A friction-reducing wear-resistant seal coating for ceramic matrix composites and a method of making the same

Abstract

The application discloses a kind of anti-friction wearproof seal coating for ceramic matrix composite and preparation method thereof, the seal coating is composed of transition layer adhered on ceramic matrix layer and 7wt%Y2O3 stabilized ZrO2 base self-lubricating layer.The preparation method includes: selecting 7wt%Y2O3 stabilized ZrO2, CaF2, Mo and Ag powder as raw material, according to the mass ratio of raw material 7wt%Y2O3 stabilized ZrO 2 40%-45%, CaF 2 35%-40%, Mo 6%-12% and Ag 8%-14% are ball milled and mixed;The powder obtained in step 1 is dried with pure Si powder, and the surface of C / SiC composite material is pretreated;Pure Si powder is used to prepare a pure Si transition layer on the surface of C / SiC composite material substrate, and the mixed powder obtained in step 1 is used to prepare a 7wt%Y2O3 stabilized ZrO2 base self-lubricating layer on the surface of the pure Si transition layer.The coating designed by the application has no obvious defects such as holes and cracks, and has excellent tribological properties, which is expected to solve the contact problem between the abradable seal coating on the engine blade and the turbine outer ring.

Description

Technical fields:

[0001] This invention belongs to the field of coating materials technology, specifically relating to a friction-reducing and wear-resistant sealing coating for ceramic matrix composites and its preparation method. Background technology:

[0002] For more than half a century, abrasive sealant coatings have been used in the booster and turbine stages of gas turbines to reduce the clearance between rotating and stationary components, making a significant contribution to protecting blades and reducing fuel consumption and greenhouse gas emissions.

[0003] With the increasing inlet temperature of future aero-engines, ceramic matrix composites such as SiC / SiC and C / SiC will replace existing high-temperature alloy components in turbine applications. Despite the enormous potential of ceramic matrix composites, a suitable sealing coating is currently lacking. Existing high-temperature sealing coatings suffer from high friction coefficients and high wear rates. Under extreme operating conditions such as high-pressure, high-speed friction, high temperature gradients, strong vibration and impact, and low lubrication and strong oxidation, blades are prone to severe wear from the coating. Therefore, there is an urgent need to develop a dedicated sealing coating for ceramic matrix composites with high reliability, long lifespan, low friction coefficient, and low wear rate to reduce friction on the coating surface, slow down wear on blades and the turbine outer ring, and extend the engine's service life. Summary of the Invention:

[0004] To address the technical problems mentioned above, this invention provides a friction-reducing and wear-resistant sealing coating for ceramic matrix composites and its preparation method. This ceramic matrix wear-resistant sealing coating, with Si as the binder layer and a 7YSZ (7wt% Y2O3-stabilized ZrO2) composite coating as the surface coating, exhibits a low coefficient of friction and wear rate. It is expected to reduce mechanical damage caused by mutual friction between engine blades and turbine outer rings during service, enhance the coating's performance and extend its service life.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] The first aspect of the present invention provides a friction-reducing and wear-resistant sealing coating for ceramic matrix composites, the friction-reducing and wear-resistant sealing coating comprising a transition layer adhered to a ceramic matrix layer and a 7wt% Y2O3-stabilized ZrO2-based self-lubricating layer.

[0007] As a further illustration of the present invention, the ceramic matrix layer is a C / SiC composite material layer; and / or the transition layer is a pure Si transition layer.

[0008] As a further explanation of the present invention, the 7wt% Y2O3 stabilized ZrO2-based self-lubricating layer is composed of the following raw material components in mass percentage: 7wt% Y2O3 stabilized ZrO2 40%-45%, CaF2 35%-40%, Mo 6%-12%, Ag 8%-14%.

[0009] A second aspect of the present invention provides a method for preparing a friction-reducing and wear-resistant sealing coating for ceramic matrix composites, comprising the following steps:

[0010] Step 1: Select 7wt% Y2O3 stabilized ZrO2, CaF2, Mo and Ag powder as raw materials, and ball mill them together according to the following raw material mass ratios: 7wt% Y2O3 stabilized ZrO2 40%-45%, CaF2 35%-40%, Mo 6%-12% and Ag 8%-14%.

[0011] Step 2: Dry the powder obtained in Step 1 and pure Si powder to pretreat the surface of the C / SiC composite material;

[0012] Step 3: A pure Si transition layer is prepared on the surface of the C / SiC composite matrix using pure Si powder, and a 7wt% Y2O3-stabilized ZrO2-based self-lubricating layer is prepared on the surface of the pure Si transition layer using the mixed powder obtained in Step 1.

[0013] As a further explanation of the present invention, the particle size of the raw materials in step 1 is 40-150μm, the ball milling parameters are 150-200Hz rotation speed, 0.5-1h ball milling time, and ball-to-material ratio of 5:1.

[0014] As a further explanation of the present invention, the pretreatment process of the C / SiC composite material surface in step 2 includes:

[0015] The C / SiC substrate was polished with a diamond grinding wheel, and the edges were chamfered. Finally, it was ultrasonically cleaned and dried.

[0016] As a further explanation of the present invention, the pure Si transition layer and the 7wt% Y2O3 stabilized ZrO2-based self-lubricating layer in step 3 were both prepared by supersonic plasma spraying.

[0017] As a further explanation of the present invention, the spraying parameters used for the pure Si transition layer are: spraying power 30-35Kw, powder feeding rate 1r / min, spraying distance 10cm, protective gas is argon with a flow rate of 6L / min and a pressure of 1.05MPa.

[0018] As a further explanation of the present invention, the spraying parameters used for the 7wt% Y2O3 stabilized ZrO2-based self-lubricating layer are as follows: spraying power 40-45Kw, powder feed rate 2r / min, spraying distance 10cm, protective gas is argon with a flow rate of 6L / min and a pressure of 1.05MPa.

[0019] As a further illustration of the present invention, the thickness of the pure Si transition layer prepared in step 3 is 180-200 μm, and the thickness of the self-lubricating layer is 400-500 μm.

[0020] Compared with the prior art, the present invention has the following beneficial technical effects:

[0021] The ceramic-based composite coating provided by this invention consists of a matrix phase 7YSZ and various solid lubricating phases. It has no obvious defects such as pores or cracks, and the composite coating bonds tightly to the substrate. Tests show that this coating exhibits excellent tribological properties at high temperatures, preventing severe frictional damage between the coating and the blades, effectively protecting the blades and extending their service life. Attached Figure Description

[0022] Figure 1 The cross-sectional morphology of the gradient YSZ ceramic matrix abrasive sealing coating prepared by supersonic plasma spraying in Example 1 is shown in backscatter mode.

[0023] Figure 2 The curve showing the change in the coefficient of friction of the YSZ ceramic-based wear-resistant sealing coating over time at 400°C in Example 1.

[0024] Figure 3 The wear rate of the YSZ ceramic-based wear-resistant sealing coating in Example 1 was measured and calculated by a three-dimensional profilometer after a 400°C friction and wear test.

[0025] Figure 4 The cross-sectional morphology of the gradient YSZ ceramic-based wearable sealing coating prepared by supersonic plasma spraying in Example 2 is shown in backscatter mode.

[0026] Figure 5 The curve showing the change in the coefficient of friction of the YSZ ceramic-based wear-resistant sealing coating over time at 800°C in Example 2.

[0027] Figure 6 The wear rate of the YSZ ceramic-based wear-resistant sealing coating in Example 2 was measured and calculated by a three-dimensional profilometer after undergoing a friction and wear test at 800°C. Detailed implementation method:

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] This invention provides a method for preparing a friction-reducing and wear-resistant sealing coating for ceramic matrix composites. The overall approach involves using a C / SiC composite material as the matrix, designing the composition ratio of the coating raw materials, and using a uniformly mixed powder of 7YSZ, CaF2, Mo, and Ag as the powder for supersonic plasma spraying. Supersonic plasma spraying is then used to prepare a self-lubricating composite coating with certain hardness and porosity, and good adhesion to the matrix, on the surface of the C / SiC composite material. Then, a reciprocating friction device is used to test the coating surface, obtaining the friction coefficient curve and corresponding wear rate under certain experimental conditions. This determines the role of the lubricating phase in resisting frictional damage, ultimately reducing the coating's friction coefficient and wear rate, effectively improving the poor wear resistance of ceramic matrix sealing coatings, and balancing the conflict between the friction coefficient and wear rate. Specifically:

[0030] The first aspect of the present invention provides a friction-reducing and wear-resistant sealing coating for ceramic matrix composites, the friction-reducing and wear-resistant sealing coating comprising a transition layer adhered to a ceramic matrix layer and a 7wt% Y2O3-stabilized ZrO2-based self-lubricating layer.

[0031] The ceramic substrate layer is preferably a C / SiC composite material layer; the transition layer is preferably a pure Si transition layer. Considering the matching degree between the thermal expansion coefficients of the substrate and the coating material, this invention uses Si as the bonding transition layer, which can alleviate thermal mismatch, increase the adhesion between the coating and the substrate, and extend the service life of the coating. Ultimately, a gradient wear-resistant sealing coating is formed with a pure Si transition layer and a self-lubricating composite coating as the surface coating.

[0032] Furthermore, the 7wt% Y2O3 stabilized ZrO2-based self-lubricating layer is composed of the following raw material components in mass percentage: 7wt% Y2O3 stabilized ZrO2 40%-45%, CaF2 35%-40%, Mo 6%-12%, Ag 8%-14%.

[0033] Among them: the mass percentage of 7wt% Y2O3 stabilized ZrO2 can be, for example, 40%, 41%, 42%, 43%, 44%, 45%, etc.; the mass percentage of CaF2 can be, for example, 35%, 36%, 37%, 38%, 39%, 40%, etc.; the mass percentage of Mo can be, for example, 6%, 7%, 8%, 9%, 10%, 11%, 12%, etc.; and the mass percentage of Ag can be, for example, 8%, 9%, 10%, 11%, 12%, 13%, 14%, etc.

[0034] The design concept of the self-lubricating layer of this invention originates from the synergistic lubrication effect between various lubricating phases. YSZ, as the matrix phase of the coating, is widely used in extreme environments due to its excellent high-temperature performance. Soft metal Ag has excellent lubrication performance at medium and low temperatures and has high thermal conductivity. At high temperatures, it can also effectively protect the friction layer by reducing local heat. CaF2 has excellent lubrication performance at 800℃, but it may volatilize during the preparation process due to its low melting point. However, after adding metallic Mo, a chemical reaction will occur under the action of heat and force. The product CaMoO4 forms a friction layer with other lubricating substances, which exists stably on the coating surface and has a significant lubrication effect.

[0035] A second aspect of the present invention provides a method for preparing a friction-reducing and wear-resistant sealing coating for ceramic matrix composites, comprising the following steps:

[0036] Step 1: Select 7wt% Y2O3 stabilized ZrO2, CaF2, Mo and Ag powder as raw materials, and ball mill them together according to the following raw material mass ratios: 7wt% Y2O3 stabilized ZrO2 40%-45%, CaF2 35%-40%, Mo 6%-12% and Ag 8%-14%.

[0037] The raw materials have a powder particle size of 40-150μm, and the ball milling parameters are a rotation speed of 150-200Hz, a ball milling time of 0.5-1h, and a ball-to-material ratio of 5:1.

[0038] Step 2: Dry the powder obtained in Step 1 and pure Si powder to pretreat the surface of the C / SiC composite material;

[0039] The pretreatment process of the C / SiC composite material surface includes: grinding the surface of the C / SiC matrix with a 60-mesh diamond grinding wheel, chamfering the edges, and finally ultrasonic cleaning and drying.

[0040] Step 3: A pure Si transition layer is prepared on the surface of the C / SiC composite matrix using pure Si powder, and a 7wt% Y2O3-stabilized ZrO2-based self-lubricating layer is prepared on the surface of the pure Si transition layer using the mixed powder obtained in Step 1.

[0041] Preferably, both the pure Si transition layer and the 7wt% Y2O3-stabilized ZrO2-based self-lubricating layer are prepared by supersonic plasma spraying.

[0042] The spraying parameters used for the pure Si transition layer are: spraying power 30-35Kw, powder feed rate 1r / min, spraying distance 10cm, protective gas is argon with a flow rate of 6L / min and a pressure of 1.05MPa; the spraying power used for the above pure Si transition layer can be, for example, 30Kw, 31Kw, 32Kw, 33Kw, 34Kw, 35Kw, etc.

[0043] The spraying parameters used for the 7wt% Y2O3 stabilized ZrO2-based self-lubricating layer are: 40-45Kw, 2r / min, spraying distance 10cm, protective gas is argon with a flow rate of 6L / min and a pressure of 1.05MPa. The spraying power used for the above self-lubricating layer can be, for example, 40Kw, 41Kw, 42Kw, 43Kw, 44Kw, 45Kw, etc.

[0044] The final pure Si transition layer has a thickness of 180-200 μm, for example, 180 μm, 185 μm, 190 μm, 195 μm, 200 μm, etc.; the self-lubricating layer has a thickness of 400-500 μm, for example, 400 μm, 420 μm, 440 μm, 460 μm, 480 μm, 500 μm, etc.

[0045] After the above friction-reducing and wear-resistant sealing coating is prepared, high-temperature friction and wear performance testing is required: after polishing the obtained coating, it is tested on a friction machine to obtain the friction coefficient curve, and the wear volume of the coating is measured using a Brook three-dimensional profilometer to calculate the wear rate.

[0046] The equipment used for testing the friction and wear performance was the Rtec MFT-5000-H high-temperature friction testing machine, with a reciprocating sliding mode. Test parameters: Al2O3 for the grinding pair, time approximately 15 minutes, frequency 8-10 Hz, stroke 4-5 mm, temperature 390-410℃, 790℃-810℃.

[0047] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments:

[0048] Example 1

[0049] A method for preparing a friction-reducing and wear-resistant sealing coating for ceramic matrix composites includes the following steps:

[0050] S1. Using C / SiC composite material as the matrix, C / SiC composite material cut to a size of 25mm×15mm×4mm is ground with a 60-mesh diamond grinding wheel to obtain a certain roughness. The edges are then chamfered to prevent the coating from peeling off due to excessive stress. The pretreated matrix material is then ultrasonically cleaned and placed in a vacuum drying oven at 100℃ for 12 hours to ensure a clean and dry surface, thus becoming the matrix material.

[0051] S2. 7YSZ, CaF2, Mo, Si, and Ag powders were selected as raw materials, with particle sizes of D=100μm, D=75μm, D=75μm, D=75μm, and D=48μm, respectively. The raw materials were weighed according to a mass ratio of 7YSZ:CaF2:Mo:Ag=40%:40%:8%:12% in a glove box. The mixed powder was then placed in a ball mill jar with 4mm diameter zirconia balls at a ball-to-powder ratio of 5:1. The ball milling parameters were set as follows: rotation speed 180Hz, forward rotation for 10 minutes, reverse rotation for 10 minutes, with a 2-minute pause in between, for a total of 1 hour. After uniform mixing, the balls and powder were separated using a sieve. The sieved powder was placed in a vacuum drying oven and kept at 80℃ for 6 hours along with the Si powder required for the bonding layer. Finally, the dried powder was placed in a vacuum bag and sealed for storage.

[0052] S3. Pure Si powder and a uniformly mixed powder are placed into the powder feeder of the HEPJ-II type supersonic plasma spraying equipment, with feed rates set to 1 r / min and 2 r / min respectively. The substrate is placed sequentially in the fixture on the operating table, and the Si bonding layer is prepared first. The spraying parameters are set as follows: laser power 35W, spraying distance 10cm, spray gun movement speed 1800cm / min, stacking cycle 15 times, protective atmosphere argon, powder feed gas flow rate 6L / min, and pressure 1.05MPa. After the bonding layer is prepared and cooled, the surface is cleaned, and then the ceramic matrix composite coating is prepared on the surface. The spraying parameters are set as follows: laser power 42W, spraying distance 10cm, spray gun movement speed 1800cm / min, stacking cycle 45 times, protective atmosphere argon, powder feed gas flow rate 6L / min, and pressure 1.05MPa. After the sample cools, the YSZ ceramic matrix wearable sealing coating sample is obtained.

[0053] S4. High-Temperature Friction and Wear Test: A high-temperature friction and wear testing machine (Rtec MFT-5000-H) was used to conduct the friction and wear test. The sample was clamped and fixed using fixtures. The Al2O3 balls (Ø=9.525) were used for the grinding pair. The test temperature was 400℃, the load was 5N, the frequency was 10Hz, and the displacement amplitude was 5mm. The friction and wear test ended after 15 minutes. A Bruker 3D optical profilometer was used to measure the wear volume of the sample and calculate the wear rate.

[0054] Example 2

[0055] A method for preparing a friction-reducing and wear-resistant sealing coating for ceramic matrix composites includes the following steps:

[0056] S1. Using C / SiC composite material as the matrix, C / SiC composite material cut to a size of 25mm×15mm×4mm is ground with a 60-mesh diamond grinding wheel to obtain a certain roughness. The edges are then chamfered to prevent the coating from peeling off due to excessive stress. The pretreated matrix material is then ultrasonically cleaned and placed in a vacuum drying oven at 100℃ for 12 hours to ensure a clean and dry surface, thus becoming the matrix material.

[0057] S2. 7YSZ, CaF2, Mo, Si, and Ag powders were selected as raw materials, with particle sizes of D=100μm, D=75μm, D=75μm, D=75μm, and D=48μm, respectively. The raw materials were weighed in a glove box according to a mass ratio of 7YSZ:CaF2:Mo:Ag=40%:40%:11%:9%. The mixed powder was then placed in a ball mill jar with 4mm diameter zirconia balls at a ball-to-powder ratio of 5:1. The ball milling parameters were set as follows: rotation speed 180Hz, forward rotation for 10 minutes, reverse rotation for 10 minutes, with a 2-minute pause in between, for a total of 1 hour. After uniform mixing, the balls and powder were separated using a sieve. The sieved powder was placed in a vacuum drying oven and kept at 80℃ for 6 hours along with the Si powder required for the bonding layer. Finally, the dried powder was placed in a vacuum bag and sealed for storage.

[0058] S3. Pure Si powder and a uniformly mixed powder are placed into the powder feeder of the HEPJ-II type supersonic plasma spraying equipment, with feed rates set to 1 r / min and 2 r / min respectively. The substrate is placed sequentially in the fixture on the operating table, and the Si bonding layer is prepared first. The spraying parameters are set as follows: laser power 35W, spraying distance 10cm, spray gun movement speed 1800cm / min, stacking cycle 15 times, protective atmosphere argon, powder feed gas flow rate 6L / min, and pressure 1.05MPa. After the bonding layer is prepared and cooled, the surface is cleaned, and then the ceramic matrix composite coating is prepared on the surface. The spraying parameters are set as follows: laser power 45W, spraying distance 10cm, spray gun movement speed 1800cm / min, stacking cycle 45 times, protective atmosphere argon, powder feed gas flow rate 6L / min, and pressure 1.05MPa. After the sample cools, the YSZ ceramic matrix wearable sealing coating sample is obtained.

[0059] S4. High-Temperature Friction and Wear Test: A high-temperature friction and wear testing machine (Rtec MFT-5000-H) was used to conduct the friction and wear test. The sample was clamped and fixed using fixtures. The Al2O3 balls (Ø=9.525) were used for the grinding pair. The test temperature was 800℃, the load was 5N, the frequency was 10Hz, and the displacement amplitude was 5mm. The friction and wear test ended after 15 minutes. A Bruker 3D optical profilometer was used to measure the wear volume of the sample and calculate the wear rate.

[0060] Figure 1 This image shows the cross-sectional morphology of the gradient YSZ ceramic-based wearable sealing coating prepared by supersonic plasma spraying in Example 1 under backscattered mode. The transition layer thickness is approximately 180 μm, and the self-lubricating layer is approximately 485 μm. The coating exhibits a typical layered structure after spraying, with different phases displaying different contrasts. There are no obvious defects such as cracks or pores; the microstructure is relatively dense, and the ceramic-based composite coating is tightly bonded to the Si bonding layer, and the Si bonding layer is tightly bonded to the C / SiC composite matrix.

[0061] Figure 2 This is a curve showing the change in the coefficient of friction of the YSZ ceramic-based wear-resistant sealing coating in Example 1 over time at 400°C. Figure 2 The friction coefficient curve shows that the friction coefficient of the ceramic-based wear-resistant sealing coating is only about 0.35 at 400℃. This is mainly because soft metal Ag is added to the coating. At high temperatures, pure metal Ag is prone to slip deformation, thus significantly reducing friction damage.

[0062] Figure 3 The wear rate of the YSZ ceramic-based wear-resistant sealing coating in Example 1, measured and calculated using a three-dimensional profilometer after a 400°C tribological test, is shown. The average wear rate of the YSZ ceramic-based wear-resistant sealing coating at 400°C is 1.03 × 10⁻⁶. -7 mm 3 / (N·m), which indicates that when the coating comes into contact with the grinding pair, it can not only reduce wear, but also has excellent wear resistance.

[0063] Figure 4 The image shows the cross-sectional morphology of the gradient YSZ ceramic-based wearable sealing coating prepared by supersonic plasma spraying in Example 2 under backscattered mode. It can be observed that the thickness of the YSZ layer and the Si binder layer are not significantly different from those in Example 1, and the coating also exhibits a typical layered structure after spraying. The bonding between layers and between phases is good, with no macroscopic defects. This indicates that the supersonic plasma spraying process for preparing the coating is relatively stable, and the prepared coating has high quality.

[0064] Figure 5This is a curve showing the coefficient of friction of the YSZ ceramic-based wear-resistant sealing coating in Example 2 as a function of time at 800°C. Figure 5 The friction coefficient curves show that the friction coefficient of the ceramic-based wear-resistant sealing coating is only about 0.29 at 800℃. This indicates that the ceramic-based wear-resistant sealing coating prepared by this method has a low friction coefficient under different high-temperature environments, achieving excellent friction reduction. This is directly related to the coating's composition design. The matrix phase YSZ in the coating has excellent high-temperature stability and a certain load-bearing capacity, and at high temperatures, a self-lubricating phase CaMoO4 is generated in situ. These calcium salts, along with fluorides and Ag, are gradually compacted and filled into the wear surface during reciprocating sliding, forming a strong, continuous, and smooth protective film. This film hinders the continuous damage to the coating by the wear pair and effectively reduces frictional damage to the coating at 800℃. It is precisely because of the good synergistic lubrication effect between different lubricating phases in the coating that the coating achieves excellent friction reduction and wear resistance effects simultaneously at different test temperatures.

[0065] Figure 6 The wear rate of the YSZ ceramic-based wear-resistant sealing coating in Example 2, measured and calculated using a three-dimensional profilometer after undergoing a tribological test at 800°C, is shown. The average wear rate of the YSZ ceramic-based wear-resistant sealing coating at 800°C is 1.03 × 10⁻⁶. -7 mm 3 / (N·m), which indicates that when the coating comes into contact with the wear pair, the friction layer formed on the surface effectively protects the coating and reduces friction and wear. This ensures that when the coating is applied to the turbine outer ring, it can not only effectively reduce wear and protect the blades, but also maintain a long service life and not fail due to chipping or peeling.

[0066] It should be noted that, in this document, terms such as “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0067] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for the preparation of a friction-reducing wear-resistant seal coat for ceramic matrix composites, characterized in that, The method comprises the following steps: Step 1: 7wt% Y2O3 stabilized ZrO2, CaF2, Mo and Ag powder are selected as raw materials, and ball milling is performed according to the mass ratio of the raw materials as follows: 7wt% Y2O3 stabilized ZrO2 40%-45%, CaF2 35%-40%, Mo 6%-12% and Ag 8%-14%; Step 2: The powder obtained in step 1 is dried with pure Si powder, and the surface of the C / SiC composite material is pretreated; Step 3: A pure Si transition layer is prepared on the surface of the C / SiC composite material substrate using pure Si powder, and a 7wt% Y2O3 stabilized ZrO2-based self-lubricating layer is prepared on the surface of the pure Si transition layer using the mixed powder obtained in step 1; wherein the pure Si transition layer and the 7wt% Y2O3 stabilized ZrO2-based self-lubricating layer are both prepared by supersonic plasma spraying; the spraying parameters for the 7wt% Y2O3 stabilized ZrO2-based self-lubricating layer are as follows: spraying power 40-45Kw, powder feeding rate 2r / min, spraying distance 10cm, protective gas argon, flow rate 6L / min, pressure 1.05MPa; the thickness of the self-lubricating layer is 400-485μm.

2. The method of producing a friction-reducing wear-sealing coating for a ceramic matrix composite according to claim 1, characterized in that, In step 1, the particle size of the powder of the raw materials is 40-150μm, the ball milling parameters are rotation speed 150-200Hz, ball milling time 0.5-1h, and ball-to-material ratio 5:

1.

3. The method of producing a friction reducing wear resistant seal coat for ceramic matrix composites of claim 1, wherein, In step 2, the pretreatment process of the surface of the C / SiC composite material comprises: The C / SiC substrate is ground using a diamond grinding disc, the edges are chamfered, and finally ultrasonic cleaning and drying are performed.

4. The method of producing a friction reducing wear resistant seal coat for ceramic matrix composites of claim 1, wherein, The spraying parameters for the pure Si transition layer are as follows: spraying power 30-35Kw, powder feeding rate 1r / min, spraying distance 10cm, protective gas argon, flow rate 6L / min, and pressure 1.05MPa.

5. The method of producing a friction reducing wear resistant seal coat for ceramic matrix composites of claim 1, wherein, The thickness of the pure Si transition layer prepared in step 3 is 180-200μm.

Images