Preparation method of high-fatigue-resistance, high-toughness and high-temperature-resistance dispersion strengthening aluminum alloy

Abstract

The invention provides a preparation method of high-fatigue-resistance, high-toughness and high-temperature-resistance dispersion-strengthened aluminum alloy, and relates to the technical field of aluminum alloy preparation. The preparation method comprises the following steps: uniformly mixing aluminum alloy powder with a certain amount of polytetrafluoroethylene-PTFE turbid liquid, drying to obtain PTFE coated aluminum alloy powder, carrying out cold isostatic pressing forming and vacuum or nitrogen sintering densification on the composite powder to prepare an aluminum-based composite material blank, and preparing the high-fatigue-resistance high-toughness high-temperature-resistant aluminum-based composite material by adopting a thermal deformation process. According to the method, an aluminum oxide film on the surface of aluminum powder is effectively broken and removed in the sintering process of aluminum alloy powder by introducing PTFE, meanwhile, a ternary nanometer dispersion strengthening phase is formed in situ, and fine grain strengthening and precipitation strengthening mechanisms are combined, so that the aluminum-based composite material has excellent mechanical performance, fatigue resistance and high-temperature performance. The method is short in technological process and easy for industrial large-scale production, and has wide application prospects in the fields of aerospace, rail transit, electromagnetic propulsion equipment and the like.

Description

Technical Field

[0001] This invention relates to the technical field of aluminum alloy preparation, and in particular to a method for preparing a high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy. Background Technology

[0002] Aluminum alloys are widely used in aerospace, automotive, electronics, and construction industries due to their low density, high strength, good machinability, and excellent corrosion resistance. However, traditional aluminum alloys often face problems such as insufficient fatigue resistance, poor thermal stability, and rapid strength degradation under high-temperature conditions in special applications requiring high strength, high toughness, and high temperature resistance. These limitations restrict the long-term use of aluminum alloys under extreme working conditions, necessitating the development of new high-performance aluminum alloy materials to meet the application requirements for high fatigue resistance, high strength and toughness, and high-temperature resistance.

[0003] To improve the fatigue resistance of aluminum alloys, researchers typically employ methods such as adding reinforcing phases, optimizing alloy composition, and improving heat treatment processes to control the precipitation of reinforcing phases and improve the microstructure of the material. However, existing reinforcing phases often suffer from the following problems: on the one hand, the uneven distribution and size of the reinforcing phases can easily lead to crack propagation and reduce the fatigue life of the material; on the other hand, in some high-strength alloys, such as Al-Si alloys and Al-Cu alloys, the stability of the reinforcing phases is poor at high temperatures, and they are prone to dissolution or precipitation, resulting in a rapid decrease in the high-temperature strength of the material.

[0004] For example, Chinese patent CN114086041A discloses a high-strength and high-toughness aluminum alloy and its preparation method, wherein the reinforcing phase is Mg2Si phase, and the product is obtained by solution treatment, quenching, rotary forging and two-stage aging treatment after pressing, sintering and hot extrusion of water-atomized polygonal aluminum alloy powder; therefore, the preparation process is complicated, difficult to operate, energy-intensive, and has poor ability to improve mechanical properties such as strength and toughness.

[0005] Chinese patent CN113234965A discloses a high-temperature resistant, high-strength aluminum alloy and its preparation method. The amount of rare earth element La added is very large, resulting in high preparation costs. Furthermore, although the smelting and hot extrusion processes used are simple, they have very poor ability to improve the mechanical properties of the product, such as strength and toughness.

[0006] Therefore, developing novel reinforcing phases and optimizing their distribution has become crucial for improving the performance of aluminum alloys. Summary of the Invention

[0007] The main objective of this invention is to address the technical problems existing in the powder metallurgy aluminum alloy preparation process, such as the difficulty in removing the oxide film on the surface of aluminum powder, insufficient sintering densification, low high-temperature structural stability, and high cost due to complex processes. Therefore, a method for preparing a high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy is proposed, which can solve the aforementioned problems.

[0008] The technical solution is as follows:

[0009] A method for preparing a high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy, comprising the following steps:

[0010] S1. Preparation of aluminum alloy powder: Weigh the raw materials according to the alloy element content of the aluminum alloy powder, and prepare aluminum alloy powder through atomization process.

[0011] S2. Preparation of composite powder: Polytetrafluoroethylene (PTFE) powder is ultrasonically mixed with one or more of water, alcohol, acetone, diethyl ether, and chloroform to form a suspension. A portion of the suspension is uniformly mixed with aluminum alloy powder from S1 and then subjected to high-energy ball milling to obtain composite powder.

[0012] S3. Cold isostatic pressing: The composite powder of S1 is loaded into a sleeve and vibrated to compact it, and then cold isostatic pressing is performed to obtain a composite powder green blank.

[0013] S4. Powder Hot Extrusion: The composite powder green blank of S2 is placed in a heating furnace for preheating. The atmosphere is one or more of air, nitrogen, and argon. After preheating, hot extrusion is performed directly to obtain extruded profiles.

[0014] S5. Heat treatment: The extruded profiles of S3 are heat treated according to different application requirements to finally obtain high fatigue resistance, high strength and toughness, and high temperature resistant dispersion-strengthened aluminum alloy products.

[0015] Optionally, the atomization process of S1 is one or more of the following: ultra-high pressure gas atomization, water atomization, and water-gas combined atomization process.

[0016] Optionally, the aluminum alloy powder of S1 is one or more of Al-Cu aluminum alloy powder, Al-Zn-Mg-Cu aluminum alloy powder, Al-Fe-Cr-Ti aluminum alloy powder, and Al-Fe-V-Si aluminum alloy powder, with an average particle size of 2-15 μm.

[0017] Optionally, the particle size D of the PTFE powder of S2 90 <1μm, suspension concentration is 10-60g / L; PTFE powder content in composite powder is 0.2-1wt%.

[0018] Optionally, in the ultrasonic process parameters of S2, the ultrasonic frequency is 20000-60000Hz, the time is 10-60min; the high-energy ball mill is one or more of planetary ball mills, stirred ball mills, and vibratory ball mills, the ball-to-material ratio is 5:1-20:1, the ball milling time is 20-50h, the ball milling speed is 100-300r / min, and the particle size of the composite powder is 5-50μm.

[0019] Optionally, the S3 can be made of rubber, silicone or polyurethane, with a pressing pressure of 500-600 MPa and a holding time of 60-180 seconds.

[0020] Optionally, the tap density of the S3 composite powder is 1.6-1.9 g / cm³. 3 .

[0021] Optionally, the preheating temperature of S4 is 450-550℃, and the holding time is 2-5h; the extrusion ratio of hot extrusion is 60:1-200:1, and the extrusion speed is 0.2-10mm / s; the deformation of the extruded profile is 70-95%, and the shape includes bars, plates, and tubes.

[0022] Optionally, the density of the extruded profile of S4 is 2.7-2.9 g / cm³. 3 At room temperature: hardness is 110-180 HV, tensile strength is 380-560 MPa, yield strength is 260-460 MPa, yield ratio is 0.65-0.85, elongation is 12-26%, strength-ductility product is 6-12 GPa%, and impact energy is 5-18 J; at 300℃: hardness is 70-115 HV, tensile strength is 180-300 MPa, yield strength is 140-260 MPa, yield ratio is 0.75-0.90, elongation is 14-28%, strength-ductility product is 3.5-8.0 GPa%, and impact energy is 4-12 J.

[0023] Optionally, the heat treatment of S5 is solution treatment + aging treatment, which involves solution treatment at 450-550℃ for 1-5 hours, quenching medium of water at 10-70℃, followed by aging at 110-200℃ for 6-24 hours, and air cooling.

[0024] Optionally, the density of S5 high-fatigue-resistance, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy products is 2.7-2.9 g / cm³. 3 At room temperature: hardness 150-270 HV, tensile strength 550-720 MPa, yield strength 510-680 MPa, yield ratio 0.88-0.96, elongation 8-18%, strength-ductility product 5-13 GPa%, impact energy 8-22 J; stress ratio R=σ max / σ min =-1, cycle life N f =107 The fatigue strength is 240-300 MPa; at 300℃: hardness is 90-140 HV, tensile strength is 250-360 MPa, yield strength is 220-340 MPa, yield ratio is 0.85-0.95, elongation is 10-20%, strength-ductility product is 3-7 GPa%, and impact energy is 5-15 J.

[0025] Technical principle of the invention:

[0026] Polytetrafluoroethylene (PTFE), a material with a low coefficient of friction, high temperature resistance, and strong chemical stability, can react with an aluminum matrix under specific conditions to form an aluminum carbide (Al4C3) phase. This process not only significantly improves the strength of aluminum alloys but also enhances their fatigue resistance and toughness. Specifically, PTFE decomposes at high temperatures to generate carbon and fluorine. The fluorine breaks down the oxide film on the aluminum surface, generating the nano-phase AlF3, and promotes the reaction between the aluminum matrix and the carbon in PTFE to form aluminum carbide (Al4C3) particles, which are uniformly distributed in the aluminum alloy matrix. Combined with the nano-Al2O3 particles formed by the breakdown of the oxide film, they form a ternary dispersed strengthening phase, which can significantly improve the hardness and strength of aluminum alloys and, to a certain extent, enhance their fatigue resistance and high-temperature stability.

[0027] First, this invention adds 0.2-1wt% PTFE to a high-strength aluminum alloy matrix, and ensures that the lubricant is evenly distributed in the aluminum matrix by high-energy ball milling uniform powder mixing technology. Then, a fully dense powder metallurgy dispersion-strengthened aluminum alloy is prepared by using a billet preheating combined with hot extrusion deformation processing technology.

[0028] Secondly, the PTFE of this invention plays two roles in the preparation process: firstly, its low coefficient of friction is beneficial for the cold isostatic pressing of high-hardness aluminum alloy powder; secondly, during the sintering process, it undergoes an in-situ reaction with the aluminum alloy matrix, in which fluorine destroys the dense oxide film on the surface of the aluminum powder to generate nano-phase AlF3 and nano-Al2O3 particles formed by the breakup of the dense oxide film. The carbon element in PTFE reacts with the aluminum matrix to generate aluminum carbide (Al4C3) particles, obtaining a ternary nano-dispersed reinforcing phase of AlF3, Al4C3, and Al2O3, which is uniformly distributed in the aluminum alloy matrix. In addition, the fine grain size of the matrix achieves a good match between the composite material's fatigue resistance, high temperature resistance, and strong plasticity.

[0029] Furthermore, by controlling the preheating temperature of the cold isostatic pressing green blank, the hot deformation processing temperature, and the heat treatment temperature, this invention reduces the processing and forming difficulty of high deformation resistance dispersion-strengthened aluminum alloys, and achieves excellent precipitation strengthening effect through heat treatment regulation, thereby ensuring the comprehensive performance of the product.

[0030] The above technical solution has at least the following advantages compared with the existing technology:

[0031] The present invention proposes a method for preparing a high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy, which can solve the technical problems existing in the preparation of high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloys, such as the difficulty in removing the oxide film on the surface of aluminum powder, insufficient densification during sintering, easy degradation of microstructure and fatigue performance under high temperature conditions, high cost due to reliance on high rare earth content or complex processes, and difficulty in synergistically improving comprehensive performance.

[0032] The PTFE used in this invention has a lower density and price than aluminum powder, giving the prepared dispersion-strengthened aluminum alloy material the characteristics of "double low"—low density and low cost; the strong interfacial bonding between the ternary nano-dispersion strengthening phase generated by the in-situ reaction and the matrix, as well as the fine microstructure of the aluminum matrix grains, enable the composite material to obtain "three high" properties—high fatigue resistance, high strength and toughness, and high temperature resistance.

[0033] Compared with the stir casting method for preparing particle-reinforced aluminum matrix composites, the method of this invention can avoid the formation of defects such as porosity and looseness, and improve the phenomena of alloy composition segregation and uneven distribution of reinforcing phases. Compared with the hot pressing and hot isostatic pressing sintering methods for preparing dispersion-strengthened aluminum alloys, it can realize the efficient manufacturing of large-size dispersion-strengthened aluminum alloy material products and broaden the application range of products.

[0034] The powder metallurgy green preheating (non-sintering) combined with hot deformation processing to prepare dispersion-strengthened aluminum alloys has unique advantages. The absence of high-temperature sintering can improve the green preparation efficiency, significantly reduce the green preparation cost, and also reduce the difficulty of plastic processing. It has strong process adaptability, high manufacturing efficiency, and high material utilization rate, and can realize large-scale industrial production.

[0035] In summary, compared with traditional methods, the method of this invention obtains a high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy through aluminum alloy powder preparation, composite powder preparation, cold isostatic pressing, powder hot extrusion, and heat treatment. The prepared high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy exhibits excellent strength and toughness, and its comprehensive properties such as high-temperature resistance, wear resistance, and mechanical properties are synergistically improved. This method is simple to operate, low in cost, and highly efficient, which is conducive to large-scale industrial production and promotion. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a microstructure diagram of the high fatigue resistance, high strength, high toughness, and high temperature resistant dispersion-strengthened aluminum alloy of Embodiment 1 of the present invention;

[0038] Figure 2 This is a microstructure diagram of the high fatigue resistance, high strength, high toughness, and high temperature resistant dispersion-strengthened aluminum alloy of Embodiment 2 of the present invention;

[0039] Figure 3 This is a microstructure diagram of the high fatigue resistance, high strength, high toughness, and high temperature resistant dispersion-strengthened aluminum alloy of Embodiment 3 of the present invention. Detailed Implementation

[0040] The technical solution of the present invention will now be described with reference to the accompanying drawings.

[0041] In embodiments of the present invention, words such as "exemplarily," "for example," etc., are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one.

[0042] In the embodiments of the present invention, the terms "image" and "picture" may sometimes be used interchangeably. It should be noted that when the distinction is not emphasized, their intended meanings are consistent.

[0043] In this embodiment of the invention, sometimes a subscript such as W1 may be written in a non-subscript form such as W1. When the difference is not emphasized, the meaning they express is the same.

[0044] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0045] A method for preparing a high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy, comprising the following steps:

[0046] S1. Preparation of aluminum alloy powder: Weigh the raw materials according to the alloy element content of the aluminum alloy powder, and prepare aluminum alloy powder through atomization process.

[0047] S2. Preparation of composite powder: Polytetrafluoroethylene (PTFE) powder is ultrasonically mixed with one or more of water, alcohol, acetone, diethyl ether, and chloroform to form a suspension. A portion of the suspension is uniformly mixed with aluminum alloy powder from S1 and then subjected to high-energy ball milling to obtain composite powder.

[0048] S3. Cold isostatic pressing: The composite powder of S1 is loaded into a sleeve and vibrated to compact it, and then cold isostatic pressing is performed to obtain a composite powder green blank.

[0049] S4. Powder Hot Extrusion: The composite powder green blank of S2 is placed in a heating furnace for preheating. The atmosphere is one or more of air, nitrogen, and argon. After preheating, hot extrusion is performed directly to obtain extruded profiles.

[0050] S5. Heat treatment: The extruded profiles of S3 are heat treated according to different application requirements to finally obtain high fatigue resistance, high strength and toughness, and high temperature resistant dispersion-strengthened aluminum alloy products.

[0051] Specifically, the atomization process of S1 is one or more of the following: ultra-high pressure gas atomization, water atomization, and water-gas combined atomization process.

[0052] Specifically, the aluminum alloy powder of S1 is one or more of Al-Cu aluminum alloy powder, Al-Zn-Mg-Cu aluminum alloy powder, Al-Fe-Cr-Ti aluminum alloy powder, and Al-Fe-V-Si aluminum alloy powder, with an average particle size of 2-15 μm.

[0053] Specifically, the particle size D of the PTFE powder of S2 90 <1μm, suspension concentration is 10-60g / L; PTFE powder content in composite powder is 0.2-1wt%.

[0054] Specifically, in the ultrasonic process parameters of S2, the ultrasonic frequency is 20000-60000Hz, the time is 10-60min; the high-energy ball mill is one or more of planetary ball mills, stirred ball mills, and vibratory ball mills, the ball-to-material ratio is 5:1-20:1, the ball milling time is 20-50h, the ball milling speed is 100-300r / min, and the particle size of the composite powder is 5-50μm.

[0055] Specifically, the S3's sheath material is rubber, silicone, or polyurethane, with a pressing pressure of 500-600 MPa and a holding time of 60-180 seconds.

[0056] Specifically, the tap density of the S3 composite powder is 1.6-1.9 g / cm³. 3 .

[0057] Specifically, the preheating temperature of S4 is 450-550℃, and the holding time is 2-5h; the hot extrusion ratio is 60:1-200:1, and the extrusion speed is 0.2-10mm / s; the deformation of the extruded profile is 70-95%, and the shapes include bars, plates, and tubes.

[0058] Specifically, the density of S4 extruded profiles is 2.7-2.9 g / cm³. 3At room temperature: hardness is 110-180 HV, tensile strength is 380-560 MPa, yield strength is 260-460 MPa, yield ratio is 0.65-0.85, elongation is 12-26%, strength-ductility product is 6-12 GPa%, and impact energy is 5-18 J; at 300℃: hardness is 70-115 HV, tensile strength is 180-300 MPa, yield strength is 140-260 MPa, yield ratio is 0.75-0.90, elongation is 14-28%, strength-ductility product is 3.5-8.0 GPa%, and impact energy is 4-12 J.

[0059] Specifically, the heat treatment of S5 is solution treatment + aging treatment, which involves solution treatment at 450-550℃ for 1-5 hours, quenching medium of water at 10-70℃, followed by aging at 110-200℃ for 6-24 hours, and air cooling.

[0060] Specifically, the density of S5 high-fatigue-resistance, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy products is 2.7-2.9 g / cm³. 3 At room temperature: hardness 150-270 HV, tensile strength 550-720 MPa, yield strength 510-680 MPa, yield ratio 0.88-0.96, elongation 8-18%, strength-ductility product 5-13 GPa%, impact energy 8-22 J; stress ratio R=σ max / σ min =-1, cycle life N f =10 7 The fatigue strength is 240-300 MPa; at 300℃: hardness is 90-140 HV, tensile strength is 250-360 MPa, yield strength is 220-340 MPa, yield ratio is 0.85-0.95, elongation is 10-20%, strength-ductility product is 3-7 GPa%, and impact energy is 5-15 J.

[0061] Example 1

[0062] This embodiment describes a method for preparing a high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy. The method comprises the following steps:

[0063] S1, Aluminum alloy powder preparation: according to Al 96 The content of Cu4 aluminum alloy element was determined by preparing Al-Cu aluminum alloy powder using ultra-high pressure water atomization process with an atomization pressure of 90 MPa. The average particle size of the prepared Al-Cu aluminum alloy powder was 6 μm.

[0064] S2, Preparation of composite powder: D 90Irregular polytetrafluoroethylene (PTFE) powder with a particle size of 0.8 µm was ultrasonically mixed with alcohol to form a suspension. The ultrasonic frequency was 40,000 Hz, the time was 30 min, and the concentration of the suspension was 60 g / L. A portion of the suspension was uniformly mixed with Al-Cu aluminum alloy powder of S1 and then subjected to high-energy ball milling in a planetary ball mill. The ball-to-powder ratio was 10:1, the ball milling time was 20 h, and the ball milling speed was 180 r / min to obtain a composite powder. The content of PTFE powder in the composite powder was 1 wt.%; the particle size of the composite powder was 8 μm.

[0065] S3. Cold isostatic pressing: The composite powder of S1 is loaded into a rubber sleeve and compacted. The compacted density of the composite powder is 1.8 g / cm³. 3 The composite powder green body was obtained by cold isostatic pressing at a pressure of 500 MPa and a holding time of 180 s.

[0066] S4. Powder Hot Extrusion: The composite powder green of S2 is placed in a heating furnace for preheating in an air atmosphere at 450℃ for 2 hours. After preheating, hot extrusion is performed directly at an extrusion ratio of 60:1 and an extrusion speed of 10 mm / s to obtain an extruded profile. The deformation of the extruded profile is 83%, and the shape is a bar with a diameter of 15 mm and a length of 800 mm.

[0067] The density of the extruded profile is 2.8 g / cm³. 3 At room temperature: hardness is 135HV, tensile strength is 452MPa, yield strength is 342MPa, yield ratio is 0.76, elongation is 19.2%, strength-ductility product is 8.55GPa%, and impact energy is 15.6J; at 300℃: hardness is 92HV, tensile strength is 230MPa, yield strength is 185MPa, yield ratio is 0.8, elongation is 22%, strength-ductility product is 5.06GPa%, and impact energy is 9.4J.

[0068] S5. Heat treatment: The extruded profiles of S3 are heat treated according to different application requirements. The heat treatment is solution treatment + aging treatment, which is solution treatment at 520℃ for 1 hour, quenching medium is water at 40℃, followed by aging at 180℃ for 10 hours, and air cooling, finally obtaining a high fatigue resistance, high strength and toughness, high temperature resistance and dispersion strengthening aluminum alloy product.

[0069] The microstructure of the high fatigue resistance, high strength, high toughness, and high temperature resistant dispersion-strengthened aluminum alloy product prepared in this embodiment is as follows: Figure 1As shown, the material matrix exhibits a dense and uniform microstructure, with no obvious pores, unbonded defects, or coarse second phases observed. Fine, discontinuous banded second phase particles are distributed within the aluminum matrix, primarily in short rod-like and granular forms, exhibiting a weak orientation along the extrusion direction. The second phase size is mainly in the sub-micron to several micron scale, with uniform spacing. Simultaneously, fine reinforcing phases are dispersed within the matrix grains and near grain boundaries, without forming continuous grain boundary precipitation or obvious precipitation-free zones. This indicates that the alloy, after T6 heat treatment, forms a stable microstructure characterized by a fine-grained matrix and a synergistic distribution of fine dispersed phases, which is beneficial for achieving high strength, high toughness, excellent fatigue performance, and good high-temperature stability.

[0070] The high fatigue resistance, high strength, high toughness, and high temperature resistant dispersion-strengthened aluminum alloy product prepared in this embodiment has a density of 2.8 g / cm³. 3 At room temperature: hardness 184 HV, tensile strength 580 MPa, yield strength 515 MPa, yield ratio 0.89, elongation 13.5%, strength-ductility product 7.83 GPa%, impact energy 18.7 J; R=-1, N f =10 7 The fatigue strength is 240 MPa; at 300℃: hardness is 118, tensile strength is 262 MPa, yield strength is 213 MPa, yield ratio is 0.81, elongation is 15%, strength-ductility product is 3.93 GPa%, and impact energy is 12.6 J.

[0071] Example 2

[0072] This embodiment describes a method for preparing a high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy. The method comprises the following steps:

[0073] S1, Aluminum alloy powder preparation: according to Al 88 Fe5Cr5Ti2 aluminum alloy element content, Al prepared by ultra-high pressure water-air combined atomization process 88 Fe5Cr5Ti2 aluminum alloy powder, atomized at a pressure of 70 MPa, was used to prepare Al 88 The average particle size of Fe5Cr5Ti2 aluminum alloy powder is 12μm;

[0074] S2, Preparation of composite powder: D 90Irregular polytetrafluoroethylene (PTFE) powder with a particle size of 0.5 µm was ultrasonically mixed with alcohol to form a suspension. The ultrasonic frequency was 40,000 Hz, the time was 30 min, and the concentration of the suspension was 30 g / L. A portion of the suspension was uniformly mixed with Al-Cu aluminum alloy powder of S1 and then subjected to high-energy ball milling in a planetary ball mill. The ball-to-powder ratio was 9:1, the ball milling time was 50 h, and the ball milling speed was 200 r / min to obtain a composite powder. The content of PTFE powder in the composite powder was 0.6 wt.%, and the particle size of the composite powder was 15 μm.

[0075] S3. Cold isostatic pressing: The composite powder of S1 is loaded into a polyurethane sleeve and compacted. The compacted density of the composite powder is 1.8 g / cm³. 3 The composite powder green body was obtained by cold isostatic pressing at a pressure of 600 MPa and a holding time of 120 s.

[0076] S4. Powder Hot Extrusion: The composite powder green of S2 is placed in a heating furnace for preheating in a nitrogen atmosphere at 550℃ for 4 hours. After preheating, hot extrusion is performed directly at an extrusion ratio of 200:1 and an extrusion speed of 0.2 mm / s to obtain an extruded profile. The extruded profile has a deformation of 90%, is in the shape of a bar, has a diameter of 10 mm, and a length of 1200 mm.

[0077] The microstructure of the high fatigue resistance, high strength, high toughness, and high temperature resistant dispersion-strengthened aluminum alloy product prepared in this embodiment is as follows: Figure 2 As shown, the material has a dense and uniform overall structure, with a continuous and intact aluminum matrix. No obvious pores, unbonded defects, or continuous brittle phases were observed. A large number of fine second-phase particles are dispersed in the matrix, mainly in the form of near-equiaxed particles, with some local irregular shapes. The particle size is mainly in the submicron to about 1-2 μm range, and the particles are evenly distributed without obvious agglomeration.

[0078] The high fatigue resistance, high strength, high toughness, and high temperature resistant dispersion-strengthened aluminum alloy product prepared in this embodiment has a density of 2.76 g / cm³. 3 At room temperature: hardness 175HV, tensile strength 604MPa, yield strength 542MPa, yield ratio 0.9, elongation 11.0%, strength-ductility product 6.6GPa%, impact energy 14.6J; R=-1, N f =10 7 The fatigue strength is 260 MPa; at 300℃: hardness is 120 HV, tensile strength is 322 MPa, yield strength is 286 MPa, yield ratio is 0.89, elongation is 14.2%, strength-ductility product is 4.48 GPa%, and impact energy is 11.7 J.

[0079] Example 3

[0080] This embodiment describes a method for preparing a high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy. The method comprises the following steps:

[0081] S1, Aluminum alloy powder preparation: according to Al 89 Fe8V1Si2 aluminum alloy element content, Al prepared by ultra-high pressure gas atomization process 89 Fe8V1Si2 aluminum alloy powder was used as the atomizing medium, nitrogen gas, and the atomization pressure was 8 MPa to prepare Al 89 The average particle size of Fe8V1Si2 aluminum alloy powder is 15μm;

[0082] S2, Preparation of composite powder: D 90 Irregular polytetrafluoroethylene (PTFE) powder with a particle size of 0.2 µm was ultrasonically mixed with alcohol to form a suspension. The ultrasonic frequency was 40,000 Hz, the time was 30 min, and the concentration of the suspension was 10 g / L. A portion of the suspension was then mixed with Al from S1. 89 Fe8V1Si2 aluminum alloy powder was uniformly mixed and then subjected to high-energy ball milling in a planetary ball mill with a ball-to-powder ratio of 15:1, a milling time of 30 hours, and a milling speed of 180 r / min to obtain composite powder; the content of PTFE powder in the composite powder was 0.2 wt.%; the particle size of the composite powder was 18 μm.

[0083] S3. Cold isostatic pressing: The composite powder of S1 is loaded into a polyurethane sleeve and compacted. The compacted density of the composite powder is 1.7 g / cm³. 3 The composite powder green body was obtained by cold isostatic pressing at a pressure of 550 MPa and a holding time of 100 s.

[0084] S4. Powder Hot Extrusion: The composite powder green of S2 is placed in a heating furnace for preheating in a nitrogen atmosphere at 500℃ for 3 hours. After preheating, hot extrusion is performed directly at an extrusion ratio of 120:1 and an extrusion speed of 0.6 mm / s to obtain an extruded profile. The extruded profile has a deformation of 85%, is in the shape of a bar, has a diameter of 15 mm, and a length of 900 mm.

[0085] The microstructure of the high fatigue resistance, high strength, high toughness, and high temperature resistant dispersion-strengthened aluminum alloy product prepared in this embodiment is as follows: Figure 3 As shown, the material has a dense and uniform overall structure, with a continuous and intact aluminum matrix. No obvious unsintered pores or macroscopic defects were observed. A large number of fine second-phase particles are dispersed within the matrix, mainly in the form of fine granules and near-equiaxed particles, with some irregular short rod-shaped particles. The particle size is mainly in the submicron to about 1μm range, with a few slightly larger particles but no obvious agglomeration.

[0086] The high fatigue resistance, high strength, high toughness, and high temperature resistant dispersion-strengthened aluminum alloy product prepared in this embodiment has a density of 2.74 g / cm³. 3 At room temperature: hardness 162 HV, tensile strength 572 MPa, yield strength 511 MPa, yield ratio 0.89, elongation 12%, strength-ductility product 6.86 GPa%, impact energy 15.4 J; R=-1, N f =10 7 The fatigue strength is 245 MPa; at 300℃: hardness is 110 HV, tensile strength is 302 MPa, yield strength is 262 MPa, yield ratio is 0.87, elongation is 16.1%, strength-ductility product is 4.8 GPa%, and impact energy is 12.3 J.

[0087] Example 4

[0088] This embodiment describes a method for preparing a high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy. The method comprises the following steps:

[0089] S1, Aluminum alloy powder preparation: according to Al 90 Zn6Mg2Cu2 aluminum alloy element content, Al prepared by ultra-high pressure gas atomization process 90 Zn6Mg2Cu2 aluminum alloy powder was used as the atomizing medium, nitrogen gas, and the atomization pressure was 8 MPa to prepare Al. 90 The average particle size of Zn6Mg2Cu2 aluminum alloy powder is 13μm;

[0090] S2, Preparation of composite powder: D 90 Irregular polytetrafluoroethylene (PTFE) powder with a particle size of 0.5 µm was ultrasonically mixed with alcohol to form a suspension. The ultrasonic frequency was 50,000 Hz, the time was 40 min, and the concentration of the suspension was 20 g / L. A portion of the suspension was uniformly mixed with Al-Cu aluminum alloy powder of S1 and then subjected to high-energy ball milling in a planetary ball mill. The ball-to-powder ratio was 5:1, the ball milling time was 40 h, and the ball milling speed was 180 r / min to obtain a composite powder. The content of PTFE powder in the composite powder was 0.5 wt%, and the particle size of the composite powder was 16 μm.

[0091] S3. Cold isostatic pressing: The composite powder of S1 is loaded into a polyurethane sleeve and compacted. The compacted density of the composite powder is 1.8 g / cm³. 3 The composite powder green body was obtained by cold isostatic pressing at a pressure of 500 MPa and a holding time of 120 s.

[0092] S4. Powder Hot Extrusion: The composite powder green of S2 is placed in a heating furnace for preheating in a nitrogen atmosphere at 480℃ for 2 hours. After preheating, hot extrusion is performed directly at an extrusion ratio of 120:1 and an extrusion speed of 0.5 mm / s to obtain an extruded profile. The extruded profile has a deformation of 83%, is in the shape of a bar, has a diameter of 12 mm, and a length of 1000 mm.

[0093] The density of the extruded profile is 2.8 g / cm³. 3 At room temperature: hardness is 175 HV, tensile strength is 558 MPa, yield strength is 452 MPa, yield ratio is 0.81, elongation is 14.3%, strength-ductility product is 7.84 GPa%, and impact energy is 16.4 J; at 300℃: hardness is 104 HV, tensile strength is 264 MPa, yield strength is 215 MPa, yield ratio is 0.81, elongation is 18%, strength-ductility product is 4.75 GPa%, and impact energy is 9.1 J.

[0094] S5. Heat treatment: The extruded profiles of S3 are heat treated according to different application requirements. The heat treatment is solution treatment + aging treatment, which is solution treatment at 475℃ for 2 hours, quenching medium is water at 20℃, followed by aging at 120℃ for 24 hours, and air cooling, finally obtaining a high fatigue resistance, high strength and toughness high temperature resistant dispersion strengthened aluminum alloy product.

[0095] The high fatigue resistance, high strength, high toughness, and high temperature resistant dispersion-strengthened aluminum alloy product prepared in this embodiment has a density of 2.82 g / cm³. 3 At room temperature: hardness 205 HV, tensile strength 658 MPa, yield strength 602 MPa, yield ratio 0.92, elongation 10.3%, strength-ductility product 6.55 GPa%, impact energy 17.8 J; R=-1, N f =10 7 The fatigue strength is 265 MPa; at 300℃: hardness is 125 HV, tensile strength is 284 MPa, yield strength is 250 MPa, yield ratio is 0.88, elongation is 14%, strength-ductility product is 3.98 GPa%, and impact energy is 10.4 J.

[0096] Comparative Example 1

[0097] In S2 of this comparative example, the PTFE suspension was planetarily ball-milled with Al-Cu aluminum alloy powder. The PTFE content in the composite powder was 5 wt%. Other steps were the same as in Example 1.

[0098] Performance tests showed a tensile strength of 385 MPa, a yield strength of 288 MPa, and an elongation of 2.2%. This indicates that an excessively high PTFE content reduces the material's forming effect and sintering density, thus affecting its properties.

[0099] Comparative Example 2

[0100] In S4 of this comparative example, the obtained green billet was sintered and densified using hot pressing sintering technology at a sintering temperature of 550°C and a holding time of 2 hours to obtain a sintered billet of dispersion-strengthened aluminum alloy. Other steps were the same as in Example 2. Using the same extrusion pressure as in Example 2, this sintered billet could not be extruded; the tonnage of the extruder had to be increased to complete the process. This indicates that sintering densification increases the difficulty of hot extrusion forming.

[0101] Comparative Example 3

[0102] In this comparative example, S4, hot extrusion was performed with an extrusion ratio of 20:1 and an extrusion temperature of 500℃. The head and edges of the sample showed obvious cracking.

[0103] Performance tests showed a tensile strength of 480 MPa, a yield strength of 407 MPa, and an elongation of 7.3%. This indicates that the extrusion ratio was too low, resulting in incomplete densification of the material, weak interfacial bonding strength, microcracks within the material, and reduced strength and plasticity.

[0104] Comparative Example 4

[0105] In S2 of this comparative example, the PTFE suspension was vibratoryly ball-milled with Al-Zn-Mg-Cu aluminum alloy powder, and the PTFE powder particle size D 90 The value is 3µm, and the other steps are the same as in Example 4.

[0106] Performance tests showed that the room temperature tensile strength was 465 MPa, the yield strength was 389 MPa, and the elongation was 5.2%; at 300℃, the tensile strength was 126 MPa, the yield strength was 90 MPa, and the elongation was 12%. This indicates that the coarser particle size of the PTFE powder increases the size of the AlF3 and Al4C3 dispersed reinforcing phases generated in situ, reduces the number density of the dispersed reinforcing phases, significantly weakens the dispersion strengthening effect, and affects the material's room temperature and high temperature performance.

[0107] Example 5

[0108] This embodiment describes a method for preparing a high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy. The method comprises the following steps:

[0109] S1. Preparation of aluminum alloy powder: According to the element content of 7055 aluminum alloy, 7055 aluminum alloy powder was prepared by ultra-high pressure gas atomization process. The atomization medium was nitrogen gas, the atomization pressure was 7MPa, and the average particle size of the prepared 7055 aluminum alloy powder was 20μm.

[0110] S2, Preparation of composite powder: D 90Irregular polytetrafluoroethylene (PTFE) powder with a particle size of 0.3 µm was ultrasonically mixed with alcohol to form a suspension. The ultrasonic frequency was 50,000 Hz, the time was 50 min, and the concentration of the suspension was 15 g / L. A portion of the suspension was uniformly mixed with Al-Cu aluminum alloy powder of S1 and then subjected to high-energy ball milling in a planetary ball mill. The ball-to-powder ratio was 12:1, the ball milling time was 25 h, and the ball milling speed was 260 r / min to obtain a composite powder. The content of PTFE powder in the composite powder was 0.4 wt%, and the particle size of the composite powder was 22 μm.

[0111] S3. Cold isostatic pressing: The composite powder of S1 is loaded into a polyurethane sleeve and compacted. The compacted density of the composite powder is 1.8 g / cm³. 3 The composite powder green body was obtained by cold isostatic pressing at a pressure of 580 MPa and a holding time of 120 s.

[0112] S4. Powder Hot Extrusion: The composite powder green of S2 is placed in a heating furnace for preheating in a nitrogen atmosphere at 400℃ for 2 hours. After preheating, hot extrusion is performed directly at an extrusion ratio of 160:1 and an extrusion speed of 0.8 mm / s to obtain an extruded profile. The extruded profile has a deformation of 88%, is in the shape of a bar, has a diameter of 12 mm, and a length of 1000 mm.

[0113] The density of the extruded profile is 2.8 g / cm³. 3 At room temperature: hardness is 178 HV, tensile strength is 585 MPa, yield strength is 458 MPa, yield ratio is 0.82, elongation is 13.6%, strength-ductility product is 7.61 GPa%, and impact energy is 16.8 J; at 300℃: hardness is 110 HV, tensile strength is 295 MPa, yield strength is 250 MPa, yield ratio is 0.85, elongation is 18%, strength-ductility product is 5.31 GPa%, and impact energy is 9.2 J.

[0114] S5. Heat treatment: The extruded profiles of S3 are heat treated according to different application requirements. The heat treatment is solution treatment + aging treatment, which is solution treatment at 485℃ for 2 hours, quenching medium is water at 20℃, followed by aging at 120℃ for 24 hours, and air cooling, finally obtaining high fatigue resistance, high strength and toughness, high temperature resistant dispersion strengthened aluminum alloy products.

[0115] The high fatigue resistance, high strength, high toughness, and high temperature resistant dispersion-strengthened aluminum alloy product prepared in this embodiment has a density of 2.81 g / cm³. 3 At room temperature: hardness 225 HV, tensile strength 705 MPa, yield strength 655 MPa, yield ratio 0.93, elongation 9.5%, strength-ductility product 6.7 GPa%, impact energy 16.4 J; R=-1, N f =107 The fatigue strength is 295 MPa; at 300℃: hardness is 135 HV, tensile strength is 322 MPa, yield strength is 270 MPa, yield ratio is 0.84, elongation is 12.5%, strength-ductility product is 4.02 GPa%, and impact energy is 11.2 J.

[0116] Example 6

[0117] This embodiment describes a method for preparing a high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy. The method comprises the following steps:

[0118] S1. Preparation of aluminum alloy powder: According to the element content of 2324 aluminum alloy, 2324 aluminum alloy powder was prepared by ultra-high pressure gas atomization process. The atomization medium was nitrogen gas, the atomization pressure was 6MPa, and the average particle size of the prepared 2324 aluminum alloy powder was 18μm.

[0119] S2, Preparation of composite powder: D 90 Irregular polytetrafluoroethylene (PTFE) powder with a particle size of 0.4 µm was ultrasonically mixed with alcohol to form a suspension. The ultrasonic frequency was 45000 Hz, the time was 35 min, and the concentration of the suspension was 18 g / L. A portion of the suspension was uniformly mixed with S1 2324 aluminum alloy powder and then subjected to high-energy ball milling in a planetary ball mill. The ball-to-powder ratio was 10:1, the ball milling time was 30 h, and the ball milling speed was 210 r / min to obtain a composite powder. The content of PTFE powder in the composite powder was 0.4 wt%, and the particle size of the composite powder was 20 μm.

[0120] S3. Cold isostatic pressing: The composite powder of S1 is loaded into a polyurethane sleeve and compacted. The compacted density of the composite powder is 1.8 g / cm³. 3 The composite powder green body was obtained by cold isostatic pressing at a pressure of 560 MPa and a holding time of 120 s.

[0121] S4. Powder Hot Extrusion: The composite powder green of S2 is placed in a heating furnace for preheating in a nitrogen atmosphere at 420℃ for 1 hour. After preheating, hot extrusion is performed directly at an extrusion ratio of 140:1 and an extrusion speed of 0.7 mm / s to obtain an extruded profile. The extruded profile has a deformation of 87%, is in the shape of a bar, has a diameter of 15 mm, and a length of 980 mm.

[0122] The density of the extruded profile is 2.78 g / cm³. 3At room temperature: hardness is 132 HV, tensile strength is 482 MPa, yield strength is 402 MPa, yield ratio is 0.83, elongation is 21.8%, strength-ductility product is 10.51 GPa%, and impact energy is 17.6 J; at 300℃: hardness is 81 HV, tensile strength is 218 MPa, yield strength is 186 MPa, yield ratio is 0.85, elongation is 25.6%, strength-ductility product is 5.58 GPa%, and impact energy is 8.4 J.

[0123] S5. Heat treatment: The extruded profiles of S3 are heat treated according to different application requirements. The heat treatment is solution treatment + cold deformation + aging treatment. The solution treatment is at 495℃ for 1.2h, the quenching medium is water at 25℃, pre-stretching (deformation amount 3.5%), followed by aging at 160℃ for 18h, and air cooling. Finally, a high fatigue resistance, high strength and toughness, high temperature resistance and dispersion strengthening aluminum alloy product is obtained.

[0124] The high fatigue resistance, high strength, high toughness, and high temperature resistant dispersion-strengthened aluminum alloy product prepared in this embodiment has a density of 2.79 g / cm³. 3 At room temperature: hardness 196 HV, tensile strength 628 MPa, yield strength 586 MPa, yield ratio 0.93, elongation 11.6%, strength-ductility product 7.29 GPa%, impact energy 21.6 J; R=-1, N f =10 7 The fatigue strength is 240 MPa; at 300℃: hardness is 128 HV, tensile strength is 284 MPa, yield strength is 246 MPa, yield ratio is 0.87, elongation is 15.4%, strength-ductility product is 5.14 GPa%, and impact energy is 12.1 J.

[0125] The present invention proposes a method for preparing a high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy. This method addresses existing techniques for preparing such alloys, which often result in a dense and uniform overall microstructure, a continuous and intact aluminum matrix without obvious unsintered pores or macroscopic defects, and a dispersed distribution of numerous fine second-phase particles within the matrix. These particles are predominantly fine granular and near-equiaxed, with some irregular short rod-shaped particles. The particle size is mainly in the submicron to approximately 1 μm range, with a few slightly larger particles that do not exhibit significant agglomeration.

[0126] The PTFE used in this invention has a lower density and price than aluminum powder, giving the prepared dispersion-strengthened aluminum alloy material the characteristics of "double low"—low density and low cost; the strong interfacial bonding between the ternary nano-dispersion strengthening phase generated by the in-situ reaction and the matrix, as well as the fine microstructure of the aluminum matrix grains, enable the composite material to obtain "three high" properties—high fatigue resistance, high strength and toughness, and high temperature resistance.

[0127] Compared with the stir casting method for preparing particle-reinforced aluminum matrix composites, the method of this invention can avoid the formation of defects such as porosity and looseness, and improve the phenomena of alloy composition segregation and uneven distribution of reinforcing phases. Compared with the hot pressing and hot isostatic pressing sintering methods for preparing dispersion-strengthened aluminum alloys, it can realize the efficient manufacturing of large-size dispersion-strengthened aluminum alloy material products and broaden the application range of products.

[0128] The powder metallurgy green preheating (non-sintering) combined with hot deformation processing to prepare dispersion-strengthened aluminum alloys has unique advantages. The absence of high-temperature sintering can improve the green preparation efficiency, significantly reduce the green preparation cost, and also reduce the difficulty of plastic processing. It has strong process adaptability, high manufacturing efficiency, and high material utilization rate, and can realize large-scale industrial production.

[0129] In summary, compared with traditional methods, the method of this invention obtains a high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy through aluminum alloy powder preparation, composite powder preparation, cold isostatic pressing, powder hot extrusion, and heat treatment. The prepared high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy exhibits excellent strength and toughness, and its comprehensive properties such as high-temperature resistance, wear resistance, and mechanical properties are synergistically improved. This method is simple to operate, low in cost, and highly efficient, which is conducive to large-scale industrial production and promotion.

[0130] It should be understood that the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. Additionally, the character " / " in this article generally indicates an "or" relationship between the preceding and following related objects, but it can also represent an "and / or" relationship. Please refer to the context for a more accurate understanding.

[0131] In this invention, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of a single item or a plurality of items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be a single item or multiple items.

[0132] It should be understood that, in various embodiments of the present invention, the order of the above-mentioned process numbers does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0133] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing a high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy, characterized in that, The preparation method of the high fatigue resistance, high strength, high toughness, and high temperature resistant dispersion-strengthened aluminum alloy is as follows: S1. Preparation of aluminum alloy powder: Weigh the raw materials according to the alloy element content of the aluminum alloy powder, and prepare aluminum alloy powder through atomization process. S2. Preparation of composite powder: Polytetrafluoroethylene (PTFE) powder is ultrasonically mixed with one or more of water, alcohol, acetone, diethyl ether, and chloroform to form a suspension. A portion of the suspension is uniformly mixed with aluminum alloy powder from S1 and then subjected to high-energy ball milling to obtain composite powder. S3. Cold isostatic pressing: The composite powder of S1 is loaded into a sleeve and vibrated to compact it, and then cold isostatic pressing is performed to obtain a composite powder green blank. S4. Powder Hot Extrusion: The composite powder green blank of S2 is placed in a heating furnace for preheating. The atmosphere is one or more of air, nitrogen, and argon. After preheating, hot extrusion is performed directly to obtain extruded profiles. S5. Heat treatment: The extruded profiles of S3 are heat treated according to different application requirements to finally obtain high fatigue resistance, high strength and toughness, and high temperature resistant dispersion-strengthened aluminum alloy products.

2. The method for preparing a high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy according to claim 1, characterized in that, The atomization process of S1 is one or more of the following: ultra-high pressure gas atomization, water atomization, and water-gas combined atomization process.

3. The method for preparing a high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy according to claim 1, characterized in that, The aluminum alloy powder of S1 is one or more of Al-Cu aluminum alloy powder, Al-Zn-Mg-Cu aluminum alloy powder, Al-Fe-Cr-Ti aluminum alloy powder, and Al-Fe-V-Si aluminum alloy powder, with an average particle size of 2-15μm.

4. The method for preparing a high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy according to claim 1, characterized in that, The particle size D of S2 PTFE powder 90 <1μm, suspension concentration is 10-60g / L; PTFE powder content in composite powder is 0.2-1wt.%.

5. The method for preparing a high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy according to claim 1, characterized in that, In the ultrasonic process parameters of S2, the ultrasonic frequency is 20000-60000Hz, the time is 10-60min; the high-energy ball mill is one or more of planetary ball mills, stirred ball mills, and vibratory ball mills, the ball-to-material ratio is 5:1-20:1, the ball milling time is 20-50h, the ball milling speed is 100-300r / min, and the particle size of the composite powder is 5-50μm.

6. The method for preparing a high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy according to claim 1, characterized in that, The S3 sheath is made of rubber, silicone, or polyurethane, with a pressing pressure of 500-600MPa and a holding time of 60-180s.

7. The method for preparing a high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy according to claim 1, characterized in that, The tap density of the S3 composite powder is 1.6-1.9 g / cm³. 3 .

8. The method for preparing a high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy according to claim 1, characterized in that, The preheating temperature of S4 is 450-550℃, and the holding time is 2-5h; the hot extrusion ratio is 60:1-200:1, and the extrusion speed is 0.2-10mm / s; the deformation of the extruded profile is 70-95%, and the shapes include bars, plates, and tubes.

9. The method for preparing a high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy according to claim 1, characterized in that, The heat treatment of S5 is solution treatment + aging treatment, which involves solution treatment at 450-550℃ for 1-5 hours, quenching medium of water at 10-70℃, followed by aging at 110-200℃ for 6-24 hours, and air cooling.

10. The method for preparing a high-fatigue-resistant, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy according to claim 1, characterized in that, The density of S5 high-fatigue-resistance, high-strength, high-toughness, and high-temperature-resistant dispersion-strengthened aluminum alloy products is 2.7-2.9 g / cm³. 3 At room temperature: hardness 150-270 HV, tensile strength 550-720 MPa, yield strength 510-680 MPa, yield ratio 0.88-0.96, elongation 8-18%, strength-ductility product 5-13 GPa%, impact energy 8-22 J; stress ratio R=σ max / σ min =-1, cycle life N f =10 7 The fatigue strength is 240-300 MPa; at 300℃: hardness is 90-140 HV, tensile strength is 250-360 MPa, yield strength is 220-340 MPa, yield ratio is 0.85-0.95, elongation is 10-20%, strength-ductility product is 3-7 GPa%, and impact energy is 5-15 J.

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