Composite material and preparation method thereof

Abstract

The present invention discloses a composite material and a preparation method thereof, wherein the steps are as follows: firstly, determining the composite material matrix structure to be printed, and using 3D modeling software to establish a composite material matrix model; then determining the planar fiber layer to be printed, and using 3D printing technology to print the composite material skeleton formed by stacking the planar fiber layers; in the process of printing the composite material skeleton, reserving channels according to the matrix model, and implanting fiber bundles in the channels of the printed composite material skeleton; and finally heating and melting the whole, solidifying and forming, to form the composite material. The method innovates the composite material molding method, and optimizes the traditional multi-step molding path of "fiber-preform-composite" to a one-step method; the method provides a technical solution for the rapid and low-cost preparation of composite materials.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite material preparation, and in particular relates to a method for preparing a composite material by adopting 3D printing technology. Background Art

[0002] Composite materials have been rapidly developed in the fields of aerospace, rail transit, ships, etc. due to their design of strong and excellent thermal and electrical properties. Existing composite materials are mostly prepared by "fiber-weaving-composite" or "fiber winding-composite" methods, with many process links and involving multiple disciplines and fields; to a certain extent, they have caused problems such as long cycle and high cost, and have affected their development in the direction of mechanization, automation, and intelligence. 3D printing technology not only solves the problem of rapid preparation of complex-shaped components with continuous high-performance fibers, but also realizes one-step molding of composite materials, meeting the rapid preparation of components such as cones, closed cavities, polyhedrons, thin-walled shells, etc., and has become one of the future development directions of aerospace, ships, and civil fields, and has a good development prospect. Summary of the invention

[0003] The purpose of the present invention is to provide a method for preparing a composite material by using 3D printing technology.

[0004] The technical solution for achieving the purpose of the present invention is: a composite material prepared based on 3D printing technology and a method thereof, comprising the following steps: first, determining the composite material matrix structure to be printed, and using 3D modeling software to establish a composite material matrix model; then determining the planar fiber layer to be printed, and using 3D printing technology to print the composite material skeleton formed by stacking the planar fiber layers, reserving channels according to the matrix model during the printing of the composite material skeleton, implanting fiber bundles or resin rods in the channels of the printed composite material skeleton, and finally heating and melting the entire structure, solidifying and forming it to form the composite material.

[0005] Preferably, the matrix structure of the composite material includes an orthogonal three-dimensional structure, a 2.5D structure, a three-dimensional multi-directional structure, or a superposition structure of any two or three of these structures.

[0006] Preferably, according to the composite material matrix structure to be printed, a matrix structure unit cell model is first established through 3D modeling software, and the unit cell size is set. The unit cell is the arrangement of fiber bundles within the smallest unit of the matrix structure. After the unit cell is designed, an overall composite material matrix model is established according to the shape and size of the matrix structure, wherein the unit cell structure includes a combination of one or more of the orthogonal three-dimensional structure, 2.5D structure and three-dimensional multi-directional structure.

[0007] Specifically, the composite material matrix structure to be printed is an orthogonal three-dimensional structure, such as a planar multi-oriented structure. The fiber bundle specifications and spacing in the X, Y, and Z directions are used as modeling parameters. The unit cell structure model of the matrix structure is first established through three-dimensional modeling software.

[0008] Specifically, the composite material matrix structure to be printed is a 2.5D structure, including all derivative structures with 2.5D structural characteristics such as 2.5D shallow straight connection, shallow bent connection, deep connection, etc. based on plain, twill and satin weaves. The warp and weft density, warp and weft yarn specifications, volume content, and structural category are used as modeling parameters. The unit cell structure model of the matrix structure is first established through 3D modeling software.

[0009] Specifically, the composite material matrix structure to be printed is a three-dimensional multi-directional structure, including three-dimensional four-directional, three-dimensional five-directional, three-dimensional six-directional, etc., with the parent direction node length, circumferential direction node length, thickness direction node length, etc. as modeling parameters. Through the three-dimensional modeling software, the unit cell structure model of the matrix structure is first established.

[0010] Preferably, the planar fiber layers to be printed are determined, and a composite material skeleton formed by stacking the planar fiber layers is printed using fiber bundles and resin using 3D printing technology.

[0011] Preferably, the channels in the composite material skeleton formed by the stacking of planar fiber layers obtained by 3D printing technology can be any one or more of straight channels, oblique straight channels, curved channels, etc.

[0012] Preferably, the method of implanting the fiber bundle into the pores of the composite material skeleton includes air flow introduction method, medium introduction method, and flexible rod direct introduction method.

[0013] Preferably, when the fiber bundles are introduced, the fiber bundles in each direction are introduced or implanted synchronously, and the fiber bundles are stationary in different directions without affecting each other.

[0014] Preferably, the heating and melting and the solidification and setting are carried out by hot pressing, wherein the solidification pressure is adjustable from 0 to 2 MPa, the solidification temperature is adjustable from 0 to 300° C., and the solidification time is adjustable.

[0015] Preferably, the fiber bundle includes any one or more of carbon fiber, quartz fiber, glass fiber, and ceramic fiber, and the state thereof includes wet state or dry state; the resin includes epoxy resin, phenolic resin, etc.; and the resin rod is composited by the fiber bundle and the resin.

[0016] Compared with the prior art, the present invention has the following significant advantages: 1. Compared with the traditional 3D printing technology, it can realize the rapid printing of continuous fibers; compared with the preform composite material preparation technology, the process is simple and easy to implement; 2. Not only can it print components with complex shapes, but it can also realize the multi-regular interweaving of continuous fiber bundles; 3. It has a short cycle and low cost; 4. It has less manual participation and high quality consistency.

[0017] It should be understood that all combinations of the aforementioned concepts and the additional concepts described in more detail below can be considered as part of the inventive subject matter of the present application as long as such concepts are not mutually contradictory. In addition, all combinations of the claimed subject matter are considered as part of the inventive subject matter of the present application.

[0018] The foregoing and other aspects, embodiments and features of the present invention can be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the present invention, such as the features and / or beneficial effects of the exemplary embodiments, will be apparent from the following description or learned from the practice of the specific embodiments according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the method of implanting fiber bundles in the composite material skeleton of the present invention, a wire introduction, b needle introduction, c air suction, d carbon rod implantation.

[0020] Figure 2 Schematic diagram of the modeling process of a typical orthogonal three-dimensional composite material matrix structure of Example 1.

[0021] Figure 3 Schematic diagram of the modeling process of a typical 2.5D shallow cross-bend structure composite material matrix structure of Example 2.

[0022] Figure 4 Schematic diagram of the modeling process of a typical three-dimensional core structure composite material matrix structure of Example 3.

[0023] Figure 5 Schematic diagram of the modeling process of a typical three-dimensional face-core structure composite material matrix structure of Example 4.

[0024] Figure 6 Schematic diagram of the modeling process of the three-dimensional four-directional cylindrical composite material matrix structure of Example 5.

[0025] Figure 7 This is a schematic diagram of the superposition of the unit cells of the three-dimensional four-directional cylindrical composite material matrix structure of Example 5 along the longitudinal direction.

[0026] Figure 8 Schematic diagram of the modeling process of the two-structure combined composite material matrix structure of Example 6. DETAILED DESCRIPTION

[0027] In order to better understand the technical content of the present invention, specific embodiments are given and described as follows in conjunction with the accompanying drawings.

[0028] Various aspects of the present invention are described in this application with reference to the accompanying drawings, in which many illustrative embodiments are shown. The embodiments of the present application are not necessarily intended to include all aspects of the present invention. It should be understood that the various concepts and embodiments introduced above, as well as those described in more detail below, can be implemented in any of many ways, because the concepts and embodiments disclosed by the present invention are not limited to any implementation. In addition, some aspects disclosed by the present invention can be used alone, or used in any appropriate combination with other aspects disclosed by the present invention.

[0029] Different composite matrix structure types form different channels according to the spatial orientation of the fiber bundles. The method is the same. The composite matrix structure is determined, and the matrix structure volume content, fiber bundle diameter, and fiber bundle ratio in each direction are designed. Based on these parameters as modeling parameters, a three-dimensional modeling method is used to establish a single cell model of the matrix structure. After the single cell structure is designed, the overall matrix structure model is established according to the shape and size of the matrix structure. The matrix structure model is implanted into the 3D printing software system, and the shape and size of the composite matrix structure to be printed are input and associated simultaneously. The channels in the matrix structure model are formed according to the spatial orientation of the fiber bundles in the composite matrix structure, and can be any one or more of straight channels, oblique straight channels, curved channels, non-penetrating channels, etc. Firstly, the planar fiber layer to be printed is determined, and a composite material skeleton formed by stacking the planar fiber layers is prepared by 3D printing technology. The printing material is a mixture of fiber bundles and resin in a certain proportion. The fiber bundle material, the specific proportion of the fiber bundle and the resin are adjusted according to the required performance of the prepared composite material. In the process of printing the composite material skeleton, channels are reserved according to the matrix model, and fiber bundles or resin rods are implanted in the channels of the printed composite material skeleton. After the yarn is stationary, in order to ensure that the composite material skeleton and the fiber bundle (fiber) are fully integrated, the overall heating and melting are required, and the solidification is fixed. The fiber bundles in all directions in the formed composite material are generally made of the same material, including any one or more of carbon fiber, quartz fiber, glass fiber, and ceramic fiber, and their states include wet or dry state; the resin includes epoxy resin, phenolic resin, etc.; the resin rod is a composite of fiber bundles and resin.

[0030] The composite skeleton uses fiber bundles and resin as printing materials. Hot pressing can melt the resin, which can fill the remaining gaps in the pores after melting, so that the resin and fiber are fully integrated. The purpose of pressurization is to promote the fluidity of the resin, speed up the filling of the gaps, and finally shape the resin-based composite material.

[0031] The method of implanting fiber bundles of the present invention includes: Figure 1 Several methods are shown:

[0032] 1) Wire lead

[0033] A fiber bundle is introduced into the tail of the steel needle, and the fiber bundle forms a loop, driving the fiber bundle to settle into the channel.

[0034] 2) Needle Induction

[0035] Directly pass the fiber bundle through the needle hole at the tail of the steel needle, and the steel needle passes through the hole to directly place the fiber bundle.

[0036] 3) Air suction

[0037] Using the vacuum negative pressure principle, the air suction tube passes through the hole and absorbs the fiber bundle from the other end of the hole. The air suction tube is pulled out of the hole and the fiber bundle is pulled out of the hole to complete the yarn stationing.

[0038] 4) Carbon rod implantation

[0039] A single fiber is directly wrapped with the impregnating agent, and after curing, its hardness increases to become a fiber rod. Through the insertion mechanism, a carbon rod is directly inserted into the channel to complete the yarn stationing.

[0040] Example 1

[0041] like Figure 2 As shown, the composite matrix structure type in this embodiment is an orthogonal three-dimensional structure. First, according to the type of composite matrix structure, the fiber bundle specifications in the three directions of X, Y, and Z (two strands of 198tex carbon fiber, respectively) and the spacing (spacing in the X and Y directions is 1.0mm, and spacing in the Z direction is 0.7mm) are used as modeling parameters, and a unit cell structure model of the composite matrix model of the orthogonal three-dimensional structure is established using three-dimensional modeling software such as Pro / E. The size of the unit cell structure model is set to 1.0mm×1.0mm×0.7mm. The unit cell structure is the arrangement of the fiber bundles in the smallest unit in the composite matrix model. After the unit cell structure model is designed, the overall composite matrix model is established according to the shape and size of the composite matrix structure by using the repeated superposition method.

[0042] The composite material matrix model is implanted into the 3D printing software system, and the shape and size of the required printed composite material matrix structure are synchronously input and associated, and the composite material skeleton is obtained through 3D printing, specifically as follows: fiber bundles and resin are used as printing materials, XOY is used as the plane, and 3D printing technology is used to print a composite material skeleton formed by stacking fiber layers in the X and Y directions. The channels in the composite material skeleton are formed according to the spatial orientation of the fiber bundles in the composite material matrix structure. During the printing of the composite material skeleton, channels are reserved.

[0043] Fiber bundles are implanted in the pores of the printed composite skeleton. Then, the printed composite material is moved into an autoclave with a designed curing pressure of 0.8 MPa, a curing temperature of 60°C, and a curing time of 3 hours.

[0044] Example 2

[0045] like Figure 3 As shown, the composite matrix structure type in this embodiment is a 2.5D shallow cross-bend structure. First, according to the type of composite matrix structure, the warp and weft density (warp density 8 strands / cm, weft density 2.5 strands / cm), warp and weft yarn specifications (2 strands of 198tex carbon fiber in the warp direction, 4 strands of 198tex carbon fiber in the weft direction), and volume content (45%) are used as modeling parameters, and the unit cell structure model of the 2.5D shallow cross-bend structure composite matrix model is established using ANSYS software. The size of the unit cell structure model is set to 1.25mm×4mm×1.20mm. The unit cell structure is the arrangement of the fiber bundles in the smallest unit in the composite matrix model. After the unit cell structure model is designed, the overall composite matrix model is established according to the shape and size of the composite matrix structure by using the repeated superposition method.

[0046] The composite material matrix model is implanted into the 3D printing software system, and the shape and size of the required printed composite material matrix structure are synchronously input and associated, and the composite material skeleton is obtained through 3D printing, specifically as follows: fiber bundles and resin are used as printing materials, X0Y is used as the plane, and 3D printing technology is used to print a composite material skeleton formed by stacking fiber layers in the X and Y directions. The channels in the composite material skeleton are formed according to the spatial orientation of the fiber bundles in the composite material matrix structure. In the process of printing the composite material skeleton, channels are reserved.

[0047] Fiber bundles are implanted in the pores of the printed composite skeleton. Then, the printed composite material is moved into an autoclave with a designed curing pressure of 0.6 MPa, a curing temperature of 60°C, and a curing time of 4 hours.

[0048] Example 3

[0049] like Figure 4 As shown, the composite matrix structure type in this embodiment is a three-dimensional four-directional structure (three-dimensional body-core structure). First, according to the type of the composite matrix structure, the mother direction node length is 4.3mm, the circumferential node length is 1.46mm, and the thickness direction node length is 0.67mm (T300-3K carbon fiber, 3 strands) are used as modeling parameters. The ANSYS software is used to establish a unit cell structure model of the three-dimensional body-core structure composite matrix model. The size of the unit cell structure model is set to 4.3mm×1.46mm×0.67mm. The unit cell structure is the arrangement of the fiber bundles in the smallest unit in the composite matrix model. After the unit cell structure model is designed, the overall composite matrix model is established according to the shape and size of the composite matrix structure by using the repeated superposition method.

[0050] The composite material matrix model is implanted into the 3D printing software system, and the shape and size of the required printed composite material matrix structure are synchronously input and associated, and the composite material skeleton is obtained through 3D printing, specifically as follows: fiber bundles and resin are used as printing materials, and the plane formed by the diagonal lines of the unit cell model body is used as the printing reference plane. 3D printing technology is used to print a composite material skeleton formed by stacking fiber layers in the plane. The channels in the composite material skeleton are formed according to the spatial orientation of the fiber bundles in the composite material matrix structure. In the process of printing the composite material skeleton, channels are reserved.

[0051] Fiber bundles are implanted in the pores of the printed composite skeleton. Then, the printed composite material is moved into an autoclave with a designed curing pressure of 0.6 MPa, a curing temperature of 60°C, and a curing time of 3 hours.

[0052] Example 4

[0053] like Figure 5 As shown, the composite material matrix structure type in this embodiment is a three-dimensional five-directional structure (three-dimensional face-core structure). First, according to the type of the composite material matrix structure, the mother direction node length is 5.2mm, the circumferential node length is 1.7mm, and the thickness direction node length is 1.3mm (T300-3K carbon fiber, 2 strands) is used as modeling parameters, and the ANSYS software is used to establish a unit cell structure model of the three-dimensional face-core structure composite material matrix model. The size of the unit cell structure model is set to 5.2mm×1.7mm×1.3mm. The unit cell structure is the arrangement of the fiber bundles in the smallest unit in the composite material matrix model. After the unit cell structure model is designed, the repeated superposition method is used to establish the overall composite material matrix model according to the shape and size of the composite material matrix structure.

[0054] The composite material matrix model is implanted into the 3D printing software system, and the shape and size of the required printed composite material matrix structure are synchronously input and associated, and the composite material skeleton is obtained through 3D printing, specifically as follows: fiber bundles and resin are used as printing materials, and the plane formed by the diagonal lines of the unit cell model surface is used as the printing reference plane. 3D printing technology is used to print a composite material skeleton formed by stacking fiber layers in the plane. The channels in the composite material skeleton are formed according to the spatial orientation of the fiber bundles in the composite material matrix structure. In the process of printing the composite material skeleton, channels are reserved.

[0055] Fiber bundles are implanted in the pores of the printed composite skeleton. Then, the printed composite material is moved into an autoclave with a designed curing pressure of 0.6 MPa, a curing temperature of 60°C, and a curing time of 3 hours.

[0056] Example 5

[0057] like Figure 6As shown, in this embodiment, the cylindrical composite matrix structure type is a three-dimensional four-directional structure. First, according to the type of the composite matrix structure, the mother-direction node length is 6.0 mm, the circumferential node length is 2.0 mm, and the thickness direction node length is 1.55 mm (T300-3K carbon fiber, 2 strands) as modeling parameters, and the ANSYS software is used to establish a unit cell structure model of the three-dimensional body core structure composite matrix model. The unit cell structure model size is set to 6.0 mm × 2.0 mm × 1.55 mm. The unit cell structure is the arrangement of the fiber bundles in the smallest unit in the composite matrix model. After the unit cell structure model is designed, the repeated superposition method is used (the unit cell size in the same circumferential direction remains unchanged, and is reduced layer by layer at an angle of 30° along the warp direction, as shown in FIG. Figure 7 As shown in the figure, an overall composite material matrix model is established according to the composite material matrix structure shape and size.

[0058] The composite material matrix model is implanted into the 3D printing software system, and the shape and size of the required printed composite material matrix structure are synchronously input and associated, and the composite material skeleton is obtained through 3D printing, specifically as follows: fiber bundles and resin are used as printing materials, and the plane formed by the diagonals of the unit cell model face is used as the printing reference plane. 3D printing technology is used to print a composite material skeleton formed by stacking fiber layers in the plane. The channels in the composite material skeleton are formed according to the spatial orientation of the fiber bundles in the composite material matrix structure. In the process of printing the composite material skeleton, channels are reserved.

[0059] Fiber bundles are implanted in the pores of the printed composite skeleton. Then, the printed composite material is moved into an autoclave with a designed curing pressure of 0.6 MPa, a curing temperature of 60°C, and a curing time of 3 hours.

[0060] Example 6

[0061] like Figure 8As shown, the composite matrix structure in this embodiment includes two structures: three-dimensional and 2.5D shallow cross bending. First, according to the structural characteristics of different regions of the composite matrix structure, the three-dimensional unit cell model is established with the fiber bundle specifications in the X, Y, and Z directions (two strands of 198tex carbon fiber, respectively), spacing (X-direction spacing is 0.6mm, Y-direction spacing is 1.25mm, and Z-direction spacing is 0.7mm) as parameters, and then the warp and weft density (warp density 8 strands / cm, weft density 2.5 strands / cm), warp and weft yarn specifications (two strands of 198tex carbon fiber in the warp direction, four strands of 198tex carbon fiber in the weft direction), and volume content (45%) as parameters. Among them, the unit cell model size at the three-dimensional structure is 1.25mm×1.25mm×0.7mm, and the unit cell model size at the 2.5D structure is 1.25mm×4mm×1.20mm; the two structural models are connected by the X-direction fiber bundle to ensure the integrity of the different structures of the composite matrix structure. The synchronous superposition method is adopted in various places to establish the overall composite material matrix model according to the shape and size of different structures.

[0062] The composite material matrix model is implanted into the 3D printing software system, and the shape and size of the required printed composite material matrix structure are synchronously input and associated, and the composite material skeleton is obtained through 3D printing, specifically as follows: fiber bundles and resin are used as printing materials, X0Y is used as the plane, and 3D printing technology is used to print a composite material skeleton formed by stacking fiber layers in the X and Y directions. The channels in the composite material skeleton are formed according to the spatial orientation of the fiber bundles in the composite material matrix structure. During the printing of the composite material skeleton, channels are reserved.

[0063] Fiber bundles are implanted in the pores of the printed composite skeleton. Then, the printed composite material is moved into an autoclave with a designed curing pressure of 0.6 MPa, a curing temperature of 60°C, and a curing time of 4 hours.

[0064] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. A person with ordinary knowledge in the technical field to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the claims.

Claims

1. A method for preparing a composite material based on 3D printing technology, characterized in that: The steps include: First, the composite material matrix structure to be printed is determined, and a composite material matrix model is established using 3D modeling software; then, the planar fiber layer to be printed is determined, and a composite material skeleton formed by stacking the planar fiber layers is printed using 3D printing technology, and during the printing of the composite material skeleton, channels are reserved according to the matrix model, and fiber bundles or resin rods are implanted in the channels of the printed composite material skeleton, and finally, the whole is heated and melted, solidified and formed, to form the composite material; Among them, according to the composite material matrix structure to be printed, the matrix structure unit cell model is first established through 3D modeling software, and the unit cell size is set. The unit cell is the arrangement of the fiber bundles in the smallest unit of the matrix structure. After the unit cell is designed, the overall composite material matrix model is established according to the shape and size of the matrix structure; Determine the planar fiber layer to be printed, and use 3D printing to obtain a composite material skeleton composed of the planar fiber layer, wherein the channels in the skeleton include any one or more of a straight channel, an oblique straight channel, and a curved channel; Determining the planar fiber layer to be printed, and using 3D printing technology to print the composite material skeleton formed by stacking the planar fiber layers with fiber bundles and resin; The composite material matrix structure includes an orthogonal three-dimensional structure, a 2.5D structure, a three-dimensional multi-directional structure, or a superposition structure of any two or three of these structures; When implanting fiber bundles or resin rods, fiber bundles or resin rods in all directions are implanted synchronously, and the yarns are stationed in different directions without affecting each other; The resin rod is made of a composite of fiber bundles and resin.

2. The method according to claim 1, characterized in that The composite material matrix structure to be printed is an orthogonal three-dimensional structure. The fiber bundle specifications and spacing in the X, Y, and Z directions are used as modeling parameters. The unit cell model of the matrix structure is first established through three-dimensional modeling software.

3. The method according to claim 1, characterized in that The composite material matrix structure to be printed is a 2.5D structure. The warp and weft density, warp and weft yarn specifications, volume content, and structural category are used as modeling parameters. The unit cell model of the matrix structure is first established through 3D modeling software.

4. The method according to claim 1, characterized in that The composite material matrix structure to be printed is a three-dimensional multi-directional structure. The node length in the parent direction, the node length in the circumferential direction, and the node length in the thickness direction are used as modeling parameters. The unit cell model of the matrix structure is first established through three-dimensional modeling software.

5. The method according to claim 1, characterized in that The fiber bundle material includes any one or more of carbon fiber, quartz fiber, glass fiber, and ceramic fiber, and the state includes wet state or dry state.

6. The method according to claim 1, characterized in that Resins include epoxy resins and phenolic resins.

7. The method according to claim 1, characterized in that The method of implanting the fiber bundle or the resin rod into the pores of the preform skeleton includes any one or more of the following methods: air flow introduction method, medium introduction method, and flexible rod direct introduction method.

8. A composite material prepared according to the method according to any one of claims 1 to 7.

Images