Application of MAX phase coating in lead bismuth environment

Abstract

The invention belongs to the technical field of nuclear energy materials and surface engineering, and particularly relates to application of an MAX phase coating in a lead bismuth environment. The MAX phase coating is deposited on the surface of the structural material, so that the corrosion resistance and wear resistance of the steam generator can be remarkably improved. The result shows that under the conditions that the temperature is 450 DEG C, the normal load is 50N, the displacement amplitude is 75 microns, the vibration frequency is 25Hz and the cycle index is 106, a stable aluminum oxide oxidation layer and a compacted abrasive dust layer can be formed, so that the Ni element is effectively prevented from being dissolved, and the corrosion rate of a structural material is reduced; meanwhile, the abrasion depth of the structural material is reduced by 70% compared with that before protection, the structure is stable, the binding force is high, and the structural material is still kept complete and has no obvious peeling or failure phenomenon even in a long-cycle test.

Description

Technical Field

[0001] This invention belongs to the field of nuclear energy materials and surface engineering technology, specifically relating to the application of a MAX phase coating in a lead-bismuth environment. Background Technology

[0002] Lead-bismuth cooled fast reactors refer to reactors that use liquid lead-bismuth alloy (LBE) as a coolant. Due to its excellent heat transfer characteristics, high chemical stability, mature technology, and high safety, LBE has become the primary coolant for fourth-generation nuclear power plant lead-cooled fast reactors. Austenitic stainless steel, due to its good mechanical properties and mature processing technology, is considered a candidate material for key components such as steam generators (SG) in nuclear power plants. However, in high-temperature lead-bismuth environments, austenitic stainless steel is prone to severe corrosion and wear: on the one hand, Ni dissolves into the liquid lead-bismuth alloy, causing uneven matrix composition and deterioration of mechanical properties; on the other hand, the pipes and support structures of the steam generator are subjected to long-term scouring by the high-speed coolant (lead / lead-bismuth), easily generating flow-induced vibrations, thereby inducing fretting wear and corrosion of the structural materials. The combined effects of these corrosion and wear significantly shorten the service life of the steam generator.

[0003] Currently, some research has been conducted on corrosion protection of steam generators in lead-bismuth environments. Common methods include sandblasting, surface modification, laser cladding, and spraying to reduce the erosion of materials by lead-bismuth alloys. However, these methods still suffer from problems such as insufficient protective layer stability, limited bonding strength, and poor wear resistance, making it difficult to meet the requirements for long-term stable operation of nuclear power systems. Summary of the Invention

[0004] The purpose of this invention is to provide an application of MAX phase coating in lead-bismuth environments. The application provided by this invention can significantly improve the corrosion resistance and wear resistance of materials, thereby effectively extending the service life of key components of steam generators.

[0005] To achieve the above objectives, the present invention provides the following technical solution: This invention provides an application of a MAX phase coating in a lead-bismuth environment, wherein the MAX phase coating includes one or more of Cr2AlC coating, Ti2AlC coating and Ti3SiC2 coating.

[0006] Preferably, the thickness of the MAX phase coating is 1~20μm.

[0007] Preferably, the lead-bismuth environment is a high-temperature lead-bismuth environment, and the temperature of the high-temperature lead-bismuth environment is 300~600℃.

[0008] Preferably, the lead-bismuth environment is a liquid lead-bismuth eutectic alloy, and the composition of the lead-bismuth eutectic alloy is 55.5 wt% lead and 44.5 wt% bismuth.

[0009] Preferably, the method of application includes the following steps: sequentially performing surface activation, coating deposition, and annealing on the structural material.

[0010] Preferably, the structural material is further subjected to pretreatment before use; the pretreatment includes the following steps: polishing and ultrasonic cleaning the structural material in sequence.

[0011] Preferably, the surface activation is ion bombardment; the ion bombardment is Ar. + Ion bombardment; the duration of the ion bombardment is 30 minutes or more.

[0012] Preferably, the method for depositing the coating is a combination of arc ion plating and magnetron sputtering; the deposition of the coating includes the following steps: using Cr or Ti as the arc source, Al or Si as the magnetron sputtering target, and CH4 as the carbon source for deposition.

[0013] Preferably, the deposition temperature is 145~155°C, the total deposition time is 2~3 hours, the power of the arc source is 1.0kW, the power of the magnetron sputtering is 3.1kW, and the substrate bias voltage is 150V.

[0014] Preferably, the annealing temperature is 600~620°C and the vacuum degree is 10. -3 Pa, the heat preservation time is 0.5~1.5h.

[0015] This invention provides an application of MAX phase coating in lead-bismuth environments. Based on MAX phase coating, this invention proposes a method for protecting structural materials in nuclear steam generators. The MAX phase coating of this invention exhibits excellent corrosion resistance and wear resistance in lead-bismuth environments, and is particularly suitable for high-temperature environments of lead-bismuth eutectic (LBE), thereby effectively extending the service life of key components of steam generators, improving the safety and reliability of nuclear power system operation, and providing a feasible technical solution for the protection of structural materials in similar harsh environments.

[0016] This invention significantly improves the corrosion resistance and wear resistance of steam generators by depositing a MAX phase coating on the surface of structural materials (e.g., 316L stainless steel). Experimental results show that under conditions of 450°C, 50N normal load, 75μm displacement amplitude, 25Hz vibration frequency, and 10 cycles, the coating is effective. 6Under these conditions, the present invention can form a stable alumina oxide layer and a compacted wear debris layer, thereby effectively preventing Ni element dissolution and reducing the corrosion rate of the structural material; at the same time, the wear depth of the structural material is reduced by 70% compared with that before protection, and the structure is stable and has strong bonding force, remaining intact even in long-cycle testing, without obvious peeling or failure. Specifically: (1) Layered crystal structure: The MAX phase coating has a unique layered crystal structure (for example, the crystal structure of Cr2AlC is composed of octahedral Cr2Al sheets and C atomic layers stacked alternately along a fixed axis, which has the characteristics of a layered structure). Under the action of friction and corrosion, it can form an adaptive third body layer (TBL) through interlayer slip or lattice misalignment. This dynamically generated dense oxide layer forms a barrier against lead bismuth penetration and tribological wear.

[0017] (2) Element action mechanism: Taking Cr2AlC as an example, the Al element in Cr2AlC reacts synergistically with oxygen in the lead-bismuth environment to preferentially generate a dense and stable α-Al2O3 oxide film, which can not only block the penetration of lead-bismuth alloy, but also continuously repair during the friction process; Cr element will form Cr2O3 with oxygen in the high temperature environment and be doped into α-Al2O3 to improve the density of the oxide film, thereby enhancing the wear resistance and corrosion resistance.

[0018] (3) Self-healing / adaptiveness: Unlike simple "corrosion-resistant materials", Cr2AlC exhibits dynamic evolution characteristics in lead-bismuth-micro-motion environment. It forms a discontinuous layer in the early stage and then evolves into a stable dense protective layer. This "wear-corrosion synergistic driven adaptive protection mechanism" is the key to the protective effect of this invention. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the process flow for preparing the MAX phase coating according to the present invention; Figure 2 The diagram shows the testing device used in this invention and its working state; where a is the overall structural diagram of the testing device, b is a schematic diagram of the method of fixing the sample in the testing device (to ensure that the sample is subjected to uniform force and is in a stable position during the test), and c is a schematic diagram of the contact state of the grinding parts. Figure 3 The surface composition (a) and cross-sectional morphology and composition (b) of the Cr2AlC coating prepared in Example 1 are shown. Figure 4 The graphs show the maximum wear depth (a), maximum wear depth fitting curve (b), wear volume (c), and wear coefficient (d) of the Cr2AlC coating prepared in Example 1 and the control group under different cycles. Figure 5 SEM morphology and EDS composition analysis of the worn surface of the 316L stainless steel control group. Figure 6 The images show the SEM morphology and EDS composition analysis of the worn surface of the Cr2AlC coating prepared in Example 1. Figure 7 SEM cross-sectional morphology and EDS composition analysis of the fretting wear zone of the 316L stainless steel control group; Figure 8 The image shows the SEM cross-sectional morphology and EDS composition analysis of the wear zone of the Cr2AlC coating in Example 1. Figure 9 XRD composition analysis of the surface micro-area of ​​Cr2AlC coating after different cycle numbers; Figure 10 The changes in surface mechanical properties (hardness H, elastic modulus E, H / E and H) of Cr2AlC coating and 316L stainless steel under different cycles. 3 / E 2 ). Detailed Implementation

[0021] This invention provides an application of MAX phase coating in a lead-bismuth environment.

[0022] In this invention, the MAX phase coating preferably includes one or more of Cr2AlC, Ti2AlC, and Ti3SiC2 coatings. The MAX phase coating used in this invention combines the toughness of metals with the high hardness of ceramics, exhibiting excellent resistance to high-temperature oxidation, corrosion resistance, and fracture toughness, making it suitable as a surface protection material under harsh working conditions.

[0023] In this invention, the thickness of the MAX phase coating is preferably 1~20 μm, more preferably 5~15 μm. This invention employs the above thickness range to adapt to the needs of different components and service environments.

[0024] In this invention, the lead-bismuth environment is preferably a high-temperature lead-bismuth environment; the temperature of the high-temperature lead-bismuth environment is preferably 300~600℃, more preferably 400~500℃; the lead-bismuth environment is preferably a liquid lead-bismuth eutectic alloy, and the composition of the lead-bismuth eutectic alloy is preferably 55.5wt% lead and 44.5wt% bismuth. The high-temperature lead-bismuth environment described above in this invention is very similar to the service conditions of modern nuclear power plant steam generators.

[0025] In this invention, the method of application preferably includes the following steps: sequentially performing surface activation, coating deposition, and annealing on the structural material.

[0026] In this invention, the structural material is preferably austenitic stainless steel; the austenitic stainless steel is preferably 316L stainless steel.

[0027] In this invention, the structural material preferably undergoes pretreatment before use; the pretreatment preferably includes the following steps: polishing and ultrasonic cleaning the structural material sequentially; the polishing preferably uses SiC sandpaper; the SiC sandpaper is preferably #800~#2000 grit, specifically #800, #1000, #1500, and #2000; the ultrasonic cleaning reagent is preferably acetone and anhydrous ethanol; the ultrasonic cleaning time for a single session is preferably 20 minutes. This invention achieves a uniform and smooth surface through polishing.

[0028] In this invention, the ultrasonic cleaning process preferably includes drying; the drying is preferably blow-drying; and the gas used for blow-drying is preferably nitrogen.

[0029] In this invention, the pretreatment preferably includes cutting the structural material to the target size.

[0030] In this invention, the surface activation is preferably ion bombardment; the ion bombardment is preferably Ar. + Ion bombardment; the ion bombardment time is preferably 30 minutes or more. This invention, through surface activation, both increases the surface activation degree of the structural material and removes residual impurities.

[0031] In this invention, the deposition method is preferably a combination of arc ion plating and magnetron sputtering; the deposition preferably includes the following steps: using Cr or Ti as the arc source, Al or Si as the magnetron sputtering target, and CH4 as the carbon source for deposition. This invention employs a combination of arc ion plating and magnetron sputtering to deposit a nano-coating on the surface of a structural material.

[0032] In this invention, the deposition temperature is preferably 145~155°C, more preferably 150°C, the Ar gas flow rate is preferably 200 sccm, the CH4 flow rate is preferably 25 sccm, the total deposition time is preferably 2~3 hours, more preferably 2 hours; the arc source power is preferably 1.0kW, the magnetron sputtering power is preferably 3.1kW, and the substrate bias voltage is preferably 150V.

[0033] In this invention, the annealing temperature is preferably 600~620°C, more preferably 610°C, and the vacuum degree is preferably 10. -3Pa, the holding time is preferably 0.5~1.5h, more preferably 1h. This invention promotes the formation of the MAX phase and improves the crystallinity and stability of the coating through annealing.

[0034] The MAX phase coating of this invention has two main functions in a lead-bismuth environment: First, it acts as a physical barrier. Cr2AlC has a nanocrystalline and layered composite structure, which can form a dense and stable oxide interface layer in a lead-bismuth environment. This structure significantly increases the penetration resistance of lead-bismuth atoms to the surface of the structural material, forming a physical barrier and slowing down element dissolution and structural material damage. Second, it has lower chemical affinity. Taking 316L as an example, compared with elements such as Ni and Fe in 316L, the main components (Al, Cr, and C) in the Cr2AlC coating have significantly lower chemical affinity to lead-bismuth, making them less prone to dissolution and interdiffusion. This low affinity makes the coating more difficult to corrode and weaken in lead-bismuth alloys, thus maintaining higher structural integrity and service stability under wear-corrosion coupling.

[0035] To further illustrate the present invention, the following detailed description of the invention's solutions, in conjunction with the accompanying drawings and embodiments, is provided, but should not be construed as limiting the scope of protection of the present invention.

[0036] Example 1 In this embodiment, a MAX phase coating was prepared on the surface of 316L austenitic stainless steel for use in the heat exchange tubes of a steam generator. The process flow is as follows: Figure 1 As shown, the details are as follows: (1) MAX phase coating and substrate: The MAX phase coating used in this embodiment is a Cr2AlC coating; the structural material (substrate) is 316L austenitic stainless steel, used for the heat exchange tubes of the steam generator, with a tube length of 22mm, a diameter of 20mm, and a wall thickness of 2mm; the anti-vibration strip has a length of 20mm and a width of 20mm.

[0037] (2) A combination of arc ion plating and magnetron sputtering was used to deposit a MAX phase coating on the heat exchange tubes of the steam generator: 316L austenitic stainless steel was cut to standard dimensions and polished sequentially using #800, #1000, #1500, and #2000 SiC sandpaper to ensure a smooth surface. The polished 316L austenitic stainless steel was then ultrasonically cleaned for 20 minutes (one round each with acetone and anhydrous ethanol), and then dried with nitrogen gas. Subsequently, Ar... +Surface bombardment with ions for 30 minutes further cleaned and activated the surface. During deposition, Cr was used as the arc source, Al as the magnetron sputtering target, and CH4 as the carbon source. Deposition was carried out at 150°C with an Ar flow rate of 200 sccm, a CH4 flow rate of 25 sccm, an arc source power of 1.0 kW, a magnetron power of 3.1 kW, and a substrate bias of 150 V for a total deposition time of 2 hours. After deposition, 316L austenitic stainless steel was subjected to 10... -3 Annealing at 600℃ for 1 hour under vacuum conditions promotes the formation of the Cr2AlC phase, and the coating thickness is 15µm.

[0038] Test Example 1 This test case involved a lead-bismuth environmental corrosion-wear test to simulate the service conditions of a steam generator. The test apparatus used was as follows: Figure 2 As shown, the specific steps are as follows: (1) Melt the solid lead-bismuth alloy by heating: raise the temperature to 300℃, heat for 0.5h and then keep it at that temperature for 1h.

[0039] (2) Install the test specimen: Fix the heat exchange tube coated with MAX phase coating on the experimental vessel clamp, install the anti-vibration strip and adjust the relative position of the tube-plate so that the two are in plane contact.

[0040] (3) Pass the liquid lead-bismuth alloy into the experimental vessel and observe the liquid level to ensure that it completely covers the specimen.

[0041] (4) Corrosion test: The specimen is immersed in a lead-bismuth environment at 450℃ for 1~2 hours, and corrosion and wear test is carried out after the temperature stabilizes.

[0042] (5) Fretting wear test: conducted in a corrosive environment, with a fretting displacement of 75 μm, a normal force of 50 N, a frequency of 25 Hz, and 10 cycles. 6 This process allows the coating to form a compacted abrasive layer and resist fretting corrosion.

[0043] (6) After the test, the temperature of the experimental vessel was reduced to 200℃ and kept warm for 1 hour. The fixture was removed, the lead-bismuth alloy residue on the surface of the specimen was removed, and subsequent observation was carried out.

[0044] (7) Observation and analysis: The control group consisted of uncoated 316L stainless steel, while the experimental group consisted of 316L stainless steel with a MAX phase coating deposited on its surface.

[0045] Before testing, the surface and cross-sectional composition of the Cr2AlC coating (which was not tested) prepared in Example 1 was analyzed. The surface morphology and grain structure of the Cr2AlC coating were observed by scanning electron microscopy (SEM). The elemental distribution and uniformity of the Cr2AlC coating were determined by energy dispersive spectroscopy (EDS). The phase composition and crystal structure of the Cr2AlC coating were analyzed by X-ray diffraction (XRD) to verify the uniformity, compactness and phase stability of the Cr2AlC coating.

[0046] After completing the tests, the friction coefficient, wear depth, wear volume, and wear coefficient of the Cr2AlC coating prepared in Example 1 were measured to quantitatively evaluate the wear resistance of the coating in a high-temperature lead-bismuth environment. SEM and EDS were used to analyze the surface and cross-section of the wear tracks, observing the wear morphology, coating peeling, formation of the oxide layer and compacted wear debris layer, and analyzing changes in elemental distribution. Micro-area XRD analysis was performed on the worn surface to determine changes in surface oxides and phase composition, and to evaluate the chemical stability of the coating under the test conditions. Mechanical property tests (such as nanoindentation hardness H and modulus E measurement) were conducted to further characterize the mechanical properties and durability of the coating after corrosion and wear.

[0047] The experimental group further conducted different number of cycles (5×10). 3 Up to 1×10 6 The coating was tested (times) to evaluate its protective capabilities and stability at different service stages, and the results were compared with those of the control group.

[0048] The surface composition, cross-sectional morphology, and composition test results of the Cr2AlC coating prepared in Example 1 are as follows: Figure 3 As shown. According to Figure 3 As can be seen, surface composition analysis shows that the Cr2AlC coating has a uniform elemental distribution and no obvious segregation; cross-sectional morphology shows that the Cr2AlC coating has a dense structure and good bonding with the substrate; cross-sectional composition analysis further confirms that the main elemental composition of the Cr2AlC coating is as expected, indicating that the Cr2AlC coating preparation process is reliable.

[0049] The maximum wear depth, maximum wear depth fitting curve, wear volume, and wear coefficient of the Cr2AlC coating prepared in Example 1 and the control group under different cycle numbers are as follows: Figure 4 As shown. Figure 4 In the diagram, the horizontal axis C1~C5 represents different cycle numbers under corresponding experimental conditions: C1-5000 fretting wear cycles, C2-50000 cycles, C3-500000 cycles, C4-1000000 cycles, and C5-2000000 cycles. Under different cycle numbers, the normal force, displacement, and temperature remain consistent, thus allowing for the study of the surface evolution law and protection mechanism of the coating under experimental conditions. Based on... Figure 4It can be seen that the wear depth of the control group 316L stainless steel is significantly greater than that of the Cr2AlC coated experimental group, indicating that the Cr2AlC coating has a significant advantage in wear resistance. As the number of cycles increases, the wear depth gradually stabilizes, and no through-failure of the Cr2AlC coating occurs. The wear volume is used to further calculate the wear coefficient K. The results show that the wear coefficient of the Cr2AlC coating is reduced by about 50% compared with that of 316L stainless steel, which fully demonstrates the excellent wear resistance of the Cr2AlC coating in the lead-bismuth environment.

[0050] SEM morphology and EDS composition analysis of the worn surface of the 316L stainless steel control group are as follows: Figure 5 As shown. According to Figure 5 As can be seen from SEM observation, there are obvious surface damage characteristics in the wear zone, and EDS analysis results show that there has been a relatively serious dissolution and loss of Ni element in this area. This phenomenon indicates that in a lead-bismuth environment, 316L stainless steel is prone to selective dissolution of elements under the combined effects of wear and corrosion, thereby accelerating its surface deterioration process.

[0051] The SEM morphology and EDS composition analysis of the worn surface of the Cr2AlC coating prepared in Example 1 are as follows: Figure 6 As shown. According to Figure 6 As can be seen from SEM, a compacted oxide particle structure is observed on the surface, and EDS analysis further confirms its oxide composition. These dense oxide particles can form a stable physical barrier on the Cr2AlC coating surface, thereby effectively preventing further penetration and erosion of lead and bismuth, and providing additional protection for the Cr2AlC coating in a lead-bismuth environment.

[0052] The SEM cross-sectional morphology and EDS composition analysis of the fretting wear zone of the 316L stainless steel control group are as follows: Figure 7 As shown. According to Figure 7 Significant wear depth was observed in this area, and the surface structure exhibited a layered characteristic, with the three-layer structure being loose and non-dense, failing to provide effective protection. Furthermore, cracks were also observed on the worn surface. These phenomena collectively indicate that 316L stainless steel, under the coupled effects of fretting wear and lead-bismuth corrosion, struggles to form a stable protective layer, thus accelerating the deterioration and damage process of the substrate.

[0053] The SEM cross-sectional morphology and EDS composition analysis of the wear zone of the Cr2AlC coating in Example 1 are as follows: Figure 8 As shown. According to Figure 8 It can be observed that a dense three-body layer is formed on the surface of the Cr2AlC coating. This three-body layer is mainly composed of compacted oxides, which effectively hinders the further penetration and corrosion of the lead-bismuth alloy and provides a reliable protective barrier for the Cr2AlC coating.

[0054] The surface micro-area XRD composition of the Cr2AlC coating in Example 1 under different cycle numbers is as follows: Figure 9 As shown. According to Figure 9 As the number of cycles increases, the formation of Al2O3 is clearly observed, and its main phase is stable α-Al2O3. This further proves that the Cr2AlC coating can enhance its wear resistance and resistance to lead-bismuth corrosion by forming a dense and stable α-Al2O3 layer during the friction-corrosion process.

[0055] Changes in surface mechanical properties (hardness H, elastic modulus E, H / E and H) of Cr2AlC coating and 316L stainless steel in Example 1 under different cycles 3 / E 2 )like Figure 10 As shown. Figure 10 In the diagram, the horizontal axis C1~C5 represents the number of cycles under different experimental conditions: C1-5000 fretting wear cycles, C2-50000 cycles, C3-500000 cycles, C4-1000000 cycles, and C5-2000000 cycles. According to... Figure 10 It can be seen that the hardness and elastic modulus of the Cr2AlC coating are much higher than those of 316L stainless steel, exhibiting better elasticity and resistance to plastic deformation. After fretting experiments, the surface mechanical properties of the Cr2AlC coating showed a non-monotonic change with the number of cycles: initially, the performance decreased due to the deposition of wear debris; in the middle stage, the performance rebounded due to the exposure of the Cr2AlC coating structure; in the later stage, the performance decreased again due to the accumulation of wear debris and a loose oxide layer; finally, in the high-cycle stage, the performance gradually increased with the formation of dense oxides such as α-Al2O3, demonstrating excellent resistance to fretting wear.

[0056] As can be seen from the above embodiments, the MAX phase coating of the present invention has both excellent corrosion resistance and wear resistance in lead-bismuth environments, and can be used in lead-bismuth eutectic high-temperature environments, thereby effectively extending the service life of key components of steam generators, improving the safety and reliability of nuclear power system operation, and providing a feasible technical solution for the protection of structural materials in similar harsh environments.

[0057] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. Other embodiments can be obtained based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. The application of a MAX phase coating in a lead-bismuth environment, wherein the MAX phase coating comprises one or more of Cr2AlC coating, Ti2AlC coating and Ti3SiC2 coating.

2. The application according to claim 1, characterized in that, The thickness of the MAX phase coating is 1~20μm.

3. The application according to claim 1, characterized in that, The lead-bismuth environment is a high-temperature lead-bismuth environment, and the temperature of the high-temperature lead-bismuth environment is 300~600℃.

4. The application according to claim 1 or 3, characterized in that, The lead-bismuth environment is a liquid lead-bismuth eutectic alloy, and the composition of the lead-bismuth eutectic alloy is 55.5 wt% lead and 44.5 wt% bismuth.

5. The application according to claim 1, characterized in that, The method of application includes the following steps: sequentially performing surface activation, coating deposition, and annealing on the structural material.

6. The application according to claim 5, characterized in that, The structural material also undergoes pretreatment before use; The pretreatment includes the following steps: polishing and ultrasonic cleaning the structural material in sequence.

7. The application according to claim 5, characterized in that, The surface activation is achieved by ion bombardment; the ion bombardment is Ar. + Ion bombardment, wherein the duration of ion bombardment is 30 minutes or more.

8. The application according to claim 5, characterized in that, The method for depositing the coating is a combination of arc ion plating and magnetron sputtering; The deposition coating includes the following steps: using Cr or Ti as the arc source, Al or Si as the magnetron sputtering target, and CH4 as the carbon source for deposition.

9. The application according to claim 8, characterized in that, The deposition temperature was 145~155°C, and the total deposition time was 2~3 hours; The arc source has a power of 1.0kW, the magnetron sputtering has a power of 3.1kW, and the substrate bias voltage is 150V.

10. The application according to claim 5, characterized in that, The annealing temperature is 600~620°C, and the vacuum degree is 10. -3 Pa, the heat preservation time is 0.5-1.5h.

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