阅读说明：本技术 一种碳-碳化硅复合材料表面抗氧化涂层及其制备方法 (Carbon-silicon carbide composite material surface oxidation resistant coating and preparation method thereof ) 是由 杨良伟 宋环君 刘伟 刘俊鹏 于新民 李晓东 霍鹏飞 于艺 杨冰洋 金鑫 张昊 于 2019-11-26 设计创作，主要内容包括：本发明涉及一种碳-碳化硅复合材料表面抗氧化涂层及其制备方法。所述抗氧化涂层包括：与基底碳-碳化硅复合材料相结合的竖直石墨烯阵列层；和在竖直石墨烯阵列层进行沉积所形成的陶瓷涂层。方法包括如下步骤：(1)采用等离子体辅助的化学气相沉积法在碳-碳化硅复合材料表面生长得到竖直石墨烯阵列层；和(2)在竖直石墨烯阵列层上沉积陶瓷涂层。本发明采用竖直石墨烯陈列对碳-碳化硅复合材料陶瓷涂层进行增韧,竖直石墨烯阵列的添加使陶瓷涂层的断裂韧性提高,降低了陶瓷涂层在高温摩擦过程中的脆性断裂,从而提高了涂层的高温抗氧化性能。(The invention relates to a carbon-silicon carbide composite material surface oxidation resistant coating and a preparation method thereof. The oxidation resistant coating comprises: a vertical graphene array layer bonded to a base carbon-silicon carbide composite; and depositing the formed ceramic coating on the vertical graphene array layer. The method comprises the following steps: (1) growing on the surface of the carbon-silicon carbide composite material by adopting a plasma-assisted chemical vapor deposition method to obtain a vertical graphene array layer; and (2) depositing a ceramic coating on the vertical graphene array layer. According to the invention, the carbon-silicon carbide composite ceramic coating is toughened by adopting the vertical graphene array, the addition of the vertical graphene array improves the fracture toughness of the ceramic coating, and the brittle fracture of the ceramic coating in the high-temperature friction process is reduced, so that the high-temperature oxidation resistance of the coating is improved.)

1. A carbon-silicon carbide composite surface oxidation resistant coating, characterized in that the oxidation resistant coating comprises:

a vertical graphene array layer bonded to a base carbon-silicon carbide composite; and

and depositing the formed ceramic coating on the vertical graphene array layer.

2. The oxidation-resistant coating according to claim 1,

the number of graphene layers in the vertical graphene array layer is 1-10;

optionally, the number of graphene layers is 2-5;

optionally, the number of graphene layers is 6-10;

most preferably, the number of layers of graphene is 1.

3. The oxidation-resistant coating according to claim 1 or 2,

the height of the vertical graphene array layer is 0.1-10 μm.

4. The oxidation-resistant coating according to any one of claims 1 to 3,

growing the vertical graphene array layer on the surface of the carbon-silicon carbide composite material by a plasma-assisted chemical vapor deposition method;

preferably, the deposition is carried out under a pressure of 0.1 to 100mbar and at a temperature of 500 and 800 ℃; more preferably, the deposition time is from 1 to 240 minutes.

5. The oxidation-resistant coating according to any one of claims 1 to 4,

the thickness of the ceramic coating is 4-20 μm;

optionally, the ceramic coating comprises a SiC coating, a ZrC coating, a HfC coating, ZrB₂Coating layer, HfB₂Any one or more of a coating;

optionally, the ceramic coating is a SiC coating with a thickness of 4-20 μm;

optionally, the ceramic coating is deposited on the vertical graphene array layer by chemical vapor deposition.

6. The oxidation-resistant coating according to any one of claims 1 to 5,

the oxidation resistant coating has the following properties:

thickness: 10-20 μm;

fracture toughness > 3 MPa.m^1/2(ii) a And/or

Oxidation resistance: oxyacetylene is ablated at 2000 ℃, and the ablation rate of the wire is less than 2 mu m/s.

7. A method for preparing the carbon-silicon carbide composite material surface oxidation resistant coating according to any one of claims 1 to 6, characterized in that the method comprises the following steps:

(1) growing on the surface of the carbon-silicon carbide composite material by adopting a plasma-assisted chemical vapor deposition method to obtain a vertical graphene array layer; and

(2) depositing a ceramic coating on the vertical graphene array layer.

8. The method of claim 7,

the step (1) comprises the following steps:

placing the carbon-silicon carbide composite material in a cavity of a chemical vapor deposition device, vacuumizing, washing gas, raising the temperature by a program, then opening a carbon source and a plasma generating device, cracking the carbon source into plasma, and depositing the plasma on the carbon-silicon carbide composite material to obtain a vertical graphene array layer;

preferably, the deposition is carried out under a pressure of 0.1 to 100mbar and at a temperature of 500 and 800 ℃; more preferably, the deposition time is from 1 to 240 minutes;

preferably, the carbon source is one or more of a hydrocarbon, an alcohol, an ether, a ketone, a phenol.

9. The method according to claim 7 or 8,

depositing the ceramic coating by using a chemical vapor deposition method;

preferably, the process conditions of the chemical vapor deposition method are as follows: the deposition temperature is 800-1200 ℃, the pressure is 1-10kPa, and the deposition time is 1-20 hours.

10. The method according to any one of claims 7 to 9,

the method further comprises the step of pre-treating the carbon-silicon carbide composite material;

preferably, the pre-treatment comprises: and (3) grinding and polishing the carbon-silicon carbide composite material, cleaning and drying.

Technical Field

The invention relates to the technical field of carbon-silicon carbide composite material ceramic coatings, in particular to a carbon-silicon carbide composite material surface antioxidant coating and a preparation method thereof.

Background

At present, the carbon-silicon carbide composite material has the excellent properties of light weight, high specific strength, high specific modulus, high temperature resistance and the like, and is widely applied to the military field of aerospace and the like. The high temperature susceptibility to oxidation of carbon-silicon carbide composites is the biggest obstacle encountered in their practical application. The ceramic coating prepared on the surface of the composite material can effectively isolate the composite material from the external environment, protect the matrix from high-temperature oxidation and exert the excellent performance of the composite material. However, the thermal expansion coefficients of the composite material and the ceramic coating are not matched and microcracks exist in the coating, so that the coating has larger thermal stress and is easy to crack in the high-temperature and low-temperature transformation process, and the high-temperature oxidation resistance effect is still to be improved.

In order to improve the performance of the carbon-silicon carbide composite material in a high-temperature aerobic environment as much as possible, the improvement of the toughness of the ceramic coating becomes a crucial problem.

Disclosure of Invention

The first purpose of the invention is to provide a carbon-silicon carbide composite material surface oxidation resistant coating; the second purpose of the invention is to provide a method for preparing the carbon-silicon carbide composite material surface oxidation resistant coating.

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

a carbon-silicon carbide composite surface oxidation resistant coating, the oxidation resistant coating comprising:

a vertical graphene array layer bonded to a base carbon-silicon carbide composite; and

and depositing the formed ceramic coating on the vertical graphene array layer.

Preferably, the number of graphene layers in the vertical graphene array layer is 1-10;

optionally, the number of graphene layers is 2-5;

optionally, the number of graphene layers is 6-10;

most preferably, the number of layers of graphene is 1.

Preferably, the height of the vertical graphene array layer is 0.1-10 μm.

Preferably, the vertical graphene array layer is grown on the surface of the carbon-silicon carbide composite material by a plasma-assisted chemical vapor deposition method;

preferably, the deposition is carried out under a pressure of 0.1 to 100mbar and at a temperature of 500 and 800 ℃; more preferably, the deposition time is from 1 to 240 minutes.

Preferably, the thickness of the ceramic coating is 4-20 μm;

optionally, the ceramic coating comprises a SiC coating, a ZrC coating, a HfC coating, ZrB₂Coating layer, HfB₂Any one or more of a coating;

optionally, the ceramic coating is a SiC coating with a thickness of 4-20 μm;

optionally, the ceramic coating is deposited on the vertical graphene array layer by chemical vapor deposition.

Preferably, the oxidation resistant coating has the following properties:

the thickness is 10-20 μm;

fracture toughness > 3 MPa.m^1/2(ii) a And/or

Oxidation resistance: oxyacetylene is ablated at 2000 ℃, and the ablation rate of the wire is less than 2 mu m/s.

A method for preparing the carbon-silicon carbide composite material surface oxidation resistant coating, which comprises the following steps:

(1) growing on the surface of the carbon-silicon carbide composite material by adopting a plasma-assisted chemical vapor deposition method to obtain a vertical graphene array layer; and

(2) depositing a ceramic coating on the vertical graphene array layer.

Preferably, step (1) comprises the steps of:

placing the carbon-silicon carbide composite material in a cavity of a chemical vapor deposition device, vacuumizing, washing gas, raising the temperature by a program, then opening a carbon source and a plasma generating device, cracking the carbon source into plasma, and depositing the plasma on the carbon-silicon carbide composite material to obtain a vertical graphene array layer;

preferably, the deposition is carried out under a pressure of 0.1 to 100mbar and at a temperature of 500 and 800 ℃; more preferably, the deposition time is from 1 to 240 minutes;

preferably, the carbon source is one or more of a hydrocarbon, an alcohol, an ether, a ketone, a phenol.

Preferably, the ceramic coating is deposited using chemical vapor deposition;

preferably, the process conditions of the chemical vapor deposition method are as follows: the deposition temperature is 800-1200 ℃, the pressure is 1-10kPa, and the deposition time is 1-20 hours.

Preferably, the method further comprises the step of pre-treating the carbon-silicon carbide composite material;

preferably, the pre-treatment comprises: and (3) grinding and polishing the carbon-silicon carbide composite material, cleaning and drying.

Advantageous effects

The technical scheme of the invention has the following advantages:

according to the invention, the carbon-silicon carbide composite ceramic coating is toughened by adopting the vertical graphene array, the addition of the vertical graphene array improves the fracture toughness of the ceramic coating, and the brittle fracture of the ceramic coating in the high-temperature friction process is reduced, so that the high-temperature oxidation resistance of the coating is improved.

The invention carries out deep research on the vertical graphene array and provides suitable conditions of the number and the size of graphene layers.

The invention provides a preparation method of a vertical graphene array.

The invention also carries out intensive research on the ceramic coating and provides a proper ceramic thickness condition.

The invention provides a preparation method of a ceramic coating.

Drawings

FIG. 1 is a composite substrate surface of example 1 grown vertical graphene by plasma chemical vapor deposition.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

The invention provides in a first aspect an oxidation resistant coating on a carbon-silicon carbide composite surface, the oxidation resistant coating comprising:

a vertical graphene array layer bonded to a base carbon-silicon carbide composite; and

and depositing the formed ceramic coating on the vertical graphene array layer.

According to the invention, the carbon-silicon carbide composite ceramic coating is toughened by adopting the vertical graphene array, the addition of the vertical graphene array improves the fracture toughness of the ceramic coating, and the brittle fracture of the ceramic coating in the high-temperature friction process is reduced, so that the high-temperature oxidation resistance of the coating is improved.

The toughening principle of the vertical graphene array is as follows:

the graphene presents a two-dimensional layered structure, when cracks are expanded to the graphene, the crack direction can be deflected, and when the cracks are pulled out, stress energy can be absorbed, so that the ceramic coating is toughened. Compared with disordered graphene, the graphene in the vertical configuration has extremely high specific surface area and orientation, and can effectively deflect the crack direction and absorb stress energy.

The inventors have conducted intensive studies on a vertical graphene array, and found several factors affecting the toughening effect of the vertical graphene array, which are described in detail below:

(a) number of layers of graphene

In some preferred embodiments of the present invention, the number of graphene layers in the vertical graphene array layer may be a single layer (i.e. the number of graphene layers is 1), or may be a few layers, where a few layers means that the number of graphene layers is less than 10, for example, 2 to 5, or 6 to 10.

Most preferably, the number of layers of graphene is 1.

(b) Size of

In some preferred embodiments of the present invention, the height of the vertical graphene array layer is 0.1 to 10 μm.

(c) Preparation method of vertical graphene array

In some preferred embodiments of the present invention, the vertical graphene array layer is grown on the surface of the carbon-silicon carbide composite material by a plasma-assisted chemical vapor deposition method.

Specifically, the method comprises the following steps: placing the carbon-silicon carbide composite material in a cavity of a chemical vapor deposition device, vacuumizing, washing gas, raising the temperature by program, then opening a carbon source and a plasma generating device, cracking the carbon source into plasma, and depositing the plasma on the carbon-silicon carbide composite material to obtain the vertical graphene array layer.

The number of layers of the graphene can be controlled and adjusted through deposition conditions, the size is positively correlated with the deposition time, and the vertical graphene with different sizes can be prepared by controlling the deposition time. The number of layers and the size have obvious influence on the toughening effect. Therefore, the preparation conditions required for the vertical graphene array layer are severe. Through research, when a plasma-assisted chemical vapor deposition method is adopted to deposit a vertical graphene array layer on the surface of a carbon-silicon carbide composite material, the better deposition conditions are as follows:

the pressure conditions are 0.1-100mbar, for example, 0.1mbar, 0.5mbar, 1mbar, 10mbar, 20mbar, 30mbar, 40mbar, 50mbar, 60mbar, 70mbar, 80mbar, 90mbar, 100 mbar;

the temperature is 500 ℃ and 800 ℃, for example, 500 ℃, 550 ℃, 600 ℃, 650 ℃, 700 ℃, 750 ℃ and 800 ℃; and/or

The deposition time is 1 to 240 minutes, and may be, for example, 1 minute, 30 minutes, 60 minutes, 90 minutes, 120 minutes, 150 minutes, 180 minutes, 210 minutes, 240 minutes. When deposition is carried out under the conditions of pressure and temperature of 0.1-100mbar and 500-800 ℃, the invention can realize continuous regulation and control of the graphene size from a few nanometers to a few micrometers by controlling the deposition time to be 1-240 minutes.

In some preferred embodiments, the ceramic coating has a thickness of 4-20 μm, for example, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm. When the thickness of the ceramic coating is too small, the coating cannot protect the composite material at high temperature for a long time; however, when the thickness of the ceramic is too large, the brittleness of the ceramic itself affects the performance of the composite material.

In some preferred embodiments, the ceramic coating comprises a SiC coating, a ZrC coating, a HfC coating, ZrB₂Coating layer, HfB₂Any one or more of the coatings. The ceramic coating can be obtained by depositing on the vertical graphene array layer through a chemical vapor deposition method, the process flow of the chemical vapor deposition method can refer to the prior art, but the deposition conditions need to be controlled to obtain the ceramic coating with the required thickness because the ceramic coating has certain requirements on the thickness of the ceramic coating.

In some preferred embodiments, the ceramic coating is a SiC coating, preferably 4-20 μm thick. When the SiC coating is deposited by adopting a chemical vapor deposition method, the precursor can adopt methyltrichlorosilane, and the better process conditions are as follows:

the deposition temperature is 800-1200 ℃, for example, 800 ℃, 850 ℃, 900 ℃, 950 ℃, 1000 ℃, 1050 ℃, 1100 ℃, 1150 ℃ and 1200 ℃;

the pressure is 1 to 10kPa, and may be, for example, 1kPa, 2kPa, 3kPa, 4kPa, 5kPa, 6kPa, 7kPa, 8kPa, 9kPa, 10 kPa; and/or

The deposition time is 1 to 20 hours, and for example, may be 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours.

Most fully, the present invention provides an oxidation resistant coating comprising:

a vertical graphene array layer bonded to a base carbon-silicon carbide composite; the number of graphene layers in the vertical graphene array layer is 1-10; optionally, the number of graphene layers is 2-5 or 6-10; most preferably, the number of layers of graphene is 1; the height of the vertical graphene array layer is 0.1-10 μm; growing the vertical graphene array layer on the surface of the carbon-silicon carbide composite material by a plasma-assisted chemical vapor deposition method; preferably, the deposition is carried out under a pressure of 0.1 to 100mbar and at a temperature of 500 and 800 ℃; more preferably, the deposition time is from 1 to 240 minutes;

depositing the formed ceramic coating on the vertical graphene array layer; the thickness of the ceramic coating is 4-20 μm; the ceramic coating comprises a SiC coating, a ZrC coating, a HfC coating and a ZrB₂Coating layer, HfB₂Any one or more of a coating; the ceramic coating is a SiC coating with the thickness of 4-20 mu m; depositing the ceramic coating on the vertical graphene array layer by a chemical vapor deposition method.

The antioxidant coating is detected to have the following properties:

the thickness is 10-20 μm;

fracture toughness > 3 MPa.m^1/2(ii) a And/or

Oxidation resistance: oxyacetylene is ablated at 2000 ℃, and the ablation rate of the wire is less than 2 mu m/s.

The invention provides in a second aspect a method for preparing the carbon-silicon carbide composite material surface oxidation resistant coating provided by the invention, which comprises the following steps:

(1) growing on the surface of the carbon-silicon carbide composite material by adopting a plasma-assisted chemical vapor deposition method to obtain a vertical graphene array layer; and

(2) depositing a ceramic coating on the vertical graphene array layer.

In some preferred embodiments, step (1) comprises the steps of: placing the carbon-silicon carbide composite material in a cavity of a chemical vapor deposition device, vacuumizing, washing gas (washing gas can be carried out by continuously introducing inert gas or reducing gas), carrying out temperature programming, then opening a carbon source and a plasma generating device, cracking the carbon source into plasma, and depositing the plasma on the carbon-silicon carbide composite material to obtain the vertical graphene array layer. The power of the plasma generating means (e.g. plasma generator) may be adjusted to ensure adequate lysis of the carbon source.

In some preferred embodiments, the deposition is carried out under pressure conditions of 0.1 to 100mbar and at a temperature of 500 and 800 ℃; more preferably, the deposition time is from 1 to 240 minutes. In some preferred embodiments, the carbon source used is one or more of hydrocarbon, alcohol, ether, ketone, phenol, and may be in the form of any one or more of a gaseous carbon source, a liquid carbon source, and a solid carbon source. For example, methane, ethylene, ethane, or the like can be used as the carbon source. In the deposition process of the vertical graphene, no metal or other catalyst is introduced, so that the vertical graphene can be directly deposited on the surface of the composite material.

In some preferred embodiments, the ceramic coating is deposited by chemical vapor deposition, using methyltrichlorosilane as a precursor; preferably, the process conditions of the chemical vapor deposition method are as follows: the deposition temperature is 800-1200 ℃, the pressure is 1-10kPa, and the deposition time is 1-20 hours.

In some preferred embodiments, the method further comprises the step of pretreating the carbon-silicon carbide composite; preferably, the pre-treatment comprises: and (3) grinding and polishing the carbon-silicon carbide composite material, cleaning and drying. The cleaning can be absolute ethyl alcohol or acetone, and the drying can be carried out at 60-100 ℃. The pretreatment may provide a clean surface for the carbon-silicon carbide composite to facilitate deposition of the vertical graphene array, and other processing steps that may achieve similar cleaning effects may also be suitable for use in the present invention.

The following are examples of the present invention.