High-temperature wear-resistant high-entropy alloy-based composite coating and preparation method thereof

Abstract

The invention relates to a high-temperature wear-resistant high-entropy alloy-based composite coating. The coating is prepared from the following components in percentage by mass: 60 to 87 percent of FeCoCrNiMn high-entropy alloy powder and 13 to 40 percent of 25NiCr-75Cr3C2 metal coated ceramic powder. Meanwhile, the invention further discloses a preparation method of the coating. The coating provided by the invention not only has the characteristics of high hardness, high temperature resistance and wear resistance, but also has the characteristics of simple preparation process and adjustable process and performance, and is suitable for surface coatings of mechanical moving parts under harsh conditions of high temperature, high speed and the like, such as wear-resistant coatings of parts such as blades, transmission rods, plane sliding bearings and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal coating, in particular to a high-temperature wear-resistant high-entropy alloy-based composite coating and a preparation method thereof. BACKGROUND

[0002] High-entropy alloy is a new alloy system proposed in recent years, which is composed of five or more main elements in equal or approximate molar ratio. Its high-entropy effect tends to form a simple solid solution structure, breaking the design limitations of traditional alloys with single-element matrix. Due to lattice distortion, slow diffusion, and "cocktail" effect, this type of alloy exhibits excellent high-temperature strength, corrosion resistance, and radiation resistance, making it suitable for extreme environments such as aerospace, nuclear power, and medical devices. Although the overall performance of single-phase high-entropy alloys is generally good, their hardness and wear resistance often cannot meet the actual application requirements. For example, patent CN119040878A prepared a FeCoCrNiMn high-entropy alloy coating by laser cladding combined with heat treatment strengthening method, and the hardness of the coating was only 185.4 HV. Due to the low hardness, the wear rate was poor, and the room temperature wear rate was as high as 10 -5 orders of magnitude. Currently, adding hard ceramic phases to high-entropy alloys to form high-entropy alloy-based composites is an effective solution that can compensate for the shortcomings of FeCoCrNiMn high-entropy alloy single-phase hardness and wear resistance. Widely used hard ceramic particles mainly include SiC, TiC, Cr3C2, ZrO2, Al2O3, etc.

[0003] In the aspect of ceramic-reinforced FeCoCrNiMn high-entropy alloy, patent CN119843135A discloses a SiC-reinforced CrMnFeCoNi high-entropy alloy composite material and its preparation method, which uses hot-pressing sintering method to improve the strength and toughness of high-entropy alloy, but its disadvantage is long holding time (0.5-1 hour). Patent CN113493913A discloses a WC ceramic particle reinforced FeCoCrNiMn coating and its preparation method, which significantly improves the wear resistance of the coating at room temperature by adding WC particles, but does not disclose the tribological performance data at high temperature environment (>400 ℃). Since WC ceramic particles are easily oxidized and decomposed above 500 ℃, the wear resistance decreases sharply, limiting its application in high-temperature working conditions. Patent CN120210634A discloses a TiC ceramic particle reinforced AlCoCrFeNi 2.1 high-entropy alloy-based composite material and its preparation method, which improves the room temperature wear rate of AlCoCrFeNi 2.1 high-entropy alloy-based composite material to 1.74×10 -6 mm 3 / Nm, but its high-temperature wear rate at 300-600 ℃ is as high as 10-4 -5 mm 3 / Nm, which restricts its application in high-temperature extreme environments. In addition, ceramic reinforced high-entropy alloys generally have poor wettability and interface bonding between the ceramic phase and the matrix phase, which easily causes problems such as cracks and wear peeling. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a high-temperature wear-resistant high-entropy alloy-based composite coating with good performance.

[0005] Another technical problem to be solved by the present application is to provide a preparation method of the high-temperature wear-resistant high-entropy alloy-based composite coating.

[0006] To solve the above problems, the high-temperature wear-resistant high-entropy alloy-based composite coating according to the present application is characterized in that the coating is composed of 60% to 87% FeCoCrNiMn high-entropy alloy powder and 13% to 40% 25NiCr-75Cr3C2 metal-coated ceramic powder.

[0007] The FeCoCrNiMn high-entropy alloy powder is a gas-atomized spherical alloy powder with a purity of 99.9% and a particle size of 15 to 53 μm.

[0008] The 25NiCr-75Cr3C2 metal-coated ceramic powder is a gas-atomized spherical ceramic powder with a purity of 99.9% and a particle size of 15 to 45 μm.

[0009] The preparation method of the high-temperature wear-resistant high-entropy alloy-based composite coating described above is characterized in that the FeCoCrNiMn high-entropy alloy powder and the 25NiCr-75Cr3C2 metal-coated ceramic powder are mixed according to the proportion, ball-milled uniformly, vacuum-dried, and then laser-cladded onto the treated metal substrate, and naturally cooled to room temperature.

[0010] The ball-milling uniformly refers to using a planetary ball mill, with a 304 stainless steel ball mill tank and 40 to 60 mm wear-resistant forged steel balls, a ball-to-material mass ratio of 1.5:1, a rotation speed of 200 r / min, and a mixing time of 5 to 6 hours.

[0011] The vacuum drying conditions refer to a vacuum degree of 85 kPa, a temperature of 90 to 100 ℃, an average heating rate of 10 ℃ / min, and a holding time of 35 to 40 min.

[0012] ​The conditions of the laser cladding refer to that the laser power is 600-800 W, the lap rate is 50%, the laser scanning speed is 6-8 mm / min, the powder feeding rate is 6-8 g / min, the protective gas and the carrier gas are both argon, and the protective gas flow is 9.5-12 L / min.

[0013] The treated metal base material refers to that the grease and the oxide on the surface of the metal base material are removed by polishing with 400-mesh, 600-mesh and 800-mesh silicon carbide sandpaper in sequence, and then the metal base material after polishing is cleaned with anhydrous ethanol.

[0014] The metal base material is steel.

[0015] Compared with the prior art, the present application has the following advantages: 1. The present application improves the bonding strength of Cr3C2 ceramic and high-entropy alloy matrix through the cladding structure, avoids peeling in the friction and wear process, and realizes the improvement of the wear resistance of the high-entropy alloy coating at room temperature and high temperature.

[0016] 2. In the present application, the NiCr cladding layer effectively isolates the direct contact between the Cr3C2 ceramic phase and the FeCoCrNiMn high-entropy alloy matrix, improves the retention rate of the Cr3C2 ceramic phase, and reduces the generation of brittle carbides (Cr7C3, Cr 23 C6).

[0017] 3. The present application prepares a dense FeCoCrNiMn high-entropy alloy matrix composite coating which is metallurgically combined with the substrate on the surface of the steel substrate through the laser cladding technology.

[0018] 4. The coating prepared by the present application has the characteristics of high hardness, high temperature resistance, wear resistance, etc., and the coating performance can be controlled by adjusting the coating composition and process parameters.

[0019] 5. The high-entropy alloy composite coating prepared by the present application has a low friction coefficient and excellent wear resistance at 200-800 DEG C, and is suitable for the surface coating of mechanical moving parts under harsh conditions such as high temperature and high speed, such as wear-resistant coating of parts such as blades, transmission rods, plane sliding bearings, etc.

[0020] 6. The preparation process of the present application is simple, and can provide an important reference for the development of second-phase ceramic reinforced high-entropy alloy matrix composite coating. BRIEF DESCRIPTION OF DRAWINGS

[0021] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0022] Figure 1 The Vickers hardness of the high-temperature wear-resistant high-entropy alloy matrix composite coating prepared in Examples 1-3 of the present application.

[0023] Figure 2 The average friction coefficient diagram of the high-temperature wear-resistant high-entropy alloy-based composite coating prepared for the present application embodiments 1-3.

[0024] Figure 3 The wear rate of the high-temperature wear-resistant high-entropy alloy-based composite coating prepared for the present application embodiments 1-3 at room temperature, 200℃, 400℃, 600℃, 800℃. DETAILED DESCRIPTION

[0025] A high-temperature wear-resistant high-entropy alloy-based composite coating, which is composed of 60%-87% FeCoCrNiMn high-entropy alloy powder and 13%-40% 25NiCr-75Cr3C2 metal-coated ceramic powder by mass percentage. The unit of mass is g.

[0026] Among them: FeCoCrNiMn high-entropy alloy powder is gas atomized spherical alloy powder, with a purity of 99.9% and a particle size of 15-53 μm.

[0027] 25NiCr-75Cr3C2 metal-coated ceramic powder is gas atomized spherical ceramic powder, with a purity of 99.9% and a particle size of 15-45 μm.

[0028] A preparation method of a high-temperature wear-resistant high-entropy alloy-based composite coating: Weigh according to the proportion; then put the FeCoCrNiMn high-entropy alloy powder and the 25NiCr-75Cr3C2 metal-coated ceramic powder into the planetary ball mill for mixing, the ball mill tank is made of 304 stainless steel, the grinding balls are 40-60 mm wear-resistant forged steel balls, the ball-to-material mass ratio (g / g) is 1.5:1, the rotation speed is 200 r / min, and the mixing time is 5-6 hours. The obtained mixed powder is vacuum dried in a vacuum dryer under the conditions of a vacuum degree of 85 kPa, a temperature of 90-100℃, an average heating rate of 10℃ / min, and a holding time of 35-40 min, and then sent to the powder feeder and laser cladded on the treated metal substrate, with a laser power of 600-800 W, an overlap rate of 50%, a laser scanning speed of 6-8 mm / min, a powder feeding rate of 6-8 g / min, and argon gas as the protective gas and carrier gas, with a protective gas flow rate of 9.5-12 L / min. After cladding, the high-temperature wear-resistant high-entropy alloy-based composite coating is obtained by natural cooling to room temperature.

[0029] Among them: the treated metal substrate refers to first polishing the metal substrate surface with 400 mesh, 600 mesh, and 800 mesh silicon carbide sandpaper to remove grease and oxides, and then cleaning the polished metal substrate with anhydrous ethanol.

[0030] The metal substrate is steel.

[0031] Example 1 A preparation method of a high-temperature wear-resistant high-entropy alloy-based composite coating 87 g of FeCoCrNiMn high-entropy alloy powder and 13 g of 25NiCr-75Cr3C2 metal-coated ceramic powder were weighed and mixed in a planetary ball mill. The ball mill tank was made of 304 stainless steel, the grinding balls were 40-60 mm wear-resistant forged steel balls, the ball-to-powder mass ratio (g / g) was 1.5:1, the rotation speed was 200 r / min, and the mixing time was 5 hours. The obtained mixed powder was vacuum dried in a vacuum dryer under the conditions of a vacuum degree of 85 kPa, a temperature of 90-100 ℃, an average heating rate of 10 ℃ / min, and a holding time of 35-40 min, and then sent to a powder feeder and laser cladded onto a treated metal substrate. The laser power was 600-800 W, the overlap rate was 50%, the laser scanning speed was 6-8 mm / min, the powder feeding rate was 6-8 g / min, the protective gas and the carrier gas were both argon, and the protective gas flow rate was 9.5-12 L / min. After cladding, the coating was naturally cooled to room temperature to obtain a high-temperature wear-resistant high-entropy alloy-based composite coating.

[0032] The obtained coating was tested for performance

Hardness

[0033] The results showed that the Vickers hardness of the high-temperature wear-resistant high-entropy alloy composite coating was 371.1 HV 0.5 , as shown in Figure 1 .

[0034]

Tribological performance

[0035] The obtained coating is subjected to hardness test and room temperature tribological performance test, and the test method is same as that in Example 1. The Vickers hardness of the coating is 516.1 HV 0.5 As shown in Figure 1 , the wear coefficient and wear rate of the coating are shown in Figures 2-3 , Table 2: Table 2 Wear coefficient and wear rate of the coating Example 3 A preparation method of a high-temperature wear-resistant high-entropy alloy-based composite coating is same as that in Example 1. Wherein: the raw material is 60g of FeCoCrNiMn high-entropy alloy powder and 40g of 25NiCr-75Cr3C2 metal-coated ceramic powder.

[0036] The obtained coating is subjected to hardness test and room temperature tribological performance test, and the test method is same as that in Example 1. The Vickers hardness of the coating is 559.2 HV 0.5 As shown in Figure 1 , the wear coefficient and wear rate of the coating are shown in Figures 2-3 , Table 3: Table 3 Wear coefficient and wear rate of the coating In summary, the high-entropy alloy composite coating prepared by the present application has the characteristics of high hardness, and has a lower friction coefficient and excellent wear resistance at 200-800℃.

Claims

1. A high-temperature wear-resistant high-entropy alloy-based composite coating, characterized by: The coating is composed of 60% to 87% by mass of FeCoCrNiMn high entropy alloy powder and 13% to 40% by mass of 25NiCr-75Cr3C2 metal-coated ceramic powder.

2. The high-temperature wear-resistant high-entropy alloy-based composite coating according to claim 1, characterized in that: The FeCoCrNiMn high entropy alloy powder is a gas-atomized spherical alloy powder with a purity of 99.9% and a particle size of 15-53 μm.

3. The high-temperature wear-resistant high-entropy alloy-based composite coating according to claim 1, characterized in that: The 25NiCr-75Cr3C2 metal-coated ceramic powder is an atomized spherical ceramic powder with a purity of 99.9% and a particle size of 15-45 μm.

4. The method for preparing a high-temperature wear-resistant high-entropy alloy-based composite coating according to claim 1, characterized in that: The powders are weighed according to the ratio; the FeCoCrNiMn high entropy alloy powder and the 25NiCr-75Cr3C2 metal-coated ceramic powder are mixed, ball-milled and mixed, vacuum-dried, and then laser-clad onto the treated metal substrate, and naturally cooled to room temperature.

5. The method for preparing a high-temperature wear-resistant high-entropy alloy-based composite coating according to claim 1, wherein: The ball milling mixing refers to using a planetary ball mill, the ball milling jar is made of 304 stainless steel, the grinding balls are 40-60 mm wear-resistant forged steel balls, the ball-to-material mass ratio is 1.5:1, the rotation speed is 200 r / min, and the mixing time is 5-6 hours.

6. The method for preparing a high-temperature wear-resistant high-entropy alloy-based composite coating according to claim 1, wherein: The vacuum drying conditions are as follows: a vacuum degree of 85 kPa, a temperature of 90-100°C, an average heating rate of 10°C / min, and a holding time of 35-40 min.

7. The method for preparing a high-temperature wear-resistant high-entropy alloy-based composite coating according to claim 1, characterized in that: The laser cladding conditions are as follows: a laser power of 600-800 W, an overlap rate of 50%, a laser scanning speed of 6-8 mm / min, a powder feeding rate of 6-8 g / min, both the shielding gas and the carrier gas being argon, and a shielding gas flow rate of 9.5-12 L / min.

8. The method for preparing a high-temperature wear-resistant high-entropy alloy-based composite coating according to claim 1, wherein: The treated metal substrate refers to the metal substrate surface first being polished with 400 mesh, 600 mesh, and 800 mesh silicon carbide sandpaper in sequence to remove grease and oxides, and then the polished metal substrate being cleaned with anhydrous ethanol.

9. The method for preparing a high-temperature wear-resistant high-entropy alloy-based composite coating according to claim 8, characterized in that: The metal substrate is steel.

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