阅读说明：本技术 一种碳纤维混杂保护方法及其耐烧蚀复合材料制备 (Carbon fiber hybrid protection method and preparation of ablation-resistant composite material thereof ) 是由 秦岩 邹镇岳 傅华东 李壮壮 黄志雄 于 2019-10-11 设计创作，主要内容包括：本发明公开了一种碳纤维混杂保护方法及其耐烧蚀复合材料制备。本发明的碳纤维保护方法为碳纤维束整体保护法,采用夹芯包覆的形式将一层短切陶瓷纤维增强复合材料包覆在一束碳纤维表面。在超高温条件下,外保护层发生熔融反应,生成的熔融物质弥散填充缝隙并与陶瓷纤维粘结形成统一结构,使短切陶瓷纤维形成类似长纤维结构,提高其强度,同时保护层转化为致密的、可绝氧的纤维增强陶瓷壳体,有效的保护碳纤维,提高碳纤维的高温力学强度,使其可满足具有高温烧蚀结构强度的应用,同时用其增强的耐烧蚀复合材料在长时间处于高温条件下可具有良好的结构力学强度。本发明的碳纤维混杂保护方法具有低成本,工艺简单,可设计性强的优点。(The invention discloses a carbon fiber hybrid protection method and preparation of an ablation-resistant composite material thereof. The carbon fiber protection method is an integral protection method of the carbon fiber bundle, and a layer of chopped ceramic fiber reinforced composite material is coated on the surface of the carbon fiber bundle in a sandwich coating mode. Under the condition of ultrahigh temperature, the outer protective layer is subjected to melting reaction, the generated molten substance is dispersed and filled in gaps and is bonded with ceramic fibers to form a unified structure, so that the chopped ceramic fibers form a long fiber-like structure, the strength of the chopped ceramic fibers is improved, meanwhile, the protective layer is converted into a compact fiber-reinforced ceramic shell capable of insulating oxygen, the carbon fibers are effectively protected, the high-temperature mechanical strength of the carbon fibers is improved, the application of the high-temperature ablation structural strength can be met, and simultaneously, the ablation-resistant composite material reinforced by the protective layer can have good structural mechanical strength under the condition of being at high temperature for a long time. The carbon fiber hybrid protection method has the advantages of low cost, simple process and strong designability.)

1. The carbon fiber hybrid protection method is characterized in that the hybrid carbon fiber protected by the method contains the following components in parts by mass: 50 parts of carbon fiber, 50-100 parts of chopped ceramic fiber and 5-10 parts of sizing agent.

2. The carbon fiber hybrid protection method according to claim 1, wherein said carbon fiber is one or more of PAN-based carbon fiber and pitch-based carbon fiber.

3. The carbon fiber hybrid protection method according to claim 1, wherein the chopped ceramic fiber is one or more of zirconia fiber, alumina fiber, silicon carbide fiber, and the fiber length is 0.1-2 mm.

4. The carbon fiber hybrid protection method according to claim 1, wherein the sizing agent is an inorganic hybrid modified high temperature resistant thermosetting resin, the inorganic is a mixture of low melting point metal oxide and mineral, and the high temperature resistant thermosetting resin is one or more of phenolic resin, modified phenolic resin, benzoxazine resin and polyarylacetylene resin.

5. The carbon fiber hybrid protection method according to claim 1, which is a carbon fiber bundle integral protection method, and specifically comprises the steps of taking a bundle of carbon fibers as a core material, and coating a layer of chopped ceramic fiber reinforced composite material on the outer surface of the core material as a protection layer to form a sandwich coating structure.

6. The carbon fiber hybrid protection method according to claim 5, wherein the protective layer is a ceramic fiber reinforced resin matrix composite shell formed by compounding a sizing agent as a matrix and chopped ceramic fibers as a reinforcing material, and the ceramic fibers are orderly arranged along the direction of the carbon fibers.

7. The carbon fiber hybrid protection method according to claim 5, wherein the carbon fiber bundle integral protection method is characterized in that a sizing agent is subjected to a melting reaction at a high temperature, and the generated molten substance is dispersed and filled in gaps and bonded with ceramic fibers to form a unified structure, so that the chopped ceramic fibers form a long fiber-like structure, the strength of the ceramic fibers is improved, and meanwhile, a protection layer is converted into a compact fiber-reinforced ceramic shell capable of insulating oxygen, and the function of preventing the carbon fibers inside from being oxidized is achieved.

8. The preparation method of the ablation-resistant composite material is characterized by preparing a carbon fiber reinforced ablation-resistant composite material protected by mixing, and is characterized by comprising the following steps of:

step 1, dissolving or diluting high-temperature-resistant resin by using a diluent, then adding inorganic powder for fully mixing, and fully infiltrating the mixed resin and the carbon fibers protected by mixing to obtain a mixed carbon fiber prepreg; the mass ratio of the three raw materials is 1: 1: 1;

and 2, putting the hybrid carbon fiber prepreg into an oven for drying, then putting the prepreg into a mold, and heating and curing to obtain the ablation-resistant composite material.

9. The preparation method of the ablation-resistant composite material as claimed in claim 8, wherein in step 1, the high-temperature-resistant resin is one or more of phenolic resin, modified phenolic resin, polyarylacetylene resin and other high-temperature-resistant resins.

10. The preparation of ablation-resistant composite material according to claim 8, wherein in step 1, the inorganic powder is one or more of refractory metal oxide, carbide ceramic.

Technical Field

The invention relates to the technical field of carbon fiber high-temperature protection and ablation-resistant composite materials, in particular to a hybrid protection method which is designed to enable carbon fibers to meet the application requirement of high-temperature ablation structural strength.

Background

When the space shuttle enters the atmosphere, the temperature on the surface of the aircraft can be rapidly raised and can reach thousands of degrees centigrade. The phenolic resin has good ablation resistance, particularly has outstanding instantaneous high-temperature ablation resistance and better scouring resistance, so that the phenolic resin is used as a base material of a high-temperature ablation-resistant composite material in the aerospace industry for a long time, but the composite material is easy to have the problems of layer uncovering, even cracking and the like under the high-temperature airflow scouring in application. The carbon fiber has excellent mechanical properties such as high specific strength, high specific modulus, good toughness and the like, and can be used for reinforcing phenolic resin composite materials, for example, Chinese patent document CN 101440193A discloses a carbon/phenolic aldehyde heat-proof composite material and a manufacturing process thereof, but the carbon fiber is easy to oxidize at high temperature and is difficult to resist high-temperature ablation, so that the performance of the composite material is reduced after the high-temperature ablation.

In order to solve the problems, researchers protect the carbon fiber by coating an anti-oxidation coating on the surface of the carbon fiber, for example, chinese patent document CN 109183422a discloses a preparation method of an anti-oxidation coated carbon fiber, which uses perhydropolysilazane as a raw material, adopts a dipping thermal conversion method, successfully coats a silicon-oxygen-nitrogen coating on the surface of the carbon fiber, rapidly absorbs oxygen molecules in the air in a high-temperature oxidation process, forms an integral protection on the surface of the material, prevents the oxygen molecules from entering the interior of the material, and protects the carbon fiber from being oxidized, thereby significantly improving the anti-oxidation performance of the carbon fiber. For example, chinese patent document CN 105859304B discloses a method for preparing an interface coating of a three-dimensional carbon fiber preform, which comprises mixing polysilazane, a catalyst and a solvent to prepare an immersion liquid, immersing the three-dimensional carbon fiber preform in the immersion liquid, drying, and heating in an atmosphere containing water vapor to form a ceramic coating. However, such methods are complicated in process, high in production cost and not favorable for engineering application.

The invention adopts a carbon fiber whole bundle protection method, a bundle of carbon fibers is taken as a core material, and a layer of chopped ceramic fiber reinforced composite material is coated on the outer surface of the core material to be taken as a protective layer, so that a sandwich coating structure is formed. Under the condition of ultrahigh temperature, the outer protective layer is subjected to melting reaction, the generated molten substance is dispersed and filled in gaps and is bonded with the ceramic fibers to form a unified structure, so that the chopped ceramic fibers form a long fiber-like structure, the strength of the ceramic fibers is improved, and meanwhile, the protective layer is converted into a compact fiber-reinforced ceramic shell capable of insulating oxygen, so that oxygen is prevented from entering the fiber-reinforced ceramic shell, and carbon fibers are effectively protected. The carbon fiber hybrid protection method has the advantages of low cost, simple process and strong designability.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the carbon fiber hybrid protection method and the preparation method of the ablation-resistant composite material are provided to overcome the problem that the carbon fiber in the prior art cannot resist high temperature, so that the problem that the ablation resistance and the mechanical property of a reinforcing material in a heat-resistant material cannot be considered at the same time is solved.

The invention adopts the following technical scheme for solving the technical problems:

the invention provides a carbon fiber hybrid protection method, which comprises the following components in parts by weight: 50 parts of carbon fiber, 50-100 parts of chopped ceramic fiber and 5-10 parts of sizing agent.

In the method, the carbon fiber is one or more of PAN-based carbon fiber and pitch-based carbon fiber.

In the method, the chopped ceramic fiber is one or more of zirconia fiber, alumina fiber and silicon carbide fiber, and the fiber length is 0.1-2 mm.

In the method, the sizing agent is an inorganic hybrid modified high-temperature-resistant thermosetting resin. The inorganic matter is a mixture of low-melting-point metal oxide and mineral matter, and the high-temperature-resistant thermosetting resin is one or more of phenolic resin, modified phenolic resin, benzoxazine resin and polyarylacetylene resin.

The method is an integral protection method for carbon fiber bundles, and particularly relates to a sandwich coating structure formed by taking a bundle of carbon fibers as a core material and coating a layer of chopped ceramic fiber reinforced composite material on the outer surface of the core material as a protection layer.

The protective layer is a ceramic fiber reinforced resin matrix composite shell compounded by taking a sizing agent as a matrix and taking short-cut ceramic fibers as a reinforcing material, and the ceramic fibers are orderly arranged along the direction of the carbon fibers.

The carbon fiber bundle integral protection method is characterized in that a sizing agent is subjected to a melting reaction at a high temperature, generated molten substances are dispersed and filled in gaps and are bonded with ceramic fibers to form a unified structure, short-cut ceramic fibers form a long fiber-like structure, the strength of the ceramic fibers is improved, and meanwhile, a protection layer is converted into a compact fiber-reinforced ceramic shell capable of insulating oxygen, so that the effect of preventing the oxidation of internal carbon fibers is achieved.

The invention provides a preparation method of an ablation-resistant composite material, which is a preparation method of a carbon fiber reinforced ablation-resistant composite material through hybrid protection, and comprises the following steps:

step 1, dissolving or diluting high-temperature-resistant resin by using a diluent, then adding inorganic powder for fully mixing, and fully infiltrating the mixed resin and the carbon fibers protected by mixing to obtain a mixed carbon fiber prepreg; the mass ratio of the three raw materials is 1: 1: 1;

and 2, putting the hybrid carbon fiber prepreg into an oven for drying, then putting the prepreg into a mold, and heating and curing to obtain the ablation-resistant composite material.

In the step 1, the high-temperature resistant resin is one or a mixture of more of high-temperature resistant resins such as phenolic resin, modified phenolic resin, polyarylacetylene resin and the like.

In the step 1, the inorganic powder is one or more of refractory metal oxide and carbide ceramic.

In the method, the drying temperature in the step 1 is 60-80 ℃, and the drying time is 2-3 h.

In the method, the curing process in the step 2 comprises the following steps: heating to 120 ℃ at the heating rate of 5-10 ℃/min, keeping the temperature for 1h, then heating to 180 ℃, pressurizing to 8-10MPa, keeping the temperature and pressure for 2h, and finally keeping the pressure unchanged, heating to 200 ℃, keeping the temperature and pressure for 1 h.

Compared with the prior carbon fiber protection technology, the invention has the following main advantages:

the carbon fiber protection method adopted by the invention is an integral bundle protection method, a bundle of carbon fibers is used as a core material, and a layer of chopped ceramic fiber reinforced composite material is coated on the outer surface of the core material and used as a protection layer to form a sandwich coating structure. The method has the advantages of simple preparation process, high efficiency and low cost.

Secondly, in the carbon fiber hybrid protection method, the low-melting-point inorganic particles are subjected to melting reaction at high temperature, and the generated molten substance is dispersed and filled in gaps, so that the protection layer is converted into a compact fiber-reinforced ceramic shell capable of insulating oxygen, oxygen is prevented from entering, and the carbon fibers are effectively protected.

Thirdly, according to the carbon fiber hybrid protection method, the chopped ceramic fibers are directionally arranged along the direction of the carbon fibers, and the molten substance is bonded with the ceramic fibers under the high-temperature condition, so that the ceramic fibers form a long fiber-like structure, the strength of the ceramic fibers is improved, and the ceramic fibers and the internal carbon fibers have a synergistic effect, so that the ablation-resistant composite material is further enhanced. Due to the adoption of the hybrid protection method, the prepared ablation-resistant composite material has good high-temperature mechanical properties.

Drawings

FIG. 1 is a schematic representation of a hybrid protected carbon fiber structure.

Detailed Description

The invention discloses a carbon fiber hybrid protection method and preparation of an ablation-resistant composite material thereof. The carbon fiber protection method is an integral protection method of the carbon fiber bundle, and a layer of chopped ceramic fiber reinforced composite material is coated on the surface of the carbon fiber bundle in a sandwich coating mode. Under the condition of ultrahigh temperature, the outer protective layer is subjected to melting reaction, the generated molten substance is dispersed and filled in gaps and is bonded with ceramic fibers to form a unified structure, so that the chopped ceramic fibers form a long fiber-like structure, the strength of the chopped ceramic fibers is improved, meanwhile, the protective layer is converted into a compact fiber-reinforced ceramic shell capable of insulating oxygen, the carbon fibers are effectively protected, the high-temperature mechanical strength of the carbon fibers is improved, the application of the high-temperature ablation structural strength can be met, and simultaneously, the ablation-resistant composite material reinforced by the protective layer can have good structural mechanical strength under the condition of being at high temperature for a long time. The carbon fiber hybrid protection method has the advantages of low cost, simple process and strong designability.

The invention is further illustrated but not limited by the following examples and the accompanying drawings.