Diamond nanocrystalline / amorphous carbon composite lubricating film, solid lubricating film and preparation method and application of diamond nanocrystalline / amorphous carbon composite lubricating film

Abstract

The invention relates to the technical field of nano composite films and solid lubrication, and provides a diamond nanocrystalline / amorphous carbon composite lubrication film, a solid lubrication film and a preparation method and application of the diamond nanocrystalline / amorphous carbon composite lubrication film and the solid lubrication film. The diamond nanocrystalline / amorphous carbon composite lubricating film provided by the invention comprises an amorphous carbon film and diamond nanocrystalline embedded in the amorphous carbon film. The diamond has excellent mechanical strength and temperature resistance, and the diamond in the amorphous carbon film is of an ordered nanocrystalline structure and can play a role of a reinforcing agent, so that the mechanical property and the temperature resistance of the amorphous carbon film are remarkably improved, and the lubricating film can be lubricated in vacuum (lt; the excellent lubricating property is kept in an environment with a wide temperature range (-200 to 600 DEG C) of 5.0 * 10 <-3 > Pa. The diamond nanocrystalline / amorphous carbon composite lubricating film provided by the invention can be widely applied to surface lubricating treatment of moving parts in vacuum high-low temperature and wide temperature range environments of aviation, aerospace, high-end equipment and the like, and has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of nano-composite films and solid lubrication, and in particular to a diamond nano-crystal / amorphous carbon composite lubricating film, a solid lubricating film, and a preparation method and application thereof. Background Art

[0002] With the development of aviation, aerospace, and high-tech, more and more moving parts are facing service environments involving extreme low temperatures (-200°C), alternating high and low temperatures (-200 to 600°C), and wide temperature ranges (-200 to 600°C). For example, the gears and bearings of liquid hydrogen and liquid oxygen engine pumps must operate at ultra-low temperatures of -200°C. Spacecraft face alternating high and low temperature environments in space, with temperatures in low-Earth orbit ranging from -150°C to 150°C. The surface temperature of the moon fluctuates between -180°C and 150°C. Deep space probes to Mercury and Venus face temperatures exceeding 500°C. The operating temperature of gears and bearings in aviation transmission systems will reach 300°C, and the service temperature of control bearings for near-space vehicles will reach over 500°C. Therefore, reliable and long-life lubrication of moving mechanisms in extreme low temperatures, alternating high and low temperatures, and wide temperature ranges is one of the key technologies for the development of high-end equipment.

[0003] Currently, moving mechanisms are typically lubricated with grease or solid lubricant films. However, grease solidifies at low temperatures (-60°C) and degrades at high temperatures (>240°C), leading to lubrication failure. Commonly used solid lubricant films, such as MoS2 and diamond-like carbon-based films, experience a friction coefficient that at least doubles at low temperatures (below -100°C) and oxidative failure at temperatures exceeding 300°C. NASA's Glene Research Center began researching wide-temperature range self-lubricating materials in the 1970s, developing the PM series of self-lubricating composite materials and the PS series of thermal spray self-lubricating coatings, achieving continuous lubrication from room temperature to 800°C. However, these coatings exhibited friction coefficients exceeding 0.3, resulting in poor lubrication performance. Furthermore, wide-temperature range lubricants are primarily designed for use in atmospheric environments, from room temperature to 800°C, with limited research on their lubrication performance under extreme low-temperature conditions in vacuum environments. In extreme low-temperature environments, the microstructure, mechanical properties, and interactions of solid lubricants with the environment undergo significant changes, significantly differing from the design concepts and preparation methods of traditional wide-temperature range lubricants.

[0004] In summary, there is an urgent need to provide a self-lubricating material with good lubrication performance and good high and low temperature resistance. Summary of the Invention

[0005] In view of this, the present invention provides a diamond nanocrystalline / amorphous carbon composite lubricating film, a solid lubricating film, and a preparation method and application thereof. The diamond nanocrystalline / amorphous carbon composite lubricating film provided by the present invention has excellent lubricating properties and good temperature resistance. -3 Pa) can maintain excellent lubrication performance under wide temperature range (-200~600℃).

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] A diamond nanocrystal / amorphous carbon composite lubricating film comprises an amorphous carbon film and diamond nanocrystals embedded in the amorphous carbon film.

[0008] Preferably, the thickness of the diamond nanocrystalline / amorphous carbon composite lubricating film is 1000-3000 nm.

[0009] The present invention also provides a solid lubricating film, comprising a transition layer, a bearing layer and a lubricating layer arranged in sequence from bottom to top, wherein the lubricating layer is the diamond nanocrystalline / amorphous carbon composite lubricating film described in the above scheme; the transition layer is titanium and / or chromium; and the bearing layer is WC.

[0010] Preferably, the thickness of the transition layer is 400-800 nm, and the thickness of the supporting layer is 800-1500 nm.

[0011] The present invention also provides a method for preparing the solid lubricating film described in the above scheme, comprising the following steps:

[0012] After cleaning the substrate, ion source etching is performed to obtain an activated substrate;

[0013] A transition layer and a bearing layer are sequentially prepared on the surface of the activated substrate by a magnetron sputtering method;

[0014] Acetylene is used as a carbon source, and a diamond nanocrystalline / amorphous carbon composite lubricating film is prepared on the surface of the bearing layer by plasma-enhanced chemical vapor deposition. The operating conditions of the plasma-enhanced chemical vapor deposition method include: an acetylene flow rate of 400 to 800 sccm, a deposition gas pressure of 0.5 to 0.8 Pa, and a DC power supply voltage of 600 to 800 V.

[0015] Preferably, the cleaning comprises: placing the substrate in petroleum ether and acetone in sequence for ultrasonic treatment, wherein the ultrasonic treatment time in the petroleum ether is 10 to 20 minutes, and the ultrasonic treatment time in the acetone is 10 to 20 minutes.

[0016] Preferably, the ion source etching conditions include: the etching gas is argon, the vacuum degree is not greater than 6.0×10 -3 Pa, the deposition gas pressure is 0.04-0.08 Pa, the substrate negative bias voltage is 200-400 V, the ion source current is 50-80 A, and the etching time is 20-40 min.

[0017] Preferably, the conditions for preparing the transition layer by magnetron sputtering include: the sputtering gas is argon, the deposition pressure is 0.1-0.3 Pa, the substrate negative bias voltage is 80-150 V, and the sputtering target is a titanium target and / or a chromium target.

[0018] Preferably, the conditions for preparing the carrier layer by magnetron sputtering include: the sputtering gas is argon, the deposition pressure is 0.1-0.3 Pa, the substrate negative bias voltage is 80-150 V, and the sputtering target is a WC target.

[0019] The present invention also provides the use of the diamond nanocrystalline / amorphous carbon composite lubricating film described in the above scheme, the solid lubricating film described in the above scheme, or the solid lubricating film prepared by the preparation method described in the above scheme in a vacuum environment; the vacuum degree of the vacuum environment is less than 5.0×10 -3 Pa, temperature is -200~600℃.

[0020] The present invention provides a diamond nanocrystal / amorphous carbon composite lubricating film, comprising an amorphous carbon film and diamond nanocrystals embedded in the amorphous carbon film. Diamond itself has excellent mechanical strength and heat resistance, and the diamond in the amorphous carbon film exhibits an ordered nanocrystalline structure, which can act as a reinforcing agent, significantly improving the mechanical properties and heat resistance of the amorphous carbon film, enabling the lubricating film to withstand high temperatures in a vacuum (<5.0×10 -3 Pa) maintains excellent lubrication properties in a wide temperature range (-200 to 600°C). The diamond nanocrystalline / amorphous carbon composite lubricating film provided by this invention can be widely used in the surface lubrication of moving parts (such as bearings, gears, and slide rails) in vacuum, high-temperature, and wide-temperature environments in aviation, aerospace, and high-end equipment, and has broad application prospects.

[0021] The present invention also provides a solid lubricating film comprising a transition layer, a bearing layer, and a lubricating layer, arranged sequentially from bottom to top. The lubricating layer is the diamond nanocrystalline / amorphous carbon composite lubricating film described in the above-mentioned embodiment; the transition layer is titanium and / or chromium; and the bearing layer is WC. By providing the transition layer and the bearing layer, the present invention improves the bonding strength (no less than 35N) and the load-bearing capacity (no less than 10GPa) of the diamond nanocrystalline / amorphous carbon composite lubricating film to the substrate, further ensuring its lubricating performance in a vacuum environment with a wide temperature range.

[0022] The present invention also provides a method for preparing the solid lubricating film described in the above-mentioned scheme. The method involves cleaning a substrate and then subjecting it to ion etching to obtain an activated substrate. A transition layer and a supporting layer are then sequentially formed on the surface of the activated substrate using magnetron sputtering. A diamond nanocrystal / amorphous carbon composite lubricating film is then formed on the surface of the supporting layer using plasma-enhanced chemical vapor deposition (PECVD) using acetylene as a carbon source. The method utilizes acetylene as a carbon source and controls the acetylene flow rate, deposition pressure, and DC power supply voltage to ensure sufficient energy to decompose the acetylene. This, in turn, ensures that the generated plasma also has sufficient energy to form diamond nanocrystals, ultimately resulting in a nanocomposite structure in which diamond nanocrystals are embedded in the amorphous carbon film. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a high-resolution transmission electron topography image of the diamond nanocrystalline / amorphous carbon composite lubricating film prepared in Example 1;

[0024] Figure 2 The friction coefficient of the diamond nanocrystalline / amorphous carbon composite lubricating film prepared in Example 1 varies with the number of sliding times at -200°C to room temperature under vacuum;

[0025] Figure 3 The friction coefficient of the diamond nanocrystalline / amorphous carbon composite lubricating film prepared in Example 1 varies with the number of sliding times at room temperature to 600°C under vacuum;

[0026] Figure 4 The results of the bonding strength test of the diamond nanocrystalline / amorphous carbon composite lubricating film prepared on the surface of M2 high-speed steel are shown;

[0027] Figure 5 The load-bearing performance test results of diamond nanocrystalline / amorphous carbon composite lubricating films prepared on different substrate surfaces. DETAILED DESCRIPTION

[0028] The present invention provides a diamond nanocrystal / amorphous carbon composite lubricating film, comprising an amorphous carbon film and diamond nanocrystals embedded in the amorphous carbon film.

[0029] In the present invention, the thickness of the diamond nanocrystalline / amorphous carbon composite lubricating film is 1000-3000 nm, specifically 1000 nm, 2000 nm or 3000 nm.

[0030] The present invention also provides a solid lubricating film, comprising a transition layer, a bearing layer and a lubricating layer arranged in sequence from bottom to top, wherein the lubricating layer is the diamond nanocrystalline / amorphous carbon composite lubricating film described in the above scheme; the transition layer is titanium and / or chromium; and the bearing layer is WC (tungsten carbide).

[0031] In the present invention, the thickness of the transition layer is preferably 400 to 800 nm, specifically 400 nm, 600 nm, or 800 nm, and the thickness of the bearing layer is preferably 800 to 1500 nm, specifically 800 nm, 1200 nm, or 1500 nm. By providing the transition layer and the bearing layer, the present invention can improve the bonding strength and load-bearing capacity of the diamond nanocrystalline / amorphous carbon composite lubricating film to the substrate.

[0032] In the present invention, the solid lubricating film is a black, dense and smooth film; the hardness of the solid lubricating film is preferably 22 to 26 GPa, and the friction coefficient in a vacuum environment at -200 to 600° C. is 0.03 to 0.29.

[0033] The present invention also provides a method for preparing the diamond nanocrystalline / amorphous carbon composite lubricating film described in the above scheme, comprising the following steps:

[0034] After cleaning the substrate, ion source etching is performed to obtain an activated substrate;

[0035] A transition layer and a bearing layer are sequentially prepared on the surface of the activated substrate by a magnetron sputtering method;

[0036] Acetylene is used as a carbon source, and a diamond nanocrystalline / amorphous carbon composite lubricating film is prepared on the surface of the bearing layer by plasma-enhanced chemical vapor deposition. The operating conditions of the plasma-enhanced chemical vapor deposition method include: an acetylene flow rate of 400 to 800 sccm, a deposition gas pressure of 0.5 to 0.8 Pa, and a DC power supply voltage of 600 to 800 V.

[0037] The present invention cleans the substrate and then etches it with an ion source to obtain an activated substrate. In the present invention, the substrate is preferably made of metal, specifically steel or an alloy, specifically a titanium alloy; in a specific embodiment of the present invention, the substrate can be a bearing, a gear, or a slide rail; the cleaning preferably includes: sequentially placing the substrate in petroleum ether and acetone for ultrasonic treatment, wherein the ultrasonic treatment time in the petroleum ether is preferably 10 to 20 minutes, specifically 10 minutes, 15 minutes, or 20 minutes, and the ultrasonic treatment time in the acetone is preferably 10 to 20 minutes, specifically 10 minutes, 15 minutes, or 20 minutes.

[0038] In the present invention, the conditions for ion source etching preferably include: the etching gas is preferably argon, the vacuum degree is not greater than 6.0×10 -3 Pa, specifically 3.0×10 -3 Pa, 4.0×10 -3 Pa or 5.0×10 -3Pa, the deposition gas pressure is preferably 0.04~0.08Pa, specifically 0.04Pa, 0.06Pa or 0.08Pa, the substrate negative bias is preferably 200~400V, specifically 200V, 300V or 400V, the ion source current is preferably 50~80A, specifically 50A, 70A or 80A, and the etching time is preferably 20~40min, specifically 20min, 30min or 40min.

[0039] In a specific embodiment of the present invention, the cleaned substrate is preferably moved into a vacuum deposition chamber and fixed on a rotating rack connected to a bias power supply, and then the vacuum deposition chamber is evacuated to a pressure of no more than 6.0×10 -3 Pa, high-purity argon gas is introduced, the deposition gas pressure is controlled and a negative bias voltage is applied to the plated substrate, and the ion source current is controlled to perform ion source etching; the present invention removes impurities and pollutants remaining on the substrate surface through ion source etching and activates the substrate at the same time.

[0040] After obtaining an activated substrate, the present invention sequentially forms a transition layer and a supporting layer on the surface of the activated substrate using magnetron sputtering. In the present invention, the conditions for forming the transition layer using magnetron sputtering preferably include: argon as the sputtering gas; a deposition pressure of 0.1 to 0.3 Pa, specifically 0.1 Pa, 0.2 Pa, or 0.3 Pa; a substrate negative bias voltage of preferably 80 to 150 V, specifically 80 V, 120 V, or 150 V; and a sputtering palladium material preferably being a titanium target and / or a chromium target.

[0041] In the present invention, the conditions for preparing the carrier layer by magnetron sputtering preferably include: the sputtering gas is argon, the deposition pressure is 0.1-0.3 Pa, specifically 0.1 Pa, 0.2 Pa, or 0.3 Pa, the substrate negative bias voltage is preferably 80-150 V, specifically 80 V, 120 V, or 150 V; and the target material for the magnetron sputtering is a WC target. In a specific embodiment of the present invention, argon gas is preferably first introduced into the vacuum deposition chamber, the deposition pressure is controlled, a negative bias voltage is applied to the activated substrate, and then the sputtering power supply of the transition layer sputtering target is turned on to deposit the transition layer. After the transition layer is deposited, the sputtering power supply of the transition layer sputtering target is turned off, and the sputtering power supply of the carrier layer sputtering target is turned on to begin sputtering the carrier layer.

[0042] After preparing the carrier layer, the present invention uses acetylene as a carbon source to deposit a diamond nanocrystal / amorphous carbon composite lubricating film on the carrier layer surface via plasma-enhanced chemical vapor deposition (PECVD). In the present invention, the operating conditions of the PECVD process include: an acetylene flow rate of 400 to 800 sccm, specifically 400 sccm, 600 sccm, or 800 sccm; a deposition gas pressure of 0.5 to 0.8 Pa, specifically 0.5 Pa, 0.6 Pa, or 0.8 Pa; and a DC power supply voltage of 600 to 800 V, specifically 600 V, 700 V, or 800 V. In the present invention, increasing the acetylene flow rate and the deposition gas pressure increases the PECVD voltage, thereby ensuring sufficient energy to crack the acetylene and generating sufficient plasma energy to form diamond nanocrystals. By controlling the PECVD process parameters within the aforementioned ranges, the present invention can produce a nanocomposite structure in which diamond nanocrystals are embedded in an amorphous carbon film.

[0043] The present invention also provides the use of the diamond nanocrystal / amorphous carbon composite lubricating film described in the above scheme or the diamond nanocrystal / amorphous carbon composite lubricating film prepared by the preparation method described in the above scheme in a vacuum environment; the vacuum degree of the vacuum environment is less than 5.0×10 -3 Pa, temperature is -200~600℃.

[0044] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0045] Example 1

[0046] (1) The substrate to be plated (bearing ring) is placed in petroleum ether and acetone for ultrasonic cleaning for 10 minutes respectively, and then moved into the vacuum deposition chamber and fixed on a turntable connected to a bias power supply.

[0047] (2) Evacuate the vacuum deposition chamber to 5.0×10 -3 Pa; high-purity argon gas (purity of 99.9%) was introduced, the deposition pressure was controlled at 0.08 Pa, a negative bias of 400 V was applied to the plated substrate (bearing ring), the ion source current was controlled at 80 A, and ion source etching was performed for 20 minutes to remove impurities and contaminants remaining on the surface.

[0048] (3) Argon gas was introduced, and the deposition pressure was controlled at 0.3 Pa. A negative bias voltage of 150 V was applied to the substrate (bearing ring). The chromium target sputtering power supply was turned on to deposit a chromium transition layer with a thickness of 800 nm. The WC target sputtering power supply was turned on to deposit a WC bearing layer with a thickness of 1500 nm.

[0049] (4) Turn off the argon flow and introduce acetylene, controlling the acetylene flow rate to 800 sccm and the deposition pressure to 0.8 Pa; turn on the DC power supply and control the voltage to 800 V. Prepare a diamond nanocrystalline / amorphous carbon composite lubricating film with a thickness of 3000 nm.

[0050] The obtained solid lubricating film has a black, dense and smooth appearance, a film thickness of 5300 nm, and a hardness of 26.0 GPa (tested by a nanoindenter).

[0051] Example 2

[0052] (1) The substrate to be plated (gear tooth surface) is placed in petroleum ether and acetone for ultrasonic cleaning for 20 minutes respectively, and then moved into the vacuum deposition chamber and fixed on a turntable connected to a bias power supply.

[0053] (2) Evacuate the vacuum deposition chamber to 3.0×10 -3 Pa; high-purity argon gas was introduced, the deposition pressure was controlled at 0.04 Pa, a negative bias of 200 V was applied to the plated substrate (gear tooth surface), the ion source current was controlled at 50 A, and ion source etching was performed for 40 minutes to remove impurities and contaminants remaining on the surface.

[0054] (3) Argon gas was introduced, and the deposition pressure was controlled at 0.1 Pa. A negative bias voltage of 80 V was applied to the substrate (gear tooth surface). The chromium target sputtering power supply was turned on to deposit a chromium transition layer with a thickness of 400 nm. The WC target sputtering power supply was turned on to deposit a WC carrier layer with a thickness of 800 nm.

[0055] (4) Turn off the argon flow and introduce acetylene, controlling the acetylene flow rate to 400 sccm and the deposition pressure to 0.5 Pa; turn on the DC power supply and control the voltage to 600 V. Prepare a diamond nanocrystalline / amorphous carbon composite lubricating film with a thickness of 1000 nm.

[0056] The obtained solid lubricating film has a black, dense and smooth appearance, a film thickness of 2200 nm, and a hardness of 22.4 GPa (tested by a nanoindenter).

[0057] Example 3

[0058] (1) The substrate to be plated (titanium alloy slide rail) was placed in petroleum ether and acetone for ultrasonic cleaning for 15 minutes respectively, and then moved into the vacuum deposition chamber and fixed on a turntable connected to a bias power supply.

[0059] (2) Evacuate the vacuum deposition chamber to 4.0×10 -3 Pa; high-purity argon gas was introduced, the deposition pressure was controlled at 0.06 Pa, a negative bias of 300 V was applied to the plated substrate (titanium alloy slide), the ion source current was controlled at 70 A, and ion source etching was performed for 30 minutes to remove impurities and contaminants remaining on the surface.

[0060] (3) Argon gas was introduced, and the deposition pressure was controlled at 0.2 Pa. A negative bias voltage of 120 V was applied to the substrate to be plated (titanium alloy slide rail). The titanium target sputtering power supply was turned on to deposit a titanium transition layer with a thickness of 600 nm. The WC target sputtering power supply was turned on to deposit a WC carrier layer with a thickness of 1200 nm.

[0061] (4) Turn off the argon flow and introduce acetylene, controlling the acetylene flow rate to 600 sccm and the deposition pressure to 0.6 Pa; turn on the DC power supply and control the voltage to 700 V. Prepare a diamond nanocrystalline / amorphous carbon composite lubricating film with a thickness of 2000 nm.

[0062] The obtained solid lubricating film has a black, dense and smooth appearance, a film thickness of 3800 nm, and a hardness of 24.6 GPa (tested by a nanoindenter).

[0063] Performance testing:

[0064] 1. Structural characterization

[0065] The diamond nanocrystalline / amorphous carbon composite lubricating film prepared in Example 1 was characterized by high-resolution transmission electron microscopy. Figure 1 As shown. Figure 1 It can be seen that the film is a nanocomposite structure in which diamond nanocrystals are embedded in an amorphous carbon film.

[0066] 2. Vacuum wide temperature range tribological performance test

[0067] (1) Low temperature tribological performance test

[0068] The tribological properties of the solid lubricating film prepared in Example 1 were tested under different low temperature conditions in a vacuum environment. The specific test conditions are as follows:

[0069] Use vacuum ultra-low temperature ball-disc friction tester to control the vacuum degree <5×10 -3 Pa, the temperature is controlled at -50℃, -100℃, -150℃, and -200℃ respectively by GM refrigerator, the friction pair is Φ6mm Al2O3 ceramic ball, the contact pressure is 2N, the rotation speed is 150rpm, and the test results are as follows Figure 2 As shown. Figure 2It can be seen that at low temperatures of -50℃, -100℃, -150℃ and -200℃, the average friction coefficients of the solid lubricating film are 0.13, 0.06, 0.03 and 0.07 respectively, showing good lubrication performance and good stability of the friction coefficient. When the number of sliding times is 10,000 times, the friction coefficient changes very little.

[0070] (2) High temperature tribological performance test

[0071] The tribological properties of the solid lubricating film prepared in Example 1 were tested under different high temperature conditions in a vacuum environment. The specific test conditions are as follows:

[0072] Use vacuum high temperature ball-disc friction tester to control vacuum degree <5×10 -3 Pa, the temperature is controlled at room temperature, 100℃, 200℃, 300℃, 400℃, 500℃, and 600℃ respectively by resistance wire heating, the friction pair is Φ6mm Al2O3 ceramic ball, the contact pressure is 2N, and the rotation speed is 150rpm. The test results are as follows Figure 3 As shown. Figure 3 It can be seen that at room temperature, 100℃, 200℃, 300℃, 400℃, 500℃ and 600℃, the average friction coefficient of the solid lubricating film is 0.29, 0.28, 0.18, 0.13, 0.12, 0.09 and 0.08, respectively, showing good lubrication performance.

[0073] The same tribological performance test was performed on the diamond nanocrystalline / amorphous carbon composite lubricating films prepared in Example 2 and Example 3. The results were similar to those in Example 1, and both films showed good lubrication performance in a vacuum and wide temperature range (-200 to 600°C).

[0074] (3) Bonding strength and load-bearing performance test

[0075] According to the preparation method of Example 2, a transition layer, a bearing layer and a diamond nanocrystalline / amorphous carbon composite lubricating film were prepared on the surface of M2 high-speed steel in sequence, and the bonding strength of the film was tested. The results are as follows: Figure 4 As shown, the bonding force is 47N, indicating that the film has good bonding strength with the substrate.

[0076] The preparation method of Example 2 was used to sequentially prepare a transition layer, a load-bearing layer, and a diamond nanocrystalline / amorphous carbon composite lubricating film on the surfaces of different substrates (9Cr18 substrate, bearing steel substrate, high-speed steel substrate, and titanium alloy substrate), and the load-bearing performance was tested. The test method is as follows: On a universal material testing machine, a φ8mm GCr15 ball was used to apply a load of 10GPa contact stress to the film-based system, holding the load for 3 minutes, and observing the indentation morphology. The results are as follows: Figure 5 As shown. Figure 5 The results show that under a contact stress of 10 GPa, the film has no cracks and peeling, indicating that the diamond nanocrystalline / amorphous carbon composite lubricating films deposited on different substrates have good load-bearing properties.

[0077] In summary, the diamond nanocrystalline / amorphous carbon composite lubricating film provided by the present invention has good lubrication properties, mechanical properties and temperature resistance, can maintain good tribological properties under vacuum and wide temperature range conditions, can adapt to service environments of extreme low temperature (-200°C), high and low temperature alternation (-200~600°C) and wide temperature range (-200~600°C), and can be used in aviation, aerospace, high-end equipment, etc. in vacuum, high and low temperature and wide temperature range environments. The surface lubrication treatment of moving parts (such as bearings, gears, and slide rails) has broad application prospects.

[0078] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A diamond nanocrystalline / amorphous carbon composite lubricating film, characterized in that: The invention comprises an amorphous carbon film and diamond nanocrystals embedded in the amorphous carbon film.

2. The diamond nanocrystalline / amorphous carbon composite lubricating film according to claim 1, characterized in that: The thickness of the diamond nanocrystalline / amorphous carbon composite lubricating film is 1000-3000 nm.

3. A solid lubricating film, characterized in that: It comprises a transition layer, a bearing layer and a lubricating layer arranged in sequence from bottom to top, wherein the lubricating layer is the diamond nanocrystalline / amorphous carbon composite lubricating film according to claim 1 or 2; the transition layer is titanium and / or chromium; and the bearing layer is WC.

4. The solid lubricating film according to claim 3, characterized in that The thickness of the transition layer is 400-800 nm, and the thickness of the supporting layer is 800-1500 nm.

5. The method for preparing a solid lubricating film according to claim 3 or 4, characterized in that: The following steps are involved: After cleaning the substrate, ion source etching is performed to obtain an activated substrate; A transition layer and a bearing layer are sequentially prepared on the surface of the activated substrate by a magnetron sputtering method; Using acetylene as a carbon source, a diamond nanocrystalline / amorphous carbon composite lubricating film is prepared on the surface of the bearing layer by plasma enhanced chemical vapor deposition; The operating conditions of the plasma enhanced chemical vapor deposition method include: an acetylene flow rate of 400 to 800 sccm, a deposition gas pressure of 0.5 to 0.8 Pa, and a DC power supply voltage of 600 to 800 V.

6. The preparation method according to claim 5, characterized in that The cleaning comprises: placing the substrate in petroleum ether and acetone in sequence for ultrasonic treatment, wherein the ultrasonic treatment time in the petroleum ether is 10 to 20 minutes, and the ultrasonic treatment time in the acetone is 10 to 20 minutes.

7. The preparation method according to claim 5, characterized in that The conditions for ion source etching include: the etching gas is argon, the vacuum degree is not greater than 6.0×10 -3 Pa, the deposition gas pressure is 0.04-0.08 Pa, the substrate negative bias voltage is 200-400 V, the ion source current is 50-80 A, and the etching time is 20-40 min.

8. The preparation method according to claim 5, characterized in that The conditions for preparing the transition layer by magnetron sputtering include: the sputtering gas is argon, the deposition pressure is 0.1-0.3 Pa, the substrate negative bias voltage is 80-150 V, and the sputtering target is a titanium target and / or a chromium target.

9. The preparation method according to claim 5, characterized in that The conditions for preparing the bearing layer by magnetron sputtering include: the sputtering gas is argon, the deposition pressure is 0.1-0.3 Pa, the substrate negative bias voltage is 80-150 V, and the sputtering target is WC target.

10. Use of the diamond nanocrystalline / amorphous carbon composite lubricating film according to claim 1 or 2, the solid lubricating film according to claim 3 or 4, or the solid lubricating film prepared by the preparation method according to any one of claims 5 to 9 in a vacuum environment; wherein the vacuum degree of the vacuum environment is less than 5.0×10 -3 Pa, temperature is -200~600℃.

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