An aluminum-iron alloy for laser powder bed fusion and a method of forming a part therefrom

Abstract

The application belongs to the technical field of metal additive manufacturing, and discloses an aluminum-iron alloy for laser powder bed fusion forming and a part forming method thereof, which comprises, in mass percentage, 6.5%-7.1% of Fe, 1.3%-1.6% of Mn, 1.3%-1.6% of Ce and 0.3%-0.8% of Sc, and the balance of Al and inevitable impurities. The application provides an aluminum-iron alloy ratio suitable for laser powder bed fusion technology, through the synergistic effect of Fe, Mn, Ce and Sc elements, the competitive precipitation relationship between Al6(Fe, Mn) phase and Al 13 Fe4 phase is utilized to improve the thermal stability and precipitation driving force of Al6(Fe, Mn) phase, effectively inhibit the coarsening of Al 13 Fe4 phase. At the same time, Sc and Ce elements refine the alloy structure, form Al3Sc phase and Al 11 Ce3 phase to improve the thermal stability and high-temperature mechanical properties of the alloy, and an aluminum-iron alloy with good mechanical properties and high thermal stability is obtained.

Description

Technical Field

[0001] This invention belongs to the field of metal additive manufacturing technology, and relates to an aluminum-iron alloy and its parts forming method for laser powder bed melting forming. Background Technology

[0002] Al-Fe eutectic aluminum alloys have great potential in high-temperature applications. On the one hand, Al and Fe are abundant, and recycled aluminum alloys often contain Fe, which can effectively reduce production costs by making reasonable use of this characteristic. On the other hand, Fe diffuses slowly in α-Al, and the hard, heat-resistant intermetallic compounds formed can effectively strengthen the alloy, enabling it to maintain high strength at temperatures above 200°C.

[0003] Under traditional preparation conditions, Fe has a low solid solution limit in Al, and Fe tends to form coarse needle-like or plate-like Al atoms in aluminum alloys. 13 The brittle Fe4 phase significantly reduces the machinability and mechanical properties of materials. The development of Laser Powder Bed Fusion (LPBF) technology has provided a new pathway for the research and development of Al-Fe alloys. This technology uses a layer-by-layer, cladding process to fabricate parts, offering high forming freedom and precision, and enabling the integrated forming of complex and precise parts. Its extremely high cooling rate can greatly enhance the solid solution limit of Fe in α-Al, which not only effectively enhances the solid solution strengthening effect of aluminum alloys but also suppresses the growth of coarse Al particles. 13 The formation of the Fe4 phase promotes the precipitation of the Al6Fe phase, thus LPBF forming of Al-Fe alloys has attracted increasing attention. However, due to the low cooling rate in the melt channel boundary region and the non-isothermal aging of the melt channel boundary region caused by the thermal cycling during LPBF forming, coarse Al phases may still form in the melt channel boundary region. 13 Fe4 phase. Meanwhile, the mechanical properties of laser powder bed molten aluminum-iron alloys are highly correlated with Fe content; the alloy strength increases with increasing Fe content, making it difficult to fully realize the alloy's performance potential at low Fe contents. At high Fe contents, both the formability and plasticity of the alloy are affected by coarse Al... 13 The Fe4 phase restricts the improvement of the alloy's mechanical properties. Therefore, there is an urgent need to design a method that can suppress the growth of coarse Al. 13 A novel aluminum-iron alloy exhibiting Fe4 phase formation and coarsening tendency.

[0004] The main method for improving the formability and mechanical properties of additively manufactured aluminum-iron alloys is to introduce rare earth elements such as Ce, Er, and Y into the alloys through pre-alloying. These elements can improve the formability of Al... 13The morphology of the Fe4 phase was observed, and the high-temperature performance of the alloy was enhanced by forming rare-earth aluminum compounds with high thermal stability. However, Al 13 The formation and coarsening mechanism of the Fe4 phase is quite complex, and the addition of a single element has a significant impact on Al. 13 The suppression effect of Fe4 phase is limited; while the simultaneous addition of multiple elements will generate a large number of brittle phases due to the complex interaction between elements, thereby weakening the modification effect and increasing the density of the alloy. Summary of the Invention

[0005] The purpose of this invention is to provide a method for forming aluminum-iron alloys and their parts using laser powder bed melting, thereby solving the problem that the simultaneous addition of multiple elements weakens the mechanical properties of aluminum-iron alloys.

[0006] To achieve the above objectives, the present invention employs the following technical solution: An aluminum-iron alloy for laser powder bed melting, comprising, by mass percentage: 6.5%~7.1% Fe, 1.3%~1.6% Mn, 1.3%~1.6% Ce and 0.3%~0.8% Sc, with the balance being Al and unavoidable impurities.

[0007] Furthermore, by mass percentage, it comprises: 7.0% Fe, 1.5% Mn, 1.5% Ce and 0.6% Sc, with the balance being Al and unavoidable impurities.

[0008] A method for forming aluminum-iron alloy parts for laser powder bed fusion molding includes the following steps: Provide Al-Fe-Mn-Ce-Sc spherical alloy powder and perform drying treatment; The substrate is sandblasted and then cleaned to obtain a cleaned substrate. The substrate is preheated in an argon atmosphere, and spherical alloy powder is laser powder bed melting and forming. After cooling, the formed part is obtained.

[0009] The formed part is heat-treated and then cooled to obtain an aluminum-iron alloy part.

[0010] Furthermore, the spherical alloy powder has a particle size of 10–80 μm and a loose packing density of 1.30–1.60 g / cm³. 3 .

[0011] Furthermore, in the laser powder bed melting process, the laser power of the laser powder bed melting is 220~380W, the scanning rate is 1000~1800 mm / s, the scanning spacing is 80~140 μm, the layer thickness is 20~40 μm, the interlayer rotation angle is 45°~90°, and the laser spot diameter is 50~70 μm.

[0012] Furthermore, in the laser powder bed melting process, the laser power for laser powder bed melting is 300 W, the scanning rate is 1700 mm / s, the scanning spacing is 100 μm, the layer thickness is 30 μm, and the interlayer rotation angle is 67°. The laser spot diameter is 60 μm.

[0013] Furthermore, the drying temperature of the spherical alloy powder is 120~130 ℃, and the time is 2~4 h.

[0014] Furthermore, the substrate is blasted with alumina sand with a particle size of 50~150 μm, the blasting pressure is 0.2~0.6 MPa, the blasting distance is 100~200 mm, the blasting angle is 45°~90°, and the blasting time is 20~90 s.

[0015] Furthermore, the preheating temperature of the substrate is 100~250 ℃.

[0016] Furthermore, the heat treatment temperature is 300~350 ℃, and the holding time is 2~4 h.

[0017] Compared with the prior art, the present invention has the following beneficial effects: This invention provides an aluminum-iron alloy for laser powder bed melting forming, characterized by the synergistic introduction of Mn, Ce, and Sc elements into an aluminum-iron alloy with an Fe content exceeding 6.5 wt.%. Mn can partially replace Fe in the Al6Fe phase lattice, forming a fine Al6(Fe,Mn) phase; Sc can reduce the solid solubility of Mn in the matrix, promote the precipitation of the Al6(Fe,Mn) phase, and simultaneously refine the grains, improving the alloy's deformation coordination; furthermore, the Al3Sc phase has a relatively fast coarsening rate, allowing for the rational design of heat treatment process windows to achieve controllable secondary precipitation of the Al3Sc phase while avoiding significant coarsening of intermetallic compounds such as Al6Fe, thereby further improving the alloy's comprehensive mechanical properties; Ce can optimize the Al... 13 The morphology of the Fe4 phase and the formation of Al 11 The Ce3 phase enhances the high-temperature performance of the alloy. Through the synergistic effect of the aforementioned elements, the Al6(Fe,Mn) phase and Al... 13 The competitive precipitation mechanism of the Fe4 phase enhances the thermal stability and precipitation driving force of the spherical Al6(Fe,Mn) phase, thereby suppressing the precipitation of coarse lamellar Al in the alloy. 13 The formation of the Fe4 phase, combined with a suitable heat treatment process, promotes the precipitation of a large amount of secondary Al3Sc phase, thereby optimizing the microstructure of the aluminum-iron alloy and obtaining an aluminum-iron alloy with good mechanical properties and high thermal stability.

[0018] This invention provides a method for forming aluminum-iron alloy parts using laser powder bed melting. It employs Al-Fe-Mn-Ce-Sc spherical alloy powder, whose morphological characteristics effectively improve the flowability and filling properties of subsequent printing. A pretreatment method involving substrate sandblasting and cleaning thoroughly removes oil and impurities from the substrate surface, increasing surface roughness and significantly enhancing the bonding strength between the printed layer and the substrate. Laser powder bed melting printing in an argon atmosphere effectively isolates oxygen and nitrogen from the air, preventing oxidation and nitriding reactions in the alloy melt and suppressing defects such as porosity. Combined with a preheating followed by laser powder bed melting printing, the temperature gradient during the forming process is significantly reduced, minimizing residual stress, deformation, and cracking in the formed parts. Finally, heat treatment further eliminates internal defects, homogenizes the alloy microstructure, and releases residual stress, ultimately producing a high-density, stable, and comprehensively mechanically excellent aluminum-iron alloy product. This invention utilizes laser powder bed melting technology and constructs a multi-level precipitation control system through the synergistic addition of multiple elements to optimize the microstructure of the aluminum-iron alloy. During the solidification stage, the Al6Mn phase, which precipitates first from Mn, serves as a heterogeneous nucleation site, promoting the nucleation of the Al6Fe phase and ultimately forming the Al6(Fe,Mn) phase. Furthermore, Sc can also promote the precipitation of the Al6(Fe,Mn) phase. In subsequent cyclic heat treatment, the high diffusion rate of Sc allows it to preferentially precipitate from the supersaturated matrix, inducing Fe to precipitate from the supersaturated α-Al matrix to form the Al6Fe phase. The low diffusion rate of Ce and its interfacial modification effects further optimize the morphology of the precipitated phases, and the high thermal stability of Al... 11 The Ce3 phase enhances the high-temperature mechanical properties of the alloy. The entire process is coherent, highly controllable, and suitable for high-precision laser additive manufacturing.

[0019] Furthermore, the particle size and loose density parameters of the spherical alloy powder were defined. A particle size range of 10–80 μm balances powder flowability and powder spreading uniformity. Fine-particle-size powder can fill the gaps between coarse-particle-size powder, avoiding voids and uneven thickness during powder spreading, ensuring the flatness of each powder layer in laser printing, and improving the forming density; 1.30–1.60 g / cm³ 3 The optimal loose packing density parameter ensures that the powder possesses excellent packing performance and compaction effect. It avoids the problems of loose powder and high porosity caused by excessively low loose packing density, as well as the problems of powder spreading blockage and uneven packing caused by excessively high density. It effectively adapts to the powder spreading process requirements of laser powder bed melting, stabilizes the printing quality from the perspective of powder properties, significantly reduces porosity defects in the formed parts, improves the stability of the alloy forming process, and increases the yield of parts.

[0020] Furthermore, the temperature and time parameters for drying the alloy powder were specified. The drying process of 120~130 ℃ for 2~4 h can completely remove the moisture, trace water vapor and volatile impurities adsorbed on the powder surface. At the same time, this temperature range will not cause powder oxidation, agglomeration, phase transformation or component failure. It preserves the original spherical morphology, particle size distribution and excellent flowability of the powder to the greatest extent, ensuring the stability of the subsequent laser printing forming process and laying the raw material foundation for the preparation of high-performance aluminum-iron alloys.

[0021] Furthermore, the substrate undergoes a sandblasting pretreatment process. Sandblasting can precisely control the micro-roughness of the substrate surface, increase the contact area between the powder and the substrate, and allow the alloy melt after laser melting to better wet the substrate surface, achieving metallurgical bonding. This significantly improves the bonding strength between the printed layer and the substrate, avoids interface peeling and cracking during the forming process, and effectively improves the overall structural stability and service life of the parts.

[0022] Furthermore, preheating the substrate within a temperature range of 100~250 ℃ can effectively alleviate the severe temperature gradient caused by rapid heating and cooling during the forming process, significantly reduce residual thermal stress inside the alloy formed part, and suppress defects such as warping, deformation, and microcracks that are prone to occur during the printing process from the source. At the same time, the preheated substrate can improve the melting and bonding effect of the bottom powder, avoid the problems of insufficient melting and loose bonding of the bottom powder, effectively improve the density of the bottom layer and the interfacial bonding strength of the formed part, reduce the accumulation of interlayer stress, improve the overall forming accuracy, and ensure structural integrity.

[0023] Furthermore, the process parameters for laser powder bed fusion scanning printing are precisely defined. The laser power, adjustable from 220 to 380 W, can be adapted to the melting characteristics of multi-element alloy powders, ensuring complete powder melting and suppressing alloy overheating, element loss, and grain coarsening caused by excessive power. Simultaneously, it avoids incomplete melting and excessive porosity caused by insufficient power. The combination of parameters—1000–1800 mm / s scanning rate, 80–140 μm scanning spacing, and 20–40 μm layer thickness—enables uniform layer-by-layer melting and deposition of powder, ensuring uniform layer thickness and tight interlayer bonding, effectively reducing porosity and improving the density of the formed part. The 45°–90° interlayer rotation angle overcomes stress concentration and anisotropy issues associated with single scanning trajectories, resulting in a more uniform alloy microstructure distribution and improved consistency of mechanical properties in all directions. The 50–70° interlayer rotation angle further enhances the process. The μm laser spot diameter can precisely control the melt channel size, ensuring a regular molten area and improving forming accuracy. The entire parameter system works together to effectively solve problems such as porosity, cracks, uneven structure, and anisotropy that easily occur in laser printing of aluminum-iron alloys, greatly improving forming quality and performance stability.

[0024] Furthermore, the heat treatment process parameters of 300~350 ℃ and 2~4 h were specified. This heat treatment process is suitable for the microstructure of aluminum-iron alloys formed by laser printing. It can effectively release the residual thermal stress and forming stress accumulated inside the formed part during the laser additive manufacturing process, eliminate the micro-stress concentration points generated during the forming process, and avoid deformation and cracking in the subsequent use of the alloy. This heat treatment process can promote the precipitation of a large number of secondary Al3Sc phases while avoiding significant coarsening of Al6(Fe,Mn) phases, further improving the comprehensive mechanical properties of the alloy and allowing the aluminum-iron alloy formed by laser printing to reach the optimal performance state. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 The results show the calculated coarsening rate coefficients of the Al3X phase (X being Sc, Er, Ti, Y, Zr) in an aluminum matrix within the temperature range of 200–400 °C.

[0027] Figure 2 is a graph showing the influence of Mn, Sc, and Ce elements on the driving force of Al6Fe phase precipitation in the aluminum-iron alloy parts prepared in Example 1 of the present invention. In the graph, (a) represents Mn element, (b) represents Sc element, and (c) represents Ce element.

[0028] Figure 3 shows the effect of Mn, Sc, and Ce elements on Al in the aluminum-iron alloy parts prepared in Example 1 of this invention. 13 The curves showing the influence of the driving force on Fe4 phase precipitation are shown, where (a) represents Mn, (b) represents Sc, and (c) represents Ce.

[0029] Figure 4 This is a particle size distribution diagram of the spherical alloy powder prepared in Example 1 of the present invention.

[0030] Figure 5 This is a scanning electron microscope image of the spherical alloy powder prepared in Example 1 of the present invention.

[0031] Figure 6 This is a cross-sectional microstructure diagram of the aluminum-iron alloy part prepared in Example 1 of the present invention.

[0032] Figure 7 This is an EBSD scan image of the cross-section of the aluminum-iron alloy part prepared in Example 1 of the present invention.

[0033] Figure 8This is a comparison chart of the room temperature tensile curves of the aluminum-iron alloy parts prepared in Example 1 and Comparative Example 1 of the present invention. Detailed Implementation

[0034] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0035] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0036] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0037] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0038] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0039] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0040] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0041] The present invention will now be described in further detail with reference to the accompanying drawings: This invention provides an aluminum-iron alloy for laser powder bed melting forming, comprising, by mass percentage, 6.5%~7.1% Fe, 1.3%~1.6% Mn, 1.3%~1.6% Ce and 0.3%~0.8% Sc, with the balance being Al and unavoidable impurities.

[0042] Preferably, the aluminum-iron alloy comprises, by mass percentage, 7.0% Fe, 1.5% Mn, 1.5% Ce and 0.6% Sc, with the balance being Al and unavoidable impurities.

[0043] This invention also provides a method for forming aluminum-iron alloy parts using laser powder bed melting, specifically including the following steps: Step 1: Determine the composition and content of the aluminum-iron alloy: like Figure 1 As shown, the coarsening rate coefficient of Al3X phase (X being Sc, Er, Ti, Y, Zr) in the aluminum matrix within the temperature range of 200–400 °C was calculated using thermodynamic software. It was found that the Al3Sc phase has a high coarsening rate in this temperature range. Considering that the minimum temperature for significant coarsening of the Al6(Fe,Mn) phase is around 360 °C, Sc element can be introduced into the Al-Fe alloy. The heat treatment process can be rationally designed by utilizing the difference in coarsening rates of different precipitates. This can further improve the mechanical properties of the Al-Fe alloy by utilizing the secondary Al3Sc phase while avoiding microstructure coarsening.

[0044] As shown in Figures 2 and 3, thermodynamic software was used to calculate the elemental relationships of Mn, Sc, and Ce on the Al6Fe (or Al6(Fe,Mn)) phase and Al... 13 The effect of Mn on the precipitation driving force of the Fe4 phase shows that Mn can increase the precipitation driving force of the Al6Fe phase while decreasing the precipitation driving force of the Al4 phase. 13 The driving force for the precipitation of Fe4 phase; both Sc and Ce elements can enhance the Al6Fe phase and Al 13The precipitation of the Fe4 phase is driven by the fact that the addition of excessive Sc or Ce will promote the precipitation of large amounts of iron-rich phases, impairing the plasticity of the alloy. Therefore, the composition ratio of the aluminum-iron alloy is determined to be: by mass percentage, including 6.5%~7.1% Fe, 1.3%~1.6% Mn, 1.3%~1.6% Ce and 0.3%~0.8% Sc, with the balance being Al and unavoidable impurities.

[0045] Step 2, Prepare powdered raw materials: Raw materials containing Al, Fe, Mn, Ce, and Sc are weighed according to a specified ratio. Spherical alloy powders are prepared using gas atomization, rotating electrode method, or other suitable methods. The particle size of the spherical alloy powders is 10–80 μm, and the loose packing density is 1.30–1.60 g / cm³. 3 .

[0046] The spherical alloy powder is dried to remove moisture and improve its flowability. The drying temperature is 120~130 ℃ and the time is 2~4 h.

[0047] Step 3, Clean the substrate: The substrate material is aluminum alloy. First, the substrate surface is sandblasted to improve the powder spreading quality and enhance the bonding force between the molded part and the substrate. Then, the substrate is cleaned with ethanol to remove oil stains from the substrate surface.

[0048] Preferably, the parameters for sandblasting are as follows: the sandblasting medium is alumina sand with a particle size of 50~150 μm, the sandblasting pressure is 0.2~0.6 MPa, the sandblasting distance is 100~200 mm, the spraying angle is 45°~90°, and the sandblasting time is 20~90 s.

[0049] Step 4, print the test specimen: Spherical alloy powder is loaded into the powder chamber of the laser powder bed of the printing equipment. High-purity argon gas is continuously introduced into the forming chamber. When the oxygen content in the forming chamber is lower than 100 ppm, the heating plate is turned on to preheat the substrate. When the substrate temperature rises to 100~250 ℃, laser powder bed melting and forming are performed according to predetermined parameters to obtain the formed part.

[0050] During the laser powder bed melting process, the laser power of the laser powder bed melting is 220~380 W, the scanning rate is 1000~1800 mm / s, the scanning spacing of the laser powder bed melting is 80~140 μm, the layer thickness is 20~40 μm, the interlayer rotation angle of each layer is 45°~90°, and the laser spot diameter is 50~70 μm.

[0051] Preferably, the laser power for the laser powder bed melting is 300 W, the scanning rate is 1700 mm / s, the scanning spacing is 100 μm, the layer thickness is 30 μm, the interlayer rotation angle is 67°, and the laser spot diameter is 60 μm.

[0052] Step 5, heat treatment: After the molded part is prepared, the specimen is removed from the substrate by wire electrical discharge machining or other suitable methods.

[0053] The formed parts are heat-treated by raising the temperature of the heat treatment furnace to 300~350 ℃, placing the formed parts in the furnace and holding them at that temperature for 2~4 h, and then cooling them to obtain aluminum-iron alloy parts.

[0054] The technical solution of the present invention will be further described in detail below through specific embodiments: Example 1: The raw materials containing 7.0% Fe, 1.5% Mn, 1.5% Ce, 0.6% Sc, and the balance Al were weighed according to mass percentage and prepared into high-performance spherical alloy powder for laser powder bed melting using a gas atomization method. The particle size of the spherical alloy powder is 10~70 μm, and the loose packing density of the powder is 1.40 g / cm³. 3 .

[0055] The spherical alloy powder was placed in a vacuum drying oven and dried at a specific temperature of 130 ℃ for 150 min.

[0056] The substrate was sandblasted with alumina sand with a particle size of approximately 80 μm. The sandblasting pressure was 0.5 MPa, the sandblasting distance was 150 mm, the spray angle was 90°, and the sandblasting time was 80 s. The surface oil was cleaned with ethanol.

[0057] Using dried spherical alloy powder as raw material, the substrate is preheated in an argon atmosphere until the surface temperature reaches 200 °C. Then, laser powder bed melting is performed. The laser power of the laser powder bed melting is 300 W, the laser scanning rate is 1700 mm / s, the laser scanning spacing is 100 μm, the layer thickness is 30 μm, the interlayer rotation angle of each layer is 67°, and the laser spot diameter is 60 μm to obtain the formed part.

[0058] The formed part was held in a heat treatment furnace at 325 ℃ for 2 h to promote the precipitation of secondary Al3Sc particles, and then air-cooled to obtain an aluminum-iron alloy part.

[0059] The aluminum-iron alloy parts obtained in this embodiment have a room temperature tensile strength of 660 MPa and an elongation of 5.3%, and a 200℃ tensile strength of 479 MPa and an elongation of 8.0%.

[0060] Example 2: The raw material, containing 7.1% Fe, 1.6% Mn, 1.5% Ce, 0.3% Sc, and the balance Al, was weighed according to mass percentage and prepared into high-performance spherical alloy powder for laser powder bed melting using a gas atomization method. The particle size of the spherical alloy powder is 10~70 μm, and the loose packing density is 1.60 g / cm³. 3 .

[0061] The spherical alloy powder was placed in a vacuum drying oven and dried at a specific temperature of 120 ℃ for 200 min.

[0062] The substrate was sandblasted with alumina sand with a particle size of approximately 100 μm. The sandblasting pressure was 0.2 MPa, the sandblasting distance was 100 mm, the spraying angle was 60°, and the sandblasting time was 90 s. The surface oil was cleaned with ethanol.

[0063] Using dried spherical alloy powder as raw material, the substrate is preheated in an argon atmosphere. When the surface temperature of the substrate rises to 150 °C, laser powder bed melting is performed. The laser power of the laser powder bed melting is 280 W, the laser scanning rate is 1000 mm / s, the laser scanning spacing is 140 μm, the layer thickness is 20 μm, the interlayer rotation angle of each layer is 90°, and the laser spot diameter is 65 μm, resulting in a shaped part.

[0064] The formed part was kept at 300 °C in a heat treatment furnace for 4 h to promote the precipitation of secondary Al3Sc particles, and then air-cooled to obtain an aluminum-iron alloy part.

[0065] The aluminum-iron alloy part obtained in this embodiment has a room temperature tensile strength of 630 MPa and an elongation of 4.0%, and a 200℃ tensile strength of 425 MPa and an elongation of 9.1%. Example 3: The raw material, containing 7.0% Fe, 1.3% Mn, 1.6% Ce, 0.8% Sc, and the balance Al, was weighed according to mass percentage and prepared into high-performance spherical alloy powder for laser powder bed melting using a gas atomization method. The particle size of the spherical alloy powder is 10~80 μm, and the loose packing density is 1.45 g / cm³. 3 .

[0066] The spherical alloy powder was placed in a vacuum drying oven and dried at a specific temperature of 130 ℃ for 180 min.

[0067] The substrate was sandblasted with alumina sand with a particle size of approximately 80 μm. The sandblasting pressure was 0.5 MPa, the sandblasting distance was 150 mm, the spraying angle was 90°, and the sandblasting time was 20 s. The surface oil was cleaned with ethanol.

[0068] Using dried spherical alloy powder as raw material, the substrate is preheated in an argon atmosphere. When the surface temperature of the substrate rises to 250 °C, laser powder bed melting is performed. The laser power of the laser powder bed melting is 380 W, the laser scanning rate is 1800 mm / s, the laser scanning spacing is 80 μm, the layer thickness is 35 μm, the interlayer rotation angle of each layer is 45°, and the laser spot diameter is 70 μm, resulting in a shaped part.

[0069] The formed part was kept in a heat treatment furnace at 350 °C for 2 h to promote the precipitation of secondary Al3Sc particles, and then air-cooled to obtain an aluminum-iron alloy part.

[0070] The aluminum-iron alloy part obtained in this embodiment has a room temperature tensile strength of 675 MPa and an elongation of 4.1%, and a 200℃ tensile strength of 465 MPa and an elongation of 8.5%. Example 4: The raw materials containing 6.5% Fe, 1.5% Mn, 1.3% Ce, 0.6% Sc, and the balance Al were weighed according to mass percentage and prepared into high-performance spherical alloy powder for laser powder bed melting using the rotating electrode method. The particle size of the spherical alloy powder is 10~80 μm, and the loose packing density of the powder is 1.40 g / cm³. 3 .

[0071] The spherical alloy powder was placed in a vacuum drying oven and dried at a specific temperature of 120 ℃ for 240 min.

[0072] The substrate was sandblasted with alumina sand with a particle size of approximately 50 μm. The sandblasting pressure was 0.6 MPa, the sandblasting distance was 200 mm, the spraying angle was 45°, and the sandblasting time was 30 s. The surface oil was cleaned with ethanol.

[0073] Using dried spherical alloy powder as raw material, the substrate is preheated in an argon atmosphere. When the surface temperature of the substrate rises to 100 ℃, laser powder bed melting is performed. The laser power of the laser powder bed melting is 220 W, the laser scanning rate is 1100 mm / s, the laser scanning spacing is 110 μm, the layer thickness is 40 μm, the interlayer rotation angle of each layer is 75°, and the laser spot diameter is 50 μm, resulting in a shaped part.

[0074] The formed part was kept in a heat treatment furnace at 310 °C for 4 h to promote the precipitation of secondary Al3Sc particles, and then air-cooled to obtain an aluminum-iron alloy part.

[0075] The aluminum-iron alloy part obtained in this embodiment has a room temperature tensile strength of 651 MPa and an elongation of 5.8%, and a 200℃ tensile strength of 446 MPa and an elongation of 9.5%. Example 5: The raw material, containing 6.8% Fe, 1.4% Mn, 1.6% Ce, 0.8% Sc, and the balance Al, was weighed according to mass percentage. High-performance spherical alloy powder for laser powder bed melting was prepared using the rotating electrode method. The particle size of the spherical alloy powder was 10–70 μm, and the loose packing density was 1.30 g / cm³. 3 .

[0076] The spherical alloy powder was placed in a vacuum drying oven and dried at a specific temperature of 130 ℃ for 120 min.

[0077] The substrate was sandblasted with alumina sand with a particle size of approximately 150 μm. The sandblasting pressure was 0.4 MPa, the sandblasting distance was 120 mm, the spray angle was 90°, and the sandblasting time was 60 s. The surface oil was cleaned with ethanol.

[0078] Using dried spherical alloy powder as raw material, the substrate is preheated in an argon atmosphere. When the surface temperature of the substrate rises to 200 ℃, laser powder bed melting is performed. The laser power of the laser powder bed melting is 330 W, the laser scanning rate is 1800 mm / s, the laser scanning spacing is 140 μm, the layer thickness is 25 μm, the interlayer rotation angle of each layer is 90°, and the laser spot diameter is 70 μm, thus obtaining the formed part.

[0079] The formed part was kept in a heat treatment furnace at 300 ℃ for 3 h to promote the precipitation of Al3Sc particles, and then air-cooled to obtain an aluminum-iron alloy part.

[0080] The final aluminum-iron alloy part obtained in this embodiment has a tensile strength of 685 MPa and an elongation of 3.1%, a tensile strength of 485 MPa at 200 ℃, and an elongation of 7.3%.

[0081] Comparative Example 1: The difference from Example 1 is that the heat treatment temperature is 200 °C and the holding time is 5 h.

[0082] The final aluminum-iron alloy part obtained in this comparative example has a tensile strength of 620 MPa and an elongation of 2.2%. At 200 °C, the tensile strength is 432 MPa and the elongation is 6.5%.

[0083] Comparative Example 2: The difference from Example 1 is that Fe 5.0%, Mn 1.5%, Ce 1.5%, Sc 0.6%, and the balance Al powder were weighed according to the mass percentage.

[0084] The final aluminum-iron alloy part obtained in this comparative example has a tensile strength of 551 MPa, an elongation of 6.3%, a tensile strength of 415 MPa at 200 °C, and an elongation of 10.1%.

[0085] Comparative Example 3: The difference from Example 1 is that Fe 7.0%, Mn 1.5%, Sc 0.6%, and the balance Al powder were weighed according to the mass percentage.

[0086] The final aluminum-iron alloy part obtained in this comparative example has a tensile strength of 650 MPa and an elongation of 1.5%, a tensile strength of 390 MPa at 200 °C, and an elongation of 5.3%.

[0087] Comparative Example 4: The difference from Example 1 is that Fe 7.0%, Mn 1.5%, Ce 1.5%, and the balance Al powder were weighed according to the mass percentage.

[0088] The final aluminum-iron alloy part obtained in this comparative example has a tensile strength of 590 MPa and an elongation of 4.2%, a tensile strength of 396 MPa at 200 ℃, and an elongation of 7.3%.

[0089] Comparing the results of Examples 1-5 with those of Comparative Examples 1-4, it can be seen that the present invention, through the rational design of the contents of Fe, Mn, Ce, and Sc, and combined with suitable laser powder bed melting and heat treatment processes, produces high-performance aluminum-iron alloy parts with excellent mechanical properties, all exhibiting tensile strengths of not less than 630 MPa and tensile strengths at 200 °C of not less than 420 MPa, achieving an effective synergy between high strength and good plasticity. In Comparative Example 1, lowering the heat treatment temperature resulted in insufficient Al3Sc precipitation, significantly reducing the material strength. In Comparative Example 2, reducing the Fe content decreased the volume fraction of the strengthening phase, leading to a decrease in tensile strength. In Comparative Example 3, removing Ce resulted in a decrease in the high-temperature mechanical properties of the alloy. In Comparative Example 4, removing Sc caused the Al3Sc precipitation strengthening to disappear, resulting in a decrease in strength but a slight increase in elongation.

[0090] Figure 4 and Figure 5 The particle size distribution and morphology of the spherical alloy powder prepared in Example 1 of the present invention are shown. It can be seen that the particle size of the spherical alloy powder is between 10 and 80 μm.

[0091] Figure 6 and Figure 7 The scanning electron microscope (SEM) image and backscattered electron diffraction (BSD) pattern of the aluminum-iron alloy part prepared in Example 1 of this invention show that there are a large number of spherical Al6(Fe,Mn) phases with a size of about 0.2~3 μm in the melt channel boundary region, as well as a small amount of square lath-shaped Al phases. 13 The Fe4 phase has a size of approximately 0.4~0.6 μm. The overall microstructure of the aluminum-iron alloy parts is dominated by columnar crystals, and due to the nucleation-induced effect of a large number of precipitated phases, the grain size in the melt channel boundary region is relatively small.

[0092] Figure 8 A comparison of the room temperature tensile curves of the aluminum-iron alloy parts prepared in Example 1 and Comparative Example 1 of the present invention shows that the tensile strength of the aluminum-iron alloy parts prepared in Example 1 of the present invention can reach 660 MPa, and the elongation is 5.3%, both of which are superior to those of Comparative Example 1. This indicates that the present invention controls the microstructure of the aluminum-iron alloy parts formed by laser powder bed melting through heat treatment process, promotes the precipitation of Al3Sc phase, and significantly improves the mechanical properties of the aluminum-iron alloy parts.

[0093] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An aluminum-iron alloy for laser powder bed melting forming, characterized in that, It comprises, by mass percentage: 6.5% to 7.1% Fe, 1.3% to 1.6% Mn, 1.3% to 1.6% Ce and 0.3% to 0.8% Sc, with the balance being Al and unavoidable impurities.

2. The aluminum-iron alloy for laser powder bed melting forming according to claim 1, characterized in that, It comprises, by mass percentage: 7.0% Fe, 1.5% Mn, 1.5% Ce and 0.6% Sc, with the balance being Al and unavoidable impurities.

3. A method for forming aluminum-iron alloy parts for laser powder bed melting as described in any one of claims 1 to 2, characterized in that, Includes the following steps: Provide Al-Fe-Mn-Ce-Sc spherical alloy powder and perform drying treatment; The substrate is sandblasted and then cleaned to obtain a cleaned substrate. Under an argon atmosphere, the substrate is preheated, and spherical alloy powder is laser powder bed melting and forming. After cooling, the formed part is obtained. The formed part is heat-treated and then cooled to obtain an aluminum-iron alloy part.

4. The method for forming aluminum-iron alloy parts for laser powder bed fusion forming according to claim 3, characterized in that, The spherical alloy powder has a particle size of 10–80 μm and a loose packing density of 1.30–1.60 g / cm³. 3 .

5. The method for forming aluminum-iron alloy parts for laser powder bed fusion forming according to claim 3, characterized in that, In the laser powder bed melting process, the laser power of the laser powder bed melting is 220~380 W, the scanning rate is 1000~1800 mm / s, the scanning spacing is 80~140 μm, the layer thickness is 20~40 μm, the interlayer rotation angle is 45°~90°, and the laser spot diameter is 50~70 μm.

6. The method for forming aluminum-iron alloy parts for laser powder bed fusion forming according to claim 5, characterized in that, In the laser powder bed melting process, the laser power is 300 W, the scanning rate is 1700 mm / s, the scanning spacing is 100 μm, the layer thickness is 30 μm, and the interlayer rotation angle is 67°. The laser spot diameter is 60 μm.

7. The method for forming aluminum-iron alloy parts for laser powder bed fusion forming according to claim 3, characterized in that, The drying temperature for the spherical alloy powder is 120~130 ℃, and the drying time is 2~4 h.

8. The method for forming aluminum-iron alloy parts for laser powder bed fusion forming according to claim 3, characterized in that, The substrate is blasted with alumina sand with a particle size of 50~150 μm, the blasting pressure is 0.2~0.6 MPa, the blasting distance is 100~200 mm, the blasting angle is 45°~90°, and the blasting time is 20~90 s.

9. The method for forming aluminum-iron alloy parts for laser powder bed fusion forming according to claim 3, characterized in that, The preheating temperature of the substrate is 100~250 ℃.

10. The method for forming aluminum-iron alloy parts for laser powder bed fusion forming according to claim 3, characterized in that, The heat treatment temperature is 300~350 ℃, and the holding time is 2~4 h.

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