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

Abstract

The application discloses a kind of high-strength anti-cracking refractory high-entropy alloy powder, coating and its application, compared with traditional refractory high-entropy alloy powder, by adding refractory alloy elements Nb, Mo, Ta, W, V forms BCC solid solution, ensure the strength, hardness and high temperature performance of refractory high-entropy alloy coating should have;By adding Cr, Co, Ni element forms FCC solid solution, FCC+BCC two-way organization synergistic cooperation, both improve the toughness of coating, and coordinate the local stress and strain in the process of laser cladding fast cooling, thereby reduce the cracking risk of refractory high-entropy alloy coating in the process of laser cladding, improve its crack resistance.The application of the strong anti-cracking refractory high-entropy alloy coating in the application, mainly can be used for carbon steel, stainless steel, nickel-based alloy and other various materials surface strengthening, the coating has no crack, pore and inclusion and other defects, and the coating hardness exceeds 700HV.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser additive manufacturing, in particular to a high-strength anti-cracking refractory high-entropy alloy powder, a coating and application thereof. BACKGROUND

[0002] As a new type of alloy material, the refractory high-entropy alloy coating has excellent high-temperature mechanical properties and good high-temperature phase stability compared with traditional coating materials, and the performance can be optimized by adjusting the content of main elements, and is widely used in extreme working conditions such as mining, metallurgy, energy and power, and ocean engineering, and has broad application prospects.

[0003] The commonly used refractory high-entropy alloy coating at present is mainly NbMoTaWV alloy system, which can still exhibit a yield strength of 477 MPa at above 1600℃, which is much higher than the yield strength of traditional high-temperature alloys in extreme environments, and therefore has great application potential in the fields of national defense, aerospace, nuclear industry, chemical industry, energy, metallurgy and the like. However, due to the repeated rapid heating and cooling in the laser cladding process, there is a high thermal stress and residual stress in the coating. At the same time, due to the poor room temperature plasticity of the traditional refractory high-entropy alloy, for example, NbMoTaW has only about 2% plastic strain at room temperature, which leads to a large cracking tendency in the laser cladding process, limiting its application in laser cladding technology. SUMMARY

[0004] In order to solve the problem of high brittleness and easy cracking of the existing refractory high-entropy alloy powder in the process of laser cladding into a coating, the present application provides a high-strength anti-cracking refractory high-entropy alloy powder, a coating and application thereof, which introduces Cr, Co and Ni elements into the NbMoTaWV single-phase BCC refractory high-entropy alloy to form an FCC+BCC dual-structure, improve the toughness of the coating, and coordinate the local stress and strain in the process of laser cladding fast heating and fast cooling, thereby reducing the cracking risk of the refractory high-entropy alloy coating in the process of laser cladding and improving its crack resistance.

[0005] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0006] The present application provides a high-strength anti-cracking refractory high-entropy alloy powder, which is composed of the following mass percentage of elements:

[0007] Nb is 12.5-15%, Mo is 12.5-15%, Ta is 24-29%, W is 24-29%, V is 6.5-8%, Cr is 1.5-6%, Co is 1.5-6%, and Ni is 1.5-6%.

[0008] Preferably, the atomic percentage of Nb, Mo, Ta, W, V elements is about 1:1:1:1:1, and the atomic percentage of Cr, Co, Ni elements is about 1:1:1.

[0009] The atomic percentage of elements in the NbMoTaWV high-entropy alloy powder and the CrCoNi medium-entropy alloy powder is close or the same, that is, the mass ratio of each element is close or the same relative to the relative atomic mass ratio.

[0010] Preferably, the refractory high-entropy alloy powder composition is (NbMoTaWV)x(CrCoNi)1-x, wherein 80%≤x≤90%.

[0011] Specifically, it refers to: under the condition that the atomic percentage of Nb, Mo, Ta, W, V elements is close to 1:1:1:1:1 and the atomic percentage of Cr, Co, Ni elements is close to 1:1:1, the NbMoTaWV high-entropy alloy and the CrCoNi medium-entropy alloy are mixed, which satisfies (NbMoTaWV)x(CrCoNi)1-x, wherein 80%≤x≤90% (wt.%), that is, the mass percentage of NbMoTaWV powder is 80-95%, and the mass percentage of CrCoNi is 5-18%.

[0012] Preferably, the refractory high-entropy alloy powder composition mass percentage expression is: Nb 14.7 Mo 15 Ta 28.4 W 28.9 V8Cr 1.6 Co 1.7 Ni 1.7 .

[0013] Preferably, the refractory high-entropy alloy powder composition mass percentage expression is: Nb 13.8 Mo 14.3 Ta 27 W 27.3 V 7. 6Cr3Co 3.5 Ni 3.5 .

[0014] Preferably, the refractory high-entropy alloy powder composition mass percentage expression is: Nb 13 Mo 13.2 Ta 24.8 W 24.7 V 6. 7Cr 5.4 Co 6.1 Ni 6.1 .

[0015] In the above technical solution:

[0016] The elements Nb, Mo, Ta, W and V in the refractory high-entropy alloy powder form a BCC solid solution during laser cladding, ensuring the strength, hardness and high-temperature performance of the refractory high-entropy alloy coating; the elements Cr, Co and Ni form an FCC solid solution during laser cladding, improving the toughness and crack resistance of the coating; by introducing a specific amount of Cr, Co and Ni elements into the NbMoTaWV single-phase BCC refractory high-entropy alloy, the solid solubility between the elements Nb, Mo, Ta, W and V and the elements Co, Cr and Ni is low, so that the elements Nb, Mo, Ta, W and V form a high-entropy alloy, and the elements Co, Cr and Ni form a medium-entropy alloy, thereby forming an FCC+BCC two-way structure, the BCC phase coordinates the local stress and strain during the laser cladding rapid cooling process, thereby reducing the cracking risk of the refractory high-entropy alloy coating during the laser cladding process and improving the crack resistance, solving the technical problem of easy cracking of the traditional high-entropy alloy coating by laser cladding.

[0017] In addition, the content of Cr, Co and Ni elements in the refractory high-entropy alloy powder system is 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 increases and the content of BCC decreases during laser cladding, which will reduce the hardness of the coating, and if the content of Cr, Co and Ni elements is too low, the content of FCC phase is too low to effectively inhibit the cracking of the coating.

[0018] Further, the refractory high-entropy alloy powder includes but is not limited to being prepared by gas atomization method, ultrasonic atomization method, plasma atomization method, rotating electrode method or ball milling method.

[0019] Further, the particle size of the refractory high-entropy alloy powder is 75-150 μm. The particle size of the refractory high-entropy alloy powder is controlled in the above range to adapt to the laser cladding process; since the width of the powder outlet hole of the powder nozzle is limited during the laser cladding process, the powder particle size is too large to cause powder blocking, and the powder particle size is too small to cause uneven powder feeding due to poor flowability.

[0020] The application also provides a high-strength and anti-cracking refractory high-entropy alloy coating, which is formed by laser cladding processing of the above-mentioned refractory high-entropy alloy powder on the surface of a substrate.

[0021] Preferably, during the laser cladding processing, the laser power is 8000-10000 W; the laser scanning speed is 5-10 mm / s; and the powder feeding rate is 30-80 g / min.

[0022] Preferably, the laser spot size is 6x19 mm, the protective gas and the powder feeding gas are both inert gases such as nitrogen and argon, and the protective gas flow is 15-20 L / min. Specifically, the laser spot size can be adaptively adjusted.

[0023] The coating has high strength and anti-cracking performance, and the coating is free of defects such as cracks, pores and inclusions, and the hardness of the coating is greater than 500HV.

[0024] The application also provides application of the high-strength anti-cracking refractory high-entropy alloy coating.

[0025] Compared with the prior art, the application has the following beneficial effects:

[0026] Compared with the conventional refractory high-entropy alloy powder, the high-strength anti-cracking refractory high-entropy alloy powder in the application forms a BCC solid solution by adding refractory alloy elements Nb, Mo, Ta, W and V, so as to ensure the strength, hardness and high-temperature performance of the refractory high-entropy alloy coating; the FCC solid solution is formed by adding Cr, Co and Ni elements, and the FCC+BCC bidirectional structure cooperates with each other, so as to improve the toughness of the coating and coordinate the local stress and strain in the laser cladding quick cooling process, thereby reducing the cracking risk of the refractory high-entropy alloy coating in the laser cladding process and improving the anti-cracking performance, and the hardness of the coating after laser cladding is greater than 500HV.

[0027] In addition, the content of the Cr, Co and Ni elements in the refractory high-entropy alloy powder system is determined through a large number of experiments, if the content of the Cr, Co and Ni elements is too high, the content of the FCC phase in the coating increases and the content of the BCC decreases during the laser cladding, so that the hardness of the coating is reduced, and if the content of the Cr, Co and Ni elements is too low, the FCC phase content is too low to effectively inhibit the cracking of the coating.

[0028] The application of the high-strength anti-cracking refractory high-entropy alloy coating can be mainly used in the surface strengthening of carbon steel, stainless steel, nickel-based alloy and other materials, the coating is free of defects such as cracks, pores and inclusions, and the hardness of the coating is greater than 700HV. BRIEF DESCRIPTION OF DRAWINGS

[0029] The application will be further described in detail below in combination with the drawings and specific embodiments.

[0030] Figure 1 It is a macroscopic morphology diagram of the refractory high-entropy alloy coating in Example 1.

[0031] Figure 2 It is a scanning electron microscope diagram of the refractory high-entropy alloy coating in Example 1.

[0032] Figure 3 It is an EDS surface analysis diagram of the refractory high-entropy alloy coating in Example 1.

[0033] Figure 4 It is a macroscopic morphology diagram of the refractory high-entropy alloy coating in Comparative Example 1.

[0034] Figure 5 Macroscopic morphology of the refractory high-entropy alloy coating in Comparative Example 2;

[0035] Figure 6 Macroscopic morphology of the refractory high-entropy alloy coating in Comparative Example 3;

[0036] Figure 7 Macroscopic morphology of the refractory high-entropy alloy coating in Comparative Example 4. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0038] Example 1

[0039] The present embodiment provides a high-strength and anti-cracking refractory high-entropy alloy powder, and the high-strength and anti-cracking refractory high-entropy alloy powder has a mass percentage expression of Nb 14.7 Mo 15 Ta 28.4 W 28.9 V8Cr 1.6 Co 1.7 Ni 1.7 .

[0040] The high-strength and anti-cracking refractory high-entropy alloy powder is prepared by mixing the above-mentioned element components in the above-mentioned proportions. The specific mixing and preparation process is as follows: first, different masses of alloy powders are weighed by an analytical balance, and then they are put into a vacuum ball mill jar for ball milling. The ball milling time is 3h, the rotation speed is 300rpm / min, and the jar is reversed every 30min.

[0041] The high-strength and anti-cracking refractory high-entropy alloy coating is formed by using the above-mentioned refractory high-entropy alloy powder, and the specific steps include the following steps:

[0042] (1) The high-strength and anti-cracking refractory high-entropy alloy powder is put into a vacuum drying oven, and dried at 120℃ for 3h to remove the crystal water in the powder.

[0043] (2) The carbon steel substrate is polished by using 80-mesh, 320-mesh, 600-mesh and 1200-mesh sandpaper in sequence, and then cleaned with deionized water for the first time, and then cleaned with anhydrous ethanol for the second time. Then, the carbon steel substrate is dried in a vacuum oven at 80℃ for 20min.

[0044] (3) The pre-processed refractory high-entropy alloy powder and the substrate are subjected to laser cladding treatment, wherein the laser spot size is 6*19 mm; the laser power is 9000 W; the laser scanning speed is 8 mm / s; the protective gas and the powder feeding gas are argon; the powder feeding rate is 50 g / min; and the protective gas flow rate is 18 L / min.

[0045] No cracks, pores, inclusions, or other defects are found in the refractory high-entropy alloy coating prepared by using the refractory high-entropy alloy powder and the laser cladding process described above, and the macroscopic morphology thereof is shown in FIG. 1. Figure 1 The microstructure thereof is observed by scanning electron microscopy (SEM), and the microstructure thereof is shown in FIG. 2. Figure 2 It can be seen from FIG. 2 that the microstructure is composed of two phases of gray and white, and the EDS area scanning analysis thereof is shown in FIG. 3. Figure 3 It can be seen from FIG. 3 that the light-colored phase is a NbMoTaWV-rich phase, and the dark-colored phase is a CrCoNi-rich phase.

[0046] The coating is subjected to microhardness testing according to GB / T 4340.2-2025 Metal Materials Vickers Hardness Test, and the coating hardness is 763.1 HV.

[0047] The coating is subjected to room temperature and 700°C high-temperature friction and wear testing according to GB / T 12444-2006 Metal Materials Wear Test Method, and the wear amounts at room temperature and 700°C high temperature are 0.0078 g / h and 0.0094 g / h, respectively.

[0048] Example 2

[0049] The present embodiment provides a high-strength and anti-cracking refractory high-entropy alloy powder, and the high-strength and anti-cracking refractory high-entropy alloy powder has a mass percentage expression of Nb 13.8 Mo 14.3 Ta 27 W 27.3 V 7.6 Cr3Co 3.5 Ni 3.5 .

[0050] The high-strength and anti-cracking refractory high-entropy alloy powder is prepared by mixing the above-mentioned element component proportions. The specific mixing and preparation process is as follows: first, different masses of alloy powders are weighed by using an analytical balance, and then the alloy powders are placed in a vacuum ball mill pot for ball milling and powder mixing. The ball milling time is 3 h, the rotation speed is 300 rpm / min, and the pot is reversed every 30 min.

[0051] In the present embodiment, the method for preparing the high-strength and anti-cracking refractory high-entropy alloy coating is the same as that in Example 1. No cracks, pores, inclusions, or other defects are found in the refractory high-entropy alloy coating prepared by using the refractory high-entropy alloy powder and the laser cladding process described above.

[0052] According to GB / T 4340.2-2025 Metal Materials Vickers Hardness Test, the microhardness of the coating is tested, and the coating hardness is 757.7HV.

[0053] According to GB / T 12444-2006 Metal Materials Wear Test Method, the friction and wear performance of the coating at room temperature and 700 DEG C high temperature is tested, and the wear amount at room temperature and 700 DEG C high temperature is 0.0083g / h and 0.0103g / h respectively.

[0054] Example 3

[0055] The present embodiment provides a high-strength anti-cracking refractory high-entropy alloy powder, and the high-strength anti-cracking refractory high-entropy alloy powder has a mass percentage expression of Nb 13 Mo 13.2 Ta 24.8 W 24.7 V 6.7 Cr 5.4 Co 6.1 Ni 6.1 .

[0056] The high-strength anti-cracking refractory high-entropy alloy powder is prepared by mixing the above-mentioned element component proportions. The specific mixing and preparation process is as follows: first, different masses of alloy powder are weighed by an analytical balance, and then they are put into a vacuum ball mill pot for ball milling powder mixing. The ball milling time is 3h, the rotation speed is 300rpm / min, and the pot is reversed every 30min.

[0057] In the present embodiment, the method for preparing the high-strength anti-cracking refractory high-entropy alloy coating is the same as that in Example 1. No cracks, pores, inclusions and other defects are found in the refractory high-entropy alloy coating prepared by using the above-mentioned refractory high-entropy alloy powder and laser cladding process.

[0058] According to GB / T 4340.2-2025 Metal Materials Vickers Hardness Test, the microhardness of the coating is tested, and the coating hardness is 808.1HV.

[0059] According to GB / T 12444-2006 Metal Materials Wear Test Method, the friction and wear performance of the coating at room temperature and 700 DEG C high temperature is tested, and the wear amount at room temperature and 700 DEG C high temperature is 0.0069g / h and 0.0085g / h respectively.

[0060] Example 4

[0061] The present embodiment provides a high-strength anti-cracking refractory high-entropy alloy powder, and the high-strength anti-cracking refractory high-entropy alloy powder has a mass percentage expression of Nb 14.7 Mo 15 Ta 28.4 W 28.9 V8Cr1.6 Co 1.7 Ni 1.7 .

[0062] The high-strength anti-cracking refractory high-entropy alloy powder is prepared by mixing the above-mentioned element component proportions. The specific mixing preparation process is as follows: first, different masses of alloy powder are weighed by using an analytical balance, and then the alloy powder is placed in a vacuum ball mill jar for ball milling, the ball milling time is 3h, the rotation speed is 300rpm / min, and the ball mill is reversed every 30min.

[0063] The method for preparing the high-strength anti-cracking refractory high-entropy alloy coating in this embodiment is basically the same as that in embodiment 1. The difference lies in that the laser power is 8000W; the laser scanning speed is 5mm / s; the powder feeding rate is 30g / min; and the protective gas flow rate is 15L / min. No cracks, pores, inclusions and other defects are found in the refractory high-entropy alloy coating prepared by using the above-mentioned refractory high-entropy alloy powder and the laser cladding process.

[0064] According to GB / T 4340.2-2025 Metal Materials Vickers Hardness Test, the microhardness of the coating is tested, and the coating hardness is 787.2HV.

[0065] According to GB / T 12444-2006 Metal Materials Wear Test Method, the room temperature and 700℃ high temperature friction and wear properties of the coating are tested, and the wear amounts at room temperature and 700℃ high temperature are 0.0085g / h and 0.0093g / h respectively.

[0066] Embodiment 5

[0067] The embodiment provides a high-strength anti-cracking refractory high-entropy alloy powder, and the high-strength anti-cracking refractory high-entropy alloy powder has a mass percentage expression of Nb 14.7 Mo 15 Ta 28.4 W 28.9 V8Cr 1.6 Co 1.7 Ni 1.7 .

[0068] The high-strength anti-cracking refractory high-entropy alloy powder is prepared by mixing the above-mentioned element component proportions. The specific mixing preparation process is as follows: first, different masses of alloy powder are weighed by using an analytical balance, and then the alloy powder is placed in a vacuum ball mill jar for ball milling, the ball milling time is 3h, the rotation speed is 300rpm / min, and the ball mill is reversed every 30min.

[0069] The method for preparing the high-strength and anti-cracking refractory high-entropy alloy coating in this embodiment is basically the same as that in Embodiment 1. The difference lies in that the laser power is 10000 W; the laser scanning speed is 10 mm / s; the powder feeding rate is 80 g / min; and the protective gas flow rate is 20 L / min. No cracks, pores, inclusions and other defects are found in the refractory high-entropy alloy coating prepared by using the above refractory high-entropy alloy powder and the laser cladding process.

[0070] According to the "GB / T 4340.2-2025 Metal Material Vickers Hardness Test", the microhardness of the coating is tested, and the hardness of the coating is 765.6 HV.

[0071] According to the "GB / T 12444-2006 Metal Material Wear Test Method", the room temperature and 700°C high temperature friction and wear properties of the coating are tested, and the wear amounts at room temperature and 700°C high temperature are 0.0090 g / h and 0.0113 g / h, respectively.

[0072] Embodiment 6

[0073] The embodiment provides a high-strength and anti-cracking refractory high-entropy alloy powder, and the high-strength and anti-cracking refractory high-entropy alloy powder has a mass percentage expression of Nb 13.8 Mo 14.3 Ta 27 W 27.3 V 7.6 Cr3Co 3.5 Ni 3.5 .

[0074] The high-strength and anti-cracking refractory high-entropy alloy powder is prepared by mixing the above-mentioned element components in the above-mentioned proportions. The specific mixing and preparation process is as follows: first, different masses of alloy powder are weighed by using an analytical balance, and then the alloy powder is put into a vacuum ball mill pot for ball milling and powder mixing. The ball milling time is 3 h, the rotation speed is 300 rpm / min, and the pot is reversed every 30 min.

[0075] The method for preparing the high-strength and anti-cracking refractory high-entropy alloy coating in this embodiment is basically the same as that in Embodiment 1. The difference lies in that the laser power is 8000 W; the laser scanning speed is 5 mm / s; the powder feeding rate is 30 g / min; and the protective gas flow rate is 15 L / min. No cracks, pores, inclusions and other defects are found in the refractory high-entropy alloy coating prepared by using the above refractory high-entropy alloy powder and the laser cladding process.

[0076] According to the "GB / T 4340.2-2025 Metal Material Vickers Hardness Test", the microhardness of the coating is tested, and the hardness of the coating is 769.5 HV.

[0077] According to GB / T 12444-2006 Metal Material Wear Test Method, the friction and wear properties of the coating at room temperature and 700 DEG C high temperature are tested, and the wear amounts at room temperature and 700 DEG C high temperature are 0.0088 g / h and 0.0102 g / h respectively.

[0078] Example 7

[0079] The embodiment provides a high-strength anti-cracking refractory high-entropy alloy powder, and the high-strength anti-cracking refractory high-entropy alloy powder has a mass percentage expression of Nb 13.8 Mo 14.3 Ta 27 W 27.3 V 7.6 Cr3Co 3.5 Ni 3.5 .

[0080] The high-strength anti-cracking refractory high-entropy alloy powder is prepared by mixing the above-mentioned element components in the above-mentioned proportions. The specific mixing and preparation process is as follows: first, different masses of alloy powders are weighed by using an analytical balance, and then the alloy powders are placed in a vacuum ball mill jar for ball milling and powder mixing, the ball milling time is 3 hours, the rotation speed is 300 rpm / min, and the ball mill is reversed every 30 minutes.

[0081] In the embodiment, the preparation method of the high-strength anti-cracking refractory high-entropy alloy coating is basically the same as that in Example 1. The difference lies in that the laser power is 10000 W; the laser scanning speed is 10 mm / s; the powder feeding rate is 80 g / min; and the protective gas flow rate is 20 L / min. No cracks, pores and inclusions are found in the refractory high-entropy alloy coating prepared by using the above-mentioned refractory high-entropy alloy powder and the laser cladding process.

[0082] According to GB / T 4340.2-2025 Metal Material Vickers Hardness Test, the microhardness of the coating is tested, and the coating hardness is 796.4 HV.

[0083] According to GB / T 12444-2006 Metal Material Wear Test Method, the friction and wear properties of the coating at room temperature and 700 DEG C high temperature are tested, and the wear amounts at room temperature and 700 DEG C high temperature are 0.0074 g / h and 0.0081 g / h respectively.

[0084] Example 8

[0085] The embodiment provides a high-strength anti-cracking refractory high-entropy alloy powder, and the high-strength anti-cracking refractory high-entropy alloy powder has a mass percentage expression of Nb 13 Mo 13.2 Ta 24.8 W 24.7 V 6.7 Cr 5.4 Co6.1 Ni 6.1 .

[0086] The high-strength anti-cracking refractory high-entropy alloy powder is prepared by mixing the above-mentioned element component proportions.

[0087] The method for preparing the high-strength anti-cracking refractory high-entropy alloy coating in this embodiment is basically the same as that in Embodiment 1. The difference lies in that the laser power is 8000 W; the laser scanning speed is 5 mm / s; the powder feeding rate is 30 g / min; and the protective gas flow rate is 15 L / min. No cracks, pores, inclusions and other defects are found in the refractory high-entropy alloy coating prepared by using the above-mentioned refractory high-entropy alloy powder and the laser cladding process.

[0088] According to the Vickers Hardness Test of GB / T 4340.2-2025 Metal Materials, the microhardness of the coating is tested, and the hardness of the coating is 756.8 HV.

[0089] According to the GB / T 12444-2006 Metal Material Wear Test Method, the room temperature and 700°C high temperature friction and wear properties of the coating are tested, and the wear amounts at room temperature and 700°C high temperature are 0.0097 g / h and 0.0110 g / h, respectively.

[0090] Embodiment 9

[0091] The embodiment provides a high-strength anti-cracking refractory high-entropy alloy powder, and the high-strength anti-cracking refractory high-entropy alloy powder has a mass percentage expression of Nb 13 Mo 13.2 Ta 24.8 W 24.7 V 6.7 Cr 5.4 Co 6.1 Ni 6.1 .

[0092] The high-strength anti-cracking refractory high-entropy alloy powder is prepared by mixing the above-mentioned element component proportions.

[0093] The method for preparing the high-strength anti-cracking refractory high-entropy alloy coating in this embodiment is basically the same as that in Embodiment 1. The difference lies in that the laser power is 10000 W; the laser scanning speed is 10 mm / s; the powder feeding rate is 80 g / min; and the protective gas flow rate is 20 L / min. No cracks, pores, inclusions and other defects are found in the refractory high-entropy alloy coating prepared by using the above-mentioned refractory high-entropy alloy powder and the laser cladding process.

[0094] According to the Vickers Hardness Test of GB / T 4340.2-2025 Metal Materials, the microhardness of the coating is tested, and the hardness of the coating is 789.7 HV.

[0095] According to GB / T 12444-2006 Metal Material Wear Test Method, the friction and wear properties of the coating at room temperature and 700 DEG C high temperature are tested, and the wear amounts at room temperature and 700 DEG C high temperature are 0.0079 g / h and 0.0089 g / h respectively.

[0096] Comparative Example 1

[0097] The present comparative example is a comparative test example of Example 1, and the main difference compared with Example 1 is that the refractory high-entropy alloy powder composition mass percentage expression in the present comparative example is Nb 15.4 Mo 15.9 Ta 29.9 W 30.4 V 8.4 .

[0098] The coating morphology prepared by the above powder composition through laser cladding processing is shown in Figure 4 , and there are obvious cracks in the coating, and the microhardness test is carried out.

[0099] According to GB / T 4340.2-2025 Metal Material Vickers Hardness Test, the microhardness test of the coating is carried out, and the coating hardness is 522.2 HV.

[0100] According to GB / T 12444-2006 Metal Material Wear Test Method, the friction and wear properties of the coating at room temperature and 700 DEG C high temperature are tested, and the wear amounts at room temperature and 700 DEG C high temperature are 0.0183 g / h and 0.0256 g / h respectively.

[0101] Comparative Example 2

[0102] The present comparative example is a comparative test example of Example 1, and the main difference compared with Example 1 is that the refractory high-entropy alloy powder composition mass percentage expression 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 .

[0103] The coating morphology prepared by the above powder composition through laser cladding processing is shown in Figure 5 , and there are no cracks, pores and inclusions in the coating, and the microhardness test is carried out.

[0104] According to GB / T 4340.2-2025 Metal Material Vickers Hardness Test, the microhardness test of the coating is carried out, and the coating hardness is 270.2 HV.

[0105] According to GB / T 12444-2006 Metal Material Wear Test Method, the friction and wear properties of the coating at room temperature and 700 DEG C high temperature are tested, and the wear amounts at room temperature and 700 DEG C high temperature are 0.0358 g / h and 0.0542 g / h respectively.

[0106] Comparative Example 3

[0107] The present comparative example is a comparative test example of Example 1, and the main difference compared with Example 1 is that the refractory high-entropy alloy powder composition is expressed by mass percentage as Nb 15 Mo 15.2 Ta 29 W 29 V8Cr 1.3 Co 1.2 Ni 1.3 .

[0108] The coating morphology prepared by the above powder composition through laser cladding processing is shown in Figure 6 There are no pores and inclusions in the coating, but there are still a small amount of cracks, and the microhardness test is carried out.

[0109] According to GB / T 4340.2-2025 Metal Material Vickers Hardness Test, the microhardness test of the coating is carried out, and the coating hardness is 714.5 HV.

[0110] According to GB / T 12444-2006 Metal Material Wear Test Method, the friction and wear properties of the coating at room temperature and 700 DEG C high temperature are tested, and the wear amounts at room temperature and 700 DEG C high temperature are 0.0132 g / h and 0.0202 g / h respectively.

[0111] Comparative Example 4

[0112] The present comparative example is a comparative test example of Example 1, and the main difference compared with Example 1 is that in the coating preparation process, the laser power in step (3) is 7000 W; the laser scanning speed is 12 mm / s; and the powder feeding rate is 90 g / min.

[0113] The coating morphology under the process parameters is shown in Figure 7 Due to the low laser power and fast scanning speed, the energy density is insufficient in the laser cladding process, the coating and the substrate are not well combined, and the coating edge has a warping phenomenon. At the same time, due to the high powder feeding rate and the high melting point of the refractory high-entropy alloy, there are a large amount of unmelted powders in the coating.

[0114] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely exemplary of the principles and application of the present application. Numerous modifications and adaptions can be effected without departing from the spirit and scope of the present application, which is not limited to the exact construction and arrangement described. It is intended, therefore, to cover all modifications and adaptions that fall within the scope of the claims and their equivalents.

Claims

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

2. The high-strength, crack-resistant, refractory high-entropy alloy powder of claim 1, wherein, The atomic percentage of Nb, Mo, Ta, W and V elements is 1:1:1:1:1, and the atomic percentage of Cr, Co and Ni elements is 1:1:

1.

3. The high-strength, crack-resistant, refractory high-entropy alloy powder of claim 2, wherein, The mass percentage of Nb, Mo, Ta, W and V elements in the refractory high-entropy alloy powder composition is 80-90%, and the mass percentage of Cr, Co and Ni elements is 10-20%.

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

5. The high-strength, crack-resistant, refractory high-entropy alloy powder of claim 4, wherein, 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 by, The coating is formed by laser cladding processing of the refractory high-entropy alloy powder according to any one of claims 1-5 on the surface of a substrate, and during the laser cladding processing, the laser power is 8000-10000 W, the laser scanning speed is 5-10 mm / s, and the powder feeding rate is 30-80 g / min.

7. The high-strength, crack-resistant, refractory, high-entropy alloy coating of claim 6, wherein, The laser spot size is 6x19 mm, and both the protective gas and the powder feeding gas are inert gases, and the protective gas flow rate is 15-20 L / min.

8. The high-strength, crack-resistant, refractory, high-entropy alloy coating of claim 6, wherein, The coating has no cracks and a hardness greater than 500 HV.

9. Use of the high-strength, crack-resistant, refractory high-entropy alloy coating according to claim 6, characterized in that The coating is used for strengthening the surface of a substrate, and the substrate includes carbon steel, stainless steel or nickel-based alloy.

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