Laser powder bed fusion of high performance al-mg-si alloys and short process preparation methods thereof

Abstract

The application provides a laser powder bed melting high-performance Al-Mg-Si alloy and a short-process preparation method thereof, and the preparation method comprises the following steps: mixing Nb powder, Al powder, B powder and C powder, coating the mixture with pure aluminum strip material, drawing the coated mixture to form a wire material, melting the wire material, and obtaining a mixture containing nanoparticles through mechanical stirring, ultrasonic treatment, casting and rolling and crushing; treating aluminum niobium alloy powder and B4C powder through electric explosion to obtain aluminum-coated nanometer NbC+NbB2 particle wire material; mixing the mixture and the wire material in different proportions, adding the mixture and the wire material into Al-Mg-Si alloy melt, and obtaining Al-Mg-Si alloy wire material coated with nanoparticles through ultrasonic treatment, casting and rolling, homogenization, hot extrusion and multi-pass drawing; melting the wire material, forming spherical droplets through ultrasonic vibration, and rapidly cooling and solidifying the spherical droplets into spherical powder; and finally, laser powder bed melting and artificial aging treatment are performed on the powder to obtain the laser powder bed melting high-performance Al-Mg-Si alloy.

Description

Technical Field

[0001] This invention belongs to the field of aluminum alloy preparation, specifically relating to a laser powder bed melting method for preparing high-performance Al-Mg-Si alloys and its short-process preparation method. Background Technology

[0002] Al-Mg-Si alloys, due to their excellent heat-treatable strengthening properties and superior corrosion resistance, have shown broad application prospects in aerospace, rail transportation, precision instruments, and the manufacture of lightweight complex components. However, this system suffers from key problems such as low alloy strength due to the presence of coarse microstructure. These problems mainly include: Al-Mg-Si alloys tend to form coarse grains and continuous network eutectic phases (such as Mg2Si phase) distributed along the grain, severely disrupting the matrix continuity, reducing interfacial bonding strength, and causing the alloy to exhibit significant anisotropy and early fracture tendency during tensile testing; simultaneously, the micro-segregation of elements such as Mg and Si leads to uneven distribution of precipitated strengthening phases (such as β″ phase) during subsequent heat treatment, making it difficult to form a uniform and fine distribution of strengthening phases, thus limiting the improvement of alloy strength. To solve these technical problems, existing technologies mainly rely on plastic deformation (such as extrusion, rolling, high-pressure torsion, etc.), the addition of rare earth elements (such as Sc, etc.), or high-temperature heat treatment, which, while improving strength and plasticity to some extent, have not been effective. However, the synergistic improvement in strength and plasticity is not ideal; moreover, most methods are only suitable for components with simple structures and small forming dimensions, making it difficult to achieve integrated near-net-shape forming of high-performance complex components. Meanwhile, existing processes generally suffer from low forming efficiency, long post-processing steps, and high costs, hindering the large-scale industrial application of Al-Mg-Si alloys in high-end equipment. Therefore, how to reduce costs, decrease the dependence of Al-Mg-Si alloys on complex post-processing, and simultaneously improve strength while maintaining high plasticity, while balancing forming efficiency and process stability, to achieve short-process, low-cost, high-performance integrated manufacturing capable of producing both simple and complex components, is a pressing technological bottleneck that needs to be overcome. Summary of the Invention

[0003] To address the aforementioned technical challenges, this invention provides a high-performance Al-Mg-Si alloy prepared by laser powder bed melting, the preparation method of which includes the following steps: (1) Nb powder, Al powder, B powder and C powder are mixed in a mass ratio of 62-71:14-19:8-13:2-9 in a mixer with a speed of 31-42 r / min for 17.5-20.5 h to obtain powder mixture 1; powder mixture 1 is coated with pure aluminum strip in a mass ratio of 1:17-19 and then drawn to form wire A; wire A is heated at 734-781℃ to form liquid flow, and then mixed with pure aluminum liquid in a mass ratio of 1:17-50, and then mechanically stirred for 5-7 min, ultrasonically treated, cast, rolled and crushed to obtain mixture 2; the obtained mixture 2 contains 2.1 wt. -5.8 wt.% nano-ceramic particles; the Nb powder has a particle size of 12.3-46.5 μm; the Al powder has a particle size of 80.7-164.2 μm; the B powder has a particle size of 112.5-176.8 μm; and the C powder has a particle size of 53.5-134.2 μm; the drawing process is carried out at 400-410℃ for 2-4 hours, with a single drawing area reduction of 15%-25%; the ultrasonic treatment is performed at a frequency of 20-25 kHz; the mechanical stirring is performed at a stirring speed of 2-4 r / s; and the casting and rolling process is performed at a casting and rolling speed of 60-120 m / h, with a rolling deformation of 20-60%. (2) Aluminum-niobium alloy powder and B4C powder are mixed in a mixer with a rotation speed of 34-46 r / min at a mass ratio of 31-38:16-27 for 2.6-8.5 h to obtain powder mixture 3; powder mixture 3 is compacted and sintered to form filament C; filament C is subjected to electro-explosion treatment to obtain aluminum-coated nano-sized NbC+NbB2 ceramic particle mixture 4; mixture 2 and mixture 4 obtained in step (1) are mixed at a mass ratio of 1-4:3-6 to obtain mixture A, and mixture A is coated with aluminum alloy plate at a mass ratio of 1:3-4. The material is then drawn into wire D; the B4C powder has a particle size of 77.4-186.2 μm, and the aluminum-niobium alloy powder has a particle size of 18.8-39.4 μm; the compaction is carried out at a pressure of 400-600 N for 10-30 s; the sintering is carried out at a heating rate of 15-50 °C / min, a reaction temperature of 800-1100 °C, and a pressure of 20-50 MPa; the electro-explosion treatment is carried out under argon protection, with a voltage of 100-300 V, a temperature of 800-1200 °C, a pressure of 0.032-0.057 MPa, and a current of 1.1 × 10⁻⁶. 5 -1.6×10 6 A / mm 2 The drawing process involves holding the material at 420-440℃ for 1-3 hours, with a single drawing area reduction of 10%-20%. (3) After melting the Al-Mg-Si alloy at 680-750℃ for 1-2 hours, a slag remover is added and the mixture is kept at 680-750℃ for 2-6 minutes to obtain the Al-Mg-Si alloy melt. The Al-Mg-Si alloy is composed of the following components by mass percentage: Mg: 0.8-1.2 wt.%; Si: 0.7-0.9 wt.%; Zr: 0.05-0.1 wt.%; unavoidable impurities ≤0.03%; the balance is Al. The slag remover is a mixture of 20-35 wt.% KCl, 25-40 wt.% MgCl2, 10-20 wt.% Na2CO3, 3-6 wt.% AlF3, 8-15 wt.% Na3AlF6, 3-8 wt.% Mg3N2 and 1-5 wt.% KBF4. (4) After preheating the wire D obtained in step (2) at 150-200℃ for 2-3 hours, it is added to the Al-Mg-Si alloy melt obtained in step (3). After mechanical stirring for 5-7 minutes, ultrasonic treatment, and solidification by pouring into a preheated steel mold, an Al-Mg-Si alloy ingot containing nanoparticles is obtained. The mass ratio of the wire D to the Al-Mg-Si alloy melt is 1:2-29. The mechanical stirring is at a stirring speed of 1-3 r / s. The ultrasonic treatment is at a frequency of 21-24 kHz. The preheated steel mold is a steel mold obtained after preheating at 150-200℃ for 0.5-1 hours. The Al-Mg-Si alloy ingot containing nanoparticles contains nanoparticles, wherein the average particle size of the nanoparticles is 50-500 nm. (5) The Al-Mg-Si alloy ingot containing nanoparticles reinforced obtained in step (4) is homogenized and hot extruded to obtain Al-Mg-Si alloy wire containing nanoparticles reinforced. The homogenization is carried out at 550-580℃ for 5-10h; the hot extrusion is carried out at 410-470℃ with an extrusion ratio of 120-140:1 and an extrusion speed of 2-4m / min. (6) After the Al-Mg-Si alloy wire containing nanoparticles obtained in step (5) is completely melted at 700-750℃ for 1-2 hours, it is then diffused by ultrasonic vibration at 25-30kHz to form spherical droplets of 5-250μm; the spherical droplets are then dropped into an atomizing tower 5-7m high, and after rapid cooling and solidification, solid spherical powder of Al-Mg-Si alloy with inner nanoparticles with a particle size of 15-53μm is obtained; the solid spherical powder of Al-Mg-Si alloy with inner nanoparticles is then subjected to 300-500 layers of laser powder bed melting treatment and artificial aging treatment to obtain laser powder bed. The high-performance Al-Mg-Si alloy is fused using laser powder bed melting, wherein each layer is processed with the following laser power: 300-500W, scanning speed: 700-1700mm / min, spot diameter: 0.5-0.75mm, overlap width: 0.1-0.14mm, and powder layer thickness: 30-90µm; the artificial aging treatment involves holding at 160-180℃ for 8-14 hours; the high-performance Al-Mg-Si alloy contains NbC+NbB2 nanoparticles, with a mass percentage of 0.1wt%-0.2wt% and a particle size of 50-500 nm. nm; while maintaining high elongation, it also has high strength, with tensile strength ≥360 MPa and yield strength ≥350 MPa. It is non-anisotropic, does not crack, has fine equiaxed grains, and has an average grain size of 1-2µm, which is much smaller than that of traditional rolled or hot-extruded Al-Mg-Si alloys. Laser powder bed melting high-performance Al-Mg-Si alloys can have both simple and complex structures.

[0004] Furthermore, the Nb powder in step (1) has a particle size of 15-30 μm.

[0005] Furthermore, the particle size of the B4C powder mentioned in step (2) is 80-150 μm.

[0006] Furthermore, the ultrasonic processing frequency in step (4) is 22-23 kHz.

[0007] Further, the artificial aging treatment described in step (6) involves holding the material at 165-177℃ for 10-12 hours; the tensile strength is 361-379 MPa, and the yield strength is 354-378 MPa.

[0008] Compared with the prior art, the advantages of the present invention are: Compared with existing technologies, this invention, through the synergistic regulation of component interactions, proportions, processes, and process parameters, provides a high-performance Al-Mg-Si alloy with the following key alloying element composition by weight percentage: magnesium 0.8%–1.2%, silicon 0.7%–0.9%, zirconium 0.05%–0.1%, and the addition of 0.1%–0.2% nanoparticles with a particle size of 50–500 nm. Compared with traditional methods that add 0.3 wt% or more of rare earth elements, the alloy obtained by this invention achieves strengthening through trace amounts of nano-ceramic particles without adding large amounts of expensive rare earth elements. Its preparation cost is only 30% or less of that of rare earth-containing Al-Mg-Si alloys, and the amount of alloying elements used is only 50% or less of the total alloying amount added in rare earth-containing Al-Mg-Si alloys. This invention, through low-temperature short-process aging treatment, simultaneously improves the strength and ductility of the alloy. That is, while maintaining high ductility, it achieves a significant increase in strength, with a room temperature yield strength ≥350 MPa and a room temperature tensile strength ≥360 MPa. It exhibits no anisotropy, no cracking, and fully equiaxed fine grains with a grain size of 1–2 µm, demonstrating good microstructure uniformity. Compared to existing Al-Mg-Si alloys obtained through complex heat treatment processes such as high-temperature solution treatment at ≥550℃ and long-term aging, and with high-cost additives, resulting in >7µm equiaxed grains and mechanical properties, the alloy obtained by this invention shows a 25%–35% increase in strength and a 70%–90% reduction in grain size. In summary, this invention overcomes the technical bottleneck of existing technologies, which can only prepare simple structures and struggle to obtain complex structures while simultaneously improving the strength and ductility of magnesium alloys. Attached Figure Description

[0009] Figure 1 The image shows the morphology of the solid spherical powder 2 of Al-Mg-Si alloy with internally coated nanoparticles prepared in Example 2.

[0010] Figure 2 The density characterization diagram is shown for the high-performance Al-Mg-Si alloy 2 prepared by laser powder bed melting in Example 2.

[0011] Figure 3 The room temperature mechanical property curves of the high-performance Al-Mg-Si alloy 3 prepared by laser powder bed melting in Example 3 are shown. Detailed Implementation

[0012] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1

[0013] A high-performance Al-Mg-Si alloy prepared by laser powder bed melting includes the following steps: (1) Mix Nb powder, Al powder, B powder, and C powder in a mass ratio of 65:15:11: 9. After mixing in a mixer at 32 r / min for 18 h, powder mixture 1 is obtained. Powder mixture 1 is coated with pure aluminum strip at a mass ratio of 1:17 and then drawn to form wire A. Wire A is heated at 736℃ to form a liquid flow, and then mixed with pure aluminum liquid at a mass ratio of 1:36. After mechanical stirring for 5-7 min, ultrasonic treatment, casting and rolling, and crushing, mixture 2 is obtained. The obtained mixture 2 contains 2.8 wt.% nano-ceramic particles. The particle size of Nb powder is 15 μm; the particle size of Al powder is 85 μm; the particle size of B powder is 115 μm; and the particle size of C powder is 54 μm. The drawing is carried out at 400℃ for 2 h, with a single drawing area reduction of 15%. The ultrasonic treatment is performed at a frequency of 22.1 kHz. The mechanical stirring is performed at a stirring speed of 2 r / s. The casting and rolling is performed at a casting and rolling speed of 60 m / h and a rolling deformation of 20%. (2) Aluminum-niobium alloy powder and B4C powder were mixed in a mixer at a mass ratio of 35:16 for 2.7 hours to obtain powder mixture 3; powder mixture 3 was compacted and sintered to form filament C; filament C was subjected to electro-explosion treatment to obtain aluminum-coated nano-sized NbC+NbB2 ceramic particle mixture 4; mixture 2 and mixture 4 obtained in step (1) were mixed in a mass ratio of 2:3 to obtain mixture A, and mixture A and Aluminum alloy sheets are coated at a 1:3 mass ratio and then drawn into wire D; the B4C powder has a particle size of 78 μm, and the aluminum-niobium alloy powder has a particle size of 22 μm; the compaction is carried out at a pressure of 400 N for 10 s; the sintering is carried out at a heating rate of 15 °C / min, a reaction temperature of 800 °C, and a pressure of 20 MPa; the electro-explosion treatment is carried out under argon protection, at a voltage of 100 V, a temperature of 800 °C, a pressure of 0.035 MPa, and a current of 1.4 × 10⁻⁶. 5 A / mm 2 The drawing process involves holding the material at 420℃ for 1 hour, with the area reduced by 10% in a single drawing operation. (3) After melting the Al-Mg-Si alloy at 690℃ for 1 hour, a slag remover is added and the mixture is kept at 690℃ for 3 minutes to obtain the Al-Mg-Si alloy melt. The Al-Mg-Si alloy is composed of the following components by mass percentage: Mg: 0.8wt.%; Si: 0.7wt.%; Zr: 0.05wt.%; unavoidable impurities ≤0.03%; balance is Al. The slag remover is a mixture of 25wt.% KCl, 30wt.% MgCl2, 14wt.% KBF4, 5wt.% AlF3, 10wt.% Na3AlF6, 8wt.% Mg3N2 and 6wt.% Na2CO3. (4) After the wire D obtained in step (2) is preheated at 160°C for 2 hours, it is added to the Al-Mg-Si alloy melt obtained in step (3). After mechanical stirring for 5 minutes, ultrasonic treatment, and solidification by injection into a preheated steel mold, an Al-Mg-Si alloy ingot containing nanoparticles is obtained. The mass ratio of the wire D to the Al-Mg-Si alloy melt is 1:29. The mechanical stirring is at a stirring speed of 1 r / s. The ultrasonic treatment is at a frequency of 21.4 kHz. The preheated steel mold is a steel mold obtained after preheating at 150°C for 0.5 hours. The Al-Mg-Si alloy ingot containing nanoparticles contains nanoparticles, wherein the average particle size of the nanoparticles is 150 nm. (5) The Al-Mg-Si alloy ingot containing nanoparticles reinforced obtained in step (4) is homogenized and hot extruded to obtain Al-Mg-Si alloy wire containing nanoparticles reinforced. The homogenization is carried out at 550℃ for 5 hours; the hot extrusion is carried out at 420℃ with an extrusion ratio of 120:1 and an extrusion speed of 2m / min. (6) After the Al-Mg-Si alloy wire containing nanoparticles obtained in step (5) is completely melted at 700℃ for 1 hour, it is then diffused by ultrasonic vibration at 25kHz to form spherical droplets of 5-250μm; the spherical droplets are then dropped into a 5.2m high atomization tower, and after rapid cooling and solidification, solid spherical powder 1 of Al-Mg-Si alloy with inner nanoparticles with a particle size of 15-53μm is obtained; the solid spherical powder of Al-Mg-Si alloy with inner nanoparticles is then subjected to 350-layer laser powder bed melting treatment and artificial... A high-performance Al-Mg-Si alloy obtained by laser powder bed melting was obtained after aging treatment. The laser powder bed melting treatment of each layer was carried out with the following parameters: laser power of 350W, scanning speed of 900mm / min, spot diameter of 0.55mm, overlap width of 0.1mm, and powder layer thickness of 30µm. The artificial aging treatment was carried out at 166℃ for 11h. The high-performance Al-Mg-Si alloy contained NbC+NbB2 nanoparticles, which accounted for 0.1wt% of the mass and had a particle size of 150 nm. It maintained high elongation while also having high strength, with a tensile strength of 361 MPa and a yield strength of 354 MPa. It was anisotropic, did not crack, and had fine equiaxed grains with an average particle size of 1.3µm, which is much smaller than that of traditional rolled or hot-extruded Al-Mg-Si alloys. The high-performance Al-Mg-Si alloy can have both simple and complex structures. Example 2

[0014] The preparation method of high-performance Al-Mg-Si alloy 2 using laser powder bed melting includes the following steps: (1) Nb powder, Al powder, B powder, and C powder were mixed in a mixer at a speed of 37 r / min for 18.5 h at a mass ratio of 66:16:13:5 to obtain powder mixture 1; powder mixture 1 was coated with pure aluminum strip at a mass ratio of 1:18 and then drawn to form wire A; wire A was heated at 755℃ to form a liquid flow, and then mixed with pure aluminum liquid at a mass ratio of 1:29. After mechanical stirring for 6 min, ultrasonic treatment, casting, rolling, and crushing, mixture 2 was obtained; The mixture 2 contains 3.4 wt.% nano-ceramic particles; the Nb powder has a particle size of 24 μm; the Al powder has a particle size of 110 μm; the B powder has a particle size of 135 μm; and the C powder has a particle size of 105 μm. The drawing process is carried out at 405℃ for 3 hours, with a single drawing area reduction of 20%. The ultrasonic treatment is performed at a frequency of 23 kHz. The mechanical stirring is performed at a stirring speed of 3 r / s. The casting and rolling process is performed at a casting and rolling speed of 90 m / h and a rolling deformation of 40%. (2) Aluminum-niobium alloy powder and B4C powder were mixed in a mixer at a mass ratio of 35:19 for 5.7 hours to obtain powder mixture 3; powder mixture 3 was compacted and sintered to form filament C; filament C was subjected to electro-explosion treatment to obtain aluminum-coated nano-sized NbC+NbB2 ceramic particle mixture 4; mixture 2 and mixture 4 obtained in step (1) were mixed in a mass ratio of 4:5 to obtain mixture A, and mixture A was mixed with aluminum Alloy plates were coated at a mass ratio of 1:3.5 and then drawn into wire D; the B4C powder had a particle size of 110 μm, and the aluminum-niobium alloy powder had a particle size of 28 μm; the compaction was carried out at a pressure of 500 N for 20 s; the sintering was carried out at a heating rate of 25 °C / min, a reaction temperature of 900 °C, and a pressure of 30 MPa; the electro-explosion treatment was carried out under argon protection at a voltage of 200 V, a temperature of 900 °C, a pressure of 0.037 MPa, and a current of 1.2 × 10⁻⁶. 6 A / mm 2 The drawing process involves holding the material at 430℃ for 2 hours, with a single drawing area reduction of 15%. (3) After melting the Al-Mg-Si alloy at 720℃ for 1 hour, a slag remover is added and the mixture is kept at 720℃ for 5 minutes to obtain the Al-Mg-Si alloy melt. The Al-Mg-Si alloy is composed of the following components by mass percentage: Mg: 0.9wt.%; Si: 0.8wt.%; Zr: 0.075wt%; unavoidable impurities ≤0.03%; balance is Al. The slag remover is a mixture of 30wt.% KCl, 20wt.% MgCl2, 20wt.% Na2CO3, 6wt.% AlF3, 15wt.% Na3AlF6, 5wt.% Mg3N2 and 4wt.% KBF4. (4) After the wire D obtained in step (2) is preheated at 176°C for 2.5h, it is added to the Al-Mg-Si alloy melt obtained in step (3). After mechanical stirring for 5.5min, ultrasonic treatment, and solidification by injection into a preheated steel mold, an Al-Mg-Si alloy ingot containing nanoparticles is obtained. The mass ratio of the wire D to the Al-Mg-Si alloy melt is 1:19. The mechanical stirring is at a stirring speed of 1.5r / s. The ultrasonic treatment is at a frequency of 21.5kHz. The preheated steel mold is a steel mold obtained after preheating at 177°C for 0.6h. The Al-Mg-Si alloy ingot containing nanoparticles contains nanoparticles, wherein the average particle size of the nanoparticles is 250 nm. (5) The Al-Mg-Si alloy ingot containing nanoparticles reinforced obtained in step (4) is homogenized and hot extruded to obtain Al-Mg-Si alloy wire containing nanoparticles reinforced. The homogenization is carried out at 565℃ for 8 hours; the hot extrusion is carried out at 435℃ with an extrusion ratio of 125:1 and an extrusion speed of 2.5m / min. (6) The Al-Mg-Si alloy wire containing nanoparticles obtained in step (5) was completely melted at 722℃ for 1.5h, and then diffused by ultrasonic vibration at 25.8kHz to form spherical droplets of 5-250μm; the spherical droplets were then dropped into a 5.6m high atomization tower, and after rapid cooling and solidification, solid spherical powder 2 of Al-Mg-Si alloy with internally coated nanoparticles with a particle size of 15-53μm was obtained. The morphology of powder 2 is as follows: Figure 1 As shown, the powder surface is smooth, has good sphericity, and no obvious satellite particles or adhesion. Then, the solid spherical powder of Al-Mg-Si alloy with internally coated nanoparticles is subjected to 420-layer laser powder bed melting and artificial aging treatment to obtain a high-performance laser powder bed fused Al-Mg-Si alloy. Its density characterization is as follows: Figure 2 As shown, the bulk density can reach over 99.8%. The laser powder bed melting process for each layer involves: laser power of 420W, scanning speed of 1250mm / min, spot diameter of 0.65mm, overlap width of 0.12mm, and powder layer thickness of 60µm. The artificial aging treatment involves holding at 175℃ for 11.5h. The laser powder bed melt high-performance Al-Mg-Si alloy contains NbC+NbB2 nanoparticles, which account for 0.15wt% of the mass and have a particle size of 250 nm. While maintaining high elongation, it also has high strength, with a tensile strength of 367 MPa and a yield strength of 363 MPa. It exhibits no anisotropy, no cracking, and has fine, equiaxed grains with an average particle size of 1.5µm, which is much smaller than that of traditional rolled or hot-extruded Al-Mg-Si alloys. The laser powder bed melt high-performance Al-Mg-Si alloy can have both simple and complex structures. Example 3

[0015] The preparation method of high-performance Al-Mg-Si alloy 3 by laser powder bed melting includes the following steps: (1) Nb powder, Al powder, B powder, and C powder were mixed in a mixer at a speed of 40 r / min for 20 h at a mass ratio of 70:19:6:5 to obtain powder mixture 1; powder mixture 1 was coated with pure aluminum strip at a mass ratio of 1:19 and then drawn to form wire A; wire A was heated at 780℃ to form a liquid flow, and then mixed with pure aluminum liquid at a mass ratio of 1:20. After mechanical stirring for 6.5 min, ultrasonic treatment, casting, rolling, and crushing, mixture 2 was obtained; The mixture 2 contains 5 wt.% nano-ceramic particles; the Nb powder has a particle size of 28 μm; the Al powder has a particle size of 150 μm; the B powder has a particle size of 155 μm; and the C powder has a particle size of 130 μm. The drawing process is carried out at 410℃ for 4 hours, with a single drawing area reduction of 25%. The ultrasonic treatment is performed at a frequency of 25 kHz. The mechanical stirring is performed at a stirring speed of 4 r / s. The casting and rolling process is performed at a casting and rolling speed of 120 m / h and a rolling deformation of 60%. (2) Aluminum-niobium alloy powder and B4C powder were mixed in a mixer at a mass ratio of 37:16 for 8.2 hours to obtain powder mixture 3; powder mixture 3 was compacted and sintered to form filament C; filament C was subjected to electro-explosion treatment to obtain aluminum-coated nano-sized NbC+NbB2 ceramic particle mixture 4; mixture 2 and mixture 4 obtained in step (1) were mixed at a mass ratio of 2:5 to obtain mixture A, and mixture A was mixed with aluminum Alloy plates were coated at a 1:4 mass ratio and then drawn into wire D; the B4C powder had a particle size of 1402 μm, and the aluminum-niobium alloy powder had a particle size of 35 μm; the compaction was carried out at a pressure of 600 N for 30 s; the sintering was carried out at a heating rate of 45 °C / min, a reaction temperature of 1100 °C, and a pressure of 50 MPa; the electro-explosion treatment was carried out under argon protection at a voltage of 300 V, a temperature of 1200 °C, a pressure of 0.05 MPa, and a current of 1.6 × 10⁻⁶. 6 A / mm 2 The drawing process involves holding the material at 440℃ for 3 hours, with the area reduced by 20% in a single drawing operation. (3) After melting the Al-Mg-Si alloy at 740℃ for 1.7h, a slag remover is added and the mixture is kept at 740℃ for 5.5min to obtain the Al-Mg-Si alloy melt. The Al-Mg-Si alloy is composed of the following components by mass percentage: Mg: 1.05wt.%; Si: 0.9wt.%; Zr: 0.08wt.%; unavoidable impurities ≤0.03%; balance is Al. The slag remover is a mixture of 30wt.% KCl, 35wt.% MgCl2, 15wt.% Na2CO3, 6wt.% AlF3, 8wt.% Na3AlF6, 4wt.% Mg3N2 and 2wt.% KBF4. (4) After the wire D obtained in step (2) is preheated at 200°C for 2.7 h, it is added to the Al-Mg-Si alloy melt obtained in step (3). After mechanical stirring for 7 min, ultrasonic treatment, and solidification by injection into a preheated steel mold, an Al-Mg-Si alloy ingot containing nanoparticles is obtained. The mass ratio of the wire D to the Al-Mg-Si alloy melt is 1:14. The mechanical stirring is at a stirring speed of 1.7 r / s. The ultrasonic treatment is at a frequency of 21.8 kHz. The preheated steel mold is a steel mold obtained after preheating at 180°C for 0.7 h. The Al-Mg-Si alloy ingot containing nanoparticles contains nanoparticles, wherein the average particle size of the nanoparticles is 350 nm. (5) The Al-Mg-Si alloy ingot containing nanoparticles reinforced obtained in step (4) is homogenized and hot extruded to obtain Al-Mg-Si alloy wire containing nanoparticles reinforced. The homogenization is carried out at 572℃ for 9 hours; the hot extrusion is carried out at 438℃ with an extrusion ratio of 130:1 and an extrusion speed of 3m / min. (6) The Al-Mg-Si alloy wire containing nanoparticles obtained in step (5) is completely melted at 725℃ for 1.7h, and then diffused by ultrasonic vibration at 28kHz to form spherical droplets of 5-250μm; the spherical droplets are then dropped into a 5.6m high atomization tower, and after rapid cooling and solidification, solid spherical powder 3 of Al-Mg-Si alloy with inner nanoparticles with a particle size of 15-53μm is obtained; the solid spherical powder of Al-Mg-Si alloy with inner nanoparticles is then subjected to 480-layer laser powder bed melting treatment and artificial aging treatment to obtain high-performance Al-Mg-Si alloy with laser powder bed melting, whose room temperature mechanical properties are as follows: Figure 3 As shown, excellent synergy between strength and plasticity was achieved. The laser powder bed melting process for each layer involved a laser power of 450W, a scanning speed of 1300mm / min, a spot diameter of 0.65mm, an overlap width of 0.14mm, and a powder layer thickness of 90µm. The artificial aging treatment involved holding at 177℃ for 12h. The laser powder bed melt high-performance Al-Mg-Si alloy contained NbC+NbB2 nanoparticles, which accounted for 0.2wt% of the mass and had a particle size of 350 nm. While maintaining high elongation, it also possessed high strength, with a tensile strength of 379 MPa and a yield strength of 378 MPa. It exhibited no anisotropy, no cracking, and fully equiaxed fine grains with an average particle size of 1.3µm, which is much smaller than that of traditional rolled or hot-extruded Al-Mg-Si alloys. The laser powder bed melt high-performance Al-Mg-Si alloy can have both simple and complex structures. Comparative Example

[0016] In 2025, Xu Yuan et al. published an article titled "Microstructures and mechanical properties of cast Al–Mg–Si alloy with combined addition of Sc and Zr" in Volume 35 of the Journal of Materials Research and Technology. They improved the strength and ductility of the Al-Mg-Si alloy by adding scandium and zirconium. After adding scandium and zirconium and undergoing solution treatment at 580℃ for 2 hours and aging at 120℃ for 24 hours, the final alloy exhibited a yield strength of 198 MPa and a tensile strength of 288 MPa. The Al-Mg-Si alloy composition, by mass percentage, was: Mg: 5.91 wt.%; Si: 0.99 wt.%; Sc: 0.33 wt.%; Zr: 0.13 wt.%; Al: balance.

[0017] In Comparative Example 1, the amounts of Mg (5.91 wt.%), Si (0.99 wt.%), and Zr (0.13 wt.%) are higher than the maximum element addition amounts of the present invention: Mg (1.2 wt.%), Si (0.9 wt.%), and Zr (0.1 wt.%). In addition, Comparative Example 1 also added rare earth precious metal elements such as Sc (0.33 wt.%), while the present invention only requires the addition of trace particles (≤0.2 wt.%), and the raw material cost is significantly lower than the cost of adding rare earth elements such as Sc (0.33 wt.%) in the prior art. At the same time, compared with the high temperature solid solution and long time (24h) aging of the prior art, the present invention does not use high temperature solid solution and only uses low temperature short time aging (≤14h) treatment, which does not require complex heat treatment procedures, and the process is simple and the processing time is short, further improving the overall economic efficiency of the process. Meanwhile, compared with existing technologies, this invention, through the synergistic control of processes and process parameters, possesses greater design flexibility. It can not only form complex geometric configurations and internal cavity structures that are difficult to achieve with traditional casting processes, but also achieve efficient machining of simple structures, eliminating assembly steps while completing the integrated net-shape forming of functional components. Furthermore, in all embodiments of this invention, the alloy in Example 1 exhibits the lowest performance. For example, its Mg, Si, and Zr content is only 0.8 wt.%, 0.7 wt.%, and 0.05 wt.%, respectively. Both the content of individual elements and the total element content are lower than in the comparative example, and only 0.1 wt.% of particles are added. While achieving fully equiaxed fine grains, the alloy's yield strength and tensile strength are 354 MPa and 358 MPa, respectively. In contrast, the content of each added element and the total element content in the comparative example, as well as the cost, are far higher than the element and nanoparticle addition amounts in Example 1 of this invention. Even with the cumbersome and time-consuming heat treatment employed in the comparative example (solution at 580℃ for 2 hours + aging at 120℃ for 24 hours), the comparative example yielded a coarse equiaxed grain structure of ~50µm, nearly 50 times the grain size of 1.3µm in Example 1 of this invention. The yield strength and tensile strength of the alloy obtained in the comparative example were 198 MPa and 288 MPa, respectively, far lower than the lowest values ​​in the examples of this invention (yield strength and tensile strength of 354 MPa and 358 MPa, respectively). In summary, compared with the prior art, this invention has lower raw material costs and a simpler process, while achieving a finer microstructure and higher strength and plasticity.

[0018] Table 1. Comparison of mechanical properties of alloys obtained in Examples 1-3 and the comparative examples.

[0019] In summary, compared with existing technologies, this invention has the following advantages: First, it eliminates the need for high-content, expensive rare-earth alloying elements, and the total amount added is low, reducing the need for long-term high-temperature heat treatment, thus significantly simplifying the process. Second, it overcomes the inherent limitations of traditional rolling / extrusion forming technologies, such as slow forming speed, poor structural adaptability, and coarse grains, achieving simultaneous improvement in strength while maintaining good alloy plasticity. Third, the produced material is anisotropic, capable of forming both simple and complex structures, achieving crack-free rapid forming, and obtaining a refined equiaxed grain structure. Therefore, this invention successfully breaks through the technical bottleneck of existing technologies that struggle to simultaneously improve strength and plasticity. Furthermore, the various embodiments of this invention differ in component ratios, processes, and process parameters, resulting in different mechanical properties and microstructures. This indicates that the optimal strengthening effect of this invention is not determined by a single component, ratio, process, or process parameter, but rather stems from the synergistic control between components, ratios, processes, and parameters. Only within the scope of the claims of this invention can the aforementioned superior comprehensive performance be achieved.

Claims

1. A high-performance Al-Mg-Si alloy prepared by laser powder bed melting includes the following steps: (1) Nb powder, Al powder, B powder and C powder are mixed in a mass ratio of 62-71:14-19:8-13:2-9 in a mixer with a speed of 31-42 r / min for 17.5-20.5 h to obtain powder mixture 1; powder mixture 1 is coated with pure aluminum strip in a mass ratio of 1:17-19 and then drawn to form wire A; wire A is heated at 734-781℃ to form liquid flow, and then mixed with pure aluminum liquid in a mass ratio of 1:17-50, and then mechanically stirred for 5-7 min, ultrasonically treated, cast, rolled and crushed to obtain mixture 2; the obtained mixture 2 contains 2.1 wt. -5.8 wt.% nano-ceramic particles; the Nb powder has a particle size of 12.3-46.5 μm; the Al powder has a particle size of 80.7-164.2 μm; the B powder has a particle size of 112.5-176.8 μm; and the C powder has a particle size of 53.5-134.2 μm; the drawing process is carried out at 400-410℃ for 2-4 hours, with a single drawing area reduction of 15%-25%; the ultrasonic treatment is performed at a frequency of 20-25 kHz; the mechanical stirring is performed at a stirring speed of 2-4 r / s; and the casting and rolling process is performed at a casting and rolling speed of 60-120 m / h, with a rolling deformation of 20-60%. (2) Aluminum-niobium alloy powder and B4C powder are mixed in a mixer with a rotation speed of 34-46 r / min at a mass ratio of 31-38:16-27 for 2.6-8.5 h to obtain powder mixture 3; powder mixture 3 is compacted and sintered to form filament C; filament C is subjected to electro-explosion treatment to obtain aluminum-coated nano-sized NbC+NbB2 ceramic particle mixture 4; mixture 2 and mixture 4 obtained in step (1) are mixed at a mass ratio of 1-4:3-6 to obtain mixture A, and mixture A is coated with aluminum alloy plate at a mass ratio of 1:3-4. The material is then drawn into wire D; the B4C powder has a particle size of 77.4-186.2 μm, and the aluminum-niobium alloy powder has a particle size of 18.8-39.4 μm; the compaction is carried out at a pressure of 400-600 N for 10-30 s; the sintering is carried out at a heating rate of 15-50 °C / min, a reaction temperature of 800-1100 °C, and a pressure of 20-50 MPa; the electro-explosion treatment is carried out under argon protection, with a voltage of 100-300 V, a temperature of 800-1200 °C, a pressure of 0.032-0.057 MPa, and a current of 1.1 × 10⁻⁶. 5 -1.6×10 6 A / mm 2 The drawing process involves holding the material at 420-440℃ for 1-3 hours, with a single drawing area reduction of 10%-20%. (3) After melting the Al-Mg-Si alloy at 680-750℃ for 1-2 hours, a slag remover is added and the mixture is held at 680-750℃ for 2-6 minutes to obtain the Al-Mg-Si alloy melt; the Al-Mg-Si alloy, by mass percentage, consists of the following components Composition: Mg: 0.8-1.2 wt.%; Si: 0.7-0.9 wt.%; Zr: 0.05-0.1 wt.%; unavoidable impurities ≤0.03%; balance Al. The slag remover is a mixture of 20-35 wt.% KCl, 25-40 wt.% MgCl2, 10-20 wt.% Na2CO3, 3-6 wt.% AlF3, 8-15 wt.% Na3AlF6, 3-8 wt.% Mg3N2 and 1-5 wt.% KBF4. (4) After preheating the wire D obtained in step (2) at 150-200℃ for 2-3 hours, it is added to the Al-Mg-Si alloy melt obtained in step (3). After mechanical stirring for 5-7 minutes, ultrasonic treatment, and solidification by pouring into a preheated steel mold, an Al-Mg-Si alloy ingot containing nanoparticles is obtained. The mass ratio of the wire D to the Al-Mg-Si alloy melt is 1:2-29. The mechanical stirring is at a stirring speed of 1-3 r / s. The ultrasonic treatment is at a frequency of 21-24 kHz. The preheated steel mold is a steel mold obtained after preheating at 150-200℃ for 0.5-1 hours. The Al-Mg-Si alloy ingot containing nanoparticles contains nanoparticles, wherein the average particle size of the nanoparticles is 50-500 nm. (5) The Al-Mg-Si alloy ingot containing nanoparticles reinforced obtained in step (4) is homogenized and hot extruded to obtain Al-Mg-Si alloy wire containing nanoparticles reinforced. The homogenization is carried out at 550-580℃ for 5-10h; the hot extrusion is carried out at 410-470℃ with an extrusion ratio of 120-140:1 and an extrusion speed of 2-4m / min. (6) After the Al-Mg-Si alloy wire containing nanoparticles obtained in step (5) is completely melted at 700-750℃ for 1-2 hours, it is then diffused by ultrasonic vibration at 25-30kHz to form spherical droplets of 5-250μm; the spherical droplets are then dropped into an atomizing tower 5-7m high, and after rapid cooling and solidification, solid spherical powder of Al-Mg-Si alloy with inner nanoparticles with a particle size of 15-53μm is obtained; the solid spherical powder of Al-Mg-Si alloy with inner nanoparticles is then subjected to 300-500 layers of laser powder bed melting treatment and artificial aging treatment to obtain laser powder bed. The high-performance Al-Mg-Si alloy is fused using laser powder bed melting, wherein each layer is processed with the following laser power: 300-500W, scanning speed: 700-1700mm / min, spot diameter: 0.5-0.75mm, overlap width: 0.1-0.14mm, and powder layer thickness: 30-90µm; the artificial aging treatment involves holding at 160-180℃ for 8-14 hours; the high-performance Al-Mg-Si alloy contains NbC+NbB2 nanoparticles, with a mass percentage of 0.1wt%-0.2wt% and a particle size of 50-500 nm. nm; while maintaining high elongation, it also has high strength, with tensile strength ≥360 MPa and yield strength ≥350 MPa. It is non-anisotropic, does not crack, has fine equiaxed grains, and has an average grain size of 1-2µm, which is much smaller than that of traditional rolled or hot-extruded Al-Mg-Si alloys. Laser powder bed melting high-performance Al-Mg-Si alloys can have both simple and complex structures.

2. The high-performance Al-Mg-Si alloy obtained by laser powder bed melting according to claim 1, characterized in that: The Nb powder in step (1) has a particle size of 15-30 μm.

3. The high-performance Al-Mg-Si alloy obtained by laser powder bed melting according to claim 1, characterized in that: The B4C powder mentioned in step (2) has a particle size of 80-150 μm.

4. The high-performance Al-Mg-Si alloy obtained by laser powder bed melting according to claim 1, characterized in that: The ultrasonic treatment frequency in step (4) is 22-23 kHz.

5. The high-performance Al-Mg-Si alloy obtained by laser powder bed melting according to claim 1, characterized in that: The artificial aging treatment described in step (6) involves holding the material at 165-177℃ for 10-12 hours; the tensile strength is 361-379 MPa, and the yield strength is 354-378 MPa.

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