High-entropy alloy component and laser direct deposition forming method thereof

Abstract

The invention provides a high-entropy alloy component and a laser direct deposition forming method thereof. The forming method comprises the following steps that high-entropy alloy powder and manganese elementary substance powder are mixed to obtain mixed powder; carrying out heat preservation on the mixed powder at a certain temperature; under the protection of inert atmosphere, cladding the pretreated mixed powder on a substrate layer by layer through a laser direct deposition technology to form a high-entropy alloy component; the obtained formed high-entropy alloy component is subjected to heat treatment under inert atmosphere protection, and the high-entropy alloy component is obtained; wherein the atomic percent x of the manganese element is more than 0 and less than or equal to 17%. According to the method, the technical bottleneck of solidification structure cracking is solved, laser direct deposition additive manufacturing of the crack-free high-toughness high-entropy alloy is achieved, the technological method is easy to implement, the cost is low, stability and robustness are good, good universality is achieved, and the method can be conveniently expanded and used in laser direct deposition additive manufacturing processes of other alloy materials.

Description

Technical Field

[0001] This invention relates to the field of laser additive manufacturing technology, and in particular to a high-entropy alloy component and its laser direct deposition forming method. Background Technology

[0002] High-entropy alloys, as a new type of multi-principal element alloy material, break through the traditional design concept of alloys based on one or two metals. They typically contain five or more metallic elements with equal or close atomic ratios. This unique compositional design gives high-entropy alloys excellent service performance, such as high strength, high toughness, corrosion resistance, and oxidation resistance. They have great potential in the development of new alloy materials and have developed rapidly in recent decades.

[0003] However, the fabrication of high-performance high-entropy alloy components is a key bottleneck in realizing their engineering applications. Traditional fabrication methods, such as casting and vacuum arc melting, can produce high-entropy alloy ingots, but they have inherent limitations such as complex processes, long production cycles, and difficulty in manufacturing complex-shaped components, which restrict the rapid development and application of high-entropy alloys.

[0004] Laser direct deposition (LDD), a crucial branch of additive manufacturing, offers a revolutionary solution for near-net-shape forming of complex metal components. This technology uses a high-energy laser as a heat source to locally melt a substrate, forming a molten pool. Simultaneously, metal material is fed into the molten pool for in-situ metallurgy and rapid solidification, achieving additive manufacturing. Subsequently, under the control of a CNC system, the material is scanned line by line and deposited layer by layer along a preset path, resulting in a near / net-shape dense three-dimensional solid part. LDD offers advantages such as mold-free operation, high flexibility, and rapid response, making it a popular technology for manufacturing metal parts. Furthermore, LDD allows for the free design and proportioning of alloy material compositions, making it ideal for the forming and manufacturing of high-entropy alloy components.

[0005] However, when using laser direct deposition technology to prepare high-entropy alloys, a large number of microcracks are often generated in the solidification structure. These microcracks cause stress concentration and induce crack propagation, which seriously reduces the mechanical properties and fatigue resistance of laser additive high-entropy alloys.

[0006] Therefore, how to suppress the generation of microcracks and improve the toughness of the formed structure during the laser direct deposition of high-entropy alloys is the key core issue in breaking through the laser additive manufacturing of high-strength and high-entropy alloys. Summary of the Invention

[0007] The purpose of this invention is to provide a high-entropy alloy component and a laser direct deposition forming method thereof, which solves at least one of the problems mentioned in the background art.

[0008] A first aspect of the present invention provides a laser direct deposition method for forming high-entropy alloy components, comprising the following steps: S1. Mix high-entropy alloy powder with manganese elemental powder to obtain a mixed powder; S2. Keep the mixed powder obtained in step S1 at a certain temperature; S3. Under an inert atmosphere, the mixed powder pretreated in step S2 is deposited layer by layer onto the substrate using laser direct deposition technology to form a high-entropy alloy component. S4. The high-entropy alloy component obtained in step S3 is heat-treated under an inert atmosphere to obtain the high-entropy alloy component. The atomic percentage x of manganese is 0 < x ≤ 17%.

[0009] According to some embodiments, the high-entropy alloy powder in step S1 is composed of five elements; preferably, the high-entropy alloy powder is one or a mixture of AlCoCrFeNi high-entropy alloy powder, CoCrFeNiMo high-entropy alloy powder, CoCrFeNiV high-entropy alloy powder, AlCrFeNiV high-entropy alloy powder, and HfNbZrTi high-entropy alloy powder; preferably, the atomic percentage of each element in the high-entropy alloy powder is 18-22%; preferably, the particle size range of the high-entropy alloy powder is 55-140 μm, and the average particle size is 70-80 μm; preferably, the purity of the manganese elemental powder is ≥99%, preferably ≥99.9%, the particle size range is 65-150 μm, and the average particle size is 70-85 μm.

[0010] According to some embodiments, the heat preservation in step S2 is carried out in a vacuum or inert environment; preferably, it is carried out at a temperature above 90°C for more than 2 hours.

[0011] According to some embodiments, the substrate surface in step S3 is subjected to grinding, sanding, ultrasonic cleaning, organic solvent cleaning, and drying; preferably, the substrate is an alloy material, preferably SS316L stainless steel; preferably, the thickness of the substrate is ≥12mm.

[0012] According to some embodiments, the process parameters for direct laser deposition in step S3 include: laser power 100~2500 W, scanning speed 1~20 mm / s; preferably, the process parameters for direct laser deposition also include: laser focal spot diameter 0.5~5.5 mm, laser defocusing amount -5~+12 mm, powder feeding rate 3~10 g / min, and scanning spacing 0.1~3.5 mm.

[0013] According to some embodiments, before deposition, the coaxiality of the laser spot and the powder spot is adjusted so that they converge coaxially and cofocally on the substrate surface; preferably, the inert atmosphere is high-purity argon with a purity ≥99.99%; and the forming area is preheated during the deposition process so that the overall preheating temperature of the component is ≥200°C.

[0014] According to some embodiments, the heat treatment is carried out in an atmosphere-protected tubular furnace, specifically including: before the heat treatment, a large flow rate of high-purity argon gas is introduced into the furnace cavity to rapidly reduce the oxygen concentration in the furnace cavity to ≤200 ppm; during the heat treatment, a small flow rate of high-purity argon gas is continuously introduced into the furnace cavity to maintain the oxygen content in the furnace cavity at ≤100 ppm.

[0015] According to some embodiments, the flow rate of high-purity argon gas introduced before heat treatment is ≥20 L / min, and the flow rate of high-purity argon gas introduced during heat treatment is ≤0.1 L / min.

[0016] According to some embodiments, in step S4, the heating rate of the heat treatment is 1~20℃ / s, the holding temperature is ≥1000℃, the holding time is 0~100 h, and the cooling rate is 1~100℃ / s.

[0017] In a second aspect, the present invention provides a high-entropy alloy component manufactured by the laser direct deposition forming method described above.

[0018] The present invention has at least the following beneficial effects: 1. The process method of the present invention solves the technical bottleneck of solidification cracking caused by the laser direct deposition forming method of high entropy alloy components, and realizes the laser direct deposition additive manufacturing of crack-free high-strength and high-toughness high entropy alloys (such as AlCoCrFeNi). 2. The process method of the present invention is simple to implement, low in cost, and has good stability and robustness; 3. The process method of the present invention has good versatility and can be easily extended and applied to laser direct deposition additive manufacturing processes for other alloy materials. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the AlCoCrFeNi high-entropy alloy part prepared in Comparative Example 1 of the present invention. Figure 2 This is an optical microscope image of the microstructure of the AlCoCrFeNi high-entropy alloy prepared in Comparative Example 1 of this invention. Figure 3 Mn prepared in Example 1 of this invention 0.25 Optical microscope image of the microstructure of AlCoCrFeNi high-entropy alloy; Figure 4 Mn prepared in Example 2 of this invention 0.5 Optical microscope image of the microstructure of AlCoCrFeNi high-entropy alloy; Figure 5 The AlCoCrFeNi high-entropy alloy prepared in Comparative Example 1 of this invention and the Mn alloy prepared in Example 1 are examples of the high-entropy alloy prepared in this invention. 0.25 AlCoCrFeNi high-entropy alloy and Mn prepared in Example 2 0.5 Comparison of tensile mechanical properties of AlCoCrFeNi high-entropy alloy; Figure 6 Mn prepared in Example 1 of this invention 0.25 A schematic diagram of an AlCoCrFeNi high-entropy alloy part. Detailed Implementation

[0021] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0022] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form includes the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0023] It should be noted that if the text uses terms such as "first" or "second", these terms are only used to distinguish similar objects and should not be interpreted as indicating or implying their relative importance, order of precedence, or implicitly indicating the number of technical features indicated. It should be understood that the data in the descriptions of "first" and "second" can be interchanged where appropriate.

[0024] Throughout the accompanying drawings, identical elements are represented by the same or similar reference numerals. Conventional structures or configurations may be omitted where they might cause confusion in understanding the invention. Furthermore, the shapes, dimensions, and positional relationships of the components in the drawings do not reflect actual size, scale, or actual positional relationships. Additionally, any reference symbols placed within parentheses in this invention should not be construed as limiting the scope of the invention.

[0025] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. 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.

[0026] One aspect of the present invention provides a laser direct deposition method for forming high-entropy alloy components, comprising the following steps: S1. Mix high-entropy alloy powder with manganese elemental powder to obtain a mixed powder; S2. The mixed powder obtained in step S1 is kept at a certain temperature to remove impurities from the powder surface; S3. Under an inert atmosphere, the pretreated mixed powder from step S2 is deposited layer by layer onto substrate 1 (e.g., ...) using laser direct deposition technology. Figure 6 (As shown) Forming high-entropy alloy components; S4. The high-entropy alloy component obtained in step S3 is heat-treated under an inert atmosphere to obtain high-entropy alloy component 2, as shown. Figure 6 As shown; The atomic percentage x of manganese is 0 < x ≤ 17%, for example, 0.5%, 3%, 7%, 11%, 15%, etc.

[0027] The method described in the above embodiments achieves laser additive manufacturing of high-strength and high-toughness high-entropy alloys by incorporating an appropriate amount of Mn into traditional high-entropy alloys and strictly controlling the Mn ratio. This method is simple to implement, low in cost, and exhibits good stability and robustness. Furthermore, this process method has good versatility and can be easily applied to laser direct deposition additive manufacturing processes for many high-entropy alloy materials.

[0028] The high-entropy alloy component 2 on the substrate 1 can be removed from the substrate by a suitable method such as cutting, and then processed later according to the intended use to obtain the final product.

[0029] The high-entropy alloy can contain five or more alloying elements. In some embodiments, the high-entropy alloy powder in step S1 can be composed of five elements.

[0030] In some embodiments, the high-entropy alloy powder can be one or more of AlCoCrFeNi high-entropy alloy powder, CoCrFeNiMo high-entropy alloy powder, CoCrFeNiV high-entropy alloy powder, AlCrFeNiV high-entropy alloy powder, and HfNbZrTi high-entropy alloy powder, preferably AlCoCrFeNi high-entropy alloy powder. The alloy formed by this method has particularly good properties, no obvious microcracks inside, and better toughness than high-entropy alloys without added Mn.

[0031] In some embodiments, the atomic percentage of each element in the high-entropy alloy powder is 18-22%. High-entropy alloy powders within this range exhibit excellent high-entropy properties and good mechanical properties. That is, the atomic percentage of each of the five elements in the high-entropy alloy powder is 18-22%, for example, 18.5%, 19%, 20%, 21%, 21.6%, etc. The proportion of each element can be the same or different; for example, the atomic percentage of each of the five elements can be 20%, or they can be 18%, 20%, 20%, 22%, 20%, respectively.

[0032] For example, when the high-entropy alloy powder is an AlCoCrFeNi high-entropy alloy powder, the atomic percentage of each element can be: Al: 19%, Co: 20%, Cr: 21%, Fe: 20%, Ni: 20%, or the atomic percentage of each element is 20%. The final component made from this type of high-entropy alloy powder has particularly high strength and toughness.

[0033] AlCoCrFeNi is a typical single-phase BCC high-entropy alloy with excellent high strength and corrosion resistance. However, AlCoCrFeNi high-entropy alloys are very hard and brittle, exhibiting extremely high crack susceptibility. Currently, AlCoCrFeNi high-entropy alloys are mainly prepared using casting and vacuum arc melting methods, which are difficult to use for the rapid and efficient manufacture of high-performance components. When using laser direct deposition technology to prepare AlCoCrFeNi high-entropy alloys, a large number of microcracks are often generated in the solidification structure. These microcracks cause stress concentration and induce crack propagation, severely reducing the mechanical properties and fatigue resistance of laser additive manufacturing of AlCoCrFeNi high-entropy alloys. The AlCoCrFeNi high-entropy alloy components prepared by the method described in this invention show no cracks in the solidification structure and possess excellent elongation and ultimate tensile strength.

[0034] In some embodiments, the particle size of the high-entropy alloy powder ranges from 55 to 140 μm, with an average particle size of 70 to 80 μm, such as 72 μm, 75 μm, or 78 μm. This powder particle size can be used for laser cladding additive manufacturing via laser powder spraying. Within the above particle size range, the powder exhibits good flowability and focusing properties, resulting in fewer internal pores and defects in the manufactured components. Furthermore, it facilitates the use of a carrier gas conveying method for the powder feeder.

[0035] In some embodiments, the purity of the manganese elemental powder is ≥99%, preferably ≥99.9%, the particle size range is 65~150 μm, and the average particle size is 70~85 μm, for example, 72 μm, 75 μm, 78 μm, 83 μm, etc. The above-mentioned particle size range of the manganese elemental powder also has the effect of the particle size range of the high-entropy alloy powder described above. Furthermore, the particle sizes of the two should not differ too much, otherwise, uneven mixing will occur, leading to a large deviation between the elemental composition and the design values ​​in the manufactured microstructure. Therefore, setting a matching particle size range in this way is beneficial for uniform mixing and achieving the desired effect.

[0036] To avoid affecting the microstructure of the mixed powder, in some embodiments, the heat preservation in step S2 is performed in a vacuum or inert environment. The inert environment can be a high-purity argon atmosphere, for example, argon with a purity ≥99.99%.

[0037] In some embodiments, the powder is kept at a temperature above 90°C for at least 2 hours to remove impurities such as moisture adhering to the powder surface and increase the flowability of the mixed powder. For example, it is kept at 100°C for 3 hours, at 95°C for 4 hours, or at 110°C for 2.2 hours.

[0038] To remove rust, oil, and other impurities from the substrate surface, ensuring these substances do not affect the laser absorption rate or contaminate the alloy composition, thereby preventing manufacturing failures, in some embodiments, the substrate surface in step S3 undergoes grinding, sanding, ultrasonic cleaning, organic solvent cleaning, and drying. The organic solvent can be alcohol, acetone, etc.

[0039] In some embodiments, the substrate is an alloy material, preferably SS316L stainless steel.

[0040] Laser additive manufacturing involves rapid heating and cooling, generating significant internal stress within the material. If the substrate is too thin, it will warp and bend under this stress, leading to manufacturing instability or even failure, or causing significant dimensional deviations in the manufactured parts. Therefore, in some embodiments, the substrate thickness is ≥12 mm, such as 15 mm, 20 mm, or 35 mm.

[0041] During deposition, the substrate can be placed on the processing table and secured with clamps. Adjust the laser cladding head to keep it vertically downward. Load the high-entropy alloy mixed powder material into the powder feeder, using argon gas (purity ≥99.99%) as the carrier gas. Using argon gas for powder feeding prevents air from entering the cladding head. Otherwise, oxygen in the air will react with the laser-melted metal to form oxides, which will enter the solidified structure and greatly weaken or even destroy the mechanical properties of the formed metal component.

[0042] To ensure a stable manufacturing process, avoid fluctuations or even failures, and meet the requirements for solidified microstructure, preventing cracks and the formation of harmful phases, in some embodiments, the laser direct deposition process parameters in step S3 include: laser power of 100~2500 W, such as 300 W, 600 W, 1000 W, 1500 W, 2000 W, 2400 W, etc., and scanning speed of 1~20 mm / s, such as 3 mm / s, 7 mm / s, 14 mm / s, 19 mm / s, etc.

[0043] In some preferred embodiments, the process parameters for direct laser deposition may also include: laser focal spot diameter of 0.5~5.5 mm, laser defocusing amount of -5~+12 mm, powder feed rate of 3~10 g / min, and scanning spacing of 0.1~3.5 mm, to further increase the stability of the manufacturing process and avoid the occurrence of cracks and the generation of a large number of harmful phases.

[0044] In some embodiments, before deposition, the coaxiality of the laser spot and the powder spot is adjusted, and the stability and convergence of the powder flow are observed to ensure that the laser beam and the powder flow can be coaxially and confocally converged on the surface of the substrate to be processed (i.e., the substrate on which a high-entropy alloy component will be deposited).

[0045] In some embodiments, the inert atmosphere in step S3 is high-purity argon gas with a purity ≥99.99%, and argon gas is used for full-process protection. Furthermore, the forming area is preheated during the deposition process to ensure the overall preheating temperature of the component is ≥200°C, thereby reducing internal stress during manufacturing and preventing substrate warping. An infrared camera can be used to monitor the temperature of the forming area in real time.

[0046] In some embodiments, the heat treatment is carried out in an atmosphere-protected tube furnace, specifically including: Before heat treatment, a large flow of high-purity argon gas is introduced into the furnace cavity to rapidly reduce the oxygen concentration in the furnace cavity to ≤200ppm; During the heat treatment process, a small flow of high-purity argon gas is continuously introduced into the furnace cavity to maintain the oxygen content in the furnace cavity at ≤100ppm.

[0047] This treatment of the atmosphere-protected tubular furnace effectively creates a positive pressure environment of argon gas within the furnace cavity, preventing air from entering the heat treatment furnace cavity and oxidizing the samples, thereby ensuring the mechanical properties of the resulting metal components.

[0048] To further ensure the mechanical properties of the resulting metal components, in some embodiments, the flow rate of high-purity argon gas introduced before heat treatment is ≥20 L / min, and the flow rate of high-purity argon gas introduced during heat treatment is ≤0.1 L / min.

[0049] In some embodiments, the heating rate of the heat treatment in step S4 is 1~20℃ / s, for example, 5℃ / s, 10℃ / s, 15℃ / s, etc.; the holding temperature is ≥1000℃, preferably 1000~1100℃; the holding time is 0~100 h, for example, 5 h, 20 h, 40 h, 60 h, 85 h, etc.; and the cooling rate is 1~100℃ / s, for example, 5℃ / s, 15℃ / s, 30℃ / s, 50℃ / s, 75℃ / s, 90℃ / s, etc. The holding temperature can be adjusted appropriately according to the amount of manganese added. Generally, the more manganese added, the higher the holding temperature, in order to avoid the formation of hard and brittle precipitates such as the sigma phase and the B2 phase, which would reduce the mechanical properties of the formed material. For example, research has found that when the atomic percentage of manganese is about 5%, the holding temperature can be set to 1050℃, and when the atomic percentage of manganese is 9%, the holding temperature can be set to 1150℃.

[0050] Another aspect of the present invention provides a high-entropy alloy component prepared by the aforementioned laser direct deposition method. The component prepared according to the method of the present invention exhibits no obvious microcracks and possesses superior toughness compared to high-entropy alloys without added Mn.

[0051] The high-entropy alloy (e.g., AlCoCrFeNi high-entropy alloy) forming method proposed in this invention, on the one hand, incorporates an appropriate amount of Mn element into traditional high-entropy alloys and strictly controls the proportion of Mn element, and on the other hand, combines with subsequent heat treatment processes to manufacture high-entropy alloy components with crack-free, high strength and toughness through a specific laser direct deposition additive manufacturing process.

[0052] The present invention will be further described in detail below with reference to specific embodiments. It should be understood that these descriptions are for illustrative purposes only and are not intended to limit the scope of the invention.

[0053] Example 1 Preparation of Mn x AlCoCrFeNi ( x=0.25, atomic percentage of 4.8%), wherein the atomic ratio of AlCoCrFeNi powder is 1:1:1:1:1, the process conditions are as follows: laser power of 2000 W, defocusing amount of 0 mm, spot size of 3.2 mm, laser scanning speed of 8 mm / s, scanning interval of 1.7 mm, powder feeding rate of 7 g / min, heat treatment heating rate of 10℃ / s, holding temperature of 1050℃, holding time of 8 h, and cooling rate of 10℃ / s. Figure 3 Mn prepared in this embodiment 0.25 An optical microscope image of the microstructure of the AlCoCrFeNi high-entropy alloy. As can be seen from the image, no cracks were observed in the solidified structure.

[0054] Example 2 Preparation of Mn x AlCoCrFeNi ( x =0.5, atomic percentage is 9.1%), wherein the ratio of atoms in AlCoCrFeNi powder is 1:1:1:1:1. The process conditions are as follows: laser power is 2000 W, defocusing amount is +6 mm, spot size is 5.0 mm, laser scanning speed is 8 mm / s, scanning interval is 1.7 mm, powder feeding rate is 7 g / min, heat treatment heating rate is 10℃ / s, holding temperature is 1150℃, holding time is 8 h, and cooling rate is 10℃ / s. Figure 4 Mn prepared in this embodiment 0.5 An optical microscope image of the microstructure of the AlCoCrFeNi high-entropy alloy. As can be seen from the image, no cracks were observed in the solidified structure.

[0055] Comparative Example 1 Preparation of Mn x AlCoCrFeNi ( x =0.0), wherein the ratio of atoms in AlCoCrFeNi powder is 1:1:1:1:1, the process conditions are as follows: laser power is 2000 W, defocusing amount is 0 mm, spot size is 3.2 mm, laser scanning speed is 8 mm / s, scanning spacing is 1.7 mm, powder feeding rate is 7 g / min, heat treatment heating rate is 10℃ / s, holding temperature is 1000℃, holding time is 8 h, and cooling rate is 10℃ / s. Figure 1 This is a schematic diagram of the AlCoCrFeNi high-entropy alloy part prepared in this comparative example. Figure 2 This is an optical microscope image of the microstructure of the AlCoCrFeNi high-entropy alloy prepared in this comparative example. From... Figure 2 As can be seen, there are a large number of fine cracks in the solidified structure.

[0056] Mn prepared in Example 1, Example 2 and Comparative Example 1 0.25 AlCoCrFeNi high-entropy alloy, Mn 0.5 Tensile mechanical properties of AlCoCrFeNi high-entropy alloy and AlCoCrFeNi high-entropy alloy were tested.

[0057] Figure 5 Mn prepared for Example 1, Example 2, and Comparative Example 1 x AlCoCrFeNi (0.0≤ x Comparison of tensile mechanical properties of solidified microstructures of high-entropy alloys (≤1.0). The comparison in the figure reveals: • In Comparative Example 1, without the addition of Mn, the AlCoCrFeNi high-entropy alloy exhibits 0.69% ductility and an ultimate tensile strength of 324 MPa. • Added in Example 1 x When Mn has a value of 0.25, Mn 0.25 The AlCoCrFeNi high-entropy alloy has an elongation of 5.99% and an ultimate tensile strength of 984 MPa. • Added in Example 2 x When Mn is equal to 0.50, Mn 0.5 The AlCoCrFeNi high-entropy alloy has an elongation of 13.87% and an ultimate tensile strength of 927 MPa. • The methods in Examples 1 and 2 yielded crack-free, high-strength and high-toughness AlCoCrFeNi high-entropy alloy parts.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for laser direct deposition forming of high-entropy alloy components, characterized in that, Includes the following steps: S1. Mix high-entropy alloy powder with manganese elemental powder to obtain a mixed powder; S2. Keep the mixed powder obtained in step S1 at a certain temperature; S3. Under an inert atmosphere, the mixed powder pretreated in step S2 is deposited layer by layer onto the substrate using laser direct deposition technology to form a high-entropy alloy component. S4. The high-entropy alloy component obtained in step S3 is heat-treated under an inert atmosphere to obtain the high-entropy alloy component. The atomic percentage x of manganese is 0 < x ≤ 17%.

2. The laser direct deposition forming method according to claim 1, characterized in that, The high-entropy alloy powder in step S1 is composed of 5 elements; Preferably, the high-entropy alloy powder is one or a mixture of AlCoCrFeNi high-entropy alloy powder, CoCrFeNiMo high-entropy alloy powder, CoCrFeNiV high-entropy alloy powder, AlCrFeNiV high-entropy alloy powder and HfNbZrTi high-entropy alloy powder; Preferably, the atomic percentage of each element in the high-entropy alloy powder is 18-22%; Preferably, the particle size range of the high-entropy alloy powder is 55~140 μm, and the average particle size is 70~80 μm; Preferably, the purity of the manganese powder is ≥99%, more preferably ≥99.9%, the particle size range is 65~150 μm, and the average particle size is 70~85 μm.

3. The laser direct deposition forming method according to claim 1 or 2, characterized in that, The heat preservation in step S2 is carried out in a vacuum or inert environment; Preferably, the temperature is maintained at 90°C or above for more than 2 hours.

4. The laser direct deposition forming method according to any one of claims 1 to 3, characterized in that, The substrate surface in step S3 undergoes grinding, sanding, ultrasonic cleaning, organic solvent cleaning, and drying. Preferably, the substrate is an alloy material, and more preferably SS316L stainless steel; Preferably, the thickness of the substrate is ≥12 mm.

5. The laser direct deposition forming method according to any one of claims 1 to 4, characterized in that, The process parameters for laser direct deposition in step S3 include: laser power 100~2500 W, scanning speed 1~20 mm / s; Preferably, the process parameters for direct laser deposition further include: laser focal spot diameter of 0.5~5.5 mm, laser defocusing amount of -5~+12 mm, powder feeding rate of 3~10 g / min, and scanning spacing of 0.1~3.5 mm.

6. The laser direct deposition forming method according to any one of claims 1 to 5, characterized in that, Before deposition, the coaxiality of the laser spot and the powder spot is adjusted so that they are coaxially and confocally converged on the substrate surface. Preferably, the inert atmosphere is high-purity argon gas with a purity ≥ 99.99%; Furthermore, the forming area is preheated during the deposition process to ensure that the overall preheating temperature of the component is ≥200℃.

7. The laser direct deposition forming method according to any one of claims 1 to 6, characterized in that, The heat treatment is carried out in a protected atmosphere tube furnace, specifically including: Before heat treatment, a large flow of high-purity argon gas is introduced into the furnace cavity to rapidly reduce the oxygen concentration in the furnace cavity to ≤200 ppm; During the heat treatment process, a small flow rate of high-purity argon gas is continuously introduced into the furnace cavity to maintain the oxygen content in the furnace cavity at ≤100 ppm.

8. The laser direct deposition forming method according to claim 7, characterized in that, Before heat treatment, the flow rate of high-purity argon gas is ≥20 L / min, and during heat treatment, the flow rate of high-purity argon gas is ≤0.1 L / min.

9. The laser direct deposition forming method according to any one of claims 1 to 8, characterized in that, In step S4, the heating rate of the heat treatment is 1~20℃ / s, the holding temperature is ≥1000℃, the holding time is 0~100 h, and the cooling rate is 1~100℃ / s.

10. A high-entropy alloy component, characterized in that, The component is prepared by the laser direct deposition forming method according to any one of claims 1 to 9.

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