High-strength heat-resistant aluminum alloy powder for additive manufacturing and preparation method and application thereof

Abstract

The application provides a high-strength heat-resistant aluminum alloy powder for additive manufacturing and a preparation method and application thereof, and the powder comprises the following components in percentage by weight: Mn 2.0-10.5%, Ce 0.5-5.5%, Sc 0.2-1%, Zr 0.05-0.5%, Mg 0.1-0.5%, Ni 0.05-0.2%, Mo 0.1-0.3%, Co 0.01-0.05%, mixed rare earth La-Ce-Pr-Nd 0.02-0.1%, and the balance is aluminum; the mass percentage of Mn and Ce is (1-3):1. The mechanical properties of the 3D printing shaped part in a heat-treated state at room temperature are as follows: a tensile strength ≥580 MPa, a yield strength ≥550 MPa, and an elongation after fracture ≥9%; the mechanical properties at 250 DEG C are as follows: a tensile strength ≥240 MPa and a yield strength ≥150 MPa; after 100h of heat preservation at 250 DEG C, the strength only decreases by 10%.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of special materials for additive manufacturing, and particularly relates to a high-strength heat-resistant aluminum alloy powder for additive manufacturing and a preparation method and application thereof. BACKGROUND

[0002] Additive manufacturing is a manufacturing method for forming a three-dimensional complex structure part by adding materials point by point, line by line and surface by surface based on a digital model. Complex-shaped, integrally formed and structure-function integrated parts, such as cavity, grid, porous and internal runner structure parts, can be manufactured. The strength of the prepared alloy is close to that of a forged part, and the alloy is widely used in the fields of aerospace, automobile, ship and die manufacturing. With the continuous upgrading of equipment, the problem of low laser absorption rate and difficulty in 3D printing forming of aluminum alloy materials is overcome. The 3D printing flexible manufacturing characteristics of the aluminum alloy, which perfectly combines product optimization design and actual application, play the advantages of the light weight preparation technology of 3D printing aluminum alloy parts in the weight reduction of spacecraft. At present, a large part of the application target of aluminum alloy is to replace titanium alloy for medium temperature application (250-450℃). However, the traditional aluminum alloy will lose a large part of the strength at 200℃ or above, which limits the application of aluminum alloy.

[0003] Therefore, it is urgent to develop a high-strength heat-resistant aluminum alloy powder suitable for additive manufacturing. SUMMARY

[0004] In order to overcome the deficiencies in the prior art, the main purpose of the present application is to provide a high-strength heat-resistant aluminum alloy powder for additive manufacturing and a preparation method and application thereof. The high-strength heat-resistant aluminum alloy powder for additive manufacturing has the advantages of uniform composition and prevention of liquid crack initiation in 3D printing. The prepared part after 3D printing forming has high room temperature strength, high temperature strength and durability after heat treatment. The room temperature mechanical properties are as follows: tensile strength ≥580MPa, yield strength ≥550MPa and elongation after fracture ≥9%; the mechanical properties at 250℃ are as follows: tensile strength ≥240MPa, yield strength ≥150MPa and elongation after fracture ≥7%, and the strength only decreases by 10% after 100 hours of heat preservation at 250℃.

[0005] The purpose of the present application is achieved by the following technical solutions:

[0006] In a first aspect, the present application provides a high-strength heat-resistant aluminum alloy powder for additive manufacturing, which comprises the following components by weight percentage: Mn 2.0-10.5%, Ce 0.5-5.5%, Sc 0.2-1%, Zr 0.05-0.5%, Mg 0.1-0.5%, Ni 0.05-0.2%, Mo 0.1-0.3%, Co 0.01-0.05%, mixed rare earth La-Ce-Pr-Nd 0.02-0.1%, and the balance being aluminum; wherein the mass percentage of Mn and Ce is (1-3): 1.

[0007] Further, the high-strength heat-resistant aluminum alloy powder comprises the following components by weight percentage: Mn 2.2-10.5%, Ce 1-5.5%, Sc 0.2-1%, Zr 0.05-0.5%, Mg 0.1-0.5%, Ni 0.05-0.2%, Mo 0.1-0.3%, Co 0.01-0.05%, mixed rare earth La-Ce-Pr-Nd 0.02-0.1%, and the balance being aluminum; wherein the mass percentage of Mn and Ce is (1-3): 1.

[0008] Further, the high-strength heat-resistant aluminum alloy powder has a sphericity of ≥95%, an oxygen content of less than 300 ppm, and a hollow powder rate of less than 3 ‰.

[0009] Further, the particle size range of the high-strength heat-resistant aluminum alloy powder includes but is not limited to 10-45 μm, 15-53 μm, 20-63 μm, and 15-75 μm.

[0010] In a second aspect, the present application provides a preparation method of a high-strength heat-resistant aluminum alloy powder for additive manufacturing.

[0011] The preparation method comprises the following steps:

[0012] (1) AlMn intermediate alloy, ALCe intermediate alloy, ALNi intermediate alloy, ALSc intermediate alloy, ALZr intermediate alloy, mixed rare earth alloy, and pure aluminum are placed in a melting crucible according to the ratio;

[0013] (2) When the alloy in step (1) starts to melt, magnesium ingot is pressed into the bottom of the alloy melt, and the temperature is raised to the melting temperature while electromagnetic stirring is performed;

[0014] (3) The metal melt prepared in step (2) is broken by using high-purity inert gas, and the pressure in the atomization chamber is 1-5 MPa;

[0015] (4) The powder prepared in step (3) is sieved by vibration to obtain the high-strength heat-resistant aluminum alloy powder for additive manufacturing.

[0016] Further, in step (1), the AlMn intermediate alloy is AlMn(30-50) intermediate alloy, the ALCe intermediate alloy is ALCe(5-30) intermediate alloy, the ALNi intermediate alloy is ALNi(20-50) intermediate alloy, the ALSc intermediate alloy is ALSc(2-10) intermediate alloy, and the ALZr intermediate alloy is ALZr(2-10) intermediate alloy.

[0017] Preferably, the mixed rare earth alloy has a composition of La 20-30%, Ce 48-58%, Pr 4-6%, Nd 15-17%, and a relative purity of ≥99%.

[0018] Further, in step (2), the melting temperature is 750-900℃, and the electromagnetic stirring is 5-10 min.

[0019] Further, in step (3), the high-purity inert gas includes but is not limited to high-purity argon and high-purity nitrogen.

[0020] In a third aspect, the application provides a use of the high-strength heat-resistant aluminum alloy powder for additive manufacturing in 3D printing.

[0021] The high-strength heat-resistant aluminum alloy powder for additive manufacturing is prepared by using the high-strength heat-resistant aluminum alloy powder for additive manufacturing provided in the first aspect of the application or the preparation method provided in the second aspect of the application.

[0022] Further, the substrate used in 3D printing is a 3-series aluminum alloy substrate, and the substrate is preheated to 200℃ before forming; the energy density range of the 3D printing process is 100-220 J / mm 3 .

[0023] In the application, the powder additive manufacturing (3D printing) process uses an aluminum-manganese aluminum alloy substrate similar in composition to the powder material; the substrate is heated to 200℃ before forming to reduce the supercooling degree during the forming process. The energy density range of the powder additive manufacturing process is 100-220 J / mm 3 ; the heating rate of the heat treatment is controlled to be 5-20℃, the temperature range is controlled to be 250-500℃, and the holding time is controlled to be 6-20h. A temperature that is too low results in too small amount of strengthening phase precipitation and low alloy strength; a temperature that is too high causes the lattice of the precipitated phase and the substrate to be incoherent, the grains to grow significantly, and the alloy strength to decrease.

[0024] In the application, the weight percentage of Mn in the high-strength heat-resistant aluminum alloy powder for additive manufacturing is 2.0-10.5%, and the supersaturated Mn can increase the solid solubility of alpha-Al, thereby improving the room temperature strength of the aluminum alloy, and can also increase the recrystallization temperature and slow down the recrystallization process of the aluminum alloy.

[0025] The weight percentage of Ce is 0.5-5.5%, and the addition of Ce can form Al20Mn2Ce, Al6Mn, AlCe3, Al11Ce3 and other high-melting-point intermetallic compounds with the Al matrix and Mn, and due to the low solubility of Ce in the FCC aluminum matrix, the alloy has good high-temperature stability and grain coarsening resistance below 400 DEG C.

[0026] The mass percentage of Mn and Ce is (1-3):1, which is to promote the generation of metastable phase Al20Mn2Ce and reduce the formation of Mn-rich intermetallic compounds.

[0027] The weight percentage of Mg is 0.1-0.5%, which can improve the strength of the alloy.

[0028] The weight percentage of Sc is 0.2-1%, and the weight percentage of Zr is 0.05-0.5%, which can reduce the initiation of thermal cracks as nucleation points, generate Al3Sc and Al3Zr nano precipitates that are coherent with the matrix, and improve the strength of the alloy.

[0029] The weight percentage of Mo is 0.1-0.3%, which can generate a dispersedly distributed high-melting-point Al12Mo phase, pin the grain boundary, and improve the high-temperature strength of the alloy.

[0030] The weight percentage of Co is 0.01-0.05%, and the weight percentage of Ni is 0.05-0.2%, which can generate a dispersedly distributed high-melting-point phase, reduce the secondary dendrite arm spacing of the alloy, and effectively refine the grains.

[0031] The weight percentage of mixed rare earth (La-Ce-Pr-Nd) is 0.02-0.1%, which can purify the melt, refine the grains, and prevent the initiation of liquid cracks in the rapid cooling process.

[0032] In the application, the alloy is melted and subjected to electromagnetic stirring for 5-10 minutes in step (1), which aims to promote the formation of AlMnCe ternary alloy, and insufficient stirring or short stirring time may cause composition segregation, resulting in the generation of columnar crystals in the molten pool in the subsequent 3D printing process, thereby reducing the strength of the 3D printed part.

[0033] The ideal organizational features of the high-strength aluminum alloy powder for additive manufacturing are composed of fine α-Al grains and uniformly dispersed high-melting-point phases. The acquisition of such an organization mainly relies on the control of the melting process and the control of the gas atomization process. In order to avoid the segregation of rare earth elements and promote the formation of high-melting-point intermetallic compounds such as Al20Mn2Ce, Al6Mn, AlCe3 and Al11Ce3, electromagnetic stirring is required during the alloy melting process. The atomization medium is high-purity inert gas, and the atomization pressure is controlled at 1-5 MPa.

[0034] The high-strength heat-resistant aluminum alloy powder for additive manufacturing has the following advantages:

[0035] 1. High strength. The high-strength heat-resistant aluminum alloy powder for additive manufacturing is used to prepare a workpiece by 3D printing, and after heat treatment, the workpiece has a tensile strength of ≥580 MPa, a yield strength of ≥550 MPa, and an elongation at break of ≥9% at room temperature.

[0036] 2. Good heat resistance. The high-strength heat-resistant aluminum alloy powder for additive manufacturing is used to prepare a workpiece by 3D printing, and after heat treatment, the workpiece has a tensile strength of ≥240 MPa, a yield strength of ≥150 MPa, and an elongation at break of ≥7% at 250℃. After 100 hours of heat preservation at 250℃, the strength decreases by only 10%.

[0037] 3. Good powder sphericity. The high-strength heat-resistant aluminum alloy powder for additive manufacturing has a sphericity (aspect ratio) of ≥97% as calculated by the aspect ratio.

[0038] 4. Low hollow powder rate. The high-strength heat-resistant aluminum alloy powder for additive manufacturing has a hollow powder rate of ≤3 ‰. BRIEF DESCRIPTION OF DRAWINGS

[0039] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of preferred embodiments, and are not meant to limit the present application. In the drawings:

[0040] Figure 1 Figure 2 is a morphology diagram of the high-strength heat-resistant aluminum alloy powder for additive manufacturing prepared in Example 2 of the present application. DETAILED DESCRIPTION

[0041] Exemplary embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the present disclosure are shown. It is to be understood that the present disclosure can be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0042] According to the specific embodiments of the present application, a high-strength heat-resistant aluminum alloy powder for additive manufacturing is provided.

[0043] The high-strength heat-resistant aluminum alloy powder for additive manufacturing in the present application includes the following components by weight percentage:

[0044] Mn 2.0-10.5%, Ce 0.5-5.5%, Sc 0.2-1%, Zr 0.05-0.5%, Mg 0.1-0.5%, Ni 0.05-0.2%, Mo 0.1-0.3%, Co 0.01-0.05%, mixed rare earth La-Ce-Pr-Nd 0.02-0.1%, the balance being aluminum; wherein the mass percentage of Mn and Ce is (1-3):1.

[0045] In some embodiments of the present application, the high-strength heat-resistant aluminum alloy powder for additive manufacturing comprises the following components by weight percentage:

[0046] Mn 2.2-10.5%, Ce 1-5.5%, Sc 0.2-1%, Zr 0.05-0.5%, Mg 0.1-0.5%, Ni 0.05-0.2%, Mo 0.1-0.3%, Co 0.01-0.05%, mixed rare earth La-Ce-Pr-Nd 0.02-0.1%, the balance being aluminum; wherein the mass percentage of Mn and Ce is (1-3):1.

[0047] In an embodiment of the present application, the sphericity of the high-strength heat-resistant aluminum alloy powder for additive manufacturing is calculated by the aspect ratio, and the sphericity of the high-strength heat-resistant aluminum alloy powder for additive manufacturing is greater than or equal to 95%.

[0048] In an embodiment of the present application, the oxygen content of the high-strength heat-resistant aluminum alloy powder for additive manufacturing is less than 300 ppm.

[0049] In an embodiment of the present application, the hollow powder rate of the high-strength heat-resistant aluminum alloy powder for additive manufacturing is less than 3 ‰.

[0050] In an embodiment of the present application, the high-strength heat-resistant aluminum alloy powder for additive manufacturing is suitable for additive manufacturing, and the particle size range of the powder includes but is not limited to 10-45 μm, 15-53 μm, 20-63 μm, and 15-75 μm.

[0051] According to the specific embodiments of the present application, a preparation method of a high-strength heat-resistant aluminum alloy powder for additive manufacturing is also provided.

[0052] The present application adopts inert gas atomization method to prepare the high-strength heat-resistant aluminum alloy powder for additive manufacturing, utilizes crucible melting alloy, the melting temperature range is 750-900 ℃, avoids composition segregation by applying electromagnetic stirring, promotes the formation of high-melting heat-resistant phase, breaks the solution into small droplets by high-speed argon, and shrinks and solidifies into near-spherical metal powder under the action of liquid droplet surface tension.

[0053] The high-strength heat-resistant aluminum alloy powder prepared in the application has the advantages that the addition of alloying elements can improve the solid solubility of the aluminum alloy, and after heat treatment, a strengthening phase is precipitated, the room temperature tensile strength is ≥580 MPa, the yield strength is ≥550 MPa, and the elongation after fracture is ≥9%. The mechanical properties at 250℃ are that the tensile strength is ≥240 MPa, the yield strength is ≥150 MPa, and after 100 hours of heat preservation at 250℃, the strength only decreases by 10%.

[0054] The preparation method of the high-strength heat-resistant aluminum alloy powder for additive manufacturing is carried out according to the following steps.

[0055] (1) AlMn intermediate alloy, ALCe intermediate alloy, ALNi intermediate alloy, ALSc intermediate alloy, ALZr intermediate alloy, mixed rare earth alloy and pure aluminum are placed in the smelting crucible according to the proportion.

[0056] In the embodiment of the application, the AlMn intermediate alloy is AlMn(30-50) intermediate alloy.

[0057] In the embodiment of the application, the ALCe intermediate alloy is ALCe(5-30) intermediate alloy.

[0058] In the embodiment of the application, the ALNi intermediate alloy is ALNi(20-50) intermediate alloy.

[0059] In the embodiment of the application, the ALSc intermediate alloy is ALSc(2-10) intermediate alloy.

[0060] In the embodiment of the application, the ALZr intermediate alloy is ALZr(2-10) intermediate alloy.

[0061] In the embodiment of the application, the composition of the mixed rare earth alloy is: La 20-30%, Ce 48-58%, Pr 4-6%, Nd 15-17%, and the relative purity is ≥99%.

[0062] (2) After the alloy in step (1) starts to melt, magnesium ingot is pressed into the bottom of the alloy melt, and the temperature is raised to the smelting temperature, and electromagnetic stirring is carried out at the same time.

[0063] In the embodiment of the application, the smelting temperature is in the range of 750-900℃, and the electromagnetic stirring is 5-10 min.

[0064] The alloy is subjected to electromagnetic stirring for 5-10 min, which aims to promote the formation of AlMnCe ternary alloy. If there is no stirring or the stirring time is too short, composition segregation may occur, which leads to the generation of columnar crystals in the molten pool during the subsequent 3D printing process, thereby reducing the strength of the 3D printed part.

[0065] In some embodiments of the present application, the melting temperature is 820℃, and the electromagnetic stirring time is 5 min.

[0066] (3) The metal melt prepared in step (2) is broken by using high-purity inert gas, and the pressure in the atomization chamber is 1-5 MPa.

[0067] In embodiments of the present application, the high-purity inert gas includes but is not limited to high-purity argon and high-purity nitrogen.

[0068] (4) The powder prepared in step (3) is sieved by vibration to obtain high-strength heat-resistant aluminum alloy powder for additive manufacturing.

[0069] In embodiments of the present application, the prepared powder is sieved to obtain high-strength heat-resistant aluminum alloy powder suitable for additive manufacturing, and the particle size range of the powder can be 10-45 μm, 15-53 μm, 20-63 μm, 15-75 μm, etc.

[0070] According to the specific embodiments of the present application, a high-strength heat-resistant aluminum alloy powder for additive manufacturing is also provided for use in 3D printing.

[0071] In embodiments of the present application, the high-strength heat-resistant aluminum alloy powder for additive manufacturing is used to prepare 3D printed parts of different shapes by powder additive manufacturing technology, wherein:

[0072] The substrate is selected to be a 3-series aluminum alloy substrate with a composition similar to that of the powder material;

[0073] The substrate is preheated to 200℃ before forming;

[0074] The energy density range of the powder additive manufacturing process is 100-220 J / mm 3 ;

[0075] After the formed part is aged, the mechanical properties of the part at room temperature are tensile strength ≥580 MPa, yield strength ≥550 MPa, and elongation after fracture ≥9%, the mechanical properties at 250℃ are tensile strength ≥240 MPa, yield strength ≥150 MPa, and elongation after fracture ≥7%, and after 100 hours of heat preservation at 250℃, the strength only decreases by 10%.

[0076] The high-strength heat-resistant aluminum alloy powder for additive manufacturing, the preparation method and the application thereof in the present application will be described in detail through specific embodiments.

[0077] Example 1

[0078] The embodiment provides a high-strength heat-resistant aluminum alloy powder for additive manufacturing and a preparation method and application thereof, wherein the high-strength heat-resistant aluminum alloy powder for additive manufacturing is composed of the following components and mass percentages: Mn 3.2%, Ce 2.1%, Sc 0.64%, Zr 0.3%, Mg 0.45%, Ni 0.12%, Mo 0.25%, Co 0.04%, mixed rare earth (La-Ce-Pr-Nd) 0.05%, and the balance is aluminum.

[0079] The preparation method of the high-strength heat-resistant aluminum alloy powder for additive manufacturing comprises the following steps:

[0080] (1) AlMn30 intermediate alloy, ALCe20 intermediate alloy, ALNi30 intermediate alloy, ALSc10 intermediate alloy, ALZr10 intermediate alloy, mixed rare earth alloy and pure aluminum are placed in a smelting crucible according to the proportion; the composition of the mixed rare earth alloy is La 20-30%, Ce 48-58%, Pr 4-6%, and Nd 15-17%, and the relative purity is 99.5%.

[0081] (2) After the intermediate alloy in step (1) is melted, magnesium ingot is pressed into the bottom of the alloy melt, heated to 820 DEG C, and electromagnetic stirring is performed for 5 min;

[0082] (3) The metal melt is broken by using high-purity argon, and the pressure in the atomization chamber is 2 MPa;

[0083] (4) The powder obtained in step (3) is sieved by vibration, and the high-strength heat-resistant aluminum alloy powder for additive manufacturing with a particle size of 15-53 mu m is obtained.

[0084] In the embodiment 1, the sphericity of the high-strength heat-resistant aluminum alloy powder for additive manufacturing is greater than or equal to 95%, the oxygen content is less than 300 ppm, and the hollow powder rate is less than 3 ‰.

[0085] Then, a workpiece is prepared by using an additive manufacturing process, the substrate material is 3004 aluminum alloy, the substrate is preheated to 200 DEG C before forming, and the energy density of the additive manufacturing process is 150 J / mm 3 .

[0086] The workpiece prepared by additive manufacturing is subjected to the following heat treatment: the heating rate is 10 DEG C / min, and the temperature is kept at 280 DEG C for 15 h.

[0087] Embodiment 2

[0088] The embodiment provides a high-strength heat-resistant aluminum alloy powder for additive manufacturing and a preparation method and application thereof, wherein the high-strength heat-resistant aluminum alloy powder for additive manufacturing is composed of the following components and mass percentages: Mn 5.6%, Ce 2.8%, Sc 0.5%, Zr 0.42%, Mg 0.15%, Ni 0.12%, Mo 0.15%, Co 0.02%, mixed rare earth (La-Ce-Pr-Nd) 0.02%, and the balance is aluminum.

[0089] The preparation method of the high-strength heat-resistant aluminum alloy powder for additive manufacturing comprises the following steps:

[0090] (1) AlMn50 intermediate alloy, ALCe20 intermediate alloy, ALNi40 intermediate alloy, ALSc10 intermediate alloy, ALZr2 intermediate alloy, mixed rare earth alloy and pure aluminum are placed in a smelting crucible according to the proportion; the mixed rare earth alloy is composed of La 20-30%, Ce 48-58%, Pr 4-6%, and Nd 15-17%, and the relative purity is 99.5%.

[0091] (2) After the intermediate alloy in step (1) is melted, magnesium ingot is pressed into the bottom of the alloy melt, heated to 820 DEG C, and electromagnetic stirring is performed for 5 min;

[0092] (3) The metal melt is broken by using high-purity nitrogen gas, and the pressure in the atomization chamber is 3 MPa;

[0093] (4) The powder obtained in step (3) is sieved by vibration, and the high-strength heat-resistant aluminum alloy powder for additive manufacturing with a particle size of 15-53 mu m is obtained, and the morphology is as shown in Figure 1 .

[0094] The sphericity of the high-strength heat-resistant aluminum alloy powder for additive manufacturing prepared in the embodiment 2 is greater than or equal to 95%, the oxygen content is less than 300 ppm, and the hollow powder rate is less than 3 ‰.

[0095] Then, a workpiece is prepared by using an additive manufacturing process, the substrate material is 3004 aluminum alloy, the substrate is preheated to 200 DEG C before forming, and the energy density of the additive manufacturing process is 183 J / mm 3 .

[0096] The workpiece prepared by additive manufacturing is subjected to the following heat treatment: the heating rate is 10 DEG C / min, and the temperature is kept at 300 DEG C for 10 h.

[0097] Embodiment 3

[0098] The embodiment provides a high-strength heat-resistant aluminum alloy powder for additive manufacturing and a preparation method and application thereof, wherein the high-strength heat-resistant aluminum alloy powder for additive manufacturing is composed of the following components and mass percentages: Mn 8%, Ce 2.67%, Sc 0.3%, Zr 0.24%, Mg 0.24%, Ni 0.06%, Mo 0.1%, Co 0.01%, mixed rare earth (La-Ce-Pr-Nd) 0.03%, and the balance of aluminum.

[0099] The preparation method of the high-strength heat-resistant aluminum alloy powder for additive manufacturing comprises the following steps:

[0100] (1) AlMn30 intermediate alloy, ALCe20 intermediate alloy, ALNi30 intermediate alloy, ALSc10 intermediate alloy, ALZr10 intermediate alloy, mixed rare earth alloy and pure aluminum are placed in a smelting crucible according to the proportion; the mixed rare earth alloy is composed of La 20-30%, Ce 48-58%, Pr 4-6%, and Nd 15-17%, and the relative purity is 99.5%.

[0101] (2) After the intermediate alloy in step (1) is melted, magnesium ingot is pressed into the bottom of the alloy melt, heated to 820 DEG C, and electromagnetic stirring is performed for 5 min;

[0102] (3) The metal melt is broken by using high-purity argon, and the pressure in the atomization chamber is 5 MPa;

[0103] (4) The powder obtained in step (3) is sieved by vibration, and the high-strength heat-resistant aluminum alloy powder for additive manufacturing with a particle size of 20-63 mu m is obtained.

[0104] In the embodiment 3, the sphericity of the high-strength heat-resistant aluminum alloy powder for additive manufacturing is greater than or equal to 95%, the oxygen content is less than 300 ppm, and the hollow powder rate is less than 3 ‰.

[0105] Then, a workpiece is prepared by using an additive manufacturing process, the substrate material is 3004 aluminum alloy, the substrate is preheated to 200 DEG C before forming, and the energy density of the additive manufacturing process is 216 J / mm 3 .

[0106] The workpiece prepared by additive manufacturing is subjected to the following heat treatment: the heating rate is 10 DEG C / min, and the temperature is kept at 380 DEG C for 8 h.

[0107] Embodiment 4

[0108] The embodiment provides a high-strength heat-resistant aluminum alloy powder for additive manufacturing and a preparation method and application thereof, wherein the high-strength heat-resistant aluminum alloy powder for additive manufacturing is composed of the following components and mass percentages: Mn 2%, Ce 1%, Sc 0.2%, Zr 0.05%, Mg 0.5%, Ni 0.05%, Mo 0.3%, Co 0.01%, mixed rare earth (La-Ce-Pr-Nd) 0.1%, and the balance of aluminum.

[0109] The preparation method of the high-strength heat-resistant aluminum alloy powder for additive manufacturing comprises the following steps:

[0110] (1) AlMn40 intermediate alloy, ALCe20 intermediate alloy, ALNi50 intermediate alloy, ALSc10 intermediate alloy, ALZr10 intermediate alloy, mixed rare earth alloy and pure aluminum are placed in a smelting crucible according to the proportion; the mixed rare earth alloy is composed of La 20-30%, Ce 48-58%, Pr 4-6%, and Nd 15-17%, and the relative purity is 99.5%.

[0111] (2) After the intermediate alloy in step (1) is melted, magnesium ingot is pressed into the bottom of the molten liquid, heated to 750 DEG C, and electromagnetic stirring is performed for 10 min;

[0112] (3) The metal melt is broken by using high-purity argon, and the pressure in the atomization chamber is 2 MPa;

[0113] (4) The powder obtained in step (3) is sieved by vibration, and the high-strength heat-resistant aluminum alloy powder for additive manufacturing with a particle size of 15-53 mu m is obtained.

[0114] In the embodiment 4, the sphericity of the high-strength heat-resistant aluminum alloy powder for additive manufacturing is greater than or equal to 95%, the oxygen content is less than 300 ppm, and the hollow powder rate is less than 3 ‰.

[0115] Then, a workpiece is prepared by using an additive manufacturing process, the substrate material is 3004 aluminum alloy, the substrate is preheated to 200 DEG C before forming, and the energy density of the additive manufacturing process is 100 J / mm 3 .

[0116] The workpiece prepared by additive manufacturing is subjected to the following heat treatment: the heating rate is 5 DEG C / min, and the temperature is kept at 250 DEG C for 20 h.

[0117] Embodiment 5

[0118] The embodiment provides a high-strength heat-resistant aluminum alloy powder for additive manufacturing and a preparation method and application thereof, wherein the high-strength heat-resistant aluminum alloy powder for additive manufacturing is composed of the following components and mass percentages: Mn 10.5%, Ce 5.5%, Sc 1%, Zr 0.5%, Mg 0.1%, Ni 0.2%, Mo 0.1%, Co 0.05%, mixed rare earth (La-Ce-Pr-Nd) 0.02%, and the balance of aluminum.

[0119] The preparation method of the high-strength heat-resistant aluminum alloy powder for additive manufacturing comprises the following steps:

[0120] (1) AlMn50 intermediate alloy, ALCe5 intermediate alloy, ALNi20 intermediate alloy, ALSc2 intermediate alloy, ALZr2 intermediate alloy, mixed rare earth alloy and pure aluminum are placed in a smelting crucible according to the proportion; the mixed rare earth alloy is composed of La 20-30%, Ce 48-58%, Pr 4-6%, and Nd 15-17%, and the relative purity is 99.5%.

[0121] (2) After the intermediate alloy in step (1) is melted, magnesium ingot is pressed into the bottom of the molten liquid, heated to 900 DEG C, and electromagnetic stirring is performed for 8 min;

[0122] (3) The metal melt is broken by using high-purity argon, and the pressure in the atomization chamber is 2 MPa;

[0123] (4) The powder obtained in step (3) is sieved by vibration, and the high-strength heat-resistant aluminum alloy powder for additive manufacturing with a particle size of 10-45 mu m is obtained.

[0124] In the embodiment 5, the sphericity of the high-strength heat-resistant aluminum alloy powder for additive manufacturing is greater than or equal to 95%, the oxygen content is less than 300 ppm, and the hollow powder rate is less than 3 ‰.

[0125] Then, a workpiece is prepared by using an additive manufacturing process, the substrate material is 3004 aluminum alloy, the substrate is preheated to 200 DEG C before forming, and the energy density of the additive manufacturing process is 220 J / mm 3 .

[0126] The workpiece prepared by additive manufacturing is subjected to the following heat treatment: the heating rate is 20 DEG C / min, and the temperature is kept at 500 DEG C for 6 h.

[0127] Embodiment 6

[0128] The embodiment provides high-strength heat-resistant aluminum alloy powder for additive manufacturing and a preparation method and application thereof, wherein the high-strength heat-resistant aluminum alloy powder for additive manufacturing is composed of the following components and mass percentages: Mn 1.5%, Ce 0.5%, Sc 1%, Zr 0.5%, Mg 0.1%, Ni 0.2%, Mo 0.1%, Co 0.05%, mixed rare earth (La-Ce-Pr-Nd) 0.02%, and the balance is aluminum.

[0129] The preparation method of the high-strength heat-resistant aluminum alloy powder for additive manufacturing comprises the following steps:

[0130] (1) AlMn30 intermediate alloy, ALCe10 intermediate alloy, ALNi20 intermediate alloy, ALSc2 intermediate alloy, ALZr2 intermediate alloy, mixed rare earth alloy and pure aluminum are placed in a smelting crucible according to the proportion; the mixed rare earth alloy is composed of La 20-30%, Ce 48-58%, Pr 4-6%, and Nd 15-17%, and the relative purity is 99.5%.

[0131] (2) After the intermediate alloy in step (1) is melted, magnesium ingot is pressed into the bottom of the molten liquid, heated to 900 DEG C, and electromagnetic stirring is performed for 8 min;

[0132] (3) The metal melt is broken by using high-purity argon, and the pressure in the atomization chamber is 1 MPa;

[0133] (4) The powder obtained in step (3) is vibrated and sieved to obtain the high-strength heat-resistant aluminum alloy powder for additive manufacturing with a particle size of 15-75 mu m.

[0134] The high-strength heat-resistant aluminum alloy powder for additive manufacturing prepared in the embodiment 6 has a sphericity of greater than or equal to 95%, an oxygen content of less than 300 ppm, and a hollow powder rate of less than 3 ‰.

[0135] Then, a workpiece is prepared by using an additive manufacturing process, the substrate material is 3004 aluminum alloy, the substrate is preheated to 200 DEG C before forming, and the energy density of the additive manufacturing process is 220 J / mm 3 .

[0136] The workpiece prepared by additive manufacturing is subjected to the following heat treatment: the heating rate is 20 DEG C / min, and the temperature is kept at 500 DEG C for 6 h.

[0137] In the application, 10*10*70 additive manufacturing samples are prepared according to the embodiments 1-3, and the tensile strength (sigma b ), yield strength (sigma 0.2 ) and elongation (A) of each 3D printing sample under room temperature and 250 DEG C conditions and different holding times are tested according to GBT228.1-2010. The test results are shown in Table 1.

[0138] Table 1 summarizes the mechanical property test results of the 3D printed parts prepared in Examples 1-3

[0139]

[0140] As can be seen from Table 1, the high-strength heat-resistant aluminum alloy powder for additive manufacturing provided by the present application has good mechanical properties and heat-resistant durability under normal temperature and high temperature conditions after 3D printing.

[0141] Among them, the room temperature tensile strength is ≥580MPa, the yield strength is ≥550MPa, and the elongation after fracture is ≥9%.

[0142] The mechanical properties at 250℃ are tensile strength ≥240MPa, yield strength ≥150MPa, and elongation after fracture ≥7%, and after 100 hours of heat preservation at 250℃, the strength only decreases by 10%.

[0143] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any changes or replacements that can be easily thought of by those skilled in the art within the technical scope disclosed by the present application should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A high-strength heat-resistant aluminum alloy powder for additive manufacturing, characterized by, The high-strength heat-resistant aluminum alloy powder comprises the following components by weight percentage: Mn 2.0~10.5%, Ce 0.5~5.5%, Sc 0.2~1%, Zr 0.05~0.5%, Mg 0.1~0.5%, Ni 0.05~0.2%, Mo 0.1~0.3%, Co 0.01~0.05%, mixed rare earth La-Ce-Pr-Nd 0.02~0.1%, and the balance being aluminum; wherein the mass percentage of Mn and Ce is (1~3):

1.

2. The high-strength heat-resistant aluminum alloy powder for additive manufacturing according to claim 1, characterized by, The high-strength heat-resistant aluminum alloy powder comprises the following components by weight percentage: Mn 2.0~10.5%, Ce 0.5~5.5%, Sc 0.2~1%, Zr 0.05~0.5%, Mg 0.1~0.5%, Ni 0.05~0.2%, Mo 0.1~0.3%, Co 0.01~0.05%, mixed rare earth La-Ce-Pr-Nd 0.02~0.1%, and the balance being aluminum; wherein the mass percentage of Mn and Ce is (1~3):

1.

3. The high-strength heat-resistant aluminum alloy powder for additive manufacturing according to claim 1, wherein The high-strength heat-resistant aluminum alloy powder has a sphericity of ≥95%, an oxygen content of less than 300ppm, and a hollow powder rate of less than 3‰.

4. The high-strength heat-resistant aluminum alloy powder for additive manufacturing according to claim 1, wherein The particle size range of the high-strength heat-resistant aluminum alloy powder includes but is not limited to 10~45μm, 15~53μm, 20~63μm, and 15~75μm.

5. A method of producing a high-strength heat-resistant aluminum alloy powder for additive manufacturing according to any one of claims 1 to 4, characterized by, The preparation method comprises the following steps: (1) placing AlMn intermediate alloy, AlCe intermediate alloy, AlNi intermediate alloy, AlSc intermediate alloy, AlZr intermediate alloy, mixed rare earth alloy, and pure aluminum in a melting crucible according to the proportion; (2) when the alloy in step (1) starts to melt, press the magnesium ingot into the bottom of the alloy melt, heat to the melting temperature, and at the same time, perform electromagnetic stirring; (3) breaking the metal melt prepared in step (2) using high-purity inert gas, and the pressure in the atomization chamber is 1~5MPa; (4) vibrating and sieving the powder prepared in step (3) to obtain the high-strength heat-resistant aluminum alloy powder for additive manufacturing.

6. The production method according to claim 5, wherein In step (1), the AlMn intermediate alloy is Al30~50Mn intermediate alloy, the AlCe intermediate alloy is Al5~30Ce intermediate alloy, the AlNi intermediate alloy is Al20~50Ni intermediate alloy, the AlSc intermediate alloy is Al2~10Sc intermediate alloy, and the AlZr intermediate alloy is Al2~10Zr intermediate alloy.

7. The production method according to claim 5, wherein The composition of the mixed rare earth alloy is: La 20~30%, Ce 48~58%, Pr 4~6%, and Nd 15~17%, and the relative purity is ≥99%.

8. The production method according to claim 5, wherein In step (2), the melting temperature is 750~900℃, and the electromagnetic stirring is performed for 5~10min.

9. The production method according to claim 5, wherein In step (3), the high-purity inert gas includes but is not limited to high-purity argon.

10. Application of the high-strength heat-resistant aluminum alloy powder for additive manufacturing according to any one of claims 1~4 or prepared by the preparation method according to any one of claims 5~9 in 3D printing.

11. Use of the high-strength heat-resistant aluminum alloy powder for additive manufacturing according to claim 10 in 3D printing, characterized in that, The substrate for 3D printing is a 3-series aluminum alloy substrate, which is preheated to 200℃ before forming; the energy density range of the 3D printing process is 100-220 J / mm 3 .

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