Al-Fe-Mn heat-resistant high-strength rare earth strengthened aluminum alloy and preparation method thereof

Abstract

The application discloses an Al-Fe-Mn heat-resistant high-strength rare earth reinforced aluminum alloy and a preparation method thereof, and belongs to the field of additive manufacturing technology.The aluminum alloy comprises Fe, Mn, Y, Sm, Er, V and Si in a mass percentage of 0.5-3 wt%, 0.5-2 wt%, 0.01-0.3 wt%, 0.05-0.2 wt%, 0.01-0.1 wt%, 0.01-0.3 wt% and 0.02-0.5 wt% respectively, and the balance is Al.The Y, Sm and Er rare earth elements are added to maintain the high-temperature stability of Al-TM particles, and the Mn and Fe elements are added to form a large number of dispersed distribution and heat-stable precipitated phases under the condition of the rapid cooling of 3D printing, so that the heat-resistant performance of the aluminum alloy is improved, and the solid solution strengthening effect can be achieved, and the problem of low solid solubility of a traditional Al-TM alloy is solved.

Description

Technical Field

[0001] This invention belongs to the field of additive manufacturing technology, specifically relating to an Al-Fe-Mn heat-resistant high-strength rare earth reinforced aluminum alloy and its preparation method. Background Technology

[0002] Aluminum alloy recycling is crucial for achieving a circular green economy and sustainable social development. Compared to virgin ore production, recycling aluminum alloys can significantly reduce energy consumption by 95% and greenhouse gas emissions by 80%, contributing to carbon balance and sustainable development. However, the introduction of impurities such as Fe, Si, and Mn during recycling increases production costs and reduces the mechanical properties of aluminum alloys, especially the high Fe content which leads to a sharp decline in the properties of as-cast recycled alloys. In additive manufacturing, the morphology of precipitated phases, such as Al, is altered through non-equilibrium solidification processes. 13 The solubility of Fe and Mn elements in aluminum matrices can be improved using methods such as laser powder bed melting, providing new insights for developing high-Fe content recyclable heat-resistant aluminum alloys. Heat-resistant aluminum alloys are widely used in high-temperature environments, and the performance and lifespan of traditional metal materials are affected by high-temperature problems. Additive manufacturing technology allows for the more precise construction of heat-resistant aluminum alloy components, improving efficiency and performance. In the aerospace field, additive manufacturing reduces overall weight, improves fuel efficiency, enhances component strength and heat resistance, and improves system reliability and safety. In the energy industry, the application of heat-resistant aluminum alloys improves the efficiency of high-temperature equipment, extends its service life, and promotes the development of clean energy technologies. Additive manufacturing provides more innovative space for materials design, optimizing material properties through microstructural control, bringing new ideas and possibilities to materials science research and engineering applications.

[0003] This invention enables the 3D printing of low-cost, heat-resistant, and high-strength aluminum alloys by adding low-cost elements such as Fe and Mn and precisely controlling the element content, thus balancing the requirements of cost, heat resistance, and high strength. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0005] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0006] Therefore, the purpose of this invention is to overcome the shortcomings of the prior art and provide an Al-Fe-Mn heat-resistant high-strength rare earth reinforced aluminum alloy.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: The aluminum alloy, by mass fraction, comprises: Fe: 0.5–3 wt%; Mn: 0.5–2 wt%; Y: 0.01–0.3 wt%; Sm: 0.05–0.2 wt%; Er: 0.01–0.1 wt%; V: 0.01–0.3 wt%; Si: 0.02–0.5 wt%, with the balance being Al.

[0008] Another objective of this invention is to overcome the shortcomings of the prior art and provide a method for preparing Al-Fe-Mn heat-resistant high-strength rare earth reinforced aluminum alloy.

[0009] To solve the above-mentioned technical problems, the present invention provides the following technical solution: including,

[0010] The raw materials were prepared into a mixture, and then dried after vacuum melting and argon atomization to obtain Al-Fe-Mn heat-resistant high-strength rare earth reinforced aluminum alloy powder.

[0011] The powder was 3D printed to obtain a sample, and the sample was annealed and then heat-treated to obtain an Al-Fe-Mn heat-resistant high-strength rare earth reinforced aluminum alloy.

[0012] In a preferred embodiment of the preparation method of the Al-Fe-Mn heat-resistant high-strength rare-earth reinforced aluminum alloy of the present invention, the raw materials include one or more constituent elements and intermediate alloys. The vacuum melting is carried out at a temperature of 800–1000°C and a pressure of 0.4–0.9 MPa.

[0013] In a preferred embodiment of the preparation method of the Al-Fe-Mn heat-resistant high-strength rare earth reinforced aluminum alloy of the present invention, the argon atomization powder preparation pressure is 6-9.5 MPa.

[0014] In a preferred embodiment of the preparation method of the Al-Fe-Mn heat-resistant high-strength rare earth reinforced aluminum alloy of the present invention, the drying temperature is 50-90℃ and the drying time is 1-8h.

[0015] As a preferred embodiment of the preparation method of the Al-Fe-Mn heat-resistant high-strength rare earth reinforced aluminum alloy of the present invention, the laser power of the 3D printing is 100-500W; the scanning speed is 100-2000mm / s; the scanning spacing is 0.05-0.20mm; the scanning layer thickness is 0.03-0.1mm; the scanning strategy is that the rotation angle between adjacent layers is 0-67°; the oxygen content is controlled below 0.35% during 3D printing; and the substrate heating temperature is 50-200℃.

[0016] In a preferred embodiment of the preparation method of the Al-Fe-Mn heat-resistant high-strength rare earth reinforced aluminum alloy of the present invention, the annealing is stress-relief annealing at 100-220℃.

[0017] In a preferred embodiment of the preparation method of the Al-Fe-Mn heat-resistant high-strength rare earth reinforced aluminum alloy of the present invention, the heat treatment temperature is 275-355℃.

[0018] In a preferred embodiment of the preparation method of the Al-Fe-Mn heat-resistant high-strength rare earth reinforced aluminum alloy of the present invention, the heating rate of the heat treatment is 50℃ / min, and the holding time is 1 to 10h.

[0019] In a preferred embodiment of the preparation method of the Al-Fe-Mn heat-resistant high-strength rare-earth reinforced aluminum alloy of the present invention, the aluminum alloy has a density exceeding 99% and an average hardness of 90-130 HV. 0.1 .

[0020] Beneficial effects of this invention:

[0021] This invention maintains the high-temperature stability of Al-TM particles by adding rare earth elements such as Y, Sm, and Er, utilizing the interfacial segregation of these rare earth elements. By adding Mn and Fe elements, a large number of diffusely distributed and thermally stable precipitates are formed under the rapid cooling conditions unique to 3D printing, improving the heat resistance of the aluminum alloy. At the same time, it can also play a role in solid solution strengthening, reducing the stacking fault energy of the alloy, forming high-density stacking faults and twins, thus solving the problem of low solid solubility in traditional Al-TM (transition metal element) alloys.

[0022] The Al-Fe-Mn heat-resistant high-strength rare-earth reinforced aluminum alloy prepared by this invention exhibits low metallurgical defects, high density, and excellent formability. Furthermore, it demonstrates superior mechanical properties at both room temperature and high temperatures, maintaining excellent thermodynamic stability even at high temperatures. Its high-temperature performance far surpasses existing 3D-printed aluminum alloys, exhibiting high yield strength and low anisotropy. It is one of the aluminum alloys with the best overall high-temperature performance reported to date. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the 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. Wherein:

[0024] Figure 1 This is a scanning image of the morphology of the aluminum alloy powder obtained in Example 1.

[0025] Figure 2 Metallographic image of the Al-Fe-Mn heat-resistant high-strength rare earth reinforced aluminum alloy sample prepared in Example 1.

[0026] Figure 3 The image shows the metallographic pattern of the molten pool on the side after corrosion of the Al-Fe-Mn heat-resistant high-strength rare earth reinforced aluminum alloy sample prepared in Example 1, which exhibits good formability.

[0027] Figure 4 The image shows a backscattered electron image of the Al-Fe-Mn heat-resistant high-strength rare earth reinforced aluminum alloy sample prepared in Example 1, revealing the alloy's equiaxed and columnar bimodal microstructure. Detailed Implementation

[0028] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0029] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0030] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0031] Unless otherwise specified, all raw materials used in this invention are commercially available in the field.

[0032] Example 1

[0033] This embodiment provides a method for preparing Al-Fe-Mn heat-resistant high-strength rare earth reinforced aluminum alloy, specifically as follows:

[0034] 1) LPBF printing of heat-resistant high-strength rare earth reinforced aluminum alloy, containing the following components by mass percentage: Fe: 3wt%; Mn: 2wt%; Y: 0.3wt%; Sm: 0.2wt%; Er: 0.1wt%; V: 0.3wt%; Si: 0.5wt%, with the remainder being Al.

[0035] 2) After mixing the raw materials, add them to the melting furnace, set the melting temperature to 950℃ and the gas pressure inside the melting furnace to 0.6MPa, and then use argon as a medium to atomize the metal droplets at an atomization pressure of 8.5MPa. Sieve out powder of 15-53μm, place it at 90℃ and vacuum dry for 8 hours to obtain aluminum alloy powder.

[0036] 3) Aluminum alloy powder was laser powder melting and forming printing. The laser power was set to 300W; the scanning speed was 1200mm / s; the scanning spacing was 0.08mm; the scanning layer thickness was 0.08mm; and the scanning strategy was to rotate the adjacent layers by 67° to obtain the printed sample.

[0037] 4) The printed sample was stress-relief annealed at 100℃, and the heating rate was set to 50℃ / min. It was then held at 325℃ for 4h to obtain an Al-Fe-Mn heat-resistant high-strength rare earth reinforced aluminum alloy sample.

[0038] Example 2

[0039] The difference between this embodiment and Embodiment 1 is that the mass fraction of Fe in the raw material components is adjusted, specifically:

[0040] 1) It contains the following components in mass percentage: Fe: 2wt%; Mn: 2wt%; Y: 0.3wt%; Sm: 0.2wt%; Er: 0.1wt%; V: 0.3wt%; Si: 0.5wt%, with the remainder being Al.

[0041] 2) After mixing the raw materials, add them to the melting furnace, set the melting temperature to 950℃ and the gas pressure inside the melting furnace to 0.6MPa, and then use argon as a medium to atomize the metal droplets at an atomization pressure of 8.5MPa. Sieve out powder of 15-53μm, place it at 90℃ and vacuum dry for 8 hours to obtain aluminum alloy powder.

[0042] 3) Aluminum alloy powder was laser powder melting and forming printing. The laser power was set to 300W; the scanning speed was 1200mm / s; the scanning spacing was 0.08mm; the scanning layer thickness was 0.08mm; and the scanning strategy was to rotate the adjacent layers by 67° to obtain the printed sample.

[0043] 4) The printed sample was stress-relief annealed at 100℃, and the heating rate was set to 50℃ / min. It was then held at 325℃ for 4h to obtain an Al-Fe-Mn heat-resistant high-strength rare earth reinforced aluminum alloy sample.

[0044] Example 3

[0045] The difference between this embodiment and Embodiment 1 is that the mass composition of Fe and Mn in the raw materials is adjusted, specifically:

[0046] 1) The components contain the following mass percentages: Fe: 2.5wt%; Mn: 1.5wt%; Y: 0.3wt%; Sm: 0.2wt%; Er: 0.1wt%; V: 0.3wt%; Si: 0.5wt%, with the remainder being Al.

[0047] 2) After mixing the raw materials, add them to the melting furnace, set the melting temperature to 950℃ and the gas pressure inside the melting furnace to 0.6MPa, and then use argon as a medium to atomize the metal droplets at an atomization pressure of 8.5MPa. Sieve out powder of 15-53μm, place it at 90℃ and vacuum dry for 8 hours to obtain aluminum alloy powder.

[0048] 3) Aluminum alloy powder was laser powder melting and forming printing. The laser power was set to 300W; the scanning speed was 1200mm / s; the scanning spacing was 0.08mm; the scanning layer thickness was 0.08mm; and the scanning strategy was to rotate the adjacent layers by 67° to obtain the printed sample.

[0049] 4) The printed sample was stress-relief annealed at 100℃, and the heating rate was set to 50℃ / min. It was then held at 325℃ for 4h to obtain an Al-Fe-Mn heat-resistant high-strength rare earth reinforced aluminum alloy sample.

[0050] Example 4

[0051] The difference between this embodiment and Embodiment 1 is that the mass composition of Fe, Mn, and rare earth elements in the raw materials is adjusted, specifically as follows:

[0052] 1) The components contain the following mass percentages: Fe: 2.8wt%; Mn: 2wt%; Y: 0.1wt%; Sm: 0.1wt%; Er: 0.1wt%; V: 0.1wt%; Si: 0.2wt%, with the remainder being Al.

[0053] 2) After mixing the raw materials, add them to the melting furnace, set the melting temperature to 950℃ and the gas pressure inside the melting furnace to 0.6MPa, and then use argon as a medium to atomize the metal droplets at an atomization pressure of 8.5MPa. Sieve out powder of 15-53μm, place it at 90℃ and vacuum dry for 8 hours to obtain aluminum alloy powder.

[0054] 3) Aluminum alloy powder was laser powder melting and forming printing. The laser power was set to 300W; the scanning speed was 1200mm / s; the scanning spacing was 0.08mm; the scanning layer thickness was 0.08mm; and the scanning strategy was to rotate the adjacent layers by 67° to obtain the printed sample.

[0055] 4) The printed sample was stress-relief annealed at 100℃, and the heating rate was set to 50℃ / min. It was then held at 325℃ for 4h to obtain an Al-Fe-Mn heat-resistant high-strength rare earth reinforced aluminum alloy sample.

[0056] Example 5

[0057] The difference between this embodiment and Embodiment 1 lies in the adjustment of the rare earth element mass composition of the raw materials, specifically:

[0058] 1) The components contain the following mass percentages: Fe: 3wt%; Mn: 2wt%, with the balance being Al;

[0059] 2) After mixing the raw materials, add them to the melting furnace, set the melting temperature to 950℃ and the gas pressure inside the melting furnace to 0.6MPa, and then use argon as a medium to atomize the metal droplets at an atomization pressure of 8.5MPa. Sieve out powder of 15-53μm, place it at 90℃ and vacuum dry for 8 hours to obtain aluminum alloy powder.

[0060] 3) Aluminum alloy powder was laser powder melting and forming printing. The laser power was set to 300W; the scanning speed was 1200mm / s; the scanning spacing was 0.08mm; the scanning layer thickness was 0.08mm; and the scanning strategy was to rotate the adjacent layers by 67° to obtain the printed sample.

[0061] 4) The printed sample was stress-relief annealed at 100℃, and the heating rate was set to 50℃ / min. It was then held at 325℃ for 4h to obtain an Al-Fe-Mn heat-resistant high-strength rare earth reinforced aluminum alloy sample.

[0062] The performance of the Al-Fe-Mn heat-resistant high-strength rare earth reinforced aluminum alloy samples prepared in Examples 1 to 5 was tested, and the results are shown in Table 1.

[0063] Table 1

[0064]

[0065] According to Table 1 and Appendix Figure 1 ~Attached Figure 4 It can be seen that the alloy system in this invention exhibits significant advantages in the comprehensive mechanical properties (yield strength, tensile strength, and elongation) of the printed samples under heat treatment. This invention, by adding appropriate percentages of rare earth elements Y, Sm, and Er to the Al-Fe-Mn alloy, not only reduces crack sensitivity but also produces alloys with excellent high-temperature mechanical properties, low metallurgical defects, high density, good heat resistance, and creep strength. Fe and Mn, due to their low equilibrium solid solubility and small diffusion coefficients, can form precipitated particles in the alloy. The segregation effect of Er on the surface of the precipitated particles significantly inhibits the high-temperature coarsening rate of the particles, resulting in thermally stable Al6Fe and Al... 13Fe2+ ​​and the icosahedral quasi-crystalline i-phase produce precipitation strengthening, hindering dislocation slip, inhibiting grain boundary sliding and vacancy diffusion, thereby improving the high-temperature strength of aluminum alloys. The introduction of Y element causes lattice distortion, limiting grain growth. These fine grains usually represent higher strength and toughness, thus effectively inhibiting the formation of solidification cracks between adjacent grains. The addition of rare earth element Sm can refine grains, improve grain boundary strength, increase the plasticity and toughness of the material, and also improve the oxidation resistance of aluminum alloys, slowing down the oxidation rate at high temperatures and extending the service life of the material. The role of trace amounts of rare earth elements Y, Sm, and Er is, on the one hand, to form primary Al3Er nanophases, which can significantly refine grains. After heat treatment, these particles are dispersed in the matrix, and their crystal structure is completely coherent with the matrix, thus effectively inhibiting recrystallization and improving the alloy strength. On the other hand, the precipitation process of each reinforcing phase gradually collects the surrounding Al3Er nanoparticles and leaves Al3Er precipitation depletion bands. This process provides conditions for the aggregation of reinforcing particles at the interface, enabling them to maintain excellent size stability even at a high temperature of 300℃; that is, Al6Fe, Al 13 Fe2, Al 12 The precipitation strengthening of (Fe,V)3Si and the icosahedral quasicrystalline i-phase, along with the interfacial stabilization effect of rare earth elements segregating at the interface, together produce multi-scale synergistic strengthening, thereby effectively improving the mechanical properties of the alloy.

[0066] Comparative Example 1

[0067] Comparative Example 1 presents a 3D-printed aluminum alloy, which is currently a commercially available high-strength aluminum alloy, AlMgScZr alloy.

[0068] Comparative Example 2

[0069] Comparative Example 2 is based on Example 1. The difference between Comparative Example 2 and Example 1 is that trace amounts of rare earth elements Y / Sm / Er are not added. Specifically, Fe: 3wt%; Mn: 2wt%; V: 0.3wt%; Si: 0.5wt%, with the remainder being Al.

[0070] Comparative Example 3

[0071] Comparative Example 3 is based on Example 1. The difference between Comparative Example 3 and Example 1 is that the mass composition of V / Si is adjusted, specifically: Fe: 3wt%; Mn: 2wt%; Y: 0.3wt%; Sm: 0.2wt%; Er: 0.1wt%; V: 0.1wt%; Si: 0.1wt%, with the remainder being Al.

[0072] Table 2

[0073]

[0074]

[0075] As shown in Table 2, commercially available high-strength AlMgScZr alloys exhibit excellent room-temperature strength and ductility, but at high temperatures, this advantage is difficult to maintain, with strength decreasing rapidly and the alloy softening severely. Rare earth elements Y / Sm / Er play a strengthening role in additive manufacturing of heat-resistant aluminum alloys and contribute to the formation of dense alloys. Y can reduce the solidification range, decrease crack sensitivity, and improve mechanical properties. By refining grains and inducing lattice distortion, it effectively inhibits the formation of solidification cracks. The introduction of Sm refines grains, increases grain boundary strength, enhances the plasticity and toughness of the material, improves oxidation resistance, and extends service life. Er maintains dimensional stability at high temperatures and enhances the thermal stability of strengthening particles by constructing a more stable internal and interfacial structure of the precipitated phase, inhibiting the coarsening of Al3RE particles. The aggregation of rare earth elements at grain boundaries helps improve the mechanical properties of heat-resistant aluminum alloys, enabling them to exhibit superior performance in high-temperature environments. V / Si elements and Fe form a heat-stable phase Al2(Fe,V)3Si in the aluminum matrix, effectively improving the high-temperature strength of the alloy.

[0076] This invention addresses the challenges of significantly reduced high-temperature mechanical properties, poor thermal stability, and low creep resistance in existing additive manufacturing aluminum alloys. It innovatively proposes a 3D-printed Al-Fe-Mn low-cost, heat-resistant, high-strength rare-earth reinforced aluminum alloy, with Al-Fe-Mn alloy as the main body and rare-earth elements such as Y, Sm, and Er added. Laser powder bed melting technology is used to achieve supersaturated solid solution of the reinforcing elements and multi-scale synergistic strengthening.

[0077] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. An Al-Fe-Mn heat resistant high strength rare earth strengthened aluminum alloy, characterized in that: The aluminum alloy comprises, by mass fraction, Fe: 0.5~3wt%; Mn: 0.5~2wt%; Y: 0.01~0.3wt%; Sm: 0.05~0.2wt%; Er: 0.01~0.1wt%; V: 0.01~0.3wt%; Si: 0.02~0.5wt%, with the balance being Al.

2. A method for producing an Al-Fe-Mn heat resistant high-strength rare earth strengthened aluminum alloy, characterized by comprising: include, The raw materials are prepared into a mixture, and then dried after vacuum melting and argon atomization to obtain the Al-Fe-Mn heat-resistant high-strength rare earth reinforced aluminum alloy powder as described in claim 1. The powder was 3D printed to obtain a sample, and the sample was annealed and then heat-treated to obtain an Al-Fe-Mn heat-resistant high-strength rare earth reinforced aluminum alloy.

3. The method of making an Al-Fe-Mn heat resistant high strength rare earth strengthened aluminum alloy according to claim 2, characterized in that: The raw materials include one or more constituent elements and intermediate alloys; the vacuum melting is carried out at a temperature of 800~1000℃ and a pressure of 0.4~0.9MPa.

4. The method of making an Al-Fe-Mn heat resistant high strength rare earth strengthened aluminum alloy according to claim 2, characterized in that: The argon atomization powder production pressure is 6~9.5MPa.

5. The method of making an Al-Fe-Mn heat resistant high strength rare earth strengthened aluminum alloy according to claim 2, characterized in that: The drying temperature is 50~90℃, and the time is 1~8h.

6. The method of making an Al-Fe-Mn heat resistant high strength rare earth strengthened aluminum alloy according to claim 2, characterized in that: The laser power for 3D printing is 100~500W; the scanning speed is 100~2000mm / s; the scanning spacing is 0.05~0.20mm; the scanning layer thickness is 0.03~0.1mm; the scanning strategy is that the rotation angle between adjacent layers is 0~67°; the oxygen content is controlled below 0.35% during 3D printing; and the substrate heating temperature is 50~200℃.

7. The method of making an Al-Fe-Mn heat resistant high strength rare earth strengthened aluminum alloy according to claim 2, characterized in that: The annealing is stress-relief annealing at 100~220℃.

8. The method of making an Al-Fe-Mn heat resistant high strength rare earth strengthened aluminum alloy according to claim 2, characterized in that: The heat treatment temperature is 275~355℃.

9. The method of making an Al-Fe-Mn heat resistant high strength rare earth strengthened aluminum alloy of claim 2, wherein: The heating rate of the heat treatment is 50℃ / min, and the holding time is 1~10h.

10. The Al-Fe-Mn heat resistant high strength rare earth strengthened aluminum alloy prepared by the method of any one of claims 2-8, characterized in that: The aluminum alloy has a density of more than 99%, an average hardness of 90-130 HV 0.1 .

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