A detailing agent and method of manufacture, method of additive manufacturing of an aluminium-based component

Abstract

The application relates to a refining agent and a preparation method and an additive manufacturing method of an aluminum-based component, and relates to the technical field of metal materials. The main technical scheme is as follows: a preparation method of a refining agent, the refining agent is used as a refining agent in additive manufacturing raw materials of an aluminum-based component, and the method comprises the following steps: 1) adding reinforcing particles into an aluminum melt to obtain a mixture; wherein the mass fraction of the reinforcing particles in the mixture is 0.5-50 wt%, and the diameter of the reinforcing particles is 5nm-10mu m; 2) performing atomization powdering treatment on the mixture to obtain the refining agent. The application mainly aims to prepare a refining agent, the refining agent is helpful to improve the forming performance of an aluminum-based material in an additive manufacturing process and improve the performance of an additive manufacturing aluminum-based component.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal materials, in particular to a refiner and preparation method, and additive manufacturing method of aluminum-based component. BACKGROUND

[0002] Additive manufacturing of aluminum-based materials has broad application prospects in the industrial field. However, due to the physicochemical properties of aluminum-based materials, the forming property of laser additive manufacturing is poor, and pores, micro-cracks, and even macro-cracks are easily generated, thereby greatly limiting the development of additive manufacturing of aluminum-based materials.

[0003] At present, the methods for improving the forming property of aluminum-based materials mainly include alloying and compounding. In the alloying method, Si, Ti, Sc, Zr and other elements are added to reduce the solidification temperature range of the melt or refine the grains. However, this method changes the original composition of the matrix, which may cause a decrease in other properties. In addition, Sc and Zr are very expensive, which is not conducive to overall cost control. In the compounding method, TiB2 and TiC particles are added to the aluminum-based material powder through in-situ reaction or mechanical mixing. This method needs to introduce particles into the aluminum alloy powder through salt reaction or ball milling during the preparation of the aluminum-based material powder. The process is complicated and inefficient. At the same time, the ball milling process may damage the sphericity of the aluminum-based material powder, reducing its flowability and further exacerbating the generation of defects.

[0004] Therefore, how to improve the additive manufacturing forming property of aluminum-based materials and improve the performance of additive manufacturing aluminum-based components is an important problem to be solved in the field. SUMMARY

[0005] Therefore, the present application provides a refiner and preparation method, and additive manufacturing method of aluminum-based component, which mainly aims to prepare a refiner that helps to improve the forming property of aluminum-based materials during additive manufacturing and improve the performance of additive manufacturing aluminum-based components.

[0006] To achieve the above-mentioned purpose, the present application mainly provides the following technical solutions:

[0007] On the one hand, the embodiment of the present application provides a preparation method of a refiner, wherein the refiner is used as a refiner in additive manufacturing raw materials of aluminum-based components, which comprises the following steps:

[0008] 1) adding reinforcing particles to the aluminum melt to obtain a mixture; wherein the mass fraction of the reinforcing particles in the mixture is 0.5-50wt%, and the diameter of the reinforcing particles is 5nm-10μm;

[0009] 2) performing atomization powder treatment on the mixture to obtain a refiner.

[0010] Preferably, the reinforcing particles are one or more of TiB2, TiC, TiN, LaB6. And / or the component of the aluminum melt is Al.

[0011] Preferably, the mixture is in a melt state; or the mixture is an ingot.

[0012] Preferably, in the step 1), the adding of the reinforcing particles is by in-situ reaction or by exogenous addition.

[0013] The in-situ reaction is by adding reaction salts into the aluminum melt, and the reaction salts react with each other to generate the reinforcing particles dispersed in the aluminum melt. But it is not limited to this, and the reinforcing particles can also be generated by matrix micro-alloying.

[0014] The exogenous addition is by adding the reinforcing particles into the aluminum melt, and stirring to disperse the reinforcing particles in the aluminum melt.

[0015] Preferably, in the step 2), the atomization powder making technology is gas atomization or ultrasonic atomization.

[0016] In another aspect, the embodiments of the present application provide a refining agent, wherein the refining agent is used as a refining agent in raw materials for additive manufacturing of aluminum-based components, and the refining agent is prepared by any of the above-mentioned methods for preparing a refining agent; preferably, the refining agent is a powder with a diameter less than 100 μm. Most of the refining agents are spherical or ellipsoidal powders, and there are a small number of irregularly shaped powders.

[0017] In still another aspect, the embodiments of the present application provide an additive manufacturing method of aluminum-based components, which comprises the following steps:

[0018] The powder mixing step: mixing the aluminum-based powder and the refining agent to obtain a mixed powder; wherein the refining agent is the above-mentioned refining agent.

[0019] The additive manufacturing step: performing additive manufacturing treatment on the mixed powder to obtain an aluminum-based component.

[0020] Preferably, in the mixing step, the mixing of the aluminum-based powder and the refining agent is by mechanical mixing or low-energy ball milling, preferably, the ball-to-powder ratio of the low-energy ball milling is 1:1-20:1, and / or the mixing time of the aluminum-based powder and the refining agent is 4-24 h; and / or the aluminum-based powder is an aluminum alloy powder; and / or in the mixed powder, the mass ratio of the aluminum-based powder and the refining agent is determined by the target alloy system and performance requirements; preferably, if the forming performance of the alloy is to be improved, the equivalent proportion of the reinforcing phase in the target alloy system is 0.5-10 wt% (the reinforcing phase refers to reinforcing particles); if the strength and plasticity of the alloy is to be improved, the equivalent proportion of the reinforcing phase in the target alloy system is 2-15 wt%; if the elastic modulus of the alloy is to be improved, the equivalent proportion of the reinforcing phase in the target alloy system is 10-50 wt%.

[0021] It should be noted that the "equivalent proportion of the reinforcing phase" refers to the mass fraction of the reinforcing particles actually doped into the aluminum-based component in the finally prepared aluminum-based component.

[0022] Preferably, in the additive manufacturing step, the additive manufacturing is a laser powder bed fusion process or a laser directed energy deposition process; preferably, in the additive manufacturing step, due to the use of the mixed powder containing the refining agent, the forming laser power range is increased at a fixed scanning speed.

[0023] In another aspect, the embodiments of the present application provide an aluminum-based component, wherein the aluminum-based component is prepared by the additive manufacturing method of any one of the aluminum-based components described above.

[0024] Preferably, if the aluminum-based component belongs to an AlSi, AlCu, or AlMg alloy, the equivalent proportion of the reinforcing phase in the alloy is 0.5-20 wt%, so that an equiaxed crystal structure is obtained; the average grain size of the aluminum-based component prepared by the laser powder bed fusion process is 0.5-5 μm; and the average grain size of the aluminum-based component prepared by the laser directed energy deposition process is 30-100 μm.

[0025] Preferably, if the aluminum-based component belongs to an AlZn, AlFe, or AlNi alloy, the equivalent proportion of the reinforcing phase in the alloy is 0.2-15 wt%, so that the aluminum-based component exhibits a morphology in which columnar crystals and equiaxed crystals coexist; the average grain size of the aluminum-based component prepared by the laser powder bed fusion process is 2-8 μm; and the average grain size of the aluminum-based component prepared by the laser directed energy deposition process is 50-150 μm.

[0026] Compared with the prior art, the refining agent and the preparation method, and the additive manufacturing method of the aluminum-based component of the present application have at least the following beneficial effects:

[0027] In one aspect, the embodiment of the present application provides a preparation method of a refining agent and the refining agent, which is used as a refining agent in additive manufacturing raw materials of an aluminum-based component, and comprises the following steps: 1) adding reinforcing particles into an aluminum melt to obtain a mixture; the mass fraction of the reinforcing particles in the mixture is 0.5-50wt%, and the diameter of the reinforcing particles is 5nm-10μm; 2) performing atomization and powdering treatment on the mixture to obtain the refining agent. In this embodiment, a general-purpose refining agent is first prepared, which can be directly mixed with aluminum-based powder in additive manufacturing of the aluminum-based component, and only ordinary mixing (mechanical mixing or low-energy ball milling mixing) is needed to obtain uniformly dispersed mixed powder (and the sphericity of the aluminum-based powder is not damaged). Then, the mixed powder is subjected to additive manufacturing, and due to the use of the above-mentioned refining agent, the formability of the additive manufacturing is significantly improved, and the optimal parameter range (such as the laser power range) is greatly expanded. In summary, the preparation method of the refining agent and the refining agent can be mass-produced, and have the advantages of simple operation, good refining effect, strong applicability, good dispersibility and the like.

[0028] Further, in the step of preparing the refining agent, the mass fraction of the reinforcing particles in the mixture is 0.5-50wt%, and in this embodiment, if the content of the reinforcing particles is higher than 50wt%, the reinforcing particles in the refining agent will have obvious agglomeration phenomenon, and finally the structure of the additive manufactured aluminum-based component will be coarsened.

[0029] Further, in the step of preparing the refining agent, the diameter of the reinforcing particles in the mixture is 5nm-10μm. In this embodiment, if the size of the reinforcing particles is greater than 10μm, there may be voids that cannot be filled before the reinforcing particles in the preparation process, and the prepared metal powder may have a decrease in sphericity and poor fluidity due to the coating of irregular reinforcing particles, and finally the aluminum-based component prepared has a tendency to have hole defects.

[0030] On the other hand, the embodiment of the present application provides an additive manufacturing method of an aluminum-based component, which mainly comprises the following steps: directly mixing the above-mentioned refining agent with aluminum-based powder by ordinary mixing, without high-energy ball milling mixing, to prepare a mixed powder with excellent uniformity and granularity, and then performing additive manufacturing on the mixed powder, and due to the use of the above-mentioned refining agent, the formability of the additive manufacturing is significantly improved, and the optimal parameter range (such as the laser power range) is greatly expanded, which can effectively improve the melt nucleation rate in the additive manufacturing process, refine the grain structure, and further reduce the material thermal cracking tendency.

[0031] In summary, the grain refiner and its preparation method, as well as the additive manufacturing method for aluminum-based components provided in this invention, can effectively improve the melt nucleation rate and refine the grain structure during additive manufacturing, thereby reducing the material's tendency to thermal crack. Simultaneously, this method significantly simplifies the addition process of nano / micron particles and reduces their agglomeration tendency, enabling mass production. Furthermore, the microstructure refinement can effectively improve the mechanical properties of the sample and reduce anisotropy. Compared to traditional casting and machining methods, it enables the rapid manufacturing of complex, lightweight components.

[0032] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0033] Figure 1 This is a microstructure diagram of the aluminum-based component sample prepared in Example 1;

[0034] Figure 2 This is a microstructure diagram of the aluminum-based component sample prepared in Example 2;

[0035] Figure 3 This is a microstructure diagram of the aluminum-based component sample prepared in Example 3;

[0036] Figure 4 This is a microstructure diagram of the aluminum-based component sample prepared in Comparative Example 1;

[0037] Figure 5 This is a microstructure diagram of the aluminum-based component sample prepared in Comparative Example 2;

[0038] Figure 6 This is a microstructure diagram of the aluminum-based component sample prepared in Comparative Example 3;

[0039] Figure 7 This is a microstructure diagram of the mixed powder in Comparative Example 4. Detailed Implementation

[0040] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the specific embodiments, structures, features, and effects according to the present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments. In the following description, different "an embodiment" or "an embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0041] In the prior art, for the additive manufacturing method of aluminum-based components, there are two composite processes when preparing the additive manufacturing process raw material powder. One process is to directly add nano-enhanced particles to the aluminum-based powder (i.e., aluminum alloy powder), but this generally requires a high-energy ball milling process to achieve sufficient mixing. However, in the high-energy ball milling process, the sphericity of the aluminum-based powder is damaged, reducing its flowability and further exacerbating defect formation. The other process is to directly introduce enhanced particles into the aluminum-based powder (i.e., aluminum alloy powder) through in-situ reaction. However, different aluminum-based powders (different systems of aluminum alloy powder) have different reaction conditions, making the process cumbersome and inefficient.

[0042] Based on the above problems, the present application first proposes the following concept: directly preparing a refiner that is a general type and can be applied to the additive manufacturing of all types of aluminum-based components. In the preparation of the raw material for additive manufacturing, only the general refiner and the aluminum-based powder need to be mixed using ordinary powder mixing methods (mechanical powder mixing methods or low-energy ball milling methods) (because the enhanced particles have been pre-prepared into the aluminum powder to form the refiner, and subsequent powder mixing only needs to mix it with aluminum-based powder of similar particle size, without considering the agglomeration of nano-particles), which ultimately achieves the effect of making the raw material mixing of aluminum-based component additive manufacturing easier and simpler, and the process of aluminum-based component additive manufacturing simpler and more efficient. The key is to effectively improve the nucleation rate of the melt during additive manufacturing, refine the grain structure, and thus reduce the tendency of material thermal cracking.

[0043] The specific solutions of the present application are as follows:

[0044] In one aspect, the present application provides a preparation method of a refiner, wherein the refiner is used as a refiner in the raw material of aluminum-based component additive manufacturing, and the method comprises the following steps:

[0045] Step 1) adding enhanced particles to an aluminum melt (pure aluminum melt) to obtain a mixture.

[0046] Here, an aluminum melt is selected for generality, rather than an aluminum alloy melt.

[0047] The enhanced particles are one or more of TiB2, TiC, TiN, and LaB6. The diameter of the enhanced particles is 5 nm-10 μm. In the mixture, the mass fraction of the enhanced particles is 0.5-50 wt%.

[0048] The mixture is in a melt state, or the mixture is an ingot. It should be noted that after adding the enhanced particles to the aluminum melt, the obtained mixture can be in a melt state or in an ingot state after cooling.

[0049] The adding method of the reinforcing particles is in-situ reaction or external addition and mixing. The in-situ reaction is adding reaction salt into the aluminum melt, making the reaction salt react with each other, generating reinforcing particles in the aluminum melt, and dispersing the reinforcing particles in the aluminum melt. The external addition and mixing is adding the reinforcing particles into the aluminum melt and stirring to disperse the reinforcing particles in the aluminum melt.

[0050] Step 2) atomizing the mixture to obtain the refiner.

[0051] The atomizing technology is gas atomization or ultrasonic atomization.

[0052] In another aspect, the embodiment of the present application provides a refiner, which is used as a refiner in additive manufacturing of an aluminum-based component, and is prepared by the preparation method of the refiner.

[0053] In another aspect, the embodiment of the present application provides an additive manufacturing method of an aluminum-based component, which comprises the following steps:

[0054] Mixing step: mixing the aluminum-based powder and the refiner to obtain a mixed powder.

[0055] In the mixing step, the mixing method of the aluminum-based powder and the refiner is mechanical mixing or low-energy ball milling. Preferably, the ball-to-material ratio of the low-energy ball milling is 1:1. The mixing time of the aluminum-based powder and the refiner is 4-24 h. The aluminum-based powder is an aluminum alloy powder.

[0056] Additive manufacturing step: additive manufacturing the mixed powder to obtain the aluminum-based component.

[0057] In the additive manufacturing step, the additive manufacturing is laser powder bed fusion or laser directed energy deposition. In the additive manufacturing step, the mixed powder containing the refiner can increase the forming laser power range at a fixed scanning speed, and improve the formability of the sample. For example, for the laser powder bed fusion technology, refer to Table 1.

[0058] Table 1

[0059]

[0060] As can be seen from Table 1, the formability of the sample additive manufacturing is obviously improved after adding the refining agent, and the best parameter range is greatly expanded. It should be pointed out that the refining agent described in the present application is theoretically applicable to all additive manufacturing aluminum alloys, and can improve the formability and comprehensive performance of each alloy system to different degrees.

[0061] The following is further illustrated by specific experimental examples as follows:

[0062] Example 1

[0063] In this embodiment, two types of aluminum-based components are prepared, and the main steps are as follows:

[0064] 1) TiB2 particles are generated in the aluminum melt (pure aluminum melt) by in-situ reaction of mixed salts of KBF4 and K2TiF6, to obtain a mixture. The reaction temperature is 780°C, the reaction time is 5h, the diameter distribution of the TiB2 particles is 100-300nm, and the mass fraction of the TiB2 particles in the mixture is 8wt%, and the proportion of the pure aluminum matrix is 92wt%.

[0065] 2) The mixture obtained in step 1) is prepared into a powder by a vacuum gas atomization method, wherein the vacuum degree is controlled below 1Pa, the inert gas pressure is 1-3MPa, and the powder with a diameter less than 30μm is sieved out as a refining agent.

[0066] The first type of aluminum-based component is prepared:

[0067] The refining agent and AlSi10Mg powder are mixed by a mechanical powder mixing method in a mass ratio of 1:4; wherein the ball-to-material ratio is 1:1 (ordinary mechanical powder mixing, steel balls also need to be added), the mixing time is 4h, and a mixed powder is obtained.

[0068] The mixed powder is formed by a laser powder bed melting technology to obtain an aluminum-based component sample (AlSi10Mg). The laser power is 275W, the scanning speed is 1.5m / s, the powder layer thickness is 30μm, the substrate preheating temperature is 50°C, and the temperature in the forming bin is 25°C. In the aluminum-based component sample, the equivalent proportion of the reinforcing phase is 1.6wt%, and the pure aluminum is 18.4wt%.

[0069] In this embodiment, the microstructure of the aluminum-based component sample is greatly refined by controlling the content of reinforcing particles in the refining agent and the key parameters in the forming process. Compared with the state without adding the refining agent (only using alloy powder for manufacturing), the average grain size is refined from 10μm to 3μm, the columnar crystal organization completely disappears, the melt pool grain is completely equiaxed, and the anisotropy is significantly reduced (see Figure 1 for details), and the obtained aluminum-based component sample is dense and has no interlayer cracking.

[0070] Preparation of the second type of aluminum-based component:

[0071] 3) The refiner and the 2024 aluminum alloy powder are mixed by mechanical powder mixing at a mass ratio of 1:7; the ball-to-powder ratio is 1:1, and the mixing time is 24 h to obtain the mixed powder.

[0072] 4) The mixed powder is formed by laser directed energy deposition technology to obtain an aluminum-based component sample (2024 aluminum alloy). The laser power is 1500 W, the scanning speed is 1 m / s, and the powder feeding amount is 5 g / min. In the aluminum-based component sample, the equivalent proportion of the reinforcing phase is 1 wt%, and the pure aluminum is 11.5 wt%.

[0073] Here, the refiner prepared in the embodiment of the present application has universality and is suitable for the preparation of aluminum-based components of various systems. Therefore, only a batch of refiners needs to be prepared (or purchased) in advance, so that the refiner can be used as a raw material for powder mixing and additive manufacturing when the aluminum-based component is prepared, thereby greatly improving the preparation efficiency of the aluminum-based component and reducing the cost.

[0074] Example 2

[0075] An aluminum-based component is prepared in this embodiment, and the main steps are as follows:

[0076] 1) TiC and TiB2 mixed particles are added to a pure aluminum melt and stirred to obtain a mixture. The diameter of the TiB2 particles is 500 nm, and the mass fraction is 5 wt%; the diameter of the TiC particles is 10 μm, and the mass fraction is 10 wt%.

[0077] 2) The mixture obtained in step 1) is prepared into a powder by ultrasonic atomization, the ultrasonic frequency is 40 KHz, the melt temperature is 820 ℃ (the temperature of the aluminum melt with added reinforcing particles), and the powder with a diameter less than 60 μm is sieved out as a refiner.

[0078] 3) The refiner powder and the 6061 aluminum alloy powder are mixed by low-energy ball milling at a mass ratio of 1:5; the ball-to-powder ratio is 1:1, and the mixing time is 6 h to obtain the mixed powder.

[0079] 4) The mixed powder is formed by laser powder bed melting technology to obtain an aluminum-based component sample. The laser power is 250 W, the scanning speed is 1.75 m / s, the powder layer thickness is 30 μm, the substrate preheating temperature is 80 ℃, and the temperature in the forming bin is 35 ℃. In the aluminum-based component sample, the equivalent proportion of the reinforcing phase is 2.5 wt%, and the pure aluminum is 14 wt%.

[0080] The embodiment improves the formability and strength of the 6061 aluminum alloy by controlling the particle content in the refiner and the key parameters in the forming process. The obtained aluminum-based component sample is dense, has no interlayer cracking, the columnar crystal structure completely disappears, the grain is equiaxed, the grain size distribution range is 2-8 pm, and the average grain size is 2.8 pm (see Figure 2 The tensile strength of the printed aluminum-based component sample is 293 MPa, and the elongation is 18%.

[0081] Example 3

[0082] The embodiment prepares an aluminum-based component, and the main steps are as follows:

[0083] 1) TiB2, TiN, and LaB6 mixed particles are added to the pure aluminum melt and stirred to obtain a mixture. The diameter of the TiB2 particles is 500 nm, and the mass fraction is 3 wt%. The diameter of the TiN particles is 10 pm, and the mass fraction is 30 wt%. The diameter of the LaB6 particles is 5 pm, and the mass fraction is 8 wt%.

[0084] 2) The mixture is prepared into a powder by an ultrasonic atomization method; the ultrasonic frequency is 20 KHz, the melt temperature is 870 °C, and the powder with a diameter less than 100 pm is sieved out as a refiner.

[0085] 3) The refiner powder and the 2024 aluminum alloy powder are mixed by mechanical powder mixing in a mass ratio of 1:7; the ball-to-material ratio is 1:1, and the mixing time is 24 h to obtain a mixed powder.

[0086] 4) The mixed powder is formed by using a laser directed energy deposition technology to obtain an aluminum-based component sample. The laser power is 1500 W, the scanning speed is 1 m / s, and the powder feeding amount is 5 g / min. In the aluminum-based component sample, the equivalent proportion of the reinforcing phase is 5.125 wt%, and the pure aluminum is 7.375 wt%.

[0087] The embodiment improves the formability and hardness of the 2024 aluminum alloy by controlling the particle content in the refiner and the key parameters in the forming process. The cracking tendency of the obtained aluminum-based component sample is significantly reduced, the microstructure is relatively uniform, the anisotropy is not obvious, and the grain size is about 38 pm (see Figure 3 The hardness of the printed aluminum-based component sample reaches 150 HV.

[0088] Comparative Example 1

[0089] Comparative Example 1 prepares an aluminum-based component, and the main steps are as follows:

[0090] 1) generating TiB2 particles in an aluminum melt (pure aluminum melt) by in-situ reaction of mixed salts of KBF4 and K2TiF6 to obtain a mixture. The diameter of the TiB2 particles is distributed in a range of 5-50 nm, and the mass fraction of the TiB2 particles in the mixture is 55 wt%.

[0091] 2) preparing a powder from the mixture obtained in step 1) by a vacuum gas atomization method, and sieving out a powder with a diameter less than 30 pm as a refining agent.

[0092] 3) mixing the refining agent powder and AlSi10Mg powder in a mass ratio of 1:4 by mechanical powder mixing; the ball-to-material ratio is 1:1, and the mixing time is 4 h to obtain a mixed powder.

[0093] 4) forming the mixed powder by a laser powder bed melting technology to obtain an aluminum-based component sample. The laser power is 275 W, the scanning speed is 1.5 m / s, the powder layer thickness is 30 pm, the substrate preheating temperature is 50°C, and the temperature in the forming bin is 25°C.

[0094] In Comparative Example 1, the content of the reinforcing particles in the refining agent is too high, and the reinforcing particles are continuously distributed along the grain boundaries of the sample, and obvious agglomeration exists (see FIG. 2), which causes the microstructure of the obtained aluminum-based component sample to be coarsened. Figure 4

[0095] Comparative Example 2

[0096] An aluminum-based component is prepared in Comparative Example 2, and the main steps are as follows:

[0097] 1) adding TiC and TiB2 mixed particles to a pure aluminum melt and stirring to obtain a mixture. The diameter of the TiB2 particles is 500 nm, and the mass fraction is 5 wt%; the diameter of the TiC particles is 50 pm, and the mass fraction is 10 wt%.

[0098] 2) preparing a powder from the mixture obtained in step 1) by an ultrasonic atomization method, and sieving out a powder with a diameter less than 60 pm as a refining agent.

[0099] 3) mixing the refining agent powder and 6061 aluminum alloy powder in a mass ratio of 1:5 by low-energy ball milling; the ball-to-material ratio is 1:1, and the mixing time is 6 h to obtain a mixed powder.

[0100] 4) forming the mixed powder by a laser powder bed melting technology to obtain an aluminum-based component sample. The laser power is 250 W, the scanning speed is 1.8 m / s, the powder layer thickness is 30 pm, the substrate preheating temperature is 80°C, and the temperature in the forming bin is 35°C.

[0101] ​In the comparative example 2, the size of the reinforcing particles in the refiner is too large, so that the obtained powder loses the spherical morphology and the fluidity becomes poor, which finally causes the hole defects in the aluminum-based component sample (see Figure 5 The tensile strength of the aluminum-based component sample obtained in the comparative example 2 is 120 MPa, and the elongation is 3%.

[0102] Comparative example 3

[0103] The aluminum-based component is prepared in the comparative example 3, and the main steps are as follows:

[0104] 1) TiB2, TiN and LaB6 mixed particles are added into the aluminum melt and stirred to obtain a mixture. The diameter of the TiB2 particles is 500 nm, and the mass fraction is 3%. The diameter of the TiN particles is 10 μm, and the mass fraction is 30%. The diameter of the LaB6 particles is 5 μm, and the mass fraction is 8 wt%.

[0105] 2) The mixture is prepared into a powder by the ultrasonic atomization method; and the powder with a diameter less than 100 μm is screened out as a refiner.

[0106] 3) The refiner powder and the 2024 aluminum alloy powder are mixed by mechanical mixing of the powder in a mass ratio of 1:1; the ball-to-material ratio is 1:1, and the mixing time is 24 h, to obtain a mixed powder.

[0107] 4) The mixed powder is formed by the laser directed energy deposition technology to obtain an aluminum-based component sample. The laser power is 1500 W, the scanning speed is 1 m / s, and the powder feeding amount is 5 g / min.

[0108] In the comparative example 3, the content of the refiner in the mixed powder is high, and the content of aluminum is high, so that the element dilution of the alloy powder is serious, the strength decreases, the tensile strength of the obtained aluminum-based component sample is 157 MPa, and the elongation is 8%. The microstructure is shown in Figure 6 In the aluminum-based component sample, the equivalent proportion of the reinforcing phase is 19 wt%, and the pure aluminum is 31 wt%.

[0109] It should be noted that according to the concept of the present application, the content of the reinforcing phase and the content of aluminum can be calculated according to the performance requirements of the selected aluminum-based component, and the aluminum-based component with different performances can be prepared by adjusting the ratio of the refiner and the alloy powder to meet the requirements of different fields.

[0110] Comparative example 4

[0111] The aluminum-based component is prepared in the comparative example 4, and the main steps are as follows:

[0112] 1) AlSi10Mg powder is used as the matrix. AlSi10Mg powder and TiB2 particles are mixed by ball milling to obtain a mixed powder. The diameter of the TiB2 particles is distributed in the range of 30-50 nm, and the mass fraction is 8wt%.

[0113] 2) The mixed powder is formed by using a laser powder bed melting technology. The laser power is 250 W, the scanning speed is 1.75 m / s, the powder layer thickness is 30 μm, the substrate preheating temperature is 80 °C, and the temperature in the forming bin is 35 °C.

[0114] The mixed powder prepared in the comparative example 4 is ball milled for a long time to ensure the uniformity of the nanoparticles, which seriously damages the sphericity of the powder (see FIG. 1), and the flowability is poor. The powder is not evenly spread, and a large number of holes exist in the additive manufacturing sample, which significantly reduces the performance. The tensile strength of the sample is 230 MPa, and the elongation is 6%. Figure 7

[0115] Comparative Example 5

[0116] The comparative example 5 is to prepare two aluminum-based components by using the existing scheme. The main steps are as follows:

[0117] 1) AlSi10Mg alloy is used as the matrix, TiB2 and TiC particles are generated by in-situ reaction, and then composite powder is prepared by gas atomization. Then, the composite powder is subjected to additive manufacturing to obtain an aluminum-based component sample (AlSi10Mg alloy component)

[0118] 2) Before the composite particle powder is prepared by changing the matrix alloy to 2024 aluminum alloy, the furnace needs to be cleaned, the in-situ reaction needs to be performed again, and the gas atomization operation needs to be performed. At the same time, the in-situ reaction temperature, time, and gas atomization parameters need to be re-set, and the total time consumption is 52 h.

[0119] In the comparative example 5, due to the lack of a general-purpose refining agent preparation method, different alloy systems need to be individually controlled to add refined particles by re-adjusting the parameters, which has a long process, low efficiency, high control difficulty, complex process, and consumes manpower and material resources for cleaning the furnace, and is easy to cause harm to the human body. In the embodiment 1 of the present application, only the refined particles need to be prepared in the pure aluminum matrix, and then mixed with the target system, which significantly improves the preparation efficiency and greatly reduces the control difficulty.

[0120] ​In summary, the embodiment of the present application provides a kind of refiner and preparation method, additive manufacturing method of aluminum base component, can effectively improve the melt nucleation rate in additive manufacturing process, refine grain structure, in turn reduce the tendency of material thermal crack. While using the method of the embodiment of the present application can greatly simplify the adding process of nano / microparticle, while reducing the agglomeration tendency of nano / microparticle, can mass production.In addition, the organization refinement can also effectively improve the mechanical properties of sample, reduce anisotropy.Compared with the traditional casting and mechanical processing method, the rapid manufacturing of complex lightweight component can be realized.

[0121] The above is only the preferred embodiment of the present application, not any form of limitation on the present application, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present application still belongs to the scope of the technical solution of the present application.

Claims

1. A method of additive manufacturing of an aluminum-based component, characterized in that, It comprises the following steps: The powder mixing step: mixing the aluminum-based powder and the refining agent to obtain a mixed powder; The additive manufacturing step: performing additive manufacturing treatment on the mixed powder to obtain an aluminum-based component; Wherein, in the mixed powder, the mass ratio of the aluminum-based powder and the refining agent is determined by the target alloy system and performance requirements; wherein, if the forming performance of the alloy is improved, the equivalent proportion of the reinforcing phase in the target alloy system is 0.5-10wt%; if the plasticity of the alloy is improved, the equivalent proportion of the reinforcing phase in the target alloy system is 2-15wt%; if the elastic modulus of the alloy is improved, the equivalent proportion of the reinforcing phase in the target alloy system is 10-50wt%; Wherein, the preparation method of the refining agent comprises the following steps: 1) adding reinforcing particles to the aluminum melt to obtain a mixture; wherein, in the mixture, the mass fraction of the reinforcing particles is 0.5-50wt%, and the diameter of the reinforcing particles is 5nm-10μm; wherein, the reinforcing particles are one or more of TiB2, TiC, TiN, and LaB6; 2) performing atomization powdering treatment on the mixture to obtain a refining agent.

2. The method of additive manufacturing of an aluminum-based component according to claim 1, characterized in that, The composition of the aluminum melt is Al.

3. The method of additive manufacturing of an aluminum-based component according to claim 1, characterized in that, The mixture is in a molten state; or the mixture is an ingot.

4. The method of additive manufacturing of an aluminum-based component according to claim 1, characterized in that, In step 1) of the preparation method of the refining agent: The way of adding reinforcing particles is in-situ reaction or exogenous mixing; Wherein, the exogenous mixing way is: adding reinforcing particles to the aluminum melt and performing stirring treatment to make the reinforcing particles disperse in the aluminum melt.

5. The method of additive manufacturing of an aluminum-based component according to claim 1, characterized in that, In step 2) of the preparation method of the refining agent: The atomization powdering selects gas atomization powdering or ultrasonic atomization powdering.

6. The method of additive manufacturing of an aluminum-based component according to claim 1, characterized in that, The refining agent is a powder with a diameter less than 100μm.

7. The method of additive manufacturing of an aluminum-based component according to claim 1, characterized in that, In the powder mixing step: The way of mixing the aluminum-based powder and the refining agent is mechanical powder mixing or low-energy ball milling.

8. The method of additive manufacturing of an aluminum-based component according to claim 7, characterized in that, The ball-to-material ratio of the low-energy ball milling is 1:1-20:

1.

9. The method of additive manufacturing of an aluminum-based component according to claim 1, characterized in that, In the powder mixing step: the mixing time of the aluminum-based powder and the refining agent is 4-24h.

10. The method of additive manufacturing of an aluminum-based component according to claim 1, characterized in that, In the powder mixing step: the aluminum-based powder is an aluminum alloy powder.

11. The method of additive manufacturing of an aluminum-based component according to claim 1, characterized in that, In the additive manufacturing step: The additive manufacturing is a laser powder bed fusion process or a laser directed energy deposition process.

12. The method of additive manufacturing of an aluminum-based component according to claim 11, characterized in that, In the additive manufacturing step: due to the use of the mixed powder including the refining agent, the forming laser power range increases after fixing the scanning speed.

13. An aluminum-based member characterized by comprising: The aluminum-based component is prepared by the additive manufacturing method of the aluminum-based component of any one of claims 1-12.

14. The aluminum-based member according to claim 13, characterized by If the aluminum-based component belongs to AlSi, AlCu, AlMg alloy: the equivalent proportion of the reinforcing phase in the alloy is 0.5-20wt%, then the equiaxed crystal structure is obtained; the average grain size of the aluminum-based component prepared by the laser powder bed fusion process is 0.5-5μm; the average grain size of the aluminum-based component prepared by the laser directed energy deposition process is 30-100μm.

15. The aluminum-based member according to claim 13, characterized by If the aluminum-based component belongs to the AlZn, AlFe, AlNi system alloy: the equivalent proportion of the reinforcing phase in the alloy is 0.2-15wt%, the aluminum-based component presents a morphology of coexistence of columnar crystals and equiaxed crystals; the average grain size of the aluminum-based component prepared by the laser powder bed melting process is 2-8μm; the average grain size of the aluminum-based component prepared by the laser directional energy deposition process is 50-150μm.

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