A high-temperature-resistant carbon-carbon composite and a production method thereof, and a carbon fiber preform

Abstract

The application provides a high-temperature-resistant carbon-carbon composite and a production method and a carbon fiber preform thereof, and relates to the technical field of solar photovoltaics. The method comprises the following steps: laying at least one layer of carbon fiber web on the surface of a low-weaving-point carbon fiber assembly, and needling to form a composite cloth; arranging a carbon fiber structure on the outer surface of a mold to obtain a carbon fiber preform; the carbon fiber structure comprises a first preform body and a machine-added layer arranged in layers; at least one layer of the machine-added layer comprises a mesh structure; the mesh structure is formed by laying at least one layer of multi-weaving-point carbon fiber fabric; the mold is removed from the carbon fiber preform, and densification treatment is performed to obtain a machine-added precursor; and the machine-added layer is removed from the machine-added precursor. The carbon fibers are arranged straight and uniformly, the tensile properties of the carbon fibers are maximized, the composite cloth reduces the invasion channels of high-temperature steam, and the service life of the high-temperature-resistant carbon-carbon composite is prolonged. The machine-added layer is beneficial to vapor deposition and can prevent surface crust formation.

Description

Technical Field

[0001] This invention relates to the field of solar photovoltaic technology, and in particular to a high-temperature resistant carbon-carbon composite and its production method, as well as a carbon fiber preform. Background Technology

[0002] High-temperature resistant carbon-carbon composites are widely used in aerospace, friction-resistant applications, and furnace thermal fields. Currently, the main production methods for high-temperature resistant carbon-carbon composites are: alternating layers of bidirectional plain weave structure and carbon fiber mesh followed by needle punching, and then densification and removal of machined layers.

[0003] During their research on the prior art, the inventors discovered that the high-temperature resistant carbon-carbon composites prepared by existing production methods have a relatively short service life. Summary of the Invention

[0004] This invention provides a high-temperature resistant carbon-carbon composite and its production method, as well as a carbon fiber preform, aiming to solve the problem of the short service life of the prepared high-temperature resistant carbon-carbon composite.

[0005] A first aspect of the present invention provides a high-temperature resistant carbon-carbon composite and a method for producing the same, the method comprising:

[0006] At least one layer of carbon fiber mesh is laid on the surface of a low-weave carbon fiber assembly, and then needle-punched to form a composite fabric; the low-weave carbon fiber assembly includes: a non-woven fabric, and / or, at least one bundle of first carbon fiber filaments arranged in parallel in a plane.

[0007] A carbon fiber structure is formed on the outer surface of a mold to obtain a carbon fiber preform; the carbon fiber structure includes: a laminated machined layer and a first preform body; the machined layer is located between the mold and the first preform body, and / or the machined layer is located on the side of the first preform body away from the mold; at least one machined layer includes a mesh structure; the mesh structure is formed by laying at least one layer of multi-dot carbon fiber fabric; the first preform body is formed by needle punching at least one layer of unit layers; the unit layer is formed by needle punching after winding the composite fabric with yarn and then laying at least one layer of carbon fiber mesh.

[0008] The mold is removed from the carbon fiber preform and densified to obtain a machining precursor;

[0009] Remove the machining layer from the machining precursor.

[0010] In this embodiment of the invention, at least one layer of carbon fiber mesh is laid on the surface of a low-dot carbon fiber aggregate, and then needle-punched to form a composite fabric. The low-dot carbon fiber aggregate has fewer weft points, which reduces the bending amplitude of the interlacing of the carbon fibers, making the carbon fibers as straight and uniform as possible, maximizing the tensile properties of the carbon fibers, improving the load-bearing limit of the composite fabric, and extending the lifespan of the high-temperature resistant carbon-carbon composite. Furthermore, in the composite fabric, the carbon fibers are more likely to be arranged straight and uniformly, with fewer weft points, reducing the intrusion channels of high-temperature steam in the high-temperature resistant carbon-carbon composite, greatly reducing the degree of corrosion from hot high-temperature steam, and further extending the lifespan of the high-temperature resistant carbon-carbon composite. Simultaneously, the multi-dot carbon fiber fabric in at least one machined layer results in a high porosity in the machined layer, which is beneficial for vapor deposition during densification treatment, preventing surface crusting. Moreover, the machined layer is removed before the finished product is made, so it does not affect the service life of the finished product. The fewer weave points in the carbon fiber aggregate, the fewer weave points in the aforementioned high-temperature resistant carbon-carbon composite, the fewer restrictions on the thickness or areal density of the high-temperature resistant carbon-carbon composite, allowing for the production of high-temperature resistant carbon-carbon composites with greater thickness and areal density, thus expanding the application range of the high-temperature resistant carbon-carbon composite.

[0011] Optionally, when the mold is a crucible mold or a thermal insulation cylinder mold, the machined layer is located only between the mold and the first preform body;

[0012] When the mold is a heat shield outer shell mold, the machined layer is located only on the side of the first preform body away from the mold.

[0013] Optionally, at least one of the machined layers includes: an allowance portion formed by needle punching of at least one layer of the unit layers.

[0014] Optionally, when one of the machined layers simultaneously includes the mesh structure and the allowance portion, the allowance portion is located between the mesh structure and the first preform body, and the allowance portion and the first preform body are integrally formed; the thickness of the allowance portion is 1-3mm; the thickness of the allowance portion is: the dimension of the allowance portion along the stacking direction of the machined layer and the first preform body.

[0015] Optionally, the mold includes a straight arm portion parallel to its axial direction, a bottom portion perpendicular to the straight arm portion, and an arc portion connecting the straight arm portion and the bottom portion;

[0016] When the thickness of the arc portion is greater than the thickness of the straight arm, and the difference between the two thicknesses is greater than or equal to 5 mm, the carbon fiber structure further includes: a second preform body located on the outer surface of the unit layer and disposed opposite to the arc portion; the second preform body is formed by winding the composite fabric; the thickness of the straight arm is: the dimension of the straight arm in the direction perpendicular to the axial direction of the mold.

[0017] Optionally, the surface density of the machined layer is less than or equal to the surface density of the first preform body, and / or the surface density of the machined layer is less than or equal to the surface density of the second preform body.

[0018] Optionally, the surface density of the machined layer is less than or equal to 350 g / m². 2 ; and / or, the areal density of the first prefabricated body is greater than or equal to 400 g / m³ 2 ; and / or, the areal density of the second prefabricated body is greater than or equal to 400 g / m³ 2 .

[0019] Optionally, the step of winding the composite fabric includes: first winding the composite fabric obliquely with a second carbon fiber filament bundle, and then winding the composite fabric circumferentially; wherein, during the circumferential winding process, the second carbon fiber filament bundle is perpendicular to the axis of the mold.

[0020] A second aspect of the present invention provides a carbon fiber preform, comprising: a first preform body and a machined layer stacked together; wherein, in the direction in which the first preform body and the machined layer are stacked, the machined layer is located on at least one side of the first preform body;

[0021] The first preform body is formed by stacking at least one unit layer; the unit layer is composed of composite fabric wound with yarn, and then stacked with at least one layer of carbon fiber mesh;

[0022] The composite fabric is composed of at least one layer of carbon fiber mesh laminated in a planar manner of a few-point carbon fiber assembly; the few-point carbon fiber assembly includes: a non-woven fabric, and / or, at least one bundle of first carbon fiber filaments arranged in parallel in a planar manner.

[0023] At least one machined layer includes a mesh structure; the mesh structure is formed by stacking at least one layer of multi-point carbon fiber fabric.

[0024] Optionally, if the number of unit layers in the first preform body is greater than 1, the included angle between the first carbon fiber filament bundles in adjacent unit layers is greater than 0.

[0025] Optionally, if the number of unit layers in the first prefabricated body is greater than or equal to 4, the first prefabricated body includes at least one first unit layer, at least one second unit layer, at least one third unit layer, and at least one fourth unit layer.

[0026] In the first unit layer, the first carbon fiber filament bundle is perpendicular to the axis of the mold; in the second unit layer, the first carbon fiber filament bundle is parallel to the axis of the mold; in the third unit layer, the angle between the first carbon fiber filament bundle and the axis of the mold is +45°; and in the fourth unit layer, the angle between the first carbon fiber filament bundle and the axis of the mold is -45°.

[0027] The production methods of the aforementioned carbon fiber preform and the aforementioned high-temperature resistant carbon-carbon composite have the same or similar beneficial effects, and will not be repeated here to avoid repetition.

[0028] A third aspect of the present invention provides a high-temperature resistant carbon-carbon composite, comprising:

[0029] At least one unit layer; if the number of unit layers is greater than 1, the unit layers are stacked.

[0030] The unit layer is composed of composite fabric wound with yarn, and then at least one layer of carbon fiber mesh is stacked on top of it;

[0031] The composite fabric is composed of at least one layer of carbon fiber mesh laminated in a planar manner of a few-weave carbon fiber assembly; the few-weave carbon fiber assembly includes: a non-weave fabric, and / or, at least one bundle of first carbon fiber filaments arranged in parallel in a planar manner.

[0032] The production methods of the aforementioned high-temperature resistant carbon-carbon composites have the same or similar beneficial effects as those of the aforementioned high-temperature resistant carbon-carbon composites, and will not be repeated here to avoid repetition. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 A flowchart illustrating the steps of a method for producing a high-temperature resistant carbon-carbon composite according to an embodiment of the present invention is shown.

[0035] Figure 2 This invention illustrates a schematic diagram of a first carbon fiber filament bundle arranged in parallel planes according to an embodiment of the invention.

[0036] Figure 3 A schematic diagram of the structure of a carbon fiber preform according to an embodiment of the present invention is shown;

[0037] Figure 4 A schematic diagram of an oblique wire winding structure according to an embodiment of the present invention is shown;

[0038] Figure 5 A schematic diagram of a circumferential wire winding structure according to an embodiment of the present invention is shown.

[0039] Explanation of the attached drawing numbers:

[0040] 101-First carbon fiber filament bundle, 102-Machine-grown layer, 103-First preform body, 104-Needle-punched buffer layer, 105-Second carbon fiber filament bundle, 200-Mold, 201-Curved part of the mold. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] Figure 1 A flowchart illustrating the steps of a method for producing a high-temperature resistant carbon-carbon composite according to an embodiment of the present invention is shown. (Refer to...) Figure 1 The production method of this high-temperature resistant carbon-carbon composite includes the following steps:

[0043] Step S1: Lay at least one layer of carbon fiber mesh on the surface of the low-weave carbon fiber assembly, and then needle punch to form a composite fabric; the low-weave carbon fiber assembly includes: a non-woven fabric, and / or, at least one bundle of first carbon fiber filaments arranged in parallel in a plane.

[0044] The non-woven fabric has fewer weft points, resulting in less bending of the interwoven carbon fibers. The carbon fibers are arranged as straight and evenly as possible, maximizing their tensile properties. At least one layer of carbon fiber mesh is laid on the surface of the non-woven fabric, which is then needle-punched to form a composite fabric. This composite fabric has better load-bearing capacity, thus extending the lifespan of the high-temperature resistant carbon-carbon composite. Furthermore, in the non-woven fabric, the carbon fibers are more likely to be arranged straight and evenly, with fewer weft points, reducing the channels for high-temperature steam intrusion into the high-temperature resistant carbon-carbon composite. This significantly reduces the degree of corrosion from hot, high-temperature steam, further extending the lifespan of the high-temperature resistant carbon-carbon composite.

[0045] Figure 2 A schematic diagram of a first carbon fiber filament bundle arranged in parallel planes is shown in an embodiment of the present invention. (Refer to...) Figure 2As shown, multiple bundles of first carbon fiber filaments 101 are arranged in parallel in a plane. At least one bundle of first carbon fiber filaments arranged in parallel in the plane has no weaving points; the carbon fibers are not interwoven or bent, and are all straight and uniformly arranged, maximizing the tensile properties of the carbon fibers. At least one layer of carbon fiber mesh is laid on the surface of at least one bundle of first carbon fiber filaments arranged in parallel in the plane, and then needle-punched to form a composite fabric. The composite fabric has good load-bearing capacity, which can improve the lifespan of the high-temperature resistant carbon-carbon composite. Moreover, in the at least one bundle of first carbon fiber filaments arranged in parallel in the plane, the carbon fibers are most likely to be straight and uniformly arranged, completely without weaving points, reducing the intrusion channels of high-temperature steam in the high-temperature resistant carbon-carbon composite, greatly reducing the degree of corrosion from hot high-temperature steam, and further extending the lifespan of the high-temperature resistant carbon-carbon composite.

[0046] Step S2: A carbon fiber structure is formed on the outer surface of the mold to obtain a carbon fiber preform; the carbon fiber structure includes: a machined layer and a first preform body stacked together; the machined layer is located between the mold and the first preform body, and / or the machined layer is located on the side of the first preform body away from the mold; at least one machined layer includes a mesh structure; the mesh structure is formed by laying at least one layer of multi-dot carbon fiber fabric; the first preform body is formed by needle punching at least one layer of unit layer stacked together; the unit layer is formed by: winding the composite fabric with yarn, then laying at least one layer of carbon fiber mesh and then needle punching.

[0047] The shape and size of the mold can correspond to and match the shape and size of the high-temperature resistant carbon-carbon composite, and this embodiment of the invention does not specifically limit this. A carbon fiber structure is formed on the outer surface of the mold to obtain a carbon fiber preform. The carbon fiber structure includes: a machined layer and a first preform body stacked together. The machined layer is located between the mold and the first preform body, and / or, the machined layer is located on the side of the first preform body away from the mold. That is, there are three possible positions for the machined layer: one is that the machined layer is only located between the mold and the first preform body; another is that the machined layer is only located on the side of the first preform body away from the mold; and the third is that the machined layer is located between the mold and the first preform body, and at the same time, the machined layer is also located on the side of the first preform body away from the mold. As for the specific position of the machined layer, it is set according to actual needs, and this embodiment of the invention does not specifically limit this.

[0048] Figure 3 A schematic diagram of the structure of a carbon fiber preform according to an embodiment of the present invention is shown. Figure 3 The middle 200 is a mold, and the carbon fiber structure includes: a machined layer 102 stacked together and a first preform body 103. Figure 3In the middle, the machining layer 102 is located between the mold 200 and the first preform body 103, and the machining layer 102 is also located on the side of the first preform body 103 away from the mold 200. Figure 3 104 can be a needle-punching buffer layer. The main function of the needle-punching buffer layer 104 is to provide cushioning for the needle during the needle-punching process. The material of the needle-punching buffer layer 104 can be PVC board, etc., and the embodiments of the present invention do not specifically limit it.

[0049] At least one machined layer includes a mesh structure, which is formed by laying at least one layer of multi-dot carbon fiber fabric. Specifically, if the machined layer is located only on the side of the first preform body away from the mold, then the machined layer contains the aforementioned mesh structure. If the machined layer is located only between the first preform body and the mold, then the machined layer contains the aforementioned mesh structure. If the machined layer is located between the mold and the first preform body, and also on the side of the first preform body away from the mold, then only the machined layer between the mold and the first preform body may contain the aforementioned mesh structure; or only the machined layer on the side of the first preform body away from the mold may contain the aforementioned mesh structure; or both the machined layer between the mold and the first preform body and the machined layer on the side of the first preform body away from the mold may contain the aforementioned mesh structure. This embodiment of the invention does not specifically limit this. The aforementioned multi-point carbon fiber fabric can be a carbon fiber fabric with more weft points than a non-weft fabric. For example, the multi-point carbon fiber fabric can be a plain weave carbon fiber fabric or a twill weave carbon fiber fabric, etc., and the embodiments of the present invention do not specifically limit this. In the mesh structure, when the number of layers of the multi-point carbon fiber fabric is greater than 1, the laid multi-point carbon fiber fabric can be needle-punched. The mesh structure may also include a carbon fiber mesh, for example, the carbon fiber mesh and the multi-point carbon fiber fabric are layered and laid, and the mesh structure is formed by needle punching.

[0050] At least one machined layer contains the aforementioned mesh structure, which is formed by laying multi-point carbon fiber fabric. The multi-point weave implies high porosity, thus the high porosity of the machined layer facilitates vapor deposition during densification, preventing surface crusting. Furthermore, the machined layer is removed before the finished product is manufactured. Even if the machined layer contains multi-point carbon fiber fabric, its removal before finishing prevents the introduction of high-temperature steam intrusion channels into the finished product, thus not affecting its service life. Moreover, the aforementioned mesh structure eliminates the need for yarn winding, simplifying the production process.

[0051] Optionally, the porosity of the mesh structure is greater than that of the first preform body, which is conducive to vapor deposition during densification and can prevent surface crusting. Furthermore, since the machined layer is removed before the finished product is made, there will be no intrusion channel for high-temperature steam into the finished product, thus not affecting the service life of the finished product.

[0052] Optionally, the areal density of the mesh structure is less than the areal density of the first preform body, and / or, the strength of the carbon fibers in the mesh structure is less than the strength of the carbon fibers in the first preform body, and / or, the modulus of the carbon fibers in the mesh structure is less than the modulus of the carbon fibers in the first preform body. On the one hand, this facilitates vapor deposition during densification, prevents surface crusting, and since the machined layer is removed before the finished product is made, it prevents the introduction of high-temperature steam intrusion channels into the finished product, thus avoiding affecting the product's service life. On the other hand, it can also reduce costs and facilitate processing.

[0053] Optionally, at least one machined layer may include a allowance portion formed by needle punching at least one layer of the aforementioned unit layers. Specifically, if the machined layer is located only on the side of the first preform body away from the mold, then the machined layer may contain the aforementioned mesh structure and allowance portion. If the machined layer is located only between the first preform body and the mold, then the machined layer may contain the aforementioned mesh structure and allowance portion. If the machined layer is located between the mold and the first preform body, and also on the side of the first preform body away from the mold, then the aforementioned allowance portion may be located in at least one of the two machined layers. Whether the allowance portion and the aforementioned mesh structure are located in the same machined layer is not specifically limited in this embodiment of the invention. For example, if the machined layer between the mold and the first preform body only contains the mesh structure, then the mesh structure directly serves as the machined layer; if the machined layer on the side of the first preform body away from the mold only contains the allowance portion, then the allowance portion directly serves as the machined layer. The aforementioned remaining portion is prepared in the same way as the first preform body, and the processing method is simple.

[0054] Optionally, when a single machined layer includes both the aforementioned mesh structure and the allowance portion, the allowance portion is located between the mesh structure and the first preform body. That is, the allowance portion, formed by the stacking and needle-punching of the aforementioned unit layers, is close to the first preform body. During the fabrication process, the first preform body and the allowance portion are integrally formed or fabricated in one step, simplifying the production method. Simultaneously, the mesh structure is located away from the first preform body, meaning it is situated on the outer side of the carbon fiber preform, which is more conducive to vapor deposition and prevents surface crusting. In this case, the allowance portion can exist as a machining allowance.

[0055] Optionally, when a machined layer includes both the aforementioned mesh structure and the allowance portion, the thickness of the allowance portion is 1-3mm. The thickness of the allowance portion is the dimension of the allowance portion along the stacking direction of the machined layer and the first preform body. A smaller allowance portion thickness is beneficial for cost savings.

[0056] After the composite fabric is wound with yarn, at least one layer of carbon fiber mesh is laid and then needle-punched to form unit layers. The first preform body is formed by stacking and needle-punching at least one unit layer. There is no specific limitation on the number of carbon fiber mesh layers laid during the unit layer formation process, nor is there a specific limitation on the number of unit layers stacked and needle-punched to form the first preform body. After subsequent processing, the first preform body becomes a high-temperature resistant carbon-carbon composite. In this high-temperature resistant carbon-carbon composite, the bending amplitude of the interwoven carbon fibers is very small or even almost non-existent, ensuring that the carbon fibers are arranged as straight and uniformly as possible, maximizing the tensile properties of the carbon fibers, improving the load-bearing limit of the composite fabric, and extending the lifespan of the high-temperature resistant carbon-carbon composite. Furthermore, the carbon fibers in the composite fabric are more likely to be arranged straight and uniformly, with fewer weave points, reducing the intrusion channels of high-temperature steam in the high-temperature resistant carbon-carbon composite, greatly reducing the degree of corrosion from hot high-temperature steam, and further extending the lifespan of the high-temperature resistant carbon-carbon composite. The carbon fiber aggregate with fewer weave points has fewer weave points, and consequently, the high-temperature resistant carbon-carbon composite has fewer weave points. This means that the thickness or areal density of the first preform or the high-temperature resistant carbon-carbon composite is less restricted, and a thicker high-area-density high-temperature resistant carbon-carbon composite can be produced, which can increase the application range of the high-temperature resistant carbon-carbon composite.

[0057] Optionally, the above-mentioned steps of winding the composite fabric may include: first winding the composite fabric obliquely with a second carbon fiber filament bundle, and then winding the composite fabric circumferentially; wherein, during the circumferential winding process, the second carbon fiber filament bundle is perpendicular to the axis of the mold. Figure 4 A schematic diagram of an oblique winding structure according to an embodiment of the present invention is shown. Figure 4 The second carbon fiber filament bundle 105 is not perpendicular to the axis L of the mold, and the included angle between the second carbon fiber filament bundle 105 and the axis L of the mold is not specifically defined. Figure 5 A schematic diagram of a circumferential wire winding structure according to an embodiment of the present invention is shown. Figure 5 The second carbon fiber filament bundle 105 is perpendicular to the axis L of the mold. The oblique winding mainly reinforces the joint, while the circumferential winding enhances the circumferential strength. It should be noted that the strength, modulus, etc., of the aforementioned second carbon fiber filament bundle may be equal to or different from those of the aforementioned first carbon fiber filament bundle; this embodiment of the invention does not impose specific limitations in this regard.

[0058] Optionally, when the mold is a crucible mold or an insulation cylinder mold, the machining layer is located only between the mold and the first preform body. That is, the machining layer is only located on the inner side of the first preform body, resulting in a smoother inner surface for the crucible and insulation cylinder after machining. Since the inner surface of the crucible and insulation cylinder needs to serve as the assembly surface, a smoother inner surface facilitates assembly. However, in practical applications, the smoothness of the outer surface of the crucible and insulation cylinder is not critical, so a machining layer can be omitted, eliminating material waste, reducing costs, and simplifying the production method.

[0059] Optionally, when the mold is a heat shield outer shell mold, the machining layer is only located on the side of the first preform body away from the mold; that is, the machining layer is only located on the outer side of the first preform body. The outer surface of the heat shield outer shell obtained after machining is smoother. Since the outer surface of the heat shield outer shell needs to serve as an assembly surface, a smoother outer surface facilitates assembly. In practical applications, the smoothness requirement for the inner surface of the heat shield outer shell is not high. Therefore, eliminating the machining layer avoids material waste, reduces costs, and simplifies the production method.

[0060] Optional, refer to Figure 3 As shown, the mold 200 includes a straight arm portion parallel to its axial direction L, a bottom portion perpendicular to the straight arm portion, and an arc portion 201 connecting the straight arm portion and the bottom portion. When the thickness of the arc portion 201 is greater than the thickness of the straight arm, and the difference between the thicknesses of the arc portion 201 and the straight arm is greater than or equal to 5 mm, the carbon fiber structure further includes a second preform body located on the outer surface of the unit layer and disposed opposite to the arc portion 201. The second preform body is formed by winding composite fabric. The thickness of the straight arm is defined as the dimension of the straight arm in the direction perpendicular to the axial direction L of the mold 200. When the difference between the two thicknesses is greater than or equal to 5 mm, the second preform body reduces the curvature of the carbon fibers in the prepared high-temperature resistant carbon-carbon composite and simplifies the preparation method.

[0061] Optionally, the areal density of the machined layer is less than or equal to the areal density of the first preform body, and / or the areal density of the machined layer is less than or equal to the areal density of the second preform body. The machined layer needs to be removed before forming the finished product; therefore, setting its areal density relatively low can reduce production costs and simplify the preparation method. It also facilitates vapor deposition during densification, prevents surface crusting, and does not affect the service life of the finished product.

[0062] Optionally, the surface density of the machined layer is less than or equal to 350 g / m². 2 ; and / or, the areal density of the first precast body is greater than or equal to 400 g / m³ 2 ; and / or, the areal density of the second prefabricated body is greater than or equal to 400 g / m³ 2It can reduce production costs and is easy to prepare. It also facilitates vapor deposition during densification, prevents surface crusting, and does not affect the service life of the finished product.

[0063] Optionally, in step S2, during the formation of the first preform body, when the unit layers are stacked, the included angle between the first carbon fiber filament bundles in adjacent unit layers is greater than 0. That is, the first carbon fiber filament bundles in adjacent unit layers do not need to be parallel. This can increase the compressive strength of the high-temperature resistant carbon-carbon composite in different directions, significantly improve its overall mechanical properties, and extend its service life. It should be noted that the included angle between the first carbon fiber filament bundles in adjacent unit layers is not specifically limited. For example, the included angle between the first carbon fiber filament bundles in adjacent unit layers can be equal. Therefore, the included angle between the first carbon fiber filament bundles and their axial direction in adjacent unit layers of the formed first preform body or finished product can successively increase or decrease, which is beneficial for preparation, and the compressive strength in different directions is approximately equal.

[0064] Optionally, in step S2, if the number of unit layers in the first preform body is greater than or equal to 4, the first preform body includes at least one first unit layer, at least one second unit layer, at least one third unit layer, and at least one fourth unit layer. Specifically, in the first unit layer, the first carbon fiber filament bundle is perpendicular to the mold axis; in the second unit layer, the first carbon fiber filament bundle is parallel to the mold axis; in the third unit layer, the angle between the first carbon fiber filament bundle and the mold axis is +45°; and in the fourth unit layer, the angle between the first carbon fiber filament bundle and the mold axis is -45°. Whether the first, second, third, and fourth unit layers are adjacent is not specifically limited. This arrangement of unit layers can further increase the compressive strength of the high-temperature carbon-carbon composite in different directions, significantly improve its overall mechanical properties, and extend its service life. For example, the flexural strength can reach over 140 MPa.

[0065] For example, adjacent layers of first unit, second unit, third unit, and fourth unit can be laid and needled in a cycle to form the first prefabricated body.

[0066] Optionally, the areal density of the composite fabric can be 300-500 g / m². 2 The carbon fiber is wound at a 45° angle, and the areal density of the carbon fiber mesh can be 50-120 g / m². 2 In step S2, the needle insertion depth can be 10-16 mm, and the needle insertion density can be 24-45 needles / cm. 2 The density of the first prefabricated body can be 0.5-0.7 g / cm³. 3 The resulting high-temperature resistant carbon-carbon composite has a long lifespan.

[0067] Step S3: Remove the mold from the carbon fiber preform and perform a densification process to obtain a machining precursor.

[0068] The densification process can be used to densify the deposit, such as through vapor deposition. In this embodiment of the invention, this step is not specifically limited.

[0069] Step S4: Remove the machining layer from the machining precursor.

[0070] This step mainly involves machining to remove the machined layer. This step may also include surface treatment, etc., but this embodiment of the invention does not specifically limit the scope of the invention.

[0071] It should be noted that when the machined layer includes a surplus portion formed by stacking and needle-punching at least one unit layer, the number of unit layers in the high-temperature carbon-carbon composite will be less than the number of unit layers in the carbon fiber preform because the stacked and needle-punched unit layers in the surplus portion are machined away as surplus. For example, if the number of unit layers in the carbon fiber preform is m and the number of unit layers in the surplus portion is n, then the number of unit layers in the high-temperature carbon-carbon composite can be mn layers. When the machined layer does not include the surplus portion, the number of unit layers in the high-temperature carbon-carbon composite and the number of unit layers in the carbon fiber preform can be equal.

[0072] This invention also provides a carbon fiber preform, comprising: a first preform body and a machined layer stacked together. In the direction in which the first preform body and the machined layer are stacked, the machined layer is located on at least one side of the first preform body. For example, in the stacking direction, the machined layer is located on only one side of the first preform. Alternatively, in the stacking direction, the machined layer is located on both sides of the first preform.

[0073] The first preform body is formed by stacking at least one unit layer. The unit layer consists of composite fabric wound with yarn, and then at least one layer of carbon fiber mesh is stacked on top. The composite fabric consists of at least one layer of carbon fiber mesh stacked in a planar manner of a few-dot carbon fiber assembly; the few-dot carbon fiber assembly includes: non-weft fabric, and / or at least one bundle of first carbon fiber filaments arranged in parallel in a planar manner.

[0074] In the carbon fiber preform, at least one machined layer includes a mesh structure; the mesh structure is formed by stacking at least one layer of multi-point carbon fiber fabric.

[0075] In the carbon fiber preform, when the number of unit layers in the first preform body is greater than 1, the included angle between the first carbon fiber filament bundles in adjacent unit layers is greater than 0.

[0076] In a carbon fiber preform, when the number of unit layers in the first preform body is greater than or equal to 4, the first preform body includes at least one first unit layer, at least one second unit layer, at least one third unit layer, and at least one fourth unit layer. Specifically, in the first unit layer, the first carbon fiber filament bundle is perpendicular to the mold axis; in the second unit layer, the first carbon fiber filament bundle is parallel to the mold axis; in the third unit layer, the angle between the first carbon fiber filament bundle and the mold axis is +45°; and in the fourth unit layer, the angle between the first carbon fiber filament bundle and the mold axis is -45°.

[0077] The carbon fiber preform can be referenced from the aforementioned production method for high-temperature resistant carbon-carbon composites, and achieves the same or similar effects. To avoid repetition, it will not be elaborated further here. It should be noted that the carbon fiber preform can be prepared using steps S1 and S2 of the aforementioned production method for high-temperature resistant carbon-carbon composites. Other production methods for the carbon fiber preform are not specifically limited.

[0078] This invention also provides a high-temperature resistant carbon-carbon composite, comprising: at least one unit layer; where the number of unit layers is greater than one, the unit layers are stacked. Each unit layer consists of a composite fabric wound with filaments, followed by at least one layer of carbon fiber mesh. The composite fabric consists of a planar stack of at least one layer of carbon fiber mesh from a low-weave carbon fiber assembly. The low-weave carbon fiber assembly includes: a non-woven fabric, and / or at least one bundle of first carbon fiber filaments arranged parallel to each other in a planar plane.

[0079] Regarding this high-temperature resistant carbon-carbon composite, the relevant descriptions of the production method for high-temperature resistant carbon-carbon composites mentioned above can be referenced, and the same or similar effects can be achieved. To avoid repetition, further details are omitted here. This high-temperature resistant carbon-carbon composite can be prepared by the aforementioned production method 2 for high-temperature resistant carbon-carbon composites. Other production methods for this high-temperature resistant carbon-carbon composite are not specifically limited.

[0080] It should be noted that, for the sake of simplicity, the method embodiments are all described as a series of actions. However, those skilled in the art should understand that the embodiments of this application are not limited to the described order of actions, because according to the embodiments of this application, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also understand that the embodiments described in the specification are all preferred embodiments, and the actions involved are not necessarily essential to the embodiments of this application.

[0081] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0082] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0083] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A method for producing a high-temperature resistant carbon-carbon composite, characterized in that, The method includes: At least one layer of carbon fiber mesh is laid on the surface of multiple bundles of first carbon fiber filaments arranged in parallel planes, and then needle punched to form a composite fabric. A carbon fiber structure is provided on the outer surface of the mold to obtain a carbon fiber preform; the carbon fiber structure includes: a laminated machining layer and a first preform body; Wherein, the machined layer is located between the mold and the first preform body, and / or, the machined layer is located on the side of the first preform body away from the mold; at least one machined layer includes a mesh structure; the mesh structure is formed by laying at least one layer of multi-point carbon fiber fabric; the multi-point carbon fiber fabric is carbon fiber plain weave fabric or carbon fiber twill weave fabric; The first preform body is formed by needle punching multiple unit layers; the unit layer is formed by needle punching after the composite fabric is wound with filaments and then at least one layer of carbon fiber mesh is laid; the step of winding the composite fabric with filaments includes: first winding the composite fabric obliquely with a second carbon fiber filament bundle, and then winding the composite fabric circumferentially; during the circumferential winding process, the second carbon fiber filament bundle is perpendicular to the axis of the mold. The mold includes a straight arm portion parallel to its axis, a bottom portion perpendicular to the straight arm portion, and an arc portion connecting the straight arm portion and the bottom portion; the thickness of the arc portion is greater than the thickness of the straight arm portion, and the thickness difference is greater than or equal to 5 mm; the carbon fiber structure further includes a second preform body located on the outer surface of the unit layer and disposed opposite to the arc portion; the second preform body is formed by winding the composite fabric. The mold is removed from the carbon fiber preform and densified to obtain a machining precursor; Remove the machining layer from the machining precursor.

2. The method for producing the high-temperature resistant carbon-carbon composite according to claim 1, characterized in that, When the mold is a crucible mold or an insulation cylinder mold, the machined layer is located only between the mold and the first preform body; When the mold is a heat shield outer shell mold, the machined layer is located only on the side of the first preform body away from the mold.

3. The method for producing the high-temperature resistant carbon-carbon composite according to claim 1, characterized in that, The at least one machined layer includes: an excess portion formed by needle punching of at least one layer of the unit layers.

4. The method for producing the high-temperature resistant carbon-carbon composite according to claim 3, characterized in that, In the case where a machined layer includes both the mesh structure and the allowance portion, the allowance portion is located between the mesh structure and the first preform body, and the allowance portion and the first preform body are integrally formed; the thickness of the allowance portion is 1-3mm; the thickness of the allowance portion is: the dimension of the allowance portion along the stacking direction of the machined layer and the first preform body.

5. The method for producing the high-temperature resistant carbon-carbon composite according to claim 1, characterized in that, The surface density of the machined layer is less than or equal to the surface density of the first preform body, and / or the surface density of the machined layer is less than or equal to the surface density of the second preform body.

6. The method for producing the high-temperature resistant carbon-carbon composite according to claim 1 or 5, characterized in that, The surface density of the machined layer is less than or equal to 350 g / m² 2 ; and / or, the areal density of the first prefabricated body is greater than or equal to 400 g / m³ 2 ; and / or, the areal density of the second prefabricated body is greater than or equal to 400 g / m³ 2 .

7. A carbon fiber preform, characterized in that, include: A mold, and a carbon fiber structure disposed on the outer surface of the mold, the carbon fiber structure comprising: a first preform body and a machined layer stacked together; in the direction of stacking of the first preform body and the machined layer, the machined layer is located on at least one side of the first preform body; The first preform body is formed by stacking multiple unit layers; the unit layer is composed of composite fabric wound with filaments, then stacked with at least one layer of carbon fiber mesh and needle punched; the composite fabric winding includes: first winding the composite fabric obliquely with a second carbon fiber filament bundle, and then winding the composite fabric circumferentially; during the circumferential winding process, the second carbon fiber filament bundle is perpendicular to the axis of the mold. The composite fabric is composed of at least one layer of carbon fiber mesh made of at least one bundle of first carbon fiber filaments arranged in parallel in a plane. At least one machined layer includes a mesh structure; the mesh structure is formed by stacking at least one layer of multi-point carbon fiber fabric; the multi-point carbon fiber fabric is a plain weave carbon fiber fabric or a twill carbon fiber fabric. The mold includes a straight arm portion parallel to its axis, a bottom portion perpendicular to the straight arm portion, and an arc portion connecting the straight arm portion and the bottom portion; the thickness of the arc portion is greater than the thickness of the straight arm portion, and the thickness difference is greater than or equal to 5 mm; the carbon fiber structure further includes a second preform body located on the outer surface of the unit layer and disposed opposite to the arc portion; the second preform body is formed by winding the composite fabric.

8. The carbon fiber preform according to claim 7, characterized in that, In adjacent unit layers, the included angle between the first carbon fiber filament bundles is greater than 0.

9. The carbon fiber preform according to claim 7 or 8, characterized in that, When the number of unit layers in the first prefabricated body is greater than or equal to 4, the first prefabricated body includes at least one first unit layer, at least one second unit layer, at least one third unit layer, and at least one fourth unit layer. In the first unit layer, the first carbon fiber filament bundle is perpendicular to the axis of the mold; in the second unit layer, the first carbon fiber filament bundle is parallel to the axis of the mold; in the third unit layer, the angle between the first carbon fiber filament bundle and the axis of the mold is +45°; and in the fourth unit layer, the angle between the first carbon fiber filament bundle and the axis of the mold is -45°.

10. A high-temperature resistant carbon-carbon composite prepared by the production method of the high-temperature resistant carbon-carbon composite according to any one of claims 1 to 6, characterized in that, include: Multiple unit layers; Each unit is layered with stacked needle-punching settings; The unit layer is formed by needle punching at least one layer of carbon fiber mesh after the composite fabric is wound with yarn. The composite fabric winding process includes: first winding the composite fabric obliquely with a second carbon fiber filament bundle, and then winding the composite fabric circumferentially. During the circumferential winding process, the second carbon fiber filament bundle is perpendicular to the axial direction of the high-temperature resistant carbon-carbon composite. The composite fabric is formed by needle punching multiple bundles of first carbon fiber filaments arranged in parallel planes, with at least one layer of carbon fiber mesh stacked on the surface.

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