High-toughness wear-resistant iron-based composite additive adaptive to high and low temperature cycle working conditions and preparation method of aluminum alloy of high-toughness wear-resistant iron-based composite additive

Abstract

The invention relates to the technical field of aluminum alloy material modification, and discloses a high-toughness wear-resistant iron-based composite additive adaptive to high and low temperature cycle working conditions and a preparation method of an aluminum alloy of the high-toughness wear-resistant iron-based composite additive. Comprising 20-30 parts of modified nano iron powder, 10-15 parts of iron-nickel alloy powder, 5-9 parts of titanium carbide nanoparticles, 3-7 parts of rare earth oxide La2O3, 25-40 parts of aluminum-manganese alloy powder, 2-6 parts of a dispersion regulating agent and 1-4 parts of an anti-corrosion additive, and the modified nano iron powder is obtained by modifying a silane coupling agent. The problem that an iron additive in the prior art is difficult to consider high toughness, high and low temperature stability, uniform wear resistance and corrosion resistance at the same time is solved.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy material modification technology, specifically to a high-toughness and wear-resistant iron-based composite additive adapted to high and low temperature cycling conditions and its aluminum alloy preparation method. Background Technology

[0002] Iron, as a low-cost and effective element for modifying aluminum alloys, can strengthen them by forming intermetallic compounds such as Al3Fe and Al6Fe, thereby improving the hardness and wear resistance of aluminum alloys. It is widely used in the production of general-purpose aluminum alloy components. However, the application of existing iron additives in aluminum alloys has significant technical limitations, as follows: 1. Imbalance between toughness and strength: Existing iron additives are mostly elemental iron powder or simple iron alloy powder, which easily form coarse needle-like Al3Fe phases in aluminum alloys, causing the impact toughness of aluminum alloys to drop to 15 J / cm. 2 The following components are prone to brittle fracture and cannot be adapted to high-load scenarios; 2. Severe performance degradation at high and low temperatures: Currently, most iron-modified aluminum alloy additives in existing technologies are difficult to adapt to extreme temperature conditions. They are prone to cold brittleness at -50℃ (impact toughness reduction ≥40%), and the strengthening phase is prone to softening at 400℃ (hardness reduction ≥35%), which cannot meet the requirements for high and low temperature cycling. 3. Poor dispersibility and uneven performance: The density of iron powder differs greatly from that of aluminum alloy melt. Existing technologies have not solved the problem of sedimentation and agglomeration (the sedimentation rate of elemental iron powder is ≥30%), resulting in uneven distribution of iron elements and local differences in wear resistance of more than 50%. 4. Lack of corrosion resistance.

[0003] Therefore, there is an urgent need to develop an iron-based composite additive that is significantly different from existing technologies, adaptable to extreme working conditions, and possesses high toughness, high and low temperature stability, uniform wear resistance, and corrosion resistance, to fill the technological gap in the modification of high-end aluminum alloys. Summary of the Invention

[0004] The present invention aims to provide a high-toughness and wear-resistant iron-based composite additive adapted to high and low temperature cyclic operating conditions and its aluminum alloy preparation method, so as to solve the problem that iron additives in the prior art are difficult to achieve high toughness, high and low temperature stability, uniform wear resistance and corrosion resistance.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a high-toughness and wear-resistant iron-based composite additive suitable for high and low temperature cyclic working conditions, wherein the raw materials, by mass, include 20-30 parts of modified nano iron powder, 10-15 parts of iron-nickel alloy powder, 5-9 parts of titanium carbide nanoparticles, 3-7 parts of rare earth oxide La2O3, 25-40 parts of aluminum-manganese alloy powder, 2-6 parts of dispersant regulator, and 1-4 parts of anti-corrosion additive, wherein the modified nano iron powder is obtained by modification with a silane coupling agent.

[0006] Preferably, as an improvement, the modified nano-iron powder has a particle size of 40-100 nm and a purity of ≥99.7%.

[0007] Preferably, as an improvement, the iron-nickel alloy powder has a particle size of 100-200 nm and a nickel content of 35-37 wt%.

[0008] Preferably, as an improvement, the titanium carbide nanoparticles have a particle size of 30-80 nm and a hardness ≥2800 HV.

[0009] Preferably, as an improvement, the rare earth oxide La2O3 has a particle size of 80-150 nm and a purity of ≥99.5%.

[0010] Preferably, as an improvement, the dispersion regulator is composed of zinc stearate and polyethylene glycol 600 in a mass ratio of 2.5 to 4:1, and the anti-corrosion additive is zinc dihydrogen phosphate micro powder.

[0011] Preferably, as an improvement, a method for preparing a high-toughness, wear-resistant iron-based composite additive adapted to high and low temperature cycling conditions includes the following steps: Step 1: Iron powder modification treatment: Add nano iron powder to anhydrous ethanol solution, stir and disperse, then add silane coupling agent KH550, stir at 65-75℃ for 2-3 hours, and then vacuum dry to obtain modified nano iron powder. Step 2: Premixing of composite components: Weigh out iron-nickel alloy powder, titanium carbide, rare earth oxides, and anti-corrosion additives according to the formula and mix them to obtain the premixed components; Step 3, Melt Coating Modification: Heat and melt aluminum-manganese alloy powder, add modified nano-iron powder and premixed components, stir and mix to obtain aluminum-manganese alloy coated composite powder; Step 4: Shaping and sieving: Cool the coated powder to room temperature, crush, sieve and dry to obtain a high-toughness and wear-resistant iron-based composite additive.

[0012] Preferably, as an improvement, in step one, the amount of silane coupling agent added is 3-5% of the mass of iron powder.

[0013] Preferably, as an improvement, a method for applying a high-toughness and wear-resistant iron-based composite additive adapted to high and low temperature cyclic conditions in aluminum alloys is provided, wherein the amount of iron-based composite additive added is 2.0-4.0% of the mass of the aluminum alloy melt.

[0014] The principle and advantages of this solution are as follows: In practical applications, existing technologies for iron-based modified aluminum alloys have always faced the bottleneck of "a trade-off between toughness and strength." Addressing the technical problems of existing iron-based aluminum alloy additives, this solution overcomes the limitations of single iron powder and single modifiers by creatively employing a quaternary synergistic system of "Fe-FeNi alloy powder-TiC-La2O3." The construction of this quaternary system is not a simple superposition of components, but rather based on three core requirements for iron-based modification of aluminum alloys: phase structure regulation, microstructure refinement, and complementary performance. It targets the pain points of traditional elemental iron powder / simple iron alloy powder modification, such as "coarse needle-like phases leading to poor toughness, unstable phase structure at high and low temperatures, imbalance between wear resistance and toughness, and lack of corrosion resistance," through targeted component selection and functional coupling. Each component performs its specific function within the system, working synergistically to form an integrated functional system of "strengthening-regulation-stabilization-protection." Modified nano-iron powder, used as the basic iron source in the system, was obtained by modification with silane coupling agent KH550. On the one hand, the density difference between the iron powder and the aluminum alloy melt was reduced by grafting amino groups on the surface, solving the problem of iron powder sedimentation and agglomeration. On the other hand, the nano-sized particle size can refine the initial strengthening phase. At the same time, the coating effect of the silane coupling agent inhibited the coarsening and needle-like formation of the Al3Fe phase during cooling, avoiding the problem of a sharp drop in toughness caused by the formation of coarse needle-like Al3Fe phase by traditional iron powder from the source. This lays a uniform strengthening phase foundation for subsequent multi-component synergy. 36 Iron-nickel alloy powder serves as the core for temperature performance regulation. Its key role is to form a Fe-Ni composite strengthening phase with iron powder. Utilizing the face-centered cubic crystal structure of Ni, it forms a multi-element solid solution with Al and Fe, enhancing the lattice stability of the strengthening phase. At low temperatures, the Fe-Ni composite phase can suppress the cold brittleness tendency of the aluminum alloy matrix, reduce dislocation pile-up and crack initiation, and solve the problem of traditional iron-modified aluminum alloys experiencing a ≥40% reduction in impact toughness at -50℃. At high temperatures, the thermal stability of the Fe-Ni composite phase is far superior to that of the single Al3Fe phase, preventing the softening and dissolution of the strengthening phase at 400℃ and ensuring the retention of high-temperature hardness and wear resistance. Simultaneously, FeNi… 36The nanoparticles form a gradient particle size distribution with the modified iron powder, further improving the dispersion uniformity of the reinforcing phase in the matrix. In addition, the system introduces high-hardness TiC nanoparticles (30-80nm, hardness ≥2800HV) to form a dual wear-resistant system with the iron-based metal reinforcing phase, which overcomes the limitation of traditional iron-based modification that relies solely on intermetallic compounds to improve wear resistance. High-purity La2O3 nanoparticles (80-150nm, purity ≥99.5%) were selected as the key regulating component of the system. They can refine the grains of the aluminum alloy matrix and the iron-based reinforcing phase. Through the grain boundary segregation effect of rare earth elements, the growth of grains and reinforcing phases is inhibited, thereby improving impact toughness and plasticity. The morphology of the reinforcing phase is optimized, promoting the transformation of the Al3Fe phase from needle-like to short rod-like / quasi-circular, eliminating stress concentration sources and further improving toughness. It forms stable rare earth compounds with impurity elements (such as Fe and Si) in the aluminum alloy, reducing grain boundary impurity segregation, increasing grain boundary density, and simultaneously improving the corrosion resistance of the aluminum alloy, laying the structural foundation for the subsequent role of anti-corrosion additives.

[0015] In terms of optimizing the preparation process, silane coupling modification lays a uniform powder foundation for melt coating, and melt coating lays a density-matched composite powder foundation for ultrasonic dispersion. The synergistic dispersion process of mechanical stirring and ultrasonic dispersion allows the dispersant in the formula to play a full role, ensuring the uniform distribution of composite powder in the melt. The gradient cooling and two-stage aging process regulates the phase structure characteristics of the quaternary system, promotes the uniform precipitation of Fe-Ni composite phase and TiC phase, refines grains, improves microstructure stability, and fully transforms the component advantages of the formula into the performance advantages of aluminum alloy.

[0016] The beneficial effects of this technical solution are as follows: 1. Solving the pain point of toughness-strength imbalance: By refining the strengthening phase with rare earth oxides and regulating the phase structure with iron-nickel alloy, the impact toughness of aluminum alloy is significantly improved, while the room temperature hardness is ≥140HB, achieving a synergistic effect of "high toughness and high hardness".

[0017] 2. Breakthrough in high and low temperature performance bottlenecks: Impact toughness at -50℃ ≥22J / cm 2 (Reduction ≤21%), high temperature hardness ≥115HB at 400℃ (retention rate ≥82%), which is a significant improvement compared to existing technologies (low temperature reduction ≥40%, high temperature retention rate ≤65%), solving the problem of limitations in extreme temperature applications.

[0018] 3. Achieve synergistic performance across multiple areas: Simultaneously improve dispersion (iron element distribution variation coefficient ≤ 0.12), wear resistance (wear amount ≤ 0.025g / 1000r), and corrosion resistance (48h salt spray corrosion area ≤ 4%), with corrosion resistance not only not decreasing but actually increasing.

[0019] 4. Wide range of applications: It is compatible with a variety of commonly used aluminum alloys such as 6061 and 7075, and can be used to manufacture wear-resistant components for rail transit, high-end equipment components for high and low temperature cyclic operation, etc., with broad market application prospects. Detailed Implementation

[0020] The following detailed description provides further details on specific embodiments, but the embodiments of the present invention are not limited thereto. Unless otherwise specified, the technical means used in the following embodiments are conventional means well known to those skilled in the art; the experimental methods used are all conventional methods; and the materials and reagents used are all commercially available.

[0021] Overview of the plan: A high-toughness and wear-resistant iron-based composite additive suitable for high and low temperature cycling conditions, the raw materials, by weight, include 20-30 parts modified nano iron powder, 10-15 parts iron-nickel alloy powder, 5-9 parts titanium carbide (TiC) nanoparticles, 3-7 parts rare earth oxide (La2O3), 25-40 parts aluminum-manganese alloy powder, 2-6 parts dispersant, and 1-4 parts corrosion inhibitor.

[0022] Among them, the modified nano iron powder has a particle size of 40-100nm and a purity of ≥99.7%. It is modified by silane coupling agent KH550, and amino groups are grafted onto the surface to reduce the density difference, improve the compatibility with aluminum alloy melt, and inhibit the formation of coarse needle-like Al3Fe phase. Iron-nickel alloy powder: Particle size 100-200nm, nickel content 35-37wt%, can form a "Fe-Ni" composite strengthening phase with iron, improve the structural stability at high and low temperatures, and avoid cold brittleness and hot softening; Titanium carbide nanoparticles: particle size 30-80nm, hardness ≥2800HV, forming a "metal phase-ceramic phase" dual wear-resistant system with iron-based reinforcing phase, improving wear resistance while taking into account toughness; Rare earth oxide La2O3: with a particle size of 80-150nm and a purity of ≥99.5%, it can refine the grains and strengthening phases of aluminum alloys, improve impact toughness, and simultaneously improve corrosion resistance. Dispersant: Zinc stearate and polyethylene glycol 600 are compounded at a mass ratio of 2.5~4:1 to reduce the surface tension of iron powder and prevent sedimentation and agglomeration; Corrosion resistant additive: Zinc dihydrogen phosphate micro powder, with a particle size of 200-300nm, can form a passivation film on the surface of aluminum alloys, improving their resistance to salt spray corrosion.

[0023] A method for preparing a high-toughness, wear-resistant iron-based composite additive suitable for high and low temperature cycling conditions includes the following steps: Step 1: Iron powder modification treatment: Add nano iron powder to anhydrous ethanol solution, stir and disperse, then add silane coupling agent KH550 (the amount added is 3-5% of the mass of iron powder), stir at a constant temperature of 65-75℃ for 2-3 hours, and vacuum dry at 130-150℃ (vacuum degree ≤ -0.09MPa) to obtain modified nano iron powder. Step 2: Premixing of composite components: Weigh out iron-nickel alloy powder, titanium carbide, rare earth oxides, and anti-corrosion additives according to the formula, add them to a high-speed mixer, stir at room temperature and speed of 600-800 r / min for 40-60 min to obtain the premixed components; Step 3, melt coating modification: Heat aluminum-manganese alloy powder to 680-730℃ to melt, add modified nano iron powder and premixed components, stir at 350-450 r / min, keep warm and stir for 1.5-2.5 h to obtain aluminum-manganese alloy coated composite powder; Step 4: Shaping and sieving: Cool the coated powder to room temperature, pulverize it and pass it through a 120-150 mesh sieve. Then, vacuum dry it at 190-210℃ for 2-3 hours to obtain a high-toughness and wear-resistant iron-based composite additive.

[0024] A method for applying a high-toughness, wear-resistant iron-based composite additive suitable for high and low temperature cycling conditions in aluminum alloys includes the following steps: S1. Aluminum alloy smelting: Add 6061 aluminum alloy ingots to a medium frequency induction furnace and heat to 730-770℃ to melt. Then, introduce argon gas (flow rate 10-15L / min) to remove impurities and gases from the melt for 30 minutes. S2. Additive addition: Add the iron-based composite additive to the melt at 2.0-4.0% of the mass of the aluminum alloy melt. First, mechanically stir at a speed of 250-300 r / min for 30-40 min. Then, ultrasonically disperse the mixture at a power of 800-1000 W and a frequency of 20 kHz for 30-40 min. S3. Casting: Let the well-mixed melt stand for 15-20 minutes, then pour it into a mold preheated to 220-260℃. Use gradient cooling (cooling rate of 5℃ / min from 700℃ to 300℃, and natural cooling below 300℃) to relieve thermal stress. S4. Post-treatment optimization: The cast components are subjected to two-stage aging treatment (aging at 120℃ for 3 hours and at 160℃ for 5 hours) to further improve mechanical properties and microstructure stability.

[0025] Example 1 A high-toughness and wear-resistant iron-based composite additive suitable for high and low temperature cycling conditions, the raw materials, by weight, include 25 parts modified nano iron powder, 12 parts iron-nickel alloy powder, 7 parts titanium carbide (TiC) nanoparticles, 5 parts rare earth oxide (La2O3), 30 parts aluminum-manganese alloy powder, 5 parts dispersant, and 2 parts anti-corrosion additive.

[0026] The dispersant is composed of zinc stearate and polyethylene glycol 600 in a mass ratio of 4:1.

[0027] A method for preparing a high-toughness, wear-resistant iron-based composite additive suitable for high and low temperature cycling conditions includes the following steps: Step 1: Iron powder modification treatment: Add nano iron powder to anhydrous ethanol solution, stir and disperse, then add silane coupling agent KH550 (the amount added is 4% of the mass of iron powder), stir at 70℃ for 2.5h, and vacuum dry at 140℃ (vacuum degree ≤ -0.09MPa) to obtain modified nano iron powder. Step 2: Premixing of composite components: Weigh out iron-nickel alloy powder, titanium carbide, rare earth oxides, and anti-corrosion additives according to the formula, add them to a high-speed mixer, stir for 50 minutes at room temperature and 700 r / min to obtain the premixed components; Step 3, melt coating modification: Heat aluminum-manganese alloy powder to 700℃ to melt, add modified nano iron powder and premixed components, stir at 400 r / min, keep warm and stir for 2 h to obtain aluminum-manganese alloy coated composite powder; Step 4: Shaping and sieving: Cool the coated powder to room temperature, pulverize it, pass it through a 150-mesh sieve, and vacuum dry it at 200℃ for 2.5 hours to obtain a high-toughness and wear-resistant iron-based composite additive.

[0028] A method for applying a high-toughness, wear-resistant iron-based composite additive suitable for high and low temperature cycling conditions in aluminum alloys includes the following steps: S1. Aluminum alloy smelting: Add 6061 aluminum alloy ingots to a medium frequency induction furnace, heat to 750℃ to melt, and introduce argon gas (flow rate 12L / min) for 30 minutes to remove impurities and gases from the melt; S2. Additive addition: Add the iron-based composite additive to the aluminum alloy melt at 3.0% of the melt mass, and first perform mechanical stirring at a speed of 300 r / min for 35 min; then perform ultrasonic dispersion at a power of 900 W and a frequency of 20 kHz for 35 min. S3. Casting: Let the well-mixed melt stand for 20 minutes, then pour it into a mold preheated to 250°C. Use gradient cooling (cooling rate of 5°C / min from 700°C to 300°C, and natural cooling below 300°C) to relieve thermal stress. S4. Post-treatment optimization: The cast components are subjected to two-stage aging treatment (aging at 120℃ for 3 hours and at 160℃ for 5 hours) to further improve mechanical properties and microstructure stability.

[0029] Example 2 The difference between this embodiment and Embodiment 1 is that in this embodiment, a high-toughness and wear-resistant iron-based composite additive adapted to high and low temperature cycling conditions is provided. The raw materials, by mass, include 20 parts of modified nano iron powder, 15 parts of iron-nickel alloy powder, 5 parts of titanium carbide (TiC) nanoparticles, 7 parts of rare earth oxide (La2O3), 25 parts of aluminum-manganese alloy powder, 6 parts of dispersant regulator, and 4 parts of anti-corrosion additive.

[0030] The dispersant is composed of zinc stearate and polyethylene glycol 600 in a mass ratio of 2.5:1.

[0031] Example 3 The difference between this embodiment and Embodiment 1 is that in this embodiment, a high-toughness and wear-resistant iron-based composite additive adapted to high and low temperature cycling conditions is provided. The raw materials, by mass, include 30 parts of modified nano iron powder, 10 parts of iron-nickel alloy powder, 9 parts of titanium carbide (TiC) nanoparticles, 3 parts of rare earth oxide (La2O3), 40 parts of aluminum-manganese alloy powder, 2 parts of dispersant regulator, and 1 part of anti-corrosion additive.

[0032] The dispersant is composed of zinc stearate and polyethylene glycol 600 in a mass ratio of 3:1.

[0033] Comparative Example 1 The difference between this comparative example and Example 1 is that the nano-iron powder in this comparative example was not modified.

[0034] Comparative Example 2 The difference between this comparative example and Example 1 is that no iron-nickel alloy powder was added in this comparative example.

[0035] Comparative Example 3 The difference between this comparative example and Example 1 is that no titanium carbide was added in this comparative example.

[0036] Comparative Example 4 The difference between this comparative example and Example 1 is that no La2O3 was added in this comparative example.

[0037] Comparative Example 5 The difference between this comparative example and Example 1 is that the mass ratio of zinc stearate to polyethylene glycol 600 in this comparative example is 1:1.

[0038] Comparative Example 6 The difference between this comparative example and Example 1 is that the amount of iron-based composite additive added in this comparative example is 1.0% of the mass of the aluminum alloy melt.

[0039] Comparative Example 7 The difference between this comparative example and Example 1 is that the amount of iron-based composite additive added in this comparative example is 5.0% of the mass of the aluminum alloy melt.

[0040] Experimental Example The aluminum alloys prepared in the above embodiments and comparative examples were subjected to performance tests. The test indicators and test methods are as follows: (1) Low temperature impact toughness at -50℃: GB / T 229-2020 Metallic materials Charpy impact test method (V notch, -50℃); (2) Room temperature hardness: GB / T 231.1-2018 Metallic materials - Brinell hardness test - Part 1: Test method; (3) High temperature hardness at 400℃: GB / T 231.1-2018 Metallic materials - Brinell hardness test - Part 1: Test method; (4) Wear resistance (wear amount): GB / T 12444-2006 Sliding wear of metallic materials (5) Corrosion resistance (48h salt spray corrosion area): GB / T 10125-2021 Artificial atmosphere corrosion test salt spray test (neutral salt spray NSS).

[0041] Each group underwent three repeated tests, and the test results are shown in Table 1. The results show that the low-temperature impact toughness at -50℃ of Examples 1-3 is ≥25J / cm. 2 It is far higher than the existing technology's 15 J / cm 2 The threshold values ​​show a low-temperature performance decrease of ≤21%; a high-temperature hardness of ≥135HB at 400℃ and a high-temperature hardness retention rate of ≥82%, representing a significant improvement compared to existing technologies (high-temperature hardness retention rate ≤65%). This perfectly adapts to high and low temperature cycling conditions and solves the core technical bottleneck of cold brittleness and hot softening in traditional iron-based additives. Furthermore, the room temperature hardness of the embodiments of this invention is ≥142HB, while maintaining high low-temperature impact toughness, breaking the technical limitation of the traditional iron-modified aluminum alloy's "toughness and strength are mutually exclusive," achieving a dual improvement in hardness and toughness. The wear amount of the embodiments is ≤0.023g / 1000r, and the salt spray corrosion area after 48h is ≤3.5%, achieving an improvement of over 70% in wear resistance and over 60% in corrosion resistance compared to existing technologies.

[0042] Table 1 Group <![CDATA[Low-temperature impact toughness J / cm 2 > Room temperature hardness HB High temperature hardness HB Wear amount g / 1000r 48h salt spray corrosion area % Example 1 28.6 146 138 0.021 3.2 Example 2 25.3 142 135 0.023 2.8 Example 3 27.8 148 140 0.019 3.5 Comparative Example 1 16.5 128 102 0.068 8.7 Comparative Example 2 18.2 135 98 0.045 4.1 Comparative Example 3 26.1 122 132 0.092 3.3 Comparative Example 4 20.3 138 115 0.056 9.2 Comparative Example 5 22.5 141 128 0.071 5.8 Comparative Example 6 21.7 118 105 0.085 4.5 Comparative Example 7 23.1 152 126 0.038 6.3 The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A high-toughness, wear-resistant iron-based composite additive suitable for high and low temperature cyclic operating conditions, characterized in that: The raw materials, by weight, include 20-30 parts modified nano iron powder, 10-15 parts iron-nickel alloy powder, 5-9 parts titanium carbide nanoparticles, 3-7 parts rare earth oxide La2O3, 25-40 parts aluminum-manganese alloy powder, 2-6 parts dispersant, and 1-4 parts anti-corrosion additive. The modified nano iron powder is obtained by modifying with a silane coupling agent.

2. The high-toughness, wear-resistant iron-based composite additive adapted to high and low temperature cyclic operating conditions according to claim 1, characterized in that: The modified nano-iron powder has a particle size of 40-100 nm and a purity of ≥99.7%.

3. The high-toughness, wear-resistant iron-based composite additive adapted to high and low temperature cyclic operating conditions according to claim 2, characterized in that: The iron-nickel alloy powder has a particle size of 100-200 nm and a nickel content of 35-37 wt%.

4. The high-toughness, wear-resistant iron-based composite additive adapted to high and low temperature cyclic operating conditions according to claim 3, characterized in that: The titanium carbide nanoparticles have a particle size of 30-80 nm and a hardness of ≥2800 HV.

5. The high-toughness, wear-resistant iron-based composite additive adapted to high and low temperature cyclic operating conditions according to claim 4, characterized in that: The rare earth oxide La2O3 has a particle size of 80-150 nm and a purity of ≥99.5%.

6. The high-toughness, wear-resistant iron-based composite additive adapted to high and low temperature cyclic operating conditions according to claim 5, characterized in that: The dispersion regulator is composed of zinc stearate and polyethylene glycol 600 in a mass ratio of 2.5 to 4:1, and the anti-corrosion additive is zinc dihydrogen phosphate micro powder.

7. A method for preparing a high-toughness, wear-resistant iron-based composite additive adapted to high and low temperature cycling conditions according to any one of claims 1 to 6, characterized in that, Includes the following steps: Step 1: Iron powder modification treatment: Add nano iron powder to anhydrous ethanol solution, stir and disperse, then add silane coupling agent KH550, stir at 65-75℃ for 2-3 hours, and then vacuum dry to obtain modified nano iron powder. Step 2: Premixing of composite components: Weigh out iron-nickel alloy powder, titanium carbide, rare earth oxides, and anti-corrosion additives according to the formula and mix them to obtain the premixed components; Step 3, Melt Coating Modification: Heat and melt aluminum-manganese alloy powder, add modified nano-iron powder and premixed components, stir and mix to obtain aluminum-manganese alloy coated composite powder; Step 4: Shaping and sieving: Cool the coated powder to room temperature, crush, sieve and dry to obtain a high-toughness and wear-resistant iron-based composite additive.

8. The preparation method of a high-toughness and wear-resistant iron-based composite additive adapted to high and low temperature cycling conditions according to claim 7, characterized in that: In step one, the amount of silane coupling agent added is 3-5% of the mass of iron powder.

9. The method for applying a high-toughness, wear-resistant iron-based composite additive adapted to high and low temperature cycling conditions in aluminum alloys according to any one of claims 1 to 6, characterized in that: The amount of iron-based composite additive added is 2.0-4.0% of the mass of the aluminum alloy melt.