CN112299865A - A kind of modified C/SiC composite material and preparation method thereof - Google Patents

Abstract

Translated fromChinese

本发明涉及一种改性C/SiC复合材料及其制备方法。所述方法包括如下步骤：(1)在碳纤维预制体中含有的碳纤维表面沉积碳界面层，得到多孔C/C复合材料预制体；(2)将所述多孔C/C复合材料预制体置于硅粉中进行熔渗反应，得到C/SiC复合材料；(3)以液态SiBCN前驱体作为浸渍液通过浸渍/固化/裂解的PIP工艺对所述C/SiC复合材料进行基体致密化，得到改性C/SiC复合材料。本发明制备改性C/SiC复合材料的工艺简单，周期短，且能获得致密度高、力学性能优异、耐烧蚀性能优异的复合材料。The invention relates to a modified C/SiC composite material and a preparation method thereof. The method includes the following steps: (1) depositing a carbon interface layer on the surface of the carbon fiber contained in the carbon fiber preform to obtain a porous C/C composite material preform; (2) placing the porous C/C composite material preform on the surface of the carbon fiber preform. The infiltration reaction is carried out in the silicon powder to obtain a C/SiC composite material; (3) the matrix densification of the C/SiC composite material is carried out by using the liquid SiBCN precursor as the impregnating liquid through the PIP process of dipping/curing/cracking, and the improved C/SiC composite material is obtained. Properties of C/SiC composites. The process for preparing the modified C/SiC composite material is simple, the cycle is short, and the composite material with high density, excellent mechanical properties and excellent ablation resistance can be obtained.

Description

Modified C/SiC composite material and preparation method thereof

Technical Field

The invention belongs to the technical field of aerospace composite material preparation, and particularly relates to a modified C/SiC composite material and a preparation method thereof.

Background

The C/SiC composite material has a series of excellent performances of low density, large specific strength, high fracture toughness and the like, and is widely applied to the fields of aviation, aerospace, metallurgy and the like. However, the preparation cost of the C/SiC composite material is high, and the mechanical property of the C/SiC composite material at a high temperature of 1600 ℃ is insufficient, so that the performance potential of the C/SiC composite material is seriously limited. With the continuous development of aerospace technology, higher requirements are put forward on the high-temperature mechanical properties of the C/SiC composite material.

For the same preform, the improvement of the mechanical property after densification mainly depends on the densification degree of the material, so that the improvement of the density of the material is very important for improving the mechanical property of the material. But simultaneously, the high-temperature oxidation resistance is required to be met, and the matrix modification is realized by a precursor impregnation cracking method (PIP process) through repeated precursor impregnation cracking processes. However, this method is costly and has a long densification cycle. The reaction infiltration method (RMI process) is characterized in that a metal melt is infiltrated into pores of a porous C/C composite material preform under the action of capillary force at high temperature to react with pyrolytic carbon in the preform to generate a high-temperature-resistant ceramic phase, the infiltration of the metal melt and the reaction of the infiltrated metal melt and the pyrolytic carbon are included, the preparation period of the C/SiC composite material can be effectively shortened through in-situ reaction, and although the preparation period of the C/SiC composite material can be shortened through the reaction infiltration process, the high-temperature ablation resistance of the prepared C/SiC composite material is lower.

At present, the C/SiC composite material prepared by adopting a single process is difficult to simultaneously meet the requirements of short preparation period, high density of the prepared composite material, and excellent ablation resistance and mechanical property. Chinese patent application CN111454073A discloses a preparation method of a high-heat-conductivity, strong-bonding and ablation-resistant ultrahigh-temperature ceramic matrix composite, which comprises the steps of firstly introducing a carbon source and a ceramic phase into a carbon fiber preform by a sol-gel method, a slurry impregnation method or a precursor impregnation cracking method, and then combining a reaction infiltration method to realize densification. In CN111454073A, a precursor impregnation cracking process is firstly carried out, then a reaction infiltration process is carried out, the prepared composite material has high surface layer open porosity, the densification degree is not as good as that of a PIP process, metal is easily remained, the oxidation resistance of the material is easily attenuated during high-temperature ablation, and oxygen permeates into pores to further damage fibers.

Disclosure of Invention

In order to solve the technical problems in the prior art, the invention provides a modified C/SiC composite material and a preparation method thereof. The method takes a needled carbon fiber preform as a reinforcement, prepares a C/SiC composite material by a reaction infiltration method, and then carries out an impregnation cracking process by using a SiBCN precursor; compared with the traditional PIP method, the preparation period of the C/SiC composite material at the early stage is greatly reduced, and the prepared modified C/SiC composite material has excellent ablation resistance and mechanical property.

The invention provides in a first aspect a process for the preparation of a modified C/SiC composite material, the process comprising the steps of:

(1) depositing a carbon interface layer on the surface of carbon fibers contained in the carbon fiber preform to obtain a porous C/C composite material preform;

(2) putting the porous C/C composite material prefabricated body into silicon powder for infiltration reaction to obtain a C/SiC composite material;

(3) and carrying out matrix densification on the C/SiC composite material by using a liquid SiBCN precursor as an impregnation liquid through a PIP (poly-p-phenylene-imide) process of impregnation/curing/cracking to obtain the modified C/SiC composite material.

Preferably, in the step (1), a carbon interface layer is deposited on the surface of the carbon fiber contained in the carbon fiber preform by a chemical vapor infiltration method at a temperature of 800 to 1200 ℃ by using propylene as a carbon source gas and nitrogen as a carrier gas.

Preferably, the density of the porous C/C composite material preform is 1.0-1.6 g/cm³。

Preferably, in the step (2), the temperature of the infiltration reaction is 1600-1700 ℃, and the time of the infiltration reaction is 1.5-2.5 h.

Preferably, in the step (3), the temperature of the pyrolysis is 600-1200 ℃, and the pyrolysis time is 2-3 h.

Preferably, the PIP process of impregnation/curing/cracking is repeated until the weight gain of the resulting modified C/SiC composite is less than 1%.

Preferably, the PIP process of impregnation/curing/cracking comprises the following sub-steps:

(a) putting the C/SiC composite material obtained in the step (2) into a vacuum bag, and taking the liquid SiBCN precursor as impregnation liquid for vacuum impregnation;

(b) putting the vacuum bag filled with the C/SiC composite material vacuum-impregnated with the liquid SiBCN precursor into a curing tank to carry out in-situ curing on the C/SiC composite material vacuum-impregnated with the liquid SiBCN precursor, so as to obtain a carbon fiber reinforced ceramic matrix composite material;

(c) taking the carbon fiber reinforced ceramic matrix composite out of the vacuum bag and then placing the composite in a cracking furnace for medium-pressure cracking; the pressure of the medium-pressure cracking is 3MPa to 6 MPa.

Preferably, the vacuum impregnation time is 1.5-3 h.

Preferably, the temperature of the in-situ curing is 180-280 ℃, and the time of the in-situ curing is 3-6 h; and/or performing the medium-pressure cracking in a nitrogen atmosphere or an argon atmosphere, wherein the temperature of the medium-pressure cracking is 600-1200 ℃, and the time of the medium-pressure cracking is 2-3 h.

The present invention provides, in a second aspect, a modified C/SiC composite material obtained by the production method according to the first aspect of the invention.

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

(1) the invention adopts a reaction infiltration method (RMI method) to prepare the C/SiC composite material firstly, and then prepares the modified C/SiC composite material by a precursor impregnation pyrolysis method (PIP method). Compared with the traditional PIP method, the preparation period of the material is greatly reduced, and the material has excellent mechanical properties; compared with the traditional RMI method, the ablation resistance of the material is obviously improved.

(2) The preparation method of the modified C/SiC composite material has the advantages of simple process and short period, and the composite material with high density, excellent mechanical property and excellent ablation resistance can be obtained.

(3) In some preferred embodiments of the present invention, the PIP process of vacuum impregnation/in-situ curing/medium pressure cracking is adopted for the densification of the matrix, the in-situ curing process is adopted to avoid the outflow of the liquid SiBCN precursor during the curing process, improve the impregnation depth and the impregnation efficiency, and the medium pressure cracking process is adopted to reduce the matrix cracks, significantly reduce the porosity of the composite material, and further improve the mechanical properties of the composite material.

Detailed Description

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

The invention provides in a first aspect a process for the preparation of a modified C/SiC composite material, the process comprising the steps of:

(1) depositing a carbon interface layer on the surface of carbon fibers contained in the carbon fiber preform to obtain a porous C/C composite material preform; in the present invention, the carbon fiber preform is, for example, a needle-punched carbon fiber preform;

(2) putting the porous C/C composite material prefabricated body into silicon powder for infiltration reaction to obtain a C/SiC composite material; in the invention, for example, the porous C/C composite material preform is placed in a graphite crucible, a proper amount of Si powder is taken and embedded, the graphite crucible is heated to 1600-1700 ℃, then the temperature is kept for 2h, the furnace is cooled after the power supply is cut off, and Si reacts and infiltrates to prepare the C/SiC composite material in the process;

(3) carrying out matrix densification on the C/SiC composite material by using a liquid SiBCN precursor (liquid polyborosilazane) as an impregnation liquid through a PIP (poly-p-phenylene-silicon-nitrogen) process of impregnation/curing/cracking to obtain a modified C/SiC composite material; in the invention, the parameters of the dipping mode and time, the curing temperature and time, the cracking temperature and time and the like can be the dipping parameters, the curing parameters and the cracking parameters related to the PIP process by taking the liquid SiBCN precursor as dipping liquid; in the invention, the liquid SiBCN precursor refers to liquid polyborosilazane.

In the invention, the obtained modified C/SiC composite material is a modified C/C-SiC composite material, and the C/C-SiC composite material comprises carbon fibers, a carbon interface layer (C interface layer), a C matrix, a SiC matrix and a SiBCN matrix; the SiBCN has better wettability, so that the ceramic matrix prepared after cracking is more compact than the SiC matrix. In the present invention, the modified C/SiC composite material is also referred to as a modified C/C-SiC composite material or a modified carbon fiber-reinforced carbon-silicon carbide composite material.

Although the PIP process and the RMI process are well known to be commonly used for preparing C/SiC composite materials, the PIP process has the problems of high cost, long densification period and the like, and the C/SiC composite materials prepared by the RMI process have the problem of low ablation resistance, no relevant report of combining the PIP process and the RMI process for preparing the C/SiC composite materials is found in the prior art, which is probably because the PIP process and the RMI process for preparing the C/SiC composite materials are mature, and most researchers are concerned with improving the mechanical property or the ablation resistance of the C/SiC composite materials by means of interface modification or ultrahigh-temperature ceramic modification. The method of the invention does not only combine the RMI process and the PIP process to prepare the C/SiC composite material, but firstly adopts a reaction infiltration method to prepare the C/SiC composite material, and then adopts a precursor impregnation pyrolysis method to modify the surface matrix of the SiBCN precursor through a liquid SiBCN precursor, so as to prepare the modified C/SiC composite material modified by the SiBCN, thereby effectively improving the ablation resistance of the surface layer material, and simultaneously, the mechanical property is obviously improved due to the improvement of the densification degree; in addition, compared with the traditional PIP method, the preparation period of the C/SiC composite material at the early stage is greatly reduced, the modified C/SiC composite material with the weight gain of less than 1% can be obtained by repeating the PIP process in the step (3) for 1-3 times, and the material with the weight gain of less than 1% can be obtained by repeating the precursor dipping and cracking process for 6-10 times if the traditional PIP method is adopted to prepare the C/SiC composite material. More importantly, the invention discovers that the modified C/SiC composite material with excellent mechanical property and ablation resistance can be ensured only by sequentially carrying out the steps (2) and (3), namely, firstly preparing the C/SiC composite material by a reaction infiltration method and then carrying out a PIP process by taking a liquid SiBCN precursor as an impregnation liquid, the bending strength of the prepared modified C/SiC composite material is even higher than the sum of the bending strength of the C/SiC composite material prepared by a single PIP process and a single RMI process, which is unexpected, and if the porous C/C composite material preform is firstly subjected to the PIP process by taking the liquid SiBCN precursor as the impregnation liquid and then subjected to the reaction infiltration process, the mechanical property and the ablation resistance of the prepared composite material are reduced, even lower than the mechanical property and ablation resistance of the C/SiC composite material prepared by a single PIP process and a single RMI process.

According to some preferred embodiments, in the step (1), a carbon interface layer is deposited on the surface of the carbon fiber contained in the carbon fiber preform by a chemical vapor infiltration method (CVI process) at a temperature of 800 to 1200 ℃, preferably 1000 ℃, using propylene as a carbon source gas and nitrogen as a carrier gas; specifically, for example, a carbon fiber preform is needled, and a carbon fiber preform blank is placed in a chemical vapor deposition furnace to obtain a porous C/C composite material preform; chemical deposition is carried out on a carbon fiber preform body by using a CVI (chemical vapor infiltration) process, a carbon source gas is cracked in a low vacuum environment and then is diffused into pores of the preform body and is deposited on the pore walls to obtain a porous C/C composite material preform, and the porous C/C composite material preform is preferably deposited until the density is 1.0-1.6 g/cm³The densification process preferably uses propylene as a carbon source gas and nitrogen as a carrier gas, and the deposition temperature is 1000 ℃.

According to some preferred embodiments, the porous C/C composite preform has a density of 1.0 to 1.6g/cm³Preferably 1.3g/cm³(ii) a In the invention, the density of the porous C/C composite material preform is preferably 1.0-1.6 g/cm³This is because, the present inventors found that, as the deposition density increases, the mechanical properties of the finally prepared modified C/SiC composite material can be improved, and when the density of the porous C/C composite material preform is 1.3g/cm³In time, the ablation resistance is most excellent; the invention discovers that when the content of the carbon matrix is too low, the excessive silicon can react with the carbon fiber to cause the damage of the fiber, thereby causing the reduction of the mechanical property, and as the density of the carbon matrix is increased, the content of the SiC matrix in the prepared material is increased, the ablation resistance of the material is improved, but the density is more than 1.3g/cm³Thereafter, the residual silicon content increases after densification, resulting in SiO formation of silicon and oxygen at high temperatures₂The gas escapes from the surface layer of the material, so that a channel is provided for further permeation of oxygen, and the ablation resistance of the finally prepared modified C/SiC composite material is reduced.

According to some preferred embodiments, in the step (2), the temperature of the infiltration reaction is 1600 to 1700 ℃ (for example 1600 ℃, 1650 ℃ or 1700 ℃), and the time of the infiltration reaction is 1.5 to 2.5h (for example 1.5, 2 or 2.5h), preferably 2 h.

According to some preferred embodiments, in step (3), the temperature of the cleavage is preferably 600 to 1000 ℃ (e.g., 600 ℃, 650 ℃, 700 ℃, 750 ℃, 800 ℃, 850 ℃, 900 ℃, 950 ℃, 1000 ℃, 1050 ℃, 1100 ℃, 1150 ℃ or 1200 ℃) and the time of the cleavage is 2 to 3 hours (e.g., 2, 2.5 or 3 hours); in the invention, the cracking temperature is more preferably 600-1000 ℃, and more preferably 1000 ℃, because the invention finds that if the cracking temperature is too low, the yield of the precursor ceramic is low, the ablation resistance of the material is affected, and if the cracking temperature is too high, the fiber is damaged, and the mechanical property of the material is affected, and through a large number of tests, the invention finds that with the increase of the cracking temperature of the SiBCN precursor, the bending strength of the modified C/SiC composite material is increased and then decreased, the ablation resistance of the modified C/SiC composite material is continuously improved, and after the cracking temperature is higher than 1000 ℃, the linear ablation rate is stable, and therefore, the cracking temperature is most preferably 1000 ℃.

According to some preferred embodiments, the PIP process of impregnation/curing/cracking is repeated until the weight gain of the resulting modified C/SiC composite is less than 1%; in the invention, if the dipping, curing and cracking processes are carried out once and the requirement of weight increase of less than 1% cannot be met, the dipping, curing and cracking processes are repeated until the requirement is met.

According to some preferred embodiments, the PIP process of impregnation/curing/cracking comprises the following sub-steps:

(a) putting the C/SiC composite material obtained in the step (2) into a vacuum bag, and taking the liquid SiBCN precursor as impregnation liquid for vacuum impregnation; in the invention, for example, after the C/SiC composite material is placed in a vacuum bag and vacuumized, a liquid SiBCN precursor is sucked for vacuum impregnation;

(b) putting the vacuum bag filled with the C/SiC composite material vacuum-impregnated with the liquid SiBCN precursor into a curing tank to carry out in-situ curing on the C/SiC composite material vacuum-impregnated with the liquid SiBCN precursor, so as to obtain a carbon fiber reinforced ceramic matrix composite material;

(c) taking the carbon fiber reinforced ceramic matrix composite out of the vacuum bag and then placing the composite in a cracking furnace for medium-pressure cracking; the pressure of the medium pressure cracking is 3MPa to 6MPa (for example, 3, 3.5, 4, 4.5, 5, 5.5 or 6 MPa).

In the invention, the C/SiC composite material which is not dipped with the liquid SiBCN precursor in vacuum is taken out from the vacuum bag and is directly put into a curing tank together with the vacuum bag for in-situ curing, and after the curing is finished, the material is taken out from the vacuum bag and is put into a medium-pressure cracking furnace for medium-pressure cracking; the PIP process is characterized in that the dipped blank body is taken out and then placed in a curing tank for curing, and then normal-pressure cracking is carried out; the invention preferably matches the improved PIP process (steps (a), (b) and (C)), namely, the PIP process of vacuum impregnation/in-situ curing/medium-pressure cracking is adopted to carry out matrix densification on the C/SiC composite material, the inventor unexpectedly finds that the in-situ curing process is adopted, so that the outflow of a liquid SiBCN precursor in the curing process is avoided, the liquid SiBCN precursor is favorably ensured to enter the interior of the C/SiC composite material, the impregnation depth and the impregnation efficiency are improved, and meanwhile, the medium-pressure cracking process is adopted, so that the cracking yield of the liquid SiBCN precursor is improved, the release of small molecules is reduced, matrix cracks are reduced, the porosity of the composite material is obviously reduced, and the mechanical property of the composite material is improved; the invention improves the cracking yield of the SiBCN precursor and reduces the damage to fibers caused by the release of small molecules in the cracking process.

According to some preferred embodiments, the vacuum impregnation is carried out for a period of 1.5 to 3 hours (e.g. 1.5, 2, 2.5 or 3 hours).

According to some preferred embodiments, the temperature of the in situ cure is 180 to 280 ℃ (e.g., 180 ℃, 190 ℃, 200 ℃, 210 ℃, 220 ℃, 230 ℃, 240 ℃, 250 ℃, 260 ℃, 270 ℃ or 280 ℃), and the time of the in situ cure is 3 to 6 hours (e.g., 3, 3.5, 4, 4.5, 5, 5.5 or 6 hours); and/or the medium-pressure cracking is carried out in a nitrogen atmosphere or an argon atmosphere, the temperature of the medium-pressure cracking is 600-1200 ℃ (such as 600 ℃, 650 ℃, 700 ℃, 750 ℃, 800 ℃, 850 ℃, 900 ℃, 950 ℃, 1000 ℃, 1050 ℃, 1100 ℃, 1150 ℃ or 1200 ℃) and is preferably 600-1000 ℃ (such as 600 ℃, 650 ℃, 700 ℃, 750 ℃, 800 ℃, 850 ℃, 900 ℃, 950 ℃ or 1000 ℃), and the time of the medium-pressure cracking is 2-3 h (such as 2, 2.5 or 3 h).

The present invention provides, in a second aspect, a modified C/SiC composite material obtained by the production method according to the first aspect of the invention.

The invention will be further illustrated by way of example, but the scope of protection is not limited to these examples.

Example 1

Preparing a porous C/C composite material preform: adopting a needle-punched carbon fiber preform, placing the needle-punched carbon fiber preform in a chemical vapor deposition furnace, taking propylene as a carbon source gas and nitrogen as a carrier gas, and carrying out chemical vapor deposition at the temperature of 1000 DEG CDepositing a carbon interface layer on the surface of the carbon fiber contained in the carbon fiber preform by a vapor infiltration method (CVI process) to obtain the carbon fiber preform with the density of 1.3g/cm³The porous C/C composite preform of (1).

Preparing a C/SiC composite material: putting the porous C/C composite material preform obtained in the step I into a graphite crucible, taking a proper amount of Si powder to embed the porous C/C composite material preform, heating the graphite crucible to 1650 ℃, then preserving heat for 2 hours, cutting off a power supply, cooling along with a furnace, and carrying out Si reaction infiltration in the process to obtain the C/SiC composite material.

Preparing the modified C/SiC composite material: taking a liquid SiBCN precursor as an impregnation liquid, adopting a PIP (poly-p-phenylene-imide) process of impregnation/curing/cracking to perform matrix densification on the C/SiC composite material, and sequentially performing impregnation, curing and cracking once respectively to obtain a modified C/SiC composite material with the weight gain of less than 1%; wherein, the PIP process of dipping/curing/cracking specifically comprises the following steps: putting the C/SiC composite material into a liquid SiBCN precursor for vacuum impregnation, taking the C/SiC composite material which is vacuum impregnated with the liquid SiBCN precursor out of the impregnation liquid after vacuum impregnation for 2h, and then putting the C/SiC composite material into a curing tank for curing, wherein the curing temperature is 250 ℃, and the curing time is 4 hours, so as to obtain the carbon fiber reinforced ceramic matrix composite material; and finally, putting the carbon fiber reinforced ceramic matrix composite material into a cracking furnace to carry out normal-pressure cracking for 3 hours at the temperature of 600 ℃ in a nitrogen atmosphere.

Example 2

Example 2 is essentially the same as example 1, except that: in the third step, the cracking temperature is 700 ℃, namely the carbon fiber reinforced ceramic matrix composite is placed in a cracking furnace to be cracked for 3 hours at the normal pressure of 700 ℃ in the nitrogen atmosphere.

Example 3

Example 3 is essentially the same as example 1, except that: in the third step, the cracking temperature is 800 ℃, namely the carbon fiber reinforced ceramic matrix composite is placed in a cracking furnace to be cracked for 3 hours at the normal pressure of 800 ℃ in the nitrogen atmosphere.

Example 4

Example 4 is essentially the same as example 1, except that: in the third step, the cracking temperature is 900 ℃, namely the carbon fiber reinforced ceramic matrix composite is placed in a cracking furnace to be cracked for 3 hours at 900 ℃ under normal pressure in the nitrogen atmosphere.

Example 5

Example 5 is essentially the same as example 1, except that: in the third step, the cracking temperature is 1000 ℃, namely the carbon fiber reinforced ceramic matrix composite is placed in a cracking furnace to be cracked for 3 hours at the normal pressure of 1000 ℃ in the nitrogen atmosphere.

Example 6

Example 6 is essentially the same as example 1, except that: in the third step, the cracking temperature is 1100 ℃, that is, the carbon fiber reinforced ceramic matrix composite is placed in a cracking furnace to be cracked for 3 hours at 1100 ℃ under normal pressure in the nitrogen atmosphere.

Example 7

Example 7 is essentially the same as example 1, except that: in the third step, the cracking temperature is 1200 ℃, that is, the carbon fiber reinforced ceramic matrix composite is placed in a cracking furnace to be cracked for 3 hours at 1200 ℃ under normal pressure in the nitrogen atmosphere.

Example 8

Example 8 is essentially the same as example 5, except that:

in the third step, the preparation of the modified C/SiC composite material comprises the following steps: taking a liquid SiBCN precursor as an impregnation liquid, adopting a PIP (poly-p-phenylene-imide) process of vacuum impregnation/in-situ curing/medium-pressure cracking to perform matrix densification on the C/SiC composite material, and sequentially performing vacuum impregnation, in-situ curing and medium-pressure cracking once respectively to obtain a modified C/SiC composite material with the weight gain of less than 1%; the PIP process of vacuum impregnation/in-situ curing/medium-pressure cracking specifically comprises the following steps: placing the C/SiC composite material in a liquid SiBCN precursor for vacuum impregnation, placing a vacuum bag filled with the C/SiC composite material vacuum-impregnated with the liquid SiBCN precursor into a curing tank after vacuum impregnation for 2 hours to carry out in-situ curing on the C/SiC composite material vacuum-impregnated with the liquid SiBCN precursor, wherein the in-situ curing temperature is 250 ℃, and the in-situ curing time is 4 hours, so as to obtain the carbon fiber reinforced ceramic matrix composite material; and finally, taking the carbon fiber reinforced ceramic matrix composite out of the vacuum bag, and then placing the carbon fiber reinforced ceramic matrix composite into a medium-pressure cracking furnace to perform high-temperature medium-pressure cracking for 3 hours at the temperature of 1000 ℃ and under the pressure of 4MPa in a nitrogen atmosphere.

Example 9

Example 9 is essentially the same as example 8, except that:

in the third step, the preparation of the modified C/SiC composite material comprises the following steps: taking a liquid SiBCN precursor as an impregnation liquid, adopting a PIP (poly-p-phenylene-imide) process of vacuum impregnation/in-situ curing/normal-pressure cracking to perform matrix densification on the C/SiC composite material, and sequentially performing vacuum impregnation, in-situ curing and normal-pressure cracking once respectively to obtain a modified C/SiC composite material with the weight gain of less than 1%; the PIP process of impregnation/in-situ curing/normal pressure cracking specifically comprises the following steps: placing the C/SiC composite material in a liquid SiBCN precursor for vacuum impregnation, placing a vacuum bag filled with the C/SiC composite material vacuum-impregnated with the liquid SiBCN precursor into a curing tank after vacuum impregnation for 2 hours to carry out in-situ curing on the C/SiC composite material vacuum-impregnated with the liquid SiBCN precursor, wherein the in-situ curing temperature is 250 ℃, and the in-situ curing time is 4 hours, so as to obtain the carbon fiber reinforced ceramic matrix composite material; and finally, taking the carbon fiber reinforced ceramic matrix composite out of the vacuum bag, and then placing the carbon fiber reinforced ceramic matrix composite into a medium-pressure cracking furnace to perform high-temperature normal-pressure cracking for 3 hours at the temperature of 1000 ℃ in a nitrogen atmosphere.

Example 10

Example 10 is essentially the same as example 8, except that:

in the third step, the preparation of the modified C/SiC composite material comprises the following steps: taking a liquid SiBCN precursor as an impregnation liquid, adopting a PIP (poly-p-phenylene-imide) process of vacuum impregnation/curing/medium-pressure cracking to perform matrix densification on the C/SiC composite material, and sequentially performing vacuum impregnation, curing and medium-pressure cracking once respectively to obtain a modified C/SiC composite material with the weight gain of less than 1%; the PIP process of vacuum impregnation/solidification/medium-pressure cracking specifically comprises the following steps: putting the C/SiC composite material into a liquid SiBCN precursor for vacuum impregnation, taking the C/SiC composite material which is vacuum impregnated with the liquid SiBCN precursor out of the impregnation liquid after vacuum impregnation for 2h, and then putting the C/SiC composite material into a curing tank for curing, wherein the curing temperature is 250 ℃, and the curing time is 4 hours, so as to obtain the carbon fiber reinforced ceramic matrix composite material; and finally, putting the carbon fiber reinforced ceramic matrix composite material into a medium-pressure cracking furnace, and carrying out high-temperature medium-pressure cracking at 1000 ℃ and 4MPa for 3 hours in a nitrogen atmosphere.

Example 11

Example 11 is essentially the same as example 5, except that:

in the step (i), the preparation of the porous C/C composite material preform comprises the following steps: adopting a needle-punched carbon fiber preform, placing the needle-punched carbon fiber preform in a chemical vapor deposition furnace, taking propylene as a carbon source gas and nitrogen as a carrier gas, and depositing a carbon interface layer on the surface of carbon fibers contained in the carbon fiber preform by a chemical vapor infiltration method (CVI process) at the temperature of 1000 ℃ to obtain the carbon interface layer with the density of 0.8g/cm³The porous C/C composite preform of (1).

Example 12

Example 12 is essentially the same as example 5, except that:

in the step (i), the preparation of the porous C/C composite material preform comprises the following steps: adopting a needle-punched carbon fiber preform, placing the needle-punched carbon fiber preform in a chemical vapor deposition furnace, taking propylene as a carbon source gas and nitrogen as a carrier gas, and depositing a carbon interface layer on the surface of carbon fibers contained in the carbon fiber preform by a chemical vapor infiltration method (CVI process) at the temperature of 1000 ℃ to obtain the carbon interface layer with the density of 1.8g/cm³The porous C/C composite preform of (1).

Comparative example 1

Comparative example 1 is substantially the same as example 5 except that step (c) is not included.

Comparative example 2

Preparing a porous C/C composite material preform: adopting a needle-punched carbon fiber preform, placing the needle-punched carbon fiber preform in a chemical vapor deposition furnace, taking propylene as a carbon source gas and nitrogen as a carrier gas, and depositing a carbon interface layer on the surface of carbon fibers contained in the carbon fiber preform by a chemical vapor infiltration method (CVI process) at the temperature of 1000 ℃ to obtain the carbon interface layer with the density of 1.3g/cm³Porous C/C composite ofA material preform.

Preparing a C/SiC composite material: taking liquid polycarbosilane as impregnation liquid, adopting a PIP (poly-p-phenylene-silane) process of impregnation/curing/cracking to perform matrix densification on the porous C/C composite material preform, and sequentially performing impregnation, curing and cracking for 8 times respectively to obtain a C/SiC composite material with the weight gain of less than 1%; wherein, the PIP process of dipping/curing/cracking specifically comprises the following steps: placing the porous C/C composite material preform in a liquid SiC precursor for vacuum impregnation, taking the porous C/C composite material preform which is vacuum impregnated with the liquid SiC precursor out of an impregnation liquid after vacuum impregnation for 2 hours, and then placing the porous C/C composite material preform in a curing tank for curing at the curing temperature of 250 ℃ for 4 hours to obtain a carbon fiber reinforced composite material; and finally, putting the carbon fiber reinforced composite material into a cracking furnace to carry out normal pressure cracking for 3 hours at 1000 ℃ in a nitrogen atmosphere.

Comparative example 3

Preparing a porous C/C composite material preform: adopting a needle-punched carbon fiber preform, placing the needle-punched carbon fiber preform in a chemical vapor deposition furnace, taking propylene as a carbon source gas and nitrogen as a carrier gas, and depositing a carbon interface layer on the surface of carbon fibers contained in the carbon fiber preform by a chemical vapor infiltration method (CVI process) at the temperature of 1000 ℃ to obtain the carbon interface layer with the density of 1.3g/cm³The porous C/C composite preform of (1).

Preparing a modified C/C composite material: modifying a porous C/C composite material preform by using a liquid SiBCN precursor as an impregnation liquid and adopting a PIP (poly-p-phenylene-imide) process of impregnation/curing/cracking, and sequentially performing impregnation, curing and cracking once to obtain a modified C/C composite material; wherein, the PIP process of dipping/curing/cracking specifically comprises the following steps: placing the porous C/C composite material preform in a liquid SiBCN precursor for vacuum impregnation, taking the porous C/C composite material preform which is subjected to vacuum impregnation with the liquid SiBCN precursor out of an impregnation liquid after vacuum impregnation for 2 hours, and then placing the porous C/C composite material preform into a curing tank for curing, wherein the curing temperature is 250 ℃, and the curing time is 4 hours, so that the carbon fiber reinforced ceramic matrix composite material is obtained; and finally, placing the carbon fiber reinforced ceramic matrix composite in a cracking furnace to carry out normal pressure cracking at 1000 ℃ for 3 hours in a nitrogen atmosphere to obtain the modified C/C composite.

Preparing the modified C/SiC composite material: and (4) placing the modified C/C composite material obtained in the second step into a graphite crucible, taking a proper amount of Si powder to embed the modified C/C composite material, heating the graphite crucible to 1650 ℃, then preserving heat for 2 hours, cutting off a power supply, cooling along with a furnace, and carrying out Si reaction infiltration in the process to obtain the modified C/SiC composite material.

Comparative example 4

A preparation method of an ultrahigh-temperature ceramic matrix composite material comprises the following specific steps:

preparing a porous C/C composite material preform: adopting a needle-punched carbon fiber preform, placing the needle-punched carbon fiber preform in a chemical vapor deposition furnace, taking propylene as a carbon source gas and nitrogen as a carrier gas, and depositing a carbon interface layer on the surface of carbon fibers contained in the carbon fiber preform by a chemical vapor infiltration method (CVI process) at the temperature of 1000 ℃ to obtain the carbon interface layer with the density of 1.3g/cm³The porous C/C composite preform of (1).

Introduction of a ceramic matrix: phenolic resin and polyvinylpyrrolidone are used as carbon sources, ethanol is used as a solvent, and the carbon sources and the ethanol are mixed with ZrC powder with the grain diameter of 1-3 mu m to form slurry. The ZrC powder accounts for 60 wt% of the slurry, and the carbon source accounts for 10 wt%. And (3) soaking the porous C/C composite material preform in the step (I) under the condition that the vacuum degree is-0.07 MPa to-0.10 MPa for 2 hours. And drying the porous C/C composite material preform at 80 ℃ for 6 hours, and then cracking at 800 ℃ under Ar protective atmosphere. And finally, Si is infiltrated under the condition of 1500 ℃ to finish the densification of the material, so as to obtain the C/ZrC-SiC composite material.

The composite materials prepared in the embodiments 1-12 and the comparative examples 1-4 are processed into bending strength test sample strips and oxyacetylene performance test sample strips, and the high-temperature bending strength at 1600 ℃ and the ablation rate (x 10) of oxyacetylene test wire at 2500 ℃ and 600s are measured by referring to a GB/T14390-93 test method^-5mm/s) results are shown in Table 1.

Table 1: the performance indexes of the composite materials prepared in examples 1 to 12 and comparative examples 1 to 4.

The invention has not been described in detail and is in part known to those of skill in the art.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims (10)

Translated fromChinese

1.一种改性C/SiC复合材料的制备方法，其特征在于，所述方法包括如下步骤：1. a preparation method of modified C/SiC composite material, is characterized in that, described method comprises the steps:(1)在碳纤维预制体中含有的碳纤维表面沉积碳界面层，得到多孔C/C复合材料预制体；(1) depositing a carbon interface layer on the surface of the carbon fiber contained in the carbon fiber preform to obtain a porous C/C composite material preform;(2)将所述多孔C/C复合材料预制体置于硅粉中进行熔渗反应，得到C/SiC复合材料；(2) placing the porous C/C composite material preform in silicon powder to carry out an infiltration reaction to obtain a C/SiC composite material;(3)以液态SiBCN前驱体作为浸渍液通过浸渍/固化/裂解的PIP工艺对所述C/SiC复合材料进行基体致密化，得到改性C/SiC复合材料。(3) densifying the C/SiC composite material by using the liquid SiBCN precursor as the impregnating liquid through the PIP process of impregnation/curing/cracking to obtain a modified C/SiC composite material.2.根据权利要求1所述的制备方法，其特征在于：2. preparation method according to claim 1, is characterized in that:在步骤(1)中，以丙烯为碳源气体，以氮气为载气，在温度为800～1200℃的条件下通过化学气相渗透法在所述碳纤维预制体中含有的碳纤维表面沉积碳界面层。In step (1), using propylene as the carbon source gas and nitrogen as the carrier gas, a carbon interface layer is deposited on the surface of the carbon fibers contained in the carbon fiber preform by chemical vapor infiltration at a temperature of 800-1200° C. .3.根据权利要求1所述的制备方法，其特征在于：3. preparation method according to claim 1, is characterized in that:所述多孔C/C复合材料预制体的密度为1.0～1.6g/cm³。The density of the porous C/C composite material preform is 1.0˜1.6 g/cm³ .4.根据权利要求1所述的制备方法，其特征在于：4. preparation method according to claim 1, is characterized in that:在步骤(2)中，所述熔渗反应的温度为1600～1700℃，所述熔渗反应的时间为1.5～2.5h。In step (2), the temperature of the infiltration reaction is 1600-1700° C., and the time of the infiltration reaction is 1.5-2.5 h.5.根据权利要求1所述的制备方法，其特征在于：5. preparation method according to claim 1, is characterized in that:在步骤(3)中，所述裂解的温度600～1200℃，所述裂解的时间为2～3h。In step (3), the temperature of the cracking is 600-1200°C, and the time of the cracking is 2-3 hours.6.根据权利要求1所述的制备方法，其特征在于：6. preparation method according to claim 1, is characterized in that:重复所述浸渍/固化/裂解的PIP工艺直至得到的所述改性C/SiC复合材料的增重小于1％。The impregnation/curing/cracking PIP process was repeated until the resulting modified C/SiC composite had a weight gain of less than 1%.7.根据权利要求1至6任一项所述的制备方法，其特征在于，所述浸渍/固化/裂解的PIP工艺包括如下子步骤：7. according to the preparation method described in any one of claim 1 to 6, it is characterized in that, the PIP process of described impregnation/solidification/cracking comprises the following substeps:(a)将步骤(2)得到的所述C/SiC复合材料置于真空袋中以所述液态SiBCN前驱体作为浸渍液进行真空浸渍；(a) placing the C/SiC composite material obtained in step (2) in a vacuum bag and performing vacuum impregnation with the liquid SiBCN precursor as an impregnating liquid;(b)将装有真空浸渍了液态SiBCN前驱体的所述C/SiC复合材料的真空袋放入固化罐内使真空浸渍了液态SiBCN前驱体的所述C/SiC复合材料进行原位固化，得到碳纤维增强陶瓷基复合材料；(b) placing the vacuum bag containing the C/SiC composite material vacuum-impregnated with the liquid SiBCN precursor into a curing tank to perform in-situ curing of the C/SiC composite material vacuum-impregnated with the liquid SiBCN precursor, A carbon fiber reinforced ceramic matrix composite material is obtained;(c)将所述碳纤维增强陶瓷基复合材料从真空袋中取出后再置于裂解炉内进行中压裂解；所述中压裂解的压力为3MPa～6MPa。(c) taking the carbon fiber reinforced ceramic matrix composite material out of the vacuum bag and then placing it in a cracking furnace for medium-pressure cracking; the pressure of the medium-pressure cracking is 3 MPa to 6 MPa.8.根据权利要求7所述的制备方法，其特征在于：8. preparation method according to claim 7, is characterized in that:所述真空浸渍的时间为1.5～3h。The time of the vacuum impregnation is 1.5-3 hours.9.根据权利要求7所述的制备方法，其特征在于：9. preparation method according to claim 7, is characterized in that:所述原位固化的温度为180～280℃，所述原位固化的时间为3～6h；和/或The temperature of the in-situ curing is 180 to 280° C., and the time of the in-situ curing is 3 to 6 hours; and/or在氮气气氛或氩气气氛中进行所述中压裂解，所述中压裂解的温度为600～1200℃，所述中压裂解的时间为2～3h。The medium-pressure cracking is performed in a nitrogen atmosphere or an argon atmosphere, the temperature of the medium-pressure cracking is 600-1200° C., and the time of the medium-pressure cracking is 2-3 hours.10.由权利要求1至9中任一项所述的制备方法制得的改性C/SiC复合材料。10. The modified C/SiC composite material prepared by the preparation method of any one of claims 1 to 9.