the deposit, and the material is rotated at high speed and pressed into the cold spray deposit for stirring. At the same time, the stirring tool head is moved to cover the entire area to be processed for friction stir processing, thereby obtaining an in-situ aluminum nitride and intermetallic compound particles with uniform ultrafine crystalline structure and dense reinforcement.

[0014] There are no special requirements for the type of matrix material in S2. It can be aluminum alloy or other metallic materials that require protection by aluminum-based composite materials, such as magnesium alloy or stainless steel. The deposit in S5 refers to the in-situ aluminum-based composite material reinforced with aluminum nitride ceramic phase and intermetallic compound phase obtained in S4.

[0015] Preferably, the pure metal powder M mentioned in step S1 specifically includes one or more metal powders such as Fe, Ni, Ti, and Al that can form intermetallic compounds with Al.

[0016] Preferably, the mass percentage of pure aluminum powder or aluminum alloy powder to pure metal powder M in step S1 is 65~40:35~60. The mass percentage of metal powder M needs to be within the above range to ensure that enough M particles are transformed into the M-Al intermetallic compound phase to improve the mechanical properties of the composite material, such as wear resistance, while preventing excessive amounts from causing insufficient Al to react with M, resulting in a large number of residual metal M particles in the composite material, thus avoiding affecting the reaction of Al and N to synthesize the AlN phase, thereby improving the performance of the aluminum-based composite material.

[0017] Preferably, the pure aluminum powder or aluminum alloy powder in step S1 has a particle size range of 50~200um and a spherical shape;

[0018] The pure metal powder M has a particle size range of 15~45μm and is spherical or irregular in shape.

[0019] Preferably, the mechanical mixing in step S1 is carried out in a planetary ball mill with a ball-to-material ratio of 2:1 to 5:1, a rotation speed of 100 to 150 rpm, and a mixing time of 60 to 120 min.

[0020] Preferably, in the cold spray solid forming process in step S3, the spraying gas is one of nitrogen, argon and helium, the accelerating gas pressure is 0.5~2.0MPa, the powder feeding gas pressure is 1~2.5MPa, the powder feeding rate is 5~15g / min, the spraying temperature is 150~300℃, the spraying distance is 10~20mm, and the spray gun moving speed is 5~20mm / s.

[0021] Experiments have shown that the above parameters can guarantee the acquisition of the required coating, and various gases can be selected according to the coating process.

[0022] Preferably, the M / Al aluminum-based composite material deposited by cold spraying in step S3 has a porosity of 10-25% and a thickness of 200μm-3mm.

[0023] A certain porosity is necessary to ensure that nitrogen gas can penetrate the coating and react with the aluminum particles during subsequent heat treatment. Too low a porosity hinders gas entry, while too high a porosity results in poor coating mechanical properties. The thickness is primarily to ensure that subsequent friction stir processing can be performed.

[0024] Preferably, step S4 involves thermal diffusion treatment in a high-purity nitrogen environment with a nitrogen purity of 99.999%, a heat treatment temperature of 500~630℃, and a heat treatment time of 5~25h.

[0025] Step S4 involves an atmospheric reaction treatment of the coating to allow the aluminum particles in the M / Al composite material obtained in step S3 to react with nitrogen gas, resulting in the in-situ synthesis of aluminum nitride. Therefore, 99.999% high-purity nitrogen gas is required. High-purity nitrogen ensures the in-situ reaction of Al and N, and the given heat treatment temperature guarantees the formation of aluminum nitride and intermetallic compounds without causing the aluminum particles to melt and create excessive voids, which would degrade the material's mechanical properties.

[0026] Preferably, in step S5, the rotation speed of the stirring tool head is 200~1000 rpm, and the moving speed of the stirring tool head is 20~100 mm / min; after the friction stir processing, the aluminum matrix grains are refined, and a dense aluminum matrix composite material with dispersed mixed reinforcement of aluminum nitride and intermetallic compounds is obtained.

[0027] An aluminum-based composite material prepared by any of the above-described methods for preparing an in-situ aluminum nitride and intermetallic compound particles hybrid reinforced aluminum-based composite material.

[0028] The beneficial effects of this invention are:

[0029] The in-situ generation of aluminum nitride-reinforced aluminum matrix composite material and its preparation method described in this invention utilizes the high-speed collision of powder particles during cold spray deposition. On the one hand, it removes the dense oxide film on the surface of the powder particles to obtain a highly active particle surface. On the other hand, through the strong plastic deformation of the collision area, a highly active deformation region with submicron grains or high-density dislocations can be obtained. Thus, during heat treatment in a nitrogen atmosphere, the solid-state reaction of Al and N to generate aluminum nitride-reinforced phase and the solid-state reaction of Al and M metal to generate intermetallic compound particles can be simultaneously achieved at a heat treatment temperature far below the melting point of aluminum. This overcomes the disadvantage of conventional methods where the reaction temperature is far above the melting point of aluminum.

[0030] The aluminum nitride and intermetallic compounds generated by the in-situ reaction of this invention can wet the aluminum matrix well and form a good bond between them, overcoming the disadvantage of poor wetting between the added particulate reinforcing phase and the aluminum alloy matrix.

[0031] This invention utilizes friction stirring to fully break down and homogenize the in-situ generated aluminum nitride and intermetallic compounds, overcoming the drawback of the original reinforcing particles not being evenly distributed. After friction stirring, a large number of uniform and dispersed aluminum nitride and intermetallic compound particles are distributed in the matrix, which can fully exert their reinforcing effect, resulting in composite materials with high strength and good plasticity. Moreover, the preparation method is relatively simple.

[0032] In summary, the various process steps of this invention are closely coordinated and work synergistically to ultimately obtain a high-performance material. First, based on the solid-state forming characteristics of cold spraying technology, an aluminum-based composite precursor (M / Al) can be obtained in a completely solid state of powder particles. Simultaneously, based on the high-speed collision and intense plastic deformation of particles during cold spraying, the inert oxide film on the surface of aluminum particles can be removed, and a highly active fine-grained or metastable structure can be formed on and inside the particles. This helps to achieve the simultaneous in-situ generation of aluminum nitride (AlN) ceramic phase and M-Al intermetallic compound phase at a solid-state heat treatment temperature below the melting point of aluminum (660°C). Finally, a friction stirring process is used for plastic processing to perform solid-state deformation treatment on the aluminum nitride ceramic, M-Al intermetallic compound, and aluminum matrix material. This achieves both particle size refinement and uniform dispersion of aluminum nitride and M-Al intermetallic compound within the aluminum matrix, as well as grain refinement and densification of the aluminum matrix material, thereby obtaining a highly wear-resistant and highly dense aluminum-based composite material. Attached Figure Description

[0033] Figure 1 This is a secondary electron image of the surface morphology of the Al-45Fe composite material formed by cold spray solid deposition in S3 of Example 1 of the present invention.

[0034] Figure 2This is a backscattered electron image of the surface morphology of the Al-45Fe composite material formed by cold spraying solid deposition in S3 of Example 1 of the present invention; wherein, gray particles are Al and white particles are Fe.

[0035] Figure 3 This is a backscattered image (low magnification) of the cross-sectional morphology of the Al-45Fe composite material formed by cold spray solid deposition in S3 of Example 1 of the present invention; wherein, the gray area is Al; and the white particles are Fe.

[0036] Figure 4 This is a backscattered image (high magnification) of the cross-sectional morphology of the Al-45Fe composite material formed by cold spray solid deposition in S3 of Example 1 of the present invention; wherein, the gray area is Al; and the white particles are Fe.

[0037] Figure 5 This is a secondary electron image of the cross-sectional morphology of the Al-45Fe composite material after in-situ synthesis following heat treatment in S4 of Example 1 of the present invention.

[0038] Figure 6 This is a backscattered electron image of the cross-sectional morphology of the Al-45Fe composite material after in-situ synthesis following heat treatment in S4 of Example 1 of the present invention; wherein, the black area represents Al; the gray area represents Al5Fe2 intermetallic compound particles synthesized in situ; and the white area represents unreacted residual Fe.

[0039] Figure 7 The cross-sectional morphology of the Al-45Fe composite material after in-situ synthesis following heat treatment in S4 of Example 1 of the present invention is shown below. Figure 6 (High-magnification photographs) and energy spectrum analysis diagrams of different regions.

[0040] Figure 8 The cross-sectional morphology and energy dispersive spectroscopy analysis of different regions of the Al-60Fe composite material after in-situ synthesis following heat treatment in S4 of Example 2 of the present invention are presented.

[0041] Figure 9 The cross-sectional morphology of the Al-70Fe composite material after in-situ synthesis under heat treatment in S4 of Comparative Example 1 of the present invention is shown in the figure: the white area is unreacted Fe, the gray area is Al2Fe5, and no aluminum nitride is formed inside the composite material.

[0042] Figure 10 The cross-sectional morphology of the Al-45Fe composite material synthesized in situ after heat treatment in S4 of Comparative Example 2 of the present invention is shown in the figure. The white area is unreacted Fe, and the black area is the Al matrix. Neither Al2Fe5 nor aluminum nitride is generated in situ inside the composite material.

[0043] Figure 11 This is a flowchart illustrating the preparation process of the present invention. Detailed Implementation

[0044] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention.

[0045] Example 1

[0046] S1. Raw material preparation: 250-mesh spherical pure aluminum powder and 400-mesh pure iron powder are mixed in a planetary ball mill at a ratio of Al-45Fe (weight percentage, %). The ball-to-powder ratio is 2:1, the rotation speed is 100 rpm, and the mixing time is 80 min to obtain Fe / Al mixed powder for cold spraying.

[0047] S2, Aluminum alloy substrate surface treatment: The aluminum alloy substrate surface is roughened by sandblasting with 45-mesh brown corundum sand at a pressure of 0.45MPa.

[0048] S3, Cold spray solid deposition molding: The Al-45Fe mixed powder prepared in step S1 is cold sprayed and deposited onto the substrate surface treated in step S2. The spraying gas is nitrogen, the accelerating gas pressure is 1.5MPa, the powder feeding gas pressure is 2MPa, the powder feeding rate is 15g / min, the spraying temperature is 250℃, the spraying distance is 15mm, and the spray gun moving speed is 20mm / s. This forms an aluminum-based composite material precursor with uniformly distributed Fe particles, with a porosity of approximately 25% and a thickness of approximately 800μm.

[0049] S4, In-situ synthesis under heat treatment: The aluminum-based composite precursor prepared in step S3 is subjected to heat diffusion treatment in a high-purity nitrogen environment, wherein the nitrogen purity is 99.999%, the heat treatment temperature is 600℃, and the heat treatment time is 5h; this promotes the in-situ reaction between the highly active outer surface of the aluminum particles in the composite material and nitrogen to form an aluminum nitride ceramic phase. At the same time, the iron particles undergo an in-situ solid-state diffusion reaction with the surrounding aluminum matrix to form Al5Fe2 intermetallic compound particles, thereby obtaining an in-situ aluminum nitride ceramic and Al5Fe2 intermetallic compound hybrid reinforced aluminum-based composite material.

[0050] S5, Friction Stir Processing: The in-situ aluminum nitride ceramic and Al5Fe2 intermetallic compound reinforced aluminum matrix composite obtained in step S4 are placed on a friction stir machine. The stirring tool head is adjusted to be aligned with the aluminum matrix composite deposit. The rotation speed is 800 rpm. The high-speed rotating tool head is pressed into the cold spray deposit for stirring. At the same time, the stirring tool head is moved at a speed of 60 mm / min to cover the entire area to be processed for friction stir processing. After friction stir processing, the aluminum matrix grains are refined, and a dense aluminum matrix composite material with dispersed and mixed in-situ aluminum nitride and Al5Fe2 intermetallic compound particles is obtained.

[0051] Example 2

[0052] S1. Raw material preparation: 250-mesh spherical pure aluminum powder and 400-mesh pure iron powder are mixed in a planetary ball mill at a ratio of Al-60Fe (weight percentage, %). The ball-to-material ratio is 5:1, the rotation speed is 150 rpm, and the mixing time is 120 min to obtain Fe / Al mixed powder for cold spraying.

[0053] S2, Surface treatment of magnesium alloy substrate: The surface of the magnesium alloy substrate is roughened by sandblasting with 45-mesh brown corundum sand at a pressure of 0.65 MPa.

[0054] S3, Cold spray solid deposition molding: The Al-45Fe mixed powder prepared in step S1 is cold sprayed and deposited onto the substrate surface treated in step S2. The spraying gas is nitrogen, the accelerating gas pressure is 2MPa, the powder feeding gas pressure is 2.5MPa, the powder feeding rate is 10g / min, the spraying temperature is 300℃, the spraying distance is 20mm, and the spray gun moving speed is 10mm / s, forming an aluminum-based composite material precursor with uniformly distributed Fe particles, a porosity of about 15%, and a thickness of about 1000μm.

[0055] S4, In-situ synthesis by heat treatment: The aluminum-based composite precursor prepared in step S3 is subjected to heat diffusion treatment in a high-purity nitrogen environment, wherein the nitrogen purity is 99.999%, the heat treatment temperature is 500℃, and the heat treatment time is 15h; this promotes the in-situ reaction between the highly active outer surface of the aluminum particles in the composite material and nitrogen to form an aluminum nitride ceramic phase, while the iron particles undergo an in-situ solid-state diffusion reaction with the surrounding aluminum matrix to form Al5Fe2 intermetallic compound particles, thereby obtaining an in-situ aluminum nitride ceramic and Al5Fe2 intermetallic compound hybrid reinforced aluminum-based composite material.

[0056] S5, Friction Stir Processing: The in-situ aluminum nitride ceramic and Al5Fe2 intermetallic compound reinforced aluminum matrix composite obtained in step S4 are placed on a friction stir machine. The stirring tool head is adjusted to be aligned with the aluminum matrix composite deposit. The rotation speed is 500 rpm. The high-speed rotating tool head is pressed into the cold spray deposit for stirring. At the same time, the stirring tool head is moved at a speed of 40 mm / min to cover the entire area to be processed for friction stir processing. After friction stir processing, the aluminum matrix grains are refined, and a dense aluminum matrix composite material with dispersed and mixed in-situ aluminum nitride and Al5Fe2 intermetallic compound particles is obtained.

[0057] Example 3

[0058] S1. Raw material preparation: 300-mesh spherical pure aluminum powder and 500-mesh pure titanium powder are mixed in a planetary ball mill at a ratio of Al-50Ti (weight percentage, %). The ball-to-material ratio is 3:1, the rotation speed is 120 rpm, and the mixing time is 100 min to obtain Ti / Al mixed powder for cold spraying.

[0059] S2, Stainless steel substrate surface treatment: The stainless steel substrate surface is roughened by sandblasting with 45-mesh brown corundum sand at a pressure of 0.75 MPa.

[0060] S3, Cold spray solid deposition molding: The Al-50Ti mixed powder prepared in step S1 is cold sprayed and deposited onto the substrate surface treated in step S2. The spraying gas is helium, the accelerating gas pressure is 1MPa, the powder feeding gas pressure is 2.5MPa, the powder feeding rate is 15g / min, the spraying temperature is 150℃, the spraying distance is 15mm, and the spray gun moving speed is 15mm / s, forming an aluminum-based composite material precursor with uniformly distributed Ti particles, with a porosity of about 25% and a thickness of about 2000μm.

[0061] S4, In-situ synthesis under heat treatment: The aluminum-based composite precursor prepared in step S3 is subjected to heat diffusion treatment in a high-purity nitrogen environment, wherein the nitrogen purity is 99.999%, the heat treatment temperature is 630℃, and the heat treatment time is 25h; this promotes the in-situ reaction between the highly active outer surface of aluminum particles in the composite material and nitrogen to form an aluminum nitride ceramic phase, while the titanium particles undergo an in-situ solid-state diffusion reaction with the surrounding aluminum matrix to form Al3Ti intermetallic compound particles, thereby obtaining an in-situ aluminum nitride ceramic and Al3Ti intermetallic compound hybrid reinforced aluminum-based composite material.

[0062] S5, Friction Stir Processing: The in-situ aluminum nitride ceramic and Al3Ti intermetallic compound reinforced aluminum matrix composite obtained in step S4 are placed on a friction stir machine. The stirring tool head is adjusted to be aligned with the aluminum matrix composite deposit. The rotation speed is 1000 rpm. The high-speed rotating tool head is pressed into the cold spray deposit for stirring. At the same time, the stirring tool head is moved at a speed of 40 mm / min to cover the entire area to be processed for friction stir processing. After friction stir processing, the aluminum matrix grains are refined, and a dense aluminum matrix composite material with dispersed and mixed aluminum nitride and Al3Ti intermetallic compound particles is obtained.

[0063] Example 4

[0064] S1, Raw material preparation: 100-mesh spherical pure aluminum powder and 600-mesh pure nickel powder are mixed in a planetary ball mill according to the Al-40Ti (weight percentage, %) ratio. The ball-to-powder ratio is 4:1, the rotation speed is 150 rpm, and the mixing time is 120 min to obtain Ni / Al mixed powder for cold spraying.

[0065] S2, Stainless steel substrate surface treatment: The stainless steel substrate surface is roughened by sandblasting with 45-mesh brown corundum sand at a pressure of 0.75 MPa.

[0066] S3, Cold spray solid deposition molding: The Al-40Ni mixed powder prepared in step S1 is cold sprayed and deposited onto the substrate surface treated in step S2. The spraying gas is helium, the accelerating gas pressure is 2MPa, the powder feeding gas pressure is 2.5MPa, the powder feeding rate is 10g / min, the spraying temperature is 300℃, the spraying distance is 10mm, and the spray gun moving speed is 5mm / s. This forms an aluminum-based composite material precursor with uniformly distributed Ni particles, with a porosity of about 10% and a thickness of about 200μm.

[0067] S4, In-situ synthesis by heat treatment: The aluminum-based composite precursor prepared in step S3 is subjected to heat diffusion treatment in a high-purity nitrogen environment, wherein the nitrogen purity is 99.999%, the heat treatment temperature is 630℃, and the heat treatment time is 20h; this promotes the in-situ reaction between the highly active outer surface of the aluminum particles in the composite material and nitrogen to form an aluminum nitride ceramic phase, while the nickel particles undergo an in-situ solid-state diffusion reaction with the surrounding aluminum matrix to form Ni2Al3 intermetallic compound particles, thereby obtaining an in-situ aluminum nitride ceramic and Ni2Al3 intermetallic compound hybrid reinforced aluminum-based composite material.

[0068] S5, Friction Stir Processing: The in-situ aluminum nitride ceramic and Ni2Al3 intermetallic compound reinforced aluminum matrix composite obtained in step S4 are placed on a friction stir machine. The stirring tool head is adjusted to be aligned with the aluminum matrix composite deposit. The rotation speed is 850 rpm. The high-speed rotating tool head is pressed into the cold spray deposit for stirring. At the same time, the stirring tool head is moved at a speed of 30 mm / min to cover the entire area to be processed for friction stir processing. After friction stir processing, the aluminum matrix grains are refined, and a dense aluminum matrix composite material with dispersed and mixed in-situ aluminum nitride and Ni2Al3 intermetallic compound particles is obtained.

[0069] Comparative Example 1

[0070] S1. Raw material preparation: 400-mesh spherical pure aluminum powder and 325-mesh pure iron powder are mixed in a planetary ball mill at a ratio of Al-70Fe (weight percentage, %). The ball-to-material ratio is 2:1, the rotation speed is 100 rpm, and the mixing time is 80 min to obtain Fe / Al mixed powder for cold spraying.

[0071] S2, Aluminum alloy substrate surface treatment: The aluminum alloy substrate surface is roughened by sandblasting with 45-mesh brown corundum sand at a pressure of 0.45MPa.

[0072] S3, Cold spray solid deposition molding: The Al-45Fe mixed powder prepared in step S1 is cold sprayed and deposited onto the substrate surface treated in step S2. The spraying gas is nitrogen, the accelerating gas pressure is 1.5MPa, the powder feeding gas pressure is 2MPa, the powder feeding rate is 15g / min, the spraying temperature is 250℃, the spraying distance is 15mm, and the spray gun moving speed is 20mm / s. This forms an aluminum-based composite material precursor with uniformly distributed Fe particles, with a porosity of approximately 25% and a thickness of approximately 800μm.

[0073] S4, In-situ synthesis under heat treatment: The aluminum-based composite precursor prepared in step S3 is subjected to heat diffusion treatment in a high-purity nitrogen environment, wherein the nitrogen purity is 99.999%, the heat treatment temperature is 600℃, and the heat treatment time is 5h. Iron particles undergo in-situ solid-state diffusion reaction with the surrounding aluminum matrix to form Al5Fe2 intermetallic compound particles. However, due to the excessive Fe content, there is not enough Al to react with Fe, resulting in a large number of unreacted Fe particles inside the composite material. At the same time, no Al reacts with nitrogen to form aluminum nitride, and ultimately, it is impossible to obtain aluminum nitride ceramic and Al5Fe2 intermetallic compound hybrid reinforced aluminum-based composite material.

[0074] Comparative Example 2

[0075] S1. Raw material preparation: 250-mesh spherical pure aluminum powder and 400-mesh pure iron powder are mixed in a planetary ball mill at a ratio of Al-45Fe (weight percentage, %). The ball-to-powder ratio is 2:1, the rotation speed is 100 rpm, and the mixing time is 80 min to obtain Fe / Al mixed powder for cold spraying.

[0076] S2, Aluminum alloy substrate surface treatment: The aluminum alloy substrate surface is roughened by sandblasting with 45-mesh brown corundum sand at a pressure of 0.45MPa.

[0077] S3, Cold spray solid deposition molding: The Al-45Fe mixed powder prepared in step S1 is cold sprayed and deposited onto the substrate surface treated in step S2. The spraying gas is nitrogen, the accelerating gas pressure is 1.5MPa, the powder feeding gas pressure is 2MPa, the powder feeding rate is 15g / min, the spraying temperature is 250℃, the spraying distance is 15mm, and the spray gun moving speed is 20mm / s. This forms an aluminum-based composite material precursor with uniformly distributed Fe particles, with a porosity of approximately 25% and a thickness of approximately 800μm.

[0078] S4, In-situ synthesis by heat treatment: The aluminum-based composite material precursor prepared in step S3 is subjected to heat diffusion treatment in a high-purity nitrogen environment, wherein the nitrogen purity is 99.999%, the heat treatment temperature is 450℃, and the heat treatment time is 25h.

[0079] Because the heat treatment temperature was too low, Fe and Al did not react to synthesize Al5Fe2 intermetallic compound, nor did Al react with nitrogen to generate aluminum nitride, so it was ultimately impossible to obtain aluminum nitride ceramic and Al5Fe2 intermetallic compound hybrid reinforced aluminum matrix composite material.

[0080] All technical features in this embodiment can be modified in appearance according to actual needs.

[0081] The above embodiments are preferred implementations of the present invention. In addition, the present invention can be implemented in other ways. Any obvious substitutions without departing from the concept of the present technical solution are within the protection scope of the present invention.

Claims

1. A method for preparing an in-situ aluminum nitride and intermetallic compound particle hybrid reinforced aluminum matrix composite material, characterized in that: Includes the following steps: S1, Raw material preparation: Spherical pure aluminum powder or aluminum alloy powder is mechanically mixed with pure metal powder M that can form intermetallic compounds with it according to the ratio to obtain M / Al mixed powder for cold spraying. S2, Surface treatment of the substrate: The surface of the substrate is roughened by sandblasting; S3, Cold spray solid deposition molding: The M / Al mixed powder prepared in step S1 is cold sprayed and deposited onto the substrate surface treated in step S2 to form an aluminum matrix composite precursor with uniformly distributed M metal particles. S4, In-situ synthesis by heat treatment: The aluminum-based composite material precursor prepared in step S3 is subjected to heat diffusion treatment in a high-purity nitrogen environment, which promotes the in-situ reaction of the highly active outer surface of aluminum particles in the composite material with nitrogen to form an aluminum nitride ceramic phase. At the same time, metal particles M undergo in-situ solid-state diffusion reaction with the surrounding aluminum matrix to form M-Al intermetallic compound phase particles, thereby obtaining an aluminum-based composite material reinforced by an in-situ aluminum nitride ceramic phase and an intermetallic compound phase. S5, Friction Stir Processing: The in-situ aluminum nitride ceramic phase and intermetallic compound phase reinforced aluminum matrix composite material obtained in step S4 is placed on a friction stir machine. The stirring tool head is adjusted to be aligned with the deposit, and the material is rotated at high speed and pressed into the cold spray deposit for stirring. At the same time, the stirring tool head is moved to cover the entire area to be processed for friction stir processing, thereby obtaining an in-situ aluminum nitride and intermetallic compound particle dispersed mixed reinforced dense aluminum matrix composite material with a uniform ultrafine crystalline structure in the aluminum matrix.

2. The method for preparing an in-situ aluminum nitride and intermetallic compound particle hybrid reinforced aluminum matrix composite material according to claim 1, characterized in that: The pure metal powder M mentioned in step S1 specifically includes Fe, Ni, Ti, and one or more metal powders that can form intermetallic compounds with Al.

3. The method for preparing an in-situ aluminum nitride and intermetallic compound particle hybrid reinforced aluminum matrix composite material according to claim 1, characterized in that: The mass percentage of pure aluminum powder or aluminum alloy powder to pure metal powder M in step S1 is 65~40:35~60.

4. The method for preparing an in-situ aluminum nitride and intermetallic compound particle hybrid reinforced aluminum matrix composite material according to claim 3, characterized in that: The pure aluminum powder or aluminum alloy powder mentioned in step S1 has a particle size range of 50~200um and a spherical shape; The pure metal powder M has a particle size range of 15~45μm and is spherical or irregular in shape.

5. The method for preparing an in-situ aluminum nitride and intermetallic compound particle hybrid reinforced aluminum matrix composite material according to claim 1, characterized in that: The mechanical mixing in step S1 is carried out in a planetary ball mill with a ball-to-material ratio of 2:1 to 5:1, a rotation speed of 100 to 150 rpm, and a mixing time of 60 to 120 min.

6. The method for preparing an in-situ aluminum nitride and intermetallic compound particle hybrid reinforced aluminum matrix composite material according to claim 1, characterized in that: In step S3, during the cold spray solid forming process, the spraying gas is one of nitrogen, argon, and helium, the accelerating gas pressure is 0.5~2.0MPa, the powder feeding gas pressure is 1~2.5MPa, the powder feeding rate is 5~15g / min, the spraying temperature is 150~300℃, the spraying distance is 10~20mm, and the spray gun moving speed is 5~20mm / s.

7. The method for preparing an in-situ aluminum nitride and intermetallic compound particle hybrid reinforced aluminum matrix composite material according to claim 1, characterized in that: The M / Al aluminum-based composite material deposited by cold spraying in step S3 has a porosity of 10-25% and a thickness of 200μm-3mm.

8. The method for preparing an in-situ aluminum nitride and intermetallic compound particle hybrid reinforced aluminum matrix composite material according to claim 1, characterized in that: Step S4 involves thermal diffusion treatment in a high-purity nitrogen environment with a nitrogen purity of 99.999%, a heat treatment temperature of 500~630℃, and a holding time of 5~25h.

9. The method for preparing an in-situ aluminum nitride and intermetallic compound particle hybrid reinforced aluminum matrix composite material according to claim 1, characterized in that: In step S5, the rotation speed of the stirring tool head is 200~1000 rpm, and the moving speed of the stirring tool head is 20~100 mm / min. After the friction stir processing, the aluminum matrix grains are refined, and a dense aluminum matrix composite material with dispersed mixed reinforcement of aluminum nitride and intermetallic compounds is obtained.

10. An aluminum-based composite material prepared by the preparation method of an in-situ aluminum nitride and intermetallic compound particle hybrid reinforced aluminum-based composite material according to any one of claims 1-9.

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