A high-entropy titanium-aluminum alloy and its laser melt deposition preparation method

Abstract

This invention provides a high-entropy titanium-aluminum alloy and its laser melt deposition preparation method, belonging to the field of alloy preparation technology. This invention utilizes laser melt deposition to prepare high-entropy titanium-aluminum alloys. Laser melt deposition has the advantages of a large temperature gradient and rapid cooling rate, thus the prepared materials often have fine grains, dense microstructure, and excellent mechanical properties. This invention combines titanium-aluminum alloys with high-entropy alloys, improving the overall strength of the alloy. Furthermore, due to the low density of titanium-aluminum alloys, the overall density of the alloy can be reduced, meeting the requirements for lightweighting. This invention changes the final composition of the high-entropy titanium-aluminum alloy by varying the powder feeding rate of different powder materials. Compared to laser melt deposition, which involves mixing powders of different contents and placing them in a powder feeding hopper, this invention saves the processes of weighing powder and mechanical mixing. Moreover, this method is more flexible in design and can produce alloys of different compositions in batches, with significantly higher efficiency than the mechanical powder mixing method.

Description

Technical Field

[0001] This invention relates to the field of alloy preparation technology, and in particular to a high-entropy titanium-aluminum alloy and its laser melt deposition preparation method. Background Technology

[0002] High-entropy alloys are a relatively new concept, initially defined as alloys composed of five or more elements, each with a composition ranging from 5 to 35 at.%. Unlike traditional alloys, high-entropy alloys lack a specific principal element; the interactions between the elements maximize their internal configurational entropy. Consequently, high-entropy alloys often form solid solution phases rather than ordered intermetallic compounds. This unique structure gives them four distinct effects compared to traditional alloys: the high-entropy effect, the hysteresis diffusion effect, the lattice distortion effect, and the "cocktail" effect. However, single high-entropy alloys exhibit relatively low strength and high density, limiting their applications in aerospace and other fields. Summary of the Invention

[0003] The purpose of this invention is to provide a high-entropy titanium-aluminum alloy and its laser melt deposition preparation method. The high-entropy titanium-aluminum alloy provided by this invention has high strength and low density.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] This invention provides a method for preparing high-entropy titanium-aluminum alloy using laser melt deposition, comprising the following steps: placing high-entropy alloy powder and titanium-aluminum alloy powder in two powder feeding bins respectively, performing laser melt deposition on the substrate surface, and obtaining high-entropy titanium-aluminum alloy on the substrate surface;

[0006] The high-entropy alloy powder has the following composition by atomic percentage: Ti3Zr. 1.5 NbVAl 0.25 The titanium-aluminum alloy powder has the composition Ti-48Al-2Cr-2Nb;

[0007] The conditions for laser fused deposition include: printing power of 1200~1800W, scanning speed of 8~12mm / s, laser spot diameter of 3.5~4.0mm, high-entropy alloy powder feeding rate of 6~10g / min, titanium-aluminum alloy powder feeding rate of 0.8~4g / min, overlap rate of 25~35%, Z-axis lift of 0.9~1.2mm, protective gas flow rate of 12~20L / min, and carrier gas flow rate of 5~8L / min.

[0008] Preferably, the high-entropy alloy powder has a spherical morphology and a particle size of 50~150μm.

[0009] Preferably, the titanium-aluminum alloy powder has a spherical morphology and a particle size of 20~40μm.

[0010] Preferably, the high-entropy alloy powder and the titanium-aluminum alloy powder are placed in front of two powder feeding bins respectively, and the high-entropy alloy powder and the titanium-aluminum alloy powder are dried respectively.

[0011] Preferably, the protective gas is high-purity argon.

[0012] Preferably, the carrier gas is high-purity argon.

[0013] Preferably, the laser melt deposition is performed in a printing chamber, where the oxygen content is ≤50ppm.

[0014] Preferably, the substrate is a TC4 substrate, a pure Ti substrate, or a pure Zr substrate.

[0015] Preferably, before the laser fused deposition, the substrate is further subjected to polishing, cleaning and drying in sequence.

[0016] This invention provides a high-entropy titanium-aluminum alloy prepared by the method described above, comprising, by atomic percentage: Ti: 40~50 at.%, Zr: 10~20 at.%, Nb: 6~15 at.%, V: 6~15 at.%, Al: 7~25 at.%, Cr: >0 and ≤1.5 at.%;

[0017] The high-entropy titanium-aluminum alloy has a compressive yield strength of 1259~1535 MPa, a compressive plasticity greater than 50%, and a microhardness of 357.0~426.8 HV. 0.2 Its density is 4.834~5.258 g / cm³. 3 Its relative density reaches over 95%.

[0018] This invention provides a method for preparing high-entropy titanium-aluminum alloys using laser melt deposition, comprising the following steps: placing high-entropy alloy powder and titanium-aluminum alloy powder separately in two powder feeding bins, and performing laser melt deposition on the substrate surface to obtain a high-entropy titanium-aluminum alloy on the substrate surface; the composition of the high-entropy alloy powder is Ti3Zr by atomic percentage. 1.5 NbVAl 0.25The titanium-aluminum alloy powder has the composition Ti-48Al-2Cr-2Nb; the laser fused deposition conditions include: printing power of 1200~1800W, scanning speed of 8~12mm / s, laser spot diameter of 3.5~4.0mm, high-entropy alloy powder feeding rate of 6~10g / min, titanium-aluminum alloy powder feeding rate of 0.8~4g / min, overlap rate of 25~35%, Z-axis lift of 0.9~1.2mm, protective gas flow rate of 12~20L / min, and carrier gas flow rate of 5~8L / min.

[0019] This invention utilizes laser melt deposition to prepare high-entropy titanium-aluminum alloys. Laser melt deposition is characterized by a large temperature gradient and rapid cooling rate, resulting in materials with fine grains, dense microstructure, and excellent mechanical properties. This invention combines titanium-aluminum alloys with high-entropy alloys, improving the overall strength of the alloy. Furthermore, due to the low density of titanium-aluminum alloys, the overall density of the alloy can be reduced, meeting lightweight requirements.

[0020] The results of the examples show that the high-entropy titanium-aluminum alloy prepared by the present invention has a compressive yield strength of 1259~1535 MPa, a compressive plasticity greater than 50%, and a microhardness of 357.0~426.8 HV. 0.2 Its density is 4.834~5.258 g / cm³. 3 Its relative density reaches over 95%.

[0021] This invention changes the final composition of high-entropy titanium-aluminum alloy by altering the powder feeding rate of different powder materials. Compared to laser melt deposition, which involves mixing powders of different contents and placing them in a powder feeding hopper, this invention saves the process of weighing powder and mechanical mixing. Moreover, this method is more flexible in design and can be used to prepare alloys of different compositions in batches, with significantly higher efficiency than the mechanical mixing method. Attached Figure Description

[0022] Figure 1 XRD patterns of high-entropy titanium-aluminum alloys with different compositions;

[0023] Figure 2 Compressive stress-strain curves of high-entropy titanium-aluminum alloys with different compositions. Detailed Implementation

[0024] This invention provides a method for preparing high-entropy titanium-aluminum alloy using laser melt deposition, comprising the following steps: placing high-entropy alloy powder and titanium-aluminum alloy powder in two powder feeding bins respectively, performing laser melt deposition on the substrate surface, and obtaining high-entropy titanium-aluminum alloy on the substrate surface;

[0025] The high-entropy alloy powder has the following composition by atomic percentage: Ti3Zr. 1.5 NbVAl0.25 The titanium-aluminum alloy powder has the composition Ti-48Al-2Cr-2Nb;

[0026] The conditions for laser fused deposition include: printing power of 1200~1800W, scanning speed of 8~12mm / s, laser spot diameter of 3.5~4.0mm, high-entropy alloy powder feeding rate of 6~10g / min, titanium-aluminum alloy powder feeding rate of 0.8~4g / min, overlap rate of 25~35%, Z-axis lift of 0.9~1.2mm, protective gas flow rate of 12~20L / min, and carrier gas flow rate of 5~8L / min.

[0027] Unless otherwise specified, all raw materials used in this invention are commercially available products well known in the art.

[0028] In this invention, Ti3Zr 1.5 NbVAl 0.25 The high-entropy alloy powder is preferably prepared by a rotating electrode, wherein the electrode running speed is preferably 1~1.5 mm / s, the arc current is preferably 1200~2000 A, and the alloy rod rotation speed is preferably 15000~25000 r / min.

[0029] In this invention, the high-entropy alloy powder is preferably spherical in shape and has a particle size of 50-150 μm; the titanium-aluminum alloy powder is preferably spherical in shape and has a particle size of 20-40 μm.

[0030] In this invention, before placing the high-entropy alloy powder and titanium-aluminum alloy powder into two separate powder feeding bins, it is preferable to further include drying the high-entropy alloy powder and titanium-aluminum alloy powder separately. In this invention, the drying temperature is preferably 80°C, and the drying time is preferably 120 minutes. In this invention, the drying is preferably carried out in a forced-air drying oven.

[0031] In this invention, the substrate is preferably a TC4 substrate, a pure Ti substrate, or a pure Zr substrate. Prior to laser fused deposition, the invention preferably further includes sequentially polishing, cleaning, and drying the substrate; the polishing is preferably sandpaper polishing; the cleaning solution used is preferably acetone; the drying temperature is preferably 80°C, and the drying time is preferably 120 minutes.

[0032] In this invention, the laser melt deposition is preferably performed in a printing chamber, and the oxygen content in the printing chamber is preferably ≤50ppm.

[0033] In this invention, the conditions for laser fused deposition include: a printing power of 1200~1800W, preferably 1300~1700W, more preferably 1400~1600W; a scanning speed of 8~12mm / s, preferably 9~11mm / s, more preferably 10mm / s; a laser spot diameter of 3.5~4.0mm, preferably 3.6~3.9mm; a high-entropy alloy powder feeding rate of 6~10g / min, preferably 7~9g / min; a titanium-aluminum alloy powder feeding rate of 0.8~4g / min, preferably 2~3g / min; an overlap rate of 25~35%, preferably 28~32%; a Z-axis lift of 0.9~1.2mm, preferably 1.0~1.1mm; a protective gas flow rate of 12~20L / min, preferably 14~18L / min; and a carrier gas flow rate of 5~8L / min, preferably 6~7L / min.

[0034] In this invention, the protective gas is preferably high-purity argon; the carrier gas is preferably high-purity argon.

[0035] This invention changes the final composition of high-entropy titanium-aluminum alloy by altering the powder feeding rate of different powder materials. Compared to laser melt deposition, which involves mixing powders of different contents and placing them in a powder feeding hopper, this invention saves the process of weighing powder and mechanical mixing. Moreover, this method is more flexible in design and can be used to prepare alloys of different compositions in batches, with significantly higher efficiency than the mechanical mixing method.

[0036] In this invention, the laser fused deposition preferably uses a YLS-4000-UK fiber laser from IPG GmbH (Germany), a six-axis linkage robotic arm from KUKA GmbH (Germany), an LH-ZSI-1020-02-201202 laser cladding head from Nanjing Huirui Co., Ltd., and a CT-1317-01-210903 nozzle from Nanjing Huirui Co., Ltd.

[0037] The present invention does not have special requirements for the implementation process of the laser fused deposition method; any implementation process well known in the art can be used. In the embodiments of the present invention, high-entropy alloy powder and titanium-aluminum alloy powder are poured into different powder feeding containers, the substrate is fixed in the printing chamber, high-purity argon gas is introduced into the printing chamber, and the oxygen content in the chamber is detected by an oxygen content meter. After the oxygen content drops below 50 ppm and stabilizes for a period of time, the printing process can begin.

[0038] This invention provides a high-entropy titanium-aluminum alloy prepared by the method described above, comprising, by atomic percentage: Ti: 40~50 at.%, Zr: 10~20 at.%, Nb: 6~15 at.%, V: 6~15 at.%, Al: 7~25 at.%, Cr: >0 and ≤1.5 at.%;

[0039] The high-entropy titanium-aluminum alloy has a compressive yield strength of 1259~1535 MPa, a compressive plasticity greater than 50%, and a microhardness of 357.0~426.8 HV. 0.2 Its density is 4.834~5.258 g / cm³. 3 Its relative density reaches over 95%.

[0040] The following detailed description of the high-entropy titanium-aluminum alloy and its laser melt deposition preparation method provided by the present invention, with reference to the embodiments, should not be construed as limiting the scope of protection of the present invention.

[0041] The preparation process of the high-entropy alloy powder in the following examples and comparative examples is as follows: Ti3Zr 1.5 NbVAl 0.25 High-entropy alloy powder was prepared by rotating an electrode with an electrode running speed of 1.4 mm / s, an arc current of 1500 A, and an alloy rod rotation speed of 21000 r / min.

[0042] Example 1

[0043] Step 1: Place the high-entropy alloy powder and titanium-aluminum alloy powder into a forced-air drying oven to remove moisture. The drying temperature is 80℃, and the drying time is 120 minutes.

[0044] Step 2: Clean the surface of the TC4 substrate with sandpaper and remove oil and dust with acetone. Then dry it in a forced-air drying oven at 80°C for 120 minutes.

[0045] Step 3: Pour the high-entropy alloy powder and titanium-aluminum alloy powder cooled to room temperature into different powder feeding containers, fix the substrate in the printing chamber, fill the printing chamber with high-purity argon gas, and detect the oxygen content in the chamber with an oxygen content meter. After the oxygen content drops to below 50 ppm and stabilizes for a period of time, the printing work can begin.

[0046] Step 4: Set the laser fused deposition program using computer software, with the following settings: printing power 1500W, scanning speed 10mm / s, laser spot diameter 3.85mm, high-entropy alloy powder feed rate 9.80g / min, titanium-aluminum alloy powder feed rate 1.09g / min, overlap rate 30%, Z-axis lift 1.07mm, protective gas flow rate 15L / min, and carrier gas (high-purity argon) flow rate 6L / min. The entire laser fused deposition process is completed using the robot's pendant driver. The printed sample cools to room temperature with the chamber. In this embodiment, the titanium-aluminum alloy mass fraction is 10%.

[0047] Step 5: Use wire cutting to cut the printing material 1mm above the substrate, clean and polish the workpiece to obtain a typical block sample. The nominal composition of the sample is Ti. 45.0 Zr 18.8 Nb 12.8 V 12.5 Al 10.5 Cr 0.3 The actual composition obtained by scanning the energy spectrum is Ti. 46.7 Zr 18.7 Nb 11.2 V 13.4 Al 9.4 Cr 0.6 .

[0048] Example 2

[0049] Step 1: Place the high-entropy alloy powder and titanium-aluminum alloy powder into a forced-air drying oven to remove moisture. The drying temperature is 80℃, and the drying time is 120 minutes.

[0050] Step 2: Clean the surface of the TC4 substrate with sandpaper and remove oil and dust with acetone. Then dry it in a forced-air drying oven at 80°C for 120 minutes.

[0051] Step 3: Pour the high-entropy alloy powder and titanium-aluminum alloy powder cooled to room temperature into different powder feeding containers, fix the substrate in the printing chamber, fill the printing chamber with high-purity argon gas, and detect the oxygen content in the chamber with an oxygen content meter. After the oxygen content drops to below 50 ppm and stabilizes for a period of time, the printing work can begin.

[0052] Step 4: Set the laser fused deposition program using computer software, with the following settings: printing power 1500W, scanning speed 10mm / s, laser spot diameter 3.85mm, high-entropy alloy powder feed rate 8.71g / min, titanium-aluminum alloy powder feed rate 2.18g / min, overlap rate 30%, Z-axis lift 1.07mm, protective gas flow rate 15L / min, and carrier gas (high-purity argon) flow rate 6L / min. The entire laser fused deposition process is completed using the robot's pendant driver. The printed sample cools to room temperature with the chamber. In this embodiment, the titanium-aluminum alloy mass fraction is 20%.

[0053] Step 5: Use wire cutting to cut the printing material 1mm above the substrate, clean and polish the workpiece to obtain a typical block sample. The nominal composition of the sample is Ti. 45.5 Zr 15.8 Nb 11.1 V 10.5 Al 16.6 Cr 0.6The actual composition obtained by scanning the energy spectrum is Ti. 47.4 Zr 16.3 Nb 10.1 V 12.0 Al 13.4 Cr 0.8 .

[0054] Example 3

[0055] Step 1: Place the high-entropy alloy powder and titanium-aluminum alloy powder into a forced-air drying oven to remove moisture. The drying temperature is 80℃, and the drying time is 120 minutes.

[0056] Step 2: Clean the surface of the TC4 substrate with sandpaper and remove oil and dust with acetone. Then dry it in a forced-air drying oven at 80°C for 120 minutes.

[0057] Step 3: Pour the high-entropy alloy powder and titanium-aluminum alloy powder cooled to room temperature into different powder feeding containers, fix the substrate in the printing chamber, fill the printing chamber with high-purity argon gas, and detect the oxygen content in the chamber with an oxygen content meter. After the oxygen content drops to below 50 ppm and stabilizes for a period of time, the printing work can begin.

[0058] Step 4: Set the laser fused deposition program using computer software, with the following settings: printing power 1500W, scanning speed 10mm / s, laser spot diameter 3.85mm, high-entropy alloy powder feed rate 7.61g / min, titanium-aluminum alloy powder feed rate 3.28g / min, overlap rate 30%, Z-axis lift 1.07mm, protective gas flow rate 15L / min, and carrier gas (high-purity argon) flow rate 6L / min. The entire laser fused deposition process is completed using the robot's pendant driver. The printed sample cools to room temperature with the chamber. In this embodiment, the titanium-aluminum alloy mass fraction is 30%.

[0059] Step 5: Use wire cutting to cut the printing material 1mm above the substrate, clean and polish the workpiece to obtain a typical block sample. The nominal composition of the sample is Ti. 45.9 Zr 13.0 Nb 9.5 V 8.7 Al 22.1 Cr 0.8 The actual composition obtained by scanning the energy spectrum is Ti. 47.8 Zr 14.1 Nb 8.8 V 10.5 Al 17.8 Cr 1.0 .

[0060] Comparative Example 1

[0061] Step 1: Place the high-entropy alloy powder and titanium-aluminum alloy powder into a forced-air drying oven to remove moisture. The drying temperature is 80℃, and the drying time is 120 minutes.

[0062] Step 2: Clean the surface of the TC4 substrate with sandpaper and remove oil and dust with acetone. Then dry it in a forced-air drying oven at 80°C for 120 minutes.

[0063] Step 3: Pour the high-entropy alloy powder and titanium-aluminum alloy powder cooled to room temperature into different powder feeding containers, fix the substrate in the printing chamber, fill the printing chamber with high-purity argon gas, and detect the oxygen content in the chamber with an oxygen content meter. After the oxygen content drops to below 50 ppm and stabilizes for a period of time, the printing work can begin.

[0064] Step 4: Set the laser fused deposition program using computer software, with the following settings: printing power 1500W, scanning speed 10mm / s, laser spot diameter 3.85mm, high-entropy alloy powder feed rate 6.53g / min, titanium-aluminum alloy powder feed rate 4.36g / min, overlap rate 30%, Z-axis lift 1.07mm, protective gas flow rate 15L / min, and carrier gas (high-purity argon) flow rate 6L / min. The entire laser fused deposition process is completed using the robot's pendant driver. The printed sample cools to room temperature with the chamber. In this example, the titanium-aluminum alloy mass fraction is 40%.

[0065] Step 5: Use wire cutting to cut the printing material 1mm above the substrate, clean and polish the workpiece to obtain a typical block sample. The nominal composition of the sample is Ti. 46.3 Zr 10.6 Nb 8.1 V 7.1 Al 26.9 Cr 1.0 The actual composition obtained by scanning the energy spectrum is Ti. 48.6 Zr 11.1 Nb 7.3 V 8.7 Al 23.2 Cr 1.1 .

[0066] Comparative Example 2

[0067] Step 1: Place the high-entropy alloy powder and titanium-aluminum alloy powder into a forced-air drying oven to remove moisture. The drying temperature is 80℃, and the drying time is 120 minutes.

[0068] Step 2: Clean the surface of the TC4 substrate with sandpaper and remove oil and dust with acetone. Then dry it in a forced-air drying oven at 80°C for 120 minutes.

[0069] Step 3: Pour the high-entropy alloy powder and titanium-aluminum alloy powder cooled to room temperature into different powder feeding containers, fix the substrate in the printing chamber, fill the printing chamber with high-purity argon gas, and detect the oxygen content in the chamber with an oxygen content meter. After the oxygen content drops to below 50 ppm and stabilizes for a period of time, the printing work can begin.

[0070] Step 4: Set the laser fused deposition program using computer software, with the following settings: printing power 1500W, scanning speed 10mm / s, laser spot diameter 3.85mm, high-entropy alloy powder feed rate 5.45g / min, titanium-aluminum alloy powder feed rate 5.45g / min, overlap rate 30%, Z-axis lift 1.07mm, protective gas flow rate 15L / min, and carrier gas (high-purity argon) flow rate 6L / min. The entire laser fused deposition process is completed using the robot's pendant driver. The printed sample cools to room temperature with the chamber. In this embodiment, the titanium-aluminum alloy mass fraction is 50%.

[0071] Step 5: Use wire cutting to cut the printing material 1mm above the substrate, clean and polish the workpiece to obtain a typical block sample.

[0072] Comparative Example 3

[0073] Ti3Zr prepared by laser fused deposition 1.5 NbVAl 0.25 Alloying, the specific steps are as follows:

[0074] Step 1: Add Ti3Zr 1.5 NbVAl 0.25 The high-entropy alloy powder was placed in a forced-air drying oven to remove moisture. The drying temperature was 80℃ and the drying time was 120 minutes.

[0075] Step 2: Clean the surface of the TC4 substrate with sandpaper and remove oil and dust with acetone. Then dry it in a forced-air drying oven at 80°C for 120 minutes.

[0076] Step 3: Cool Ti3Zr to room temperature 1.5 NbVAl 0.25 High-entropy alloy powder is poured into the powder feeding hopper, the substrate is fixed in the printing chamber, high-purity argon gas is introduced into the printing chamber, and the oxygen content in the chamber is detected by an oxygen content meter. After the oxygen content drops to below 50ppm and stabilizes for a period of time, the printing work can begin.

[0077] Step 4: Set the laser fused deposition program using computer software, with the following settings: printing power 1500W, scanning speed 10mm / s, laser spot diameter 3.85mm, high-entropy alloy powder feed rate 10.89g / min, overlap rate 30%, Z-axis lift 1.07mm, protective gas flow rate 15L / min, and carrier gas (high-purity argon) flow rate 6L / min. The entire laser fused deposition process is completed using the robot's calibration device driver. The printed sample cools to room temperature with the chamber.

[0078] Step 5: Use wire cutting to cut the printing material 1mm above the substrate, clean and polish the workpiece to obtain a typical block sample.

[0079] Structural and performance testing:

[0080] Thin slices with a thickness of 2 mm were cut from the samples prepared in each embodiment and comparative example along the scanning direction for Vickers hardness testing, and cylindrical compressed samples with a diameter of 3 × 4.5 mm were cut along the deposition direction.

[0081] Comparative Example 2 cracked during the laser melt deposition process and could not be processed into a shaped compressed sample, indicating that when the content of titanium-aluminum alloy increased to 50%, the brittleness of the high-entropy titanium-aluminum alloy increased sharply.

[0082] Figure 1 XRD patterns of high-entropy titanium-aluminum alloys with different compositions, by Figure 1 It can be seen that each alloy is composed of the BCC phase.

[0083] Figure 2 The compressive stress-strain curves of high-entropy titanium-aluminum alloys with different compositions were obtained, showing that the strength of the material increases with the increase of titanium-aluminum alloy content. Examples 1-3 exhibited good compressive plasticity, and no fracture occurred when the strain reached 50%. With the increase of titanium-aluminum alloy content, the plasticity decreased significantly. Comparative Example 1 fractured during compression, and its compressive fracture plasticity was only 30%.

[0084] Table 1 shows the mechanical and density data of high-entropy titanium-aluminum alloys with different compositions.

[0085] Table 1. Mechanical and density data of high-entropy titanium-aluminum alloys with different compositions

[0086]

[0087] As shown in Table 1, the experimental results indicate that the hardness and compressive yield strength of the high-entropy titanium-aluminum alloy gradually increase with increasing titanium-aluminum alloy content, suggesting that the addition of titanium-aluminum alloy has a certain strengthening effect on the material. Furthermore, the material density decreases with increasing titanium-aluminum alloy content. (Compared to Ti3Zr)1.5 NbVAl 0.25 The high-entropy alloy in Example 3 showed a 15.7% decrease in density, which is significant for improving specific strength. The relative densities of the materials in both the examples and the comparative examples were above 95%, indicating that the choice of laser fused deposition process was appropriate.

[0088] Matters not covered in this invention are common knowledge.

[0089] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing high-entropy titanium-aluminum alloys using laser melt deposition, characterized in that, Includes the following steps: High-entropy alloy powder and titanium-aluminum alloy powder were placed in two powder feeding bins respectively, and laser melt deposition was performed on the substrate surface to obtain a high-entropy titanium-aluminum alloy on the substrate surface. The high-entropy alloy powder has the following composition by atomic percentage: Ti3Zr. 1.5 NbVAl 0.25 The titanium-aluminum alloy powder has the composition Ti-48Al-2Cr-2Nb; The conditions for laser fused deposition include: printing power of 1200~1800W, scanning speed of 8~12mm / s, laser spot diameter of 3.5~4.0mm, high-entropy alloy powder feeding rate of 6~10g / min, titanium-aluminum alloy powder feeding rate of 0.8~4g / min, overlap rate of 25~35%, Z-axis lift of 0.9~1.2mm, protective gas flow rate of 12~20L / min, and carrier gas flow rate of 5~8L / min.

2. The method according to claim 1, characterized in that, The high-entropy alloy powder has a spherical morphology and a particle size of 50~150μm.

3. The method according to claim 1, characterized in that, The titanium-aluminum alloy powder has a spherical morphology and a particle size of 20~40μm.

4. The method according to any one of claims 1 to 3, characterized in that, The high-entropy alloy powder and titanium-aluminum alloy powder are placed in front of two powder feeding hoppers respectively, and the high-entropy alloy powder and titanium-aluminum alloy powder are dried respectively.

5. The method according to claim 1, characterized in that, The protective gas is high-purity argon.

6. The method according to claim 1, characterized in that, The carrier gas is high-purity argon.

7. The method according to claim 1, 5, or 6, characterized in that, The laser melt deposition is performed in a printing chamber with an oxygen content ≤50ppm.

8. The method according to claim 1, characterized in that, The substrate is a TC4 substrate, a pure Ti substrate, or a pure Zr substrate.

9. The method according to claim 1 or 8, characterized in that, Before the laser melt deposition, the substrate is also subjected to polishing, cleaning and drying in sequence.

10. The high-entropy titanium-aluminum alloy prepared by the method according to any one of claims 1 to 9, comprising, by atomic percentage: Ti: 40-50 at.%, Zr: 10-20 at.%, Nb: 6-15 at.%, V: 6-15 at.%, Al: 7-25 at.%, Cr: >0 and ≤1.5 at.%; The high-entropy titanium-aluminum alloy has a compressive yield strength of 1259~1535 MPa, a compressive plasticity greater than 50%, and a microhardness of 357.0~426.8 HV. 0.2 Its density is 4.834~5.258 g / cm³. 3 Its relative density reaches over 95%.

Images