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

Abstract

The invention discloses a method for manufacturing a TiZrNbHfTa refractory high-entropy alloy through electron beam three-wire in-situ additive manufacturing and application. The invention belongs to the technical field of additive manufacturing. The invention aims to solve the technical problems that the current refractory high-entropy alloy is high in melting point and difficult to process and form. The method comprises the following steps: firstly, carrying out three-dimensional modeling on a target component, and carrying out slicing treatment; then three-wire printing is adopted, the relative position relation of three wires and the angles and distances between the three wires and the substrate are set, the wire feeding speed is set, and an electron beam scanning mode is set; and finally carrying out 3D printing. According to the method, flexible regulation and control of alloy components are achieved, and integrated forming of the refractory high-entropy alloy is achieved. The non-equal-atomic-ratio refractory TiZrNbHfTa high-entropy alloy prepared through the method is uniform in component, the non-penetration condition is not observed, the alloy has a dendritic structure, grain orientation perpendicular to the deposition direction is random, and the alloy has excellent high-temperature mechanical performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of additive manufacturing, and in particular relates to a method and application of electron beam three-wire in-situ additive manufacturing of TiZrNbHfTa refractory high-entropy alloy. Background Art

[0002] Refractory high entropy alloys are a new type of high-temperature structural material, and their room temperature and high temperature properties are usually better than those of traditional refractory metals and alloys. Therefore, refractory high entropy alloys have obvious application potential in the fields of high temperature, high strength, and corrosion resistance: such as high-temperature components of aircraft engines, heat exchanger piping, and high-temperature alloy components in the chemical processing industry, which currently widely use nickel-based high-temperature alloys. Although refractory high entropy alloys have a series of excellent properties, due to the high melting points of the constituent elements of refractory high entropy alloys (generally above 1800°C) and the large difference in melting points between each other, it brings great challenges to the preparation, microstructure and performance regulation, and component forming of refractory high entropy alloys, limiting the further application and promotion of this type of alloy.

[0003] In the past decade, the application of additive manufacturing technology has achieved a qualitative change from prototype manufacturing to direct manufacturing. With its simple preparation process and flexible forming freedom, it has effectively improved the problems of traditional casting-forging-machining preparation, such as long time consumption, high cost and low utilization rate. Electron beam fuse deposition technology, which uses high-energy electron beam as heat source and metal wire as raw material, has the advantages of high power, high energy utilization, vacuum processing environment and high deposition efficiency, and can realize near-net rapid preparation and forming of large and complex metal components. Therefore, how to use electron beam fuse deposition technology to achieve high-quality, high-speed, large-size preparation and forming integration of refractory high-entropy alloys is a technical problem that this field has been committed to solving. Summary of the invention

[0004] The purpose of the present 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 of electron beam three-wire in-situ additive manufacturing of TiZrNbHfTa refractory high entropy alloy.

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

[0006] One of the purposes of the present invention is to provide a method for electron beam three-wire in-situ additive manufacturing of TiZrNbHfTa refractory high entropy alloy, the method is carried out according to the following steps:

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

[0008] S2: Ti-45Nb alloy wire, 702Zr wire and pure Ta wire are used as printing wire materials. Ti-45Nb alloy wire and 702Zr wire are fed at a constant speed using the same wire nozzle, and pure Ta wire is fed using a separate wire nozzle. The two wire nozzles are opposite to each other, and 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 of the three wires is 0.36-1.1m / min, and the intersection of the three wires intersects the central axis of the electron beam.

[0009] S3: Setting the electron beam fuse additive manufacturing parameters, the electron beam scanning mode is drop-shaped, crescent-shaped or circular, and then 3D printing is performed under vacuum conditions according to the slice data.

[0010] It is further defined that in S1: pretreatment includes grinding, polishing, cleaning and drying.

[0011] It is further defined that in S2: the angles between the two wires fed by the same wire nozzle and the horizontal direction are the same.

[0012] It is further defined that in S2: the vertical distance between the front ends of the two wires fed by the same wire nozzle and the substrate is the same.

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

[0014] It is further defined that in S3: the electron beam scanning pattern is preferably a water drop shape.

[0015] It is further defined that in S3: the height of the water drop shape is 350-450 μm, the bottom width is 250-350 μm, the straight-line distance between the midpoints of the two arcs of the crescent shape is 300-400 μm, the straight-line distance between the two end points is 250-350 μm, and the circular diameter is 200-400 μm.

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

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

[0018] The third object of the present invention is to provide a refractory high entropy alloy prepared by the above method as a high temperature resistant alloy component for use in aircraft engines, heat exchangers and chemical processing fields.

[0019] A fourth object of the present invention is to provide an application of the above method in preparing other alloys with high melting points and large melting point differences.

[0020] Compared with the prior art, the present invention has the following advantages:

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

[0022] (2) The non-equiatomic refractory TiZrNbHfTa high entropy alloy prepared by the present invention has uniform composition, no incomplete penetration is 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 at 450°C, an ultimate tensile strength of 731 MPa, and an elongation of ~22%.

[0023] (3) The present invention is conducive to the preparation of such a high-activity refractory high-entropy alloy under a vacuum environment, and effectively improves the alloy forming purity.

[0024] (4) Because the refractory TiZrNbHfTa high entropy alloy has a high melting point, it is very difficult to use traditional preparation and processing technology, or to perform powder additive manufacturing by melting and casting. Using electron beam as the heat source, this technology has high power and high energy utilization, which also reflects that the electron beam three-wire in-situ additive preparation method of the present invention is extensible and can be applied to the in-situ fused wire deposition of large-sized complex components of other high-activity high-temperature alloys / high-entropy alloys, and has strong practicality. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0026] Figure 2 It is a schematic diagram of the position relationship of three wires in the method of the present invention;

[0027] Figure 3 This is a physical picture of the refractory TiZrNbHfTa high entropy alloy obtained in Example 1 of the present invention;

[0028] Figure 4This is a grain orientation (IPF) diagram of the refractory TiZrNbHfTa high entropy alloy obtained in Example 1 of the present invention;

[0029] Figure 5 This is a microstructure morphology diagram of the refractory TiZrNbHfTa high entropy alloy obtained in Example 1 of the present invention;

[0030] Figure 6 This is a high temperature tensile stress-strain curve diagram of the refractory TiZrNbHfTa high entropy alloy obtained in Example 1 of the present invention at 450°C;

[0031] Figure 7 This is a physical picture of the refractory TiZrNbHfTa high entropy alloy obtained in Example 2 of the present invention. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0033] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, methods and instruments used are conventional materials, reagents, methods and instruments in the art unless otherwise specified, and can be obtained through commercial channels by those skilled in the art.

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

[0035] Embodiment 1:

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

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

[0038] (2) The processed Ti-45Nb alloy wire, 702Zr wire and pure Ta wire were fixed on different wire feeding mechanisms respectively, the substrate was fixed on the workbench, the angle between the wire feeding nozzle and the substrate and the distance between the wire and the electron beam were adjusted, and the cabin door was closed to evacuate the vacuum to achieve the predetermined working vacuum degree (<9.9×10 -3 Pa) and then set the program. Ti-45Nb alloy wire and 702Zr wire are fed together by the same wire nozzle, and pure Ta wire is fed by a separate wire nozzle. The two wire nozzles are opposite to each other. Ti-45Nb alloy wire and 702Zr wire are fed at a common point and at a constant speed. The intersection of the three wires intersects at the central axis of the electron beam. The angles between the double wires on the same side (Ti-45Nb alloy wire and 702Zr wire) and the horizontal direction are the same, both 54°, and the angle between the pure Ta wire and the horizontal direction is 54°. The vertical distance between the front end of the double wires on the same side (Ti-45Nb alloy wire and 702Zr wire) and the substrate is 0.7mm, and the vertical distance between the front end of the pure Ta wire and the substrate is 0.5mm. The wire feeding speed is V 702Zr =V Ti-45Nb =1m / min, V Ta =0.9m / min.

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

[0040] (4) Set the parameters for electron beam fuse additive manufacturing. The electron beam scanning mode is a water drop shape (such as Figure 1 ② As shown in the figure, the height L1 of the water drop shape is 400 μm, the bottom width L2 is 300 μm), the scanning frequency is 300 Hz, and 3D printing is performed under vacuum conditions according to the slice data. The printing process parameters are: focusing current I f is 1080mA, beam current I bThe current is 180mA, the printing path is a reciprocating straight line, and the printing speed is V print The speed was 600 mm / min, and a total of 20 layers were printed. The inter-layer cooling time was 40 seconds. After the deposition was completed, the layers were naturally cooled for 6 hours in a vacuum environment, and then air was introduced. The hatch was opened to take samples. The actual picture of the refractory TiZrNbHfTa high entropy alloy is shown in the figure below. Figure 2 shown.

[0041] Figure 3 This is a grain orientation diagram perpendicular to the deposition direction of the refractory TiZrNbHfTa high entropy alloy obtained in Example 1. The results show that the grains have random orientations and the grain size is about 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 consisting of the deposition height direction and the movement direction). Figure 4 Similar dendritic structures can also be observed in .

[0043] Figure 5 This is the high temperature tensile mechanical property curve at 450° C. for the refractory TiZrNbHfTa high entropy alloy obtained in Example 1. The results show that the tensile yield strength at 450° C. reaches 649 MPa, the ultimate tensile strength is 731 MPa, and the elongation is ˜22%.

[0044] In summary, the present invention provides a method for preparing a TiZrNbHfTa refractory high-entropy alloy by electron beam three-wire in-situ additive based on an electron beam scanning mode. 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 plastic refractory TiZrNbHfTa medium-entropy alloy can be achieved. By adjusting the process parameters, a TiZrNbHfTa refractory high-entropy alloy with excellent forming, random orientation and excellent high-temperature mechanical properties can be obtained, which has a great effect on the large-scale rapid preparation of such refractory high-entropy alloys, and can be extended to the near-net rapid formation preparation of other high-melting point and high-activity alloys.

[0045] Embodiment 2:

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

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

[0048] (2) The processed Ti-45Nb alloy wire, 702Zr wire and pure Ta wire were fixed on different wire feeding mechanisms respectively, the substrate was fixed on the workbench, the angle between the wire feeding nozzle and the substrate and the distance between the wire and the electron beam were adjusted, and the cabin door was closed to evacuate the vacuum to achieve the predetermined working vacuum degree (<9.9×10 -3 Pa) and then set the program. Ti-45Nb alloy wire and 702Zr wire are fed together by the same wire nozzle, and pure Ta wire is fed by a separate wire nozzle. The two wire nozzles are opposite to each other. Ti-45Nb alloy wire and 702Zr wire are fed at a common point and at a constant speed. The intersection of the three wires intersects at the central axis of the electron beam. The angles between the double wires on the same side (Ti-45Nb alloy wire and 702Zr wire) and the horizontal direction are the same, both 54°, and the angle between the pure Ta wire and the horizontal direction is 58°. The vertical distance between the front end of the double wires on the same side (Ti-45Nb alloy wire and 702Zr wire) and the substrate is 2.5mm, and the vertical distance between the front end of the pure Ta wire and the substrate is 0.5mm. The wire feeding speed is V 702Zr =V Ti-45Nb =1m / min, V Ta =0.9m / min.

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

[0050] (4) Set the parameters for electron beam fuse additive manufacturing. The electron beam scanning mode is a water drop shape (such as Figure 1 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 is 1080mA, beam current I bThe current is 130mA, the printing path is a reciprocating straight line, and the printing speed is V print The speed was 600 mm / min, and a total of 20 layers were printed. The inter-layer cooling time was 60 seconds. After the deposition was completed, the layers were naturally cooled for 6 hours in a vacuum environment, and then air was introduced. The hatch was opened to take samples. The actual picture of the refractory TiZrNbHfTa high entropy alloy is shown in the figure below. Figure 6 shown.

[0051] Embodiment 3:

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

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

[0054] (2) The processed Ti-45Nb alloy wire, 702Zr wire and pure Ta wire were fixed on different wire feeding mechanisms respectively, the substrate was fixed on the workbench, the angle between the wire feeding nozzle and the substrate and the distance between the wire and the electron beam were adjusted, and the cabin door was closed to evacuate the vacuum to achieve the predetermined working vacuum degree (<9.9×10 -3 Pa) and then set the program. Ti-45Nb alloy wire and 702Zr wire are fed together by the same wire nozzle, and pure Ta wire is fed by a separate wire nozzle. The two wire nozzles are opposite to each other. Ti-45Nb alloy wire and 702Zr wire are fed at a common point and at a constant speed. The intersection of the three wires intersects at the central axis of the electron beam. The angles between the double wires on the same side (Ti-45Nb alloy wire and 702Zr wire) and the horizontal direction are the same, both 54°, and the angle between the pure Ta wire and the horizontal direction is 58°. The vertical distance between the front end of the double wires on the same side (Ti-45Nb alloy wire and 702Zr wire) and the substrate is 0.7mm, and the vertical distance between the front end of the pure Ta wire and the substrate is 0.5mm. The wire feeding speed is V 702Zr =V Ti-45Nb =1m / min, V Ta =0.9m / min.

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

[0056] (4) Set the parameters for electron beam fuse additive manufacturing. The electron beam scanning mode is a water drop shape (such as Figure 1 As shown in ③, the straight-line distance L1 between the midpoints of the two arcs is 350μm, and the straight-line distance L2 between the two end points 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 is 1080mA, beam current I b The current is 160mA, the printing path is a reciprocating straight line, and the printing speed is V print The speed was 600 mm / min, 20 layers were printed in total, and the inter-layer cooling time was 40 s. After the deposition was completed, it was naturally cooled for 6 hours in a vacuum environment, and then air was introduced and the hatch was opened for sampling.

[0057] The above are only preferred specific embodiments of the present invention, which are all different implementations based on the overall concept of the present invention, and the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for electron beam three-wire in-situ additive manufacturing of TiZrNbHfTa refractory high entropy alloy, characterized in that: The method: S1: 3D modeling of the target component and slicing, and pre-processing of the printing filament and substrate; S2: Ti-45Nb alloy wire, 702Zr wire and pure Ta wire are used as printing wire materials. Ti-45Nb alloy wire and 702Zr wire are fed at a constant speed by the same wire nozzle, and pure Ta wire is fed by a separate wire nozzle. The two wire nozzles are opposite to each other, and the angle between the three wires and the horizontal direction is 45-60°. The vertical distance between the front end of the three wires and the substrate is 0.6-3mm. The wire feeding speed of the three wires is 0.36-1.1m / min, and the intersection of the three wires intersects at the central axis of the electron beam. S3: Setting the electron beam fuse additive manufacturing parameters, the electron beam scanning mode is drop-shaped, crescent-shaped or circular, and then 3D printing is performed under vacuum conditions according to the slice data.

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

3. The method according to claim 1, characterized in that In S2: the angles between the double wires fed by the same wire nozzle and the horizontal direction are the same.

4. The method according to claim 1, characterized in that: In S2: the vertical distance between the front end of the double wires fed by the same wire nozzle and the substrate is the same.

5. 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 current is 130-180mA, the scanning frequency is 200-400HZ, the printing path is a reciprocating straight line, and the printing speed is V print 500-700mm / min, interlayer cooling time is 30-60s, vacuum degree is <9.9×10 -3 Pa.

6. The method according to claim 1, characterized in that In S3: the height of the water drop 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 circular diameter is 200-400μm.

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

8. A refractory high entropy alloy obtained by the method according to any one of claims 1 to 7, characterized in that: The alloy has a tensile yield strength of ≥640 MPa, an ultimate tensile strength of ≥730 MPa and an elongation of ≥20% at 450°C.

9. The refractory high entropy alloy according to claim 8 is used as a high temperature resistant alloy component in the fields of aircraft engines, heat exchangers and chemical processing.

10. Use of the method according to any one of claims 1 to 7 in preparing other alloys with high melting points and large melting point differences.

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