Wear-resistant and corrosion-resistant high-entropy alloy composite coating and preparation method thereof

Abstract

The invention relates to the field of coatings, and discloses a wear-resistant and corrosion-resistant high-entropy alloy composite coating and a preparation method thereof.The wear-resistant and corrosion-resistant high-entropy alloy composite coating is prepared by depositing functional high-entropy alloy composite powder on the surface of a base body in a laser cladding mode, the functional high-entropy alloy composite powder comprises high-entropy alloy powder, a modified additive and composite ceramic powder, the modified additive is prepared by using urea and titanium tetrachloride as raw materials, growing nano titanium nitride particles on the surface of a silicon carbide nanowire in situ to prepare a nano titanium nitride / silicon carbide nanowire composite material, and then coating a layer of nano titanium dioxide particles on the surface of the nano titanium nitride / silicon carbide nanowire composite material by using tetrabutyl titanate; and the composite ceramic powder is prepared by compounding zirconium carbide, niobium carbide, hafnium carbide and tantalum disilicide. The hardness, wear resistance and corrosion resistance of the high-entropy alloy coating are enhanced by adding the modified additive and the composite ceramic powder.

Description

Technical Field

[0001] The present invention belongs to the technical field of coatings, and particularly relates to an anti-wear and corrosion-resistant high-entropy alloy composite coating and a preparation method thereof. Background Art

[0002] Coatings are one of the more effective and economical methods for protecting metal components. Coatings are usually prepared by processes such as atmospheric plasma spraying, vacuum plasma spraying, electron beam physical vapor deposition, and laser cladding. Laser cladding is a low-cost, reliable, and convenient coating preparation scheme. High-entropy alloys have been widely studied due to their excellent comprehensive properties. High-entropy alloys, also known as multi-component alloys, contain five or more main elements. High-entropy alloy coatings have attracted wide attention in the coating field because they exhibit more unique physical and chemical properties than traditional coatings, such as excellent corrosion resistance, wear resistance, and good mechanical strength.

[0003] As one of the most widely studied high-entropy alloy systems, AlCoCrFeNi has a single-phase BCC structure, with relatively high strength and hardness, and exhibits excellent high-temperature mechanical properties. However, with the development of the machinery industry, higher requirements are put forward for materials serving in extreme environments (severe wear and corrosive media), and their surface properties, especially hardness, wear resistance, and corrosion resistance, still need to be further strengthened and improved. Summary of the Invention

[0004] To solve the deficiencies mentioned in the above background art, the purpose of the present invention is to provide an anti-wear and corrosion-resistant high-entropy alloy composite coating and a preparation method thereof. Using high-entropy alloy powder as the matrix, the hardness, wear resistance, and corrosion resistance of the high-entropy alloy coating are enhanced by adding modified additives and composite ceramic powder.

[0005] The purpose of the present invention can be achieved by the following technical solutions: An anti-wear and corrosion-resistant high-entropy alloy composite coating is made by depositing functional high-entropy alloy composite powder on the surface of a substrate by laser cladding. The functional high-entropy alloy composite powder includes the following components in parts by weight: 85 - 100 parts of high-entropy alloy powder, 1 - 4 parts of modified additive, and 1.5 - 3 parts of composite ceramic powder; The modified additive is made by using urea and titanium tetrachloride as raw materials, in-situ growing nano titanium nitride particles on the surface of silicon carbide nanowires to form a nano titanium nitride / silicon carbide nanowire composite material, and then coating a layer of nano titanium dioxide particles on the surface of the nano titanium nitride / silicon carbide nanowire composite material using tetrabutyl titanate; The composite ceramic powder is made by compounding zirconium carbide, niobium carbide, hafnium carbide, and tantalum disilicide in equal mass ratio.

[0006] Preferably, the high-entropy alloy powder is AlCoCrFeNi.

[0007] Preferably, the preparation method of the modified additive comprises the following steps: (1) Urea and titanium tetrachloride were added to ethanol and stirred continuously until the solution turned light yellow to obtain a precursor solution, and then silicon carbide nanowires were added for impregnation and then taken out for drying. Subsequently, the solution was placed in a nitrogen atmosphere at 1100-1300°C for 2-3 hours for heat treatment to prepare a nano-titanium nitride / silicon carbide nanowire composite material; (2) Tetrabutyl titanate was dissolved in a reactor filled with ethanol, and then nano-titanium nitride / silicon carbide nanowire composite materials were added for ultrasonic dispersion. The reactor was then placed in a beaker filled with distilled water. The beaker was sealed with a plastic film and placed in a water bath at 75-85°C for 10-12 hours. The reaction product was washed, filtered, and dried, and finally calcined at 350-400°C for 2-3 hours to prepare a modified additive.

[0008] Preferably, the diameter of the silicon carbide nanowires in step (1) is 0.1-0.6 nm.

[0009] Preferably, in step (1), the precursor solution contains Ti 4+ The concentration is 0.05~0.30mmol / mL.

[0010] Preferably, the composite ceramic powder is formed by mixing zirconium carbide, niobium carbide, hafnium carbide, and tantalum disilicide in equal mass ratios.

[0011] Preferably, the particle size of the zirconium carbide, niobium carbide, hafnium carbide and tantalum disilicide is 1-10 μm.

[0012] A method for preparing a wear-resistant and corrosion-resistant high-entropy alloy composite coating comprises the following steps: weighing raw materials in parts by weight, fully mixing high-entropy alloy powder, modifying additives and composite ceramic powder to obtain functional high-entropy alloy composite powder, then mixing the functional high-entropy alloy composite powder with anhydrous ethanol and uniformly coating the powder on the surface of a substrate, introducing high-purity argon gas for protection during the reaction, and performing a laser cladding process to prepare the wear-resistant and corrosion-resistant high-entropy alloy composite coating.

[0013] Preferably, the preset thickness of the functional high entropy alloy composite powder is 1-5 mm.

[0014] Preferably, the laser cladding process parameters are: scanning speed V=300 mm / min, laser power P=3 kW, and spot size 2.5 mm×11.5 mm.

[0015] Beneficial effects of the present invention: The present invention uses urea and titanium tetrachloride as raw materials, and nano-titanium nitride particles are in-situ grown on the surface of silicon carbide nanowires. Nano-titanium nitride has a high melting point, good chemical stability and excellent oxidation resistance. Then, tetrabutyl titanate is used to coat a layer of nano-titanium dioxide particles on the surface of the nano-titanium nitride / silicon carbide nanowire composite material to prepare a modified additive. By introducing nano-titanium dioxide particles, titanium monoxide and aluminum oxide hard reinforcement phases are precipitated in situ during the laser cladding process, thereby improving the surface properties of the coating and making the hardness and resistance of the coating higher. The abrasiveness is improved, and a composite ceramic powder composed of zirconium carbide, niobium carbide, hafnium carbide and tantalum disilicide is used as a reinforcing phase. Zirconium carbide is a ceramic material with high hardness and high melting point. It has the advantages of high strength, corrosion resistance and not easily oxidized in high temperature environments. Niobium carbide has a melting point of up to 3610°C and high chemical stability. Hafnium carbide has a high elastic modulus, good thermal conductivity and a small thermal expansion coefficient. Tantalum disilicide can be oxidized to generate silicon dioxide, which closes the larger pores in the coating and makes the coating surface denser. The present invention uses high-entropy alloy powder as a matrix, mixes zirconium carbide, niobium carbide, hafnium carbide, and tantalum disilicide to obtain a composite ceramic powder, and uses the composite ceramic powder and a modifying additive together as a reinforcing phase. The silicon carbide nanowires in the modifying additive are a one-dimensional material, and mixing them with the composite ceramic powder can make up for the insufficient fracture toughness of the composite ceramic powder, and to a certain extent avoid the defect of brittle fracture of the coating under stress. At the same time, the addition of the modifying additive and the composite ceramic powder enhances the hardness, wear resistance, and corrosion resistance of the high-entropy alloy coating. DETAILED DESCRIPTION

[0016] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0017] The AlCoCrFeNi high entropy alloy powder in the embodiments and comparative examples of the present invention was prepared by vacuum atomization and was produced by Beijing Jiaming Platinum Nonferrous Metals Co., Ltd. with a particle size of 10-50 μm and a purity of ≥99.9%.

[0018] Example 1 A method for preparing a modified additive comprises the following steps: (1) Take 1.04g urea and 0.45mL titanium tetrachloride and add them to 80mL ethanol. Stir continuously until the solution turns light yellow to obtain a solution containing 0.05mmol / mLTi 4+The precursor solution was then added with silicon carbide nanowires for immersion, and then taken out and dried. The mixture was then heat treated at 1200°C in a nitrogen atmosphere for 3 hours to prepare a nano-titanium nitride / silicon carbide nanowire composite material. (2) Take 5 mL of tetrabutyl titanate and dissolve it in a reactor filled with 30 mL of ethanol. Then add the obtained nano-titanium nitride / silicon carbide nanowire composite material and ultrasonically disperse it. Then place the reactor in a beaker filled with distilled water. The beaker mouth is sealed with plastic film and placed in an 80°C water bath for 12 hours. The reaction product is washed, filtered, dried, and finally calcined at 400°C for 2 hours to prepare a modified additive.

[0019] Example 2 A functional high entropy alloy composite powder comprises the following components in parts by weight: 85 parts of AlCoCrFeNi high entropy alloy powder, 1.5 parts of the modifying additive prepared in Example 1, and 1.5 parts of composite ceramic powder, wherein the composite ceramic powder is a mixture of zirconium carbide, niobium carbide, hafnium carbide, and tantalum disilicide in equal mass proportions.

[0020] A method for preparing a wear-resistant and corrosion-resistant high-entropy alloy composite coating comprises the following steps: Weigh each raw material by weight, fully mix the high entropy alloy powder, the modified additive and the composite ceramic powder to obtain a functional high entropy alloy composite powder, and then mix the functional high entropy alloy composite powder with anhydrous ethanol and evenly coat it on the surface of a 304 stainless steel substrate. The size of the 304 stainless steel substrate is 200×200×5mm. 3 , polished with 400~1200 grit sandpaper, and ultrasonically cleaned the cladding surface with alcohol. The preset powder thickness was 2mm. High-purity argon gas was introduced during the reaction process for protection. The laser cladding process was carried out. The laser cladding process parameters were: scanning speed V=300mm / min, laser power P=3kW, spot size 2.5mm×11.5mm, and a wear-resistant and corrosion-resistant high-entropy alloy composite coating was prepared.

[0021] Example 3 A functional high entropy alloy composite powder comprises the following components in parts by weight: 90 parts of AlCoCrFeNi high entropy alloy powder, 3 parts of the modifying additive prepared in Example 1, and 2 parts of composite ceramic powder, wherein the composite ceramic powder is a mixture of zirconium carbide, niobium carbide, hafnium carbide, and tantalum disilicide in equal mass proportions.

[0022] The preparation method of a wear-resistant and corrosion-resistant high-entropy alloy composite coating is the same as that of Example 2.

[0023] Example 4 A functional high entropy alloy composite powder includes the following components in weight: 95 parts of AlCoCrFeNi high entropy alloy powder, 4 parts of the modifying additive prepared in Example 1, and 2.5 parts of composite ceramic powder, wherein the composite ceramic powder is a mixture of zirconium carbide, niobium carbide, hafnium carbide, and tantalum disilicide in equal mass proportions.

[0024] The preparation method of an anti-wear and corrosion-resistant high-entropy alloy composite coating is the same as that of Example 2.

[0025] Comparative Example 1 A functional high-entropy alloy composite powder includes the following components in parts by weight: 95 parts of AlCoCrFeNi high-entropy alloy powder, 4 parts of the nano-titanium nitride / silicon carbide nanowire composite material prepared in Example 1, and 2.5 parts of composite ceramic powder, wherein the composite ceramic powder is composed of zirconium carbide, niobium carbide, hafnium carbide, tantalum disilicide, etc. mixed in equal mass ratio.

[0026] Compared with the preparation method of an anti-wear and corrosion-resistant high-entropy alloy composite coating in Example 2, the modified additive is replaced with the nano-titanium nitride / silicon carbide nanowire composite material in equal amount, and the other components and steps are the same.

[0027] Comparative Example 2 A functional high-entropy alloy composite powder includes the following components in parts by weight: 95 parts of AlCoCrFeNi high-entropy alloy powder and 2.5 parts of composite ceramic powder, wherein the composite ceramic powder is composed of zirconium carbide, niobium carbide, hafnium carbide, tantalum disilicide, etc. mixed in equal mass ratio.

[0028] Compared with the preparation method of an anti-wear and corrosion-resistant high-entropy alloy composite coating in Example 2, the modified additive is not added, and the other components and steps are the same.

[0029] Comparative Example 3 A functional high-entropy alloy composite powder includes the following components in parts by weight: 95 parts of AlCoCrFeNi high-entropy alloy powder and 4 parts of the modified additive prepared in Example 1.

[0030] Compared with the preparation method of an anti-wear and corrosion-resistant high-entropy alloy composite coating in Example 2, the composite ceramic powder is not added, and the other components and steps are the same.

[0031] Performance detection: Perform performance detection on the high-entropy alloy composite coatings prepared in Examples 2-4 and Comparative Examples 1-3: Use a microhardness tester (MCS-1000) to measure the microhardness of the coating; Use a reciprocating friction and wear tester to detect the tribological properties of the coating, select an Al2O3 grinding ball with a diameter of 5 mm as the counter-material, the reciprocating stroke length is 5 mm, the frequency is 2 Hz, the load is 5 N, and the test time is 60 min; The electrochemical corrosion experiment is detected with reference to GB / T 40299-2021; The impact resistance detection is carried out with reference to GB / T2423.5-2019, and the data results are shown in Table 1.

[0032] Table 1 Performance detection results of samples

[0033] As can be seen from the data in Table 1, the high-entropy alloy composite coatings prepared in Examples 2-4 of the present invention have high hardness, good wear resistance, corrosion resistance and impact resistance. In Comparative Example 1, the modified additive was replaced with an equal amount of nano-titanium nitride / silicon carbide nanowire composite material, and the measured hardness was lower than that in Examples 2-4, and the friction coefficient and wear loss weight were higher than those in Examples 2-4, indicating that the introduction of nano-titanium dioxide particles can improve the hardness and wear resistance of the coating. In Comparative Example 2, the modified additive component was not added, and in Comparative Example 3, the composite ceramic powder component was not added. The measured hardness of Comparative Examples 2-3 was lower than that in Examples 2-4, and the friction coefficient, wear loss weight and corrosion current density were higher than those in Examples 2-4, indicating that the addition of the modified additive component and the composite ceramic powder component can improve the hardness, wear resistance and corrosion resistance of the coating to a certain extent. And the impact work in Comparative Example 2 was lower than that in Examples 2-4 and Comparative Examples 1 and 3, indicating that the addition of the nano-titanium nitride / silicon carbide nanowire composite material can improve the impact resistance of the coating.

[0034] In the description of this specification, the descriptions referring to the terms "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0035] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art of this industry should understand that the present invention is not limited by the above embodiments, and the above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. An anti-wear and corrosion-resistant high-entropy alloy composite coating, characterized in that, The functional high entropy alloy composite powder is deposited on the surface of the substrate by laser cladding, and the functional high entropy alloy composite powder comprises the following components by weight: 85-100 parts of high entropy alloy powder, 1-4 parts of modifying additives, and 1.5-3 parts of composite ceramic powder; The modified additive is prepared by in-situ growing nano-titanium nitride particles on the surface of silicon carbide nanowires using urea and titanium tetrachloride as raw materials to prepare a nano-titanium nitride / silicon carbide nanowire composite material, and then coating the surface of the nano-titanium nitride / silicon carbide nanowire composite material with a layer of nano-titanium dioxide particles using tetrabutyl titanate; the composite ceramic powder is prepared by compounding zirconium carbide, niobium carbide, hafnium carbide and tantalum disilicide in equal mass ratios.

2. The anti-wear and corrosion-resistant high-entropy alloy composite coating according to claim 1, wherein, The high entropy alloy powder is AlCoCrFeNi.

3. The anti-wear and corrosion-resistant high-entropy alloy composite coating according to claim 1, wherein The preparation method of the modified additive comprises the following steps: (1) Urea and titanium tetrachloride were added to ethanol and stirred continuously until the solution turned light yellow to obtain a precursor solution, and then silicon carbide nanowires were added for impregnation and then taken out for drying. Subsequently, the solution was placed in a nitrogen atmosphere at 1100-1300°C for 2-3 hours for heat treatment to prepare a nano-titanium nitride / silicon carbide nanowire composite material; (2) Tetrabutyl titanate was dissolved in a reactor filled with ethanol, and then nano-titanium nitride / silicon carbide nanowire composite materials were added for ultrasonic dispersion. The reactor was then placed in a beaker filled with distilled water. The beaker was sealed with a plastic film and placed in a water bath at 75-85°C for 10-12 hours. The reaction product was washed, filtered, and dried, and finally calcined at 350-400°C for 2-3 hours to prepare a modified additive.

4. The anti-wear and corrosion-resistant high-entropy alloy composite coating according to claim 3, wherein, The diameter of the silicon carbide nanowires in step (1) is 0.1-0.6 nm.

5. The anti-wear and corrosion-resistant high-entropy alloy composite coating according to claim 3, wherein The Ti in the precursor solution in step (1) 4+ has a concentration of 0.05 to 0.30 mmol / mL.

6. The anti-wear and corrosion-resistant high-entropy alloy composite coating according to claim 1, wherein The composite ceramic powder is prepared by mixing zirconium carbide, niobium carbide, hafnium carbide and tantalum disilicide in equal mass proportions.

7. The anti-wear and corrosion-resistant high-entropy alloy composite coating according to claim 6, characterized in that The particle size of the zirconium carbide, niobium carbide, hafnium carbide and tantalum disilicide is 1-10 μm.

8. A method for preparing an anti-wear and corrosion-resistant high-entropy alloy composite coating according to any one of claims 1 to 7, characterized in that, The method comprises the following steps: weighing raw materials in parts by weight, fully mixing high-entropy alloy powder, modifying additives and composite ceramic powder to obtain functional high-entropy alloy composite powder, then mixing the functional high-entropy alloy composite powder with anhydrous ethanol and uniformly coating the powder on the surface of a substrate, introducing high-purity argon gas for protection during the reaction, performing a laser cladding process, and preparing a wear-resistant and corrosion-resistant high-entropy alloy composite coating.

9. The preparation method of the anti-wear and corrosion-resistant high-entropy alloy composite coating according to claim 8, characterized in that, The preset thickness of the functional high entropy alloy composite powder is 1-5 mm.

10. The preparation method of the anti-wear and corrosion-resistant high-entropy alloy composite coating according to claim 8, characterized in that, The laser cladding process parameters are: scanning speed V=300 mm / min, laser power P=3 kW, and spot size 2.5 mm×11.5 mm.

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