CN117586018A - A carbon nanotube fiber toughened ceramic matrix composite material and its preparation method - Google Patents

Abstract

The invention relates to a carbon nanotube fiber-toughened ceramic matrix composite material and a preparation method thereof. The method includes: providing continuous carbon nanotube fibers and pretreating them with hydroxylation; soaking the hydroxylated pretreated carbon nanotube fibers in a graphene oxide aqueous solution to obtain carbon nanotube fibers with a graphene oxide interface layer; and then subjecting them to annealing treatment , obtain a carbon nanotube fiber with a graphene interface layer; use polysilocarbazane as a precursor, deposit a SiCN interface layer on the surface of the graphene interface layer of the carbon nanotube fiber through chemical vapor deposition, and obtain a graphene/SiCN interface layer. The carbon nanotube fibers of the composite interface layer are woven into a preform, and the ceramic precursor and the preform are reacted by the impregnation cracking method to prepare a ceramic matrix composite material toughened by carbon nanotube fibers. The ceramic matrix composite material prepared by the invention not only has high thermal conductivity, but also has significantly improved mechanical and oxidation resistance properties.

Description

A carbon nanotube fiber-reinforced ceramic matrix composite material and preparation method thereof

Technical Field

The invention belongs to the technical field of preparation of ceramic-based composite materials, and in particular relates to a carbon nanotube fiber-reinforced ceramic-based composite material and a preparation method thereof.

Background Art

In the field of aerospace, carbon fiber-reinforced ceramic-based composites have excellent properties such as light weight, high strength, high toughness, and high temperature resistance. They are the main candidate materials for many thermal structural components, and their application range is becoming more and more extensive. However, the thermal conductivity of carbon fiber and ceramic matrix is lower than 50W/(m·K), resulting in the thermal conductivity of carbon fiber-reinforced ceramic-based composites being only 10-20W/(m·K). The use environment of application parts such as the leading edge is extremely harsh, and the local temperature is too high. If the thermal conductivity is low, the heat cannot be effectively channeled, and it is very likely that the temperature resistance limit of the composite material will be exceeded, resulting in the collapse of the overall structure and performance failure, thus causing irreversible damage.

As a new type of carbon nanofiber, carbon nanotube fiber can achieve a thermal conductivity of more than 200W/mK at room temperature, and the thermal conductivity decreases less at high temperature, and the thermal conductivity performance decays slightly. At the same time, the elongation at break is greater than 4%, which is much higher than the elongation at break of carbon fiber (1.5-2.2%), showing more excellent mechanical properties. The thermal conductivity of the ceramic-based composite material prepared by impregnation and pyrolysis technology using carbon nanotube fiber as the toughening phase can reach 40-150W/(m·K), and the mechanical properties are also significantly improved. Therefore, the ceramic-based composite material toughened by carbon nanotube fiber is expected to be used as the next generation of thermal structural components in the leading edge and other parts to quickly conduct heat and avoid excessive local temperature.

However, the ceramic matrix composites toughened by carbon nanotube fibers also face many problems. One of them is that the carbon nanotube fibers have weak antioxidant capacity. At the same time, their special nanostructure leads to weak interface bonding between the traditional pyrolytic carbon interface layer and the carbon nanotube fibers. Therefore, how to improve the bonding strength between the interface layer and the carbon nanotube fibers and further improve its antioxidant capacity is the key problem for the ceramic matrix composites toughened by carbon nanotube fibers to exert their excellent performance.

In summary, it is very necessary to provide a carbon nanotube fiber-reinforced ceramic-based composite material and a preparation method thereof.

Summary of the invention

In order to solve one or more technical problems existing in the prior art, the present invention provides a carbon nanotube fiber-reinforced ceramic matrix composite material and a preparation method thereof. The method of the present invention improves the bonding strength between the interface layer and the carbon nanotube fiber, and further improves the oxidation resistance of the carbon nanotube fiber-reinforced ceramic matrix composite material.

In a first aspect, the present invention provides a method for preparing a carbon nanotube fiber-reinforced ceramic-based composite material, the method comprising the following steps:

(1) providing continuous carbon nanotube fibers and performing hydroxylation pretreatment to obtain hydroxylated pretreated carbon nanotube fibers;

(2) preparing a graphene oxide aqueous solution, and then immersing the hydroxylated pretreated carbon nanotube fibers in the graphene oxide aqueous solution to obtain carbon nanotube fibers having a graphene oxide interface layer;

(3) annealing the carbon nanotube fiber having a graphene oxide interface layer and cooling it to room temperature to obtain a carbon nanotube fiber having a graphene interface layer;

(4) using polysilicon carbazane as a precursor, depositing a SiCN interface layer on the surface of the graphene interface layer of the carbon nanotube fiber having a graphene interface layer by chemical vapor deposition to obtain a carbon nanotube fiber having a graphene/SiCN composite interface layer;

(5) Weaving the carbon nanotube fibers with the graphene/SiCN composite interface layer into a preform, reacting a ceramic precursor with the preform by an impregnation pyrolysis method, and obtaining a carbon nanotube fiber-reinforced ceramic-based composite material.

Preferably, the continuous carbon nanotube fiber has a tensile strength of not less than 3 GPa, a single filament diameter of 8 to 15 μm, a continuous length of not less than 10 m, a room temperature thermal conductivity of not less than 200 W/(m·K), and/or an elongation at break of not less than 4%.

Preferably, the hydroxylation pretreatment is to immerse the continuous carbon nanotube fibers in a mixed solution of concentrated sulfuric acid and hydrogen peroxide in a volume ratio of (6-8): (2-4) at 75-88°C for 0.5-1.5h, and then immerse and dry in distilled water to obtain hydroxylation pretreated carbon nanotube fibers.

Preferably, in step (2), the concentration of the graphene oxide aqueous solution is 0.6 to 6.0 mg/mL; in step (2), the immersion time is 10 to 60 min; and/or the thickness of the graphene oxide interface layer is 0.05 to 0.5 μm.

Preferably, in step (3): the temperature of the annealing treatment is 800-1000° C., the time of the annealing treatment is 1-5 hours; and/or the cooling rate is not greater than 1° C./min.

Preferably, in step (4): polysilicon carbazane is heated and then introduced into a chemical vapor deposition furnace through a carrier gas nitrogen, and hydrogen and ammonia are simultaneously introduced into the chemical vapor deposition furnace to deposit the SiCN interface layer; wherein the volume flow ratio of nitrogen, hydrogen and ammonia is 10:5:(1-4).

Preferably, the heating temperature of the polysilicon carbazane is 110-150° C.; and/or the temperature for depositing the SiCN interface layer is 1200-1500° C., the time is 3.5-5 hours, and the pressure in the chemical vapor deposition furnace is 10-150 Pa.

Preferably, the thickness of the SiCN interface layer is 0.3-1.0 μm.

Preferably, the ceramic precursor is one or more of a zirconium silicon precursor, a silicon carbide precursor, a zirconium carbide precursor, and a hafnium carbide precursor; and/or the density of the carbon nanotube fiber-toughened ceramic matrix composite material is 2.0-2.5 g/cm ³ .

In a second aspect, the present invention provides a carbon nanotube fiber-reinforced ceramic-based composite material prepared by the preparation method described in the first aspect of the present invention.

Compared with the prior art, the present invention has at least the following beneficial effects:

(1) The present invention uses carbon nanotube fibers as a toughening phase, and prepares a graphene interface layer on the fiber surface by a self-assembly method. Both carbon nanotubes and graphene are nanocarbon materials with sp2 hybridization of carbon atoms. With the help of high-temperature annealing technology, the two can form a moderate π-π interaction force, effectively improving the bonding strength between the carbon nanotube fibers and the graphene interface layer, which helps to improve the mechanical properties of the composite material.

(2) The present invention adopts chemical vapor deposition technology, uses polymer polysilicon carbazane as an organic precursor, prepares a SiCN interface layer on the surface of the graphene interface layer, and finally obtains a graphene/SiCN composite interface layer. Compared with traditional pyrolytic carbon interface layers, SiC interface layers, etc., the present invention finds that the introduction of a SiCN interface layer on the surface of the graphene interface layer has better antioxidant and ablation resistance than the introduction of a pyrolytic carbon interface layer or a SiC interface layer. At the same time, the method of forming the SiCN interface layer of the present invention, compared with the traditional SiC deposition method, can effectively avoid the structural and performance damage caused by the corrosion of hydrogen chloride gas to carbon nanotube fibers, and effectively improve the antioxidant properties and high-temperature mechanical properties of ceramic-based composite materials.

(3) The present invention effectively solves the problem of poor bonding strength between the interface layer and the carbon nanotube fibers and damage to the carbon nanotube fibers by hydrogen chloride products in the traditional deposition method. The carbon nanotube fiber-reinforced ceramic-based composite material prepared by the present invention not only has a high thermal conductivity, but also has significantly improved mechanical and antioxidant properties. It has the advantages of high toughness and strong antioxidant properties, and is manifested in excellent mechanical properties in a high-temperature aerobic environment.

DETAILED DESCRIPTION

In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

In a first aspect, the present invention provides a method for preparing a carbon nanotube fiber-reinforced ceramic-based composite material, the method comprising the following steps:

(1) providing continuous carbon nanotube fibers and performing hydroxylation pretreatment to obtain hydroxylated pretreated carbon nanotube fibers; the present invention does not specifically limit the source of the continuous carbon nanotube fibers, which may be directly purchased products or products prepared by existing methods;

(2) preparing a graphene oxide aqueous solution, and then immersing the hydroxylated pretreated carbon nanotube fibers in the graphene oxide aqueous solution to obtain carbon nanotube fibers having a graphene oxide interface layer; the present invention prepares a graphene oxide aqueous solution of a certain concentration, and self-assembles the graphene oxide interface layer on the surface of the carbon nanotube fibers by immersion-adsorption; in the present invention, for example, after immersing in the graphene oxide aqueous solution, the carbon nanotube fibers having the graphene oxide interface layer are separated; the separation can be, for example, pulling the immersed carbon nanotube fibers out of the graphene oxide aqueous solution to obtain the carbon nanotube fibers having the graphene oxide interface layer;

(3) annealing the carbon nanotube fiber having a graphene oxide interface layer, cooling it to room temperature (room temperature 15-35° C.), and obtaining a carbon nanotube fiber having a graphene interface layer; in the present invention, the bonding strength between the carbon nanotube fiber and the graphene interface layer can be improved by high temperature annealing technology;

(4) Using polysilicon carbazane (polymer polysilicon carbazane) as a precursor, depositing a SiCN interface layer on the surface of the graphene interface layer of the carbon nanotube fiber having the graphene interface layer by chemical vapor deposition, and obtaining a carbon nanotube fiber having a graphene/SiCN composite interface layer; that is, using polymer polysilicon carbazane as an organic precursor, using chemical vapor deposition technology, preparing a SiCN interface layer on the surface of the graphene interface layer, and finally obtaining a graphene/SiCN composite interface layer; the present invention does not specifically limit the source of polysilicon carbazane, which can be a directly purchased product or a product prepared by an existing method; in the present invention, the polysilicon carbazane is liquid polysilicon carbazane; specifically, for example, placing the carbon nanotube fiber having the graphene interface layer in a chemical vapor deposition furnace, by controlling the heating temperature of the polysilicon carbazane, nitrogen, hydrogen and ammonia are introduced under vacuum and high temperature conditions, and after a certain period of time, a SiCN interface layer is formed on the surface of the carbon nanotube fiber;

(5) Weaving the carbon nanotube fibers with the graphene/SiCN composite interface layer into a preform, reacting a ceramic precursor with the preform by an impregnation pyrolysis method (impregnation/curing/pyrolysis PIP process) to obtain a carbon nanotube fiber-reinforced ceramic matrix composite material. In other words, the ceramic precursor is used as a reactant, and the carbon nanotube fiber-reinforced ceramic matrix composite material is prepared by precursor impregnation pyrolysis. In the present invention, the weaving method can be, for example, one or more of puncture, suturing or acupuncture. In the present invention, the ceramic precursor is, for example, one or more of a zirconium silicon precursor, a silicon carbide precursor, a zirconium carbide precursor, and a hafnium carbide precursor, preferably a zirconium silicon precursor. In the present invention, the zirconium silicon precursor is a polymer mainly composed of zirconium and silicon. This polymer can be converted into ZrC/SiC ceramics after high-temperature pyrolysis treatment. It is a known product in the prior art, for example, it can be purchased from the Institute of Chemistry, Chinese Academy of Sciences, or it can be synthesized by referring to the existing method. In the PIP process of impregnation/curing/cracking, a zirconium silicon precursor solution is used as an impregnation liquid; the zirconium silicon precursor solution uses a zirconium silicon precursor as a solute and xylene as a solvent, and the solid content of the zirconium silicon precursor solution can be, for example, 50 to 70 wt %; in the present invention, preferably, when performing the PIP process of impregnation/curing/cracking, the impregnation is first performed by vacuum impregnation, the pressure of the vacuum impregnation is, for example, 20 to 200 Pa, and then pressure impregnation is performed, the pressure of the pressure impregnation is 1 to 2 MPa, The time of each vacuum impregnation is 1 to 2 hours, the time of each pressure impregnation is 1 to 2 hours, the temperature of the curing is 200 to 300°C, the time of each curing is 1 to 3 hours, the curing is carried out in an argon atmosphere, the temperature of the cracking is 1400 to 1600°C, the insulation time of each cracking is 1 to 4 hours, and the cracking is carried out in an argon atmosphere. The present invention does not specifically limit the number of times the impregnation, curing and cracking are repeated, until the density of the ceramic-based composite material reaches 2.0 to 2.5 g/ ^cm3 ; in the present invention, the pressure involved refers to the absolute pressure.

The present invention gives full play to the advantage of high thermal conductivity of carbon nanotube fibers, deposits graphene oxide on the fiber surface by immersion-adsorption, and uses rapid high-temperature annealing technology to further improve the bonding strength between graphene and carbon nanotube fibers. At the same time, a suitable chemical vapor deposition process is used to construct a SiCN interface layer, which effectively solves the problem of poor bonding strength between the interface layer and the carbon nanotube fibers and damage to the carbon nanotube fibers by hydrogen chloride products in traditional deposition methods, and effectively improves the antioxidant properties and high-temperature mechanical properties of ceramic-based composite materials.

The present invention adopts chemical vapor deposition technology, uses polymer polysilicon carbazane as an organic precursor, prepares a SiCN interface layer on the surface of the graphene interface layer, and finally obtains a graphene/SiCN composite interface layer. Compared with traditional pyrolytic carbon interface layers, SiC interface layers, etc., the present invention finds that the introduction of a SiCN interface layer on the surface of the graphene interface layer has more excellent antioxidant and ablation resistance than the introduction of a pyrolytic carbon interface layer or a SiC interface layer. The carbon nanotube fiber-reinforced ceramic-based composite material prepared by the present invention not only has a higher thermal conductivity, but also has significantly improved mechanical and antioxidant properties, has the advantages of high toughness and strong antioxidant properties, and is manifested as excellent mechanical properties in a high-temperature aerobic environment.

According to some preferred embodiments, the tensile strength of the continuous carbon nanotube fiber is not less than 3 GPa, the single filament diameter is 8 to 15 μm, the continuous length is not less than 10 m, the room temperature thermal conductivity is not less than 200 W/(m·K), and/or the elongation at break is not less than 4%; the continuous carbon nanotube fiber has excellent toughness.

According to some preferred embodiments, the hydroxylation pretreatment is to immerse the continuous carbon nanotube fibers in a mixed solution of concentrated sulfuric acid and hydrogen peroxide in a volume ratio of (6-8): (2-4) (for example, 6:4, 7:3 or 8:2) at 75-88°C (for example, 75°C, 80°C, 85°C or 88°C) for 0.5-1.5h (for example, 0.5, 1 or 1.5h), and then soak them in distilled water for 0.5-2h and dry them to obtain hydroxylation pretreated carbon nanotube fibers; in the present invention, the concentrated sulfuric acid is, for example, concentrated sulfuric acid with a mass fraction of 98wt% (abbreviated as 98% concentrated sulfuric acid), and the hydrogen peroxide is, for example, hydrogen peroxide with a mass fraction of 30wt% (abbreviated as 30% hydrogen peroxide); in the present invention, the distilled water immersion is carried out at room temperature (for example, room temperature 15-35°C); the present invention does not specifically limit the drying conditions, which is a conventional technology in the field.

According to some specific embodiments, the hydroxylation pretreatment is to soak the dried continuous carbon nanotube fiber in a mixed solution of 98% concentrated sulfuric acid and 30% hydrogen peroxide in a volume ratio of 7:3, and place it in a 75-88°C oil bath for 0.5-1.5 hours. After the end, take it out and soak it in distilled water, dry it and use it again. At this time, a large number of hydrophilic hydroxyl groups are formed on the surface of the carbon nanotube fiber; in the present invention, by controlling the heat preservation and standing time in the mixed solution of 98% concentrated sulfuric acid and 30% hydrogen peroxide in a volume ratio of 7:3, the content of hydrophilic hydroxyl groups can be adjusted.

According to some preferred embodiments, in step (2), the concentration of the graphene oxide aqueous solution is 0.6 to 6.0 mg/mL (e.g., 0.6, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5 or 6 mg/mL), that is, the concentration of graphene oxide in the graphene oxide aqueous solution is 0.6 to 6.0 mg/mL; the present invention has no particular limitation on graphene oxide, and it can be graphene oxide obtained by strong oxidation of graphite flakes or graphene oxide obtained by other methods; in the present invention, preferably, the concentration of the graphene oxide aqueous solution is 0.6 to 6. 0mg/mL, so as to ensure that a high-quality graphene interface layer that can well play the role of an interface layer is finally obtained; the present invention finds that if the mass concentration of the graphene oxide aqueous solution is higher than 6.0mg/mL, the graphene oxide is too aggregated, and its self-assembly stacking effect is poor, and a high-quality graphene oxide interface layer cannot be obtained, and thus a high-quality graphene interface layer cannot be formed; if the mass concentration of the graphene oxide aqueous solution is lower than 0.6mg/mL, the graphene oxide in the solution is too sparse, and even after a long time, the surface of the carbon nanotube fiber cannot be completely covered, and the interface layer cannot play a good role.

According to some preferred embodiments, in step (2), the immersion time is 10 to 60 min (e.g., 10, 15, 20, 25, 30, 35, 40, 45, 50, 55 or 60 min); and/or the thickness of the graphene oxide interface layer is 0.05 to 0.5 μm (e.g., 0.05, 0.08, 0.1, 0.2, 0.3, 0.4 or 0.5 μm); in the present invention, the thickness of the interface layer can be regulated by regulating the graphene oxide concentration and the standing time (immersion time).

According to some specific embodiments, step (2) is: by placing the hydroxylated pretreated carbon nanotube fibers with a large amount of hydrophilicity formed on the surface in a graphene oxide aqueous solution with a concentration of 0.6-6.0 mg/mL and letting it stand (immerse) for 10-60 minutes, pulling out the solution, a graphene oxide interface layer can be self-assembled on the fiber surface, and the thickness of the interface layer is 0.05-0.5 μm.

According to some preferred embodiments, in step (3): the annealing temperature is 800-1000°C (e.g., 800°C, 850°C, 900°C, 950°C or 1000°C), the annealing time is 1-5h (e.g., 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5 or 5h); and/or the cooling rate is not greater than 1°C/min; in the present invention, the annealing is carried out in an inert atmosphere.

In the present invention, through the high temperature annealing technology, the processing temperature is 800-1000°C, and the cooling rate is ≤1°C/min. On the one hand, graphene oxide can be converted into graphene, and at the same time, carbon nanotubes and graphene form a π-π interaction force, which effectively improves the bonding strength between the carbon nanotube fiber and the graphene interface layer; the present invention finds that during the annealing treatment, it is very important to control the cooling rate to be ≤1°C/min. The use of this slow cooling method has two advantages. On the one hand, graphene oxide can be converted into graphene, and on the other hand, carbon nanotubes and graphene form a moderate π-π interaction force, which effectively improves the bonding strength between the carbon nanotube fiber and the graphene interface layer; and if the cooling rate is higher than 1°C/min, small molecular gases such as CO and _CO2 formed by the decomposition of graphene oxide may escape quickly, resulting in the formation of larger pores between layers, and the graphene stacking effect is poor, which will significantly affect the performance of the formed graphene interface layer.

According to some specific implementation methods, step (3) is: placing the carbon nanotube fiber with a graphene oxide interface layer in a high-temperature furnace, evacuating the vacuum to 20-50 Pa, and continuously introducing nitrogen or argon, setting the annealing temperature to 800-1000°C, the holding time to 1-5h, and the cooling rate ≤1°C/min.

According to some preferred embodiments, polysilicon carbazane is heated and then introduced into a chemical vapor deposition furnace through a carrier gas nitrogen, and hydrogen and ammonia are simultaneously introduced into the chemical vapor deposition furnace to deposit the SiCN interface layer; wherein the volume flow ratio of nitrogen, hydrogen and ammonia is 10:5:(1-4) (e.g., 10:5:1, 10:5:2, 10:5:3 or 10:5:4).

According to some preferred embodiments, the heating temperature of the polysilicon carbazane is 110-150°C (e.g., 110°C, 120°C, 130°C, 140°C or 150°C); and/or the temperature for depositing the SiCN interface layer is 1200-1500°C (e.g., 1200°C, 1250°C, 1300°C, 1350°C, 1400°C, 1450°C or 1500°C), the time is 3.5-5h (e.g., 3.5, 4, 4.5 or 5h), and the pressure in the chemical vapor deposition furnace is 10-150Pa (e.g., 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140 or 150Pa).

The present invention has found through a large number of creative experiments that when the SiCN interface layer is prepared by chemical vapor deposition using polysilicon carbazane as a reactant, it is preferred to control the chemical vapor deposition temperature in the reaction furnace to be 1200-1500°C and adjust the flow rate ratio of nitrogen, hydrogen and ammonia to be 10:5:(1-4), so that a ceramic-based composite material with strong antioxidant properties and significantly improved mechanical properties in a high-temperature aerobic environment can be obtained; the present invention has found that if the chemical vapor deposition temperature is higher than 1500°C, SiCN will be thermally decomposed to form substances such as Si ₃ N ₄ , and the antioxidant property will decrease; if the chemical vapor deposition temperature is lower than 1200°C, the SiCN precursor will not be fully cracked and a stable SiCN interface layer will not be formed; and if the flow rate ratio of nitrogen, hydrogen and ammonia is higher than 10:5:4, a considerable proportion of SiCN will be converted into Si ₃ N ₄ ; and if it is lower than 10:5:1, SiCN will be converted into SiC, both of which will affect the antioxidant property of the ceramic-based composite material.

According to some specific embodiments, step (4) is: placing the carbon nanotube fiber with the graphene interface layer in a chemical vapor deposition furnace (reactor), drawing a vacuum, the pressure in the reactor is 10-150Pa, and the temperature in the reactor is controlled at 1200-1500°C, and the temperature is kept for 10 minutes to ensure that the temperature inside the furnace reaches a uniform state. Next, the heated polysilicon carbazane is brought into the chemical vapor deposition furnace cavity by nitrogen as a carrier gas, and the heating temperature of the polysilicon carbazane is controlled at 110-150°C. While the carrier gas nitrogen is kept continuously carrying the polysilicon carbazane into the cavity, hydrogen and ammonia are also introduced into the furnace cavity. The flow ratio of nitrogen, hydrogen and ammonia is 10:5:1-4, wherein the flow rate of the carrier gas nitrogen is controlled at 0.1-2L/min. After the reactor is kept warm for 3.5-5h, a SiCN interface layer is formed on the surface of the carbon nanotube fiber, with a thickness of 0.3-1.0μm. Then the temperature is lowered, and the heating of polysilicon carbazane and the introduction of ammonia and hydrogen are stopped in turn. Nitrogen is introduced throughout the entire cooling process until the temperature drops to room temperature, and the sample is taken out; in the present invention, the room temperature is, for example, room temperature of 15 to 35°C.

According to some preferred embodiments, the thickness of the SiCN interface layer is 0.3-1.0 μm (eg, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1 μm).

According to some preferred embodiments, the ceramic precursor is one or more of a zirconium silicon precursor, a silicon carbide precursor, a zirconium carbide precursor, and a hafnium carbide precursor; and/or the density of the carbon nanotube fiber-toughened ceramic matrix composite material is 2.0 to 2.5 g/cm ^3. The present invention preferably uses a zirconium silicon precursor as a reactant to prepare a carbon nanotube fiber-toughened ceramic matrix composite material by precursor impregnation and pyrolysis, and preferably prepares a carbon nanotube fiber-toughened ceramic matrix composite material with a density of 2.0 to 2.5 g/cm ^3. The carbon nanotube fiber-toughened ceramic matrix composite material prepared by the present invention not only has a high thermal conductivity, but also has significantly improved mechanical and antioxidant properties.

In a second aspect, the present invention provides a carbon nanotube fiber-reinforced ceramic-based composite material prepared by the preparation method described in the first aspect of the present invention.

The present invention will be further described below by way of examples, but the protection scope of the present invention is not limited to these embodiments. The present invention may also have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may make various corresponding changes and deformations according to the present invention, but these corresponding changes and deformations shall all belong to the protection scope of the claims attached to the present invention. The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, etc. used in the following examples, unless otherwise specified, can be obtained from commercial sources or prepared by existing methods.

Example 1

① Provide continuous carbon nanotube fibers and perform hydroxylation pretreatment to obtain hydroxylation pretreated carbon nanotube fibers; the continuous carbon nanotube fibers have a tensile strength of 4GPa, a single fiber diameter of 10μm, a continuous length of 15m, a room temperature thermal conductivity of 270W/mK, and a breaking elongation of 4.8%; the hydroxylation pretreatment is as follows: immerse the above-mentioned dried continuous carbon nanotube fibers in a mixed solution of 98% concentrated sulfuric acid and 30% hydrogen peroxide in a volume ratio of 7:3, and keep them in an 80°C oil bath for 1.0h. After the end, take them out and immerse them in distilled water at room temperature for 0.5h, and finally dry them to obtain hydroxylation pretreated carbon nanotube fibers.

②Preparation of graphene oxide interface layer: Prepare a graphene oxide aqueous solution with a concentration of 0.6 mg/mL, place the hydroxylated pretreated carbon nanotube fibers in the graphene oxide aqueous solution and let it stand for 30 minutes, pull out the solution to obtain carbon nanotube fibers with a graphene oxide interface layer, and the thickness of the graphene oxide interface layer is 0.05 μm.

③ Preparation of graphene interface layer by high temperature annealing technology: Place the above-mentioned carbon nanotube fiber with graphene oxide interface layer in a high temperature furnace, evacuate to 20Pa, and continuously introduce argon gas, set the annealing temperature to 1000℃, and set the holding time (annealing time) to 2h. After annealing, cool it to room temperature at a cooling rate of 0.5℃/min to obtain carbon nanotube fiber with graphene interface layer.

④Preparation of SiCN interface layer: Place the carbon nanotube fiber with graphene interface layer in a chemical vapor deposition furnace, draw a vacuum, and the pressure in the reactor is 25Pa. At the same time, the temperature in the reactor is controlled at 1300℃ and kept warm for 10 minutes to ensure that the temperature inside the furnace reaches a uniform state. Next, the heated polysilicon carbazole will be brought into the chemical vapor deposition furnace cavity by nitrogen as a carrier gas. The heating temperature of polysilicon carbazole is controlled at 120℃. While the carrier gas continues to carry polysilicon carbazole into the cavity, hydrogen and ammonia are introduced into the furnace cavity. The volume flow ratio of nitrogen, hydrogen and ammonia is 10:5:2, and the nitrogen flow rate is controlled at 2L/min. After the reactor is kept at 1300℃ for 4 hours, a SiCN interface layer is formed on the surface of the graphene interface layer of the carbon nanotube fiber, and the thickness of the SiCN interface layer is 1.0μm. The temperature is then lowered, and the heating of the polysilicon carbazane and the introduction of ammonia and hydrogen are stopped in turn. Nitrogen is introduced throughout the entire cooling process until the temperature drops to room temperature. The sample is taken out to obtain a carbon nanotube fiber with a graphene/SiCN composite interface layer.

⑤ The carbon nanotube fibers having the graphene/SiCN composite interface layer are woven to obtain a puncture preform, and the zirconium silicon precursor solution is reacted with the puncture preform by an impregnation pyrolysis method (impregnation/curing/pyrolysis PIP process) to prepare a carbon nanotube fiber-reinforced ceramic-based composite material having a density of 2.1 g/cm ³ ; the zirconium silicon precursor solution has the zirconium silicon precursor as a solute and xylene as a solvent, and the solid content of the zirconium silicon precursor solution is 60 wt%; in each impregnation/curing/pyrolysis round, the impregnation is first performed by vacuum impregnation at a pressure of 200 Pa, and then by pressure impregnation at a pressure of 1.5 MPa, and the time for each vacuum impregnation is 1.5 h, and the time for each pressure impregnation is 1.5 h. The curing temperature is 200 ° C, and the curing time is 1 h each time. The curing is carried out in an argon atmosphere, and the pyrolysis temperature is 1400 ° C, and the pyrolysis time is 2 h each time. The pyrolysis is carried out in an argon atmosphere.

Mechanical properties test under high temperature oxygen environment: The tensile strength of the carbon nanotube fiber toughened ceramic matrix composite material prepared in this embodiment is 278MPa in an air environment of 1500°C. The room temperature thermal conductivity of the carbon nanotube fiber toughened ceramic matrix composite material prepared in this embodiment is 53W/(m·K).

Example 2

① Provide continuous carbon nanotube fibers and perform hydroxylation pretreatment to obtain hydroxylated pretreated carbon nanotube fibers; the continuous carbon nanotube fibers have a tensile strength of 4GPa, a single fiber diameter of 10μm, a continuous length of 15m, a room temperature thermal conductivity of 270W/mK, and a breaking elongation of 4.8%; the hydroxylation pretreatment is as follows: immerse the dried continuous carbon nanotube fibers in a mixed solution of 98% concentrated sulfuric acid and 30% hydrogen peroxide in a volume ratio of 7:3, and keep them in an 80°C oil bath for 1.0h. After the end, take them out and immerse them in distilled water at room temperature for 0.5h, and finally dry them to obtain hydroxylated pretreated carbon nanotube fibers.

② Preparation of graphene oxide interface layer: Prepare a graphene oxide aqueous solution with a concentration of 2.8 mg/mL, place the hydroxylated pretreated carbon nanotube fibers in the graphene oxide aqueous solution and let it stand for 30 minutes, pull out the solution to obtain carbon nanotube fibers with a graphene oxide interface layer, and the thickness of the graphene oxide interface layer is 0.23 μm.

③ Preparation of graphene interface layer by high temperature annealing technology: Place the above-mentioned carbon nanotube fiber with graphene oxide interface layer in a high temperature furnace, evacuate to 20Pa, and continuously introduce argon gas, set the annealing temperature to 1000℃, and set the holding time (annealing time) to 2h. After annealing, cool it to room temperature at a cooling rate of 0.5℃/min to obtain carbon nanotube fiber with graphene interface layer.

④Preparation of SiCN interface layer: Place the carbon nanotube fiber with graphene interface layer in a chemical vapor deposition furnace, draw a vacuum, and the pressure in the reactor is 25Pa. At the same time, the temperature in the reactor is controlled at 1300℃ and kept warm for 10 minutes to ensure that the temperature inside the furnace reaches a uniform state. Next, the heated polysilicon carbazole will be brought into the chemical vapor deposition furnace cavity by nitrogen as a carrier gas. The heating temperature of polysilicon carbazole is controlled at 120℃. While the carrier gas continues to carry polysilicon carbazole into the cavity, hydrogen and ammonia are introduced into the furnace cavity. The volume flow ratio of nitrogen, hydrogen and ammonia is 10:5:2, and the nitrogen flow rate is controlled at 2L/min. After the reactor is kept at 1300℃ for 4 hours, a SiCN interface layer is formed on the surface of the graphene interface layer of the carbon nanotube fiber, and the thickness of the SiCN interface layer is 1.0μm. The temperature is then lowered, and the heating of the polysilicon carbazane and the introduction of ammonia and hydrogen are stopped in turn. Nitrogen is introduced throughout the entire cooling process until the temperature drops to room temperature. The sample is taken out to obtain a carbon nanotube fiber with a graphene/SiCN composite interface layer.

⑤ The carbon nanotube fibers having the graphene/SiCN composite interface layer are woven to obtain a puncture preform, and the zirconium silicon precursor solution is reacted with the puncture preform by an impregnation pyrolysis method (impregnation/curing/pyrolysis PIP process) to prepare a carbon nanotube fiber-reinforced ceramic-based composite material having a density of 2.1 g/cm ³ ; the zirconium silicon precursor solution has the zirconium silicon precursor as a solute and xylene as a solvent, and the solid content of the zirconium silicon precursor solution is 60 wt%; in each impregnation/curing/pyrolysis round, the impregnation is first performed by vacuum impregnation at a pressure of 200 Pa, and then by pressure impregnation at a pressure of 1.5 MPa, and the time for each vacuum impregnation is 1.5 h, and the time for each pressure impregnation is 1.5 h. The curing temperature is 200 ° C, and the curing time is 1 h each time. The curing is carried out in an argon atmosphere, and the pyrolysis temperature is 1400 ° C, and the pyrolysis time is 2 h each time. The pyrolysis is carried out in an argon atmosphere.

Mechanical property test under high temperature aerobic environment: It was measured that the carbon nanotube fiber-reinforced ceramic-based composite material prepared in this embodiment had a tensile strength of 309 MPa under 1500° C. air environment.

Example 3

① Provide continuous carbon nanotube fibers and perform hydroxylation pretreatment to obtain hydroxylation pretreated carbon nanotube fibers; the continuous carbon nanotube fibers have a tensile strength of 4GPa, a single fiber diameter of 10μm, a continuous length of 15m, a room temperature thermal conductivity of 270W/mK, and a breaking elongation of 4.8%; the hydroxylation pretreatment is as follows: immerse the above-mentioned dried continuous carbon nanotube fibers in a mixed solution of 98% concentrated sulfuric acid and 30% hydrogen peroxide in a volume ratio of 7:3, and keep them in an 80°C oil bath for 1.0h. After the end, take them out and immerse them in distilled water at room temperature for 0.5h, and finally dry them to obtain hydroxylation pretreated carbon nanotube fibers.

②Preparation of graphene oxide interface layer: Prepare a graphene oxide aqueous solution with a concentration of 0.6 mg/mL, place the hydroxylated pretreated carbon nanotube fibers in the graphene oxide aqueous solution and let it stand for 30 minutes, pull out the solution to obtain carbon nanotube fibers with a graphene oxide interface layer, and the thickness of the graphene oxide interface layer is 0.05 μm.

③ Preparation of graphene interface layer by high temperature annealing technology: Place the carbon nanotube fiber with graphene oxide interface layer in a high temperature furnace, evacuate to 20Pa, and continuously introduce argon gas, set the annealing temperature to 1000°C, and set the holding time (annealing time) to 2h. After annealing, cool to room temperature at a cooling rate of 0.1°C/min to obtain carbon nanotube fiber with graphene interface layer.

④Preparation of SiCN interface layer: Place the carbon nanotube fiber with graphene interface layer in a chemical vapor deposition furnace, draw a vacuum, and the pressure in the reactor is 25Pa. At the same time, the temperature in the reactor is controlled at 1300℃ and kept warm for 10 minutes to ensure that the temperature inside the furnace reaches a uniform state. Next, the heated polysilicon carbazole will be brought into the chemical vapor deposition furnace cavity by nitrogen as a carrier gas. The heating temperature of polysilicon carbazole is controlled at 120℃. While the carrier gas continues to carry polysilicon carbazole into the cavity, hydrogen and ammonia are introduced into the furnace cavity. The volume flow ratio of nitrogen, hydrogen and ammonia is 10:5:2, and the nitrogen flow rate is controlled at 2L/min. After the reactor is kept at 1300℃ for 4 hours, a SiCN interface layer is formed on the surface of the graphene interface layer of the carbon nanotube fiber, and the thickness of the SiCN interface layer is 1.0μm. The temperature is then lowered, and the heating of the polysilicon carbazane and the introduction of ammonia and hydrogen are stopped in turn. Nitrogen is introduced throughout the entire cooling process until the temperature drops to room temperature. The sample is taken out to obtain a carbon nanotube fiber with a graphene/SiCN composite interface layer.

⑤ The carbon nanotube fibers having the graphene/SiCN composite interface layer are woven to obtain a puncture preform, and the zirconium silicon precursor solution is reacted with the puncture preform by an impregnation pyrolysis method (impregnation/curing/pyrolysis PIP process) to prepare a carbon nanotube fiber-reinforced ceramic-based composite material having a density of 2.1 g/cm ³ ; the zirconium silicon precursor solution has the zirconium silicon precursor as a solute and xylene as a solvent, and the solid content of the zirconium silicon precursor solution is 60 wt%; in each impregnation/curing/pyrolysis round, the impregnation is first performed by vacuum impregnation at a pressure of 200 Pa, and then by pressure impregnation at a pressure of 1.5 MPa, and the time for each vacuum impregnation is 1.5 h, and the time for each pressure impregnation is 1.5 h. The curing temperature is 200 ° C, and the curing time is 1 h each time. The curing is carried out in an argon atmosphere, and the pyrolysis temperature is 1400 ° C, and the pyrolysis time is 2 h each time. The pyrolysis is carried out in an argon atmosphere.

Mechanical property test under high temperature aerobic environment: It was measured that the carbon nanotube fiber-reinforced ceramic-based composite material prepared in this embodiment had a tensile strength of 295 MPa under 1500° C. air environment.

Example 4

① Provide continuous carbon nanotube fibers and perform hydroxylation pretreatment to obtain hydroxylation pretreated carbon nanotube fibers; the continuous carbon nanotube fibers have a tensile strength of 4GPa, a single fiber diameter of 10μm, a continuous length of 15m, a room temperature thermal conductivity of 270W/mK, and a breaking elongation of 4.8%; the hydroxylation pretreatment is as follows: immerse the above-mentioned dried continuous carbon nanotube fibers in a mixed solution of 98% concentrated sulfuric acid and 30% hydrogen peroxide in a volume ratio of 7:3, and keep them in an 80°C oil bath for 1.0h. After the end, take them out and immerse them in distilled water at room temperature for 0.5h, and finally dry them to obtain hydroxylation pretreated carbon nanotube fibers.

②Preparation of graphene oxide interface layer: Prepare a graphene oxide aqueous solution with a concentration of 0.6 mg/mL, place the hydroxylated pretreated carbon nanotube fibers in the graphene oxide aqueous solution and let it stand for 30 minutes, pull out the solution to obtain carbon nanotube fibers with a graphene oxide interface layer, and the thickness of the graphene oxide interface layer is 0.05 μm.

③ Preparation of graphene interface layer by high temperature annealing technology: Place the above-mentioned carbon nanotube fiber with graphene oxide interface layer in a high-temperature furnace, evacuate to 20Pa, and continuously introduce argon gas, set the annealing temperature to 1000°C, and set the holding time (annealing time) to 2h. After annealing is completed, cool it to room temperature at a cooling rate of 0.5°C/min to obtain carbon nanotube fiber with graphene interface layer.

④Preparation of SiCN interface layer: Place the carbon nanotube fiber with graphene interface layer in a chemical vapor deposition furnace, draw a vacuum, and the pressure in the reactor is 25Pa. At the same time, the temperature in the reactor is controlled at 1300℃ and kept warm for 10 minutes to ensure that the temperature inside the furnace reaches a uniform state. Next, the heated polysilicon carbazole will be brought into the cavity by nitrogen as a carrier gas. The heating temperature of polysilicon carbazole is controlled at 120℃. While the carrier gas continues to carry polysilicon carbazole into the cavity, hydrogen and ammonia are introduced into the furnace cavity. The volume flow ratio of nitrogen, hydrogen and ammonia is 10:5:2, and the nitrogen flow rate is controlled at 1L/min. After the reactor is kept at 1300℃ for 4 hours, a SiCN interface layer is formed on the surface of the graphene interface layer of the carbon nanotube fiber, and the thickness of the SiCN interface layer is 0.6μm. The temperature is then lowered, and the heating of the polysilicon carbazane and the introduction of ammonia and hydrogen are stopped in turn. Nitrogen is introduced throughout the entire cooling process until the temperature drops to room temperature. The sample is taken out to obtain a carbon nanotube fiber with a graphene/SiCN composite interface layer.

⑤ The carbon nanotube fibers having the graphene/SiCN composite interface layer are woven to obtain a puncture preform, and the zirconium silicon precursor solution is reacted with the puncture preform by an impregnation pyrolysis method (impregnation/curing/pyrolysis PIP process) to prepare a carbon nanotube fiber-reinforced ceramic-based composite material having a density of 2.1 g/cm ³ ; the zirconium silicon precursor solution has the zirconium silicon precursor as a solute and xylene as a solvent, and the solid content of the zirconium silicon precursor solution is 60 wt%; in each impregnation/curing/pyrolysis round, the impregnation is first performed by vacuum impregnation at a pressure of 200 Pa, and then by pressure impregnation at a pressure of 1.5 MPa, and the time for each vacuum impregnation is 1.5 h, and the time for each pressure impregnation is 1.5 h. The curing temperature is 200 ° C, and the curing time is 1 h each time. The curing is carried out in an argon atmosphere, and the pyrolysis temperature is 1400 ° C, and the pyrolysis time is 2 h each time. The pyrolysis is carried out in an argon atmosphere.

Mechanical property test under high temperature aerobic environment: It was measured that the carbon nanotube fiber-reinforced ceramic-based composite material prepared in this embodiment had a tensile strength of 253 MPa under 1500° C. air environment.

It can be seen from the above-mentioned Examples 1 to 4 that, compared with Example 1, when preparing the graphene oxide interface layer in Example 2, the graphene oxide concentration is increased from 0.6 mg/mL to 2.8 mg/mL, so that the thickness of the graphene oxide interface layer is increased from 0.05 μm to 0.23 μm, which significantly improves the mechanical properties of the final ceramic-based composite material, and the tensile strength in an air environment of 1500°C is increased from 278 MPa to 309 MPa. Compared with Example 1, when preparing the graphene interface layer in Example 3, the high-temperature annealing rate is reduced from 0.5°C/min to 0.1°C/min, so that the graphene interface layer has a better lamination effect, and the bonding strength between the carbon nanotube fiber and the graphene interface layer is further improved, which significantly improves the mechanical properties of the final ceramic-based composite material, and the tensile strength in an air environment of 1500°C is increased from 278 MPa to 295 MPa. Compared with Example 1, when preparing the SiCN interface layer in Example 4, the nitrogen flow rate is reduced from 2 L/min to 1 L/min, so that the thickness of the SiCN interface layer is reduced from 1.0 μm to 0.6 μm, resulting in a decrease in the antioxidant ability of the composite material. This also significantly reduces the mechanical properties of the final ceramic-based composite material, and the tensile strength in an air environment of 1500°C is reduced from 278 MPa to 253 MPa.

Embodiments 5 to 11

The specific process parameters of Examples 5 to 11 and the performance indicators of the finally prepared ceramic-based composite materials are shown in Table 1. The other preparation processes are the same as those of Example 1.

As can be seen from Table 1, compared with Example 1, when preparing the graphene oxide interface layer in Example 5, the graphene oxide concentration is reduced from 0.6mg/mL to 0.5mg/mL, so that the thickness of the graphene oxide interface layer is reduced from 0.05μm to 0.03μm, resulting in that the graphene interface layer in some areas may not be completely covered, which makes the final ceramic-based composite material mechanical properties decrease, and the tensile strength in an air environment of 1500℃ decreases from 278MPa to 186MPa. Compared with Example 1, when preparing the graphene oxide interface layer in Example 6, the graphene oxide concentration is increased from 0.6mg/mL to 8mg/mL, although the thickness of the graphene oxide interface layer can be increased from 0.05μm to 0.65μm, but the graphene oxide is too aggregated, and its self-assembly lamination effect is poor, and it is impossible to obtain a high-quality and complete graphene oxide interface layer, which makes the final ceramic-based composite material mechanical properties decrease, and the tensile strength in an air environment of 1500℃ decreases from 278MPa to 233MPa. Compared with Example 1, when preparing the graphene interface layer in Example 7, the high temperature annealing rate is increased from 0.5°C/min to 2°C/min, resulting in poor lamination effect of the graphene interface layer, and the bonding strength between the carbon nanotube fiber and the graphene interface layer is extremely weak, which reduces the mechanical properties of the final ceramic matrix composite material, and the tensile strength in an air environment of 1500°C is reduced from 278MPa to 143MPa. Compared with Example 1, when preparing the SiCN interface layer in Example 8, the deposition temperature is reduced from 1300°C to 1000°C, resulting in insufficient cracking of the SiCN precursor and failure to form a stable SiCN interface layer, resulting in poor mechanical properties of the final ceramic matrix composite material, and the tensile strength in an air environment of 1500°C is reduced from 278MPa to 208MPa. Compared with Example 1, when preparing the SiCN interface layer in Example 9, the deposition temperature is increased from 1300°C to 1600°C, resulting in the thermal decomposition of SiCN to form substances such as Si ₃ N ₄ , and the antioxidant performance is reduced, resulting in poor mechanical properties of the final ceramic matrix composite material, and the tensile strength in an air environment at 1500°C is reduced from 278MPa to 221MPa. Compared with Example 1, when preparing the SiCN interface layer in Example 10, the volume flow ratio of nitrogen, hydrogen and ammonia is reduced from 10:5:2 to 10:5:0.5, resulting in the conversion of SiCN into SiC, affecting the high-temperature mechanical properties of the composite material, and the tensile strength in an air environment at 1500°C is reduced from 278MPa to 243MPa. Compared with Example 1, in Example 11, when preparing the SiCN interface layer, the flow ratio of nitrogen, hydrogen and ammonia was increased from 10:5:2 to 10:5:5, resulting in the conversion of SiCN into Si ₃ N ₄ , which also affected the high temperature mechanical properties of the composite material, and the tensile strength in an air environment at 1500°C was reduced from 278MPa to 196MPa.

Comparative Example 1

① Provide continuous carbon nanotube fibers and perform hydroxylation pretreatment to obtain hydroxylation pretreated carbon nanotube fibers; the continuous carbon nanotube fibers have a tensile strength of 4GPa, a single fiber diameter of 10μm, a continuous length of 15m, a room temperature thermal conductivity of 270W/mK, and a breaking elongation of 4.8%; the hydroxylation pretreatment is as follows: immerse the above-mentioned dried continuous carbon nanotube fibers in a mixed solution of 98% concentrated sulfuric acid and 30% hydrogen peroxide in a volume ratio of 7:3, and keep them in an 80°C oil bath for 1.0h. After the end, take them out and immerse them in distilled water at room temperature for 0.5h, and finally dry them to obtain hydroxylation pretreated carbon nanotube fibers.

②Preparation of graphene oxide interface layer: Prepare a graphene oxide aqueous solution with a concentration of 0.6 mg/mL, place the hydroxylated pretreated carbon nanotube fibers in the graphene oxide aqueous solution and let it stand for 30 minutes, pull out the solution to obtain carbon nanotube fibers with a graphene oxide interface layer, and the thickness of the graphene oxide interface layer is 0.05 μm.

③ Preparation of graphene interface layer by high temperature annealing technology: Place the above-mentioned carbon nanotube fiber with graphene oxide interface layer in a high-temperature furnace, evacuate to 20Pa, and continuously introduce argon gas, set the annealing temperature to 1000°C, and set the holding time (annealing time) to 2h. After annealing is completed, cool it to room temperature at a cooling rate of 0.5°C/min to obtain carbon nanotube fiber with graphene interface layer.

④ The carbon nanotube fibers with a graphene interface layer are woven to obtain a puncture preform, and the zirconium silicon precursor solution is reacted with the puncture preform by an impregnation pyrolysis method (impregnation/curing/pyrolysis PIP process) to prepare a ceramic-based composite material with a density of 2.1 g/ ^cm3 ; the zirconium silicon precursor solution has a zirconium silicon precursor as a solute and xylene as a solvent, and the solid content of the zirconium silicon precursor solution is 60wt%; in each impregnation/curing/pyrolysis round, the impregnation is first performed by vacuum impregnation at a pressure of 200Pa, and then by pressure impregnation at a pressure of 1.5MPa, and the time for each vacuum impregnation is 1.5h, and the time for each pressure impregnation is 1.5h. The curing temperature is 200°C, and the curing time is 1h each time. The curing is carried out in an argon atmosphere. The pyrolysis temperature is 1400°C, and the pyrolysis time is 2h each time. The pyrolysis is carried out in an argon atmosphere.

Mechanical property test under high temperature aerobic environment: It was measured that the ceramic-based composite material prepared in this comparative example had a tensile strength of 72 MPa under 1500°C air environment.

Comparative Example 2

① Providing continuous carbon nanotube fibers; the continuous carbon nanotube fibers have a tensile strength of 4 GPa, a single filament diameter of 10 μm, a continuous length of 15 m, a room temperature thermal conductivity of 270 W/mK, and an elongation at break of 4.8%.

②Preparation of SiCN interface layer: The continuous carbon nanotube fiber is placed in a chemical vapor deposition furnace, and a vacuum is drawn. The pressure in the reactor is 25Pa. At the same time, the temperature in the reactor is controlled at 1300℃, and the temperature is kept for 10 minutes to ensure that the temperature inside the furnace reaches a uniform state. Next, the heated polysilicon carbon azane will be brought into the cavity by nitrogen as a carrier gas. The heating temperature of polysilicon carbon azane is controlled at 120℃. While the carrier gas continues to carry polysilicon carbon azane into the cavity, hydrogen and ammonia are introduced into the furnace cavity. The volume flow ratio of nitrogen, hydrogen and ammonia is 10:5:2, and the nitrogen flow rate is controlled at 2L/min. After the reactor is kept at 1300℃ for 4 hours, a SiCN interface layer is formed on the surface of the carbon nanotube fiber, and the thickness of the SiCN interface layer is 1.0μm. The temperature is then lowered, and the heating of the polysilicon carbazane and the introduction of ammonia and hydrogen are stopped in turn. Nitrogen is introduced throughout the entire cooling process until the temperature drops to room temperature. The sample is taken out to obtain a carbon nanotube fiber with a SiCN interface layer.

③ The carbon nanotube fibers with the SiCN interface layer are woven to obtain a puncture preform, and the zirconium silicon precursor solution is reacted with the puncture preform by an impregnation pyrolysis method (impregnation/curing/pyrolysis PIP process) to prepare a ceramic-based composite material with a density of 2.1 g/ ^cm3 ; the zirconium silicon precursor solution has the zirconium silicon precursor as the solute and xylene as the solvent, and the solid content of the zirconium silicon precursor solution is 60wt%; in each impregnation/curing/pyrolysis round, the impregnation is first performed by vacuum impregnation, the vacuum impregnation pressure is 200Pa, and then the pressure impregnation is performed by pressure impregnation, the pressure of the pressure impregnation is 1.5MPa, the time of each vacuum impregnation is 1.5h, the time of each pressure impregnation is 1.5h, the temperature of the curing is 200°C, the time of each curing is 1h, the curing is carried out in an argon atmosphere, the temperature of the pyrolysis is 1400°C, the time of each pyrolysis is 2h, and the pyrolysis is carried out in an argon atmosphere.

Mechanical property test under high temperature aerobic environment: The ceramic-based composite material prepared in this comparative example was measured to have a tensile strength of 119 MPa under 1500°C air environment.

Comparative Example 3

①Same as step ① of Example 1.

②Same as step ② of Example 1.

③ is the same as step ③ of Example 1.

④ Preparation of pyrolytic carbon interface layer: placing the carbon nanotube fiber with a graphene interface layer in a chemical vapor deposition furnace, and depositing the pyrolytic carbon interface layer on the surface of the graphene interface layer of the carbon nanotube fiber by chemical vapor deposition in an atmosphere containing argon and methane gas at 1000°C and 25Pa, wherein the thickness of the pyrolytic carbon interface layer is 1.0 μm, to obtain a carbon nanotube fiber with a graphene/pyrolytic carbon composite interface layer; wherein the volume flow ratio of argon and methane gas is 1:1.

⑤ The carbon nanotube fibers having the graphene/pyrolytic carbon composite interface layer are woven to obtain a puncture preform, and the zirconium silicon precursor solution is reacted with the puncture preform by an impregnation pyrolysis method (impregnation/curing/pyrolysis PIP process) to prepare a ceramic-based composite material with a density of 2.1 g/cm ³ ; the zirconium silicon precursor solution has the zirconium silicon precursor as the solute and xylene as the solvent, and the solid content of the zirconium silicon precursor solution is 60 wt%; in each impregnation/curing/pyrolysis round, the impregnation is first performed by vacuum impregnation at a pressure of 200 Pa, and then by pressure impregnation at a pressure of 1.5 MPa, and the time for each vacuum impregnation is 1.5 h, and the time for each pressure impregnation is 1.5 h. The curing temperature is 200 ° C, and the curing time is 1 h each time. The curing is carried out in an argon atmosphere, and the pyrolysis temperature is 1400 ° C, and the pyrolysis time is 2 h each time. The pyrolysis is carried out in an argon atmosphere.

Mechanical property test under high temperature aerobic environment: The ceramic-based composite material prepared in this comparative example was measured to have a tensile strength of 95 MPa under 1500°C air environment.

Comparative Example 4

①Same as step ① of Example 1.

②Same as step ② of Example 1.

③ is the same as step ③ of Example 1.

④ Preparation of SiC interface layer: The carbon nanotube fiber with a graphene interface layer is placed in a chemical vapor deposition furnace, and a silicon carbide interface layer (SiC interface layer) is deposited on the surface of the graphene interface layer of the carbon nanotube fiber by chemical vapor deposition in an atmosphere containing trichloromethylsilane, hydrogen and argon (the volume flow ratio of trichloromethylsilane, hydrogen and argon is 1:2:10) at 1050°C and 25Pa. The thickness of the silicon carbide interface layer is 1.0 μm, and a carbon nanotube fiber with a graphene/silicon carbide composite interface layer is obtained.

⑤ The carbon nanotube fibers having the graphene/silicon carbide composite interface layer are woven to obtain a puncture preform, and the zirconium silicon precursor solution is reacted with the puncture preform by an impregnation pyrolysis method (impregnation/curing/pyrolysis PIP process) to prepare a ceramic-based composite material with a density of 2.1 g/cm ³ ; the zirconium silicon precursor solution has the zirconium silicon precursor as a solute and xylene as a solvent, and the solid content of the zirconium silicon precursor solution is 60 wt%; in each impregnation/curing/pyrolysis round, the impregnation is first performed by vacuum impregnation at a pressure of 200 Pa, and then by pressure impregnation at a pressure of 1.5 MPa, and the time for each vacuum impregnation is 1.5 h, and the time for each pressure impregnation is 1.5 h. The curing temperature is 200 ° C, and the curing time is 1 h each time. The curing is carried out in an argon atmosphere, and the pyrolysis temperature is 1400 ° C, and the pyrolysis time is 2 h each time. The pyrolysis is carried out in an argon atmosphere.

Mechanical property test under high temperature aerobic environment: The ceramic-based composite material prepared in this comparative example was measured to have a tensile strength of 231 MPa under 1500°C air environment.

Parts of the present invention that are not described in detail are well known to those skilled in the art.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (10)

1. The preparation method of the carbon nanotube fiber toughened ceramic matrix composite is characterized by comprising the following steps of:

(1) Providing continuous carbon nano tube fibers and carrying out hydroxylation pretreatment to obtain hydroxylation pretreatment carbon nano tube fibers;

(2) Preparing graphene oxide aqueous solution, and then soaking the hydroxylation pretreatment carbon nanotube fiber in the graphene oxide aqueous solution to obtain the carbon nanotube fiber with a graphene oxide interface layer;

(3) Annealing the carbon nanotube fiber with the graphene oxide interface layer, and cooling to room temperature to obtain the carbon nanotube fiber with the graphene oxide interface layer;

(4) Depositing SiCN interface layers on the surfaces of the graphene interface layers of the carbon nanotube fibers with the graphene interface layers by using polysilocarb as a precursor through a chemical vapor deposition method to obtain the carbon nanotube fibers with the graphene/SiCN composite interface layers;

(5) And weaving the carbon nano tube fiber with the graphene/SiCN composite interface layer into a preform, and reacting a ceramic precursor with the preform by a dipping cracking method to prepare the carbon nano tube fiber toughened ceramic matrix composite.

2. The method of manufacturing according to claim 1, characterized in that:

the continuous carbon nanotube fiber has a tensile strength of not less than 3GPa, a filament diameter of 8-15 μm, a continuous length of not less than 10m, a room temperature thermal conductivity of not less than 200W/(m.K), and/or an elongation at break of not less than 4%.

3. The method of manufacturing according to claim 1, characterized in that:

the hydroxylation pretreatment is to soak the continuous carbon nano tube fiber in a volume ratio of (6-8): and (2) preserving heat for 0.5-1.5 h at 75-88 ℃ in the mixed solution of the concentrated sulfuric acid and the hydrogen peroxide in the (2-4), and then soaking and drying in distilled water to obtain the hydroxylation pretreatment carbon nano tube fiber.

4. The method of manufacturing according to claim 1, characterized in that:

in the step (2), the concentration of the graphene oxide aqueous solution is 0.6-6.0 mg/mL;

in the step (2), the soaking time is 10-60 min; and/or

The thickness of the graphene oxide interface layer is 0.05-0.5 mu m.

5. The method of claim 1, wherein in step (3):

the temperature of the annealing treatment is 800-1000 ℃, and the time of the annealing treatment is 1-5 h; and/or

The cooling rate is not more than 1 ℃/min.

6. The method of claim 1, wherein in step (4):

heating polysilocarb, introducing nitrogen into a chemical vapor deposition furnace through carrier gas, and simultaneously introducing hydrogen and ammonia into the chemical vapor deposition furnace to deposit the SiCN interface layer; wherein, the volume flow ratio of nitrogen, hydrogen and ammonia is 10:5: (1-4).

7. The method of manufacturing according to claim 6, wherein:

the heating temperature of the polysilocarb is 110-150 ℃; and/or

The temperature of the SiCN interface layer is 1200-1500 ℃, the time is 3.5-5 h, and the pressure in the chemical vapor deposition furnace is 10-150 Pa.

8. The method of manufacture of claim 1, wherein:

the thickness of the SiCN interface layer is 0.3-1.0 mu m.

9. The production method according to any one of claims 1 to 8, characterized in that:

the ceramic precursor is one or more of a zirconium silicon precursor, a silicon carbide precursor, a zirconium carbide precursor and a hafnium carbide precursor; and/or

The density of the ceramic matrix composite toughened by the carbon nano tube fiber is 2.0-2.5 g/cm ³ 。

10. A carbon nanotube fiber-toughened ceramic matrix composite made by the method of any of claims 1 to 9.