An apparatus and method for preparing carbon fiber reinforced thermosetting composite materials

Abstract

An apparatus and method for preparing carbon fiber reinforced thermosetting composite materials are disclosed. The apparatus includes a top plate, an upper template, a lower mold fixing base, a base support, and an ultrasonic vibration device. The method is an RTM molding method for improving porosity defects in carbon fiber reinforced thermosetting composite materials. Specifically, carbon fiber fabric is used as the reinforcement and thermosetting resin is used as the matrix. The process involves cutting, layup, resin impregnation of the fabric while simultaneously activating the ultrasonic device, followed by deactivation of the ultrasonic device after impregnation and curing. Using this invention, resin flow can be accelerated during molding, increasing the resin penetration rate into the fiber fabric. The carbon fiber surface can be etched to increase roughness and improve the wetting performance between the matrix and the fiber fabric, thereby reducing porosity defects and further improving the interlaminar shear properties of the carbon fiber composite material. The process is simple and highly efficient.

Description

Technical Field

[0001] This invention belongs to the field of carbon fiber reinforced thermosetting composite material manufacturing, specifically relating to an apparatus and method for preparing carbon fiber reinforced thermosetting composite materials. Background Technology

[0002] Liquid molding transfer (RTM) is a composite material molding process based on thermosetting resins and carbon fiber reinforcements. Due to its advantages such as semi-closed-mold injection, high efficiency, and applicability to molding complex structures, it has become a research hotspot in the automotive composite material manufacturing field. However, the RTM process, due to the characteristic of using liquid resin to impregnate dry fiber fabrics, can lead to insufficient or uneven fiber impregnation during the impregnation process, inevitably resulting in porosity defects within the material. Studies have shown that the presence of porosity significantly reduces the interlaminar shear, tensile, and fatigue mechanical properties of carbon fiber reinforced polymer (CFRP) composites. Therefore, developing innovative RTM molding methods to reduce porosity defects in composite materials is crucial for improving their mechanical properties.

[0003] Although Jiang Zaixing et al. (CN 101549524A) improved resin-fiber wettability and tensile strength of RTM products by applying ultrasound to the resin storage tank during RTM molding, the continuous treatment of the resin and the thermal effect caused by ultrasonic vibration can lead to premature curing of the remaining resin, which is detrimental to industrial production and product stability. Furthermore, according to literature reports, the porosity in RTM-molded carbon fiber composites originates not only from air bubbles dissolved in the resin, but also more significantly from the uneven flow of resin within the fiber filaments and bundles during resin impregnation. Therefore, this technology is not suitable for improving porosity defects in RTM products.

[0004] Currently, there are no studies or reports on using ultrasonic vibration to suppress pore defects and improve interlaminar shear properties in carbon fiber composites formed by RTM process. Summary of the Invention

[0005] The technical problem to be solved by this invention is to provide a preparation apparatus and method that utilizes ultrasonic vibration to increase the penetration rate of fiber fabrics, improve the wetting performance between resin and fiber fabrics, and reduce pore defects in composite materials. This invention is simple to operate, highly efficient, and can effectively improve the interlaminar shear properties of carbon fiber reinforced thermosetting composites.

[0006] The technical solution adopted by this invention to solve its technical problem is:

[0007] An apparatus for preparing carbon fiber reinforced thermosetting composite materials includes a top plate, an upper template, a lower template fixing base, a base support, and an ultrasonic vibration device.

[0008] The upper template is provided with a punch positioning plate, a punch, an adjusting screw, and a resin outlet; the punch positioning plate is installed below the upper template by a fixing screw; the punch is installed in the punch positioning plate and a connecting screw is installed between it and the upper template, and a sealing ring is provided on the side of the punch; the adjusting screw is installed on the upper template and its bottom can contact the punch; the upper template and the punch positioning plate are provided with a mold-lifting connecting rod positioning hole, and a mold-lifting connecting rod is installed; the resin outlet is located on the left side of the upper template and is connected to the bottom surface of the punch through a pipeline;

[0009] The lower mold fixing base is provided with a concave mold and an electric heating rod; the concave mold is installed in the middle of the lower mold fixing base, and a gasket is installed between the concave mold and the lower mold fixing base, and a washer is provided on the upper end face of the concave mold; the electric heating rod is installed in the lower mold fixing base and is located below the concave mold; the punch and the concave mold are combined to form a closed molding cavity; the concave mold includes a lifting module, a resin guide channel, a resin inlet and a connecting boss; the lifting module is connected to the lifting connecting rod, the resin inlet is located on the right side of the bottom of the concave mold, the resin guide channel is located at the resin inlet and arranged along the width direction of the concave mold, the connecting boss is fixedly installed in the middle position of the bottom of the concave mold, the connecting boss is provided with a threaded hole, and the ultrasonic vibration device is connected to the connecting boss through bolts and threaded holes.

[0010] Preferably, the ultrasonic vibration device includes an ultrasonic amplitude transformer, a transducer, and a power supply box; the ultrasonic amplitude transformer is connected to the connecting boss via bolts and threaded holes; the transducer is connected to the ultrasonic amplitude transformer, and the power supply box is connected to the transducer via a power cable.

[0011] Preferably, the device further includes a resin tank, a vacuum tube, a flow stop clamp, a waste collection tank, and a vacuum pump; one end of the vacuum tube is connected to the resin inlet in the mold cavity, and the other end is connected to the resin tank through the flow stop clamp; one end of the waste collection tank is connected to the resin outlet through the vacuum tube and the flow stop clamp, and the other end is connected to the vacuum pump through the vacuum tube.

[0012] Preferably, there are four fixing screws arranged in a square on the upper template; four connecting screws arranged in a square on the upper template; three adjusting screws arranged in a triangular shape on the upper template; and four positioning holes for the mold-lifting connecting rod, each for mounting a mold-lifting connecting rod.

[0013] Preferably, there are four electric heating rods arranged in parallel; there are four lifting modules, which are respectively installed around the concave mold and connected to the lifting rod.

[0014] A method for preparing carbon fiber reinforced thermosetting composite materials, comprising the following specific steps:

[0015] (a) Material selection: Carbon fiber fabric is selected as the reinforcement and thermosetting resin is selected as the matrix material. The thermosetting resin is placed in a resin tank.

[0016] (II) Preparation: Adjust the relative position of the punch by adjusting the screw in the upper template to control the height of the molding cavity; apply a layer of release agent to the surface of the die and the punch respectively; connect the resin inlet and the resin tank through the vacuum tube and the stop clamp, and close the stop clamp; connect the resin outlet and the waste collection tank through the vacuum tube and the stop clamp, and open the stop clamp, while connecting the waste collection tank and the vacuum pump through the vacuum tube.

[0017] (III) Preparation of composite materials: Place the carbon fiber fabric into the molding cavity, control the upper template to move downwards, and seal the molding cavity; turn on the vacuum pump to make the molding cavity a vacuum state and wait for the pressure to stabilize; turn on the ultrasonic vibration device, set the power and time, and start ultrasonic vibration. The direction of ultrasonic vibration is the normal to the resin flow direction. Open the inlet stop clamp, and when the thermosetting resin wets the carbon fiber fabric and reaches the outlet side, turn off the ultrasonic vibration, wait for the thermosetting resin to flow out from the outlet for two minutes, close the inlet stop clamp and the outlet stop clamp, and turn off the vacuum pump; turn on the electric heating rod, set the heating temperature, and wait for a certain time to cure and form a carbon fiber reinforced thermosetting composite material.

[0018] Preferably, in step (i), the carbon fiber fabric is a ±45° non-bending carbon fiber fabric; the thermosetting resin is a uniform mixture of IN2 epoxy resin and AT-30 slow curing agent at a mass ratio of 100:25-35.

[0019] Preferably, in step (ii), the height of the molding cavity is 1-5 mm.

[0020] Preferably, in step (iii), the pressure gauge on the vacuum pump displays -0.09MPa to -0.1MPa, at which point the molding cavity is in a vacuum state.

[0021] Preferably, in step (iii), the ultrasonic vibration device has a frequency of 20kHz and a power of 0-1000W; ultrasonic vibration is applied during the process of impregnating the carbon fiber fabric with thermosetting resin, and the power of the ultrasonic vibration device is set to 400-600W for 2-6 minutes; when the electric heating rod is turned on, the heating temperature is set to room temperature - 200℃.

[0022] The beneficial effects of this invention are:

[0023] Advantages of the device: Compared with traditional RTM molding, in addition to the heating function, this device has the functions of ultrasonic vibration, observation of resin flow front, variable molding thickness and convenient demolding. The mold is designed for molding carbon fiber fabrics, including but not limited to plain weave fabrics, stitched fabrics and non-cribable fabric composites.

[0024] The following improvements were made in the connection between ultrasonic waves and RTM molds: (1) In order to apply ultrasonic waves to large-sized metal molds, the lower mold was designed as two parts: a concave mold and a lower mold fixing base. The ultrasonic vibration device was directly connected to the concave mold, and the heating device was designed on the lower mold fixing base to prevent the heating rod from being affected by ultrasonic vibration and reducing its lifespan; (2) In order to ensure the uniformity of ultrasonic vibration and the effective transmission of ultrasonic waves to the molding cavity, a cylindrical boss with a length of 20mm was first machined in the middle of the bottom of the concave mold, and a threaded hole was machined inside it. Then, the ultrasonic amplitude transformer was connected to the middle of the bottom of the concave mold in the form of bolts.

[0025] The following improvements were made to the selection of the ultrasonic vibration direction: the previous injection molding method along the flow direction was changed, and ultrasonic vibration perpendicular to the flow direction was selected. On the one hand, vibration perpendicular to the flow direction can improve the impregnation performance of multi-layer fiber fabrics in the thickness direction and reduce porosity defects; on the other hand, ultrasonic vibration can be converted into vibration along the flow direction through the elastic deformation of the mold, promoting the flow of resin towards the outlet direction, thereby causing bubbles to stretch, deform and eventually burst along with the resin flow, ultimately improving the porosity defects distributed along the flow direction in the product.

[0026] In the upper template design, a split design is adopted, with a punch and a punch positioning plate designed separately. Three adjusting screws are set in the upper template to control the relative position of the punch and the punch positioning plate, thereby achieving the purpose of variable forming cavity thickness and realizing the forming of composite materials of different thicknesses.

[0027] Advantages of the method:

[0028] This method preferably applies ultrasonic vibration during the resin impregnation stage, which allows for real-time online processing of both the fiber fabric and the resin. This process improves the resin's impregnation rate and performance on the fibers, avoiding the problem of premature curing when ultrasonic vibration is applied to the resin storage tank. This enhances product stability, reduces porosity in the final product, and improves its interlaminar shear properties.

[0029] This method preferably uses ultrasonic vibration at a frequency of 20 kHz. Regarding the direction of ultrasonic vibration, the direction perpendicular to the resin flow direction is preferred. On one hand, vibration perpendicular to the flow direction can improve the impregnation performance of multilayer fiber fabrics in the thickness direction and reduce porosity defects. On the other hand, ultrasonic vibration can be converted into vibration along the flow direction through elastic deformation, promoting resin flow towards the outlet direction. This causes bubbles to stretch, deform, and eventually burst along with the resin flow, ultimately improving the porosity defects distributed along the flow direction in the product.

[0030] The results show that even short-duration ultrasonic vibration can improve the interlayer properties of the product. Therefore, this method can be applied not only to vacuum-assisted resin transfer molding (VARTM) but also to high-pressure resin transfer molding (HP-RTM) to achieve industrialized production and integrated manufacturing. Attached Figure Description

[0031] Figure 1 This is a three-dimensional structural schematic diagram of an embodiment of the apparatus for preparing carbon fiber reinforced thermosetting composite materials according to the present invention;

[0032] Figure 2 for Figure 1 A front view of the device shown;

[0033] Figure 3 for Figure 1 The assembly side view of the upper template and punch of the device shown;

[0034] Figure 4 for Figure 1 A top view of the assembly of the upper template and the punch of the device shown;

[0035] Figure 5 for Figure 1 A top view of the assembly of the concave mold and the ultrasonic amplitude transformer of the device shown.

[0036] Figure 6 for Figure 1 A side view of the assembly of the die and the ultrasonic amplitude transformer of the device shown.

[0037] Figure 7 for Figure 1 A schematic diagram of the device configuration is shown.

[0038] Figure 8 The effects of different ultrasonic vibration process parameters on the permeation rate;

[0039] Figure 9 The effect of different ultrasonic vibration process parameters on the surface roughness of carbon fiber;

[0040] Figure 10 The effect of different ultrasonic vibration process parameters on the contact angle between fibers and resin;

[0041] Figure 11 High-resolution X-ray scan results;

[0042] In the diagram: 1. Rotary wheel, 2. Transmission belt, 3. First nut seat, 4. Top plate, 5. Guide post, 6. Screw, 7. Second nut seat, 8. Upper template, 9. Demolding connecting rod, 10. Demolding module, 11. Die, 12. Lower mold fixing base, 13. Electric heating rod, 14. Ultrasonic amplitude transformer, 15. Fixing flange, 16. Fixing plate, 17. Screw, 18. Base bracket, 19. Adjusting screw, 20. Punch positioning plate, 21. O-ring seal 21. Ring, 22. Punch, 23. Fixing screw, 24. Demolding rod positioning hole, 25. Resin outlet, 26. Resin guide channel, 27. Resin inlet, 28. Connecting boss, 29. Observation window, 30. Washer, 31. Molding cavity, 32. Gasket, 33. Vacuum tube, 34. Flow stop clamp, 35. Resin tank, 36. Camera, 37. Waste collection tank, 38. Vacuum pump, 39. Transducer, 40. Power cord, 41. Power supply box. Detailed Implementation

[0043] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0044] Example 1

[0045] Reference Figures 1-7 An apparatus for preparing carbon fiber reinforced thermosetting composite materials includes a top plate 4, an upper template 8, a lower mold fixing base 12, a base support 18, and an ultrasonic vibration device. The top plate 4, upper template 8, and lower mold fixing base 12 are connected by guide posts 5 and screws 6. Four guide posts 5 are distributed at the four corners of the lower mold fixing base 12, upper template 8, and top plate 4, and are fixedly connected to the top plate 4 via first nut seats 3. Two screws 6 are distributed on the middle of both sides of the lower mold fixing base 12, template 8, and top plate 4, and are slidably connected to the upper template 8 via second nut seats 7. A rotating wheel 1 is mounted on each screw 6, and the rotating wheel 1 is connected via a transmission belt 2. The lower mold fixing base 12 is fixedly mounted on the base support 18. The ultrasonic vibration device is fixedly mounted at the bottom of the lower mold fixing base 12.

[0046] The upper template 8 is provided with a punch positioning plate 20, a punch 22, adjusting screws 19, an observation window 29, and a resin outlet 25. The punch positioning plate 20 is installed below the upper template 8 by fixing screws 23. There are four fixing screws 23, which are distributed in a square on the upper template 8. The punch 22 is installed in the punch positioning plate 20 and is connected to the upper template 8 by connecting screws. There are four connecting screws, which are distributed in a square on the upper template 8. The side of the punch 22 is provided with an O-ring seal 21, which serves to seal the cavity of the die. There are three adjusting screws 19, which are distributed in a triangle on the upper template 8 and whose bottoms can contact the punch 22. The upper template 8 and the punch positioning plate 20 are provided with four lifting rod positioning holes 24, and lifting rods 9 are installed thereon. The resin outlet 25 is located on the left side of the upper template 8 and is connected to the bottom surface of the punch 22 through a pipeline. The upper template 8 and the punch 22 are made of transparent material.

[0047] The lower mold fixing base 12 is provided with a concave mold 11 and an electric heating rod 13; the concave mold 11 is installed in the middle of the lower mold fixing base 12, and a gasket 32 ​​is installed between the concave mold 11 and the lower mold fixing base 12. A gasket 30 is provided on the upper end face of the concave mold 11 to play a secondary sealing role; the electric heating rod 13 is installed in the lower mold fixing base 12 and located below the concave mold 11. There are four electric heating rods 13, which are arranged in parallel; the punch 22 and the concave mold 11 are combined to form a closed molding cavity 31; the concave mold 11 includes a lifting module 10 and a tree The mold includes a resin channel 26, a resin inlet 27, and a connecting boss 28. Four mold-raising modules 10 are installed around the cavity 11 and connected to the mold-raising connecting rod 9. The resin inlet 27 is located on the right side of the bottom of the cavity 11. The resin channel 26 is located at the resin inlet 27 and arranged along the width of the cavity. The connecting boss 28 is fixedly installed at the middle of the bottom of the cavity 11. The connecting boss 28 has a threaded hole, which is used to connect with the bolt at the front end of the ultrasonic amplitude transformer 14, thus enabling ultrasonic waves to be transmitted to the cavity.

[0048] The ultrasonic vibration device includes an ultrasonic amplitude transformer 14, a transducer 39, and a power supply box 41; the ultrasonic amplitude transformer 14 is connected to the connecting boss 28 by bolts and threaded holes; the transducer 39 is connected to the ultrasonic amplitude transformer 14, and the power supply box 41 is connected to the transducer 39 by a power cable 40.

[0049] The base support 18 is provided with a fixing flange 15 and a fixing plate 16; the fixing plate 16 is fixed to the base support 18 by screws 17, and the ultrasonic vibration device is fixed to the fixing plate 16 by the fixing flange 15.

[0050] The device also includes a resin tank 35, a vacuum tube 33, a flow stop clamp 34, a camera 36, ​​a waste collection tank 37, and a vacuum pump 38; one end of the vacuum tube 33 is connected to the resin inlet 27 in the concave mold 11, and the other end is connected to the resin tank 35 through the flow stop clamp 34; one end of the waste collection tank 37 is connected to the resin outlet 25 through the vacuum tube 33 and the flow stop clamp 34, and the other end is connected to the vacuum pump 38 through the vacuum tube 33; the camera 36 is positioned directly above the observation window 29.

[0051] A method for preparing carbon fiber reinforced thermosetting composite materials, comprising the following specific steps:

[0052] (a) Material selection: ±45° non-bending carbon fiber fabric is selected as the reinforcement and cut into six pieces of 110mm×100mm shape; IN2 epoxy resin and AT-30 slow curing agent are selected. The IN2 epoxy resin and AT-30 slow curing agent are mixed evenly in a mass ratio of 100:30. The mixed resin is placed in resin tank 35 as the matrix material.

[0053] (II) Preparation: Adjust the relative position of the punch 22 by adjusting the screw 19 in the upper template 8 to make the height of the molding cavity 2mm; apply a layer of release agent to the surfaces of the die 11 and the punch 22 respectively; connect the resin inlet 27 and the resin tank 35 through the vacuum tube 33 and the stop clamp, and close the stop clamp; connect the resin outlet 25 and the waste collection tank 37 through the vacuum tube and the stop clamp 34, and open the stop clamp 34; at the same time, connect the waste collection tank 37 and the vacuum pump 38 through the vacuum tube; place the camera 36 above the observation window of the upper template, adjust the position, focus, and set the acquisition frequency to 1 frame / second;

[0054] (III) Composite Material Preparation: Six layers of ±45° non-bending carbon fiber fabric, each 110mm × 100mm in size, are stacked sequentially in the molding cavity 31. The rotating wheel 1 is rotated, and the upper template 8 is moved downwards via the screw 6, sealing the molding cavity 31. The vacuum pump 38 is turned on, and the pressure gauge on the vacuum pump reads -0.1MPa. At this time, the molding cavity is in a vacuum state. Wait for the pressure to stabilize. The ultrasonic vibration device (selecting an ultrasonic vibration device with a frequency of 20KHZ and a power of 0-1000W) is turned on, and the power is set to 400W. The ultrasonic vibration time is 2min. The direction of ultrasonic vibration is normal to the resin flow direction. The flow stop clamp of the resin inlet 27 is opened. The mixed resin is then used to impregnate the fabric. After the mixed resin has completely impregnated the fabric, the mixed resin is allowed to flow out from the resin outlet 25 for two minutes. The flow stop clamps at the resin inlet 27 and the resin outlet 25 are then closed. The vacuum pump 38 and the camera 36 are then turned off. The electric heating rod 13 is turned on and the heating temperature is set to 25°C. After 24 hours, the mixture is cured into a carbon fiber / epoxy resin composite material. The rotating wheel 1 is rotated, and the upper template 8 is moved upward through the screw 6 to open the molding cavity 31. The lifting module 10 in the die 11 is moved upward through the lifting connecting rod 9 in the upper template 8. The cured carbon fiber / epoxy resin composite material is then removed through the four lifting modules 10.

[0055] Example 2

[0056] The device used is the same as in Example 1.

[0057] The method for preparing carbon fiber reinforced thermosetting composite materials differs from that in Example 1 in that the ultrasonic power is set to 400W and the ultrasonic time is set to 4min.

[0058] Example 3

[0059] The device used is the same as in Example 1.

[0060] The method for preparing carbon fiber reinforced thermosetting composite materials differs from that in Example 1 in that the ultrasonic power is set to 600W and the ultrasonic time is set to 2min.

[0061] Comparative Example

[0062] The apparatus used is the same as in Example 1.

[0063] The method for preparing carbon fiber reinforced thermosetting composite materials differs from that in Example 1 in that the ultrasonic power is set to 0, which is equivalent to not applying ultrasonic vibration.

[0064] Experimental Analysis:

[0065] 1. The acoustic flow effect of ultrasonic vibration can accelerate the flow rate of resin in fabric and increase the penetration rate of fabric.

[0066] The position of the resin flow front at different times was recorded using a camera when the resin-impregnated ±45° non-bending carbon fiber fabric was used. Figure 8 As shown in the figure. Experimental results indicate that ultrasound accelerates resin flow, and the permeation rate is significantly increased at an ultrasonic power of 600W.

[0067] 2. Ultrasonic vibration can etch the surface of carbon fiber, increase its roughness, and improve the wetting properties between the resin and the fiber fabric.

[0068] The surface roughness of the carbon fiber was tested using atomic force microscopy, such as... Figure 9 As shown, the surface roughnesses are 82.1 nm, 82.9 nm, 88.6 nm, and 88.3 nm, respectively. Experimental results indicate that the fiber surface roughness is lowest without ultrasonic vibration, and the roughness is improved after ultrasonic vibration is applied. Especially at 400 W and 600 W, the fiber surface roughness is significantly improved.

[0069] The contact angle between carbon fiber and resin was measured using a contact angle meter, such as Figure 10 As shown, the contact angles were 57.8°, 57.27°, 36.6°, and 55.0°. A smaller contact angle indicates better wetting performance between the fiber and resin; therefore, the wetting performance was ranked from strongest to weakest as follows: Example 2 > Example 3 > Example 1 > Comparative Example. The experimental results show that the fiber surface roughness was lowest and the wetting performance between the fiber and resin was worst when no ultrasonic vibration was applied. Applying ultrasound improved the fiber surface roughness, and consequently, the wetting performance between the fiber and resin also improved. Especially at 400W for 4 minutes, the fiber surface roughness and wetting performance were the highest.

[0070] 3. Ultrasonic vibration can promote the flow of bubbles towards the outlet, thereby stretching, deforming and eventually bursting the bubbles as they flow with the resin, ultimately improving the porosity defects distributed along the flow direction in the product and enhancing its interlaminar shear properties.

[0071] (1) Cut 3-5 specimens from the middle of the laminate. The specimen size is 20×10×2mm. Perform short beam shear tests on the test specimens according to the JC / T773-2010 test standard. The shear test was carried out on MTS E45.105-B. The stress of the test specimen was calculated using the following formula: τ=0.75F / (b•h), where τ is the interlaminar shear strength. F To destroy the load, b The width of the sample. h The thickness of the sample is given. The average value of the calculated results is then taken, as shown in Table 1. When the ultrasonic power is 400W and applied for 2 minutes, the interlaminar performance is not significantly improved. However, when the ultrasonic time is further increased to 4 minutes, the interlaminar performance is significantly improved.

[0072] Table 1

[0073] sample Comparative Example Example 1 Example 2 Example 3 Interlaminar shear strength 27.14 MPa 28.50MPa 39.46MPa 37.28MPa

[0074] (2) Samples were cut from the resin inlet and middle positions of the composite material plates prepared under conditions of no ultrasound and ultrasound power of 400W for 4min, respectively, and subjected to high-resolution X-ray scanning to detect internal pore defects. The test results are shown in Table 2 and Figure 11 As shown, the porosity of CFRP in the non-ultrasonic group was between 2% and 4%, while the porosity in the ultrasonic group was reduced to less than 1%, with the porosity at the inlet and middle positions being basically the same. In contrast, the porosity at the inlet of the non-ultrasonic group was much higher than that at the middle position. This achieved the desired effect.

[0075] Table 2

[0076] variable Comparative Example Example 2 Import location 3.78% 0.67% Middle position 2.41% 0.66%

Claims

1. An apparatus for preparing carbon fiber reinforced thermosetting composite materials, comprising a top plate, an upper template, a lower template fixing base, a base support, and an ultrasonic vibration device, characterized in that: The upper template is provided with a punch positioning plate, a punch, an adjusting screw, and a resin outlet; the punch positioning plate is installed below the upper template by a fixing screw; the punch is installed in the punch positioning plate and a connecting screw is installed between it and the upper template, and a sealing ring is provided on the side of the punch; the adjusting screw is installed on the upper template and its bottom can contact the punch; the upper template and the punch positioning plate are provided with a mold-lifting connecting rod positioning hole, and a mold-lifting connecting rod is installed; the resin outlet is located on the left side of the upper template and is connected to the bottom surface of the punch through a pipeline; The lower mold fixing base is provided with a concave mold and an electric heating rod; the concave mold is installed in the middle of the lower mold fixing base, and a gasket is installed between the concave mold and the lower mold fixing base, and a washer is provided on the upper end face of the concave mold; the electric heating rod is installed in the lower mold fixing base and is located below the concave mold; the punch and the concave mold are combined to form a closed molding cavity; the concave mold includes a lifting module, a resin guide channel, a resin inlet and a connecting boss; the lifting module is connected to the lifting connecting rod, the resin inlet is located on the right side of the bottom of the concave mold, the resin guide channel is located at the resin inlet and arranged along the width direction of the concave mold, the connecting boss is fixedly installed in the middle position of the bottom of the concave mold, the connecting boss is provided with a threaded hole, and the ultrasonic vibration device is connected to the connecting boss through bolts and threaded holes.

2. The apparatus for preparing carbon fiber reinforced thermosetting composite materials according to claim 1, characterized in that: The ultrasonic vibration device includes an ultrasonic amplitude transformer, a transducer, and a power supply box; the ultrasonic amplitude transformer is connected to the connecting boss through bolts and threaded holes; the transducer is connected to the ultrasonic amplitude transformer, and the power supply box is connected to the transducer through a power cable.

3. The apparatus for preparing carbon fiber reinforced thermosetting composite materials according to claim 1 or 2, characterized in that: It also includes a resin tank, a vacuum tube, a flow stop clamp, a waste collection tank, and a vacuum pump; one end of the vacuum tube is connected to the resin inlet in the mold cavity, and the other end is connected to the resin tank through the flow stop clamp; one end of the waste collection tank is connected to the resin outlet through the vacuum tube and the flow stop clamp, and the other end is connected to the vacuum pump through the vacuum tube.

4. The apparatus for preparing carbon fiber reinforced thermosetting composite materials according to claim 1 or 2, characterized in that: There are four fixing screws, arranged in a square on the upper template; there are four connecting screws, arranged in a square on the upper template; there are three adjusting screws, arranged in a triangular shape on the upper template; there are four positioning holes for the mold-lifting connecting rod, each for mounting a mold-lifting connecting rod.

5. The apparatus for preparing carbon fiber reinforced thermosetting composite materials according to claim 4, characterized in that: There are four electric heating rods arranged in parallel; there are four lifting modules, which are installed around the concave mold and connected to the lifting rod.

6. A method for preparing carbon fiber reinforced thermosetting composite materials using the apparatus described in claim 3, characterized in that, The specific steps are as follows: (a) Material selection: Carbon fiber fabric is selected as the reinforcement and thermosetting resin is selected as the matrix material. The thermosetting resin is placed in a resin tank. (II) Preparation: Adjust the relative position of the punch by adjusting the screw in the upper template to control the height of the molding cavity; apply a layer of release agent to the surface of the die and the punch respectively; connect the resin inlet and the resin tank through the vacuum tube and the stop clamp, and close the stop clamp; connect the resin outlet and the waste collection tank through the vacuum tube and the stop clamp, and open the stop clamp, while connecting the waste collection tank and the vacuum pump through the vacuum tube. (III) Preparation of composite materials: Place the carbon fiber fabric into the molding cavity, control the upper template to move downwards, and seal the molding cavity; turn on the vacuum pump to make the molding cavity a vacuum state and wait for the pressure to stabilize; turn on the ultrasonic vibration device, set the power and time, and start ultrasonic vibration. The direction of ultrasonic vibration is the normal to the resin flow direction. Open the inlet stop clamp, and when the thermosetting resin wets the carbon fiber fabric and reaches the outlet side, turn off the ultrasonic vibration, wait for the thermosetting resin to flow out from the outlet for two minutes, close the inlet stop clamp and the outlet stop clamp, and turn off the vacuum pump. Turn on the electric heating rod, set the heating temperature, and wait for a certain time to cure and form a carbon fiber reinforced thermosetting composite material.

7. The method for preparing carbon fiber reinforced thermosetting composite materials according to claim 6, characterized in that: In step (i), the carbon fiber fabric is a ±45° non-bending carbon fiber fabric; the thermosetting resin is a mixture of IN2 epoxy resin and AT-30 slow curing agent at a mass ratio of 100:25-35.

8. The method for preparing carbon fiber reinforced thermosetting composite materials according to claim 6 or 7, characterized in that: In step (ii), the height of the molding cavity is 1-5mm.

9. The method for preparing carbon fiber reinforced thermosetting composite materials according to claim 6 or 7, characterized in that: In step (3), the pressure gauge on the vacuum pump shows -0.09MPa to -0.1MPa, at which point the molding cavity is in a vacuum state.

10. The method for preparing carbon fiber reinforced thermosetting composite materials according to claim 6 or 7, characterized in that: In step (iii), the ultrasonic vibration device has a frequency of 20kHz and a power of 0-1000W; ultrasonic vibration is applied during the process of impregnating the carbon fiber fabric with thermosetting resin, and the power of the ultrasonic vibration device is set to 400-600W for 2-6 minutes; when the electric heating rod is turned on, the heating temperature is set to room temperature - 200℃.

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