CN111424248A - Preparation method of high-temperature oxidation-resistant SiC/ZrC coating on surface of carbon/carbon composite material - Google Patents

Abstract

The invention provides a preparation method of a high-temperature oxidation-resistant SiC/ZrC coating on the surface of a carbon/carbon composite material. Vacuuming; main bombardment step: filling the sputtering chamber with argon gas, applying voltage and current to the Si target, Zr target and C target for bombardment; coating step: turning on the DC power supply controlling the Si target and the C target, sputtering and depositing Then prepare the SiC layer that meets the stoichiometric ratio, then turn on the DC power supply that controls the Si target and the C target, and prepare the ZrC layer that meets the stoichiometric ratio after sputtering and deposition; After multiple sputtering and deposition, the coating is completed. The SiC/ZrC coating prepared by the method can effectively prevent excessive cracks formed due to its excessive thermal expansion coefficient, and has the advantages of simple operation process, simple coating structure and easy industrial production.

Description

Preparation method of high temperature oxidation-resistant SiC/ZrC coating on the surface of carbon/carbon composites

technical field

The invention relates to the technical field of surface thermal protection of carbon materials, in particular to a preparation method of a high-temperature oxidation-resistant SiC/ZrC coating on the surface of a carbon/carbon composite material.

Background technique

C/C composites have the advantages of low density, high specific modulus, high specific strength, high toughness, ablation resistance and thermal shock resistance, low thermal expansion, thermal shock resistance, etc., and have high strength and creep resistance under high temperature conditions. performance. Due to its excellent mechanical properties at high temperatures, it has broad application prospects in the aerospace industry such as rocket nozzles, nozzles, leading edges of re-entry vehicles, and gas turbine engine components. However, in an aerobic environment, when the temperature exceeds 500 °C, carbon materials will oxidatively decompose, which greatly limits its application in an oxygen-containing environment. Surface coatings or matrix doping are usually used to improve the oxidation resistance of C/C composites. At present, the application of anti-oxidation coatings is considered to be an effective way to solve the oxidation problem of C/C composites.

High-temperature oxidation-resistant ceramics are the most promising high-temperature oxidation-resistant coating materials because of their good high-temperature phase stability, chemical stability and high hardness. And it has an oxide layer with low oxygen diffusion coefficient, so it has good ablation resistance. Among the carbide high-temperature oxidation-resistant ceramics, silicon carbide has stable chemical properties, high thermal conductivity, small thermal expansion coefficient, good wear resistance, thermal shock, small size, light weight, high strength, and high hardness, with a Mohs hardness of 9.5. grade, second only to the world's hardest diamond (grade 10), has excellent thermal conductivity, and is a high-temperature anti-oxidation coating material. With the application requirements of ultra-high temperature environments, the anti-oxidation coatings of C/C composites are also developing in the direction of refractory metal coatings and ultra-high temperature ceramic coatings. At present, the ultra-high temperature ceramic coating of C/C composites is also a research hotspot, and the preparation methods studied include chemical vapor deposition, coating reactive sintering (or embedding), reactive infiltration and spraying.

ZrC has good thermal stability, relatively low density and strong Zr-C covalent bond, which makes it have the characteristics of high melting point (3420℃) and high hardness (25.5GPa). In addition, its corresponding oxide ZrO ₂ also has a high melting point (2677 °C), good high temperature stability and chemical stability, these performance characteristics make ZrC one of the ideal anti-oxidation coating materials.

Because the thermal expansion coefficient of the ceramic coating (ZrC single coating) and the C/C composite material is quite different, the thermal stress caused can easily lead to the cracking and peeling of the coating, which will seriously affect the use of the coating. The thermal performance mismatch between the coating and the substrate can be mitigated by preparing a transition layer or preparing a gradient coating between the substrate and the coating. For example, Xiong Xiang et al. used CVD method to prepare ZrC-C transition layer between C/C composites and ZrC, and achieved good results.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a preparation method of a high temperature oxidation-resistant SiC/ZrC coating on the surface of a carbon/carbon composite material.

In order to achieve the above object, the present invention provides the following technical solutions:

A preparation method of a high-temperature oxidation-resistant SiC/ZrC coating on the surface of a carbon/carbon composite material, comprising the following steps:

Sample delivery step: transfer the sample stage on which the sample is placed to the sputtering chamber, and evacuate the sputtering chamber;

Main bombardment step: After completing the sample delivery step, fill the sputtering chamber with argon gas, and apply voltage and current to the Si target, Zr target and C target for bombardment. After the bombardment is completed, turn off the power of all targets. , adjust the sample stage so that the sample can be coated;

Coating step: turn on the DC power supply that controls the Si target and the C target, and prepare a SiC layer that meets the stoichiometric ratio after sputtering and deposition.

Then turn the sample stage to the target positions of the Zr target and the C target, turn on the DC power supply that controls the Si target and the C target, and prepare a ZrC layer that meets the stoichiometric ratio after sputtering and deposition;

After multiple sputtering and deposition, the SiC/ZrC coating is formed to complete the coating.

Further, in the above preparation method, a preparation step is also included before the sample delivery step, and the preparation step includes the following operations:

Sample surface pretreatment: ultrasonically clean the sample, and then put the cleaned sample into the environment of 70℃ to dry for 1h;

Cleaning: Use sandpaper to grind the inner wall of the vacuum furnace, the sample mold and the target cylinder;

Pumping: After cleaning, load the sample into the vacuum furnace and install the Si target, Zr target and C target, and then vacuumize the cleaning chamber;

Cleaning: After the pumping is completed, the cleaning chamber is evacuated to 0.7×10 ^-3 Pa, and then argon gas is introduced to increase the pressure to 20Pa-30Pa, and the ionization power supply is turned on to perform glow cleaning in the cleaning chamber;

Preferably, in the sample surface pretreatment step, first put the sample in acetone for ultrasonic cleaning for 15 minutes, and then put it into absolute ethanol for ultrasonic cleaning for 15 minutes; preferably, in the cleaning step, glow cleaning is performed on the cleaning chamber 25 minutes – 35 minutes.

Further, in the above preparation method, in the sample sending step, the sputtering chamber is firstly evacuated to make the vacuum degree of the sputtering chamber reach below 3.0×10 ⁰ Pa, and then the sputtering chamber is finely evacuated , when the vacuum degree in the sputtering chamber reaches 1×10 ^-3 Pa or less, it ends, and the vacuuming time is more than 6 hours.

Further, in the above preparation method, in the main bombardment step, the voltage of the Si target, the Zr target and the C target are all 480V, the current is 0.3A, and the bombardment time is 5 minutes-15 minutes; preferably, Argon gas was filled into the sputtering chamber to make the pressure in the sputtering chamber reach (3-5)×10 ^-1 Pa.

Further, in the above preparation method, in the coating step, when the sample is at the target position of the Si target and the C target, the power of the Si target is 50W-150W, and the power of the C target is 100W-200W. The shooting time is 30 minutes-120 minutes, and the deposition time is 0.5 hours-3 hours; when the sample is in the target position of the Zr target and the C target, the power of the Zr target is 100W-250W, the power of the C target is 100W-250W, and the Zr target is 100W-250W. The target and C target each sputter time is 30 minutes - 120 minutes, the deposition time is 0.5 hours - 3 hours.

Further, in the above preparation method, the thickness of each deposited SiC layer is 3 μm-5 μm; the thickness of each deposited ZrC layer is 3 μm-5 μm; the SiC/ZrC coating is a multi-layer coating structure, including multiple layers. One of the SiC layers and a plurality of the ZrC layers, the SiC layers and the ZrC layers are arranged at intervals; preferably, the thickness of the SiC/ZrC coating is more than 100 μm.

Further, in the above preparation method, in the coating step, the working parameters of the vacuum furnace are: the working pressure is 4Pa-6Pa, the negative bias voltage is -200V, the working voltage is 400V-450V, the substrate temperature of the sample is 180°C–220°C.

Further, in the above preparation method, argon gas is continuously filled during the coating step, and the flow rate of argon gas is 10 sccm-30 sccm.

Further, in the above-mentioned preparation method, a passivation step is also included after the coating step, and the passivation step includes the following operations:

First, the temperature of the sputtering chamber should be lowered, then argon gas should be introduced to passivate the surface of the sample, and then the vacuum furnace should be filled with gas when the temperature of the vacuum chamber drops to 120 °C to make the pressure in the vacuum furnace reach 1 atmosphere; Preferably, in the passivation step, the flow rate of argon gas is 30 sccm-40 sccm, and the time is 2 minutes.

Further, in the above preparation method, the target material purities of the Si target, the Zr target and the C target are all greater than 99.99 wt %.

Analysis shows that the present invention discloses a preparation method of high temperature oxidation-resistant SiC/ZrC coating on the surface of carbon/carbon composite material. The method adopts magnetron sputtering equipment to prepare SiC/ZrC coating, which is suitable for high temperature of carbon/carbon composite material Antioxidant protection. A multi-target magnetron sputtering coating equipment including Si target, Zr target and C target is used. The Si target, Zr target and C target are controlled by independent DC power supply respectively. Argon gas is used as sputtering gas and carrier gas. SiC/ZrC multi-layer coating is prepared by sputtering. The multi-layer coating structure is formed by depositing the substrate multiple times in front of Si target, C target, Zr target and C target. The thickness of SiC/ZrC is controlled by adjusting the target power and deposition time. . The structure of the multi-layer coating can reduce the thermal stress between the carbon matrix and the coating, and prevent the coating from cracking and peeling due to the excessive difference in thermal expansion coefficients between the materials. The coating of the invention has the advantages of simple structure, simple operation process and easy industrial production.

Description of drawings

The accompanying drawings forming a part of the present application are used to provide further understanding of the present invention, and the exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. in:

Fig. 1 is the X-ray phase composition analysis of the SiC/ZrC coating prepared in Example 1, wherein the ordinate is the diffraction peak intensity and the abscissa is the diffraction angle.

FIG. 2 is the cross-sectional morphology of the SiC/ZrC coating prepared in Example 1.

FIG. 3 is the X-ray phase composition analysis of the ZrC layer prepared in Comparative Example 1, wherein the ordinate is the diffraction peak intensity, and the abscissa is the diffraction angle.

FIG. 4 is the cross-sectional morphology of the ZrC layer prepared in Comparative Example 1. FIG.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments. The various examples are provided by way of explanation of the invention and do not limit the invention. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For example, features illustrated or described as part of one embodiment can be used on another embodiment to yield yet another embodiment. Therefore, it is intended that the present invention embrace such modifications and variations as come within the scope of the appended claims and their equivalents.

As shown in FIG. 1 to FIG. 2 , according to an embodiment of the present invention, a method for preparing a high-temperature oxidation-resistant SiC/ZrC coating on the surface of a carbon/carbon composite material is provided. In Figure 1, the ordinate is the diffraction peak intensity, and the abscissa is the diffraction angle. The SiC/ZrC coating is suitable for high-temperature oxidation protection on the surface of carbon/carbon composite materials. The preparation method is multi-target magnetron sputtering coating. The equipment also uses the magnetron sputtering method to prepare SiC/ZrC coating. The multi-target magnetron sputtering coating equipment includes Si target, Zr target and C target. The Si target, Zr target and C target are respectively powered by independent DC power supply. For control, the target purity of Si target, Zr target and C target are all greater than 99.99wt%. In the process of preparing SiC/ZrC coating, argon gas is used as sputtering gas and carrier gas, and SiC/ZrC is prepared by reactive sputtering Coating, the SiC/ZrC coating is a multi-layer coating structure, including multiple SiC layers and multiple ZrC layers. The target position and the target position of Zr target and C target are successively formed by multiple reactive sputtering and deposition on the surface of the substrate. The thickness of the SiC layer and the ZrC layer is controlled by adjusting the power and deposition time of the Si target, Zr target and C target.

The design principle of the present invention is:

Aiming at the high-temperature oxidation and ablation protection requirements of carbon/carbon composite materials, the present invention designs a high-temperature oxidation-resistant SiC/ZrC coating. At high temperature, SiC is oxidized to form a continuous glassy SiO2 protective layer, which effectively prevents the damage caused by ZrC and the matrix carbon material. If there are too many cracks formed by the excessive thermal expansion coefficient between them, the formed glassy SiO2 can cover the original cracks and prevent the erosion of oxygen to the matrix carbon, thereby preventing the intrusion of oxygen, that is, droplet filling. Both carbon/carbon composites and graphite have very low thermal expansion coefficients of 1.0×10 ^-6 /K and 2.1–2.6×10 ^-6 /K, respectively, while ZrC has a thermal expansion coefficient of 6.7×10 ^-6 /K and SiC's The thermal expansion coefficient (3.8×10 ^-6 /K) is between the carbon material and ZrC, the thermal expansion coefficient of the ceramic coating (ZrC single coating) is different, and the film is not under the same stress. The ceramic coating (ZrC single coating) will crack On, a SiC layer is introduced between the ZrC layer and the carbon matrix (carbon/carbon composite material) as a transition layer. The thermal expansion coefficients of SiC and ZrC and carbon/carbon composite materials are similar, and the relative stress is small, which can effectively reduce the use of materials The crack gradient coating caused by the thermal stress in the process makes the concentration and composition of the interface region between the coating and the substrate two-phase continuous distribution, which can realize the gradient distribution of the thermal expansion coefficient, eliminate the interface stress, and relieve the ceramic coating (ZrC single coating). Cracking tendency, thereby improving the integrity of the coating and improving the resistance of the material to oxidative ablation.

The preparation method includes a preparation step, a sample delivery step, a main bombardment step, a coating step and a passivation step:

(1) preparation step, the carbon/carbon composite material is pretreated on the surface, and the vacuum furnace used for coating is prepared, so that the environmental conditions in the vacuum furnace meet the requirements of the subsequent coating steps, and the preparation steps specifically include the following operations:

Sample surface pretreatment: clean the sample (the sample is a carbon/carbon composite material whose surface needs to be treated with high-temperature anti-oxidation protection), put the sample in acetone for ultrasonic cleaning for 15 minutes, and then put it into anhydrous ethanol ultrasonically After cleaning for 15 minutes, the samples after cleaning were placed in an oven at 70 °C for 1 hour.

Cleaning: Use sandpaper to grind the inner wall of the vacuum furnace, the sample mold and the target barrel to remove dirt, attachments and deposits, so that the inner wall of the vacuum furnace, the surface of the sample mold and the target barrel are smooth and free of contamination.

Air extraction: After the cleaning is completed, load the sample into the vacuum furnace and install the Si target, Zr target and C target target material, then close the furnace door, use the mechanical pump to vacuum the cleaning chamber, and remove it during the cleaning process. A lightweight object that is sanded off.

Preferably, the vacuuming time of the cleaning chamber is 30 minutes, and this setting can ensure that the light objects polished by sandpaper in the cleaning chamber can be extracted cleanly.

Cleaning: After the pumping is completed, put the sample on the sample stage of the sample cleaning chamber, and place the side of the sample that needs to be sputtered down, so that the sample can be transferred to the sputtering chamber. Able to oppose the target and accept deposition. Evacuate the cleaning chamber to 0.7×10 ^-3 Pa or below 0.7×10 ^-3 Pa, and then pass argon gas into the cleaning chamber to increase the pressure in the cleaning chamber to 20Pa-30Pa (for example: 20Pa, 21Pa, 22Pa, 23Pa , 24Pa, 25Pa, 26Pa, 27Pa, 28Pa, 29Pa, 30Pa), turn on the ionization power supply for glow cleaning, and perform glow cleaning on the cleaning chamber for 25-35 minutes (for example: 25 minutes, 26 minutes, 27 minutes, 28 minutes minutes, 29 minutes, 30 minutes, 31 minutes, 32 minutes, 33 minutes, 34 minutes, 35 minutes), preferably 30 minutes. Glow cleaning of the cleaning chamber removes contamination from surfaces such as the inner walls of the vacuum furnace, specimens, and turrets.

(2) Sample delivery step: After the preparation step is completed, the cleaning chamber is evacuated to ensure that the vacuum degree between the cleaning chamber and the sputtering chamber is within 50Pa, and then the transfer valve is opened and the transfer valve is clicked on the control panel to place the test chamber. Transfer the sample stage to the sputtering chamber, then click back to origin on the control panel and close the transfer valve. The sputtering chamber was evacuated so that the degree of vacuum in the sputtering chamber was 1×10 ^-3 Pa or less.

Preferably, the specific operation of vacuuming the sputtering chamber is as follows: firstly, use a mechanical pump to ^roughen the sputtering chamber to make the vacuum degree of the sputtering chamber reach below 3.0×100 Pa, and then use a molecular pump to pump the sputtering chamber. Fine pumping is completed when the vacuum degree in the sputtering chamber reaches 1×10 ^-3 Pa or less, and the vacuum pumping time is more than 6 hours.

(3) Main bombardment step: after the sample delivery step is completed, argon gas is filled into the sputtering chamber to make the pressure in the sputtering chamber reach (3–5)×10 ^-1 Pa. The argon gas acts as a protection to make the sample And the carbide film is not oxidized and does not participate in the reaction. Open the target cover of Si target, C target and Zr target, adjust the voltage of Si target, Zr target and C target to 480V and current to 0.3A, bombard for 5 minutes to 15 minutes (for example: 5 minutes, 6 minutes, 7 minutes minutes, 8 minutes, 9 minutes, 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, 15 minutes), turn off the power of all targets after the bombardment is completed.

The purpose of the main bombardment is to make the target glow by adjusting the current and voltage of the cathode target (Si target, C target, Zr target), so as to achieve the purpose of cleaning the surface of the target. At this time, the sample stage baffle of the sputtering chamber is When it is closed, it sputters on the shutter, and the shutter is opened to sputter on the sample during the coating step.

After the main bombardment is completed, adjust the sample stage so that the sample can be coated; the sample stage can be adjusted so that the sample stage is lowered to the target base distance of 70mm, so that the sample can be coated.

(4) Coating step: adjust the sample stage, the sample stage makes the sample at the target position of Si target and C target, open the target cover of Si target and C target and open the baffle of the sample stage of the sputtering chamber, and open the control Si target and C target. The DC power supply of the target, adjust the power of the Si target to 50W-150W (for example: 50W, 60W, 70W, 80W, 90W, 100W, 110W, 120W, 130W, 140W, 150W), the power of the C target is 100W-200W (for example: 100W, 110W, 120W, 130W, 140W, 150W, 160W, 170W, 180W, 190W, 200W), sputtering and deposition at this power prepare a SiC layer that meets the stoichiometric ratio.

Sputtering time for Si target and C target is 30 minutes – 120 minutes (eg: 30 minutes, 40 minutes, 50 minutes, 60 minutes, 70 minutes, 80 minutes, 90 minutes, 100 minutes, 110 minutes, 120 minutes), deposition Time is 0.5 hours – 3 hours (eg: 0.5 hours, 0.7 hours, 0.9 hours, 1 hour, 1.2 hours, 1.4 hours, 1.6 hours, 1.8 hours, 2 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours, 3 hours hours), the thickness of the deposited SiC layer is 3 μm–5 μm (for example: 3 μm, 3.2 μm, 3.4 μm, 3.6 μm, 3.8 μm, 4 μm, 4.2 μm, 4.4 μm, 4.6 μm, 4.8 μm, 5 μm).

Then turn the sample stage to the target position of the Zr target and the C target, turn on the DC power supply that controls the Zr target and the C target, and adjust the power of the Zr target to 100W-250W (for example: 100W, 110W, 120W, 130W, 140W, 150W, 160W, 170W, 180W, 190W, 200W, 210W, 220W, 230W, 240W, 250W). 190W, 200W, 210W, 220W, 230W, 240W, 250W), and after sputtering and deposition at this power, a ZrC layer that meets the stoichiometric ratio is prepared.

The sputtering time of Zr target and C target is 30 minutes - 120 minutes (eg: 30 minutes, 40 minutes, 50 minutes, 60 minutes, 70 minutes, 80 minutes, 90 minutes, 100 minutes, 110 minutes, 120 minutes), deposition Time is 0.5 hours – 3 hours (eg: 0.5 hours, 0.7 hours, 0.9 hours, 1 hour, 1.2 hours, 1.4 hours, 1.6 hours, 1.8 hours, 2 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours, 3 hours hours), the thickness of the deposited ZrC layer is 3 μm–5 μm (for example: 3 μm, 3.2 μm, 3.4 μm, 3.6 μm, 3.8 μm, 4 μm, 4.2 μm, 4.4 μm, 4.6 μm, 4.8 μm, 5 μm).

Then follow the above steps to deposit 3μm-5μm SiC layer, 3μm-5μm ZrC layer, 3μm-5μm SiC layer, 3μm-5μm ZrC layer... After multiple sputtering and deposition, SiC/ZrC is formed Coating, so that the total thickness of the SiC layer and the ZrC layer (the thickness of the SiC/ZrC coating) is more than 100 μm to complete the coating.

The preparation of SiC/ZrC coating is realized by depositing the Si target, C target and Zr target and C target respectively on the sample stage.

Preferably, argon gas is continuously charged during the coating process, and the flow rate of argon gas is controlled by controlling the potentiometer of the flow measuring instrument according to the proportion of the gas pressure occupied by argon gas in the sputtering chamber, thereby controlling the silicon carbide film (SiC layer), the quality of the zirconium carbide film (ZrC layer), when there is an abnormal situation in the sputtering chamber (the target should be ignited during magnetron sputtering, the current is too large or too small, and the vacuum is too large or too small, it will not light up , or the ignition is not obvious, that is, it cannot be sputtered or the sputtering effect is not good), adjust the flow rate of argon gas and the working voltage of the cathode target to keep the work in the furnace stable.

Preferably, the working parameters of the vacuum furnace during the coating step are: the working pressure is 4Pa-6Pa (for example: 4Pa, 4.2Pa, 4.4Pa, 4.6Pa, 4.8Pa, 5Pa, 5.2Pa, 5.4Pa, 5.6Pa, 5.8Pa Pa, 6Pa), negative bias voltage is -200V, working voltage is 400V–450V (for example: 400V, 405V, 410V, 415V, 420V, 425V, 430V, 435V, 440V, 445V, 450V), argon flow rate is 10sccm –30sccm (standard ml/min) (eg: 10sccm, 13sccm, 15sccm, 18sccm, 20sccm, 23sccm, 25sccm, 28sccm, 30sccm), the substrate temperature of the sample (carbon/carbon composite material) 180°C–220°C (eg: 180°C, 185°C, 190°C, 195°C, 200°C, 205°C, 210°C, 215°C, 220°C), preferably, the substrate temperature of the sample (carbon/carbon composite material) is 200°C, so setting can Improves adhesion between substrate and coating.

The multi-target magnetron sputtering coating equipment was used for coating, and the multi-target co-sputtering reactive magnetron sputtering technology was used to prepare the multi-layer coating. The Si target, Zr target and C target are controlled by independent DC power supply respectively, and argon gas is used as sputtering gas and carrier gas to prepare SiC layer and ZrC layer by reactive sputtering. SiC and ZrC were deposited successively, and the coating thickness was controlled by adjusting the target power and deposition time.

(5) Passivation step: After the coating step is completed, the ZrC layer on the surface of the sample is still very active and has a certain temperature. If the vacuum furnace is opened immediately, the sample will come into contact with the air, and the sample will be oxidized immediately and cause the test The surface of the sample changes color. Therefore, first reduce the temperature of the sputtering chamber; then pass argon gas of 30sccm-40sccm (for example: 30sccm, 31sccm, 32sccm, 33sccm, 34sccm, 35sccm, 36sccm, 37sccm, 38sccm, 39sccm, 40sccm) for 2 minutes. The surface is passivated, and the target surface is protected to prevent oxidation or reaction; then, when the temperature of the vacuum chamber drops to 120 °C, the vacuum furnace is filled with gas to make the pressure in the vacuum furnace reach 1 atmosphere.

After completing all the above steps, you can open the furnace to take out the parts, open the furnace door of the vacuum furnace, and take out the samples.

The invention has many advantages under the ultra-high temperature service environment by designing the transition coating (SiC layer). First, considering the structural design of the coating, the structural design of the transition coating helps to improve the thermal shock resistance of the coating. Secondly, the thermal expansion coefficient of the transition coating and the substrate and the thermal expansion coefficient of the transition coating and the surface coating (ZrC layer) are much smaller, so that the microcracks between the surface coating, the transition coating and the surface of the substrate are much smaller than that of the single layer The microcracks in the coating are much smaller, and the microcracks are also covered by the upper coating, thereby effectively reducing the oxidation of the matrix caused by the diffusion of oxygen along the through cracks to the surface of the matrix.

Example 1:

(1) Preparation steps:

Sample surface pretreatment: clean the sample, put the sample into acetone for ultrasonic cleaning for 15 minutes, then put it into absolute ethanol for ultrasonic cleaning for 15 minutes, and put the cleaned sample into an oven at 70 °C for 1 hour.

Cleaning: Use sandpaper to grind the inner wall of the vacuum furnace, the sample mold and the target barrel.

Air extraction: After cleaning, install Si target, Zr target and C target in the vacuum furnace, then close the furnace door and turn on the mechanical pump to evacuate the sputtering chamber for 30 minutes.

Cleaning: After the pumping is completed, put the sample on the sample stage of the sample cleaning chamber and close the furnace door of the cleaning chamber. The cleaning chamber was evacuated to 0.7×10 ^-3 Pa, and then argon gas was introduced into the cleaning chamber to increase the pressure to 20Pa, and glow cleaning was performed for about 30 minutes.

(2) Sample delivery step: After the preparation step is completed, the sample stage on which the sample is placed is transferred to the sputtering chamber. The sputtering chamber is roughly pumped by a mechanical pump and finely pumped by a molecular pump, so that the vacuum degree in the sputtering chamber reaches 0.7×10 ^{- 3} Pa.

(3) Main bombardment step: after completing the sample delivery step, fill the sputtering chamber with argon gas to make the pressure in the sputtering chamber reach (3-5)×10 ^-1 Pa, and turn on the control Si target, Zr target and C The DC power supply of the target was turned on and the ion source was turned on for the main bombardment. The voltage of the Si target, the Zr target and the C target were adjusted to 480V and the current was 0.3A, bombarded for 10 minutes, and then turned off the power of all targets.

(4) Coating step: After completing the main bombardment step, adjust the sample stage so that the sample stage is lowered to a distance of 70 mm from the target base, open the Si target, C target target cover and the sputtering chamber sample stage baffle and close the Zr The target cover of the target, turn on the DC power supply that controls the Si target and the C target, adjust the power of the Si target to 120W and the power of the C target to 150W, and perform sputtering and deposition at this power to prepare a stoichiometric SiC layer, Si target And C target sputtering for 40min, deposition time is 1h, the thickness of the deposited SiC layer is 3.5μm.

Then turn off the power of the Si target and the C target, close the target cover of the Si target and open the target cover of the Zr target. Turn on the DC power supply to control the Zr target and the C target, and adjust the power of the Zr target to 100W and the power of the C target to 220W. , in this power sputtering and deposition to prepare a ZrC layer that meets the stoichiometric ratio, the Zr target and the C target are sputtered for 90 min, the deposition time is 2 h, and the thickness of the deposited ZrC layer is 4.5 μm.

Then follow the above steps to deposit a 3.5μm SiC layer, a 4.5μm ZrC layer, a 3.5μm SiC layer, a 4.5μm ZrC layer..., the SiC layer is 49μm in total after 14 sputtering and deposition, and the ZrC layer is After 14 sputtering and deposition, the total thickness is 63 μm, which makes the total thickness of SiC layer and ZrC layer reach 112 μm to complete the coating.

The working parameters of the vacuum furnace during the coating step are: working pressure of 5-6Pa, negative bias of -200V, argon flow rate of 10-30sccm (standard ml/min), sample (carbon/carbon composite material) ) at a substrate temperature of 200 °C.

(5) Passivation step: After the coating step is completed, the temperature of the sputtering chamber should be lowered first; then 30 sccm of argon gas was introduced for 2 minutes to passivate the surface of the sample, while protecting the target surface from oxidation or reaction; then When the temperature of the vacuum chamber drops to 120°C, gas is charged into the vacuum furnace to make the air pressure in the vacuum furnace reach 1 atmosphere.

After completing all the above steps, you can open the furnace to take out the parts, open the furnace door of the vacuum furnace, and take out the samples.

In this embodiment, the thickness of the deposited SiC layer is about 49 μm, the thickness of the deposited ZrC layer is about 63 μm, and the total thickness of the SiC/ZrC coating prepared on the carbon/carbon composite material is about 112 μm.

Figure 1 shows the X-ray phase composition analysis of the ZrC layer prepared on the surface of the carbon/carbon composite matrix with SiC as the transition layer. It can be seen that a well-crystallized SiC/ZrC layer can be prepared under the above preparation conditions. Figure 2 shows the cross-sectional morphology of the coating. It can be seen from the figure that the thickness of the coating between the single layers is uniform, the bonding between the layers is good, and there are no defects such as cracks.

Example 2:

(1) Preparation steps:

Sample surface pretreatment: clean the sample, put the sample into acetone for ultrasonic cleaning for 15 minutes, then put it into absolute ethanol for ultrasonic cleaning for 15 minutes, and put the cleaned sample into an oven at 70 °C for 1 hour.

Cleaning: Use sandpaper to grind the inner wall of the vacuum furnace, the sample mold and the target barrel.

Pumping: After cleaning, install Si target, Zr target and C target in the vacuum furnace, then close the furnace door and turn on the mechanical pump to evacuate the sputtering chamber for 30 minutes.

Cleaning: After the pumping is completed, put the sample on the sample stage of the sample cleaning chamber and close the furnace door of the cleaning chamber. The cleaning chamber was evacuated to 0.7×10 ^-3 Pa, and then argon gas was introduced into the cleaning chamber to increase the pressure in the cleaning chamber to 20Pa, and glow cleaning was performed on the sample for about 30 minutes.

(2) Sample delivery step: After the preparation step is completed, the sample stage on which the sample is placed is transferred to the sputtering chamber. The sputtering chamber is roughly pumped by a mechanical pump and finely pumped by a molecular pump, so that the vacuum degree in the sputtering chamber reaches 0.6×10 ^{- 3} Pa.

(3) Main bombardment step: After completing the sample delivery step, continue to fill the sputtering chamber with argon gas to make the pressure in the sputtering chamber reach (3–5)×10 ^-1 Pa, and turn on the control Si target, Zr target and The DC power of the C target was turned on and the ion source was turned on for the main bombardment. The voltages of the Si target, Zr target and C target were adjusted to 480V and the current was 0.3A, bombarded for 15 minutes, and then turned off the power of all targets.

(4) Coating step: After completing the main bombardment step, adjust the sample stage so that the sample stage is lowered to a distance of 70 mm from the target base, open the Si target, C target target cover and the sputtering chamber sample stage baffle and close the Zr The target cover of the target, turn on the DC power supply that controls the Si target and the C target, adjust the power of the Si target to 80W and the power of the C target to 150W, and perform sputtering and deposition at this power to prepare a stoichiometric SiC layer, Si target And C target sputtering for 110min, deposition time is 1.5h, the thickness of the deposited SiC layer is 4.5μm.

Then turn off the power of the Si target and the C target, then close the target cover of the Si target and open the target cover of the Zr target. Turn on the DC power supply to control the Zr target and the C target, and adjust the power of the Zr target to 100W and the power of the C target to 150W. , in this power sputtering and deposition to prepare a ZrC layer that meets the stoichiometric ratio, the Zr target and the C target are sputtered for 100 min, the deposition time is 2.5 h, and the thickness of the deposited ZrC layer is 4.8 μm.

Then follow the above steps to deposit a 4.5μm SiC layer, a 4.8μm ZrC layer, a 4.5μm SiC layer, a 4.8μm ZrC layer.... After 11 sputtering and deposition, the SiC layer is a total of 49.5μm, ZrC layer After 11 times of sputtering and deposition, the total thickness is 52.8 μm, so that the total thickness of the SiC layer and the ZrC layer reaches 102.3 μm to complete the coating.

The working parameters of the vacuum furnace during the coating step are: working pressure of 5-6Pa, negative bias of -200V, argon flow rate of 10sccm-30sccm (standard ml/min), sample (carbon/carbon composite material) ) at a substrate temperature of 190°C.

(5) Passivation step: After the coating step is completed, the temperature of the sputtering chamber should be lowered first; then argon gas of 40 sccm was introduced for 2 minutes to passivate the surface of the sample, while protecting the target surface from oxidation or reaction; then When the temperature of the vacuum chamber drops to 120°C, gas is charged into the vacuum furnace to make the air pressure in the vacuum furnace reach 1 atmosphere.

After completing all the above steps, you can open the furnace to take out the parts, open the furnace door of the vacuum furnace, and take out the samples.

In this embodiment, the thickness of the deposited SiC layer is about 49.5 μm, the thickness of the deposited ZrC layer is about 52.8 μm, and the total thickness of the SiC/ZrC coating prepared on the carbon/carbon composite material is about 102.3 μm.

In the analysis of the SiC/ZrC coating obtained in Example 2, the bonding between the layers is good, and there are no defects such as cracks.

Examples 3-7

Except that (4) the coating step in Examples 3-7 is different from that of Example 1, other steps are the same as those of Example 1. (4) The coating steps of Examples 3-7 are as follows.

Example 3

(4) Coating step: After completing the main bombardment step, adjust the sample stage so that the sample stage is lowered to a distance of 70 mm from the target base, open the Si target, C target target cover and the sputtering chamber sample stage baffle and close the Zr The target cover of the target, turn on the DC power supply that controls the Si target and the C target, adjust the power of the Si target to 60W and the power of the C target to 120W, and perform sputtering and deposition at this power to prepare a stoichiometric SiC layer, Si target And C target sputtering for 50min, deposition time is 1.8h, the thickness of the deposited SiC layer is 3.8μm.

Then turn off the power of the Si target and the C target, close the target cover of the Si target and open the target cover of the Zr target. Turn on the DC power supply to control the Zr target and the C target, and adjust the power of the Zr target to 120W and the power of the C target to 150W. , in this power sputtering and deposition to prepare a ZrC layer that meets the stoichiometric ratio, the Zr target and the C target are sputtered for 120 min, the deposition time is 3 h, and the thickness of the deposited ZrC layer is 4.9 μm.

Then follow the above steps to deposit a 3.8μm SiC layer, a 4.9μm ZrC layer, a 3.8μm SiC layer, a 4.9μm ZrC layer.... After 12 sputtering and deposition, the SiC layer is a total of 45.6μm and ZrC layers. After 12 times of sputtering and deposition, the total thickness is 58.8 μm, so that the total thickness of the SiC layer and the ZrC layer reaches 104.4 μm to complete the coating.

The working parameters of the vacuum furnace during the coating step are: working pressure of 5Pa-6Pa, negative bias of -200V, argon flow of 10sccm-20sccm (standard ml/min), sample (carbon/carbon composite) Substrate temperature 180°C.

Example 4

(4) Coating step: After completing the main bombardment step, adjust the sample stage so that the sample stage is lowered to a distance of 70 mm from the target base, open the Si target, C target target cover and the sputtering chamber sample stage baffle and close the Zr The target cover of the target, turn on the DC power supply that controls the Si target and the C target, adjust the power of the Si target to 90W and the power of the C target to 140W, and perform sputtering and deposition at this power to prepare a stoichiometric SiC layer, Si target And C target sputtering for 80min, deposition time is 1.5h, the thickness of the deposited SiC layer is 4.1μm.

Then turn off the power of the Si target and the C target, close the target cover of the Si target and open the target cover of the Zr target. Turn on the DC power supply to control the Zr target and the C target, and adjust the power of the Zr target to 140W and the power of the C target to 180W. , in this power sputtering and deposition to prepare a ZrC layer that meets the stoichiometric ratio, the Zr target and the C target are sputtered for 90 min, the deposition time is 2.5 h, and the thickness of the deposited ZrC layer is 4.7 μm.

Then follow the above steps to deposit a 4.1μm SiC layer, a 4.7μm ZrC layer, a 4.1μm SiC layer, a 4.7μm ZrC layer.... After 12 sputtering and deposition, the SiC layer is a total of 49.2μm and ZrC layers. After 12 times of sputtering and deposition, the total thickness is 56.4 μm, so that the total thickness of the SiC layer and the ZrC layer reaches 105.6 μm to complete the coating.

The working parameters of the vacuum furnace during the coating step are: working pressure of 5Pa-6Pa, negative bias of -200V, argon flow of 20sccm-25sccm (standard ml/min), sample (carbon/carbon composite) The substrate temperature was 200°C.

Example 5

(4) Coating step: After completing the main bombardment step, adjust the sample stage so that the sample stage is lowered to a distance of 70 mm from the target base, open the Si target, C target target cover and the sputtering chamber sample stage baffle and close the Zr The target cover of the target, turn on the DC power supply that controls the Si target and the C target, adjust the power of the Si target to 130W and the power of the C target to 160W, and perform sputtering and deposition at this power to prepare a stoichiometric SiC layer, Si target And C target sputtering for 120min, deposition time is 3h, the thickness of the deposited SiC layer is 4.8μm.

Then turn off the power of the Si target and the C target, close the target cover of the Si target and open the target cover of the Zr target. Turn on the DC power supply to control the Zr target and the C target, and adjust the power of the Zr target to 160W and the power of the C target to 170W. , in this power sputtering and deposition to prepare a ZrC layer that meets the stoichiometric ratio, the Zr target and the C target are sputtered for 60 min, the deposition time is 2.2 h, and the thickness of the deposited ZrC layer is 4.3 μm.

Then follow the above steps to deposit a 4.8μm SiC layer, a 4.3μm ZrC layer, a 4.8μm SiC layer, a 4.3μm ZrC layer.... After 11 sputtering and deposition, the SiC layer is a total of 52.8μm, ZrC layer After 11 times of sputtering and deposition, the total thickness is 47.3 μm, so that the total thickness of the SiC layer and the ZrC layer reaches 100.1 μm to complete the coating.

The working parameters of the vacuum furnace during the coating step are: working pressure of 4-6Pa, negative bias of -200V, argon flow of 20-30sccm (standard ml/min), sample (carbon/carbon composite) The substrate temperature was 210°C.

Example 6

(4) Coating step: After completing the main bombardment step, adjust the sample stage so that the sample stage is lowered to a distance of 70 mm from the target base, open the Si target, C target target cover and the sputtering chamber sample stage baffle and close the Zr The target cover of the target, turn on the DC power supply that controls the Si target and the C target, adjust the power of the Si target to 100W and the power of the C target to 180W, and perform sputtering and deposition at this power to prepare a stoichiometric SiC layer, Si target And C target sputtering for 60min, deposition time is 2.5h, the thickness of the deposited SiC layer is 4.3μm.

Then turn off the power of the Si target and the C target, close the target cover of the Si target and open the target cover of the Zr target. Turn on the DC power supply to control the Zr target and the C target, and adjust the power of the Zr target to 190W and the power of the C target to 200W. , in this power sputtering and deposition to prepare a ZrC layer that meets the stoichiometric ratio, the Zr target and the C target are sputtered for 50 min, the deposition time is 1.8 h, and the thickness of the deposited ZrC layer is 4.0 μm.

Then follow the above steps to deposit a 4.3μm SiC layer, a 4.0μm ZrC layer, a 4.3μm SiC layer, a 4.0μm ZrC layer.... After 13 sputtering and deposition, the SiC layer is a total of 55.9μm, ZrC layer After 13 times of sputtering and deposition, the total thickness is 52 μm, so that the total thickness of the SiC layer and the ZrC layer reaches 107.9 μm to complete the coating.

The working parameters of the vacuum furnace during the coating step are: working pressure of 4-6Pa, negative bias of -200V, argon flow of 10-25sccm (standard ml/min), sample (carbon/carbon composite) The substrate temperature was 220°C.

Example 7

(4) Coating step: After completing the main bombardment step, adjust the sample stage so that the sample stage is lowered to a distance of 70 mm from the target base, open the Si target, C target target cover and the sputtering chamber sample stage baffle and close the Zr The target cover of the target, turn on the DC power supply that controls the Si target and the C target, adjust the power of the Si target to 70W and the power of the C target to 110W, and perform sputtering and deposition at this power to prepare a stoichiometric SiC layer, Si target And C target sputtering for 30min, deposition time is 2.0h, the thickness of the deposited SiC layer is 3.3μm.

Then turn off the power of the Si target and the C target, close the target cover of the Si target and open the target cover of the Zr target. Turn on the DC power supply to control the Zr target and the C target, and adjust the power of the Zr target to 230W and the power of the C target to 230W. , in this power sputtering and deposition to prepare a ZrC layer that meets the stoichiometric ratio, the Zr target and the C target are sputtered for 40 min, the deposition time is 0.8 h, and the thickness of the deposited ZrC layer is 3.8 μm.

Then follow the above steps to deposit a 3.3μm SiC layer, a 3.8μm ZrC layer, a 3.3μm SiC layer, a 3.8μm ZrC layer.... After 15 times of sputtering and deposition, the SiC layer is a total of 49.5μm and ZrC layers. After 15 times of sputtering and deposition, the total thickness is 57 μm, so that the total thickness of the SiC layer and the ZrC layer reaches 106.5 μm to complete the coating.

The working parameters of the vacuum furnace during the coating step are: working pressure of 5-6Pa, negative bias of -200V, argon flow of 10-25sccm (standard ml/min), sample (carbon/carbon composite) The substrate temperature was 200°C.

In Examples 3–7, the total thickness of the SiC/ZrC coatings prepared on the carbon/carbon composites was greater than 100 μm. In the analysis of the SiC/ZrC coatings obtained in Examples 3-7, the bonding between the layers is good, and there are no defects such as cracks.

Comparative Example 1

In Comparative Example 1, except (4) the coating step is different from that in Example 1, other steps are the same as in Example 1. (4) The coating step of Comparative Example 1 is as follows.

(4) Coating step: A ZrC single coating is prepared on the surface of the sample. During the coating process, the power of the Zr target is 100W and the power of the C target is 130W, the working pressure of the vacuum furnace is 5.5Pa, and the negative bias voltage is -200V , the flow rate of argon gas is 25sccm (standard ml/min), and the substrate temperature of the sample (carbon/carbon composite material) is 200°C. The Zr target and the C target are sputtered for 130 min each time, each deposition time is 2.5 h, and the thickness of the ZrC layer deposited each time is 5 μm.

In this embodiment, the thickness of the deposited ZrC layer is about 55 μm.

Figure 3 shows the X-ray phase composition analysis of the prepared coating. In Figure 3, the ordinate is the diffraction peak intensity, and the abscissa is the diffraction angle. It can be seen from Figure 3 that the ZrC layer can be prepared under the above preparation conditions, Figure 4 shows the cross-sectional morphology. Due to the large difference in thermal expansion coefficient between ZrC and C/C composites, the bonding between the matrix and the coating is not tight and small crack defects appear.

From the above description, it can be seen that the above-mentioned embodiments of the present invention achieve the following technical effects:

A preparation method of a high-temperature oxidation-resistant SiC/ZrC coating on the surface of a carbon/carbon composite material. The design scheme of the present invention enables the SiC/ZrC coating to have many advantages in the ultra-high temperature service environment by designing a transition layer (SiC layer) between the surface of the carbon/carbon composite material and the ZrC layer. First, considering the structural design of the coating, the structural design of the transition layer helps to improve the thermal shock resistance of the coating. Secondly, the difference of thermal expansion coefficient between the transition layer and the substrate, and the difference between the thermal expansion coefficient of the transition layer and the surface layer are much smaller than that of the substrate and the surface layer, so that the microcracks between the layers are much smaller than the microcracks in the single layer. It is much smaller and is covered by the upper layer, thereby effectively reducing the matrix oxidation caused by the diffusion of oxygen along the through cracks to the surface of the matrix.

The preparation method has the following advantages:

(1) Aiming at the high temperature protection of carbon/carbon composite materials, the present invention designs a high-temperature oxidation-resistant SiC/ZrC coating structure. coating. The coating system forms a protective semi-solid oxide layer composed of ZrO ₂ solid phase and SiO ₂ liquid phase under aerobic conditions, which can effectively prevent cracks, prevent crack propagation, and prevent further oxidation, so it has excellent high-temperature oxidation resistance. . SiC (3.8×10 ^-6 /K) acts as a transition layer between C (1.0×10 ^-6 and 2.1–2.6×10 ^-6 /K,) and ZrC (6.7×10 ^-6 /K), effectively preventing the If the thermal expansion coefficient is too large and the excessive cracks are formed, the formed semi-solid SiO ₂ and ZrO ₂ can cover the original cracks and prevent the erosion of the matrix carbon by oxygen.

(2) The high-temperature oxidation-resistant SiC/ZrC coating on the surface of the carbon material according to the present invention has simple and convenient preparation operation process, simple coating structure, and easy industrial production.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. A preparation method of a high-temperature oxidation-resistant SiC/ZrC coating on the surface of a carbon/carbon composite material is characterized by comprising the following steps:

a sample sending step: conveying the sample stage with the sample to a sputtering chamber, and vacuumizing the sputtering chamber;

a main bombardment step: after the sample feeding step is completed, argon is filled into the sputtering chamber, voltage and current are applied to the Si target, the Zr target and the C target for bombardment, all target power supplies are turned off after the bombardment is completed, and the sample stage is adjusted after the main bombardment is completed so as to facilitate the coating of the sample;

coating: starting a direct current power supply for controlling the Si target and the C target, sputtering and depositing to prepare the SiC layer meeting the stoichiometric ratio,

then, the sample platform is transferred to the target positions of the Zr target and the C target, and a direct current power supply for controlling the Si target and the C target is started to prepare a ZrC layer meeting the stoichiometric ratio after sputtering and deposition;

and after multiple times of sputtering and deposition, forming the SiC/ZrC coating to finish coating.

2. The production method according to claim 1,

before the sample sending step, a preparation step is also included, and the preparation step comprises the following operations:

sample surface pretreatment: carrying out ultrasonic cleaning on the sample, and then drying the cleaned sample in an environment at 70 ℃ for 1 h;

cleaning: polishing the inner wall of the vacuum furnace, the sample mold and the target material cylinder by using sand paper;

air extraction: after cleaning, loading a sample in a vacuum furnace, mounting target materials of a Si target, a Zr target and a C target, and then vacuumizing a cleaning chamber;

cleaning, after the air exhaust is finished, the cleaning chamber is vacuumized to 0.7 × 10^-3Pa, introducing argon to increase the pressure to 20-30 Pa, and switching on an ionization power supply to perform glow cleaning on the cleaning chamber;

preferably, in the step of pretreating the surface of the sample, the sample is firstly put into acetone for ultrasonic cleaning for 15min, and then is put into absolute ethyl alcohol for ultrasonic cleaning for 15 min;

preferably, in the washing step, the washing chamber is glow-washed for 25 minutes to 35 minutes.

3. The production method according to claim 1,

in the sample feeding step, rough pumping is firstly carried out on the sputtering chamber, so that the vacuum degree of the sputtering chamber reaches 3.0 × 10⁰Pa below, then performing fine pumping on the sputtering chamber until the vacuum degree in the sputtering chamber reaches 1 × 10^-3Pa or less, and the evacuation time is 6 hours or more.

4. The production method according to claim 1,

in the main bombardment step, the voltage and the current of the Si target, the Zr target and the C target are all 480V and 0.3A, and the bombardment time is 5-15 minutes;

preferably, argon is introduced into the chamber to achieve a pressure of (3-5) × 10 in the chamber^-1Pa。

5. The production method according to claim 1,

in the coating step, when a sample is at a target position of an Si target and a C target, the power of the Si target is 50W-150W, C, the power of the target is 100W-200W, the sputtering time is 30 minutes-120 minutes each time, and the deposition time is 0.5 hour-3 hours;

when the sample is at the target position of the Zr target and the C target, the power of the Zr target is 100W-250W, C, the power of the Zr target is 100W-250W, the sputtering time of the Zr target and the C target is 30 minutes-120 minutes each time, and the deposition time is 0.5 hour-3 hours.

6. The production method according to claim 5,

the thickness of each SiC layer is 3-5 μm;

the thickness of the ZrC layer deposited each time is 3-5 mu m;

the SiC/ZrC coating is of a multilayer coating structure and comprises a plurality of SiC layers and a plurality of ZrC layers, and the SiC layers and the ZrC layers are arranged at intervals;

preferably, the thickness of the SiC/ZrC coating is more than 100 μm.

7. The production method according to claim 1,

in the coating step, the working parameters of the vacuum furnace are as follows: the working pressure is 4 Pa-6 Pa, the negative bias is-200V, the working voltage is 400V-450V, and the substrate temperature of the sample is 180-220 ℃.

8. The production method according to claim 1,

argon is continuously filled in the process of the film coating step, and the flowing speed of the argon is 10 sccm-30 sccm.

9. The production method according to claim 1,

the method also comprises a passivation step after the coating step, wherein the passivation step comprises the following operations:

firstly, reducing the temperature of a sputtering chamber, introducing argon to passivate the surface of a sample, and then introducing gas into a vacuum furnace when the temperature of the vacuum chamber is reduced to 120 ℃ so that the pressure in the vacuum furnace reaches 1 atmosphere;

preferably, the flow rate of argon in the passivation step is 30sccm to 40sccm for 2 minutes.

10. The production method according to claim 1,

the target purities of the Si target, the Zr target and the C target are all more than 99.99 wt%.

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