A high-formability, high-strength, and heat-resistant additive manufacturing aluminum alloy

Abstract

This invention provides a highly formable, high-strength, and heat-resistant additive manufacturing aluminum alloy, relating to the field of aluminum alloy additive manufacturing. The aluminum alloy contains the following elemental mass percentages: Zn 4.5~6.5%, Mg 1.5~3.0%, Cu 1.0~2.0%, Ti 1.0~3.0%, Nb 1.0~3.0%, Cr 0.15~0.3%, Fe 0.1~1.0%, Si 0.05~0.5%, Mn 0.05~0.5%, with the balance being aluminum. Compared to adding elemental Ti / Ni / Nb / Ta or particles, adding alloy powder containing both Ti and Nb allows for the precipitation of more precipitated phases in the additively manufactured aluminum alloy and produces a stronger solid solution strengthening effect. Therefore, it significantly improves the strength of the additively manufactured aluminum alloy, making it comparable to the strength of traditionally cast and forged aluminum alloys such as 7075 / 7050 / 2024. Furthermore, the alloy exhibits superior high-temperature performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of additive manufacturing of aluminum alloys, and particularly relates to an additive manufacturing aluminum alloy with high formability, high strength and high heat resistance. BACKGROUND

[0002] High-strength aluminum alloys have a wide range of applications in the fields of aviation, aerospace, automobiles, etc. due to their low density and high specific strength. Additive manufacturing can be used to prepare complex components and structures due to its excellent near-net-shape forming capability, and is expected to promote the application of high-strength aluminum alloys in many fields. However, the melt pool formed by metal additive manufacturing has a steep thermal gradient and an ultrafast cooling rate, which leads to the formation of coarse columnar crystals and large internal stress in the material during solidification. This promotes the formation of cracks in materials such as high-temperature alloys, intermetallic compounds and high-strength aluminum alloys (such as 7075, 7050 and 2024) during additive manufacturing, and exhibits extremely low formability. The presence of columnar crystals also leads to serious mechanical property anisotropy and performance instability of the material.

[0003] The addition of single elements or particles such as Zr, Sc, Ti, Ni, Ta, Nb, etc. to high-strength aluminum alloys such as 7075 can promote the preferential formation of Al3X precipitates (X = Zr / Sc / Ti / Ni / Ta / Nb) during solidification. Such precipitates have a high lattice matching degree with the α-Al matrix, can act as a strong nucleating agent, promote the nucleation of grains during solidification, help promote the transformation of columnar crystals to equiaxed crystals and grain refinement, and effectively inhibit the cracking problem of additive manufacturing of high-strength aluminum alloys. However, the strength of 7075 or 2024 modified by single Ti / Ni / Ta / Nb elements or particles is low after additive manufacturing, and the yield strength and tensile strength are lower than those of 7075 or 2024 aluminum alloys prepared by traditional casting and forging processes, which greatly limits the application of such additive manufacturing aluminum alloys. In addition, elements such as Ta and Nb can only be added to high-strength aluminum alloys in the form of ultrafine particles (particle size of several hundred nanometers to 1-2 microns) due to their high melting point, and special powder mixing equipment such as a horizontal ball mill and an electrostatic assembly method are required to add them to the aluminum alloy, which is costly. If pre-alloying + gas atomization is used to add Ta or Nb, such as adding Ta / Nb in the form of elemental metal blocks to the aluminum alloy, it will lead to difficulties in melting, difficulty in accurately controlling the alloy composition, etc.

[0004] Recently, some new types of additive manufacturing aluminum alloys designed with Sc, Zr elements not only have high formability, but also exhibit comparable or even better strength than high-strength aluminum alloys prepared by traditional manufacturing methods. However, such additive manufacturing high-strength aluminum alloys are very expensive, with powder prices 3-4 times that of 7075 powder material, and after additive manufacturing, such high-strength aluminum alloys are prone to form heterogeneous structures between columnar crystals and equiaxed crystals, or between coarse equiaxed crystals and fine equiaxed crystals, and have lower performance and quality stability. In addition, such Zr / Sc / Ti / Ni / Ta / Nb modified additive manufacturing aluminum alloys exhibit lower heat resistance at high temperatures, with rapid reduction in strength. Therefore, it is imperative to develop low-cost additive manufacturing aluminum alloys with high formability and high strength in a wide temperature range. SUMMARY

[0005] The present application aims to solve the problems of high-strength aluminum alloys such as 2xxx series and 7xxx series aluminum alloys prone to form cracks and coarse columnar crystals during laser additive manufacturing, and the problem of low strength of such alloys after additive manufacturing by single element / particle modification, and aims to design a new type of aluminum alloy that can form a completely equiaxed crystal structure after additive manufacturing and has high strength in a wide temperature range, and ensure that the material price of the alloy is similar to that of existing 2xxx series and 7xxx series aluminum alloy powder.

[0006] The present application provides a high-formability high-strength heat-resistant additive manufacturing aluminum alloy, wherein the mass percentage of each element is: Zn 4.5-6.5%, Mg 1.5-3.0%, Cu 1.0-2.0%, Ti 1.0-3.0%, Nb 1.0-3.0%, Cr 0.15-0.3%, Fe 0.1-1.0%, Si 0.05-0.5%, Mn 0.05-0.5%, and the balance is aluminum.

[0007] Preferably, in the aluminum alloy, the mass percentage of Ti and Nb together is 4.0-6.0%.

[0008] Preferably, in the preparation process of the aluminum alloy, Ti and Nb are added to the aluminum alloy in the form of an alloy, rather than in the form of a single element or a single particle of a metal. They can be added to the aluminum alloy powder in the form of a Ti and Nb containing alloy powder, or by melting a bulk Ti and Nb alloy with a bulk aluminum alloy and using a gas atomization method. The added bulk alloy or alloy powder contains Ti and Nb, which promotes the formation of high-melting-point Al3(Ti,Nb) particles during solidification, and promotes nucleation and grain equiaxed refinement using its high-matching crystallographic properties with alpha-Al. The precipitated phase formed can also serve as a strengthening agent. And because such precipitated phase can maintain high stability at high temperatures, it helps to improve the heat resistance of the aluminum alloy.

[0009] Preferably, in the added Ti, Nb-containing alloy (including both alloy blocks and alloy powders, which will not be described hereinafter), the atomic percentage of Ti is 52-54 at.%, the atomic percentage of Nb is 24-26 at.%, and the oxygen content is ≤1000 ppm. The particle size of the alloy powder is 15-53 μm. Compared with elemental ultrafine nanoparticles of Ti and Nb, the alloy powder has a lower cost.

[0010] Preferably, the added Ti, Nb-containing alloy can also contain one or more of Zn, Mg, Cu, Cr, Fe, Si, Mn, and Al elements, which can also be solid-solved into the matrix or promote the formation of more new precipitates, further strengthening the prepared aluminum alloy.

[0011] The application also provides a preparation method of the aluminum alloy. One is to add Ti, Nb-containing alloy powder to aluminum alloy powder in a similar particle size by powder mixing, so as to prevent the addition of Nb / Ti in the form of elemental nanoparticles, which helps to keep the low powder price. Two is to mix a 7075 or 7050 aluminum alloy ingot with a Ti, Nb-containing alloy ingot in a proportion, wherein the proportion of the Ti, Nb-containing alloy is 4wt.%-6wt.%, and then melt the metal by arc melting or electromagnetic induction melting to form a new alloy ingot, and then melt the alloy ingot and use gas atomization / plasma atomization / rotating electrode method for powdering.

[0012] Further, the aluminum alloy is prepared by the following method:

[0013] S1, preparing an aluminum alloy powder;

[0014] S2, using a selective laser melting device, a selective electron beam melting device, or a laser direct deposition device to melt and sample.

[0015] Preferably, in S1, the aluminum alloy powder and the Ti, Nb-containing alloy powder are mixed in an inert gas by using a metal powder mixer to obtain an aluminum alloy powder, the mixing speed is 25-35 rpm, and the mixing time is 1-3 hours. Further preferably, the particle size of the aluminum alloy powder and the Ti, Nb-containing alloy powder is 15-53 μm. The proportion of the Ti, Nb-containing alloy powder is 4wt.%-6wt.%, the atomic percentage of Ti in the alloy powder is 52-54 at.%, and the atomic percentage of Nb is 24-26 at.%.

[0016] Preferably, in step S1, the metal raw materials are mixed in a specific ratio, wherein Zn accounts for 5-5.5 wt.%, Mg accounts for 2-2.5 wt.%, Cu accounts for 1-1.5 wt.%, Ti accounts for 2-2.5 wt.%, Nb accounts for 2-2.5 wt.%, Cr accounts for 0.2-0.5 wt.%, Fe accounts for 0.1-0.5 wt.%, Si accounts for 0.05 wt.%, and Mn accounts for 0.05-0.1 wt.%, with Ti and Nb added in the form of alloy ingots, and other elements added in the form of elemental or alloy ingots. Pre-alloyed bars are prepared by arc melting or electromagnetic induction melting and casting processes, and then aluminum alloy powder is prepared by inert gas atomization, plasma atomization, or rotating electrode methods.

[0017] Preferably, in S2, the parameters for melting and sample preparation using a selective laser melting device or a selective electron beam melting device are: power 300W, scanning rate 950mm / s, line spacing 80μm, and layer thickness 30μm.

[0018] Preferably, in S2, the parameters for melting and sample preparation using a laser direct deposition device are: power 1000W, scanning rate 950mm / min, and powder feed rate 6g / min.

[0019] In one embodiment of the present invention, a powder mixing method is used for powder preparation, including the following steps: aluminum alloy powder with a particle size of similar size (15-53 μm) and Ti- and Nb-containing alloy powder are mixed in argon / nitrogen / helium gas in a certain proportion using a metal powder mixer, wherein the proportion of Ti- and Nb-containing alloy powder is 4 wt.% to 6 wt.%, the atomic percentage of Ti in the alloy powder is 52-54 at.%, the atomic percentage of Nb is 24-26 at.%, the mixing speed is 25-35 rpm, and the mixing time is 1-3 hours.

[0020] Subsequently, a selective laser melting (SLM) or selective electron beam melting (SEBLM) system was used to melt and prepare mixed powders with particle sizes of 15–53 μm under the following conditions: 300 W power, 950 mm / s scan rate, 80 μm line spacing, and 30 μm layer thickness. Alternatively, a laser direct deposition (LDD) system was used to melt and prepare mixed powders with particle sizes of 53–105 μm under the following conditions: 1000 W power, 950 mm / min scan rate, and 6 g / min powder feed rate.

[0021] The applicant's research revealed that if single Nb powder particles with a particle size comparable to aluminum alloy powder are added, the Nb particles cannot melt during the 3D printing process and can only be added in the form of nano-Nb particles. This requires specialized powder mixing equipment such as a horizontal ball mill or electrostatic assembly facilities. However, nano-Nb particles are expensive, and the strength of the printed product is low when added alone. Adding alloy powder containing Ti and Nb, on the other hand, allows for the addition of particles with a particle size comparable to aluminum alloy powder. This enables the use of ordinary powder mixing equipment, reducing production costs and achieving high strength and high heat resistance.

[0022] In another embodiment of the present invention, pre-alloyed powder preparation is employed, comprising the following steps: metal raw materials (proportioned as follows: Zn 5-5.5 wt.%, Mg 2-2.5 wt.%, Cu 1-1.5 wt.%, Ti 2-2.5 wt.%, Nb 2-2.5 wt.%, Cr 0.2-0.5 wt.%, Fe 0.1-0.5 wt.%, Si 0.05 wt.%, Mn 0.05-0.1 wt.%) are added in the form of alloy ingots, while other elements are added in the form of elemental or alloy ingots. Pre-alloyed rods are prepared by arc melting or electromagnetic induction melting (melting temperature range 1500-2500°C) and casting. Pre-alloyed powder is then prepared using inert gas atomization, plasma atomization, or rotating electrode methods.

[0023] Then, alloy powder with a particle size of 15–53 μm is melted and prepared using a selective laser melting (SLM) or selective electron beam (SEB) system under the following conditions: 300 W power, 950 mm / s scanning rate, 80 μm line spacing, and 30 μm layer thickness. Alternatively, alloy powder with a particle size of 53–105 μm is melted and prepared using a laser direct deposition (LDD) system under the following conditions: 1000 W power, 950 mm / min scanning rate, and 6 g / min powder feed rate.

[0024] The applicant's research found that during alloy smelting, directly adding Nb blocks is difficult to melt and requires smelting at higher temperatures. This can lead to the volatilization of low-melting-point elements such as Zn, Mg, and Al, making it difficult to control the alloy composition. However, alloy ingots containing lower-melting-point elements such as Ti and Nb do not have these problems, and the alloy composition is easier to control.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] In existing technologies, Nb is added in the form of extremely expensive nanoparticles and requires specialized equipment (such as horizontal ball mills or electrostatic assembly methods). Unlike existing technologies, this invention adds Ti- and Nb-containing alloy powders with particle sizes comparable to aluminum alloy powders, which can be mixed using ordinary powder mixing techniques. This ensures that the price of the synthesized powder is comparable to that of 2xxx and 7xxx series aluminum alloy powders.

[0027] Compared to adding elemental Ti / Ni / Nb / Ta or particles, adding alloy powder containing both Ti and Nb can result in the precipitation of more precipitated phases in additively manufactured aluminum alloys and produce a stronger solid solution strengthening effect. Therefore, it can significantly improve the strength of additively manufactured aluminum alloys, making them comparable to the strength of traditionally cast or forged aluminum alloys such as 7075 / 7050 / 2024. Compared to adding expensive Nb / Ta nanoparticles or rare metals such as Sc / Zr, adding Ti- and Nb-containing alloy powder particles with a particle size similar to that of aluminum alloy powder particles (which are inherently less expensive) or directly preparing novel aluminum alloy powders through pre-alloying + gas atomization methods will result in much lower powder synthesis costs.

[0028] Furthermore, compared to aluminum alloys modified with elemental Ti / Ni / Nb / Ta / Sc / Zr or by particle modification, aluminum alloys containing Ti and Nb alloy powder particles exhibit higher microstructure thermal stability and heat resistance. These novel high-strength, heat-resistant, and low-cost aluminum alloys are expected to be widely used in aerospace, automotive, and other fields, promoting additive manufacturing. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 The images shown are scanning electron microscope (SEM) images of the aluminum alloy prepared in Example 1, where (a) is magnified 5000 times and (b) is magnified 10000 times.

[0031] Figure 2 The images shown are transmission electron microscope (TEM) images of the aluminum alloy prepared in Example 1, where (a) is a TEM image of the grain structure and Al3(Ti,Nb) precipitate phase, (b) is a TEM image of the MgZn2 precipitate phase and its diffraction pattern, (c) is a TEM image of the banded Al7Cu2Fe precipitate phase, and (d) is an electron diffraction pattern of the banded Al7Cu2Fe precipitate phase.

[0032] Figure 3The images shown are grain boundary test images of the aluminum alloy prepared in Example 1, where (a) is a transmission electron microscope (TEM) image of a certain grain and grain boundary region used for composition analysis, (b) is an energy dispersive spectral density (EDS) distribution map of Mg in the selected region, (c) is an EDS distribution map of Cu in the selected region, (d) is an EDS distribution map of Zn in the selected region, (e) is a TEM image of the grain boundary precipitate phase, (f) is an electron diffraction pattern of the grain boundary precipitate phase MgCu2, (g) is an electron diffraction pattern of the grain boundary quasicrystalline phase, and (h) is a high-resolution transmission electron image and its Fourier transform pattern of the grain boundary quasicrystalline phase.

[0033] Figure 4 The tensile curves of the aluminum alloy prepared in Example 1 at room temperature and high temperature are shown.

[0034] Figure 5 The mechanical properties of the aluminum alloy prepared in Example 1 (marked with an asterisk) are compared with those of other additively manufactured aluminum alloys or forged aluminum alloys, where (a) represents room temperature mechanical properties and (b) represents high temperature mechanical properties.

[0035] Figure 6 The images shown are test images of the aluminum alloy prepared in Example 2, where (a) is a SEM image, (b) is a TEM image, and (c) is a room temperature tensile curve.

[0036] Figure 7 The images shown are test images of aluminum alloy in Comparative Example 1, where (a)-(c) are SEM images and (d) is a tensile curve. Detailed Implementation

[0037] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0038] Example 1

[0039] Aluminum alloy powder with a particle size of similar size (15-53 μm) and Ti- and Nb-containing alloy powder were mixed in an argon / nitrogen / helium atmosphere using a metal powder mixer. The Ti- and Nb-containing alloy powder accounted for 5 wt.%, the atomic percentage of Ti in the alloy powder was 53 at.%, and the atomic percentage of Nb was 25 at.%. The mixing speed was 28 rpm and the mixing time was 3 hours.

[0040] Subsequently, a selective laser melting device was used to melt and prepare a sample of the mixed powder with a particle size of 15-53 μm under the process conditions of 300W power, 950mm / s scanning rate, 80μm line spacing, and 30μm layer thickness to obtain the additively manufactured aluminum alloy.

[0041] Figure 1SEM images of the aluminum alloy prepared in Example 1 are shown to observe its microstructure. This aluminum alloy was modified with alloy powder containing Ti and Nb, resulting in a 7075 alloy. Image (a) is magnified 5000x, and image (b) is magnified 10000x. It can be seen that the prepared alloy consists entirely of fine equiaxed crystals, with grain sizes ranging from several hundred nanometers to 1 μm. The alloy is completely crack-free.

[0042] Figure 2 The images shown are transmission electron microscopy (TEM) images of the aluminum alloy prepared in Example 1, used to observe the internal precipitates within its grains. (a) is a TEM image of the grain structure and the Al3(Ti,Nb) precipitate phase; (b) is a TEM image of the MgZn2 precipitate phase and its diffraction pattern; (c) is a TEM image of the banded Al7Cu2Fe precipitate phase; and (d) is the electron diffraction pattern of the banded Al7Cu2Fe precipitate phase. It can be seen that various precipitates exist, including relatively coarse Al3(Ti,Nb) particles (acting as nucleation particles), very fine MgZn2 precipitates, and banded Al7Cu2Fe precipitates.

[0043] Figure 3 The images shown are grain boundary test images of the aluminum alloy prepared in Example 1, used to observe its grain boundary compositional segregation and precipitate phases. (a) is a transmission electron microscope (TEM) image of a specific grain and grain boundary region used for compositional analysis; (b) is the energy dispersive spectral density (EDS) distribution of Mg in the selected region; (c) is the EDS distribution of Cu in the selected region; (d) is the EDS distribution of Zn in the selected region; (e) is a TEM image of the grain boundary precipitate phase; (f) is the electron diffraction pattern of the grain boundary precipitate phase MgCu2; (g) is the electron diffraction pattern of the grain boundary quasicrystalline phase; and (h) is a high-resolution TEM image and its Fourier transform pattern of the grain boundary quasicrystalline phase. Figure 3 As can be seen from (a)-(d), there is obvious compositional segregation at the grain boundaries of the alloy, mainly the segregation of Mg, Cu, and Zn. Figure 3 As shown in (e)-(h), compositional segregation at grain boundaries also promotes the formation of some precipitate phases, including MgCu2, Al2CuMg, and some quasicrystalline phases. The presence of these uniformly distributed precipitate phases can effectively hinder dislocation movement during alloy deformation, thereby strengthening the alloy and promoting its high strength. In addition, these precipitate phases, such as Al3(Ti,Nb), have high melting points (>1500°C) and can maintain high stability at high temperatures, which helps to improve the high-temperature strength and heat resistance of the alloy.

[0044] Figure 4The tensile curves of the aluminum alloy prepared in Example 1 at room temperature and high temperature are shown. It can be seen that the additively manufactured aluminum alloy has a yield strength of 470 MPa at room temperature, comparable to the strength level of forged 7075 aluminum alloy. At 200°C, the alloy still retains a yield strength of 375 MPa; at 300°C, the additively manufactured aluminum alloy still has a yield strength of 275 MPa. This demonstrates that the alloy exhibits high strength over a wide temperature range.

[0045] Figure 5 The mechanical properties of the aluminum alloy prepared in Example 1 (marked with an asterisk) are compared with those of other additively manufactured or forged aluminum alloys, where (a) represents room temperature mechanical properties and (b) represents high temperature mechanical properties. Figure 5 (a) It is known that, compared with additively manufactured 7075 or 2024 aluminum alloys modified with elemental elements (such as Ti / Nb / Zr / Si / Er), the additively manufactured 7075 aluminum alloy with Ti and Nb alloy modification provided by the present invention exhibits a high room temperature yield strength, which is comparable to that of forged 7075 aluminum alloy. Figure 5 (b) It can be seen that the room temperature yield strength of the additively manufactured aluminum alloy provided by this invention is slightly lower than that of some new additively manufactured aluminum alloys containing Sc and Zr, but its strength under high temperature conditions is much higher than these alloys. In fact, the high temperature strength of the additively manufactured aluminum alloy provided by this invention is higher than that of most current additively manufactured aluminum alloys, and much higher than that of forged 7075 aluminum alloy. Therefore, it is evident that the additively manufactured aluminum alloy provided by this invention possesses excellent mechanical properties over a wide temperature range.

[0046] Example 2

[0047] Metal raw materials were mixed in the following proportions: Zn 5.36 wt.%, Mg 2.2 wt.%, Cu 1.33 wt.%, Ti 2.33 wt.%, Nb 2.13 wt.%, Cr 0.21 wt.%, Fe 0.3 wt.%, Si 0.05 wt.%, Mn 0.08 wt.%, with the balance being aluminum. Ti and Nb were added in the form of alloy ingots, accounting for 5 wt.% of the total added elements, while the other elements were added in the form of 7075 alloy ingots. The above metal raw materials were subjected to arc melting at a melting temperature of 2500℃ to cast pre-alloyed bars, which were then atomized into aluminum alloy powder using an inert gas atomization method. Finally, a selective laser melting (SLM) device was used to prepare samples with the following parameters: power 300W, scanning rate 950 mm / s, line spacing 80 μm, and layer thickness 30 μm.

[0048] Figure 6The images shown are test images of the aluminum alloy prepared in Example 2, where (a) is a SEM image of the aluminum alloy prepared in Example 2, magnified 5000 times, used to observe its microstructure. It can be seen that the aluminum alloy prepared in this example, like the aluminum alloy prepared in Example 1, is composed of equiaxed crystals, with grain sizes ranging from several hundred nanometers to 1 μm. The alloy is completely crack-free.

[0049] (b) is a transmission electron microscope (TEM) image of the aluminum alloy prepared in Example 2, used to observe the internal precipitated phases of its grains. Similar to the aluminum alloy prepared in Example 1, the aluminum alloy prepared in this example also contains precipitated phases such as Al3(Ti,Nb), MgZn2, and Al7Cu2Fe.

[0050] (c) The room temperature tensile curve of the aluminum alloy prepared in Example 2. It can be seen that this alloy also has a yield strength of 470 MPa at room temperature, comparable to the aluminum alloy prepared in Example 1. Therefore, the aluminum alloy prepared in Example 2 maintains the same microstructure and mechanical properties as that in Example 1, and both methods can produce high-strength aluminum alloys.

[0051] Comparative Example 1

[0052] Using a horizontal ball mill, aluminum alloy powder with a particle size of 15-53 μm was mixed with elemental Nb particles with a particle size of 100 nm-2 μm in argon gas. The mass ratio of steel balls to powder was 5:1, the diameter of the steel balls was 5 mm, the shaft speed of the horizontal ball mill was 500 rpm, and the ball milling was carried out for 10 minutes. The subsequent selective laser melting steps were the same as in Example 1, and additive manufacturing aluminum alloy was obtained.

[0053] Figure 7 The images shown are test results for the aluminum alloy in Comparative Example 1. (a)-(c) are SEM images, showing that Nb particles have been added / assembled onto the surface of the 7075 aluminum alloy, and the white particles on the surface are nano-Nb particles. (d) is the tensile curve of the aluminum alloy in Comparative Example 1, indicating that although the selective laser melting of the 7075-Nb alloy overcomes the cracking problem, its tensile yield strength is too low (<290MPa), which is far lower than the strength level of the 7075 alloy prepared by traditional casting and forging (yield strength can reach 450MPa).

[0054] Therefore, if elemental Nb / Ta is added to aluminum alloys in the form of nanoparticles using special equipment such as horizontal ball mills or electrostatic assembly equipment, the powder cost and manufacturing cost are both high, and the yield strength cannot meet the requirements of high-strength application scenarios.

[0055] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A high formability high strength heat resistant additive manufacturing aluminum alloy, characterized by, The aluminum alloy contains the following elements in the following mass percentages: Zn 4.5-6.5%, Mg 1.5-3.0%, Cu 1.0-2.0%, Ti 1.0-3.0%, Nb 1.0-3.0%, Cr 0.15-0.3%, Fe 0.1-1.0%, Si 0.05-0.5%, Mn 0.05-0.5%, and the balance being aluminum. In the preparation process of the aluminum alloy, Ti and Nb are added to the aluminum alloy in the form of an alloy rather than in the form of elemental particles or single elements; in the Ti and Nb-containing alloy, the atomic percentage of Ti is 52-54 at.%, the atomic percentage of Nb is 24-26 at.%, and the oxygen content is ≤1000 ppm.

2. The high formability, high strength, heat resistant, additive manufactured aluminum alloy of claim 1, wherein, In the aluminum alloy, the mass percentage of Ti and Nb is 4.0-6.0%.

3. The high formability, high strength, heat resistant, additive manufactured aluminum alloy of claim 1, wherein, The Ti and Nb-containing alloy is added in the form of an alloy powder or an alloy block.

4. The high formability, high strength, heat resistant, additive manufactured aluminum alloy of claim 3, wherein, The particle size of the alloy powder is 15-53 μm.

5. The high formability, high strength, heat resistant, additive manufactured aluminum alloy of claim 3 or 4, wherein, The Ti and Nb-containing alloy also contains one or more of Zn, Mg, Cu, Cr, Fe, Si, Mn, and Al.

6. The method of making the aluminum alloy of any of claims 1-5, wherein, The method comprises the following steps: S1, preparing an aluminum alloy powder; S2, using a selective laser melting device, a selective electron beam melting device, or a laser direct deposition device to melt and prepare a sample.

7. The method of making the aluminum alloy of claim 6, wherein, In S1, the aluminum alloy powder and the Ti and Nb-containing alloy powder are mixed in an inert gas using a metal powder mixer to obtain the aluminum alloy powder, the mixing speed is 25-35 rpm, and the mixing time is 1-3 hours. The particle size of the aluminum alloy powder and the Ti and Nb-containing alloy powder is 15-53 μm.

8. The method of making the aluminum alloy of claim 6, wherein, In S1, the metal raw materials are mixed in proportion, wherein Zn accounts for 5-5.5 wt.%, Mg accounts for 2-2.5 wt.%, Cu accounts for 1-1.5 wt.%, Ti accounts for 2-2.5 wt.%, Nb accounts for 2-2.5 wt.%, Cr accounts for 0.2-0.5 wt.%, Fe accounts for 0.1-0.5 wt.%, Si accounts for 0.05 wt.%, and Mn accounts for 0.05-0.1 wt.%; Ti and Nb are added in the form of an alloy ingot, and other elements are added in the form of an elemental substance or an alloy ingot; the pre-alloyed rod is prepared by arc melting or electromagnetic induction melting and casting process; and the aluminum alloy powder is prepared by an inert gas atomization method, a plasma atomization method, or a rotating electrode method.

9. The method of making the aluminum alloy of claim 6, wherein, In S2, the parameters for melting and preparing a sample using a selective laser melting device or a selective electron beam melting device are as follows: power 300 W, scanning speed 950 mm / s, line spacing 80 μm, and layer thickness 30 μm. In S2, the parameters for melting and preparing a sample using a laser direct deposition device are as follows: power 1000 W, scanning speed 950 mm / min, and powder feeding rate 6 g / min.

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