A FeCrAl-based gradient nano-multilayered high-entropy alloy coating and its preparation method

Abstract

The present invention discloses a FeCrAl-based gradient nano-multilayered high-entropy alloy coating and a preparation method thereof. After sequentially depositing a Cr film and an AlCr film on a substrate by using a method combining multi-arc ion plating and magnetron sputtering, a multi-layer structure of a FeCrAl / FeCrAlTiSiY composite film is formed by alternately depositing a single-layer FeCrAl film and a single-layer FeCrAlTiSiY film. The coating obtained by the present invention has high film-substrate adhesion, high hardness, high wear resistance, and high thermal stability, meeting the requirements of industrial applications of high-entropy alloy coatings.

Description

Technical Field

[0001] The present invention relates to an FeCrAl-based gradient nano-multilayered structure high-entropy alloy coating and a preparation method thereof, belonging to the fields of coating materials and surface science and technology. Background Art

[0002] In 2004, scholar Ye Junwei proposed a brand-new alloy design mode, pioneering a new research field of metallic materials - multi-component high-entropy alloys. This design mode breaks the design concept of traditional alloys. By using multiple main elements as basic components and mixing these components in an equal proportion or nearly equal proportion, a single-phase solid solution is expected to be formed under the action of high mixing configurational entropy. High-entropy alloys have four major effects, namely high-entropy effect, lattice distortion effect, sluggish diffusion effect, and cocktail effect. Their structures and properties are different from those of traditional alloys in many aspects. High-entropy alloys have excellent mechanical properties, friction and wear properties, corrosion resistance, high temperature resistance, etc., and have become one of the new materials with the most development potential in the future.

[0003] With the in-depth research, the design concept of high-entropy alloys has gradually evolved from the initial goal of obtaining a single-phase solid solution through equiatomic ratios to an alloy system with non-equiatomic ratios and coexistence of multiple phases. At present, the preparation and research of high-entropy alloys mainly focus on bulk-structured materials. However, high-entropy alloy materials have more components, and the industrial use cost of their bulk-structured materials is relatively high. In addition, high-entropy alloy materials have high hardness and strength, and their processing and forming are relatively difficult. Therefore, the application of high-entropy alloys is greatly restricted, especially for some components with complex structures. Preparing high-entropy alloys into coatings is expected to solve the above problems, which can not only save material costs but also maintain the excellent properties of high-entropy alloy materials such as high strength, high hardness, and high wear resistance, thereby expanding the application scope of high-entropy alloys.

[0004] Currently, there are three commonly used techniques for preparing high-entropy alloy coatings: magnetron sputtering, cold / hot spraying, and laser cladding. For coating structures with a small thickness (<30μm), magnetron sputtering technology is mainly used. Although this method is very suitable for preparing high-entropy alloy coatings with uniform and dense structures, the problems of low deposition rate and insufficient bonding force also make this method unable to meet the requirements of industrial applications of high-entropy alloy coatings. Summary of the Invention

[0005] Aiming at the problems existing in the above-mentioned prior art, the present invention provides an FeCrAl-based gradient nano-multilayered structure high-entropy alloy coating and a preparation method thereof, aiming to prepare a novel Cr / Al x1 Cr y1 / (Fe x2 Cr y2 Al z2 / Fex3 Cr y3 Al z3 Ti k3 Si r3 Y p3 ) n Coating

[0006] To achieve the purpose, the present invention adopts the following technical solutions:

[0007] A FeCrAl-based gradient nano-multilayered high-entropy alloy coating, characterized in that: the coating is formed by sequentially depositing a Cr thin film and an AlCr thin film on a substrate, and then forming a multi-layer structure of a FeCrAl / FeCrAlTiSiY composite film by alternately depositing a single-layer FeCrAl thin film and a single-layer FeCrAlTiSiY thin film.

[0008] Furthermore: the thickness of the Cr thin film is 10-20 nm; the thickness of the AlCr thin film is 20-30 nm; the thicknesses of both the single-layer FeCrAl thin film and the single-layer FeCrAlTiSiY thin film are between 1 nm and 30 nm; the number of layers of the FeCrAl / FeCrAlTiSiY composite film (here, the number of layers means that a single-layer FeCrAl + a single-layer FeCrAlTiSiY is counted as one layer of the composite film) is n, where n is an integer greater than 2.

[0009] Furthermore, the composition of each element in the AlCr thin film according to the atomic ratio is Al x1 Cr y1 , where x1 + y1 = 100, 0 < x1 < 30, 25 < y1 < 85.

[0010] Furthermore, the composition of each element in the FeCrAl thin film according to the atomic ratio is Fe x2 Cr y2 Al z2 , where x2 + y2 + z2 = 100, 20 < x2, y2, z2 < 50.

[0011] Furthermore, the composition of each element in the FeCrAlTiSiY thin film according to the atomic ratio is Fe x3 Cr y3 Al z3 Ti k3 Si r3 Y p3 , where x3 + y3 + z3 + k3 + r3 + p3 = 100, 0 < x3, y3, z3, k3, r3, p3 < 50.

[0012] The preparation method of the FeCrAl-based gradient nano-multilayered high-entropy alloy coating of the present invention includes the following steps:

[0013] Step 1: The substrate is mechanically polished, ultrasonically cleaned, and dried for later use.

[0014] Step 2: The substrate is loaded onto the sample stage.

[0015] Step 3: The Cr target and the AlCr target are respectively installed on the multi-arc source, and the FeCrAl target and the FeCrAlTiSiY target are respectively installed on the magnetron sputtering cathode. The distance between the target and the substrate is adjusted to 150 - 300 mm.

[0016] Step 4: The vacuum is pumped to 2×10 -4 Pa, the substrate is heated to 200 - 450 °C, and then argon is introduced. The argon flow rate is controlled to be 50 - 100 sccm, and the working pressure is set to 0.2 - 1.5 Pa. The DC bias power supply is turned on, the substrate bias is adjusted to -500 V to -1000 V, and the sputtering time is 10 - 15 min to perform sputtering cleaning on the substrate.

[0017] Step 5: The pulsed multi-arc sputtering power supply of the Cr target is turned on. The sputtering current is set to 30 - 60 A, the substrate bias is set to -200 to -400 V, and the sputtering time is controlled for 1 - 3 min to deposit a Cr film on the substrate. After completion, the power supply is turned off.

[0018] Step 6: The pulsed multi-arc sputtering power supply of the AlCr target is turned on. The sputtering current is set to 30 - 70 A, the substrate bias is set to -200 to -400 V, and the sputtering time is controlled for 1 - 10 min to deposit an AlCr film on the Cr film. After completion, the power supply is turned off.

[0019] Step 7: The DC sputtering power supplies of the FeCrAl target and the FeCrAlTiSiY target are turned on. The sputtering powers are set to 50 - 100 W respectively, and the respective sputtering times are controlled for 1 - 10 min. Single-layer FeCrAl films and single-layer FeCrAlTiSiY films are alternately deposited on the Cr / Al-Cr film, and the total sputtering time is controlled for 2 - 3 hours to form a multi-layer structure of FeCrAl / FeCrAlTiSiY composite film.

[0020] Step 8: The sputtering and heating power supplies are turned off. The temperature is reduced to below 100 °C under the condition of pumping vacuum by the molecular pump. The molecular pump is turned off, the power supply is turned off, and it is cooled to room temperature under natural vacuum. Then the sample is taken out, and a FeCrAl-based gradient nano-multi-layer structure high-entropy alloy coating Cr / Al x1 Cr y1 / (Fe x2 Cr y2 Al z2 / Fe x3 Cr y3 Al z3 Ti k3Si r3 Y p3 ) n 。

[0021] Furthermore, the substrate is selected from metal, ceramic or glass.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] The present invention uses a method combining multi-arc ion plating and magnetron sputtering to prepare a novel Cr / Al x1 Cr y1 / (Fe x2 Cr y2 Al z2 / Fe x3 Cr y3 Al z3 Ti k3 Si r3 Y p3 ) n coating, which has high film-substrate bonding strength, high hardness, high wear resistance and high thermal stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The cross-sectional TEM image of the Cr / Al 20 Cr 80 / (Fe 28 Cr 43 Al 29 / Fe 25 Cr 36 Al 24 Ti7Si4Y4) 60 coating obtained in Example 1 can be seen that the single-layer thicknesses of Fe 28 Cr 43 Al 29 and Fe 25 Cr 36 Al 24 Ti7Si4Y4 are 6 nm and 8 nm respectively.

[0025] Figure 2 The nano-indentation hardness and film-substrate bonding strength of the Cr / Al 20 Cr 80 / (Fe 28 Cr 43 Al 29 / Fe 25 Cr 36 Al 24 Ti7Si4Y4) n coatings obtained in each example.

[0026] Figure 3Cr / Al obtained for each embodiment 20 Cr 80 / (Fe 28 Cr 43 Al 29 / Fe 25 Cr 36 Al 24 Ti7Si4Y4) n The wear rate and the highest thermal stability temperature of the coating Detailed implementation manners

[0027] The present invention will be further described in conjunction with the following embodiments

[0028] In the following embodiments, the equipment used for preparing the Cr / AlCr / (FeCrAl / FeCrAlTiSiY) n coating is a magnetron-multi-arc composite vacuum ion coating equipment

[0029] The target materials used in the following embodiments are target materials obtained by powder metallurgy method, and can also be purchased on the market

[0030] The nano-indentation hardness of the coatings obtained in the following embodiments is tested by a nano-indentation instrument

[0031] The film-substrate bonding strength of the coatings obtained in the following embodiments is measured by a scratch tester

[0032] The wear rate of the coatings obtained in the following embodiments is measured by a friction and wear tester

[0033] The highest thermal stability temperature of the coatings obtained in the following embodiments is obtained according to the mechanical properties and the temperature at which the grain size changes abruptly after vacuum heat treatment at different temperatures

[0034] Embodiment 1

[0035] This embodiment provides a FeCrAl-based gradient nano-multilayered high-entropy alloy coating. After depositing a Cr film and an AlCr film on a substrate in sequence, a multi-layer structure of a FeCrAl / FeCrAlTiSiY composite film is formed by alternately depositing a single-layer FeCrAl film and a single-layer FeCrAlTiSiY film. The composition of each element in the AlCr film according to the atomic ratio is Al 20 Cr 80 , and the composition of each element in FeCrAl according to the atomic ratio is Fe 28 Cr 43 Al 29 , and the composition of each element in FeCrAlTiSiY according to the atomic ratio is Fe 25 Cr 36 Al 24 Ti7Si4Y4. The preparation steps of the coating are as follows

[0036] Step 1: Select 314L stainless steel as the substrate. After mechanical polishing, ultrasonic cleaning with acetone and alcohol, and drying, it is ready for use.

[0037] Step 2: Load the substrate onto the sample stage.

[0038] Step 3: Install the Cr target and the Al 20 Cr 80 targets on the multi-arc source respectively, and install the Fe 37 Cr 38 Al 25 target and the Fe 28 Cr 27 Al 18 Ti 17 Si5Y5 targets on the magnetron sputtering cathodes respectively, and adjust the distance between the targets and the substrate to 200 mm.

[0039] Step 4: Pump the vacuum to 2×10 -4 Pa, heat the substrate to 350 °C, then introduce argon, control the argon flow rate to 50 sccm, and set the working pressure to 0.6 Pa; turn on the DC bias power supply, adjust the sputtering bias to -700 V, and the sputtering time to 15 min to perform sputtering cleaning on the substrate.

[0040] Step 5: Turn on the pulsed multi-arc sputtering power supply of the Cr target, set the sputtering current to 50 A, set the substrate bias to -200 V, control the sputtering time to 2 min, and deposit a Cr film with a thickness of 18 nm on the substrate. After that, turn off the power supply.

[0041] Step 6: Turn on the pulsed sputtering power supply of the Al 20 Cr 80 target, set the sputtering current to 50 A, set the substrate bias to -200 V, control the sputtering time to 3 min, and deposit an Al 20 Cr 80 film with a thickness of 21 nm on the Cr film. After that, turn off the power supply.

[0042] Step 7: Turn on the DC sputtering power supplies of the Fe 37 Cr 38 Al 25 target and the Fe 28 Cr 27 Al 18 Ti 17 Si5Y5 targets, set the sputtering powers to 50 W and 60 W respectively, set the substrate bias to -200 V, control the respective sputtering times to 1 min, and alternately deposit single layers of Fe with a thickness of 6 nm on the Cr / Al-Cr film by controlling the front baffle in front of the targets 28 Cr 43 Al29 A thin film and a single layer of Fe with a thickness of 8 nm 25 Cr 36 Al 24 Ti7Si4Y4 thin film, controlling the total sputtering time to 2 hours to form Fe 28 Cr 43 Al 29 / Fe 25 Cr 36 Al 24 A multi-layer structure of Ti7Si4Y4 film

[0043] Step 8: Turn off the sputtering and heating power supplies, cool down to below 100 °C under the condition of pumping vacuum by the molecular pump, turn off the molecular pump, turn off the power supply, cool to room temperature under natural vacuum, and then take out the sample, that is, a FeCrAl-based gradient nano-multi-layered structure high-entropy alloy coating Cr / Al 20 Cr 80 / (Fe 28 Cr 43 Al 29 / Fe 25 Cr 36 Al 24 Ti7Si4Y4) n , n = 60

[0044] After testing, the coating obtained in this example has high film-substrate bonding strength (85 MPa), high hardness (30 GPa), high wear resistance (wear rate of 0.3×10 -3 mg / Nm), and high thermal stability (650 °C).

[0045] Example 2

[0046] This example provides a FeCrAl-based gradient nano-multi-layered structure high-entropy alloy coating, which is formed by sequentially depositing a Cr thin film and an AlCr thin film on a substrate, and then forming a multi-layer structure of a FeCrAl / FeCrAlTiSiY composite film by alternately depositing a single layer of FeCrAl thin film and a single layer of FeCrAlTiSiY thin film. The atomic ratio of each element in the AlCr thin film is Al 20 Cr 80 , and the atomic ratio of each element in FeCrAl is Fe 28 Cr 43 Al 29 , and the atomic ratio of each element in FeCrAlTiSiY is Fe 25 Cr 36 Al 24 Ti7Si4Y4. The preparation steps of the coating are as follows

[0047] Step 1: Select 314L stainless steel as the substrate. After mechanical polishing, ultrasonic cleaning with acetone and alcohol, and drying, it is ready for use.

[0048] Step 2: Load the substrate onto the sample stage.

[0049] Step 3: Install the Cr target and the Al 20 Cr 80 targets on the multi-arc source respectively, and install the Fe 37 Cr 38 Al 25 target and the Fe 28 Cr 27 Al 18 Ti 17 Si5Y5 targets on the magnetron sputtering cathodes respectively. Adjust the distance between the targets and the substrate to 200 mm.

[0050] Step 4: Pump the vacuum to 2×10 -4 Pa, heat the substrate to 350 °C, then introduce argon gas, control the argon gas flow rate to 50 sccm, and set the working gas pressure to 0.6 Pa; turn on the DC bias power supply, adjust the sputtering bias voltage to -700 V, and the sputtering time to 15 min to perform sputtering cleaning on the substrate.

[0051] Step 5: Turn on the pulsed multi-arc sputtering power supply of the Cr target, set the sputtering current to 50 A, set the substrate bias voltage to -200 V, control the sputtering time to 2 min, and deposit a Cr film with a thickness of 18 nm on the substrate. After completion, turn off the power supply.

[0052] Step 6: Turn on the pulsed sputtering power supply of the Al 20 Cr 80 target, set the sputtering current to 50 A, set the substrate bias voltage to -200 V, control the sputtering time to 3 min, and deposit an Al 20 Cr 80 film with a thickness of 21 nm on the Cr film. After completion, turn off the power supply.

[0053] Step 7: Turn on the DC sputtering power supplies of the Fe 37 Cr 38 Al 25 target and the Fe 28 Cr 27 Al 18 Ti 17 Si5Y5 targets, set the sputtering powers to 50 W and 60 W respectively, set the substrate bias voltage to -200 V, control the respective sputtering times to 2 min, and alternately deposit a single-layer FeCrAl film with a thickness of 12 nm and a single-layer FeCrAlTiSiY film with a thickness of 16 nm on the Cr / Al-Cr film by controlling the front baffle in front of the target. Control the total sputtering time to 2 hours to form Fe 28Cr 43 Al 29 / Fe 25 Cr 36 Al 24 Multilayer structure of Ti7Si4Y4 composite film.

[0054] Step 8: Turn off the sputtering and heating power supplies. Cool down to below 100 °C under the condition of pumping vacuum by a molecular pump, turn off the molecular pump, turn off the power supply, cool to room temperature under natural vacuum, and then take out the sample, thus forming an FeCrAl-based gradient nano-multilayer structured high-entropy alloy coating Cr / Al on the substrate 20 Cr 80 / (Fe 28 Cr 43 Al 29 / Fe 25 Cr 36 Al 24 Ti7Si4Y4) n , n = 30.

[0055] After testing, the coating obtained in this example has high film-substrate bonding strength (88 MPa), high hardness (28 GPa), high wear resistance (wear rate of 0.5×10 -3 mg / Nm), and high thermal stability (750 °C).

[0056] Example 3

[0057] This example provides an FeCrAl-based gradient nano-multilayer structured high-entropy alloy coating. After depositing a Cr thin film and an AlCr thin film on the substrate in sequence, a multilayer structure of an FeCrAl / FeCrAlTiSiY composite film is formed by alternately depositing a single-layer FeCrAl thin film and a single-layer FeCrAlTiSiY thin film. The composition of each element in the AlCr thin film is Al 20 Cr 80 , and the composition of each element in FeCrAl is Fe 28 Cr 43 Al 29 , and the composition of each element in FeCrAlTiSiY is Fe 25 Cr 36 Al 24 Ti7Si4Y4. The preparation steps of the coating are as follows:

[0058] Step 1: Select 314L stainless steel as the substrate, polish it mechanically, clean it ultrasonically with acetone and alcohol, and dry it for later use.

[0059] Step 2: Load the substrate onto the sample stage.

[0060] Step 3: Place the Cr target and Al 20Cr 80 The targets are installed on the multi-arc source, and the Fe 37 Cr 38 Al 25 Target and Fe 28 Cr 27 Al 18 Ti 17 The Si5Y5 targets were respectively mounted on the magnetron sputtering cathodes, and the distance between the targets and the substrates was adjusted to 200 mm.

[0061] Step 4: Vacuum to 2×10 -4 pa, heat the substrate to 350℃, then introduce argon, control the argon flow rate to 50sccm, set the working pressure to 0.6Pa; turn on the DC bias power supply, adjust the sputtering bias to -700V, the sputtering time to 15min, and sputter clean the substrate.

[0062] Step 5: Turn on the Cr target pulse multi-arc sputtering power supply, set the sputtering current to 50 A, set the substrate bias to -200 V, control the sputtering time to 2 minutes, prepare a Cr film with a thickness of 18 nm on the substrate, and turn off the power after completion.

[0063] Step 6. Open Al 20 Cr 80 The target pulse sputtering power supply was set to 50A, the substrate bias was set to -200V, and the sputtering time was controlled to 3min. Al with a thickness of 21nm was prepared on the Cr film. 20 Cr 80 Film, turn off the power when finished.

[0064] Step 7. Open Fe 37 Cr 38 Al 25 Target and Fe 28 Cr 27 Al 18 Ti 17 Si5Y5 target DC sputtering power supply, set the sputtering power to 50W and 60W respectively, set the substrate bias to -200V, control the sputtering time of each to be 3min, and control the target front baffle to alternately deposit a single layer of FeCrAl film with a thickness of 18nm and a single layer of FeCrAlTiSiY film with a thickness of 24nm on the Cr / Al-Cr film. The total sputtering time is controlled to be 2 hours to form Fe 28 Cr 43 Al 29 / Fe 25 Cr 36 Al 24 Multilayer structure of Ti7Si4Y4 composite film.

[0065] Step 8: Turn off the sputtering and heating power supplies. Cool down the temperature to below 100 °C under the condition of molecular pump vacuum pumping. Turn off the molecular pump, turn off the power supply, and cool down to room temperature under natural vacuum. Then take out the sample, and a FeCrAl-based gradient nano-multilayered structure high-entropy alloy coating Cr / Al is formed on the substrate. 20 Cr 80 / (Fe 28 Cr 43 Al 29 / Fe 25 Cr 36 Al 24 Ti7Si4Y4) n , n = 20.

[0066] After testing, the coating obtained in this example has high film-substrate adhesion (87 MPa), high hardness (26 GPa), high wear resistance (wear rate of 1×10 -3 mg / Nm), and high thermal stability (800 °C).

[0067] Comparative Example 1

[0068] The difference between the coating of this comparative example and that of Example 1 is that no Cr thin film is set, and only an Al 20 Cr 80 thin film with a thickness of 21 nm and a (Fe 28 Cr 43 Al 29 / Fe 25 Cr 36 Al 24 Ti7Si4Y4) 60 nano-multilayer film are set. After testing, the performance parameters of the coating obtained in this comparative example are: film-substrate adhesion (51 MPa), hardness (28 GPa), wear resistance (wear rate of 1.5×10 -3 mg / Nm), and thermal stability (720 °C).

[0069] Comparative Example 2

[0070] The difference between the coating of this comparative example and that of Example 1 is that no Al 20 Cr 80 thin film is set, and only a Cr thin film with a thickness of 18 nm and a (Fe 28 Cr 43 Al 29 / Fe 25 Cr 36 Al 24 Ti7Si4Y4) 60Nanomultilayer film. After testing, the performance parameters of the coating obtained in this comparative example are: film-substrate adhesion (61 MPa), hardness (28 GPa), wear resistance (wear rate of 1.2×10 -3 mg / Nm), and thermal stability (730 °C).

[0071] Comparative Example 3

[0072] The difference between the coating of this comparative example and that of Example 1 is that the Al 20 Cr 80 thin film and the Cr thin film are not provided, and only a (Fe 28 Cr 43 Al 29 / Fe 25 Cr 36 Al 24 Ti7Si4Y4) with a thickness of 0.84 μm is provided 60 Nanomultilayer film. After testing, the performance parameters of the coating obtained in this comparative example are: film-substrate adhesion (48 MPa), hardness (28 GPa), wear resistance (wear rate of 2.2×10 -3 mg / Nm), and thermal stability (690 °C).

[0073] The above content is only an example and explanation of the structure of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the specific embodiments described or use similar methods to replace them. As long as they do not deviate from the structure of the invention or exceed the scope defined by this claim book, they should fall within the protection scope of the present invention.

Claims

1. A FeCrAl-based gradient nanomultilayered high-entropy alloy coating, characterized in that: The coating is a multi-layer structure of a FeCrAl / FeCrAlTiSiY composite film formed by sequentially depositing a Cr film and an AlCr film on a substrate, and then alternately depositing a single-layer FeCrAl film and a single-layer FeCrAlTiSiY film; among them, the Cr film and the AlCr film are deposited by a multi-arc ion plating method, and the single-layer FeCrAl film and the single-layer FeCrAlTiSiY film are deposited by a magnetron sputtering method.

2. The FeCrAl-based gradient nano-multilayered structure high-entropy alloy coating according to claim 1, wherein: The thickness of the Cr film is 10 - 20 nm; the thickness of the AlCr film is 20 - 30 nm; the thicknesses of the single-layer FeCrAl film and the single-layer FeCrAlTiSiY film are both between 1 nm and 30 nm; the number of layers of the FeCrAl / FeCrAlTiSiY composite film is n, and n is an integer greater than 2.

3. The FeCrAl-based gradient nanomultilayered structure high-entropy alloy coating according to claim 1, characterized in that: The composition of each element in the AlCr thin film by atomic ratio is Al x1 Cr y1 , where x1 + y1 = 100, 0 < x1 < 30, 25 < y1 < 85.

4. The FeCrAl-based gradient nano-multilayered structure high-entropy alloy coating according to claim 1, characterized in that: The composition of each element in the FeCrAl thin film by atomic ratio is Fe x2 Cr y2 Al z2 , where x2 + y2 + z2 = 100, and 20 < x2, y2, z2 < 50.

5. The FeCrAl-based gradient nanomultilayered high-entropy alloy coating according to claim 1, characterized in that: In the FeCrAlTiSiY thin film, the composition of each element according to the atomic ratio is Fe x3 Cr y3 Al z3 Ti k3 Si r3 Y p3 , where x3 + y3 + z3 + k3 + r3 + p3 = 100, and 0 < x3, y3, z3, k3, r3, p3 < 50.

6. A method for preparing the FeCrAl-based gradient nano-multilayered structure high-entropy alloy coating according to any one of claims 1 to 5, characterized in that, It includes the following steps: Step 1: The substrate is mechanically polished, ultrasonically cleaned, and dried for later use. Step 2: The substrate is loaded onto the sample stage. Step 3: The Cr target and the AlCr target are respectively installed on the multi-arc sources, and the FeCrAl target and the FeCrAlTiSiY target are respectively installed on the magnetron sputtering cathodes. The distance between the target and the substrate is adjusted to 150 - 300 mm. Step 4: Evacuate to 2×10 -4 Pa, heat the substrate to 200 - 450 °C, then introduce argon, control the argon flow rate to be 50 - 100 sccm, set the working gas pressure to 0.2 - 1.5 Pa; turn on the DC bias power supply, adjust the sputtering bias voltage to -500 V to -1000 V, and the sputtering time to be 10 - 15 min to perform sputtering cleaning on the substrate; Step 5: Turn on the pulsed multi-arc sputtering power supply of the Cr target, set the sputtering current to 30 - 60 A, set the substrate bias voltage to -200~-400 V, control the sputtering time for 1 - 3 min, prepare the Cr film on the substrate, and turn off the power supply after completion. Step 6: Turn on the pulsed sputtering power supply of the AlCr target, set the sputtering current to 30 - 70 A, set the substrate bias voltage to -200~-400 V, control the sputtering time for 1 - 10 min, prepare the AlCr film on the Cr film, and turn off the power supply after completion. Step 7: Turn on the DC sputtering power supplies of the FeCrAl target and the FeCrAlTiSiY target, set the sputtering powers to 50 - 100 W respectively, control their respective sputtering times to be 1 - 10 min respectively, alternately deposit a single-layer FeCrAl film and a single-layer FeCrAlTiSiY film on the Cr / Al-Cr film, control the total sputtering time to be 2 - 3 hours, and form a multi-layer structure of the FeCrAl / FeCrAlTiSiY composite film. Step 8: Turn off the sputtering and heating power supplies. Cool down the temperature to below 100 °C under the condition of pumping vacuum by the molecular pump. Turn off the molecular pump and the power supply. Cool it down to room temperature under natural vacuum, and then take out the sample, thus forming a FeCrAl-based gradient nanomultilayered structure high-entropy alloy coating Cr / AlCr / (FeCrAl / FeCrAlTiSiY) on the substrate n .

7. The preparation method according to claim 6, characterized in that: The substrate is selected from metal, ceramic or glass.

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