阅读说明：本技术 一种碳/碳复合材料表面宽温域复合抗氧化涂层及制备方法 (Wide-temperature-range composite anti-oxidation coating on surface of carbon/carbon composite material and preparation method thereof ) 是由 付前刚 周磊 李贺军 张佳平 丁伍庆 侯佳琪 于 2021-06-10 设计创作，主要内容包括：本发明涉及一种碳/碳复合材料表面宽温域复合抗氧化涂层及制备方法,采用料浆浸涂结合气相渗硅工艺制备了一种SiC-Si/TiB-(2)-SiC-Si/SiC-Si/SiO-(2)-B多层复合抗氧化涂层。最外层B-SiO-(2)作为封填层,填充裂纹,在低于900℃时产生低熔点的硼硅玻璃,可以有效愈合裂纹等缺陷；外层SiC-Si陶瓷涂层作为阻挡层,既在1500℃起到良好的抗氧化作用,又避免高温时产生过多的低熔点相；TiB-(2)-SiC-Si层作为中间层在1300℃快速氧化产生低熔点相封填裂纹；最内层的SiC-Si陶瓷涂层作为过渡层,起到缓解热膨胀系数不匹配的作用。复合涂层试样在900℃氧化182h后仅失重0.18％,在1300℃氧化164h后增重0.26％,在1500℃氧化196h增重0.32％。(The invention relates to a wide temperature range composite oxidation resistant coating on the surface of a carbon/carbon composite material and a preparation method thereof, and SiC-Si/TiB is prepared by adopting a slurry dip-coating combined gas phase siliconizing process 2 ‑SiC‑Si/SiC‑Si/SiO 2 -B multilayer composite oxidation resistant coating. Outermost layer of B-SiO 2 The borosilicate glass which is used as a sealing and filling layer and is filled with cracks and has a low melting point is generated at the temperature lower than 900 ℃, so that the defects such as cracks and the like can be effectively healed; the outer SiC-Si ceramic coating is used as a barrier layer, which not only has good antioxidation at 1500 ℃, but also avoids generating excessive low-melting-point phase at high temperature; TiB 2 the-SiC-Si layer is used as an intermediate layer and is rapidly oxidized at 1300 ℃ to generate low-melting-point phase packing cracks; the SiC-Si ceramic coating on the innermost layer is used as a transition layer and plays a role in relieving the mismatching of the thermal expansion coefficients. The composite coating sample only loses weight by 0.18 percent after being oxidized for 182h at 900 ℃, gains weight by 0.26 percent after being oxidized for 164h at 1300 ℃, and gains weight by 0.32 percent after being oxidized for 196h at 1500 ℃.)

1. A carbon/carbon composite material surface wide temperature range compound anti-oxidation coating, characterized by that the coating structure is the multilayer complex, it is made up of ceramic coating and glass coating; wherein the ceramic coating comprises three layers: the innermost layer is a SiC-Si buffer layer, and the middle layer is TiB₂A SiC-Si layer, wherein the outer layer is a SiC-Si layer; outermost glassThe coating is B modified SiO₂And (3) a layer.

2. A method for preparing the wide-temperature-range composite oxidation-resistant coating on the surface of the carbon/carbon composite material as described in claim 1, which is characterized by comprising the following steps:

step 1: mixing phenolic resin with absolute ethyl alcohol, performing ultrasonic treatment, and uniformly stirring to obtain a phenolic resin solution A; wherein the mass fraction of the ethanol is 80-90 wt%, and the mass fraction of the phenolic resin is 10-20 wt%;

step 2: adding silica sol into the powder B, and uniformly stirring after ultrasonic treatment to obtain suspension slurry B; wherein the mass fraction of the silica sol is 80-90 wt%, and the mass fraction of the B powder is 10-20 wt%;

and step 3: adding SiC powder into the phenolic resin solution A, and uniformly stirring to obtain slurry C; wherein the mass fraction of SiC is 30-40 wt%;

adding TiB into the phenolic resin solution A₂And SiC powder are evenly stirred to obtain slurry D; wherein the mass fraction of SiC is 20-30 wt%, TiB₂The mass fraction of (B) is 10-20 wt%;

and 4, step 4: dipping the C/C composite material into the slurry C for precoating and dip-coating, taking out and drying in an oven, and repeating the process for multiple times to obtain a SiC inner coating;

dipping the C/C composite material with the SiC inner coating into the slurry D for dip coating, taking out and drying in an oven, and repeating the process for multiple times to obtain TiB₂-a SiC intermediate layer;

finally, the SiC inner coating and TiB are coated₂Soaking the C/C composite material with the-SiC intermediate layer into the slurry C again for dip coating, taking out and drying in an oven, and repeating the process for multiple times to obtain the TiB composite material with the SiC inner coating₂-a SiC intermediate layer and a SiC outer coating;

and 5: continuously carrying out curing treatment in a tubular atmosphere furnace at the curing temperature of 150-;

carbonizing at the temperature of 900 ℃ and 1100 ℃ for 2-4h to obtain a precoat;

step 6: placing the material obtained in the step 5 in a graphite crucible, placing a silicon block at the bottom of the crucible, separating the material and the silicon block through a porous graphite plate, sealing the crucible, placing the crucible in a high-temperature graphitization furnace, performing gas phase siliconizing under the protection of argon at the temperature of 1800 plus 2000 ℃ for 15-30min, and then cooling along with the furnace;

and 7: soaking the coating of the material obtained in the step 6 in the suspension slurry B, taking out the suspension slurry B, and drying the suspension slurry B in an oven to obtain SiC-Si/TiB₂-SiC-Si/SiC-Si/SiO₂-B composite oxidation resistant coating.

3. The method of claim 2, further comprising: the times of the step 4 are 3 times.

4. The method of claim 2, further comprising: the dip coating time of the step 4 is 5-10 s.

5. The method of claim 2, further comprising: the drying temperature of the step 4 is 60-90 ℃, and the drying time is 10-30 min.

Technical Field

The invention belongs to the preparation technology of an antioxidant coatingThe technical field relates to a wide temperature range composite oxidation resistant coating on the surface of a carbon/carbon composite material and a preparation method thereof, in particular to SiC-Si/TiB₂-SiC-Si/SiC-Si/SiO₂-B wide-temperature-range composite antioxidant coating and preparation method thereof.

Background

The carbon/carbon (C/C) composite material has excellent performances of high specific strength, low thermal expansion coefficient, high temperature resistance and the like, and particularly can still keep the characteristic of high strength at ultrahigh temperature, so that the carbon/carbon (C/C) composite material is widely applied to high-temperature structural components in the aerospace field. However, the mechanical properties and various physical and chemical properties of the C/C composite material are rapidly reduced due to the easy oxidation of the C/C composite material in an aerobic environment at the temperature of more than 370 ℃, and stable and durable antioxidant protection becomes a key for ensuring the application of the C/C composite material to the new generation of advanced weaponry and the engineering application in a harsh environment.

The oxidation resistant coating is considered to be an effective method for solving the problem of high temperature oxidation protection of the C/C composite material. In order to prevent the C/C composite material from being oxidized at high temperature, researchers at home and abroad carry out a large number of theoretical and experimental researches and develop various antioxidant coating systems.

Among the numerous coating systems, ceramic coatings are the focus of current research. In a ceramic coating system, a composite coating structure with SiC as an inner coating is generally adopted, and different types of high-temperature ceramics are adopted for an outer coating of the composite coating. A more studied class of coatings is silicon-based ceramic coatings, such as SiC-Si [ L.Zhou, Q.G.Fu, D.Hu, Y.L.Wei, M.D.Tong, J.P.Zhang, Oxidation protective SiC-Si coating for carbon/carbon compositions by gas silicon activation and coating, A composition activation, J.Eur.Ceram.Soc.41 (2021)194-]、SiC-MoSi₂[Z.Q.Yan,X.Xiong,P.Xiao,F.Chen,H.B. Zhang,B.Y.Huang,A multilayer coating of dense SiC alternated with porous Si-Mo for the oxidation protection of carbon/carbon silicon carbide composites[J].Carbon 46(2008) 149-153]、MoSi₂-CrSi₂-Si[H.J.Li,T.Feng,Q.G.Fu,H.Wu,X.T.Shen,Oxidation and erosion resistance of MoSi₂-CrSi₂-Si/SiC coated C/C composites in static and aerodynamic oxidation environment Carbon 48(2010)1636-1642]、SiC-ZrB₂[X.R.Ren,H.J.Li,Y.H. Chu,Q.G.Fu,K.Z.Li,Preparation of oxidation protective ZrB₂-SiC coating by in-situ reaction method on SiC-coated carbon/carbon composites,Surf.Coat.Technol.247(2014) 61-67]Etc. silicon-based ceramic coatings. The main oxidation protection mechanism is to utilize SiO generated by coating oxidation at high temperature₂The defects such as cracks in the coating are healed, the low oxygen permeability is utilized to prevent the diffusion of oxygen, and further the oxidation protection of the C/C composite material is realized. However, the temperature at which the above-mentioned silicon-based ceramic coating is used is mostly concentrated in a high-temperature environment of 1773K, and evaluation over a wide temperature range is poor, and SiO₂The silicon-based ceramic has high viscosity and poor fluidity at a lower temperature, and can not effectively heal the defects generated in the using process of the coating, so that the oxidation protection performance of the silicon-based ceramic at the low temperature is poor. Therefore, improving the healing efficiency of the coating to the defects in the low-temperature environment becomes the key for improving the anti-oxidation performance of the silicon-based ceramic coating in the wide temperature range.

Disclosure of Invention

Technical problem to be solved

In order to avoid the defects of the prior art, the invention provides a wide-temperature-range composite oxidation-resistant coating on the surface of a carbon/carbon composite material and a preparation method thereof.

Technical scheme

A carbon/carbon composite material surface wide temperature range compound anti-oxidation coating, characterized by that the coating structure is the multilayer complex, it is made up of ceramic coating and glass coating; wherein the ceramic coating comprises three layers: the innermost layer is a SiC-Si buffer layer, and the middle layer is TiB₂A SiC-Si layer, wherein the outer layer is a SiC-Si layer; the outermost glass coating is B modified SiO₂And (3) a layer.

A method for preparing the wide-temperature-range composite antioxidant coating on the surface of the carbon/carbon composite material is characterized by comprising the following steps:

step 1: mixing phenolic resin with absolute ethyl alcohol, performing ultrasonic treatment, and uniformly stirring to obtain a phenolic resin solution A; wherein the mass fraction of the ethanol is 80-90 wt%, and the mass fraction of the phenolic resin is 10-20 wt%;

step 2: adding silica sol into the powder B, and uniformly stirring after ultrasonic treatment to obtain suspension slurry B; wherein the mass fraction of the silica sol is 80-90 wt%, and the mass fraction of the B powder is 10-20 wt%;

and step 3: adding SiC powder into the phenolic resin solution A, and uniformly stirring to obtain slurry C; wherein the mass fraction of SiC is 30-40 wt%;

adding TiB into the phenolic resin solution A₂And SiC powder are evenly stirred to obtain slurry D; wherein the mass fraction of SiC is 20-30 wt%, TiB₂The mass fraction of (B) is 10-20 wt%;

and 4, step 4: dipping the C/C composite material into the slurry C for precoating and dip-coating, taking out and drying in an oven, and repeating the process for multiple times to obtain a SiC inner coating;

dipping the C/C composite material with the SiC inner coating into the slurry D for dip coating, taking out and drying in an oven, and repeating the process for multiple times to obtain TiB₂-a SiC intermediate layer;

finally, the SiC inner coating and TiB are coated₂Soaking the C/C composite material with the-SiC intermediate layer into the slurry C again for dip coating, taking out and drying in an oven, and repeating the process for multiple times to obtain the TiB composite material with the SiC inner coating₂-a SiC intermediate layer and a SiC outer coating;

and 5: continuously carrying out curing treatment in a tubular atmosphere furnace at the curing temperature of 150-;

carbonizing at the temperature of 900 ℃ and 1100 ℃ for 2-4h to obtain a precoat;

step 6: placing the material obtained in the step 5 in a graphite crucible, placing a silicon block at the bottom of the crucible, separating the material and the silicon block through a porous graphite plate, sealing the crucible, placing the crucible in a high-temperature graphitization furnace, performing gas phase siliconizing under the protection of argon at the temperature of 1800 plus 2000 ℃ for 15-30min, and then cooling along with the furnace;

and 7: soaking the coating of the material obtained in the step 6 in the suspension slurry B, taking out the suspension slurry B, and drying the suspension slurry B in an oven to obtain SiC-Si/TiB₂-SiC-Si/SiC-Si/SiO₂-B composite oxidation resistant coating.

The times of the step 4 are 3 times.

The dip coating time of the step 4 is 5-10 s.

The drying temperature of the step 4 is 60-90 ℃, and the drying time is 10-30 min.

Advantageous effects

The invention provides a carbon/carbon composite material surface wide temperature range composite oxidation resistant coating and a preparation method thereof, the invention provides a multilayer composite coating structure, which consists of a ceramic coating and a glass coating, wherein the ceramic coating comprises three layers, an innermost SiC-Si buffer layer is respectively used for relieving the thermal mismatch between the coating and a substrate, and TiB is arranged in the middle₂A SiC-Si layer which exerts the self-healing performance under the condition of medium temperature, the outer layer is the SiC-Si layer and inhibits the intermediate layer TiB₂Fast oxidation at high temperature and B₂O₃The rapid volatilization of the volatile oil ensures the oxidation protection performance under the high-temperature condition. The outermost layer is B modified SiO₂Layer of B formed by oxidation of B at low temperature₂O₃The defects in the coating are healed in time, and the use of the coating under the low-temperature condition is realized.

The invention adopts the slurry dip-coating combined gas-phase siliconizing process to prepare SiC-Si/TiB₂-SiC-Si/SiC-Si/SiO₂A B multilayer composite oxidation resistant coating, an innermost SiC-Si buffer layer for relieving the thermal mismatch between the coating and the substrate, and a middle TiB layer₂A SiC-Si layer which exerts the self-healing performance under the condition of medium temperature, the outer layer is the SiC-Si layer and inhibits the intermediate layer TiB₂Fast oxidation at high temperature and B₂O₃The rapid volatilization of the volatile oil ensures the oxidation protection performance under the high-temperature condition. The outermost layer is B modified SiO₂Layer of B formed by oxidation of B at low temperature₂O₃The defects in the coating are healed in time, the use of the coating under the low-temperature condition is realized, and the effective protection of the coating on the C/C composite material under the wide-temperature-range condition is finally realized. The SiC-Si/TiB prepared by the invention₂-SiC-Si/SiC-Si/SiO₂the-B multilayer composite antioxidant coating can realize wide-temperature-range oxidation resistance at 450-1500 ℃. Outermost layer of B-SiO₂As a sealing layer, filling cracks, produced at temperatures below 900 deg.CThe borosilicate glass with low melting point can effectively heal the defects of cracks and the like; the outer SiC-Si ceramic coating is used as a barrier layer, which not only can play a good role in antioxidation at 1500 ℃, but also can avoid excessive low-melting-point phases generated at high temperature; TiB₂the-SiC-Si layer as the intermediate layer can be quickly oxidized at 1300 ℃ to generate low-melting-point phase-sealed cracks; the SiC-Si ceramic coating on the innermost layer is used as a transition layer and plays a role in relieving the mismatching of the thermal expansion coefficients. The composite coating sample only loses weight by 0.18 percent after being oxidized for 182h at 900 ℃, gains weight by 0.26 percent after being oxidized for 164h at 1300 ℃, and gains weight by 0.32 percent after being oxidized for 196h at 1500 ℃.

Drawings

FIG. 1SiC/TiB₂SEM photograph and elemental area distribution of SiC/SiC precoat: (a) SEM photograph of the surface of the precoat; (b) SEM photograph of the cross section of the precoat; (c) cross section element distribution diagram

FIG. 2 SiO coating₂SEM photographs and EDS analysis of front and back coatings: (a) SEM pictures of the surface of the coating after siliconizing; (b) SiO 2₂-B coating surface SEM pictures; (c) with SiO₂-cross-sectional SEM photograph of the B layer; (d) c-picture element surface distribution diagram

FIG. 3 Mass Curve of composite coating sample from 450 ℃ to 1550 ℃

Detailed Description

The invention will now be further described with reference to the following examples and drawings:

example 1:

(1) weighing a certain amount of phenolic resin in a beaker, adding a certain amount of absolute ethyl alcohol into the beaker, wherein the mass ratio of the phenolic resin to the absolute ethyl alcohol is 1:9, and performing ultrasonic treatment on the phenolic resin and the absolute ethyl alcohol, and uniformly stirring the mixture to obtain a phenolic resin solution A;

(2) weighing a certain amount of B powder in a beaker, adding a certain amount of silica sol into the beaker, wherein the mass ratio of the silica sol to the B powder is 8:2, and uniformly stirring the mixture after ultrasonic treatment to obtain suspension slurry B;

(3) adding SiC powder into the phenolic resin solution A, and uniformly stirring to obtain slurry C, wherein the mass fraction of SiC is 40 wt%; adding TiB into the phenolic resin solution A₂And SiC powder, wherein the mass fraction of SiC is 30 wt%, TiB₂The mass fraction of the slurry is 10 wt%, and slurry D is obtained after uniform stirring;

(4) soaking the C/C composite material into the slurry C for 5s, taking out, drying in an oven at 60 ℃ for 30min, and repeating the process for 3 times to obtain a SiC inner coating; soaking the C/C composite material with the SiC inner coating into the slurry D for 5s, taking out, drying in an oven at 60 ℃ for 30min, repeating the process for 3 times to obtain TiB₂-a SiC intermediate layer; finally, the SiC inner coating and TiB are coated₂Soaking the C/C composite material with the-SiC intermediate layer into the slurry C for 5s, taking out, drying in an oven at 60 ℃ for 30min, repeating the process for 3 times to obtain the composite material with the SiC inner coating TiB₂-SiC intermediate layer and SiC outer coating coupon;

(5) preserving the temperature of the sample obtained in the step (4) in a tubular atmosphere furnace at 150 ℃ for 4 hours under the protection of argon atmosphere, immediately heating to 900 ℃, and carrying out heat treatment for 4 hours to obtain a precoat sample;

(6) placing the precoating sample obtained in the step (5) into a self-made graphite crucible, placing a certain amount of silicon blocks at the bottom of the crucible, separating the sample and the silicon blocks through a porous graphite plate, sealing the crucible, placing the crucible into a high-temperature graphitization furnace, carrying out gas phase siliconizing under the protection of argon, wherein the siliconizing temperature is 1900 ℃, the heat preservation time is 20min, and then cooling along with the furnace;

(7) dip-coating the coating sample obtained in the step (6) in suspension slurry B for 10s, taking out the suspension slurry B, and drying the suspension slurry B in an oven at 100 ℃ for 2h to obtain SiC-Si/TiB₂-SiC-Si/SiC-Si/SiO₂-B composite oxidation resistant coating.

Example 2:

(1) weighing a certain amount of phenolic resin in a beaker, adding a certain amount of absolute ethyl alcohol into the beaker, wherein the mass ratio of the phenolic resin to the absolute ethyl alcohol is 2:8, and performing ultrasonic treatment on the phenolic resin and the absolute ethyl alcohol, and uniformly stirring the mixture to obtain a phenolic resin solution A;

(2) weighing a certain amount of B powder in a beaker, adding a certain amount of silica sol into the beaker, wherein the mass ratio of the silica sol to the B powder is 8:2, and uniformly stirring the mixture after ultrasonic treatment to obtain suspension slurry B;

(3) adding SiC powder into the phenolic resin solution A, and uniformly stirring to obtain slurry C, wherein the mass fraction of SiC30 wt%; adding TiB into the phenolic resin solution A₂And SiC powder, wherein the mass fraction of SiC is 20 wt%, TiB₂The mass fraction of the slurry is 20 wt%, and slurry D is obtained after uniform stirring;

(4) soaking the C/C composite material into the slurry C for 10s, taking out, drying in an oven at 90 ℃ for 10min, and repeating the process for 3 times to obtain a SiC inner coating; soaking the C/C composite material with the SiC inner coating into the slurry D for 10s, taking out, drying in an oven at 90 ℃ for 10min, repeating the process for 3 times to obtain TiB₂-a SiC intermediate layer; finally, the SiC inner coating and TiB are coated₂Soaking the C/C composite material with the-SiC intermediate layer into the slurry C for 10s, taking out, drying in an oven at 90 ℃ for 10min, repeating the process for 3 times to obtain the composite material with the SiC inner coating TiB₂-SiC intermediate layer and SiC outer coating coupon;

(5) preserving the temperature of the sample obtained in the step (4) in a tubular atmosphere furnace at 200 ℃ for 1h under the protection of argon atmosphere, then heating to 1100 ℃, and carrying out heat treatment for 2h to obtain a precoat sample;

(6) placing the precoating sample obtained in the step (5) into a self-made graphite crucible, placing a certain amount of silicon blocks at the bottom of the crucible, separating the sample and the silicon blocks through a porous graphite plate, sealing the crucible, placing the crucible into a high-temperature graphitization furnace, carrying out gas phase siliconizing under the protection of argon, wherein the siliconizing temperature is 1000 ℃, the heat preservation time is 15min, and then cooling along with the furnace;

(7) dip-coating the coating sample obtained in the step (6) in suspension slurry B for 30s, taking out the suspension slurry B, and drying the suspension slurry B in an oven at 120 ℃ for 1.5h to obtain SiC-Si/TiB₂-SiC-Si/SiC-Si/SiO₂-B composite oxidation resistant coating.

Example 3:

(1) weighing a certain amount of phenolic resin in a beaker, adding a certain amount of absolute ethyl alcohol into the beaker, wherein the mass ratio of the phenolic resin to the absolute ethyl alcohol is 1:9, and performing ultrasonic treatment on the phenolic resin and the absolute ethyl alcohol, and uniformly stirring the mixture to obtain a phenolic resin solution A;

(2) weighing a certain amount of B powder in a beaker, adding a certain amount of silica sol into the beaker, wherein the mass ratio of the silica sol to the B powder is 9:1, and performing ultrasonic treatment on the mixture and uniformly stirring the mixture to obtain suspension slurry B;

(3) adding SiC powder into the phenolic resin solution A, and uniformly stirring to obtain slurry C, wherein the mass fraction of SiC is 35 wt%; adding TiB into the phenolic resin solution A₂And SiC powder, wherein the mass fraction of SiC is 25 wt%, TiB₂The mass fraction of the slurry is 15 wt%, and slurry D is obtained after uniform stirring;

(4) soaking the C/C composite material into the slurry C for 8s, taking out, drying in an oven at 80 ℃ for 20min, and repeating the process for 3 times to obtain a SiC inner coating; soaking the C/C composite material with the SiC inner coating into the slurry D for 8s, taking out the C/C composite material, drying the C/C composite material in an oven at 80 ℃ for 20min, and repeating the process for 3 times to obtain TiB₂-a SiC intermediate layer; finally, the SiC inner coating and TiB are coated₂Soaking the C/C composite material with the-SiC intermediate layer into the slurry C for 8s, taking out, drying in an oven at 80 ℃ for 20min, repeating the process for 3 times to obtain the composite material with the SiC inner coating TiB₂-SiC intermediate layer and SiC outer coating coupon;

(5) keeping the sample obtained in the step (4) at 180 ℃ for 3 hours in a tubular atmosphere furnace under the protection of argon atmosphere, then heating to 1000 ℃, and carrying out heat treatment for 3 hours to obtain a precoat sample;

(6) placing the precoating sample obtained in the step (5) into a self-made graphite crucible, placing a certain amount of silicon blocks at the bottom of the crucible, separating the sample and the silicon blocks through a porous graphite plate, sealing the crucible, placing the crucible into a high-temperature graphitization furnace, carrying out gas phase siliconizing under the protection of argon, wherein the siliconizing temperature is 1800 ℃, keeping the temperature for 30min, and then cooling along with the furnace;

dip-coating the coating sample obtained in the step (6) in the suspension slurry B for 20s, taking out the suspension slurry B, and drying the suspension slurry B in an oven at 150 ℃ for 1h to obtain SiC-Si/TiB₂-SiC-Si/SiC-Si/SiO₂-B composite oxidation resistant coating.