Erbium-containing aluminum alloy for additive manufacturing, and preparation method therefor and use thereof

Abstract

An erbium-containing aluminum alloy for additive manufacturing. Alloying elements in the aluminum alloy comprise (mass percentage): W(Mg): 4.0-7.0%; W(Mn): 0.5-0.8%; W(Er): 0.61-1.5%; W(Sc): 0.1-0.4%; W(Si)+W(Fe): 0.4-0.7%; 0.2%≤W(Fe)≤0.34W(Er); and 2.6W(Sc)+0.7W(Er)≤W(Zr)≤2.1%, with the balance being Al. A preparation method for the aluminum alloy comprises: alloy powder preparation, additive manufacturing forming, and a heat treatment, wherein the alloy powder preparation comprises raw material smelting, atomization powder preparation, powder screening, and drying under heat preservation conditions. The aluminum alloy has good printing formability and a wide forming process interval; and a formed test piece has a high density, and has good room-temperature and high-temperature mechanical properties after being subjected to a heat treatment. The present invention further relates to a preparation method for and the use of the erbium-containing aluminum alloy for additive manufacturing.

Description

Erbium-containing aluminum alloy for additive manufacturing and preparation method and application thereof Technical Field

[0001] The present invention relates to an erbium-containing aluminum alloy for additive manufacturing, a preparation method thereof, and applications thereof, and belongs to the technical field of additive manufacturing. Background Art

[0002] Currently, laser additive manufacturing of aluminum alloys mainly uses traditional casting grade alloys, which has the following problems:

[0003] [Corrected 05.12.2024 according to Rule 91] (1) Al-Si based near-eutectic alloys represented by AlSi10Mg and AlSi12 are currently the most suitable aluminum alloys for additive manufacturing due to their low melting point and narrow solidification temperature range. Although their mechanical strength in the printed deposition state is better than that of traditional cast Al-Si alloys, their tensile strength is around 450MPa, their elongation is only 6%, and their strength is greatly reduced after heat treatment, which cannot meet the use requirements of high-performance parts; (2) Traditional 2xxx series (Al-Cu based) and 7xxx series (Al-Zn based) medium-high strength aluminum alloys are prone to thermal cracking during additive manufacturing due to their wide solidification temperature range, which is a constraint on their progress. The key bottleneck of the next step of development is currently focusing on how to improve the thermal cracking resistance of these two alloys and improve their printing formability; (3) Traditional Al-Mg based 5xxx series medium strength aluminum alloys are usually not suitable for additive manufacturing and heat treatment strengthening, but after alloying with elements such as Sc or Zr, their printing formability is improved, and Al3 (Sc, Zr) nanoprecipitates can be precipitated during the heat treatment process, which has a significant second phase strengthening effect and greatly improves the mechanical properties of the alloy. Therefore, additive manufacturing of Sc-Zr composite strengthened Al-Mg alloys has received widespread attention and is a current research hotspot. The most representative one is Scalmalloy alloy (Al-Mg-Sc-Zr).

[0004] [Corrected 05.12.2024 according to Rule 91] However, for Scalmalloy and Al-Mg alloys with similar compositions, avoiding hot cracking tendencies and improving mechanical properties largely depend on the addition of large amounts of the rare earth element Sc (>0.66wt%), but Sc is expensive and costly, which is not conducive to its large-scale promotion and application. In addition, although the room temperature mechanical strength of the alloy is greatly improved after Sc-Zr composite strengthening, the problems of poor high-temperature mechanical properties and thermal stability also limit their application expansion. Currently, well-known aluminum alloys will experience significant performance degradation at high temperatures. Common additively manufactured Al-Si series, Scalmalloy alloys, 2000 series and 7000 series aluminum alloys have a maximum tensile strength of only 147MPa at 200℃, and the operating temperature is generally below 200℃, which cannot meet the new requirements for heat resistance of aluminum alloy parts in the aerospace and automotive industries. Regarding Al-Mg alloys, Chinese patent application CN115874088A discloses a high-strength, heat-resistant, and damage-resistant aluminum alloy, Al-Mg-Ca-Sc-Mn-Zr. By adding high proportions of Ca and Sc, its tensile strength at 250°C is approximately 172 MPa, but its room-temperature tensile strength is relatively low, below 500 MPa. Furthermore, the high Sc content increases costs. Chinese patent application CN115194140A discloses an Al-Mg aluminum-based composite powder. Al-Mg-Sc-Zr powder is mixed uniformly with a Co-Cr-Ni medium-entropy alloy powder and a bait oxide powder and then printed. The composite powder-printed specimens exhibit excellent high-temperature strength, but a poor elongation of only 5%, and low room-temperature mechanical strength, below 500 MPa. Furthermore, the high Sc content increases costs. Furthermore, existing technical solutions address the technical problem of cracking in conventional additive manufacturing of Al-Mg alloys by adding a combination of rare earth elements, Zr, Ti, and Si. However, this may result in a narrow printing process window.

[0005] Therefore, based on Al-Mg alloy, how to achieve low-cost, high-quality printing production while taking into account both room temperature performance and high temperature performance has become an urgent problem to be solved in the development of high-performance additive manufacturing aluminum alloys in the new era. Summary of the Invention

[0006] In response to the deficiencies in the prior art, the present invention provides an erbium-containing aluminum alloy for additive manufacturing, a preparation method thereof, and applications thereof. The aluminum alloy has good print formability, a wide forming process range, high density of the formed specimens, and excellent room temperature and high temperature mechanical properties after heat treatment.

[0007] The technical solution of the present invention to solve the above technical problems is as follows: an erbium-containing aluminum alloy for additive manufacturing, wherein the alloying elements in the aluminum alloy are calculated as follows by mass percentage: W(Mg): 4.0-7.0%; W(Mn): 0.5-0.8%; W(Er): 0.61-1.5%; W(Sc): 0.1-0.4%; W(Si)+W(Fe): 0.4-0.7%; 0.2%≤W(Fe)≤0.34W(Er); 2.6W(Sc)+0.7W(Er)≤W(Zr)≤2.1%, and the balance is Al.

[0008] Furthermore, the alloying elements in the aluminum alloy are calculated in percentage by mass as follows: W(Mg): 4.0-7.0%; W(Mn): 0.5-0.7%; W(Er): 0.61-1.2%; W(Sc): 0.1-0.4%; W(Si)+W(Fe): 0.5-0.7%; 0.2%≤W(Fe)≤0.34W(Er); 2.6W(Sc)+0.7W(Er)≤W(Zr)≤1.8%, and the balance is Al.

[0009] The present invention also discloses a method for preparing erbium-containing aluminum alloy powder for additive manufacturing, the preparation method comprising:

[0010] S1. Raw material smelting: Heat and smelt pure metal or master alloy raw materials under vacuum conditions according to the formula to obtain pre-alloyed metal;

[0011] S2. Atomization powdering: The smelted pre-alloyed metal is atomized and powdered using argon gas to obtain pre-alloyed metal powder;

[0012] S3, powder screening: screening and grading the pre-alloyed metal powder prepared in step S2 under an inert gas protective atmosphere;

[0013] S4, heat preservation and drying: drying the powder screened in step S3 to obtain the aluminum alloy powder.

[0014] [Corrected 05.12.2024 according to Rule 91] Furthermore, in step S1, the smelting temperature is 700-850°C, and the smelting time is 10-40 minutes.

[0015] Furthermore, in step S2, the atomization air pressure of the atomization powder making is 0.8-4.0 MPa.

[0016] Furthermore, in step S3, the pressure of the inert gas protective atmosphere is 0.05-0.95 MPa, and the particle size range of the powder after screening is 15-53 μm.

[0017] [Corrected 05.12.2024 according to Rule 91] Further, in step S4, the drying temperature is 100-120°C and the drying time is 4-12 hours.

[0018] The present invention also discloses an erbium-containing aluminum alloy for additive manufacturing, a preparation method thereof, and an application thereof. The aluminum alloy powder can be used to prepare alloy test pieces through additive manufacturing technology.

[0019] Furthermore, the process parameters of the additive manufacturing are: laser power of 250 to 400 W; laser scanning speed of 900 to 1500 mm / s; scanning spacing of 0.09 to 0.11 mm; and interlayer thickness of 0.02 to 0.04 mm.

[0020] Furthermore, the alloy specimen formed by the additive manufacturing technology is subjected to heat treatment to obtain a final alloy specimen product;

[0021] [Corrected 05.12.2024 according to Rule 91] The heat treatment temperature is 312-405°C, the holding time is 2-8 hours, and the final alloy specimen product is obtained after cooling in the furnace.

[0022] [Corrected 05.12.2024 according to Rule 91] Further, the heat treatment temperature is (T±5)°C, and T=432-25000W(Sc)-1000W(Er).

[0023] The functions of the elements in the erbium-containing aluminum alloy used for additive manufacturing of the present invention are:

[0024] 1) Mg element: As the main alloying element, it can be supersaturated and dissolved in the aluminum matrix during the rapid solidification process, playing a role of solid solution strengthening;

[0025] 2) Mn element: It mainly plays a role of solid solution strengthening. In addition, it can also form Al6Mn strengthening phase, which plays a role of second phase strengthening;

[0026] 3) Sc element: During the printing solidification process, the Al3Sc primary phase is formed, which can serve as a heterogeneous nucleation point to promote the formation of equiaxed crystals and inhibit the generation of thermal cracks; and during the heat treatment process, Al3Sc nanoprecipitates are precipitated, which has a precipitation strengthening effect;

[0027] 4) Zr: It has a similar effect to Sc. It can also form Al3(Sc, Zr) or Al3(Er, Zr) phases with Sc or Er to improve its thermal stability.

[0028] 5) Er element: During the printing solidification process, an Al3Er eutectic phase is formed at the grain boundary, which refines the grain structure and plays a role in grain boundary strengthening. It also pins the grain boundary at high temperature and inhibits grain growth. During heat treatment, an Al3Er nano-precipitate phase is precipitated, which has a precipitation strengthening effect.

[0029] 6) Si element: reduces the solidification temperature range and improves the ability to heal initial cracks. At the same time, it forms Mg2Si strengthening phase, which plays a role of second phase strengthening;

[0030] 7) Fe element: improves melt fluidity, replenishes intergranular thermal cracks, and improves printability.

[0031] The beneficial effects of the present invention are:

[0032] (1) The aluminum alloy of the present invention has both high room temperature mechanical strength and high temperature mechanical strength.

[0033] By adding Er, Zr and Sc in combination to aluminum alloys, Al3M phase (M is one or more elements among Er, Zr and Sc) can be generated during printing and subsequent heat treatment, which has significant fine grain strengthening and second phase strengthening effects. Unlike the prior art, the present invention further increases the content of Er and Zr elements, thereby further improving the mechanical strength at room temperature. At the same time, in order to improve the high-temperature performance of the alloy, this technology establishes a proportional relationship between the Zr content and the Er and Sc contents on the basis of increasing the Er and Zr contents, and limits the minimum added content of Zr; on the other hand, the heat treatment system is optimized, and the relationship between the heat treatment temperature and the Sc and Er contents is established. Different heat treatment temperatures are used for alloys with different rare earth element contents.

[0034] Er forms Al3(Er,M) phase at grain boundaries, refining the grains. It also pins the grain boundaries during heat treatment and high temperatures, hindering grain boundary migration and inhibiting grain growth, thereby improving the alloy's structural stability. Increasing Er content improves both the room temperature and high temperature mechanical strength of the alloy.

[0035] Zr can be combined with Er and Sc elements to form an Al3M composite phase, which has a lower coarsening tendency than single Al3Sc or Al3Er, and can improve the alloy's high-temperature strength and thermal stability. Through suitable heat treatment, Zr, Er or Sc are fully diffused in the Al3M phase, forming a complete and stable core-shell structure with an inner layer enriched with Er or Sc elements and an outer layer enriched with Zr elements. This can effectively suppress the coarsening of the Al3M precipitate phase and maximize the strengthening effect and thermal stability of this phase. Therefore, only when the Zr element addition amount is sufficient and the heat treatment system is reasonable, can the nano-Al3M precipitate phase be quickly and dispersedly separated and fully formed into a complete core-shell structure. The present invention controls the minimum Zr addition content and heat treatment temperature, making the Al3M phase structure stable and the strengthening effect significant. The alloy has higher mechanical strength at room temperature and high temperature, and has good thermal stability. The aluminum alloy of the present invention has a room temperature tensile strength of 510 MPa or more and an elongation of 10% or more; a tensile strength at 250° C. of 180 MPa or more and an elongation of 30% or more.

[0036] (2) The present invention innovatively adds Fe elements. Through the synergistic effect of Fe and Si, the alloy printing process range is wide, the density is high, and the printing forming performance is excellent. The existing technology mainly suppresses the generation of thermal cracks during the printing process of Al-Mg alloy by adding rare earth elements, Zr, Ti and Si elements. However, Fe elements are generally controlled within a relatively low content range as common impurity elements, and conventional technology adds a small amount of Fe. Its main purpose is to make Fe absorb other impurity elements in the alloy, inhibit the formation of brittle phases at grain boundaries, or perform solid solution strengthening to improve the material's stress corrosion resistance and mechanical properties. However, the present invention adds an appropriate amount of Fe elements. Fe and Al can undergo eutectic reaction at 660°C, which has a significant effect on improving melt fluidity and shrinkage compensation capabilities. Through the composite addition and synergistic effect of Fe and Si, the alloy's resistance to thermal cracking is further improved. Compared with the addition of Si elements alone, the alloy has a wider printing process range and a higher density of printed specimens. However, the Fe content must be controlled within a reasonable range. When the Fe content is too high, it is easy to form coarse intermetallic compounds with elements such as Al, Si, Er, and Mn, which weakens the effect of Er and other elements in the alloy and is detrimental to the mechanical properties of the alloy. Therefore, the present invention controls the Fe and Si content to make the alloy have excellent print formability and can be used in a wide process range (energy density 50-150 J / mm 3 ) Achieve alloy density of more than 99.5% and crack-free printing.

[0037] In addition, the Sc element content in the alloy of the present invention is relatively low, which greatly reduces the production cost.

[0038] In summary, the technical solution of the present invention starts from achieving excellent room temperature and high temperature mechanical properties of Al-Mg-based alloys, as well as low-cost, high-quality printing production. It adopts Er and Zr to replace part of Sc, and adopts the route of Er-Zr-Sc element composite strengthening. For different Er and Sc contents, the Zr element addition amount and heat treatment temperature are synergistically optimized, and finally an alloy with a large number of grain boundary pinning phases, fully dispersed and precipitated nano-precipitated phases to form a complete core-shell structure, and fine grain structure is obtained, so that the room temperature mechanical strength and high temperature mechanical strength are improved at the same time; at the same time, Si-Fe composite microalloying is adopted to further enhance the alloy's resistance to thermal cracking, improve the printing formability, expand the process range, and greatly improve the printing quality and printing production stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] FIG1 is a diagram showing room temperature mechanical properties of aluminum alloys formed by additive manufacturing technology in Examples 1-3 and Comparative Examples 1-4 of the present invention;

[0040] [Corrected 05.12.2024 according to Rule 91] FIG2 is a graph showing the high temperature (250°C) mechanical properties of the aluminum alloys formed by additive manufacturing technology in Examples 1-3 of the present invention and Comparative Examples 1, 2, and 4;

[0041] FIG3 is a metallographic image of an aluminum alloy formed by additive manufacturing technology in Example 3 of the present invention;

[0042] FIG4 is a metallographic image of the aluminum alloy formed by additive manufacturing technology in Comparative Example 3 of the present invention. DETAILED DESCRIPTION

[0043] To make the above-mentioned objects, features, and advantages of the present invention more readily apparent, specific embodiments of the present invention are described in detail below. The following description sets forth numerous specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0045] Disclosed is an erbium-containing aluminum alloy for additive manufacturing. The alloying elements in the aluminum alloy are, by mass percentage, as follows: W(Mg): 4.0-7.0%; W(Mn): 0.5-0.8%; W(Er): 0.61-1.5%; W(Sc): 0.1-0.4%; W(Si)+W(Fe): 0.4-0.7%; 0.2%≤W(Fe)≤0.34W(Er); 2.6W(Sc)+0.7W(Er)≤W(Zr)≤2.1%, and the balance is Al.

[0046] Specifically, the alloying elements in the aluminum alloy are calculated in percentage by mass as follows: W(Mg): 4.0-7.0%; W(Mn): 0.5-0.7%; W(Er): 0.61-1.2%; W(Sc): 0.1-0.4%; W(Si)+W(Fe): 0.5-0.7%; 0.2%≤W(Fe)≤0.34W(Er); 2.6W(Sc)+0.7W(Er)≤W(Zr)≤1.8%, and the balance is Al.

[0047] A method for preparing erbium-containing aluminum alloy powder for additive manufacturing, the preparation method comprising:

[0048] S1. Raw material smelting: Heat and smelt pure metal or master alloy raw materials under vacuum conditions according to the formula to obtain pre-alloyed metal;

[0049] S2. Atomization powdering: The smelted pre-alloyed metal is atomized and powdered using argon gas to obtain pre-alloyed metal powder;

[0050] S3, powder screening: screening and grading the pre-alloyed metal powder prepared in step S2 under an inert gas protective atmosphere;

[0051] S4, heat preservation and drying: drying the powder screened in step S3 to obtain the aluminum alloy powder.

[0052] [Corrected 05.12.2024 according to Rule 91] Specifically, in step S1, the smelting temperature is 700-850°C, and the smelting time is 10-40 minutes.

[0053] Specifically, in step S2, the atomization air pressure of the atomization powder making is 0.8-4.0 MPa.

[0054] Specifically, in step S3, the pressure of the inert gas protective atmosphere is 0.05 to 0.95 MPa, and the particle size of the powder after screening is in the range of 15 to 53 μm;

[0055] [Corrected 05.12.2024 according to Rule 91] In step S4, the drying temperature is 100-120°C and the drying time is 4-12 hours.

[0056] An erbium-containing aluminum alloy for additive manufacturing, a preparation method thereof, and an application thereof; the aluminum alloy powder can be used to prepare alloy specimen products through additive manufacturing technology.

[0057] Specifically, the process parameters of additive manufacturing are: laser power of 250 to 400 W; laser scanning speed of 900 to 1500 mm / s; scanning spacing of 0.09 to 0.11 mm; and interlayer thickness of 0.02 to 0.04 mm.

[0058] Specifically, the alloy specimen formed by the additive manufacturing technology is subjected to heat treatment to obtain the final alloy specimen product;

[0059] [Corrected 05.12.2024 according to Rule 91] The heat treatment temperature is 312-405°C, the holding time is 2-8 hours, and the final alloy specimen product is obtained after cooling in the furnace.

[0060] [Corrected 05.12.2024 according to Rule 91] More specifically, the heat treatment temperature is (T±5)°C, and T=432-25000W(Sc)-1000W(Er).

[0061] Example 1

[0062] The chemical composition of the erbium-containing aluminum alloy used for additive manufacturing is (mass fraction, the same below): W(Mg): 7.0%, W(Mn): 0.5%, W(Er): 1.2%, W(Sc): 0.2%, W(Zr): 1.4%, W(Si): 0.3%, W(Fe): 0.4%, and the balance is Al.

[0063] The preparation method of the aluminum alloy powder is:

[0064] [Corrected 05 / 12 / 2024 according to Rule 91] (1) Raw material smelting: pure Al, Al-Mg, Al-Mn, Al-Si, Al-Fe, Al-Er, Al-Zr, Al-Sc alloy raw materials are heated and smelted under vacuum conditions at a melting temperature of 710°C for 40 min;

[0065] (2) Atomization powdering: The smelted pre-alloyed metal is atomized into powder using argon gas at an atomization pressure of 4.0 MPa;

[0066] (3) Powder screening: The prepared pre-alloyed metal powder is screened and graded under an inert gas protective atmosphere with an atmosphere pressure of 0.1 MPa and a powder particle size range of 15 to 53 μm;

[0067] [Corrected 05.12.2024 according to Rule 91] (4) Heat preservation and drying: Dry the powder after screening in step (3) at a drying temperature of 120° C. for 5 h to obtain aluminum alloy powder.

[0068] The aluminum alloy powder was formed using additive manufacturing technology with a laser power of 250W, a laser scanning speed of 1500mm / s, a scanning spacing of 0.11mm, and an interlayer thickness of 0.02mm.

[0069] [Corrected 05.12.2024 according to Rule 91] The alloy specimen formed by additive manufacturing technology was heat treated at a temperature of 375°C for a holding time of 4 hours, and cooled in the furnace to obtain the final alloy specimen product.

[0070] [Corrected 05.12.2024 according to Rule 91] Specific data on the alloy test piece products, such as printing energy density, density, tensile strength at room temperature (25°C) and high temperature (250°C), and elongation at break, are shown in Table 1.

[0071] Example 2

[0072] The chemical composition of the erbium-containing aluminum alloy used for additive manufacturing is: W(Mg): 5.0%, W(Mn): 0.6%, W(Er): 0.9%, W(Sc): 0.4%, W(Zr): 1.8%, W(Si): 0.3%, W(Fe): 0.3%, and the balance is Al.

[0073] The preparation method of the aluminum alloy powder is:

[0074] [Corrected 05 / 12 / 2024 according to Rule 91] (1) Raw material smelting: pure Al, Al-Mg, Al-Mn, Al-Si, Al-Fe, Al-Er, Al-Zr, Al-Sc alloy raw materials are heated and smelted under vacuum conditions according to the formula at a melting temperature of 850°C for 15 minutes;

[0075] (2) Atomization powdering: The smelted pre-alloyed metal is atomized into powder using argon gas with an atomization pressure of 0.9 MPa;

[0076] (3) Powder screening: The prepared pre-alloyed metal powder is screened and graded under an inert gas protective atmosphere with an atmosphere pressure of 0.9 MPa and a powder particle size range of 15 to 53 μm;

[0077] [Corrected 05.12.2024 according to Rule 91] (4) Drying by heat preservation: Dry the powder after screening in step (3) at a drying temperature of 100°C for 11 hours to obtain aluminum alloy powder.

[0078] The aluminum alloy powder was formed using additive manufacturing technology with a laser power of 400W, a laser scanning speed of 900mm / s, a scanning spacing of 0.1mm, and an interlayer thickness of 0.04mm.

[0079] [Corrected 05.12.2024 according to Rule 91] The test piece formed by additive manufacturing technology was heat treated at a temperature of 325°C for 5 hours and cooled in the furnace to obtain the final alloy test piece product.

[0080] [Corrected 05.12.2024 according to Rule 91] Specific data on the alloy test piece products, such as printing energy density, density, tensile strength at room temperature (25°C) and high temperature (250°C), and elongation at break, are shown in Table 1.

[0081] Example 3

[0082] The chemical composition of the erbium-containing aluminum alloy powder used for additive manufacturing is: W(Mg): 4.0%, W(Mn): 0.7%, W(Er): 0.61%, W(Sc): 0.1%, W(Zr): 0.69%, W(Si): 0.3%, W(Fe): 0.2%, and the balance is Al.

[0083] The preparation method of the aluminum alloy powder is:

[0084] [Corrected 05 / 12 / 2024 according to Rule 91] (1) Raw material smelting: pure Al, Al-Mg, Al-Mn, Al-Si, Al-Fe, Al-Er, Al-Zr, Al-Sc alloy raw materials are heated and smelted under vacuum conditions according to the formula at a melting temperature of 800°C for 25 min;

[0085] (2) Atomization powdering: The smelted pre-alloyed metal is atomized into powder using argon gas at an atomization pressure of 2 MPa;

[0086] (3) Powder screening: The prepared pre-alloyed metal powder is screened and graded under an inert gas protective atmosphere with an atmosphere pressure of 0.45 MPa and a powder particle size range of 15 to 53 μm;

[0087] [Corrected 05.12.2024 according to Rule 91] (4) Heat preservation and drying: Dry the powder after screening in step (3) at a drying temperature of 110° C. for 8 h to obtain aluminum alloy powder.

[0088] The aluminum alloy powder was formed using additive manufacturing technology with a laser power of 300W, a laser scanning speed of 1200mm / s, a scanning pitch of 0.09mm, and an interlayer thickness of 0.03mm.

[0089] [Corrected 05.12.2024 according to Rule 91] The test piece formed by additive manufacturing technology was heat treated at a temperature of 400°C for a holding time of 2 hours, and cooled in the furnace to obtain the final alloy test piece product.

[0090] [Corrected 05.12.2024 according to Rule 91] Specific data such as the printing energy density, density, tensile strength at room temperature (25°C) and high temperature (250°C), and elongation at break of the alloy test piece are shown in Table 1, and its metallographic diagram is shown in Figure 3.

[0091] Example 4

[0092] The chemical composition of the erbium-containing aluminum alloy powder used for additive manufacturing is (mass fraction, the same below): W(Mg): 7.0%, W(Mn): 0.5%, W(Er): 1.2%, W(Sc): 0.2%, W(Zr): 1.4%, W(Si): 0.3%, W(Fe): 0.4%, and the balance is Al.

[0093] The preparation method of the aluminum alloy powder is:

[0094] [Corrected 05 / 12 / 2024 according to Rule 91] (1) Raw material smelting: pure Al, Al-Mg, Al-Mn, Al-Si, Al-Fe, Al-Er, Al-Zr, Al-Sc alloy raw materials are heated and smelted under vacuum conditions according to the formula at a melting temperature of 700°C for 40 minutes;

[0095] (2) Atomization powdering: The smelted pre-alloyed metal is atomized into powder using argon gas with an atomization pressure of 0.8 MPa;

[0096] (3) Powder screening: The prepared pre-alloyed metal powder is screened and graded under an inert gas protective atmosphere with an atmosphere pressure of 0.05 MPa and a powder particle size range of 15 to 53 μm;

[0097] [Corrected 05.12.2024 according to Rule 91] (4) Heat preservation and drying: Dry the powder after screening in step (3) at a drying temperature of 120° C. for 4 hours to obtain aluminum alloy powder.

[0098] The aluminum alloy powder was formed using additive manufacturing technology with a laser power of 250W, a laser scanning speed of 1500mm / s, a scanning spacing of 0.1mm, and an interlayer thickness of 0.03mm.

[0099] [Corrected 05.12.2024 according to Rule 91] The alloy specimen formed by additive manufacturing technology was heat treated at a temperature of 365°C for 8 hours and cooled in the furnace to obtain the final alloy specimen product.

[0100] [Corrected 05.12.2024 according to Rule 91] Specific data on the alloy test piece products, such as printing energy density, density, tensile strength at room temperature (25°C) and high temperature (250°C), and elongation at break, are shown in Table 1.

[0101] Example 5

[0102] The chemical composition of the erbium-containing aluminum alloy powder used for additive manufacturing is: W(Mg): 5.0%, W(Mn): 0.6%, W(Er): 0.9%, W(Sc): 0.4%, W(Zr): 1.8%, W(Si): 0.3%, W(Fe): 0.3%, and the balance is Al.

[0103] The preparation method of the aluminum alloy powder is:

[0104] [Corrected 05 / 12 / 2024 according to Rule 91] (1) Raw material smelting: pure Al, Al-Mg, Al-Mn, Al-Si, Al-Fe, Al-Er, Al-Zr, Al-Sc alloy raw materials are heated and smelted under vacuum conditions according to the formula at a melting temperature of 850°C for 10 min;

[0105] (2) Atomization powdering: The smelted pre-alloyed metal is atomized into powder using argon gas at an atomization pressure of 3 MPa;

[0106] (3) Powder screening: The prepared pre-alloyed metal powder is screened and graded under an inert gas protective atmosphere with an atmosphere pressure of 0.95 MPa and a powder particle size range of 15 to 53 μm;

[0107] [Corrected 05.12.2024 according to Rule 91] (4) Heat preservation and drying: Dry the powder after screening in step (3) at a drying temperature of 100°C for 12 hours to obtain aluminum alloy powder.

[0108] The aluminum alloy powder was formed using additive manufacturing technology with a laser power of 400W, a laser scanning speed of 900mm / s, a scanning pitch of 0.1mm, and an interlayer thickness of 0.03mm.

[0109] [Corrected 05.12.2024 according to Rule 91] The test piece formed by additive manufacturing technology was heat treated at a temperature of 318°C for 6 hours and cooled in the furnace to obtain the final alloy test piece product.

[0110] [Corrected 05.12.2024 according to Rule 91] Specific data on the alloy test piece products, such as printing energy density, density, tensile strength at room temperature (25°C) and high temperature (250°C), and elongation at break, are shown in Table 1.

[0111] Comparative Example 1 (low Er content)

[0112] Except for the Er content being different from that in Example 3, the other conditions in this comparative example are the same as those in Example 3.

[0113] The chemical composition of the erbium-containing aluminum alloy powder used for additive manufacturing in this comparative example is: W(Mg): 4.0%, W(Mn): 0.7%, W(Er): 0.4%, W(Sc): 0.1%, W(Zr): 0.69%, W(Si): 0.3%, W(Fe): 0.2%, and the balance is Al.

[0114] Comparative Example 2 (Insufficient Zr Content)

[0115] Except for the Zr content, the other conditions in this comparative example are the same as those in Example 3.

[0116] The chemical composition of the erbium-containing aluminum alloy powder used for additive manufacturing in this comparative example is: W(Mg): 4.0%, W(Mn): 0.7%, W(Er): 0.61%, W(Sc): 0.1%, W(Zr): 0.4%, W(Si): 0.3%, W(Fe): 0.2%, and the balance is Al.

[0117] Comparative Example 3 (Fe-free)

[0118] No Fe element was added to the aluminum alloy of this comparative example, and the other conditions were the same as those in Example 3.

[0119] The chemical composition of the erbium-containing aluminum alloy powder used for additive manufacturing in this comparative example is: W(Mg): 4.0%, W(Mn): 0.7%, W(Er): 0.61%, W(Sc): 0.1%, W(Zr): 0.69%, W(Si): 0.3%, and the balance is Al.

[0120] The metallographic image of the aluminum alloy formed by additive manufacturing technology in this comparative example is shown in FIG4 .

[0121] [Corrected 05.12.2024 according to Rule 91] Comparative Example 4 (heat treatment temperature does not conform to the rule of (T±5)°C, T=432-25000W(Sc)-1000W(Er))

[0122] The experimental method is the same as that of Example 3 except that the heat treatment temperature is different from that of Example 3.

[0123] [Corrected 05.12.2024 according to Rule 91] The 3D printed specimens were heat treated at 410°C for 2 h and then cooled in the furnace.

[0124] [Corrected 05.12.2024 according to Rule 91] Specific data such as printing energy density, density, tensile strength at room temperature (25°C) and high temperature (250°C), and elongation at break of the alloy test products in the above Examples 1-5 and Comparative Examples 1-4 are shown in Table 1.

[0125] Table 1 Performance data of alloy test pieces obtained in Examples and Comparative Examples

[0126] [Corrected 05.12.2024 according to Rule 91] From Examples 1-5, it can be seen that the composition alloy of the present invention is formed in a wide range of process conditions, i.e., the energy density range of 50-150 J / mm 3 Within the range, crack-free printed specimens with a density of more than 99.5% can be obtained. After insulation treatment at a reasonable heat treatment temperature, the alloy has excellent room temperature and high temperature mechanical properties. The room temperature tensile strength is above 510MPa and the elongation is above 10%. The tensile strength at 250℃ is above 180MPa and the elongation is above 30%.

[0127] As can be seen from Example 3 and Comparative Example 1, when the Er content is insufficient, the room temperature and high temperature tensile strength of the alloy decreases. Insufficient Er content prevents the formation of sufficient Al3(Er,M) eutectic phase at the grain boundaries during solidification, resulting in coarse grain size. Furthermore, grain growth cannot be effectively suppressed at higher temperatures, and the grain boundary strengthening effect is weakened, resulting in a decrease in the room temperature and high temperature mechanical strength of the alloy.

[0128] As can be seen from Example 3 and Comparative Example 2, when the Zr content is insufficient, the room temperature and high temperature tensile strength of the alloy decreases. On the one hand, the reduced Zr content reduces the amount of Al3(Sc,Zr) or Al3Zr phase precipitation during solidification to a certain extent, reducing the formation of equiaxed crystals and hindering grain size refinement. On the other hand, the low Zr content prevents the formation of Al3(Er,Zr) or Al3(Sc,Zr) nanoprecipitates with a complete core-shell structure during heat treatment, which easily grows and coarsens at high temperatures, reducing the strengthening effect of the precipitate phase.

[0129] As can be seen from Example 3 and Comparative Example 3, when only Si is added to the alloy without Fe, the alloy porosity increases (as can also be clearly seen from the comparison of Figures 3 and 4), the density decreases, and thus the room temperature tensile strength decreases. A small amount of Fe helps to reduce the solidification temperature range, improve melt fluidity, and enhance printability and specimen density.

[0130] [Corrected 05 / 12 / 2024 according to Rule 91] As can be seen from Example 3 and Comparative Example 4, when the heat treatment temperature does not conform to the rule of (T ± 5)°C, T = 432-25000W(Sc)-1000W(Er), the room temperature and high temperature tensile strength of the alloy decreases. When the heat treatment temperature is not appropriate, the precipitate phase cannot precipitate quickly and fully or coarsens, reducing the strengthening effect of the precipitate phase.

[0131] [Corrected 05.12.2024 according to Rule 91] Among them, the room temperature mechanical properties of the aluminum alloys formed by additive manufacturing technology in Examples 1-3 and Comparative Examples 1-4 are shown in Figure 1; the high temperature (250°C) mechanical properties of the aluminum alloys formed by additive manufacturing technology in Examples 1-3 and Comparative Examples 1, 2, and 4 are shown in Figure 2.

[0132] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0133] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. An erbium-containing aluminum alloy for additive manufacturing, characterized in that: The alloy elements in the aluminum alloy are calculated in percentage by mass as follows: W(Mg): 4.0-7.0%; W(Mn): 0.5-0.8%; W(Er): 0.61-1.5%; W(Sc): 0.1-0.4%; W(Si)+W(Fe): 0.4-0.7%; 0.2%≤W(Fe)≤0.34W(Er); 2.6W(Sc)+0.7W(Er)≤W(Zr)≤2.1%, and the balance is Al.

2. The erbium-containing aluminum alloy for additive manufacturing according to claim 1, characterized in that: The alloy elements in the aluminum alloy are calculated in percentage by mass as follows: W(Mg): 4.0-7.0%; W(Mn): 0.5-0.7%; W(Er): 0.61-1.2%; W(Sc): 0.1-0.4%; W(Si)+W(Fe): 0.5-0.7%; 0.2%≤W(Fe)≤0.34W(Er); 2.6W(Sc)+0.7W(Er)≤W(Zr)≤1.8%, and the balance is Al.

3. An erbium-containing aluminum alloy for additive manufacturing according to claim 1 or 2, characterized in that: The preparation method of the alloy powder is: S1. Raw material smelting: heating and smelting the pure metal or intermediate alloy raw materials under vacuum conditions according to the formula to obtain pre-alloyed metal; S2, atomization powder making: atomizing the smelted pre-alloyed metal using argon gas to obtain pre-alloyed metal powder; S3, powder screening: screening and grading the pre-alloyed metal powder prepared in step S2 under an inert gas protective atmosphere; S4, heat preservation and drying: drying the powder screened in step S3 to obtain the aluminum alloy powder.

4. [Corrected 05.12.2024 according to Rule 91] A method for preparing erbium-containing aluminum alloy powder for additive manufacturing according to claim 3, characterized in that: In step S1, the smelting temperature is 700-850°C, and the smelting time is 10-40 minutes.

5. The method for preparing erbium-containing aluminum alloy powder for additive manufacturing according to claim 3, characterized in that: In step S2, the atomization gas pressure of the atomization powder making is 0.8-4.0 MPa.

6. [Corrected 05.12.2024 in accordance with Rule 91] A method for preparing erbium-containing aluminum alloy powder for additive manufacturing according to claim 3, characterized in that: In step S3, the pressure of the inert gas protective atmosphere is 0.05-0.95 MPa, and the particle size range of the powder after screening is 15-53 μm; In step S4, the drying temperature is 100-120° C., and the drying time is 4-12 hours.

7. An erbium-containing aluminum alloy for additive manufacturing according to claim 1 or 2, and a preparation method and application thereof, characterized in that: The aluminum alloy can be used to prepare alloy test pieces through additive manufacturing technology.

8. The erbium-containing aluminum alloy for additive manufacturing and its preparation method and application according to claim 7, characterized in that: The process parameters of the additive manufacturing are: laser power of 250-400W; laser scanning speed of 900-1500mm / s; scanning spacing of 0.09-0.11mm; and interlayer thickness of 0.02-0.04mm.

9. [Corrected 05.12.2024 according to Rule 91] An erbium-containing aluminum alloy for additive manufacturing and its preparation method and use according to claim 7, characterized in that: The alloy specimens formed by additive manufacturing technology need to be heat treated to obtain the final alloy specimen products; The heat treatment temperature is 312-405° C., the heat preservation time is 2-8 hours, and the final alloy test piece product is obtained after cooling in the furnace.

10. [Corrected 05.12.2024 according to Rule 91] An erbium-containing aluminum alloy for additive manufacturing and its preparation method and application according to claim 7, characterized in that: The heat treatment temperature is (T±5)°C, and T=432-25000W(Sc)-1000W(Er).

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