Hydrophobic diamond-like coating and preparation method thereof

Abstract

The invention discloses a hydrophobic diamond-like carbon coating and a preparation method thereof. The hydrophobic diamond-like carbon coating comprises a transition layer and an F-DLC layer. The preparation method comprises the following steps: S1, cleaning the substrate; s2, the coating chamber is vacuumized and heated, and the coating chamber and the base body are baked; s3, carrying out ion etching cleaning on the surface of the substrate; s4, after etching is completed, a Cr layer or a Ti layer is deposited on the surface of the base body in a magnetron sputtering mode to serve as a transition layer; and S5, inert gas and carbon tetrafluoride are introduced, the graphite target is started, and the F-DLC layer is deposited in an arc ion plating mode. Wherein in the step S5, the ratio of the introduced inert gas to the carbon tetrafluoride is 1: 0.3-1: 4, the cavity pressure of the coating cavity is 0.1-5.0 Pa, the bias voltage of the substrate is 20-800 V, and the target current of the graphite target is 20-400 A. The hydrophobic diamond-like coating is prepared in an electric arc ion plating mode, the characteristics that the target material particle energy is improved, the deposition rate is high, and the film layer compactness is good are achieved, and the prepared coating is better in hydrophobic angle and excellent in anti-sticking performance.

Description

Technical Field

[0001] This application relates to the technical field of coating preparation, and particularly relates to a hydrophobic diamond-like carbon coating and a preparation method thereof. Background Art

[0002] Diamond like Carbon (DLC) film is an amorphous carbon film that contains both sp 3 bonds and sp 2 bonds in its microstructure. DLC coatings have been proven to have both the high wear resistance of graphite and the low friction and high hardness of diamond. At the same time, they also have unique properties of high corrosion resistance and chemical inertness. The surface water contact angle of conventional DLC is only about 80°, and it is easy to stick fingerprints. Therefore, preparing a highly hydrophobic DLC film can improve the application of DLC film in the fields of hydrophobicity and anti-sticking.

[0003] The wetting state of a liquid droplet on a solid surface is jointly determined by the surface roughness and chemical composition. Due to its better durability and heat resistance than ordinary organic polymer coatings, fluorine-doped diamond-like carbon film (F-doped Diamond-like-carbon, F-DLC) has the property of low surface energy due to the presence of -CFx groups, and the DLC coating has mechanical properties similar to inorganic ceramic materials and a low friction coefficient, making it the first choice for developing hydrophobic engineering coating materials and a research hotspot in the field of hydrophobic materials. F-DLC has a hydrophobic C—Fx bond similar to polytetrafluoroethylene (PTFE) and can be used to make hydrophobic coatings for material devices.

[0004] In related technologies, magnetron sputtering is mostly used to prepare fluorine-doped diamond-like carbon coatings with or without hydrogen. Magnetron sputtering is a technical method in which ionized argon ions bombard the surface of the target, and the sputtered target generates ions for film formation. Its sputtering energy is low and the deposition efficiency is low. Therefore, the hydrophobic angle generally remains at about 85°. Therefore, developing a simple process, high production efficiency, and effective preparation of hydrophobic DLC coatings is a technical problem that needs to be solved urgently. Summary of the Invention

[0005] To solve at least one of the above technical problems, this application provides a hydrophobic diamond-like carbon coating and a preparation method thereof, and the technical solutions adopted are as follows.

[0006] The preparation method of the hydrophobic diamond-like carbon coating provided by this application includes the following steps:

[0007] S1, cleaning the substrate;

[0008] S2, evacuating and heating the coating chamber, and baking the coating chamber and the substrate;

[0009] S3, performing ion etching cleaning on the substrate surface;

[0010] S4. After etching is completed, a Cr layer or a Ti layer is deposited on the surface of the substrate by magnetron sputtering as a transition layer;

[0011] S5. An inert gas and carbon tetrafluoride are introduced, the graphite target is turned on, and an F-DLC layer is deposited by arc ion plating;

[0012] Among them, in step S5, the ratio of the inert gas to carbon tetrafluoride introduced is 1:0.3 to 1:4, the chamber pressure of the coating chamber is 0.1 to 5.0 Pa, the substrate bias voltage is 20 to 800 V, and the target current of the graphite target is 20 to 400 A.

[0013] In some embodiments of the present application, in step S5, the coating time for depositing the F-DLC layer is 1 to 120 min.

[0014] In some embodiments of the present application, in step S4, an inert gas is introduced, the chamber pressure of the coating chamber is 0.1 to 5.0 Pa, the target power is 1000 to 15000 W, and the substrate bias voltage is 20 to 800 V.

[0015] In some embodiments of the present application, in step S3, an inert gas is introduced, the chamber pressure of the coating chamber is 0.1 to 5.0 Pa, the substrate bias voltage is 20 to 1000 V, and the etching and cleaning time is 1 to 120 min.

[0016] In some embodiments of the present application, the inert gas is Ar.

[0017] The hydrophobic diamond-like carbon coating provided by the present application is obtained by the preparation method as described above, and the hydrophobic diamond-like carbon coating includes a transition layer and an F-DLC layer.

[0018] In some embodiments of the present application, the thickness of the transition layer is 0.1 to 2.5 μm.

[0019] In some embodiments of the present application, the thickness of the F-DLC layer is 0.5 to 4.0 μm.

[0020] In some embodiments of the present application, the transition layer is a Cr layer or a Ti layer.

[0021] In some embodiments of the present application, the hardness of the hydrophobic diamond-like carbon coating is 300 to 2500 HV.

[0022] The present application has at least the following beneficial effects: The hydrophobic diamond-like carbon coating is prepared by arc ion plating in the present application, which has the characteristics of improving the energy of target particles, fast deposition rate, and good film layer compactness. The prepared coating has a better hydrophobic angle and excellent anti-sticking performance.

[0023] Additional aspects and advantages of the present application will be given in part in the following description, become apparent in part from the following description, or be learned by practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. At the same time, it should be noted that the following examples can all effectively deposit a fluorinated diamond-like carbon (F-DLC) coating on the substrate surface. The main differences lie in the selection of the negative bias voltage, the flow ratio of the process gas, the magnitude of the chamber pressure, and the control of the coating time when depositing the F-DLC coating.

[0025] Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0026] Figure 1 It is a schematic flow chart of a method for preparing a hydrophobic diamond-like carbon coating in some embodiments of the present application.

[0027] Figure 2 It is a scanning electron microscope image of the cross-section of the coating in Example 1.

[0028] Figure 3 It is a hydrophobic angle image of the coating in Example 1.

[0029] Figure 4 It is a Rockwell indentation image of the coating in Example 1.

[0030] Figure 5 It is a scanning electron microscope image of the cross-section of the coating in Example 2.

[0031] Figure 6 It is a hydrophobic angle image of the coating in Example 2.

[0032] Figure 7 It is a Rockwell indentation image of the coating in Example 2.

[0033] Figure 8 It is a scanning electron microscope image of the cross-section of the coating in Example 3.

[0034] Figure 9 It is a hydrophobic angle image of the coating in Example 3.

[0035] Figure 10 It is a Rockwell indentation image of the coating in Example 3.

[0036] Figure 11 It is a scanning electron microscope image of the cross-section of the coating in Example 4.

[0037] Figure 12Hydrophobic angle diagram of the coating in Example 4.

[0038] Figure 13 Rockwell indentation diagram of the coating in Example 4.

[0039] Figure 14 Scanning electron microscope image of the cross-section of the coating in Comparative Example 1.

[0040] Figure 15 Hydrophobic angle diagram of the coating in Comparative Example 1.

[0041] Figure 16 Rockwell indentation diagram of the coating in Comparative Example 1.

[0042] Figure 17 Scanning electron microscope image of the cross-section of the coating in Comparative Example 2.

[0043] Figure 18 Hydrophobic angle diagram of the coating in Comparative Example 2.

[0044] Figure 19 Rockwell indentation diagram of the coating in Comparative Example 2.

[0045] Figure 20 Schematic structural diagram of the hydrophobic diamond-like carbon coating in the present application. Detailed Description of the Preferred Embodiments

[0046] The following Figures 1 to 20 describes in detail the embodiments of the present application, where the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary only for explaining the present application and should not be construed as limiting the present application.

[0047] In the description of the present application, it should be understood that if terms such as "center", "middle", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. are used to indicate the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present application.

[0048] In the description of this application, "several" means more than one, "multiple" means more than two, and understandings such as "greater than", "less than", "exceeding", etc. do not include the corresponding number, while understandings such as "above", "below", "within", etc. include the corresponding number. If there is a description of "first" and "second", it is only for the purpose of distinguishing technical features and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features or implicitly specifying the sequence relationship of the indicated technical features.

[0049] In the description of this application, unless otherwise clearly specified and limited, the terms "arranged", "installed", "connected", "coupled" should be understood in a broad sense. For example: it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0050] In the description of this application, if there are descriptions of reference terms such as "an embodiment", "some embodiments", "an example", "some examples", "some embodiments", "schematic embodiments", "examples", "specific examples", "some examples", etc., it means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0051] This application relates to a hydrophobic diamond-like carbon coating, which has advantages such as high hydrophobicity and good anti-adhesion, and mainly solves problems such as food adhesion during the use of kitchen utensils or material adhesion on the surface of parts in industry.

[0052] The hydrophobic diamond-like carbon coating includes a transition layer and an F-DLC layer.

[0053] The transition layer is a Cr layer or a Ti layer. The thickness of the transition layer is 0.1 to 2.5 μm. Further, the thickness of the transition layer is 0.2 to 0.3 μm, and a better adhesion can be achieved within this range of the transition layer thickness.

[0054] The thickness of the F-DLC layer is 0.5 to 4.0 μm. Further, the thickness of the F-DLC layer is 1 to 2.0 μm. If the coating is too thin, the wear resistance becomes poor; if the coating is too thick, the bonding strength becomes poor, which may lead to easy peeling of the coating. In some examples, the thickness of the F-DLC layer is 1.0 to 2.0 μm. If the coating is too thin, the wear resistance may be poor; if the coating is too thick, the bonding strength may be poor, which may lead to easy peeling of the coating.

[0055] The hardness of the coating of the present application is 300 to 2500 HV, and it has good wear resistance. Further, the hardness of the coating is 800 to 2500 HV.

[0056] The indentation adhesion of the coating of the present application is HF1 grade.

[0057] The present application relates to a preparation method of a hydrophobic diamond-like carbon coating, which has low process cost and high production efficiency.

[0058] The preparation method includes the following process steps.

[0059] S1. Clean the substrate.

[0060] S2. Evacuate and heat the coating chamber, and bake the coating chamber and the substrate.

[0061] S3. Perform ion etching cleaning on the surface of the substrate.

[0062] S4. After the etching is completed, deposit a Cr layer or a Ti layer on the surface of the substrate by magnetron sputtering as a transition layer.

[0063] S5. Introduce inert gas and carbon tetrafluoride, turn on the graphite target, and deposit an F-DLC layer by arc ion plating.

[0064] It should be noted that in step S1, the substrate is made of stainless steel, and the substrate is cleaned with a chemical solution to remove surface oil stains and dust, and then ultrasonically cleaned with alcohol and pure water.

[0065] In step S2, the coating chamber is evacuated to less than 5×10 -3 Pa, and the water vapor on the surface of the coating chamber and the substrate is removed by baking.

[0066] In step S3, ion etching cleaning is performed on the surface of the substrate. The coating chamber is evacuated to less than 5×10 -3 Pa, inert gas is introduced, the chamber pressure of the coating chamber is 0.1 to 5.0 Pa, the substrate bias voltage is 20 to 1000 V, and the etching cleaning time is 1 to 120 min.

[0067] Further, in step 3, the inert gas is Ar, and the surface of the substrate is etched and cleaned by using Ar ions. The chamber pressure of the coating chamber is 0.4 to 0.5 Pa. The substrate bias voltage is 60 to 200 V. The etching cleaning time is 30 to 60 min.

[0068] In step S4, a Cr target or a Ti target is used, inert gas is introduced, the chamber pressure of the coating chamber is 0.1 to 5.0 Pa, the target power is 1000 to 15000 W, and the substrate bias voltage is 20 to 800 V.

[0069] Further, in step S4, the inert gas is Ar. The chamber pressure of the coating chamber is 0.4 to 0.6 Pa. The target power is 3000 to 5000 W. The substrate bias voltage is 60 to 100 V.

[0070] In step S5, a graphite target is used, and the gas flow rate, coating time, power supply parameters, etc. are controlled. Plasma is generated by arc discharge for coating. The ratio of the inert gas to carbon tetrafluoride is 1:0.3 to 1:4. The chamber pressure of the coating chamber is 0.1 to 5.0 Pa. The substrate bias voltage is 20 to 800 V. The target current of the graphite target is 20 to 400 A.

[0071] Further, in step S5, the inert gas is Ar. The chamber pressure of the coating chamber is 0.5 to 1.1 Pa. The substrate bias voltage is 70 to 100 V. The target current of the graphite target is 50 to 100 A.

[0072] In step S5, the coating time for depositing the F-DLC layer is 1 to 120 min. Further, the coating time for depositing the F-DLC layer is 30 to 60 min.

[0073] After coating, degassing is carried out. The bias voltage is disconnected, the intake valve is closed, and after degassing treatment by vacuum pumping, the furnace is opened to take out the coated product.

[0074] It should be noted that the preparation method of the present application adopts the arc ion plating technology, which can effectively and stably generate plasma. Compared with the magnetron sputtering technology, it has the advantages of significantly improving the energy of target particles, fast deposition rate, good film layer compactness, etc. The deposition rate can reach at least 1.5 μm / h. The arc ion plating technology can further reduce the surface energy of the film layer, so that the hydrophobic angle can reach at least 120°. In addition, the power supply equipment adopted by the arc ion plating technology is simple, reducing the equipment cost and operation difficulty.

[0075] The content of the present application will be described in detail below with specific embodiments. It should be noted that the following description is only for illustrative purposes and not a specific limitation of the present application.

[0076] Example 1

[0077] Sample preparation: The sample is cleaned and dried using an ultrasonic cleaning line to remove surface oil and other impurities.

[0078] Etching and cleaning: The vacuum pumping system of the coating machine is turned on, and the water vapor in the coating chamber is removed by heating to make the coating chamber reach the set base vacuum degree. 75 sccm of argon gas is introduced, the chamber pressure is controlled at about 0.4 Pa, and at the same time, the bias voltage power supply is turned on to apply a negative bias voltage of 200 V for 30 min. The argon gas is ionized by the glow discharge effect to clean the surface of the substrate.

[0079] Preparation of the transition layer: After cleaning was completed, the argon gas supply was stopped and the bias power supply was disconnected. The vacuum system was used to pump the vacuum in the coating chamber to the set background vacuum degree. 150 sccm of argon gas was introduced, the chamber pressure was controlled at about 0.6 Pa, the power of the magnetron Cr target was set at 8000 w, and at the same time, the bias power supply was turned on to apply a negative bias of 200 V for a working time of 30 min to deposit the transition layer.

[0080] Preparation of the F-DLC coating: The gas supply was stopped and the bias power supply was disconnected. The vacuum system was used to pump the vacuum in the coating chamber to the set background vacuum degree. The arc power supply of the graphite target was turned on, the target current was 200 A, 50 sccm of argon gas and 50 sccm of carbon tetrafluoride were introduced, the chamber pressure was controlled at about 0.64 Pa, and at the same time, the bias power supply was turned on to apply a negative bias of 200 V for a working time of 30 min to deposit the F-DLC coating.

[0081] Unloading: The gas was disconnected and the power was turned off. After the temperature of the coating chamber dropped to room temperature, the coating chamber was opened to take out the sample, and the surface of the sample was the F-DLC coating.

[0082] An electron scanning microscope was used to observe the cross-section of the coating. No obvious defects were observed in the cross-section of the coating, and the distribution in the longitudinal direction of the coating was uniform. The overall thickness of the F-DLC coating was 0.803 μm, the deposition time was 30 min, so the deposition rate was 1.606 μm / h, as Figure 2 shown. The measured hydrophobic angle was 123.9 degrees, as Figure 3 shown. A 150 Kg Rockwell indentation was used, and the coating adhesion was judged according to the DIN-VDI3198 standard. The adhesion rating was HF1, indicating good adhesion between the coating and the sample, effectively preventing the coating from peeling off. The Rockwell indentation diagram was as Figure 4 shown, and the indentation cracks were regular and clear.

[0083] Example 2

[0084] Sample preparation: An ultrasonic cleaning line was used to clean and dry the sample to remove surface oil and other impurities.

[0085] Etching and cleaning: The vacuum pumping system of the coating machine was turned on, and the water vapor in the coating chamber was removed by heating to make the coating chamber reach the set background vacuum degree. 75 sccm of argon gas was introduced, the chamber pressure was controlled at about 0.4 Pa, and at the same time, the bias power supply was turned on to apply a negative bias of 200 V for a working time of 30 min. The argon gas was ionized by the glow discharge effect to clean the surface of the substrate.

[0086] Preparation of the transition layer: After the cleaning is completed, stop the argon gas supply and disconnect the bias power supply. Cool down the temperature to below 150 °C, and use the vacuum system to pump the vacuum of the coating chamber to the set base vacuum degree. Introduce 150 sccm of argon gas, control the chamber pressure at about 0.6 Pa, set the power of the magnetron Cr target to 8000 W, and at the same time turn on the bias power supply to apply a negative bias of 200 V for a working time of 50 min to deposit the transition layer.

[0087] Preparation of the F-DLC coating: Stop the gas supply and disconnect the bias power supply. Use the vacuum system to pump the vacuum of the coating chamber to the set base vacuum degree. Turn on the arc power supply of the graphite target, with the target current of 200 A. Introduce 50 sccm of argon gas and 80 sccm of carbon tetrafluoride, control the chamber pressure at about 0.75 Pa, and at the same time turn on the bias power supply to apply a negative bias of 200 V for a working time of 30 min to deposit the F-DLC coating.

[0088] Unloading: Disconnect the gas and turn off the power supply. Wait for the temperature of the coating chamber to drop to room temperature, open the coating chamber and take out the sample. The surface of this sample is the F-DLC coating.

[0089] Use an electron scanning microscope to observe the cross-section of the coating. No obvious defects are observed in the cross-section of the coating, and the coating is evenly distributed in the longitudinal direction. The overall thickness of the F-DLC coating is 1.947 μm, and the deposition time is 60 min. Therefore, the deposition rate is 1.947 μm / h, as Figure 5 shown. The measured hydrophobic angle is 120.2 degrees, as Figure 6 shown. Adopt a 150 Kg Rockwell indentation, and judge the coating adhesion according to the DIN-VDI3198 standard. The adhesion rating is HF1, indicating that the adhesion between the coating and the sample is good. The Rockwell indentation diagram is as Figure 7 shown, and the indentation cracks are regular and clear.

[0090] Example 3

[0091] Sample preparation: Use an ultrasonic cleaning line to clean and dry the sample to remove surface oil and other impurities.

[0092] Etching and cleaning: Turn on the vacuum system of the coating machine, heat to remove the water vapor in the coating chamber, make the coating chamber reach the set base vacuum degree, introduce 75 sccm of argon gas, control the chamber pressure at about 0.4 Pa, and at the same time turn on the bias power supply to apply a negative bias of 200 V for a working time of 30 min. Use the glow discharge effect to ionize the argon gas and clean the surface of the substrate.

[0093] Preparation of the transition layer: After cleaning is completed, stop the argon gas supply and disconnect the bias power supply. Cool down to below 150 °C, and use the vacuum system to pump the vacuum in the coating chamber to the set appropriate base vacuum. Introduce 150 sccm of argon gas, control the chamber pressure at about 0.6 Pa, set the power of the magnetron Cr target to 8000 W, and at the same time turn on the bias power supply to apply a negative bias of 200 V for a working time of 30 min to deposit the transition layer.

[0094] Preparation of the F-DLC coating: Stop the gas supply and disconnect the bias power supply. Use the vacuum system to pump the vacuum in the coating chamber to the set base vacuum. Turn on the arc power supply of the graphite target, with the target current of 200 A. Introduce 50 sccm of argon gas and 100 sccm of carbon tetrafluoride, control the chamber pressure at about 0.81 Pa, and at the same time turn on the bias power supply to apply a negative bias of 200 V for a working time of 30 min to deposit the F-DLC coating.

[0095] Unloading: Disconnect the gas and turn off the power. Wait for the temperature of the coating chamber to drop to room temperature, open the coating chamber and take out the sample. The surface of this sample is the F-DLC coating.

[0096] Use an electron scanning microscope to observe the cross-section of the coating. No obvious defects are observed in the cross-section of the coating, and the distribution in the longitudinal direction of the coating is uniform. The overall thickness of the F-DLC coating is 0.900 μm, and the deposition time is 30 min. Therefore, the deposition rate is 1.800 μm / h, as Figure 8 shown. The measured hydrophobic angle is 129.7 degrees, as Figure 9 shown. Use a 150 Kg Rockwell indentation to determine the coating adhesion according to the DIN-VDI3198 standard. The adhesion rating is HF1, indicating good adhesion between the coating and the sample. The Rockwell indentation diagram is as Figure 10 shown, and the indentation cracks are regular and clear.

[0097] Example 4

[0098] Sample preparation: Use an ultrasonic cleaning line to clean and dry the sample to remove surface oil and other impurities.

[0099] Etching and cleaning: Turn on the vacuum system of the coating machine, heat to remove the water vapor in the coating chamber, make the coating chamber reach the set base vacuum, introduce 75 sccm of argon gas, control the chamber pressure at about 0.4 Pa, and at the same time turn on the bias power supply to apply a negative bias of 200 V for a working time of 30 min. Use the glow discharge effect to ionize argon gas and clean the surface of the substrate.

[0100] Preparation of the transition layer: After cleaning is completed, stop the argon gas supply and disconnect the bias power supply. Cool down to below 150 °C, and use the vacuum system to pump the vacuum in the coating chamber to the set base vacuum degree. Introduce 150 sccm of argon gas, control the chamber pressure at about 0.6 Pa, set the power of the magnetron Cr target to 8000 W, and at the same time turn on the bias power supply to apply a negative bias of 200 V for a working time of 30 min to deposit the transition layer.

[0101] Preparation of the F-DLC coating: Stop the gas supply and disconnect the bias power supply. Use the vacuum system to pump the vacuum in the coating chamber to the set base vacuum degree. Turn on the arc power supply of the graphite target, with the target current of 200 A. Introduce 200 sccm of argon gas and 400 sccm of carbon tetrafluoride, control the chamber pressure at about 2.3 Pa, and at the same time turn on the bias power supply to apply a negative bias of 200 V for a working time of 30 min to deposit the F-DLC coating.

[0102] Unloading: Disconnect the gas and turn off the power. Wait for the temperature in the coating chamber to drop to room temperature, open the coating chamber and take out the sample. The surface of this sample is the F-DLC coating.

[0103] Use an electron scanning microscope to observe the cross-section of the coating. No obvious defects are observed in the cross-section of the coating, and the coating is evenly distributed in the longitudinal direction. The overall thickness of the F-DLC coating is 0.922 μm, and the deposition time is 30 min. Therefore, the deposition rate is 1.844 μm / h, as Figure 11 shown. The measured hydrophobic angle is 120.1 degrees, as Figure 12 shown. Use a 150 Kg Rockwell indentation to determine the coating adhesion according to the DIN-VDI3198 standard. The adhesion rating is HF1, indicating good adhesion between the coating and the sample. The Rockwell indentation diagram is as Figure 13 shown, and the indentation cracks are regular and clear.

[0104] Comparative Example 1

[0105] Sample preparation: Use an ultrasonic cleaning line to clean and dry the sample to remove surface oil and other impurities.

[0106] Etching and cleaning: Turn on the vacuum system of the coating machine, heat to remove the water vapor in the coating chamber, make the coating chamber reach the set base vacuum degree, introduce 75 sccm of argon gas, control the chamber pressure at about 0.4 Pa, and at the same time turn on the bias power supply to apply a negative bias of 200 V for a working time of 30 min. Use the glow discharge effect to ionize the argon gas and clean the surface of the substrate.

[0107] Preparation of the transition layer: After cleaning is completed, stop the argon gas supply and disconnect the bias power supply. Cool down to below 150 °C, and use the vacuum system to pump the vacuum in the coating chamber to the set base vacuum level. Introduce 150 sccm of argon gas, control the chamber pressure at about 0.6 Pa, set the power of the magnetron Cr target to 8000 W, and at the same time turn on the bias power supply to apply a negative bias of 200 V for a working time of 30 min to deposit the transition layer.

[0108] Preparation of the DLC coating: Stop the gas supply and disconnect the bias power supply. Use the vacuum system to pump the vacuum in the coating chamber to the set base vacuum level. Turn on the arc power supply of the graphite target, with the target current of 200 A. Introduce 50 sccm of argon gas and 200 sccm of acetylene, control the chamber pressure at about 1.4 Pa, and at the same time turn on the bias power supply to apply a negative bias of 200 V for a working time of 30 min to deposit the DLC coating.

[0109] Unloading: Disconnect the gas and turn off the power. Wait for the temperature in the coating chamber to drop to room temperature, open the coating chamber and take out the sample, and the surface of this sample is the DLC coating.

[0110] Use an electron scanning microscope to observe the cross-section of the coating. No obvious defects are observed in the cross-section of the coating, and the coating is evenly distributed in the longitudinal direction. The overall thickness of the DLC coating is 0.820 μm, and the deposition time is 30 min. Therefore, the deposition rate is 1.640 μm / h, as Figure 14 shown. Since acetylene gas without F is used, the obtained is pure DLC without F doping on the surface. The measured hydrophobic angle is 83 degrees, and it does not have hydrophobic properties, as Figure 15 shown. Adopt a 150 Kg Rockwell indentation, and judge the coating adhesion according to the DIN-VDI3198 standard. The adhesion rating is HF1, indicating good adhesion between the coating and the sample. The Rockwell indentation diagram is as Figure 16 shown, and the indentation cracks are regular and clear.

[0111] Comparative Example 2

[0112] Sample preparation: Use an ultrasonic cleaning line to clean and dry the sample to remove surface oil and other impurities.

[0113] Etching and cleaning: Turn on the vacuum system of the coating machine, heat to remove the water vapor in the coating chamber, make the coating chamber reach the set base vacuum level, introduce 75 sccm of argon gas, control the chamber pressure at about 0.4 Pa, and at the same time turn on the bias power supply to apply a negative bias of 200 V for a working time of 30 min. Use the glow discharge effect to ionize argon gas and clean the surface of the substrate.

[0114] Preparation of the transition layer: After cleaning is completed, stop the supply of argon gas and disconnect the bias power supply. Cool down the temperature to below 150 degrees Celsius, and use the vacuum system to pump the vacuum in the coating chamber to the set base vacuum degree. Introduce 150 sccm of argon gas, control the chamber pressure at about 0.6 Pa, set the power of the magnetron Cr target to 8000 w, and at the same time turn on the bias power supply to apply a negative bias of 200 V for a working time of 30 minutes to deposit the transition layer.

[0115] Preparation of the F-DLC coating: Stop the gas supply and disconnect the bias power supply. Use the vacuum system to pump the vacuum in the coating chamber to the set base vacuum degree. Turn on the magnetron power supply of the graphite target, with the target power of 8000 w. Introduce 150 sccm of argon gas and 200 sccm of carbon tetrafluoride, control the chamber pressure at about 1.7 Pa, and at the same time turn on the bias power supply to apply a negative bias of 200 V for a working time of 30 minutes to deposit the F-DLC coating.

[0116] Unloading: Disconnect the gas and turn off the power supply. Wait for the temperature in the coating chamber to drop to room temperature, open the coating chamber and take out the sample. The surface of this sample is the F-DLC coating.

[0117] Use an electron scanning microscope to observe the cross-section of the coating. No obvious defects are observed in the cross-section of the coating, and the distribution in the longitudinal direction of the coating is uniform. The overall thickness of the F-DLC coating is 0.683 μm, and the deposition time is 30 minutes. Therefore, the deposition rate is 1.366 μm / h, as Figure 17 shown. The measured hydrophobic angle is 83.3 degrees, and it cannot achieve the same effect as arc ionization, as Figure 18 shown. Adopt a 150 Kg Rockwell indentation, and judge the coating adhesion according to the DIN-VDI3198 standard. The adhesion rating is HF1, indicating that the adhesion between the coating and the sample is good. The Rockwell indentation diagram is as Figure 19 shown, and the indentation cracks are regular and clear.

[0118] The above has described the embodiments of the present application in detail in conjunction with the accompanying drawings. However, the present application is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art in the technical field, various changes can be made without departing from the purpose of the present application. In addition, without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other.

Claims

1. A method for preparing a hydrophobic diamond-like carbon coating, characterized in that, It includes the following steps: S1, cleaning the substrate; S2, evacuating and heating the coating chamber, baking the coating chamber and the substrate; S3, performing ion etching cleaning on the substrate surface; S4, after the etching is completed, depositing a Cr layer or a Ti layer on the substrate surface by magnetron sputtering as a transition layer; S5, introducing an inert gas and carbon tetrafluoride, turning on the graphite target, and depositing an F-DLC layer by arc ion plating; Among them, in step S5, the ratio of the inert gas to carbon tetrafluoride introduced is 1:0.3 to 1:4, the chamber pressure of the coating chamber is 0.1 to 5.0 Pa, the substrate bias voltage is 20 to 800 V, and the target current of the graphite target is 20 to 400 A.

2. The preparation method of the hydrophobic diamond-like carbon coating according to claim 1, wherein: In step S5, the coating time for depositing the F-DLC layer is 1 to 120 min.

3. The preparation method of the hydrophobic diamond-like carbon coating according to claim 1, wherein: In step S4, an inert gas is introduced, the chamber pressure of the coating chamber is 0.1 to 5.0 Pa, the target power is 1000 to 15000 W, and the substrate bias voltage is 20 to 800 V.

4. The preparation method of the hydrophobic diamond-like carbon coating according to claim 1, characterized in that: In step S3, an inert gas is introduced, the chamber pressure of the coating chamber is 0.1 to 5.0 Pa, the substrate bias voltage is 20 to 1000 V, and the etching cleaning time is 1 to 120 min.

5. The method for preparing a hydrophobic diamond-like carbon coating according to claim 1 or 3 or 4, characterized in that: The inert gas is Ar.

6. A hydrophobic diamond-like carbon coating, characterized in that: The hydrophobic diamond-like carbon coating is obtained by using the preparation method described in any one of claims 1 to 5, and the hydrophobic diamond-like carbon coating includes a transition layer and an F-DLC layer.

7. The hydrophobic diamond-like carbon coating according to claim 6, wherein: The thickness of the transition layer is 0.1 to 2.5 μm.

8. The hydrophobic diamond-like carbon coating according to claim 6, characterized in that: The thickness of the F-DLC layer is 0.5 to 4.0 μm.

9. The hydrophobic diamond-like carbon coating according to any one of claims 6 to 8, characterized in that: The transition layer is a Cr layer or a Ti layer.

10. The hydrophobic diamond-like carbon coating according to any one of claims 6 to 8, characterized in that: The hardness of the hydrophobic diamond-like carbon coating is 300 to 2500 HV.

Images