Wear-resistant Cr / CrN nano coating as well as preparation method and application thereof

Abstract

The invention provides a wear-resistant Cr / CrN nano coating and a preparation method and application thereof.The preparation method of the wear-resistant Cr / CrN nano coating comprises the steps that firstly, a Cr binding force layer is deposited on the surface of a base material through high-power pulse magnetron sputtering, and then the Cr binding force layer is compositely deposited through high-power pulse magnetron sputtering and pulse direct current sputtering; and a CrN layer is compositely deposited on the surface of the Cr binding force layer by adopting high-power pulse magnetron sputtering and pulse direct current sputtering. The nano coating is high in bonding strength with a base material and high in mechanical strength, the preparation method adopts a mode of combining high-power pulse magnetron sputtering and pulse direct-current magnetron sputtering, pulse parameters, deposition conditions and bias voltage are accurately regulated and controlled, the performance of the coating can be accurately controlled, the deposition rate is high, operation is easy and convenient, cost is low, and the method is suitable for batch production.

Description

Technical Field

[0001] The invention belongs to the technical field of wear-resistant coating preparation, and in particular relates to a wear-resistant Cr / CrN nano coating, a preparation method and application thereof. Background Art

[0002] Cement kiln scraper, also known as kiln scraper or kiln lining scraper, is a key component in cement rotary kiln. Cement kiln scraper is mainly installed inside the cement rotary kiln, especially in the area in direct contact with cement clinker. Cement kiln scraper is used to scrape and push materials, prevent crusting and blockage, and protect kiln lining. Cement kiln scraper is usually made of high temperature resistant and wear resistant materials, such as alloy steel, heat resistant alloy, etc., to adapt to high temperature and high wear working environment. However, despite the excellent performance of these materials, the scraper will still be subject to a certain degree of wear and corrosion during long-term use. The most common wear is the wear between the scraper and materials such as sand and stone during low-speed mixing at an operating temperature of ≤400℃. This wear is manifested as scratches, pits, and even peeling of materials on the scraper surface.

[0003] In order to improve the wear resistance of the cement kiln scraper, a wear-resistant coating can be provided on the surface of the cement kiln scraper. Magnetron sputtering is a method of transferring target atoms to the surface of the substrate to form a thin film using the sputtering effect. A wear-resistant layer can be formed on the surface of the cement kiln scraper using magnetron sputtering technology. The Chinese patent document with publication number CN117568763A discloses a method for preparing a Ti-doped ta-C coating using high-power pulsed magnetron sputtering technology, which forms a Ti-doped ta-C coating on the surface of the tool using high-power pulsed magnetron sputtering to improve the wear resistance and hardness of the tool. However, the wear-resistant coating prepared by the existing method of preparing a wear-resistant layer by magnetron sputtering is used for cement kiln scrapers. The film-base bonding force is not strong. The wear-resistant coating is still easy to fall off after long-term use under low-speed stirring conditions. The wear-resistant coating itself has insufficient mechanical strength and insufficient antioxidant performance, and cannot meet the needs of the application scenarios of cement kiln scrapers. Summary of the invention

[0004] The technical problem solved by the present invention is to provide a wear-resistant Cr / CrN nano coating, a preparation method and application thereof. The nano coating has high bonding strength with a substrate and high mechanical strength. The preparation method adopts a combination of high-power pulsed magnetron sputtering and pulsed DC magnetron sputtering, and accurately controls pulse parameters, deposition conditions and bias voltage, so as to accurately control the performance of the coating, has a fast deposition rate, is easy to operate, and has low cost, and is suitable for mass production.

[0005] In order to solve the above problems, a first aspect of the present invention provides a wear-resistant Cr / CrN nano-coating, comprising a Cr bonding layer formed on the surface of a substrate and a CrN layer formed on the surface of the Cr bonding layer.

[0006] Preferably, the total thickness of the wear-resistant Cr / CrN nano-coating is 200-500 μm; and the thickness of the Cr bonding layer is 10-100 μm.

[0007] A second aspect of the present invention provides a method for preparing the above-mentioned wear-resistant Cr / CrN nano-coating, comprising:

[0008] A Cr bonding layer is first deposited on the surface of the substrate by high-power pulsed magnetron sputtering, and then a Cr bonding layer is deposited by a combination of high-power pulsed magnetron sputtering and pulsed DC sputtering;

[0009] A CrN layer is deposited on the surface of the Cr bonding layer by composite deposition of high-power pulsed magnetron sputtering and pulsed DC sputtering.

[0010] Preferably, when depositing the Cr bonding layer, the chamber pressure is 0.3-2 Pa, the argon flow rate is 100-130 sccm, and the bias voltage is -30--100 V; the pulse width of high-power pulsed magnetron sputtering is 2-40 μs, and the average power is 2-10 kW; the power of pulsed DC sputtering is 2-5 kW, and the frequency is 100 kHz.

[0011] Preferably, when depositing the CrN layer, the chamber pressure is 0.6-1.5 Pa, the argon flow rate is 100-130 sccm, the nitrogen flow rate is 20-60 sccm, and the bias voltage is -60--150 V; the pulse width of high-power pulsed magnetron sputtering is 2-40 μs, and the average power is 2-10 kW; the power of pulsed DC sputtering is 2-5 kW, and the frequency is 100 kHz.

[0012] Preferably, the method specifically comprises the following steps:

[0013] S1. Cleaning the surface of the substrate with a solvent;

[0014] S2. performing ion cleaning on the surface of the substrate after solvent cleaning;

[0015] S3. The substrate surface after ion cleaning is subjected to high-power pulse ion bombardment cleaning;

[0016] S4. Depositing a Cr bonding layer by high-power pulsed magnetron sputtering on the surface of the substrate after high-power pulsed ion bombardment cleaning, and then depositing a Cr bonding layer by high-power pulsed magnetron sputtering and pulsed DC sputtering;

[0017] S5. A CrN layer is deposited on the surface of the Cr bonding layer by composite deposition of high-power pulsed magnetron sputtering and pulsed DC sputtering to obtain the wear-resistant Cr / CrN nanocoating.

[0018] Preferably, the ion cleaning of the substrate surface after solvent cleaning specifically includes the following steps: placing the substrate in a vacuum chamber, connecting a pulsed DC power supply to the substrate, setting pulse parameters: bias voltage of -500 to 600 V, frequency of 100 KHz, pulse width of 1 μs, gas pressure of 0.3 to 2 Pa, argon flow rate of 100 to 130 sccm, and performing ion cleaning on the substrate surface for 30 to 60 minutes.

[0019] Preferably, the high-power pulse ion bombardment cleaning of the substrate surface after ion cleaning specifically includes the following steps: starting high-power pulse magnetron sputtering, setting the pulse width to 2 to 40 μs, the average power to 2 to 10 kW, the gas pressure to 0.3 to 2 Pa, the argon flow rate to 120 to 160 sccm, the bias voltage to -100 to -200 V, and performing high-power pulse ion bombardment cleaning on the substrate surface for 10 to 15 minutes.

[0020] Preferably, a four-target closed-field unbalanced magnetron sputtering system is used to perform the high-power pulsed magnetron sputtering and the pulsed DC sputtering;

[0021] The four-target closed-field unbalanced magnetron sputtering system includes four metal Cr targets, two high-power pulsed magnetron sputtering power supplies and two pulsed DC sputtering power supplies, each power supply is connected to one metal Cr target, and the metal Cr targets connected to the high-power pulsed magnetron sputtering power supplies and the metal Cr targets connected to the pulsed DC sputtering power supplies are arranged alternately.

[0022] The third aspect of the present invention provides an application of the above-mentioned wear-resistant Cr / CrN nano-coating or the wear-resistant Cr / CrN nano-coating prepared by the above-mentioned preparation method, which is used to be formed on the surface of a cement kiln scraper to improve the wear resistance of the cement kiln scraper.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The wear-resistant Cr / CrN nano coating of the present invention adopts a temperature-resistant Cr layer as a bonding layer, has excellent bonding performance with a base material, and continuously grows a dense CrN layer on the Cr bonding layer. The CrN layer has better oxidation resistance and mechanical properties than the Cr layer. CrN can be used as a gradient transition layer, can maintain continuous and dense growth in structure, and maintain a gradient increase in mechanical properties.

[0025] The preparation method of the wear-resistant Cr / CrN nano coating of the present invention adopts a method of first bombarding the substrate surface with high-power pulsed magnetron sputtering ions, and then combining high-power pulsed magnetron sputtering with pulsed DC sputtering for composite deposition to deposit the nano coating on the substrate surface. Preliminary high-power pulsed magnetron sputtering can activate the substrate surface, improve the ion surface mobility, and be beneficial to improving the bonding strength. Afterwards, high-power pulsed magnetron sputtering combined with pulsed DC sputtering is used for composite deposition, which can achieve high ionization rate and high deposition rate high-energy deposition.

[0026] The present invention further achieves precise control of coating properties by precisely controlling the pulse parameters, deposition conditions, and bias settings of high-power pulsed magnetron sputtering and pulsed DC magnetron sputtering, so that the coating has excellent bonding force and mechanical strength, a thickness of 200-500 μm, a nanohardness of 35-45 GPa, an H / E* (E* is the effective Young's modulus) greater than 0.1, and an H 3 / E *2 ≥0.3, membrane-base bonding strength (Rockwell indentation bonding strength ≥HF1), elastic recovery ≥60%, fracture toughness K IC ≥3MPa·m 1 / 2 , high temperature resistance 400-800℃ friction coefficient ≤0.5, which meets the application requirements of cement kiln scrapers, and has fast deposition rate, easy operation, low cost, and is suitable for mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is the bonding force indentation of the wear-resistant Cr / CrN nano-coating obtained in Example 1 of the present invention;

[0028] Figure 2 is the micrometer indentation of the wear-resistant Cr / CrN nano-coating obtained in Example 1 of the present invention;

[0029] Figure 3 This is a graph showing the change in friction coefficient of the wear-resistant Cr / CrN nano-coating obtained in Example 1 of the present invention within 2 hours of friction and wear;

[0030] Figure 4 The utility model relates to a cement kiln scraper formed with a wear-resistant Cr / CrN nano-coating. DETAILED DESCRIPTION

[0031] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solution of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] A first aspect of an embodiment of the present invention provides a wear-resistant Cr / CrN nano-coating, comprising a Cr bonding layer formed on a surface of a substrate and a CrN layer formed on a surface of the Cr bonding layer.

[0033] The wear-resistant Cr / CrN nano-coating of the embodiment of the present invention adopts a temperature-resistant Cr layer as a bonding layer, has excellent bonding properties with a base material, and continuously grows a dense CrN layer on the Cr bonding layer. The CrN layer has better antioxidant properties and mechanical properties than the Cr layer. CrN can be used as a gradient transition layer, which can maintain continuous and dense growth in structure and maintain a gradient increase in mechanical properties.

[0034] In some embodiments, the total thickness of the wear-resistant Cr / CrN nano-coating is 200-500 μm.

[0035] In some embodiments, the thickness of the Cr bonding layer is 10-100 μm. Adjustment of the bonding layer thickness and the total thickness will significantly affect the bonding strength, wear resistance and corrosion resistance of the coating.

[0036] Preferably, nano hardness is 35-45 GPa, H / E * (E * is the effective Young's modulus) greater than 0.1, H 3 / E *2 ≥0.3, membrane-base bonding strength (Rockwell indentation bonding strength ≥HF1), elastic recovery ≥60%, fracture toughness K IC ≥3MPa·m 1 / 2 , high temperature resistance 400-800℃ friction coefficient ≤0.5.

[0037] A second aspect of an embodiment of the present invention provides a method for preparing the above-mentioned wear-resistant Cr / CrN nano-coating, comprising:

[0038] A Cr bonding layer is first deposited on the surface of the substrate by high-power pulsed magnetron sputtering, and then a Cr bonding layer is deposited by a combination of high-power pulsed magnetron sputtering and pulsed DC sputtering;

[0039] A CrN layer is deposited on the surface of the Cr bonding layer by composite deposition of high-power pulsed magnetron sputtering and pulsed DC sputtering.

[0040] The preparation method of the wear-resistant Cr / CrN nano coating of the embodiment of the present invention adopts a method of first bombarding the substrate surface with high-power pulsed magnetron sputtering ions, and then combining high-power pulsed magnetron sputtering with pulsed DC sputtering for composite deposition to deposit the nano coating on the substrate surface. Preliminary high-power pulsed magnetron sputtering can activate the substrate surface, improve the ion surface mobility, and is conducive to improving the bonding strength. High-power pulsed magnetron sputtering and pulsed DC sputtering are then combined for composite deposition, which can achieve high ionization rate and high deposition rate. High-power pulsed magnetron sputtering (HiPIMS) has the characteristics of high ionization rate and high deposition particle energy, and can produce highly ionized plasma, thereby increasing the energy of deposited particles, thereby strengthening the density and bonding strength of the coating. At the same time, HiPIMS uses low pulse frequency and low duty cycle to ensure that the average power is equivalent to that of traditional magnetron sputtering, avoiding the problem of target overheating. In addition, HiPIMS technology can also increase the energy of deposited particles by increasing the ionization rate, thereby achieving the purpose of strengthening the density and bonding strength of the coating. Combining HiPIMS with pulsed DC sputtering can further increase the deposition rate and achieve a highly efficient deposition process.

[0041] In some embodiments, the method for preparing the wear-resistant Cr / CrN nano-coating specifically comprises the following steps:

[0042] S1. Cleaning the surface of the substrate with a solvent;

[0043] S2. performing ion cleaning on the surface of the substrate after solvent cleaning;

[0044] S3. The substrate surface after ion cleaning is subjected to high-power pulse ion bombardment cleaning;

[0045] S4. Depositing a Cr bonding layer by high-power pulsed magnetron sputtering on the surface of the substrate after high-power pulsed ion bombardment cleaning, and then depositing a Cr bonding layer by high-power pulsed magnetron sputtering and pulsed DC sputtering;

[0046] S5. A CrN layer is deposited on the surface of the Cr bonding layer by composite deposition of high-power pulsed magnetron sputtering and pulsed DC sputtering to obtain the wear-resistant Cr / CrN nanocoating.

[0047] In some embodiments, cleaning the surface of the substrate with a solvent specifically includes the following steps: placing the substrate in the solvent, cleaning with ultrasonic waves for 10 to 60 minutes, and then taking out and drying.

[0048] Specifically, the solvent may be anhydrous alcohol or acetone, or other organic solvents that can clean the substrate.

[0049] In some embodiments, the ion cleaning of the substrate surface after solvent cleaning specifically includes the following steps: placing the substrate in a vacuum chamber, connecting a pulsed DC power supply to the substrate, setting pulse parameters: bias voltage of -500 to 600 V, frequency of 100 KHz, pulse width of 1 μs, gas pressure of 0.3 to 2 Pa, argon gas flow rate of 100 to 130 sccm, and ion cleaning the substrate surface for 30 to 60 minutes. Ion cleaning can remove other impurities on the target surface, improve the uniformity and adhesion of the coating, and thus improve the overall performance of the coating.

[0050] In some embodiments, the high-power pulse ion bombardment cleaning of the substrate surface after ion cleaning specifically includes the following steps: starting high-power pulse magnetron sputtering, setting the pulse width to 2-40 μs, the average power to 2-10 kW, the gas pressure to 0.3-2 Pa, the argon gas flow rate to 120-160 sccm, the bias voltage to -100--200 V, and performing high-power pulse ion bombardment cleaning on the substrate surface for 10-15 minutes. High-power pulse ion bombardment cleaning of the substrate surface can activate the surface, improve ion mobility, enhance the bonding strength between the coating and the substrate, and improve the uniformity and density of the coating, thereby improving the performance of the film, including adhesion, hardness, wear resistance and corrosion resistance, and ultimately achieving the effect of enhancing the film-base bonding and reducing the stress of the film layer.

[0051] In some embodiments, when depositing the Cr bonding layer, the chamber pressure is 0.3-2 Pa, the argon flow rate is 100-130 sccm, and the bias voltage is -30--100 V; the pulse width of high-power pulsed magnetron sputtering is 2-40 μs, and the average power is 2-10 kW; the power of pulsed DC sputtering is 2-5 kW, and the frequency is 100 kHz. The present invention further achieves precise control of coating performance by precisely controlling the pulse parameters, deposition conditions, and bias settings of high-power pulsed magnetron sputtering and pulsed DC magnetron sputtering, so that the coating has excellent bonding and mechanical strength, meets the application requirements of cement kiln scrapers, and has a fast deposition rate, simple operation, low cost, and is suitable for mass production.

[0052] Furthermore, the Cr bonding layer is first deposited by high-power pulsed magnetron sputtering alone for 3 to 5 minutes, and then the Cr bonding layer is deposited by high-power pulsed magnetron sputtering and pulsed DC sputtering in combination for 3 to 5 minutes.

[0053] In some embodiments, when depositing the CrN layer, the chamber pressure is 0.6-1.5 Pa, the argon flow rate is 100-130 sccm, the nitrogen flow rate is 20-60 sccm, and the bias voltage is -60--150 V; the pulse width of high-power pulsed magnetron sputtering is 2-40 μs, and the average power is 2-10 kW; the power of pulsed DC sputtering is 2-5 kW, and the frequency is 100 kHz. The present invention further achieves precise control of coating performance by precisely controlling the pulse parameters, deposition conditions, and bias settings of high-power pulsed magnetron sputtering and pulsed DC magnetron sputtering, so that the coating has excellent bonding force and mechanical strength, meets the application requirements of cement kiln scrapers, and has a fast deposition rate, simple operation, low cost, and is suitable for mass production.

[0054] Furthermore, a CrN layer is deposited by combining high-power pulsed magnetron sputtering and pulsed DC sputtering for 1 to 3 hours.

[0055] In some embodiments, a four-target closed-field unbalanced magnetron sputtering system is used to perform the high-power pulsed magnetron sputtering and the pulsed DC sputtering; the four-target closed-field unbalanced magnetron sputtering system includes four metal Cr targets, two high-power pulsed magnetron sputtering power supplies, and two pulsed DC sputtering power supplies, each power supply is connected to one metal Cr target, and the metal Cr targets connected to the high-power pulsed magnetron sputtering power supply and the metal Cr targets connected to the pulsed DC sputtering power supply are arranged alternately. The four-target closed-field unbalanced magnetron sputtering can form a higher plasma density on the surface of the substrate and increase the gas ionization rate. A higher plasma density means that more sputtering ions can reach the surface of the substrate and deposit, so the deposition rate using closed-field unbalanced magnetron sputtering is higher. Using four power supplies to connect the targets separately can ensure the uniformity of the coating, improve production efficiency, and meet mass production requirements.

[0056] A third aspect of an embodiment of the present invention provides an application of the above-mentioned wear-resistant Cr / CrN nanocoating or the wear-resistant Cr / CrN nanocoating prepared by the above-mentioned preparation method, which is used to be formed on the surface of a cement kiln scraper to improve the wear resistance of the cement kiln scraper.

[0057] In the following embodiments, a four-target closed-field unbalanced magnetron sputtering system is used to perform high-power pulsed magnetron sputtering and pulsed DC sputtering; the four-target closed-field unbalanced magnetron sputtering system includes four metal Cr targets, two high-power pulsed magnetron sputtering power supplies and two pulsed DC sputtering power supplies, each power supply is connected to one metal Cr target, and the metal Cr targets connected to the high-power pulsed magnetron sputtering power supplies and the metal Cr targets connected to the pulsed DC sputtering power supplies are arranged alternately.

[0058] Example 1

[0059] The preparation method of the wear-resistant Cr / CrN nano coating of this embodiment comprises the following steps:

[0060] 1. Place the substrate in a container filled with anhydrous alcohol, clean it with an ultrasonic cleaning instrument for 30 minutes, take it out and blow dry the substrate with compressed air, and set it aside for use.

[0061] 2. Open the vacuum chamber of the magnetron sputtering instrument, place the substrate on the sample stage, close the vacuum chamber door, and evacuate the chamber until the vacuum degree is lower than 1×10 -4 Pa.

[0062] 3. Use a pulsed DC power supply to connect to the substrate, set the pulse parameters: bias voltage -500V, frequency 100KHz, pulse width 1μs, gas pressure 0.3Pa, argon flow rate 100sccm, and clean the sample for 40min.

[0063] 4. Start two high-power pulsed magnetron sputtering power supplies, set the pulse width to 2μs, the average power to 8kW, the gas pressure to 1Pa, the argon flow rate to 160sccm, the bias voltage to -200V, and bombard the substrate with high energy for 15min.

[0064] 5. Start two high-power pulsed magnetron sputtering power supplies, set the pulse width to 10μs, the average power to 5kW, the gas pressure to 0.6Pa, the argon flow rate to 120sccm, the bias voltage to -30V, and magnetron sputtering for 5min. Then start two pulsed DC magnetron sputtering power supplies, set the power to 5kW, the frequency to 100kHz, and magnetron sputtering for 5min to prepare a 20μm thick Cr bonding layer.

[0065] 6. While starting a high-power pulsed magnetron sputtering power supply and a pulsed DC magnetron sputtering power supply and keeping the parameters unchanged, adjust the argon flow rate to 120 sccm, the nitrogen flow rate to 60 sccm, the gas pressure to 0.6 Pa, adjust the bias voltage to -60 V, and magnetron sputter for 1 hour to prepare a 200 μm thick CrN nanocoating.

[0066] 7. After the coating preparation is completed, sample is taken after 30 minutes to obtain the wear-resistant Cr / CrN nano-coating.

[0067] Figure 1 It is the bonding force indentation of the wear-resistant Cr / CrN nano-coating obtained in this embodiment. Figure 2 This is the micrometer indentation of the wear-resistant Cr / CrN nano-coating obtained in this embodiment. It can be seen that no cracks are generated and the fracture toughness is good. Figure 3 This is a graph showing the change in friction coefficient of the wear-resistant Cr / CrN nano coating obtained in this embodiment after 2 hours of friction and wear. The coating is not damaged under the conditions of 2N load and 1Hz friction and wear for 2 hours. Figure 4 This is a photo of a cement kiln scraper having a wear-resistant Cr / CrN nano-coating formed on the surface.

[0068] Example 2

[0069] The preparation method of the wear-resistant Cr / CrN nano-coating in this embodiment is different from the preparation method in Example 1 in that:

[0070] In step 5, two high-power pulsed magnetron sputtering power supplies were started, and the pulse width was set to 2 μs, the average power was 5 kW, the gas pressure was 0.6 Pa, the argon gas flow rate was 120 sccm, the bias voltage was -100 V, and the magnetron sputtering was performed for 5 min. Then, two pulsed DC magnetron sputtering power supplies were started again, and the power was set to 5 kW, the frequency was 100 kHz, and the magnetron sputtering was performed for 5 min to prepare a 20 μm thick Cr bonding layer. In step 6, the above parameters were kept unchanged.

[0071] Example 3

[0072] The preparation method of the wear-resistant Cr / CrN nano-coating in this embodiment is different from the preparation method in Example 1 in that:

[0073] In step 5, two high-power pulsed magnetron sputtering power supplies were started, and the pulse width was set to 40 μs, the average power was 5 kW, the gas pressure was 0.6 Pa, the argon gas flow rate was 120 sccm, the bias voltage was -50 V, and the magnetron sputtering was performed for 5 min. Then, two pulsed DC magnetron sputtering power supplies were started again, and the power was set to 5 kW, the frequency was 100 kHz, and the magnetron sputtering was performed for 5 min to prepare a 20 μm thick Cr bonding layer. In step 6, the above parameters were kept unchanged.

[0074] Example 4

[0075] The preparation method of the wear-resistant Cr / CrN nano-coating in this embodiment is different from the preparation method in Example 1 in that:

[0076] In step 5, two high-power pulsed magnetron sputtering power supplies were started, with pulse width of 50 μs, average power of 5 kW, gas pressure of 0.6 Pa, argon flow rate of 120 sccm, bias voltage of -120 V, and magnetron sputtering for 5 min, and then two pulsed DC magnetron sputtering power supplies were started, with power of 5 kW and frequency of 100 kHz, and magnetron sputtering for 5 min to prepare a 20 μm thick Cr bonding layer. In step 6, the above parameters were kept unchanged.

[0077] Example 5

[0078] The preparation method of the wear-resistant Cr / CrN nano-coating in this embodiment is different from the preparation method in Example 1 in that:

[0079] In step 5, two high-power pulsed magnetron sputtering power supplies were started, and the pulse width was set to 1 μs, the average power was 5 kW, the gas pressure was 0.6 Pa, the argon gas flow rate was 120 sccm, the bias voltage was -20 V, and the magnetron sputtering was performed for 5 min. Then, two pulsed DC magnetron sputtering power supplies were started again, and the power was set to 5 kW, the frequency was 100 kHz, and the magnetron sputtering was performed for 5 min to prepare a 20 μm thick Cr bonding layer. In step 6, the above parameters were kept unchanged.

[0080] Example 6

[0081] The preparation method of the wear-resistant Cr / CrN nano-coating in this embodiment is different from that in Example 1 in that in step 6, nitrogen gas is introduced at a flow rate of 20 sccm.

[0082] Example 7

[0083] The preparation method of the wear-resistant Cr / CrN nano-coating in this embodiment is different from that in Example 1 in that in step 6, nitrogen gas is introduced at a flow rate of 10 sccm.

[0084] Example 8

[0085] The preparation method of the wear-resistant Cr / CrN nano-coating in this embodiment is different from the preparation method in Example 1 in that in step 6, the nitrogen gas flow rate is 70 sccm.

[0086] Comparative Example 1

[0087] The preparation method of the wear-resistant Cr / CrN nano-coating of this comparative example uses 4 high-power pulsed magnetron sputtering power supplies to deposit the Cr bonding layer and the CrN nano-coating. The specific parameters are the same as those in Example 1.

[0088] Comparative Example 2

[0089] The preparation method of the wear-resistant Cr / CrN nano-coating of this comparative example is different from that of Example 1 in that in step 5, two high-power pulsed magnetron sputtering power supplies are not started in advance, but two high-power pulsed magnetron sputtering power supplies and two pulsed DC magnetron sputtering power supplies are directly started at the same time.

[0090] The bonding strength, hardness, fracture toughness and elastic recovery of the wear-resistant Cr / CrN nano-coatings obtained in the above-mentioned embodiments and comparative examples were measured, and the results are shown in Table 1 below.

[0091] It can be seen from the data in Table 1 that the preparation method of Comparative Example 1 only uses a high-power pulsed magnetron sputtering power supply to deposit the coating, and the bonding strength, hardness, and toughness of the obtained coating are not as good as those of the embodiments of the present invention. The preparation method of Comparative Example 2 directly starts two high-power pulsed magnetron sputtering power supplies and two pulsed DC magnetron sputtering power supplies at the same time, and does not use a high-power pulsed magnetron sputtering power supply to first sputter and activate the substrate surface, and the bonding strength of the obtained coating is not as good as the coating obtained in the embodiments of the present invention.

[0092] The embodiments of the present invention use a high-power pulsed magnetron sputtering power supply and a pulsed DC magnetron sputtering power supply in combination, which can better control the growth process of the coating, obtain a more uniform and smooth coating surface, improve the adhesion and hardness / toughness of the coating, and increase the deposition rate. In the embodiments of the present invention, in embodiments 1-5, the magnetron sputtering bias and pulse width are different, among which the parameters of embodiments 1-3 can obtain a coating with better bonding and mechanical properties, which is a preferred embodiment.

[0093] In Examples 1, 6-8, the nitrogen flow rates are different, among which the coating composition obtained by the parameters of Examples 1 and 6 is more optimal and the coating performance is better, which is the preferred embodiment.

[0094] Table 1

[0095]

[0096]

[0097] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A wear-resistant Cr / CrN nano coating, characterized in that: The invention comprises a Cr bonding layer formed on the surface of a substrate and a CrN layer formed on the surface of the Cr bonding layer.

2. The wear-resistant Cr / CrN nano coating according to claim 1, characterized in that: The total thickness of the wear-resistant Cr / CrN nano coating is 200-500 μm; the thickness of the Cr bonding layer is 10-100 μm.

3. A method for preparing the wear-resistant Cr / CrN nano-coating according to claim 1 or 2, characterized in that: include: A Cr bonding layer is first deposited on the surface of the substrate by high-power pulsed magnetron sputtering, and then a Cr bonding layer is deposited by a combination of high-power pulsed magnetron sputtering and pulsed DC sputtering; A CrN layer is deposited on the surface of the Cr bonding layer by composite deposition of high-power pulsed magnetron sputtering and pulsed DC sputtering.

4. The preparation method according to claim 3, characterized in that: When depositing the Cr bonding layer, the chamber pressure is 0.3-2 Pa, the argon flow rate is 100-130 sccm, and the bias voltage is -30--100 V; the pulse width of high-power pulse magnetron sputtering is 2-40 μs, and the average power is 2-10 kW; the power of pulsed DC sputtering is 2-5 kW, and the frequency is 100 kHz.

5. The preparation method according to claim 3, characterized in that: When depositing the CrN layer, the chamber pressure is 0.6-1.5 Pa, the argon flow rate is 100-130 sccm, the nitrogen flow rate is 20-60 sccm, and the bias voltage is -60--150 V; the pulse width of high-power pulse magnetron sputtering is 2-40 μs, and the average power is 2-10 kW; the power of pulsed DC sputtering is 2-5 kW, and the frequency is 100 kHz.

6. The preparation method according to claim 3, characterized in that: The specific steps include: S1. Cleaning the surface of the substrate with a solvent; S2. performing ion cleaning on the surface of the substrate after solvent cleaning; S3. The substrate surface after ion cleaning is subjected to high-power pulse ion bombardment cleaning; S4. Depositing a Cr bonding layer by high-power pulsed magnetron sputtering on the surface of the substrate after high-power pulsed ion bombardment cleaning, and then depositing a Cr bonding layer by high-power pulsed magnetron sputtering and pulsed DC sputtering; S5. A CrN layer is deposited on the surface of the Cr bonding layer by composite deposition of high-power pulsed magnetron sputtering and pulsed DC sputtering to obtain the wear-resistant Cr / CrN nanocoating.

7. The preparation method according to claim 6, characterized in that: The ion cleaning of the substrate surface after solvent cleaning specifically includes the following steps: placing the substrate in a vacuum chamber, connecting a pulsed DC power supply to the substrate, setting pulse parameters: bias voltage of -500 to 600 V, frequency of 100 KHz, pulse width of 1 μs, gas pressure of 0.3 to 2 Pa, argon gas flow rate of 100 to 130 sccm, and performing ion cleaning on the substrate surface for 30 to 60 minutes.

8. The preparation method according to claim 6, characterized in that: The high-power pulse ion bombardment cleaning of the substrate surface after ion cleaning specifically includes the following steps: starting high-power pulse magnetron sputtering, setting the pulse width to 2-40μs, the average power to 2-10kW, the gas pressure to 0.3-2Pa, the argon gas flow rate to 120-160sccm, the bias voltage to -100--200V, and performing high-power pulse ion bombardment cleaning on the substrate surface for 10-15min.

9. The preparation method according to claim 3, characterized in that: A four-target closed-field unbalanced magnetron sputtering system is used to perform the high-power pulsed magnetron sputtering and the pulsed DC sputtering; The four-target closed-field unbalanced magnetron sputtering system includes four metal Cr targets, two high-power pulsed magnetron sputtering power supplies and two pulsed DC sputtering power supplies, each power supply is connected to one metal Cr target, and the metal Cr targets connected to the high-power pulsed magnetron sputtering power supplies and the metal Cr targets connected to the pulsed DC sputtering power supplies are arranged alternately.

10. Use of the wear-resistant Cr / CrN nanocoating according to claim 1 or 2 or the wear-resistant Cr / CrN nanocoating prepared by the preparation method according to any one of claims 3 to 9, characterized in that: Used to form on the surface of cement kiln scraper to improve the wear resistance of the cement kiln scraper.

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