A ceramic matrix composite material with water-oxygen corrosion resistance and high thermal insulation performance and a preparation method thereof

Abstract

The application relates to a ceramic matrix composite material with water-oxygen corrosion resistance and high heat insulation performance and a preparation method thereof, and the method comprises the following steps: preliminarily densifying a porous ceramic matrix composite material by a PIP process with a PCS solution as an impregnation solution; preparing n impregnation solutions with gradient concentrations, wherein the impregnation solution comprises a solid component A, a solid component B and a PCS solution; densifying the preliminarily densified ceramic matrix composite material by the PIP process with the n impregnation solutions with gradient concentrations, so that a ceramic matrix composite material containing the solid component A and the solid component B in the surface layer is obtained, the content of the solid component A presents a decreasing trend in the surface layer, and the content of the solid component B presents an increasing trend in the surface layer; and then the ceramic matrix composite material is placed in silicon dioxide for a melt infiltration reaction, so that the ceramic matrix composite material is prepared; the ceramic matrix composite material prepared by the application has the water-oxygen corrosion resistance and the high heat insulation performance, the combination strength of the water-oxygen corrosion resistance and the high heat insulation component is higher, the protection effect is better, and the service life is better.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of ceramic matrix composite material preparation, and particularly relates to a ceramic matrix composite material with water-oxygen corrosion resistance and high thermal insulation performance and a preparation method thereof. BACKGROUND

[0002] The ceramic matrix composite material is widely used in the field of aerospace due to its excellent high-temperature resistance, low density, high specific strength and high toughness. However, as the working conditions become more and more severe, the traditional ceramic matrix composite material is easily subjected to water-oxygen corrosion in a high-temperature environment containing water vapor and oxygen, which leads to degradation of the material performance and further affects the service life. In addition, the extreme high-temperature heat flow on the surface during service can quickly heat the ceramic matrix composite material, causing the internal material temperature to rise sharply and reducing the service performance and service life of the material. Therefore, in order to improve the service performance of the ceramic matrix composite material, it is urgent to develop a ceramic matrix composite material with high-temperature water-oxygen corrosion resistance and high thermal insulation performance.

[0003] In order to improve the water vapor corrosion resistance and thermal insulation performance of the ceramic matrix composite material, the method of preparing environmental barrier coatings and thermal barrier / environmental barrier coatings on the surface thereof by thermal spraying, plasma deposition and slurry coating is usually used to improve the water-oxygen corrosion resistance of the ceramic matrix composite material. However, due to the mismatch of the thermal expansion coefficients between the coating material and the ceramic matrix composite material substrate, multiple layers of coatings need to be coated to enhance the physical compatibility between the coatings. Although this method can alleviate the thermal mismatch stress between the coatings to some extent, it cannot fundamentally change the problem of the mismatch of the thermal expansion coefficients between the coatings / coatings and the coatings / substrate. Therefore, under the relatively low bonding strength, the environmental barrier and thermal barrier / environmental barrier coatings will still crack and peel off during service, further reducing their water-oxygen corrosion resistance. In addition, due to the large number of types and layers of environmental barrier coatings and thermal barrier / environmental barrier coatings, they cannot be formed at one time, which limits the further application of this method.

[0004] Chinese Patent CN202110573926.X discloses a method for preparing a bonding layer / Yb2Si2O7 / Yb2SiO5 / modified Gd2Zr2O7 thermal / environmental barrier composite coating system on the surface of a ceramic matrix composite material by thermal spraying, thereby improving the water-oxygen corrosion resistance and thermal insulation capacity of the ceramic matrix composite material. In this patent, the difference in the thermal expansion coefficients between the layers is the main reason for the interlayer cracking, which makes the coating interface become a weak area prone to failure in the coating system. The composite coating has a large number of layers, which can alleviate the mismatch of the thermal expansion coefficients between different materials to some extent, but introduces more coating interfaces and more weak areas that will fail and peel off due to thermal mismatch stress, thereby weakening the protective effect of the coating and reducing the protective life of the coating.

[0005] Chinese patent CN202410315852.3 discloses a kind of multiphase oxide ceramic modified ceramic matrix composite and its preparation method, which first introduces high-entropy rare earth double silicate into porous ceramic matrix composite by slurry impregnation method, and then further densifies the composite by glass powder embedding infiltration. But this method still has certain limitations. The porosity of SiC / SiC composite after CVI densification is relatively small, and it is difficult to introduce high-entropy rare earth double silicate slurry into the densified composite by vacuum impregnation. In addition, although high-entropy rare earth double silicate also has water vapor corrosion resistance, it has little effect on the heat insulation of ceramic matrix composite, and cannot have both water and oxygen corrosion resistance and high heat insulation performance.

[0006] Therefore, how to make ceramic matrix composite have both water and oxygen corrosion resistance and high heat insulation performance under the premise of ensuring its mechanical properties is a key problem to improve its service life in high temperature water and oxygen environment. SUMMARY

[0007] In order to solve one or more technical problems existing in the prior art, the present application provides a kind of ceramic matrix composite with both water and oxygen corrosion resistance and high heat insulation performance and its preparation method. The ceramic matrix composite prepared by the method of the present application has excellent water and oxygen corrosion resistance (high temperature water and oxygen corrosion resistance), good heat insulation effect, low preparation cost, and can realize the integrated preparation of ceramic matrix composite with both water and oxygen corrosion resistance and high heat insulation performance.

[0008] The present application provides in the first aspect a kind of preparation method of ceramic matrix composite with both water and oxygen corrosion resistance and high heat insulation performance, the method comprises the following steps:

[0009] (1) preparing a porous ceramic matrix composite;

[0010] (2) densifying the porous ceramic matrix composite by precursor impregnation and pyrolysis process with polycarbosilane solution as impregnation liquid to obtain a preliminary densification ceramic matrix composite;

[0011] (3) preparing n gradient concentration precursor impregnation liquids, each precursor impregnation liquid contains solid component A, solid component B and polycarbosilane solution, the solid component A contains ytterbium oxide powder, titanium oxide powder and hafnium oxide powder, and the solid component B contains zirconium oxide powder and magnesium oxide powder;

[0012] (4) sequentially densifying the preliminary densification ceramic matrix composite by precursor impregnation and pyrolysis process (PIP process) with n gradient concentration precursor impregnation liquids to obtain a ceramic matrix composite containing solid component A and solid component B in the surface layer; wherein the content of solid component A shows a decreasing trend in the surface layer, and the content of solid component B shows an increasing trend in the surface layer;

[0013] (5) The ceramic matrix composite material containing solid component A and solid component B in the surface layer is placed in silica powder for infiltration reaction to obtain the ceramic matrix composite material with high water-oxygen corrosion resistance and high thermal insulation performance.

[0014] Preferably, in the n gradient concentration precursor impregnation solutions, the content of solid component A has a decreasing trend, and the content of solid component B has an increasing trend; n≥2 and n is a positive integer; the concentration of solid component A in the n gradient concentration precursor impregnation solutions ranges from 10 to 50 wt%, and the concentration of solid component B in the n gradient concentration precursor impregnation solutions ranges from 10 to 50 wt%; and / or the surface layer of the ceramic matrix composite material with high water-oxygen corrosion resistance and high thermal insulation performance is a mixed dense layer containing ytterbia, titania, hafnia, zirconia, magnesia, silicon carbide, silica and a fiber framework, wherein the total content of ytterbia, titania and hafnia in the surface layer has a decreasing trend, and the total content of zirconia and magnesia in the surface layer has an increasing trend.

[0015] Preferably, in step (1), the porous ceramic matrix composite material is obtained by depositing an interface layer on the fibers of the fiber woven body; preferably, the fiber woven body is a carbon fiber woven body or a silicon carbide fiber woven body; preferably, the density of the fiber woven body is 0.4-0.7 g / cm 3 ; preferably, the interface layer is one or more of pyrolytic carbon interface layer, silicon carbide interface layer or boron nitride interface layer; preferably, the density of the porous ceramic matrix composite material is 0.8-1.2 g / cm 3 .

[0016] Preferably, in step (2), the polycarbosilane solution is a xylene solution of polycarbosilane, and preferably the mass fraction of polycarbosilane in the polycarbosilane solution is 35-60%; and / or the precursor impregnation and pyrolysis process is repeated multiple times until a preliminary densified ceramic matrix composite material with a density of 1.3-1.5 g / cm 3 .

[0017] Preferably, in step (3), the polycarbosilane solution contained in the precursor impregnation solution is a xylene solution of polycarbosilane, and preferably the mass fraction of polycarbosilane in the polycarbosilane solution is 10-30%; the particle size D50 of ytterbia powder, titania powder and / or hafnia powder is 0.1-1 μm; and / or the solid component A contains ytterbia powder 40-60%, titania powder 20-30% and hafnia powder 20-30% by mass fraction.

[0018] Preferably, in step (3), the particle size D50 of the zirconium oxide powder and / or the magnesium oxide powder is 0.1-1 μm; the solid component B comprises 40-60% by mass of the zirconium oxide powder and 40-60% by mass of the magnesium oxide powder.

[0019] Preferably, in step (4), the thickness of the surface layer containing the solid component A and the solid component B in the ceramic matrix composite containing the solid component A and the solid component B is 500-2000 μm; and / or the density of the surface layer containing the solid component A and the solid component B in the ceramic matrix composite is 1.8-2.1 g / cm 3 .

[0020] Preferably, in step (5), the particle size D50 of the silicon dioxide powder is 0.1-1 μm; the temperature of the infiltration reaction is 1400-1700 °C, and the time of the infiltration reaction is 60-180 min; and / or the heating rate for heating to the temperature of the infiltration reaction is 2-4 °C / min.

[0021] Preferably, in step (5), the thickness of the mixed dense layer is 500-2000 μm; the density of the ceramic matrix composite with both water-oxygen corrosion resistance and high thermal insulation performance is 2.2-2.5 g / cm 3 ; the 1500 °C thermal conductivity of the ceramic matrix composite with both water-oxygen corrosion resistance and high thermal insulation performance is not more than 5 W / m·K, and the ceramic matrix composite has excellent water-oxygen corrosion resistance at 1200-1500 °C.

[0022] The present application provides, in a second aspect, a ceramic matrix composite with both water-oxygen corrosion resistance and high thermal insulation performance prepared by the preparation method described in the first aspect of the present application.

[0023] Compared with the prior art, the present application has at least the following beneficial effects:

[0024] (1) The present application prepares a mixed dense layer of Yb2SiO5, TiSiO4, HfSiO4, ZrSiO4, Mg2SiO4, SiC and SiO2 matrix and fiber skeleton in a certain thickness area on the surface of the composite material. The present application finds that Yb2SiO5 and TiSiO4 have good high-temperature phase stability and excellent high-temperature water vapor corrosion resistance, HfSiO4 has extremely high high-temperature oxidation resistance and excellent oxidation corrosion resistance, which can provide the composite material with more excellent high-temperature water vapor corrosion resistance; ZrSiO4 and Mg2SiO4 have good phase stability and thermal physical properties, with the advantages of low sintering rate and low thermal conductivity, which can provide the composite material with excellent heat insulation capacity; molten SiO2 can further fill the pores on the surface of the composite material, prevent oxygen from diffusing along the pores to the core, and prevent the core from oxidizing; the fiber skeleton can effectively ensure that the mixed dense layer has sufficient mechanical properties, avoiding the failure and peeling of the dense layer under thermal shock conditions. Compared with Chinese patent CN202110573926.X and other methods for preparing environmental barriers or thermal / environmental barrier coatings by spraying, the present application forms the mixed dense layer in situ on the surface of the ceramic matrix composite during the preparation process, without the need for subsequent coating treatment of the composite material, saving production costs, and the mixed dense layer formed on the surface of the ceramic matrix composite by the method of the present application improves the water and oxygen corrosion resistance (high-temperature water and oxygen corrosion resistance) and heat insulation capacity of the ceramic matrix composite, while avoiding the generation of low bonding strength interfaces between the coating / substrate and the coating / coating, effectively preventing interface cracking and coating peeling caused by incompatible thermal expansion coefficients in the coating system, and effectively prolonging the protection time.

[0025] (2) The present application can realize the uniform dispersion of a large amount of water and oxygen corrosion resistant components and high thermal insulation components in a certain thickness of the region by mixing a large amount of sub-micron ceramic powder into the PCS precursor and then using SiO2 infiltration treatment to form silicate products in situ. By introducing high thermal insulation components, the temperature borne by the water and oxygen corrosion resistant components during service is reduced, and the premature failure of the water and oxygen corrosion resistant components at a higher service temperature is avoided, thereby further prolonging the service life of the ceramic matrix composite with water and oxygen corrosion resistance and high thermal insulation performance. However, the Chinese patent CN202410315852.3 introduces the water and gas corrosion resistant components after the ceramic matrix composite is highly densified, the pores of the composite material are relatively small, the introduction is relatively difficult, and only a single water and gas corrosion resistant effect can be achieved; the present application introduces ceramic powder into the ceramic matrix composite after the preliminary densification, i.e. when the density is relatively low, the introduction is relatively low in difficulty, the filling effect of the pores of the composite material is better, and more water and oxygen corrosion resistant components and high thermal insulation component products are formed with SiO2 in situ after infiltration, so that the composite material has better water and oxygen corrosion resistance and high temperature thermal insulation performance. In addition, the present application realizes the gradient distribution of the water and oxygen corrosion resistant components and the high thermal insulation components by preparing a gradient concentration precursor solution, and the content of each component can be adjusted according to the service environment to design and optimize the water and oxygen corrosion resistance and the thermal insulation performance, so as to better match and meet the service requirements.

[0026] Drawings

[0027] The drawings of the present application are provided only for illustrative purposes, and the proportions and sizes of the layers in the drawings may not be consistent with the actual products.

[0028] Figure 1 is a cross-sectional structure schematic diagram of the ceramic matrix composite with water and oxygen corrosion resistance and high thermal insulation performance prepared in some specific embodiments of the present application.

[0029] In the figure: 1: high thermal insulation component: ZrSiO4, Mg2SiO4; 2: water and gas corrosion resistant component: Yb2SiO5, TiSiO4, HfSiO4; 3: SiC and SiO2 matrix; 4: ceramic fiber skeleton; 5: ceramic matrix composite. DETAILED DESCRIPTION

[0030] To make the purpose, technical scheme and advantages of the present application clearer, the technical scheme of the present application will be described clearly and completely below in combination with the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0031] The application provides a preparation method of a ceramic matrix composite material with water-oxygen corrosion resistance and high thermal insulation performance.

[0032] (1) preparing a porous ceramic matrix composite material (also referred to as a porous low-density ceramic matrix composite material);

[0033] (2) densifying the porous ceramic matrix composite material by a precursor impregnation and pyrolysis process (i.e. a PIP process) using a polycarbosilane solution (PCS solution) as an impregnation liquid to obtain a preliminarily densified ceramic matrix composite material; the application does not make specific limitations on the densification process conditions of the PIP process using the polycarbosilane solution as the impregnation liquid, and the process conditions can be routinely selected by those skilled in the art; preferably, the PIP process is repeated for multiple times to obtain the preliminarily densified ceramic matrix composite material with a density of 1.3-1.5 g / cm 3

[0034] (3) preparing n precursor impregnation liquids (also referred to as polycarbosilane precursor impregnation liquids) with gradient concentrations, each of which contains a solid component A, a solid component B and a polycarbosilane solution (PCS precursor solution), wherein the solid component A contains ytterbium oxide powder (Yb2O3 powder), titanium oxide powder (TiO2 powder) and hafnium oxide powder (HfO2 powder), and the solid component B contains zirconium oxide powder (ZrO2 powder) and magnesium oxide powder (MgO powder); in some specific embodiments, each of the precursor impregnation liquids consists of the solid component A, the solid component B and the polycarbosilane solution, and each of the precursor impregnation liquids contains different contents of the solid component A and the solid component B; in the application, for example, n PCS precursor impregnation liquids with gradient concentrations are prepared by mixing a large amount of submicron Yb2O3, TiO2, HfO2, ZrO2 and MgO powders with PCS and dimethylbenzene; when the precursor impregnation liquid is prepared, the solid component A and the solid component B can be uniformly dispersed in the PCS precursor solution by stirring and / or ball milling and the like;

[0035] ​(4) n gradient concentrations of precursor impregnation solution is sequentially through the precursor impregnation pyrolysis process (PIP process) to the preliminary densification of ceramic matrix composite material densification, get the surface layer containing (rich) solid component A and solid component B of ceramic matrix composite material;Wherein, the content of solid component A in the surface layer from inside to outside shows a decreasing trend, the content of solid component B in the surface layer from inside to outside shows a increasing trend;That is, in the step (4) of the application, the Yb2O3, TiO2, HfO2, ZrO2 and MgO region is formed in the surface layer of the ceramic matrix composite material, wherein the total content of Yb2O3, TiO2 and HfO2 shows a decreasing trend towards the surface, and the total content of ZrO2 and MgO shows an increasing trend towards the surface;In the present application, the direction from inside to outside is the direction towards the surface of the ceramic matrix composite material;In the present application, the interior of the preliminary densification of ceramic matrix composite material is not easy to be impregnated into the precursor impregnation solution in step (3), which can ensure the formation of Yb2O3, TiO2, HfO2, ZrO2 and MgO region in the surface layer of the ceramic matrix composite material, and the preliminary densification of the porous ceramic matrix composite material in step (2) of the present application obtains the preliminary densification of the ceramic matrix composite material, which is beneficial to ensure that the interior of the ceramic matrix composite material has excellent mechanical properties;The conditions of the PIP process using the precursor impregnation solution containing solid component A, solid component B and polycarbosilane solution in step (4) of the present application are not specifically limited, and can be selected conventionally by those skilled in the art, preferably, for example, the same as the conditions of the PIP process using polycarbosilane solution as the impregnation solution;

[0036] (5) the ceramic matrix composite material containing solid component A and solid component B in the surface layer is placed in the silicon dioxide powder for infiltration reaction, and the ceramic matrix composite material with water oxygen corrosion resistance and high thermal insulation performance is prepared;That is, in step (5) of the present application, the ceramic matrix composite material containing solid component A and solid component B in the surface layer is treated by infiltration with silicon dioxide (SiO2) powder as the reaction source, SiO2 reacts in situ with Yb2O3, TiO2 and HfO2 to form ytterbia (Yb2SiO5), titanium silicate (TiSiO4) and hafnium silicate (HfSiO4) which are resistant to water vapor corrosion and high temperature oxidation, SiO2 reacts in situ with ZrO2 and MgO to form zircon silicate (ZrSiO4) and magnesium silicate (Mg2SiO4) with high thermal insulation effect, and finally a mixed dense layer containing Yb2SiO5, TiSiO4, HfSiO4, ZrSiO4, Mg2SiO4, SiC and SiO2 matrix, and fiber skeleton is formed in the surface layer of the ceramic matrix composite material, wherein the total content of Yb2SiO5, TiSiO4 and HfSiO4 shows a decreasing trend towards the surface, and the total content of ZrSiO4 and Mg2SiO4 shows an increasing trend towards the surface.

[0037] The application prepares a mixed dense layer of Yb2SiO5, TiSiO4, HfSiO4, ZrSiO4, Mg2SiO4, SiC and SiO2 matrix and fiber framework in a certain thickness area on the surface of the composite material; the application finds that Yb2SiO5 and TiSiO4 have good high-temperature phase stability and excellent high-temperature water vapor corrosion resistance, HfSiO4 has extremely high high-temperature oxidation resistance and excellent oxidation corrosion resistance, which can provide the composite material with more excellent high-temperature water vapor corrosion resistance; ZrSiO4 and Mg2SiO4 have good phase stability and thermal physical properties, have the advantages of low sintering rate and low thermal conductivity, and can provide the composite material with excellent heat insulation capacity; molten SiO2 can further fill the pores on the surface of the composite material, prevent oxygen from diffusing along the pores to the core, and prevent the core from oxidizing; the fiber framework can effectively ensure that the mixed dense layer has sufficient mechanical properties, and avoid the failure and peeling of the dense layer under thermal shock conditions. Compared with the environmental barrier or thermal / environmental barrier coating prepared by spraying and other methods in Chinese patent CN202110573926.X, the mixed dense layer is formed in situ on the surface of the ceramic matrix composite material during the preparation process of the ceramic matrix composite material, and the composite material does not need to be treated with a subsequent coating, which saves production cost, and the mixed dense layer formed on the surface of the ceramic matrix composite material by the method of the application improves the water and oxygen corrosion resistance (high-temperature water and oxygen corrosion resistance) and heat insulation capacity of the ceramic matrix composite material, avoids the generation of low bonding strength interfaces between the coating and the matrix and between the coatings, effectively prevents interface cracking and coating peeling caused by incompatible thermal expansion coefficients in the coating system, effectively prolongs the protection time, that is, the bonding strength between the water and oxygen corrosion resistant component and the high heat insulation component in the application is higher, the protection effect is better, and the service life is more optimal.

[0038] The application can realize the uniform dispersion of a large amount of water-oxygen corrosion-resistant components and high-thermal insulation components in a certain thickness area by mixing a large amount of sub-micron ceramic powder into the PCS precursor and then using the SiO2 infiltration treatment to form silicate products in situ. By introducing the high-thermal insulation components, the temperature borne by the water-oxygen corrosion-resistant components during service is reduced, the premature failure of the water-oxygen corrosion-resistant components at a higher service temperature is avoided, and the service life of the ceramic matrix composite with water-oxygen corrosion resistance and high-thermal insulation performance is further prolonged. However, the Chinese patent CN202410315852.3 introduces the water-oxygen corrosion-resistant components after the ceramic matrix composite is highly densified, the pores of the composite are relatively small, the introduction is relatively difficult, and only a single water-oxygen corrosion-resistant effect can be achieved. The application introduces ceramic powder into the ceramic matrix composite after the preliminary densification, i.e., when the density is relatively low, the introduction is relatively low, the filling effect on the pores of the composite is better, more water-oxygen corrosion-resistant components and high-thermal insulation component products are formed with SiO2 in situ after infiltration, and the composite has better water-oxygen corrosion resistance and high-temperature thermal insulation performance. In addition, the application realizes the gradient distribution of the water-oxygen corrosion-resistant components and the high-thermal insulation components by preparing a gradient concentration precursor solution, and the content of each component can be adjusted according to the service environment to design and optimize the water-oxygen corrosion resistance and the thermal insulation performance, and better match and meet the service requirements.

[0039] According to some preferred embodiments, in the n precursor impregnation solutions (polycarbosilane precursor impregnation solutions) of gradient concentrations, the content of the solid component A (mass percentage) presents a decreasing trend, and the content of the solid component B (mass percentage) presents an increasing trend; n≥2 and n is a positive integer; in the present application, the n precursor impregnation solutions of gradient concentrations are prepared by mixing the solid component A, the solid component B and the PCS solution with different contents; the concentration of the solid component A in the n precursor impregnation solutions of gradient concentrations ranges from 10wt% to 50wt% (for example, 10wt%, 20wt%, 30wt%, 40wt% or 50wt%); the concentration of the solid component B in the n precursor impregnation solutions of gradient concentrations ranges from 10wt% to 50wt% (for example, 10wt%, 20wt%, 30wt%, 40wt% or 50wt%); and / or the surface layer of the ceramic matrix composite with both water-oxygen corrosion resistance and high thermal insulation performance is a mixed dense layer (also recorded as a mixed dense layer with water-oxygen corrosion resistance and high thermal insulation performance) comprising ytterium silicate, titanium silicate, hafnium silicate, zirconium silicate, magnesium silicate, silicon carbide (SiC) and silicon dioxide (SiO2) matrix, and fiber framework, wherein the total content (total mass percentage) of ytterium silicate, titanium silicate and hafnium silicate presents a decreasing trend from inside to outside in the surface layer, and the total content (total mass percentage) of zirconium silicate and magnesium silicate presents an increasing trend from inside to outside in the surface layer; in the present application, ytterium silicate, titanium silicate and hafnium silicate constitute the water-oxygen corrosion resistance component (also recorded as the water-oxygen corrosion resistance component), and zirconium silicate and magnesium silicate constitute the high thermal insulation component.

[0040] According to some preferred embodiments, in step (1), the porous ceramic matrix composite is obtained by depositing an interface layer on the fibers of the fiber woven body, the porous ceramic matrix composite takes the fiber woven body as the framework, the fibers can be carbon fibers or silicon carbide fibers, and the weaving method can be any one of needling or sewing, etc., the fibers of the fiber woven body have an interface layer deposited by chemical vapor deposition (CVD) or the like, and the interface layer includes but is not limited to one or more of pyrolytic carbon (PyC), silicon carbide (SiC) or boron nitride (BN); preferably, the fiber woven body is a carbon fiber woven body or a silicon carbide fiber woven body; preferably, the density of the fiber woven body is 0.4-0.7g / cm 3 (for example, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65 or 0.7g / cm 3 ); the present application does not specifically limit the source of the fiber woven body, and a product that can be directly purchased or prepared by an existing method can be used; preferably, the interface layer is one or more of pyrolytic carbon interface layer, silicon carbide interface layer or boron nitride interface layer; preferably, the density of the porous ceramic matrix composite is 0.8-1.2g / cm 3(e.g. 0.8, 0.9, 1.0, 1.1 or 1.2 g / cm 3 ); the process conditions for depositing the interface layer are not specifically limited in the present application, which are conventional techniques in the art, and preferably are such that the density of the porous ceramic matrix composite after depositing the interface layer is 0.8-1.2 g / cm 3 .

[0041] According to some preferred embodiments, in step (2): the polycarbosilane solution is a xylene solution of polycarbosilane, preferably the mass fraction of polycarbosilane in the polycarbosilane solution is 35-60% (e.g. 35%, 40%, 45%, 50%, 55% or 60%); and / or the PIP process is repeated for multiple times until a preliminary densified ceramic matrix composite with a density of 1.3-1.5 g / cm 3 is obtained.

[0042] According to some preferred embodiments, in step (3): the precursor impregnation solution is composed of solid component A, solid component B and a polycarbosilane solution, the polycarbosilane solution is a xylene solution of polycarbosilane, preferably the mass fraction of polycarbosilane in the polycarbosilane solution is 10-30 wt% (e.g. 10 wt%, 15 wt%, 20 wt%, 25 wt% or 30 wt%); the particle size D50 of the Yb2O3 powder, TiO2 powder and / or HfO2 powder is 0.1-1 μm (e.g. 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1 μm); and / or the solid component A comprises Yb2O3 powder 40-60% (e.g. 40%, 45%, 50%, 55% or 60%), TiO2 powder 20-30% (e.g. 20%, 22%, 24%, 26%, 28% or 30%) and HfO2 powder 20-30% (e.g. 20%, 22%, 24%, 26%, 28% or 30%) by mass fraction.

[0043] The solid component A in the application can generate an optimized high-temperature water-oxygen corrosion resistant structure composed of ytterbia (Yb2SiO5), titania (TiSiO4) and hafnia (HfSiO4) by in-situ reaction of the ytterbia (Yb2O3), titania (TiO2) and hafnia (HfO2) with silica with a suitable mass fraction. The balanced distribution of the components ensures the compactness, uniformity and high-temperature stability of the silicate layer, which is conducive to preventing further penetration and corrosion of water vapor and oxygen and improving the coordination of Yb2SiO5, TiSiO4 and HfSiO4 silicates at high temperatures, thereby further enhancing the water-oxygen corrosion resistance and achieving excellent high-temperature water-oxygen corrosion resistance effect. It is found that if the content of ytterbia powder in the solid component A is too low, the generated Yb2SiO5 is insufficient, which leads to insufficient integrity and sealing of the protective layer, thereby weakening the water-oxygen corrosion resistance. If the content of ytterbia powder in the solid component A is too high, the structure contains too much Yb2SiO5, and the internal stress in the protective layer is large, which is prone to premature failure under high-temperature conditions. If the content of titania in the solid component A is too low, the generated TiSiO4 is insufficient, which leads to a decrease in the thermal stability and water-oxygen corrosion resistance of the protective layer. If the content of titania in the solid component A is too high, the generated TiSiO4 is too much, which leads to an excessively high material hardness and a decrease in overall toughness. If the content of hafnia in the solid component A is too low, the content of HfSiO4 is insufficient, which weakens the oxidation resistance and thermal stability of the material, thereby reducing the synergistic water-oxygen corrosion resistance. If the content of hafnia in the solid component A is too high, it greatly increases the preparation cost and also reduces the formation amount of Yb2SiO5 and TiSiO4, which also reduces the overall mechanical properties of the water-oxygen corrosion resistant layer.

[0044] According to some preferred embodiments, in step (3): the particle size D50 of the zirconia powder and / or the magnesium oxide powder is 0.1-1 μm (e.g. 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1 μm); the solid component B comprises 40-60% (e.g. 40%, 45%, 50%, 55% or 60%) zirconia powder and 40-60% (e.g. 40%, 45%, 50%, 55% or 60%) magnesium oxide powder by mass fraction; and preferably, the solid component B comprises 40-60% zirconia powder and 40-60% magnesium oxide powder by mass fraction, which forms a high-thermal-insulation component composed of zircon silicate (ZrSiO4) and magnesia silicate (Mg2SiO4) after in-situ reaction with the silica powder, and the present application finds that the high-thermal-insulation component has better thermal insulation performance than single zircon silicate (ZrSiO4) or single magnesia silicate (Mg2SiO4) because ZrSiO4 and Mg2SiO4 have different crystal structures and thermal expansion coefficients, the multiphase structure formed can scatter heat flow at the grain boundaries, effectively reducing the overall thermal conductivity of the material, and ZrSiO4 and Mg2SiO4 each have excellent high-temperature resistance and thermal insulation, the composite structure can remain stable in a high-temperature environment, delaying the penetration of heat, their combination not only has the advantages of both materials but also takes advantage of the synergistic effect between the materials, significantly improving the thermal insulation performance; and the present application finds that, compared with the Yb-doped Gd2Zr2O7 thermal insulation layer, the ZrSiO4 and Mg2SiO4 high-thermal-insulation component has a lower thermal expansion coefficient and lower thermal mismatch stress with the ceramic matrix composite, and is less likely to produce cracks, so ZrSiO4 and Mg2SiO4 have better adaptability with the ceramic matrix composite and can maintain better thermal insulation effect for a longer time.

[0045] According to some preferred embodiments, in step (4): the thickness of the solid component A and the solid component B in the surface layer containing the solid component A and the solid component B of the ceramic matrix composite is 500-2000 μm (e.g. 500, 750, 1000, 1250, 1500, 1750 or 2000 μm); that is, the present application uses a gradient concentration precursor impregnating solution to perform subsequent densification on the preliminary densification ceramic matrix composite by the PIP process, forming a Yb2O3, TiO2, HfO2, ZrO2 and MgO-rich region on the surface of the ceramic matrix composite, wherein the total content of Yb2O3, TiO2 and HfO2 decreases towards the surface, and the total content of ZrO2 and MgO increases towards the surface, and the thickness of the region is 500-2000 μm; and / or the density of the surface layer containing the solid component A and the solid component B of the ceramic matrix composite is 1.8-2.1 g / cm3. 3 .

[0046] According to some preferred embodiments, in step (5): the particle size D50 of the silica powder is 0.1-1 μm (e.g. 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1 μm); the temperature of the infiltration reaction is 1400-1700 °C (e.g. 1400 °C, 1450 °C, 1500 °C, 1550 °C, 1600 °C, 1650 °C or 1700 °C), the time of the infiltration reaction is 60-180 min (e.g. 60, 90, 120, 150 or 180 min); and / or the heating rate to the temperature of the infiltration reaction is 2-4 °C / min (e.g. 2, 2.5, 3, 3.5 or 4 °C / min).

[0047] According to some preferred embodiments, in step (5): the thickness of the mixed dense layer is 500-2000 μm (e.g. 500, 750, 1000, 1250, 1500, 1750 or 2000 μm); the density of the ceramic matrix composite with both water-oxygen corrosion resistance and high thermal insulation performance is 2.2-2.5 g / cm 3 ; the 1500 °C thermal conductivity of the ceramic matrix composite with both water-oxygen corrosion resistance and high thermal insulation performance is not more than 5 W / m·K and has excellent water-oxygen corrosion resistance at 1200-1500 °C, specifically, the ceramic matrix composite with both water-oxygen corrosion resistance and high thermal insulation performance in the present application has a weight loss rate of not more than 0.5 mg / cm 2 , i.e. a weight loss rate of not more than 0.5 mg / cm 2 under water-oxygen corrosion conditions of 90 vol.% water (H2O) and 10 vol.% oxygen (O2) at 1500 °C for 100 h; in the present application, "vol.%" means volume percentage.

[0048] The present application provides, in a second aspect, a ceramic matrix composite with both water-oxygen corrosion resistance and high thermal insulation performance prepared by the preparation method described in the first aspect of the present application. Compared with the prior art, the ceramic matrix composite prepared by the present application has both water-oxygen corrosion resistance and high thermal insulation performance, higher bonding strength between the water-oxygen corrosion resistance and high thermal insulation components, better protection effect and longer service life.

[0049] The present application will be further described below by way of examples, but the scope of protection of the present application is not limited to these examples. The present application can also have other various embodiments, and those skilled in the art can make various corresponding changes and modifications to the present application without departing from the spirit and essence of the present application, but these corresponding changes and modifications shall all belong to the protection scope of the claims attached to the present application.

[0050] Example 1

[0051] ①Preparation of porous ceramic matrix composite: carbon fibers were used as the skeleton, and needle-braiding method was used to obtain a carbon fiber braid with a density of 0.5 g / cm 3 . A pyrolytic carbon interface layer was deposited on the carbon fibers of the carbon fiber braid by chemical vapor deposition method to obtain a porous ceramic matrix composite with a density of 0.9 g / cm 3 .

[0052] ②Preliminary densification process: PCS solution (polycarbosilane solution) was used as the impregnation liquid, and PIP process was used to densify the SiC matrix of the porous ceramic matrix composite obtained in step ①, and the PIP process was repeated 3 times to obtain a preliminarily densified ceramic matrix composite with a density of 1.4 g / cm 3 ; the polycarbosilane solution is a xylene solution of polycarbosilane, and the mass fraction of polycarbosilane in the polycarbosilane solution is 55%.

[0053] ③Preparation of precursor impregnation liquid with gradient concentration: two precursor impregnation liquids with gradient concentration were prepared, each of which was composed of solid component A, solid component B and polycarbosilane solution, the solid component A was composed of Yb2O3 powder 50wt%, TiO2 powder 25wt% and HfO2 powder 25wt%, the particle size D50 of the Yb2O3 powder, the TiO2 powder and the HfO2 powder was 0.5μm, the solid component B was composed of ZrO2 powder 50wt% and MgO powder 50wt%, the particle size D50 of the ZrO2 powder and the MgO powder was 0.5μm, the polycarbosilane solution in the two precursor impregnation liquids with gradient concentration was a xylene solution of polycarbosilane, and the mass fraction of polycarbosilane in the polycarbosilane solution was 20%; the mass fraction of solid component A in one precursor impregnation liquid was 40%, and the mass fraction of solid component B was 20%, the mass fraction of solid component A in the other precursor impregnation liquid was 20%, and the mass fraction of solid component B was 40%.

[0054] (4) Subsequent densification process: the preliminary densified ceramic matrix composite obtained in step (2) is subjected to subsequent densification by PIP process with two gradient concentrations of precursor impregnation solution prepared in step (3) to obtain a ceramic matrix composite with surface layer rich in solid component A and solid component B, and a thickness of about 1000 μm of Yb2O3, TiO2, HfO2, ZrO2 and MgO rich region is formed in the surface layer; during the PIP process of this step (4), first 4 rounds of PIP process are carried out with precursor impregnation solution containing 40wt% of solid component A and 20wt% of solid component B as the impregnation solution, and then 4 rounds of PIP process are carried out with precursor impregnation solution containing 20wt% of solid component A and 40wt% of solid component B as the impregnation solution, so that the content of solid component A in the surface layer decreases from inside to outside, and the content of solid component B in the surface layer increases from inside to outside; after this process, a ceramic matrix composite with density of 2.0 g / cm 3 , surface layer rich in solid component A and solid component B is obtained.

[0055] (5) Silicon dioxide infiltration process: the ceramic matrix composite with surface layer rich in solid component A and solid component B obtained in step (4) is placed in SiO2 powder (particle size D50 is 0.5 μm) for infiltration reaction, the temperature of the infiltration reaction is 1650℃, the time of the infiltration reaction is 120 min, the heating rate to the temperature of the infiltration reaction is 3℃ / min, and a ceramic matrix composite with density of 2.39 g / cm 3 , which has both water-oxygen corrosion resistance and high thermal insulation performance, is prepared, the surface layer of the ceramic matrix composite with both water-oxygen corrosion resistance and high thermal insulation performance is a mixed dense layer composed of ytterbia, titania, hafnia, zirconia, magnesia, silicon carbide and silica matrix, and fiber skeleton, and the thickness of the mixed dense layer is about 1000 μm, wherein the total content of ytterbia, titania and hafnia in the surface layer decreases from inside to outside, and the total content of zirconia and magnesia in the surface layer increases from inside to outside.

[0056] Performance test: the prepared ceramic matrix composite with both water-oxygen corrosion resistance and high thermal insulation performance is measured to have a weight loss rate of 0.36 mg / cm 2 under the water-oxygen corrosion condition of 1500℃, 90H2O-10O2(vol.%) for 100h, and the thermal conductivity of the prepared ceramic matrix composite at 1500℃ is 3.2 W / (m·K).

[0057] Example 2

[0058] Example 2 is basically the same as Example 1, except that:

[0059] 3 3

[0060] ② preliminary densification process: using PCS solution (polycarbosilane solution) as precursor impregnation solution, the porous ceramic matrix composite material obtained in step ① is densified by PIP process, and the PIP process is repeated for 3 times to obtain a preliminary densified ceramic matrix composite material with a density of 1.48g / cm 3

[0061] ③ preparation of precursor impregnation solution with gradient concentration: two precursor impregnation solutions with gradient concentration are prepared, each of which is composed of solid component A, solid component B and polycarbosilane solution, the solid component A is composed of Yb2O3 powder 50wt%, TiO2 powder 25wt% and HfO2 powder 25wt%, the particle size D50 of Yb2O3 powder, TiO2 powder and HfO2 powder is 0.5μm, the solid component B is composed of ZrO2 powder 50wt% and MgO powder 50wt%, the particle size D50 of ZrO2 powder and MgO powder is 0.5μm, the polycarbosilane solution in the two precursor impregnation solutions with gradient concentration is polycarbosilane xylene solution, and the mass fraction of polycarbosilane is 20%; one precursor impregnation solution contains 30wt% of solid component A and 15wt% of solid component B, and the other precursor impregnation solution contains 15wt% of solid component A and 30wt% of solid component B.

[0062] ​​​​3

[0063] After the subsequent silica infiltration process, the ceramic matrix composite material prepared in this embodiment has a density of 2.23 g / cm 3 .

[0064] Performance test: The weight loss rate of the ceramic matrix composite material prepared in this embodiment under the water-oxygen corrosion condition of 1500℃, 90H2O-10O2(vol.%) for 100h is 0.41 mg / cm 2 , and the thermal conductivity of the ceramic matrix composite material prepared is 4.6 W / (m·K) at 1500℃.

[0065] Example 3

[0066] Example 3 is basically the same as Example 1, except that:

[0067] ① Preparation of porous ceramic matrix composite material: carbon fibers are used as the skeleton, and a needle-braiding method is used to obtain a carbon fiber braided body with a density of 0.45 g / cm 3 . A pyrolytic carbon interface layer is deposited on the carbon fibers of the carbon fiber braided body by chemical vapor deposition to obtain a porous ceramic matrix composite material with a density of 0.82 g / cm 3 .

[0068] ② Preliminary densification process: PCS solution (polycarbosilane solution) is used as a precursor impregnation solution to densify the SiC matrix of the porous ceramic matrix composite material obtained in step ① by PIP process. The PIP process is repeated 3 times to obtain a ceramic matrix composite material with a density of 1.33 g / cm 3 ​​a preliminary densification ceramic matrix composite material; the polycarbosilane solution is a xylene solution of polycarbosilane, and the mass fraction of polycarbosilane in the polycarbosilane solution is 40%.

[0069] ④Subsequent densification process: the two gradient concentration precursor impregnation solutions prepared in step ③ are used to perform PIP process on the preliminary densification ceramic matrix composite material obtained in step ② to obtain a ceramic matrix composite material with surface layer rich in solid component A and solid component B, and a thickness of about 1500 μm of the Yb2O3, TiO2, HfO2, ZrO2 and MgO rich region is formed in the surface layer; in the PIP process of this step ④, first, the precursor impregnation solution containing 40wt% of solid component A and 20wt% of solid component B is used as the impregnation solution to perform 4 rounds of PIP process, and then the precursor impregnation solution containing 20wt% of solid component A and 40wt% of solid component B is used as the impregnation solution to perform 4 rounds of PIP process, so that the content of solid component A in the surface layer decreases from inside to outside, and the content of solid component B in the surface layer increases from inside to outside; after this process, a ceramic matrix composite material with surface layer rich in solid component A and solid component B is obtained, and the density of the ceramic matrix composite material is 2.11 g / cm 3 .

[0070] ⑤Silicon dioxide infiltration process: the ceramic matrix composite material with surface layer rich in solid component A and solid component B obtained in step ④ is placed in SiO2 powder (particle size D50 is 0.5 μm) to perform a infiltration reaction, the temperature of the infiltration reaction is 1700℃, the time of the infiltration reaction is 120 min, the heating rate for heating to the temperature of the infiltration reaction is 3℃ / min, and a ceramic matrix composite material with water-oxygen corrosion resistance and high thermal insulation performance is prepared, and the density of the ceramic matrix composite material is 2.48 g / cm 3 .

[0071] Performance test: the ceramic matrix composite material with water-oxygen corrosion resistance and high thermal insulation performance prepared in this embodiment has a weight loss rate of 0.24 mg / cm 2 under the water-oxygen corrosion condition of 1500℃, 90H2O-10O2(vol.%) for 100 h, and the thermal conductivity of the ceramic matrix composite material prepared is 2.6 W / (m·K) at 1500℃.

[0072] Example 4

[0073] Example 4 is substantially the same as Example 1, except that:

[0074] ①Preparation of porous ceramic matrix composite: carbon fibers are used as the framework, and a needle-braiding method is used to obtain a carbon fiber braid with a density of 0.5 g / cm 3 ; a boron nitride interface layer is deposited on the carbon fibers of the carbon fiber braid by chemical vapor deposition to obtain a porous ceramic matrix composite with a density of 1.02 g / cm 3 .

[0075] ②Preliminary densification process: a PCS solution (polycarbosilane solution) is used as the impregnation liquid, and PIP technology is used to densify the SiC matrix of the porous ceramic matrix composite obtained in step ①, and the PIP process is repeated 3 times to obtain a preliminarily densified ceramic matrix composite with a density of 1.34 g / cm 3 ; the polycarbosilane solution is a xylene solution of polycarbosilane, and the mass fraction of polycarbosilane in the polycarbosilane solution is 55%.

[0076] ④Subsequent densification process: two precursor impregnation liquids with gradient concentrations prepared in step ③ are used to perform subsequent densification on the preliminarily densified ceramic matrix composite obtained in step ② by PIP technology to obtain a ceramic matrix composite with a surface layer rich in solid component A and solid component B, and a Yb2O3, TiO2, HfO2, ZrO2, and MgO-rich region with a thickness of about 1000 μm is formed on the surface layer; during the PIP process of this step ④, first, a precursor impregnation liquid containing 40 wt% of solid component A and 20 wt% of solid component B is used as the impregnation liquid to perform 4 cycles of PIP process, and then a precursor impregnation liquid containing 20 wt% of solid component A and 40 wt% of solid component B is used as the impregnation liquid to perform 4 cycles of PIP process, so that the content of solid component A in the surface layer decreases from inside to outside, and the content of solid component B in the surface layer increases from inside to outside; after this process, a ceramic matrix composite with a surface layer rich in solid component A and solid component B with a density of 1.94 g / cm 3 is obtained.

[0077] ⑤Silicon dioxide infiltration process: the ceramic matrix composite with a surface layer rich in solid component A and solid component B obtained in step ④ is placed in SiO2 powder (particle size D50 is 0.5 μm) for infiltration reaction, the temperature of the infiltration reaction is 1500℃, the time of the infiltration reaction is 90 min, the heating rate for heating to the temperature of the infiltration reaction is 3℃ / min, and a ceramic matrix composite with a density of 2.29 g / cm 3The ceramic matrix composite material with high thermal insulation and water-oxygen corrosion resistance has a surface layer composed of a mixed dense layer composed of ytterbia, titania, hafnia, zirconia, magnesia, silicon carbide and a silicon dioxide matrix, and a fiber framework, and the thickness of the mixed dense layer is about 800 microns, wherein the total content of ytterbia, titania and hafnia in the surface layer decreases from inside to outside, and the total content of zirconia and magnesia in the surface layer increases from inside to outside.

[0078] Performance test: The weight loss rate of the prepared ceramic matrix composite material with high thermal insulation and water-oxygen corrosion resistance under the water-oxygen corrosion condition of 1500 DEG C, 90H2O-10O2 (vol.%) for 100 hours is 0.42 mg / cm 2 The thermal conductivity of the prepared ceramic matrix composite material at 1500 DEG C is 4.7 W / (m·K).

[0079] Example 5

[0080] Example 5 is basically the same as Example 1, except that:

[0081] In step ③, the particle size D50 of the Yb2O3 powder, the TiO2 powder and the HfO2 powder is 0.1 microns, and the particle size D50 of the ZrO2 powder and the MgO powder is 0.1 microns.

[0082] In step ④, the thickness of the Yb2O3, TiO2, HfO2, ZrO2 and MgO-rich region of the surface layer is about 1500 microns, and the density of the ceramic matrix composite material rich in solid component A and solid component B in the surface layer is 2.05 g / cm 3 .

[0083] In step ⑤, the particle size D50 of the SiO2 powder is 0.1 microns; after the silica infiltration process of this step ⑤, the thickness of the mixed dense layer is about 1500 microns, and the density of the prepared ceramic matrix composite material with high thermal insulation and water-oxygen corrosion resistance is 2.46 g / cm 3 .

[0084] Performance test: The weight loss rate of the prepared ceramic matrix composite material with high thermal insulation and water-oxygen corrosion resistance under the water-oxygen corrosion condition of 1500 DEG C, 90H2O-10O2 (vol.%) for 100 hours is 0.42 mg / cm 2 The thermal conductivity of the prepared ceramic matrix composite material at 1500 DEG C is 4.7 W / (m·K).

[0085] Example 6

[0086] Example 6 is basically the same as Example 1, except that:

[0087] ③Preparation of precursor impregnation solutions with gradient concentrations: two precursor impregnation solutions with gradient concentrations are prepared, each of which is composed of solid component A, solid component B and polycarbosilane solution, the solid component A is composed of Yb2O3 powder 40wt%, TiO2 powder 30wt% and HfO2 powder 30wt% in mass fraction, the particle size D50 of the Yb2O3 powder, the TiO2 powder and the HfO2 powder is 0.5μm, the solid component B is composed of ZrO2 powder 50wt% and MgO powder 50wt% in mass fraction, the particle size D50 of the ZrO2 powder and the MgO powder is 0.5μm; in the two precursor impregnation solutions with gradient concentrations, the polycarbosilane solution is a xylene solution of polycarbosilane with a mass fraction of 20%; one precursor impregnation solution contains 40% of solid component A and 20% of solid component B in mass fraction, and the other precursor impregnation solution contains 20% of solid component A and 40% of solid component B in mass fraction.

[0088] In step ④, the density of the ceramic matrix composite material rich in solid component A and solid component B in the surface layer is 2.03g / cm 3 .

[0089] After the subsequent step ⑤ of the silicon dioxide infiltration process, the density of the ceramic matrix composite material prepared in this embodiment with both water-oxygen corrosion resistance and high thermal insulation performance is 2.42g / cm 3 .

[0090] Performance test: the weight loss rate of the ceramic matrix composite material prepared in this embodiment with both water-oxygen corrosion resistance and high thermal insulation performance under the water-oxygen corrosion condition of 1500℃, 90H2O-10O2(vol.%) for 100h is 0.30mg / cm 2 , and the thermal conductivity of the ceramic matrix composite material prepared is 3.1W / (m·K) at 1500℃.

[0091] Example 7

[0092] Example 7 is basically the same as Example 1, except that:

[0093] ③Preparation of precursor impregnation solutions with gradient concentrations: two precursor impregnation solutions with gradient concentrations are prepared, each of which is composed of solid component A, solid component B and polycarbosilane solution, the solid component A is composed of Yb2O3 powder 60wt%, TiO2 powder 20wt% and HfO2 powder 20wt% in mass fraction, the particle size D50 of the Yb2O3 powder, the TiO2 powder and the HfO2 powder is 0.5μm, the solid component B is composed of ZrO2 powder 50wt% and MgO powder 50wt% in mass fraction, the particle size D50 of the ZrO2 powder and the MgO powder is 0.5μm, the polycarbosilane solution in the two precursor impregnation solutions with gradient concentrations is a xylene solution of polycarbosilane, and the mass fraction of polycarbosilane is 20%; the mass fraction of solid component A in one precursor impregnation solution is 40%, and the mass fraction of solid component B is 20%, the mass fraction of solid component A in the other precursor impregnation solution is 20%, and the mass fraction of solid component B is 40%.

[0094] In step ④, the density of the ceramic matrix composite material with the surface layer rich in solid component A and solid component B is 1.95g / cm 3 .

[0095] After the subsequent step ⑤ of the silicon dioxide infiltration process, the density of the ceramic matrix composite material with both water-oxygen corrosion resistance and high thermal insulation performance after the subsequent silicon dioxide infiltration process is 2.31g / cm 3 .

[0096] Performance test: the weight loss rate of the prepared ceramic matrix composite material with both water-oxygen corrosion resistance and high thermal insulation performance under the water-oxygen corrosion condition of 1500℃, 90H2O-10O2(vol.%) for 100h is 0.42mg / cm 2 , and the thermal conductivity of the prepared ceramic matrix composite material at 1500℃ is 3.3W / (m·K).

[0097] Comparative Example 1

[0098] Comparative Example 1 is basically the same as Example 1, except that:

[0099] ③ Preparation of precursor impregnation solution: the precursor impregnation solution is composed of solid component A, solid component B and polycarbosilane solution, the solid component A is composed of Yb2O3 powder 50wt%, TiO2 powder 25wt% and HfO2 powder 25wt% by mass fraction, the particle size D50 of the Yb2O3 powder, the TiO2 powder and the HfO2 powder are all 0.5μm, the solid component B is composed of ZrO2 powder 50wt% and MgO powder 50wt% by mass fraction, the particle size D50 of the ZrO2 powder and the MgO powder are all 0.5μm, in the precursor impregnation solution, the polycarbosilane solution is xylene solution of polycarbosilane, the mass fraction of polycarbosilane is 20%; the mass fraction of solid component A in the precursor impregnation solution is 40%, the mass fraction of solid component B is 20%.

[0100] ④ Subsequent densification process: the precursor impregnation solution prepared in step ③ is used to carry out 8 cycles of PIP process on the preliminary densification ceramic matrix composite material obtained in step ② to obtain a ceramic matrix composite material with surface layer rich in solid component A and solid component B, the thickness of the Yb2O3, TiO2, HfO2, ZrO2 and MgO rich region formed in the surface layer is about 1000μm, the density of the ceramic matrix composite material with surface layer rich in solid component A and solid component B obtained is 1.90g / cm 3 .

[0101] After the silica infiltration process of subsequent step ⑤, the ceramic matrix composite material obtained has a density of 2.18g / cm 3 .

[0102] Performance test: the weight loss rate of the prepared ceramic matrix composite material under the water-oxygen corrosion condition of 1500℃, 90H2O-10O2(vol.%) for 100h is 0.43mg / cm 2 , the thermal conductivity of the prepared ceramic matrix composite material at 1500℃ is 10.7W / (m·K).

[0103] Comparative Example 2

[0104] Comparative Example 2 is basically the same as Example 1, the difference is that:

[0105] ③Preparation of precursor impregnation solution: the precursor impregnation solution is composed of solid component A, solid component B and polycarbosilane solution, the solid component A is composed of Yb2O3 powder 50wt%, TiO2 powder 25wt% and HfO2 powder 25wt% by mass fraction, the particle size D50 of the Yb2O3 powder, the TiO2 powder and the HfO2 powder are all 0.5μm, the solid component B is composed of ZrO2 powder 50wt% and MgO powder 50wt% by mass fraction, the particle size D50 of the ZrO2 powder and the MgO powder are both 0.5μm, the polycarbosilane solution in the precursor impregnation solution is polycarbosilane solution in xylene, the mass fraction of polycarbosilane in the polycarbosilane solution is 20%; the mass fraction of solid component A in one precursor impregnation solution is 20%, the mass fraction of solid component B in one precursor impregnation solution is 40%.

[0106] ④Subsequent densification process: the precursor impregnation solution prepared in step ③ is used to perform subsequent densification on the preliminary densification ceramic matrix composite material obtained in step ② through 8 cycles of PIP process, to obtain a ceramic matrix composite material with surface layer rich in solid component A and solid component B, the thickness of the Yb2O3, TiO2, HfO2, ZrO2 and MgO rich region formed in the surface layer is about 1000μm, the density of the ceramic matrix composite material with surface layer rich in solid component A and solid component B is 1.84g / cm 3 .

[0107] After the ceramic matrix composite material obtained in the above step ⑤ is subjected to the subsequent silica infiltration process, the density of the ceramic matrix composite material obtained is 2.07g / cm 3 .

[0108] Performance test: the weight loss rate of the prepared ceramic matrix composite material under the water-oxygen corrosion condition of 1500℃, 90H2O-10O2(vol.%) for 100h is 2.9mg / cm 2 , and the thermal conductivity of the prepared ceramic matrix composite material at 1500℃ is 3.4W / (m·K).

[0109] Comparative Example 3

[0110] Comparative Example 3 is basically the same as Example 1, except that:

[0111] ③Preparation of precursor impregnation solution: the precursor impregnation solution is prepared, the precursor impregnation solution is composed of solid component A and polycarbosilane solution, the solid component A is only Yb2O3 powder, the particle size D50 of the Yb2O3 powder is 0.5μm, the polycarbosilane solution is polycarbosilane solution in xylene, the mass fraction of polycarbosilane in the polycarbosilane solution is 30%; the mass fraction of solid component A in the precursor impregnation solution is 40wt%.

[0112] (iv) Subsequent densification process: the precursor impregnation solution prepared in step (iii) is used to perform subsequent densification on the preliminarily densified ceramic matrix composite obtained in step (ii) through 8 cycles of PIP process, to obtain a ceramic matrix composite with surface layer rich in solid component A, and the density of the ceramic matrix composite is 1.86 g / cm 3 .

[0113] (v) Silicon dioxide infiltration process: the ceramic matrix composite with surface layer rich in solid component A obtained in step (iv) is placed in SiO2 powder (particle size D50 is 0.5 μm) to perform infiltration reaction, the temperature of the infiltration reaction is 1650℃, the time of the infiltration reaction is 120 min, the heating rate for heating to the temperature of the infiltration reaction is 3℃ / min, to obtain a ceramic matrix composite, and the density of the ceramic matrix composite is 2.02 g / cm 3 .

[0114] Performance test: the ceramic matrix composite prepared in the present example is measured to have a weight loss rate of 0.75 mg / cm 2 under the water-oxygen corrosion condition of 1500℃, 90H2O-10O2 (vol.%) for 100h, and the thermal conductivity of the ceramic matrix composite prepared is 11.9 W / (m·K) at 1500℃.

[0115] Comparative Example 4

[0116] Comparative Example 4 is basically the same as Example 1, except that:

[0117] (iii) Preparation of precursor impregnation solution: a precursor impregnation solution is prepared, which is composed of solid component B and polycarbosilane solution, the solid component B is ZrO2 powder, the particle size D50 of the ZrO2 powder is 0.5 μm, the polycarbosilane solution is xylene solution of polycarbosilane, and the mass fraction of polycarbosilane in the polycarbosilane solution is 30%; the mass fraction of solid component B in the precursor impregnation solution is 40wt%.

[0118] (iv) Subsequent densification process: the precursor impregnation solution prepared in step (iii) is used to perform subsequent densification on the preliminarily densified ceramic matrix composite obtained in step (ii) through 8 cycles of PIP process, to obtain a ceramic matrix composite with surface layer rich in solid component B, and the density of the ceramic matrix composite is 1.73 g / cm 3 .

[0119] (v) Silicon dioxide infiltration process: the ceramic matrix composite with surface layer rich in solid component B obtained in step (iv) is placed in SiO2 powder (particle size D50 is 0.5 μm) to perform infiltration reaction, the temperature of the infiltration reaction is 1650℃, the time of the infiltration reaction is 120 min, the heating rate for heating to the temperature of the infiltration reaction is 3℃ / min, to obtain a ceramic matrix composite, and the density of the ceramic matrix composite is 1.99 g / cm3 .

[0120] Performance test: the prepared ceramic matrix composite material in this example has a weight loss rate of 4.8 mg / cm 2 at 1500℃, 90H2O-10O2(vol.%) water-oxygen corrosion conditions for 100h, and the thermal conductivity of the prepared ceramic matrix composite material is 7.7 W / (m·K) at 1500℃.

[0121] Comparative Example 5

[0122] Comparative Example 5 is basically the same as Example 1, except that:

[0123] 2. Preliminary densification process: the PCS solution (polycarbosilane solution) is used as the precursor impregnation solution, and the porous ceramic matrix composite material obtained in step 1 is subjected to SiC matrix densification by PIP process, and the PIP process is repeated multiple times until a preliminary densified ceramic matrix composite material with a density of 1.85 g / cm 3 is obtained; the polycarbosilane solution is a xylene solution of polycarbosilane, and the mass fraction of polycarbosilane in the polycarbosilane solution is 60%.

[0124] In step 4, the thickness of the Yb2O3, TiO2, HfO2, ZrO2 and MgO region formed on the surface layer is about 300 μm, and the density of the ceramic matrix composite material containing solid component A and solid component B in the surface layer is 1.96 g / cm 3 .

[0125] After the silica infiltration process of subsequent step 5, the thickness of the mixed densification layer is about 1500 μm, and the density of the obtained ceramic matrix composite material is 2.05 g / cm 3 .

[0126] Performance test: the prepared ceramic matrix composite material in this example has a weight loss rate of 6.8 mg / cm 2 at 1500℃, 90H2O-10O2(vol.%) water-oxygen corrosion conditions for 100h, and the thermal conductivity of the prepared ceramic matrix composite material is 12.8 W / (m·K) at 1500℃.

[0127] Comparative Example 6

[0128] Comparative Example 6 is basically the same as Example 1, except that:

[0129] The silica infiltration process of step 5 is not included.

[0130] Performance test: the prepared ceramic matrix composite material in this comparative example has a weight loss rate of 14.7 mg / cm 2 The thermal conductivity of the prepared ceramic matrix composite material is 13.1 W / (m·K) at 1500℃.

[0131] Comparative Example 7

[0132] Comparative Example 7 is basically the same as Example 1, except that:

[0133] ③Prepare a gradient concentration precursor solution: prepare two gradient concentration precursor solutions, each of which is composed of solid component A, solid component B and polycarbosilane solution, the solid component A is composed of Yb2O3 powder 50wt%, TiO2 powder 25wt% and HfO2 powder 25wt%, the particle size D50 of the Yb2O3 powder, the TiO2 powder and the HfO2 powder is 0.5μm, the solid component B is ZrO2 powder, the particle size D50 of the ZrO2 powder is 0.5μm, the polycarbosilane solution in the two gradient concentration precursor solutions is xylene solution of polycarbosilane, and the mass fraction of polycarbosilane is 20%; one precursor solution contains 40% of solid component A and 20% of solid component B, and the other precursor solution contains 20% of solid component A and 40% of solid component B.

[0134] In step ④, the density of the ceramic matrix composite material rich in solid component A and solid component B in the surface layer is 2.06g / cm 3 .

[0135] After the subsequent step ⑤ of the silica infiltration process, the density of the prepared ceramic matrix composite material is 2.41g / cm 3 .

[0136] Performance test: the prepared ceramic matrix composite material in this comparative example has a weight loss rate of 14.7 mg / cm 2 , the thermal conductivity of the prepared ceramic matrix composite material is 13.1 W / (m·K) at 1500℃.

[0137] Comparative Example 8

[0138] Comparative Example 8 is basically the same as Example 1, except that:

[0139] (3) Preparation of precursor impregnation solution with gradient concentration: two precursor impregnation solutions with gradient concentration were prepared, each of which was composed of solid component A, solid component B and polycarbosilane solution, the solid component A was composed of Yb2O3 powder 50wt%, TiO2 powder 25wt% and HfO2 powder 25wt% by mass fraction, the particle size D50 of the Yb2O3 powder, the TiO2 powder and the HfO2 powder was 0.5μm, the solid component B was MgO powder, the particle size D50 of the MgO powder was 0.5μm, in the two precursor impregnation solutions with gradient concentration, the polycarbosilane solution was xylene solution of polycarbosilane, the mass fraction of polycarbosilane was 20%, one of the precursor impregnation solutions contained 40% of solid component A by mass fraction and 20% of solid component B by mass fraction, the other of the precursor impregnation solutions contained 20% of solid component A by mass fraction and 40% of solid component B by mass fraction.

[0140] In step (4), the density of the ceramic matrix composite material rich in solid component A and solid component B in the surface layer was 1.92g / cm3. 3 .

[0141] The ceramic matrix composite material prepared by the subsequent step (5) of the silicon dioxide infiltration process had a density of 2.30g / cm3. 3 .

[0142] Performance test: the weight loss rate of the prepared ceramic matrix composite material under the water-oxygen corrosion condition of 1500℃, 90H2O-10O2(vol.%) for 100h was 0.37mg / cm2. 2 The thermal conductivity of the prepared ceramic matrix composite material at 1500℃ was 5.2W / (m·K).

[0143] Comparative Example 9

[0144] Comparative Example 9 was basically the same as Example 1, except that:

[0145] (3) Preparation of precursor impregnation solution with gradient concentration: two precursor impregnation solutions with gradient concentration were prepared, each of which was composed of solid component A, solid component B and polycarbosilane solution, the solid component A was composed of Yb2O3 powder 50wt%, TiO2 powder 25wt% and HfO2 powder 25wt% by mass fraction, the particle size D50 of the Yb2O3 powder, the TiO2 powder and the HfO2 powder was 0.5μm, the solid component B was Gd 1.8 Yb 0.2 Zr2O7 powder, the Gd 1.8 Yb 0.2The particle size D50 of the Zr2O7 powder is 0.5 μm, the polycarbosilane solution in the two precursor impregnation solutions with gradient concentrations is a xylene solution of polycarbosilane, and the mass fraction of polycarbosilane is 20%; the mass fraction of the solid component A in one precursor impregnation solution is 40%, and the mass fraction of the solid component B is 20%; the mass fraction of the solid component A in the other precursor impregnation solution is 20%, and the mass fraction of the solid component B is 40%.

[0146] In step IV, the density of the surface layer of the ceramic matrix composite rich in the solid component A and the solid component B is 2.11 g / cm 3 .

[0147] The ceramic matrix composite prepared through the subsequent step V of the silicon dioxide infiltration process has a density of 2.53 g / cm 3 .

[0148] Performance test: the weight loss rate of the ceramic matrix composite prepared in the present example under the water-oxygen corrosion condition of 1500℃, 90H2O-10O2 (vol.%) for 100h is 0.36 mg / cm 2 , and the thermal conductivity of the ceramic matrix composite prepared is 6.8 W / (m·K).

[0149] The performance indexes of the ceramic matrix composites prepared in examples 1-7 and comparative examples 1-9 are shown in Table 1. The examples of the present application are superior to the comparative examples in terms of thermal conductivity and water-oxygen corrosion resistance. This is mainly due to the innovative method of using gradient concentration precursor impregnation solution and preparing silicate through silicon dioxide infiltration reaction, which enables the composite to maintain low thermal conductivity while having excellent water-oxygen corrosion resistance.

[0150] The examples of the present application use gradient concentration design to realize the gradient distribution of the water and gas corrosion resistant components (Yb2SiO5, TiSiO4, HfSiO4) and the high thermal insulation components (ZrSiO4, Mg2SiO4) in the surface layer of the composite. Benefiting from the synergistic effect of the water and gas corrosion resistant components and the high thermal insulation components, the water and gas corrosion resistance and the thermal insulation capacity of the surface layer are improved, and the service life of the material is prolonged. Compared with the ceramic matrix composites prepared by using fixed concentration components or only one component in the comparative examples, the ceramic matrix composites prepared in the examples of the present application are superior to the comparative examples in terms of thermal conductivity and weight loss rate. Especially in the weight loss rate under high temperature water-oxygen corrosion condition, the examples show lower results, indicating that the water-oxygen corrosion resistance is more excellent. The ceramic matrix composites prepared in the examples of the present application have lower thermal conductivity at high temperature 1500℃, and have more excellent thermal insulation performance.

[0151] Table 1 Performance indicators of ceramic matrix composites prepared in Examples 1-7 and Comparative Examples 1-9

[0152]

[0153] The part of the present application not described in detail is the technology known to the person skilled in the art. Finally, it should be pointed out that the above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the foregoing examples, the person skilled in the art should understand that the technical solutions recorded in the foregoing examples can still be modified, or some technical features can be replaced by equivalent features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for preparing a ceramic matrix composite material with both resistance to water and oxygen corrosion and high thermal insulation properties, characterized in that, The method includes the following steps: (1) Preparation of porous ceramic matrix composites; (2) Using polycarbosilane solution as impregnation liquid, the porous ceramic matrix composite material is densified by precursor impregnation pyrolysis process to obtain a preliminary densified ceramic matrix composite material. (3) Prepare n gradient concentrations of precursor impregnation solutions, each precursor impregnation solution containing solid component A, solid component B and polycarbosilane solution, wherein solid component A contains ytterbium oxide powder, titanium oxide powder and hafnium oxide powder, wherein the particle size D50 of the ytterbium oxide powder, titanium oxide powder and hafnium oxide powder is 0.1μm~1μm; The solid component B comprises zirconium oxide powder and magnesium oxide powder, wherein the particle size D50 of the zirconium oxide powder and the magnesium oxide powder is 0.1 μm to 1 μm; (4) The precursor impregnation liquids of n gradient concentrations are sequentially passed through the precursor impregnation pyrolysis process to densify the pre-densified ceramic matrix composite material, so as to obtain a ceramic matrix composite material with solid component A and solid component B on the surface; wherein, the content of solid component A decreases from the inside to the outside in the surface layer, and the content of solid component B increases from the inside to the outside in the surface layer, and the direction from the inside to the outside is the direction towards the surface of the ceramic matrix composite material. (5) The ceramic matrix composite material containing solid component A and solid component B on the surface is placed in silica powder for melt infiltration reaction to obtain a ceramic matrix composite material with both water and oxygen corrosion resistance and high heat insulation performance.

2. The preparation method according to claim 1, characterized in that: In the precursor impregnation solutions with n gradient concentrations, the content of solid component A decreases and the content of solid component B increases. n≥2 and n is a positive integer; The concentration range of solid component A in the n gradient concentration precursor impregnation solutions is 10~50wt%, and the concentration range of solid component B in the n gradient concentration precursor impregnation solutions is 10~50wt%; and / or The surface layer of the ceramic matrix composite material, which combines resistance to water and oxygen corrosion and high thermal insulation performance, is a mixed dense layer containing ytterbium silicate, titanium silicate, hafnium silicate, zirconium silicate, magnesium silicate, silicon carbide, silicon dioxide, and a fiber skeleton. The total content of ytterbium silicate, titanium silicate, and hafnium silicate decreases towards the surface, while the total content of zirconium silicate and magnesium silicate increases towards the surface.

3. The preparation method according to claim 1 or 2, characterized in that, In step (1): The porous ceramic matrix composite material is obtained by depositing an interface layer on the fibers of a fiber braid.

4. The preparation method according to claim 3, characterized in that: The fiber braid is a carbon fiber braid or a silicon carbide fiber braid.

5. The preparation method according to claim 3, characterized in that: The density of the fiber braid is 0.4~0.7 g / cm³. 3 .

6. The preparation method according to claim 3, characterized in that: The interface layer is one or more of the following: a pyrolytic carbon interface layer, a silicon carbide interface layer, or a boron nitride interface layer.

7. The preparation method according to claim 3, characterized in that: The density of the porous ceramic matrix composite material is 0.8~1.2 g / cm³. 3 .

8. The preparation method according to claim 1 or 2, characterized in that, In step (2): The polycarbosilane solution is a xylene solution of polycarbosilane; and / or Repeat the precursor impregnation and pyrolysis process multiple times until a density of 1.3~1.5 g / cm³ is obtained. 3 Preliminary densification of ceramic matrix composites.

9. The preparation method according to claim 8, characterized in that, In step (2): The polycarbosilane solution contains 35-60% polycarbosilane by mass.

10. The preparation method according to claim 1 or 2, characterized in that, In step (3): The polycarbosilane solution is a xylene solution of polycarbosilane; and / or The solid component A comprises, by mass fraction, 40-60% ytterbium oxide powder, 20-30% titanium oxide powder, and 20-30% hafnium oxide powder.

11. The preparation method according to claim 10, characterized in that, In step (3): The polycarbosilane solution contains 10-30% polycarbosilane by mass.

12. The preparation method according to claim 1 or 2, characterized in that, In step (3): The solid component B comprises 40-60% zirconium oxide powder and 40-60% magnesium oxide powder by mass fraction.

13. The preparation method according to claim 1 or 2, characterized in that, In step (4): The thickness of the ceramic matrix composite material containing solid component A and solid component B in the surface layer is 500~2000μm. and / or The density of the ceramic matrix composite material containing solid component A and solid component B on the surface is 1.8~2.1 g / cm³. 3 .

14. The preparation method according to claim 1 or 2, characterized in that, In step (5): The particle size D50 of the silica powder is 0.1 μm to 1 μm; The melting and infiltration reaction is carried out at a temperature of 1400–1700°C for a duration of 60–180 min; and / or The heating rate to the melting and infiltration reaction temperature is 2~4°C / min.

15. The preparation method according to claim 2, characterized in that, In step (5): The thickness of the hybrid dense layer is 500~2000 μm; The density of the ceramic matrix composite material, which combines resistance to water and oxygen corrosion with high thermal insulation properties, is 2.2~2.5 g / cm³. 3 ; The ceramic matrix composite material, which combines resistance to water and oxygen corrosion and high thermal insulation performance, has a thermal conductivity of no more than 5 W / m·K at 1500°C and exhibits excellent resistance to water and oxygen corrosion at 1200~1500°C.

16. A ceramic matrix composite material with both resistance to water and oxygen corrosion and high thermal insulation properties, prepared by any one of claims 1 to 15.

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