Aluminum alloy powder for additive manufacturing and preparation method therefor, and aluminum alloy part

Abstract

An aluminum alloy powder for additive manufacturing and a preparation method therefor, and an aluminum alloy part. The aluminum alloy powder comprises, in percentages by mass: Si: 0.1% to 2.0%; Fe: 0.1% to 1.0%; Cu: 0.1% to 1.0%; Mn: 0.01% to 1.5%; Mg: 0.1% to 1.5%; Cr: 0.01% to 0.5%; Zn: 0.1% to 0.5%; a first component: 0.8% to 3.0%, the first component being Ti, Zr or a combination of Ti and Zr; a second component: less than 0.05%, the second component being a combination of O and N; and the balance of Al and inevitable impurities.

Description

Aluminum alloy powder for additive manufacturing, preparation method thereof, and aluminum alloy parts CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to the Chinese patent application filed with the Patent Office of China on November 29, 2023, with application number 2023116136814, and invention name “A kind of aluminum alloy powder for additive manufacturing, preparation method thereof, and aluminum alloy parts”. The contents of the Chinese patent application are hereby incorporated into this application by reference. Technical Field

[0002] The present disclosure relates to the technical field of metal materials, and more specifically to an aluminum alloy powder for additive manufacturing, a preparation method thereof, and aluminum alloy parts. Background Art

[0003] With the continuous development of material manufacturing technology, additive manufacturing technology, especially selective laser melting (SLM) technology, has become a new processing technology for manufacturing aluminum alloy parts due to its advantages such as highly flexible design, simple processing process and integrated structure and function.

[0004] Currently, there are only a few types of aluminum alloy powders available for additive manufacturing (AM). Most are Al-Si alloy powders (such as AlSi10Mg) or Al-Mg-Sc-Zr alloy powders with near-eutectic compositions. However, while 6XXX aluminum alloys (such as 6061) offer advantages such as high machinability, excellent weldability, good corrosion resistance, and resistance to post-processing deformation, as well as ease of polishing and coloring, they exhibit a high tendency to thermal cracking, making it difficult to produce crack-free aluminum alloy parts using AM techniques. This has limited the further promotion and application of these 6XXX aluminum alloy powders. Technical content

[0005] Embodiments of the present disclosure provide an aluminum alloy powder for additive manufacturing, a preparation method thereof, and an aluminum alloy part; these can reduce or eliminate the phenomenon of existing 6XXX series aluminum alloy powders being prone to cracking during additive manufacturing, and improve the mechanical properties of aluminum alloy parts obtained through additive manufacturing.

[0006] The technical solution of the embodiment of the present disclosure is achieved as follows:

[0007] In a first aspect, an embodiment of the present disclosure provides an aluminum alloy powder for additive manufacturing, wherein the aluminum alloy powder comprises, by mass percentage:

[0008] Si: 0.1% to 2.0%;

[0009] Fe: 0.1% to 1.0%;

[0010] Cu: 0.1% to 1.0%;

[0011] Mn: 0.01% to 1.5%;

[0012] Mg: 0.1% to 1.5%;

[0013] Cr: 0.01% to 0.5%;

[0014] Zn: 0.1% to 0.5%;

[0015] First component: 0.8% to 3.0%, wherein the first component is Ti, Zr, or a combination of Ti and Zr;

[0016] Second component: less than 0.05%, and the second component is a combination of O and N;

[0017] The balance is Al and inevitable impurities.

[0018] Optionally, in some examples, the first component is greater than or equal to 0.8% and less than 2.0%.

[0019] Optionally, in some examples, the first component is greater than 2.0% and less than or equal to 3.0%.

[0020] Optionally, in some examples, the aluminum alloy powder includes at least one of the following by mass percentage:

[0021] Si: 0.6% to 0.8%;

[0022] Fe: 0.6% to 0.8%;

[0023] Cu: 0.2% to 0.4%;

[0024] Mn: 0.1% to 0.2%;

[0025] Mg: 0.8% to 1.2%;

[0026] Cr: 0.2% to 0.3%;

[0027] Zn: 0.2% to 0.3%.

[0028] Optionally, in some examples, the aluminum alloy powder has a particle size less than 180 μm.

[0029] Optionally, in some examples, the aluminum alloy powder has a particle size of 20 μm to 63 μm.

[0030] In a second aspect, an embodiment of the present disclosure provides a method for preparing aluminum alloy powder for additive manufacturing, the method comprising:

[0031] The metal raw materials of the set ratio are uniformly melted; wherein, in terms of mass percentage, the metal raw materials of the set ratio include:

[0032] Si: 0.1% to 2.0%;

[0033] Fe: 0.1% to 1.0%;

[0034] Cu: 0.1% to 1.0%;

[0035] Mn: 0.01% to 1.5%;

[0036] Mg: 0.1% to 1.5%;

[0037] Cr: 0.01% to 0.5%;

[0038] Zn: 0.1% to 0.5%;

[0039] First component: 0.8% to 3.0%, wherein the first component is Ti, Zr, or a combination of Ti and Zr;

[0040] Second component: less than 0.05%, and the second component is a combination of O and N;

[0041] The balance is Al and unavoidable impurities;

[0042] Based on the uniformly melted metal raw material, an aluminum alloy powder is prepared by a gas atomization method; wherein the sphericity of the aluminum alloy powder is not less than 0.8, and the hollow powder rate of the aluminum alloy powder does not exceed 10%.

[0043] Optionally, in some examples, the first component is greater than or equal to 0.8% and less than 2.0%.

[0044] Optionally, in some examples, the first component is greater than 2.0% and less than or equal to 3.0%.

[0045] Optionally, in some examples, the metal raw materials with a set ratio include at least one of the following by mass percentage:

[0046] Si: 0.6% to 0.8%;

[0047] Fe: 0.6% to 0.8%;

[0048] Cu: 0.2% to 0.4%;

[0049] Mn: 0.1% to 0.2%;

[0050] Mg: 0.8% to 1.2%;

[0051] Cr: 0.2% to 0.3%;

[0052] Zn: 0.2% to 0.3%.

[0053] In a third aspect, an embodiment of the present disclosure provides an aluminum alloy part, which is obtained by additive manufacturing using the aluminum alloy powder described in the first aspect.

[0054] Optionally, in some examples, the aluminum alloy parts have a tensile strength of not less than 316 MPa, a yield strength of not less than 293 MPa, and an elongation after fracture of not less than 17% after heat treatment; wherein, the heat treatment process of the aluminum alloy parts is to keep the temperature at 150°C to 180°C for 8 to 12 hours and cool in air.

[0055] Optionally, in some examples, the aluminum alloy part has a tensile strength of 316 MPa to 370 MPa, a yield strength of 293 MPa to 347 MPa, and an elongation at break of 17% to 22% after heat treatment.

[0056] The embodiments of the present disclosure provide an aluminum alloy powder for additive manufacturing, a preparation method thereof, and an aluminum alloy part. The aluminum alloy powder is obtained by adding element Ti and / or element Zr to the existing 6XXX series aluminum alloy powder, so that the element Ti and / or element Zr will form Al3Ti phase and / or Al3Zr phase with Al during the additive manufacturing process. During the solidification process, the Al3Ti phase and / or Al3Zr phase can serve as heterogeneous nucleation sites of α-Al to refine the grains, transforming the coarse columnar crystals inside the molten pool into fine equiaxed crystals, thereby eliminating the thermal cracks generated during the solidification process, and solving the problem that the existing 6XXX series aluminum alloy powder is prone to thermal cracks during the additive manufacturing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for describing the embodiments. The drawings described below are only exemplary embodiments of the present disclosure.

[0058] FIG1 is a schematic diagram of the metallographic microstructure of a deposited aluminum alloy part manufactured using the SLM technology using existing 6XXX series aluminum alloy powder under a 100x optical microscope.

[0059] FIG2 is a schematic diagram of the metallographic microstructure of a deposited aluminum alloy part manufactured using the SLM technology using existing 6XXX series aluminum alloy powder under a 200x optical microscope.

[0060] FIG3 is a schematic diagram of the metallographic microstructure of the deposited aluminum alloy parts obtained by manufacturing the aluminum alloy powder provided in Examples 1 to 3 of the present disclosure using the SLM technology under an optical microscope at a magnification of 100 times.

[0061] FIG4 is a schematic diagram of the metallographic microstructure of the deposited aluminum alloy parts obtained by manufacturing the aluminum alloy powder provided in Examples 1 to 3 of the present disclosure using the SLM technology under an optical microscope at a magnification of 200 times.

[0062] FIG5 is a schematic diagram of the metallographic microstructure of the deposited aluminum alloy parts obtained by manufacturing the aluminum alloy powder provided in Comparative Examples 1 to 3 of the present disclosure by SLM technology under an optical microscope at a magnification of 100 times.

[0063] FIG6 is a schematic diagram of the metallographic microstructure of the deposited aluminum alloy parts obtained by manufacturing the aluminum alloy powder provided in Comparative Examples 1 to 3 of the present disclosure by SLM technology under an optical microscope at a magnification of 200 times. DETAILED DESCRIPTION

[0064] In order to make the purpose, technical solutions and advantages of the present disclosure more apparent, the following will describe in detail exemplary embodiments of the present disclosure with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments of the present disclosure, and it should be understood that the present disclosure is not limited to the exemplary embodiments described herein.

[0065] Refer to Figure 1, which shows a schematic diagram of the metallographic microstructure of an aluminum alloy part in a deposited state obtained by manufacturing the existing 6XXX series aluminum alloy powder using the SLM technology under a 100x optical microscope. Refer to Figure 2, which shows a schematic diagram of the metallographic microstructure of an aluminum alloy part in a deposited state obtained by manufacturing the existing 6XXX series aluminum alloy powder using the SLM technology under a 200x optical microscope. As shown in Figures 1 and 2, a large number of thermal cracks are present in the metallographic microstructure of the aluminum alloy part in a deposited state obtained by manufacturing the existing 6XXX series aluminum alloy powder using the SLM technology, and some of the thermal cracks penetrate multiple molten pools. According to measurements, the length of some of the thermal cracks is about hundreds of microns. The above-mentioned thermal cracks seriously affect the mechanical properties of the above-mentioned aluminum alloy parts, thereby limiting the application of the above-mentioned aluminum alloy parts in technical fields such as automobiles and aerospace.

[0066] Based on the above, the present disclosure provides an aluminum alloy powder for additive manufacturing. This aluminum alloy powder is prepared by adding the element Ti and / or the element Zr to existing 6XXX series aluminum alloy powders to eliminate the thermal cracking phenomenon in aluminum alloy parts obtained by additive manufacturing, thereby improving the mechanical properties of the aluminum alloy parts obtained by additive manufacturing. The components and contents of the aluminum alloy powder provided in the present disclosure are specifically shown below, in percentage by mass:

[0067] Si: 0.1% to 2.0%;

[0068] Fe: 0.1% to 1.0%;

[0069] Cu: 0.1% to 1.0%;

[0070] Mn: 0.01% to 1.5%;

[0071] Mg: 0.1% to 1.5%;

[0072] Cr: 0.01% to 0.5%;

[0073] Zn: 0.1% to 0.5%;

[0074] First component: 0.8% to 3.0%, wherein the first component is Ti, Zr, or a combination of Ti and Zr;

[0075] Second component: less than 0.05%, and the second component is a combination of O and N;

[0076] The balance is Al and inevitable impurities.

[0077] In some examples, the content of each of the unavoidable impurities is less than 0.05%.

[0078] In some examples, the first component is greater than or equal to 0.8% and less than 2.0%.

[0079] In some examples, the first component is greater than 2.0% and less than or equal to 3.0%.

[0080] In some examples, the aluminum alloy powder includes, by mass percentage, at least one of the following:

[0081] Si: 0.6% to 0.8%;

[0082] Fe: 0.6% to 0.8%;

[0083] Cu: 0.2% to 0.4%;

[0084] Mn: 0.1% to 0.2%;

[0085] Mg: 0.8% to 1.2%;

[0086] Cr: 0.2% to 0.3%;

[0087] Zn: 0.2% to 0.3%.

[0088] In the disclosed embodiments, elemental Ti and elemental Zr can be added individually to an existing 6XXX series aluminum alloy powder. When elemental Ti is added individually to an existing 6XXX series aluminum alloy powder, the Ti content is 0.8% to 3.0% by mass. When elemental Zr is added individually to an existing 6XXX series aluminum alloy powder, the Zr content is 0.8% to 3.0% by mass. Of course, elemental Ti and elemental Zr can also be added simultaneously to an existing 6XXX series aluminum alloy powder. When elemental Ti and elemental Zr are added simultaneously to an existing 6XXX series aluminum alloy powder, the total content of Ti and Zr is 0.8% to 3.0%.

[0089] In a specific implementation, after fully and evenly melting metal raw materials of a predetermined ratio, the aluminum alloy powder for additive manufacturing provided by the disclosed embodiments is prepared using a gas atomization method or other powder preparation technology. In some examples, the aluminum alloy powder has a sphericity of not less than 0.8 and a hollow powder ratio of not more than 10%.

[0090] In some examples, the aluminum alloy powder is stored in a vacuum seal and dried before additive manufacturing. The drying process is as follows: maintaining the temperature at 100°C to 150°C for 2 hours, and the drying process and subsequent cooling process are both performed in an argon protective atmosphere.

[0091] In some examples, the aluminum alloy powder has a particle size of less than 180 μm. Optionally, the aluminum alloy powder has a particle size of 20 μm to 63 μm.

[0092] In other examples, when the above-mentioned aluminum alloy powder is additively manufactured using the laser selective melting technology, the aluminum alloy powder is added to the powder feeding bin in the additive manufacturing equipment, and when the oxygen content of the forming chamber in the additive manufacturing equipment drops below 0.02%, the laser starts to scan the aluminum alloy powder supplied by the powder feeding bin on the substrate, and stacks it layer by layer to eventually form an aluminum alloy part. Optionally, the process of starting the laser scanning of the aluminum alloy powder supplied by the powder feeding bin on the substrate and stacking it layer by layer can be implemented using the laser selective melting method. Specifically, when the oxygen content in the forming chamber drops below 0.02%, a layer of aluminum alloy powder supplied by the powder feeding bin is laid on the surface of the substrate, and the laser is used to scan the aluminum alloy powder on the surface of the substrate to form a first layer of laser selective melting. After the first layer of laser selective melting solidifies, the substrate is lowered. A layer of aluminum alloy powder supplied from a powder feeder is laid on top of the solidified first laser selective melting layer. A laser is then used to scan the aluminum alloy powder on top of the first laser selective melting layer to form a second laser selective melting layer. This process is repeated layer by layer until the aluminum alloy part is manufactured.

[0093] It can be understood that the embodiments of the present disclosure adjust the composition of existing 6XXX series aluminum alloy powders, specifically by adding elemental Ti and / or elemental Zr to the existing 6XXX series aluminum alloy powders, so that the elemental Ti and / or elemental Zr will form Al3Ti phase and / or Al3Zr phase with Al during the additive manufacturing process. During the solidification process, the Al3Ti phase and / or Al3Zr phase can serve as heterogeneous nucleation sites for α-Al to refine the grains, transforming the coarse columnar crystals within the molten pool into fine equiaxed crystals, thereby eliminating the thermal cracks generated during the solidification process and solving the problem that existing 6XXX series aluminum alloy powders are prone to thermal cracking during additive manufacturing.

[0094] Example 1

[0095] This embodiment provides an aluminum alloy powder for additive manufacturing, which is obtained by adding elements Ti and Zr to existing 6XXX series aluminum alloy powders. Specifically, the components and contents of the aluminum alloy powder provided in this embodiment 1 are as follows, calculated by mass percentage: Si: 0.1%, 0.6%, 0.7%, 0.8% or 2.0%; Fe: 0.1%, 0.6%, 0.7%, 0.8% or 1.0%; Cu: 0.1%, 0.2%, 0.3%, 0.4% or 1.0%; Mn: 0.01%, 0.1%, 0.15%, 0.2%, 0.7% or 1.5%; Mg: 0.1%, 0.8%, 1.0% or 1.0%; .0%, 1.2% or 1.5%; Cr: 0.01%, 0.2%, 0.25%, 0.3% or 0.5%; Zn: 0.1%, 0.2%, 0.25%, 0.3% or 0.5%; Ti: 0.2%, 0.55%, 0.8% or 0.9%; Zr: 0.6%, 0.65%, 0.7% or 1.0%; O: 0.032% or 0.041%; N: 0.004% or 0.005%; the balance is Al and unavoidable impurities.

[0096] In some examples, after fully and evenly melting metal raw materials of a predetermined ratio, nitrogen atomization was used to prepare the aluminum alloy powder for additive manufacturing provided in Example 1. The aluminum alloy powder provided in Example 1 had a sphericity of 0.85 and a hollow powder fraction of 0.4%.

[0097] For Example 1 above, the aluminum alloy powder provided in Example 1 needs to be stored in a vacuum seal and dried before additive manufacturing. The drying process is as follows: keeping the powder at 120°C for 2 hours, and both the drying process and the subsequent cooling process are performed in an argon protective atmosphere. It should be noted that after the drying and cooling processes, the aluminum alloy powder needs to be sieved to obtain a particle size of 20 μm to 180 μm.

[0098] The aluminum alloy powder provided in Example 1 is additively manufactured using a laser selective melting method to obtain an aluminum alloy part, and the aluminum alloy part is heat treated. The specific heat treatment process is to keep the temperature at 150° C. for 8 hours and cool it in air.

[0099] In some examples, the aluminum alloy powder provided in the above-mentioned embodiment 1 can be processed through an additive manufacturing process using additive manufacturing equipment such as BLT-S310, BLT-S320, BLT-S400, and BLT-S600.

[0100] Example 2

[0101] The element Ti and the element Zr in Example 1 are replaced by the element Zr, and in terms of mass percentage, the Zr content is 0.8%, 1.2%, 1.5% or 1.9%.

[0102] The particle size of the aluminum alloy powder in Example 1 was adjusted from 20 μm to 180 μm to 20 μm to 63 μm.

[0103] The aluminum alloy powder described in Example 2 was additively manufactured using the laser selective melting method to obtain an aluminum alloy part, and the aluminum alloy part was heat treated. The specific heat treatment process was to keep the temperature at 180° C. for 12 hours and cool it in air.

[0104] The remaining technical features are the same as those in Example 1.

[0105] Example 3

[0106] The element Ti and the element Zr in Example 1 are replaced by element Ti, and in terms of mass percentage, Ti is: 0.8%, 1.2%, 1.5% or 1.9%.

[0107] The particle size of the aluminum alloy powder in Example 1 was adjusted from 20 μm to 180 μm to 20 μm to 63 μm.

[0108] The aluminum alloy powder described in Example 3 was additively manufactured using a laser selective melting method to obtain an aluminum alloy part, and the aluminum alloy part was heat treated. The specific heat treatment process was to keep the temperature at 160° C. for 10 hours and cool it in air.

[0109] The remaining technical features are the same as those in Example 1.

[0110] Samples of the as-deposited aluminum alloy parts obtained by additive manufacturing in Examples 1 to 3 were observed using an optical microscope, and the metallographic microstructures are shown in Figures 3 and 4. Figure 3 is a schematic diagram of the metallographic microstructures of the as-deposited aluminum alloy parts obtained by additive manufacturing in Examples 1 to 3 under an optical microscope at 100x magnification. Figure 4 is a schematic diagram of the metallographic microstructures of the as-deposited aluminum alloy parts obtained by additive manufacturing in Examples 1 to 3 under an optical microscope at 200x magnification. As can be seen from Figures 3 and 4, the metallographic microstructures of the aluminum alloy parts obtained by additive manufacturing in Examples 1 to 3 are free of hot cracks and are dense and uniform.

[0111] Mechanical property testing was performed on transverse specimens corresponding to the heat-treated aluminum alloy parts in Examples 1 to 3. The mechanical properties of the transverse specimens were used to characterize the mechanical properties of the heat-treated aluminum alloy parts. When the lower limit of the tensile strength of the heat-treated aluminum alloy parts was 320 MPa, the median tensile strength was 332 MPa, and the upper limit of the tensile strength was 345 MPa, the remaining mechanical property parameters of the heat-treated aluminum alloy parts are shown in Table 1.

[0112] Mechanical properties test temperature Tensile strength Rm (MPa) Yield strength Rp0.2 (MPa) Elongation after fracture A (%) Shrinkage after fracture Z (%) Room temperature 320 29 32257 Room temperature 332 314 2055 Room temperature 345 325 2049

[0113] Table 1

[0114] In some examples, the transverse specimen refers to sampling along the transverse direction of the aluminum alloy part during the mechanical property test of the aluminum alloy part. The transverse direction of the aluminum alloy part is defined as the XY axis, where the X axis refers to the length of the substrate in the forming chamber of the additive manufacturing apparatus, and the Y axis refers to the width of the substrate.

[0115] Example 4

[0116] This embodiment provides an aluminum alloy powder for additive manufacturing, which is obtained by adding the elements Ti and Zr to the existing 6XXX series aluminum alloy powder. Specifically, the components and contents of the aluminum alloy powder provided in this embodiment 4 are as follows, in terms of mass percentage: Si: 0.1%, 0.6%, 0.7%, 0.8% or 2.0%; Fe: 0.1%, 0.6%, 0.7%, 0.8% or 1.0%; Cu: 0.1%, 0.2%, 0.3%, 0.4% or 1.0%; Mn: 0.01%, 0.1%, 0.15%, 0.2%, 0.7% or 1.5%; Mg: 0.1%, 0.2%, 0.7%, 0.8% or 1.0%; .8%, 1.0%, 1.2% or 1.5%; Cr: 0.01%, 0.2%, 0.25%, 0.3% or 0.5%; Zn: 0.1%, 0.2%, 0.25%, 0.3% or 0.5%; Ti: 1.0%, 1.25% or 1.5%; Zr: 1.2%, 1.25% or 1.3%; O: 0.025% or 0.038%; N: 0.004% or 0.005%; the balance is Al and unavoidable impurities.

[0117] In a specific implementation, after fully and evenly melting the metal raw materials of a predetermined ratio, nitrogen atomization was used to prepare the aluminum alloy powder for additive manufacturing provided in Example 4. The aluminum alloy powder provided in Example 4 had a sphericity of 0.84 and a hollow powder fraction of 0.35%.

[0118] For Example 4 above, the aluminum alloy powder provided in Example 4 needs to be stored in a vacuum seal and dried before additive manufacturing. The drying process is as follows: keeping the temperature at 120°C for 2 hours, and both the drying process and the subsequent cooling process are performed in an argon protective atmosphere. It should be noted that after the drying and cooling processes, the aluminum alloy powder needs to be sieved to obtain a particle size of 20 μm to 180 μm.

[0119] The aluminum alloy powder provided in the above-mentioned Example 4 is additively manufactured using the laser selective melting method to obtain an aluminum alloy part, and the aluminum alloy part is heat treated. The specific heat treatment process is to keep the temperature at 150° C. for 8 hours and cool it in air.

[0120] In some examples, the aluminum alloy powder provided in the above-mentioned embodiment 4 can be processed through an additive manufacturing process using additive manufacturing equipment such as BLT-S310, BLT-S320, BLT-S400, and BLT-S600.

[0121] Example 5

[0122] The element Ti and the element Zr in Example 4 are replaced by the element Zr, and in terms of mass percentage, the Zr is: 2.2%, 2.5% or 2.8%.

[0123] The particle size of the aluminum alloy powder in Example 4 was adjusted from 20 μm to 180 μm to 20 μm to 63 μm.

[0124] The aluminum alloy powder described in Example 5 was additively manufactured using a laser selective melting method to obtain an aluminum alloy part, and the aluminum alloy part was heat treated. The specific heat treatment process was to keep the temperature at 180° C. for 12 hours and cool it in air.

[0125] The remaining technical features are the same as those of Example 4.

[0126] Example 6

[0127] The element Ti and the element Zr in Example 4 are replaced by element Ti, and in terms of mass percentage, Ti is: 2.2%, 2.5% or 2.8%.

[0128] The particle size of the aluminum alloy powder in Example 4 was adjusted from 20 μm to 180 μm to 20 μm to 63 μm.

[0129] The aluminum alloy powder described in Example 6 was additively manufactured using a laser selective melting method to obtain an aluminum alloy part, and the aluminum alloy part was heat treated. The specific heat treatment process was to keep the temperature at 160° C. for 10 hours and cool it in air.

[0130] The remaining technical features are the same as those of Example 4.

[0131] Mechanical property testing was performed on transverse specimens corresponding to the heat-treated aluminum alloy parts in Examples 4 to 6. The mechanical properties of the transverse specimens are used to characterize the mechanical properties of the heat-treated aluminum alloy parts. When the lower limit of the tensile strength of the heat-treated aluminum alloy parts is 350 MPa, the median tensile strength is 361 MPa, and the upper limit of the tensile strength is 370 MPa, the remaining mechanical property parameters of the heat-treated aluminum alloy parts are shown in Table 2.

[0132] Mechanical properties test temperature Tensile strength Rm (MPa) Yield strength Rp0.2 (MPa) Elongation after fracture A (%) Shrinkage after fracture Z (%) Room temperature 350 328 18.543 Room temperature 361 336 1840 Room temperature 370 347 1748

[0133] Table 2

[0134] In some examples, the transverse specimen refers to sampling along the transverse direction of the aluminum alloy part during the mechanical property test of the aluminum alloy part. The transverse direction of the aluminum alloy part is defined as the XY axis, where the X axis refers to the length of the substrate in the forming chamber of the additive manufacturing apparatus, and the Y axis refers to the width of the substrate.

[0135] It can be seen from Table 2 that with the increase of the content of element Ti or element Zr, or the increase of the total content of Ti and element Zr, the aluminum alloy parts obtained by additive manufacturing of the aluminum alloy powder provided in Examples 4 to 6 have a tensile strength of not less than 344 MPa, a yield strength of not less than 314 MPa, and an elongation at break of not less than 16.5% after heat treatment.

[0136] Comparative Example 1

[0137] This comparative example provides an aluminum alloy powder for additive manufacturing, which is obtained by adding elements Ti and Zr to existing 6XXX series aluminum alloy powders. The components and contents of the aluminum alloy powder provided in this comparative example 1 are as follows: Si: 0.1%, 0.6%, 0.7%, 0.8% or 2.0%; Fe: 0.1%, 0.6%, 0.7%, 0.8% or 1.0%; Cu: 0.1%, 0.2%, 0.3%, 0.4% or 1.0%; Mn: 0.01%, 0.1%, 0.15%, 0.2%, 0.7% or 1.5%; Mg: 0.1%, 0.8%, 1.0% or 2.0%; .0%, 1.2% or 1.5%; Cr: 0.01%, 0.2%, 0.25%, 0.3% or 0.5%; Zn: 0.1%, 0.2%, 0.25%, 0.3% or 0.5%; Ti: 0.1%, 0.2% or 0.3%; Zr: 0.1%, 0.2% or 0.3%; O: 0.022% or 0.041%; N: 0.002% or 0.004%; the balance is Al and unavoidable impurities.

[0138] In some examples, after fully and evenly melting metal raw materials of a predetermined ratio, nitrogen atomization was used to prepare the aluminum alloy powder for additive manufacturing provided in Comparative Example 1. The aluminum alloy powder provided in Comparative Example 1 had a sphericity of 0.88 and a hollow powder fraction of 0.5%.

[0139] For Comparative Example 1, the aluminum alloy powder provided in Comparative Example 1 was stored in a vacuum-sealed container and dried prior to additive manufacturing. The drying process involved maintaining the powder at 120°C for two hours, with both the drying process and subsequent cooling performed in an argon atmosphere. It should be noted that after drying and cooling, the aluminum alloy powder was sieved to achieve a particle size of 20 to 180 μm.

[0140] The aluminum alloy powder provided in the above comparative example 1 was additively manufactured using the laser selective melting method to obtain an aluminum alloy part, and the aluminum alloy part was heat treated. The specific heat treatment process was to keep the temperature at 150° C. for 8 hours and cool it in air.

[0141] In some examples, the aluminum alloy powder provided in the above-mentioned comparative example 1 can be processed through an additive manufacturing process using additive manufacturing equipment such as BLT-S310, BLT-S320, BLT-S400, and BLT-S600.

[0142] Comparative Example 2

[0143] The element Ti and the element Zr in Comparative Example 1 are replaced by the element Zr, and in terms of mass percentage, the Zr is: 0.2%, 0.4% or 0.6%.

[0144] The particle size of the aluminum alloy powder in Comparative Example 1 was adjusted from 20 μm to 180 μm to 20 μm to 63 μm.

[0145] The aluminum alloy powder described in Comparative Example 2 was additively manufactured using a laser selective melting method to obtain an aluminum alloy part, and the aluminum alloy part was heat treated. The specific heat treatment process was to keep the temperature at 180° C. for 12 hours and cool it in air.

[0146] The remaining technical features are the same as those of Comparative Example 1.

[0147] Comparative Example 3

[0148] The element Ti and the element Zr in Comparative Example 1 are replaced by element Ti, and in terms of mass percentage, Ti is: 0.2%, 0.4%, or 0.6%.

[0149] The particle size of the aluminum alloy powder in Comparative Example 1 was adjusted from 20 μm to 180 μm to 20 μm to 63 μm.

[0150] The aluminum alloy powder described in Comparative Example 3 was additively manufactured using a laser selective melting method to obtain an aluminum alloy part, and the aluminum alloy part was heat treated. The specific heat treatment process was to keep the temperature at 160° C. for 10 hours and cool it in air.

[0151] The remaining technical features are the same as those of Comparative Example 1.

[0152] The as-deposited aluminum alloy parts obtained by additive manufacturing in Comparative Examples 1 to 3 were observed under an optical microscope, and the metallographic microstructures are shown in Figures 5 and 6. Figure 5 is a schematic diagram of the metallographic microstructures of the as-deposited aluminum alloy parts obtained by additive manufacturing in Comparative Examples 1 to 3 under an optical microscope at 100x magnification. Figure 6 is a schematic diagram of the metallographic microstructures of the as-deposited aluminum alloy parts obtained by additive manufacturing in Comparative Examples 1 to 3 under an optical microscope at 200x magnification. As can be seen from Figures 5 and 6, hot cracks still exist in the metallographic microstructures of the aluminum alloy parts obtained by additive manufacturing in Comparative Examples 1 to 3, but the length and width of the hot cracks have been reduced to varying degrees. This indicates that when the content of the element Ti or the element Zr added to the existing 6XXX series aluminum alloy powder is low, or the total content of the element Ti and the element Zr is low, hot cracking in the aluminum alloy parts obtained by additive manufacturing can be improved, but it is difficult to completely eliminate hot cracks in the aluminum alloy parts.

[0153] Comparative Example 4

[0154] This comparative example provides an aluminum alloy powder for additive manufacturing, which is obtained by adding the elements Ti and Zr to the existing 6XXX series aluminum alloy powder. Specifically, the components and contents of the aluminum alloy powder provided in this comparative example 4 are as follows, calculated by mass percentage: Si: 0.1%, 0.6%, 0.7%, 0.8% or 2.0%; Fe: 0.1%, 0.6%, 0.7%, 0.8% or 1.0%; Cu: 0.1%, 0.2%, 0.3%, 0.4% or 1.0%; Mn: 0.01%, 0.1%, 0.15%, 0.2%, 0.7% or 1.5%; Mg: 0.1%, 0.8%, 1.0%, 1.2% or 1.5%; Cr: 0.01%, 0.2%, 0.25%, 0.3% or 0.5%; Zn: 0.1%, 0.2%, 0.25%, 0.3% or 0.5%; Ti: 1.5%, 1.8% or 2.0%; Zr: 1.7%, 1.8% or 2.0%; O: 0.027% or 0.035%, N: 0.001% or 0.003%; the balance is Al and unavoidable impurities.

[0155] In the specific implementation process, after the metal raw materials of the set ratio are fully and evenly melted, the aluminum alloy powder for additive manufacturing provided in Comparative Example 4 is prepared by nitrogen atomization. The aluminum alloy powder provided in Comparative Example 4 has a sphericity of 0.87 and a hollow powder ratio of 0.45%.

[0156] For Comparative Example 4, the aluminum alloy powder provided in Comparative Example 4 was stored in a vacuum seal and dried prior to additive manufacturing. The drying process involved maintaining the powder at 120°C for 2 hours, with both the drying process and subsequent cooling performed in an argon atmosphere. It should be noted that after drying and cooling, the aluminum alloy powder was sieved to achieve a particle size of 20 to 180 μm.

[0157] The aluminum alloy powder provided in the above comparative example 4 was additively manufactured using the laser selective melting method to obtain an aluminum alloy part, and the aluminum alloy part was heat treated. The specific heat treatment process was to keep the temperature at 150° C. for 8 hours and cool it in air.

[0158] In some examples, the aluminum alloy powder provided in Comparative Example 4 can be processed through additive manufacturing equipment such as BLT-S310, BLT-S320, BLT-S400, and BLT-S600 to complete the additive manufacturing process.

[0159] Comparative Example 5

[0160] The element Ti and the element Zr in Comparative Example 4 are replaced by the element Zr, and in terms of mass percentage, the Zr is: 3.2%, 3.6% or 4.0%.

[0161] The particle size of the aluminum alloy powder in Comparative Example 4 was adjusted from 20 μm to 180 μm to 20 μm to 63 μm.

[0162] The aluminum alloy powder described in Comparative Example 5 was additively manufactured using the laser selective melting method to obtain an aluminum alloy part, and the aluminum alloy part was heat treated. The specific heat treatment process was to keep the temperature at 180° C. for 12 hours and cool it in air.

[0163] The remaining technical features are the same as those of Comparative Example 4.

[0164] Comparative Example 6

[0165] The element Ti and the element Zr in Comparative Example 4 are replaced by element Ti, and in terms of mass percentage, Ti is: 3.2%, 3.6% or 4.0%.

[0166] The particle size of the aluminum alloy powder in Comparative Example 4 was adjusted from 20 μm to 180 μm to 20 μm to 63 μm.

[0167] The aluminum alloy powder described in Comparative Example 6 was additively manufactured using the laser selective melting method to obtain an aluminum alloy part, and the aluminum alloy part was heat treated. The specific heat treatment process was to keep the temperature at 160° C. for 10 hours and cool it in air.

[0168] The remaining technical features are the same as those of Comparative Example 4.

[0169] Mechanical property testing was performed on transverse specimens corresponding to the heat-treated aluminum alloy parts in Comparative Examples 4 to 6. The mechanical properties of these transverse specimens are used to characterize the mechanical properties of the heat-treated aluminum alloy parts. When the lower limit of the tensile strength of the heat-treated aluminum alloy parts is 375 MPa, the median tensile strength is 382 MPa, and the upper limit of the tensile strength is 388 MPa, the remaining mechanical property parameters of the heat-treated aluminum alloy parts are shown in Table 3.

[0170] Mechanical properties test temperature Tensile strength Rm (MPa) Yield strength Rp0.2 (MPa) Elongation after fracture A (%) Shrinkage after fracture Z (%) Room temperature 37535115.525 Room temperature 3823531535 Room temperature 3883551430

[0171] Table 3

[0172] When the content of element Ti or element Zr added to the existing 6XXX aluminum alloy powder is greater than 3.0%, or the total content of element Ti and element Zr is greater than 3.0%, although the hot cracking phenomenon in the aluminum alloy parts obtained by additive manufacturing can be eliminated, as shown in Table 3, the tensile strength and yield strength of the above-mentioned aluminum alloy parts are not significantly improved, and the elongation after fracture is lower than the elongation after fracture of the aluminum alloy parts in Examples 1 to 6. In addition, excessive content of element Ti or element Zr, or excessive total content of element Ti and element Zr, causes element Ti and / or element Zr to become one of the main components in the aluminum alloy powder, resulting in changes in the properties of the aluminum alloy powder and increased manufacturing costs.

[0173] As can be seen from Examples 1 to 6 and Comparative Examples 1 to 6, adding 0.8% to 3.0% Ti or Zr to existing 6XXX aluminum alloy powders, or a combined Ti and Zr content of 0.8% to 3.0%, improves the tensile strength and yield strength of additively manufactured aluminum alloy parts while also increasing the elongation after fracture. This allows these additively manufactured aluminum alloy parts to be applied in technical fields such as automotive and aerospace. Furthermore, the aluminum alloy powders provided by the disclosed embodiments can eliminate the cracking problem of existing 6XXX aluminum alloy powders during additive manufacturing.

[0174] The exemplary embodiments of the present disclosure described in detail above are merely illustrative and not restrictive. Those skilled in the art will appreciate that various modifications and combinations may be made to these embodiments or their features without departing from the principles and spirit of the present disclosure, and such modifications should fall within the scope of the present disclosure. Industrial Applicability

[0175] The embodiments of the present disclosure provide an aluminum alloy powder for additive manufacturing, a preparation method thereof, and an aluminum alloy part. The aluminum alloy powder is obtained by adding element Ti and / or element Zr to the existing 6XXX series aluminum alloy powder, so that the element Ti and / or element Zr will form Al3Ti phase and / or Al3Zr phase with Al during the additive manufacturing process. During the solidification process, the Al3Ti phase and / or Al3Zr phase can serve as heterogeneous nucleation sites of α-Al to refine the grains, transforming the coarse columnar crystals inside the molten pool into fine equiaxed crystals, thereby eliminating the thermal cracks generated during the solidification process, and solving the problem that the existing 6XXX series aluminum alloy powder is prone to thermal cracks during the additive manufacturing process.

Claims

1. An aluminum alloy powder for additive manufacturing, characterized in that, by mass percentage, the aluminum alloy powder comprises: Si: 0.1% to 2.0%; Fe: 0.1% to 1.0%; Cu: 0.1% to 1.0%; Mn: 0.01% to 1.5%; Mg: 0.1% to 1.5%; Cr: 0.01% to 0.5%; Zn: 0.1% to 0.5%; The first component: 0.8% to 3.0%, and the first component is Ti, Zr, or a combination of Ti and Zr; The second component: less than 0.05%, and the second component is a combination of O and N; The balance is Al and unavoidable impurities.

2. The aluminum alloy powder according to claim 1, characterized in that, the first component: greater than or equal to 0.8% and less than 2.0%.

3. The aluminum alloy powder according to claim 1, characterized in that, the first component: greater than 2.0% and less than or equal to 3.0%.

4. The aluminum alloy powder according to any one of claims 1 to 3, characterized in that, by mass percentage, the aluminum alloy powder comprises at least one of the following: Si: 0.6% to 0.8%; Fe: 0.6% to 0.8%; Cu: 0.2% to 0.4%; Mn: 0.1% to 0.2%; Mg: 0.8% to 1.2%; Cr: 0.2% to 0.3%; Zn: 0.2% to 0.3%.

5. The aluminum alloy powder according to claim 4, characterized in that, the particle size of the aluminum alloy powder is less than 180 μm.

6. The aluminum alloy powder according to claim 5, characterized in that, the particle size of the aluminum alloy powder is 20 μm to 63 μm.

7. A method for preparing an aluminum alloy powder for additive manufacturing, characterized in that, the preparation method comprises: uniformly melting the set ratio of metal raw materials; wherein, by mass percentage, the set ratio of metal raw materials comprises: Si: 0.1% to 2.0%; Fe: 0.1% to 1.0%; Cu: 0.1% to 1.0%; Mn: 0.01% to 1.5%; Mg: 0.1% to 1.5%; Cr: 0.01% to 0.5%; Zn: 0.1% to 0.5%; The first component: 0.8% to 3.0%, and the first component is Ti, Zr, or a combination of Ti and Zr; The second component: less than 0.05%, and the second component is a combination of O and N; The balance is Al and unavoidable impurities; Based on the uniformly melted metal raw materials, an aluminum alloy powder is prepared by gas atomization method; wherein, the sphericity of the aluminum alloy powder is not less than 0.8, and the hollow powder rate of the aluminum alloy powder does not exceed 10%.

8. The preparation method according to claim 6, characterized in that, the first component: greater than or equal to 0.8% and less than 2.0%.

9. The preparation method according to claim 6, characterized in that, the first component: greater than 2.0% and less than or equal to 3.0%.

10. The preparation method according to any one of claims 7 to 9, characterized in that, By mass percentage, the metal raw materials in the set ratio include at least one of the following: Si: 0.6% to 0.8%; Fe: 0.6% to 0.8%; Cu: 0.2% to 0.4%; Mn: 0.1% to 0.2%; Mg: 0.8% to 1.2%; Cr: 0.2% to 0.3%; Zn: 0.2% to 0.3%.

11. An aluminum alloy part, characterized in that the aluminum alloy part is obtained by additive manufacturing from the aluminum alloy powder according to any one of claims 1 to 6.

12. The aluminum alloy part according to claim 11, characterized in that the tensile strength of the aluminum alloy part after heat treatment is not less than 316 MPa, the yield strength is not less than 293 MPa, and the elongation after fracture is not less than 17%; wherein, the heat treatment process of the aluminum alloy part is to keep warm at 150°C to 180°C for 8 hours to 12 hours and perform air cooling treatment.

13. The aluminum alloy part according to claim 12, characterized in that the tensile strength of the aluminum alloy part after heat treatment is 316 MPa to 370 MPa, the yield strength is 293 MPa to 347 MPa, and the elongation after fracture is 17% to 22%.

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