Inorganic phase synergistically reinforced wear-resistant and heat-resistant aluminum matrix composite material

Abstract

This invention relates to the field of metal matrix composites, specifically to a wear-resistant and heat-resistant aluminum matrix composite material with synergistic inorganic phase reinforcement, aiming to solve the problems of poor strength and toughness matching, poor interfacial bonding, and insufficient high-temperature stability in existing aluminum matrix composites. The composite material of this invention consists of an aluminum alloy matrix and multi-scale reinforcing phases, including micron-sized silicon carbide, submicron-sized in-situ nitrides, carbides, and nano-sized in-situ oxides and intermetallic compounds. This invention first prepares a directional layered porous ceramic preform, then uses unidirectional cryogenic casting to obtain a silicon carbide-based ceramic preform with directional parallel channels. Next, vacuum pressure infiltration is combined with the addition of an aluminum alloy ingot containing copper oxide, allowing the molten aluminum alloy to penetrate into the channels of the preform and undergo an in-situ reaction to generate fine reinforcing phases. Finally, after two-stage solution treatment and low-temperature aging heat treatment, nano-sized Al2Cu phases precipitate in the aluminum matrix.

Description

Technical Field

[0001] This invention relates to the field of metal matrix composites, and more specifically to a wear-resistant and heat-resistant aluminum matrix composite material with synergistic inorganic phase reinforcement. Background Technology

[0002] Aluminum-based composites are widely used in aerospace, automotive, and other industries due to their lightweight and high specific strength. However, traditional aluminum-based composites typically use single-scale or single-component reinforcing phases to improve strength and wear resistance, often resulting in insufficient toughness and a difficulty in achieving a balance between strength and toughness. Existing patent CN118060850A discloses a method for preparing graphene-aluminum-based composites and the graphene-aluminum-based composite material itself. This method involves encapsulating graphene between two aluminum materials, mixing the graphene and aluminum through stirring and friction, and then subjecting the billet to multi-directional forging or die forging. However, methods to increase the hardness and strength of aluminum-based composites lead to a decrease in fracture toughness, while measures to improve toughness reduce overall strength. Therefore, particle-reinforced aluminum-based composites produced using traditional processes still face irreconcilable contradictions and technical bottlenecks in practical applications.

[0003] (1) The Inverse Problem of Strength-Toughness Matching: In classical materials science theory, strength and toughness often have an inverse relationship. For particle-reinforced aluminum matrix composites, increasing the volume fraction of ceramic particles can significantly improve the hardness, modulus, and wear resistance of the material, but this will lead to a severe disruption of the matrix continuity and an exacerbation of stress concentration effects. During loading, cracks are very likely to initiate and propagate rapidly inside the brittle ceramic particles or at the interface, resulting in extremely low fracture toughness and elongation of the material. This brittle characteristic severely limits the application of high volume fraction AMCs in components subjected to impact loads or complex stress states.

[0004] (2) Insufficient high-temperature stability: Currently widely used precipitation-strengthened aluminum alloys mainly rely on the strengthening effect of nano-precipitates. However, these metastable precipitates have poor thermal stability. When the service temperature exceeds 150-200℃, the precipitates will coarsen or even dissolve, leading to a sharp decrease in the strength of the matrix. Although single micron-sized particle reinforcement can provide some load transfer, it cannot effectively pin dislocation climb and grain boundary sliding at high temperatures.

[0005] To address the aforementioned issues, there is an urgent need to develop a method that comprehensively improves strength, toughness, interface properties, and high-temperature performance, thereby achieving dual optimization of structure and function. Summary of the Invention

[0006] The purpose of this invention is to address the problems of poor strength-toughness matching, poor interfacial bonding, and insufficient high-temperature stability in existing aluminum-based composite materials, and to provide a wear-resistant and heat-resistant aluminum-based composite material with synergistic reinforcement by inorganic phases and its preparation method. This composite material achieves high strength, high toughness, and excellent wear resistance at both room temperature and high temperature through the synergistic effect of multi-scale inorganic reinforcing phases and a special preparation process, meeting the requirements for high-temperature load-bearing components in aerospace and other fields.

[0007] An inorganic phase synergistic reinforcement wear-resistant and heat-resistant aluminum-based composite material, the technical solution of which is as follows:

[0008] S1: Take 70-80 parts by weight of silicon carbide, 8-10 parts by weight of TiH2, 4-6 parts by weight of B4C, 0.4-0.6 parts by weight of ammonium polyacrylate dispersant, and 5-6 parts by weight of gelatin binder, add them together to 90-100 parts by weight of deionized water, stir for 1 hour to form a uniform slurry, perform unidirectional freeze casting to obtain a solidified green body, transfer the green body to a freeze dryer for vacuum drying, take it out and place it in a tube furnace, heat it to 1100℃ at 5℃ / min in an argon atmosphere, hold it at the temperature for 2 hours, and then cool it down in the furnace for sintering to prepare a ceramic preform;

[0009] S2: Take 90-100 parts of Al-10Si-0.5Mg aluminum alloy atomized powder and 2-3 parts of nano CuO powder, add them to a ball mill jar for mixing and ball milling, and then melt them by melting and casting to obtain composite aluminum alloy ingots;

[0010] S3: Vertically fix the ceramic preform prepared in step S1 in the high-temperature resistant mold and place it above the crucible of the infiltration furnace. Place the composite aluminum alloy ingot prepared in step S2 into the crucible, directly below the preform. Close the furnace and evacuate to a high vacuum of 1000°C. -2 The furnace body is heated to 700℃~800℃ in the Pa range. Under an argon atmosphere and a pressure of 1MPa~10MPa, the molten aluminum flows upward and completely fills the directional layered channels in the preform. The temperature is maintained for 30 minutes, and after depressurization, it is cooled to room temperature to obtain the shaped component.

[0011] S4: The shaped component prepared in step S3 is subjected to two-stage solid solution treatment, then quenched in hot water, then rapidly transferred from room temperature to an oil bath furnace for heat preservation, and then air-cooled to room temperature to obtain the aluminum-based composite material of the present invention.

[0012] Furthermore, the unidirectional cryogenic casting described in step S1 specifically involves pouring slurry into a cylindrical mold with an inner diameter of 50 mm and a height of 100 mm, pre-positioning a copper cold platform at the bottom of the mold, placing the mold in a liquid nitrogen cold bath to maintain the temperature of the copper bottom at -30°C, and allowing the slurry to completely freeze into a solidified blank after 30 minutes.

[0013] Furthermore, the vacuum drying described in step S1 specifically involves drying at -55°C and a vacuum of 10 Pa for 48 hours.

[0014] Furthermore, the mixing ball milling described in step S2 specifically involves mixing and milling at a speed of 100 rpm to 300 rpm for 1 to 3 hours under argon protection.

[0015] Furthermore, the melting and casting method described in step S2 has the following parameters: under an argon atmosphere, the temperature is 700℃~800℃.

[0016] Furthermore, the two-stage solution treatment described in step S4 specifically involves solution treatment at 460–480°C for 2–3 hours, followed by heating to 510–530°C for 1–2 hours.

[0017] Furthermore, the heat preservation described in step S4 specifically involves maintaining the temperature at 155°C for 8 hours.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) This invention improves the strength and fracture toughness of aluminum-based composite materials through biomimetic layered structure design and multi-scale reinforcement synergy, effectively solving the problem of difficulty in achieving both strength and toughness.

[0020] (2) This invention utilizes in-situ reaction to generate transition phase particles such as TiB2 and TiC at the ceramic / metal interface, achieving chemical metallurgical bonding at the interface and avoiding the defect of easy debonding at purely mechanical bonding interfaces. The process of molten metal penetrating the preform channels enables the ceramic reinforcing phase and the solidified aluminum matrix to conformally interlock, forming an interpenetrating network structure with strong integrity.

[0021] (3) After precipitation strengthening treatment, the matrix structure of the composite material of the present invention is strengthened by the dispersion of nano-Al2O3 particles and the precipitation of Al2Cu phase. It not only improves the hardness at room temperature, but also maintains high hardness and strength at higher temperatures. The wear rate of the material of the present invention is significantly lower than that of the comparative material. Its excellent high-temperature wear resistance is attributed to the continuous wear-resistant skeleton composed of hard ceramic layers and Al2O3.

[0022] (4) This invention innovatively combines the technology of cryogenic casting of porous ceramic supports with vacuum pressure infiltration in additive manufacturing. Cryogenic casting makes the ceramic reinforcing phases arranged in a preferred orientation, while vacuum pressure infiltration process precisely controls the spatiotemporal process of filling the metal matrix and generating the reinforcing phase in situ. The combination of the two achieves a special structure that cannot be obtained by traditional aluminum-based composite material manufacturing, greatly reducing the amount of post-processing, saving materials and shortening the manufacturing cycle. Attached Figure Description

[0023] Figure 1This is a process flow diagram for preparing an inorganic phase synergistically reinforced wear-resistant and heat-resistant aluminum-based composite material according to the present invention.

[0024] Figure 2 The XRD pattern is from Experiment Example 1.

[0025] Figure 3 This is a comparison chart of the mechanical property test results for Experiment Example 2.

[0026] Figure 4 This is a comparison chart of the high-temperature hardness and wear rate test results for Experiment Example 2. Detailed Implementation

[0027] The following embodiments further explain and illustrate the technical solutions of the present invention. It is particularly noted that each specific embodiment is a specific interpretation of the technical solution and should not be considered as a limitation on the scope of protection of the present invention. Those skilled in the art still have the right to modify the technical solutions of these embodiments and make equivalent substitutions for some or all of the technical features, and these modifications or substitutions do not change the essence of the corresponding technical solutions, nor do they cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions described in the present invention. Figure 1 The diagram shows the preparation process of an inorganic phase synergistically reinforced wear-resistant and heat-resistant aluminum-based composite material. The detailed preparation steps are as follows:

[0028] The aluminum-based composite material is composed of an aluminum alloy matrix and multiple reinforcing phases, including micron-scale reinforcing phases, submicron-scale reinforcing phases, and nano-scale reinforcing phases. It is prepared by combining unidirectional freeze casting and vacuum pressure infiltration processes, and forms a biomimetic shell-like "brick-mud" layered structure inside: ceramic reinforcements are distributed interspersed with the aluminum matrix in the form of layered "bricks".

[0029] The micron-scale reinforcing phase is a micron-scale SiC layer, which acts as a skeleton in the composite material. According to the shear hysteresis theory, the high aspect ratio SiC layer can effectively share the load transmitted by the matrix through interfacial shear stress. Under friction and wear conditions, the continuous ceramic skeleton prevents abrasive particles from micro-cutting and micro-fatigue spalling of the soft matrix, thereby significantly improving wear resistance. The layered structure imparted by freeze casting provides a toughening mechanism similar to nacre: when cracks encounter SiC layers during propagation, they are forced to deflect, greatly increasing the length of the crack propagation path and surface energy consumption. The submicron-scale reinforcing phase is a submicron TiB2 / TiC layer (interfacial bridging). The TiB2 / TiC layer located between SiC and the Al matrix plays a crucial bridging role. TiB2 and TiC exist in the form of fine particles at the interface, constructing a gradient modulus transition zone, effectively alleviating interfacial stress. The difference in thermal expansion coefficients between the ceramic phase and the metal matrix induces a high density of geometrically necessary dislocations in the matrix during cooling. The presence of the TiB2 / TiC layer further increases the area of ​​this mismatched interface, thereby increasing the dislocation density and significantly improving the yield strength of the matrix. The nanoscale reinforcing phase is nanoscale Al2O3 / Al2Cu, with the dispersed nano-Al2O3 particles acting as pinning points for dislocation movement. Traditional precipitated reinforcing phases tend to coarsen or even dissolve at high temperatures, leading to the loss of their strengthening effect. However, the in-situ generated Al2O3 ceramic particles are not only stable at high temperatures but also pin grain boundaries, inhibiting grain growth and grain boundary slip in the matrix, thus endowing the material with excellent high-temperature creep resistance.

[0030] 1. Preparation of ceramic preforms

[0031] Micron-sized silicon carbide powder, submicron-sized precursor powder containing Ti and other reactive components are mixed with dispersant and binder, and solvent is added and stirred evenly to prepare ceramic slurry. The slurry is poured into a mold and placed in a temperature gradient field for unidirectional cryogenic casting, which solidifies directionally from bottom to top to form an ice template. Then, it is vacuum freeze-dried at -50°C to sublimate and remove the ice phase, obtaining a ceramic green body with parallel layered channels. The green body is then sintered for several hours to enhance its strength, resulting in a porous ceramic preform. The preform contains a large number of parallel pores oriented along the solidification direction. During sintering, the atmosphere is controlled to induce partial in-situ reactions in the precursor to generate fine reinforcing phases. During vacuum or inert atmosphere sintering, the carbon generated by the pyrolysis of the binder reacts with the Ti precursor to generate submicron TiC particles, thus preloading the ceramic wall with fine reinforcing phases to prepare for subsequent metal infiltration. Throughout the reaction process, the generated TiB2 / TiC has good chemical compatibility with the SiC matrix and high bonding strength. The particles generated by the reaction are submicron in size and uniformly distributed, which can effectively pin dislocations and strengthen the interface.

[0032] 2. Preparation of composite aluminum alloy powder

[0033] Aluminum alloy pre-alloyed powder was selected as the matrix metal powder, and nano-CuO powder was added. The two were mixed evenly in a ball mill, and then melted under an argon atmosphere using a melting and casting method to obtain a composite aluminum alloy ingot. In the subsequent vacuum pressure melting, the nano-CuO will undergo an aluminothermic reduction reaction with aluminum to generate Al2O3 nanoparticles and metallic Cu in situ. The metallic Cu further forms an Al-Cu alloy with the aluminum matrix and precipitates the Al2Cu phase through solution / aging. Thus, a nano-reinforcing phase is introduced into the matrix without reducing the fluidity and sinterability of the aluminum powder.

[0034] 3. Vacuum pressure infiltration

[0035] The prepared ceramic preform was vertically fixed in a high-temperature resistant mold and placed above the crucible of the infiltration furnace. The prepared composite aluminum alloy ingot was placed in the crucible, positioned directly below the preform, the furnace was closed, and a high vacuum of 1000 kJ / m² was evacuated. -2 The furnace body is heated to the Pa level, and under an argon atmosphere, the molten aluminum flows upward to completely fill the directional layered channels in the preform. The temperature is maintained for 30 minutes, and after depressurization, it is cooled to room temperature to obtain the shaped component.

[0036] In a vacuum environment, molten metal is forced into all the channels of the preform entirely and in one go by the applied high-pressure gas. The external pressure overcomes the wetting and flow resistance between the melt and the preform, achieving complete filling. The reaction occurs between the molten metal and the entire preform. The preform is held at a high temperature and pressure for a period of time, providing more sufficient thermodynamic conditions and a longer reaction time for the aluminothermic reaction between CuO and Al, as well as the reaction between TiH2 / B4C and Al, which is conducive to a more complete reaction. The whole process is a "near-net-shape" process, where the preform determines the initial shape and internal structure of the final part, and the metal matrix fills the space between them.

[0037] 4. Subsequent heat treatment

[0038] The composite parts, after vacuum pressure infiltration molding, undergo heat treatment to fully utilize their material properties. A two-stage solution treatment + aging process is employed: first, solution treatment is performed at a lower temperature to initially dissolve the supersaturated phase in the matrix; then, the temperature is raised to a higher temperature for further solution treatment to completely dissolve the insoluble Al2Cu particles and other second phases; subsequently, rapid water quenching is used to retain the supersaturated solid solution structure. Then, heat treatment is applied to allow the Cu elements dissolved in the matrix to precipitate as nano-Al2Cu phases, while fine Al2O3 particles precipitate or grow. This two-stage solution treatment ensures that the Cu-containing reinforcing phase is fully dissolved, avoiding coarse residues, and precipitates more uniformly dispersed reinforcing phases compared to single-stage solution treatment. After aging, the hardness and strength of the aluminum matrix are significantly improved. Simultaneously, the presence of nano-oxide particles enhances the matrix's stability at high temperatures, hindering grain boundary slip and migration, thereby improving high-temperature performance.

[0039] The composite material obtained through the above process forms an alternating structure of parallel-oriented ceramic layers and metal filling layers, i.e., a shell-like nacreous layer structure. The reinforcing phases at each scale are uniformly distributed and work together: micron-sized silicon carbide ceramic layers provide skeletal support and the main wear-resistant phase, submicron TiB2 / TiC particles enhance the ceramic-metal interface transition layer, and nano-Al2O3 particles and Al2Cu precipitates significantly enhance the metal bonding layer.

[0040] Example 1

[0041] Table 1 Raw Material Information Table

[0042] Raw material name Model / Dosage Form CAS number silicon carbide Average particle size is 5–50 micrometers 409-21-2 <![CDATA[TiH2]]> Particle size 10-50μm 7704-98-5 <![CDATA[B4C]]> Average particle size 1-50 μm 12069-32-8 ammonium polyacrylate Industrial grade 9003-03-6 gelatin Industrial grade 9000-70-8 Argon Purity ≥ 99.99% 7440-37-1 Al-10Si-0.5Mg aluminum alloy Particle size 20–40 μm - Nano CuO Average particle size 20nm 1317-38-0

[0043] An inorganic phase synergistic reinforcement wear-resistant and heat-resistant aluminum-based composite material is prepared by the following steps:

[0044] S1: Take 75 parts by weight of silicon carbide, 9 parts by weight of TiH2, 5 parts by weight of B4C, 0.5 parts by weight of ammonium polyacrylate dispersant, and 5.5 parts by weight of gelatin binder, and add them to 95 parts by weight of deionized water. Stir for 1 hour to form a uniform slurry. Pour the slurry into a cylindrical mold with an inner diameter of 50 mm and a height of 100 mm. Place a copper cold stage at the bottom of the mold and place the mold in a liquid nitrogen cold bath to keep the temperature of the copper bottom at about -30°C. Perform unidirectional cryogenic casting. After 30 minutes, the slurry is completely frozen into a solidified blank. Transfer the blank to a freeze dryer and dry it at -55°C and vacuum 10 Pa for 48 hours to sublimate the ice phase. Take it out and place it in a tube furnace. Heat it to 1100°C at 5°C / min in an argon atmosphere. Hold it at that temperature for 2 hours and then cool it down in the furnace to sinter it to obtain a ceramic preform.

[0045] S2: Take 95 parts of Al-10Si-0.5Mg aluminum alloy atomized powder and 2.5 parts of nano CuO powder and add them to a ball mill jar. Under argon protection, mix and ball mill at 200 rpm for 2 hours. Then, melt and cast the mixture under argon atmosphere at 750℃ to obtain a composite aluminum alloy ingot.

[0046] S3: Vertically fix the ceramic preform prepared in step S1 in the high-temperature resistant mold and place it above the crucible of the infiltration furnace. Place the composite aluminum alloy ingot prepared in step S2 into the crucible, directly below the preform, close the furnace, and evacuate to a high vacuum of 10... -2 The furnace body is heated to 750°C in the Pa range. Under an argon atmosphere and a pressure of 5 MPa, the molten aluminum flows upward and completely fills the directional layered channels in the preform. The temperature is maintained for 30 minutes. After depressurization, the pressure is released and the furnace is cooled to room temperature to obtain the shaped component.

[0047] S4: The shaped component prepared in step S3 is solution-treated at 470°C for 2.5 hours, then heated to 520°C for 1.5 hours, then quenched in hot water, and then quickly transferred to an oil bath furnace at room temperature and held at 155°C for 8 hours, and then air-cooled to room temperature to obtain the aluminum-based composite material of the present invention.

[0048] Example 2

[0049] In step S1: Take 70 parts by weight of silicon carbide, 8 parts by weight of TiH2, 4 parts by weight of B4C, 0.4 parts by weight of ammonium polyacrylate dispersant, and 5 parts by weight of gelatin adhesive and add them together to 90 parts by weight of deionized water;

[0050] In step S2: 90 parts of Al-10Si-0.5Mg aluminum alloy atomized powder and 2 parts of nano CuO powder were added to a ball mill jar, mixed and ball-milled at 100 rpm for 3 hours under argon protection, and then melted at 700℃ under argon atmosphere by melting and casting method to obtain composite aluminum alloy ingot.

[0051] In step S3: the furnace body is heated to 700°C under an argon atmosphere and a pressure of 1 MPa;

[0052] In step S4: the shaped component prepared in step S3 is dissolved at 460°C for 3 hours, and then heated to 510°C for 2 hours.

[0053] Example 3

[0054] In step S1: Take 80 parts by weight of silicon carbide, 10 parts by weight of TiH2, 6 parts by weight of B4C, 0.6 parts by weight of ammonium polyacrylate dispersant, and 6 parts by weight of gelatin adhesive and add them together to 100 parts by weight of deionized water;

[0055] In step S2: 100 parts of Al-10Si-0.5Mg aluminum alloy atomized powder and 3 parts of nano CuO powder were added to a ball mill jar, mixed and ball milled at 300 rpm for 1 hour under argon protection, and then melted at 800℃ under argon atmosphere to obtain composite aluminum alloy ingot.

[0056] In step S3: the furnace body is heated to 800°C under an argon atmosphere and a pressure of 10 MPa;

[0057] In step S4: the shaped component prepared in step S3 is dissolved at 480°C for 2 hours, and then heated to 530°C for 1 hour.

[0058] Comparative Example 1

[0059] Referring to the composition and proportions in Example 1, but without using the cryogenic casting process to prepare the preform, ceramic powder and aluminum alloy powder are directly and uniformly mixed and placed in a steel mold for hot pressing and sintering to prepare the composite material.

[0060] Comparative Example 2

[0061] The preparation method of Example 1 is followed, but a layered composite material without in-situ nano-reinforcing phase is prepared, i.e., CuO powder is not added in step S2. The remaining steps are the same.

[0062] Comparative Example 3

[0063] The preparation method of Example 1 is followed, but vacuum pressure infiltration is not performed. That is, step S3 is replaced with conventional casting infiltration: the preform is preheated to 300°C and then immersed in molten aluminum alloy. The remaining steps are the same.

[0064] Experimental Example 1

[0065] XRD characterization was performed on the raw material mixing stage, the ceramic preform after sintering, the vacuum pressure infiltration stage, and the final sample prepared in Example 1. The raw material mixing stage sample consisted of a powder sample obtained by simple physical mixing of micron-sized SiC, micron-sized TiH2, and micron-sized B4C powders with aluminum alloy powder and nano-CuO powder. High-resolution X-ray diffractometer was used for testing, with Cu target Kα rays as the radiation source, tube voltage / current of 40 kV / 40 mA, scanning range of 20°–80°, and scanning speed of 2° / min. The test results are as follows: Figure 2 As shown;

[0066] Raw material mixing stage: The spectrum shows a simple superposition of the components, with no new phase formation;

[0067] After sintering of the ceramic preform: During the sintering process, TiH2 completely decomposes and dehydrogenates, and the peak of TiH2 disappears in the spectrum. In its place, the characteristic peak of metallic Ti is replaced. Under the protective atmosphere of argon, B4C does not oxidize, thus preserving its activity for subsequent in-situ reactions. The SiC peak remains stable, indicating that the layered framework structure has not been chemically eroded.

[0068] After vacuum pressure infiltration: multiple in-situ reactions occurred. In the high-temperature molten aluminum environment, Ti and B4C on the preform wall reacted with Al. The spectrum showed a strong TiB2 peak near 44.4° and a characteristic TiC peak near 41.7°, which confirmed the successful construction of the submicron interface transition layer.

[0069] Finished product: After solution treatment and aging, Cu elements precipitate from the matrix, and enhanced diffraction peaks of the Al2Cu phase can be observed near 47.8°. No Al4C3 diffraction peaks were detected in the 32°-35° range, because the matrix alloy uses Al-10Si. The high Si content thermodynamically inhibits interfacial reactions, avoids the formation of brittle phases, and ensures the material's corrosion resistance and interfacial bonding strength.

[0070] Experiment Example 2

[0071] The wear-resistant and heat-resistant aluminum-based composite materials prepared in Examples 1-3 and Comparative Examples 1-3 were used to determine their comprehensive properties.

[0072] Mechanical property testing: Referring to standard GB / T 228.1-2021 "Metallic materials - Tensile testing - Part 1: Test method at room temperature", a universal testing machine was used to process the material into standard tensile specimens, and tensile tests were performed along the orientation direction of the ceramic layers. The tensile strength was recorded. Referring to standard GB / T 21143-2025 "Unified test method for quasi-static fracture toughness of metallic materials", a universal testing machine was used to process three-point bending specimens with pre-existing fatigue cracks, and the plane strain fracture toughness was tested and calculated.

[0073] High-temperature hardness test: Using a high-temperature Vickers hardness tester, the sample and indenter are kept at 350°C for a sufficient time, then a load is applied and held, and after cooling, the diagonal of the indentation is measured to calculate the high-temperature hardness.

[0074] Wear resistance test: Referring to standard GB / T 12444-2006 "Test Methods for Wear of Metallic Materials - Sliding Wear Test of Test Rings and Blocks", a high-temperature friction and wear testing machine was used, employing a SiC / Al2O3 ceramic disc. The test was conducted at 300℃ under dry conditions, with a load of 50N, a sliding speed of 0.2m / s, a sliding radius of 5mm, and a total sliding distance of 1000m. The sample mass was accurately weighed before and after the test, and the volumetric wear rate was calculated.

[0075] The specific test comparison results are shown in Table 2. Figure 3 , Figure 4 As shown:

[0076] Table 2. Comparison of overall performance between Examples 1-3 and Comparative Examples 1-3

[0077] experimental group Tensile strength (MPa) <![CDATA[Fracture toughness (MPa·m 1 / 2 ).]]> High-temperature hardness (HV) <![CDATA[Wear rate (10 -5 mm 3 / N·m)]]> Example 1 460±13 25±1.2 150±5 4.0±0.3 Example 2 455±14 24±1.2 149±5 4.0±0.2 Example 3 457±15 25±1.3 150±4 3.9±0.3 Comparative Example 1 320±13 8±1.2 95±5 12.8±0.2 Comparative Example 2 350±14 12±1.1 110±5 7.5±0.3 Comparative Example 3 400±14 18±1.2 149±4 3.9±0.2

[0078] The comparison results above show that the composite material prepared in Comparative Example 1 lacks a layered structure, and its tensile strength and fracture toughness are significantly lower than those of Example 1, as is its high-temperature hardness. It also exhibits a high wear rate, with large areas of matrix material peeling off in the wear marks, indicating that the absence of a layered structure significantly reduces the material's strength, toughness, and high-temperature performance. The composite material prepared in Comparative Example 2 lacks a nano-reinforcing phase, resulting in lower mechanical properties. The matrix, lacking nanoparticles, undergoes significant grain growth and softening at high temperatures, and the absence of Cu element reinforcement further contributes to poor high-temperature performance. Therefore, although the layered SiC reinforcement structure provides some toughening effect, the lack of a nano-scale in-situ reinforcing phase still results in unsatisfactory high-temperature mechanical and wear-resistant properties. Comparative Example 3 underwent traditional casting impregnation, but the insufficient penetration during traditional pressure impregnation led to poor mechanical properties.

Claims

1. A wear-resistant and heat-resistant aluminum-based composite material with inorganic phase synergistic reinforcement, comprising an aluminum alloy matrix and a reinforcing phase, characterized in that, The composite material exhibits a structure in which ceramic layers and a metal matrix are stacked alternately; the aluminum alloy matrix is ​​an aluminum alloy containing silicon and magnesium, and nano-sized copper oxide is introduced; The ceramic layer is formed from a directional layered porous ceramic preform, and the metal matrix is ​​melt-permeated into the channels of the preform by a vacuum pressure infiltration process; the reinforcing phase includes: micron-sized silicon carbide, submicron-sized in-situ titanium diboride, in-situ titanium carbide, nano-sized in-situ alumina, and intermetallic compound Al2Cu.

2. The inorganic phase synergistic reinforcement wear-resistant and heat-resistant aluminum-based composite material according to claim 1, characterized in that, The porous ceramic preform is prepared by mixing 70-80 parts by weight of silicon carbide, 8-10 parts by weight of TiH2, 4-6 parts by weight of B4C, 0.4-0.6 parts by weight of ammonium polyacrylate dispersant, and 5-6 parts by weight of gelatin binder with 90-100 parts by weight of deionized water.

3. The inorganic phase synergistic reinforcement wear-resistant and heat-resistant aluminum-based composite material according to claim 1, characterized in that, The aluminum alloy matrix is ​​composed of 90-100 parts of Al-10Si-0.5Mg aluminum alloy atomized powder and 2-3 parts of nano CuO powder.

4. The inorganic phase synergistic reinforcement wear-resistant and heat-resistant aluminum-based composite material according to claim 1, characterized in that, The preparation steps include the following: S1: Add silicon carbide, TiH2, B4C, ammonium polyacrylate dispersant, and gelatin binder to deionized water and stir for 1 hour to form a uniform slurry. Perform unidirectional freeze casting to obtain a solidified green body. Transfer the green body to a freeze dryer for vacuum drying. Take it out and place it in a tube furnace. Heat it to 1100℃ at 5℃ / min in an argon atmosphere. Hold it at that temperature for 2 hours and then cool it down in the furnace for sintering to prepare a ceramic preform. S2: Take Al-10Si-0.5Mg aluminum alloy atomized powder and nano CuO powder, add them to a ball mill jar for mixing and ball milling, and then melt them by melting and casting to obtain composite aluminum alloy ingots; S3: Vertically fix the ceramic preform prepared in step S1 in the high-temperature resistant mold and place it above the crucible of the infiltration furnace. Place the composite aluminum alloy ingot prepared in step S2 into the crucible, directly below the preform. Close the furnace and evacuate to a high vacuum of 1000°C. -2 The furnace body is heated to 700℃~800℃ in the Pa range. Under an argon atmosphere and a pressure of 1MPa~10MPa, the molten aluminum flows upward and completely fills the directional layered channels in the preform. The temperature is maintained for 30 minutes, and after depressurization, it is cooled to room temperature to obtain the shaped component. S4: The shaped component prepared in step S3 is subjected to two-stage solid solution treatment, then quenched in hot water, then rapidly transferred from room temperature to an oil bath furnace for heat preservation, and then air-cooled to room temperature to obtain the aluminum-based composite material of the present invention.

5. The inorganic phase synergistic reinforcement wear-resistant and heat-resistant aluminum-based composite material according to claim 4, characterized in that, The unidirectional cryogenic casting described in step S1 specifically involves pouring slurry into a cylindrical mold with an inner diameter of 50 mm and a height of 100 mm, pre-positioning a copper cold platform at the bottom of the mold, placing the mold in a liquid nitrogen cold bath to keep the temperature of the copper bottom at -30°C, and allowing the slurry to completely freeze into a solidified blank after 30 minutes.

6. The inorganic phase synergistic reinforcement wear-resistant and heat-resistant aluminum-based composite material according to claim 4, characterized in that, The vacuum drying described in step S1 specifically refers to drying at -55°C and a vacuum of 10 Pa for 48 hours.

7. The inorganic phase synergistic reinforcement wear-resistant and heat-resistant aluminum-based composite material according to claim 4, characterized in that, The mixing ball milling described in step S2 specifically involves mixing and milling at a speed of 100 rpm to 300 rpm for 1 to 3 hours under argon protection.

8. The inorganic phase synergistic reinforcement wear-resistant and heat-resistant aluminum-based composite material according to claim 4, characterized in that, The melting and casting method described in step S2 has the following parameters: temperature 700℃~800℃ under an argon atmosphere.

9. The inorganic phase synergistic reinforcement wear-resistant and heat-resistant aluminum-based composite material according to claim 4, characterized in that, The two-stage solution treatment described in step S4 specifically involves solution treatment at 460℃~480℃ for 2~3 hours, followed by heating to 510℃~530℃ for 1~2 hours.

10. The inorganic phase synergistic reinforcement wear-resistant and heat-resistant aluminum-based composite material according to claim 4, characterized in that, The heat preservation described in step S4 specifically involves maintaining the temperature at 155°C for 8 hours.

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