Gluing tool for low-defect composite material with controllable glue film thickness and preparation method of low-defect composite material with controllable glue film thickness

Abstract

The invention discloses a low-defect glue film thickness controllable composite material glue joint tool and a preparation method, the glue joint tool comprises a curing box, a glue joint clamp and an ultrasonic vibration auxiliary device, and the glue joint tool solves the contradiction that the glue film thickness controllability and the pressure reachability cannot be met at the same time during forming. The preparation method of the low-defect adhesive film thickness-controllable composite material is provided for solving the problem that the requirement of high-performance manufacturing of a composite material bonding component for the controllable precision of the adhesive film thickness is high, ultrasonic vibration in the in-plane direction is introduced, bubbles are eliminated through the resonance effect of the ultrasonic vibration, and the pore defect caused by pressure loss is overcome; the fluidity and wettability of the adhesive film in the curing process of the adhesive film are further enhanced; and through space composite ultrasonic vibration, most of bubbles are eliminated, the defects of the component are further reduced, and the mechanical property of the composite material bonding component is enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of structural bonding of composite materials, and in particular to a bonding tool and a preparation method of a composite material with low-defect adhesive film and controllable thickness. Background Art

[0002] With the development of aerospace and high-speed trains, the connection of multiple materials has become increasingly important. Compared with traditional mechanical fastening and welding, adhesive bonding technology has the advantages of more uniform stress distribution, better fatigue and impact resistance, prevention of electrochemical corrosion and weight reduction, especially in the field of lightweighting. At present, traditional autoclave technology is mostly used for composite bonding. This process has a wide range of applications and strong flexibility in pressurization. However, due to the pre-control of the gap between the layers of the composite material, the applied external pressure cannot be transmitted to the adhesive film, resulting in a low curing pressure, which will cause an increase in porosity; if the adhesive film is first filled into the gap between the layers of the composite material and then pressurized, the curing pressure reaches the requirement, but the thickness of the adhesive film will be affected by the change in pressure.

[0003] In the composite material bonding process, if the gap distance between composite material layers is pre-controlled by the fixture according to the film thickness requirement in advance, and then the film is filled into the gap, the purpose of controllable film thickness can be achieved. However, because the interlayer spacing is pre-controlled, the pressure transmission of the fixture cannot be transmitted to the film, and the pores in the film cannot be effectively reduced. If the film is placed in the interlayer gap and then pressure is applied, the pores in the film will be effectively reduced, but the film will be deformed, causing the film thickness of the composite material bonded under this process to fail to meet the experimental and production requirements. In the fields of aerospace and rail transportation, the porosity of the main load-bearing structural parts should be less than 1%, the porosity of the secondary load-bearing structural parts should be less than 2%, and there are high requirements for the film thickness of the component bonding area. Therefore, when using a bonding tooling system with controllable film thickness, if you want to obtain a composite material bonding component that meets the experimental and production standards, solving the contradiction that the film thickness can be controlled and the pressure can be reached at the same time is the main goal of the bonding tooling system with controllable film thickness, and it is also a problem that technicians in this field need to solve.

[0004] Due to the contradiction between the controllable film thickness and the achievable pressure at the bonding of composite materials, the pre-controlled film process is an appropriate means. In order to solve the problem of high porosity of components under the pre-filled film process, it is a problem to be solved by relevant personnel to select a suitable method to suppress pore defects with different morphological characteristics, improve the mechanical and mechanical properties of the parts, and obtain excellent macro-micro interface properties. Summary of the invention

[0005] The object of the present invention is to provide a bonding tool for composite materials with low-defect adhesive film and controllable thickness, so as to solve the problem in the background art that the controllable adhesive film thickness and the achievable pressure cannot be satisfied at the same time.

[0006] To achieve the above-mentioned purpose, the present invention provides a bonding tool for composite materials with low-defect adhesive film and controllable thickness, including a curing box, a bonding fixture arranged in the curing box, and an ultrasonic vibration auxiliary device for ultrasonic vibration treatment of the bonding part of the composite material; the bonding fixture includes a fixture body, a large pressure plate and a small pressure plate, the large pressure plate and the small pressure plate are two pieces arranged vertically and parallel, the distance between the two large pressure plates is adjustable in the cavity of the fixture body, the two small pressure plates are arranged between the two large pressure plates, and the small pressure plates The two small pressure plates are arranged in parallel with the large pressure plate, and are respectively used to cooperate with the two large pressure plates to position the two pre-glued composite material plates; the large pressure plate is equipped with at least one first adjustment rod, and the small pressure plate is equipped with at least one second adjustment rod; the ultrasonic vibration auxiliary device includes an ultrasonic rod, an ultrasonic vibrator and an ultrasonic generator, the ultrasonic rod is arranged in the curing box, the ultrasonic vibrator is arranged at the bottom of the ultrasonic rod and located above the bonding fixture, and the ultrasonic generator is arranged outside the curing box and connected to the ultrasonic vibrator.

[0007] Furthermore, each of the large pressure plates is configured with two first adjusting rods, the first adjusting rods are horizontally inserted from one side of the clamp body into the interior of the clamp body from the outside to the inside, and are connected to the corresponding large pressure plate; the second adjusting rods pass through a side wall of the clamp body and the large pressure plate close to the side wall in sequence from the outside to the inside, and are connected to the corresponding small pressure plate.

[0008] Furthermore, the ultrasonic vibration auxiliary device includes a fixed bracket that supports the ultrasonic rod, and the fixed bracket includes a bracket base, a support rod and a connecting piece. The bracket base is located at the bottom of the gluing clamp, and the support rod is arranged at one end of the gluing clamp, and the lower end is connected to the bracket base.

[0009] The present invention also provides a method for preparing a composite material with low defect film thickness and controllable thickness, wherein the composite material is prepared by using the above-mentioned bonding tool, and the preparation method comprises the following steps:

[0010] Step S1, determining the thickness of the adhesive film according to preparation requirements;

[0011] Step S2, using a bonding fixture to fix the two composite material panels to be bonded, and placing a bonding film that meets the thickness requirements between the bonded parts of the composite material, thereby obtaining a composite material preform;

[0012] Step S3, placing the bonding fixture and the composite material preform to be processed flat as a whole in a heating furnace for heating and heat preservation treatment; wherein, during a certain period of the heat preservation process, ultrasonic vibration along the in-plane direction is provided to the bonding part of the composite material by an ultrasonic auxiliary device;

[0013] Step S4: After the heat preservation is completed, the composite material preform is heated for a second time and subsequently cured, thereby finally obtaining a composite material with a low-defect film and controllable thickness.

[0014] Furthermore, in step S2, the two pre-glued composite panels are first placed on the inner sides of two large pressure plates respectively, and then the two small pressure plates are clamped respectively by adjusting the second adjusting rod, and then the two large pressure plates are adjusted by the first adjusting rod, and the gap distance between the two composite panels is determined by using a vernier caliper.

[0015] Furthermore, the specific implementation of the heating treatment in step S3 is: heating the composite material preform to be processed from room temperature to 140-150° C. at a heating rate of 1.5-2.5° C. / min in a heating platform.

[0016] Furthermore, the power of the ultrasonic vibration in step S3 is 400-600 W, the amplitude percentage is 40%; the insulation time is 45-80 min, and the ultrasonic vibration is added 30 s to 10 min before the start of insulation.

[0017] Furthermore, the secondary heating in step S4 is to heat the composite material preform to be processed from 140-150° to 195-205° C., and the heat preservation time is 120-180 minutes.

[0018] Furthermore, a nickel-chromium alloy electric heating wire heater is used to heat the air, and the hot air is used to heat or keep the composite material plate or composite material preform warm by forced convection.

[0019] Furthermore, the power of the ultrasonic vibration auxiliary device is adjustable in the range of 0 to 900 W; the ultrasonic vibration auxiliary device outputs ultrasonic waves with a constant frequency of 20 kHz and an adjustable amplitude of 20% to 100%.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) The low-defect adhesive film with controllable thickness of composite materials of the present invention is a low-cost and convenient composite material adhesive bonding tool. The main difference between it and the traditional adhesive bonding tool is that it solves the contradiction that the controllable thickness of the adhesive film and the achievable pressure during molding cannot be satisfied at the same time.

[0022] (2) The present invention aims to solve the problem of high-performance manufacturing of composite adhesive components requiring high controllable film thickness, and proposes a method for preparing composite materials with low-defect and controllable film thickness. By introducing ultrasonic vibration along the in-plane direction, the resonance effect is used to eliminate bubbles, compensate for the pore defects caused by the lack of pressure, and further enhance the fluidity and wettability of the film during the curing process. The spatially compounded ultrasonic vibration eliminates most of the bubbles, further reduces the defects of the components, and enhances the mechanical properties of the composite adhesive components.

[0023] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. In the accompanying drawings:

[0025] Figure 1 It is a structural schematic diagram of a bonding tool for composite materials with low-defect adhesive film and controllable thickness according to the present invention;

[0026] Figure 2 for Figure 1 A schematic diagram of the structure of the ultrasonic vibration auxiliary device;

[0027] Figure 3 for Figure 1 A schematic diagram of the top view of the adhesive bonding fixture;

[0028] Figure 4 This is a flow chart of a method for preparing a composite material with low defect film and controllable thickness according to the present invention;

[0029] Figure 5 is a schematic diagram of a composite material sample in the present invention;

[0030] Among them, 1-curing box; 2-gluing fixture; 2.1-clamp body; 2.2-large pressure plate; 2.3-small pressure plate; 2.4-first adjusting rod; 2.5-second adjusting rod; 3-ultrasonic vibration auxiliary device; 3.1-ultrasonic vibrator; 3.2-ultrasonic rod; 3.3-ultrasonic generator; 3.4-bracket base; 3.5-support rod; 3.6-connector; A-composite material board, B-adhesive film, C-metal gasket. DETAILED DESCRIPTION

[0031] The present invention will be described in detail below in conjunction with the various embodiments shown in the accompanying drawings, but it should be noted that these embodiments are not limitations of the present invention, and any equivalent transformations or substitutions in functions, methods, or structures made by ordinary technicians in the field based on these embodiments are all within the scope of protection of the present invention.

[0032] See also Figures 1 to 3 The embodiment of the present invention provides a bonding tool for composite materials with low-defect adhesive film and controllable thickness, including a curing box 1, a bonding fixture 2 and an ultrasonic vibration auxiliary device 3; the specific structure is as follows:

[0033] The adhesive clamp 2 is arranged in the curing box 1, and includes a clamp body 2.1, two large pressure plates 2.2 arranged in parallel in the inner cavity of the clamp body 2.1, and two small pressure plates 2.3 located between the two large pressure plates 2.2 and parallel to the large pressure plates 2.2. Each large pressure plate 2.2 is equipped with at least one first adjustment rod 2.4, which penetrates a side wall of the clamp body 2.1 and is connected to the corresponding large pressure plate 2.2. Each small pressure plate 2.3 is equipped with a second adjustment rod 2.5; the second adjustment rod 2.5 penetrates a side wall of the clamp body 2.1 and the large pressure plate 2.2 close to the side wall from the outside to the inside, and is connected to the small pressure plate 2.3. The ultrasonic vibration auxiliary device 3 includes an ultrasonic vibrator 3.1, an ultrasonic rod 3.2 and an ultrasonic generator 3.3. The ultrasonic vibrator 3.1 is arranged in the curing box 1 and above the bonding fixture 2. The ultrasonic rod 3.2 is arranged at the bottom of the ultrasonic vibrator 3.1. The ultrasonic generator 3.3 is arranged outside the curing box 1. The ultrasonic generator 3.3 is connected to the ultrasonic vibrator 3.1 and is used to perform ultrasonic vibration treatment on the adhesive film B at the bonding place of the composite material with bonding to reduce the porosity. The ultrasonic vibration auxiliary device 3 includes a fixed bracket supporting the ultrasonic rod 3.1. The fixed bracket includes a bracket base 3.4, a support rod 3.5 and a connecting piece 3.6. The bracket base 3.4 is located at the bottom of the bonding fixture 2. The support rod 3.5 is arranged at one end of the bonding fixture 2, and the lower end is connected to the bracket base 3.4; a plurality of connecting holes are arranged on the support rod 3.5. The connecting piece 3.6 is arranged on the support rod 3.5 so as to be adjustable up and down through these connecting holes. The connecting piece 3.6 is used to clamp the ultrasonic rod 3.1. In this structural setting, metal gaskets C are also provided between the first adjusting rod 2.4 and the large pressure plate 2.2 and between the second adjusting rod 2.5 and the small pressure plate 2.3; each large pressure plate 2.2 is equipped with two or more first adjusting rods 2.4 to evenly apply bonding pressure to the composite material plate A to be bonded.

[0034] Compared with the traditional clamps that control the thickness of the adhesive film by squeezing or placing a metal plate between two composite material plates A, the adhesive clamp of the present invention effectively controls the thickness of the adhesive film through the bolt structure and the equalizing plate and avoids the problem of processing metal plates with different thickness requirements, which not only improves the production efficiency, but also well controls the production cost. The specific clamping process of the adhesive bonding of this embodiment is: first fix any composite material plate to one end of the adhesive bonding clamp (located between one of the large pressure plates 2.2 and one of the small pressure plates 2.3), and then use a vernier caliper to determine the spacing between the two composite material plates, and then rotate the bolt structure (including: the first adjustment rod 2.4 and the second adjustment rod 2.5) to make the other composite material plate (located between the other large pressure plate 2.2 and the other small pressure plate 2.3) reach the predetermined position, and clamp the two composite material plates A respectively at the same time to achieve the purpose of fixing, and finally fill the adhesive film between the two composite material plates A, thereby completing the entire clamping process.

[0035] See also Figure 4 The present invention also provides a method for preparing a composite material with low defect film thickness and controllable thickness, wherein the composite material is prepared by using the above-mentioned bonding tool, and the preparation method comprises the following steps:

[0036] Step S1, determine the thickness of the adhesive film B according to the preparation requirements; wherein, when selecting the thickness of the adhesive film, it is necessary to comprehensively consider the material properties, thickness, bonding strength, application environment and economic factors. Before actual application, some experiments are carried out to determine the most suitable adhesive film thickness for a specific composite material according to different requirements and the characteristics of the composite material. For example: in the adhesive repair structure of carbon fiber reinforced composite materials, the adhesive area is very thin, and its thickness is generally only 0.1 to 0.2 mm. Too high or too low will affect the performance of the repaired component.

[0037] Step S2, using the adhesive fixture 2 to fix the two composite material plates A (interlayer hybrid composite material) to be glued, and placing the adhesive film that meets the thickness requirements of step S1 between the glued parts of the two composite material plates A, so as to obtain a composite material preform. In this step, firstly place the two pre-glued composite material plates A inside the two large pressure plates 2.2 respectively, and then adjust the second adjustment rod 2.5 to make the two small pressure plates 2.3 clamp the two composite material plates A respectively, and then adjust the two large pressure plates 2.2 by adjusting the first adjustment rod 2.4, and finally determine the gap distance between the two composite material plates A with the help of a vernier caliper. Specifically, the unidirectional carbon fiber reinforced bismaleimide resin (ZT7H / 5429) and woven quartz fiber reinforced bismaleimide resin (QW280 / 5429) composite laminates to be processed are placed on the inner sides of two large pressure plates 2.2 respectively, and then the two small pressure plates 2.3 are respectively pressed against the two composite plates A by rotating the second adjusting rod 2.5 to achieve a clamping effect; and then the gap distance between the two composite plates A is determined by rotating the first adjusting rod 2.4 and using a vernier caliper to achieve a controllable effect on the thickness of the film.

[0038] Step S3, placing the bonding fixture 2 and the composite material preform to be processed flat as a whole in a heating furnace for heating and heat preservation treatment; wherein, the heating and heat preservation treatment is to heat the composite material preform to be bonded in a curing box at a heating rate of 1.5-2.5℃ / min from room temperature to 140-150℃, and keep it warm for 60min; heating and heat preservation use a nickel-chromium alloy electric heating wire heater to heat the air, and the heated air mainly enters the curing box through the hot air outlet to heat the preform in a forced convection manner. During a certain period of the heat preservation process, ultrasonic vibration along the in-plane direction is provided to the composite material bonding point through an ultrasonic auxiliary device; the power of the ultrasonic vibration is 400-600W, and the amplitude percentage is 40%; the heat preservation time is 60min, and ultrasonic vibration is added 30s-10min before the start of heat preservation.

[0039] Step S4: After the heat preservation is completed, the composite material preform treated in step S3 is heated for a second time and subsequently cured, and finally a composite material with low defect film thickness and controllable thickness is obtained. In this step, the second heating is to heat the interlayer hybrid composite material preform from 120°C to 180°C at a heating rate of 1.5°C / min and keep it warm for 150 minutes; the second heating uses a nickel-chromium alloy electric heating wire heater to heat and keep warm in the same way as the first heating.

[0040] The ultrasonic generator DW-S20-1000 of the ultrasonic auxiliary device used in the present invention is manufactured by Hangzhou Titanium Ultrasonic Technology Co., Ltd. The output frequency of the ultrasonic generator is 20kHz, the amplitude percentage is 20% to 100%, and the output power adjustment range is 0 to 900W. The ultrasonic vibrator of the ultrasonic vibration auxiliary device is fixed just above the adhesive film to provide ultrasonic vibration transmitted along the in-plane direction to the interlayer hybrid composite material preform. In the present invention, the equivalent diameter of the pores of the composite film is mainly distributed in the range of [5 to 50] μm. When 20kHz ultrasonic vibration is applied during the curing process of the composite adhesive component, the collapse of bubbles will be accelerated, the porosity in the component will be effectively reduced, and the mechanical properties of the component will be improved.

[0041] Example:

[0042] The preparation method of the present invention is used to cure the unidirectional carbon fiber reinforced bismaleimide resin / quartz fiber interlayer hybrid composite material, the unidirectional carbon fiber reinforced bismaleimide resin is selected from ZT7H / 5429, and the quartz fiber is selected from QW280 / 5429. Referring to the standard ASTM D3165, the laminate preparation size is 75mm×160mm, the bonding area size is 30mm×160mm, and after the secondary bonding, the left and right edges are cut off by a metallographic grinding wheel cutter to remove 15mm each, and then the test sample size is cut out to be 120mm×25.4mm, and 5 samples are taken. Figure 5 The composite material sample is shown in FIG. 1 , where the film thickness is 0.2 mm and the film system is J-116B.

[0043] 1. When the film thickness is controlled at 0.2mm:

[0044] (1) Comparative analysis from the perspective of porosity: When the interlayer hybrid composite material preform was subjected to ultrasonic vibration treatment at 0W, 300W, 600W, and 900W in the first heating stage and cured in the 0MPa pressure range, the porosity was 6.78%, 2.11%, 1.08%, and 2.34%, respectively. The overall porosity was less than 7%, and when the vibration power was 600W, the lowest porosity was 1.08%. Compared with the 0MPa workpiece without vibration treatment, the porosity dropped from 6.78% to 1.08%, indicating that the effect of low-defect cured formed components can be achieved after ultrasonic vibration treatment.

[0045] (2) Comparative analysis from the perspective of mechanical properties: Shear strength of bonded structures after different ultrasonic vibration treatments: The shear strengths of bonded components cured by 0W, 300W, 600W, and 900W power treatments were 10.89MPa, 12.58MPa, 15.45MPa, and 12.03MPa, respectively. The shear strength of bonded components treated with 600W ultrasonic vibration was 41.9% higher than that of samples without ultrasonic vibration treatment.

[0046] 2. When the ultrasonic vibration power is controlled at 600W:

[0047] (1) Comparative analysis from the perspective of porosity: When the thickness of the adhesive film in the interlayer hybrid composite preform is controlled at 0.1 mm, 0.2 mm, 0.5 mm, and 0.9 mm, respectively, the porosity is 1.78%, 1.06%, 1.25%, and 1.43%, respectively, and the porosity difference is not obvious.

[0048] (2) Comparative analysis from the perspective of mechanical properties: When the thickness of the adhesive film in the interlayer hybrid composite material is controlled at 0.1mm, 0.2mm, 0.5mm, and 0.9mm, the shear strength is 13.37MPa, 15.47MPa, 12.58MPa, and 10.78MPa, respectively. Therefore, when the thickness of the adhesive film is 0.2mm, the shear strength is the best.

[0049] It can be concluded that the porosity of the interlayer hybrid composite material component treated with ultrasonic vibration after forming is significantly reduced compared with the porosity of the component without vibration treatment, and the mechanical properties are better.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A bonding tool for composite materials with low defect film thickness and controllable thickness, characterized in that: The invention comprises a curing box (1), a bonding fixture (2) arranged in the curing box (1), and an ultrasonic vibration auxiliary device (3) for performing ultrasonic vibration treatment on the bonding part of the composite material; the bonding fixture (2) comprises a fixture body (2.1), a large pressure plate (2.2) and a small pressure plate (2.3); the large pressure plate (2.2) and the small pressure plate (2.3) are two pieces arranged vertically and in parallel; the distance between the two large pressure plates (2.2) is adjustable in the cavity of the fixture body (2.1); the two small pressure plates (2.3) are arranged between the two large pressure plates (2.2), and the small pressure plates (2.3) are arranged parallel to the large pressure plates (2.2); the two small pressure plates (2.3) They are respectively used to cooperate with the two large pressure plates (2.2) to position the two pre-glued composite material plates (A); the large pressure plate (2.2) is provided with at least one first adjustment rod (2.4), and the small pressure plate (2.3) is provided with at least one second adjustment rod (2.5); the ultrasonic vibration auxiliary device (3) comprises an ultrasonic rod (3.1), an ultrasonic vibrator (3.2) and an ultrasonic generator (3.3); the ultrasonic rod (3.1) is provided in the curing box (1), the ultrasonic vibrator (3.2) is provided at the bottom of the ultrasonic rod (3.1) and is located above the bonding fixture (2); the ultrasonic generator (3.3) is provided outside the curing box (1) and is connected to the ultrasonic vibrator (3.1).

2. The gluing tool according to claim 1, characterized in that: Each of the large pressure plates (2.2) is provided with two first adjustment rods (2.4), wherein the first adjustment rods (2.4) are horizontally inserted from one side of the clamp body (2.1) into the interior of the clamp body (2.1) from the outside to the inside, and are connected to the corresponding large pressure plate (2.2); the second adjustment rods (2.5) sequentially penetrate a side wall of the clamp body (2.1) and the large pressure plate (2.2) close to the side wall from the outside to the inside, and are connected to the corresponding small pressure plate (2.3).

3. The gluing tool according to claim 1, characterized in that: The ultrasonic vibration auxiliary device (3) comprises a fixed bracket that supports the ultrasonic rod (3.1), the fixed bracket comprising a bracket base (3.4), a support rod (3.5) and a connecting piece (3.6), the bracket base (3.4) is located at the bottom of the adhesive clamp (2), the support rod (3.5) is arranged at one end of the adhesive clamp (2), and the lower end is connected to the bracket base (3.4).

4. A method for preparing a composite material with low defect film and controllable thickness, characterized in that: The composite material is prepared by using the bonding tool as described in claim 1 or 2, and the preparation method comprises the following steps: Step S1, determining the thickness of the adhesive film according to preparation requirements; Step S2, using a bonding fixture (2) to fix the two composite material plates (A) to be bonded, and placing a bonding film that meets the thickness requirements between the bonding parts of the two composite material plates (A), thereby obtaining a composite material preform; Step S3, placing the bonding fixture (2) and the composite material plate preform to be processed flat as a whole in a heating furnace for heating and heat preservation treatment; wherein, during a certain period of the heat preservation process, ultrasonic vibration along the in-plane direction is provided to the bonding position of the composite material by the ultrasonic auxiliary device (3); Step S4: After the heat preservation is completed, the composite material preform is heated for a second time and subsequently cured, thereby finally obtaining a composite material with a low-defect film and controllable thickness.

5. The preparation method according to claim 4, characterized in that: In the step S2, the two pre-glued composite material plates (A) are first placed inside the two large pressure plates (2.2) respectively, and then the two small pressure plates (2.3) are clamped respectively by adjusting the second adjustment rod (2.5), and then the two large pressure plates (2.2) are adjusted by the first adjustment rod (2.4), and the gap distance between the two composite material plates (A) is determined in conjunction with a vernier caliper.

6. The preparation method according to claim 4, characterized in that: The specific implementation method of the heating treatment in step S3 is: heating the composite material preform to be processed from room temperature to 140-150° C. at a heating rate of 1.5-2.5° C. / min in a heating platform.

7. The preparation method according to claim 4, characterized in that: The power of the ultrasonic vibration in step S3 is 400-600 W, and the amplitude percentage is 40%; the insulation time is 45-80 min, and the ultrasonic vibration is added 30 s-10 min before the start of insulation.

8. The preparation method according to claim 4, characterized in that: The secondary heating in step S4 is to heat the composite material preform to be processed from 140-150° to 195-205° C., and the heat preservation time is 120-180 minutes.

9. The preparation method according to claim 4, characterized in that: A nickel-chromium alloy electric heating wire heater is used to heat the air, and the hot air is used to heat or keep warm the composite material board or composite material preform by forced convection.

10. The preparation method according to claim 4, characterized in that: The power adjustable range of the ultrasonic vibration auxiliary device (3) is 0 to 900 W; the ultrasonic vibration auxiliary device (3) outputs ultrasonic waves with a constant frequency of 20 kHz and an adjustable amplitude frequency of 20% to 100%.

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