CN115056512B - Co-curing molding composite material and preparation method thereof - Google Patents

Abstract

The invention provides a co-curing molding composite material and a preparation method thereof, wherein the preparation method comprises the following steps: drilling the solid structural member to obtain at least one reserved hole; wherein the preformed hole is a through hole or a blind hole; paving a fiber material layer on the solid structural part comprising the at least one preformed hole, and preparing a riveting structure for connecting the solid structural part and the fiber material layer according to the preformed hole and the fiber bundle to obtain a prefabricated body; and carrying out molding treatment on the prefabricated body by adopting a liquid molding process or a prepreg compression molding process to obtain the co-curing molding composite material. The co-curing molding composite material provided by the invention is connected by adopting a high-fiber volume content riveting structure, has a complete structure and excellent mechanical property, and obviously improves the interface property.

Description

A kind of co-curing molding composite material and preparation method thereof

technical field

The invention relates to the technical field of composite materials, in particular to a co-cured molding composite material and a preparation method thereof.

Background technique

Resin-based composite materials are widely used in the aerospace field for main load-bearing parts such as cabins and airfoil structures due to their high specific stiffness, specific strength, corrosion resistance, and strong designability. . At present, the overall design of the composite material component structure can be integrally formed. The advantage of the integral forming is that the mechanical strength of the composite material component is high, and the number of parts is reduced at the same time, which significantly reduces the cost.

Because the structure of large composite material components is often extremely complex, and there are some metal structures, etc., it is very difficult to form a whole at one time. Therefore, in the design process, the complex product structure is often divided into simple parts and solid structures, and finally assembled together. Cured monolithic molding. For these simple parts, if the bonding method is used alone, the strength of the composite member will be too low; if the riveting and screw connection methods are used, it will not only damage the structure of the composite member and increase the weight, but also its performance It is also lower than the overall molding composite material structure, which is difficult to apply to the final overall molding; if the adjacent through holes are used for two-hole suture, the suture itself has a certain thickness because the direction of the hole is too oriented. , as the number of sutures between the two holes increases, the sutures will become thicker and thicker, which will affect the final composite material layup and affect the mechanical properties of the product; at the same time, sutures with better toughness are often used for sutures, so Its stiffness is poor, and its ability to improve interface performance is limited.

Contents of the invention

The embodiments of the present invention provide a co-cured molding composite material and a preparation method thereof. The co-cured molding composite material has high connection strength, significantly improves its interface performance, and the riveted structure prepared by fiber bundles has a high volume content of fibers and a complete structure Moreover, the mechanical properties are excellent, and the preparation method not only simplifies the molding process, but also ensures the integral molding of large and complex components, and at the same time realizes weight reduction and cost reduction.

In a first aspect, the present invention provides a method for preparing a co-cured molding composite material, the preparation method comprising:

Drilling the solid structure to obtain at least one reserved hole; wherein the reserved hole is a through hole or a blind hole;

laying a fiber material layer on the solid structural member including the at least one reserved hole, and preparing a riveting structure for connecting the solid structural member and the fiber material layer according to the reserved hole and fiber bundles, so as to get the prefab;

The prefabricated body is molded by using a liquid molding process or a prepreg compression molding process to obtain the co-cured molding composite material.

Preferably, the solid structural member is a metal member or a composite sheet member;

The blind hole is a stepped blind hole, and the hole diameter of the bottom area is larger than the hole diameter of the upper end area.

Preferably, the preparation method also includes:

The surface of the solid structural member is pretreated to roughen the surface.

More preferably, the pretreatment is sandblasting or grinding.

Preferably, when the number of the reserved hole is one, preferably the reserved hole is located at the center of the solid structure.

Preferably, said riveting structure is made of said fiber bundles.

Preferably, the fiber material layer is prepreg or dry fabric.

More preferably, the fiber material layer is a carbon fiber layer.

Preferably, the fiber bundle is composed of dipped fiber strands or dry fiber strands.

More preferably, the fiber bundles are carbon fibers.

Preferably, when the reserved hole is a through hole, the solid structural member including the at least one reserved hole is covered with a fiber material layer, and the fiber material layer is prepared according to the reserved hole and the fiber bundle for connecting the The riveted structure of the solid structural member and the fiber material layer, comprising:

The upper surface and the lower surface of the solid structural member including the through holes are respectively covered with fiber material layers, the fiber bundles are passed through the reserved holes and the fiber material layer, and covered on the fiber material The surface of the layer is shaped, and then the fiber bundle is shaped to obtain the riveted structure.

Preferably, when the reserved hole is a blind hole, the solid structural member including the at least one reserved hole is covered with a layer of fiber material, and prepared according to the reserved hole and fiber bundles for connecting the The riveted structure of the solid structural member and the fiber material layer, comprising:

Lay a fiber material layer on the surface of the solid structural member provided with the blind hole, fix one end of the fiber bundle at the bottom area of the blind hole, and pass the other end through the fiber material layer through the blind hole , and spread on the surface of the fiber material layer, and then shape the fiber bundle to obtain the riveted structure.

Preferably, the covering on the surface of the fiber material layer includes:

The fiber bundles are distributed on the surface of the fiber material layer one by one in the manner of equally dividing a circle with the reserved hole as the center of a circle; wherein, the fiber bundles are composed of several sub-fiber bundles.

More preferably, the thickness of the sub-fiber bundles is less than 1/5 of the thickness of the co-cured molded composite material.

Preferably, when the number of the reserved holes is at least two, L ₀ >2l; wherein, L ₀ is the edge distance of the holes, and 1 is the fiber bundle laid on the fiber material through the reserved holes The length of the layer surface.

More preferably, l is greater than the corresponding thickness of the co-cured molding composite material.

Preferably, laying a fiber material layer on the solid structural member including the at least one reserved hole, and preparing the solid structural member and the fiber material layer according to the reserved hole and fiber bundles The riveted structure, including:

According to the thickness of the co-cured molding composite material, determine the number of laying layers of the fiber material layer;

A riveted structure is prepared by laying at least one fiber material layer on the solid structural member including the at least one reserved hole until the number of laying layers is reached.

Preferably, laying a fiber material layer on the solid structural member including the at least one reserved hole, and preparing the solid structural member and the fiber material layer according to the reserved hole and fiber bundles The riveted structure, including:

According to the thickness of the co-cured molding composite material, determine the number of laying layers of the fiber material layer;

A fiber material layer is laid on the solid structure including the at least one reserved hole, and the riveted structure is prepared after the number of laying layers is reached.

Preferably, after preparing the riveted structure and before obtaining the prefabricated body, further comprising: laying a layer of fiber material on the outermost fiber material layer, so as to cover the riveted structure on the prefabricated the interior of the body.

More preferably, the preform is formed by using the liquid forming process; the liquid forming process includes a resin transfer molding process and a vacuum assisted forming process.

In a second aspect, the present invention provides a co-cured molding composite material prepared by the preparation method described in the first aspect above.

Compared with the prior art, the present invention has at least the following beneficial effects:

(1) The present invention provides a method for the preparation of integrally co-cured composite materials based on a riveted structure with high fiber volume content. The method uses fiber bundles to form a riveted structure with high fiber volume content in the reserved holes of solid structural parts , and connect the fiber material layer and the solid structural part through the riveting structure to obtain a prefabricated body. Among them, the fiber volume content in the riveted structure can reach more than 40%. At the same time, the riveted structure is evenly spread on the fiber material layer after the reserved holes, so as to avoid repeated superposition in the same direction when two parts are connected by suture, and then It leads to too thick accumulation, which affects the layering of the reinforcement fiber of the main structure and the strength of the formed product. In addition, the preparation method simplifies the molding process, ensures the integral molding of complex components, and greatly improves the interface performance between the fiber material layer and the solid structure.

(2) The present invention determines the relationship between the hole edge distance and the length of the fiber bundle that is laid on the surface of the fiber material layer after the fiber bundle is drawn out of the reserved hole, and reasonably designs the position of the fiber bundle laying, the state of the fiber bundle, The thickness of the fiber bundle laying, etc., adopts the method of co-curing integral molding, which not only ensures the strength of the co-curing molding composite material obtained after molding, but also significantly improves the connection strength between the solid structural part and the fiber material.

(3) The present invention uses fiber bundles to prepare the riveted structure. While ensuring the connection strength, it can also maximize the weight reduction effect and cost reduction potential of the composite material, making it have a broader application prospect in the aerospace field.

(4) The preparation method provided by the present invention has good manufacturability and operability, greatly improves the reliability of connection between different types of materials, and adopts integral molding to improve production efficiency, simplify assembly, and greatly reduce production costs , has a good promotion and application value.

Description of drawings

Fig. 1 is the flow chart of the preparation method of a kind of co-curing molding composite material provided by the present invention;

Fig. 2 is a schematic top view of a solid structural member provided with a single through hole provided by the present invention;

3 is a schematic cross-sectional view of a co-cured molding composite material provided by the present invention;

Fig. 4 is a schematic diagram of the distribution of a riveting structure provided by the present invention on the surface of the fiber material layer;

5 is a schematic cross-sectional view of a co-cured molding composite material provided by the present invention;

Fig. 6 is a schematic diagram of the distribution of a riveting structure provided by the present invention on the surface of the fiber material layer;

Fig. 7 is a schematic diagram of the distribution of a riveting structure provided by the present invention on the surface of the fiber material layer;

8 is a schematic cross-sectional view of a co-cured molding composite material provided by the present invention;

Fig. 9 is a schematic top view of a solid structural member provided with through holes and blind holes provided by the present invention;

Fig. 10 is a schematic bottom view of the solid structure corresponding to Fig. 9 provided by the present invention;

Fig. 11 is a schematic diagram of the distribution of a riveting structure provided by the present invention on the surface of one side of the fiber material layer;

Fig. 12 is a schematic diagram of the distribution of the riveting structure corresponding to Fig. 11 provided by the present invention on the surface of the fiber material layer on the other side;

Among them, solid structural part: 201, reserved hole: 2011, fiber material layer: 202, riveting structure: 203.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention and the accompanying drawings. Obviously, the described embodiments are Some embodiments of the present invention, rather than all embodiments, based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work, all belong to the protection scope of the present invention .

The embodiment of the present invention provides a method for preparing a co-cured molding composite material, as shown in Figure 1, the preparation method includes:

Step 100: Drilling the solid structural member to obtain at least one reserved hole; wherein, the reserved hole is a through hole or a blind hole;

Step 102: laying a fiber material layer on the solid structural member including at least one reserved hole, and preparing a riveting structure for connecting the solid structural member and the fiber material layer according to the reserved hole and fiber bundles, so as to obtain a prefabricated body;

Step 104: Molding the prefabricated body using a liquid molding process or a prepreg compression molding process to obtain a co-cured molding composite material.

According to some preferred embodiments, the riveted structure is made of fiber bundles.

In the present invention, the riveted structure is made of fiber bundles instead of traditional rivets or screw connections, which avoids damage to the structure of composite components by riveted or screwed connections, increases weight, and also leads to poor performance. Composite construction below monolithic molding.

It should be noted that the present invention has no special requirements on the types of fibers used in the fiber material layers and fiber bundles, and those skilled in the art can select suitable fiber materials according to actual needs.

According to some preferred embodiments, the solid structural member is a metal member or a composite sheet member.

In particular, a solid structural member, ie a formed member of any material that can be used as a substrate, is distinguished from a layer of fibrous material. Among them, metal components include but are not limited to plates made of aluminum and aluminum alloy substrates, steel plate substrates, stainless steel substrates, copper substrates, etc.; composite sheet components include but are not limited to metal composite panels and polymer materials. Composite panels (such as thermosetting composite panels), etc.

According to some preferred embodiments, the preparation method also includes:

The surface of the solid structural member is pretreated to roughen the surface.

According to some more preferred embodiments, the pretreatment is sandblasting or grinding.

In the present invention, by roughening the solid structure, the surface area of the solid structure can be increased and physical engagement or chemical connection can occur, so that after solidification and molding, the gap between the solid structure and the fiber material layer can be further improved. Excellent interface performance and enhanced connection strength.

According to some preferred embodiments, when the number of the reserved hole is one, the reserved hole is located at the center of the solid structure.

According to some preferred embodiments, the fiber material layer is a prepreg or a dry fabric.

According to some preferred embodiments, the fiber bundle consists of dipped fiber strands or dry fiber strands.

In the present invention, the dry fabric is selected from any one of fiber cloths, and the fiber cloth is selected from any one of unidirectional carbon cloth, plain carbon cloth or satin carbon cloth; the dry fiber thread is selected from carbon fiber, Kai Any one of the tows; the prepreg is selected from any of the carbon fibers; the impregnated fiber line is selected from any of the carbon fibers and Kevlar fibers; wherein, the resin used for the prepreg can be selected according to the actual application Need to choose.

According to some more preferred embodiments, the fiber material layer is a carbon fiber layer.

According to some more preferred embodiments, the fiber bundles are carbon fibers.

In the present invention, it is preferable that the fiber material layer and fiber bundles are all carbon fibers. Carbon fibers have characteristics such as high temperature resistance, friction resistance, electrical conductivity, heat conduction and corrosion resistance. Has high strength and modulus. Carbon fiber has a low density, so its specific strength and specific modulus are high. Compared with aramid fibers commonly used as sutures, carbon fibers have better stiffness, and the riveted structure prepared by carbon fibers has stronger stiffness, so it can significantly improve the interfacial properties of co-cured composite materials.

According to some preferred implementation manners, when the reserved hole is a through hole, step 102 includes:

Lay fiber material layers on the upper and lower surfaces of the solid structure including through holes, pass the fiber bundles through the reserved holes and the fiber material layer, and lay them on the surface of the fiber material layer, and then shape the fiber bundles , to obtain a riveted structure.

According to some preferred embodiments, when the reserved hole is a blind hole, step 102 includes:

Lay a fiber material layer on the surface of a solid structural member with a blind hole, fix one end of the fiber bundle to the bottom area of the blind hole, and pass the other end through the fiber material layer through the blind hole, and lay it on the surface of the fiber material layer , and then shape the fiber bundle to obtain a riveted structure.

According to some preferred embodiments, the blind hole is a stepped blind hole, and the diameter of the bottom region is larger than the diameter of the upper region.

In the present invention, the blind hole is set as a stepped hole, and the aperture of the bottom area is larger than the aperture of the upper end area. When one end of the fiber bundle is fixed on the bottom area of the blind hole, a barb structure can be formed, thereby further improving the fiber bundle. The connection strength in the blind hole of the solid structural part enhances the reliability of the riveted structure.

It should be noted that the fiber material layer is at least one layer, for example, may be 2 layers, 3 layers, 6 layers, 10 layers, and the like. Specifically, those skilled in the art can design according to the requirements for the co-cured molding composite material.

According to some preferred embodiments, in step 102, covering the surface of the fiber material layer includes:

The fiber bundles are distributed on the surface of the fiber material layer one by one in the manner of equally dividing the circle with the reserved hole as the center of the circle; wherein, the fiber bundles are composed of several sub-fiber bundles.

It should be noted that, the fiber bundles laid on the surface of the fiber material layer can also be arranged and distributed on the surface of the fiber material layer bundle by bundle with the reserved hole as the center to avoid overlapping arrangement.

According to some more preferred embodiments, the thickness of the sub-fiber bundles is less than 1/5 of the thickness of the co-cured molded composite material.

According to some preferred embodiments, when the number of reserved holes is at least two, L ₀ >2l; wherein, L ₀ is the hole margin, and 1 is the length of fiber bundles laid on the surface of the fiber material layer through the reserved holes .

According to some more preferred embodiments, l is greater than the thickness of the corresponding co-cured molded composite.

In the present invention, by limiting the relationship between the hole spacing and l when a plurality of reserved holes are provided, lapping and overlapping of fiber bundles drawn out from adjacent reserved holes and covered on the surface of the fiber material layer can be avoided. The phenomenon, so as to ensure the smoothness of the internal structure of the prepared co-cured molding composite material while ensuring the l length. By setting l greater than the thickness of the corresponding co-cured molding composite material, the reinforcement effect of the riveted structure is ensured, and the situation that the reinforcement effect of the riveted structure is weak or even ineffective when l is too short. Similarly, since the thickness of the sub-fiber bundles laid on the surface of the fiber material layer may affect the overall thickness of the co-cured composite material, the thickness of the sub-fiber bundles needs to be limited. When the thickness of the sub-fiber bundles is less than 1/5 of the thickness of the co-cured molding composite material, the influence of the overall thickness brought by the thickness of the sub-fiber bundles may not be considered. However, for co-curing composite materials with special requirements, the thickness of the sub-fiber bundles needs to be considered. According to mechanical calculations, the thickness of the fiber material layer should be correspondingly deleted, or the original fiber corresponding to the position of the sub-fiber bundles should be extracted from the fiber material layer. The fibers, replaced by sub-fiber bundles of equal length, can also maintain the overall thickness of the co-cured molded composite.

In a preferred embodiment, when the reserved hole is a through hole, step 102 includes: laying a layer of fiber material on the upper surface and lower surface of the solid structural member respectively, passing the fiber bundle through the reserved hole and the fiber material layer, Since the fiber bundles are composed of several sub-fiber bundles, the fiber bundles are distributed on the surface of the fiber material layer one by one (i.e., sub-fiber bundles) in the manner of equal circles with the through hole as the center of the circle, and then the fiber bundles are shaped to obtain the following: A riveted structure composed of several I-shaped.

In a preferred embodiment, when the reserved hole is a blind hole, step 102 includes: laying a fiber material layer on the surface of the solid structural member provided with the blind hole, fixing one end of the fiber bundle to the bottom area of the blind hole, The other end passes through the fiber material layer through the blind hole. Since the fiber bundle is composed of several sub-fiber bundles, the fiber bundles take the blind hole as the center of the circle and distribute bundle by bundle (that is, sub-fiber bundles) in the fiber material layer in the manner of equal circles. surface, and then shape the fiber bundles to obtain a riveted structure.

It should be noted that fixing one end of the fiber bundle to the bottom of the blind hole may adopt but not limited to glue injection and curing. Moreover, for the blind hole, it is necessary to fix one end of the fiber bundle to the bottom of the blind hole before laying the fiber material layer. The fiber bundle is shaped, and for the dry fiber line, spraying setting agent, migration method or powder setting method can be used. The hole positions of the reserved holes of the solid structural member after laying the fiber material layer can be determined by using a template.

Specifically, when the reserved holes are through holes, the distribution schematic diagrams of the riveting structure on the surface of the fiber material layer can be shown in FIGS. 4 , 6 and 7 . That is to say, the riveting structure can form a circular surface or a semicircular surface with a radius of l on the surface of the fiber material layer.

In the present invention, the fiber bundles can fill the positions of the reserved holes, and the remaining gaps can be further filled by injecting glue during the molding process. The fiber volume content in the riveted structure can reach more than 40%. At the same time, the riveted structure is evenly spread on the fiber material layer after passing through the reserved holes, so as to avoid repeated superposition in the same direction when two parts are connected by suture, and then It leads to too thick accumulation, which affects the layering of the reinforcement fiber of the main structure and the strength of the formed product.

According to some preferred implementation manners, step 102 includes:

According to the thickness of the co-cured composite material, determine the number of laying layers of the fiber material layer;

A riveted structure is prepared by laying at least one layer of fibrous material on the solid structure including at least one reserved hole, until the number of laying layers is reached.

According to some preferred implementation manners, step 102 includes:

According to the thickness of the co-cured composite material, determine the number of laying layers of the fiber material layer;

A layer of fibrous material is laid on a solid structural member including at least one reserved hole, and a riveted structure is prepared after reaching the number of laying layers.

In the present invention, the riveting structure can be prepared after laying one layer of fiber material layer or after laying several layers or after complete laying is completed during the laying process until the prefabricated body is laid. For example, the fiber bundle has 16 sub-fiber bundles, and the upper surface and the lower surface of the solid structure are covered with 5 layers of fiber material layers. The fiber bundles are used to prepare the riveted structure, and when the fifth layer of fiber material is laid on the upper and lower surfaces, 8 bundles of sub-fiber bundles are used to prepare the riveted structure (as shown in Figure 6). That is to say, in this case, the number of layers of fiber material layers passed by the sub-fiber bundles of different layers of riveted structure is different. For the entire co-cured molding composite material, there are 2 sub-fiber bundles passing through 2 layers of fiber material Layers, 2 beams through 4 layers, 2 beams through 6 layers, 2 beams through 8 layers, 8 beams through 10 layers.

More specifically, as mentioned in the previous example, the laying direction of the sub-fiber bundles on the surface of each layer of fiber material can be the same or different, and those skilled in the art can according to the design requirements, application scenarios, etc. specific design.

In the present invention, for example, the fiber bundle has 16 sub-fiber bundles, and the upper surface and the lower surface of the solid structure are covered with 5 layers of fiber material layers. After all the 10 layers of fiber material layers have been covered, the 16 bundles of sub-fiber bundles are drawn from the reserved holes, and are distributed on the surface of the fiber material layer one by one in the manner of equal circles, forming a circular surface, that is, the angle between adjacent fiber bundles is 22.5° (as shown in Figure 4 ); or according to the application scene of the co-cured molding composite material, it can be distributed on the surface of the fiber material layer one by one in the manner of equal circles to form a semicircular surface, that is, the angle between adjacent fiber bundles is 12°. That is to say, in this case, for the entire co-cured molded composite material, all 16 sub-fiber bundles pass through 10 layers of fiber materials.

According to some preferred embodiments, in step 102, after preparing the riveted structure and before obtaining the prefabricated body, it also includes: laying a layer of fiber material on the outermost fiber material layer, so as to cover the riveted structure on the prefabricated the interior of the body.

In the present invention, after the riveted structure is prepared, a layer of fiber material is laid on the outermost side, and the quasi-riveted structure is covered inside, so as to prevent the riveted structure from being exposed and easily damaged. And after laying the layer of fiber material, the prepared co-cured molding composite material can reach the expected target thickness.

According to some more preferred embodiments, the preform is formed by a liquid forming process; the liquid forming process includes a resin transfer molding process and a vacuum assisted forming process.

In the present invention, the liquid molding process is selected from resin transfer molding process, vacuum assisted molding process, vacuum assisted resin transfer molding process, vacuum infusion process, thermal expansion resin transfer molding process, rubber assisted resin transfer molding process, lightweight Any of resin transfer molding, Seaman resin injection molding, co-injection resin transfer molding, and resin film injection molding.

Specifically, taking resin transfer molding (RTM) as an example, after the preform is obtained, the preform including the riveted structure is put into the lower mold of the RTM mold, and then the upper mold of the mold is closed. After the mold is closed, it is sealed, and then the resin is injected to make the resin infiltrate the prefabricated body. Then, through curing molding and demolding, a co-curing molding composite material is obtained, in which the solid structure part and the fiber material layer are integrally formed.

The present invention also provides the co-cured molding composite material prepared by the above-mentioned preparation method.

In order to illustrate the technical solution and advantages of the present invention more clearly, a co-cured molding composite material and its preparation method will be described in detail below through several examples.

Example 1

Prepare a co-cured molding composite material with a thickness of 5mm, the solid structure 201 (thickness is 1mm, is an aluminum plate), the thickness of the fiber material layer 202 on the upper surface and the lower surface of the solid structure 201 is 2mm, and the size of the fiber material layer 202 Both are 50mm*50mm.

(1) As shown in Fig. 2, carry out drilling process at the central position of solid structural member 201, obtain a through hole 2011 (diameter is 2mm), and carry out sandblasting to the surface of this solid structural member 201;

(2) As shown in Figure 3, lay 9 layers of plain carbon fiber fabrics on the upper surface of solid structure 201 (the thickness of each layer of plain carbon fiber fabrics is 0.2mm), and spread 9 layers of plain carbon fiber fabrics on the lower surface; then the fibers Bundle (T300-3K fiber tow, a total of 16 sub-bundles, each sub-bundle has 3000 monofilaments, the fiber diameter of the monofilament is 7*10 ^-3 mm) through the through hole and a total of 18 layers on the upper and lower surfaces The plain weave carbon fiber fabric, with the through hole as the center of the circle, bends and spreads the surface of the outermost plain weave carbon fiber fabric (as shown in Figure 4) according to the method of equally dividing the circle (i.e. sub-fiber bundles), l=15mm , and then shape the fiber bundles to obtain a riveted structure; finally, use the 10th layer of plain carbon fiber fabric to cover the riveted structure on the upper and lower surfaces to obtain a prefabricated body;

Among them, the fiber volume content in the riveted structure is 58.5%;

(3) Install the metal male mold and the metal female mold, place the prefabricated body in the mold, use the VARTM molding process (vacuum assisted resin transfer molding process), infiltrate the prefabricated body prepared by resin, and remove the metal male mold in turn after curing And a metal female mold to obtain a co-cured molding composite material with a high fiber volume content, light weight and high strength carbon fiber riveted structure.

Example 2

Embodiment 2 is basically the same as Embodiment 1, and its difference is:

(2) As shown in Figure 5, lay 3 layers of plain carbon fiber fabrics on the upper surface of the solid structure 201 (the thickness of each layer of plain carbon fiber fabrics is 0.2mm), and spread 3 layers of plain carbon fiber fabrics on the lower surface; then the fibers Bundles (T300-3K fiber tows, a total of 16 sub-fiber bundles, each sub-fiber bundle has 3000 monofilaments, and the fiber diameter of the monofilaments is 7*10 ^-3 mm) through the through hole and a total of 6 layers on the upper and lower surfaces Plain weave carbon fiber fabric, then take the through hole as the center of the circle, take 4 bundles of sub-fiber bundles according to the way of equal circles (that is, sub-fiber bundles) and lay them on the third layer (counting from the solid structure to both sides) plain weave The surface of the carbon fiber fabric, l=15mm, and then the fiber bundles are shaped to obtain the first riveted structure;

Then continue to pave 3 layers of plain carbon fiber fabric on the upper surface of the first riveted structure, and pave 3 layers of plain carbon fiber fabric on the lower surface; then pass the remaining 12 sub-fiber bundles through the 6 layers of plain carbon fiber fabric covered this time, and Take the through hole as the center of the circle, take 4 bundles of sub-fiber bundles and bend them one by one according to the method of equally dividing the circle, and spread them on the surface of the plain carbon fiber fabric on the sixth layer (counting from the solid structural part to both sides), l=15mm, and then the fibers The beam is shaped to obtain the second riveted structure;

Then continue to pave 3 layers of plain carbon fiber fabric on the upper surface of the second riveting structure, and pave 3 layers of plain carbon fiber fabric on the lower surface; then pass the remaining 8 sub-fiber bundles through the 6 layers of plain carbon fiber fabric covered this time, and The through hole is the center of the circle, and 8 bundles of sub-fiber bundles are taken and bent one by one according to the method of equally dividing the circle, and are distributed on the surface of the plain carbon fiber fabric on the ninth layer (counting from the solid structural part to both sides) (as shown in Figure 6). l=15mm, then shape the fiber bundle to obtain the third riveted structure;

Finally, the third riveted structure covering the upper and lower surfaces with the tenth layer of plain carbon fiber fabric was used to obtain a prefabricated body; wherein, the volume content of fibers in the riveted structure was 58.5%.

Example 3

Embodiment 3 is basically the same as Embodiment 2, and its difference is:

The structural schematic diagram of the third riveting structure on the surface of the plain carbon fiber fabric is shown in FIG. 7 .

Example 4

Prepare a co-cured molding composite material with a thickness of 5 mm, a solid structural member 201 (a thickness of 3 mm, which is an aluminum plate), a fiber material layer 202 with a thickness of 2 mm, and the dimensions of the solid structural member 201 and the fiber material layer 202 are 50 mm*50 mm.

(1) As shown in Figure 8, drilling is carried out at the central position of the solid structural member 201 to obtain a blind hole 2011 (the diameter of the upper end area is 2 mm), and the surface of the solid structural member 201 is sandblasted;

(2) As shown in Figure 8, lay 9 layers of plain carbon fiber fabrics on the upper surface of the solid structure 201 (the thickness of each layer of plain carbon fiber fabrics is 0.2mm), and spread 9 layers of plain carbon fiber fabrics on the lower surface; then the fibers One end of the bundle (T300-3K fiber bundle, 16 sub-bundles in total, each sub-bundle has 3000 monofilaments, and the fiber diameter of the monofilament is 7*10 ^-3 mm) is fixed at the bottom area of the blind hole, and the other One end is drawn through the blind hole through 9 layers of plain carbon fiber fabric, and then with the blind hole as the center of the circle, it is bent and distributed on the surface of the ninth layer of plain carbon fiber fabric (such as As shown in Figure 4), l=15mm, then the fiber bundles are shaped to obtain a riveted structure; finally, the 10th layer of plain carbon fiber fabric is used to cover the surface of the riveted structure to obtain a prefabricated body;

Among them, the fiber volume content in the riveted structure is 58.5%;

(3) Install the metal male mold and the metal female mold, place the prefabricated body in the mold, use the VARTM molding process (vacuum assisted resin transfer molding process), infiltrate the prefabricated body prepared by resin, and remove the metal male mold in turn after curing And a metal female mold to obtain a co-cured molding composite material with a high fiber volume content, light weight and high strength carbon fiber riveted structure.

Example 5

Prepare a co-cured molding composite material with a thickness of 5 mm, a solid structural part 201 (a thickness of 1 mm, a carbon fiber composite material plate), the thickness of the fiber material layer 202 on the upper surface and the lower surface of the solid structural part 201 is 2 mm, and the solid structural part 201 and the size of the fiber material layer 202 are both 50mm*50mm.

(1) As shown in Figures 9 and 10, drilling is performed at the center of the solid structure 201 to obtain 4 reserved holes 2011, of which 2 through holes (2mm in diameter) and 2 blind holes (upper region The diameter is 2 mm), and the surface of the solid structure 201 is polished with 60 mesh sandpaper;

(2) As shown in Figures 11 and 12, lay 9 layers of plain carbon fiber fabrics on the upper surface of the solid structure 201 (the thickness of each layer of plain carbon fiber fabrics is 0.2 mm), and lay 9 layers of plain carbon fiber fabrics on the lower surface;

For the through hole, the steps of preparing the riveted structure include: fiber bundles (T300-3K fiber bundles, a total of 16 sub-fiber bundles, each sub-fiber bundle has 3000 monofilaments, and the fiber diameter of the monofilaments is 7*10 ^-3 mm) A total of 18 layers of plain carbon fiber fabrics that pass through the through hole and the upper and lower surfaces, and then take the through hole as the center of the circle, bend and lay the plain carbon fiber fabric distributed on the outermost side according to the method of equal circles (ie sub-fiber bundles) surface, l=10mm, and then shape the fiber bundle to obtain a riveted structure;

For blind holes, the steps of preparing the riveted structure include: fiber bundles (T300-3K fiber bundles, a total of 16 sub-fiber bundles, each sub-fiber bundle has 3000 monofilaments, and the fiber diameter of the monofilaments is 7*10 ^-3 mm) is fixed at the bottom area of the blind hole, and the other end is led out from the blind hole through 9 layers of plain carbon fiber fabric, and then with the blind hole as the center of the circle, it is bent and laid bundle by bundle (that is, sub-fiber bundles) in the manner of equal circles. Cover and distribute on the surface of the ninth layer of plain carbon fiber fabric, l=10mm, and then shape the fiber bundles to obtain a riveted structure;

Finally, the tenth layer of plain carbon fiber fabric is used to cover the riveted structure of the upper and lower surfaces to obtain a prefabricated body; wherein, the fiber volume content in the riveted structure is 58.5%;

(3) Install the metal male mold and the metal female mold, place the prefabricated body in the mold, use the VARTM molding process (vacuum assisted resin transfer molding process), infiltrate the prefabricated body prepared by resin, and remove the metal male mold in turn after curing And a metal female mold to obtain a co-cured molding composite material with a high fiber volume content, light weight and high strength carbon fiber riveted structure.

Example 6

Embodiment 6 is substantially the same as Embodiment 5, and its difference is:

The two blind holes are respectively arranged on both sides of the solid structural member 201 .

It should be noted that Fig. 3, Fig. 5 and Fig. 8 are schematic cross-sectional views obtained by taking the plane where the center of the reserved hole is located as the cutting plane. Fig. 3, Fig. 5 and Fig. 8 do not show a layer of fiber material laid on the riveted structure, and the figure does not show a complete solid structure, that is, the length or width of the solid structure is greater than 2l.

It should be noted that, the fiber bundle shaping in Example 2 can be shaped in layers as shown in Embodiment 2, that is, the fiber bundle shaping can be performed three times; after all the riveting structures are obtained, the fiber bundle shaping can be performed for the last time. Among them, the fiber bundle shaping method is determined according to the application and requirements of the co-cured composite material.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent replacements are made to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention. Parts not described in detail in the present invention are well-known technologies for those skilled in the art.

Claims (16)

1. A method of making a co-cured molded composite material, the method comprising:

drilling a solid structural member to obtain at least one preformed hole; wherein the preformed hole is a through hole or a blind hole;

laying a layer of fibrous material on the solid structure comprising said at least one preformed hole and preparing a riveted structure according to said preformed hole and the fibre bundle for joining said solid structure and said layer of fibrous material, so as to obtain a preform, comprising:

when the preformed hole is a through hole, respectively paving fiber material layers on the upper surface and the lower surface of the solid structural member comprising the through hole, enabling the fiber bundle to penetrate through the preformed hole and the fiber material layers and be paved on the surfaces of the fiber material layers, and then shaping the fiber bundle to obtain the riveting structure;

when the preformed hole is a blind hole, paving a fiber material layer on the surface of the solid structural member provided with the blind hole, fixing one end of the fiber bundle in the bottom area of the blind hole, enabling the other end of the fiber bundle to penetrate through the fiber material layer through the blind hole and be paved on the surface of the fiber material layer, and then shaping the fiber bundle to obtain the riveting structure;

wherein, the surface of the fiber material layer is paved with the fiber material layer, and the fiber material layer comprises: the fiber bundles are distributed on the surface of the fiber material layer one by one in an equicircular mode by taking the reserved holes as circle centers; wherein the fiber bundle consists of a plurality of sub-fiber bundles;

and carrying out molding treatment on the prefabricated body by adopting a liquid molding process or a prepreg compression molding process to obtain the co-curing molding composite material.

2. The method of claim 1, wherein:

the solid structural part is a metal component or a composite board component;

the blind hole is a stepped blind hole, and the aperture of the bottom area is larger than that of the upper end area.

3. The method of claim 1, further comprising:

pretreating the surface of the solid structural part to make the surface rough; the pretreatment is sand blasting or grinding.

4. The method of claim 1, wherein:

when the number of the preformed holes is one, the preformed holes are located in the center of the solid structural member.

5. The method of claim 1, wherein:

the riveted structure is made of the fiber bundle.

6. The production method according to claim 1, characterized in that:

the fiber material layer is prepreg or dry fabric.

7. The production method according to claim 1, characterized in that:

the fiber material layer is a carbon fiber layer.

8. The production method according to claim 1, characterized in that:

the fiber bundle consists of a gum dipping fiber thread or a dry fiber thread.

9. The production method according to claim 1, characterized in that:

the fiber bundle is carbon fiber.

10. The production method according to claim 1, characterized in that:

the thickness of the sub-fiber bundle is less than 1/5 of the thickness of the co-cured molding composite material.

11. The method of claim 1, wherein:

when the number of the prepared holes is at least two,L ₀ ＞2l(ii) a Wherein,L ₀ the distance between the edges of the holes is,land laying the fiber bundles on the surface of the fiber material layer through the preformed holes.

12. The method of claim 11, wherein:

lgreater than the thickness of the co-cured molded composite material.

13. The method of claim 1, wherein:

the laying of a layer of fibrous material on the solid structure comprising the at least one preformed hole and the preparation of a riveted structure according to the preformed hole and the fibre bundle for connecting the solid structure and the layer of fibrous material, comprises:

determining the number of paving layers of the fiber material layer according to the thickness of the co-cured molding composite material;

paving at least one fiber material layer on the solid structural member comprising the at least one preformed hole, and preparing a riveting structure until the number of the paving layers is reached;

or,

determining the number of paving layers of the fiber material layer according to the thickness of the co-cured molding composite material;

and paving a fiber material layer on the solid structural member comprising the at least one preformed hole, and preparing the riveting structure after the number of paving layers is reached.

14. The production method according to any one of claims 1 to 13, characterized in that:

after the preparation of the riveted structure and before the obtaining of the preform, the method further includes: and paving a fiber material layer on the outermost fiber material layer to cover the riveted structure in the inner part of the prefabricated body.

15. The production method according to any one of claims 1 to 13, characterized in that:

molding the prefabricated body by adopting the liquid molding process; the liquid forming process comprises a resin transfer molding process and a vacuum auxiliary forming process.

16. A co-cured shaped composite material, characterized in that it is obtained by the process according to any one of claims 1 to 15.

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