FeCunital-based high-entropy alloy composite coating and preparation method and application thereof

Abstract

The application provides a FeCuNiTiAl-based high-entropy alloy composite coating and a preparation method and application thereof, and belongs to the technical field of coatings.The preparation method of the FeCuNiTiAl-based high-entropy alloy composite coating provided by the application comprises the following steps: mixing FeCuNiTiAl high-entropy alloy powder and tungsten carbide powder to obtain cladding powder; the mass content of the tungsten carbide powder in the cladding powder is 5-15%; the cladding powder is laid on the surface of a base material to form a cladding powder layer, and then laser cladding treatment is performed to form a FeCuNiTiAl-based high-entropy alloy composite coating on the surface of the base material.The FeCuNiTiAl high-entropy alloy powder and the tungsten carbide powder are mixed and then subjected to laser cladding treatment, so that the corrosion resistance of the FeCuNiTiAl high-entropy alloy coating can be effectively improved.

Description

Technical Field

[0001] This invention relates to the field of coating technology, and in particular to a FeCuNiTiAl-based high-entropy alloy composite coating, its preparation method, and its application. Background Technology

[0002] FeCuNiTiAl high-entropy alloys possess excellent corrosion resistance, wear resistance, oxidation resistance, and high hardness, making them ideal materials for marine engineering. However, due to limitations in FeCuNiTiAl high-entropy alloy preparation technology, large-scale production of bulk FeCuNiTiAl high-entropy alloy materials is currently not possible; FeCuNiTiAl high-entropy alloy powder materials are more commonly available on the market. Using FeCuNiTiAl high-entropy alloy powder materials to prepare FeCuNiTiAl high-entropy alloy coatings can achieve surface modification of marine engineering materials, thereby achieving corrosion resistance. However, the elemental stability of the various metal elements in FeCuNiTiAl high-entropy alloys is poor, and they easily lose outer electrons during use, leading to corrosion. Therefore, although the corrosion resistance of FeCuNiTiAl high-entropy alloys is significantly improved compared to traditional marine engineering materials, it still cannot meet the requirements for marine engineering materials with high corrosion resistance. Summary of the Invention

[0003] The purpose of this invention is to provide a FeCuNiTiAl-based high-entropy alloy composite coating, its preparation method, and its application. The FeCuNiTiAl-based high-entropy alloy composite coating prepared by the method of this invention has excellent corrosion resistance.

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

[0005] This invention provides a method for preparing a FeCuNiTiAl-based high-entropy alloy composite coating, comprising the following steps:

[0006] FeCuNiTiAl high-entropy alloy powder is mixed with tungsten carbide powder to obtain cladding powder; the mass content of tungsten carbide powder in the cladding powder is 5-15%;

[0007] The cladding powder is laid on the surface of the substrate material to form a cladding powder layer, and then laser cladding is performed to form a FeCuNiTiAl-based high-entropy alloy composite coating on the surface of the substrate material.

[0008] Preferably, the particle size of the tungsten carbide powder is 770–870 nm.

[0009] Preferably, the particle size of the FeCuNiTiAl high-entropy alloy powder is 45–70 μm.

[0010] Preferably, the FeCuNiTiAl high-entropy alloy powder contains the same atomic percentages of Fe, Cu, Ni, Ti, and Al.

[0011] Preferably, the thickness of the cladding powder layer is 1 mm.

[0012] Preferably, the conditions for the laser cladding process include: laser power of 1400W, spot diameter of 2mm, laser scanning rate of 500mm / min, overlap rate of 40%, and laser defocusing amount of +5mm.

[0013] Preferably, the base material is 316 stainless steel.

[0014] The present invention provides a FeCuNiTiAl-based high-entropy alloy composite coating prepared by the preparation method described above, comprising a FeCuNiTiAl high-entropy alloy matrix and tungsten carbide particles distributed in the FeCuNiTiAl high-entropy alloy matrix.

[0015] Preferably, the thickness of the FeCuNiTiAl-based high-entropy alloy composite coating is 0.8–1.2 mm.

[0016] This invention provides the application of the FeCuNiTiAl-based high-entropy alloy composite coating described above in bridges, ships, aerospace or chemical machinery equipment.

[0017] This invention provides a method for preparing a FeCuNiTiAl-based high-entropy alloy composite coating, comprising the following steps: mixing FeCuNiTiAl high-entropy alloy powder with tungsten carbide powder to obtain cladding powder; the mass content of tungsten carbide powder in the cladding powder is 5-15%; laying the cladding powder on the surface of a substrate material to form a cladding powder layer, and then performing laser cladding treatment to form a FeCuNiTiAl-based high-entropy alloy composite coating on the surface of the substrate material. In this invention, tungsten carbide powder has stable chemical properties, hardly participates in chemical reactions, and has extremely outstanding corrosion resistance, but it is brittle and has poor toughness. This invention, by mixing FeCuNiTiAl high-entropy alloy powder with tungsten carbide powder and then performing laser cladding treatment, can effectively improve the corrosion resistance of the FeCuNiTiAl high-entropy alloy coating. Detailed Implementation

[0018] This invention provides a method for preparing a FeCuNiTiAl-based high-entropy alloy composite coating, comprising the following steps:

[0019] FeCuNiTiAl high-entropy alloy powder is mixed with tungsten carbide powder to obtain cladding powder; the mass content of tungsten carbide powder in the cladding powder is 5-15%;

[0020] The cladding powder is laid on the surface of the substrate material to form a cladding powder layer, and then laser cladding is performed to form a FeCuNiTiAl-based high-entropy alloy composite coating on the surface of the substrate material.

[0021] Unless otherwise specified, all raw materials used in this invention are commercially available products well known to those skilled in the art.

[0022] This invention mixes FeCuNiTiAl high-entropy alloy powder with tungsten carbide powder to obtain a cladding powder. In this invention, the mass content of tungsten carbide powder in the cladding powder is 5-15%, specifically 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, or 15%. Limiting the mass content of tungsten carbide powder in the cladding powder to the above range is beneficial in ensuring that the FeCuNiTiAl-based high-entropy alloy composite coating has excellent corrosion resistance. If the amount of tungsten carbide powder is too small, the improvement in corrosion resistance is not significant; if the amount of tungsten carbide powder is too large, the prepared composite coating is prone to cracking, and when used in a marine environment, the composite coating will form a galvanic cell effect, with tungsten carbide typically acting as the cathode and the FeCuNiTiAl high-entropy alloy acting as the anode, thus forming a large cathode-small anode pattern, which exacerbates corrosion.

[0023] In this invention, the particle size of the tungsten carbide powder is preferably 770–870 nm, more preferably 800–840 nm, and even more preferably 820 nm. In this invention, the particle size of the FeCuNiTiAl high-entropy alloy powder is preferably 45–70 μm; the atomic percentages of Fe, Cu, Ni, Ti, and Al in the FeCuNiTiAl high-entropy alloy powder are preferably the same. This invention preferably uses a composite of FeCuNiTiAl high-entropy alloy powder with the above-mentioned particle size and tungsten carbide powder. The smaller particle size of the tungsten carbide powder facilitates uniform coating on the surface of the FeCuNiTiAl high-entropy alloy powder. Subsequent laser cladding treatment, due to the grain refinement and strengthening effect, helps to ensure a composite coating with high density, high hardness, and excellent corrosion resistance. In this invention, the mixing method of the FeCuNiTiAl high-entropy alloy powder and tungsten carbide powder is preferably ball milling. The ball milling speed is preferably 500–700 rpm, more preferably 600 rpm; the time is preferably 1.5–2.5 h, more preferably 2 h.

[0024] After obtaining the cladding powder, the present invention lays the cladding powder on the surface of the substrate material to form a cladding powder layer, and then performs laser cladding treatment to form a FeCuNiTiAl-based high-entropy alloy composite coating on the surface of the substrate material. In the present invention, the substrate material is preferably 316 stainless steel. In the present invention, the substrate material is preferably pretreated before use, and the pretreatment preferably includes sequential grinding and cleaning, specifically grinding the surface of the substrate material with sandpaper and cleaning the surface of the substrate material with ethanol. In the present invention, the thickness of the cladding powder layer is preferably 1 mm. The present invention does not have a special limitation on the laying method of the cladding powder; any method well known to those skilled in the art can be used. In the present invention, the conditions for the laser cladding treatment include: laser power preferably 1400W; spot diameter preferably 2 mm; laser scanning rate preferably 500 mm / min; overlap rate preferably 40%; and laser defocusing amount preferably +5 mm.

[0025] This invention provides a FeCuNiTiAl-based high-entropy alloy composite coating prepared by the preparation method described above, comprising a FeCuNiTiAl high-entropy alloy substrate and tungsten carbide particles distributed in the FeCuNiTiAl high-entropy alloy substrate. In this invention, the thickness of the FeCuNiTiAl-based high-entropy alloy composite coating is preferably 0.8–1.2 mm, more preferably 1.0 mm.

[0026] This invention provides the application of the FeCuNiTiAl-based high-entropy alloy composite coating described above in bridges, ships, aerospace or chemical machinery equipment.

[0027] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0028] The FeCuNiTiAl high-entropy alloy powder used in the following examples and comparative examples has a particle size range of 45–70 μm, and the elements in the FeCuNiTiAl high-entropy alloy powder are in equimolar ratio, that is, the atomic percentage of each element is the same; the particle size of the tungsten carbide powder used is 820 nm.

[0029] Example 1

[0030] FeCuNiTiAl high-entropy alloy powder and tungsten carbide powder were ball-milled at 600 rpm for 2 h using a planetary ball mill, and then dried in an oven at 100 °C for 2 h to obtain cladding powder. The mass content of tungsten carbide powder in the cladding powder was 5%.

[0031] Using 316 stainless steel as the base material, the surface of the base material is sanded with sandpaper and cleaned with ethanol. Then, the cladding powder is laid on the surface of the base material to form a cladding powder layer with a thickness of 1 mm. Then, laser cladding treatment is performed to form a composite coating with a thickness of 1.0 mm on the surface of the base material. The conditions of the laser cladding treatment include: laser power of 1400W, spot diameter of 2 mm, laser scanning rate of 500 mm / min, overlap rate of 40%, and laser defocusing amount of +5 mm.

[0032] Example 2

[0033] The composite coating was prepared according to the method of Example 1, except that the mass content of tungsten carbide powder in the cladding powder of this example was 10%.

[0034] Example 3

[0035] The composite coating was prepared according to the method of Example 1, except that the mass content of tungsten carbide powder in the cladding powder of this example was 15%.

[0036] Comparative Example 1

[0037] The coating was prepared according to the method of Example 1, except that tungsten carbide powder was not added.

[0038] Comparative Example 2

[0039] The composite coating was prepared according to the method of Example 1, except that the mass content of tungsten carbide powder in the cladding powder of this comparative example was 20%.

[0040] Comparative Example 3

[0041] The composite coating was prepared according to the method of Example 1, except that the mass content of tungsten carbide powder in the cladding powder of this comparative example was 25%.

[0042] Comparative Example 4

[0043] The composite coating was prepared according to the method of Example 1, except that the mass content of tungsten carbide powder in the cladding powder of this comparative example was 30%.

[0044] Test Example 1

[0045] The corrosion resistance of the coatings in the examples and comparative examples in 3.5 wt% sodium chloride solution at room temperature (25°C) was measured using an electrochemical workstation (CHI660E, Chen Hua Instruments, Shanghai, China). The test voltage range was -1.4V to +0.5V. Specifically, a three-electrode battery system including a reference electrode, working electrode, and auxiliary electrode was used for testing. Each coating sample was prepared according to a standard size of 1 mm × 1 mm. The electrochemical performance of each coating sample was tested after exposure to 3.5 wt% sodium chloride solution for 30 min, and compared with 316 stainless steel without coating. The specific results are shown in Table 1 (the appearance morphology was characterized by optical microscopy and scanning electron microscopy). As shown in Table 1, the composite coating prepared by the method of this invention has excellent corrosion resistance and is free of pores and cracks.

[0046] Table 1. Performance test results of the coating in each embodiment and comparative example.

[0047]

[0048]

[0049] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a FeCuNiTiAl-based high-entropy alloy composite coating, comprising the following steps: FeCuNiTiAl high-entropy alloy powder is mixed with tungsten carbide powder to obtain cladding powder; the mass content of tungsten carbide powder in the cladding powder is 10~15%; the particle size of tungsten carbide powder is 770~870nm, and the particle size of FeCuNiTiAl high-entropy alloy powder is 45~70μm; The cladding powder is laid on the surface of the substrate material to form a cladding powder layer, and then laser cladding is performed to form a FeCuNiTiAl-based high-entropy alloy composite coating on the surface of the substrate material.

2. The preparation method according to claim 1, characterized in that, The FeCuNiTiAl high-entropy alloy powder contains Fe, Cu, Ni, Ti, and Al with the same atomic percentage.

3. The preparation method according to claim 1, characterized in that, The thickness of the cladding powder layer is 1 mm.

4. The preparation method according to claim 1, characterized in that, The conditions for the laser cladding process include: laser power of 1400W, spot diameter of 2mm, laser scanning rate of 500mm / min, overlap rate of 40%, and laser defocusing amount of +5mm.

5. The preparation method according to claim 1, characterized in that, The base material is 316 stainless steel.

6. The FeCuNiTiAl-based high-entropy alloy composite coating prepared by the preparation method according to any one of claims 1 to 5 comprises a FeCuNiTiAl high-entropy alloy matrix and tungsten carbide particles distributed in the FeCuNiTiAl high-entropy alloy matrix.

7. The FeCuNiTiAl-based high-entropy alloy composite coating according to claim 6, characterized in that, The thickness of the FeCuNiTiAl-based high-entropy alloy composite coating is 0.8~1.2 mm.

8. The application of the FeCuNiTiAl-based high-entropy alloy composite coating of claim 6 or 7 in bridges, ships, aerospace or chemical machinery equipment.

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