阅读说明：本技术 一种耐高温陶瓷基复合材料界面复合涂层及制备方法 (High-temperature-resistant ceramic matrix composite interface composite coating and preparation method thereof ) 是由 杨芳红 周长灵 徐鸿照 姜凯 李涵 刘瑞祥 张家路 于 2020-04-23 设计创作，主要内容包括：本发明公开了一种耐高温陶瓷基复合材料界面复合涂层及制备方法,所述界面复合涂层包括碳纤维、热解碳层和SiC层,所述热解碳层包覆于碳纤维上,所述SiC层包覆于热解碳层上。本申请所述的热解碳/碳化硅复合界面涂层,一方面可以缓解碳纤维与陶瓷基体的热膨胀系数不匹配,另一方面复合界面层能够在氧化或高温烧蚀环境中生成SiO2玻璃相保护层,保护碳纤维不受氧化侵蚀,从而提高复合材料的耐高温抗氧化性能。(The invention discloses a high-temperature-resistant ceramic matrix composite interface composite coating and a preparation method thereof. The application pyrolytic carbon/silicon carbide composite interface coating can alleviate the mismatch of the thermal expansion coefficient of carbon fiber and ceramic base body on the one hand, and on the other hand composite interface layer can generate a SiO2 glass phase protective layer in an oxidation or high-temperature ablation environment to protect the carbon fiber from oxidation erosion, thereby improving the high-temperature resistance and oxidation resistance of the composite material.)

1. The utility model provides a high temperature resistant ceramic matrix composite interface composite, its characterized in that, interface composite includes carbon fiber, pyrolysis carbon layer and SiC layer, the pyrolysis carbon layer cladding is on the carbon fiber, the SiC layer cladding is on the pyrolysis carbon layer.

2. The interface composite coating of the high temperature resistant ceramic matrix composite according to claim 1, wherein: the thickness of the pyrolytic carbon layer is 100nm-1 mu m; the thickness of the SiC layer is 1-10 μm.

3. The preparation method of the high-temperature-resistant ceramic matrix composite interface composite coating is characterized by comprising the following steps of:

the method comprises the following steps: putting the carbon fiber into a vacuum furnace in a prefabricated form for degreasing treatment in a vacuum state, wherein the treatment temperature is 600-1200 ℃, and the treatment time is 1-4 h;

step two: putting the carbon fiber preform obtained in the step one into a chemical vapor deposition furnace, and performing pyrolytic carbon layer deposition;

step three: placing the carbon fiber preform obtained in the step two into polycarbosilane solution for dipping;

step four: placing the carbon fiber preform subjected to dipping in the step three in an oven for drying and curing;

step five: and C, placing the carbon fiber preform dried and cured in the step four in a vacuum furnace for high-temperature cracking.

4. The method for preparing the carbon fiber reinforced high temperature resistant ceramic matrix composite interfacial composite coating according to claim 3, wherein the carbon fiber preform in the first step is of a needle punched structure, a three-dimensional woven structure or a 2.5D woven structure.

5. The preparation method of the carbon fiber reinforced high temperature resistant ceramic matrix composite interface composite coating according to claim 3, wherein the polycarbosilane solution solvent in the third step is an organic solvent, the organic solvent is one or more of toluene, xylene, n-hexane and chloroform, and the concentration of the polycarbosilane solution is 40-60% by mass.

6. The method for preparing the carbon fiber reinforced high temperature resistant ceramic matrix composite interface composite coating according to claim 3, wherein in the third vacuum impregnation step, the loading amount of the polycarbosilane solution on the carbon fiber preform is 5-10% of the mass of the preform; in the pressure impregnation process, the loading amount of the polycarbosilane solution on the carbon fiber preform is 10-15% of the mass of the preform.

7. The preparation method of the carbon fiber reinforced high temperature resistant ceramic matrix composite interface composite coating according to claim 3, wherein the deposition of the pyrolytic carbon layer in the second step is carried out at a temperature of 800-.

8. The method for preparing the carbon fiber reinforced high temperature resistant ceramic matrix composite interface composite coating according to claim 3, wherein the step of dipping in the step three is as follows: and (3) dipping the carbon fiber preform obtained in the step two into the polycarbosilane solution at the normal temperature environment with the vacuum degree of-0.05 to-0.1 MPa for 0.5 to 2 hours, and then continuously dipping the polycarbosilane solution at the normal temperature environment with the pressure of 1.0 to 8.0MPa for 0.5 to 2 hours.

9. The method for preparing the carbon fiber reinforced high temperature resistant ceramic matrix composite interface composite coating according to claim 3, wherein the drying and curing steps in the fourth step are as follows: curing for 1-10h in an oven at 50-100 ℃ and curing for 1-10h in an environment at 100-200 ℃.

10. The method for preparing the carbon fiber reinforced high temperature resistant ceramic matrix composite interfacial composite coating according to claim 3, wherein the high temperature cracking step in the fifth step is as follows: and (3) cracking at the temperature of 1000-1500 ℃ for 1-5h under the protection of inert gas, so that polycarbosilane is cracked to generate SiC ceramic, and a SiC layer is obtained.

11. The preparation method of the carbon fiber reinforced high temperature resistant ceramic matrix composite interface composite coating according to claim 3, wherein the degreasing treatment temperature in the first step is 600-1200 ℃ for 1-4 h.

Technical Field

The invention relates to the technical field of interface modification of carbon fiber reinforced ceramic matrix composites, and particularly provides a high-temperature-resistant ceramic matrix composite interface composite coating and a preparation method thereof.

Background

The parts of the hypersonic aircraft for new generation weaponry, such as the windward end head, the wing front edge and the like, need to bear the harsh conditions of high Mach flight speed, ultrahigh temperature heat flow and ultrahigh temperature oxidation environment, and put forward severe requirements on the thermal protection material of the high temperature resistant parts. Compared with other ultra-high temperature resistant materials, the carbon fiber reinforced ceramic matrix composite has the characteristics of light specific gravity, low thermal conductivity, low thermal expansion coefficient, chemical corrosion resistance, high strength, high hardness and the like, and becomes an ideal high-temperature structural material.

The ceramic matrix composite is a composite material compounded with various fibers by taking ceramic as a matrix. The ceramic matrix can be high temperature structural ceramic such as silicon nitride, silicon carbide, etc. These advanced ceramics have excellent properties of high temperature resistance, high strength and rigidity, relatively light weight, corrosion resistance and the like, and have the fatal weakness of brittleness, and when in a stress state, the advanced ceramics can generate cracks and even break to cause material failure. The adoption of high-strength and high-elasticity fiber and matrix composite is an effective method for improving the toughness and reliability of the ceramic. The fiber can prevent the crack from expanding, thereby obtaining the fiber reinforced ceramic matrix composite material with excellent toughness. The ceramic matrix composite material has been used as a liquid rocket engine nozzle, a missile radome, a nose cone of a space shuttle, a brake disc of an airplane, a brake disc of a high-grade automobile and the like, and becomes an important branch of a high-technology new material.

However, the difference in properties between the carbon fibers of the reinforcement of the ceramic matrix composite and the ceramic matrix causes the mismatch in the thermal expansion coefficients and the mismatch in the microscopic lattices. The interface between the two is susceptible to brittle fracture when stress is applied, resulting in a reduction in material strength and toughness. In addition, the carbon fiber of the reinforcement of the ceramic matrix composite material has no oxidation resistance, and is easy to be oxidized and ablated in the environment with the temperature higher than 400 ℃.

Disclosure of Invention

The technical task of the invention is to provide a carbon fiber reinforced high-temperature-resistant ceramic matrix composite interface composite coating and a preparation method thereof aiming at the problems, so that the mechanical property and the oxidation resistance of the ceramic matrix composite are improved.

The interface plays a role in transferring load, heat and the like in the composite material, and is also a concentrated area of cracks, defects and the like in the material fracture process, and the interface performance has obvious influence on the mechanical performance and the thermophysical performance of the composite material, so that the interface modification is an important way for improving the mechanical performance and the oxidation and ablation resistance of the composite material.

In order to achieve the purpose, the invention provides the following technical scheme:

the utility model provides a high temperature resistant ceramic matrix composite interface composite, interface composite includes carbon fiber, pyrolysis carbon-layer and SiC layer, the pyrolysis carbon-layer cladding is on the carbon fiber, the SiC layer cladding is on the pyrolysis carbon-layer, during the application, will interface composite sets up between carbon fiber and ceramic base member, and the SiC layer is laminated with ceramic base member.

The thickness of the pyrolytic carbon layer is 100nm-1 mu m; the thickness of the SiC layer is 1-10 μm.

A preparation method of a high-temperature-resistant ceramic matrix composite interface composite coating comprises the following steps:

the method comprises the following steps: putting the carbon fiber into a vacuum furnace in a prefabricated form for degreasing treatment in a vacuum state;

step two: putting the carbon fiber preform obtained in the step one into a chemical vapor deposition furnace, and performing pyrolytic carbon layer deposition;

step three: placing the carbon fiber preform obtained in the step two into polycarbosilane solution for dipping;

step four: placing the carbon fiber preform subjected to dipping in the step three in an oven for drying and curing;

step five: and C, placing the carbon fiber preform dried and cured in the step four in a vacuum furnace for high-temperature cracking.

The carbon fiber preform in the first step is in a needle punched structure, a three-dimensional weaving structure or a 2.5D weaving structure.

In the third step, the polycarbosilane solution solvent is an organic solvent, the organic solvent is one or more of toluene, xylene, normal hexane and chloroform, and the polycarbosilane solution has a concentration of 40-60% by mass.

In the third vacuum impregnation process, the loading amount of the polycarbosilane solution on the carbon fiber preform is 5-10% of the mass of the preform; in the pressure impregnation process, the loading amount of the polycarbosilane solution on the carbon fiber preform is 10-15% of the mass of the preform.

And in the second step, when the pyrolytic carbon layer is deposited, the temperature is 800-1200 ℃, the carbon source gas is propane, the carrier gas is argon, the flow rate of the propane gas is 1.0-10.0L/min, the flow rate of the argon gas is 1.0-10.0L/min, the pressure in the furnace is 1.0-10.0KPa, and the deposition time is 10-50 h.

The impregnation in the third step is as follows: and (3) dipping the carbon fiber preform obtained in the step two into the polycarbosilane solution at the normal temperature environment with the vacuum degree of-0.05 to-0.1 MPa for 0.5 to 2 hours, and then continuously dipping the polycarbosilane solution at the normal temperature environment with the pressure of 1.0 to 8.0MPa for 0.5 to 2 hours.

The drying and curing steps in the fourth step are as follows: curing for 1-10h in an oven at 50-100 ℃ and curing for 1-10h in an environment at 100-200 ℃.

The high-temperature cracking step in the fifth step is as follows: and (3) cracking at the temperature of 1000-1500 ℃ for 1-5h under the protection of inert gas, so that polycarbosilane is cracked to generate SiC ceramic, and a SiC layer is obtained.

In the first step, the degreasing treatment temperature is 600-1200 ℃, and the time is 1-4 h.

Compared with the prior art, the interface composite coating of the high-temperature-resistant ceramic matrix composite and the preparation method have the following outstanding beneficial effects:

the interface bonding state and the microstructure of the carbon fiber/ceramic matrix are effectively improved, the mechanical property and the oxidation resistance of the composite material are greatly improved, on one hand, the mismatch of the thermal expansion coefficients of the carbon fiber and the ceramic matrix can be relieved, on the other hand, the composite interface layer can generate a SiO2 glass phase protective layer in an oxidation or high-temperature ablation environment to protect the carbon fiber from oxidation erosion, and therefore the high-temperature resistance and the oxidation resistance of the composite material are improved.

Drawings

FIG. 1 is a scanning electron microscope image of the surface state of carbon fiber without vacuum degreasing treatment;

FIG. 2 is a scanning electron microscope image of the surface state of the carbon fiber after vacuum degreasing treatment;

FIG. 3 is a scanning electron microscope image of a carbon fiber with a pyrolytic carbon interface layer deposited on the surface;

FIG. 4 is a scanning electron microscope image of the carbon fiber surface deposited with a pyrolytic carbon interface layer and coated with a silicon carbide layer.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.