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

Abstract

The embodiment of the invention discloses aluminum alloy powder for additive manufacturing, a preparation method of the aluminum alloy powder and an aluminum alloy part. The aluminum alloy powder comprises the following components in percentage by mass: 0.1%-2.0% of Si; fe: 0.1% to 1.0%; cu: 0.1% to 1.0%; 0.01% to 1.5% of Mn; mg: 0.1% to 1.5%; 0.01% to 0.5% of Cr; zn: 0.1% to 0.5%; 0.8% to 3.0% of a first component, and the first component is Ti, Zr, or a combination of Ti and Zr; less than 0.05% of a second component, wherein the second component is a combination of O and N; and the balance of Al and inevitable impurities.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to the technical field of metal materials, and in particular, to an aluminum alloy powder for additive manufacturing, a preparation method thereof, and an aluminum alloy part. Background Art

[0002] 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 integration of structure and function.

[0003] Currently, the types of existing aluminum alloy powders that can be used for additive manufacturing are few, mostly Al-Si series aluminum alloy powders (such as AlSi10Mg) with near-eutectic composition or Al-Mg-Sc-Zr aluminum alloy powders. However, for 6XXX series aluminum alloys (such as the aluminum alloy of 6061 grade), although this 6XXX series aluminum alloy has high processing performance, excellent welding performance, good corrosion resistance, and is not prone to deformation after processing and is easy to polish and color, etc., due to its high tendency to form hot cracks, it is impossible to manufacture crack-free aluminum alloy parts through additive manufacturing technology, thus restricting the further popularization and application of this 6XXX series aluminum alloy powder. Summary of the Invention

[0004] In view of this, embodiments of the present disclosure are expected to provide an aluminum alloy powder for additive manufacturing, a preparation method thereof, and an aluminum alloy part; which can reduce or eliminate the phenomenon of easy cracking of existing 6XXX series aluminum alloy powders during additive manufacturing, and improve the mechanical properties of aluminum alloy parts obtained by additive manufacturing.

[0005] The technical solution of the embodiments of the present disclosure is implemented as follows:

[0006] In a first aspect, embodiments of the present disclosure provide an aluminum alloy powder for additive manufacturing. By mass percentage, the aluminum alloy powder includes:

[0007] Si: 0.1% to 2.0%;

[0008] Fe: 0.1% to 1.0%;

[0009] Cu: 0.1% to 1.0%;

[0010] Mn: 0.01% to 1.5%;

[0011] Mg: 0.1% to 1.5%;

[0012] Cr: 0.01% to 0.5%;

[0013] Zn: 0.1% to 0.5%;

[0014] The first component: 0.8% to 3.0%, and the first component is Ti, Zr, or a combination of Ti and Zr;

[0015] The second component: less than 0.05%, and the second component is a combination of O and N;

[0016] The balance is Al and unavoidable impurities.

[0017] Optionally, in some examples, the first component: greater than or equal to 0.8% and less than 2.0%.

[0018] Optionally, in some examples, the first component: greater than 2.0% and less than or equal to 3.0%.

[0019] Optionally, in some examples, by mass percentage, the aluminum alloy powder includes at least one of the following:

[0020] Si: 0.6% to 0.8%;

[0021] Fe: 0.6% to 0.8%;

[0022] Cu: 0.2% to 0.4%;

[0023] Mn: 0.1% to 0.2%;

[0024] Mg: 0.8% to 1.2%;

[0025] Cr: 0.2% to 0.3%;

[0026] Zn: 0.2% to 0.3%.

[0027] Optionally, in some examples, the particle size of the aluminum alloy powder is less than 180 μm.

[0028] Optionally, in some examples, the particle size of the aluminum alloy powder is 20 μm to 63 μm.

[0029] In a second aspect, embodiments of the present disclosure provide a method for preparing an aluminum alloy powder for additive manufacturing, the preparation method including:

[0030] Uniformly melting metal raw materials in a set ratio; wherein, by mass percentage, the metal raw materials in the set ratio include:

[0031] Si: 0.1% to 2.0%;

[0032] Fe: 0.1% to 1.0%;

[0033] Cu: 0.1% to 1.0%;

[0034] Mn: 0.01% to 1.5%;

[0035] Mg: 0.1% to 1.5%;

[0036] Cr: 0.01% to 0.5%;

[0037] Zn: 0.1% to 0.5%;

[0038] The first component: 0.8% to 3.0%, and the first component is Ti, Zr, or a combination of Ti and Zr;

[0039] The second component: less than 0.05%, and the second component is a combination of O and N;

[0040] The balance is Al and unavoidable impurities;

[0041] Based on the uniformly melted metal raw materials, aluminum alloy powder is prepared by gas atomization; 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%.

[0042] Optionally, in some examples, the first component: greater than or equal to 0.8% and less than 2.0%.

[0043] Optionally, in some examples, the first component: greater than 2.0% and less than or equal to 3.0%.

[0044] Optionally, in some examples, by mass percentage, the metal raw materials with the set ratio include at least one of the following:

[0045] Si: 0.6% to 0.8%;

[0046] Fe: 0.6% to 0.8%;

[0047] Cu: 0.2% to 0.4%;

[0048] Mn: 0.1% to 0.2%;

[0049] Mg: 0.8% to 1.2%;

[0050] Cr: 0.2% to 0.3%;

[0051] Zn: 0.2% to 0.3%.

[0052] In a third aspect, embodiments of the present disclosure provide an aluminum alloy part, and the aluminum alloy part is obtained by additive manufacturing according to the aluminum alloy powder described in the first aspect.

[0053] Optionally, in some examples, 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 it at 150°C to 180°C for 8 to 12 hours and then cool it in air.

[0054] Optionally, in some examples, 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%.

[0055] The embodiments of the present disclosure provide an aluminum alloy powder for additive manufacturing, its preparation method, and an aluminum alloy part. This aluminum alloy powder is obtained by adding element Ti and / or element Zr to the existing 6XXX series aluminum alloy powder, so that during the additive manufacturing process, element Ti and / or element Zr will form Al 3 Ti phase and / or Al 3 Zr phase. During the solidification process, the Al 3 Ti phase and / or Al 3 Zr phase can act as heterogeneous nucleation sites for α-Al to refine the grains, transforming the coarse columnar grains inside the molten pool into fine equiaxed grains, 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. Description of the Drawings

[0056] Figure 1(a) is a schematic diagram of the metallographic microstructure of an as-deposited aluminum alloy part manufactured from the existing 6XXX series aluminum alloy powder by SLM technology under a 100-fold optical microscope.

[0057] Figure 1(b) is a schematic diagram of the metallographic microstructure of an as-deposited aluminum alloy part manufactured from the existing 6XXX series aluminum alloy powder by SLM technology under a 200-fold optical microscope.

[0058] Figure 2(a) is a schematic diagram of the metallographic microstructure of an as-deposited aluminum alloy part manufactured from the aluminum alloy powder provided in Embodiments 1 to 3 of the present disclosure by SLM technology under a 100-fold optical microscope.

[0059] Figure 2(b) is a schematic diagram of the metallographic microstructure of an as-deposited aluminum alloy part manufactured from the aluminum alloy powder provided in Embodiments 1 to 3 of the present disclosure by SLM technology under a 200-fold optical microscope.

[0060] Figure 3(a) is a schematic diagram of the metallographic microstructure of an as-deposited aluminum alloy part manufactured from the aluminum alloy powder provided in Comparative Examples 1 to 3 of the present disclosure by SLM technology under a 100-fold optical microscope;

[0061] Figure 3(b) is a schematic diagram of the metallographic microstructure of the as-deposited aluminum alloy parts obtained by manufacturing the aluminum alloy powders provided in Comparative Examples 1 to 3 of the present disclosure using the SLM technology under a 200-fold optical microscope. Specific Embodiments

[0062] Next, the technical solutions in the embodiments of the present disclosure will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present disclosure.

[0063] Referring to Figure 1(a), it shows a schematic diagram of the metallographic microstructure of the as-deposited aluminum alloy parts obtained by manufacturing the existing 6XXX series aluminum alloy powders using the SLM technology under a 100-fold optical microscope. Referring to Figure 1(b), it shows a schematic diagram of the metallographic microstructure of the as-deposited aluminum alloy parts obtained by manufacturing the existing 6XXX series aluminum alloy powders using the SLM technology under a 200-fold optical microscope. As shown in Figures 1(a) and 1(b), there are a large number of hot cracks in the metallographic microstructure of the as-deposited aluminum alloy parts obtained by manufacturing the existing 6XXX series aluminum alloy powders using the SLM technology, and some of the hot cracks penetrate multiple melt pools. After measurement, the length of some of the hot cracks is about hundreds of micrometers. The above-mentioned hot cracks seriously affect the mechanical properties of the above-mentioned aluminum alloy parts, and thus limit the application of the above-mentioned aluminum alloy parts in technical fields such as automobiles and aerospace.

[0064] Based on the above description, the embodiments of the present disclosure are expected to provide an aluminum alloy powder for additive manufacturing. This aluminum alloy powder is obtained by adding element Ti and / or element Zr to the existing 6XXX series aluminum alloy powders, so as to eliminate the phenomenon of hot cracks existing in the aluminum alloy parts obtained by additive manufacturing, and thus improve the mechanical properties of the aluminum alloy parts obtained by additive manufacturing. By mass percentage, the components and contents of the aluminum alloy powder provided in the embodiments of the present disclosure are specifically as follows:

[0065] Si: 0.1% to 2.0%;

[0066] Fe: 0.1% to 1.0%;

[0067] Cu: 0.1% to 1.0%;

[0068] Mn: 0.01% to 1.5%;

[0069] Mg: 0.1% to 1.5%;

[0070] Cr: 0.01% to 0.5%;

[0071] Zn: 0.1% to 0.5%;

[0072] The first component: 0.8% to 3.0%, and the first component is Ti, Zr, or a combination of Ti and Zr;

[0073] The second component: less than 0.05%, and the second component is a combination of O and N;

[0074] The balance is Al and unavoidable impurities.

[0075] In some examples, among the above-mentioned unavoidable impurities, the content of each impurity is less than 0.05%.

[0076] In some examples, the first component: greater than or equal to 0.8% and less than 2.0%.

[0077] In some examples, the first component: greater than 2.0% and less than or equal to 3.0%.

[0078] In some examples, by mass percentage, the aluminum alloy powder includes at least one of the following:

[0079] Si: 0.6% to 0.8%;

[0080] Fe: 0.6% to 0.8%;

[0081] Cu: 0.2% to 0.4%;

[0082] Mn: 0.1% to 0.2%;

[0083] Mg: 0.8% to 1.2%;

[0084] Cr: 0.2% to 0.3%;

[0085] Zn: 0.2% to 0.3%.

[0086] In the embodiments of the present disclosure, the elements Ti and Zr can be separately added to the existing 6XXX series aluminum alloy powder. When the element Ti is separately added to the existing 6XXX series aluminum alloy powder, Ti: 0.8% to 3.0% by mass percentage. When the element Zr is separately added to the existing 6XXX series aluminum alloy powder, Zr: 0.8% to 3.0% by mass percentage. Of course, the elements Ti and Zr can also be added to the existing 6XXX series aluminum alloy powder at the same time. When the elements Ti and Zr are added to the existing 6XXX series aluminum alloy powder at the same time, the total content of Ti and Zr is 0.8% to 3.0%.

[0087] In the specific implementation process, after the metal raw materials with set ratios are fully and evenly melted, the aluminum alloy powder for additive manufacturing provided by the embodiments of the present disclosure is prepared by gas atomization or other powder preparation technologies. In some examples, 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%.

[0088] In some examples, the aluminum alloy powder is stored in a vacuum-sealed manner and dried before additive manufacturing. Among them, the process of the above drying treatment is: keeping warm at 100°C to 150°C for 2 hours, and both the drying treatment and the subsequent cooling treatment are carried out in an argon protective atmosphere.

[0089] In some examples, the particle size of the above aluminum alloy powder is less than 180 μm. Optionally, the particle size of the above aluminum alloy powder is 20 μm to 63 μm.

[0090] In other examples, when additive manufacturing is carried out on the above aluminum alloy powder by selective laser melting technology, the aluminum alloy powder is added to the powder feeding bin in the additive manufacturing equipment, and when the oxygen content in the forming chamber of the additive manufacturing equipment drops to less than 0.02%, the laser starts to scan the aluminum alloy powder supplied by the powder feeding bin on the substrate, layer by layer stacking, and finally an aluminum alloy part is formed. Optionally, the process of the laser starting to scan the aluminum alloy powder supplied by the powder feeding bin on the substrate and layer by layer stacking can be implemented by selective laser melting method. Specifically, when the oxygen content in the forming chamber drops to less than 0.02%, a layer of aluminum alloy powder supplied by the powder feeding bin is laid on the surface of the substrate, and the aluminum alloy powder on the surface of the substrate is scanned by the laser to form the first layer of selective laser melting layer. After the first layer of selective laser melting layer solidifies, the substrate is lowered. A layer of aluminum alloy powder supplied by the powder feeding bin is laid on the upper surface of the solidified first layer of selective laser melting layer, and the aluminum alloy powder on the upper surface of the first layer of selective laser melting layer is scanned by the laser to form the second layer of selective laser melting layer. Repeat the stacking layer by layer until an aluminum alloy part is manufactured.

[0091] It can be understood that the embodiments of the present disclosure adjust the components of the existing 6XXX series aluminum alloy powder, specifically by adding element Ti and / or element Zr to the existing 6XXX series aluminum alloy powder, so that during the additive manufacturing process, element Ti and / or element Zr will form Al 3 Ti phase and / or Al 3 Zr phase. During the solidification process, Al 3 Ti phase and / or Al 3The Zr phase can act as a heterogeneous nucleation site for α-Al to refine the grains, transforming the coarse columnar grains inside the molten pool into fine equiaxed grains, thereby eliminating the thermal cracks generated during solidification and solving the problem that the existing 6XXX series aluminum alloy powders are prone to thermal cracks during additive manufacturing.

[0092] Example 1

[0093] An aluminum alloy powder for additive manufacturing provided in this example is obtained by adding element Ti and element Zr to the existing 6XXX series aluminum alloy powder. Specifically, by mass percentage, the components and contents of the aluminum alloy powder provided in 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%, 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.

[0094] In some examples, after the metal raw materials with set ratios are fully and evenly melted, the aluminum alloy powder for additive manufacturing provided in Example 1 above is prepared by the nitrogen atomization method. The sphericity of the aluminum alloy powder provided in Example 1 above is 0.85, and the hollow powder rate of the aluminum alloy powder is 0.4%.

[0095] For the above Example 1, the aluminum alloy powder provided in Example 1 needs to be stored in a vacuum-sealed manner and dried before additive manufacturing. Among them, the process of the above drying treatment is: keep warm at 120°C for 2 hours, and both the drying treatment and the cooling treatment after drying are carried out in an argon protection atmosphere. It should be noted that after the above aluminum alloy powder is dried and cooled, particle size screening needs to be carried out so that the particle size of the above aluminum alloy powder is 20 μm to 180 μm.

[0096] The aluminum alloy powder provided in Example 1 is used for additive manufacturing by selective laser melting to obtain an aluminum alloy part, and the aluminum alloy part is heat-treated. The specific heat treatment process is to keep warm at 150°C for 8 hours and carry out air cooling treatment.

[0097] In some examples, the aluminum alloy powder provided in the above-mentioned Embodiment 1 can complete the additive manufacturing process via additive manufacturing equipment such as models BLT-S310, BLT-S320, BLT-S400, and BLT-S600.

[0098] Embodiment 2

[0099] Replace element Ti and element Zr in Embodiment 1 with element Zr, and by mass percentage, Zr: 0.8%, 1.2%, 1.5%, or 1.9%.

[0100] Adjust the particle size of the aluminum alloy powder in Embodiment 1 from 20 μm to 180 μm to 20 μm to 63 μm.

[0101] Use the selective laser melting method to perform additive manufacturing on the aluminum alloy powder described in Embodiment 2 to obtain an aluminum alloy part, and perform heat treatment on the aluminum alloy part. The specific heat treatment process is to hold at 180°C for 12 hours and perform cooling treatment in air.

[0102] The remaining technical features are the same as those in Embodiment 1.

[0103] Embodiment 3

[0104] Replace element Ti and element Zr in Embodiment 1 with element Ti, and by mass percentage, Ti: 0.8%, 1.2%, 1.5%, or 1.9%.

[0105] Adjust the particle size of the aluminum alloy powder in Embodiment 1 from 20 μm to 180 μm to 20 μm to 63 μm.

[0106] Use the selective laser melting method to perform additive manufacturing on the aluminum alloy powder described in Embodiment 3 to obtain an aluminum alloy part, and perform heat treatment on the aluminum alloy part. The specific heat treatment process is to hold at 160°C for 10 hours and perform cooling treatment in air.

[0107] The remaining technical features are the same as those in Embodiment 1.

[0108] The samples of the above-mentioned aluminum alloy parts in the as-deposited state obtained by additive manufacturing in Examples 1 to 3 were observed using an optical microscope, and the metallographic microstructures are shown in Figures 2(a) and 2(b). Among them, Figure 2(a) is a schematic diagram of the metallographic microstructure of the aluminum alloy parts in the as-deposited state obtained by additive manufacturing in Examples 1 to 3 under an optical microscope at 100 times magnification. Figure 2(b) is a schematic diagram of the metallographic microstructure of the aluminum alloy parts in the as-deposited state obtained by additive manufacturing in Examples 1 to 3 under an optical microscope at 200 times magnification. It can be seen from Figures 2(a) and 2(b) that there are no thermal cracks in the metallographic microstructures of the aluminum alloy parts obtained by additive manufacturing in Examples 1 to 3, and the metallographic microstructures are dense and uniform.

[0109] Mechanical property tests were carried out on the transverse samples corresponding to the heat-treated aluminum alloy parts in Examples 1 to 3. Among them, the mechanical properties of the transverse samples 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 part is 320 MPa, the median value of the tensile strength is 332 MPa, and the upper limit of the tensile strength is 345 MPa, the other mechanical property parameters of the heat-treated aluminum alloy part are shown in Table 1.

[0110]

[0111] Table 1

[0112] In some examples, the above-mentioned transverse sample refers to sampling along the transverse direction of the above-mentioned aluminum alloy part when performing the above-mentioned mechanical property test on the above-mentioned aluminum alloy part. Among them, the transverse direction of the above-mentioned aluminum alloy part is set as the X-Y axis, where the above-mentioned X axis refers to the length direction of the substrate in the forming chamber of the additive manufacturing equipment, and the Y axis refers to the width direction of the above-mentioned substrate.

[0113] Example 4

[0114] An aluminum alloy powder for additive manufacturing provided in this embodiment is obtained by adding element Ti and element Zr to the existing 6XXX series aluminum alloy powder. Specifically, by mass percentage, the components and contents of the aluminum alloy powder provided in this Example 4 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%, 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 inevitable impurities.

[0115] In the specific implementation process, after the metal raw materials with set ratios are fully and evenly melted, the aluminum alloy powder for additive manufacturing provided in the above Example 4 is prepared by the nitrogen atomization method. The sphericity of the aluminum alloy powder provided in the above Example 4 is 0.84, and the hollow powder rate of the aluminum alloy powder is 0.35%.

[0116] For the above Example 4, the aluminum alloy powder provided in the above Example 4 needs to be stored in a vacuum-sealed manner and dried before additive manufacturing. Among them, the process of the above drying treatment is: heat preservation at 120 °C for 2 hours, and both the drying treatment and the cooling treatment after drying are carried out in an argon protection atmosphere. It should be noted that after the above aluminum alloy powder is dried and cooled, particle size screening is required to make the particle size of the above aluminum alloy powder 20 μm to 180 μm.

[0117] The aluminum alloy powder provided in the above Example 4 is used for additive manufacturing by selective laser melting to obtain an aluminum alloy part, and the aluminum alloy part is heat-treated. The specific heat treatment process is heat preservation at 150 °C for 8 hours and air cooling treatment.

[0118] In some examples, the aluminum alloy powder provided in the above Example 4 can complete the additive manufacturing process through additive manufacturing equipment such as models BLT-S310, BLT-S320, BLT-S400, and BLT-S600.

[0119] Example 5

[0120] Replace the elements Ti and Zr in Example 4 with element Zr, and by mass percentage, Zr: 2.2%, 2.5% or 2.8%.

[0121] Adjust the particle size of the aluminum alloy powder in Example 4 from 20 μm to 180 μm to 20 μm to 63 μm.

[0122] Use the selective laser melting method to perform additive manufacturing on the aluminum alloy powder described in Example 5 to obtain an aluminum alloy part, and perform heat treatment on the aluminum alloy part. The specific heat treatment process is to hold at 180 °C for 12 hours and perform air cooling treatment.

[0123] The remaining technical features are the same as those in Example 4.

[0124] Example 6

[0125] Replace the elements Ti and Zr in Example 4 with element Ti, and by mass percentage, Ti: 2.2%, 2.5% or 2.8%.

[0126] Adjust the particle size of the aluminum alloy powder in Example 4 from 20 μm to 180 μm to 20 μm to 63 μm.

[0127] Use the selective laser melting method to perform additive manufacturing on the aluminum alloy powder described in Example 6 to obtain an aluminum alloy part, and perform heat treatment on the aluminum alloy part. The specific heat treatment process is to hold at 160 °C for 10 hours and perform air cooling treatment.

[0128] The remaining technical features are the same as those in Example 4.

[0129] Perform mechanical property tests on the transverse specimens corresponding to the heat-treated aluminum alloy parts in Examples 4 to 6. Among them, 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 part is 350 MPa, the median value of the 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 part are shown in Table 2.

[0130]

[0131] Table 2

[0132] In some examples, the above-mentioned transverse specimen refers to sampling along the transverse direction of the above-mentioned aluminum alloy part when performing the above-mentioned mechanical property test on the above-mentioned aluminum alloy part. Among them, the transverse direction of the above-mentioned aluminum alloy part is set as the X-Y axis, where the above-mentioned X axis refers to the length direction of the substrate in the forming chamber of the additive manufacturing equipment, and the Y axis refers to the width direction of the above-mentioned substrate.

[0133] As can be seen from Table 2, with the increase in the content of element Ti or element Zr, or the increase in the total content of Ti and element Zr, the tensile strength of the aluminum alloy parts obtained by additive manufacturing of the aluminum alloy powders provided in Examples 4 to 6 after heat treatment is not less than 344 MPa, the yield strength is not less than 314 MPa, and the elongation after fracture is not less than 16.5%.

[0134] Comparative Example 1

[0135] An aluminum alloy powder for additive manufacturing provided in this comparative example. This aluminum alloy powder is obtained by adding element Ti and element Zr to the existing 6XXX series aluminum alloy powder. The components and contents of the aluminum alloy powder provided in 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%, 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.

[0136] In some examples, after the metal raw materials with a set ratio are fully and uniformly melted, the aluminum alloy powder for additive manufacturing provided in Comparative Example 1 above is prepared by the nitrogen atomization method. The sphericity of the aluminum alloy powder provided in Comparative Example 1 above is 0.88, and the hollow powder rate of the aluminum alloy powder is 0.5%.

[0137] For the above Comparative Example 1, the aluminum alloy powder provided in Comparative Example 1 needs to be stored in a vacuum-sealed manner and dried before additive manufacturing. Among them, the process of the above drying treatment is: keeping warm at 120°C for 2 hours, and both the drying treatment and the cooling treatment after drying are carried out in an argon protection atmosphere. It should be noted that after the above drying treatment and cooling treatment of the aluminum alloy powder, particle size screening needs to be carried out so that the particle size of the aluminum alloy powder is 20 μm to 180 μm.

[0138] The aluminum alloy powder provided in Comparative Example 1 above is used for additive manufacturing to obtain an aluminum alloy part by selective laser melting method, and the aluminum alloy part is heat-treated. The specific heat treatment process is to keep warm at 150°C for 8 hours and carry out air cooling treatment.

[0139] In some examples, the aluminum alloy powder provided in Comparative Example 1 above can complete the additive manufacturing process via additive manufacturing equipment such as models BLT-S310, BLT-S320, BLT-S400, and BLT-S600.

[0140] Comparative Example 2

[0141] Replace elements Ti and Zr in Comparative Example 1 with element Zr, and by mass percentage, Zr: 0.2%, 0.4%, or 0.6%.

[0142] Adjust the particle size of the aluminum alloy powder in Comparative Example 1 from 20 μm to 180 μm to 20 μm to 63 μm.

[0143] Use the selective laser melting method to perform additive manufacturing on the aluminum alloy powder described in Comparative Example 2 to obtain an aluminum alloy part, and perform heat treatment on the aluminum alloy part. The specific heat treatment process is to hold at 180°C for 12 hours and perform cooling treatment in air.

[0144] The remaining technical features are the same as those in Comparative Example 1.

[0145] Comparative Example 3

[0146] Replace elements Ti and Zr in Comparative Example 1 with element Ti, and by mass percentage, Ti: 0.2%, 0.4%, or 0.6%.

[0147] Adjust the particle size of the aluminum alloy powder in Comparative Example 1 from 20 μm to 180 μm to 20 μm to 63 μm.

[0148] Use the selective laser melting method to perform additive manufacturing on the aluminum alloy powder described in Comparative Example 3 to obtain an aluminum alloy part, and perform heat treatment on the aluminum alloy part. The specific heat treatment process is to hold at 160°C for 10 hours and perform cooling treatment in air.

[0149] The remaining technical features are the same as those in Comparative Example 1.

[0150] The tests of the as-deposited above-mentioned aluminum alloy parts obtained by additive manufacturing in Comparative Examples 1 to 3 were observed by optical microscopy, and the metallographic microstructures are shown in Figures 3(a) and 3(b). Among them, Figure 3(a) is a schematic diagram of the metallographic microstructure of the as-deposited aluminum alloy parts obtained by additive manufacturing in Comparative Examples 1 to 3 under an optical microscope at 100 times magnification. Figure 3(b) is a schematic diagram of the metallographic microstructure of the as-deposited aluminum alloy parts obtained by additive manufacturing in Comparative Examples 1 to 3 under an optical microscope at 200 times magnification. It can be seen from Figures 3(a) and 3(b) that there are still thermal cracks 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 thermal cracks have decreased to varying degrees. This shows that when the content of element Ti or element Zr added to the existing 6XXX series aluminum alloy powder is low, or the total content of element Ti and element Zr is low, it can play an improvement role in the thermal cracks in the aluminum alloy parts obtained by additive manufacturing, but it is difficult to completely eliminate the thermal cracks in the aluminum alloy parts.

[0151] Comparative Example 4

[0152] An aluminum alloy powder for additive manufacturing provided in this comparative example, which is obtained by adding element Ti and element Zr to the existing 6XXX series aluminum alloy powder. Specifically, by mass percentage, the components and contents of the aluminum alloy powder provided in Comparative Example 4 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%, 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.

[0153] In the specific implementation process, after the metal raw materials with set ratios are fully and evenly melted, the aluminum alloy powder for additive manufacturing provided in Comparative Example 4 is prepared by nitrogen atomization method. The sphericity of the aluminum alloy powder provided in Comparative Example 4 is 0.87, and the hollow powder rate of the aluminum alloy powder is 0.45%.

[0154] For Comparative Example 4 described above, the aluminum alloy powder provided by the above Comparative Example 4 needs to be stored in a vacuum-sealed manner and dried before additive manufacturing. Among them, the process of the above drying treatment is: heat preservation at 120°C for 2 hours, and both the drying treatment and the subsequent cooling treatment are carried out in an argon protective atmosphere. It should be noted that after the above drying treatment and cooling treatment of the aluminum alloy powder, particle size screening needs to be carried out so that the particle size of the above aluminum alloy powder is 20 μm to 180 μm.

[0155] The aluminum alloy powder provided by the above Comparative Example 4 is used for additive manufacturing by selective laser melting to obtain an aluminum alloy part, and the aluminum alloy part is heat-treated. The specific heat treatment process is heat preservation at 150°C for 8 hours and air cooling treatment.

[0156] In some examples, the aluminum alloy powder provided by the above Comparative Example 4 can complete the additive manufacturing process through additive manufacturing equipment such as models BLT-S310, BLT-S320, BLT-S400, and BLT-S600.

[0157] Comparative Example 5

[0158] Element Ti and element Zr in Comparative Example 4 are replaced with element Zr, and by mass percentage, Zr: 3.2%, 3.6%, or 4.0%.

[0159] The particle size of the aluminum alloy powder in Comparative Example 4, which is 20 μm to 180 μm, is adjusted to 20 μm to 63 μm.

[0160] The aluminum alloy powder described in Comparative Example 5 is used for additive manufacturing by selective laser melting to obtain an aluminum alloy part, and the aluminum alloy part is heat-treated. The specific heat treatment process is heat preservation at 180°C for 12 hours and air cooling treatment.

[0161] The remaining technical features are the same as those of Comparative Example 4.

[0162] Comparative Example 6

[0163] Element Ti and element Zr in Comparative Example 4 are replaced with element Ti, and by mass percentage, Ti: 3.2%, 3.6%, or 4.0%.

[0164] The particle size of the aluminum alloy powder in Comparative Example 4, which is 20 μm to 180 μm, is adjusted to 20 μm to 63 μm.

[0165] The aluminum alloy powder described in Comparative Example 6 is used for additive manufacturing by selective laser melting to obtain an aluminum alloy part, and the aluminum alloy part is heat-treated. The specific heat treatment process is heat preservation at 160°C for 10 hours and air cooling treatment.

[0166] The remaining technical features are the same as those of Comparative Example 4.

[0167] Mechanical property tests were carried out on the transverse specimens corresponding to the heat-treated aluminum alloy parts in Comparative Examples 4 to 6. Among them, 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 part is 375 MPa, the median value of the tensile strength is 382 MPa, and the upper limit of the tensile strength is 388 MPa, the other mechanical property parameters of the heat-treated aluminum alloy part are shown in Table 3.

[0168]

[0169] Table 3

[0170] 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 phenomenon of hot cracks existing in the aluminum alloy parts obtained by additive manufacturing can be eliminated, as shown in Table 3, the improvement degrees of the tensile strength and yield strength of the above aluminum alloy parts are not obvious, and the elongation after fracture is lower than that of the aluminum alloy parts in Examples 1 to 6. In addition, when the content of element Ti or element Zr is too high, or the total content of element Ti and element Zr is too high, element Ti and / or element Zr becomes one of the main components in the aluminum alloy powder, resulting in a change in the properties of the aluminum alloy powder and an increase in the manufacturing cost.

[0171] It can be seen from the above Examples 1 to 6 and Comparative Examples 1 to 6 that when the content of element Ti or element Zr added to the existing 6XXX series aluminum alloy powder is 0.8% to 3.0%, or the total content of element Ti and element Zr is 0.8% to 3.0%, while improving the tensile strength and yield strength of the aluminum alloy parts obtained by additive manufacturing, the elongation after fracture of the aluminum alloy parts obtained by additive manufacturing is also improved, so that the above aluminum alloy parts obtained by additive manufacturing can be applied to technical fields such as automobiles and aerospace. In addition, the aluminum alloy powder provided by the embodiments of the present disclosure can also eliminate the phenomenon of easy cracking of the existing 6XXX series aluminum alloy powder during the additive manufacturing process.

[0172] It should be noted that: among the technical solutions recorded in the embodiments of the present disclosure, they can be combined arbitrarily without conflict.

[0173] As described above, it is only the specific implementation manner of the present disclosure. However, the protection scope of the present disclosure is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present disclosure can easily think of changes or substitutions, which should all be covered within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claimed rights.

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 preparation method of an aluminum alloy powder for additive manufacturing, characterized in that, the preparation method comprises: uniformly melting the metal raw materials with a set ratio; wherein, by mass percentage, the metal raw materials with the set ratio comprise: 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; 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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