High-strength eutectic aluminum alloy and laser powder bed melting preparation method thereof

Abstract

The invention discloses a high-strength eutectic aluminum alloy and a laser powder bed melting preparation method thereof, and belongs to the technical field of aluminum alloys. The alloy comprises the following components in percentage by mass: 5%-9% of Ce, 6%-8% of Mg, 0.3%-0.7% of Mn, 0.1%-0.5% of Ca and the balance of Al and inevitable impurities. According to the method, the aluminum alloy material is prepared through laser powder bed melting and heat treatment, the high-strength eutectic aluminum alloy is obtained, the obtained high-strength eutectic aluminum alloy comprises an alpha-Al matrix phase and an Al11Ce3 eutectic phase, meanwhile, an AlMg secondary phase which is 0.2-2 microns in particle distribution is formed at the bottom of a molten pool, an important role is played in improvement of the mechanical property, and the mechanical property of the aluminum alloy material is improved. The finally prepared aluminum alloy has the yield strength of 340-400 MPa, the tensile strength of 440-580 MPa, the elongation of 1%-3.5% and the average hardness of 130-170 HV0.2. The obtained aluminum alloy has wide application prospects in the fields of aerospace, aviation, military industry and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of laser additive manufacturing, and in particular relates to a high-strength eutectic aluminum alloy and a laser powder bed melting preparation method thereof. Background Art

[0002] Additive Manufacturing (AM), also known as 3D printing, is an advanced manufacturing technology that manufactures three-dimensional solid parts by stacking materials layer by layer. Compared with traditional manufacturing methods, additive manufacturing has the advantages of high design freedom, high material utilization, and the ability to manufacture complex geometric shapes. Therefore, it has been widely used in aerospace, automotive, energy, and biomedicine. Aluminum alloy has become one of the material systems that has attracted much attention in additive manufacturing due to its low density, high specific strength, and good corrosion resistance. However, traditional aluminum alloys (such as Al-Si series) have certain limitations in high temperature performance and strength, and it is difficult to meet the application requirements under extreme working conditions. In recent years, Al-Ce (aluminum-cerium) alloy has gradually become a research hotspot in the field of additive manufacturing due to its unique performance advantages.

[0003] Al-Ce alloy is an aluminum alloy system with cerium (Ce) as the main alloying element. The addition of cerium can not only refine the grains, but also form intermetallic compounds with extremely high thermal stability, thereby significantly improving the room temperature mechanical properties and high temperature properties of the alloy. In addition, Al-Ce alloy can form a uniform microstructure under rapid solidification conditions, further optimizing its mechanical properties. Studies have shown that the tensile strength of additively manufactured Al-Ce alloys is usually in the range of 250-400 MPa at room temperature, and the yield strength can reach 200-300 MPa. In addition, the microhardness of Al-Ce alloys is usually between 100-150 HV0.2. The tensile strength of the current additively manufactured Al-Ce alloy is between 250-400 MPa, which is difficult to meet the demand for higher strength materials in aerospace, automotive and other fields; with the increase in lightweight demand, the development of higher strength aluminum alloys has become the key to replace traditional steel to achieve weight reduction and energy saving and emission reduction. Therefore, a new type of aluminum alloy material needs to be developed to make up for the shortcomings of existing technologies. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and to provide a high-strength eutectic aluminum alloy and a laser powder bed melting method for preparing the same, so as to solve the problem in the prior art that the performance of aluminum alloys is difficult to meet the requirements of the service environment when manufacturing forged aluminum alloys.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A high-strength eutectic aluminum alloy, comprising, by mass percentage: Ce 5%-9%, Mg 6%-8%, Mn 0.3%-0.7%, Ca 0.1%-0.5%, and the balance being Al and unavoidable impurities; The high-strength eutectic aluminum alloy includes an α-Al matrix phase and an Al 11 Ce 3 The eutectic phase also contains secondary phase particles AlMg.

[0006] A further improvement of the present invention is: Preferably, the size of the AlMg phase is 0.2 um to 2 um.

[0007] A method for preparing the above-mentioned high-strength eutectic aluminum alloy comprises the following steps: Step 1, preparing aluminum alloy powder according to a set mass fraction; Step 2: Prepare the aluminum alloy powder by laser powder bed melting to obtain a high-strength eutectic aluminum alloy.

[0008] Preferably, in step 1, the particle size of the aluminum alloy powder is 15~53 um.

[0009] Preferably, in step 2, the energy density of laser powder bed melting is 80-110 J / mm 3 , scanning speed is 700~1500 mm / s, and laser power is 200~400 W.

[0010] Preferably, the method further includes step 3 of annealing the high-strength eutectic aluminum alloy.

[0011] Preferably, the annealing temperature is 250° C. and the annealing time is 2 hours.

[0012] Preferably, the high-strength eutectic aluminum alloy prepared by S2 has a yield strength of 350 MPa~400 MPa, a tensile strength of 550 MPa~580 MPa, an elongation of 2%~3.5%, and an average hardness of 150~170 HV0.2.

[0013] Preferably, in step 2, the laser powder bed is preheated before the aluminum alloy part is prepared by the laser powder bed.

[0014] Preferably, the high-strength eutectic aluminum alloy has a yield strength of 340 MPa to 380 MPa, a tensile strength of 440 MPa to 560 MPa, an elongation of 1% to 3%, and an average hardness of 130 to 152 HV0.2.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The invention discloses a high-strength eutectic aluminum alloy and a laser powder bed melting preparation method thereof, belonging to the technical field of aluminum alloys. The mass fraction of the alloy components is: Ce 5%~9%, Mg 6%~8%, Mn 0.3%~0.7%, Ca 0.1%~0.5%, and the balance is Al and inevitable impurities. The aluminum alloy material is prepared by laser powder bed melting to obtain the aluminum alloy material; the energy density of the laser powder bed melting is maintained at 80~110J / mm 3 The scanning speed is between 0.7 and 1.5 m / s, and the laser power is between 200 and 400 W. By controlling the above-mentioned components and process parameters of the preparation process, a high-strength eutectic aluminum alloy can be obtained. During the additive manufacturing process, rapid cooling and temperature gradients can easily induce thermal stress, leading to cracking. The eutectic structure in the aluminum alloy of the present invention is evenly distributed, so that local stress concentration can be reduced, and then plastic deformation can occur under stress, absorbing part of the stress, thereby relieving stress. The fine phase in the eutectic structure can effectively hinder the crack propagation, and the phase boundary between the eutectic phase and the matrix can prevent the crack from further expanding, thereby reducing the possibility of cracking.

[0016] In the present invention, Mg, Mn and Ca elements are added to the Al-Ce alloy system. The three elements provide solid solution strengthening, and the Al generated in the Al-Ce alloy system 11 Ce 3 The eutectic phase can reduce the possibility of cracking during the printing process, and by adding a high-mass fraction of Mg, a 0.2 um to 2 um AlMg secondary phase with granular distribution is formed at the bottom of the molten pool. 11 Ce 3 The eutectic phase and secondary phase particles jointly realize the second phase strengthening. Under the action of solid solution strengthening and second phase strengthening, they can jointly hinder the dislocation movement and improve the yield strength and tensile strength. The grain structure presents a bimodal grain structure, and the fine grains are distributed at the bottom of the molten pool, providing fine grain strengthening contribution, further improving the yield strength and tensile strength. With the aid of the additive manufacturing method, the prepared aluminum alloy can achieve a yield strength of 340-400 MPa, a tensile strength of 440-580 MPa, an elongation of 1%-3.5%, and an average hardness of 130-170 HV0.2. The aluminum alloy obtained by the present invention has broad application prospects in the fields of aerospace, aviation, military industry, etc., and can significantly improve production efficiency and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the binary phase diagram of Al-Ce alloy.

[0018] Figure 2 This is the XRD pattern of Example 1.

[0019] Figure 3This is the microstructure and element distribution image of Example 1.

[0020] Figure 4 This is the XZ plane bimodal grain structure morphology image of Example 4.

[0021] Figure 5 This is the TEM-EDS image of Example 1.

[0022] Figure 6 For Al 11 Ce 3 The element distribution and atomic arrangement of the phase; Among them, (a) Figure is Al 11 Ce 3 Phase TEM-EDS image; (b) Al 11 Ce 3 Phase high-resolution image; (c) Figure is Al 11 Ce 3 Phase FFT image.

[0023] Figure 7 The element distribution and atomic arrangement of the AlMg phase; Among them, (a) is the TEM-EDS image of AlMg phase; (b) is the high-resolution image of AlMg phase; (c) is the FFT image of AlMg phase.

[0024] Figure 8 The figure shows a comparison of the mechanical properties of Example 1, Example 2, and Example 3.

[0025] Fig. 9 The mechanical properties of Example 4, Example 5, Example 6, Example 7, and Example 8 are compared. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below in conjunction with the accompanying drawings: In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.

[0027] In this document, unless otherwise specified, “includes,” “including,” “contains,” “has,” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”

[0028] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0029] The following examples use conventional instruments and equipment in the art. The experimental methods in the following examples where specific conditions are not specified are usually carried out under conventional conditions or under conditions recommended by the manufacturer. The various raw materials used in the following examples are conventional commercial products unless otherwise specified, and their specifications are conventional specifications in the art. In the specification of the present invention and the following examples, unless otherwise specified, "%" means weight percentage, "part" means weight part, and ratio means weight ratio.

[0030] The invention discloses a high-strength eutectic aluminum alloy, which comprises, by mass fraction, Ce 5% to 9%, Mg 6% to 8%, Mn 0.3% to 0.7%, Ca 0.1% to 0.5%, and the balance is Al and inevitable impurities; the aluminum alloy comprises an α-Al matrix phase and Al 11 Ce 3 Eutectic phase, the high-strength eutectic aluminum alloy contains AlMg phase.

[0031] The size of the AlMg phase is 0.2 um to 2 um, which can enhance the mechanical properties of the entire aluminum alloy.

[0032] The prepared high-strength eutectic aluminum alloy has a yield strength of 340~400 MPa, a tensile strength of 440~580 MPa, an elongation of 1%~3.5%, and an average hardness of 130~170 HV0.2.

[0033] A second aspect of the present invention discloses a method for preparing a high-strength eutectic aluminum alloy, comprising the following steps: Step 1, preparing aluminum alloy powder according to a set mass fraction; Step 2, preparing the aluminum alloy powder by laser powder bed melting to obtain an aluminum alloy part; In some embodiments of the present invention, in step 1, the particle size of the aluminum alloy powder raw material configured according to a set mass fraction is 15-53 um.

[0034] In some embodiments of the present invention, in step 2, the energy density of laser powder bed melting is 80-110 J / mm 3 The scanning speed is between 0.7 and 1.5 m / s, and the laser power is between 200 and 400 W.

[0035] In some embodiments of the present invention, the laser powder bed is preheated to 80-150° C. before printing.

[0036] In some embodiments of the present invention, the aluminum alloy product after forging is further annealed to obtain a high-strength eutectic aluminum alloy.

[0037] Before preparing the aluminum alloy parts by laser powder bed, the laser powder bed is not preheated. The high-strength eutectic aluminum alloy has a yield strength of 350 MPa~400 MPa, a tensile strength of 550 MPa~580 MPa, an elongation of 2%~3.5%, and an average hardness of 150~170 HV0.2.

[0038] Before laser powder bed preparation of aluminum alloy parts, the laser powder bed is preheated. The high-strength eutectic aluminum alloy has a yield strength of 340 MPa to 380 MPa, a tensile strength of 440 MPa to 560 MPa, an elongation of 1% to 3%, and an average hardness of 130 to 152 HV0.2.

[0039] Verification found that preheating the substrate can reduce the temperature difference between the molten pool and the surrounding materials, reduce thermal stress, and thus reduce the risk of cracking; uniform preheating can reduce deformation caused by local rapid cooling and improve dimensional accuracy. Preheating can reduce residual stress and reduce the occurrence of cracks; preheating helps reduce pores and unfused defects and improve density.

[0040] The following is further described in conjunction with specific embodiments.

[0041] Example 1 This embodiment provides an additively manufactured aluminum alloy material and a preparation method, including: selecting an aluminum alloy powder raw material with a particle size in the range of 15 to 53 μm; the aluminum alloy powder raw material is Al-7Ce-8Mg-0.5Mn-0.4Ca; preparing the aluminum alloy material by laser powder bed melting to obtain an aluminum alloy material product; the energy density of the selective laser melting is 87 J / m, the scanning speed is 800 mm / s, and the laser power is 330 W; stress relief annealing is performed on the aluminum alloy material product, the stress relief annealing temperature is 250°C, and the time is 2h; to eliminate the internal stress of the aluminum alloy material product. The final aluminum alloy material of this embodiment has a yield strength of 400 MPa, a tensile strength of 575 MPa, and an elongation of 2.5%; and the average hardness reaches 170 HV0.2.

[0042] The XRD pattern of this example is as follows Figure 2 As shown in the figure, by calibrating the diffraction peaks, it can be determined that the α-Al matrix phase and the Al 11 Ce 3 The microstructure and element distribution were observed by scanning electron microscopy. Figure 3 As shown, Figure 3 (a) shows the entire molten pool morphology, and its elements are evenly distributed. Figure 3 (b), the eutectic structure can be clearly observed. Through elemental analysis, the white phase is Al 11 Ce 3 Eutectic phase, black phase is α-Al matrix phase. Observe the bottom of the molten pool, such as Figure 3 (c) Compared with the center of the molten pool, the volume fraction of the α-Al matrix phase at the bottom of the molten pool is larger. In addition, the AlMg second phase particles with a size of 0.2 um to 2 um can be observed at the bottom of the molten pool through the element distribution. Figure 1 The Al-Ce binary phase diagram analysis shows that the composition of this embodiment is within the hypoeutectic composition. Before the eutectic structure is precipitated, the α-Al primary phase will precipitate first. Figure 3 This is consistent with the result that the volume fraction of α-Al matrix phase at the bottom of the molten pool is larger in (c).

[0043] The TEM observation of the bottom and center of the molten pool is carried out, as shown in FIG. Figure 5 As shown, the structure of the bottom of the molten pool is as follows Figure 5 As shown in (a), by means of element distribution analysis, Al 11 Ce 3 phase and AlMg second phase particles with a size of 0.2 um to 2 um. The structure at the bottom of the molten pool is as follows Figure 5 (b) shown in which Al 11 Ce 3 The phase and the α-Al matrix phase present a eutectic distribution, and Al 11 Ce 3 The phase is rich in Mg compared to the matrix phase.

[0044] The Al 11 Ce 3 Phase and AlMg second phase particles were analyzed by high-resolution images, such as Figure 6 and Figure 7 As shown, according to the calibration of its FFT image diffraction spots, it can be judged that its lattice structure satisfies Al 11 Ce 3 Lattice structure of AlMg phase and AlMg phase.

[0045] Example 2 The present embodiment provides an additively manufactured aluminum alloy material and a preparation method, comprising: selecting an aluminum alloy powder raw material with a particle size in the range of 15 to 53 μm; the aluminum alloy powder raw material is Al-5Ce-8Mg-0.7Mn-0.5Ca; preparing the aluminum alloy material by laser powder bed melting to obtain an aluminum alloy material product; the energy density of the selective laser melting is 93 J / m, the scanning speed is 1200 mm / s, and the laser power is 370 W; stress relief annealing is performed on the aluminum alloy material product, and the stress relief annealing temperature is 250°C and the time is 2h; the final aluminum alloy material of the present embodiment has a yield strength of 360MPa, a tensile strength of 567MPa, and an elongation of 2%; and the average hardness reaches 152 HV0.2.

[0046] Example 3 The present embodiment provides an additively manufactured aluminum alloy material and a preparation method, comprising: selecting an aluminum alloy powder raw material with a particle size in the range of 15 to 53 μm; the aluminum alloy powder raw material is Al-9Ce-6Mg-0.3Mn-0.1Ca; preparing the aluminum alloy material by laser powder bed melting to obtain an aluminum alloy material product; the energy density of the selective laser melting is 106 J / m, the scanning speed is 1000 mm / s, and the laser power is 350 W; stress relief annealing is performed on the aluminum alloy material product, and the stress relief annealing temperature is 250°C and the time is 2h; the final aluminum alloy material of the present embodiment has a yield strength of 378MPa, a tensile strength of 572MPa, and an elongation of 3.5%; and the average hardness reaches 152 HV0.2.

[0047] Example 4 The present embodiment provides an additively manufactured aluminum alloy material and a preparation method, comprising: selecting an aluminum alloy powder raw material with a particle size in the range of 15 to 53 μm; the aluminum alloy powder raw material is Al-7Ce-8Mg-0.5Mn-0.4Ca; preparing the aluminum alloy material by laser powder bed melting, preheating the laser powder bed to 120°C before printing, and obtaining an aluminum alloy material product; the energy density of the selective laser melting is 87 J / m, the scanning speed is 800 mm / s, and the laser power is 230 W; stress relief annealing is performed on the aluminum alloy material product, the stress relief annealing temperature is 250°C, and the time is 2h; the final aluminum alloy material of the present embodiment has a yield strength of 359.5 MPa, a tensile strength of 555.5 MPa, and an elongation of 3%; and the average hardness reaches 152 HV0.2.

[0048] The XZ-plane bimodal grain structure of this embodiment is as follows Figure 4 As shown, a double-peak grain morphology can be observed at the bottom and center of the molten pool. By analyzing its grain orientation, no obvious texture was found.

[0049] Example 5 The present embodiment provides an additively manufactured aluminum alloy material and a preparation method, comprising: selecting an aluminum alloy powder raw material with a particle size in the range of 15 to 53 μm; the aluminum alloy powder raw material is Al-9Ce-6Mg-0.3Mn-0.1Ca; preparing the aluminum alloy material by laser powder bed melting, preheating the laser powder bed to 130°C before printing, and obtaining an aluminum alloy material product; the energy density of the selective laser melting is 100 J / m, the scanning speed is 1000 mm / s, and the laser power is 330 W; stress relief annealing is performed on the aluminum alloy material product, the stress relief annealing temperature is 250°C, and the time is 2h; the final aluminum alloy material of the present embodiment has a yield strength of 345 MPa, a tensile strength of 514.5 MPa, and an elongation of 2%; and the average hardness reaches 147 HV0.2.

[0050] Example 6 The present embodiment provides an additively manufactured aluminum alloy material and a preparation method, comprising: selecting an aluminum alloy powder raw material with a particle size in the range of 15 to 53 μm; the aluminum alloy powder raw material is Al-5Ce-8Mg-0.7Mn-0.5Ca; preparing the aluminum alloy material by laser powder bed melting, preheating the laser powder bed to 80°C before printing, and obtaining an aluminum alloy material product; the energy density of the selective laser melting is 106 J / m, the scanning speed is 1000 mm / s, and the laser power is 350 W; stress relief annealing is performed on the aluminum alloy material product, the stress relief annealing temperature is 250°C, and the time is 2h; the final aluminum alloy material of the present embodiment has a yield strength of 345 MPa, a tensile strength of 441.5 MPa, and an elongation of 1%; and the average hardness reaches 138 HV0.2.

[0051] Example 7 The present embodiment provides an additively manufactured aluminum alloy material and a preparation method, comprising: selecting an aluminum alloy powder raw material with a particle size in the range of 15 to 53 μm; the aluminum alloy powder raw material is Al-5Ce-8Mg-0.7Mn-0.5Ca; preparing the aluminum alloy material by laser powder bed melting, preheating the laser powder bed to 150°C before printing, and obtaining an aluminum alloy material product; the energy density of the selective laser melting is 88 J / m, the scanning speed is 1200 mm / s, and the laser power is 350 W; stress relief annealing is performed on the aluminum alloy material product, the stress relief annealing temperature is 250°C, and the time is 2h; the final aluminum alloy material of the present embodiment has a yield strength of 342 MPa, a tensile strength of 471 MPa, and an elongation of 1.25%; and the average hardness reaches 143 HV0.2.

[0052] Example 8 The present embodiment provides an additively manufactured aluminum alloy material and a preparation method, including: selecting an aluminum alloy powder raw material with a particle size in the range of 15 to 53 μm; the aluminum alloy powder raw material is Al-9Ce-6Mg-0.3Mn-0.1Ca; preparing the aluminum alloy material by laser powder bed melting, preheating the laser powder bed to 100°C before printing, and obtaining an aluminum alloy material product; the energy density of the selective laser melting is 80 J / m, the scanning speed is 1400 mm / s, and the laser power is 370 W; stress relief annealing is performed on the aluminum alloy material product, the stress relief annealing temperature is 250°C, and the time is 2h; the final aluminum alloy material of the present embodiment has a yield strength of 362 MPa, a tensile strength of 482.5 MPa, and an elongation of 2%; and the average hardness reaches 130HV0.2.

[0053] Example 9 The present embodiment provides an additively manufactured aluminum alloy material and a preparation method, including: selecting an aluminum alloy powder raw material with a particle size in the range of 15 to 53 μm; the aluminum alloy powder raw material Al-9Ce-7Mg-0.3Mn-0.1Ca; preparing the aluminum alloy material by laser powder bed melting, preheating the laser powder bed by 100°C before printing, and obtaining an aluminum alloy material product; the energy density of the selective laser melting is 86 J / m, the scanning speed is 700 mm / s, and the laser power is 200 W; stress relief annealing is performed on the aluminum alloy material product, the stress relief annealing temperature is 250°C, and the time is 2h, to obtain a high-strength eutectic aluminum alloy.

[0054] Example 10 The present embodiment provides an additively manufactured aluminum alloy material and a preparation method, comprising: selecting an aluminum alloy powder raw material with a particle size in the range of 15 to 53 μm; the aluminum alloy powder raw material Al-9Ce-7Mg-0.3Mn-0.1Ca; preparing the aluminum alloy material by laser powder bed melting, preheating the laser powder bed by 100°C before printing, and obtaining an aluminum alloy material product; the energy density of the selective laser melting is 80 J / m, the scanning speed is 1500 mm / s, and the laser power is 400 W; stress relief annealing is performed on the aluminum alloy material product, the stress relief annealing temperature is 250°C, and the time is 2h, to obtain a high-strength eutectic aluminum alloy.

[0055] Embodiment 11 The present embodiment provides an additively manufactured aluminum alloy material and a preparation method, including: selecting an aluminum alloy powder raw material with a particle size in the range of 15 to 53 μm; the aluminum alloy powder raw material Al-9Ce-7Mg-0.3Mn-0.1Ca; preparing the aluminum alloy material by laser powder bed melting, preheating the laser powder bed by 100°C before printing, and obtaining an aluminum alloy material product; the energy density of the selective laser melting is 110 J / m, the scanning speed is 1100 mm / s, and the laser power is 400 W; stress relief annealing is performed on the aluminum alloy material product, the stress relief annealing temperature is 250°C, and the time is 2h, to obtain a high-strength eutectic aluminum alloy.

[0056] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-strength eutectic aluminum alloy, characterized in that: In terms of mass percentage, it includes: Ce 5%~9%, Mg 6%~8%, Mn0.3%~0.7%, Ca 0.1%~0.5%, and the balance is Al and unavoidable impurities; The high-strength eutectic aluminum alloy includes an α-Al matrix phase and an Al 11 Ce3 eutectic phase, also contains secondary phase particles AlMg.

2. A high-strength eutectic aluminum alloy according to claim 1, characterized in that: The size of the AlMg phase is 0.2 um to 2 um.

3. A method for preparing the high-strength eutectic aluminum alloy according to claim 1, characterized in that: The following steps are involved: Step 1, preparing aluminum alloy powder according to a set mass fraction; Step 2: Prepare the aluminum alloy powder by laser powder bed melting to obtain a high-strength eutectic aluminum alloy.

4. The method for preparing a high-strength eutectic aluminum alloy according to claim 3, characterized in that: In step 1, the particle size of the aluminum alloy powder is 15~53 um.

5. The method for preparing the high-strength eutectic aluminum alloy according to claim 3, characterized in that: In step 2, the energy density of laser powder bed melting is 80~110 J / mm 3 , scanning speed is 700~1500 mm / s, and laser power is 200~400 W.

6. The method for preparing the high-strength eutectic aluminum alloy according to claim 3, characterized in that: The method further includes step 3 of annealing the high-strength eutectic aluminum alloy.

7. The method for preparing a high-strength eutectic aluminum alloy according to claim 6, characterized in that: The annealing temperature is 250° C. and the annealing time is 2 hours.

8. The method for preparing a high-strength eutectic aluminum alloy according to claim 3, characterized in that: The high-strength eutectic aluminum alloy prepared by S2 has a yield strength of 350 MPa~400 MPa, a tensile strength of 550 MPa~580 MPa, an elongation of 2%~3.5%, and an average hardness of 150~170 HV0.

2.

9. The method for preparing a high-strength eutectic aluminum alloy according to claim 3, characterized in that: In step 2, the laser powder bed is preheated before the aluminum alloy part is prepared by the laser powder bed.

10. The high-strength eutectic aluminum alloy according to claim 9, characterized in that: The high-strength eutectic aluminum alloy has a yield strength of 340 MPa to 380 MPa, a tensile strength of 440 MPa to 560 MPa, an elongation of 1% to 3%, and an average hardness of 130 to 152 HV0.2.

Images