Preparation system and application of fiber-reinforced ceramic-based composite material

Abstract

The invention provides a preparation system of a fiber reinforced ceramic matrix composite material. The preparation system comprises a pressure device, a precursor resin providing device, a hot pressing device, a to-be-impregnated vacuum film bag, a precursor resin collecting device and a vacuum pump, the pressure device is connected with the precursor resin supply device; the to-be-impregnated vacuum film bag is arranged in the hot pressing device and is connected with the precursor resin supplying device and the precursor resin collecting device through the hot pressing device; an outlet of the hot pressing device is connected with an inlet of the precursor resin collecting device, and an outlet of the precursor resin collecting device is connected with the vacuum pump. The invention further provides application of the preparation system. According to the preparation system provided by the invention, efficient preparation of the fiber reinforced ceramic matrix composite can be realized, and the impregnation efficiency is improved; furthermore, the preparation system provided by the invention can be used for preparing large-size and complex-structure composite materials.

Description

Technical Field

[0001] The invention relates to the technical field of fiber reinforced ceramic matrix composite materials, and in particular to a preparation system and application of a fiber reinforced ceramic matrix composite material. Background Art

[0002] Fiber-reinforced ceramic matrix composites have attracted more and more attention from material workers in recent years due to their excellent properties such as high strength, high toughness, high temperature resistance, good corrosion resistance and low density at high temperatures. At present, there are many process methods for preparing fiber-reinforced ceramic matrix composites, mainly including hot pressing, reaction sintering, direct melt oxidation, chemical vapor infiltration, sol-gel, precursor conversion method (PIP), etc. Among them, the precursor conversion method uses the technology of converting precursor organic polymers into ceramics to prepare ceramics and ceramic matrix composites. It is a relatively advanced and effective method with the advantages of simple process and low cost. An important process link in the process of preparing fiber-reinforced ceramic matrix composite preforms by the precursor conversion method is the impregnation process. The quality of the impregnation process directly affects the densification of the fiber-reinforced ceramic matrix composites, thereby affecting the material properties.

[0003] In the traditional PIP process, due to the volatilization of organic solvents and the escape of low-density hydrocarbons, the number of PIP cycles eventually reaches more than ten times, resulting in a long preparation cycle for composite materials prepared by the PIP process. According to the engineering application needs of fiber-reinforced ceramic matrix composites, shortening the composite material manufacturing cycle and reducing production costs are the only way for future development; and for the adjustment of composite material processes, providing a new system for PIP process impregnation is of great significance. Summary of the invention

[0004] The technical problem solved by the present invention is to provide a preparation system for fiber-reinforced ceramic-based composite materials. The preparation system provided by the present application can realize the efficient preparation of fiber-reinforced ceramic-based composite materials and improve the impregnation efficiency; further, the preparation system provided by the present application can also prepare large-sized and complex-structured composite materials.

[0005] In view of this, the present application provides a preparation system for a fiber-reinforced ceramic matrix composite material, comprising: a pressure device, a precursor resin providing device, a hot pressing device, a vacuum film bag to be impregnated, a precursor resin collecting device and a vacuum pump;

[0006] The pressure device is connected to the precursor resin providing device;

[0007] The vacuum membrane bag to be impregnated is arranged inside the hot pressing device, and is respectively connected to the precursor resin providing device and the precursor resin collecting device through the hot pressing device;

[0008] The outlet of the hot pressing device is connected to the inlet of the precursor resin collecting device, and the outlet of the precursor resin collecting device is connected to the vacuum pump.

[0009] Preferably, the number of the precursor resin providing devices is ≥1.

[0010] Preferably, the number of the precursor resin providing devices and the number of the precursor resin collecting devices are the same.

[0011] Preferably, the number of the vacuum membrane bags to be impregnated is the same as the number of the precursor resin devices.

[0012] Preferably, the preparation system further comprises a connecting component, which is disposed between the hot pressing device and the precursor resin providing device and the precursor resin collecting device, and is used for connecting the three.

[0013] Preferably, the connecting component is a flange;

[0014] The flange plate consists of a large hole side and a small hole side, the large hole side is connected to the hot pressing device, the first row of small holes on the side is connected to the precursor resin collecting device, and the second row is connected to the precursor resin providing device.

[0015] Preferably, the vacuum membrane bag to be impregnated consists of a first vacuum membrane bag and a second vacuum membrane bag sleeved on the surface of the first vacuum membrane bag.

[0016] Preferably, the first vacuum film bag is provided with a first interface and a second interface, and the second vacuum film bag is provided with a third interface;

[0017] The first interface is connected to the precursor resin collecting device through the first row of small holes on one side of the flange, the second interface is connected to the precursor resin providing device through the second row of small holes on one side of the flange, and the third interface is connected to the precursor resin collecting device through one side of the small holes on the flange.

[0018] Preferably, a vacuum device is also provided inside the precursor resin providing device to achieve vacuum treatment of the precursor resin.

[0019] The present application also provides the application of the preparation system in the PIP process of fiber-reinforced ceramic matrix composite materials.

[0020] The present application provides a preparation system for fiber-reinforced matrix composite materials, which includes a pressure device, a precursor resin supply device, a hot pressing device, a vacuum membrane bag to be impregnated, a precursor resin collecting device and a vacuum pump; wherein the pressure device is connected to the precursor resin supply device, the vacuum membrane bag to be impregnated is arranged inside the hot pressing device, and is respectively connected to the precursor resin supply device and the precursor collecting device through the hot pressing device, the outlet of the hot pressing device is connected to the inlet of the precursor resin collecting device, and the outlet of the precursor resin collecting device is connected to the vacuum pump; in the preparation system provided in the present application, the fiber pre-impregnation vacuum membrane bag is placed by using the precursor resin supply device. Because of the variable structure and flexibility of the vacuum membrane bag to be impregnated, a composite material with large size and complex structure can be prepared; at the same time, the vacuum membrane bag to be impregnated is placed in a hot pressing system, which can realize heating and pressurizing of the precursor resin, overcome flow resistance, and improve the fluidity of the precursor resin in the fiber preform, drive the precursor resin to flow to the fiber preform in the vacuum membrane bag to be impregnated, and at the same time, the precursor resin is impregnated into the fiber preform under pressure without dead ends in the hot pressing device, so that the pressure acting on the normal line of each point on the surface of the true vacuum membrane bag is the same, which greatly improves the impregnation efficiency and is conducive to the densification preparation of the composite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of the structure of a system for preparing a fiber-reinforced ceramic-based composite material provided by the present invention;

[0022] Figure 2 A schematic diagram of the structure of the flange provided by the present invention;

[0023] Among them, 1 is a pressure device, 2 is a precursor resin providing device, 3 is a connecting component, 4 is a hot pressing device, 5 is a precursor resin collecting device, and 6 is a vacuum pump. DETAILED DESCRIPTION

[0024] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0025] In view of the problem of long preparation cycle of fiber-reinforced ceramic-based composite materials in the prior art, the present application provides a preparation system of fiber-reinforced ceramic-based composite materials, which can improve the impregnation efficiency, and only requires 5 to 8 PIP cycles to obtain dense fiber-reinforced ceramic-based composite materials, and can prepare large-sized and complex-shaped fiber-reinforced ceramic-based composite materials; further, the fiber-reinforced ceramic-based composite materials of the present application are prepared in a hot pressing device, and there is no need to move the composite materials during the preparation process, thereby ensuring the stability of the composite materials performance; specifically, the embodiment of the present invention discloses a preparation system of fiber-reinforced ceramic-based composite materials, including: a pressure device, a precursor resin providing device, a hot pressing device, a vacuum membrane bag to be impregnated, a precursor resin collecting device and a vacuum pump;

[0026] The pressure device is connected to the precursor resin providing device;

[0027] The vacuum membrane bag to be impregnated is arranged inside the hot pressing device, and is respectively connected to the precursor resin providing device and the precursor resin collecting device through the hot pressing device;

[0028] The outlet of the hot pressing device is connected to the inlet of the precursor resin collecting device, and the outlet of the precursor resin collecting device is connected to the vacuum pump.

[0029] The structural schematic diagram of the preparation system provided in this application is as follows Figure 1 As shown, 1 is a pressure device, 2 is a precursor resin providing device, 3 is a connecting component, 4 is a hot pressing device, 5 is a precursor resin collecting device, and 6 is a vacuum pump.

[0030] Specifically, the vacuum membrane bag to be impregnated (not marked in the figure) is used to place the fiber preform to be impregnated. The vacuum membrane bag to be impregnated is a vacuum film well known to those skilled in the art, which has the characteristics of good flexibility, large size, and arbitrarily adjustable structure. The vacuum membrane bag to be impregnated is used as a sealing model for the fiber preform, which can wrap the fiber preform as a whole, so that the precursor resin is subjected to the normal force without dead angles, thereby improving the impregnation driving force and being more conducive to the preparation of large-sized and complex-structured components. In order to ensure the sealing effect, the vacuum membrane bag to be impregnated is composed of a first vacuum membrane bag and a second vacuum membrane bag sleeved on the surface of the first vacuum membrane bag.

[0031] The vacuum membrane bag to be impregnated is arranged inside the hot pressing device (4). In a specific embodiment, the hot pressing device (4) is a hot pressing tank. In addition to retaining all the functions of conventional hot pressing tanks in the prior art, such as heating and pressurizing, it also needs to have a channel for the precursor resin to enter and a channel for the precursor resin to flow out. The channel for the precursor resin to enter is connected to the precursor resin supply device (2), and the channel for the precursor resin to flow out is connected to the precursor resin collection device (5); therefore, the hot pressing tank should be provided with a channel at a suitable position on the tank wall to achieve the above connection. The channel is used to connect the vacuum membrane bag to be impregnated inside the hot pressing device (3) with the precursor resin supply device (2) and the precursor resin collection device (5) outside the hot pressing device (3) through a connecting component (3), specifically a flange; the flange is preferably arranged on the outer wall of the hot pressing device (3).

[0032] In some specific embodiments, three interfaces are reserved on the vacuum membrane bag to be impregnated, the first vacuum membrane bag is provided with two interfaces, and the second vacuum membrane bag is provided with one interface; the two interfaces reserved on the first vacuum membrane bag are respectively connected to the precursor resin providing device (2) and the precursor resin collecting device (5), which are respectively used for the inflow of the precursor resin and the vacuum treatment of the vacuum membrane bag to be impregnated, and the outflow of the precursor resin; one interface of the second vacuum membrane bag is connected to the precursor resin collecting device (5), and the vacuum pump connected to the precursor resin collecting device (5) is used to realize the vacuum treatment of the vacuum membrane bag to be impregnated, so that the vacuum membrane bag to be impregnated is in a negative pressure state, which is conducive to the introduction of the precursor resin.

[0033] In some specific embodiments, the connecting member (3) is specifically a flange, and its structure is as follows: Figure 2 As shown, one side is a large hole and the other side is a small hole, and the large hole side is connected to the hot pressing device (4), and the small hole side is divided into a first row and a second row distributed up and down, wherein the first row is connected to the precursor resin collecting device (5) through a hose, and the second row is connected to the precursor resin providing device (2) through a hose, and the connecting component (3) can change the number of small holes by replacing the flange component.

[0034] In some specific embodiments, the number of the precursor resin providing device (2) is ≥1. On this basis, the number of the precursor resin providing device (2) and the precursor resin collecting device (5) is the same. The precursor resin providing device (2) is divided into multiple pipelines through a connecting component (3) and connected to the interior of a hot pressing device (4) to connect with an equal number of vacuum membrane bags to be impregnated, thereby realizing the preparation of multiple fiber-reinforced ceramic-based composite materials at the same time. In the example, three precursor resin providing devices (2) are respectively connected to the three small holes at the lower end of the flange (3) through hoses, and the corresponding small holes on the inner side of the flange (3) are also connected to one side of the vacuum membrane bag to be impregnated with the fiber preform through hoses, and the other side of the vacuum membrane bag to be impregnated is also connected to the three small holes on the upper inner side of the flange (3) through hoses, and the three small holes on the upper outer side of the flange (3) are respectively connected to the three precursor resin providing devices (5) through polyurethane hoses; the three precursor resin providing devices (5) are all connected to the vacuum pump (6); the flange provides a multi-channel function, which can realize the simultaneous preparation of multiple fiber-reinforced ceramic-based composite materials.

[0035] The preparation system provided in the present application can realize the simultaneous vacuuming of n fiber preforms in vacuum membrane bags to be impregnated, and control the injection of n precursor resins of the same or different types by switching ball valves. At the same time, the resin overflow can be observed from the resin precursor collection device (5) outside the hot pressing device (4), and the process setting program is executed. After the impregnation is completed, the resin is heated and cured, cooled and depressurized, and the sample is demoulded.

[0036] The precursor resin providing device (2) is a storage container for the precursor resin, which is used to provide the precursor resin. In some specific embodiments, the precursor resin providing device (2) is provided with a vacuum device. After the precursor resin is prepared, the precursor resin is vacuumed to remove the air in the precursor resin. The precursor resin providing device (2) is also connected to the pressure device (1) through a metal pipe, so that the pressure device (1) can pressurize the precursor resin providing device (2) and introduce the precursor resin into the vacuum film bag to be impregnated in the hot pressing device (4) to impregnate the fiber preform. The pressure device can apply pressure through air, nitrogen, or other means, and the present application does not impose any special restrictions on this. In some specific embodiments, the precursor resin providing device (2) is also provided with a heating control unit to heat the precursor resin with higher viscosity, reduce the viscosity, and improve its fluidity.

[0037] The above-mentioned precursor resin collection device (5) is a collection container for surplus resin, which is connected to the vacuum membrane bag to be impregnated through a connecting component (3). The pipeline material therein is a high-pressure resistant pipeline. There should be a valve switch in the pipeline, which is opened during the vacuuming and precursor resin solution entry process and closed when the entry process is completed.

[0038] The outlet of the precursor resin collecting device (5) is connected to the vacuum pump (6), and the vacuum pump (6) is used to perform vacuum treatment on the vacuum membrane bag to be impregnated.

[0039] The present application also provides application of the preparation system in a PIP process of fiber-reinforced ceramic-based composite materials.

[0040] In some specific embodiments, the preparation method of the preparation system in the fiber reinforced ceramic matrix composite material PIP process is specifically as follows:

[0041] Placing the fiber preform in the vacuum bag film to be impregnated, placing the vacuum bag film to be impregnated in a hot pressing device (4), and then evacuating the vacuum bag film to be impregnated by a vacuum pump (6) so that the vacuum bag film to be impregnated is in a negative pressure state;

[0042] Placing the precursor resin in a precursor resin providing device (2), and starting the vacuum system of the precursor resin providing device (2) to evacuate the precursor resin;

[0043] The flow of the precursor resin is controlled by a switch valve in the pipeline of the precursor resin providing device (2). First, the precursor resin is slowly introduced into the fiber preform through the vacuum negative pressure in the vacuum film bag to be impregnated. When the precursor resin flows into the precursor resin collecting device (5) connected to the vacuum pump (6), the switch valve for the outflow of the precursor resin is closed, and the pressure device (1) is used to apply pressure to the precursor resin providing device so that the fiber preform in the vacuum film bag to be impregnated is in the precursor resin-rich area. Then, the entry channel of the precursor resin is closed to complete the first round of impregnation process; during the impregnation process, the pressurization program of the hot pressing device (4) is started to perform pressurized impregnation;

[0044] After the pressurized impregnation, the temperature-raising curing program of the hot pressing device (4) is started to cure and crosslink the precursor; then pyrolysis is carried out in a high-temperature furnace; and finally the above impregnation-curing-pyrolysis process is repeated at least once, preferably 5 to 8 times.

[0045] In the present application, the fiber preform is selected from fibers that have been needled, stitched or woven, and the fibers are selected from one or more of carbon fiber T300, carbon fiber T700, carbon fiber M40 and silicon carbide fiber; in some specific embodiments, the fiber preform can be of regular shape or irregular shape. The precursor resin is selected from one of polycarbosilane, polysiloxane, polynitrosilane and polyborosilazane.

[0046] The experimental results show that the Cf / SiC composite material prepared by the preparation system of the fiber-reinforced ceramic matrix composite material provided by the present application is preferably subjected to 6 to 8 repeated impregnation-curing-cracking, and the density of the composite material is 2.1 to 2.2 g / cm 3 The open porosity is 5-8%. The prepared Cf / SiOC composite material is preferably subjected to 6-8 repeated impregnation-curing-cracking processes, and the density of the composite material is 1.9-2.1 g / cm 3 , the open porosity is 5-8%.

[0047] The above embodiments are only used to help understand the method and core idea of ​​the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0048] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A system for preparing a fiber-reinforced ceramic matrix composite material, comprising: A pressure device, a precursor resin supply device, a hot pressing device, a vacuum membrane bag to be impregnated, a precursor resin collection device and a vacuum pump; The pressure device is connected to the precursor resin providing device; The vacuum membrane bag to be impregnated is arranged inside the hot pressing device, and is respectively connected to the precursor resin providing device and the precursor resin collecting device through the hot pressing device; The outlet of the hot pressing device is connected to the inlet of the precursor resin collecting device, and the outlet of the precursor resin collecting device is connected to the vacuum pump.

2. The preparation system according to claim 1, characterized in that: The number of the precursor resin providing devices is ≥1.

3. The preparation system according to claim 2, characterized in that: The number of the precursor resin providing devices and the number of the precursor resin collecting devices are the same.

4. The preparation system according to claim 3, characterized in that: The number of the vacuum membrane bags to be impregnated is the same as the number of the precursor resin devices.

5. The preparation system according to claim 1, characterized in that: The preparation system further comprises a connecting component, which is arranged between the hot pressing device and the precursor resin providing device and the precursor resin collecting device, and is used for connecting the three.

6. The preparation system according to claim 5, characterized in that: The connecting component is a flange; The flange plate consists of a large hole side and a small hole side, the large hole side is connected to the hot pressing device, the first row of small holes on the side is connected to the precursor resin collecting device, and the second row is connected to the precursor resin providing device.

7. The preparation system according to claim 6, characterized in that: The vacuum membrane bag to be impregnated consists of a first vacuum membrane bag and a second vacuum membrane bag sleeved on the surface of the first vacuum membrane bag.

8. The preparation system according to claim 7, characterized in that: The first vacuum film bag is provided with a first interface and a second interface, and the second vacuum film bag is provided with a third interface; The first interface is connected to the precursor resin collecting device through the first row of small holes on one side of the flange, the second interface is connected to the precursor resin providing device through the second row of small holes on one side of the flange, and the third interface is connected to the precursor resin collecting device through one side of the small holes on the flange.

9. The preparation system according to claim 1, characterized in that: The precursor resin providing device is also provided with a vacuum device inside to realize vacuum treatment of the precursor resin.

10. Use of the preparation system according to any one of claims 1 to 9 in a PIP process of fiber reinforced ceramic matrix composites.

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