Wide-temperature-range anti-ablation glass-ceramic multilayer composite coating and preparation method

Abstract

The present application relates to a kind of wide temperature range long-life ablation glass-ceramic multilayer composite coating and preparation method. By high temperature in-situ reaction, plasma spraying is alternately deposited and hot coating composite process, a kind of YAS-[HfC / ZrC]3-SiC multilayer composite ablation-resistant coating is prepared on the surface of carbon / carbon composite material, SiC ceramic inner layer is used to relieve the thermal mismatch between coating and matrix, (Hf,Zr) O2 binary solid solution formed by in-situ oxidation of [HfC / ZrC]3 ceramic intermediate layer improves the high-temperature oxygen resistance of coating, YAS outer layer cooperates with the crack healing, pore filling effect of glass to synergistically improve the medium-low temperature oxygen resistance and strong scouring resistance of coating, the multilayer coating structure can realize the long-time effective ablation protection of carbon / carbon composite material under the coupling of " wide temperature range oxidation-strong scouring ". The YAS-[HfC / ZrC]3-SiC multilayer composite coating prepared by the present application has an ablation resistance time of more than 1000s in Ar-O2 plasma ablation environment, more than 300s in oxyacetylene ablation environment and more than 60s in laser ablation environment.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of anti-oxidation / ablation coating preparation, and relates to a wide-temperature-range anti-ablation glass-ceramic multilayer composite coating and a preparation method, in particular to a YAS-[HfC / ZrC]3-SiC multilayer composite anti-ablation coating and a preparation method. BACKGROUND

[0002] As one of the important candidate materials for high-speed aircraft thermal structural components, carbon / carbon composites have excellent high-temperature mechanical properties such as low density, high specific strength and high-temperature resistance, but also have the problem of mechanical property damage caused by high-temperature oxidation, which makes it difficult to directly use as a thermal structural material for long life in a high-temperature oxygen-containing environment. In order to take advantage of the lightweight and high-strength structure of carbon / carbon composites while giving them long-term oxygen resistance, surface anti-oxidation / ablation coating technology has received extensive attention. At present, the oxidation protection system developed for coated carbon / carbon composites has achieved protection effects of hundreds of hours or even thousands of hours in static air environment, 1700℃ and below temperature range, such as (Hf 0.25 Zr 0.25 Ta 0.25 Ti 0.25 )B2-SiC-Si silicon-based ceramic coating [Patent 1: Fu Qiang, Zhou Lei, Li Hujun, et al. A carbon / carbon composite material surface high-temperature long-life composite coating and a preparation method, CN113387724A, 2021-09-14.], the oxidation protection mechanism of which is to use silicon-based ceramic oxidation to form a dense and continuous SiO2 glass to prevent rapid oxygen penetration. However, when the environmental temperature is higher than the decomposition temperature of silicon-based ceramic or the active oxidation temperature of Si element, especially in the ablation environment of 2000℃ and above, silicon-based ceramic is often difficult to oxidize to form a dense and continuous SiO2 glass, and even volatile gaseous by-products containing Si will destroy the coating structure [Literature 1: T. Liu, Y. R. Niu, C. Li, et al. Ablation resistance of ZrC-MoSi2 / ZrC-SiC double-layered coating in a plasma flame, Corros. Sci. 145 (2018) 239-248.], thus it cannot be used as a main component in the ablation-resistant coating to achieve long-term ablation protection.

[0003] In recent years, the design of multiphase ceramic coating with ultra-high temperature ceramics as the main component and silicon-based ceramics or low-melting oxides as the modified component [Literature 2: R.C. Chen, Y.L. Zhang, J. Zhang, et al., MoSi2 modified HfC coating for the ablation protection of SiC-coated C / C composites: Ablation resistance and behavior, Corros. Sci. 205 (2022) 110418.] has become an effective strategy to improve the ablation resistance of the coating in an ablation environment above 2000°C. However, ultra-high temperature ceramics represented by ZrC and HfC are prone to pulverization and oxidation in the medium and low temperature range [Literature 3: G.H. Feng, H.J. Li, X.Y. Yao, et al. Ablation behavior of ZrC and ZrO2 coatings on SiC coated C / C composites under oxyacetylene torch with different heat fluxes, Ceram. Int. 47 (2021) 21721-21729.], and the porous oxide film on its surface is easily stripped off under strong scouring action. The ZrC-La2O3 multiphase ceramic coating reported in Patent 2 [Li HJ, Jia YJ, Fu QG, et al. A carbon / carbon composite material surface long-time ablation-resistant composite coating and preparation method, CN107056336B, 2020-06-16.] provides 700s ablation protection for C / C composites in an oxyacetylene ablation environment with a heat flux of 2.4MW / m2, and its ablation protection mechanism is to use the low-volatility composite oxide formed by La2O3 and ZrO2 at ultra-high temperature to heal pores and cracks. However, since this multiphase ceramic design only focuses on improving the oxygen resistance of the ZrC coating at high temperatures, the strong scouring resistance and medium-low temperature oxidation resistance of the ablation-resistant coating have not been effectively improved. 2

[0004] In summary, the multiphase ceramic coating systems reported so far often only focus on the high-temperature oxygen resistance of the ablation-resistant coating, making it difficult to meet the "wide temperature range oxygen resistance-strong scouring resistance" coupled protection requirements faced by thermal structural materials. Therefore, the "wide temperature range oxygen resistance-strong scouring resistance" coupled protection capability of the ablation-resistant coating has become a bottleneck for the long-life application of coated C / C composites in ablation environments above 2000°C. SUMMARY

[0005] ​In order to solve the problems in the prior art, the application provides a wide-temperature-range anti-ablation glass-ceramic multilayer composite coating and a preparation method, which solves the problem that the wide-temperature-range anti-ablation glass-ceramic multilayer composite coating in the prior art is difficult to coordinate the abilities of resisting wide-temperature-range oxygen resistance and strong scouring.

[0006] In order to achieve the above-mentioned purpose, the technical scheme adopted by the application is as follows: a wide-temperature-range anti-ablation glass-ceramic multilayer composite coating, comprising a SiC ceramic inner layer, a [HfC / ZrC]3 ceramic intermediate layer and a YAS glass outer layer, the thickness of the SiC ceramic inner layer is 50-100 μm, the thickness of the [HfC / ZrC]3 ceramic intermediate layer is 100-300 μm, and the thickness of the YAS glass outer layer is 10-100 μm, wherein the YAS glass outer layer is prepared by using Y2O3 powder with a mole fraction of 10-20 mol.%, Al2O3 powder with a mole fraction of 10-30 mol.% and SiO2 powder with a mole fraction of 50-80 mol.%.

[0007] Meanwhile, the application also provides a preparation method of the wide-temperature-range anti-ablation glass-ceramic multilayer composite coating, comprising the following steps:

[0008] Preparation of the SiC ceramic inner layer on the substrate;

[0009] Preparation of the YAS glass outer layer on the surface of the [HfC / ZrC]3 ceramic intermediate layer to obtain a YAS-[HfC / ZrC]3-SiC multilayer composite coating.

[0010] Preparation of the YAS glass outer layer on the surface of the [HfC / ZrC]3 ceramic intermediate layer to obtain a YAS-[HfC / ZrC]3-SiC multilayer composite coating.

[0011] Further, when the SiC ceramic inner layer is prepared on the substrate, the mixed powder used is Si powder with a mass fraction of 75wt.%-85wt.%, C powder with a mass fraction of 10wt.%-15wt.% and Al2O3 powder with a mass fraction of 5wt.%-10wt.%.

[0012] Further, when the SiC ceramic inner layer is prepared on the substrate, high-temperature in-situ reaction is carried out at 1900-2100 ℃ for 2 h under the protection of Ar gas atmosphere.

[0013] Further, the SiC ceramic inner layer is sequentially sprayed with HfC layer for 4-8 cycles, ZrC layer for 4-8 cycles and HfC layer for 4-8 cycles by using the plasma spraying method.

[0014] Further, the plasma spraying process parameters are as follows: spraying direct current: 400-420 A; spraying direct voltage: 110-120 V; main gas Ar flow rate: 70-75 L / min; auxiliary gas Ar flow rate: 5-10 L / min; powder feeding rate: 6-12 g / min; spraying distance: 90-100 mm.

[0015] Further, the preparation of the HfC and ZrC powders for plasma spraying comprises the following steps:

[0016] The HfC and ZrC powders are respectively configured with a polyvinyl alcohol suspension with a concentration of 2wt.%-4wt.% as a binder, and a feed slurry is prepared after ball milling for 4-6 h according to the proportions of anhydrous ethanol 5wt.%-10wt.%, binder 40wt.%-55wt.%, and ceramic powder 40wt.%-50wt.%;

[0017] After spray drying granulation and multi-stage screening treatment, the HfC and ZrC powders for plasma spraying are obtained, wherein the inlet temperature of the spray drying granulation process is 300-350℃, the outlet temperature is 100-120℃, and the spray head rotation speed is controlled at 10000-12000 r / min.

[0018] Further, the preparation of the YAS glass outer layer comprises the following steps:

[0019] a. heating the [HfC / ZrC]3-SiC coating and the substrate attached thereto to 120-160℃;

[0020] b. coating the YAS glass slurry on the surface of the heated [HfC / ZrC]3-SiC coating;

[0021] Steps a and b are repeated several times, and drying is performed after each coating; the dried YAS glass slurry layer is heat treated until the YAS slurry layer is completely whitened, and a YAS-[HfC / ZrC]3-SiC multilayer composite coating is obtained on the substrate.

[0022] Further, the preparation of the YAS glass slurry comprises the following steps:

[0023] The Y2O3 powder with a mole fraction of 10mol.%-20mol.%, the Al2O3 powder with a mole fraction of 10mol.%-30mol.%, and the SiO2 powder with a mole fraction of 50mol.%-80mol.% are uniformly mixed to form a mixed powder A, then distilled water and Si sol are ultrasonically treated to obtain a suspension B, and finally the mixed powder A is added to the suspension B, and the YAS glass slurry is obtained after uniform stirring.

[0024] The YAS-[HfC / ZrC]3-SiC multilayer composite coating is used for protecting a carbon / carbon composite material substrate, a graphite material substrate or a carbon fiber woven material substrate.

[0025] Compared with the prior art, the present application has at least the following beneficial effects: the present application proposes a wide-temperature-range anti-ablation glass-ceramic multilayer composite coating and a preparation method, which adopts a three-step method, first, a SiC ceramic inner layer is prepared on the surface of the carbon / carbon composite material by high-temperature in-situ reaction, then a [HfC / ZrC]3 ceramic intermediate layer is prepared by plasma spraying, and finally a YAS glass outer layer is prepared by thermal coating; the prepared YAS-[HfC / ZrC]3-SiC multilayer composite coating realizes effective protection of the carbon / carbon composite material for more than 1000s in an Ar-O2 plasma ablation environment, more than 300s in an oxyacetylene ablation environment, and more than 60s in a laser ablation environment;

[0026] The YAS glass, [HfC / ZrC]3 ceramic and SiC ceramic multilayer composite structure formed by the present application can realize the synchronous improvement of the wide-temperature-range oxygen resistance and strong erosion resistance of the carbon / carbon composite material surface anti-ablation coating, on the basis of maintaining the high-temperature stability of the interface between the SiC ceramic inner layer and the sprayed ultra-high-temperature ceramic intermediate layer, by exerting the improvement effect of the (Hf, Zr)O2 binary solid solution formed by the oxidation of the [HfC / ZrC]3 ultra-high-temperature ceramic on the high-temperature oxygen resistance of the coating, and the improvement effect of the crack healing and pore sealing of the YAS glass on the medium-low-temperature oxygen resistance and strong erosion resistance of the coating. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 SEM photos of the cross section of the YAS-[HfC / ZrC]3-SiC multilayer composite coating

[0028] Figure 2 is the SEM photos of the surface and cross section of the coating after 39.8MW / m 2 The surface and cross section SEM photos of the coating after laser ablation for 60s.

[0029] Figure 3 is the SEM photos of the surface and cross section of the coating after 39.8MW / m 2 The (a) surface maximum temperature curve (the inset is an infrared imaging photo) and (b, c) cross section temperature distribution of the ZrC-SiC double-layer composite coating and the YAS-[HfC / ZrC]3-SiC multilayer composite coating at the 15th s, 50th s and 62nd s during the laser ablation process;

[0030] Figure 4 is the SEM photos of the surface and cross section of the coating after 7.26MW / m 2 of Ar-O2 plasma ablation for 360s;

[0031] Figure 5 Macroscopic optical photographs of YAS-[HfC / ZrC]3-SiC multilayer composite coating after testing in different ablation environments. DETAILED DESCRIPTION

[0032] The application will be further described in conjunction with the embodiments and drawings:

[0033] Example 1:

[0034] Step 1: Preparation of SiC ceramic inner layer. The specific process is as follows: (1) After the carbon / carbon composite material is polished and deburred with a 600-mesh diamond sand disc and cleaned with industrial alcohol, it is dried in a 70℃ oven for 6h for standby; (2) Si powder 150g, C powder 30g and Al2O3 powder 20g are weighed respectively, and the powder is placed in a polytetrafluoroethylene resin tank and ball-milled with Al2O3 grinding balls of different sizes and different diameters for 6h to obtain the mixed powder for in-situ high-temperature reaction preparation of SiC ceramic inner layer; (3) half of the above Si, C and Al2O3 mixed powder is evenly spread in a graphite crucible, and the cleaned carbon / carbon composite material is placed on the mixed powder, then the other half of the Si, C and Al2O3 mixed powder is placed to completely cover the sample, and finally the graphite crucible is sealed and transferred to a high-temperature graphitization furnace. The high-temperature graphitization furnace is vacuumized to a vacuum degree of-0.1MPa, and Ar gas is introduced after vacuum preservation for 40min until normal pressure. After repeating the vacuumization-Ar gas introduction process twice, the furnace temperature is raised to 1900℃ at a rate of 10℃ / min, and the temperature is kept for 2h, and finally the graphite crucible is cooled to room temperature with the furnace after power off. After taking out the carbon / carbon composite material sample in the graphite crucible, the residual powder on the surface of the sample with coating is cleaned to obtain a carbon / carbon composite material with SiC ceramic inner layer.

[0035] Step 2: Preparation of HfC and ZrC powder for spraying by spray drying method. The specific process is as follows: (1) a polyvinyl alcohol suspension with a concentration of 3wt.% is configured as a binder, and commercial ceramic powders of HfC and ZrC with a D50 particle size of 1-3 microns are selected, and the three are mixed in an Al2O3 ball mill tank according to the proportions of anhydrous ethanol 8wt.%, binder 52wt.% and ceramic powder 40wt.% for 4h to obtain two kinds of feed slurries; (2) the inlet temperature of the spray drying tower is raised to 300℃, the outlet temperature is raised to 120℃, the rotation speed of the spray head is adjusted to 10000r / min, then the prepared feed slurry is sent into the spray drying tower through a peristaltic pump at a speed of 15rpm, after all the feed slurry is fed, the dried powder is collected at the outlet, and after screening treatment with a 200-mesh sieve, the ceramic powder for spraying is obtained.

[0036] Step 3: Preparation of [HfC / ZrC]3 ceramic interlayer: The carbon / carbon composite material with SiC ceramic inner layer prepared in step 1 was fixed with a clamp, the sprayed powders obtained in step 2 were respectively loaded into double-cylinder powder feeders, the plasma spraying equipment was opened, and whether the equipment leaked water and gas and whether the operation of the machine hand running program was correctly set was checked, and after confirming that the equipment was in good condition, the HfC and ZrC powders were alternately sprayed onto the surface of the carbon / carbon composite material with SiC ceramic inner layer according to the following spraying parameters to obtain a [HfC / ZrC]3-SiC coating coated carbon / carbon composite material. The specific spraying process parameters are: spraying direct current: 420 A; spraying direct voltage: 110 V; main gas Ar gas flow: 70 L / min; auxiliary gas Ar gas flow: 5 L / min; ZrC powder feeding rate: 6 g / min, HfC powder feeding rate: 12 g / min; spraying distance: 100 mm; spraying sequence and spraying cycle: first spray 6 cycles of HfC layer, then spray 8 cycles of ZrC layer, and finally spray 4 cycles of HfC layer.

[0037] Step 4: Preparation of YAS glass outer layer. The specific process is: (1) preparation of YAS glass slurry: 24 g of distilled water and 8 g of commercial Si sol are weighed into a glass beaker, and then 2.5 g of Y2O3 powder, 2 g of Al2O3 powder and 4 g of SiO2 powder are weighed into the beaker, and after ultrasonic dispersion for 5 min, the mixture is stirred with a magnetic rotor for 1 h to form a uniformly dispersed YAS glass slurry; (2) preparation of YAS glass layer by hot coating method: the [HfC / ZrC]3-SiC coating coated carbon / carbon composite material obtained in step 3 is heated to 150°C with a heating plate, and then the YAS glass slurry is dipped with a soft brush and uniformly coated on the surface of the [HfC / ZrC]3-SiC coating, and the coating process is repeated 5 times. After the YAS glass slurry layer on the coating surface is dried, it is heat treated for 2 min using an oxygen-butane spray gun, and the YAS slurry layer turns completely white to obtain a YAS-[HfC / ZrC]3-SiC multilayer composite coating coated carbon / carbon composite material.

[0038] Example 2:

[0039] Step 1: Preparation of SiC ceramic inner layer. The specific process is as follows: (1) After the carbon / carbon composite material is polished and deburred with a 600-mesh diamond sand disc and cleaned with industrial alcohol, it is dried in a 70℃ oven for 6h for standby; (2) Si powder 170g, C powder 20g and Al2O3 powder 10g are weighed respectively, and the powder is placed in a polytetrafluoroethylene resin tank and ball-milled with different amounts and diameters of Al2O3 grinding balls for 6h to obtain the mixed powder for in-situ high-temperature reaction preparation of SiC ceramic inner layer; (3) half of the above Si, C and Al2O3 mixed powder is evenly laid in a graphite crucible, and the cleaned carbon / carbon composite material is placed on the mixed powder, then the other half of the Si, C and Al2O3 mixed powder is placed to completely cover the sample, and finally the graphite crucible is sealed and transferred to a high-temperature graphitization furnace. The high-temperature graphitization furnace is vacuumized to a vacuum degree of-0.1MPa, and Ar gas is introduced until normal pressure after vacuum preservation for 40min. After repeating the vacuumization-Ar gas introduction process twice, the furnace temperature is raised to 2000℃ at a rate of 10℃ / min, and the temperature is kept for 2h, and finally the graphite crucible is cooled to room temperature with the furnace after power off. After taking out the carbon / carbon composite material sample in the graphite crucible, the residual powder on the surface of the sample with coating is cleaned, and the carbon / carbon composite material with SiC ceramic inner layer is obtained.

[0040] Step 2: Preparation of HfC and ZrC powders for spraying by spray drying method. The specific process is as follows: (1) a polyvinyl alcohol suspension with a concentration of 4wt.% is prepared as a binder, and 800-mesh commercial ceramic powders of HfC and ZrC are selected respectively, and the two kinds of feed slurries are prepared by mixing and ball-milling in an Al2O3 ball mill for 6h according to the proportions of anhydrous ethanol 5wt.%, binder 55wt.% and ceramic powder 40wt.%; (2) the inlet temperature of the spray drying tower is raised to 350℃, the outlet temperature is raised to 120℃, the rotation speed of the spray head is adjusted to 12000r / min, then the prepared feed slurry is sent into the spray drying tower through a peristaltic pump at a speed of 15rpm, after all the feed slurry is fed, the dried powder is collected at the outlet, and after screening treatment through 200-mesh and 300-mesh screens, the ceramic powder for spraying with a diameter of 200-mesh to 300-mesh is obtained.

[0041] Step 3: Preparation of [HfC / ZrC]3 ceramic interlayer: The carbon / carbon composite material with SiC ceramic inner layer prepared in step 1 was fixed with a clamp, the sprayed powders obtained in step 2 were respectively loaded into double-cylinder powder feeders, the plasma spraying equipment was opened, and whether the equipment leaked water and gas and whether the operation of the machine hand running program was correctly set was checked, and after confirming that the equipment was in good condition, the HfC and ZrC powders were alternately sprayed onto the surface of the carbon / carbon composite material with SiC ceramic inner layer according to the following spraying parameters to obtain a [HfC / ZrC]3-SiC coating coated carbon / carbon composite material. The specific spraying process parameters are: spraying direct current: 410 A; spraying direct voltage: 120 V; main gas Ar gas flow: 75 L / min; auxiliary gas Ar gas flow: 10 L / min; ZrC powder feeding rate: 6 g / min, HfC powder feeding rate: 12 g / min; spraying distance: 90 mm; spraying sequence and spraying cycle: first spray 4 cycles of HfC layer, then spray 6 cycles of ZrC layer, and finally spray 8 cycles of HfC layer.

[0042] Step 4: Preparation of YAS glass outer layer. The specific process is: (1) preparation of YAS glass slurry: 24 g of distilled water and 8 g of commercial Si sol are weighed into a glass beaker, and then 2.5 g of Y2O3 powder, 2 g of Al2O3 powder and 4 g of SiO2 powder are weighed into the beaker, and after ultrasonic dispersion for 5 min, the mixture is stirred with a magnetic rotor for 1 h to form a uniformly dispersed YAS glass slurry; (2) preparation of YAS glass layer by hot coating method: the [HfC / ZrC]3-SiC coating coated carbon / carbon composite material obtained in step 3 is heated to 160°C with a heating plate, and then the YAS glass slurry is dipped with a soft brush and uniformly coated on the surface of the [HfC / ZrC]3-SiC coating, and after the YAS glass slurry layer on the surface of the coating is dried, it is heat treated with an oxygen-butane spray gun for 3 min, and the YAS slurry layer is completely whitened to obtain a YAS-[HfC / ZrC]3-SiC multilayer composite coating coated carbon / carbon composite material.

[0043] Example 3:

[0044] Step 1: Preparation of SiC ceramic inner layer. The specific process is as follows: (1) After the carbon / carbon composite material is polished and deburred with a 600-mesh diamond sand disc and cleaned with industrial alcohol, it is dried in a 70℃ oven for 6h for standby use; (2) 100g of Si powder, 20g of C powder and 10g of Al2O3 powder are weighed respectively, and the powder is placed in a polytetrafluoroethylene resin tank and ball-milled with different amounts and diameters of Al2O3 grinding balls for 4h to obtain the mixed powder for in-situ high-temperature reaction preparation of SiC ceramic inner layer; (3) half of the above-mentioned Si, C and Al2O3 mixed powder is evenly laid in a graphite crucible, and the cleaned carbon / carbon composite material is placed on the mixed powder, followed by placing the other half of the Si, C and Al2O3 mixed powder to completely cover the sample, and finally the graphite crucible is sealed and transferred to a high-temperature graphitization furnace. The high-temperature graphitization furnace is subjected to vacuum treatment, and the vacuum degree reaches-0.1MPa. After vacuum preservation for 40min, Ar gas is introduced until normal pressure. After repeating the vacuum-Ar gas introduction process twice, the furnace temperature is raised to 2100℃ at a rate of 10℃ / min, and the temperature is kept for 2h. Finally, the graphite crucible is cooled to room temperature with the furnace after power-off. After taking out the carbon / carbon composite material sample in the graphite crucible, the residual powder on the surface of the sample with coating is cleaned, and the carbon / carbon composite material with SiC ceramic inner layer is obtained.

[0045] Step 2: Preparation of HfC and ZrC powders for spraying by spray drying method. The specific process is as follows: (1) a polyvinyl alcohol suspension with a concentration of 2wt.% is configured as a binder, and commercial ceramic powders of ZrC with a D50 particle size of 800 mesh and HfC with a particle size of 1-3 microns are selected. After mixing in an Al2O3 ball mill jar for 4h according to the ratio of 10wt.% anhydrous ethanol, 50wt.% binder and 40wt.% ceramic powder, two kinds of feed slurries are prepared; (2) the inlet temperature of the spray drying tower is raised to 330℃, the outlet temperature is raised to 100℃, the rotation speed of the spray head is adjusted to 10000r / min, then the prepared feed slurry is sent into the spray drying tower through a peristaltic pump at a speed of 15rpm, after all the feed slurry is fed, the dried powder is collected at the outlet, and after screening treatment with 200-mesh and 300-mesh sieves, the ceramic powder for spraying with a diameter of 200-mesh to 300-mesh is obtained.

[0046] Step 3: Preparation of [HfC / ZrC]3 ceramic interlayer: The carbon / carbon composite material with SiC ceramic inner layer prepared in step 1 was fixed with a clamp, the sprayed powders obtained in step 2 were respectively loaded into double-cylinder powder feeders, the plasma spraying equipment was opened, and whether the equipment leaked water and gas and whether the operation of the machine hand running program was correctly set was checked, and after confirming that the equipment was in good condition, the HfC and ZrC powders were alternately sprayed onto the surface of the carbon / carbon composite material with SiC ceramic inner layer according to the following spraying parameters to obtain a [HfC / ZrC]3-SiC coating coated carbon / carbon composite material. The specific spraying process parameters are: spraying direct current: 400 A; spraying direct voltage: 120 V; main gas Ar gas flow: 70 L / min; auxiliary gas Ar gas flow: 10 L / min; ZrC powder feeding rate: 6 g / min, HfC powder feeding rate: 12 g / min; spraying distance: 100 mm; spraying sequence and spraying cycle: first spray 6 cycles of HfC layer, then spray 6 cycles of ZrC layer, and finally spray 6 cycles of HfC layer.

[0047] Step 4: Preparation of YAS glass outer layer. The specific process is: (1) preparation of YAS glass slurry: 24 g of distilled water and 8 g of commercial Si sol are weighed into a glass beaker, and then 2.5 g of Y2O3 powder, 2 g of Al2O3 powder and 3.5 g of SiO2 powder are weighed into the beaker, and after ultrasonic dispersion for 5 min, the mixture is stirred with a magnetic rotor for 1 h to form a uniformly dispersed YAS glass slurry; (2) preparation of YAS glass layer by hot coating method: the [HfC / ZrC]3-SiC coating coated carbon / carbon composite material obtained in step 3 is heated to 120°C with a heating plate, and then the YAS glass slurry is dipped with a soft brush and uniformly coated on the surface of the [HfC / ZrC]3-SiC coating, and after the YAS glass slurry layer on the surface of the coating is dried, it is heat treated with an oxygen-butane spray gun for 1 min, and the YAS slurry layer is completely whitened to obtain a YAS-[HfC / ZrC]3-SiC multilayer composite coating coated carbon / carbon composite material.

[0048] Comparative Example 1:

[0049] Step 1: Preparation of SiC ceramic inner layer. The specific process is as follows: (1) After the carbon / carbon composite material is polished and deburred with a 600-mesh diamond sand disc and cleaned with industrial alcohol, it is dried in a 70℃ oven for 6h for standby; (2) Si powder 100g, C powder 20g and Al2O3 powder 10g are weighed respectively, and the powder is placed in a polytetrafluoroethylene resin tank and ball milled with different amounts and diameters of Al2O3 grinding balls for 4h to obtain the mixed powder for in-situ high-temperature reaction preparation of SiC ceramic inner layer; (3) half of the above Si, C and Al2O3 mixed powder is evenly laid in a graphite crucible, and the cleaned carbon / carbon composite material is placed on the mixed powder, then the other half of the Si, C and Al2O3 mixed powder is placed to completely cover the sample, and finally the graphite crucible is sealed and transferred to a high-temperature graphitization furnace. The high-temperature graphitization furnace is vacuumized to a vacuum degree of-0.1MPa, and Ar gas is introduced until normal pressure after vacuum preservation for 40min. After repeating the vacuumization-Ar gas introduction process twice, the furnace temperature is raised to 2100℃ at a rate of 10℃ / min, and the temperature is kept for 2h, and finally the graphite crucible is cooled to room temperature with the furnace after power off. After taking out the carbon / carbon composite material sample in the graphite crucible, the residual powder on the surface of the sample with coating is cleaned, and the carbon / carbon composite material with SiC ceramic inner layer is obtained.

[0050] Step 2: Preparation of ZrC powder for spraying by spray drying method. The specific process is as follows: (1) a polyvinyl alcohol suspension with a concentration of 2wt.% is configured as a binder, and 800-mesh ZrC commercial ceramic powder is selected, and the ratio of anhydrous ethanol 10wt.%, binder 50wt.% and ceramic powder 40wt.% is mixed in an Al2O3 ball mill jar for 4h to prepare two kinds of feed slurries; (2) the inlet temperature of the spray drying tower is raised to 330℃, the outlet temperature is raised to 100℃, the rotation speed of the spray head is adjusted to 10000r / min, then the prepared feed slurry is sent into the spray drying tower through a peristaltic pump at a speed of 15rpm, after all the feed slurry is fed, the dried powder is collected at the outlet, and after screening treatment through 200-mesh and 300-mesh screens, the ceramic powder for spraying with a diameter of 200-mesh to 300-mesh is obtained.

[0051] Step 3: Preparation of [HfC / ZrC]3 ceramic interlayer: The carbon / carbon composite material with SiC ceramic inner layer prepared in step 1 was fixed with a clamp, the sprayed powder obtained in step 2 was respectively loaded into the double cylinder powder feeder, the plasma spraying equipment was opened, and whether the equipment leaked water, gas and whether the operation of the machine hand running program was set correctly was checked, and after confirming that the equipment was in good condition, the ZrC powder was sprayed to the surface of the carbon / carbon composite material with SiC ceramic inner layer according to the following spraying parameters, and the carbon / carbon composite material coated with ZrC-SiC double-layer composite coating was obtained. The specific spraying process parameters are: spraying direct current: 400 A; spraying direct voltage: 120 V; main gas Ar gas flow: 70 L / min; auxiliary gas Ar gas flow: 10 L / min; powder feeding rate: 6 g / min; spraying distance: 100 mm; spraying period: 14 periods.

[0052] Comparative Example 2:

[0053] Step 1: Preparation of SiC ceramic inner layer. The specific process is: (1) After the carbon / carbon composite material is polished and deburred with a 600 mesh diamond sand disc, it is cleaned with industrial alcohol and dried in a 70°C oven for 6h for standby; (2) Si powder 100g, C powder 20g and Al2O3 powder 10g are weighed respectively, the powder is placed in a polytetrafluoroethylene resin tank and different amounts of Al2O3 grinding balls of different diameters are added for ball milling and mixing treatment for 4h to obtain the mixed powder for in-situ reaction preparation of SiC ceramic inner layer; (3) Half of the above Si, C and Al2O3 mixed powder is evenly laid in a graphite crucible, and the cleaned carbon / carbon composite material is placed on the mixed powder, then the other half of the Si, C and Al2O3 mixed powder is placed to completely cover the sample, and finally the graphite crucible is sealed and transferred to a high-temperature graphitization furnace. The high-temperature graphitization furnace is subjected to vacuum treatment, and the vacuum degree reaches-0.1 MPa. After vacuum preservation for 40 min, Ar gas is introduced until normal pressure. After repeating the vacuum-Ar gas introduction process twice, the furnace temperature is raised to 2100°C at a rate of 10°C / min, and the temperature is maintained for 2h. Finally, the graphite crucible is cooled to room temperature with the furnace after power off. After taking out the carbon / carbon composite material sample in the graphite crucible, the residual powder on the surface of the coated sample is cleaned, and the carbon / carbon composite material with SiC ceramic inner layer is obtained.

[0054] Step 2: Spray HfC and ZrC powder for spraying was prepared by spray drying method. The specific process is as follows: (1) prepare a 2wt.% polyvinyl alcohol suspension as a binder, select 800 mesh HfC and ZrC commercial ceramic powder, and mix in an Al2O3 ball mill jar according to the ratio of 10wt.% anhydrous ethanol, 50wt.% binder and 40wt.% ceramic powder, ball mill for 4h to obtain two kinds of feed slurries; (2) the inlet temperature of the spray drying tower is raised to 330℃, the outlet temperature is raised to 100℃, the spray head speed is adjusted to 10000r / min, then the prepared feed slurry is sent into the spray drying tower by peristaltic pump at a speed of 15rpm, after all the feed slurry is fed, the dry powder is collected at the outlet, and after screening treatment through 200 and 300 meshes, the ceramic powder for spraying with a diameter of 200-300 meshes is obtained.

[0055] Step 3: Prepare [HfC / ZrC]3 ceramic interlayer: fix the carbon / carbon composite material with SiC ceramic inner layer prepared in step 1 with a clamp, load the spray powder obtained in step 2 into the double cylinder powder feeder respectively, open the plasma spraying equipment, check whether the equipment leaks water and gas and whether the operation machine hand program is set correctly, confirm that the equipment is in good condition, and then spray HfC and ZrC powder alternately to the surface of the carbon / carbon composite material with SiC ceramic inner layer according to the following spraying parameters to obtain [HfC / ZrC]3-SiC coating coated carbon / carbon composite material. The specific spraying process parameters are: spraying direct current: 400A; spraying direct voltage: 120V; main gas Ar gas flow: 70L / min; auxiliary gas Ar gas flow: 10L / min; powder feeding rate: 6g / min; spraying distance: 100mm; spraying sequence and spraying cycle: first spray 6 cycles of HfC layer, then spray 6 cycles of ZrC layer, and finally spray 6 cycles of HfC layer.

[0056] Figure 1 is the cross-section backscattered photo of the YAS-[HfC / ZrC]3-SiC multilayer composite coating prepared in Example 3. As can be seen from the figure, the prepared coating is a multilayer structure, the outer YAS glass, the intermediate [HfC / ZrC]3 ultra-high temperature ceramic and the inner SiC ceramic are well combined with each other.

[0057] Figure 2 is the cross-section backscattered photo of the YAS-[HfC / ZrC]3-SiC multilayer composite coating prepared in Example 3. As can be seen from the figure, the prepared coating is a multilayer structure, the outer YAS glass, the intermediate [HfC / ZrC]3 ultra-high temperature ceramic and the inner SiC ceramic are well combined with each other. 2Surface and cross-section backscattered images of the two types of coatings after laser ablation for 60 s. (a1-a2) ZrC-SiC double-layer composite coating; (b1-b2) YAS-[HfC / ZrC]3-SiC multilayer composite coating. As can be seen from the figure, the ZrC-SiC double-layer composite coating has obvious structural damage after 60 s of laser ablation, and the ZrC ceramic layer in the laser ablation area is basically depleted, and the SiC ceramic layer also has ablation damage; while the YAS-[HfC / ZrC]3-SiC multilayer composite coating can still maintain the oxidation layer after 60 s of laser ablation due to the synergistic effect of the (Hf, Zr)O2 binary solid solution oxide layer protection and the YAS glass defect sealing, indicating that the glass-ceramic multilayer composite design can effectively improve the laser ablation resistance of the coating.

[0058] Figure 3 Surface and cross-section backscattered images of the ZrC-SiC double-layer coating prepared in Comparative Example 1 and the YAS-[HfC / ZrC]3-SiC multilayer composite coating prepared in Example 3 after 39.8 MW / m 2 Surface highest temperature curve and cross-section temperature distribution at different times during 60 s of laser ablation. As can be seen from the figure, the highest temperature of the two types of coatings in the laser ablation area reaches above 2500℃ during 60 s of ablation, and the surface temperature of the two types of coatings in the non-laser ablation area gradually increases to about 1000℃ as the ablation time prolongs. From the infrared imaging photo after laser ablation, it can be seen that the ZrC-SiC double-layer coating has obviously peeled off during the 60 s low-temperature oxidation process, while the YAS-[HfC / ZrC]3-SiC multilayer composite coating remains structurally intact under the protection of the YAS glass outer layer, indicating that the glass-ceramic multilayer composite coating has good low-temperature oxidation resistance.

[0059] Figure 4 Surface and cross-section backscattered images of the [HfC / ZrC]3-SiC double-layer composite coating prepared in Comparative Example 2 and the YAS-[HfC / ZrC]3-SiC multilayer composite coating prepared in Example 3 after 7.26 MW / m 2 of Ar-O2 plasma jet ablation for 360 s. As can be seen from the figure, the [HfC / ZrC]3-SiC double-layer composite coating has obvious peeling after 360 s of plasma jet ablation, and the SiC ceramic inner layer is exposed, while the YAS-[HfC / ZrC]3-SiC multilayer composite coating can still maintain the oxidation layer structure intact after 360 s of plasma jet ablation due to the defect sealing effect of the YAS glass outer layer, indicating that the glass-ceramic multilayer composite coating has good strong scouring resistance.

[0060] Figure 5 Surface and cross-section backscattered images of the YAS-[HfC / ZrC]3-SiC multilayer composite coating prepared in Example 3 after 7.26 MW / m 2Plasma flame ablation 1080s, 4.18MW / m 2 Oxyacetylene ablation at 300 s and 39.8 MW / m 2 Macroscopic optical image after 60 s of laser ablation. (a) Heat flux density is 7.26 MW / m³. 2 (a) The Ar-O2 plasma ablation environment had an ablation time of 1080 s and an ablation distance of 20 mm; (b) The heat flux density was 4.18 MW / m 2 (c) The oxyacetylene ablation environment had an ablation time of 300 s and an ablation distance of 15 mm; the heat flux density was 39.8 MW / m 2 The CO2 laser ablation environment was used with a laser power of 500W and a spot diameter of 4mm, and ablation was performed in an air atmosphere. As shown in the figure, the glass-ceramic multilayer composite coating can protect the C / C composite material for more than 1000s in an Ar-O2 plasma ablation environment, more than 300s in an oxyacetylene ablation environment, and more than 60s in a laser ablation environment.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wide-temperature-range ablation-resistant glass-ceramic multilayer composite coating, characterized in that, The coating comprises a SiC ceramic inner layer, a [HfC / ZrC]3 ceramic intermediate layer, and a YAS glass outer layer. The SiC ceramic inner layer has a thickness of 50-100 μm, the [HfC / ZrC]3 ceramic intermediate layer has a thickness of 100-300 μm, and the YAS glass outer layer has a thickness of 10-100 μm. The YAS glass outer layer is prepared using 10-20 mol.% Y2O3 powder, 10-30 mol.% Al2O3 powder, and 50-80 mol.% SiO2 powder. The preparation method of the wide-temperature-range ablation-resistant glass-ceramic multilayer composite coating includes the following steps: Prepare a SiC ceramic inner layer on a substrate; A [HfC / ZrC]3 ceramic intermediate layer was obtained by sequentially spraying HfC, ZrC, and HfC layers onto the inner surface of SiC ceramic using plasma spraying. A YAS glass outer layer was prepared on the surface of the [HfC / ZrC]3 ceramic intermediate layer to obtain a YAS-[HfC / ZrC]3-SiC multilayer composite coating. When preparing the SiC ceramic inner layer on the substrate, the mixed powder used was a mixture of 75wt.%-85wt.% Si powder, 10wt.%-15wt.% C powder, and 5wt.%-10wt.% Al2O3 powder. The SiC ceramic inner layer was prepared by high-temperature in-situ reaction at 1900-2100℃ for 2 hours under Ar atmosphere protection. The surface of the SiC ceramic inner layer was sequentially sprayed with 4-8 cycles of HfC layer, 4-8 cycles of ZrC layer, and 4-8 cycles of HfC layer using a plasma spraying method. The preparation of the outer layer of YAS glass includes the following steps: a. Heat the [HfC / ZrC]3-SiC coating and the substrate to which it is attached to to 120-160℃; b. Apply YAS glass paste to the heated [HfC / ZrC]3-SiC coating surface; Steps a and b are repeated several times, and each coating is dried; the dried YAS glass slurry layer is heat-treated until the YAS slurry layer turns completely white to obtain a YAS-[HfC / ZrC]3-SiC multilayer composite coating on the substrate. The prepared YAS-[HfC / ZrC]3-SiC multilayer composite coating achieves effective protection of carbon / carbon composite materials for more than 1000 s in Ar-O2 plasma ablation environment, more than 300 s in oxyacetylene ablation environment, and more than 60 s in laser ablation environment.

2. The wide-temperature-range ablation-resistant glass-ceramic multilayer composite coating according to claim 1, characterized in that, Plasma spraying process parameters: spraying DC current: 400-420A; spraying DC voltage: 110-120V; main gas Ar flow rate: 70-75L / min; auxiliary gas Ar flow rate: 5-10L / min; powder feeding rate: 6-12g / min; spraying distance: 90-100 mm.

3. The wide-temperature-range ablation-resistant glass-ceramic multilayer composite coating according to claim 1, characterized in that, The preparation of HfC and ZrC powders for plasma spraying includes the following steps: For HfC and ZrC powders, polyvinyl alcohol suspensions with a concentration of 2wt.%-4wt.% were prepared as binders. The feed slurry was prepared by ball milling the mixture of anhydrous ethanol (5wt.%-10wt.%), binder (40wt.%-55wt.%), and ceramic powder (40wt.%-50wt.%) for 4-6 hours. After spray drying granulation and multi-stage sieving, HfC and ZrC powders for plasma spraying are obtained. The inlet temperature of the spray drying granulation process is 300-350℃, the outlet temperature is 100-120℃, and the spray head speed is controlled at 10000-12000r / min.

4. The wide-temperature-range ablation-resistant glass-ceramic multilayer composite coating according to claim 2, characterized in that, The preparation of YAS glass slurry includes the following steps: Y₂O₃ powder with a molar fraction of 10 mol.%-20 mol.%, Al₂O₃ powder with a molar fraction of 10 mol.%-30 mol.%, and SiO₂ powder with a molar fraction of 50 mol.%-80 mol.% are uniformly mixed to form mixed powder A. Then, distilled water and Si sol are ultrasonically treated to obtain suspension B. Finally, mixed powder A is added to suspension B and stirred evenly to obtain YAS glass slurry.

5. The application of the wide-temperature-range ablation-resistant glass-ceramic multilayer composite coating as described in claim 1, characterized in that, Used for protection of carbon / carbon composite matrix, graphite matrix or carbon fiber woven matrix.

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