Core-shell structure reinforced aluminum-based composite material with intermetallic compound particles coated with in-situ aluminum nitride and preparation method of core-shell structure reinforced aluminum-based composite material
By combining cold spraying technology with hot rolling, a core-shell structure of aluminum nitride-coated intermetallic compound particles is generated in situ, which solves the problems of insufficient interfacial bonding and complex process of aluminum-based composite materials, and prepares high-strength and ductile aluminum-based composite materials.
Patent Information
- Application Number
- CN202511549616.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-28
- Publication Date
- 2026-01-09
AI Technical Summary
Existing aluminum-based composite materials suffer from problems such as insufficient interfacial bonding, process limitations, and performance defects. Traditional preparation methods are energy-intensive, complex, and prone to brittle fracture, which limits their application scenarios.
By employing cold spraying technology combined with hot rolling, a core-shell structure of aluminum nitride-coated intermetallic compound particles is generated in situ, enabling the low-temperature and efficient preparation of aluminum-based composite materials and enhancing the interfacial bonding between the phase and the matrix.
Aluminum-based composite materials with excellent mechanical properties were prepared at temperatures below the melting point of aluminum, solving the problems of insufficient interfacial bonding and complex processes, and improving the strength and plasticity of the materials.
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Figure CN121294920A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of aluminum matrix composite material preparation, in particular to a kind of in-situ aluminum nitride coated intermetallic compound particle core-shell structure reinforced aluminum matrix composite material and preparation method thereof. BACKGROUND
[0002] With the increasing demand for lightweight materials in the fields of aerospace, new energy vehicles and the like, aluminum matrix composites (AMCs) have become a research hotspot due to their high specific strength, excellent thermal conductivity and low density. Aluminum matrix composites can make materials have good strength and plasticity by adding or in-situ generating ceramic or intermetallic compound particles to compensate for the shortcomings of single materials. Traditional externally added ceramic reinforcing phases (such as silicon carbide and aluminum oxide) have problems such as weak interface bonding and uneven distribution, while in-situ generated intermetallic compound (IMC) particles can improve mechanical properties but are prone to brittle fracture. Moreover, existing preparation techniques mostly use powder metallurgy or casting methods, which have defects such as high energy consumption and complex process, and there is an urgent need to develop a new preparation process that is low-temperature and efficient and has strong interface strengthening.
[0003] Although the prior art has carried out a lot of research on the above technical defects, the aluminum matrix composites (AMCs) prepared still have the following defects: 1) insufficient interface bonding: such as weak bonding layer formed between the externally added IMC particles and the aluminum matrix, leading to stress concentration and insufficient interface bonding; 2) process limitations: high temperature (>600℃) is required for casting method, which easily causes particle agglomeration; mechanical mixing method cannot achieve uniform distribution; 3) performance defects: traditional composites are prone to interface debonding under high temperature or dynamic load, limiting their application scenarios. Core-shell structure is an important way to solve the strength and plasticity problem of aluminum matrix composites. The main feature of core-shell structure is that continuous or discontinuous "soft" phase is wrapped by "hard" phase, and the interface bonding between the reinforcing phase and the matrix is strong. The strengthening and toughening effect of core-shell structure mainly comes from the interaction between the continuously and discontinuously precipitated core-shell structure reinforcing phase on the grain boundary and dislocations, which generates isotropic tensile stress or elastic strain energy in the matrix, thereby effectively inhibiting crack propagation and reducing stress concentration, thereby improving the strength and plasticity of aluminum matrix composites.
[0004] Based on the above various defects and research progress, we propose a preparation method of in-situ aluminum nitride coated intermetallic compound particle core-shell structure reinforced aluminum matrix composite material, which can effectively solve the various problems existing in the prior art. SUMMARY
[0005] The technical problem solved by the present application is to provide an in-situ core-shell structure intermetallic compound particle reinforced aluminum matrix composite material and a preparation method thereof.
[0006] To solve the above technical problems, the present application adopts the following technical solutions:
[0007] A preparation method of an in-situ core-shell structure intermetallic compound particle reinforced aluminum matrix composite material, comprising the following steps:
[0008] S1, raw material preparation: mechanically mixing spherical pure aluminum powder or aluminum alloy powder with pure metal powder M capable of forming intermetallic compounds with the aluminum powder according to a ratio to obtain M / Al mixed powder for cold spraying;
[0009] S2, substrate surface treatment: performing sandblasting roughening treatment on the substrate surface;
[0010] S3, cold spraying solid-state deposition forming: cold spraying and depositing the M / Al mixed powder prepared in step S1 on the substrate surface treated in step S2 to form an aluminum matrix composite material precursor with uniformly distributed M metal particles;
[0011] S4, heat treatment in-situ synthesis: performing heat diffusion treatment on the aluminum matrix composite material precursor prepared in step S3 in a high-purity nitrogen environment to promote solid-state diffusion reaction between the metal particles M and the surrounding aluminum matrix, so that the metal particles M are converted into M-Al intermetallic compound particles in-situ as a whole, and at the same time, the aluminum matrix around the intermetallic compound particles reacts with nitrogen to form an in-situ aluminum nitride ceramic coating layer, thereby obtaining an intermetallic compound reinforced aluminum matrix composite material with a core-shell structure of aluminum nitride ceramic phase coated M-Al intermetallic compound particles;
[0012] S5, hot rolling densification treatment: placing the AlN and intermetallic compound core-shell structure reinforced aluminum matrix composite material prepared in step S4 in a heating furnace for heat preservation, and then performing hot rolling treatment on it at room temperature using a rolling mill with a single pass deformation amount of 5% to 25% to obtain an in-situ core-shell structure intermetallic compound particle reinforced dense aluminum matrix composite material.
[0013] The substrate material type has no special requirements and can be an aluminum alloy or other metal materials that need to be protected by an aluminum matrix composite material, such as magnesium alloy or stainless steel, etc.
[0014] Preferably, the pure metal powder M in step S1 specifically includes Fe, Ni, Ti and one or more metal powder that can form intermetallic compound with Al.
[0015] Preferably, the mass percentage of the pure aluminum powder or aluminum alloy powder in step S1 to the pure metal powder M is 90-70:10-30.
[0016] The percentage can ensure the formation of AlN ceramic coating layer in-situ on the surface of M-Al intermetallic compound particles, otherwise it is impossible to obtain AlN ceramic phase or the synthesized AlN ceramic phase is dispersedly distributed instead of being coated on the surface of M-Al intermetallic compound particles.
[0017] Preferably, the particle size of the pure aluminum powder or aluminum alloy powder in step S1 is between 10-50 um, and the shape is spherical; the particle size of the pure metal powder M is between 15-45 um, and the shape is spherical or irregular.
[0018] During the cold spraying deposition of M / Al metal composite material, the M particles not only deform and deposit themselves, but also impact the already deposited Al particles, thereby breaking the surface oxide film of the Al particles to obtain a clean surface. This is beneficial to the mechanical combination between particles to obtain better mechanical properties, and also beneficial to the reaction between nitrogen and high-activity Al surface to synthesize AlN ceramic phase during the later heat treatment in a nitrogen environment. To achieve the above purpose, the particle size of M particles must be strictly controlled. If the particle size of M powder is too small, the surface area of the particles will increase significantly, which will lead to an increase in the surface oxide film, which is not conducive to the deformation and deposition during cold spraying. At the same time, too small particle size will lead to a significant decrease in powder flowability, which is not conducive to the normal flow and transportation of powder during cold spraying. If the particle size of M powder is too large, the acceleration effect of the gas flow on the particles will decrease significantly during the cold spraying deposition process, which will lead to an increase in the rebound of M particles and a significant decrease in the deposition efficiency.
[0019] Preferably, the mechanical mixing in step S1 is carried out in a planetary ball mill with a ball-to-powder ratio of 2:1-5:1, a rotation speed of 100-150 rpm, and a mixing time of 60-120 min.
[0020] Through multiple tests, it is found that too large ball-to-powder ratio will lead to an increase in the collision effect of the milling balls on the powder, which will damage the original morphology of the powder and is not conducive to the later deposition. At the same time, it may also lead to cold welding between the powders. Too small rotation speed will make it difficult to effectively achieve the uniform mixing of M powder and Al powder, while too large rotation speed will lead to cold welding between the powders, even causing the phenomenon of sticking to the tank and the balls. The mixing time is determined by considering the mixing effect and time efficiency.
[0021] 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 2.0~3.5MPa, the powder feeding gas pressure is 2.5~4.0MPa, the powder feeding rate is 10~25g / min, the spraying temperature is 200~400℃, the spraying distance is 10~20mm, and the spray gun moving speed is 10~30mm / s.
[0022] Under these optimized parameters, it is necessary to ensure that the powder particles undergo strong plastic deformation during the collision process to achieve effective deposition and remove the oxide film on the powder surface. This is beneficial for the in-situ synthesis of M-Al intermetallic compounds and AlN ceramic phases at solid-state temperatures below the melting point of aluminum during subsequent heat treatment. At the same time, it is also necessary to ensure that the coating has a certain porosity, which is beneficial for the effective penetration of nitrogen during nitrogen atmosphere heat treatment to form the required AlN ceramic phase.
[0023] Preferably, the M / Al aluminum-based composite material deposited by cold spraying in step S3 has a porosity of 5-10% and a thickness of 500μm-10mm.
[0024] Experiments showed that within this optimized coating porosity range, effective nitrogen penetration during nitrogen atmosphere heat treatment is beneficial for forming the desired AlN ceramic phase, while also ensuring the mechanical properties of the composite material. The thickness range also allows for subsequent hot rolling processing.
[0025] 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 500~600℃, and a heat treatment time of 5~10h.
[0026] High-purity nitrogen gas ensures the in-situ reaction of Al and N. The given heat treatment temperature can ensure the acquisition of aluminum nitride and intermetallic compounds without causing aluminum particles to melt and generate too many voids, which would lead to the deterioration of the material's mechanical properties.
[0027] Preferably, in step S5, the furnace temperature is 350℃~500℃, the heating time is 5min~15min, and the heating process is carried out under argon protection to prevent oxidation of the composite material; then, a single-pass hot rolling is performed using a two-roll mill, with a compression deformation of 5%~20%.
[0028] The reinforced aluminum matrix composite material prepared by the preparation method of the core-shell structure of in-situ aluminum nitride-coated intermetallic compound particles as described in any one of the above methods.
[0029] The beneficial effects of this invention are:
[0030] This invention utilizes the solid-state forming characteristics of cold spraying technology to obtain aluminum matrix composite precursors (M / Al) 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 highly active fine-grained or metastable structures can be formed on and inside the particles. This facilitates 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℃), achieving AlN coating of M-Al intermetallic compounds. Finally, hot rolling is used to eliminate the porosity that appears before and after heat treatment, thereby obtaining a core-shell structure intermetallic compound reinforced aluminum matrix composite material with AlN ceramic phase coating M-Al intermetallic compounds.
[0031] The various process steps and parameter settings of this invention work together to overcome the various defects existing in the preparation process of silicon carbide particle-reinforced aluminum matrix composites in the prior art, and obtain a high-performance in-situ aluminum nitride-coated intermetallic compound particle core-shell structure-reinforced dense aluminum matrix composite. Attached Figure Description
[0032] Figure 1 This is a secondary electron image of the surface morphology of the Al-15Fe composite material formed by cold spray solid deposition in S3 of Example 1 of the present invention.
[0033] Figure 2 This is a backscattered electron image of the surface morphology of the Al-15Fe 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.
[0034] Figure 3 This is a backscattered image (low magnification) of the cross-sectional morphology of the Al-15Fe 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.
[0035] Figure 4 This is a backscattered image (high magnification) of the cross-sectional morphology of the Al-15Fe 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 5 This is a backscattered electron image of the cross-sectional morphology of the Al-15Fe 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 white area represents Al5Fe2 intermetallic compound particles synthesized in situ; and the outer surface of the white particles is an in-situ formed AlN ceramic phase coating layer.
[0037] Figure 6The cross-sectional morphology of the Al-15Fe composite material after in-situ synthesis following heat treatment in S4 of Example 1 of the present invention is shown below. Figure 5 (High-magnification photographs) and energy spectrum analysis diagrams of different regions.
[0038] Figure 7 The cross-sectional morphology and composition of different regions of the Al-15Fe composite material after in-situ synthesis following heat treatment in S4 of Example 2 of the present invention are shown.
[0039] Figure 8 The cross-sectional morphology of the Al-25Fe composite material after in-situ synthesis under heat treatment in S4 of Example 3 of the present invention is as follows: a layer of AlN ceramic layer is wrapped around the white Al5Fe2 intermetallic compound particles.
[0040] Figure 9 The cross-sectional morphology of the Al-45Fe composite material synthesized in situ after heat treatment in S4 of Comparative Example 1 of this invention is as follows: white Al5Fe2 intermetallic compound particles are mixed with dark AlN phase, and the core-shell structure of Al5Fe2 intermetallic compound particles coated with AlN ceramic phase cannot be obtained.
[0041] Figure 10 This is a flowchart illustrating the preparation process of the present invention.
[0042] Figure 11 This is a schematic diagram of the material structure of the present invention. Detailed Implementation
[0043] 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.
[0044] Example 1
[0045] S1. Raw material preparation: 400-mesh spherical pure aluminum powder and 300-mesh polygonal iron powder are mixed in a planetary ball mill according to the ratio of Al-15Fe (weight percentage, %). The ball-to-material ratio is 2:1, the rotation speed is 100 rpm, and the mixing time is 60 min to obtain Fe / Al mixed powder for cold spraying.
[0046] 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 0.45 MPa.
[0047] S3, Cold spray solid deposition molding: The Al-15Fe 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 2.0 MPa, the powder feeding gas pressure is 2.5 MPa, the powder feeding rate is 10 g / min, the spraying temperature is 200℃, the spraying distance is 10 mm, and the spray gun moving speed is 10 mm / s. This forms an aluminum-based composite material precursor with uniformly distributed Fe particles, with a porosity of about 5% and a thickness of about 5000 μm.
[0048] 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 550℃, 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-coated Al5Fe2 intermetallic compound-reinforced aluminum-based composite material.
[0049] S5, Hot rolling densification treatment: The AlN-coated Al5Fe2 intermetallic compound reinforced aluminum matrix composite material prepared in step S4 is placed in an argon-protected heating furnace and held at 350℃ for 5 min. Then, it is hot rolled at room temperature using a two-roll mill with a single-pass deformation of 5% to obtain an in-situ aluminum nitride ceramic-coated Al5Fe2 intermetallic compound core-shell structure intermetallic compound particle-reinforced dense aluminum matrix composite material.
[0050] Example 2
[0051] S1, Raw material preparation: 400-mesh spherical pure aluminum powder and 300-mesh polygonal iron powder are mixed in a planetary ball mill according to the ratio of Al-15Fe (weight percentage, %). The ball-to-material ratio is 2:1, the rotation speed is 100 rpm, and the mixing time is 60 min to obtain Fe / Al mixed powder for cold spraying.
[0052] 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.
[0053] S3, Cold spray solid deposition molding: The Al-15Fe 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 2.0 MPa, the powder feeding gas pressure is 2.5 MPa, the powder feeding rate is 10 g / min, the spraying temperature is 200℃, the spraying distance is 10 mm, and the spray gun moving speed is 10 mm / s. This forms an aluminum-based composite material precursor with uniformly distributed Fe particles, with a porosity of about 5% and a thickness of about 5000 μm.
[0054] S4, In-situ Synthesis via Heat Treatment: The aluminum-based composite precursor prepared in step S3 was subjected to heat diffusion treatment in a high-purity nitrogen environment (99.999% nitrogen purity), at a temperature of 600℃, and for 5 hours. This process promoted the in-situ reaction between the highly active outer surface of the aluminum particles and nitrogen to form an aluminum nitride ceramic phase. Simultaneously, iron particles underwent an in-situ solid-state diffusion reaction with the surrounding aluminum matrix to form Al5Fe2 intermetallic compound particles, thus obtaining an in-situ aluminum nitride ceramic-coated Al5Fe2 intermetallic compound-reinforced aluminum-based composite material. Due to the increased heat treatment temperature (600℃), the thickness of the AlN ceramic coating layer around the Al5Fe2 intermetallic compound particles significantly increased.
[0055] S5, Hot rolling densification treatment: The AlN-coated Al5Fe2 intermetallic compound reinforced aluminum matrix composite material prepared in step S4 is placed in an argon-protected heating furnace and held at 350℃ for 5 min. Then, it is hot rolled at room temperature using a two-roll mill with a single-pass deformation of 5% to obtain an in-situ aluminum nitride ceramic-coated Al5Fe2 intermetallic compound core-shell structure intermetallic compound particle-reinforced dense aluminum matrix composite material.
[0056] Example 3
[0057] S1, Raw material preparation: 500-mesh spherical pure aluminum powder and 350-mesh polygonal iron powder are mixed in a planetary ball mill according to the ratio of Al-25Fe (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 Fe / Al mixed powder for cold spraying.
[0058] 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.
[0059] S3, Cold spray solid deposition molding: The Al-25Fe 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 3.0 MPa, the powder feeding gas pressure is 3.5 MPa, the powder feeding rate is 20 g / min, the spraying temperature is 350℃, the spraying distance is 20 mm, and the spray gun moving speed is 30 mm / s. This forms an aluminum-based composite material precursor with uniformly distributed Fe particles, with a porosity of about 10% and a thickness of about 8000 μm.
[0060] S4, In-situ Synthesis via Heat Treatment: The aluminum-based composite precursor prepared in step S3 is subjected to heat diffusion treatment in a high-purity nitrogen environment. The nitrogen purity is 99.999%, the heat treatment temperature is 600℃, and the holding time is 5 hours. This promotes the in-situ reaction between the highly active outer surface of the aluminum particles and nitrogen to form an aluminum nitride ceramic phase. Simultaneously, iron particles undergo an in-situ solid-state diffusion reaction with the surrounding aluminum matrix to form Al5Fe2 intermetallic compound particles, thus obtaining an in-situ aluminum-based composite material reinforced with Al5Fe2 intermetallic compounds coated with aluminum nitride ceramics. Due to the fixing and strengthening effect of the AlN ceramic coating, the Al5Fe2 intermetallic compound particles maintain their intact morphology, without exhibiting the particle fragmentation phenomenon often seen after heat treatment in an inert gas (e.g., argon) environment.
[0061] S5, Hot rolling densification treatment: The AlN-coated Al5Fe2 intermetallic compound reinforced aluminum matrix composite material prepared in step S4 is placed in an argon-protected heating furnace and held at 450℃ for 15 min. Then, it is hot rolled at room temperature using a two-roll mill with a single-pass deformation of 15% to obtain an in-situ aluminum nitride ceramic-coated Al5Fe2 intermetallic compound core-shell structure intermetallic compound particle-reinforced dense aluminum matrix composite material.
[0062] Comparative Example 1
[0063] The composition is Al-45Fe, with an Fe content > 40%.
[0064] 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.
[0065] 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 0.45 MPa.
[0066] 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.
[0067] S4, In-situ Synthesis via Heat Treatment: The aluminum-based composite precursor prepared in step S3 is subjected to heat diffusion treatment in a high-purity nitrogen environment. The nitrogen purity is 99.999%, the heat treatment temperature is 600℃, and the holding time is 5 hours. This promotes the in-situ reaction between the highly active outer surface of the aluminum particles and nitrogen to form an aluminum nitride ceramic phase. Simultaneously, iron particles undergo in-situ solid-state diffusion reaction with the surrounding aluminum matrix to form Al5Fe2 intermetallic compound particles. However, the AlN ceramic phase and Al5Fe2 intermetallic compound particles are mixed and not a core-shell structure of AlN coating Al5Fe2 intermetallic compound particles. Therefore, it is impossible to obtain a dense aluminum-based composite material with a core-shell structure of Al5Fe2 intermetallic compound particles reinforced by in-situ aluminum nitride ceramic coating.
[0068] Comparative Example 2
[0069] Unlike Example 1, the heat treatment temperature was reduced to 450°C.
[0070] S1, Raw material preparation: 400-mesh spherical pure aluminum powder and 300-mesh polygonal iron powder are mixed in a planetary ball mill according to the ratio of Al-15Fe (weight percentage, %). The ball-to-material ratio is 2:1, the rotation speed is 100 rpm, and the mixing time is 60 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-15Fe 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 2.0 MPa, the powder feeding gas pressure is 2.5 MPa, the powder feeding rate is 10 g / min, the spraying temperature is 200℃, the spraying distance is 10 mm, and the spray gun moving speed is 10 mm / s. This forms an aluminum-based composite material precursor with uniformly distributed Fe particles, with a porosity of about 5% and a thickness of about 5000 μm.
[0073] 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 5h.
[0074] The results showed that, due to the excessively low heat treatment temperature, Fe did not react with Al to synthesize Al5Fe2 intermetallic compound, nor did Al react with nitrogen to generate aluminum nitride. As a result, it was ultimately impossible to obtain aluminum nitride ceramics and Al5Fe2 intermetallic compound hybrid reinforced aluminum matrix composites.
[0075] All technical features in this embodiment can be modified in appearance according to actual needs.
[0076] 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 a core-shell structured reinforced aluminum-based composite material with in-situ aluminum nitride-coated intermetallic compound particles, 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 solid-state diffusion reaction between the metal particles M and the surrounding aluminum matrix, so that the metal particles M are transformed into M-Al intermetallic compound particles in situ. At the same time, the aluminum matrix around the intermetallic compound particles reacts with nitrogen to form an aluminum nitride coating layer in situ, thereby obtaining a core-shell structure reinforced aluminum-based composite material with aluminum nitride ceramic phase coating M-Al intermetallic compound particles. S5, Hot rolling densification treatment: The aluminum matrix composite material prepared in step S4 is kept at a temperature in a heating furnace, and then hot rolled at room temperature using a rolling mill. The deformation per pass is 5%~25%, to obtain a core-shell structure reinforced dense aluminum matrix composite material with in-situ aluminum nitride-coated intermetallic compound particles.
2. The method for preparing a core-shell structured reinforced aluminum matrix composite material with in-situ aluminum nitride-coated intermetallic compound particles 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 a core-shell structured reinforced aluminum matrix composite material with in-situ aluminum nitride-coated intermetallic compound particles according to claim 2, characterized in that: The mass percentage of pure aluminum powder or aluminum alloy powder to pure metal powder M in step S1 is 90~70:10~30.
4. The method for preparing a core-shell structured reinforced aluminum matrix composite material with in-situ aluminum nitride-coated intermetallic compound particles 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 10~50um 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 a core-shell structured reinforced aluminum matrix composite material with in-situ aluminum nitride-coated intermetallic compound particles 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 a core-shell structured reinforced aluminum matrix composite material with in-situ aluminum nitride-coated intermetallic compound particles 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 2.0~3.5MPa, the powder feeding gas pressure is 2.5~4.0MPa, the powder feeding rate is 10~25g / min, the spraying temperature is 200~400℃, the spraying distance is 10~20mm, and the spray gun moving speed is 10~30mm / s.
7. The method for preparing a core-shell structured reinforced aluminum matrix composite material with in-situ aluminum nitride-coated intermetallic compound particles 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 5-10% and a thickness of 500μm-10mm.
8. The method for preparing a core-shell structured reinforced aluminum matrix composite material with in-situ aluminum nitride-coated intermetallic compound particles 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 500~600℃, and a holding time of 5~10h.
9. The method for preparing a core-shell structured reinforced aluminum matrix composite material with in-situ aluminum nitride-coated intermetallic compound particles according to claim 1, characterized in that: In step S5, the furnace temperature is 350℃~500℃, the heating time is 5min~15min, and the heating process is carried out under argon protection; then, a single-pass hot rolling is performed using a two-roll mill, with a compression deformation of 5%~20%.
10. A reinforced aluminum matrix composite material prepared by the preparation method of a core-shell structure reinforced aluminum matrix composite material with in-situ aluminum nitride-coated intermetallic compound particles as described in any one of claims 1-9.