WO2023124122A1

WO2023124122A1 - Carbon fiber preform and production method therefor, and high-temperature-resistant carbon-carbon composite

Info

Publication number: WO2023124122A1
Application number: PCT/CN2022/113343
Authority: WO
Inventors: 杜路路; 赵领航; 成路; 姚宏; 段滨; 范文斌; 黄志鹏; 高攀红
Original assignee: 隆基绿能科技股份有限公司
Priority date: 2021-12-30
Filing date: 2022-08-18
Publication date: 2023-07-06

Abstract

A carbon fiber preform and a production method therefor. The production method comprises: laying at least one layer of a first carbon fiber web on a surface of a carbon fiber aggregate, and then performing needling to form a composite fabric; and arranging a preform main body on the outer surface of a mold. The preform main body is formed by stacking m unit layers, and at least one first region and one second region exist in the preform main body. The density of short carbon fiber filaments penetrating through the unit layer in the first region is greater than the density of short carbon fiber filaments penetrating through the unit layer in the second region, and the unit layer is formed by laying, after the composite fabric is wound, at least one layer of a second carbon fiber web. The first region can greatly increase the longitudinal binding force of the carbon fiber preform, the second region can reduce the damage of longitudinal penetration to continuous carbon fiber bundles and long fibers in wound wires, and the service life of the carbon fiber preform is prolonged by means of the combined action of the first region and the second region.

Description

A carbon fiber prefabricated body and its production method, high temperature resistant carbon-carbon composite body

Cross References to Related Applications

This disclosure is required to be submitted to the China Patent Office on December 30, 2021, with the application number 202111680790.9, titled "a carbon fiber prefabricated body and its production method, and a high-temperature resistant carbon-carbon composite body" and submitted to China on December 30, 2021. Patent Office, application number 202123431482.0, entitled "a carbon fiber prefabricated body and high temperature resistant carbon-carbon composite", the entire content of which is incorporated in this disclosure by reference.

technical field

The present application relates to the technical field of preparation of high-temperature resistant composite materials, in particular to a carbon fiber prefabricated body and a production method thereof, and a high-temperature resistant carbon-carbon composite body.

Background technique

Carbon fiber prefabricated bodies are widely used in the fields of aerospace, friction resistance, and furnace heat field. At present, the production method of carbon fiber prefabricated body is mainly: using two-way plain weave structure and carbon fiber mesh tire to be alternately laminated and needle-punched.

During the study of the above-mentioned prior art, the applicant found that: the carbon fiber preform produced by the existing carbon fiber preform production method has poor longitudinal bonding force and is prone to separation in the longitudinal direction.

Contents of the invention

The present application provides a carbon fiber prefabricated body and its production method, and a high-temperature-resistant carbon-carbon composite body, aiming to solve the problem that the prepared carbon fiber prefabricated body has poor longitudinal bonding force and is prone to separation in the longitudinal direction.

The first aspect of the present application provides a method for producing a carbon fiber preform, the method comprising:

Laying at least one layer of the first carbon fiber grid tire on the surface of the carbon fiber aggregate, and then needling to form a composite cloth; the carbon fiber aggregate includes: continuous carbon fiber bundles;

A preform body is arranged on the outer surface of the mold; the preform body is formed by stacking m unit layers, and each unit layer is stacked with needles, so that there is at least one first region and the preform body in the preform body. A second region; the density of short carbon fiber filaments passing through the unit layer in the first region is greater than the density of short carbon fiber filaments passing through the unit layer in the second region; the first region and the second region are along the unit The stacking direction of the layers is stacked, and the first area is closer to the mold than the second area; m≥1;

The unit layer is formed by laying at least one layer of second carbon fiber mesh after winding the composite cloth.

In the embodiment of the present application, at least one layer of the first carbon fiber mesh tire is laid on the surface of the carbon fiber aggregate, and then needle punched to form a composite cloth, which can strengthen the bonding force between the carbon fiber aggregate and the first carbon fiber mesh tire in the longitudinal direction, and reduce the carbon fiber aggregate. The carbon fiber aggregate is layered with the first carbon fiber mesh tire. In the first region of the carbon fiber prefabricated body, the density of the short carbon fiber filaments passing through the unit layer is relatively high. In the longitudinal direction, it can not only prevent the prefabricated body from being separated from the needle-punched buffer layer, but also reduce the bond between the composite cloth and the first carbon fiber mesh tire and the second carbon fiber mesh tire. Separation between carbon fiber mesh tires. At the same time, the density of the short carbon fiber filaments penetrating through the unit layer in the second region of the carbon fiber preform is relatively small, which can minimize the damage to the continuous carbon fiber bundles and long fibers in the winding filaments caused by longitudinal penetration. That is to say, the first area can greatly improve the longitudinal bonding force of the carbon fiber preform, so that the carbon fiber preform is not easy to separate in the longitudinal direction; The joint effect of the first area and the second area greatly improves the life of the carbon fiber prefabricated body. The first area is closer to the mold than the second area, which is easier to achieve by needling. Moreover, the density of short carbon fiber filaments penetrating through the unit layer in the second region is slightly smaller, which can reduce the needling time, thereby improving the production efficiency.

Optionally, the needling density of the first region is greater than that of the second region.

Optionally, the total thickness of the m unit layers stacked in the prefabricated body is h millimeters, h>0, and the needling depth is fixed at x millimeters, x>0, each needle After piercing a unit layer, the needle is lifted by y millimeters away from the mold, y>0, so that among the stacked m unit layers, the front (h-x+y) thickness area is the first area, and the remaining areas are the second area .

Optionally, h>x, in the body of the preform, the needle punching density of the front (h-x+y) thickness region is equal, and the needle punching density of the remaining regions is smaller than the needle punching density of the front (h-x+y) thickness region Prick density.

Optionally, in the process of needling the stacked unit layers, x is the thickness of the first n unit layers, n≥1, m>n, and y is the thickness of 1 unit layer, so that the first n+1 unit layers The needle punching density is equal, ranging from the n+2th unit layer to the mth unit layer; the thickness of the unit layer is the size of the unit layer in the direction in which the unit layer is stacked; the first n+1 layer The unit layer is the first area, and the unit layers from the n+2th layer to the mth layer are the second area.

Optionally, the thickness of each unit layer is equal, and the needling density decreases successively from the n+2th unit layer to the mth unit layer.

Optionally, the thickness of the composite cloth is greater than 0.5mm.

Optionally, the needling density of the first region is greater than or equal to 20 needles/cm ² .

Optionally, the areal density of the first carbon fiber mesh tire is 50g/m ² -120g/m ² ; the areal density of the second carbon fiber mesh tire is less than or equal to the areal density of the first carbon fiber mesh tire; and/or, the composite cloth The surface density is 100g/m ² -600g/m ² .

The second aspect of the present application provides a carbon fiber prefabricated body, including: a prefabricated body body; the prefabricated body body is composed of m stacked unit layers; m≥1;

The unit layer is composed of at least one layer of second carbon fiber mesh after the composite cloth is wound;

The composite cloth is composed of at least one layer of the first carbon fiber net tire stacked on the plane of the fiber assembly; the carbon fiber assembly includes: continuous carbon fiber bundles;

In the preform body, there are at least one first region and one second region, the density of the short carbon fiber filaments passing through the unit layer in the first region is greater than the density of the short carbon fiber filaments passing through the unit layer in the second region; the first The area and the second area are stacked and distributed along the stacking direction of the unit layers, and the first area is closer to the axis of the preform body than the second area.

Optionally, the total thickness of the m unit layers stacked in the preform body is h millimeters, h>0, the acupuncture depth of the unit layer after stacking is fixed at x mm, x>0, after each unit layer is needled, The puncturing needle is lifted by y millimeters away from the mold, y>0, and among the stacked m unit layers, the front (h-x+y) thickness area is the first area, and the remaining areas are the second area.

Optionally, x is the thickness of the first n unit layers, n≥1, m>n, y is the thickness of 1 unit layer, and the needle punching density of the first n+1 unit layers is equal, starting from the n+2th layer The needle punching density of the unit layer to the mth layer unit layer is not equal; the thickness of the unit layer is the size of the unit layer in the direction in which the unit layer is stacked; the first n+1 layer unit layer is the first area, and the nth The +2 unit layer to the mth unit layer are the second area.

Optionally, the thickness of the composite cloth is greater than 0.5mm.

In the third aspect of the present application, a high temperature resistant carbon-carbon composite body is provided, including:

p unit layers; p≥1; in the case of p>1, each unit layer is stacked;

The composite cloth is composed of at least one layer of carbon fiber nets stacked on the plane of carbon fiber aggregates; the carbon fiber aggregates include: continuous carbon fiber bundles;

There is at least one first region and one second region in the high-temperature-resistant carbon-carbon composite, and the density of short carbon fiber filaments penetrating the unit layer in the first region is greater than the density of short carbon fiber filaments penetrating the unit layer in the second region; The first area and the second area are stacked and distributed along the stacking direction of the unit layers, and the first area is closer to the axis of the high temperature resistant carbon-carbon composite than the second area.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments of the present application. Obviously, the accompanying drawings in the following description are only some embodiments of the present application , for those skilled in the art, other drawings can also be obtained according to these drawings without paying creative labor.

Fig. 1 shows the step flowchart of the production method of a kind of carbon fiber prefabricated body in the embodiment of the present application;

Fig. 2 shows a schematic structural view of a carbon fiber preform in the embodiment of the present application;

Fig. 3 shows a schematic structural view of another carbon fiber preform in the embodiment of the present application.

Explanation of attached drawing numbers:

101 - first area, 102 - second area, 103 - mold.

specific embodiment

The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of them. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts all belong to the scope of protection of this application.

Fig. 1 shows a flowchart of steps of a method for producing a carbon fiber preform in an embodiment of the present application. Fig. 2 shows a schematic structural view of a carbon fiber preform in an embodiment of the present application. With reference to Fig. 1, the production method of this carbon fiber preform comprises the steps:

Step S1, laying at least one layer of the first carbon fiber mat on the surface of the carbon fiber aggregate, and then needling to form a composite cloth; the carbon fiber aggregate includes: continuous carbon fiber bundles.

The carbon fiber assembly includes continuous carbon fiber bundles. Specifically, the carbon fiber assembly may include at least one of: carbon fiber plain weave cloth, carbon fiber twill cloth, carbon fiber non-woven cloth, and at least one bundle of carbon fiber filament bundles arranged in parallel in a plane.

Lay at least one layer of the first carbon fiber mesh tire on the surface of the carbon fiber aggregate, and then needle punch to form a composite cloth, which can enhance the bonding force between the carbon fiber aggregate and the first carbon fiber mesh tire, and reduce the carbon fiber aggregate and the first carbon fiber mesh tire. layered. The number of layers of the first carbon fiber mesh laid on the surface of the carbon fiber aggregate is not specifically limited.

Step S2, setting the preform body on the outer surface of the mold; the preform body is formed by stacking m unit layers, and after each unit layer is stacked, it is needled with a needle, so that there is at least one first unit layer in the preform body A region and a second region; the density of the short carbon fiber filaments passing through the unit layer in the first region is greater than the density of the short carbon fiber filaments passing through the unit layer in the second region; the first region and the second region are along the The stacking direction of the unit layer is stacked and distributed, and the first area is closer to the mold than the second area; m≥1; the unit layer is: after winding the composite cloth, laying At least one layer of second carbon fiber net tire is formed.

The shape and size of the mold can correspond to those of the high-temperature-resistant carbon-carbon composite or carbon fiber preform, which is not specifically limited in this embodiment of the present application.

After winding the composite cloth, at least one layer of the second carbon fiber net tire is laid and needle-punched to form a unit layer. In the process of forming the unit layer, how many layers of the second carbon fiber mesh tire are laid is not specifically limited. The preform body is formed by stacking m unit layers, m≧1, and there is no specific limitation on how many unit layers the preform body is formed by stacking. Each unit layer is stacked and punched with a needle, so that at least one first region and one second region exist in the preform body. The specific number of the first region and the second region in the preform body is not specifically limited, and whether the two numbers are equal is also not specifically limited. The density of short carbon fiber filaments penetrating the unit layer in the first region is greater than the density of short carbon fiber filaments penetrating the unit layer in the second region. The first area and the second area are stacked and distributed along the stacking direction of the unit layers, and the first area is closer to the mold than the second area. That is to say, the first area is located on the inner side of the carbon fiber preform, and the second area is located on the outer side of the carbon fiber preform.

As shown with reference to FIG. 2 , FIG. 2 may be a sectional view of the carbon fiber preform along the stacking direction of the unit layers. The carbon fiber preform shown in FIG. 2 may include a first region 101 and a second region 102 , and the first region 101 is closer to the mold 103 than the second region 102 . The black dots in the figure are short carbon fiber filaments penetrating the unit layer. The density of the short carbon fiber filaments penetrating the unit layer in the first region 101 is obviously higher than the density of the short carbon fiber filaments penetrating the unit layer in the second region 102 .

The carbon fiber short filaments running through the unit layer mainly play the role of increasing the longitudinal bonding force and preventing longitudinal separation. In the prior art, in order to reduce the separation of carbon fiber preforms in the longitudinal direction, only the method of increasing needle punching is usually used. The applicant found that only a single method of increasing needle punching would cause the carbon fiber filaments in the carbon fiber preform to be A large number of punctures reduces the overall strength. However, in the embodiment of the present application, the density of short carbon fiber filaments penetrating through the unit layer in the first region 101 of the carbon fiber preform is relatively high. In the longitudinal direction, it can not only prevent the preform from being separated from the needle-punched buffer layer, but also reduce the contact between the composite cloth and the needle-punched buffer layer. The first carbon fiber net tire and the second carbon fiber net tire are separated. At the same time, the density of the short carbon fiber filaments penetrating through the unit layer in the second region 102 of the carbon fiber preform is relatively small, so that the damage to the continuous carbon fiber bundles and the long fibers in the winding filaments caused by longitudinal penetration can be reduced as much as possible. That is to say, the first region 101 can greatly improve the longitudinal bonding force of the carbon fiber preform, so that the carbon fiber preform is not easy to separate in the longitudinal direction, and the second region 102 can reduce the damage to the continuous carbon fiber bundle and the long fiber in the winding through the longitudinal penetration. , through the joint action of the first region 101 and the second region 102, the service life of the carbon fiber preform is greatly improved. The first area 101 is closer to the mold 103 than the second area 102, which is easy to implement by needling. Moreover, the density of short carbon fiber filaments penetrating through the unit layer in the second region 102 is slightly smaller, which can reduce the needling time and improve the production efficiency.

The above-mentioned short carbon fiber filaments penetrating the unit layer may be short carbon fiber filaments in the first carbon fiber mesh tire and the second carbon fiber mesh tire, or carbon fiber short filaments formed by punctured carbon fiber filaments. In the embodiment of the present application, no specific limitation is made on this.

The density of short carbon fiber filaments that penetrate the unit layer in the first region is greater than the density of short carbon fiber filaments that penetrate the unit layer in the second region, which may make the density of the first region greater than the density of the second region. The unit of density is g/ cm ³ (g/cubic centimeter), that is to say, the bulk density of the first region is relatively large.

Optionally, the needle punching density of the first region is greater than the needle punching density of the second region, and the unit of the needle punching density can be needles/cm ² (needles/square centimeter), and then the short carbon fibers brought through the unit layer by the needles The density of the filaments is also high, and the needle punching density in the second area is small, and the density of the short carbon fiber filaments brought in by the needles through the unit layer is also small, which is easy to process and realize, and the needle punching density in the second area is small, which can reduce needle punching. time, thereby increasing the production efficiency. The unit of needling density may be needles/cm ² .

Optionally, the total thickness of the m unit layers stacked in the prefabricated body is h millimeters, h>0, and the needling depth is fixed at x millimeters, x>0, each needle After piercing a unit layer, the needle is lifted by y millimeters away from the mold, y>0, so that among the stacked m unit layers, the front (h-x+y) thickness area is the first area, and the remaining areas are the second area , the acupuncture method is more specific and easy to implement. The total thickness of the stacked m unit layers is the size of the stacked m unit layers in the stacking direction.

For example, the total thickness of the stacked m unit layers in the prefabricated body is 28mm (millimeters). In the process of needling the stacked unit layers, the needling depth is fixed at 1.4mm. Lift 1 mm away from the mold. That is to say, h=28, x=1.4, y=1, then, h-x+y=27.6mm. Among the stacked m unit layers, the first 27.6 mm is the first area, and the remaining areas are the second area. The density of short carbon fiber filaments penetrating the unit layer in the first 27.6 mm region is greater than the density of short carbon fiber filaments penetrating the unit layer in the rear 0.4 mm region.

Optionally, h>x, in the body of the preform, the needle punching density of the front (h-x+y) thickness region is equal, and the needle punching density of other regions is less than the needle punching density of the front (h-x+y) thickness region , the densities of short carbon fiber filaments running through the unit layer in the front (h-x+y) thickness region are also roughly equal, and the force in the front (h-x+y) thickness region is more uniform, which is beneficial to improve the life of the carbon fiber preform, and The needling method is easier to implement.

Optionally, in the process of needling the stacked unit layers, x is the thickness of the first n unit layers, n≥1, m>n, and y is the thickness of 1 unit layer, so that the first n+1 unit layers The needle punching density is equal, and the needle punching density varies from the n+2th unit layer to the mth unit layer; the thickness of the unit layer is the size of the unit layer in the direction of the unit layer stacking. The first n+1 unit layer is the first area, and the n+2th unit layer to the m-th unit layer is the second area. The needling method is related to the thickness of the unit layer, making it easier to implement.

For example, m=20, n=10, the thickness x of the first n unit layers is 14mm, and the thickness y of one unit layer is 1.4mm. After each needle-punched unit layer, the needle lifts 1.4mm away from the mold, The first 11 unit layers were completely pierced 10 times, the needle punching density of the first 11 unit layers was equal, and the needle punching density varied from the 12th unit layer to the 20th unit layer. The thickness of the unit layer is the dimension of the unit layer in the direction in which the unit layers are stacked. The first 11 unit floors are the first area, and the unit floors from the 12th to the 20th floor are the second area.

Optionally, the thickness of each unit layer is equal, and the needle punching density decreases successively from the n+2th unit layer to the mth unit layer, thereby successively reducing the impact of needle punching on the continuous carbon fiber bundle and the long fiber in the winding. damage, and further greatly increase the life of the carbon fiber prefabricated body.

For example, for the above example, if the thickness of each unit layer is equal to 1.4mm, then the first 11 unit layers are completely pierced 10 times, and the acupuncture density of the first 11 unit layers is equal. The 12th unit layer was completely pierced 9 times, the 13th unit layer was completely pierced 8 times, the 14th unit layer was completely pierced 7 times, the 15th unit layer was completely pierced 6 times, the 16th unit layer was completely pierced The layer unit layer is completely pierced 5 times, the 17th layer unit layer is completely pierced 4 times, the 18th layer unit layer is completely pierced 3 times, the 19th layer unit layer is completely pierced 2 times, the 20th unit layer is completely pierced The layers were completely pierced once, and the needle punching density decreased sequentially from the 12th unit layer to the 20th unit layer.

Optionally, the thickness of the composite cloth is greater than 0.5mm, and the thickness of the composite cloth is thicker, which can increase the overall mechanical properties of the carbon fiber prefabricated body or the high-temperature-resistant carbon-carbon composite body, and prolong its service life.

Optionally, the above-mentioned step of winding the composite cloth may include: using carbon fiber filament bundles to wind the composite cloth obliquely, and then wrap the composite cloth in a hoop direction; wherein, during the hoop winding process, the carbon fiber length The tow is perpendicular to the axis of the die. The oblique wire winding mainly reinforces the seam, and the hoop wire winding can enhance the hoop strength. It should be noted that the strength and modulus of the above-mentioned carbon fiber filament bundles wrapped around the filaments may be equal to or different from those of the aforementioned carbon fiber filament bundles for preparing the composite cloth, which is not specifically limited in this embodiment of the present application.

Optionally, the needling density of the first region is greater than or equal to 20 needles/cm ² , the needling density of the above-mentioned first region makes the density of short carbon fiber filaments penetrating through the unit layer in the first region higher and more suitable, It is not only easy to produce, but also can effectively prevent the separation of the prefabricated body and the needle-punched buffer layer, and effectively reduce the separation between the composite cloth and the first carbon fiber mesh tire and the second carbon fiber mesh tire. It should be noted that during the needling process, the needling density and the number of layers of a unit layer constitute the needling density of the first region or the second region, and the needling density of the inner region is equal to the needling density of the unit layer multiplied by the layer number. For example, if the unit layer density of the first region is 5 needles/cm ² , and the first region has 5 layers, then the needling density of the first region is 25 needles/cm ² .

Optionally, the areal density of the first carbon fiber mesh tire is 50g/m ² -120g/m ² (grams per square meter); the areal density of the second carbon fiber mesh tire is less than or equal to the areal density of the first carbon fiber mesh tire; and Or, the surface density of the composite cloth is 100g/m ² -600g/m ² , the carbon fiber prefabricated body of the above material is not only easy to produce, but also can effectively prevent longitudinal separation, and has excellent overall mechanical properties.

Optionally, in the carbon fiber prefabricated body, the mass ratio of the winding wire is 5%-20%, the mass ratio of the carbon fiber aggregate is 50%-80%, and the mass ratio of the first carbon fiber net tire and the first carbon fiber net tire is 5%-30%. The carbon fiber prefabricated body with the above mass ratio has excellent mechanical properties and long service life.

The embodiment of the present application also provides a carbon fiber preform, including: a preform body. The prefabricated body is composed of m stacked unit layers; m≥1. The unit layer is composed of composite cloth wound with filaments, and then laminated with at least one layer of second carbon fiber mesh tire. The composite cloth is composed of at least one layer of the first carbon fiber network tire stacked on the plane of the fiber assembly. The carbon fiber assembly includes: continuous carbon fiber bundles.

In the preform body, there are at least one first region and one second region, and the density of the short carbon fiber filaments penetrating the unit layer in the first region is greater than the density of the short carbon fiber filaments penetrating the unit layer in the second region. The first area and the second area are stacked and distributed along the stacking direction of the unit layers, and the first area is closer to the axis of the preform body than the second area. In other words, the first area is closer to the geometric center of the preform body than the second area, that is to say, the first area is located on the inner side of the preform body.

For the carbon fiber preform, reference can be made to the relevant records about the carbon fiber preform in the production method of the aforementioned carbon fiber preform, and the same or similar effects can be achieved. In order to avoid repetition, details are not repeated here. It should be noted that the carbon fiber preform can be prepared by the aforementioned production method of the carbon fiber preform. There are no specific limitations on other production and preparation methods of the carbon fiber preform.

The embodiment of the present application also provides a high-temperature-resistant carbon-carbon composite body, including: p unit layers; p≥1; in the case of p>1, each unit layer is stacked. Here p≤m, mainly because the carbon fiber prefabricated body usually needs to be machined to obtain a high temperature resistant carbon-carbon composite body, and some unit layers may be removed during the machined process. How much p is smaller than m is not specifically limited.

The unit layer is composed of composite cloth wound with filaments, and then laminated with at least one layer of second carbon fiber mesh tire.

The composite cloth is composed of a flat layer of carbon fiber aggregates and at least one layer of carbon fiber mesh. Carbon fiber aggregates include: continuous carbon fiber bundles.

There is at least one first region and one second region in the high temperature resistant carbon-carbon composite, the density of the short carbon fiber filaments penetrating the unit layer in the first region is greater than the density of the short carbon fiber filaments penetrating the unit layer in the second region; the first The region and the second region are stacked and distributed along the stacking direction of the unit layers, and the first region is closer to the axis of the high-temperature-resistant carbon-carbon composite than the second region. In other words, the first region is closer to the geometric center of the high-temperature-resistant carbon-carbon composite than the second region, that is to say, the first region is located further inside the high-temperature-resistant carbon-carbon composite.

Regarding the high-temperature-resistant carbon-carbon composite body, reference can be made to relevant records in the relevant parts of the production method of the aforementioned carbon fiber prefabricated body, and the same or similar effects can be achieved. In order to avoid repetition, details are not repeated here. It should be noted that the high-temperature-resistant carbon-carbon composite body can be obtained by machining the carbon fiber preform obtained by the production method of the aforementioned carbon fiber preform. As for other production and preparation methods of the high-temperature-resistant carbon-carbon composite body, no specific limitation is made.

The high-temperature-resistant carbon-carbon composite body can be applied in the aerospace field, the friction-resistant field, the heat field of a furnace body, and the like. This embodiment of the present application does not specifically limit it.

Below in conjunction with embodiment, this application is further explained:

Example 1

Example 1 A carbon fiber prefabricated body corresponding to a crucible was prepared, and the thickness of the side of the crucible was 30 mm. Fig. 3 shows a schematic structural view of another carbon fiber preform in the embodiment of the present application. Fig. 3 is a schematic diagram of the three-dimensional structure of the carbon fiber preform. Fig. 3 may be a schematic diagram of a crucible, or Fig. 3 may be a schematic diagram of a carbon fiber preform corresponding to the crucible.

The first step, as shown in Figure 3, is to select a suitable wooden mold and attach the heat shrinkable film and PVC board. The wooden mold is the mold corresponding to the crucible. The main function of the PVC board is acupuncture cushioning.

The second step is to weave plain carbon cloth with an area density of 350g/m ² , weave the first carbon fiber mesh tire with an area density of 80g/m ² -90g/m ² , and weave an area density of 55g/m ² -65g/m ² The second carbon fiber mesh tire.

In the third step, the plain carbon cloth and the first carbon fiber net tire are needled and fixed into a composite cloth by a flat needle punching machine.

The fourth step, layer laying: Lay layers on the mold in the order of a layer of composite cloth, oblique winding wire, circumferential winding wire, and the second carbon fiber mesh tire. During this period, a hand-held acupuncture handle can be used for simple fixing to prevent the composite cloth from , The second carbon fiber net tire falls off.

In the fifth step, the needling depth is set to 14 mm, the needling density of the unit layer is 5 needles/cm ² , and the needling board rises by 1.4 mm after needling a unit layer.

In the sixth step, repeat the fourth and fifth steps until the dimensions are combined.

In Example 1, the total thickness h of the stacked unit layers is 30 mm, the needle-punching depth x is fixed at 14 mm, and after each needle-punched unit layer, the needle lifts y to 1.4 mm away from the mold, then, h-x +y=30-14+1.4=17.4mm. Furthermore, the front 17.4 mm of the carbon fiber preform corresponding to the crucible prepared in Example 1 is a needling equal-density area, and the needling density gradually decreases from 17.4 mm to 30 mm. The first 17.4mm is the first area, and the second area is from 17.4mm-30mm. The first zone is closer to the mold.

Example 2

Example 2 A carbon fiber prefabricated body corresponding to the heat shield is prepared, and the thickness of the heat shield is 20 mm.

The first step is to choose a suitable wooden formwork and attach heat shrinkable film and PVC board. The main function of the PVC board is also acupuncture cushioning.

The second step is to weave plain carbon cloth with an area density of 350g/m ² , weave the first carbon fiber mesh tire with an area density of 55g/m ² -65g/m ² , and weave an area density of 50g/m ² -60g/m ² The second carbon fiber mesh tire.

In the fifth step, the needling depth is set to 10 mm, the needling density of a unit layer is 5 needles/cm ² , and the needling board rises by 1.4 mm after needling a unit layer.

In Example 2, the total thickness h of the laminated unit layers is 20 mm, the needle-punching depth x is fixed at 10 mm, and after each needle-punched unit layer, the needle lifts y to 1.4 mm away from the mold, then, h-x +y=20-10+1.4=11.4mm. Furthermore, the front 11.4 mm of the carbon fiber preform corresponding to the heat shield prepared in Example 2 is a needling equal-density area, and the needling density gradually decreases from 11.4 mm to 20 mm. The first 11.4mm is the first area, and the second area is from 11.4mm-20mm. The first zone is closer to the mold.

It should be noted that, for the method embodiment, for the sake of simple description, it is expressed as a series of action combinations, but those skilled in the art should know that the embodiment of the present application is not limited by the described action sequence, because According to the embodiment of the present application, certain steps may be performed in other orders or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification belong to preferred embodiments, and the actions involved are not necessarily required by the embodiments of the present application.

It should be noted that, in this document, the term "comprising", "comprising" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article or apparatus comprising a set of elements includes not only those elements, It also includes other elements not expressly listed, or elements inherent in the process, method, article, or device. Without further limitations, an element defined by the phrase "comprising a ..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus comprising that element.

Through the description of the above embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus a necessary general-purpose hardware platform, and of course also by hardware, but in many cases the former is better implementation. Based on such an understanding, the technical solution of the present application can be embodied in the form of a software product in essence or the part that contributes to the prior art, and the computer software product is stored in a storage medium (such as ROM/RAM, disk, CD) contains several instructions to enable a terminal (which may be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to execute the methods described in various embodiments of the present application.

The embodiments of the present application have been described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementations. The above-mentioned specific implementations are only illustrative and not restrictive. Those of ordinary skill in the art will Under the enlightenment of this application, many forms can also be made without departing from the purpose of this application and the scope of protection of the claims, and these all belong to the protection of this application.

Claims

A method for producing a carbon fiber preform, characterized in that the method comprises:

Laying at least one layer of the first carbon fiber grid tire on the surface of the carbon fiber aggregate, and then needling to form a composite cloth; the carbon fiber aggregate includes: continuous carbon fiber bundles;

A preform body is arranged on the outer surface of the mold; the preform body is formed by stacking m unit layers, and each unit layer is stacked with needles, so that there is at least one first region and A second region; the density of short carbon fiber filaments passing through the unit layer in the first region is greater than the density of short carbon fiber filaments passing through the unit layer in the second region; the first region and the second region are along the unit The stacking direction of the layers is stacked, and the first area is closer to the mold than the second area; m≥1;

The unit layer is formed by laying at least one layer of second carbon fiber mesh after winding the composite cloth.
The method for producing a carbon fiber preform according to claim 1, characterized in that the needling density of the first region is greater than that of the second region.
The production method of carbon fiber prefabricated body according to claim 2, it is characterized in that, the total thickness of the m unit layers stacked in the prefabricated body body is h mm, h>0, in the process of needling the stacked unit layers, The needle punching depth is fixed at x mm, x>0, after each needle punching a unit layer, the needle is lifted y mm away from the mold, y>0, so that among the stacked m unit layers, the front (h-x+y ) thickness area is the first area, and the remaining areas are the second area.
The production method of carbon fiber preform according to claim 3, characterized in that h>x, in the preform body, the needle punching density of the front (h-x+y) thickness region is equal, and the needle punching density of the remaining regions The density is less than the needling density of the front (h-x+y) thickness region.
The production method of carbon fiber prefabricated body according to claim 4, it is characterized in that, in the process of needling the unit layer after stacking, x is the thickness of the first n unit layers, n≥1, m>n, y is 1 The thickness of the unit layer makes the needle punching density of the first n+1 layer unit layer equal, and the needle punching density varies from the n+2 layer unit layer to the m layer unit layer; the thickness of the unit layer is the unit layer in the unit layer Dimensions in the stacking direction: the first n+1 layer of unit layers is the first area, and the unit layers from the n+2th layer to the mth layer of unit layers are the second area.
The method for producing a carbon fiber prefabricated body according to claim 5, wherein the thickness of each unit layer is equal, and the needling density decreases sequentially from the n+2th unit layer to the mth unit layer.
The method for producing a carbon fiber preform according to any one of claims 1-6, characterized in that the thickness of the composite cloth is greater than 0.5mm.
The method for producing a carbon fiber preform according to any one of claims 2-6, characterized in that the needling density of the first region is greater than or equal to 20 needles/cm 2 .
According to the production method of the carbon fiber preform described in any one of claims 1-6, it is characterized in that the area density of the first carbon fiber net tire is 50g/m 2 -120g/m 2 ; the area density of the second carbon fiber net tire Less than or equal to the areal density of the first carbon fiber mesh tire; and/or, the areal density of the composite cloth is 100g/m 2 -600g/m 2 .
A carbon fiber prefabricated body, characterized in that it comprises: a prefabricated body body; the prefabricated body body is composed of m stacked unit layers; m≥1;

The unit layer is composed of at least one layer of second carbon fiber mesh after the composite cloth is wound;

The composite cloth is composed of at least one layer of the first carbon fiber net tire stacked on the plane of the fiber assembly; the carbon fiber assembly includes: continuous carbon fiber bundles;

In the preform body, there are at least one first region and one second region, the density of the short carbon fiber filaments passing through the unit layer in the first region is greater than the density of the short carbon fiber filaments passing through the unit layer in the second region; the first The area and the second area are stacked and distributed along the stacking direction of the unit layers, and the first area is closer to the axis of the preform body than the second area.
The carbon fiber preform according to claim 10, characterized in that the needling density of the first region is greater than that of the second region.
The carbon fiber prefabricated body according to claim 11, wherein the total thickness of the m unit layers stacked in the prefabricated body body is h millimeters, h>0, and the acupuncture depth of the unit layers after lamination is fixed to be x millimeters, x >0, after punching a unit layer, the needle lifts y millimeters away from the mold, y>0, in the stacked m unit layers, the front (h-x+y) thickness area is the first area, and the rest areas for the second area.
The carbon fiber preform according to claim 12, characterized in that, h>x, in the preform body, the needle punching density in the front (h-x+y) thickness region is equal, and the needle punching density in the other regions is smaller than that in the front (h-x+y) Needling density in the thickness region.
The carbon fiber prefabricated body according to claim 13, wherein x is the thickness of the first n unit layers, n≥1, m>n, y is the thickness of 1 unit layer, and the first n+1 unit layers The needling density is equal, and the needling density varies from the n+2th unit layer to the mth unit layer; the thickness of the unit layer is the size of the unit layer in the direction in which the unit layer is stacked; the first n+1 layer unit The layer is the first area, and the unit layers from the n+2th layer to the mth layer are the second area.
The carbon fiber prefabricated body according to claim 14, wherein the thickness of each unit layer is equal, and the needle punching density of the n+2th unit layer to the mth unit layer decreases successively.
The carbon fiber preform according to any one of claims 10-15, characterized in that the thickness of the composite cloth is greater than 0.5mm.
The carbon fiber preform according to any one of claims 11-15, characterized in that the needling density of the first region is greater than or equal to 20 needles/cm 2 .
The carbon fiber prefabricated body according to any one of claims 10-15, characterized in that, the surface density of the first carbon fiber mesh is 50g/m 2 -120g/m 2 ; the surface density of the second carbon fiber mesh is less than or equal to The areal density of the first carbon fiber mesh tire; and/or, the areal density of the composite cloth is 100g/m 2 -600g/m 2 .
A high temperature resistant carbon-carbon composite body, characterized in that it comprises:

p unit layers; p≥1; in the case of p>1, each unit layer is stacked;

The unit layer is composed of at least one layer of second carbon fiber mesh after the composite cloth is wound;

The composite cloth is composed of at least one layer of carbon fiber nets stacked on the plane of carbon fiber aggregates; the carbon fiber aggregates include: continuous carbon fiber bundles;

There is at least one first region and one second region in the high-temperature-resistant carbon-carbon composite, and the density of the short carbon fiber filaments penetrating the unit layer in the first region is greater than the density of the short carbon fiber filaments penetrating the unit layer in the second region; The first area and the second area are stacked and distributed along the stacking direction of the unit layers, and the first area is closer to the axis of the high temperature resistant carbon-carbon composite than the second area.