A zirconium nitride coating, method for its production and use

Abstract

The application discloses a ZrN coating and a preparation method and application thereof, and belongs to the technical field of coating. The preparation method comprises the following steps: S1, depositing a PVD nitride coating on the surface of a metal-based substrate; S2, zirconium infiltration treatment: the furnace pressure in a vacuum furnace is extracted to be less than or equal to 200 Pa, then heating to completely melt a zirconium-based amorphous blank into a melt, then hot-dipping the PVD nitride coating into the zirconium-based amorphous melt, keeping warm for a period of time, then taking out, and preparing a ZrN coating; wherein, in the step S1, the thickness of the PVD nitride coating is 1-10 microns; in the step S2, the temperature of the zirconium-based amorphous melt is 1000-1500 DEG C, and the keeping warm time is 0.5-10 hours. The ZrN coating prepared by the application has a thickness of more than 2 microns, and the ZrN coating has excellent hardness, wear resistance, corrosion resistance and conductivity, and can be used as a fuel cell bipolar plate protective coating and a medical instrument coating.

Description

Technical Field

[0001] This invention belongs to the field of coating technology, specifically relating to a ZrN coating, its preparation method, and its application. Background Technology

[0002] ZrN coatings have high hardness, excellent wear resistance and corrosion resistance, and good biocompatibility, and have been widely used in surface coatings for cutting tools, molds, decorations, medical devices, fuel cell bipolar plates, etc.

[0003] Currently, the main methods for preparing ZrN coatings are laser cladding and physical vapor deposition. Among them, laser cladding can usually only prepare ZrN-containing metal matrix composites, and it is difficult to prepare high-purity ZrN coatings.

[0004] Existing technology discloses a method for preparing a ZrN-CrAlN composite coating, with a ZrN coating on the surface and a CrAlN coating on the bottom. The specific preparation process involves first preparing a hard CrAlN coating using cathodic arc plating; secondly, pre-forming ZrN grain growth points through Zr ion bombardment; then, depositing a soft ZrN layer on the CrAlN coating surface using cathodic arc plating; and finally, using ZrO2 nanoparticles to bombard the ZrN layer on the CrAlN-ZrN composite layer surface to form the ZrN coating. This process for preparing the ZrN coating is complex, involves numerous process parameters, and suffers from poor controllability. Furthermore, the ZrN coating prepared by this process has a thickness of less than 2.0 μm and exhibits poor wear resistance. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the defects of existing ZrN coating preparation and provide a ZrN coating preparation method that can prepare a ZrN coating with a large thickness and the coating has excellent hardness, wear resistance, corrosion resistance and conductivity.

[0006] Another object of the present invention is to provide a ZrN coating.

[0007] Another object of the present invention is to provide the application of ZrN coating in products such as fuel cell bipolar plates and medical devices.

[0008] To achieve the above objectives, the present invention employs the following technical solutions:

[0009] A method for preparing a ZrN coating includes the following steps:

[0010] S1. Deposit a PVD nitride coating on the surface of a metal substrate;

[0011] S2. Reduce the furnace pressure in the vacuum furnace to less than or equal to 200 Pa, then heat until the zirconium-based amorphous billet is completely melted into the melt. Then, immerse the PVD nitride coating in the zirconium-based amorphous melt, hold it at that temperature for a period of time, and then remove it to prepare the ZrN coating.

[0012] In step S1, the thickness of the PVD nitride coating is 1 to 10 μm.

[0013] In step S2, the temperature of the zirconium-based amorphous melt is 1000–1500℃, and the holding time is 0.5–10h.

[0014] PVD nitride coatings include one or more of CrN, AlCrN, TiSiN, and TiN.

[0015] The method of this invention can prepare ZrN coatings because, for coatings such as CrN and AlCrN, Cr and Cr2N decompose at temperatures above 900℃, releasing a large number of active nitrogen atoms. These active nitrogen atoms diffuse to the coating surface and combine with Zr to form a ZrN coating. For coatings such as TiN and TiSiN, although these coatings can withstand high temperatures, the Gibbs free energy of TiN at temperatures above 900℃ is higher than that of ZrN. Therefore, at high temperatures, the Zr + TiN → Ti + ZrN reaction easily occurs, forming a ZrN coating on the PVD coating surface.

[0016] The ZrN coating prepared by the method of this invention has a large thickness and exhibits excellent wear resistance, corrosion resistance, biocompatibility, and electrical conductivity.

[0017] In step S1, the metal substrate can be steel.

[0018] In step S1, the metal substrate can be pretreated, for example, polished to a roughness of ≤0.1μm, and then ultrasonically cleaned with acetone and anhydrous ethanol for 30 min in sequence, and dried with an air gun to obtain a sample with a clean surface.

[0019] In step S2, the pressure inside the furnace can be reduced to 30-180 Pa, for example, 150 Pa, 100 Pa, or 50 Pa.

[0020] Preferably, in step S2, the temperature of the zirconium-based amorphous melt is 1050–1100°C.

[0021] Preferably, in step S2, the heat preservation time is 1 to 5 hours.

[0022] Preferably, step S1 includes the following steps: placing the metal substrate on the substrate holder of the PVD furnace, opening the metal target, introducing nitrogen gas, and preparing a PVD nitride coating.

[0023] In step S1, the PVD deposition parameters include: furnace pressure of 1-5 Pa, target current of 80-200 A, substrate bias of -40-150 V, nitrogen flow rate of 300-700 sccm, deposition temperature of 350-550 °C, and deposition time of 1-10 h.

[0024] Preferably, the metal target is one or more of the following: Cr-containing target, AlCr target, TiSi target, and Ti target.

[0025] Preferably, the PVD nitride coating in step S1 is one or more of CrN, AlCrN, TiSiN, and TiN.

[0026] Preferably, the thickness of the PVD nitride coating in step S1 is 5–10 μm.

[0027] This invention also protects a ZrN coating prepared by any of the preparation methods described above.

[0028] Optionally, the thickness of the ZrN coating is 3 to 50 μm.

[0029] Preferably, the thickness of the ZrN coating is 4–30 μm.

[0030] More preferably, the thickness of the ZrN coating in step S2 is 5–20 μm.

[0031] This invention also protects the application of ZrN coatings in products such as fuel cell bipolar plates or medical devices.

[0032] Compared with the prior art, the beneficial effects of the present invention are:

[0033] This invention prepares a ZrN coating by depositing a PVD nitride coating on the surface of a metal substrate and then hot-dipping the PVD nitride coating into a zirconium-based amorphous melt for zirconium infiltration.

[0034] The ZrN coating prepared by this invention has a large thickness, reaching over 2 μm, and exhibits excellent wear resistance, corrosion resistance, conductivity, and biocompatibility. Its microhardness can reach 1800–2796 HV, and its wear rate can be as low as 0.65–5.26 × 10⁻⁶ HV. -15 m 3 The ZrN coating exhibits a high corrosion potential (-0.44 to -0.3V) and a low resistivity (200 to 300 μΩ·cm, compared to 100 to 500 μΩ·cm for stainless steel). This invention provides a promising application for ZrN coatings in medical devices and fuel cell bipolar plates. Attached Figure Description

[0035] Figure 1The image shows the surface SEM morphology of the CrN coating after immersion in zirconium-based amorphous melt for 5 hours in Example 1, along with the elemental distribution in the boxed area.

[0036] Figure 2 The image shows the cross-sectional morphology of the CrN coating after being hot-dipped into the zirconium-based amorphous melt for 5 hours in Example 1.

[0037] Figure 3 The XRD pattern of the CrN coating after hot immersion in zirconium-based amorphous melt for 5 hours in Example 1.

[0038] Figure 4 The XRD pattern of the CrN-coated zirconium-based amorphous melt after 5 hours of hot-dip immersion in the melt is shown in Example 1. Detailed Implementation

[0039] The present invention is further illustrated below with reference to specific embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions in the art or as recommended by the manufacturer; the raw materials and reagents used, unless otherwise specified, are all commercially available from the conventional market. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention are within the scope of protection claimed by the present invention.

[0040] Example 1

[0041] This embodiment provides a method for preparing a ZrN coating, including the following steps:

[0042] S1. Polish the 8407 mold steel metal substrate to a roughness ≤0.1μm, then ultrasonically clean it with acetone and anhydrous ethanol for 30min in sequence, and dry it with an air gun. Place it on the substrate holder of the PVD furnace, turn on the Cr target, introduce nitrogen gas, and adjust the PVD deposition parameters as follows: PVD furnace pressure 3.0Pa, target current 160A, substrate bias voltage -80V, nitrogen flow rate 500sccm, deposition temperature 420℃ and deposition time 3h to prepare a CrN coating with a thickness of 5.0μm.

[0043] S2. Zirconium infiltration treatment: The furnace pressure in the vacuum furnace is reduced to 50 Pa, and then heated until the zirconium-based amorphous billet is completely melted into the melt. The zirconium-based amorphous billet in the furnace is heated to 1050℃ and completely melted. The CrN coating is hot-immersed into the zirconium-based amorphous melt and held for 5 hours. Then it is cooled and removed to prepare the ZrN coating. The average thickness of the ZrN coating is about 12 μm.

[0044] Example 2

[0045] This embodiment provides a method for preparing a ZrN coating, which differs from Example 1 in that:

[0046] S1. Adjust the PVD deposition parameters to PVD furnace pressure 3.0 Pa, target current 160 A, substrate bias voltage -80 V, nitrogen flow rate 500 sccm, deposition temperature 420 ℃ and deposition time 0.5 h to prepare a CrN coating with a thickness of 1.0 μm.

[0047] The rest is the same as in Example 1, and will not be repeated here.

[0048] Example 3

[0049] This embodiment provides a method for preparing a ZrN coating, which differs from Example 1 in that:

[0050] S1. Adjust the PVD deposition parameters to PVD furnace pressure 3.0 Pa, target current 160 A, substrate bias voltage -80 V, nitrogen flow rate 500 sccm, deposition temperature 420 ℃ and deposition time 5.5 h to prepare a CrN coating with a thickness of 10.0 μm.

[0051] The rest is the same as in Example 1, and will not be repeated here.

[0052] Example 4

[0053] This embodiment provides a method for preparing a ZrN coating, which differs from Example 1 in that:

[0054] S2. Zirconium infiltration treatment: The furnace pressure in the vacuum furnace is reduced to 50 Pa, and then heated until the zirconium-based amorphous billet is completely melted into the melt. The zirconium-based amorphous billet in the furnace is heated to 1000℃ and completely melted. The CrN coating is hot-immersed into the zirconium-based amorphous melt, held at the temperature for 5 hours, and then cooled and removed to prepare the ZrN coating.

[0055] The rest is the same as in Example 1, and will not be repeated here.

[0056] Example 5

[0057] This embodiment provides a method for preparing a ZrN coating, which differs from Example 1 in that:

[0058] S2. Zirconium infiltration treatment: The furnace pressure in the vacuum furnace is reduced to 50 Pa, and then heated until the zirconium-based amorphous billet is completely melted into the melt. The zirconium-based amorphous billet in the furnace is heated to 1500℃ and completely melted. The CrN coating is hot-immersed into the zirconium-based amorphous melt, held at that temperature for 5 hours, and then cooled and removed to prepare the ZrN coating.

[0059] The rest is the same as in Example 1, and will not be repeated here.

[0060] Example 6

[0061] This embodiment provides a method for preparing a ZrN coating, which differs from Example 1 in that:

[0062] S2. Zirconium infiltration treatment: The furnace pressure in the vacuum furnace is reduced to 50 Pa, and then heated until the zirconium-based amorphous billet is completely melted into the melt. The zirconium-based amorphous billet in the furnace is heated to 1050℃ and completely melted. The CrN coating is hot-immersed into the zirconium-based amorphous melt and held at that temperature for 0.5 h. Then it is cooled and removed to prepare the ZrN coating.

[0063] The rest is the same as in Example 1, and will not be repeated here.

[0064] Example 7

[0065] This embodiment provides a method for preparing a ZrN coating, which differs from Example 1 in that:

[0066] S2. Zirconium infiltration treatment: The furnace pressure in the vacuum furnace is reduced to 50 Pa, and then heated until the zirconium-based amorphous billet is completely melted into the melt. The zirconium-based amorphous billet in the furnace is heated to 1050℃ and completely melted. The CrN coating is hot-immersed into the zirconium-based amorphous melt, held at the temperature for 10 hours, and then cooled and removed to prepare the ZrN coating.

[0067] The rest is the same as in Example 1, and will not be repeated here.

[0068] Example 8

[0069] This embodiment provides a method for preparing a ZrN coating, which differs from Example 1 in that:

[0070] S2. Zirconium infiltration treatment: The furnace pressure in the vacuum furnace is reduced to 200 Pa, and then heated until the zirconium-based amorphous billet is completely melted into the melt. The zirconium-based amorphous billet in the furnace is heated to 1050℃ and completely melted. The CrN coating is hot-immersed into the zirconium-based amorphous melt, held at that temperature for 5 hours, and then cooled and removed to prepare the ZrN coating.

[0071] The rest is the same as in Example 1, and will not be repeated here.

[0072] Example 9

[0073] This embodiment provides a method for preparing a ZrN coating, which differs from Example 1 in that:

[0074] S1. Polish the 8407 mold steel metal substrate to a roughness ≤0.1μm, then ultrasonically clean it with acetone and anhydrous ethanol for 30min in sequence, and dry it with an air gun. Place it on the substrate holder of the PVD furnace, turn on the target material AlCr, introduce nitrogen gas, and adjust the PVD deposition parameters as follows: PVD furnace pressure 3.0Pa, target current 160A, substrate bias voltage -80V, nitrogen flow rate 500sccm, deposition temperature 420℃ and deposition time 3h to prepare an AlCrN coating with a thickness of 5.0μm.

[0075] The rest is the same as in Example 1, and will not be repeated here.

[0076] Example 10

[0077] This embodiment provides a method for preparing a ZrN coating, which differs from Example 1 in that:

[0078] S1. Polish the 8407 mold steel metal substrate to a roughness ≤0.1μm, then ultrasonically clean it with acetone and anhydrous ethanol for 30min in sequence, and dry it with an air gun. Place it on the substrate holder of the PVD furnace, turn on the target material Ti, introduce nitrogen gas, and adjust the PVD deposition parameters as follows: PVD furnace pressure 3.0Pa, target current 160A, substrate bias voltage -80V, nitrogen flow rate 500sccm, deposition temperature 420℃ and deposition time 3h to prepare a TiN coating with a thickness of 5.0μm.

[0079] The rest is the same as in Example 1, and will not be repeated here.

[0080] Example 11

[0081] This embodiment provides a method for preparing a ZrN coating, which differs from Example 1 in that:

[0082] S1. Polish the 8407 mold steel metal substrate to a roughness ≤0.1μm, then ultrasonically clean it sequentially with acetone and anhydrous ethanol for 30min, and dry it with an air gun. Place it on the substrate holder of the PVD furnace, turn on the TiSi target, introduce nitrogen gas, and adjust the PVD deposition parameters as follows: PVD furnace pressure 3.0Pa, target current 160A, substrate bias voltage -80V, nitrogen flow rate 500sccm, deposition temperature 420℃, and deposition time 3h. Prepare a TiSiN coating with a thickness of 5.0μm. The rest is the same as in Example 1, and will not be repeated here.

[0083] Examples 2-11 provide methods for preparing ZrN coatings of different thicknesses. The only differences from Example 1 are the PVD coating type and thickness in step S1, and the vacuum furnace pressure, heating temperature, and holding time in step S2. The rest are the same as in Example 1, as shown in Table 1 below:

[0084] Table 1. PVD coating type, thickness, and Zr infiltration process parameters for Examples 2-6

[0085]

[0086] Comparative Examples 1-7

[0087] Comparative Examples 1-7 provide methods for preparing ZrN coatings of different thicknesses. The differences from Example 2 lie in steps S1 and S2, as detailed in Table 2 below:

[0088] Table 2 shows the PVD coating type, thickness, and Zr infiltration process parameters for Comparative Examples 4–6.

[0089]

[0090]

[0091] Comparative Example 8

[0092] ZrN coatings were prepared according to the process described in the publicly available document (CN 202310384312). The main process parameters are as follows:

[0093] S1: A CrAlN coating is deposited on the surface of a metal substrate by cathodic arc plating. Argon and nitrogen are introduced, with a gas flow rate of 400-550 sccm and an atomic ratio of nitrogen to argon of 3:1. An AlCr alloy target is used, the substrate temperature is 500℃, the bias voltage is -80V, the target current is 80A, and the CrAlN coating thickness is 3.0μm.

[0094] S2: Zr ion bombardment of the CrAlN coating was used to implant ZrN crystal growth points. The process parameters were: bias voltage, -200V; argon flow rate, 400 sccm; target current, 120A; thickness of the Zr-implanted CrAlN layer, 3.0 μm.

[0095] S3: A ZrN soft layer is deposited on the CrAlN coating surface by cathodic arc deposition. The deposition process parameters are: nitrogen and argon flow rate, 500 sccm, and nitrogen to argon ratio 3:1; substrate temperature 500℃, substrate bias voltage -80V; target current 80A.

[0096] S4: ZrO2 nanoparticles are used to bombard the surface of the ZrN soft coating to form a ZrN coating.

[0097] Performance testing

[0098] Figure 1 This is a schematic diagram of the structure of the metal substrate and ZrN coating in Example 1.

[0099] Figure 2This image shows the SEM morphology of the CrN-coated zirconium-based amorphous melt after 5 hours of hot-dip immersion in the melt, along with the elemental distribution of the boxed region. (From...) Figure 2 As can be seen, the surface of the hot-dip coating is rich in Zr and N elements, which indicates the formation of the ZrN coating.

[0100] Figure 3 This image shows the cross-sectional morphology of the CrN-coated zirconium-based amorphous melt after 5 hours of hot-dip immersion. From... Figure 3 As can be seen, a ZrN coating of a certain thickness was formed on the surface of the hot-dip coating.

[0101] Figure 4 The image shows the surface XRD pattern of the CrN-coated zirconium-based amorphous melt after 5 hours of hot-dip immersion in the melt. From... Figure 4 As can be seen, the ZrN coating is composed entirely of the ZrN phase and does not contain any other phases.

[0102] The surface oxide film density, adhesion, wear resistance, and anti-adhesion properties of the PVD oxide composite coatings in each embodiment and comparative example were tested.

[0103] (1) Microhardness test

[0104] The coating hardness of the examples and comparative examples was tested using a microhardness tester. The test load was 50g.

[0105] (2) Abrasion resistance test

[0106] The wear rate of the composite coatings in each embodiment and comparative example was tested using a room temperature friction and wear tester. The lower the wear rate, the better the wear resistance.

[0107] (3) Electrochemical performance testing

[0108] The corrosion potential of the coating was tested using an electrochemical workstation. A higher corrosion potential indicates better corrosion resistance. The corrosion solution was a 3.5 wt.% NaCl solution, and the test temperature was room temperature.

[0109] (4) Resistivity test: The resistivity of various coatings is tested using a resistivity tester. The higher the resistivity, the worse its conductivity.

[0110] The experimental test results are shown in Table 3.

[0111] Table 3 Performance test results of coatings in each embodiment and comparative example

[0112]

[0113]

[0114] The ZrN coating prepared by this invention has a large thickness, ranging from 4.5 to 46.9 μm, and exhibits excellent hardness, wear resistance, corrosion resistance, and electrical conductivity. The microhardness can reach 1800–2796 HV, and the wear rate can be as low as 0.65–5.26 × 10⁻⁶ HV. -15 m 3 / Nm, corrosion potential can be as high as -0.44 to -0.3V, and resistivity can be as low as 205-299μΩ·cm.

[0115] By comparing the data in Table 1 and conducting data analysis, it can be found that if the PVD coating is too thin (Comparative Example 1), it can provide fewer nitrogen atoms. A thin ZrN coating results in low conductivity but poor hardness and wear resistance. If the PVD coating is too thick (Comparative Example 2), further thickening the PVD coating slightly increases the ZrN thickness, but the wear resistance and corrosion resistance are too poor. At a low Zr diffusion temperature (Comparative Example 3), the Zr alloy is difficult to completely melt, and Zr diffusion is slow, resulting in an extremely thin ZrN layer. Although the resistivity decreases, the corrosion resistance and wear resistance significantly deteriorate. At a high Zr diffusion temperature (Comparative Example 4), the CrN coating decomposes rapidly, quickly forming a ZrN layer on its surface. This hinders the outward diffusion of nitrogen atoms, thus preventing the formation of a hard ZrN coating. Consequently, the ZrN layer becomes thinner, resulting in reduced corrosion resistance and resistivity, but also reduced hardness and wear resistance.

[0116] Short Zr infiltration time (Comparative Example 5) results in a thin ZrN layer with poor wear resistance; long Zr infiltration time (Comparative Example 6) does not significantly increase the thickness of the ZrN layer, but significantly reduces its wear resistance.

[0117] In Comparative Example 7, excessive pressure inside the vacuum furnace resulted in a high residual oxygen content. Since Zr is a strong oxygen-binding element, it readily forms the ZrO2 phase, thus affecting the formation quality and performance of the ZrN layer. Consequently, the coating's hardness and wear resistance decreased, corrosion resistance worsened, resistivity increased, and conductivity deteriorated. Furthermore, this process is extremely complex, with numerous adjustable process parameters.

[0118] Comparative Example 8, using a publicly available process to prepare a ZrN coating with a thickness of approximately 2.0 μm, showed that its surface hardness, wear resistance, and corrosion resistance were all lower than those of the present invention. This indicates that the ZrN coating is too thin to provide adequate protection to the metal substrate.

[0119] As can be seen from Examples 1 to 3, when the thickness of the PVD nitride coating is 5 to 10 μm, it has superior hardness, wear resistance, corrosion resistance and conductivity.

[0120] As can be seen from Examples 1, 4 and 5, in step S2 zirconium infiltration treatment, the temperature of the zirconium-based amorphous melt is 1050-1100℃, which has better hardness, wear resistance, corrosion resistance and conductivity.

[0121] As can be seen from Examples 1, 6 and 7, the heat preservation time of 5 to 10 hours in step S2 zirconium infiltration treatment results in superior hardness, wear resistance, corrosion resistance and electrical conductivity.

[0122] As can be seen from Examples 1 and 8, in step S2, the furnace pressure in the vacuum furnace is 50-100 Pa, which results in superior hardness, wear resistance, corrosion resistance and electrical conductivity.

[0123] As can be seen from Examples 1 and 9-11, in step S1, the PVD nitride coating is CrN or AlCrN, which has better hardness, wear resistance and corrosion resistance.

[0124] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a ZrN coating, characterized in that, Includes the following steps: S1. Deposit a PVD nitride coating on the surface of a metal substrate; S2. Zirconium infiltration treatment: The furnace pressure in the vacuum furnace is reduced to less than or equal to 200 Pa, and then heated until the zirconium-based amorphous billet is completely melted into the melt. Then, the PVD nitride coating is hot-immersed into the zirconium-based amorphous melt, held at the temperature for a period of time, and then removed to prepare the ZrN coating. In step S1, the thickness of the PVD nitride coating is 1~10μm; The PVD nitride coating mentioned in step S1 is one or more of CrN, TiSiN, and TiN; In step S2, the temperature of the zirconium-based amorphous melt is 1000~1500℃, and the holding time is 0.5~10h.

2. The preparation method according to claim 1, characterized in that, In step S2, the furnace pressure in the vacuum furnace is reduced to 50~100Pa, the temperature of the zirconium-based amorphous melt is 1050~1100℃, and the holding time is 5~10h.

3. The preparation method according to claim 1, characterized in that, In step S1, the thickness of the PVD nitride coating is 5~10μm.

4. The preparation method according to claim 1, characterized in that, Step S1 includes the following steps: placing the metal substrate on the substrate holder of the PVD furnace, opening the metal target, introducing nitrogen gas, adjusting the PVD process parameters, and preparing a PVD nitride coating.

5. The preparation method according to claim 4, characterized in that, The metal target material is one or more of Cr-containing targets, TiSi targets, and Ti targets.

6. The preparation method according to claim 4, characterized in that, In step S1, the PVD process includes an internal furnace pressure of 1~5 Pa, a titanium-containing target current of 80~200A, a substrate bias voltage of -40~-150V, a nitrogen flow rate of 300~700sccm, a deposition temperature of 350~550℃, and a deposition time of 1~10h.

7. A ZrN coating, characterized in that, It is prepared by any of the preparation methods described in claims 1 to 6.

8. The ZrN coating according to claim 7, characterized in that, The thickness of the ZrN coating is 4~30μm.

9. The application of the ZrN coating of claim 8 in fuel cell bipolar plates or medical devices.

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