A high-strength aluminum-nickel alloy powder for additive manufacturing and preparation method thereof

Abstract

The present invention provides a high-strength aluminum-nickel alloy powder for additive manufacturing and a preparation method thereof; the chemical composition of the aluminum-nickel alloy powder is 0 < w(Ni) ≤ 15%, 0 < w(Mg) ≤ 1% or 4 < w(Mg) ≤ 10%, 0 < w(Mn) ≤ 10%, 0 < w(Sc) ≤ 0.9%, 0 < w(Zr) ≤ 0.4%, with Al as the balance. The main steps of the preparation method are: smelting the alloy prefabricated ingot and atomizing the alloy powder. The block material printed with the aluminum-nickel alloy powder of the present invention is crack-free and has a uniform structure. After simple heat treatment, the tensile strength can be greater than 700 MPa, the yield strength is greater than 500 MPa, and the elongation is greater than 10%, exceeding the average level of high-strength deformable aluminum alloys. The aluminum-nickel alloy powder preparation method of the present invention is simple, mature, low-cost, and highly efficient, and can be used for large-scale industrial production.

Description

Technical Field

[0001] The present invention belongs to the field of aluminum alloy smelting, and relates to the composition design and preparation of high-strength aluminum alloy powder for additive manufacturing, and specifically relates to a high-strength aluminum-nickel alloy powder for additive manufacturing and a preparation method thereof. Background Art

[0002] Aluminum alloys are key lightweight materials for defense, aerospace, transportation, and other fields. As the structural design of aluminum alloy components becomes increasingly complex, traditional manufacturing processes are facing technical difficulties such as low forming freedom and multiple processing steps. Compared to traditional manufacturing processes, additive manufacturing offers greater forming freedom, providing unprecedented opportunities for customized production of complex aluminum alloy components (such as complex frame beams, thin-walled structures, and internal flow channel structures) in aerospace and other fields.

[0003] However, the solidification process of additive manufacturing has a fast cooling rate (>10 3 ℃ / s) and large temperature gradients (~10 6 Due to the characteristics of high strength (K / m) and harsh solidification conditions, the aluminum alloy systems suitable for additive manufacturing are mainly traditional casting systems. Al-Si alloys are widely used in the field of selective laser melting (SLM) due to their excellent forming properties, but their strength and elongation are relatively low. For example, the yield strength of AlSi10Mg prepared by SLM is 300MPa, the tensile strength is 490MPa, and the elongation is only 4%. Even AlSi10Mg composites reinforced by the introduction of ceramic particles still have a significant gap in mechanical properties compared to traditional 2-series (Al-Cu) and 7-series (Al-Zn) high-strength aluminum alloy forgings (tensile strength greater than 600MPa). Unfortunately, the 2-series and 7-series aluminum alloys currently prepared by SLM technology contain a large number of defects, resulting in their mechanical properties far below the level of forgings, making them still unusable in key components. The reason is that the solidification range of Al-Cu and Al-Zn systems is large and there is no primary heterogeneous nucleation phase. Solidification occurs in columnar crystal growth, and there is a serious tendency to hot cracking. According to the hot cracking sensitivity evaluation method and the phase diagram thermodynamic solidification simulation results, the hot cracking sensitivity factors (f s 1 / 2 <0.99|dT / d(f s 1 / 2 )|, where f s The solid fraction (solid fraction) is as high as 13261K and 6389K, respectively, which is 7 to 16 times that of AlSi10Mg (830K). As a result, solidification cracks easily form and propagate along columnar grain boundaries during selective laser printing, making it difficult for printed components to meet load-bearing service requirements. Therefore, the development of high-strength aluminum alloy systems with low hot crack sensitivity suitable for additive manufacturing is urgent. Summary of the Invention

[0004] The present invention provides a high-strength aluminum-nickel alloy powder for additive manufacturing and a preparation method thereof, which are used to solve the technical problem of the current additive manufacturing industry lacking high-strength aluminum alloy powder with low thermal cracking sensitivity.

[0005] The object of the present invention is achieved through the following solutions:

[0006] In a first aspect, the present invention relates to a high-strength aluminum-nickel alloy powder for additive manufacturing, which comprises the following components, calculated based on the sum of the chemical elements of the aluminum-nickel alloy powder being 100%:

[0007] 0<Ni≤15%,

[0008] 0≤Mg≤1%or 4≤w(Mg)≤10%,

[0009] 0≤Mn≤10%,

[0010] 0<Sc≤0.9%,

[0011] 0<Zr≤0.4%,

[0012] Al: margin.

[0013] In a second aspect, the present invention relates to a method for preparing high-strength aluminum-nickel alloy powder for additive manufacturing, which is characterized in that an aluminum-nickel alloy prefabricated ingot is obtained by smelting, and the high-strength aluminum-nickel alloy powder is obtained by a gas atomization powder making method.

[0014] As an embodiment, the preparation of the aluminum-nickel alloy prefabricated ingot comprises the following steps:

[0015] S1. According to the alloy component ratio, weigh Al block, Mg block, Al-Ni master alloy block, Al-Mn master alloy block, Al-Sc master alloy block, and Al-Zr master alloy block as raw materials;

[0016] S2, mixing the Al block and the Al-Ni master alloy block, heating, melting, and stirring to obtain a melt A;

[0017] S3, adding Al-Sc master alloy blocks and Al-Zr master alloy blocks into melt A, heating, melting and stirring to obtain melt B;

[0018] When the aluminum-nickel alloy contains Mn, an Al-Mn master alloy block is also added to the melt A;

[0019] When the aluminum-nickel alloy contains Mg, the Mg block is pressed into the melt B to obtain melt C;

[0020] S4, adding a refining agent and a covering agent to the melt obtained in step S3 and vacuum degassing to obtain a melt D;

[0021] S5. After removing the slag, the melt D is poured into a preheated mold to obtain a metal ingot.

[0022] As an embodiment, the heating temperature in step S2 is 730-750° C., and the stirring time is 1-3 minutes.

[0023] As an embodiment, the heating temperature in step S3 is 730-800° C., and the stirring time is 1-3 minutes.

[0024] As an embodiment, the heating temperature for pressing the Mg block into the melt B is 730-750° C., and the stirring time is 1-3 minutes.

[0025] As an embodiment, the degassing time in step S4 is 5 to 10 minutes; and the preheating temperature is 200 to 250°C.

[0026] As an embodiment, aerosol forming includes the following steps:

[0027] A1. Place the aluminum-nickel alloy prefabricated ingot in a vacuum environment and heat and melt it;

[0028] A2. The molten melt flows under the action of gravity. The outflowing melt is broken into droplets of different sizes under the impact of atomized nitrogen. The droplets solidify into powder during the falling process, and high-strength aluminum-nickel alloy powder is collected.

[0029] As an embodiment, the heating in step A1 is electromagnetic induction heating, the heating temperature is 750-800° C., and the insulation time is 0.5-0.8 h.

[0030] As an implementation scheme, step A1 specifically includes:

[0031] a. Place the aluminum-nickel alloy prefabricated ingot in the graphite crucible in the smelting chamber, close the chamber door, reduce the vacuum degree in the smelting chamber through the vacuum system, and then introduce nitrogen into the chamber to further replace the air in the chamber and reduce the oxygen content in the chamber;

[0032] b. The cavity is heated by electromagnetic induction to completely melt the ingot.

[0033] As an embodiment, in step A2, after collecting the powder, the method further includes vacuum packaging the collected powder.

[0034] In some specific embodiments, aluminum-nickel alloy powder for additive manufacturing is prepared by a gas atomization powder making method, and the steps are as follows:

[0035] (1) Raw material preparation:

[0036] The Al-Ni-Mg-Mn-Sc-Zr alloy powder for additive manufacturing is prepared according to its chemical element composition and mass percentage formula; pure Al is used as the Al source material, Al-Ni master alloy is used as the Ni source material, pure Mg is used as the Mg source material, Al-Mn master alloy is used as the Mn source material, Al-Sc master alloy is used as the Sc source material, and Al-Zr master alloy is used as the Zr source material; Al blocks, Mg blocks, Al-Ni master alloy blocks, Al-Mn master alloy blocks, Al-Sc master alloy blocks, and Al-Zr master alloy blocks are weighed as raw materials respectively, and according to the standard of Mg, Sc, and Zr recovery rate of 95%, additional Mg blocks, Al-Sc master alloy blocks, and Al-Zr master alloy blocks are weighed as raw materials to supplement the burned-out portion;

[0037] (2) Melting of Al-Ni-Mg-Mn-Sc-Zr alloy prefabricated ingot:

[0038] a. Mix Al blocks, Mg blocks, and Al-Ni master alloy blocks in a graphite crucible, heat to 730-750°C in a resistance furnace, and stir with a graphite stirring rod for 3 minutes.

[0039] b. Add Al-Sc master alloy block and Al-Zr master alloy block to the melt and stir with a graphite stirring rod for 3 minutes;

[0040] c. Add the Mg block to the melt and use a graphite rod to press it into the bottom of the melt to dissolve;

[0041] d. Add refining agent for refining, then scrape off the surface slag, sprinkle covering agent, and vacuum degas for 5 to 10 minutes;

[0042] e. Remove the surface slag and cast it into a cylindrical mold preheated at 250°C to obtain a cylindrical ingot;

[0043] f. Use mechanical processing methods to remove the oxide scale on the surface of the ingot.

[0044] (3) Gas atomization forming of Al-Ni-Mg-Mn-Sc-Zr alloy powder:

[0045] a. Place the Al-Ni-Mg-Mn-Sc-Zr prefabricated ingot in a graphite crucible in the melting chamber, close the chamber door, reduce the vacuum degree in the melting chamber through the vacuum system, and then introduce nitrogen into the chamber to further replace the air in the chamber and reduce the oxygen content in the chamber;

[0046] b. Heating the cavity by electromagnetic induction to a target temperature of 750-800°C for 0.5 h to completely melt the ingot;

[0047] c. The molten melt flows along the nozzle under the action of gravity and is broken into droplets of different sizes under the impact of the fast-moving atomized nitrogen gas. The droplets solidify into powder as they fall, and the falling powder is collected at the bottom of the cavity;

[0048] d. The collected powder is vacuum packed to prevent the powder from being oxidized.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] (1) The high-strength aluminum-nickel alloy powder of the present invention is based on the Al-Ni eutectic system, and additional peritectic elements (Sc, Zr) are introduced to further improve the solidification characteristics of the aluminum alloy, which plays a role in heterogeneous nucleation, grain refinement, and reduction of the solidification range and the slope of the solidification curve, significantly reducing the thermal cracking sensitivity of the aluminum alloy during rapid solidification, and making the material have excellent additive manufacturing forming performance.

[0051] (2) In SLM samples produced using the high-strength aluminum-nickel alloy powder raw material of the present invention, Ni, Sc, and Zr have a high supersaturated solid solubility in the matrix, and Al3Ni and Al3(Sc,Zr) nanoparticles can be obtained through simple heat treatment and aging. In addition, the elements Mg and Mn act as solid solution strengthening, further enhancing mechanical properties. Materials formed by SLM from the alloy powder of the present invention exhibit outstanding mechanical properties, with tensile strength exceeding 700 MPa, yield strength exceeding 500 MPa, and elongation exceeding 10%, exceeding the average level of existing commercial high-strength deformable aluminum alloys.

[0052] (3) The method for preparing high-strength aluminum-nickel alloy powder of the present invention has simple and mature process operation, low cost and high efficiency, and can realize large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0054] Figure 1 is the change of hot cracking sensitivity factor of Al-Ni system with Ni content;

[0055] Figure 2 The hot cracking sensitivity factor of Al-Ni-Mg-Mn system changes with the Mg and Mn contents;

[0056] Figure 3 The hot cracking sensitivity factor of Al-Ni-Sc-Zr system changes with the content of Sc and Zr;

[0057] Figure 4 Typical particle morphology (a) and typical microstructure (b) of Al-Ni-Mg-Mn-Sc-Zr powder;

[0058] Figure 5 This is a typical XRD pattern of Al-5.1Ni-5.0Mg-0.3Mn-0.6Sc-0.1Zr alloy powder;

[0059] Figure 6 Typical microstructure of the Al-5.1Ni-5.0Mg-0.3Mn-0.6Sc-0.1Zr alloy prepared in Example 1;

[0060] Figure 7 This is a backscattered electron diffraction photograph of the Al-5.1Ni-5.0Mg-0.3Mn-0.6Sc-0.1Zr bulk material in Example 1;

[0061] Figure 8 This is a typical XRD pattern of the printed Al-5.1Ni-5.0Mg-0.3Mn-0.6Sc-0.1Zr alloy;

[0062] Figure 9 This is the typical microstructure of the 2024 printed alloy used as a comparison in Example 1;

[0063] Figure 10 is the tensile curve of the Al-5.1Ni-5.0Mg-0.3Mn-0.6Sc-0.1Zr alloy in Example 1;

[0064] Figure 11 This is a typical tensile curve of the Al-5.7Ni-0.5Mg-6.0Mn-0.6Sc-0.4Zr bulk material after heat treatment in Example 2;

[0065] Figure 12 This is a typical tensile curve of the Al-5.7Ni-5.0Mg-6.0Mn-0.6Sc-0.3Zr bulk material after heat treatment in Example 3;

[0066] Figure 13 This is a typical tensile curve of the Al-5.7Ni-0.6Sc-0.3Zr bulk material after heat treatment in Example 4;

[0067] Figure 14 This is a typical tensile curve of the Al-8.0Ni-0.6Sc-0.3Zr bulk material after heat treatment in Example 5;

[0068] Figure 15 This is a typical tensile curve of the Al-10.0Ni-0.6Sc-0.3Zr bulk material after heat treatment in Example 6;

[0069] Figure 16 Backscattered electron diffraction image of the Al-6.0Ni-5.0Mg bulk material in Example 7

[0070] Figure 17 This is a typical tensile curve of the Al-6.0Ni-5.0Mg bulk material after heat treatment in Example 7; DETAILED DESCRIPTION

[0071] The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0072] The high-throughput Scheil solidification path simulation of the Al-Ni-Mg-Mn-Sc-Zr system was performed using the phase diagram thermodynamic calculation method to obtain the solid phase fraction f s The curve of the change with temperature T. The hot crack sensitivity factor (CSI) is defined as: f s 1 / 2 <0.99|dT / d(f s ) 1 / 2 The calculated trends of the hot cracking sensitivity factors of Al-Ni, Al-Ni-Mg-Mn and Al-Ni-Sc-Zr systems with composition are as follows: Figure 1 、 Figure 2 and Figure 3 As shown. The hot cracking sensitivity factors of aluminum alloys (AlSi10Mg, AlSi7Mg, AlSi12Mg) manufactured by additive manufacturing in current industrial applications are all less than 5000K. As for Sc and Zr, although Sc and Zr have been used as additives to improve the performance of alloy powders, their optimal ratio is unknown and difficult to determine. Through high-throughput calculation of thermodynamic solidification paths, it is clear that only when the addition amount of Sc and Zr is as follows Figure 3 When the alloy powder is within the preferred composition range shown, it has excellent solidification characteristics, namely, a thermal cracking sensitivity factor below 5000K. When the addition amounts of Sc and Zr are outside this preferred composition range, the alloy powder is prone to cracking and being scrapped during the laser additive manufacturing process. The chemical composition of the Al-Ni-Mg-Mn-Sc-Zr alloy powder finally optimized by the present invention is: 0 < w(Ni) ≤ 15%; 0 ≤ w(Mg) ≤ 1% and 4 ≤ w(Mg) ≤ 10%; 0 ≤ w(Mn) ≤ 10%; 0 ≤ w(Sc) ≤ 0.9%; 0 ≤ w(Zr) ≤ 0.4%; Al remainder.

[0073] Example 1

[0074] From the chemical composition range of Al-Ni-Mg-Mn-Sc-Zr alloy, Al-5.7Ni-5.0Mg-0.3Mn-0.6Sc-0.3Zr was selected as the nominal composition for powder preparation. The preparation steps are as follows:

[0075] (1) Raw material preparation:

[0076] 0.16 kg of Al block, 2.63 kg of Mg block, 28.50 kg of Al-10Ni master alloy block, 1.50 kg of Al-10Mn master alloy block, 15.79 kg of Al-2Sc master alloy block, and 1.58 kg of Al-10Zr master alloy block were weighed as raw materials, and according to the standard of 95% recovery rate of Mg, Sc, and Zr, 0.13 kg of Mg block, 0.02 kg of Al-Sc master alloy block, and 0.01 kg of Al-Zr master alloy block were additionally weighed as raw materials to supplement the burn-out.

[0077] (2) Melting of Al-Ni-Mg-Mn-Sc-Zr alloy prefabricated ingot:

[0078] a. Mix the Al block, Mg block, and Al-Ni master alloy block in a graphite crucible, heat to 750°C in a resistance furnace, and stir for 3 minutes with a graphite stirring rod;

[0079] b. Add Al-Sc master alloy block and Al-Zr master alloy block to the melt and stir with a graphite stirring rod for 3 minutes;

[0080] c. Add the Mg block to the melt and use a graphite rod to press it into the bottom of the melt to dissolve;

[0081] d. Add refining agent for refining, then remove the surface slag, sprinkle with covering agent, and vacuum degas for 10 minutes;

[0082] e. Remove the surface slag and cast it into a cylindrical mold preheated at 250°C to obtain a cylindrical ingot;

[0083] f. Use mechanical processing methods to remove the oxide scale on the surface of the ingot.

[0084] (3) Gas atomization forming of Al-Ni-Mg-Mn-Sc-Zr alloy powder:

[0085] a. Place the Al-Ni-Mg-Mn-Sc-Zr prefabricated ingot in a graphite crucible in the melting chamber, close the chamber door, reduce the vacuum degree in the melting chamber through the vacuum system, and then introduce nitrogen into the chamber to further replace the air in the chamber and reduce the oxygen content in the chamber;

[0086] b. Heating the cavity by electromagnetic induction to a target temperature of 800°C for 0.5 h to completely melt the ingot;

[0087] c. The molten melt flows along the nozzle under the action of gravity and is broken into droplets of different sizes under the impact of the fast-moving atomized nitrogen gas. The droplets solidify into powder as they fall, and the falling powder is collected at the bottom of the cavity;

[0088] d. The collected powder is vacuum packed to prevent the powder from being oxidized.

[0089] The composition of the Al-Ni-Mg-Mn-Sc-Zr powder prepared in this embodiment was obtained by inductively coupled plasma optical emission spectrometry and was Al-5.1Ni-5.0Mg-0.3Mn-0.6Sc-0.1Zr, which fell within the preferred composition range and was consistent with the designed nominal composition value.

[0090] The typical particle morphology and microstructure of Al-5.1Ni-5.0Mg-0.3Mn-0.6Sc-0.1Zr powder prepared in this embodiment are as follows: Figure 4 The typical XRD pattern is shown in Figure 5 The powder used for SLM has a particle size of 15 to 53 μm and high sphericity. The powder contains α-Al and Al₃Ni, with α-Al / Al₃Ni eutectics between the α-Al cells.

[0091] The Al-5.1Ni-5.0Mg-0.3Mn-0.6Sc-0.1Zr powder prepared in this embodiment was processed by conventional aluminum alloy selective laser melting process to obtain Al-5.1Ni-5.0Mg-0.3Mn-0.6Sc-0.1Zr alloy block, whose typical microstructure is as follows: Figure 6 As shown, the electron backscattered photograph of the grain structure is as follows Figure 7 The typical XRD pattern is shown in Figure 8 As shown. The Al-5.1Ni-5.0Mg-0.3Mn-0.6Sc-0.1Zr alloy prepared by SLM technology has no cracks, no large number of holes, and fine grain structure. For comparison, the 2024 aluminum alloy prepared by the same printing equipment and printing process as in this embodiment is shown in FIG. Figure 9 As shown, it can be seen that the crack defect is distributed throughout the entire specimen.

[0092] It shows that the printing performance of the Al-5.1Ni-5.0Mg-0.3Mn-0.6Sc-0.1Zr alloy in this embodiment is far superior to that of the traditional high-strength 2024 aluminum alloy.

[0093] Due to the rapid cooling during SLM, no lamellar eutectic phase forms in the alloy. The absence of a clear Al3Ni diffraction peak in the XRD pattern indicates that the rapid cooling results in a high degree of supersaturation of Ni within the Al matrix. Subsequent aging treatment can precipitate Al3Ni as nanoparticles, further enhancing the strengthening effect.

[0094] The printed Al-5.1Ni-5.0Mg-0.3Mn-0.6Sc-0.1Zr alloy block was kept at 350°C for 15 minutes. Then, according to ASTM E8 / E8M-15a, its tensile strength was measured to be 670 MPa, its yield strength was 540 MPa, and its elongation was 6.8%. The tensile curve was as follows: Figure 10 As shown, the performance of the alloys is 37%, 80% and 70% higher than that of the AlSi10Mg alloy processed by the same additive manufacturing process in the industry.

[0095] Example 2

[0096] Al-5.7Ni-0.5Mg-6.0Mn-0.6Sc-0.4Zr was selected as the nominal composition from the chemical composition range of Al-Ni-Mg-Mn-Sc-Zr alloy for powder preparation;

[0097] In this embodiment, a method for preparing Al-Ni-Mg-Mn-Sc-Zr alloy powder for additive manufacturing comprises the following steps:

[0098] (1) Raw material preparation:

[0099] 1.01 kg of Al block, 0.26 kg of Mg block, 28.50 kg of Al-10Ni master alloy block, 15.00 kg of Al-20Mn master alloy block, 3.16 kg of Al-10Sc master alloy block, and 2.11 kg of Al-10Zr master alloy block were weighed as raw materials, and according to the standard of 95% recovery rate of Mg, Sc, and Zr, 0.01 kg of Mg block, 0.02 kg of Al-10Sc master alloy block, and 0.01 kg of Al-10Zr master alloy block were additionally weighed as the raw materials to be replenished for burn-out;

[0100] (2) (3) Steps are the same as those in Example 1.

[0101] The tensile strength measured by the test method of Example 1 is 555 MPa, the yield strength is 495 MPa, and the elongation is 11.2%. The tensile curve is as follows: Figure 11 As shown, they are 13%, 65% and 180% higher than the AlSi10Mg alloy processed by the same additive manufacturing process in the industry.

[0102] Example 3

[0103] Al-5.7Ni-5.0Mg-6.0Mn-0.6Sc-0.3Zr was selected as the nominal composition in the chemical composition range of Al-Ni-Mg-Mn-Sc-Zr alloy for powder preparation;

[0104] In this embodiment, a method for preparing Al-Ni-Mg-Mn-Sc-Zr alloy powder for additive manufacturing comprises the following steps:

[0105] (1) Raw material preparation:

[0106] 4.29 kg of Al block, 2.63 kg of Mg block, 28.50 kg of Al-10Ni master alloy block, 10 kg of Al-30Mn master alloy block, 3.16 kg of Al-10Sc master alloy block, and 1.58 kg of Al-10Zr master alloy block were weighed as raw materials, and according to the standard of 95% recovery rate of Mg, Sc, and Zr, 0.13 kg of Mg block, 0.02 kg of Al-10Sc master alloy block, and 0.01 kg of Al-10Zr master alloy block were additionally weighed as the raw materials to be replenished for burn-out;

[0107] (2) (3) Steps are the same as those in Example 1.

[0108] The tensile strength measured by the test method of Example 1 is 715 MPa, the yield strength is 580 MPa, and the elongation is 5.5%. The tensile curve is as follows: Figure 12 As shown, they are 46%, 93% and 38% higher than the AlSi10Mg alloy processed by the same additive manufacturing process in the industry.

[0109] In addition, excessive amounts of Mn and Mg lead to reduced plasticity of the material of the present invention. Comparing Examples 1, 2, and 3, it can be seen that the elongation (5.5%) when both 6% Mn and 5% Mg are contained is lower than the elongation (11.2% and 6.8%, respectively) when only 6% Mn or 5% Mg is contained. Considering the solidification characteristics and mechanical properties of the alloy powder, the content of Mn and Mg should not exceed 10%, respectively. Further, with regard to the Mg content, through high-throughput calculation of the thermodynamic solidification path, it was found that the thermal cracking sensitivity factor of the alloy powder with a Mg content of 1-4% was higher than 5000K (see Figure 2 ), that is, the solidification characteristics of the alloy powder are poor, and it is impossible to obtain an alloy material without crack defects by additive manufacturing.

[0110] Example 4

[0111] In this embodiment, a method for preparing an Al-5.7Ni-0.6Sc-0.3Zr alloy powder free of Mg and Mn for additive manufacturing comprises the following steps:

[0112] (1) Raw material preparation:

[0113] 16.79 kg of Al block, 28.50 kg of Al-10Ni master alloy block, 3.16 kg of Al-10Sc master alloy block, and 1.58 kg of Al-10Zr master alloy block were weighed as raw materials, and according to the standard of 95% recovery rate of Mg, Sc, and Zr, 0.02 kg of Al-10Sc master alloy block and 0.01 kg of Al-10Zr master alloy block were additionally weighed as the raw materials to be replenished due to burnout;

[0114] (2) (3) Steps are the same as those in Example 1.

[0115] The tensile strength measured by the test method of Example 1 is 530 MPa, the yield strength is 470 MPa, and the elongation is 11.3%. The tensile curve is as follows: Figure 13 As shown, they are 8%, 57% and 183% higher than the AlSi10Mg alloy processed by the same additive manufacturing process in the industry.

[0116] Example 5

[0117] Al-8.0Ni-0.6Sc-0.3Zr was selected as the nominal composition in the chemical composition range of Al-Ni-Mg-Mn-Sc-Zr alloy for powder preparation;

[0118] In this embodiment, a method for preparing Al-Ni-Sc-Zr alloy powder for additive manufacturing comprises the following steps:

[0119] (1) Raw material preparation:

[0120] 5.29 kg of Al block, 40.00 kg of Al-10Ni master alloy block, 3.16 kg of Al-10Sc master alloy block, and 1.58 kg of Al-10Zr master alloy block were weighed as raw materials, and according to the standard of 95% recovery rate of Mg, Sc, and Zr, 0.02 kg of Al-10Sc master alloy block and 0.01 kg of Al-10Zr master alloy block were additionally weighed as the raw materials to be replenished due to burnout;

[0121] (2) (3) Steps are the same as those in Example 1.

[0122] The tensile strength measured by the test method of Example 1 is 570 MPa, the yield strength is 500 MPa, and the elongation is 9.6%. The tensile curve is as follows: Figure 14 As shown, they are 16%, 67% and 140% higher than the AlSi10Mg alloy processed by the same additive manufacturing process in the industry.

[0123] Example 6

[0124] Al-10.0Ni-0.6Sc-0.3Zr was selected as the nominal composition in the chemical composition range of Al-Ni-Mg-Mn-Sc-Zr alloy for powder preparation;

[0125] In this embodiment, a method for preparing Al-Ni-Sc-Zr alloy powder for additive manufacturing comprises the following steps:

[0126] (1) Raw material preparation:

[0127] 20.29 kg of Al block, 25.00 kg of Al-20Ni master alloy block, 3.16 kg of Al-10Sc master alloy block, and 1.58 kg of Al-10Zr master alloy block were weighed as raw materials, and according to the standard of 95% recovery rate of Mg, Sc, and Zr, 0.02 kg of Al-10Sc master alloy block and 0.01 kg of Al-10Zr master alloy block were additionally weighed as the raw materials to be replenished due to burnout;

[0128] (2) (3) Steps are the same as those in Example 1.

[0129] The tensile strength was 625 MPa and the yield strength was 530 MPa as measured by the test method of Example 1. The tensile curve was as follows: Figure 15 As shown in Figure 2, the elongation is 8.3%, which is 28%, 77% and 108% higher than the AlSi10Mg alloy processed by the same additive manufacturing process in the industry.

[0130] Example 7

[0131] Al-6.0Ni-5.0Mg was selected as the nominal composition in the chemical composition range of Al-Ni-Mg-Mn-Sc-Zr alloy for powder preparation;

[0132] In this embodiment, a method for preparing Al-Ni-Mg alloy powder for additive manufacturing comprises the following steps:

[0133] (1) Raw material preparation:

[0134] 29.36 kg of Al block, 2.63 kg of Mg block, and 15 kg of Al-20Ni master alloy block were weighed as raw materials, and according to the standard of Mg recovery rate of 95%, 0.13 kg of Mg block was additionally weighed as the burn-off part to supplement the raw materials;

[0135] (2) (3) Steps are the same as those in Example 1.

[0136] The Al-6.0Ni-5.0Mg in this embodiment has good printing performance and few solidification cracks, but the grain size is mainly developed columnar crystals (see Figure 16). The tensile strength measured by the test method of Example 1 is 560MPa, the yield strength is 470MPa, and the elongation is 15.6%. The tensile curve is as follows Figure 17 As shown, they are 14%, 90% and 290% higher than the AlSi10Mg alloy processed by the same additive manufacturing process in the industry.

[0137] Examples 1-7 show that the high-strength aluminum-nickel alloy powder for additive manufacturing of the present invention has excellent mechanical properties and excellent solidification properties. The printed α-Al grains and Al3Ni particles are small and have few defects. In addition, the tensile strength, yield strength, and elongation of the printed metal alloy of the present invention are all improved. On the one hand, the present invention is based on the material design concept of adding Sc, Zr, Mg, and Mn to the Al-Ni eutectic to improve the printing performance and strength of the alloy powder. On the other hand, high-throughput calculation of the thermodynamic solidification path is used to evaluate the effect of Sc, Zr, Mg, and Mn on the hot crack sensitivity factor, optimize the composition ratio range, and avoid the deterioration of solidification characteristics caused by improper or excessive addition of Sc, Zr, Mg, and Mn, which makes it impossible to print.

[0138] The above describes specific embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. The embodiments of this application and the features in the embodiments may be combined with each other in any manner unless there is a conflict.

Claims

1. A high-strength aluminum-nickel alloy powder for additive manufacturing, characterized in that: Based on the calculation that the sum of the chemical elements of the aluminum-nickel alloy powder is 100%, it includes the following components: 5.1%≤Ni≤15%, 0≤Mg≤1% or 4%≤Mg≤10%, 0≤Mn≤10%, 0<Sc≤0.9%, 0＜Zr≤0.4％, Al: margin.

2. A method for preparing high-strength aluminum-nickel alloy powder for additive manufacturing according to claim 1, characterized in that: An aluminum-nickel alloy prefabricated ingot is obtained by smelting, and the high-strength aluminum-nickel alloy powder is obtained by a gas atomization powder making method.

3. The method for preparing high-strength aluminum-nickel alloy powder for additive manufacturing according to claim 2, wherein: The preparation of aluminum-nickel alloy prefabricated ingots includes the following steps: S1. According to the alloy component ratio, weigh Al block, Mg block, Al-Ni master alloy block, Al-Mn master alloy block, Al-Sc master alloy block, and Al-Zr master alloy block as raw materials; S2, mixing the Al block and the Al-Ni master alloy block, heating, melting, and stirring to obtain a melt A; S3, adding Al-Sc master alloy blocks and Al-Zr master alloy blocks into melt A, heating, melting and stirring to obtain melt B; When the aluminum-nickel alloy contains Mn, an Al-Mn master alloy block is also added to the melt A; When the aluminum-nickel alloy contains Mg, the Mg block is pressed into the melt B to obtain melt C; S4, adding a refining agent and a covering agent to the melt obtained in step S3 and vacuum degassing to obtain a melt D; S4. After removing the slag, the melt D is poured into a preheated mold to obtain a metal ingot.

4. The method for preparing high-strength aluminum-nickel alloy powder for additive manufacturing according to claim 3, wherein: The heating temperature in step S2 is 730-750° C., and the stirring time is 1-3 minutes.

5. The method for preparing high-strength aluminum-nickel alloy powder for additive manufacturing according to claim 3, wherein: The heating temperature in step S3 is 730-800° C., and the stirring time is 1-3 minutes; the heating temperature for pressing the Mg block into the melt B is 730-750° C., and the stirring time is 1-3 minutes.

6. The method for preparing high-strength aluminum-nickel alloy powder for additive manufacturing according to claim 3, wherein: The degassing time in step S4 is 5 to 10 minutes; the preheating temperature is 200 to 250°C.

7. The method for preparing high-strength aluminum-nickel alloy powder for additive manufacturing according to claim 2, wherein: The aerosol powder making method includes the following steps: A1. Place the aluminum-nickel alloy prefabricated ingot in a vacuum environment and heat and melt it; A2. The molten melt flows under the action of gravity. The outflowing melt is broken into droplets of different sizes under the impact of atomized nitrogen. The droplets solidify into powder during the falling process, and high-strength aluminum-nickel alloy powder is collected.

8. The method for preparing high-strength aluminum-nickel alloy powder for additive manufacturing according to claim 7, characterized in that: The heating in step A1 is electromagnetic induction heating, the heating temperature is 750-800° C., and the heat preservation time is 0.5-0.8 h.

9. The method for preparing high-strength aluminum-nickel alloy powder for additive manufacturing according to claim 7, characterized in that: Step A1 is specifically as follows: a. Place the aluminum-nickel alloy prefabricated ingot in the graphite crucible in the smelting chamber, close the chamber door, reduce the vacuum degree in the smelting chamber through the vacuum system, and then introduce nitrogen into the chamber to further replace the air in the chamber and reduce the oxygen content in the chamber; b. The cavity is heated by electromagnetic induction to completely melt the ingot.

10. The method for preparing high-strength aluminum-nickel alloy powder for additive manufacturing according to claim 7, characterized in that: In step A2, after collecting the powder, the method further includes vacuum packaging the collected powder.

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