阅读说明：本技术 一种碳纤维增强SiZrOC复合材料及其制备方法 (Carbon fiber reinforced SiZrOC composite material and preparation method thereof ) 是由 郭蕾 马青松 于 2020-07-10 设计创作，主要内容包括：本发明公开了一种碳纤维增强SiZrOC复合材料及其制备方法,以碳纤维预制件为增强体,采用含Zr的聚硅氧烷为先驱体,通过反复浸渍-固化-裂解获得C/SiZrOC复合材料,该过程中采用的碳纤维预制件为三维四向编织件、二维布、二维穿刺编织件等,含Zr的聚硅氧烷中Zr含量的质量比为5-30％,经浸渍-固化-裂解反复致密化后当本周期样品质量较上周期结束时样品质量增重不超过1％时得到C/SiZrOC复合材料。本发明所述的一种碳纤维增强SiZrOC复合材料的制备方法,提高了C/SiOC复合材料的高温稳定性,具有成本低廉、耐高温性能好且对设备要求低等优点。(The invention discloses a carbon fiber reinforced SiZrOC composite material and a preparation method thereof, wherein a carbon fiber prefabricated part is used as a reinforcement body, polysiloxane containing Zr is used as a precursor body, the C/SiZrOC composite material is obtained through repeated dipping-curing-cracking, the carbon fiber prefabricated part adopted in the process is a three-dimensional four-way weaving piece, two-dimensional cloth, a two-dimensional puncture weaving piece and the like, the mass ratio of Zr content in the polysiloxane containing Zr is 5-30%, and the C/SiZrOC composite material is obtained when the weight gain of the sample mass is not more than 1% when the sample mass in the period is repeatedly densified through dipping-curing-cracking compared with that at the end of the upper period. The preparation method of the carbon fiber reinforced SiZrOC composite material improves the high-temperature stability of the C/SiOC composite material, and has the advantages of low cost, good high-temperature resistance, low requirement on equipment and the like.)

1. A preparation method of a carbon fiber reinforced SiZrOC composite material is characterized by comprising the following steps: the method comprises the following steps:

1) dipping: preparing a carbon fiber prefabricated part, placing the carbon fiber prefabricated part under the vacuum condition with the pressure of less than 500Pa, and soaking the carbon fiber prefabricated part by using a polysiloxane precursor solution containing Zr;

the Zr-containing polysiloxane precursor solution is a mixed sol of zirconium sol and a silicon resin ethanol solution, and the mass ratio of Zr element to silicon resin is 5-30%; zirconium sol ZrOCl₂·8H₂O is dissolved in ethanol and added with chelating agent to prepare ZrOCl₂·8H₂The mass ratio of O to ethanol is 2-5: 10;

the chelating agent and ZrOCl₂·8H₂The mass ratio of O is 1-4: 1;

the carbon fiber prefabricated part is one of a 2.5-dimensional braided fabric, a plain cloth laminated sewing prefabricated part, a three-dimensional needled felt, a three-dimensional four-way braided fabric, a three-dimensional five-way braided fabric or a three-dimensional six-way braided fabric;

2) and (3) curing: standing the carbon fiber prefabricated part dipped in the step for 5-30h to form gel, and then crosslinking and curing the carbon fiber prefabricated part subjected to gel at the temperature of 120-200 ℃ for 4-8 h;

3) cracking: performing pyrolysis on the carbon fiber prefabricated part subjected to crosslinking and curing in the previous step in an inert atmosphere, wherein the pyrolysis temperature is 1000-1200 ℃, and the pyrolysis time is 30-120 min;

and repeating the dipping-curing-cracking cycle for multiple times until the weight of the sample is increased by no more than 1% when the cycle is finished compared with the weight of the sample when the cycle is finished, and finishing the preparation to obtain the carbon fiber reinforced SiZrOC composite material.

2. The method for preparing a carbon fiber reinforced SiZrOC composite material as claimed in claim 1, wherein: the silicone resin in the step 1) is selected from methyl silicone resin, the chelating agent is selected from acetylacetone, and the mass concentration of the silicone resin ethanol solution is 20-60%.

3. The method for preparing a carbon fiber reinforced SiZrOC composite material as claimed in claim 1, wherein: step 1) soaking with a Zr-containing polysiloxane precursor solution for 2-4 h.

4. The method for preparing a carbon fiber reinforced SiZrOC composite material as claimed in claim 1, wherein: and 2) standing the carbon fiber prefabricated part impregnated in the step 2) to form gel, wherein the carbon fiber prefabricated part impregnated in the step is standing to form gel.

5. The method for preparing a carbon fiber reinforced SiZrOC composite material as claimed in claim 1, wherein: the above dipping-curing-cracking cycle is repeated for a plurality of times, which means that the above dipping-curing-cracking cycle is repeated for 8-14 times.

6. A carbon fiber reinforced SiZrOC composite material is characterized in that: obtained by the method for preparing a carbon fiber reinforced SiZrOC composite material according to any one of the claims 1 to 5.

Technical Field

The invention belongs to the technical field of high-temperature-resistant ceramic matrix composite materials, and particularly relates to a carbon fiber reinforced SiZrOC composite material and a preparation method thereof.

Background

SiOC ceramic is a light high-temperature resistant structural material with high cost performance and low density<2.2g/cm³) Better high-temperature stability, chemical stability and the like. In the field of aerospaceThe domain has good application value. The mechanical property, high-temperature stability, chemical stability and the like of the SiOC ceramic material are obviously superior to those of the traditional SiO₂A material; meanwhile, the SiOC ceramic material may have diversified molecular structures or components, so that it has functional characteristics of luminescence, dielectric and the like, and can be used as a light high-temperature structural material, an optical material, an electronic packaging ceramic substrate material, a lithium ion battery electrode material and the like, so that the SiOC ceramic material has attracted extensive attention and research.

The Polysiloxane (PSO) derived SiOC ceramic is a high-cost-performance light high-temperature-resistant structural material, and the fiber-reinforced composite material taking the SiOC ceramic as the matrix has wide application prospect in the field of aerospace. The carbon fiber has the advantages of high strength, good high temperature resistance and the like, and the C fiber reinforced SiOC (C/SiOC) composite material has good performance potential.

However, the high temperature resistance of the existing C/SiOC composite material is limited, and the service temperature of the existing C/SiOC composite material in an inert environment is 1400 ℃. The structure instability of the SiOC ceramic matrix at high temperature is mainly caused, if the high-temperature stability of the SiOC matrix can be improved, the service temperature of the C/SiOC composite material can be improved, and the application range can be further widened.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a carbon fiber reinforced SiZrOC composite material and a preparation method thereof, namely a C/SiZrOC composite material and a preparation method thereof, which can effectively improve the high-temperature stability of the C/SiOC composite material and have the advantages of low cost, good high-temperature resistance, low requirement on equipment and the like.

The invention relates to a preparation method of a carbon fiber reinforced SiZrOC composite material, which comprises the following steps:

1) dipping: preparing a carbon fiber prefabricated part, placing the carbon fiber prefabricated part under the vacuum condition with the pressure of less than 500Pa, and soaking the carbon fiber prefabricated part by using a polysiloxane precursor solution containing Zr;

the Zr-containing polysiloxane precursor solution is a mixed sol of zirconium sol and a silicon resin ethanol solution, the mass ratio of Zr element to silicon resin is 5-30%, and the zirconium sol is formed by ZrOCl₂·8H₂O is dissolved inAlcohol and chelating agent are added to obtain ZrOCl₂·8H₂The mass ratio of O to ethanol is (2-5): 10, the mass concentration of the silicon resin ethanol solution is 20-60 percent, and the chelating agent and ZrOCl₂·8H₂The mass ratio of O is (1-4): 1;

the carbon fiber prefabricated part is one of a 2.5-dimensional braided fabric, a plain cloth laminated sewing prefabricated part, a three-dimensional needled felt, a three-dimensional four-way braided fabric, a three-dimensional five-way braided fabric or a three-dimensional six-way braided fabric;

2) and (3) curing: standing the carbon fiber prefabricated part dipped in the step to form gel, and crosslinking and curing the gelled prefabricated part at the temperature of 120-200 ℃ for 4-8 h;

3) cracking: performing pyrolysis on the carbon fiber prefabricated part subjected to crosslinking and curing in the previous step in an inert atmosphere, wherein the pyrolysis temperature is 1000-1200 ℃, and the pyrolysis time is 30-120 min;

and repeating the dipping-curing-cracking cycle for multiple times until the weight of the sample is increased by no more than 1% when the cycle is finished compared with the weight of the sample when the cycle is finished, and finishing the preparation to obtain the carbon fiber reinforced SiZrOC composite material.

The silicone resin in step 1) of the present invention is selected from low molecular weight methyl silicone resin (MK), which is methyl silicone resin dissolved in toluene and has high SiO₂Content, after complete oxidation, 80% SiO₂Calculated as solid resin content.

The chelating agent in the step 1) is selected from acetylacetone.

Impregnating the substrate with the Zr-containing polysiloxane precursor solution in the step 1), wherein the impregnation time is 2-4 h.

And 2) standing the carbon fiber prefabricated part impregnated in the step 2) to form gel, wherein the carbon fiber prefabricated part impregnated in the step is kept standing for 5-30 hours to form gel.

The above dipping-curing-cracking cycle is repeated for a plurality of times, preferably for 8 to 14 times.

The invention also relates to a carbon fiber reinforced SiZrOC composite material obtained by the preparation method of the carbon fiber reinforced SiZrOC composite material, under the condition of the same preparation process, the heat-resistant temperature of the C/SiOC composite material in an inert environment can be improved by 100-200 ℃ by the carbon fiber reinforced SiZrOC composite material (namely C/SiZrOC composite material) obtained by the preparation method, and the prepared C/SiZrOC composite material has better high temperature resistance.

Compared with the prior art, the invention has the following advantages:

1. the preparation method can effectively improve the high temperature resistance of the SiOC ceramic matrix through matrix modification, the introduction of heterogeneous elements into PSO molecules can regulate and control the fine structure of the SiOC ceramic at the molecular level or even the atomic level, the applicability to the preparation of continuous fiber reinforced SiOC composite materials is strong, and the introduction of Zr element can generate ZrO in the SiOC ceramic₂Or ZrSiO₄The high temperature resistance is improved, and the cost can be reduced while the introduction amount of Zr is increased by using the inorganic Zr salt as the Zr source.

2. The preparation method adopts micromolecular silicon resin and inorganic zirconium salt as raw materials, synthesizes a polysiloxane precursor containing Zr through a sol-gel technology, and prepares the C/SiZrOC composite material through a precursor impregnation cracking method. Compared with the prior C/SiOC composite material, the C/SiZrOC composite material introduces Zr element into the SiOC matrix, and ZrO is generated during high-temperature treatment₂And ZrSiO₄The phase improves the high-temperature stability of the matrix, thereby having better high-temperature resistance.

3. The preparation method is simple, the operation is convenient, the cost is low, and the obtained C/SiZrOC composite material can increase the long-life service temperature of the C/SiOC composite material in an inert environment to over 1600 ℃.

Drawings

FIG. 1 is a SEM image of a cross section of a C/SiOC composite material prepared in example 1 of the present invention after heat treatment in an inert atmosphere at 1300 ℃ and 1600 ℃.

FIG. 2 is a cross-sectional SEM of a carbon fiber reinforced SiZrOC (C/SiZrOC) composite material prepared in example 1 of the present invention after heat treatment in an inert atmosphere at 1300 ℃ and 1600 ℃.

Detailed Description

The present invention is described in further detail below by way of examples, which should not be construed as limiting the invention thereto.