Method and application of electron beam three-wire in-situ additive manufacturing of refractory high-entropy alloy TiZrNbHfTa

Abstract

The application relates to a method for electron beam three-wire in-situ additive manufacturing of a TiZrNbHfTa refractory high-entropy alloy and application. The application belongs to the technical field of additive manufacturing. The application aims to solve the technical problems of high melting point, difficult processing and forming of the refractory high-entropy alloy. The method comprises the following steps: firstly, three-dimensional modeling is carried out on a target component, and slicing processing is carried out; then, three-wire printing is adopted, the relative position relationship of the three wires, the angle and distance between the three wires and a substrate are set, the wire feeding speed is set, and the electron beam scanning mode is set; finally, 3D printing is carried out. The method realizes flexible regulation and control of alloy components and integrated forming of the refractory high-entropy alloy. The non-equiatomic refractory TiZrNbHfTa high-entropy alloy prepared by the application is uniform in components, no non-penetration condition is observed, has a dendritic crystal organization, the grain orientation perpendicular to the deposition direction is random, and has excellent high-temperature mechanical properties.

Description

Technical Field

[0001] This invention belongs to the field of additive manufacturing technology, specifically relating to a method and application of in-situ electron beam three-wire additive manufacturing of refractory high-entropy alloys TiZrNbHfTa. Background Technology

[0002] Refractory high-entropy alloys are a novel type of high-temperature structural material, whose room-temperature and high-temperature properties are generally superior to those of traditional refractory metals and alloys. Therefore, refractory high-entropy alloys have significant application potential in high-temperature, high-strength, and corrosion-resistant fields, such as high-temperature components in aero-engines, heat exchanger piping, and high-temperature alloy components in the chemical processing industry, where nickel-based superalloys are currently widely used. Despite these excellent properties, the high melting points of the constituent elements (generally above 1800℃) and the large differences in melting points between them pose significant challenges to the preparation, microstructure and property control, and component forming of refractory high-entropy alloys, thus limiting their further application and promotion.

[0003] Over the past decade, additive manufacturing technology has achieved a qualitative leap from prototyping to direct manufacturing. Its simple preparation process and flexible forming freedom have effectively improved the problems of long preparation time, high cost, and low utilization rate associated with traditional casting-forging-machining methods. Electron beam fused deposition technology, using high-energy electron beams as heat sources and metal wires as raw materials, boasts advantages such as high power, high energy utilization, a vacuum processing environment, and high deposition efficiency, enabling near-net-shape rapid fabrication of large and complex metal components. Therefore, how to achieve high-quality, high-speed, large-size integrated fabrication and forming of refractory high-entropy alloys using electron beam fused deposition technology has been a key technical challenge that the field has been committed to solving. Summary of the Invention

[0004] The purpose of this invention is to solve the technical problems of high melting point, difficult processing and forming of refractory high-entropy alloys, and to provide a method and application for in-situ additive manufacturing of TiZrNbHfTa refractory high-entropy alloys using electron beam three-wire additive manufacturing.

[0005] The technical solution of the present invention is as follows:

[0006] One objective of this invention is to provide a method for in-situ additive manufacturing of refractory high-entropy alloys TiZrNbHfTa using electron beam three-wire technology, the method comprising the following steps:

[0007] S1: Perform 3D modeling of the target component and slice it, while pre-processing the printing filament and substrate;

[0008] S2: Ti-45Nb alloy wire, 702Zr wire and pure Ta wire are used as printing wires. Ti-45Nb alloy wire and 702Zr wire are fed at the same speed by the same nozzle. Pure Ta wire is fed by a separate nozzle. The two nozzles are opposite each other. The angle between the three wires and the horizontal direction is 45-60°. The vertical distance between the front end (free end) of the three wires and the substrate is 0.6-3mm. The wire feeding speed is 0.36-1.1m / min. The intersection of the three wires is at the central axis of the electron beam.

[0009] S3: Set the electron beam filament additive manufacturing parameters. The electron beam scanning mode is teardrop, crescent, or circle. Then, 3D printing is performed under vacuum conditions according to the slice data.

[0010] Further specifying, in S1: pretreatment includes grinding, polishing, cleaning, and drying.

[0011] Further specifying, in S2: the angle between the two wires fed by the same wire nozzle and the horizontal direction is the same.

[0012] Further specified, in S2: the vertical distance between the leading edge of the two wires fed by the same wire nozzle and the substrate is the same.

[0013] Further specifying, in S3: the printing process parameters are: focusing current I f 1080-1130mA, beam current I b The A current is 130-180mA, the scanning frequency is 200-400Hz, the printing path is a repetitive straight line, and the printing speed is V. print The flow rate is 500-700 mm / min, the interlayer cooling time is 30-60 s, and the vacuum degree is <9.9 × 10⁻⁶. -3 Pa.

[0014] Further specifying, in S3: the preferred electron beam scanning mode is teardrop shape.

[0015] Further specifying S3: the teardrop shape has a height of 350-450μm, a bottom width of 250-350μm, a straight-line distance between the midpoints of the two arcs of the crescent shape of 300-400μm, a straight-line distance between the two end points of 250-350μm, and a circular diameter of 200-400μm.

[0016] Further specifying, in S3: substrate preheating before printing, I b 60mA, printing speed V print The speed is 600 mm / min.

[0017] The second objective of this invention is to provide a refractory high-entropy alloy prepared by the above method, wherein the alloy has a tensile yield strength ≥640MPa, an ultimate tensile strength ≥730MPa, and an elongation ≥20% at 450℃.

[0018] The third objective of this invention is to provide a refractory high-entropy alloy prepared by the above method as a high-temperature alloy component for use in aero-engines, heat exchangers, and chemical processing.

[0019] The fourth objective of this invention is to provide an application of the above method in the preparation of other high-melting-point alloys with large melting point differences.

[0020] The advantages of this invention compared to the prior art are:

[0021] (1) The present invention adopts an electron beam three-wire in-situ additive manufacturing method. By setting the relative position relationship of the three wires, the angle and distance between the three wires and the substrate, and by controlling the wire feeding speed of the three wires, the alloy composition can be flexibly adjusted to achieve the integrated forming of refractory high-entropy alloy.

[0022] (2) The non-equiatomic ratio refractory TiZrNbHfTa high entropy alloy prepared by the present invention has a uniform composition, no incomplete melting was observed, has a dendritic structure, and the grain orientation perpendicular to the deposition direction is random. It has excellent high temperature mechanical properties, with a tensile yield strength of 649 MPa and an ultimate tensile strength of 731 MPa at 450℃, and an elongation of ~22%.

[0023] (3) The present invention is made in a vacuum environment, which is conducive to the preparation of this highly active refractory high-entropy alloy and effectively improves the purity of the alloy forming.

[0024] (4) Because refractory TiZrNbHfTa high-entropy alloys have high melting points, it is very difficult to use traditional preparation and processing techniques, or to carry out powder additive manufacturing through casting. Using an electron beam as a heat source, this technology has high power and high energy utilization, which also reflects the applicability of the electron beam three-wire in-situ additive manufacturing method of this invention. It can be applied to the in-situ fused wire deposition of large-size complex components of other high-activity high-temperature alloys / high-entropy alloys, and has strong practicality. Attached Figure Description

[0025] Figure 1 The diagram shows the shape of the electron beam scanning mode in the method of the present invention; ①-circular, ②-teardrop, ③crescent-shaped;

[0026] Figure 2 This is a schematic diagram showing the positional relationship of the three wires in the method of the present invention;

[0027] Figure 3 A photograph of the refractory TiZrNbHfTa high-entropy alloy obtained in Example 1 of this invention;

[0028] Figure 4The grain orientation (IPF) diagram of the refractory TiZrNbHfTa high-entropy alloy obtained in Example 1 of this invention;

[0029] Figure 5 The microstructure of the refractory TiZrNbHfTa high-entropy alloy obtained in Example 1 of this invention is shown in the figure.

[0030] Figure 6 The image shows the high-temperature tensile stress-strain curve at 450°C of the refractory TiZrNbHfTa high-entropy alloy obtained in Example 1 of this invention.

[0031] Figure 7 This is a physical image of the refractory TiZrNbHfTa high-entropy alloy obtained in Example 2 of the present invention. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0033] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials, reagents, methods, and instruments used are all conventional materials, reagents, methods, and instruments in the art, and can be obtained commercially by those skilled in the art.

[0034] The terms “comprising,” “including,” “having,” “containing,” or any other variations thereof, as used in the following embodiments, are intended to cover a non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such a composition, step, method, article, or apparatus.

[0035] Example 1:

[0036] The method for in-situ additive manufacturing of refractory high-entropy alloys TiZrNbHfTa using electron beam three-wire additive manufacturing in this embodiment is carried out according to the following steps:

[0037] (1) Ti-45Nb alloy wire (Ti:Nb = 55:45 wt.%), 702Zr wire (Zr:Hf = 97.8:2.08 wt.%), and pure Ta wire with diameters of 1.6 mm, 1.2 mm, and 1.2 mm, respectively, were polished to a bright state using an angle grinder. The substrate surface was then cleaned with acetone and alcohol to remove surface impurities and contaminants. After cleaning, each substrate was placed in a 50°C constant temperature drying oven and dried for 2 hours to remove excess moisture. A TA1 substrate with dimensions of 150 mm × 10 mm × 20 mm was polished to a bright state using an angle grinder. The substrate surface was then cleaned with acetone and alcohol to remove surface impurities and contaminants. After cleaning, it was placed in a 50°C constant temperature drying oven and dried for 2 hours to remove excess moisture.

[0038] (2) Fix the processed Ti-45Nb alloy wire, 702Zr wire, and pure Ta wire onto different wire feeding mechanisms. Fix the substrate to the worktable, adjust the angle between the wire feeding nozzle and the substrate, and adjust the distance between the wire and the electron beam. Close the chamber door and evacuate to achieve the predetermined working vacuum level (<9.9×10). -3 After Pa), the program settings are performed. Ti-45Nb alloy wire and 702Zr wire are fed together using the same nozzle, while pure Ta wire is fed separately using a separate nozzle. The two nozzles are positioned opposite each other. The Ti-45Nb alloy wire and 702Zr wire are fed at a constant speed using a common point. The intersection of the three wires is at the central axis of the electron beam. The angles between the two wires on the same side (Ti-45Nb alloy wire and 702Zr wire) and the horizontal direction are the same, both being 54°. The angle between the pure Ta wire and the horizontal direction is also 54°. The vertical distance between the tip of the two wires on the same side (Ti-45Nb alloy wire and 702Zr wire) and the substrate is 0.7 mm, and the vertical distance between the tip of the pure Ta wire and the substrate is 0.5 mm. The wire feeding speed is V. 702Zr =V Ti-45Nb =1m / min, V Ta =0.9 m / min.

[0039] (3) Before printing, the substrate is preheated by single-pass remelting, with a beam current density of I. b 60mA, printing speed V print The speed is 600 mm / min, the scanning path is a reciprocating linear motion, and the scanning mode is the same as the deposition mode.

[0040] (4) Set the electron beam filament additive manufacturing parameters, and set the electron beam scanning mode to teardrop shape (e.g., ...). Figure 1 As shown in ②, the teardrop shape has a height L1 of 400 μm and a bottom width L2 of 300 μm. The scanning frequency is 300 Hz. 3D printing is performed under vacuum conditions according to the slice data. The printing process parameters are: focusing current I... f 1080mA, beam current I bThe current is 180mA, the printing path is a repetitive straight line, and the printing speed is V. print The deposition rate was 600 mm / min, with a total of 20 layers printed. The interlayer cooling time was 40 s. After deposition, the material was allowed to cool naturally in a vacuum environment for 6 hours before air was introduced, the chamber door was opened, and samples were taken. The actual image of the refractory TiZrNbHfTa high-entropy alloy is shown below. Figure 2 As shown.

[0041] Figure 3 The image shows the grain orientation of the refractory TiZrNbHfTa high-entropy alloy obtained in Example 1, perpendicular to the deposition direction. The results show that the grains have random orientations and the grain size is approximately 20 μm-400 μm. Dendritic structures can be clearly observed inside the grains.

[0042] Figure 4 This is a cross-sectional view of the refractory TiZrNbHfTa high-entropy alloy deposit obtained in Example 1 (a plane composed of the deposition height direction and the motion direction). Similarly, from... Figure 4 Similar dendritic structures can also be observed in [the text].

[0043] Figure 5 The high-temperature tensile mechanical property curves of the refractory TiZrNbHfTa high-entropy alloy obtained in Example 1 at 450℃ are shown. The results show that the tensile yield strength reaches 649 MPa and the ultimate tensile strength is 731 MPa at 450℃, while the elongation is ~22%.

[0044] In summary, this invention provides a method for preparing refractory high-entropy TiZrNbHfTa refractory additive manufacturing using electron beam scanning mode in situ. By changing the electron beam scanning mode and adjusting the electron beam heat input distribution, high-quality and rapid deposition and preparation of ultra-high melting point, high-strength, and ductile refractory TiZrNbHfTa medium-entropy alloys can be achieved. By adjusting process parameters, refractory high-entropy TiZrNbHfTa refractory alloys with excellent shape, random orientation, and superior high-temperature mechanical properties can be obtained. This method is of great significance for the rapid preparation of large-size refractory high-entropy alloys and can be extended to the near-net-shape rapid formation of other high-melting-point and highly reactive alloys.

[0045] Example 2:

[0046] The method for in-situ additive manufacturing of refractory high-entropy alloys TiZrNbHfTa using electron beam three-wire additive manufacturing in this embodiment is carried out according to the following steps:

[0047] (1) Ti-45Nb alloy wire (Ti:Nb = 55:45 wt.%), 702Zr wire (Zr:Hf = 97.8:2.08 wt.%), and pure Ta wire with diameters of 1.6 mm, 1.2 mm, and 1.2 mm, respectively, were polished to a bright state using an angle grinder. The substrate surface was then cleaned with acetone and alcohol to remove surface impurities and contaminants. After cleaning, each substrate was placed in a 50°C constant temperature drying oven and dried for 2 hours to remove excess moisture. A TA1 substrate with dimensions of 150 mm × 10 mm × 20 mm was polished to a bright state using an angle grinder. The substrate surface was then cleaned with acetone and alcohol to remove surface impurities and contaminants. After cleaning, it was placed in a 50°C constant temperature drying oven and dried for 2 hours to remove excess moisture.

[0048] (2) Fix the processed Ti-45Nb alloy wire, 702Zr wire, and pure Ta wire onto different wire feeding mechanisms. Fix the substrate to the worktable, adjust the angle between the wire feeding nozzle and the substrate, and adjust the distance between the wire and the electron beam. Close the chamber door and evacuate to achieve the predetermined working vacuum level (<9.9×10). -3 After Pa), the program settings are performed. Ti-45Nb alloy wire and 702Zr wire are fed together using the same nozzle, while pure Ta wire is fed separately using a separate nozzle. The two nozzles are positioned opposite each other. The Ti-45Nb alloy wire and 702Zr wire are fed at a constant speed using a common point. The intersection of the three wires is at the central axis of the electron beam. The angles between the two wires on the same side (Ti-45Nb alloy wire and 702Zr wire) and the horizontal direction are the same, both 54°. The angle between the pure Ta wire and the horizontal direction is 58°. The vertical distance between the tip of the two wires on the same side (Ti-45Nb alloy wire and 702Zr wire) and the substrate is 2.5 mm, and the vertical distance between the tip of the pure Ta wire and the substrate is 0.5 mm. The wire feeding speed is V. 702Zr =V Ti-45Nb =1m / min, V Ta =0.9 m / min.

[0049] (3) Before printing, the substrate is preheated by single-pass remelting, with a beam current density of I. b 60mA, printing speed V print The speed is 600 mm / min, the scanning path is a reciprocating linear motion, and the scanning mode is the same as the deposition mode.

[0050] (4) Set the electron beam filament additive manufacturing parameters, and set the electron beam scanning mode to teardrop shape (e.g., ...). Figure 1 As shown in ①, the diameter is 300μm, the scanning frequency is 300Hz, and 3D printing is performed under vacuum conditions according to the slice data. The printing process parameters are: focusing current I... f 1080mA, beam current I bThe current is 130mA, the printing path is a repetitive straight line, and the printing speed is V. print The deposition rate was 600 mm / min, with a total of 20 layers printed. The interlayer cooling time was 60 s. After deposition, the material was allowed to cool naturally in a vacuum environment for 6 hours before air was introduced, the chamber door was opened, and samples were taken. The actual image of the refractory TiZrNbHfTa high-entropy alloy is shown below. Figure 6 As shown.

[0051] Example 3:

[0052] The method for in-situ additive manufacturing of refractory high-entropy alloys TiZrNbHfTa using electron beam three-wire additive manufacturing in this embodiment is carried out according to the following steps:

[0053] (1) Ti-45Nb alloy wire (Ti:Nb = 55:45 wt.%), 702Zr wire (Zr:Hf = 97.8:2.08 wt.%), and pure Ta wire with diameters of 1.6 mm, 1.2 mm, and 1.2 mm, respectively, were polished to a bright state using an angle grinder. The substrate surface was then cleaned with acetone and alcohol to remove surface impurities and contaminants. After cleaning, each substrate was placed in a 50°C constant temperature drying oven and dried for 2 hours to remove excess moisture. A TA1 substrate with dimensions of 150 mm × 10 mm × 20 mm was polished to a bright state using an angle grinder. The substrate surface was then cleaned with acetone and alcohol to remove surface impurities and contaminants. After cleaning, it was placed in a 50°C constant temperature drying oven and dried for 2 hours to remove excess moisture.

[0054] (2) Fix the processed Ti-45Nb alloy wire, 702Zr wire, and pure Ta wire onto different wire feeding mechanisms. Fix the substrate to the worktable, adjust the angle between the wire feeding nozzle and the substrate, and adjust the distance between the wire and the electron beam. Close the chamber door and evacuate to achieve the predetermined working vacuum level (<9.9×10). -3 After Pa), the program settings are performed. Ti-45Nb alloy wire and 702Zr wire are fed together using the same nozzle, while pure Ta wire is fed separately using a separate nozzle. The two nozzles are positioned opposite each other. The Ti-45Nb alloy wire and 702Zr wire are fed at a constant speed using a common-point method. The intersection of the three wires is at the central axis of the electron beam. The angles between the two wires on the same side (Ti-45Nb alloy wire and 702Zr wire) and the horizontal direction are the same, both 54°. The angle between the pure Ta wire and the horizontal direction is 58°. The vertical distance between the tip of the two wires on the same side (Ti-45Nb alloy wire and 702Zr wire) and the substrate is 0.7 mm, and the vertical distance between the tip of the pure Ta wire and the substrate is 0.5 mm. The wire feeding speed is V. 702Zr =V Ti-45Nb =1m / min, V Ta =0.9 m / min.

[0055] (3) Before printing, the substrate is preheated by single-pass remelting, with a beam current density of I. b 60mA, printing speed V print The speed is 600 mm / min, the scanning path is a reciprocating linear motion, and the scanning mode is the same as the deposition mode.

[0056] (4) Set the electron beam filament additive manufacturing parameters, and set the electron beam scanning mode to teardrop shape (e.g., ...). Figure 1 As shown in ③, the straight-line distance L1 between the midpoints of the two arcs is 350 μm, and the straight-line distance L2 between the two endpoints is 300 μm. The scanning frequency is 300 Hz. 3D printing is performed under vacuum conditions according to the slice data. The printing process parameters are: focusing current I... f 1080mA, beam current I b The current is 160mA, the printing path is a repetitive straight line, and the printing speed is V. print The speed was 600 mm / min, a total of 20 layers were printed, the interlayer cooling time was 40 s, after deposition, the layers were allowed to cool naturally in a vacuum environment for 6 hours, then air was introduced and the chamber door was opened to take samples.

[0057] The above description is merely a preferred embodiment of the present invention. These specific embodiments are different implementations based on the overall concept of the present invention, and the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for in-situ additive manufacturing of refractory high-entropy alloys TiZrNbHfTa using electron beam three-wire additive manufacturing, characterized in that... The method described: S1: Perform 3D modeling of the target component and slice it, while pre-processing the printing filament and substrate; S2: Ti-45Nb alloy wire, 702Zr wire, and pure Ta wire are used as printing filaments. Ti-45Nb alloy wire and 702Zr wire are fed at the same speed using the same nozzle, while pure Ta wire is fed using a separate nozzle. The two nozzles are opposite each other, and the angle between the three wires and the horizontal direction is 45-60°. The vertical distance between the leading edge of the three wires and the substrate is 0.6-3mm. The wire feeding speed is 0.36-1.1m / min. The intersection of the three wires is at the central axis of the electron beam. S3: Set the electron beam filament additive manufacturing parameters, and set the electron beam scanning mode to teardrop, crescent, or circle. Then, perform 3D printing under vacuum conditions according to the slice data. In S2: the angle between the two wires fed by the same wire nozzle and the horizontal direction is the same; In S2: The leading edge of the two wires fed by the same wire nozzle is at the same vertical distance from the substrate.

2. The method according to claim 1, characterized in that, In S1: Pre-treatment includes grinding, polishing, cleaning, and drying.

3. The method according to claim 1, characterized in that, In S3: The printing process parameters are: Focusing current I f 1080-1130mA, beam current I b The A current is 130-180mA, the scanning frequency is 200-400Hz, the printing path is a repetitive straight line, and the printing speed is V. print The flow rate is 500-700 mm / min, the interlayer cooling time is 30-60 s, and the vacuum degree is <9.9 × 10⁻⁶. -3 Pa.

4. The method according to claim 1, characterized in that, In S3: the height of the teardrop shape is 350-450μm, the bottom width is 250-350μm, the straight-line distance between the midpoints of the two arcs of the crescent shape is 300-400μm, the straight-line distance between the two end points is 250-350μm, and the diameter of the circle is 200-400μm.

5. The method according to claim 1, characterized in that, S3: Preheating of the substrate before printing, I b 60mA, printing speed V print The speed is 600 mm / min.

6. The refractory high-entropy alloy prepared by the method according to any one of claims 1-5, characterized in that, The alloy has a tensile yield strength ≥640 MPa, an ultimate tensile strength ≥730 MPa, and an elongation ≥20% at 450℃.

7. The refractory high-entropy alloy described in claim 6 is used as a high-temperature alloy component in aero-engines, heat exchangers, and chemical processing.

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