High-entropy alloy / high-entropy alloy carbonitride bilayer film

Abstract

This invention provides a high-entropy alloy / high-entropy alloy carbonitride bilayer thin film, relating to the field of high-entropy alloy carbonitride thin film technology. The high-entropy alloy / high-entropy alloy carbonitride thin film has a bilayer structure, comprising a lower TiNbCrZrMo high-entropy alloy thin film and an upper (TiNbCrZrMo)C... x N y High-entropy alloy carbonitride thin films, in which (TiNbCrZrMo)C x N y The high-entropy alloy carbonitride thin film exhibits a face-centered cubic crystal structure. This high-entropy alloy / high-entropy alloy carbonitride bilayer film was deposited using dual-target magnetron sputtering technology, with a TiNbCrZrMo high-entropy alloy transition layer and a (TiNbCrZrMo)C layer sequentially deposited from the inside out on the substrate surface. x N y High-entropy alloy carbonitride thin films. The high-entropy alloy carbonitride thin films of this invention exhibit high hardness, high elastic modulus, and good wear resistance. The peak hardness and elastic modulus reach 33.57 GPa and 303.88 GPa, respectively, with a minimum average friction coefficient of 0.32 and a minimum wear rate of 9.4 × 10⁻⁶. ‑7 mm 3 / (N·m).

Description

Technical Field

[0001] This invention provides a high-entropy alloy / high-entropy alloy carbonitride bilayer film, relating to the field of surface protection technology. Background Technology

[0002] In various mechanical systems, the surface properties of moving parts (such as bearing raceways and slide rails) directly determine the reliability, efficiency, and lifespan of the equipment. However, the losses caused by mechanical material failure due to friction and wear are enormous. Developing high-performance solid lubricating films is of significant engineering and scientific value for ensuring the long lifespan, high precision, and stable operation of high-end equipment.

[0003] Carbide films possess excellent properties such as high wear resistance and long service life, while nitride films combine excellent protective performance and high hardness, making them promising candidates for surface protection films. High-entropy alloys, with their diverse elemental composition and simple single-phase structure, offer vast development potential for novel material design. Therefore, introducing carbon and nitrogen into high-entropy alloy films facilitates the formation of high-hardness nitride ceramic phases and wear-resistant carbide ceramic phases, thereby reducing the film's wear rate and enhancing its durability. By combining high-entropy alloys with carbon and nitrogen elements, high-entropy carbonitride films can be constructed, combining the structural stability of high-entropy alloys with the high hardness and wear resistance of carbides and nitrides, showing broad application prospects in extreme environment protection films. In 2024, Yi and his team synthesized (TiZrNbMoTa)C using reactive magnetron sputtering technology. x N 1-x High-entropy alloy carbonitride coatings were developed, with the highest-percentage high-entropy carbonitride coating exhibiting a friction coefficient of 0.39. In 2025, LV et al. fabricated a hard and tough self-lubricating (TiZrHfNbTa)C coating using magnetron sputtering. x N y High-entropy carbonitride films with a minimum wear rate of 1.3 × 10⁻⁶. -6 mm 3 / Nm. The high-entropy alloy / high-entropy alloy carbonitride bilayer film synthesized in this application achieves synergistic optimization of hardness and wear resistance. Summary of the Invention

[0004] This invention provides a high-entropy alloy / high-entropy alloy carbonitride bilayer film, which solves the technical problem that high-entropy alloy films in the prior art cannot simultaneously possess high hardness and high wear resistance.

[0005] The present invention is achieved as follows: the film has a double-layer structure, including a lower high-entropy alloy film and an upper high-entropy alloy carbonitride film. The high-entropy alloy composition elements of the high-entropy alloy film are the same as those of the high-entropy alloy composition elements of the high-entropy alloy carbonitride film, both of which are strong carbonitride forming elements.

[0006] As a further preferred embodiment, the high-entropy alloy carbonitride film contains 56.24 at.% to 58.15 at.% of C atoms, 17.90 at.% to 21.04 at.% of N atoms, and 21.64 at.% to 25.86 at.% of high-entropy alloy.

[0007] As a further preferred embodiment, the high-entropy alloy is composed of Ti, Nb, Cr, Zr, and Mo.

[0008] As a further preferred embodiment, the thickness of the high-entropy alloy carbonitride film is 1.66~1.90 μm.

[0009] A method for preparing high-entropy alloy / high-entropy alloy carbonitride bilayer thin films includes the following steps: (1) Initial cleaning of the substrate; (2) Place the substrate obtained in step (1) into the coating chamber, draw a high vacuum, introduce inert gas, adjust the bias voltage, and perform a second cleaning. (3) Adjust the gas pressure, adjust the inert gas flux, and adjust the deposition gas pressure in sequence. Use TiNbCrZrMo pentagonal alloy target as target material to deposit high-entropy alloy thin film. Then adjust the deposition conditions. Use TiNbCrZrMo pentagonal alloy target and graphite target as target material and nitrogen as nitrogen source to deposit high-entropy alloy carbonitride thin film. (4) After the thin film deposition is completed, continue to evacuate for 30 minutes. After the chamber cools down, remove the substrate.

[0010] As a further preferred embodiment, in step (2), the substrate is placed on a rotating frame inside the coating cavity. The rotating frame remains stationary during the secondary cleaning and rotates at a constant speed during the deposition of the thin film.

[0011] As a further preferred embodiment, the rotational speed of the rotating frame is 6 r / min.

[0012] As a further preferred option, in step (3), the high-entropy alloy thin film deposition conditions are as follows: maintain a gas pressure of 0.45 Pa, an argon flow rate of 40 sccm, adjust the bias voltage to -120 V, and the duty cycle to 80%; turn on the DC power supply, control the current of the high-entropy alloy target at 2~3 A, and deposit for 10 min.

[0013] As a further preferred option, in step (3), the deposition conditions for high-entropy alloy carbonitride thin films are as follows: maintain a gas pressure of 0.3 Pa, an argon flow rate of 30 sccm, a nitrogen flow rate of 10 sccm, adjust the bias voltage to -150 V, and the duty cycle to 80%; control the current of the high-entropy alloy target with a DC power supply of 1.5~3.5 A, control the current of the graphite target with a medium-frequency power supply of 3~4 A, and deposit for 90 min.

[0014] As a further preferred option, in step (2), the secondary cleaning conditions are: vacuum pressure 4 × 10⁻⁶. -3 Pa, introduce argon gas, adjust the bias voltage to -600 V, and clean for 20 minutes.

[0015] The beneficial effects of this invention are as follows: High-entropy alloy / high-entropy alloy carbonitride bilayer films are prepared using magnetron sputtering technology. Strong carbonitride-forming elements are selected, as these elements readily form strong covalent bonds with carbon and nitrogen atoms. This allows the film to combine the advantages of high-entropy alloys, carbides, and nitrides, improving the film's mechanical properties, reducing the coefficient of friction, and enhancing wear resistance. The core advantage of the Ti, Nb, Cr, Zr, and Mo combination lies in its high-entropy effect. This application does not simply superimpose the properties of these strong carbonitride-forming elements, but rather achieves unique properties that are difficult to obtain in traditional single or binary systems through multi-principal element synergy. Attached Figure Description

[0016] Figure 1 This is a grazing incidence X-ray diffraction image of a thin film from Embodiment 1 of the present invention; Figure 2 This is a scanning electron microscope image of the thin film cross-section in Embodiment 2 of the present invention; Figure 3 This is a surface morphology diagram of the thin film in Embodiment 2 of the present invention; Figure 4 This is an elemental distribution diagram of the thin film of Embodiment 2 of the present invention; Figure 5 This is a surface morphology diagram of the thin film in Embodiment 3 of the present invention. Detailed Implementation

[0017] The high-entropy alloy / high-entropy alloy carbonitride bilayer film has a bilayer structure, including a lower high-entropy alloy film and an upper high-entropy alloy carbonitride film. The high-entropy alloy composition elements of the high-entropy alloy film are the same as those of the high-entropy alloy carbonitride film, both of which are strong carbonitride forming elements.

[0018] Further, in the high-entropy alloy carbonitride film, the C atom content is 56.24 at.%~58.15 at.%, the N atom content is 17.90 at.%~21.04 at.%, and the high-entropy alloy content is 21.64 at.%~25.86 at.%. In this application, the strong carbonitride agglomerates are selected from Ti, Nb, Cr, Zr, and Mo. Further, the thickness of the high-entropy alloy carbonitride film is 1.66~1.90 μm.

[0019] A method for preparing high-entropy alloy / high-entropy alloy carbonitride bilayer thin films includes the following steps: (1) For the initial cleaning of the substrate, a cleaning method known in the art can be used.

[0020] (2) Place the substrate obtained in step (1) into the coating chamber, draw a high vacuum, introduce inert gas, adjust the bias voltage, and perform a second cleaning. (3) Adjust the gas pressure, adjust the inert gas flux, and adjust the deposition gas pressure in sequence. Use TiNbCrZrMo pentagonal alloy target as target material to deposit high-entropy alloy thin film. Then adjust the deposition conditions. Use TiNbCrZrMo pentagonal alloy target and graphite target as target material and nitrogen as nitrogen source to deposit high-entropy alloy carbonitride thin film. (4) After the thin film deposition is completed, continue to evacuate for 30 minutes. After the chamber cools down, remove the substrate.

[0021] Furthermore, in step (2), the substrate is placed on a sample rotating frame with clamping function inside the coating chamber. The rotating frame remains stationary during the secondary cleaning and rotates at a uniform speed during film deposition. Furthermore, the rotation speed of the rotating frame is 6 r / min.

[0022] Further, in step (3), the high-entropy alloy thin film deposition conditions are as follows: maintain a gas pressure of 0.45 Pa, an argon flow rate of 40 sccm, adjust the bias voltage to -120 V, and the duty cycle to 80%; turn on the DC power supply, control the current of the high-entropy alloy target at 2~3 A, and deposit for 10 min.

[0023] Further, in step (3), the deposition conditions for high-entropy alloy carbonitride thin films are as follows: maintain a gas pressure of 0.3 Pa, an argon flow rate of 30 sccm, a nitrogen flow rate of 10 sccm, adjust the bias voltage to -150 V, and the duty cycle to 80%; control the current of the high-entropy alloy target with a DC power supply of 1.5~3.5 A, control the current of the graphite target with a medium-frequency power supply of 3~4 A, and deposit for 90 min.

[0024] Furthermore, in step (2), the secondary cleaning conditions are: vacuum pressure 4 × 10⁻⁶. -3 Pa, introduce argon gas, adjust the bias voltage to -600 V, and clean for 20 minutes.

[0025] The specific embodiments of the present invention will be further described below through specific examples.

[0026] The examples used a near equimolar ratio of TiNbCrZrMo pentagonal alloy target and a graphite target as the target materials, with both targets having a purity >99.99%. All examples used a dual-target magnetron sputtering technique to deposit thin films on silicon wafers and 9Cr18 steel blocks as substrates. The steel block was chosen as the substrate for testing the mechanical properties of the thin film, while the silicon wafer was chosen to facilitate testing the film thickness and cross-sectional SEM morphology. Those skilled in the art can choose other substrate materials as needed.

[0027] The test method for the hardness and elastic modulus of the thin film in the example is as follows: The hardness and elastic modulus of the (TiNbCrZrMo)C film were tested using a nanoindenter (Anton Paar). x N y The mechanical properties of high-entropy alloy carbonitride films were investigated using indentation curves. Specific test conditions included: a load of 8 mN, applied to the maximum load, held for 10 s, and then completely unloaded. To prevent the substrate from influencing the indentation results, the indentation depth was controlled to approximately 10%. Each sample was tested at least three times, and the average value was taken to ensure accurate results. The wear rate was tested using a CSM friction testing machine for (TiNbCrZrMo)C. x N y The tribological properties of high-entropy alloy carbonitride films were investigated using friction curves. Specific conditions: The friction test was conducted in an atmospheric environment in rotational mode, using Al2O3 ceramic spheres with a radius of 3 mm as the friction pair. Under a normal load of 2 N, the rotational frequency was 40 Hz, and the rotational friction test was performed at a speed of 120 r / min for 30 min. Each sample was tested three times. Example

[0028] (1) Select 9Cr18 steel blocks and silicon wafers as the workpieces to be plated, and put them into anhydrous ethanol and petroleum ether respectively for ultrasonic cleaning, 10 minutes each time, and clean three times each. After cleaning, use air to dry to remove surface contaminants. (2) Load the cleaned silicon wafer and 9Cr18 steel block onto the rotating frame inside the coating chamber, ensuring that it can rotate 360°, and close the vacuum chamber door; (3) Evacuate the coating vacuum chamber to 4×10 -3 Pa, keep the workpiece fixed, turn on the bias power supply, adjust the bias voltage to -600 V, introduce 110 sccm of argon gas, and clean for 20 minutes; (4) Maintain a gas pressure of 0.45 Pa, an argon flow rate of 40 sccm, adjust the bias voltage to -120 V, and the duty cycle to 80%; turn on the DC power supply, control the current of the high-entropy alloy target to 2 A, deposit for 10 min, and deposit a high-entropy alloy transition layer with a thickness of 600~700 nm on the surface of the workpiece. (5) Maintain a gas pressure of 0.30 Pa, an argon flow rate of 30 sccm, a nitrogen flow rate of 10 sccm, adjust the bias voltage to -150 V, and the duty cycle to 80%; control the current of the high-entropy alloy target with a DC power supply of 3.5 A, control the current of the graphite target with a medium-frequency power supply to 3 A, and deposit for 90 min to deposit (TiNbCrZrMo)C on the surface of the workpiece. x N y A high-entropy alloy carbonitride thin film with a thickness of 1.66 μm and X:Y = 2.7; (6) Turn off the high-entropy alloy target and graphite target, turn off the power and gas, allow it to cool naturally, and take out the plated part.

[0029] (7) The hardness and elastic modulus of the film in Example 1 were tested to be 22.71 GPa and 196.60 GPa, respectively, the coefficient of friction was 0.41, and the wear rate was 9.4 × 10⁻⁶. -7 mm 3 / (N·m).

[0030] The crystal structure of the high-entropy alloy carbonitride thin film on the upper layer of Example 1 was tested using a Rigaku Smartlab 9KW grazing incidence XRD (GIXRD) system from Japan. The test parameters were: grazing incidence angle of 1°; sample scan at an angle ranging from 20° to 80° within the 2θ range; and scan speed of 10° / min. (See also...) Figure 1 The upper layer (TiNbCrZrMo)C x N y High-entropy alloy carbonitride thin films have a face-centered cubic crystal structure. Example

[0031] (1) Select 9Cr18 steel blocks and silicon wafers as the workpieces to be plated, and put them into anhydrous ethanol and petroleum ether respectively for ultrasonic cleaning, 10 minutes each time, and clean three times each. After cleaning, use air to dry to remove surface contaminants. (2) Load the cleaned silicon wafer and 9Cr18 steel block onto the rotating frame inside the coating chamber, ensuring that it can rotate 360°, and close the vacuum chamber door; (3) Evacuate the coating vacuum chamber to 4×10 -3 Pa, keep the workpiece fixed; turn on the bias power supply, adjust the bias voltage to -600 V, introduce 110 sccm of argon gas, and clean for 20 minutes; (4) Maintain a gas pressure of 0.45 Pa, an argon flow rate of 40 sccm, adjust the bias voltage to -120 V, and the duty cycle to 80%; turn on the DC power supply, control the current of the high-entropy alloy target at 2.5 A, deposit for 10 min, and deposit a high-entropy alloy transition layer on the surface of the workpiece. The thickness of the transition layer is 600~700 nm. (5) Maintain a gas pressure of 0.30 Pa, an argon flow rate of 30 sccm, a nitrogen flow rate of 10 sccm, adjust the bias voltage to -150 V, and the duty cycle to 80%; control the current of the high-entropy alloy target with a DC power supply of 2.5 A and the current of the graphite target with a medium-frequency power supply of 4 A, and deposit for 90 min to deposit (TiNbCrZrMo)C on the surface of the high-entropy alloy transition layer. x N y A high-entropy alloy carbonitride thin film with a thickness of 1.88 μm and X:Y = 3.1; (6) Turn off the high-entropy alloy target and graphite target, turn off the power and gas, allow it to cool naturally, and take out the plated part.

[0032] (7) The film's hardness and elastic modulus were tested to be 33.57 GPa and 303.88 GPa, respectively, with a friction coefficient of 0.49 and a wear rate of 1.15 × 10⁻⁶. -6 mm 3 / (N·m).

[0033] To analyze the cross-sectional morphology and thickness of the thin film, samples were prepared using a standard metallographic sample preparation process (cutting, mounting, grinding, and polishing). After gold sputtering, the prepared cross-sectional samples were observed using a JSM-7900F scanning electron microscope. x N y Surface morphology and cross-section of high-entropy alloy carbonitride thin films. (See also...) Figure 2 Example 2 (TiNbCrZrMo)C x N y The cross-section of high-entropy alloy carbonitride thin films typically exhibits a columnar crystalline structure. (See also...) Figure 3 (TiNbCrZrMo)C x N y Surface morphology of high-entropy alloy carbonitride films, such as Figure 3 The SEM images show uniform and continuous coverage with no obvious defects, and all film surfaces are smooth and flat. (See also...) Figure 4 (TiNbCrZrMo)C x N y The elemental distribution of high-entropy alloy carbonitride thin films was obtained by EDS surface scanning analysis, yielding elemental distribution maps of Ti, Nb, Cr, Zr, and Mo. All elements were uniformly distributed and granular. Example

[0034] (1) Select 9Cr18 steel blocks and silicon wafers as the workpieces to be plated, and put them into anhydrous ethanol and petroleum ether respectively for ultrasonic cleaning, 10 minutes each time, and clean three times each. After cleaning, use air to dry to remove surface contaminants. (2) Load the cleaned silicon wafer and 9Cr18 steel block onto the rotating frame inside the coating chamber, ensuring that it can rotate 360°, and close the vacuum chamber door; (3) Evacuate the coating vacuum chamber to 4×10 -3 Pa, keep the workpiece fixed; turn on the bias power supply, adjust the bias voltage to -600 V, introduce 110 sccm of argon gas, and clean for 20 minutes; (4) Maintain a gas pressure of 0.45 Pa, an argon flow rate of 40 sccm, adjust the bias voltage to -120 V, and the duty cycle to 80%; turn on the DC power supply, control the current of the high-entropy alloy target to 3 A, deposit for 10 min, and deposit a high-entropy alloy transition layer on the surface of the workpiece. The thickness of this transition layer is 600~700 nm. (5) Maintain a gas pressure of 0.30 Pa, an argon flow rate of 30 sccm, a nitrogen flow rate of 10 sccm, adjust the bias voltage to -150 V, and the duty cycle to 80%; control the current of the high-entropy alloy target with a DC power supply of 1.5 A, control the current of the graphite target with a medium-frequency power supply to 3.5 A, and deposit for 90 min to deposit (TiNbCrZrMo)C on the surface of the workpiece. x N y A high-entropy alloy carbonitride thin film with a thickness of 1.90 μm and X:Y = 2.9; (6) Turn off the high-entropy alloy target and graphite target, turn off the power and gas, allow it to cool naturally, and take out the plated part.

[0035] (7) The film's hardness and elastic modulus were tested to be 19.73 GPa and 231.71 GPa, respectively, with a friction coefficient of 0.32 and a wear rate of 1.43 × 10⁻⁶. -6 mm 3 / (N·m).

[0036] Example 3 (TiNbCrZrMo)C x N y Surface morphology of high-entropy alloy carbonitride films, such as Figure 5 The SEM images show uniform and continuous coverage with no obvious defects, and all film surfaces are smooth and flat.

[0037] The beneficial effects of this invention are as follows: High-entropy alloy / high-entropy alloy carbonitride bilayer films are prepared using magnetron sputtering technology. Strong carbonitride-forming elements are selected, as these elements readily form strong covalent bonds with carbon and nitrogen atoms. This allows the film to combine the advantages of high-entropy alloys, carbides, and nitrides, improving the film's mechanical properties, reducing the coefficient of friction, and enhancing wear resistance. The core advantage of the Ti, Nb, Cr, Zr, and Mo combination lies in its high-entropy effect. This application does not simply superimpose the properties of these strong carbonitride-forming elements, but rather achieves unique properties that are difficult to obtain in traditional single or binary systems through multi-principal element synergy.

Claims

1. A high-entropy alloy / high-entropy alloy carbonitride bilayer thin film, characterized in that, The film has a double-layer structure, including a lower high-entropy alloy film and an upper high-entropy alloy carbonitride film. The high-entropy alloy composition elements of the high-entropy alloy film are the same as those of the high-entropy alloy carbonitride film, both of which are strong carbonitride forming elements.

2. The high-entropy alloy / high-entropy alloy carbonitride bilayer thin film according to claim 1, characterized in that, The high-entropy alloy carbonitride film contains 56.24 at.% to 58.15 at.% of C atoms, 17.90 at.% to 21.04 at.% of N atoms, and 21.64 at.% to 25.86 at.% of high-entropy alloy.

3. The high-entropy alloy / high-entropy alloy carbonitride bilayer thin film according to claim 2, characterized in that, The high-entropy alloy is composed of Ti, Nb, Cr, Zr, and Mo.

4. The high-entropy alloy / high-entropy alloy carbonitride bilayer thin film according to claim 1, characterized in that, The thickness of the high-entropy alloy carbonitride film is 1.66–1.90 μm.

5. The method for preparing a high-entropy alloy / high-entropy alloy carbonitride bilayer thin film as described in claim 1, characterized in that, Includes the following steps: (1) Initial cleaning of the substrate; (2) Place the substrate obtained in step (1) into the coating chamber, draw a high vacuum, introduce inert gas, adjust the bias voltage, and perform a second cleaning. (3) Adjust the gas pressure, adjust the inert gas flux, and adjust the deposition gas pressure in sequence. Use TiNbCrZrMo pentagonal alloy target as target material to deposit high-entropy alloy thin film. Then adjust the deposition conditions. Use TiNbCrZrMo pentagonal alloy target and graphite target as target material and nitrogen as nitrogen source to deposit high-entropy alloy carbonitride thin film. (4) After the thin film deposition is completed, continue to evacuate for 30 minutes. After the chamber cools down, remove the substrate.

6. The preparation method according to claim 5, characterized in that, In step (2), the substrate is placed on a rotating frame inside the coating chamber. The rotating frame remains stationary during the secondary cleaning and rotates at a constant speed during the deposition of the thin film.

7. The preparation method according to claim 6, characterized in that, The rotational speed of the rotating frame is 6 r / min.

8. The preparation method according to claim 5, characterized in that, In step (3), the high-entropy alloy thin film deposition conditions are as follows: maintain a gas pressure of 0.45 Pa, an argon flow rate of 40 sccm, adjust the bias voltage to -120 V, and the duty cycle to 80%. Turn on the DC power supply, control the current of the high-entropy alloy target at 2~3A, and deposit for 10 minutes.

9. The preparation method according to claim 5, characterized in that, In step (3), the deposition conditions for high-entropy alloy carbonitride thin films are as follows: maintain a gas pressure of 0.3 Pa, an argon flow rate of 30 sccm, a nitrogen flow rate of 10 sccm, adjust the bias voltage to -150 V, and the duty cycle to 80%; control the current of the high-entropy alloy target with a DC power supply of 1.5~3.5 A, control the current of the graphite target with a medium-frequency power supply of 3~4 A, and deposit for 90 min.

10. The preparation method according to claim 5, characterized in that, In step (2), the secondary cleaning conditions are: vacuum pressure 4×10 -3 Pa, introduce argon gas, adjust the bias voltage to -600 V, and clean for 20 minutes.

Images