Laser additive manufacturing aluminum alloy and preparation method and application thereof

Abstract

The invention belongs to the technical field of additive manufacturing, and particularly relates to a laser additive manufacturing aluminum alloy and a preparation method and application thereof. The laser additive manufacturing aluminum alloy provided by the invention contains a magnesium element, a boron element and an aluminum element, and the molar ratio of the magnesium element to the boron element to the aluminum element is 1: (0.1-10): X, and Xgt; 10; the high-temperature-resistant metal element comprises at least one of a vanadium element, a niobium element, a nickel element, an iron element, a manganese element and a copper element; the laser additive manufacturing aluminum alloy comprises a MgAlBx crystal whisker and a two-dimensional nanosheet, namely a Mg-Al-B phase MgAlBx two-dimensional nanosheet; when the high-temperature-resistant metal element comprises at least one of a vanadium element, a niobium element and a nickel element, the mass content of the high-temperature-resistant metal element is 0.1-22wt%; when the high-temperature-resistant metal element does not comprise at least one of the vanadium element, the niobium element and the nickel element, the mass content of the high-temperature-resistant metal element is 6-22 wt%. The alloy material obtained by the invention has excellent comprehensive mechanical properties of high tensile strength and high yield strength at room temperature and high temperature.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of additive manufacturing, and particularly relates to a laser additive manufacturing aluminum alloy and a preparation method and application thereof. BACKGROUND

[0002] The demand for lightweight materials in the fields of aerospace and transportation is increasingly urgent, and the service temperature of many components / structures gradually exceeds 150 DEG C. New lightweight, high-strength and heat-resistant metal materials have great application potential. Compared with other metal materials, aluminum alloy is the most competitive high-strength lightweight alloy material in this temperature range. However, the nano-particle precipitates in the traditional aluminum alloy will be severely coarsened at a temperature above 200 DEG C, which will seriously damage the strengthening effect of the matrix. In particular, under the high-temperature creep condition of external force, the traditional aluminum alloy material will rapidly soften and cause the final structure to be unstable. At present, additive manufacturing technology has been widely used in the development of a large number of special-shaped parts in the field of aerospace. In the field of additive manufacturing, many aluminum alloy systems with excellent high-temperature performance in casting process are difficult to be additive manufactured and are no longer applicable, and the aluminum alloy prepared by the existing additive manufacturing technology has poor thermal stability and low mechanical properties at high temperatures. SUMMARY

[0003] Therefore, the technical problem to be solved by the present application is to overcome the defects of the aluminum alloy prepared by the existing additive manufacturing technology, such as poor thermal stability and low mechanical properties at high temperatures, so as to provide a laser additive manufacturing aluminum alloy and a preparation method and application thereof.

[0004] The present application provides a laser additive manufacturing aluminum alloy, which contains magnesium element, boron element and aluminum element, and the molar ratio of magnesium element, boron element and aluminum element is 1:(0.1-10):X, and X>10.

[0005] The laser additive manufacturing aluminum alloy further comprises a high-temperature-resistant metal element, and the high-temperature-resistant metal element comprises at least one of vanadium element, niobium element, nickel element, iron element, manganese element and copper element.

[0006] The laser additive manufacturing aluminum alloy comprises MgAlB x whiskers and MgAlB x two-dimensional nanosheets.

[0007] The mass content of the high-temperature-resistant metal element in the laser additive manufacturing aluminum alloy is 6-22 wt%.

[0008] Preferably, the raw material of the laser additive manufacturing aluminum alloy comprises aluminum alloy powder; after the aluminum alloy powder is melted in the preparation process, the components of the aluminum alloy powder are uniformly dispersed, so that the use of the aluminum alloy powder can more effectively realize the uniform dispersion effect of various elements in the raw material of the laser additive manufacturing aluminum alloy, facilitate the same in-situ reaction at various positions in the subsequent 3D printing process, and avoid the inconsistent reaction at different positions due to uneven powder dispersion.

[0009] Preferably, the raw material of the laser additive manufacturing aluminum alloy comprises boron powder, aluminum-magnesium alloy powder and high-temperature-resistant metal powder.

[0010] Preferably, the high-temperature-resistant metal powder comprises at least one of vanadium powder, niobium powder, nickel powder, iron powder, manganese powder and copper powder.

[0011] And / or, the aluminum-magnesium alloy powder comprises at least one of pure aluminum-magnesium alloy powder, 2024 aluminum alloy powder, 7075 aluminum alloy powder and aluminum-copper-magnesium alloy powder.

[0012] The pure aluminum-magnesium alloy powder of the application is an alloy powder containing only magnesium and aluminum elements, and no other elements.

[0013] Preferably, the high-temperature-resistant metal elements in the laser additive manufacturing aluminum alloy include vanadium element 0-5wt%, niobium element 0-4wt%, nickel element 0-3wt%, iron element 0-4wt%, manganese element 0-3wt% and copper element 0-6wt%, and the mass percentages of vanadium element, niobium element, nickel element, iron element, manganese element and copper element are not zero at the same time.

[0014] And / or, the mass content of magnesium element in the laser additive manufacturing aluminum alloy is 1-5wt%.

[0015] And / or, the mass content of boron element in the laser additive manufacturing aluminum alloy is 0.5-4wt%.

[0016] Optionally, the laser additive manufacturing aluminum alloy further comprises zinc element 0-6wt%.

[0017] Preferably, the raw material of the laser additive manufacturing aluminum alloy comprises, by mass percentage: boron 0.5-4wt%, vanadium 0.2-5wt%, and the balance being 2024 aluminum alloy.

[0018] Alternatively, the raw material of the laser additive manufacturing aluminum alloy comprises, by mass percentage: boron 0.5-4wt%, niobium 0.3-5wt%, and the balance being 2024 aluminum alloy.

[0019] Alternatively, the raw material of the laser additive manufacturing aluminum alloy comprises, by mass percentage: boron 0.5-4wt%, nickel 0.5-5wt%, and the balance being 2024 aluminum alloy.

[0020] Alternatively, the raw material for the laser additive manufacturing aluminum alloy comprises, by mass percent: boron 0.5-4wt%, vanadium 0.2-5wt%, niobium 0.3-5wt%, nickel 0.5-5wt%, iron 0.5-5wt%, and the balance of 2024 aluminum alloy.

[0021] Alternatively, the raw material for the laser additive manufacturing aluminum alloy comprises, by mass percent: magnesium 1-5wt%, boron 0.5-4wt%, vanadium 0.2-5wt%, niobium 0.3-5wt%, nickel 0.5-5wt%, copper 2-5wt%, manganese 0.1-1.53wt%, iron 0.1-1.5wt%, and the balance of aluminum.

[0022] Preferably, the raw material for the laser additive manufacturing aluminum alloy comprises, by mass percent: boron 0.5-4wt%, vanadium 0.2-3wt%, and the balance of 2024 aluminum alloy.

[0023] Alternatively, the raw material for the laser additive manufacturing aluminum alloy comprises, by mass percent: boron 0.5-4wt%, niobium 0.3-3.5wt%, and the balance of 2024 aluminum alloy.

[0024] Alternatively, the raw material for the laser additive manufacturing aluminum alloy comprises, by mass percent: boron 0.5-4wt%, nickel 0.5-2wt%, and the balance of 2024 aluminum alloy.

[0025] Alternatively, the raw material for the laser additive manufacturing aluminum alloy comprises, by mass percent: boron 0.5-4wt%, vanadium 0.2-3wt%, niobium 0.3-3.5wt%, nickel 0.5-2wt%, iron 0.5-1.5wt%, and the balance of 2024 aluminum alloy.

[0026] Alternatively, the raw material for the laser additive manufacturing aluminum alloy comprises, by mass percent: magnesium 1-5wt%, boron 0.5-4wt%, vanadium 0.2-3wt%, niobium 0.3-3.5wt%, nickel 0.5-2wt%, copper 2-5wt%, manganese 0.1-1.53wt%, iron 0.1-1.5wt%, and the balance of aluminum.

[0027] Optionally, the components of the 2024 aluminum alloy powder comprise, by mass percent: copper 3.8-4.9wt%, magnesium 1.2-1.8wt%, manganese 0.3-1.0wt%, and the balance of aluminum and unavoidable impurities.

[0028] Optionally, the components of the aluminum-copper-magnesium alloy powder comprise, by mass percent: copper 3-5wt%, magnesium 1-2wt%, and the balance of aluminum.

[0029] The application provides a preparation method of the laser additive manufacturing aluminum alloy, comprising the following steps:

[0030] 1) The raw materials are mixed in a certain amount to obtain a composite powder for laser additive manufacturing;

[0031] 2) The composite powder for laser additive manufacturing obtained in step 1) is formed by laser additive manufacturing, and then is subjected to solid solution and water quenching to obtain the laser additive manufacturing aluminum alloy.

[0032] In-situ generation of MgAlB x whiskers and MgAlB x two-dimensional nanosheets. The effect of rapid cooling by means of 3D printing enables a large number of nano Mg-Al-B phase (MgAlB x whiskers and MgAlB x two-dimensional nanosheets) reinforcing phases to be generated in-situ during the forming process.

[0033] Preferably, the rotation speed of the raw material mixing in step 1) is 10-80 rpm, and the raw material mixing time is 1-20 h;

[0034] In step 2), the aluminum alloy composite powder obtained in step 1) is placed into a laser powder bed fusion printer to perform 3D printing forming, and then is subjected to solid solution and water quenching to obtain the laser additive manufacturing aluminum alloy.

[0035] Preferably, the 3D printing forming parameters specifically include that the laser power is 200-500 W, the laser scanning speed is 500-2000 mm / s, the scanning line spacing is 80-180 μm, the powder layer thickness is 30-120 μm, and the laser layer rotation angle is 0°-90°.

[0036] Preferably, the 3D printing forming parameters specifically include that the laser power is 220-320 W, the laser scanning speed is 850-1250 mm / s, the scanning line spacing is 90-150 μm, the powder layer thickness is 30-60 μm, and the laser layer rotation angle is 15°-70°.

[0037] Optionally, the laser additive manufacturing forming step in step 2) further comprises a drying treatment of the aluminum alloy composite powder before the laser additive manufacturing forming step.

[0038] Optionally, the drying temperature is 90-100 ℃, and the drying time is 3-6 h.

[0039] Optionally, the drying is vacuum drying.

[0040] Preferably, the solid solution temperature in step 2) is 450-530 ℃, and the solid solution time is 0.5-2 h.

[0041] The temperature of the quenching agent used in the quenching in step 2) is 15-50℃, and the quenching time is 1-10 min.

[0042] The quenching agent used in the quenching comprises water.

[0043] Preferably, the solid solution step in step 2) further comprises an annealing step before the solid solution step.

[0044] And / or, the quenching step in step 2) further comprises an artificial aging treatment step after the quenching step.

[0045] Optionally, the annealing temperature is 200-380℃, and the annealing time is 0.5-3h.

[0046] And / or, the artificial aging treatment temperature is 100-200℃, and the artificial aging treatment time is 30s-20h.

[0047] Optionally, the artificial aging treatment temperature is 100-200℃, and the artificial aging treatment time is 9-20h.

[0048] The application provides an application of the laser additive manufacturing aluminum alloy or the laser additive manufacturing aluminum alloy prepared by the preparation method in heat-resistant metal parts.

[0049] The technical scheme of the application has the following advantages:

[0050] 1. The laser additive manufacturing aluminum alloy provided by the application contains magnesium elements, boron elements and aluminum elements, and the molar ratio of the magnesium elements, the boron elements and the aluminum elements is 1:(0.1-10):X, and X>10; the laser additive manufacturing aluminum alloy further contains high-temperature-resistant metal elements, the high-temperature-resistant metal elements include at least one of vanadium elements, niobium elements, nickel elements, iron elements, manganese elements and copper elements; the laser additive manufacturing aluminum alloy contains MgAlB x whiskers and MgAlB x two-dimensional nanosheets; when the high-temperature-resistant metal elements include at least one of vanadium elements, niobium elements and nickel elements, the mass content of the high-temperature-resistant metal elements in the laser additive manufacturing aluminum alloy is 0.1-22wt%; when the high-temperature-resistant metal elements do not include at least one of vanadium elements, niobium elements and nickel elements, the mass content of the high-temperature-resistant metal elements in the laser additive manufacturing aluminum alloy is 6-22wt%. The B element is added in the composite powder to ensure that the material has sufficient laser absorption capacity, so that the material can be successfully formed by basic laser additive manufacturing (3D printing). The laser additive manufacturing aluminum alloy provided by the application utilizes the characteristics of laser additive manufacturing to form nanoscale MgAlB x whiskers and MgAlB xComposite reinforcing phase of two-dimensional nanosheet. The composite nanostructure realizes high number density nucleation during solidification and achieves uniform dispersion distribution in three-dimensional space in the matrix. The core of the strengthening mechanism lies in the complementarity of the two nano-morphology structures and the functional synergy. The sheet-like structure of the two-dimensional nanosheet provides wide-area interface pinning: at high temperatures, these large-area nanosheet / matrix interfaces can strongly drag and split the grain boundaries, greatly reducing the driving force and rate of grain boundary migration, which is the dominant factor limiting grain coarsening. At the same time, the fibrous structure of the nanowhisker plays a role of high-density point pinning: these small whiskers, like "rivets", are pinned to the grain boundaries or the intersection of grain boundaries, directly hindering the local movement of the grain boundaries from their equilibrium position. The synergistic strengthening effect of the two lies in the fact that the "macroscopic" obstacles constructed by the two-dimensional nanosheet limit the large-scale movement path of the grain boundaries, while the densely distributed nanowhiskers provide additional "microscopic" fixed points in between. This point-plane combined, multi-level spatial pinning network produces a pinning efficiency far beyond that of a single morphology nano-phase. As a result, the grain boundary migration is strongly inhibited at high temperatures, and the grain size stability is significantly improved. At the same time, these in-situ nano-phases themselves act as reinforcing particles, and their hindering effect on dislocation movement, together with the above-mentioned grain boundary pinning effect, greatly improve the high-temperature mechanical properties of the material. At the same time, specific elements with good high-temperature stability, in a specific content, can form nanoscale precipitates with good high-temperature stability with aluminum elements after laser additive manufacturing, thereby inhibiting the coarsening behavior of the matrix structure and synergistically improving the high-temperature mechanical properties of the material with the in-situ nanowhiskers. The laser additive manufacturing aluminum alloy provided by the present application has excellent comprehensive mechanical properties of high tensile strength and high yield strength at room temperature (25℃) and high temperature (200-300℃).

[0051] 2. The preparation method of the laser additive manufacturing aluminum alloy provided by the present application comprises the following steps: 1) weighing and mixing raw materials to obtain the composite powder for laser additive manufacturing; 2) forming the composite powder for laser additive manufacturing obtained in step 1) through laser additive manufacturing, and then performing solid solution and water quenching to obtain the laser additive manufacturing aluminum alloy. The specific preparation method of the present application can realize the re-solid solution of the precipitates of the aluminum alloy matrix composite material at high temperature in the additive manufacturing process through the solid solution and water quenching process, achieve the effect of solid solution strengthening, and further improve the strength of the material.

[0052] 3. The preparation method of the laser additive manufacturing aluminum alloy provided by the present application, wherein the solid solution step in step 2) further comprises an annealing step before the solid solution step; and / or, the quenching step in step 2) further comprises an artificial aging treatment step after the quenching step. The annealing process can eliminate the internal stress of the aluminum alloy, coarsen the grains to a certain extent, thereby improving the elongation at room temperature (about 25℃) and achieving good strength and plasticity matching. BRIEF DESCRIPTION OF DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the specific embodiments of the present application or the prior art, the drawings required to be used in the description of the specific embodiments or the prior art will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative effort.

[0054] Figure 1 Stress-strain curve of laser additive manufacturing aluminum alloy prepared for example 1 of the present application;

[0055] Figure 2 Stress-strain curve of laser additive manufacturing aluminum alloy prepared for example 2 of the present application;

[0056] Figure 3 Stress-strain curve of laser additive manufacturing aluminum alloy prepared for example 3 of the present application;

[0057] Figure 4 Stress-strain curve of laser additive manufacturing aluminum alloy prepared for example 4 of the present application;

[0058] Figure 5 Stress-strain curve of laser additive manufacturing aluminum alloy prepared for example 5 of the present application;

[0059] Figure 6 Stress-strain curve of laser additive manufacturing aluminum alloy prepared for example 6 of the present application;

[0060] Figure 7 Stress-strain curve of laser additive manufacturing aluminum alloy prepared for example 7 of the present application;

[0061] Figure 8 Stress-strain curve of laser additive manufacturing aluminum alloy prepared for example 8 of the present application;

[0062] Figure 9 Stress-strain curve of laser additive manufacturing aluminum alloy prepared for example 9 of the present application;

[0063] Figure 10 Stress-strain curve of laser additive manufacturing aluminum alloy prepared for example 10 of the present application;

[0064] Figure 11 Stress-strain curve of laser additive manufacturing aluminum alloy prepared for comparative example 1 of the present application;

[0065] Figure 12 TEM morphology of laser additive manufacturing aluminum alloy prepared for example 1 of the present application under different magnifications, wherein figure a is MgAlBx TEM morphology of whiskers, Figure b is a TEM morphology of laser additive manufacturing aluminum alloy at a lower magnification;

[0066] Figure 13 EBSD comparison chart of cross section of laser additive manufacturing aluminum alloy prepared in Example 1 before and after heat exposure at 300℃ for 100 hours. DETAILED DESCRIPTION

[0067] The following examples are provided to better further understand the present application, and are not limited to the best mode, and do not constitute limitations on the content and scope of protection of the present application, and any person under the inspiration of the present application or the combination of the present application with other prior art features, any product identical or similar to the present application falls within the scope of protection of the present application.

[0068] The specific experimental steps or conditions are not indicated in the examples, and can be operated according to the conventional experimental steps described in the literature in the art or the conditions. The reagents or instruments used are not indicated by the manufacturer, and are conventional reagent products that can be obtained by purchase.

[0069] The components of the 2024 aluminum alloy powder used in the examples and comparative examples of the present application include, in terms of mass percentage: copper (Cu) 4.69wt%, magnesium (Mg) 1.66wt%, manganese (Mn) 0.6wt%, silicon (Si) 0.04wt%, iron (Fe) 0.08wt%, and the balance of aluminum (Al).

[0070] The amorphous boron powder, vanadium powder, niobium powder, nickel powder, iron powder, manganese powder, and copper powder used in the examples and comparative examples of the present application are pure substances.

[0071] The components of the aluminum-copper-magnesium alloy powder used in the examples and comparative examples of the present application include, in terms of mass percentage: copper 4.6wt%, magnesium 1.6wt%, and the balance of aluminum.

[0072] Example 1

[0073] The present embodiment provides a preparation method of a laser additive manufacturing aluminum alloy, comprising the following steps:

[0074] 1) 15g of amorphous boron powder, 5g of vanadium powder, and 980g of 2024 aluminum alloy powder were weighed and placed in a 5L stainless steel tank, and a mixer was used to disperse for 16 hours at 80rpm to obtain a composite powder for laser additive manufacturing;

[0075] 2) drying treatment of the composite powder for laser additive manufacturing obtained in step 1) in a vacuum drying oven at 100℃ for 5 hours, laser additive manufacturing forming by a laser powder bed fusion 3D printer, using a laser power of 300W, a laser scanning speed of 1000mm / s, a scanning line spacing of 100μm, a powder layer thickness of 40μm, and a laser layer rotation angle of 17°, then solid solution at 505℃ for 30min, water quenching in water at 25℃ for 2min, to obtain the laser additive manufacturing aluminum alloy.

[0076] The mass content of boron element in the laser additive manufacturing aluminum alloy prepared in this example is about 1.5wt%, the mass content of vanadium element is about 0.5wt%, the mass content of magnesium element is about 1.6268wt%, the mass content of copper element is about 4.5962wt%, the mass content of manganese element is about 0.588wt%, the mass content of silicon element is about 0.0392wt%, the mass content of iron element is about 0.0784wt%, and the balance is aluminum element. The molar ratio of magnesium element, boron element and aluminum element is about 1:2.07:50.43; the laser additive manufacturing aluminum alloy includes in-situ formed MgAlB x whiskers and MgAlB x two-dimensional nanosheets; using a transmission electron microscope to observe the laser additive manufacturing aluminum alloy of this example, the transmission electron microscope images of different magnifications are as shown in Figure 12 , Figure 12 Fig. a in the figure is a transmission electron microscope image of MgAlB x whiskers in the laser additive manufacturing aluminum alloy at high magnification, Fig. b is a TEM morphology image of the laser additive manufacturing aluminum alloy at lower magnification, and the MgAlB x whiskers and MgAlB x two-dimensional nanosheets in the laser additive manufacturing aluminum alloy observed in Fig. b, the MgAlB x whiskers under the yellow arrow, and the MgAlB x two-dimensional nanosheets under the red arrow.

[0077] Example 2

[0078] This example provides a preparation method of a laser additive manufacturing aluminum alloy, comprising the following steps:

[0079] 1) weighing 15g of amorphous boron powder, 5g of vanadium powder, and 980g of 2024 aluminum alloy powder, placing them in a 5L stainless steel tank, and dispersing them by a mixer at 80rpm for 16 hours to obtain a composite powder for laser additive manufacturing;

[0080] 2) The laser additive manufacturing composite powder obtained in step 1) is dried in a vacuum drying oven at 100°C for 5 hours, and then laser additive manufacturing is performed by a laser powder bed fusion 3D printer, using a laser power of 300W, a laser scanning speed of 1000mm / s, a scanning line spacing of 100pm, a powder layer thickness of 40pm, and a laser interlayer rotation angle of 17°, and then annealed at 300°C for 1h, solution treated at 505°C for 30min, and water quenched in water at 25°C for 2min to obtain the laser additive manufacturing aluminum alloy.

[0081] The laser additive manufacturing aluminum alloy prepared in this example has a mass content of boron of about 1.5wt%, a mass content of vanadium of about 0.5wt%, a mass content of magnesium of about 1.6268wt%, a mass content of copper of about 4.5962wt%, a mass content of manganese of about 0.588wt%, a mass content of silicon of about 0.0392wt%, a mass content of iron of about 0.0784wt%, and the balance being aluminum. The molar ratio of magnesium, boron and aluminum is about 1:2.07:50.43; the laser additive manufacturing aluminum alloy includes in-situ formed MgAlB x whiskers and MgAlB x two-dimensional nanosheets.

[0082] Example 3

[0083] This example provides a preparation method of a laser additive manufacturing aluminum alloy, comprising the following steps:

[0084] 1) 15g of amorphous boron powder, 5g of niobium powder, and 980g of 2024 aluminum alloy powder are weighed and placed in a 5L stainless steel tank, and a mixer is used to disperse at 80rpm for 16 hours to obtain a laser additive manufacturing composite powder;

[0085] 2) The laser additive manufacturing composite powder obtained in step 1) is dried in a vacuum drying oven at 100°C for 5 hours, and then laser additive manufacturing is performed by a laser powder bed fusion 3D printer, using a laser power of 300W, a laser scanning speed of 1000mm / s, a scanning line spacing of 100pm, a powder layer thickness of 40pm, and a laser interlayer rotation angle of 17°, and then annealed at 300°C for 1h, solution treated at 505°C for 30min, and water quenched in water at 25°C for 2min to obtain the laser additive manufacturing aluminum alloy.

[0086] The mass content of boron element in the laser additive manufacturing aluminum alloy prepared in this embodiment is about 1.5 wt%, the mass content of niobium element is about 0.5 wt%, the mass content of magnesium element is about 1.6268 wt%, the mass content of copper element is about 4.5962 wt%, the mass content of manganese element is about 0.588 wt%, the mass content of silicon element is about 0.0392 wt%, the mass content of iron element is about 0.0784 wt%, and the balance is aluminum element. The molar ratio of magnesium element, boron element and aluminum element is about 1:2.07:50.43; the laser additive manufacturing aluminum alloy includes in-situ formed MgAlB x whiskers and MgAlB x two-dimensional nanosheets.

[0087] Example 4

[0088] The embodiment provides a preparation method of a laser additive manufacturing aluminum alloy, comprising the following steps:

[0089] 1) 15 g of amorphous boron powder, 5 g of niobium powder and 980 g of 2024 aluminum alloy powder are weighed and placed in a 5L stainless steel tank, and a mixer is used to disperse for 16 hours at 80 rpm to obtain a composite powder for laser additive manufacturing;

[0090] 2) The composite powder for laser additive manufacturing obtained in step 1) is dried in a vacuum drying box at 100°C for 5 hours, and laser additive manufacturing is performed by a laser powder bed fusion 3D printer, using a laser power of 300W, a laser scanning speed of 1000mm / s, a scanning line spacing of 100μm, a powder layer thickness of 40μm, and a laser layer rotation angle of 17°, and then annealed at 300°C for 1h, solid-solution treated at 505°C for 30min, and water quenched in water at 25°C for 2min to obtain the laser additive manufacturing aluminum alloy.

[0091] The mass content of boron element in the laser additive manufacturing aluminum alloy prepared in this embodiment is about 1.5 wt%, the mass content of niobium element is about 0.5 wt%, the mass content of magnesium element is about 1.6268 wt%, the mass content of copper element is about 4.5962 wt%, the mass content of manganese element is about 0.588 wt%, the mass content of silicon element is about 0.0392 wt%, the mass content of iron element is about 0.0784 wt%, and the balance is aluminum element. The molar ratio of magnesium element, boron element and aluminum element is about 1:2.07:50.43; the laser additive manufacturing aluminum alloy includes in-situ formed MgAlB x whiskers and MgAlB x two-dimensional nanosheets.

[0092] Example 5

[0093] The embodiment provides a preparation method of a laser additive manufacturing aluminum alloy, and comprises the following steps:

[0094] 1) 15 g of amorphous boron powder, 10 g of nickel powder and 975 g of 2024 aluminum alloy powder are weighed and placed in a 5L stainless steel tank, and a mixer is used to disperse under the condition of 80 rpm for 16 hours to obtain a composite powder for laser additive manufacturing;

[0095] 2) the composite powder for laser additive manufacturing obtained in step 1) is dried in a vacuum drying box at 100 DEG C for 5 hours, laser additive manufacturing is performed by using a laser powder bed fusion 3D printer, laser power is 300 W, laser scanning speed is 1000 mm / s, scanning line spacing is 100 mu m, powder layer thickness is 40 mu m, laser layer rotation angle is 17 DEG, then solid solution is performed at 505 DEG C for 30 min, water quenching is performed in water at 25 DEG C for 2 min, and the laser additive manufacturing aluminum alloy is obtained.

[0096] The laser additive manufacturing aluminum alloy prepared in the embodiment has the following mass content: the mass content of boron element is about 1.5 wt%, the mass content of nickel element is about 1 wt%, the mass content of magnesium element is about 1.6185 wt%, the mass content of copper element is about 4.57275 wt%, the mass content of manganese element is about 0.585 wt%, the mass content of silicon element is about 0.039 wt%, the mass content of iron element is about 0.078 wt%, and the balance is aluminum element. The molar ratio of magnesium element, boron element and aluminum element is about 1:2.08:50.43; the laser additive manufacturing aluminum alloy comprises in-situ formed MgAlB x whiskers and MgAlB x two-dimensional nanosheets.

[0097] Embodiment 6

[0098] The embodiment provides a preparation method of a laser additive manufacturing aluminum alloy, and comprises the following steps:

[0099] 1) 15 g of amorphous boron powder, 10 g of nickel powder and 975 g of 2024 aluminum alloy powder are weighed and placed in a 5L stainless steel tank, and a mixer is used to disperse under the condition of 80 rpm for 16 hours to obtain a composite powder for laser additive manufacturing;

[0100] 2) The laser additive manufacturing composite powder obtained in step 1) is dried in a vacuum drying oven at 100°C for 5 hours, and then laser additive manufacturing is performed by a laser powder bed fusion 3D printer, using a laser power of 300W, a laser scanning speed of 1000mm / s, a scanning line spacing of 100pm, a powder layer thickness of 40pm, and a laser interlayer rotation angle of 17°, and then annealed at 300°C for 1h, solution treated at 505°C for 30min, and water quenched in water at 25°C for 2min to obtain the laser additive manufacturing aluminum alloy.

[0101] The mass content of boron in the laser additive manufacturing aluminum alloy prepared in this example is about 1.5wt%, the mass content of nickel is about 1wt%, the mass content of magnesium is about 1.6185wt%, the mass content of copper is about 4.57275wt%, the mass content of manganese is about 0.585wt%, the mass content of silicon is about 0.039wt%, the mass content of iron is about 0.078wt%, and the balance is aluminum. The molar ratio of magnesium, boron and aluminum is about 1:2.08:50.43; the laser additive manufacturing aluminum alloy includes in-situ formed MgAlB x whiskers and MgAlB x two-dimensional nanosheets.

[0102] Example 7

[0103] This example provides a preparation method of a laser additive manufacturing aluminum alloy, comprising the following steps:

[0104] 1) Weigh 15g of amorphous boron powder, 8g of manganese powder, 2.5g of vanadium powder, 2.5g of niobium powder, 2.5g of iron powder, 2.5g of nickel powder, and 967g of aluminum-copper-magnesium alloy powder (the aluminum-copper-magnesium alloy powder used has a composition of copper 4.6wt%, magnesium 1.6wt%, and the balance of aluminum), and place them in a 5L stainless steel tank. Disperse them using a mixer at 80rpm for 16 hours to obtain a laser additive manufacturing composite powder;

[0105] 2) The laser additive manufacturing composite powder obtained in step 1) is dried in a vacuum drying oven at 100°C for 5 hours, and then laser additive manufacturing is performed by a laser powder bed fusion 3D printer, using a laser power of 300W, a laser scanning speed of 1000mm / s, a scanning line spacing of 100pm, a powder layer thickness of 40pm, and a laser interlayer rotation angle of 17°, and then annealed at 300°C for 1h, solution treated at 505°C for 30min, and water quenched in water at 25°C for 2min to obtain the laser additive manufacturing aluminum alloy.

[0106] The laser additive manufacturing aluminum alloy prepared in this embodiment contains boron with a mass content of about 1.5 wt%, manganese with a mass content of about 0.8 wt%, vanadium with a mass content of about 0.25 wt%, niobium with a mass content of about 0.25 wt%, iron with a mass content of about 0.25 wt%, nickel with a mass content of about 0.25 wt%, magnesium with a mass content of about 1.5472 wt%, copper with a mass content of about 4.4482 wt%, and the balance of aluminum. The molar ratio of magnesium, boron and aluminum is about 1:2.18:52.82; the laser additive manufacturing aluminum alloy contains in-situ formed MgAlB x whiskers and MgAlB x two-dimensional nanosheets.

[0107] Example 8

[0108] The present embodiment provides a preparation method of a laser additive manufacturing aluminum alloy, comprising the following steps:

[0109] 1) 15 g of amorphous boron powder, 8 g of manganese powder, 2.5 g of vanadium powder, 2.5 g of niobium powder, 2.5 g of iron powder, 2.5 g of nickel powder and 967 g of aluminum-copper-magnesium alloy powder (the aluminum-copper-magnesium alloy powder used has a composition of copper 4.6 wt%, magnesium 1.6 wt%, and the balance of aluminum) are weighed and placed in a 5L stainless steel tank, and a mixer is used to disperse at 80 rpm for 16 hours to obtain a composite powder for laser additive manufacturing;

[0110] 2) The composite powder for laser additive manufacturing obtained in step 1) is dried in a vacuum drying oven at 100°C for 6 hours, and then laser additive manufacturing is performed by a laser powder bed fusion 3D printer, using a laser power of 200 W, a laser scanning speed of 700 mm / s, a scanning line spacing of 80 μm, a powder layer thickness of 30 μm, and a laser layer rotation angle of 17°, followed by solid solution at 505°C for 30 min and then water quenching in water at 25°C for 1 min to obtain the laser additive manufacturing aluminum alloy.

[0111] The laser additive manufacturing aluminum alloy prepared in this embodiment contains boron with a mass content of about 1.5 wt%, manganese with a mass content of about 0.8 wt%, vanadium with a mass content of about 0.25 wt%, niobium with a mass content of about 0.25 wt%, iron with a mass content of about 0.25 wt%, nickel with a mass content of about 0.25 wt%, magnesium with a mass content of about 1.5472 wt%, copper with a mass content of about 4.4482 wt%, and the balance of aluminum. The molar ratio of magnesium, boron and aluminum is about 1:2.18:52.82; the laser additive manufacturing aluminum alloy contains in-situ formed MgAlB x whiskers and MgAlBx Two-dimensional nanosheets.

[0112] Example 9

[0113] The embodiment provides a preparation method of a laser additive manufacturing aluminum alloy, comprising the following steps:

[0114] 1) 15 g of amorphous boron powder, 8 g of manganese powder, 2.5 g of vanadium powder, 2.5 g of niobium powder, 2.5 g of iron powder, 2.5 g of nickel powder and 967 g of aluminum-copper-magnesium alloy powder (the aluminum-copper-magnesium alloy powder used has a composition of copper 4.6 wt%, magnesium 1.6 wt%, and the balance of aluminum) are weighed and placed in a 5L stainless steel tank, and a mixer is used to disperse at 80 rpm for 16 hours to obtain a composite powder for laser additive manufacturing;

[0115] 2) the composite powder for laser additive manufacturing obtained in step 1) is dried in a vacuum drying box at 100°C for 4 hours, and laser additive manufacturing is performed by a laser powder bed fusion 3D printer, using a laser power of 450W, a laser scanning speed of 2000mm / s, a scanning line spacing of 160μm, a powder layer thickness of 60μm, and a laser layer rotation angle of 67°, and then solid solution at 505°C for 2h and water quenching in water at 50°C for 10min to obtain the laser additive manufacturing aluminum alloy.

[0116] The laser additive manufacturing aluminum alloy prepared in the embodiment has a mass content of boron of about 1.5 wt%, a mass content of manganese of about 0.8 wt%, a mass content of vanadium of about 0.25 wt%, a mass content of niobium of about 0.25 wt%, a mass content of iron of about 0.25 wt%, a mass content of nickel of about 0.25 wt%, a mass content of magnesium of about 1.5472 wt%, a mass content of copper of about 4.4482 wt%, and the balance of aluminum. The molar ratio of magnesium, boron and aluminum is about 1:2.18:52.82; and the laser additive manufacturing aluminum alloy comprises in-situ formed MgAlB x whiskers and MgAlB x Two-dimensional nanosheets.

[0117] Example 10

[0118] The embodiment provides a preparation method of a laser additive manufacturing aluminum alloy, comprising the following steps:

[0119] 1) Take 15 g of amorphous boron powder, 8 g of manganese powder, 2.5 g of vanadium powder, 2.5 g of niobium powder, 2.5 g of iron powder, 2.5 g of nickel powder and 967 g of aluminum-copper-magnesium alloy powder (the aluminum-copper-magnesium alloy powder used has a composition of copper 4.6 wt%, magnesium 1.6 wt%, and the balance of aluminum) into a 5L stainless steel tank, and disperse for 16 hours at 80 rpm using a mixer to obtain a composite powder for laser additive manufacturing;

[0120] 2) Dry the composite powder for laser additive manufacturing obtained in step 1) in a vacuum drying oven at 100°C for 5 hours, and then use a laser powder bed fusion 3D printer to perform laser additive manufacturing to form a shape, using a laser power of 300W, a laser scanning speed of 1000mm / s, a scanning line spacing of 100μm, a powder layer thickness of 40μm, and a laser layer rotation angle of 17°, and then perform solid solution treatment at 505°C for 30min, water quenching in water at 25°C for 2min, and then artificial aging treatment at 120°C for 10h to obtain the laser additive manufacturing aluminum alloy.

[0121] The laser additive manufacturing aluminum alloy prepared in this example has a mass content of boron element of about 1.5wt%, a mass content of manganese element of about 0.8wt%, a mass content of vanadium element of about 0.25wt%, a mass content of niobium element of about 0.25wt%, a mass content of iron element of about 0.25wt%, a mass content of nickel element of about 0.25wt%, a mass content of magnesium element of about 1.5472wt%, a mass content of copper element of about 4.4482wt%, and the balance being aluminum element. The molar ratio of magnesium element, boron element and aluminum element is about 1:2.18:52.82; and the laser additive manufacturing aluminum alloy includes in-situ formed MgAlB x whiskers and MgAlB x two-dimensional nanosheets.

[0122] Comparative Example 1

[0123] This comparative example provides a preparation method of a laser additive manufacturing aluminum alloy, which is compared with Example 1 only in that step 1) lacks vanadium powder.

[0124] Comparative Example 2

[0125] This comparative example provides a preparation method of a laser additive manufacturing aluminum alloy, which is compared with Example 1 only in that step 1) lacks amorphous boron powder.

[0126] Test Example

[0127] The laser additive manufacturing aluminum alloys of the embodiments 1-10 and the comparative examples 1-2 are respectively heat treated at room temperature (25℃), 200℃, 250℃ and 300℃ for 15 min, and then subjected to quasi-static uniaxial tensile test at the corresponding temperature to evaluate the mechanical properties of the metal materials. The specific test method is as follows:

[0128] The two ends of the metal material sample are clamped by using a Shanghai Litex instrument LD26.105 electronic universal testing machine, and the tension is increased at a constant and low speed (strain rate 8x10 -4 / s) along the axial direction of the sample until the sample is broken. During the process, the stress-strain curve is recorded, and the yield strength, tensile strength and elongation of the metal material under quasi-static conditions are reflected according to the curve. The stress-strain curves of the embodiments 1-10 are shown in Figures 1-10 , the stress-strain curve of the comparative example 1 is shown in Figure 11 , and the yield strength, tensile strength and elongation are shown in Table 1.

[0129] The TEM images of the laser additive manufacturing aluminum alloy obtained by the embodiment 1 under different magnifications are shown in Figure 12 , and Figure 12 b in the figure can observe that the laser additive manufacturing aluminum alloy includes MgAlB x whiskers and MgAlB x two-dimensional nanosheet, and the morphology of MgAlB x whiskers can be observed under high magnification in a.

[0130] The cross sections of the laser additive manufacturing aluminum alloy obtained by the embodiment 1 before and after heat exposure at 300℃ for 100 hours are scanned by electron backscatter diffraction (EBSD), and the scanning equipment is a Zeiss scanning electron microscope Sigma 200 equipped with a Bruker EBSD probe, and the working voltage is set to 20 kV. The comparison chart of the scanning results is shown in Figure 13 . Figure 13 The EBSD analysis results of show that a is the EBSD graph of the laser additive manufacturing aluminum alloy in the printing state before heat exposure at 300℃, and the average grain size is 1.18 μm; b is the EBSD graph of the laser additive manufacturing aluminum alloy after heat exposure at 300℃ for 100 hours, and the average grain size increases to 1.71 μm, indicating that the material has excellent microstructure stability in a long-term thermal environment, and the grain coarsening phenomenon is very weak.

[0131] Table 1

[0132]

[0133] The mechanical property of the alloy powder without boron element in Inventive Example 2 is extremely low after 3D printing. The tensile strength of the laser additive manufacturing aluminum alloy after printing is less than 30 MPa at room temperature, the elongation is only 0.3%, the overall plasticity is extremely poor, and the sample almost shows the brittle failure characteristic of "breaks at one touch". Since the strength and plasticity of the material at room temperature are significantly insufficient, the performance at high temperature is even worse, so the subsequent high-temperature tensile test is not performed.

[0134] The laser additive manufacturing aluminum alloy material of the present application has uniform structure and no obvious segregation, and the room temperature and high temperature mechanical properties meet the harsh requirements of temperature-resistant additive manufacturing. The room temperature performance reaches the tensile strength of 516-610 MPa, the yield strength of 350-450 MPa, and the elongation of 10-15%; the 200℃ performance reaches the tensile strength of 340-450 MPa, the yield strength of 330-381 MPa, and the elongation of 8-17.9%; the 250℃ performance reaches the tensile strength of 250-342 MPa, the lower yield strength of 230-326 MPa, and the elongation of 12.5-18.3%; the 300℃ performance reaches the tensile strength of 130-170 MPa, the lower yield strength of 130-163 MPa, and the elongation of 19.1-27.4%; therefore, the powder material of the present application has excellent mechanical properties at high temperature, especially at 200℃ and 250℃.

[0135] Obviously, the above examples are only examples for clearly illustrating, but not limitation to the embodiments. For ordinary skilled in the art, other different forms of changes or variations can be made on the basis of the above description. Here, all the embodiments need not and cannot be exhausted. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A laser additive manufacturing aluminum alloy, characterized in that, The laser additive manufacturing aluminum alloy contains magnesium, boron, and aluminum, and the molar ratio of magnesium, boron, and aluminum is 1:(0.1-10):X, where X>10; The laser additive manufacturing aluminum alloy also includes high-temperature resistant metal elements, which include at least one of vanadium, niobium, nickel, iron, manganese, and copper. The laser additive manufacturing aluminum alloy includes MgAlB. x Whiskers and MgAlB x Two-dimensional nanosheets; When the high-temperature resistant metal element includes at least one of vanadium, niobium, and nickel, the mass content of the high-temperature resistant metal element in the laser additive manufacturing aluminum alloy is 0.1-22 wt%. When the high-temperature resistant metal element does not include at least one of vanadium, niobium, and nickel, the mass content of the high-temperature resistant metal element in the laser additive manufacturing aluminum alloy is 6-22 wt%.

2. The laser additive manufacturing aluminum alloy according to claim 1, characterized in that, The raw materials for the laser additive manufacturing of aluminum alloys include aluminum alloy powder; Preferably, the raw materials for the laser additive manufacturing of aluminum alloys include boron powder, aluminum-magnesium alloy powder, and high-temperature resistant metal powder.

3. The laser additive manufacturing aluminum alloy according to claim 1 or 2, characterized in that, The high-temperature resistant metal powder includes at least one of vanadium powder, niobium powder, nickel powder, iron powder, manganese powder, and copper powder; And / or, the aluminum-magnesium alloy powder includes at least one of aluminum-magnesium pure alloy powder, 2024 aluminum alloy powder, 7075 aluminum alloy powder, and aluminum-copper-magnesium alloy powder.

4. The laser additive manufacturing aluminum alloy according to any one of claims 1-3, characterized in that, The high-temperature resistant metal elements included in the laser additive manufacturing aluminum alloy are: vanadium 0-5wt%, niobium 0-4wt%, nickel 0-3wt%, iron 0-4wt%, manganese 0-3wt%, and copper 0-6wt%, and the mass percentages of vanadium, niobium, nickel, iron, manganese, and copper are not all zero at the same time. And / or, the magnesium content in the laser additive manufacturing aluminum alloy is 1-5 wt%; And / or, the boron content in the laser additive manufacturing aluminum alloy is 0.5-4 wt% by mass; Optionally, the laser additive manufacturing aluminum alloy also includes 0-6 wt% zinc.

5. A method for preparing a laser additive manufacturing aluminum alloy according to any one of claims 1-4, characterized in that, Includes the following steps: 1) Weigh the raw materials according to the specified amounts and mix them to obtain composite powder for laser additive manufacturing; 2) The composite powder for laser additive manufacturing obtained in step 1) is formed by laser additive manufacturing, and then subjected to solution treatment and water quenching to obtain the laser additive manufactured aluminum alloy.

6. The method for preparing laser additive manufacturing aluminum alloy according to claim 5, characterized in that, The mixing speed of the raw materials in step 1) is 10-80 rpm, and the mixing time is 1-20 h; In step 2), the aluminum alloy composite powder obtained in step 1) is placed into a laser powder bed fusion printer for 3D printing, and then subjected to solution treatment and water quenching to obtain the laser additive manufacturing aluminum alloy.

7. The method for preparing laser additive manufacturing aluminum alloy according to claim 6, characterized in that, The specific parameters for 3D printing include: laser power of 200-500W, laser scanning rate of 500-2000mm / s, scanning line spacing of 80-180μm, powder layer thickness of 30-120μm, and laser interlayer rotation angle of 0°-90°. Preferably, the 3D printing molding parameters include: laser power of 220-320W, laser scanning rate of 850-1250mm / s, scanning line spacing of 90-150μm, powder layer thickness of 30-60μm, and laser interlayer rotation angle of 15°-70°.

8. The method for preparing laser additive manufacturing aluminum alloy according to any one of claims 5-7, characterized in that, The solution temperature mentioned in step 2) is 450-530℃, and the solution time is 0.5-2h; The quenching agent used in step 2) has a temperature of 15-50℃ and a quenching time of 1-10 min; The quenching agent used in the quenching includes water.

9. The method for preparing laser additive manufacturing aluminum alloy according to any one of claims 5-8, characterized in that, The solution treatment step described in step 2) is preceded by an annealing step; And / or, after the quenching step described in step 2), an artificial aging treatment step is also included; Optionally, the annealing temperature is 200-380℃, and the annealing time is 0.5-3h; And / or, the artificial aging treatment temperature is 100-200℃, and the artificial aging treatment time is 30s-20h.

10. The application of the laser additive manufacturing aluminum alloy according to any one of claims 1-4 or the laser additive manufacturing aluminum alloy prepared by the preparation method according to any one of claims 5-9 in heat-resistant metal parts.

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