3D printing high-performance alloy material and preparation method thereof

Abstract

The application relates to the technical field of alloy materials, in particular to a 3D printing high-performance alloy material and a preparation method thereof. The structural formula of the alloy material is FeCoCrNi, and the atomic percentage content of each element is equal proportion or approximately equal proportion. High-purity FeCoCrNi metal powder is adopted, 3D printing is carried out based on a selective laser melting technology, and parameters such as laser power and scanning speed are controlled to achieve the best combination of strength and plasticity. The results show that when the laser power is 180-250 W, the scanning speed is 550-600 mm / s, the layer thickness is 25-30 mu m, and the scanning interval is 60-70 mu m, the compactness of the formed piece can reach more than 98%. The yield strength of the FeCoCrNi alloy at room temperature is more than 900 MPa, the tensile strength is more than 1000 MPa, and the elongation is more than 25%, so the FeCoCrNi alloy has great application potential in the fields of high-mechanical-performance-required key parts of mechanical equipment and the like.

Description

Technical Field

[0001] This invention relates to the field of alloy materials technology, specifically to a 3D-printed high-performance alloy material and its preparation method. Background Technology

[0002] Traditional alloy systems primarily use an element with specific properties as the matrix, adding small amounts of other elements to improve its performance. The types and amounts of commonly used metallic elements are limited, which inherently restricts the quantity of alloy materials that can be used. The concept of multi-component alloys (high-entropy alloys) breaks this limitation. Their high-entropy effect can suppress the formation of brittle intermetallic compounds between elements, thus forming solid solutions with simple face-centered cubic, body-centered cubic, and other structures. However, melting high-melting-point high-entropy alloys is difficult. With the continuous development of 3D printing technology, selective laser melting (SLM) has become an important means of manufacturing high-performance metallic materials, especially in fields such as machinery, aerospace, automotive manufacturing, and medical devices. SLM technology melts metal powder layer by layer using a laser beam, enabling the manufacture of complex shapes and high-performance key metal components that meet performance requirements.

[0003] However, SLM technology still faces some challenges in practical applications, especially in the selection of metal powders and process optimization. The morphology, particle size distribution, and flowability of metal powders directly affect the uniformity of powder spreading and the density of the material during the 3D printing process. Existing processes often result in porosity defects in 3D-printed metal materials after powder forming, affecting the material's mechanical properties.

[0004] Therefore, there is an urgent need for a new type of 3D printing high-performance alloy material and its preparation method, which can improve the material's density, strength, plasticity and other comprehensive mechanical properties by optimizing powder morphology and process parameters, and expand the range of materials for key components with high performance requirements in engineering fields such as mechanical equipment. Summary of the Invention

[0005] To address the aforementioned problems in existing technologies, this invention provides a 3D-printed high-performance alloy material and its preparation method. Using FeCoCrNi alloy metal powder as raw material, selective laser melting technology is employed for 3D printing. The overall performance is significantly improved compared to similar alloys, effectively overcoming the shortcomings of existing technologies.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A high-performance alloy material for 3D printing, wherein the alloy material has the structural formula FeCoCrNi, and the atomic percentage content of each element is in equal or approximately equal proportion, specifically ranging from 23.5% to 26.5%.

[0007] The raw material is spherical FeCoCrNi metal powder with a purity of 99.9 wt%, and meets the following characteristics: (1) The particle size range of the raw material powder is 10-53 μm, of which large particles larger than 40 μm account for less than 5%; (2) The sphericity of the raw material powder is > 0.9; (3) The Hall flow rate (flowability) of the raw material powder is 15-25 g / cm³. 3 ; (4) The loose packing density of the raw material powder is >4 g / cm³. 3 ; (5) The tap density of the raw material powder is >5 g / cm³. 3 .

[0008] A method for preparing high-performance alloy materials for 3D printing: Selective laser melting (SLM) technology is used for 3D printing. The laser spot diameter is 40-50 μm. During printing, strip scanning is performed. The strip width is 4-6 mm. The layer-by-layer rotation angle of the strip is 67°. The thickness of each print is 25-35 μm.

[0009] Specifically, the following steps are included: (1) Dry the raw metal powder to remove residual moisture; (2) Load the dried powder into the printer's toner cartridge; (3) Insert the 316L stainless steel substrate into the printing chamber and adjust it to be level, ensuring that the substrate surface is smooth and free of pits; (4) Preheat the substrate and pre-lay a layer of raw material powder 25-35 μm thick; (5) The chamber is first evacuated and then backfilled with argon gas to use a protective atmosphere to avoid oxidation reaction; (6) Import the 3D model into the slicing software for layer processing, export the 2D graphics, and input the process parameters; (7) The laser selectively melts and shapes the powder according to the set scanning path. After one layer is completed, the substrate drops by 25-35 μm. The equipment automatically continues to lay another layer of powder on the substrate through the scraper, repeating the melting and shaping until all printing is completed, and an alloy block sample based on 3D printing is obtained.

[0010] In step (1), the drying temperature is 80℃~120℃ and the drying time is 2~3 h.

[0011] In step (2), the printer toner cartridge has a size of 170 mm × 170 mm × 300 mm.

[0012] In step (3), the substrate is 170 mm × 170 mm × 30 mm in size. It is polished using an angle grinder and then wiped with ether before use.

[0013] In step (4), the preheating temperature of the substrate is 100-120°C.

[0014] In step (5), a mechanical pump is used to evacuate the chamber to <5 Pa, and the argon flow rate is 5-10 L / min. During the printing process, the oxygen concentration in the chamber is kept below 0.1%.

[0015] The process parameters set in step (6) are optimized through orthogonal experiments. The preferred parameters are laser power of 180W to 250W, scanning speed of 550 to 600mm / s, and scanning spacing of 60 to 70μm.

[0016] Compared with the prior art, the beneficial effects of the present invention are: (1) The FeCoCrNi multi-component alloy system provided by the present invention has significant advantages over existing materials in terms of main mechanical properties such as yield strength and plasticity by optimizing process parameters such as laser power, scanning speed and protective gas. Moreover, the obtained material can be directly applied in engineering without heat treatment, saving a lot of heat treatment costs.

[0017] (2) The alloy material of the present invention is dominated by FCC single-phase solid solution during the plastic deformation stage. This feature is closely related to the high dislocation density and fine grain structure formed during the rapid solidification of SLM. The fracture surface of the sample is dominated by a large number of uniformly distributed dimples, indicating that the fracture mechanism is dominated by ductile fracture dominated by micropore nucleation, growth and aggregation, which makes the alloy have high strength while maintaining good plasticity. Attached Figure Description

[0018] Figure 1 (Top) shows the prepared FeCoCrNi bulk alloy, (bottom left) shows the XRD patterns of Example 1 and the metal powder raw material, and (bottom right) shows a magnified view at 41°~46°. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Unless otherwise specifically stated, the numerical values ​​set forth in these embodiments do not limit the scope of this application. Techniques and methods known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques and methods should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0021] Unless otherwise specified, the experimental methods used in the embodiments of this application are all conventional methods.

[0022] In the following examples and comparative examples, unless otherwise specified, all raw materials can be prepared by commercial purchase or conventional methods.

[0023] The following embodiment provides a 3D printing alloy bulk material with the structural formula FeCoCrNi, wherein each element accounts for 25%. The raw material is FeCoCrNi alloy metal powder with a purity of 99.9 wt%, characterized by: a particle size range of 15–50 μm, with less than 5% of the powder being larger than 40 μm; a sphericity > 0.9; and a Hall flow rate (flowability) of 15–25 g / cm³. 3 The loose bulk density of the powder is >4 g / cm³. 3 The tap density of the powder is >5 g / cm³. 3 .

[0024] Printing was performed using a Leijia DiMetal-150H SLM scanner. The scanner has a maximum laser power of 500W, a maximum scanning speed of 7.8m / s, and a laser spot diameter of 40–50μm. Strip scanning was used during printing, with a strip width of 4–6 mm and a layer-by-layer rotation angle of 67°. Example 1

[0025] A method for preparing a FeCoCrNi multi-component alloy, the specific steps of which are as follows: (1) Dry the raw metal powder at 120°C for 2 hours to remove residual moisture; (2) Load the dried powder into the printer toner cartridge; the printer toner cartridge size is 170 mm × 170 mm × 300 mm; (3) Use an angle grinder to grind and polish the 316L stainless steel substrate to ensure that the substrate surface is smooth and free of pits. After cleaning with ether, it is installed into the printing chamber and the substrate is leveled. The substrate size is 170 mm × 170 mm × 30 mm. (4) Preheat the substrate to 120°C and pre-lay a 30μm thick layer of raw material powder on the substrate; (5) First, evacuate the chamber to below 5 Pa, then backfill with argon gas at a flow rate of 8 L / min. During the printing process, ensure that the oxygen concentration in the chamber is below 0.1% to avoid oxidation reaction; (6) Import the three-dimensional model into the slicing software for layer processing, export the two-dimensional graphic, and input the process parameters: laser power 200W, scanning speed 600mm / s, layer thickness 30μm, scanning spacing 70μm; (7) The laser selectively melts and shapes the powder according to the set scanning path. After one layer is completed, the substrate is lowered by 30 μm. Another layer of powder is then laid on the substrate, and the melting and shaping are repeated until all printing is completed, resulting in an alloy block sample based on 3D printing. Example 2

[0026] A method for preparing a FeCoCrNi multi-component alloy, the specific steps of which are as follows: (1) Dry the raw metal powder at 80°C for 3 hours to remove residual moisture; (2) Load the dried powder into the printer toner cartridge; the printer toner cartridge size is 170 mm × 170 mm × 300 mm; (3) Use an angle grinder to grind and polish the 316L stainless steel substrate to ensure that the substrate surface is smooth and free of pits. After cleaning with ether, it is installed into the printing chamber and the substrate is leveled. The substrate size is 170 mm × 170 mm × 30 mm. (4) Preheat the substrate to 120°C and pre-lay a 28μm thick layer of raw material powder on the substrate; (5) First, evacuate the chamber to below 5 Pa, then backfill with argon gas at a flow rate of 6 L / min. During the printing process, ensure that the oxygen concentration in the chamber is below 0.1% to avoid oxidation reaction; (6) Import the three-dimensional model into the slicing software for layer processing, export the two-dimensional graphic, and input the process parameters: laser power 180W, scanning speed 580mm / s, layer thickness 28μm, scanning spacing 68μm; (7) The laser selectively melts and shapes the powder according to the set scanning path. After one layer is completed, the substrate is lowered by 28 μm. Another layer of powder is then laid on the substrate, and the melting and shaping are repeated until all printing is completed, resulting in an alloy block sample based on 3D printing. Example 3

[0027] A method for preparing a FeCoCrNi multi-component alloy, the specific steps of which are as follows: (1) Dry the raw material metal powder at 100°C for 2.5 hours to remove residual moisture; (2) Load the dried powder into the printer toner cartridge; the printer toner cartridge size is 170 mm × 170 mm × 300 mm; (3) Use an angle grinder to grind and polish the 316L stainless steel substrate to ensure that the substrate surface is smooth and free of pits. After cleaning with ether, it is installed into the printing chamber and the substrate is leveled. The substrate size is 170 mm × 170 mm × 30 mm. (4) Preheat the substrate to 120°C and pre-lay a 30μm thick layer of raw material powder on the substrate; (5) First, evacuate the chamber to below 5 Pa, then backfill with argon gas at a flow rate of 10 L / min. During the printing process, ensure that the oxygen concentration in the chamber is below 0.1% to avoid oxidation reaction; (6) Import the three-dimensional model into the slicing software for layer processing, export the two-dimensional graphic, and input the process parameters: laser power 220W, scanning speed 600mm / s, layer thickness 30μm, scanning spacing 65μm; (7) The laser selectively melts and shapes the powder according to the set scanning path. After one layer is completed, the substrate is lowered by 30 μm. Another layer of powder is then laid on the substrate, and the melting and shaping are repeated until all printing is completed, resulting in an alloy block sample based on 3D printing.

[0028] Comparative Example 1 The FeCoCrNi multi-component alloy provided in this comparative example was prepared by electric arc melting.

[0029] Comparative Example 2 Step (6) uses a laser power of 150W, and the other processes are the same as in Example 1.

[0030] Comparative Example 3 Step (6) uses a laser power of 250W, and the other processes are the same as in Example 1.

[0031] Comparative Example 4 Step (6) The scanning spacing is set to 100 μm, and the other processes are the same as in Example 1.

[0032] Test case (1) X-ray diffractometer was used to analyze the phase composition of Example 1 and the raw material powder. The working voltage and current were 40 kV and 20 mA, respectively. The X-ray source was CuKα (λ=0.1542nm) rays, and the scanning angle 2θ ranged from 20 to 90°.

[0033] The alloy XRD patterns of Example 1 and the raw material powder are as follows: Figure 1 As shown, by Figure 1 It can be seen that both the powder and bulk XRD patterns show three characteristic diffraction peaks (111), (200), and (220), and the peak positions perfectly match the standard diffraction peaks of the face-centered cubic (FCC) crystal structure. This is mainly due to the rapid cooling of the SLM (cooling rate 10). 5~10 6 K / s) further suppressed atomic diffusion, prevented the nucleation and growth of intermetallic compounds, and perfectly preserved the FCC single-phase structure of the powder.

[0034] (2) Density measurements and tensile property tests were performed on Examples 1-3 and Comparative Examples 1-4. The density of these specimens was tested according to Archimedes' displacement method. Dog-bone shaped tensile specimens were tested at room temperature using a universal testing machine (Suns UTM5305-G) at a pressure of 1×10⁻⁶. -3 s -1 Tensile tests were conducted at the strain rate. The test data are shown in Table 1.

[0035] Table 1 Performance data of the embodiments and comparative examples As can be seen from the results in Table 1: The density of Examples 1-3 all exceeded 98%, and the mechanical properties such as yield strength and tensile strength were stable, showing a significant improvement compared to the bulk high-entropy alloy prepared by arc melting in Comparative Example 1. At the same time, it maintained a high elongation after fracture, indicating that while improving tensile strength, it retained good plasticity and had excellent comprehensive mechanical properties of strength and plasticity.

[0036] In Comparative Example 2, the laser power was too low, and when the energy was insufficient, the volumetric energy density (VED) was in an "unfused" state, resulting in low density. In Comparative Example 3, the energy was too high, causing the VED to be in an "over-melted" state, also resulting in low density and thus affecting the mechanical properties of the alloy. In Comparative Example 4, the scanning spacing was too wide, leading to insufficient molten pool overlap, which severely affected the density of the alloy.

[0037] Due to variations in SLM process parameters, multi-component alloys exhibit differences in density, ultimately leading to variations in performance. It is reasonable to infer that the optimal strength-ductility combination can be achieved by adjusting process parameters to meet the demands of high-performance materials.

[0038] This invention provides a 3D-printed high-performance alloy material and its preparation method, offering valuable insights into how to improve and control alloy properties by adjusting SLM process parameters. Furthermore, the preparation method presented in this application is simple and reliable, the selected elements are all non-toxic and readily available, the alloy exhibits significant advantages in overall performance compared to existing materials, and it is economical, making it highly valuable for engineering applications in critical metal components with high performance requirements.

[0039] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A high-performance alloy material for 3D printing, characterized in that: The alloy material has the structural formula FeCoCrNi, wherein the atomic percentage content of each element is in equal or approximately equal proportion, and the range is 23.5% to 26.5%.

2. The 3D printing high-performance alloy material according to claim 1, characterized in that: The raw material is spherical FeCoCrNi metal powder with a purity of 99.9 wt%, and meets the following characteristic requirements: (1) The particle size range of the raw material powder is 10-53 μm, of which large particles larger than 40 μm account for less than 5%; (2) The sphericity of the raw material powder is > 0.9; (3) The Hall flow rate of the raw material powder is 15-25 g / cm. 3 ; (4) The loose packing density of the raw material powder is >4 g / cm³. 3 ; (5) The tap density of the raw material powder is >5 g / cm³. 3 .

3. A method for preparing the 3D-printed high-performance alloy material according to claim 1 or 2, characterized in that: Selective laser melting technology is used for 3D printing. The laser spot diameter is 40-50 μm. During printing, a strip is scanned with a strip width of 4-6 mm. The strip rotates layer by layer at an angle of 67°. The thickness of each print is 25-35 μm.

4. The method for preparing 3D printed high-performance alloy materials according to claim 3, characterized in that, Includes the following steps: (1) Dry the raw metal powder to remove residual moisture; (2) Load the dried powder into the printer's toner cartridge; (3) Insert the 316L stainless steel substrate into the printing chamber and adjust it to be level, ensuring that the substrate surface is smooth and free of pits; (4) Preheat the substrate and pre-lay a layer of raw material powder 25-35 μm thick; (5) The chamber is first evacuated and then backfilled with argon gas to use a protective atmosphere to avoid oxidation reaction; (6) Import the 3D model into the slicing software for layer processing, export the 2D graphics, and input the process parameters; (7) The laser selectively melts and shapes the powder according to the set scanning path. After one layer is completed, the substrate drops by 25-35 μm. The equipment automatically continues to lay another layer of powder on the substrate through the scraper, repeating the melting and shaping until all printing is completed, and an alloy block sample based on 3D printing is obtained.

5. The method for preparing 3D printed high-performance alloy materials according to claim 4, characterized in that: In step (1), the drying temperature is 80℃~120℃ and the drying time is 2~3 h.

6. The method for preparing 3D printed high-performance alloy materials according to claim 4, characterized in that: In step (2), the printer toner cartridge has a size of 170 mm × 170 mm × 300 mm.

7. The method for preparing 3D printed high-performance alloy materials according to claim 4, characterized in that: In step (3), the substrate has a size of 170 mm × 170 mm × 30 mm. It is polished using an angle grinder and then wiped with ether before use.

8. The method for preparing 3D printed high-performance alloy materials according to claim 4, characterized in that: In step (4), the preheating temperature of the substrate is 100-120°C.

9. The method for preparing 3D printed high-performance alloy materials according to claim 4, characterized in that: In step (5), a mechanical pump is used to evacuate the chamber to <5 Pa, and the argon flow rate is 5-10 L / min. During the printing process, the oxygen concentration in the chamber is kept below 0.1%.

10. The method for preparing 3D printed high-performance alloy materials according to claim 4, characterized in that: The process parameters set in step (6) are: laser power 180W~250W, scanning speed 550~600mm / s, and scanning spacing 60~70μm.

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