A method for improving room temperature / high temperature strength and high temperature endurance properties of 3D printed aluminum alloys

Abstract

The application provides a method for improving the room temperature / high temperature strength and high temperature durability of a 3D printed aluminum alloy, by adding at least one of La, Ce, Er, Ti and Zr elements in the alloy material, on the one hand, primary Al 11 La3, Al3Ti, Al3Zr second phase particles play the role of heterogeneous nucleation, promote the formation of equiaxed grains in the printing process, reduce the formation of columnar grains, and achieve the effect of refining grains; on the other hand, the secondary nano Al 11 La3, AlCe, Al3Er phase has good thermal stability, can produce dispersion strengthening and improve the high temperature structure stability. Under the action of primary and secondary second phases, the dislocation movement is inhibited, the structure stability is improved, and finally the room temperature / high temperature tensile strength, yield strength and high temperature durability are improved.

Description

TECHNICAL FIELD

[0001] The application relates to a method for improving the room temperature / high temperature strength and high temperature durability of a 3D printed aluminum alloy, and belongs to the technical field of additive manufacturing. BACKGROUND

[0002] 3D printing, also known as additive manufacturing, is an intelligent manufacturing technology that has developed rapidly in recent years. It has attracted widespread attention due to its lightweight design and rapid and accurate shaping of complex parts. At present, AlSi 10 Mg is one of the relatively mature 3D printed aluminum alloys, which has been applied in the field of aerospace. The alloy has good 3D printing process adaptability, but the room temperature / high temperature strength and high temperature durability after annealing are relatively low, which is difficult to meet the requirements of long-term service under high load and high temperature conditions. Research has found that the room temperature tensile strength of the 3D printed AlSi 10 The room temperature tensile strength of the 3D printed AlSi

[0003] In view of the problem of insufficient room temperature and high temperature performance of the 3D printed AlSi 10 Mg alloy after annealing, it is necessary to provide a solution. SUMMARY

[0004] In order to improve the room temperature service capability and high temperature service capability of the 3D printed aluminum alloy, the application provides a method for improving the room temperature / high temperature strength and high temperature durability of a 3D printed aluminum alloy, in particular a method for improving the room temperature / high temperature strength and high temperature durability of a 3D printed AlSi 10 Mg alloy. The method can obtain a 3D printed aluminum alloy with good room temperature strength, high temperature strength and high temperature durability, in particular a 3D printed AlSi 10 Mg alloy with good room temperature strength, high temperature strength and high temperature durability.

[0005] The application is realized by the following technical scheme:

[0006] A method for improving the room temperature / high temperature strength and high temperature durability of a 3D printed aluminum alloy, the method comprising the following steps:

[0007] (1) selecting a preparation raw material of a 3D printing aluminum alloy, the preparation raw material of the 3D printing aluminum alloy comprising a first component and a second component; the first component being aluminum ingot, magnesium ingot and aluminum-silicon intermediate alloy ingot; the second component being at least one of aluminum-lanthanum intermediate alloy ingot, aluminum-cerium intermediate alloy ingot, aluminum-erbium intermediate alloy ingot, aluminum-zirconium intermediate alloy ingot and aluminum-titanium intermediate alloy ingot;

[0008] (2) using a laser selective melting equipment to perform 3D printing forming on the preparation raw material of the 3D printing aluminum alloy in step (1);

[0009] (3) performing annealing treatment on the product after 3D printing forming in step (2).

[0010] According to the embodiment of the present application, in step (1), the first component comprises the following components in mass fraction: aluminum ingot 5-12 parts; magnesium ingot 1-2 parts; aluminum-silicon intermediate alloy ingot 160-200 parts.

[0011] According to the embodiment of the present application, in step (1), the second component comprises the following components in mass fraction: aluminum-lanthanum intermediate alloy ingot 0-10 parts, aluminum-cerium intermediate alloy ingot 0-10 parts, aluminum-erbium intermediate alloy ingot 0-10 parts, aluminum-zirconium intermediate alloy ingot 0-10 parts, aluminum-titanium intermediate alloy ingot 0-10 parts, and the sum of the mass fractions of the aluminum-lanthanum intermediate alloy ingot, the aluminum-cerium intermediate alloy ingot, the aluminum-erbium intermediate alloy ingot, the aluminum-zirconium intermediate alloy ingot and the aluminum-titanium intermediate alloy ingot is not 0.

[0012] According to the embodiment of the present application, in step (1), the first component comprises the following components in mass fraction: aluminum ingot 5-12 parts; magnesium ingot 1-2 parts; aluminum-silicon intermediate alloy ingot 170-190 parts.

[0013] According to the embodiment of the present application, in step (1), the second component comprises the following components in mass fraction: aluminum-lanthanum intermediate alloy ingot 0-10 parts, aluminum-cerium intermediate alloy ingot 0-10 parts, aluminum-erbium intermediate alloy ingot 0-10 parts, aluminum-zirconium intermediate alloy ingot 0-10 parts, aluminum-titanium intermediate alloy ingot 0-10 parts, and the sum of the mass fractions of the aluminum-lanthanum intermediate alloy ingot, the aluminum-cerium intermediate alloy ingot, the aluminum-erbium intermediate alloy ingot, the aluminum-zirconium intermediate alloy ingot and the aluminum-titanium intermediate alloy ingot is not 0 and less than or equal to 10 parts.

[0014] Exemplarily, the preparation raw material of the 3D printing aluminum alloy comprises aluminum ingot 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 11 or 12 parts. The aluminum ingot is pure aluminum ingot, for example, aluminum ingot with purity of 99.99% or above.

[0015] Exemplarily, the raw material for preparing the 3D printing aluminum alloy comprises 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 or 2 parts of magnesium ingot. The magnesium ingot is a pure magnesium ingot, for example, a magnesium ingot with a purity of 99.99% or above.

[0016] Exemplarily, the raw material for preparing the 3D printing aluminum alloy comprises 160, 162, 164, 165, 168, 170, 172, 174, 178, 180, 182, 185, 188, 190, 192, 195, 198 or 200 parts of aluminum-silicon intermediate alloy ingot. The aluminum-silicon intermediate alloy ingot is AlSi11 or AlSi11A.

[0017] Exemplarily, the raw material for preparing the 3D printing aluminum alloy comprises 0.1, 0.2, 0.5, 0.6, 0.8, 1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.2, 2.5, 2.8, 3, 4, 5, 6, 7, 8, 9 or 10 parts of aluminum-lanthanum intermediate alloy ingot. The aluminum-lanthanum intermediate alloy ingot is AlLa10.

[0018] Exemplarily, the raw material for preparing the 3D printing aluminum alloy comprises 0.1, 0.2, 0.5, 0.6, 0.8, 1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.2, 2.5, 2.8, 3, 4, 5, 6, 7, 8, 9 or 10 parts of aluminum-cerium intermediate alloy ingot. The aluminum-cerium intermediate alloy ingot is AlCe10.

[0019] Exemplarily, the raw material for preparing the 3D printing aluminum alloy comprises 0.1, 0.2, 0.5, 0.6, 0.8, 1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.2, 2.5, 2.8, 3, 4, 5, 6, 7, 8, 9 or 10 parts of aluminum-erbium intermediate alloy ingot. The aluminum-erbium intermediate alloy ingot is AlEr30.

[0020] Exemplarily, the raw material for preparing the 3D printing aluminum alloy comprises 0.1, 0.2, 0.5, 0.6, 0.8, 1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.2, 2.5, 2.8, 3, 4, 5, 6, 7, 8, 9 or 10 parts of aluminum-zirconium intermediate alloy ingot. The aluminum-zirconium intermediate alloy ingot is AlZr2 or AlZr2A.

[0021] Exemplarily, the preparation raw material of the 3D printed aluminum alloy comprises 0.1, 0.2, 0.5, 0.6, 0.8, 1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.2, 2.5, 2.8, 3, 4, 5, 6, 7, 8, 9 or 10 parts of aluminum-titanium intermediate alloy ingot. The aluminum-titanium intermediate alloy ingot is AlTi5 or AlTi5A.

[0022] According to the embodiment of the present application, in step (1), the mass ratio of the first component and the second component is 1:1.

[0023] According to the embodiment of the present application, in step (2), the method specifically comprises the following steps:

[0024] (2-1) loading the preparation raw material of the 3D printed aluminum alloy in step (1) into a crucible, vacuumizing in a closed furnace body, then filling nitrogen or argon to positive pressure, and using electromagnetic induction heating to obtain a molten alloy liquid;

[0025] (2-2) atomizing the molten alloy liquid in step (2-1) into powder by using high-pressure nitrogen or high-pressure argon;

[0026] (2-3) classifying the atomized powder in step (2-2) under the protection of nitrogen or argon, and then screening by using an ultrasonic vibration screening machine to obtain powder with a particle size range of 15-74 μm;

[0027] (2-4) drying the powder with a particle size range of 15-74 μm in step (2-3) in an explosion-proof drying box, and then 3D printing forming by using a laser selective melting device.

[0028] According to the embodiment of the present application, in step (2-1), the vacuum degree is not more than 10 Pa.

[0029] According to the embodiment of the present application, in step (2-1), the pressure range of the positive pressure is 0-0.1 MPa.

[0030] According to the embodiment of the present application, in step (2-1), electromagnetic induction heating is used to heat to 800-900 ℃, and after melting, heat preservation is performed for 30-60 min to obtain a molten alloy liquid.

[0031] According to the embodiment of the present application, in step (2-2), the gas flow pressure of the high-pressure nitrogen is 1-5 MPa. The gas flow pressure of the high-pressure argon is 1-5 MPa.

[0032] According to the embodiment of the present application, in step (2-3), the atomized powder is classified under the protection of nitrogen or argon, the classification wheel frequency is 10-30 Hz, the feeder frequency is 10-20 Hz; then the powder is classified by using an ultrasonic vibration screening machine, the mesh number of the screen is 200-325 meshes, and finally the powder with a particle size range of 15-74 μm is obtained.

[0033] According to the embodiment of the present application, in step (2-4), the drying temperature is 60-90 ℃, and the drying time is 5-12 h.

[0034] According to the embodiment of the present application, in step (2-4), the scanning path is rotated by 67° layer by layer during printing, and the energy density is 30-50 J / mm 3 The printing process is protected by argon, and the oxygen content in the controlled atmosphere is less than 100 ppm.

[0035] According to the embodiment of the present application, in step (3), the deposited alloy material is taken off from the substrate by wire cutting, which is the product after 3D printing.

[0036] According to the embodiment of the present application, in step (3), the annealing treatment is performed by using a resistance heating furnace to heat the product to 250-300 ℃ (such as 250 ℃, 260 ℃, 270 ℃, 280 ℃, 290 ℃ or 300 ℃) at a heating rate of 5-15 ℃ / min (such as 10 ℃ / min), and the product is kept at the temperature for 120-180 min (such as 120 min, 130 min, 140 min, 150 min, 160 min, 170 min or 180 min).

[0037] The present application also provides a 3D printed aluminum alloy prepared by the above method.

[0038] The present application also provides a 3D printed aluminum alloy, wherein the raw materials for preparing the 3D printed aluminum alloy include a first component and a second component; the first component is aluminum ingot, magnesium ingot and aluminum-silicon intermediate alloy ingot; and the second component is at least one of aluminum-lanthanum intermediate alloy ingot, aluminum-cerium intermediate alloy ingot, aluminum-erbium intermediate alloy ingot, aluminum-zirconium intermediate alloy ingot and aluminum-titanium intermediate alloy ingot.

[0039] According to the embodiment of the present application, the first component includes the following components in mass fraction: aluminum ingot, 5-12 parts; magnesium ingot, 1-2 parts; and aluminum-silicon intermediate alloy ingot, 160-200 parts.

[0040] According to an embodiment of the present application, the second component comprises the following components in mass fraction: aluminum lanthanum intermediate alloy ingot 0-10 parts, aluminum cerium intermediate alloy ingot 0-10 parts, aluminum erbium intermediate alloy ingot 0-10 parts, aluminum zirconium intermediate alloy ingot 0-10 parts, and aluminum titanium intermediate alloy ingot 0-10 parts, and the sum of the mass fractions of the aluminum lanthanum intermediate alloy ingot, the aluminum cerium intermediate alloy ingot, the aluminum erbium intermediate alloy ingot, the aluminum zirconium intermediate alloy ingot, and the aluminum titanium intermediate alloy ingot is not 0.

[0041] According to an embodiment of the present application, the first component comprises the following components in mass fraction: aluminum ingot 5-12 parts, magnesium ingot 1-2 parts, and aluminum silicon intermediate alloy ingot 170-190 parts.

[0042] According to an embodiment of the present application, the second component comprises the following components in mass fraction: aluminum lanthanum intermediate alloy ingot 0-10 parts, aluminum cerium intermediate alloy ingot 0-10 parts, aluminum erbium intermediate alloy ingot 0-10 parts, aluminum zirconium intermediate alloy ingot 0-10 parts, and aluminum titanium intermediate alloy ingot 0-10 parts, and the sum of the mass fractions of the aluminum lanthanum intermediate alloy ingot, the aluminum cerium intermediate alloy ingot, the aluminum erbium intermediate alloy ingot, the aluminum zirconium intermediate alloy ingot, and the aluminum titanium intermediate alloy ingot is not 0 and is less than or equal to 10 parts.

[0043] According to an embodiment of the present application, the mass ratio of the first component and the second component is 1:1.

[0044] Exemplarily, the preparation raw material of the 3D printing aluminum alloy comprises aluminum ingot 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 11, or 12 parts. The aluminum ingot is a pure aluminum ingot, for example, an aluminum ingot with a purity of 99.99% or above.

[0045] Exemplarily, the preparation raw material of the 3D printing aluminum alloy comprises magnesium ingot 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2 parts. The magnesium ingot is a pure magnesium ingot, for example, a magnesium ingot with a purity of 99.99% or above.

[0046] Exemplarily, the preparation raw material of the 3D printing aluminum alloy comprises aluminum silicon intermediate alloy ingot 160, 162, 164, 165, 168, 170, 172, 174, 178, 180, 182, 185, 188, 190, 192, 195, 198, or 200 parts. The aluminum silicon intermediate alloy ingot is AlSi11 or AlSi11A.

[0047] Exemplarily, the preparation raw material of the 3D printing aluminum alloy comprises 0.1, 0.2, 0.5, 0.6, 0.8, 1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.2, 2.5, 2.8, 3, 4, 5, 6, 7, 8, 9 or 10 parts of aluminum lanthanum intermediate alloy ingot. The aluminum lanthanum intermediate alloy ingot is AlLa10.

[0048] Exemplarily, the preparation raw material of the 3D printing aluminum alloy comprises 0.1, 0.2, 0.5, 0.6, 0.8, 1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.2, 2.5, 2.8, 3, 4, 5, 6, 7, 8, 9 or 10 parts of aluminum cerium intermediate alloy ingot. The aluminum cerium intermediate alloy ingot is AlCe10.

[0049] Exemplarily, the preparation raw material of the 3D printing aluminum alloy comprises 0.1, 0.2, 0.5, 0.6, 0.8, 1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.2, 2.5, 2.8, 3, 4, 5, 6, 7, 8, 9 or 10 parts of aluminum erbium intermediate alloy ingot. The aluminum erbium intermediate alloy ingot is AlEr30.

[0050] Exemplarily, the preparation raw material of the 3D printing aluminum alloy comprises 0.1, 0.2, 0.5, 0.6, 0.8, 1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.2, 2.5, 2.8, 3, 4, 5, 6, 7, 8, 9 or 10 parts of aluminum zirconium intermediate alloy ingot. The aluminum zirconium intermediate alloy ingot is AlZr2 or AlZr2A.

[0051] Exemplarily, the preparation raw material of the 3D printing aluminum alloy comprises 0.1, 0.2, 0.5, 0.6, 0.8, 1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.2, 2.5, 2.8, 3, 4, 5, 6, 7, 8, 9 or 10 parts of aluminum titanium intermediate alloy ingot. The aluminum titanium intermediate alloy ingot is AlTi5 or AlTi5A.

[0052] The present application further provides a 3D printing aluminum alloy, which comprises the following chemical components and weight ratios: Si: 9-13%, Mg: 0.3-0.6%, La: 0-0.16%, Ce: 0-0.06%, Er: 0-0.2%, Ti: 0-0.2%, Zr: 0-0.1%, and the weight ratios of La, Ce, Er, Ti and Zr are not all 0, and the balance is aluminum and inevitable impurities.

[0053] According to embodiments of the present application, the 3D-printed aluminum alloy includes 9%, 10%, 11%, 12%, or 13% Si.

[0054] According to embodiments of the present application, the 3D-printed aluminum alloy includes 0.3%, 0.4%, 0.5%, or 0.6% Mg.

[0055] According to embodiments of the present application, the 3D-printed aluminum alloy includes 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.08%, 0.1%, 0.12%, 0.13%, 0.14%, 0.15%, or 0.16% La.

[0056] According to embodiments of the present application, the 3D-printed aluminum alloy includes 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, or 0.06% Ce.

[0057] According to embodiments of the present application, the 3D-printed aluminum alloy includes 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.08%, 0.1%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, or 0.2% Er.

[0058] According to embodiments of the present application, the 3D-printed aluminum alloy includes 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.08%, 0.1%, 0.12%, 0.13%, 0.14%, 0.15%, 0.16%, 0.17%, 0.18%, 0.19%, or 0.2% Ti.

[0059] According to embodiments of the present application, the 3D-printed aluminum alloy includes 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.08%, or 0.1% Zr.

[0060] According to embodiments of the present application, the 3D-printed aluminum alloy has a tensile strength at room temperature of 350-410 MPa and a yield strength of 220-240 MPa.

[0061] According to embodiments of the present application, the 3D-printed aluminum alloy has a tensile strength at 200°C of 200-240 MPa and a yield strength of 160-190 MPa.

[0062] According to an embodiment of the present application, the 3D printed aluminum alloy has a fracture time of more than 270 hours at a temperature of 200 DEG C, an initial stress of 78 MPa, a continuous loading time of 167 hours, and an increase of 8 MPa every 12 hours.

[0063] The present application has the following beneficial effects:

[0064] The present application provides a method for improving the room temperature / high temperature strength and high temperature durability of a 3D printed aluminum alloy. The present application aims to solve the problems of low room temperature and 200 DEG C tensile strength and yield strength and short 200 DEG C durability fracture time of the laser selective melting aluminum alloy after annealing. The alloy modification is implemented to improve the strength and durability. Specifically, at least one of La, Ce, Er, Ti and Zr elements is added to the alloy material. On the one hand, primary Al 11 La3, Al3Ti and Al3Zr second phase particles play a role of heterogeneous nucleation, promote the formation of equiaxed grains in the printing process, reduce the formation of columnar grains, and achieve the effect of refining grains. On the other hand, the secondary nano Al 11 La3, AlCe and Al3Er phases have good thermal stability, can produce dispersion strengthening and improve the effect of high temperature structure stability. Under the action of primary and secondary second phases, the dislocation movement is inhibited, the structure stability is improved, and finally the room temperature / high temperature tensile strength, yield strength and high temperature durability are improved. DETAILED DESCRIPTION

[0065] The method of the present application will be further described in detail below in conjunction with specific examples. It should be understood that the following examples are only illustrative and explanatory of the present application, and should not be interpreted as limiting the scope of protection of the present application. Any technology realized based on the above description of the present application is covered within the scope of protection intended by the present application.

[0066] The experimental methods used in the following examples are conventional methods unless otherwise specified. The reagents, materials, etc. used in the following examples can be obtained from commercial channels unless otherwise specified.

[0067] In the following examples, "parts" refer to "mass parts" unless otherwise specified.

[0068] The aluminum ingot used in the following examples is pure aluminum.

[0069] The magnesium ingot used in the following examples is pure magnesium.

[0070] The aluminum-silicon intermediate alloy ingot used in the following examples is AlSi11A.

[0071] The aluminum-cerium master alloy ingot used in the following examples was AlCe10.

[0072] The aluminum-cerium master alloy ingot used in the following examples was AlCe10.

[0073] The aluminum-erbium master alloy ingot used in the following examples was AlEr30.

[0074] The aluminum-zirconium master alloy ingot used in the following examples was AlZr2A.

[0075] The aluminum-titanium master alloy ingot used in the following examples was AlTi5A.

[0076] Example 1

[0077] An aluminum ingot 6 parts, a magnesium ingot 1 part, an aluminum-silicon master alloy ingot 185 parts, and an aluminum-zirconium master alloy ingot 8 parts (the added amount of Zr element is 0.08%) were weighed and cleaned, and then loaded into a crucible. After vacuumizing (5 Pa) in a vacuum atomization furnace, nitrogen was filled to a slight positive pressure (about 0.05 MPa) for protection. Electromagnetic induction heating was used to heat to 820°C, and after sufficient melting, the temperature was maintained for 30 min. The molten alloy liquid was atomized into powder by using high-pressure nitrogen gas, and the gas flow pressure was 2.6 MPa. After atomization, the powder was cooled to room temperature under nitrogen protection.

[0078] The atomized powder was classified under nitrogen protection conditions, the classification wheel frequency was 15 Hz, and the feeder frequency was 15 Hz. Then, the powder was sieved by using an ultrasonic vibration sieve machine, and the mesh size of the sieve was 250 meshes. Finally, a powder with a particle size range of 15-58 μm was obtained, and the powder alloy composition was Al-10Si-0.5Mg-0.08Zr.

[0079] The powder with a particle size of 15-58 μm was dried in an explosion-proof drying box, the drying temperature was 70°C, and the drying time was 12 hours.

[0080] EOS M290 type laser selective melting equipment was used for 3D printing forming. During printing, a chessboard scanning strategy was used, the scanning path was rotated by 67° layer by layer, the energy density was 45 J / mm 3 , and argon was used for protection during the printing process, and the oxygen content in the atmosphere was controlled to be 50 ppm.

[0081] After printing, the alloy material was heated to 260°C at a heating rate of 10°C / min by using an electric resistance furnace, and after reaching the temperature, the temperature was maintained for 120 min.

[0082] Example 2

[0083] Al ingot 5 parts, Mg ingot 1 part, Al-Si intermediate alloy ingot 185 parts, Al-Zr intermediate alloy ingot 8 parts (the added amount of Zr element is 0.08%), Al-Er intermediate alloy ingot 1.1 parts (the added amount of Er element is 0.17%) are weighed and cleaned, and then loaded into a crucible. After vacuumizing (5 Pa) in a vacuum atomization furnace, nitrogen is filled to a slight positive pressure (about 0.05 MPa) for protection. Electromagnetic induction heating is adopted to heat to 830 ℃. After sufficient melting, the temperature is kept for 40 min. The molten alloy liquid is atomized into powder by high-pressure nitrogen gas, and the gas flow pressure is 2.8 MPa. After atomization, the powder is cooled to room temperature under nitrogen protection.

[0084] The atomized powder is classified under nitrogen protection condition, the classification wheel frequency is 15 Hz, and the feeder frequency is 15 Hz. Then, the powder is screened by an ultrasonic vibration screening machine, and the screen mesh size is 230 meshes. Finally, the powder with a particle size range of 15-62 μm is obtained, and the powder alloy composition is Al-10Si-0.5Mg-0.08Zr-0.17Er.

[0085] The powder with a particle size of 15-62 μm is dried in an explosion-proof drying box, the drying temperature is 80 ℃, and the drying time is 10 hours.

[0086] EOS M290 type laser selective melting equipment is used for 3D printing forming. When printing, the chessboard scanning strategy is adopted, the scanning path is rotated by 67° layer by layer, the energy density is 50 J / mm 3 , and the printing process is protected by argon gas, and the oxygen content in the atmosphere is controlled to be 80 ppm.

[0087] After printing, the alloy material is heated to 270 ℃ at a heating rate of 10 ℃ / min by using a resistance furnace, and the temperature is kept for 140 min after reaching the temperature.

[0088] Example 3

[0089] Al ingot 10 parts, Mg ingot 1 part, Al-Si intermediate alloy ingot 185 parts, Al-La intermediate alloy ingot 2 parts (the added amount of La element is 0.1%), and Al-Ce intermediate alloy ingot 0.6 parts (the added amount of Ce element is 0.03%) are weighed and cleaned, and then loaded into a crucible. After vacuumizing (5 Pa) in a vacuum atomization furnace, nitrogen is filled to a slight positive pressure (about 0.05 MPa) for protection. Electromagnetic induction heating is adopted to heat to 800 ℃. After sufficient melting, the temperature is kept for 35 min. The molten alloy liquid is atomized into powder by high-pressure nitrogen gas, and the gas flow pressure is 2.2 MPa. After atomization, the powder is cooled to room temperature under nitrogen protection.

[0090] The atomized powder was classified under nitrogen protection conditions with a classification wheel frequency of 15 Hz and a feeder frequency of 15 Hz. It was then sieved using an ultrasonic vibrating sieve with a screen mesh of 270 mesh, finally obtaining powder with a particle size range of 15-53 μm and a powder alloy composition of Al-10Si-0.5Mg-0.1La-0.03Ce.

[0091] The powder with a diameter of 15–53 μm was dried in an explosion-proof drying oven at 100°C for 5 hours.

[0092] 3D printing was performed using an EOS M290 laser selective melting system, employing a checkerboard scanning strategy with the scanning path rotating 67° layer by layer, achieving an energy density of 35 J / mm². 3 The printing process is protected by argon gas, and the oxygen content of the atmosphere is controlled at 100ppm.

[0093] The printed alloy material was heated to 280°C using a resistance furnace at a heating rate of 10°C / min, and then held at that temperature for 120 minutes.

[0094] Comparative Example 1

[0095] Fourteen parts of aluminum ingot, one part of magnesium ingot, and 185 parts of aluminum-silicon master alloy ingot were weighed, cleaned, and placed into a crucible. The crucible was then evacuated (5 Pa) in a vacuum atomization furnace and filled with nitrogen to a slightly positive pressure (approximately 0.05 MPa) for protection. Electromagnetic induction heating was used to raise the temperature to 800°C, and the melt was held for 30 minutes after complete melting. The molten alloy was then atomized into powder using high-pressure nitrogen at a pressure of 2.0 MPa. After atomization, the powder was cooled to room temperature under nitrogen protection.

[0096] The atomized powder was classified under nitrogen protection conditions with a classification wheel frequency of 15 Hz and a feeder frequency of 15 Hz. It was then sieved using an ultrasonic vibrating sieve with a screen mesh of 250 mesh, finally obtaining powder with a particle size range of 15-58 μm and a powder alloy composition of Al-10Si-0.5Mg.

[0097] The powder with a diameter of 15–58 μm was dried in an explosion-proof drying oven at 100°C for 5 hours.

[0098] 3D printing was performed using an EOS M290 laser selective melting system, employing a checkerboard scanning strategy with the scanning path rotating 67° layer by layer, achieving an energy density of 40 J / mm². 3 The printing process is protected by argon gas, and the oxygen content of the atmosphere is controlled at 80ppm.

[0099] The printed alloy material is heated to 260℃ at a heating rate of 10℃ / min using an electric resistance furnace, and after reaching the temperature, is kept at 260℃ for 120min.

[0100] Test Example:

[0101] The tensile strength and yield strength of the printed alloy material in each of the above examples and comparative examples at room temperature are tested according to HB 5143-1996, the results are shown in Table 1; the tensile strength and yield strength of the printed alloy material in each of the above examples and comparative examples at 200℃ are tested according to HB 5195-1996, the results are shown in Table 2; the high temperature enduring performance of the printed alloy material in each of the above examples and comparative examples is tested according to HB 5150-1996, the results are shown in Table 3.

[0102] Table 1 Tensile strength and yield strength of the printed alloy material in examples and comparative examples at room temperature

[0103]

[0104] Table 2 Tensile strength and yield strength of the printed alloy material in examples and comparative examples at 200℃

[0105]

[0106]

[0107] Table 3 High temperature enduring performance of the printed alloy material in examples and comparative examples

[0108]

[0109] The results show that, compared with the 3D printed aluminum alloy in Comparative Example 1, the method of the present application improves the tensile strength of the printed alloy material at room temperature by 11.8% to 19.6%, and the yield strength by 11.1% to 18%; the tensile strength at 200℃ is improved by 9.9% to 22.5%, and the yield strength is improved by 3.9% to 18.2%; at 200℃, under the condition of initial stress of 78MPa, the fracture time is prolonged by 11.1% to 32.2% after 167h of continuous loading, and every 12h increase of 8MPa.

[0110] The above describes embodiments of the present application. However, the present application is not limited to the above-described embodiments. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for improving the room temperature / high temperature strength and high temperature durability of 3D printed aluminum alloy, wherein the chemical composition and weight ratio of the 3D printed aluminum alloy are as follows: Si: 9-13%, Mg: 0.3-0.6%, La: 0-0.16%, Ce: 0-0.06%, Er: 0-0.2%, Ti: 0-0.2%, Zr: 0-0.1%, and the weight ratio of La, Ce, Er, Ti and Zr is not simultaneously 0, with the balance being aluminum and unavoidable impurities; The method includes the following steps: (1) Select the raw materials for preparing 3D printed aluminum alloy, wherein the raw materials for preparing 3D printed aluminum alloy include a first component and a second component; the first component is aluminum ingot, magnesium ingot and aluminum-silicon master alloy ingot; the second component is at least one of aluminum-lanthanum master alloy ingot, aluminum-cerium master alloy ingot, aluminum-erbium master alloy ingot, aluminum-zirconium master alloy ingot and aluminum-titanium master alloy ingot. (2) The raw material for preparing the 3D printing aluminum alloy in step (1) is 3D printed using a laser selective melting device; (3) Anneal the 3D printed product formed in step (2); the annealing process is to use a resistance heating furnace to heat to 250℃~300℃ at a heating rate of 5~15℃ / min, and then hold at the temperature for 120min~180min. The tensile strength of the 3D printed aluminum alloy at 200℃ is 200-240MPa, and the yield strength is 160-190MPa. The fracture time of the 3D printed aluminum alloy at 200℃ with an initial stress of 78MPa and a continuous loading time of 167h, with an increase of 8MPa every 12h, reaches more than 270h.

2. The method according to claim 1, wherein, In step (1), the first component includes the following components in parts by mass: aluminum ingot, 5 to 12 parts; magnesium ingot, 1 to 2 parts; aluminum-silicon master alloy ingot, 160 to 200 parts; And / or, in step (1), the second component includes the following components in parts by mass: 0-10 parts of aluminum lanthanum master alloy ingot, 0-10 parts of aluminum cerium master alloy ingot, 0-10 parts of aluminum erbium master alloy ingot, 0-10 parts of aluminum zirconium master alloy ingot, and 0-10 parts of aluminum titanium master alloy ingot, and the sum of the parts by mass of aluminum lanthanum master alloy ingot, aluminum cerium master alloy ingot, aluminum erbium master alloy ingot, aluminum zirconium master alloy ingot and aluminum titanium master alloy ingot is not 0.

3. The method according to claim 1, wherein, In step (1), the first component includes the following components in parts by mass: aluminum ingot, 5 to 12 parts; magnesium ingot, 1 to 2 parts; aluminum-silicon master alloy ingot, 170 to 190 parts; And / or, in step (1), the second component includes the following components in parts by mass: 0-10 parts of aluminum lanthanum master alloy ingot, 0-10 parts of aluminum cerium master alloy ingot, 0-10 parts of aluminum erbium master alloy ingot, 0-10 parts of aluminum zirconium master alloy ingot, and 0-10 parts of aluminum titanium master alloy ingot, and the sum of the parts by mass of aluminum lanthanum master alloy ingot, aluminum cerium master alloy ingot, aluminum erbium master alloy ingot, aluminum zirconium master alloy ingot and aluminum titanium master alloy ingot is not 0 and is less than or equal to 10 parts.

4. The method according to claim 1, wherein, In step (1), the mass ratio of the first component and the second component is 1:

1.

5. The method according to claim 1, wherein, Step (2) specifically includes the following steps: (2-1) The raw materials for preparing the 3D printed aluminum alloy in step (1) are loaded into a crucible, and after vacuuming in a closed furnace, nitrogen or argon is introduced to positive pressure. Electromagnetic induction heating is used to obtain molten alloy liquid. (2-2) Use high-pressure nitrogen or high-pressure argon to atomize the molten alloy liquid in step (2-1) into powder; (2-3) The atomized powder from step (2-2) is classified under nitrogen or argon protection, and then screened using an ultrasonic vibrating sieve to obtain powder with a particle size range of 15-74 μm. (2-4) The powder with a particle size range of 15-74μm from step (2-3) is dried in an explosion-proof drying oven and then 3D printed using a laser selective melting device.

6. The method according to claim 5, wherein, In step (2-1), the vacuum degree is no greater than 10 Pa; And / or, in step (2-1), the pressure range of the positive pressure is 0 to 0.1 MPa; And / or, in step (2-1), electromagnetic induction heating is used to 800-900℃, and after melting, the temperature is held for 30-60 minutes to obtain a molten alloy liquid; And / or, in step (2-2), the gas flow pressure of the high-pressure nitrogen is 1-5 MPa; the gas flow pressure of the high-pressure argon is 1-5 MPa; And / or, in steps (2-3), the atomized powder is classified under nitrogen or argon protection conditions, with the classifier wheel frequency being 10-30Hz and the feeder frequency being 10-20Hz; then, it is sieved using an ultrasonic vibrating sieve with a screen mesh size of 200-325 mesh, finally obtaining powder with a particle size range of 15-74μm. And / or, in steps (2-4), the drying temperature is 60-90°C and the drying time is 5-12 hours; And / or, in steps (2-4), the scanning path is rotated 67° layer by layer during printing, with an energy density of 30–50 J / mm². 3 The printing process uses argon gas for protection, and the oxygen content in the controlled atmosphere is kept below 100 ppm.

7. The 3D printed aluminum alloy prepared by the method according to any one of claims 1-6.

8. The 3D printed aluminum alloy according to claim 7, wherein, The raw materials for preparing the 3D printed aluminum alloy include a first component and a second component; the first component is aluminum ingot, magnesium ingot and aluminum-silicon master alloy ingot; the second component is at least one of aluminum-lanthanum master alloy ingot, aluminum-cerium master alloy ingot, aluminum-erbium master alloy ingot, aluminum-zirconium master alloy ingot and aluminum-titanium master alloy ingot.

9. The 3D printed aluminum alloy according to claim 8, wherein, The first component comprises the following components in parts by weight: aluminum ingot, 5-12 parts; magnesium ingot, 1-2 parts; aluminum-silicon master alloy ingot, 160-200 parts; And / or, the second component comprises the following components in parts by mass: 0-10 parts of aluminum-lanthanum master alloy ingot, 0-10 parts of aluminum-cerium master alloy ingot, 0-10 parts of aluminum-erbium master alloy ingot, 0-10 parts of aluminum-zirconium master alloy ingot, and 0-10 parts of aluminum-titanium master alloy ingot, and the sum of the parts by mass of aluminum-lanthanum master alloy ingot, aluminum-cerium master alloy ingot, aluminum-erbium master alloy ingot, aluminum-zirconium master alloy ingot, and aluminum-titanium master alloy ingot is not 0.

10. The 3D printed aluminum alloy according to claim 9, wherein the first component comprises the following components in parts by mass: aluminum ingot, 5-12 parts; magnesium ingot, 1-2 parts; aluminum-silicon master alloy ingot, 170-190 parts; And / or, the second component comprises the following components in parts by mass: 0-10 parts of aluminum-lanthanum master alloy ingot, 0-10 parts of aluminum-cerium master alloy ingot, 0-10 parts of aluminum-erbium master alloy ingot, 0-10 parts of aluminum-zirconium master alloy ingot, and 0-10 parts of aluminum-titanium master alloy ingot, and the sum of the parts by mass of aluminum-lanthanum master alloy ingot, aluminum-cerium master alloy ingot, aluminum-erbium master alloy ingot, aluminum-zirconium master alloy ingot, and aluminum-titanium master alloy ingot is not 0 and is less than or equal to 10 parts.

11. The 3D printed aluminum alloy according to claim 7, wherein the chemical composition and weight ratio of the 3D printed aluminum alloy are as follows: Si: 9-13%, Mg: 0.3-0.6%, La: 0-0.16%, Ce: 0-0.06%, Er: 0-0.2%, Ti: 0-0.2%, Zr: 0-0.1%, and the weight ratio of La, Ce, Er, Ti and Zr is not simultaneously 0, with the balance being aluminum and unavoidable impurities.

12. The 3D-printed aluminum alloy according to any one of claims 7-11, wherein, The room temperature tensile strength of the 3D printed aluminum alloy is 350-410 MPa, and the yield strength is 220-240 MPa. And / or, the 3D printed aluminum alloy has a tensile strength of 200-240 MPa at 200°C and a yield strength of 160-190 MPa; And / or, the fracture time of the 3D printed aluminum alloy under the following conditions is more than 270 hours after continuous loading for 167 hours at 200℃ and initial stress of 78MPa, with an increase of 8MPa every 12 hours.

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