High-strength anti-cracking refractory high-entropy alloy powder, coating and application of high-strength anti-cracking refractory high-entropy alloy powder

Abstract

The invention discloses high-strength anti-cracking refractory high-entropy alloy powder, a coating and application of the high-strength anti-cracking refractory high-entropy alloy powder, compared with traditional refractory high-entropy alloy powder, refractory alloy elements Nb, Mo, Ta, W and V are added to form a BCC solid solution, and the due strength, hardness and high-temperature performance of the refractory high-entropy alloy coating are guaranteed; according to the method, Cr, Co and Ni elements are added to form an FCC solid solution, FCC and BCC bidirectional structures are cooperatively matched, the toughness of the coating is improved, local stress and strain in the laser cladding rapid cooling process are coordinated, and therefore the cracking risk of the refractory high-entropy alloy coating in the laser cladding process is reduced, and the crack resistance of the refractory high-entropy alloy coating is improved. The high-cracking-resistance refractory high-entropy alloy coating can be mainly applied to surface strengthening of various materials such as carbon steel, stainless steel and nickel-based alloy, the coating is free of defects such as cracks, air holes and inclusions, and the hardness of the coating exceeds 700 HV.

Description

Technical Field

[0001] This invention relates to the field of laser additive manufacturing technology, specifically to a high-strength, crack-resistant, refractory, high-entropy alloy powder, coating, and their applications. Background Technology

[0002] Refractory high-entropy alloy coatings, as a new type of alloy material, have superior high-temperature mechanical properties and good high-temperature phase stability compared with traditional coating materials. Moreover, their performance can be optimized by adjusting the content of main elements. They are widely used in extreme working conditions such as mining and metallurgy, energy and power, and marine engineering, and have broad application prospects.

[0003] Currently, the most commonly used refractory high-entropy alloy coating is the NbMoTaWV alloy system, which can still exhibit a yield strength of 477 MPa above 1600℃, far exceeding the yield strength of traditional high-temperature alloys in extreme environments. Therefore, it shows great application potential in defense, aerospace, nuclear industry, chemical industry, energy, metallurgy and other fields. However, due to the repeated rapid heating and cooling in the laser cladding process, high thermal stress and residual stress exist in the coating. At the same time, because traditional refractory high-entropy alloys have poor room temperature plasticity, for example, NbMoTaW has only about 2% plastic strain at room temperature, resulting in a large tendency to crack during the laser cladding process, which limits its application in laser cladding technology. Summary of the Invention

[0004] To address the problem of high brittleness and easy cracking in existing refractory high-entropy alloy powders during laser cladding coatings, this invention provides a high-strength, crack-resistant refractory high-entropy alloy powder, coating, and its application. By introducing Cr, Co, and Ni elements into the NbMoTaWV single-phase BCC refractory high-entropy alloy, a bidirectional FCC+BCC microstructure is formed, improving the coating's toughness and coordinating local stress and strain during the rapid heating and cooling process of laser cladding. This reduces the risk of cracking in the refractory high-entropy alloy coating during laser cladding and enhances its crack resistance.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a high-strength, crack-resistant, refractory, high-entropy alloy powder, composed of the following elements by mass percentage: The percentages of Nb, Mo, Ta, W, V, Cr, Co, and Ni are 12.5-15%, 12.5-15%, 24-29%, 24-29%, 6.5-8%, 1.5-6%, 1.5-6%, and 1.5-6%, respectively.

[0006] Preferably, the atomic percentages of Nb, Mo, Ta, W, and V are approximately 1:1:1:1:1, and the atomic percentages of Cr, Co, and Ni are approximately 1:1:1.

[0007] The atomic percentages of elements in NbMoTaWV high-entropy alloy powder and CrCoNi medium-entropy alloy powder are close to or the same, that is, the ratio of the mass of each element to the relative atomic mass of each element is close to or the same.

[0008] Preferably, the composition of the refractory high-entropy alloy powder is (NbMoTaWV)x(CrCoNi)1-x, wherein 80%≤x≤90%.

[0009] Specifically, this refers to the following conditions: the atomic percentages of Nb, Mo, Ta, W, and V are approximately 1:1:1:1:1, and the atomic percentages of Cr, Co, and Ni are approximately 1:1:1. Then, a high-entropy NbMoTaWV alloy and a medium-entropy CrCoNi alloy are mixed, satisfying (NbMoTaWV)x(CrCoNi)1-x, where 80%≤x≤90% (wt.%). That is, the mass percentage of NbMoTaWV powder is 80-95%, and the mass percentage of CrCoNi is 5-18%.

[0010] Preferably, the mass percentage expression for the composition of the refractory high-entropy alloy powder is: Nb 14.7 Mo 15 Ta 28.4 W 28.9 V8Cr 1.6 Co 1.7 Ni 1.7 .

[0011] Preferably, the mass percentage expression for the composition of the refractory high-entropy alloy powder is: Nb 13.8 Mo 14.3 Ta 27 W 27.3 V 7. 6Cr3Co 3.5 Ni 3.5 .

[0012] Preferably, the mass percentage expression for the composition of the refractory high-entropy alloy powder is: Nb 13 Mo 13.2 Ta 24.8 W 24.7 V 6. 7Cr 5.4 Co 6.1 Ni 6.1 .

[0013] In the above technical solution: In refractory high-entropy alloy powder, Nb, Mo, Ta, W, and V elements form a BCC solid solution during laser cladding, ensuring the required strength, hardness, and high-temperature performance of the refractory high-entropy alloy coating. Cr, Co, and Ni elements form an FCC solid solution during laser cladding, improving the coating's toughness and crack resistance. By introducing specific amounts of Cr, Co, and Ni elements into the NbMoTaWV single-phase BCC refractory high-entropy alloy, the solid solubility between NbMoTaWV and CoCrNi elements is very low. Therefore, NbMoTaWV elements are mutually soluble to form a high-entropy alloy, while CoCrNi elements are mutually soluble to form a medium-entropy alloy, thus forming an FCC+BCC bidirectional microstructure. The BCC element coordinates the local stress and strain during the rapid cooling process of laser cladding, thereby reducing the cracking risk of the refractory high-entropy alloy coating during laser cladding and improving its crack resistance, solving the technical problem of easy cracking in traditional high-entropy alloy coatings clad by laser cladding.

[0014] In addition, the content of Cr, Co, and Ni elements in the refractory high-entropy alloy powder system has been determined through a large number of experiments. If the content of Cr, Co, and Ni elements is too high, the content of FCC phase in the coating will increase and the content of BCC will decrease during laser cladding, which will reduce the hardness of the coating. If the content of Cr, Co, and Ni elements is too low, the FCC phase content will be too small to effectively inhibit the cracking of the coating.

[0015] Furthermore, the refractory high-entropy alloy powder includes, but is not limited to, preparations made by gas atomization, ultrasonic atomization, plasma atomization, rotating electrode method, or ball milling.

[0016] Furthermore, the particle size of the refractory high-entropy alloy powder is 75-150 μm. Controlling the particle size of the refractory high-entropy alloy powder within this range is necessary to adapt to the laser cladding process. Since the width of the powder outlet hole in the nozzle is limited during laser cladding, excessively large powder particles will cause powder blockage, while excessively small particles will result in uneven powder feeding due to poor flowability.

[0017] The present invention also provides a high-strength, crack-resistant, refractory high-entropy alloy coating, wherein the coating is formed by laser cladding of the above-mentioned refractory high-entropy alloy powder on the surface of a substrate.

[0018] Preferably, during the laser cladding process, the laser power is 8000-10000W; the laser scanning speed is 5-10mm / s; and the powder feeding rate is 30-80g / min.

[0019] Preferably, the laser spot size is 6×19mm, and both the protective gas and the powder feeding gas are inert gases such as nitrogen and argon, with a protective gas flow rate of 15-20L / min. The laser spot size can be adjusted for specific applications.

[0020] The coating has high strength and crack resistance, and is free from defects such as cracks, pores and inclusions. The coating hardness is greater than 500 HV.

[0021] The present invention also provides an application of the above-mentioned high-strength, crack-resistant, refractory, high-entropy alloy coating, wherein the coating is used to strengthen the surface of a substrate, and the substrate includes various materials such as carbon steel, stainless steel, or nickel-based alloys.

[0022] Compared with the prior art, the present invention has the following beneficial effects: Compared with traditional refractory high-entropy alloy powders, the high-strength, crack-resistant refractory high-entropy alloy powder of this invention, by adding refractory alloying elements Nb, Mo, Ta, W, and V to form a BCC solid solution, ensures the required strength, hardness, and high-temperature performance of the refractory high-entropy alloy coating; by adding Cr, Co, and Ni elements to form an FCC solid solution, the FCC+BCC bidirectional microstructure works synergistically to improve the coating toughness and coordinate local stress and strain during the rapid cooling process of laser cladding, thereby reducing the risk of cracking of the refractory high-entropy alloy coating during laser cladding and improving its crack resistance, while also ensuring that the coating hardness after laser cladding is greater than 500 HV.

[0023] In addition, the content of Cr, Co, and Ni elements in the refractory high-entropy alloy powder system has been determined through a large number of experiments. If the content of Cr, Co, and Ni elements is too high, the content of FCC phase in the coating will increase and the content of BCC will decrease during laser cladding, which will reduce the hardness of the coating. If the content of Cr, Co, and Ni elements is too low, the FCC phase content will be too small to effectively inhibit the cracking of the coating.

[0024] The application of the high crack-resistant refractory high entropy alloy coating in this invention can be used for surface strengthening of various materials such as carbon steel, stainless steel, and nickel-based alloys. The coating is free of defects such as cracks, pores, and inclusions, and the coating hardness exceeds 700HV. Attached Figure Description

[0025] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0026] Figure 1 This is a macroscopic morphology image of the refractory high-entropy alloy coating in Example 1; Figure 2 This is a scanning electron microscope image of the refractory high-entropy alloy coating in Example 1; Figure 3 This is an EDS surface scan analysis image of the refractory high-entropy alloy coating in Example 1; Figure 4 The image shows the macroscopic morphology of the refractory high-entropy alloy coating in Comparative Example 1. Figure 5 The image shows the macroscopic morphology of the refractory high-entropy alloy coating in Comparative Example 2. Figure 6 The image shows the macroscopic morphology of the refractory high-entropy alloy coating in Comparative Example 3. Figure 7 This is a macroscopic morphology image of the refractory high-entropy alloy coating in Comparative Example 4. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Example 1 This embodiment provides a high-strength, crack-resistant, refractory high-entropy alloy powder. The mass percentage expression for the composition of the high-strength, crack-resistant, refractory high-entropy alloy powder is Nb. 14.7 Mo 15 Ta 28.4 W 28.9 V8Cr 1.6 Co 1.7 Ni 1.7 .

[0029] The high-strength, crack-resistant, refractory, high-entropy alloy powder was prepared by mixing the above-mentioned elemental components in the specified proportions. The specific mixing and preparation process is as follows: First, alloy powders of different masses were weighed using an analytical balance, and then they were placed in a vacuum ball mill jar for ball milling and mixing. The ball milling time was 3 hours, the rotation speed was 300 rpm / min, and the mill was reversed once every 30 minutes.

[0030] The formation of a high-strength, crack-resistant refractory high-entropy alloy coating using the aforementioned refractory high-entropy alloy powder specifically includes the following steps: (1) The above high-strength, crack-resistant, refractory, high-entropy alloy powder was placed in a vacuum drying oven and dried at 120°C for 3 hours to remove the water of crystallization in the powder.

[0031] (2) The carbon steel substrate was polished in sequence with 80-grit, 320-grit, 600-grit and 1200-grit sandpaper. After polishing, the substrate was cleaned with deionized water for the first time, and then cleaned with anhydrous ethanol for the second time. The carbon steel substrate was then placed in a vacuum oven and dried at 80°C for 20 minutes.

[0032] (3) The pretreated refractory high entropy alloy powder and the substrate are subjected to laser cladding treatment, wherein the laser spot size is 6×19mm; the laser power is 9000W; the laser scanning speed is 8mm / s; the protective gas and the powder feeding gas are argon; the powder feeding rate is 50g / min; and the protective gas flow rate is 18L / min.

[0033] No defects such as cracks, pores, or inclusions were found in the refractory high-entropy alloy coating prepared using the above-mentioned refractory high-entropy alloy powder and laser cladding process. Its macroscopic morphology is as follows: Figure 1 As shown. Its microstructure was observed using scanning electron microscopy (SEM), as shown in the figure. Figure 2 It can be seen that its microstructure consists of two phases, gray and white, and EDS surface scan analysis was performed on it. Figure 3 As shown in the figure, the light-colored phase is rich in NbMoTaWV phase, while the dark-colored phase is rich in CrCoNi phase.

[0034] According to GB / T 4340.2-2025 "Metallic Materials Vickers Hardness Test", the microhardness of the coating was tested and the coating hardness was 763.1 HV.

[0035] According to GB / T 12444-2006 Test Method for Wear of Metallic Materials, the tribological properties of the coating at room temperature and at 700℃ were tested, and the wear amounts at room temperature and at 700℃ were 0.0078 g / h and 0.0094 g / h, respectively.

[0036] Example 2 This embodiment provides a high-strength, crack-resistant, refractory high-entropy alloy powder. The mass percentage expression for the composition of the high-strength, crack-resistant, refractory high-entropy alloy powder is Nb. 13.8 Mo 14.3 Ta 27 W 27.3 V 7.6 Cr3Co 3.5 Ni 3.5 .

[0037] The high-strength, crack-resistant, refractory, high-entropy alloy powder was prepared by mixing the above-mentioned elemental components in the specified proportions. The specific mixing and preparation process is as follows: First, alloy powders of different masses were weighed using an analytical balance, and then they were placed in a vacuum ball mill jar for ball milling and mixing. The ball milling time was 3 hours, the rotation speed was 300 rpm / min, and the mill was reversed once every 30 minutes.

[0038] The method for preparing the high-strength, crack-resistant, refractory high-entropy alloy coating in this embodiment is the same as in Example 1. No defects such as cracks, pores, or inclusions were found in the refractory high-entropy alloy coating prepared using the above-mentioned refractory high-entropy alloy powder and laser cladding process.

[0039] According to GB / T 4340.2-2025 Vickers Hardness Test for Metallic Materials, the microhardness of the coating was tested and the coating hardness was 757.7 HV.

[0040] According to GB / T 12444-2006 Test Method for Wear of Metallic Materials, the tribological properties of the coating at room temperature and at 700℃ were tested, and the wear amounts at room temperature and at 700℃ were 0.0083 g / h and 0.0103 g / h, respectively.

[0041] Example 3 This embodiment provides a high-strength, crack-resistant, refractory high-entropy alloy powder. The mass percentage expression for the composition of the high-strength, crack-resistant, refractory high-entropy alloy powder is Nb. 13 Mo 13.2 Ta 24.8 W 24.7 V 6.7 Cr 5.4 Co 6.1 Ni 6.1 .

[0042] The high-strength, crack-resistant, refractory, high-entropy alloy powder was prepared by mixing the above-mentioned elemental components in the specified proportions. The specific mixing and preparation process is as follows: First, alloy powders of different masses were weighed using an analytical balance, and then they were placed in a vacuum ball mill jar for ball milling and mixing. The ball milling time was 3 hours, the rotation speed was 300 rpm / min, and the mill was reversed once every 30 minutes.

[0043] The method for preparing the high-strength, crack-resistant, refractory high-entropy alloy coating in this embodiment is the same as in Example 1. No defects such as cracks, pores, or inclusions were found in the refractory high-entropy alloy coating prepared using the above-mentioned refractory high-entropy alloy powder and laser cladding process.

[0044] The coating was subjected to microhardness testing according to GB / T 4340.2-2025 Vickers Hardness Test for Metallic Materials, and the coating hardness was 808.1 HV.

[0045] According to GB / T 12444-2006 Test Method for Wear of Metallic Materials, the tribological properties of the coating at room temperature and at 700℃ were tested, and the wear amounts at room temperature and at 700℃ were 0.0069 g / h and 0.0085 g / h, respectively.

[0046] Example 4 This embodiment provides a high-strength, crack-resistant, refractory high-entropy alloy powder. The mass percentage expression for the composition of the high-strength, crack-resistant, refractory high-entropy alloy powder is Nb. 14.7 Mo 15 Ta 28.4 W 28.9 V8Cr 1.6 Co 1.7 Ni 1.7 .

[0047] The high-strength, crack-resistant, refractory, high-entropy alloy powder was prepared by mixing the above-mentioned elemental components in the specified proportions. The specific mixing and preparation process is as follows: First, alloy powders of different masses were weighed using an analytical balance, and then they were placed in a vacuum ball mill jar for ball milling and mixing. The ball milling time was 3 hours, the rotation speed was 300 rpm / min, and the mill was reversed once every 30 minutes.

[0048] The method for preparing the high-strength, crack-resistant, refractory high-entropy alloy coating in this embodiment is basically the same as that in Example 1. The difference lies in the laser power being 8000W; the laser scanning speed being 5mm / s; the powder feeding rate being 30g / min; and the protective gas flow rate being 15L / min. No defects such as cracks, pores, or inclusions were found in the refractory high-entropy alloy coating prepared using the above-mentioned refractory high-entropy alloy powder and laser cladding process.

[0049] According to GB / T 4340.2-2025 Vickers Hardness Test for Metallic Materials, the microhardness of the coating was tested and the coating hardness was 787.2 HV.

[0050] According to GB / T 12444-2006 Test Method for Wear of Metallic Materials, the tribological properties of the coating at room temperature and at 700℃ were tested, and the wear amounts at room temperature and at 700℃ were 0.0085 g / h and 0.0093 g / h, respectively.

[0051] Example 5 This embodiment provides a high-strength, crack-resistant, refractory high-entropy alloy powder. The mass percentage expression for the composition of the high-strength, crack-resistant, refractory high-entropy alloy powder is Nb. 14.7 Mo 15 Ta 28.4 W 28.9 V8Cr 1.6 Co 1.7 Ni 1.7 .

[0052] The high-strength, crack-resistant, refractory, high-entropy alloy powder was prepared by mixing the above-mentioned elemental components in the specified proportions. The specific mixing and preparation process is as follows: First, alloy powders of different masses were weighed using an analytical balance, and then they were placed in a vacuum ball mill jar for ball milling and mixing. The ball milling time was 3 hours, the rotation speed was 300 rpm / min, and the mill was reversed once every 30 minutes.

[0053] The method for preparing the high-strength, crack-resistant, refractory high-entropy alloy coating in this embodiment is basically the same as that in Example 1. The difference lies in the laser power being 10000W; the laser scanning speed being 10mm / s; the powder feeding rate being 80g / min; and the protective gas flow rate being 20L / min. No defects such as cracks, pores, or inclusions were found in the refractory high-entropy alloy coating prepared using the above-mentioned refractory high-entropy alloy powder and laser cladding process.

[0054] According to GB / T 4340.2-2025 Vickers Hardness Test for Metallic Materials, the microhardness of the coating was tested and the coating hardness was 765.6 HV.

[0055] According to GB / T 12444-2006 Test Method for Wear of Metallic Materials, the tribological properties of the coating at room temperature and at 700℃ were tested, and the wear amounts at room temperature and at 700℃ were 0.0090 g / h and 0.0113 g / h, respectively.

[0056] Example 6 This embodiment provides a high-strength, crack-resistant, refractory high-entropy alloy powder. The mass percentage expression for the composition of the high-strength, crack-resistant, refractory high-entropy alloy powder is Nb. 13.8 Mo 14.3 Ta 27 W 27.3 V 7.6 Cr3Co 3.5 Ni 3.5 .

[0057] The high-strength, crack-resistant, refractory, high-entropy alloy powder was prepared by mixing the above-mentioned elemental components in the specified proportions. The specific mixing and preparation process is as follows: First, alloy powders of different masses were weighed using an analytical balance, and then they were placed in a vacuum ball mill jar for ball milling and mixing. The ball milling time was 3 hours, the rotation speed was 300 rpm / min, and the mill was reversed once every 30 minutes.

[0058] The method for preparing the high-strength, crack-resistant, refractory high-entropy alloy coating in this embodiment is basically the same as that in Example 1. The difference lies in the laser power being 8000W; the laser scanning speed being 5mm / s; the powder feeding rate being 30g / min; and the protective gas flow rate being 15L / min. No defects such as cracks, pores, or inclusions were found in the refractory high-entropy alloy coating prepared using the above-mentioned refractory high-entropy alloy powder and laser cladding process.

[0059] According to GB / T 4340.2-2025 Vickers Hardness Test for Metallic Materials, the microhardness of the coating was tested and the coating hardness was 769.5 HV.

[0060] According to GB / T 12444-2006 Test Method for Wear of Metallic Materials, the tribological properties of the coating at room temperature and at 700℃ were tested, and the wear amounts at room temperature and at 700℃ were 0.0088 g / h and 0.0102 g / h, respectively.

[0061] Example 7 This embodiment provides a high-strength, crack-resistant, refractory high-entropy alloy powder. The mass percentage expression for the composition of the high-strength, crack-resistant, refractory high-entropy alloy powder is Nb. 13.8 Mo 14.3 Ta 27W 27.3 V 7.6 Cr3Co 3.5 Ni 3.5 .

[0062] The high-strength, crack-resistant, refractory, high-entropy alloy powder was prepared by mixing the above-mentioned elemental components in the specified proportions. The specific mixing and preparation process is as follows: First, alloy powders of different masses were weighed using an analytical balance, and then they were placed in a vacuum ball mill jar for ball milling and mixing. The ball milling time was 3 hours, the rotation speed was 300 rpm / min, and the mill was reversed once every 30 minutes.

[0063] The method for preparing the high-strength, crack-resistant, refractory high-entropy alloy coating in this embodiment is basically the same as that in Example 1. The difference lies in the laser power being 10000W; the laser scanning speed being 10mm / s; the powder feeding rate being 80g / min; and the protective gas flow rate being 20L / min. No defects such as cracks, pores, or inclusions were found in the refractory high-entropy alloy coating prepared using the above-mentioned refractory high-entropy alloy powder and laser cladding process.

[0064] According to GB / T 4340.2-2025 Vickers Hardness Test for Metallic Materials, the microhardness of the coating was tested and the coating hardness was 796.4 HV.

[0065] According to GB / T 12444-2006 Test Method for Wear of Metallic Materials, the tribological properties of the coating at room temperature and 700℃ were tested, and the wear amounts at room temperature and 700℃ were 0.0074 g / h and 0.0081 g / h, respectively.

[0066] Example 8 This embodiment provides a high-strength, crack-resistant, refractory high-entropy alloy powder. The mass percentage expression for the composition of the high-strength, crack-resistant, refractory high-entropy alloy powder is Nb. 13 Mo 13.2 Ta 24.8 W 24.7 V 6.7 Cr 5.4 Co 6.1 Ni 6.1 .

[0067] The above-mentioned high-strength, crack-resistant, refractory, high-entropy alloy powder was prepared by mixing the above-mentioned elemental composition ratios.

[0068] The method for preparing the high-strength, crack-resistant, refractory high-entropy alloy coating in this embodiment is basically the same as that in Example 1. The difference lies in the laser power being 8000W; the laser scanning speed being 5mm / s; the powder feeding rate being 30g / min; and the protective gas flow rate being 15L / min. No defects such as cracks, pores, or inclusions were found in the refractory high-entropy alloy coating prepared using the above-mentioned refractory high-entropy alloy powder and laser cladding process.

[0069] According to GB / T 4340.2-2025 Vickers Hardness Test for Metallic Materials, the microhardness of the coating was tested and the coating hardness was 756.8 HV.

[0070] According to GB / T 12444-2006 Test Method for Wear of Metallic Materials, the tribological properties of the coating at room temperature and 700℃ were tested, and the wear amounts at room temperature and 700℃ were 0.0097 g / h and 0.0110 g / h, respectively.

[0071] Example 9 This embodiment provides a high-strength, crack-resistant, refractory high-entropy alloy powder. The mass percentage expression for the composition of the high-strength, crack-resistant, refractory high-entropy alloy powder is Nb. 13 Mo 13.2 Ta 24.8 W 24.7 V 6.7 Cr 5.4 Co 6.1 Ni 6.1 .

[0072] The above-mentioned high-strength, crack-resistant, refractory, high-entropy alloy powder was prepared by mixing the above-mentioned elemental composition ratios.

[0073] The method for preparing the high-strength, crack-resistant, refractory high-entropy alloy coating in this embodiment is basically the same as that in Example 1. The difference lies in the laser power being 10000W; the laser scanning speed being 10mm / s; the powder feeding rate being 80g / min; and the protective gas flow rate being 20L / min. No defects such as cracks, pores, or inclusions were found in the refractory high-entropy alloy coating prepared using the above-mentioned refractory high-entropy alloy powder and laser cladding process.

[0074] According to GB / T 4340.2-2025 Vickers Hardness Test for Metallic Materials, the microhardness of the coating was tested and the coating hardness was 789.7 HV.

[0075] According to GB / T 12444-2006 Test Method for Wear of Metallic Materials, the tribological properties of the coating at room temperature and at 700℃ were tested, and the wear amounts at room temperature and at 700℃ were 0.0079 g / h and 0.0089 g / h, respectively.

[0076] Comparative Example 1 This comparative example is a comparative test case of Example 1. The main difference between this comparative example and Example 1 is that the mass percentage expression of the refractory high-entropy alloy powder composition in this comparative example is Nb. 15.4 Mo 15.9 Ta 29.9 W 30.4 V 8.4 .

[0077] The coating morphology prepared from the above powder components by laser cladding is as follows: Figure 4 As shown, there are obvious cracks in the coating, and microhardness tests were performed on it.

[0078] According to GB / T 4340.2-2025 Vickers Hardness Test for Metallic Materials, the microhardness of the coating was tested and the coating hardness was 522.2 HV.

[0079] According to GB / T 12444-2006 Test Method for Wear of Metallic Materials, the tribological properties of the coating at room temperature and at 700℃ were tested, and the wear amounts at room temperature and at 700℃ were 0.0183 g / h and 0.0256 g / h, respectively.

[0080] Comparative Example 2 This comparative example is a comparative test case of Example 1. The main difference between Example 1 and Example 1 is that the mass percentage expression of the refractory high-entropy alloy powder composition is Nb. 12.0 Mo 12.4 Ta 22.4 W 23.7 V 6.6 Cr 7.7 Co 7.6 Ni 7.6 .

[0081] The coating morphology prepared from the above powder components by laser cladding is as follows: Figure 5 As shown, no defects such as cracks, pores, or inclusions were found in the coating, and its microhardness was tested.

[0082] According to GB / T 4340.2-2025 Vickers Hardness Test for Metallic Materials, the microhardness of the coating was tested and the coating hardness was 270.2 HV.

[0083] According to GB / T 12444-2006 Test Method for Wear of Metallic Materials, the tribological properties of the coating at room temperature and at 700℃ were tested, and the wear amounts at room temperature and at 700℃ were 0.0358 g / h and 0.0542 g / h, respectively.

[0084] Comparative Example 3 This comparative example is a comparative test case of Example 1. The main difference between Example 1 and Example 1 is that the mass percentage expression of the refractory high-entropy alloy powder composition is Nb. 15 Mo 15.2 Ta 29 W 29 V8Cr 1.3 Co 1.2 Ni 1.3 .

[0085] The coating morphology prepared from the above powder components by laser cladding is as follows: Figure 6 As shown, the coating is free of defects such as pores and inclusions, but there are still a few cracks. Microhardness tests were performed on it.

[0086] According to GB / T 4340.2-2025 Vickers Hardness Test for Metallic Materials, the microhardness of the coating was tested and the coating hardness was 714.5 HV.

[0087] According to GB / T 12444-2006 Test Method for Wear of Metallic Materials, the tribological properties of the coating at room temperature and at 700℃ were tested, and the wear amounts at room temperature and at 700℃ were 0.0132 g / h and 0.0202 g / h, respectively.

[0088] Comparative Example 4 This comparative example is a comparative test example of Example 1. The main difference between Example 1 and Example 1 is that: in the coating preparation process, the laser power in step (3) is 7000W; the laser scanning speed is 12mm / s; and the powder feeding rate is 90g / min.

[0089] The coating morphology under these process parameters is as follows: Figure 7 As shown, due to the low laser power and high scanning speed, the energy density during laser cladding is insufficient, resulting in poor bonding between the coating and the substrate and causing warping at the coating edges. Simultaneously, the excessively high powder feed rate, coupled with the high melting point of the refractory high-entropy alloy, leads to a large amount of unmelted powder within the coating.

[0090] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-strength, crack-resistant, refractory, high-entropy alloy powder, characterized in that, It is composed of the following elements by mass percentage: The percentages of Nb, Mo, Ta, W, V, Cr, Co, and Ni are 12.5-15%, 12.5-15%, 24-29%, 24-29%, 6.5-8%, 1.5-6%, 1.5-6%, and 1.5-6%, respectively.

2. The high-strength, crack-resistant, refractory, high-entropy alloy powder according to claim 1, characterized in that, The atomic percentages of Nb, Mo, Ta, W, and V are 1:1:1:1:1, and the atomic percentages of Cr, Co, and Ni are 1:1:

1.

3. The high-strength, crack-resistant, refractory, high-entropy alloy powder according to claim 2, characterized in that, The mass percentages of Nb, Mo, Ta, W, and V in the refractory high-entropy alloy powder are 80-90%, and the mass percentages of Cr, Co, and Ni are 10-20%.

4. The high-strength, crack-resistant, refractory, high-entropy alloy powder according to claim 1, characterized in that, The refractory high-entropy alloy powder is prepared by gas atomization, ultrasonic atomization, plasma atomization, rotating electrode method or ball milling.

5. The high-strength, crack-resistant, refractory, high-entropy alloy powder according to claim 4, characterized in that, The particle size of the refractory high-entropy alloy powder is 75-150 μm.

6. A high-strength, crack-resistant, refractory, high-entropy alloy coating, characterized in that, The coating is formed by laser cladding of the refractory high-entropy alloy powder according to any one of claims 1-5 onto the surface of a substrate.

7. The high-strength, crack-resistant, refractory, high-entropy alloy coating according to claim 6, characterized in that, During the laser cladding process, the laser power is 8000-10000W; the laser scanning speed is 5-10mm / s; and the powder feeding rate is 30-80g / min.

8. The high-strength, crack-resistant, refractory, high-entropy alloy coating according to claim 7, characterized in that, The laser spot size is 6×19mm. Both the protective gas and the powder feeding gas are inert gases, and the protective gas flow rate is 15-20L / min.

9. The high-strength, crack-resistant, refractory, high-entropy alloy coating according to claim 6, characterized in that, The coating is free of cracks and has a hardness greater than 500 HV.

10. An application of the high-strength, crack-resistant, refractory, high-entropy alloy coating as described in claim 6, characterized in that, The coating is used to strengthen the surface of a substrate, which may include carbon steel, stainless steel, or nickel-based alloys.

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