Composite material electric heating cementing device and electric heating cementing method

Abstract

The invention belongs to the field of composite material manufacturing, and particularly relates to a composite material electric heating cementing device and an electric heating cementing method. Local heating is carried out in an electric heating mode, thermal aging and thermal deformation caused by overall heating of the composite material structure are avoided, meanwhile, the energy utilization rate is increased, and energy waste is greatly reduced. The heating and cooling process of the glue joint area is controllable through the electric heating mode, the thermal stress of the glue joint area can be eliminated, the thermal stress of the glue joint area can be fully released, and the glue joint quality is improved. And in the cementing process, curing in an autoclave is not needed, so that the cementing efficiency is greatly improved, the dependence on equipment is reduced, and the manufacturability and economy of the cementing process are further improved. The glue film body in the glue joint area uniformly emits heat, so that the heat transfer process is omitted, the temperature field distribution in the glue joint area is more uniform, and meanwhile, the heating efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the field of composite material manufacturing, and particularly relates to a composite material electrothermal bonding device and an electrothermal bonding method. Background Art

[0002] With the increasing demand for structural lightweight in fields such as aviation, aerospace, and automotive, composite materials have broad application prospects in the above fields due to their characteristics of light weight, high strength, and good weather resistance. However, due to the particularity of the composite material forming process, it is often necessary to connect different composite material parts through connection technologies to achieve the assembly of the structure and the improvement of the load-bearing function. The connection methods of composite materials mainly include mechanical connection, adhesive bonding connection, and hybrid connection technology. Mechanical connection includes traditional riveting, bolt connection, etc. This connection method has the advantages of high reliability, repeatable assembly and disassembly. However, mechanical connection will cause stress concentration at the connection, the introduction of metal parts will increase the structural weight, and punching holes in composite materials may damage the fiber continuity and affect the overall strength of the structure.

[0003] Adhesive bonding is a connection method realized through adhesives, which has the characteristics of light weight, non-destructive, and easy to achieve integral molding. The formed structure can greatly reduce stress concentration and has good sealing and vibration damping performance. Composite material adhesives usually include carrier film adhesives, non-carrier film adhesives, and liquid or paste adhesives, etc. The carrier film adhesive is a film formed by impregnating a matrix resin on a fiber cloth such as glass fiber, nylon, or aramid as a skeleton carrier. It has the advantages of uniform thickness, no need for on-site mixing and application of adhesives, and uniform and controllable adhesive application amount, and is widely used in the connection of composite materials. The carrier film adhesive usually needs to be cured in an autoclave. During this process, in addition to the bonding area being heated, the entire composite material component is heated simultaneously, resulting in the deformation of the composite material component under the combined action of temperature and pressure, affecting the geometric accuracy of the component, causing assembly difficulties and even part scrapping; on the other hand, after the composite material structure is heated as a whole, there is a risk of thermal aging, which will reduce the service life of the composite material component. In addition, due to the pressurization mode of the autoclave being an overall increase in pressure in the tank, it is very difficult to ensure that the bonding surface of the composite material component is pressurized in place. Therefore, it is difficult to effectively control the quality of the bonding area. Moreover, the heating rate of the autoclave is low, the energy consumption is high, and the overall heating of the composite material component during the bonding process results in low energy utilization efficiency, causing a large amount of energy waste, which does not meet the requirements of sustainable development.

[0004] Based on the above problems, there is an urgent need to develop an adhesive bonding device and an adhesive bonding method that can accurately heat and pressurize the bonding surface of composite materials, ensure that the bonding area can be uniformly and efficiently heated to cure the adhesive film, and at the same time do not have a thermal impact on the overall structure of the composite material to meet the use requirements of composite material component bonding. Summary of the Invention

[0005] The composite material electrothermal bonding device and electrothermal bonding method provided by the present invention can be used in the bonding process of composite materials. The adhesive film is cured by mechanical pressing and electrothermal heating, replacing the traditional autoclave heating and pressing process, so as to solve the problems that the overall structure of the composite material is deformed and thermally aged due to heat during the curing process of the existing adhesive film. This method has the advantages of high heating efficiency and process controllability.

[0006] According to one aspect of the present application, a composite material electrothermal bonding device is provided, which can monitor the temperature of the composite material bonding area in real time;

[0007] It is composed of a power cabinet 1, an infrared thermal imager bracket 2, an infrared thermal imager 3, a support column 4, an upper baffle 5, a pneumatic pressure cylinder 6, an upper clamp 7, a lower clamp 8, an air compressor 9, an air duct 9-1, a pneumatic controller 9-2, a power supply 10, a positive wire 10-1, a positive clamp 10-3, a negative wire 10-2, and a negative clamp 10-4;

[0008] The power cabinet 1 is connected to the infrared thermal imager bracket 2, and the infrared thermal imager 3 is fixed on the infrared thermal imager bracket 2;

[0009] The support column 4 penetrates through the power cabinet 1 and extends to the ground, and at the same time supports the upper baffle 5;

[0010] The pneumatic pressure cylinder 6 is fixed on the lower surface of the upper baffle 5;

[0011] The upper clamp 7 and the lower clamp 8 are placed on the upper surface of the power cabinet 1;

[0012] The air compressor 9 and the power supply 10 are integrated inside the power cabinet 1.

[0013] The power cabinet 1 has a thick-walled box structure.

[0014] The infrared thermal imager 3 is fixed on the infrared thermal imager bracket 2 by screws.

[0015] The support column 4 plays a bearing role and stabilizes the entire device.

[0016] The pneumatic pressure cylinder 6 is fixed on the lower surface of the upper baffle 5 by studs and plays a pressurizing role during bonding.

[0017] The upper clamp 7 and the lower clamp 8 play a role in clamping the composite material during bonding, and their shapes match the surface of the composite material to be welded.

[0018] There are cooling water tanks in the upper clamp 7 and the lower clamp 8. Cooling water flows into the upper and lower clamps through the water inlets 7-1 and 8-1 respectively, and flows out through the water outlets 7-2 and 8-2 respectively, playing a role in assisting the cooling of the bonding area after bonding.

[0019] The air duct 9-1 connects the air compressor 9 and the pneumatic pressure cylinder 6, and functions to conduct air pressure.

[0020] The pneumatic controller 9-2 functions to control air pressure.

[0021] The power supply 10 functions to provide electric energy and control energy output.

[0022] The power supply 10 outputs electric energy through the positive wire 10-1 and the negative wire 10-2.

[0023] The power supply 10 is connected to the adhesive film to be heated through the positive clamp 10-3 and the negative clamp 10-4.

[0024] The air compressor 9 provides pressure for the pneumatic pressure cylinder 6.

[0025] The composite material is composed of an upper composite member 11, a lower composite member 13, and a conductive carrier adhesive film 12 sandwiched in the middle.

[0026] The upper composite member 11 and the lower composite member 13 are carbon fiber composite materials or glass fiber composite materials.

[0027] The conductive carrier adhesive film 12 is composed of a conductive carrier and an adhesive;

[0028] The adhesive covers and infiltrates part of the area of the conductive carrier, and at least each side of the conductive carrier retains an area with a width of 5-50 mm that is not covered or infiltrated by the adhesive;

[0029] The conductive carrier is modified with a conductive nanomaterial;

[0030] The conductive carrier is selected from at least one of carbon fiber, glass fiber, quartz fiber, nylon fiber, polyimide fiber, and non-woven fabric;

[0031] The adhesive is composed of 0.1-3 parts of a stabilizer, 1-10 parts of a toughening agent, and 90-100 parts of a resin;

[0032] The thickness of the conductive carrier is 50-300 μm;

[0033] Optionally, the thickness of the conductive carrier is any value among 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm or a range value between any two of them.

[0034] The thickness of the conductive carrier adhesive film is 80-500 μm.

[0035] Optionally, the thickness of the conductive carrier film is any value among 80μm, 100μm, 150μm, 200μm, 250μm, 300μm, 350μm, 400μm, 450μm, 500μm or a range value between any two of them.

[0036] The conductive nanomaterial is selected from at least one of carbon nanofibers, graphene, graphene oxide, carbon nanotubes, transition metal carbides, transition metal nitrides, and transition metal carbonitrides;

[0037] The mass fraction of the conductive nanomaterial on the conductive carrier is 0.1 - 3wt%;

[0038] Optionally, the mass fraction of the conductive nanomaterial on the conductive carrier is any value among 0.1wt%, 0.2wt%, 0.5wt%, 1wt%, 2wt%, 3wt% or a range value between any two of them.

[0039] The size of the conductive nanomaterial is 10 - 100nm.

[0040] Optionally, the size of the conductive nanomaterial is any value among 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm or a range value between any two of them.

[0041] The modification includes the following steps:

[0042] Immerse the conductive carrier in a solvent solution containing the conductive nanomaterial and dry it;

[0043] The solvent is selected from at least one of water, ethanol, and acetone;

[0044] In the solvent solution containing the conductive nanomaterial, the concentration of the conductive nanomaterial is 0.5 - 3wt%;

[0045] Optionally, in the solvent solution containing the conductive nanomaterial, the concentration of the conductive nanomaterial is any value among 0.5wt%, 1wt%, 2wt%, 3wt% or a range value between any two of them.

[0046] The immersion time is 5 - 180s;

[0047] Optionally, the immersion time is any value among 5s, 10s, 20s, 50s, 100s, 150s, 180s or a range value between any two of them.

[0048] The drying temperature is 50 - 120°C;

[0049] Optionally, the drying temperature is any value among 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C or a range value between any two of them.

[0050] The drying time is 30 - 300 s.

[0051] Optionally, the drying time is any value among 30 s, 50 s, 100 s, 150 s, 200 s, 250 s, 300 s or a range value between any two of them.

[0052] The drying method is selected from at least one of freeze drying, heat drying, and normal temperature drying.

[0053] The stabilizer is selected from at least one of phenol and its derivatives, benzoquinone and its derivatives, and aromatic amine compounds;

[0054] The toughening agent is selected from at least one of polysulfide rubber, polybutadiene rubber, nitrile rubber, ethylene - propylene rubber, styrene - butadiene rubber, polyethersulfone, polyphenylene sulfide, polyetheretherketone, and polyetherketoneketone;

[0055] The resin is selected from resins containing epoxy groups, resins containing two maleimide groups, resins containing imide groups, and resins containing cyanate ester groups.

[0056] When using resins containing epoxy groups, resins containing two maleimide groups, or resins containing imide groups, a curing agent needs to be added simultaneously;

[0057] The curing agent is selected from amine curing agents and / or anhydride curing agents;

[0058] The amine curing agents are selected from at least one of ethylenediamine, diethylenetriamine, m - phenylenediamine, p - phenylenediamine, and dimethylaniline;

[0059] The anhydride curing agents are selected from at least one of maleic anhydride, methylhexahydrophthalic anhydride, trimellitic anhydride, and maleic anhydride;

[0060] The addition amount of the curing agent is 5 - 40 wt% of the resins containing epoxy groups, resins containing two maleimide groups, or resins containing imide groups used.

[0061] Optionally, the addition amount of the curing agent is any value among 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt% of the resins containing epoxy groups, resins containing two maleimide groups, or resins containing imide groups used or a range value between any two of them.

[0062] According to another aspect of the present application, there is provided a method for preparing the above-mentioned conductive carrier adhesive film, including the following steps:

[0063] Roll the adhesive into a film to obtain an adhesive film, sandwich the conductive carrier between two adhesive films, and perform hot pressing to obtain the conductive carrier adhesive film.

[0064] The temperature for rolling into a film is 25 to 100 °C;

[0065] Optionally, the temperature for rolling into a film is any value among 25 °C, 50 °C, 75 °C, 100 °C or a range value between any two of them.

[0066] The pressure for rolling into a film is 0.1 to 0.3 MPa;

[0067] Optionally, the pressure for rolling into a film is any value among 0.1 MPa, 0.2 MPa, 0.3 MPa or a range value between any two of them.

[0068] The temperature for hot pressing is 30 to 150 °C;

[0069] Optionally, the temperature for hot pressing is any value among 30 °C, 40 °C, 50 °C, 60 °C, 70 °C, 80 °C, 90 °C, 100 °C, 110 °C, 120 °C, 130 °C, 140 °C, 150 °C or a range value between any two of them.

[0070] The pressure for hot pressing is 0.1 to 0.7 MPa.

[0071] Optionally, the pressure for hot pressing is any value among 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa or a range value between any two of them.

[0072] The method for preparing the above-mentioned conductive carrier adhesive film includes the following steps:

[0073] Coat the adhesive on the surface of the conductive carrier and perform pressing to obtain the conductive carrier adhesive film.

[0074] The temperature for pressing is 30 to 150 °C;

[0075] Optionally, the temperature for pressing is any value among 30 °C, 40 °C, 50 °C, 60 °C, 70 °C, 80 °C, 90 °C, 100 °C, 110 °C, 120 °C, 130 °C, 140 °C, 150 °C or a range value between any two of them.

[0076] The pressure for pressing is 0.1 to 0.7 MPa.

[0077] Optionally, the pressure for pressing is any value among 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa or a range value between any two of them.

[0078] According to another aspect of the present application, there is provided a method for electrothermal bonding of composite materials, which is carried out by using the above-mentioned electrothermal bonding device for composite materials;

[0079] It includes the following steps:

[0080] Place the conductive carrier film 12 between the upper composite material component 11 and the lower composite material component 13 to be bonded, heat it by energization, and press it to obtain the composite material.

[0081] The composite material to be bonded, which is composed of the upper composite material component 11, the conductive carrier film 12, and the lower composite material component 13, is placed between the upper fixture 7 and the lower fixture 8.

[0082] The pressure for pressing is the downward pressure applied by the pneumatic pressure cylinder 6 above the upper fixture 7.

[0083] The positive electrode clamp 10-3 and the negative electrode clamp 10-4 are clamped on the conductive carriers exposed at both ends of the conductive carrier film 12.

[0084] The energization specifically includes:

[0085] Set the parameters on the power supply 10, start the power supply 10, so that the current flows through the positive electrode wire 10-1, the positive electrode clamp 10-3, the conductive carrier film 12, the negative electrode wire 10-2 and the negative electrode clamp 10-4 to form a loop, and the conductive carrier film 12 generates heat under the action of the current.

[0086] After the energization heating is completed, adjust the parameters of the power supply 10 to reduce the voltage, and introduce cooling water into the upper fixture 7 and the lower fixture 8 through the water inlet 7-1 and the water inlet 8-1 respectively to achieve controllable cooling.

[0087] The pressure for pressing is 0.05 to 0.6 MPa.

[0088] Optionally, the pressure for pressing is any value among 0.05 MPa, 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa or a range value between any two of them.

[0089] The voltage output by the power supply 10 acts on both ends of the conductive carrier film 12 to be 3 to 50 V.

[0090] Optionally, the voltage output by the power supply 10 acts on both ends of the conductive carrier adhesive film 12 and is any value among 3V, 5V, 10V, 15V, 20V, 25V, 30V, 35V, 40V, 45V, 50V or a range value between any two of them.

[0091] The heating rate of the electric heating is 0.1 - 5 °C.

[0092] When the temperature of the bonding area rises to within the range of 0 - +30 °C of the initial curing temperature of the conductive carrier adhesive film 12, keep the temperature and pressure constant for 30 - 180 min;

[0093] When the temperature of the bonding area rises to within the range of -20 - +20 °C of the post - treatment temperature of the conductive carrier adhesive film 12, keep the temperature and pressure constant for 60 - 300 min.

[0094] The cooling rate is 1 - 10 °C / min. After cooling to room temperature, keep the pressure constant for 10 - 120 min.

[0095] The adhesive undergoes a curing reaction under the action of heat, and at the same time, under the pressure of the pneumatic pressure cylinder 6, the upper composite member 11 to be bonded and the lower composite member 13 are bonded into a whole.

[0096] Beneficial effects brought by the technical solution of the present invention

[0097] 1. Adopting the method of electric heating for local heating avoids the thermal aging and thermal deformation caused by the overall heating of the composite material structure. At the same time, it improves the energy utilization rate and greatly reduces the waste of energy.

[0098] 2. The electric heating method enables the temperature rise and fall process in the bonding area to be controllable, can eliminate the thermal stress in the bonding area, is conducive to fully releasing the thermal stress in the bonding area, and improves the bonding quality.

[0099] 3. The bonding process does not require hot - press autoclave curing, greatly improves the bonding efficiency, reduces the dependence on equipment, and further improves the processability and economy of the bonding process.

[0100] 4. The adhesive film body in the bonding area generates heat uniformly, omitting the heat transfer process, making the temperature field distribution in the bonding area more uniform while improving the heating efficiency.

[0101] 5. During the bonding process, the state change of the bonding area can be observed, and the bonding process is controllable.

[0102] 6. Since the conductive carriers on the entire bonding surface generate heat synchronously, the temperature field distribution in the bonding area is more uniform, enabling the adhesive film to cure synchronously and uniformly, and avoiding stress concentration caused by uneven curing.

[0103] 7. The electric heating is mainly carried out on the bonding area, omitting the complex heat transfer process, improving the heating efficiency, and at the same time being able to adjust parameters such as voltage and time, making the entire heating process and the cooling process after the adhesive film is cured controllable.

[0104] 8. This process does not require the use of an autoclave, greatly improving the bonding efficiency and reducing the dependence on equipment.

[0105] 9. Precisely heat the bonding area, and locally heat the bonding area of the composite material by the method of heat generated by electricity, avoiding the overall heat aging or thermal deformation of the composite material, resulting in performance degradation.

[0106] 10. Design a cooling water tank in the fixture to assist in controlling the cooling rate. Description of the Drawings

[0107] Figure 1 It is a schematic diagram of the overall structure of the electrothermal bonding device for composite materials;

[0108] Figure 2 It is a schematic diagram of the power box of the electrothermal bonding device for composite materials;

[0109] Figure 3 It is a schematic diagram of the fixture of the electrothermal bonding device for composite materials;

[0110] Figure 4 It is a schematic cross-sectional view of the assembly relationship of the electrothermal bonding area;

[0111] Among them, 1 is the frame, 2 is the balance drive motor, and 3 is the steel cable.

[0112] Figure 5 It is a schematic diagram of the conductive carrier adhesive film;

[0113] Figure 6 It is a cross-sectional view of the conductive carrier adhesive film;

[0114] Among them, 1-1 is the upper release paper, 1-2 is the conductive carrier area impregnated with the adhesive, 1-3 is the conductive carrier, and 1-4 is the lower release paper. Specific Embodiments

[0115] The following describes the present application in detail with reference to the embodiments, but the present application is not limited to these embodiments.

[0116] Preparation Example 1

[0117] 1) Prepare an aqueous solution of graphene oxide with a mass fraction of 2%, soak a glass fiber fabric with a thickness of 0.1 mm in the graphene oxide solution for 30 seconds, and then dry it at 120 °C. Repeat the operation 5 times to obtain the conductive carrier;

[0118] 2) Add 1 part of phenol stabilizer and 5 parts of polythiol rubber toughening agent to the bismaleimide resin and mix evenly to prepare the adhesive system. Roll the adhesive mechanically at 45 °C to form an adhesive film;

[0119] 3) Stack the conductive carrier prepared in step 1 and the adhesive film prepared in step 2 together, and perform mechanical pressing and compounding at a pressure of 0.3 MPa and a temperature of 50 °C to obtain the conductive carrier adhesive film.

[0120] Example 1

[0121] The present invention is a composite material electrothermal bonding device. As Figures 1 to 3 shown, the composite material electrothermal bonding device provided by the present invention includes: a power cabinet 1, an infrared thermal imager bracket 2, an infrared thermal imager 3, a support column 4, an upper baffle 5, a pneumatic pressure cylinder 6, an upper clamp 7, a lower clamp 8, an air compressor 9, an air duct 9-1, a pneumatic controller 9-2, a power supply 10, a positive electrode wire 10-1, a positive electrode clamp 10-3, a negative electrode wire 10-2, and a negative electrode clamp 10-4. Specifically, this device can be divided into a main body bearing structure, a temperature monitoring device, a power device, and a tooling.

[0122] The main body bearing structure includes a power cabinet 1, a support column 4, and an upper baffle 5. The power cabinet 1 serves as the base of the device, and at the same time, the power cabinet 1 houses power equipment such as a power supply 10 and an air compressor 9; the support column 4 plays a supporting role to stabilize the entire device; the upper baffle 5 plays a role in fixing the pneumatic pressure cylinder 6.

[0123] The temperature monitoring device includes an infrared thermal imager bracket 2 and an infrared thermal imager 3. The infrared thermal imager bracket 2 is connected to one side of the power cabinet and plays a role in supporting and fixing the infrared thermal imager 3; the infrared thermal imager 3 plays a role in real-time monitoring of the temperature change in the bonding area during the heating process.

[0124] The power system includes a pneumatic pressure cylinder 6, a power supply 10, and an air compressor 9. The pneumatic pressure cylinder 6 plays a role in applying pressure during the bonding process and is connected to the upper baffle 5 through a stud; the power supply 10 provides energy during the bonding process and controls the electrothermal bonding process by adjusting the power output parameters. The power supply outputs electric energy through the positive electrode wire 10-1 and the negative electrode wire 10-2, and is connected to the adhesive film to be heated through the positive electrode clamp 10-3 and the negative electrode clamp 10-4 connected to the wires to form a closed loop; the air compressor 9 uses compressed air as a medium to provide power for the pneumatic pressure cylinder 6. The air compressor 9 is connected to the pneumatic pressure cylinder 6 through the air duct 9-1, and the pneumatic controller 9-2 plays a role in controlling the air pressure. The air duct 9-1 transmits the pressure of the air compressor 9 to the pneumatic pressure cylinder 6 for pressurizing the composite material component; among them, the power supply 10 and the air compressor 9 are integrated inside the power cabinet 1.

[0125] The tooling includes an upper fixture 7 and a lower fixture 8, which are respectively placed on the upper and lower sides of the composite material component to be bonded, and play a role in fixing the composite material component. The upper fixture 7 and the lower fixture 8 are respectively provided with a water inlet 7-1, a water inlet 8-1, a water outlet 7-2 and a water outlet 8-2. When the cooling water flows through the fixture, the temperature of the fixture can be reduced, thereby assisting in cooling the composite material component; the upper fixture 7 and the lower fixture 8 are placed on the upper surface of the power cabinet, and the fixtures can be replaced according to different composite material components.

[0126] The specific method for electrothermal bonding of composite materials is specifically completed according to the following steps:

[0127] 1. Place the conductive carrier adhesive film 12 obtained in Preparation Example 1 between the upper composite material component 11 and the lower composite material component 13 to be bonded, as Figure 4 shown, and turn on the air compressor 9 to adjust the pneumatic controller 9-2 to make the pneumatic pressure cylinder 6 apply a pressure of 0.5 MPa on both sides of the composite material component to be bonded.

[0128] 2. Connect the power supply 10 to the conductive carriers exposed at both ends of the conductive carrier adhesive film 12 through the positive wire 10-1, the positive clamp 10-3, the negative wire 10-2 and the negative clamp 10-4 respectively, and apply a voltage of 10 V at both ends of the conductive carrier adhesive film 12 to make the current flow through the conductive carrier. The conductive carrier generates heat under the action of the current. Adjust the output voltage of the power supply 10 and the cooling water flow rate in the upper fixture 7 and the lower fixture 8, and monitor the temperature of the bonding area through the infrared thermal imager 3 to make the heating rate of the bonding area 0.1-5 °C / min. When the temperature of the bonding area rises to 180 °C, keep the temperature and pressure for 30 min, and then raise the temperature to 200 °C and keep the temperature and pressure for 120 min.

[0129] 3. After the adhesive film is cured, adjust the output voltage of the power supply 10 and the cooling water flow rate in the upper fixture 7 and the lower fixture 8 to make the temperature of the bonding area decrease to room temperature at a rate of 1-10 °C / min, and then keep the pressure for 30 min.

[0130] 4. After the pressure holding is completed, adjust the pneumatic pressure cylinder 6 to remove the pressure applied on the upper composite material component 11 and the lower composite material component 13 to be bonded, and trim the bonding area to remove the excess, that is, obtain the bonded composite material structure.

[0131] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can make several deformations or substitutions, which should all be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A composite material electrothermal bonding device, characterized in that it is composed of a power cabinet (1), an infrared thermal imager bracket (2), an infrared thermal imager (3), a support column (4), an upper baffle (5), a pneumatic pressure cylinder (6), an upper fixture (7), a lower fixture (8), an air compressor (9), an air duct (9-1), a pneumatic controller (9-2), a power supply (10), a positive wire (10-1), a positive clamp (10-3), a negative wire (10-2), and a negative clamp (10-4); the power cabinet (1) is connected to the infrared thermal imager bracket (2), and the infrared thermal imager (3) is fixed on the infrared thermal imager bracket (2); the support column (4) penetrates through the power cabinet (1) and extends to the ground, and at the same time supports the upper baffle (5); the pneumatic pressure cylinder (6) is fixed on the lower surface of the upper baffle (5) through; the upper fixture (7) and the lower fixture (8) are placed on the upper surface of the power cabinet (1); the air compressor (9) and the power supply (10) are integrated inside the power cabinet (1).

2. The composite material electrothermal bonding device according to claim 1, characterized in that the power cabinet (1) is a thick-walled box structure.

3. The composite material electrothermal bonding device according to claim 1, characterized in that the infrared thermal imager (3) is fixed on the infrared thermal imager bracket (2) by screws.

4. The composite material electrothermal bonding device according to claim 1, characterized in that the support column (4) plays a bearing role and stabilizes the entire device.

5. The composite material electrothermal bonding device according to claim 1, characterized in that the pneumatic pressure cylinder (6) is fixed on the lower surface of the upper baffle (5) by studs and plays a pressurizing role during bonding.

6. The composite material electrothermal bonding device according to claim 1, characterized in that the upper fixture (7) and the lower fixture (8) play a role in clamping the composite material during bonding, and the shape matches the surface of the composite material to be welded.

7. The composite material electrothermal bonding device according to claim 1, characterized in that there are cooling water tanks in the upper fixture (7) and the lower fixture (8), and the cooling water flows into the upper and lower fixtures through the water inlet (7-1) and the water inlet (8-1) respectively, and flows out from the water outlet (7-2) and the water outlet (8-2) respectively, and plays a role in assisting in cooling the bonding area after bonding.

8. The composite material electrothermal bonding device according to claim 1, characterized in that the air duct (9-1) connects the air compressor (9) and the pneumatic pressure cylinder (6) and plays a role in conducting air pressure.

9. The composite material electrothermal bonding device according to claim 1, characterized in that the pneumatic controller (9-2) plays a role in controlling air pressure.

10. The composite material electrothermal bonding device according to claim 1, characterized in that the power supply (10) plays a role in providing electric energy and controlling energy output.

11. The composite material electrothermal bonding device according to claim 1, characterized in that the power supply (10) outputs electric energy through the positive wire (10-1) and the negative wire (10-2).

12. The composite material electrothermal bonding device according to claim 1, characterized in that the power supply (10) is connected to the adhesive film to be heated through the positive clamp (10-3) and the negative clamp (10-4).

13. The composite material electrothermal bonding device according to claim 1, characterized in that the air compressor (9) provides pressure to the pneumatic pressure cylinder (6).

14. The composite material electrothermal bonding device according to claim 1, characterized in that the composite material is composed of an upper composite material member (11), a lower composite material member (13) and a conductive carrier adhesive film (12) sandwiched therebetween.

15. The composite material electrothermal bonding device according to claim 14, characterized in that the upper composite material member (11) and the lower composite material member (13) are carbon fiber composite materials or glass fiber composite materials.

16. The composite material electrothermal bonding device according to claim 14, characterized in that the conductive carrier adhesive film (12) is composed of a conductive carrier and an adhesive; the adhesive covers and infiltrates part of the area of the conductive carrier, and at least each side of the conductive carrier retains an area with a width of 5-50 mm not covered or infiltrated by the adhesive; the conductive carrier is modified with a conductive nanomaterial; the conductive carrier is selected from at least one of carbon fiber, glass fiber, quartz fiber, nylon fiber, polyimide fiber, and non-woven fabric; the adhesive is composed of 0.1-3 parts of a stabilizer, 1-10 parts of a toughening agent, and 90-100 parts of a resin; the thickness of the conductive carrier is 50-300 μm; the thickness of the conductive carrier adhesive film is 80-500 μm.

17. The composite material electrothermal bonding device according to claim 16, characterized in that the conductive nanomaterial is selected from at least one of carbon nanofiber, graphene, graphene oxide, carbon nanotube, transition metal carbide, transition metal nitride, and transition metal carbonitride; the mass fraction of the conductive nanomaterial on the conductive carrier is 0.1-3 wt%; the size of the conductive nanomaterial is 10-100 nm.

18. The composite material electrothermal bonding device according to claim 16, characterized in that the modification includes the following steps: immersing the conductive carrier in a solvent solution containing a conductive nanomaterial and drying; the solvent is selected from at least one of water, ethanol, and acetone; in the solvent solution containing a conductive nanomaterial, the concentration of the conductive nanomaterial is 0.5-3 wt%; the immersion time is 5-180 s; the drying temperature is 50-120 °C; the drying time is 30-300 s.

19. The composite material electrothermal bonding device according to claim 16, characterized in that the stabilizer is selected from at least one of phenol and its derivatives, benzoquinone and its derivatives, and aromatic amine compounds; the toughening agent is selected from at least one of polysulfide rubber, polybutadiene rubber, nitrile rubber, ethylene-propylene rubber, styrene-butadiene rubber, polyethersulfone, polyphenylene sulfide, polyether ether ketone, and polyether ketone ketone; The resin is selected from resins containing epoxy groups, resins containing two maleimide groups, resins containing imide groups, and resins containing cyanate ester groups.

20. The composite material electrothermal bonding device according to claim 16, wherein When using resins containing epoxy groups, resins containing two maleimide groups, and resins containing imide groups, a curing agent needs to be added simultaneously; The curing agent is selected from amine curing agents and / or anhydride curing agents; The amine curing agent is selected from at least one of ethylenediamine, diethylenetriamine, m-phenylenediamine, p-phenylenediamine, and dimethylaniline; The anhydride curing agent is selected from at least one of maleic anhydride, methylhexahydrophthalic anhydride, trimellitic anhydride, and maleic anhydride; The addition amount of the curing agent is 5-40 wt% of the resins containing epoxy groups, resins containing two maleimide groups, and resins containing imide groups used.

21. A method for electrothermal bonding of composite materials, characterized in that It is carried out by using the composite material electrothermal bonding device according to any one of claims 1-20; It includes the following steps: Place the conductive carrier film (12) between the upper composite material component (11) and the lower composite material component (13) to be bonded, heat by energization, and press to obtain the composite material.

22. The method according to claim 21, wherein The composite material to be bonded composed of the upper composite material component (11), the conductive carrier film (12), and the lower composite material component (13) is placed between the upper fixture (7) and the lower fixture (8).

23. The method according to claim 21, wherein The pressing pressure is the downward pressure applied by the pneumatic pressure cylinder (6) above the upper fixture (7).

24. The method according to claim 21, wherein The positive electrode clamp (10-3) and the negative electrode clamp (10-4) are clamped on the conductive carriers exposed at both ends of the conductive carrier film (12).

25. The method according to claim 21, wherein The energization specifically includes: Set the parameters on the power supply (10), start the power supply (10), so that the current flows through the positive electrode wire (10-1), the positive electrode clamp (10-3), the conductive carrier film (12), the negative electrode wire (10-2) and the negative electrode clamp (10-4) to form a loop, and the conductive carrier film (12) generates heat under the action of the current.

26. The method according to claim 21, wherein After the energization heating is completed, adjust the parameters of the power supply (10) to reduce the voltage, and pass cooling water into the upper fixture (7) and the lower fixture (8) respectively through the water inlet (7-1) and the water inlet (8-1) to achieve controllable cooling.

27. The method according to claim 21, wherein The pressing pressure is 0.05-0.6 MPa.

28. The method according to claim 21, wherein The voltage output by the power supply (10) acting on both ends of the conductive carrier film (12) is 3-50 V.

29. The method according to claim 21, wherein The heating rate of the electric heating is 0.1 to 5 °C; When the temperature of the bonding area rises to within the range of 0 to +30 °C of the initial curing temperature of the conductive carrier adhesive film (12), keep the temperature and pressure constant for 30 to 180 min; When the temperature of the bonding area rises to within the range of -20 to +20 °C of the post-treatment temperature of the conductive carrier adhesive film (12), keep the temperature and pressure constant for 60 to 300 min.

30. The method according to claim 26, wherein, The cooling rate is 1 to 10 °C / min. After cooling to room temperature, keep the pressure constant for 10 to 120 min.

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