Composition screening method and preparation method for additive manufacturing of refractory high entropy alloys

Abstract

The present invention provides a method for screening the components of refractory high-entropy alloys suitable for additive manufacturing and a method for preparing the components. The present invention adopts a laser air-scanning remelting operation method to more accurately screen out the refractory high-entropy alloy components suitable for additive manufacturing. The refractory high-entropy alloys obtained by screening are prepared using a laser additive manufacturing process to obtain a refractory high-entropy alloy with unified strength and plasticity.

Description

Technical Field

[0001] The present invention belongs to the field of high entropy alloy preparation, and relates to a composition screening method and a preparation method suitable for additive manufacturing of refractory high entropy alloys. Background Art

[0002] High-entropy alloys (HEAs) are a new type of alloy material designed using the "multi-principal element" concept. Their excellent physical and chemical properties have attracted widespread attention. Unlike intermetallic compounds, HEAs readily form solid solution phases, such as simple body-centered cubic (BCC) or face-centered cubic (FCC) phases. HEAs are generally defined as alloys containing five or more constituent elements, or with a mixed entropy ≥ -1.6R. Refractory HEAs are primarily composed of Group IVB (Ti, Zr, Hf), Group VB (V, Nb, Ta), and Group VIB (Cr, Mo, W) metals, and exhibit a single or predominantly BCC crystal structure. Refractory HEAs offer numerous advantages, including high melting points (above approximately 2123K), high hardness, and excellent high-temperature strength (superior to conventional high-temperature alloys such as Inconel 718). With application temperatures as high as 1373-1593K, they are expected to be used in high-temperature structural components such as turbines, rocket nozzles, and nuclear reactors. Therefore, they hold potential for application in aerospace, the nuclear industry, and other fields.

[0003] The traditional preparation process of refractory high-entropy alloys is generally arc melting or powder metallurgy. For example, patent document CN113373366B discloses a multi-component refractory high-entropy alloy and its preparation method, which uses a melting and casting method to prepare the refractory high-entropy alloy. These methods have various problems: first, there must be high selectivity for the alloy components. Otherwise, the alloy will produce defects such as casting shrinkage due to its high melting point, high viscosity, and poor fluidity, which will reduce the density; second, the preparation method is single, and the size and shape of the parts are limited. In the face of the demand for precision structural parts, traditional preparation processes are difficult to achieve one-piece forming; third, refractory high-entropy alloys are extremely sensitive to interstitial atoms (such as oxygen) and are easily oxidized during processing. Therefore, there is an urgent need to propose a new preparation process.

[0004] Laser additive manufacturing technology uses high-power lasers to melt synchronously conveyed alloy powders, and then deposits parts with dense structure and excellent performance layer by layer. Its forming process has the advantages of no need for molds, providing a protective atmosphere, short manufacturing cycle, flexibility and automation. It can be used to prepare refractory high-entropy alloy parts with high melting points, difficult processing and easy oxidation.

[0005] However, the high temperature gradient and fast cooling rate during additive manufacturing usually lead to high thermal residual stress. For refractory high-entropy alloys with poor plasticity, cracks and other defects are also very likely to occur during the printing process, affecting the structural integrity and overall performance of the component. In other words, not all refractory high-entropy alloys are suitable for preparation using additive manufacturing methods. Therefore, it is necessary to design refractory high-entropy alloys suitable for laser additive manufacturing. Unlike traditional melting and casting methods, the additive manufacturing process involves many reactions, which easily produce multiple precipitated phases and affect the overall performance. Therefore, the alloy performance change laws explored by traditional melting and casting methods are not applicable to additive manufacturing. Therefore, how to design refractory high-entropy alloys suitable for laser additive manufacturing is a key issue that needs to be solved in this field. Summary of the Invention

[0006] The purpose of the present invention is to provide a composition screening method and a preparation method for refractory high-entropy alloys suitable for additive manufacturing, which can more accurately screen out the refractory high-entropy alloy components suitable for additive manufacturing. The refractory high-entropy alloys obtained by screening are prepared by a laser additive manufacturing process to obtain a refractory high-entropy alloy with unified strength and plasticity.

[0007] The present invention is achieved through the following technical solutions:

[0008] Composition screening methods for additive manufacturing of refractory high-entropy alloys include:

[0009] A plurality of as-cast refractory high-entropy alloy samples with different compositions were taken, the surface of each as-cast refractory high-entropy alloy sample was polished and cleaned, and the cleaned surface was subjected to a laser air-scanning remelting operation to obtain each laser remelted sample;

[0010] The obtained laser remelted samples were cut along the longitudinal section, and after rough grinding, polishing and corrosion treatment, the crack defects in the laser remelted samples were observed, and the elemental composition corresponding to the laser remelted samples with relatively few crack defects was screened as the elemental composition suitable for additive manufacturing of refractory high-entropy alloys.

[0011] Preferably, the element composition of the refractory high entropy alloy obtained by screening is Ti a V b Nb c Hf d Mo e , where a, b, c, d and e correspond to the molar ratios of the elements, respectively, a = 41 at%, b = 27 at%, c = 13 at%, d = 13 at%, and e = 6 at%.

[0012] The preparation method of the refractory high entropy alloy suitable for additive manufacturing obtained by the above screening includes:

[0013] According to the elemental composition of the refractory high-entropy alloy suitable for additive manufacturing obtained by screening, metal raw materials corresponding to each element are taken, smelted, pickled and milled into rods; the rods are processed into high-entropy alloy pre-alloyed spherical powder, sieved to obtain high-entropy alloy powder, and dried;

[0014] The dried high entropy alloy powder is prepared by laser additive manufacturing to obtain a refractory high entropy alloy.

[0015] The above-mentioned screening results are suitable for additive manufacturing of refractory high entropy alloy Ti a V b Nb c Hf d Mo e The preparation method is characterized by comprising:

[0016] According to Ti a V b Nb c Hf d Mo e Elemental composition Ti 41 V 27 Nb 13 Hf 13 Mo6, take the metal raw materials corresponding to each element, smelt, pickle and mill into rods; process the rods into high entropy alloy pre-alloyed spherical powder, sieve to obtain high entropy alloy powder, and dry;

[0017] The dried high entropy alloy powder is prepared by laser additive manufacturing to obtain a refractory high entropy alloy.

[0018] Preferably, the additive manufacturing process parameters are as follows: laser power is 1800-2000W, and scanning rate is 6-8mm / s.

[0019] Preferably, the additive manufacturing process parameters are as follows: powder feeding speed is 11.2 g / min, Z-axis lifting amount is 0.4-0.6 mm, spot diameter is 5 mm, overlap rate is 50%, and the scanning path adopts a vertical reciprocating interwoven path.

[0020] Preferably, the particle size of the high entropy alloy powder obtained by sieving is 53-150 μm.

[0021] Preferably, the dried high entropy alloy powder is prepared on a substrate by a laser additive manufacturing method to obtain a refractory high entropy alloy, and the substrate is pre-polished, cleaned and dried.

[0022] Preferably, the additive manufacturing process is performed under an argon protective atmosphere.

[0023] The refractory high entropy alloy Ti obtained by the above preparation method a V b Nbc Hf d Mo e .

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The concept behind this invention is to first screen for refractory high-entropy alloy components suitable for additive manufacturing using laser remelting technology, and then use laser energy deposition technology to prepare the refractory high-entropy alloy. Because both laser remelting and additive manufacturing have relatively fast cooling rates and high temperature gradients, the effect of laser remelting on the microstructure reflects the alloy's additive formability to a certain extent. Therefore, the suitability of a refractory high-entropy alloy for additive manufacturing can be inferred based on the crack defects generated by laser remelting in the cast refractory high-entropy alloy. This screening method of the present invention lays a foundation for additive manufacturing of refractory high-entropy alloys.

[0026] The present invention uses a laser additive manufacturing process to prepare refractory high-entropy alloys suitable for additive manufacturing, obtained through screening. The alloys prepared by this method have higher mechanical strength than alloys obtained by melting and casting, and this method can be applied to the preparation of complex structures and has a wider range of applications. The refractory high-entropy alloys manufactured by laser additive manufacturing of the present invention can obtain alloys with both strength and plasticity without the need for subsequent heat treatment, saving time and cost. The present invention combines high-performance materials with advanced material preparation methods, which is cutting-edge and groundbreaking.

[0027] The present invention uses laser remelting technology to select a five-element TiVNbHfMo component with strong BCC phase stability and strong plasticity for additive manufacturing. The prepared refractory high-entropy alloy has a dense structure and good room-temperature tensile plasticity and strength. Its maximum tensile strength can reach 1308MPa, its yield strength can reach 1195MPa, and its optimal elongation can reach 11.3%. This makes up for the poor plastic deformation ability of refractory high-entropy alloys and meets the needs of high-performance, complex-structure metal structural materials, thus making it have great application potential.

[0028] Furthermore, the present invention reduces additive defects such as cracks and holes by regulating parameters such as laser power and scanning speed, and prepares a five-element TiVNbHfMo high-entropy alloy material with high density and excellent mechanical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Observation results of the laser remelted sample microstructure and defects: (a) Laser remelting of the as-cast sample surface; (b) Secondary electron morphology and defect characterization of the longitudinal section microstructure of the laser remelted sample.

[0030] Figure 2Preparation of TiVHfNbMo alloy by laser energy deposition: (a) Laser melting and synchronous powder feeding process; (b) Real-time monitoring of melt pool morphology; (c) Schematic diagram of scanning path; (d) Scanning electron micrograph of prefabricated powder; (e) Powder particle size distribution; (f) Additive block.

[0031] Figure 3 Figure 2 shows the microstructure of the additive TiVNbHfMo alloy: (a) secondary electron morphology along the longitudinal cross section; (b) microstructure along the deposition direction from the substrate to the additive; (c) microstructure near the edge of the additive body; (d) melt pool morphology; (e) energy spectrum EDS line scanning composition analysis; (f) electron backscatter diffraction EBSD image of the typical microstructure in the middle of the additive body.

[0032] Figure 4 Secondary electron morphology of the alloy structure of TiVNbHfMo additively manufactured under different process parameters: (a) 2500W-8mm / s; (b) 2000W-8mm / s; (c) 1800W-6mm / s.

[0033] Figure 5 The tensile stress-strain curve of the additively manufactured TiVNbHfMo alloy under different process parameters.

[0034] Figure 6 Comparison of mechanical properties of additive TiVNbHfMo alloy with other additive and cast refractory high entropy alloys under process parameters of 1800W-6mm / s.

[0035] Figure 7 Tensile fracture of additively manufactured TiVNbHfMo alloy under the process parameters of 1800W-6mm / s: (a) ductile fracture morphology; (b) dimple. DETAILED DESCRIPTION

[0036] In order to further understand the present invention, the present invention is described below in conjunction with embodiments. These descriptions are only for further explaining the features and advantages of the present invention and are not intended to limit the claims of the present invention.

[0037] Example 1 Screening of Refractory High Entropy Alloy Compositions Suitable for Additive Manufacturing

[0038] Prepare typical cast refractory high entropy alloys with different compositions, including TiVHf, Ti 41 V 27 Nb 13 Hf 13 Mo6、Ti 41 V 27 Nb 11.5 Hf 11.5Cr3Al6 as-cast block specimens were 60×10×8 mm in size. The 60×10 mm side surfaces of the as-cast specimens were polished using 240#, 800#, and 2500# sandpaper and cleaned with alcohol to obtain smooth, clean laser-remelted substrate specimens. Laser scanning remelting was performed on these specimens using a laser stereolithography machine. The remelting parameters were standardized as follows: laser power 2500 W, scanning speed 6 mm / s, and spot diameter 3 mm.

[0039] The laser remelted samples were cut along the longitudinal section using wire cutting, and the microstructure and defects were observed after rough grinding, polishing and corrosion treatment.

[0040] The results are as follows Figure 1 As shown, from Figure 1 It can be seen that the laser remelted sample TiVHf has more crack defects, and the laser remelted sample Ti 41 V 27 Nb 11.5 Hf 11.5 Cr3Al6 also has more crack defects, while the laser remelted sample Ti 41 V 27 Nb 13 Hf 13 Mo6 has no crack defects.

[0041] Because both laser remelting and additive manufacturing have faster cooling rates and higher temperature gradients, the laser remelting results reflect the additive processing formability of the alloy to a certain extent, so it is inferred that the remelted sample with fewer crack defects has a higher composition of Ti. 41 V 27 Nb 13 Hf 13 Mo6 should be a refractory high entropy alloy suitable for additive manufacturing. 41 V 27 Nb 13 Hf 13 The example of Mo6 refractory high entropy alloy was used for verification.

[0042] Example 2 Preparation of Refractory High Entropy Alloy Ti by Additive Manufacturing 41 V 27 Nb 13 Hf 13 Mo6 (see Figure 2 )

[0043] Step 1: Preparation and pretreatment of refractory high entropy alloy powder

[0044] According to Ti 41 V 27 Nb 13 Hf 13To determine the molar percentage of Mo6, high-purity (≥99.95%) metal raw materials corresponding to each element are melted, pickled, and milled into rods. The rods are processed into pre-alloyed high-entropy alloy spherical powder using a plasma rotating electrode (PREP) process. This is then sieved to obtain a high-entropy alloy powder with a particle size of 53-150μm. The pre-alloyed high-entropy alloy powder is then dried at 80°C for 6 hours to remove moisture before use.

[0045] Step 2: Substrate surface treatment

[0046] A Ti-6Al-4V alloy substrate was selected, and the surface of the substrate was polished with 240# sandpaper and 800# sandpaper in turn. The substrate was cleaned with alcohol to remove surface oil and then dried. The substrate was mounted on a laser stereo forming platform and leveled.

[0047] Step 3, laser energy deposition Ti 41 V 27 Nb 13 Hf 13 Mo6 refractory high entropy alloy

[0048] A 3D solid model (CAD model file) is created based on the geometry of the alloy component to be fabricated. The CAD model file is uploaded to the Ytterbium Laser System (YLS-10000) laser stereo forming equipment. High-purity argon gas is introduced as a protective atmosphere, and the additive manufacturing process parameters and scanning path are set. A coaxial nozzle is used to feed the refractory high-entropy alloy powder into the molten pool formed by the high-energy laser beam. The refractory high-entropy alloy component is printed by depositing the powder point by point, line by line, and layer by layer on the substrate.

[0049] The laser process parameters are as follows: laser power is 2500 W, scanning rate is 8 mm / s, powder feeding speed is 11.2 g / min, Z-axis lifting amount is 0.5 mm, spot diameter is 5 mm, overlap rate is 50%, and the scanning path adopts a vertical reciprocating interwoven path.

[0050] Example 3 Preparation of Refractory High Entropy Alloy Ti by Additive Manufacturing 41 V 27 Nb 13 Hf 13 Mo6

[0051] Step 1: Preparation and pretreatment of refractory high entropy alloy powder

[0052] According to Ti 41 V 27 Nb 13 Hf 13To determine the molar percentage of Mo6, high-purity (≥99.95%) metal raw materials corresponding to each element are melted, pickled, and milled into rods. The rods are processed into a high-entropy alloy pre-alloyed spherical powder using a plasma rotating electrode method. The powder is then sieved to obtain a high-entropy alloy powder with a particle size of 53-150μm. The pre-fabricated high-entropy alloy powder is then dried at 80°C for 6 hours to remove moisture before use.

[0053] Step 2: Substrate surface treatment

[0054] A Ti-6Al-4V alloy substrate was selected, and the surface of the substrate was polished with 240# sandpaper and 800# sandpaper in turn. The substrate was cleaned with alcohol to remove surface oil and then dried. The substrate was mounted on a laser stereo forming platform and leveled.

[0055] Step 3, laser energy deposition Ti 41 V 27 Nb 13 Hf 13 Mo6 refractory high entropy alloy

[0056] A 3D solid model (CAD model file) is created based on the geometry of the alloy component to be fabricated. The CAD model file is uploaded to the Ytterbium Laser System (YLS-10000) laser stereo forming equipment. High-purity argon gas is introduced as a protective atmosphere, and the additive manufacturing process parameters and scanning path are set. A coaxial nozzle is used to feed the refractory high-entropy alloy powder into the molten pool formed by the high-energy laser beam. The refractory high-entropy alloy component is printed by depositing the powder point by point, line by line, and layer by layer on the substrate.

[0057] The laser process parameters are as follows: laser power is 2000 W, scanning rate is 8 mm / s, powder feeding speed is 11.2 g / min, Z-axis lifting amount is 0.5 mm, spot diameter is 5 mm, overlap rate is 50%, and the scanning path adopts a vertical reciprocating interwoven path.

[0058] Example 4 Preparation of Refractory High Entropy Alloy Ti by Additive Manufacturing 41 V 27 Nb 13 Hf 13 Mo6

[0059] Step 1: Preparation and pretreatment of refractory high entropy alloy powder

[0060] According to Ti 41 V 27 Nb 13 Hf 13To determine the molar percentage of Mo6, high-purity (≥99.95%) metal raw materials corresponding to each element are melted, pickled, and milled into rods. The rods are processed into a high-entropy alloy pre-alloyed spherical powder using a plasma rotating electrode method. The powder is then sieved to obtain a high-entropy alloy powder with a particle size of 53-150μm. The pre-fabricated high-entropy alloy powder is then dried at 80°C for 6 hours to remove moisture before use.

[0061] Step 2: Substrate surface treatment

[0062] A Ti-6Al-4V alloy substrate was selected, and the surface of the substrate was polished with 240# sandpaper and 800# sandpaper in turn. The substrate was cleaned with alcohol to remove surface oil and then dried. The substrate was mounted on a laser stereo forming platform and leveled.

[0063] Step 3, laser energy deposition Ti 41 V 27 Nb 13 Hf 13 Mo6 refractory high entropy alloy

[0064] A 3D solid model (CAD model file) is created based on the geometry of the alloy component to be fabricated. The CAD model file is uploaded to the Ytterbium Laser System (YLS-10000) laser stereo forming equipment. High-purity argon gas is introduced as a protective atmosphere, and the additive manufacturing process parameters and scanning path are set. A coaxial nozzle is used to feed the refractory high-entropy alloy powder into the molten pool formed by the high-energy laser beam. The refractory high-entropy alloy component is printed by depositing the powder point by point, line by line, and layer by layer on the substrate.

[0065] The laser process parameters are as follows: laser power is 1800 W, scanning rate is 6 mm / s, powder feeding speed is 11.2 g / min, Z-axis lifting amount is 0.5 mm, spot diameter is 5 mm, overlap rate is 50%, and the scanning path adopts a vertical reciprocating interwoven path.

[0066] The microstructure, structure characterization and performance testing of the additive TiVNbHfMo alloy prepared in Examples 2-4 above were carried out, as follows.

[0067] Figure 2During the laser energy deposition (LASD) forming process of a TiVHfNbMo alloy, the melt pool morphology was monitored in real time to assess forming quality and determine if parameter adjustments were made. After additively preparing the bulk TiVNbHfMo alloy, XRD phase analysis was performed. The X-ray diffractometer operated at 40 kV and 40 mA, with a Cu Kα (λ = 0.1542 nm) X-ray source at a scan rate of 5° / min, a scan step of 0.02° / step, and a scanning range of 20° to 100°. Microstructure characterization was performed using secondary electron microscopy (SEM), energy dispersive spectroscopy (EDS), and electron backscatter diffraction (EBSD). Prior to measurement, the upper and lower surfaces of the sample were polished flat and parallel, and the measurement surfaces were electropolished. Tensile mechanical properties of the 26 x 4 mm plate specimens were tested along the additive deposition direction (Z direction) using a KW in-situ tensile stage.

[0068] Figure 3 The alloy microstructures of different regions of the TiVNbHfMo additive body prepared in Example 2 (a), (b), (c), (d), and (f) show that the TiVNbHfMo refractory high-entropy alloy primarily possesses a single-phase BCC structure. Intragranular component segregation occurs near the melt pool, including Hf-enriched regions and a transition from columnar to equiaxed crystals at the top and edges of the specimen. (e) shows that the additive body is composed of five elements: Ti, V, Nb, Hf, and Mo.

[0069] Figure 4 Figure 2 shows the secondary electron micrographs of the TiVNbHfMo alloy microstructures under different process parameters. (a) shows the formation of deplastic cracks under the parameter combination of 2500W laser power and 8mm / s scanning speed in Example 2, (b) shows the formation of voids under the parameter combination of 2000W laser power and 8mm / s scanning speed in Example 3, and (c) shows the dense microstructure with virtually no cracks or voids under the parameter combination of 1800W laser power and 6mm / s scanning speed in Example 4. The optimal process parameters were determined to be: laser power of 1800W, scanning speed of 6mm / s, powder feed rate of 11.2g / min, Z-axis lift of 0.5mm, spot diameter of 5mm, and overlap ratio of 50%.

[0070] Figure 5 The tensile stress-strain curves of the additive TiVNbHfMo alloy under different process parameters show that the Ti formed under the parameter combination of laser power 2500W and scanning speed 8mm / s in Example 2 is 41 V 27 Nb 13 Hf 13The room temperature plasticity of Mo6 alloy is about 1.3%, the tensile strength is 1182MPa, and the yield strength is 1118MPa; Example 3 Ti formed under the parameter combination of laser power 2000W-scanning speed 8mm / s 41 V 27 Nb 13 Hf 13 The room temperature plasticity of Mo6 alloy is about 3.8%, the tensile strength is 1276MPa, and the yield strength is 1171MPa. The Ti formed by the optimal process parameters (laser power 1800W-scanning speed 6mm / s) 41 V 27 Nb 13 Hf 13 The room temperature plasticity of Mo6 alloy is about 11.3%, the tensile strength can reach 1308MPa, and the yield strength can reach 1195MPa. 41 V 27 Nb 13 Hf 13 The tensile strength of Mo6 is only 1219MPa and the yield strength is 1112MPa.

[0071] Figure 6 A comparison of the mechanical properties of an additively manufactured TiVNbHfMo alloy with other additives and a cast refractory high-entropy alloy using the 1800W-6mm / s process parameters. Through additive manufacturing, this invention achieves a TiVNbHfMo refractory high-entropy alloy with both strength and ductility. Its room-temperature tensile yield strength is the highest to date for laser additively manufactured refractory high-entropy alloys.

[0072] Figure 7 The tensile fracture of the additive TiVNbHfMo alloy under the process parameters of 1800W-6mm / s shows a ductile fracture with dimples, indicating that ductile fracture occurred, indicating that the alloy has good plasticity.

Claims

1. A preparation method for additive manufacturing of refractory high entropy alloys, characterized in that: The composition suitable for additive manufacturing of refractory high entropy alloys is screened according to the following method: A plurality of as-cast refractory high-entropy alloy samples with different compositions were taken, the surface of each as-cast refractory high-entropy alloy sample was polished and cleaned, and the cleaned surface was subjected to a laser air-scanning remelting operation to obtain each laser remelted sample; The laser remelted samples were cut along the longitudinal section, and subjected to rough grinding, polishing and corrosion treatment. The crack defects in the laser remelted samples were observed, and the elemental composition corresponding to the laser remelted samples with relatively few crack defects was selected as the elemental composition suitable for additive manufacturing of refractory high-entropy alloys; The element composition of the refractory high entropy alloy screened for additive manufacturing is Ti a V b Nb c Hf d Mo e , where a, b, c, d and e correspond to the molar ratios of the elements, a=41 at%, b=27 at%, c=13 at%, d=13 at%, and e=6 at%; The preparation method suitable for additive manufacturing of refractory high entropy alloys comprises: According to the elemental composition of the refractory high-entropy alloy suitable for additive manufacturing obtained by screening, metal raw materials corresponding to each element are taken, smelted, pickled and milled into rods; the rods are processed into high-entropy alloy pre-alloyed spherical powder, sieved to obtain high-entropy alloy powder, and dried; The dried high entropy alloy powder is prepared by laser additive manufacturing to obtain a refractory high entropy alloy; The additive manufacturing process parameters are as follows: laser power is 1800-2000 W, scanning rate is 6-8 mm / s; powder feeding speed is 11.2 g / min, Z-axis lift is 0.4-0.6 mm, spot diameter is 5 mm, overlap rate is 50%, and the scanning path adopts a vertical reciprocating interwoven path.

2. The preparation method for additive manufacturing of refractory high entropy alloys according to claim 1, characterized in that: The particle size of the high entropy alloy powder obtained by sieving is 53-150 μm.

3. The preparation method for additive manufacturing of refractory high entropy alloys according to claim 1, characterized in that: The refractory high entropy alloy is prepared on a substrate by a laser additive manufacturing method using dried high entropy alloy powder, and the substrate is pre-polished, cleaned and dried.

4. The preparation method for additive manufacturing of refractory high entropy alloys according to claim 1, characterized in that: The additive manufacturing process is carried out under an argon protective atmosphere.

5. The refractory high entropy alloy Ti obtained by the preparation method according to any one of claims 1 to 4 a V b Nb c Hf d Mo e .

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