阅读说明：本技术 一种提高rmi工艺制陶瓷基复合材料性能的方法及制得的陶瓷基复合材料 (Method for improving performance of ceramic-based composite material prepared by RMI process and prepared ceramic-based composite material ) 是由 金鑫 左红军 杨冰洋 霍鹏飞 张宝鹏 于艺 于 2020-07-13 设计创作，主要内容包括：本发明涉及一种提高RMI工艺制陶瓷基复合材料性能的方法及制得的陶瓷基复合材料。所述方法包括如下步骤：(1)提供经RMI工艺制备的陶瓷基复合材料；(2)采用有机溶剂稀释SiBCN前驱体,得到SiBCN前驱体溶液；(3)以SiBCN前驱体溶液作为浸渍液通过前驱体浸渍裂解法对RMI工艺制备的陶瓷基复合材料依次进行浸渍、固化和裂解的步骤,以提高RMI工艺制陶瓷基复合材料的性能,得到综合性能优异的陶瓷基复合材料。本发明方法能够优化RMI法工艺制陶瓷基复合材料的力学性能,在拉伸强度、弯曲强度等力学性能方面均有一定程度的提高,从而提高了陶瓷基复合材料的综合性能。(The invention relates to a method for improving the performance of a ceramic-based composite material prepared by an RMI process and the prepared ceramic-based composite material. The method comprises the following steps: (1) providing a ceramic matrix composite prepared by an RMI process; (2) diluting a SiBCN precursor by using an organic solvent to obtain a SiBCN precursor solution; (3) and taking the SiBCN precursor solution as impregnation liquid, and sequentially carrying out impregnation, curing and cracking on the ceramic matrix composite material prepared by the RMI process by a precursor impregnation cracking method so as to improve the performance of preparing the ceramic matrix composite material by the RMI process and obtain the ceramic matrix composite material with excellent comprehensive performance. The method can optimize the mechanical properties of the ceramic-based composite material prepared by the RMI process, and improves the mechanical properties such as tensile strength, bending strength and the like to a certain extent, thereby improving the comprehensive properties of the ceramic-based composite material.)

1. The method for improving the performance of the ceramic-based composite material prepared by the RMI process is characterized by comprising the following steps of:

(1) providing a ceramic matrix composite prepared by an RMI process;

(2) diluting a SiBCN precursor by using an organic solvent to obtain a SiBCN precursor solution;

(3) and taking the SiBCN precursor solution as impregnation liquid, and sequentially carrying out impregnation, curing and cracking on the ceramic matrix composite material prepared by the RMI process by a precursor impregnation cracking method so as to improve the performance of preparing the ceramic matrix composite material by the RMI process and obtain the ceramic matrix composite material with excellent comprehensive performance.

2. The method of claim 1, wherein:

the density of the ceramic matrix composite material prepared by the RMI process is 1.90-2.80 g/cm³(ii) a And/or

The concentration of the SiBCN precursor solution is 5-40 wt%, and preferably 5-25 wt%.

3. The method according to claim 1 or 2, characterized in that:

the concentration of the SiBCN precursor solution and the density of the ceramic matrix composite prepared by the RMI process are in a negative correlation relationship.

4. The method of claim 1, wherein:

the SiBCN precursor is polyborosilazane.

5. The method of claim 1, wherein:

the organic solvent is toluene or xylene, preferably xylene.

6. The method according to claim 1, wherein before the step (3), the method further comprises the steps of mechanically or abrasively cleaning the surface of the ceramic matrix composite prepared by the RMI process, and wiping off dust on the surface by ultrasonic cleaning or solvent and then drying the surface.

7. The method of claim 1, wherein:

the RMI process may be, but is not limited to, one of a reactive melt siliconizing process, a reactive melt siliconizing zirconium process.

8. The method of claim 1, wherein:

repeating the step (3) at least 1 time, preferably 1-3 times.

9. The method of claim 1, wherein:

the impregnation is carried out by vacuum impregnation and then pressure impregnation, wherein the pressure during pressure impregnation is 1.5-3 MPa;

the curing temperature is 180-280 ℃, and the curing time is 3-6 h; and/or

And carrying out the cracking in a nitrogen atmosphere or an argon atmosphere, wherein the cracking temperature is 800-1100 ℃, and the cracking time is 3-7 h.

10. A ceramic matrix composite material having superior overall properties, made by the method of any one of claims 1-9.

Technical Field

The invention belongs to the technical field of composite material thermal protection, and particularly relates to a method for improving the performance of a ceramic-based composite material prepared by an RMI (RMI) process and a ceramic-based composite material with excellent comprehensive performance prepared by the method.

Background

The ceramic matrix composite has the characteristics of low density, high temperature resistance, high hardness, oxidation resistance, excellent mechanical property and the like, and is widely applied to the field of aerospace as a high-temperature thermal structure material. The prior ceramic matrix composite material forming process methods include a Chemical Vapor Infiltration (CVI) method, a precursor conversion (PIP) method and a Reaction Melt Infiltration (RMI) method.

The basic principle of the RMI method (reaction melt infiltration) is that the infiltration metal is heated to a molten liquid state, then the infiltration metal penetrates into the interior of a preform by utilizing the capillary action under a certain pressure or no pressure condition, and a required product is generated after a chemical reaction to prepare the ceramic matrix composite material. The method is widely applied to the prior reaction melting siliconizing method, the reaction melting siliconizing method and other processes. Compared with Chemical Vapor Infiltration (CVI) and precursor-conversion process (PIP), the reactive infiltration (RMI) process has the significant advantages of short production cycle, low production cost, no limitation by the shape of the component, and low residual porosity of the material. However, because the temperature is high due to the need of melting infiltration metal in the RMI process, micropores and microcracks still exist in the composite material matrix after reaction, so that the oxidation reaction of the oxidation medium and the carbon fiber is carried out through the internal permeation channel, and the performance of the composite material is influenced.

Chinese patent application CN110423119A discloses a preparation method of an ablation-resistant C/SiC ceramic matrix composite, which aims to improve the high-temperature mechanical property and the ablation property of the material, adopts SiBCN precursor solution containing polysilazane, boron powder and a solvent to carry out impregnation curing cracking on the C/SiC ceramic matrix composite, and introduces B, N elements into the C/SiC ceramic matrix composite, thereby improving the high-temperature mechanical property and the ablation property of the material, but the SiBCN precursor solution in the patent application is only suitable for carrying out secondary impregnation curing cracking on the C/SiC ceramic matrix composite prepared by a PIP method by adopting polycarbosilane solution. Compared with the composite material prepared by the PIP method, the composite material prepared by the RMI process has low open porosity on the outer surface, boron powder in the SiBCN precursor solution disclosed in CN110423119A exists in a solid form and is difficult to penetrate into the composite material, polysilazane and a solvent enter the composite material, the pores of the composite material are filled with a small amount of boron powder, the boron powder is easy to gather on the surface of the material, and the method disclosed in the Chinese patent application CN110423119A has no obvious effect on improving the performance of the composite material prepared by the RMI process because the passage of the precursor solution into the material is blocked for the composite material prepared by the RMI process with low open porosity.

In view of the above problems, it is very necessary to provide a method for improving the performance of ceramic-based composite materials prepared by RMI process and ceramic-based composite materials prepared by the method with excellent comprehensive performance.

Disclosure of Invention

In order to solve the technical problems in the prior art, the invention provides a method for improving the performance of a ceramic-based composite material prepared by an RMI process and a ceramic-based composite material with excellent comprehensive performance prepared by the method.

The invention provides in a first aspect a method for improving the performance of a ceramic-based composite produced by an RMI process, the method comprising the steps of:

(1) providing a ceramic matrix composite prepared by an RMI process;

(2) diluting a SiBCN precursor by using an organic solvent to obtain a SiBCN precursor solution;

(3) and taking the SiBCN precursor solution as impregnation liquid, and sequentially carrying out impregnation, curing and cracking on the ceramic matrix composite material prepared by the RMI process by a precursor impregnation cracking method so as to improve the performance of preparing the ceramic matrix composite material by the RMI process and obtain the ceramic matrix composite material with excellent comprehensive performance.

Preferably, the density of the ceramic matrix composite material prepared by the RMI process is 1.90-2.80 g/cm³(ii) a And/or the concentration of the SiBCN precursor solution is 5-40 wt%, preferably 5-25 wt%.

Preferably, the concentration of the SiBCN precursor solution adopted is in a negative correlation relationship with the density of the provided ceramic matrix composite material prepared by the RMI process.

Preferably, the SiBCN precursor is polyborosilazane.

Preferably, the organic solvent is toluene or xylene, preferably xylene.

Preferably, before the step (3), the method further comprises the steps of cleaning the surface of the ceramic matrix composite material prepared by the RMI process by means of machining or grinding, wiping off dust on the surface by using ultrasonic cleaning or a solvent, and then drying.

Preferably, the RMI process may be, but is not limited to, one of a reactive melt siliconizing process, a reactive melt siliconizing zirconium process.

Preferably, step (3) is repeated at least 1 time, preferably 1-3 times.

Preferably, the impregnation is carried out by vacuum impregnation and then pressure impregnation, wherein the pressure during pressure impregnation is 1.5-3 MPa; the curing temperature is 180-280 ℃, and the curing time is 3-6 h; and/or carrying out the cracking in a nitrogen atmosphere or an argon atmosphere, wherein the cracking temperature is 800-1100 ℃, and the cracking time is 3-7 h.

In a second aspect, the present invention provides a ceramic matrix composite having superior combinations of properties produced by the method of the first aspect of the present invention.

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

(1) the method introduces a SiBCN impregnation cracking process after an RMI process, has good SiBCN precursor solution wettability, can further enter compact C/SiC, C/SiC-ZrC and other composite materials to perform micro-crack and micro-pore filling and sealing, and reduces holes and cracks in a composite material matrix; the method can optimize the mechanical properties of the ceramic-based composite material prepared by the RMI process, and improves the mechanical properties such as tensile strength, bending strength and the like to a certain extent, thereby improving the comprehensive properties of the ceramic-based composite material.

(2) The method has short period and simple process.

(3) The holes and cracks in the composite material obtained by the method are filled by SiBCN, so that the compactness of the material is improved, the porosity of the material is reduced, the comprehensive performance of the composite material is improved, and the service life of the composite material is prolonged.

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 a method for improving the performance of a ceramic-based composite material prepared by an RMI process in a first aspect, which comprises the following steps:

(1) providing a ceramic matrix composite prepared by an RMI (reactive melt infiltration) process; in the present invention, the ceramic matrix composite may be, for example, a carbon fiber-reinforced silicon carbide ceramic matrix composite (C/SiC ceramic matrix composite), a carbon fiber-reinforced silicon carbide-zirconium carbide ceramic matrix composite (C/SiC-ZrC ceramic matrix composite); according to the invention, the ceramic matrix composite material prepared by the RMI method (reaction melt infiltration method) process provided in the step (1), such as C/SiC and C/SiC-ZrC, is taken as a semi-finished ceramic matrix composite material; in the invention, the semi-finished ceramic matrix composite materials such as C/SiC, C/SiC-ZrC and the like are prepared by adopting the prior RMI process;

(2) diluting a SiBCN precursor by using an organic solvent to obtain a SiBCN precursor solution; in the invention, the SiBCN precursor is polyborosilazane, the organic solvent is toluene or xylene, preferably xylene, and the SiBCN precursor solution obtained by diluting the polyborosilazane with the organic solvent has good wettability;

(3) The preparation method comprises the steps of sequentially carrying out impregnation, curing and cracking (impregnation curing cracking) on the ceramic matrix composite material prepared by the RMI process by using a SiBCN precursor solution as an impregnation solution through a precursor impregnation cracking method (PIP method) so as to improve the performance of the ceramic matrix composite material prepared by the RMI process and obtain the ceramic matrix composite material with excellent comprehensive performance; in the invention, SiBCN precursor solution is used as impregnation liquid to carry out impregnation, curing and cracking on the semi-finished ceramic matrix composite prepared by the RMI process through a PIP (precursor impregnation cracking) process, and the micropores and microcracks of the composite are filled, so that the performance of the C/SiC, C/SiC-ZrC and other composite prepared by the RMI process is improved, and the composite with optimized performance is obtained; in the present invention, the precursor is subjected to a precursor impregnation cracking process, i.e., a precursor conversion process.

As is well known, compared with the ceramic matrix composite prepared by the PIP method, the ceramic matrix composite prepared by RMI (such as C/SiC composite and C/SiC-ZrC composite) has higher density and lower porosity, and resin solution is difficult to infiltrate into the interior of the composite prepared by RMI, so that the subsequent process treatment is not generally carried out on the composite after the RMI process except for the surface coating. The method overcomes the technical prejudice, introduces SiBCN impregnation cracking process after the RMI process for the first time, and aims to repair the internal defects of the composite material prepared by RMI and reduce the porosity of the composite material so as to strengthen the mechanical property of the composite material. The SiBCN precursor solution adopted by the method is suitable for impregnating, curing and cracking the ceramic-based composite material prepared by the RMI process, so that the performance of the ceramic-based composite material is improved.

Compared with the prior art (see Chinese patent application CN109400168A), the application of SiBCN precursor solution obtained by diluting polyborosilazane with an organic solvent is generally different in order to introduce a SiBCN coating (SiBCN interface layer) on SiC fibers, the purpose of the invention is different from the requirement on the applicability of the SiBCN precursor solution, the method mainly utilizes the characteristic of good wettability of the SiBCN precursor solution, and the SiBCN precursor solution can be further added into the compact composite materials such as C/SiC, C/SiC-ZrC and the like prepared by the RMI process to carry out the filling of microcracks and microporosities, thereby reducing holes and cracks in the composite material matrix; the method can optimize the mechanical properties of the ceramic-based composite material prepared by the RMI process, and improves the mechanical properties such as tensile strength, bending strength and the like to a certain extent, thereby improving the comprehensive properties of the ceramic-based composite material. The method has short period and simple process. The internal holes and cracks of the composite material obtained by the method are filled by SiBCN, so that the compactness of the material is improved, the porosity of the composite material prepared by the RMI (reactive melt infiltration) process is reduced, the mechanical property of the composite material is improved, the comprehensive performance of the composite material is improved, and the service life of the composite material is prolonged.

According to some preferred embodiments, the density of the ceramic matrix composite material prepared by the RMI process is 1.90-2.80 g/cm³(ii) a And/or the concentration of the SiBCN precursor solution is 5 to 40 wt% (e.g., 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, or 40 wt%), preferably 5 to 25 wt% (e.g., 5 wt%, 10 wt%, 15 wt%, 20 wt%, or 25 wt%). In the invention, the concentration of the SiBCN precursor solution refers to the mass percentage content of SiBCN precursors contained in the SiBCN precursor solution; in the invention, the concentration of the SiBCN precursor solution is preferably 5-40 wt%, more preferably 5-25 wt%, if the concentration of the SiBCN precursor solution is too high, the wettability of the SiBCN precursor solution on the composite material can be reduced, the SiBCN precursor solution can not enter the composite material for sealing, and the holes and cracks in the composite material can not be effectively reduced, so that the material performance is improved; if the concentration of the SiBCN precursor solution is too low, the filling and sealing of holes and cracks in the composite material are insufficient, and the performance of the material cannot be effectively improved.

According to some preferred embodiments, the concentration of the SiBCN precursor solution used is in a negative correlation with the density of the ceramic matrix composite material prepared by the RMI process provided, that is, in the present invention, as the density of the ceramic matrix composite material prepared by the RMI process provided increases, the concentration of the SiBCN precursor solution correspondingly used should decrease, and as the density of the ceramic matrix composite material prepared by the RMI process provided decreases, the concentration of the SiBCN precursor solution correspondingly used should increase; in the invention, the density of the ceramic matrix composite prepared by the RMI process is more preferably 1.90-2.80 g/cm ³The concentration of the SiBCN precursor solution is 5-40 wt%, and the concentration of the adopted SiBCN precursor solution and the density of the provided ceramic matrix composite material prepared by the RMI process are in a negative correlation relationship; the inventor unexpectedly finds that, in the invention, when the concentration of the SiBCN precursor solution adopted is in a negative correlation relationship with the density of the ceramic matrix composite material prepared by the RMI process, the tensile strength and the bending strength can be remarkably improvedThe ceramic matrix composite material with high comprehensive performance is probably because the composite material prepared by RMI is difficult to have resin solution to fill and seal internal pore cracks, and when the use concentration of SiBCN precursor solution and the density of the ceramic matrix composite material are in a negative correlation relationship, in the range of the density, the higher the density of the composite material is, the smaller the densification degree and the open porosity of the composite material are, the lower the concentration of the required SiBCN precursor solution is, the higher the wettability of the SiBCN precursor solution is, the more the SiBCN precursor solution can effectively permeate into the composite material, and the pore cracks can be filled; the lower the density of the composite material is, the higher the densification degree and the pore opening rate of the composite material are, the higher the concentration of the needed SiBCN precursor solution is, and under the condition of ensuring the wettability of the composite material, more SiBCN is needed to permeate into the composite material to fill up pore cracks; however, the concentration of the SiBCN precursor solution is lower than 5 wt%, the effective components are too little to be filled, and the wettability is not enough to go deep into the composite material prepared by RMI when the concentration is higher than 40 wt%.

According to the method, according to the density of the ceramic matrix composite material prepared by the RMI process, SiBCN precursor solution with proper concentration is used as the impregnation liquid, so that the mechanical properties of the ceramic matrix composite material prepared by the RMI process can be obviously optimized, and the mechanical properties such as tensile strength, bending strength and the like are obviously improved, so that the comprehensive properties of the ceramic matrix composite material are obviously improved.

According to some preferred embodiments, the SiBCN precursor is polyborosilazane.

According to some preferred embodiments, the organic solvent is toluene or xylene, preferably xylene.

According to some preferred embodiments, before step (3), the method further comprises the steps of cleaning the surface of the ceramic matrix composite material prepared by the RMI process by machining or grinding, wiping off dust on the surface by using ultrasonic cleaning or a solvent, and then drying.

According to some preferred embodiments, the RMI process may be, but is not limited to, one of a reactive melt siliconizing process, a reactive melt siliconizing zirconium process; in the present invention, it is preferable that the RMI process is a reaction melt siliconizing process or a reaction melt siliconizing zirconium process (reaction melt siliconizing process).

According to some preferred embodiments, step (3) is repeated at least 1 time, preferably 1 to 3 times (e.g. 1, 2 or 3 times).

According to some preferred embodiments, the impregnation is performed by vacuum impregnation and then pressure impregnation, wherein the pressure of the pressure impregnation is 1.5-3 MPa (e.g. 1.5, 2, 2.5 or 3 MPa); the curing temperature is 180-280 ℃ (e.g., 180 ℃, 190 ℃, 200 ℃, 210 ℃, 220 ℃, 230 ℃, 240 ℃, 250 ℃, 260 ℃, 270 ℃ or 280 ℃), and the curing time is 3-6 h (e.g., 3, 3.5, 4, 4.5, 5, 5.5 or 6 h); and/or the cracking is carried out in a nitrogen atmosphere or an argon atmosphere, the cracking temperature is 800-1100 ℃ (such as 800 ℃, 850 ℃, 900 ℃, 950 ℃, 1000 ℃, 1050 ℃ or 1100 ℃), and the cracking time is 3-7 h (such as 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5 or 7 h). In the invention, the preferred cracking temperature is 800-1100 ℃, if the cracking temperature is too low, the SiBCN can be cracked incompletely, and the efficiency is reduced; if the cracking temperature is too high, new cracks may form inside the composite, adversely affecting the properties of the composite.

According to some specific embodiments, the method comprises the steps of:

Firstly, providing a C/SiC and C/SiC-ZrC semi-finished composite material prepared by an RMI (reaction melt infiltration) process; the density of the C/SiC and C/SiC-ZrC semi-finished composite material is 1.90-2.80 g/cm³To (c) to (d); the RMI process may be, but is not limited to, one of a reactive siliconizing, reactive siliconizing zirconium process.

Diluting SiBCN precursor with organic solvent to obtain SiBCN precursor solution; the organic solvent is toluene or xylene, preferably xylene; the SiBCN precursor is polyborosilazane; the SiBCN precursor solution is a solution with a concentration of 5 wt% to 40 wt%, preferably a solution with a concentration of 5 wt% to 25 wt%.

Thirdly, cleaning the surface of the C/SiC and C/SiC-ZrC composite material melted and infiltrated by the RMI process by adopting machining, grinding and other modes before PIP, wiping off the surplus materials such as dust and the like on the surface by using ultrasonic cleaning or a solvent, and drying.

Soaking and cracking the semi-finished composite material by taking SiBCN precursor solution as soaking solution through a PIP (precursor soaking and cracking) process, and filling and sealing micropores and microcracks of the composite material, so that the performance of the C/SiC and C/SiC-ZrC composite material prepared by the RMI process is improved; the PIP method process is realized by the following steps: impregnating the semi-finished composite material by using SiBCN precursor solution under vacuum condition and pressurization condition, firstly carrying out vacuum impregnation, wherein a vacuum pressure gauge shows that the pressure is less than or equal to-0.095 MPa, and then carrying out pressure impregnation, wherein the impregnation pressure is 1.5-3 MPa; then curing at 180-280 ℃ for 3-6 hours; the cracking is carried out in a nitrogen atmosphere or an argon atmosphere, the temperature is 800-1100 ℃, and the cracking time is 3-7 hours.

Fifthly, repeating the step (iv) at least once, preferably 1 to 3 times.

In a second aspect, the present invention provides a ceramic matrix composite having superior combinations of properties produced by the method of the first aspect of the present invention.

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