阅读说明：本技术 一种非晶硅氧碳复合陶瓷热障涂层的制备方法 (Preparation method of amorphous silicon-oxygen-carbon composite ceramic thermal barrier coating ) 是由 苏冬 田正凯 万萌 孙晓亮 王昊 于 2021-01-15 设计创作，主要内容包括：本发明涉及一种非晶硅氧碳陶瓷复合热障涂层的制备方法。将含氢聚硅氧烷和四甲基四乙烯基环四硅氧烷,搅拌得到PSO前驱体；将氧化硅、氧化铝、氧化硼、铝和镍作为固体填料,加入溶剂混合,然后进行球磨,得到的固体填料和溶剂的混合物作为球磨浆料；将球磨浆料加入PSO前驱体中得到PSO前驱体浆料；采用提拉浸渍法,将PSO前驱体浆料在基体表面包覆一层PSO浆料；将得到的包覆了PSO浆料的基体放入烘箱中交联,在基体表面形成PSO复合涂层；放入管式炉,在惰性气氛中热解,得到硅氧碳复合涂层。陶瓷复合涂层具有较低的热导率0.314W/(m·K),且涂层与基体之间的结合强度大于10MPa,满足目前热障涂层的要求。(The invention relates to a preparation method of an amorphous silicon-oxygen-carbon ceramic composite thermal barrier coating. Stirring hydrogen-containing polysiloxane and tetramethyl tetravinylcyclotetrasiloxane to obtain a PSO precursor; taking silicon oxide, aluminum oxide, boron oxide, aluminum and nickel as solid fillers, adding a solvent for mixing, and then carrying out ball milling to obtain a mixture of the solid fillers and the solvent as ball milling slurry; adding the ball-milling slurry into a PSO precursor to obtain PSO precursor slurry; coating a layer of PSO slurry on the surface of the substrate by adopting a pulling and dipping method; putting the obtained substrate coated with the PSO slurry into an oven for crosslinking to form a PSO composite coating on the surface of the substrate; putting the coating into a tubular furnace, and pyrolyzing the coating in an inert atmosphere to obtain the silicon-oxygen-carbon composite coating. The ceramic composite coating has lower thermal conductivity of 0.314W/(m.K), and the bonding strength between the coating and the substrate is more than 10MPa, thereby meeting the requirements of the current thermal barrier coating.)

1. A preparation method of an amorphous silicon-oxygen-carbon ceramic composite thermal barrier coating; the method comprises the following steps:

1) preparing PSO precursor slurry: weighing hydrogen-containing polysiloxane and tetramethyl tetravinylcyclotetrasiloxane, and uniformly stirring to obtain a PSO precursor; weighing silicon oxide, aluminum oxide, boron oxide, aluminum and nickel as solid fillers, adding a solvent, uniformly mixing, then carrying out ball milling, and taking a mixture of the solid fillers and the solvent obtained after the ball milling as ball milling slurry; adding the ball-milling slurry into a PSO precursor to obtain PSO precursor slurry;

2) preparing the silicon-oxygen-carbon ceramic composite thermal barrier coating: pulling the PSO precursor slurry obtained in the step 1) for 1-3 times by adopting a pulling and dipping method, dipping for 5-10 s each time, and coating a layer of uniform PSO slurry on the surface of the substrate;

3) crosslinking and pyrolysis of PSO precursors: putting the substrate coated with the PSO slurry obtained in the step 2) into an oven for crosslinking to form a uniform PSO composite coating on the surface of the substrate; and putting the coating into a tubular furnace, and pyrolyzing the coating in an inert atmosphere to obtain the silicon-oxygen-carbon composite coating.

2. The method as set forth in claim 1, characterized in that the solid filler in the step 1) has a mass ratio of silica, alumina, boria, aluminum and nickel of 1 (1-2) to 1: 1.

3. The method according to claim 1, wherein the mass ratio of the hydrogenpolysiloxane to the tetramethyltetravinylcyclotetrasiloxane in the step 1) is 1 (1-2).

4. The method as set forth in claim 1, wherein the mass ratio of the PSO precursor to the solid filler in the step 1) is 1 (2-4).

5. The method as set forth in claim 1, wherein the ball-milling solvent in step 1) is n-hexane, cyclohexane or ethanol.

6. The method as set forth in claim 1, characterized in that the ball-milling slurry in the step 1) has a solid content (mass fraction of solid filler in the ball-milling slurry) of 40 to 50%.

7. The method according to claim 1, wherein the drawing speed in the step 2) is 1000 to 5000 μm/s.

8. The method as set forth in claim 1, wherein the crosslinking temperature in step 3) is 60 to 100 ℃ and the crosslinking time is 1 to 2 hours.

9. The method as set forth in claim 1, wherein the pyrolysis temperature in the step 3) is 1000 to 1200 ℃ and the holding time is 2 hours.

10. The method according to claim 1, wherein the temperature rise rate in the step 3) is 3 to 5 ℃/min.

Technical Field

The invention relates to the field of turbine blades of aero-engines and heavy-duty gas turbines, in particular to a preparation method of an amorphous silicon-oxygen-carbon ceramic composite thermal barrier coating.

Background

In order to improve the performance of aeroengines and heavy-duty gas turbines, new requirements are made on the maximum service temperature and service time of turbine blades, however, the maximum bearing temperature of the most advanced single crystal blade materials does not exceed 1326 ℃, and the improvement of the thermal efficiency of the engine is greatly limited. The surface of the turbine blade is coated with a thermal barrier coating with low thermal conductivity, so that the temperature of the surface of the turbine blade can be greatly reduced, and the turbine blade can normally work under high ambient temperature. The thermal barrier coating material is generally an inorganic ceramic material, and generally has the following characteristics because the thermal barrier coating material works in a high-temperature extreme environment: low thermal conductivity, high thermal expansion coefficient, high bonding strength with the matrix material, no phase change and certain mechanical strength at high temperature. The thermal barrier coating commonly used is a zirconia-based series of materials, pure zirconia is prone to crack formation and development due to temperature-type phase transition, accompanied by large volume change, and even causes cracking and spalling of the coating, so a stabilizer is usually added to zirconia to inhibit phase transition, and yttria-doped stabilized zirconia (YSZ) is the best performance at present. However, YSZ has poor high temperature phase stability and can only be used at 1300 ℃, and at the same time, the sintering rate increases with increasing temperature, the porosity decreases and the thermal conductivity increases. In order to search for thermal barrier coating materials capable of normally working at higher temperature, thermal barrier coating materials of pyrochlore, fluorite and other compound systems are developed successively, but the thermal barrier coating materials cannot be popularized and applied in a large scale because of certain problems.

Atmospheric plasma spraying and electron beam physical vapor deposition are main processes for preparing thermal barrier coating materials, but have certain defects respectively, and thermal barrier coatings prepared by atmospheric plasma spraying have poor bonding strength and are easy to crack in the service process; the thermal barrier coating prepared by electron beam physical vapor deposition has high thermal conductivity, and the heat insulation performance of the thermal barrier coating is seriously reduced at high temperature. Both processes require extremely high temperature environments and have large requirements on equipment. Therefore, the development of a simple preparation process of the thermal barrier coating has certain market demand, and the application field of the thermal barrier coating can be expanded.

The precursor ceramic is inorganic amorphous ceramic obtained by utilizing an organic-inorganic conversion mechanism of a polymer precursor which is pyrolyzed at high temperature. The precursor ceramic has many excellent characteristics, excellent mechanical properties, high phase stability and high oxidation resistance, wherein the most important advantage is the designability of the polymer precursor, and allows one to control and adjust the composition and structure of the precursor ceramic by changing the composition of the precursor, thereby enabling one to prepare a suitable precursor ceramic according to the needs of one. The polymer precursor converted siloxycarbon ceramic is obtained by pyrolyzing a polysiloxane precursor, and can be regarded as that part of oxygen in siloxytetrahedron in silicon dioxide is replaced by carbon, so that the performance of the siloxycarbon ceramic is greatly improved compared with that of the traditional silicon dioxide, and the elastic modulus, the hardness, the glass transition temperature and the crystallization temperature are improved to a certain extent (J.Am.Ceram.Soc.2018,101, 4817).

In recent years, silicon-oxygen-carbon ceramics have been used for the search of the coating field due to their excellent oxidation resistance and corrosion resistance, and are mostly used for oxidation resistance (j.eur.ceram.soc.2017,37,4559) and corrosion resistance coating (j.eur.ceram.soc.2014,34,3597) of the surface of a substrate. The method has the characteristics of designability of precursor slurry, simplicity of coating process, easiness in preparation of the surface coating of the substrate with the complex shape, low-temperature sintering and the like, and is attracting more and more attention. However, the application of the silicon-oxygen-carbon ceramic in the field of thermal barrier coatings is not reported yet and is still blank. Meanwhile, the silicon-oxygen-carbon ceramic has lower thermal conductivity and better high-temperature stability, and has certain application potential in the field of thermal barrier coatings.

Disclosure of Invention

The invention aims to provide a silicon-oxygen-carbon composite thermal barrier coating prepared by a polymer precursor conversion method. The obtained silicon-oxygen-carbon composite ceramic thermal barrier coating has a hierarchical pore structure, can effectively reduce the thermal conductivity of the coating, has certain bonding strength with a substrate, and can adapt to the working environment under extreme conditions.

The invention discloses a silicon-oxygen-carbon ceramic composite thermal barrier coating by utilizing the excellent thermodynamic property of silicon-oxygen-carbon ceramic. The composite material has the advantages of low thermal conductivity, high bonding, corrosion resistance and the like, and is an ideal thermal barrier coating material. The invention further expands the application space of the silicon-oxygen-carbon ceramic material in the coating field (especially in the thermal barrier coating field), can be used in the conventional environment, has excellent performance in the extreme environment, and meets the requirements of the aerospace field and other fields on high-performance hot end components.

The silicon-oxygen-carbon composite ceramic thermal barrier coating utilizes hydrogen-containing Polysiloxane (PHMS) and tetramethyl-tetravinylcyclotetrasiloxane (D)₄Vi) as a Polysiloxane (PSO) precursor, suppressing shrinkage during pyrolysis of the polymer by adding inert ceramic powder to the precursor, increasing the coefficient of thermal expansion of the composite coating by adding metal powder, and achieving self-healing of defects such as cracks in the coating by adding glass powder. And coating the precursor composite coating on the nickel alloy substrate by a pulling and dipping method, and crosslinking and pyrolyzing the precursor composite coating to obtain the silicon-oxygen-carbon composite thermal barrier coating.

A preparation method of an amorphous silicon-oxygen-carbon composite ceramic thermal barrier coating comprises the following steps of; the method comprises the following steps:

1) preparing PSO precursor slurry: weighing hydrogen-containing polysiloxane and tetramethyl tetravinylcyclotetrasiloxane, and uniformly stirring to obtain a PSO precursor; weighing silicon oxide, aluminum oxide, boron oxide, aluminum and nickel as solid fillers, adding a solvent, uniformly mixing, then carrying out ball milling, and taking a mixture of the solid fillers and the solvent obtained after the ball milling as ball milling slurry; adding the ball-milling slurry into a PSO precursor to obtain PSO precursor slurry;

2) preparing the silicon-oxygen-carbon composite coating: pulling the PSO precursor slurry obtained in the step 1) for 1-3 times by adopting a pulling and dipping method, dipping for 5-10 s each time, and coating a layer of uniform PSO slurry on the surface of the substrate;

3) crosslinking and pyrolysis of PSO precursors: putting the substrate coated with the PSO slurry obtained in the step 2) into an oven for crosslinking to form a uniform PSO composite coating on the surface of the substrate; and putting the coating into a tubular furnace, and pyrolyzing the coating in an inert atmosphere to obtain the silicon-oxygen-carbon composite coating.

Preferably, the mass ratio of the silicon oxide to the aluminum oxide to the boron oxide to the aluminum to the nickel in the solid filler in the step 1) is 1 (1-2) to 1: 1.

Preferably, the mass ratio of the hydrogenpolysiloxane and the tetramethyltetravinylcyclotetrasiloxane in the step 1) is 1 (1-2).

Preferably, the mass ratio of the PSO precursor to the solid filler in the step 1) is 1 (2-4).

Preferably, the ball milling solvent in step 1) may be n-hexane, cyclohexane or ethanol.

Preferably, the solid content (mass fraction of solid filler in the ball-milling slurry) of the ball-milling slurry in the step 1) is 40-50%.

Preferably, the pulling speed in the step 2) is 1000-5000 μm/s.

Preferably, the substrate in step 2) is a high temperature K3 nickel alloy.

Preferably, the crosslinking temperature in the step 3) is 60-100 ℃, and the crosslinking time is 1-2 h.

Preferably, the pyrolysis temperature in the step 3) is 1000-1200 ℃, and the heat preservation time is 2 h.

Preferably, the heating rate in the step 3) is 3-5 ℃/min.

The invention uses the process to prepare the silicon-oxygen-carbon composite ceramic thermal barrier coating by a polymer precursor conversion method.

Advantageous results of the invention

The invention provides a novel silicon-oxygen-carbon composite ceramic thermal barrier coating by utilizing the excellent thermodynamic property and forming advantage of silicon-oxygen-carbon ceramic, which has the outstanding performances of low thermal conductivity, high bonding strength with a matrix, 10MPa, high-temperature stability, high oxidation resistance and the like, wherein the thermal conductivity is 0.314W/(m.K).

The novel silicon-oxygen-carbon composite ceramic coating has the largest thickness of about 100 mu m and uniform and compact surface appearance in a metal or alloy matrix precursor ceramic coating, and fully overcomes the defects of easy shrinkage and more defects of precursor ceramics.

Drawings

Fig. 1 is a surface SEM image of the silicon-oxygen-carbon composite ceramic coating prepared in example 1.

FIG. 2 is a sectional SEM photograph of the silicon-oxygen-carbon composite ceramic coating prepared in example 1.

Detailed Description

The present invention will now be described in further detail with reference to specific examples, which are intended to be illustrative, but not limiting, of the invention.

Example 1

1) Preparing PSO precursor slurry: 1.25g of hydrogen-containing polysiloxane and 1.25g of tetramethyl tetravinylcyclotetrasiloxane are weighed and stirred for 1 hour by magnetic force, so as to obtain a PSO precursor. Weighing 1.25g, 2.5g, 1.25g and 1.25g of silicon dioxide, aluminum oxide, boron oxide, aluminum and nickel serving as solid fillers and adding the solid fillers into a 100ml ball milling tank, adding 11.25g of n-hexane to enable the solid content to be 40%, and performing ball milling for 1h by using a planetary ball mill at 400r/min to obtain ball milling slurry consisting of the solid fillers and a solvent; transferring the ball-milled slurry into a PSO precursor, and mechanically stirring for 1h to obtain the PSO precursor slurry.

2) Preparing the silicon-oxygen-carbon composite coating: pulling the PSO precursor slurry obtained in the step 1) on the surface of a K3 high-temperature nickel alloy substrate for 3 times by adopting a pulling and dipping method, wherein the dipping time is 5s, and the pulling speed is 1000 mu m/s, so as to obtain a silicon-oxygen-carbon composite coating;

3) putting the high-temperature K3 nickel alloy substrate coated with the PSO slurry obtained in the step 2) into an oven for crosslinking for 2h at 60 ℃, and forming a uniform PSO composite coating on the surface of the nickel alloy; and putting the mixture into a tube furnace, and pyrolyzing the mixture for 2 hours at 1000 ℃ in an inert atmosphere to obtain the SiOC composite coating.

The silicon-oxygen-carbon composite ceramic coating has uniform and compact surface and no obvious cracks as shown in figure 1. The silicon-oxygen-carbon composite ceramic coating has the thickness of about 150 mu m, has a hierarchical pore structure, and is tightly combined with the matrix without obvious cracking phenomenon as shown in figure 2. The thermal conductivity of the silicon-oxygen-carbon composite ceramic coating at room temperature measured by a hot wire method was 0.314W/(m.K). The bonding strength of the silicon-oxygen-carbon composite ceramic coating and the matrix is 10MPa measured by a pull-off method.

Example 2

1) Preparing PSO precursor slurry: weighing 1.73g of hydrogen-containing polysiloxane and 2.16g of tetramethyl tetravinylcyclotetrasiloxane in mass ratio, and magnetically stirring for 1h to obtain a PSO precursor. Weighing 1.25g, 2.50g, 1.25g and 1.25g of silicon dioxide, aluminum oxide, boron oxide, aluminum and nickel serving as solid fillers and adding the solid fillers into a 100ml ball milling tank, adding 7.5g of n-hexane to enable the solid content to be 50%, and performing ball milling for 1h by using a planetary ball mill at 400r/min to obtain ball milling slurry consisting of the solid fillers and a solvent; transferring the ball-milled slurry into a PSO precursor, and mechanically stirring for 1h to obtain the PSO precursor slurry.

2) Preparing the silicon-oxygen-carbon composite coating: pulling the PSO precursor slurry obtained in the step 1) on the surface of a K3 high-temperature nickel alloy substrate for 2 times by adopting a pulling and dipping method, wherein the dipping time is 8s, and the pulling speed is 1000 mu m/s, so that the silicon-oxygen-carbon composite coating is obtained.

3) Putting the high-temperature K3 nickel alloy substrate coated with the PSO slurry obtained in the step 2) into an oven to crosslink for 1.5h at 60 ℃, and forming a uniform PSO composite coating on the surface of the nickel alloy; and putting the mixture into a tube furnace, and pyrolyzing the mixture for 2 hours at 1000 ℃ in an inert atmosphere to obtain the SiOC composite coating.

Example 3

1) Preparing PSO precursor slurry: weighing 1.875g of hydrogen-containing polysiloxane and 1.875g of tetramethyl tetravinylcyclotetrasiloxane, and magnetically stirring for 1h to obtain a PSO precursor. Weighing 1.25g, 1.88g, 2.50g, 1.25g and 1.25g of silicon dioxide, aluminum oxide, boron oxide, aluminum and nickel serving as solid fillers and adding the solid fillers into a 100ml ball milling tank, adding 12.20g of n-hexane to enable the solid content to be 40%, and performing ball milling for 1h by using a planetary ball mill at 400r/min to obtain ball milling slurry consisting of the solid fillers and a solvent; transferring the ball-milled slurry into a PSO precursor, and mechanically stirring for 1h to obtain the PSO precursor slurry.

2) Preparing the silicon-oxygen-carbon composite coating: pulling the PSO precursor slurry obtained in the step 1) on the surface of a K3 high-temperature nickel alloy substrate for 1 time by adopting a pulling and dipping method, wherein the dipping time is 10s, and the pulling speed is 1000 mu m/s, so as to obtain the silicon-oxygen-carbon composite coating.

3) Putting the high-temperature K3 nickel alloy substrate coated with the PSO slurry obtained in the step 2) into an oven for crosslinking for 2h at 60 ℃, and forming a uniform PSO composite coating on the surface of the nickel alloy; and putting the mixture into a tube furnace, and pyrolyzing the mixture for 2 hours at 1000 ℃ in an inert atmosphere to obtain the SiOC composite coating.

Example 4

1) Preparing PSO precursor slurry: 1.5g of hydrogen-containing polysiloxane and 2.25g of tetramethyl tetravinylcyclotetrasiloxane are weighed and stirred for 1 hour by magnetic force, so as to obtain a PSO precursor. Weighing 1.25g, 1.88g, 1.25g and 1.25g of silicon dioxide, aluminum oxide, boron oxide, aluminum and nickel serving as solid fillers and adding the solid fillers into a 100ml ball milling tank, adding 6.88g of n-hexane to enable the solid content to be 50%, and performing ball milling for 1h by using a planetary ball mill at 400r/min to obtain ball milling slurry consisting of the solid fillers and a solvent; transferring the ball-milled slurry into a PSO precursor, and mechanically stirring for 1h to obtain the PSO precursor slurry.

2) Preparing the silicon-oxygen-carbon composite coating: pulling the PSO precursor slurry obtained in the step 1) on the surface of a K3 high-temperature nickel alloy substrate for 3 times by adopting a pulling and dipping method, wherein the dipping time is 5s, and the pulling speed is 5000 mu m/s, so as to obtain the silicon-oxygen-carbon composite coating.

3) Putting the high-temperature K3 nickel alloy substrate coated with the PSO slurry obtained in the step 2) into an oven to crosslink for 1h at 100 ℃, and forming a uniform PSO composite coating on the surface of the nickel alloy; and putting the SiOC composite coating into a tube furnace, and pyrolyzing the SiOC composite coating for 2 hours at 1200 ℃ in an inert atmosphere.

Example 5

1) Preparing PSO precursor slurry: and weighing hydrogen-containing polysiloxane and tetramethyl tetravinylcyclotetrasiloxane in a mass ratio of 0.86g to 1.29g, and magnetically stirring for 1h to obtain a PSO precursor. Weighing 1.25g, 1.88g, 1.25g and 1.25g of silicon dioxide, aluminum oxide, boron oxide, aluminum and nickel serving as solid fillers and adding the solid fillers into a 100ml ball milling tank, adding 7.51g of n-hexane to enable the solid content to be 50%, and performing ball milling for 1h by using a planetary ball mill at 400r/min to obtain ball milling slurry consisting of the solid fillers and a solvent; transferring the ball-milled slurry into a PSO precursor, and mechanically stirring for 1h to obtain the PSO precursor slurry.

2) Preparing the silicon-oxygen-carbon composite coating: pulling the PSO precursor slurry obtained in the step 1) on the surface of a K3 high-temperature nickel alloy substrate for 3 times by adopting a pulling and dipping method, wherein the dipping time is 5s, and the pulling speed is 3000 mu m/s, so as to obtain the silicon-oxygen-carbon composite coating.

3) Putting the high-temperature K3 nickel alloy substrate coated with the PSO slurry obtained in the step 2) into an oven for crosslinking for 2h at 60 ℃, and forming a uniform PSO composite coating on the surface of the nickel alloy; and putting the SiOC composite coating into a tube furnace, and pyrolyzing the SiOC composite coating for 2 hours at 1200 ℃ in an inert atmosphere.

Example 6

1) Preparing PSO precursor slurry: 1.56g of hydrogen-containing polysiloxane and 1.56g of tetramethyl tetravinylcyclotetrasiloxane are weighed and stirred for 1 hour by magnetic force, so as to obtain a PSO precursor. Weighing 1.25g, 1.25g and 1.25g of silicon dioxide, aluminum oxide, boron oxide, aluminum and nickel serving as solid fillers respectively, adding the solid fillers into a 100ml ball milling tank, adding 7.64g of n-hexane to enable the solid content to be 45%, and performing ball milling for 1h by using a planetary ball mill at 400r/min to obtain ball milling slurry consisting of the solid fillers and a solvent. Transferring the ball-milled slurry into a PSO precursor, and mechanically stirring for 1h to obtain the PSO precursor slurry.

2) Preparing the silicon-oxygen-carbon composite coating: pulling the PSO precursor slurry obtained in the step 1) on the surface of a K3 high-temperature nickel alloy substrate for 3 times by adopting a pulling and dipping method, wherein the dipping time is 5s, and the pulling speed is 5000 mu m/s, so as to obtain the silicon-oxygen-carbon composite coating.

3) Putting the high-temperature K3 nickel alloy substrate coated with the PSO slurry obtained in the step 2) into an oven to crosslink for 1h at 100 ℃, and forming a uniform PSO composite coating on the surface of the nickel alloy; and putting the SiOC composite coating into a tube furnace, and pyrolyzing the SiOC composite coating for 2 hours at 1100 ℃ in an inert atmosphere.

Example 7

1) Preparing PSO precursor slurry: weighing 1.25g of hydrogen-containing polysiloxane and 3g of tetramethyl tetravinylcyclotetrasiloxane in a mass ratio, and magnetically stirring for 1h to obtain a PSO precursor. Weighing 1.25g, 2.50g, 1.25g and 1.25g of silicon oxide, aluminum oxide, boron oxide, aluminum and nickel serving as solid fillers respectively, adding the solid fillers into a 100ml ball milling tank, adding 9.17g of n-hexane to enable the solid content to be 45%, and performing ball milling for 1h by using a planetary ball mill at 400r/min to obtain ball milling slurry consisting of the solid fillers and a solvent. Transferring the ball-milled slurry into a PSO precursor, and mechanically stirring for 1h to obtain the PSO precursor slurry.

2) Preparing the silicon-oxygen-carbon composite coating: pulling the PSO precursor slurry obtained in the step 1) on the surface of a K3 high-temperature nickel alloy substrate for 3 times by adopting a pulling and dipping method, wherein the dipping time is 5s, and the pulling speed is 1000 mu m/s, so as to obtain the silicon-oxygen-carbon composite coating.

3) Putting the high-temperature K3 nickel alloy substrate coated with the PSO slurry obtained in the step 2) into an oven to crosslink for 2 hours at 100 ℃, and forming a uniform PSO composite coating on the surface of the nickel alloy; and putting the mixture into a tube furnace, and pyrolyzing the mixture for 2 hours at 1000 ℃ in an inert atmosphere to obtain the SiOC composite coating.

The invention relates to a thermal barrier coating of composite ceramic of polymer precursor converted silicon-oxygen-carbon. Taking hydrogen-containing polysiloxane and tetravinyl cyclotetrasiloxane as polymer precursors, adding a plurality of ceramic, metal and glass fillers such as silicon oxide, aluminum oxide, boron oxide, aluminum, nickel and the like, preparing a coating on the surface of a high-temperature nickel alloy matrix by using a pulling and dipping method, and then crosslinking and pyrolyzing at high temperature to obtain a compact and crack-free silicon-oxygen-carbon ceramic composite coating. The ceramic composite coating has lower thermal conductivity of 0.314W/(m.K), and the bonding strength between the coating and the substrate is more than 10MPa, thereby meeting the requirements of the current thermal barrier coating. The invention provides a preparation method of a novel silicon-oxygen-carbon composite thermal barrier coating material, and further expands the application of silicon-oxygen-carbon ceramic in a high-performance coating. The silicon-oxygen-carbon thermal barrier coating can protect the hot end part, so that the hot end part has longer service life under the action of thermal load in an extreme working environment, and the economic loss caused by thermal erosion is reduced.

The preparation of the silicon-oxygen-carbon composite ceramic coating can be realized by adjusting the process parameters recorded in the content of the invention, and the performance is basically consistent with that of the example. The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.