Manufacturing method of carbon fiber reinforced plastic dovetail joint structure

Abstract

The invention discloses a manufacturing method of a carbon fiber reinforced plastic dovetail joint structure, and belongs to the technical field of dovetail joint manufacturing, and the manufacturing method comprises the following steps: S1, respectively producing 0-degree and 90-degree T300 carbon fiber unidirectional prepreg cloth by adopting prepreg; s2, putting the prepreg cloth into a hot press according to a laying sequence of [0 degree / 90 degree] 25, setting the temperature to be 120 DEG C and the pressure intensity to be 0.1 MPa, and keeping for 12 hours to manufacture a carbon fiber plate; s3, the tenon is cut through a three-axis numerical control machine tool, and a male tenon and a female tenon are obtained; s4, the tenon head of the male tenon is inserted into the mortise of the female tenon, and a CFRP dovetail tenon structure is obtained; and S5, the CFRP dovetail joint structure is subjected to surface treatment. According to the invention, the laying sequence of [0 degree / 90 degree] 25 is adopted, so that the carbon fiber plate has better mechanical properties and uniformity, and the dovetail joint has higher tensile strength, bending strength and compression strength by controlling the coating amount and curing conditions of the resin and improving the performance of the prepreg.

Description

Technical Field

[0001] The invention relates to the technical field of dovetail joint manufacturing, and in particular to a method for manufacturing a carbon fiber reinforced plastic dovetail joint structure. Background Art

[0002] Dovetail joint structure is a traditional woodworking connection method. Through the special design of tenon and tenon groove, two or more wood components can be closely combined to form a strong connection. The dovetail joint structure is characterized by the tenon in the shape of a dovetail and the tenon groove matching it. When the tenon is inserted into the tenon groove, the dovetail-shaped tenon can prevent the components from moving relative to each other, thereby providing good tensile and shear resistance.

[0003] The current method of making dovetail structure is: design, cutting, grinding, assembly, curing, surface treatment. The existing carbon fiber surface treatment method is not enough to improve the bonding strength between carbon fiber and resin, resulting in poor interface performance of CFRP, thus affecting the mechanical properties of the overall structure.

[0004] Specifically, the bonding between carbon fiber and resin mainly relies on physical adsorption and chemical bonding. When the surface treatment is insufficient, the defects and contaminants on the carbon fiber surface will hinder the contact between the resin and the fiber, reduce the area of ​​physical adsorption and chemical bonding, and lead to a decrease in the interfacial bonding strength. And when subjected to external force, weak interfacial bonding can easily cause the fiber to debond from the resin matrix, forming microcracks, which then develop into macrocracks and eventually lead to structural failure. To this end, a method for manufacturing a carbon fiber reinforced plastic dovetail structure is proposed.

[0005] The above information disclosed in this background technology is only used to increase the understanding of the background technology of the present invention and therefore, it may include information that does not constitute the prior art known to a person of ordinary skill in the art. Summary of the invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art, such as insufficient surface treatment of carbon fiber. To this end, one object of the present invention is to provide a method for manufacturing a carbon fiber reinforced plastic dovetail structure.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A method for manufacturing a carbon fiber reinforced plastic dovetail structure comprises the following steps:

[0009] S1, using prepreg to produce 0° and 90° T300 carbon fiber unidirectional prepreg fabrics respectively;

[0010] S2. Place the prepreg into a hot press in a plying order of [0° / 90°]25, set the temperature to 120°C, and maintain the pressure at 0.1 MPa for 12 hours to produce a carbon fiber plate;

[0011] S3, using a three-axis CNC machine tool to cut it to obtain a male tenon and a female tenon;

[0012] S4, inserting the male tenon into the female tenon groove to obtain the CFRP dovetail structure;

[0013] S5. Perform surface treatment on the CFRP dovetail structure.

[0014] As a further optimization scheme of the present invention, in step S1, the specific steps of making the carbon fiber reinforced plastic are:

[0015] S101, selecting T300 carbon fiber precursor and cutting it, and performing surface electroplating or chemical treatment on the cut carbon fiber precursor;

[0016] S102, using epoxy resin, heating the resin to 70-80° C., and preparing prepregs with different resin contents;

[0017] S103, coating the resin evenly on the carbon fiber precursor by a resin coating device, controlling the coating amount of the resin, and during the coating process, controlling the coating speed and the resin temperature;

[0018] S104, sending the resin-coated carbon fiber precursor into a curing furnace for curing;

[0019] S105, rolling up the cured prepreg into a roll and cutting it, and the cut prepreg is 0° and 90° T300 carbon fiber unidirectional prepreg.

[0020] As a further optimization solution of the present invention, in step S2, [0° / 90°]25 is alternately stacked at angles of 0° and 90°, with a total of 25 layers stacked.

[0021] As a further optimization solution of the present invention, in step S5, the specific steps of surface treatment of the CFRP dovetail structure are:

[0022] S501, using dimethylformamide as a solvent and preparing it, DMF: water is 70:30, and the prepared DMF solution is placed in a cleaning tank;

[0023] S502, placing the CFRP dovetail structure into a DMF solution for treatment, and during the cleaning process, shaking the cleaning tank to allow the surface of the CFRP dovetail structure to fully contact with the solvent;

[0024] S503, after the cleaning is completed, the CFRP dovetail structure is cleaned with clean water to remove the DMF residue on the surface, and then the CFRP dovetail structure is placed in a drying oven and dried at a temperature of 70-80° C. to make sure that there is no moisture residue on the surface of the CFRP dovetail structure.

[0025] As a further optimization scheme of the present invention, the CFRP dovetail structure is placed in the DMF solution for a treatment time of 10-60 minutes.

[0026] As a further optimization solution of the present invention, in step S104, the curing temperature is 120° C. and the curing time is 12 hours.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present invention adopts a [0° / 90°]25 ply sequence to make the carbon fiber board have better mechanical properties and uniformity. By controlling the coating amount and curing conditions of the resin, the performance of the prepreg is improved, and the dovetail joint has higher tensile strength, bending strength and compressive strength. In Example 1, the carbon fiber precursor is surface treated by an electroplating method to improve the bonding strength between the carbon fiber and the resin. In Example 2, the oxide layer and impurities on the surface of the carbon fiber are removed by using sodium hydroxide and sulfuric acid solutions to improve the surface activity of the carbon fiber, and improve the infiltration and bonding of the resin. After the production is completed, the CFRP dovetail joint structure is surface treated and cleaned with a dimethylformamide solution to effectively remove the resin and impurities remaining on the surface, thereby improving the surface quality of the structure.

[0029] The above summary is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the present invention will be readily apparent by reference to the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a flow chart of the method for manufacturing a carbon fiber reinforced plastic dovetail structure of the present invention;

[0031] Figure 2 This is a schematic diagram of the carbon fiber reinforced plastic dovetail structure of the present invention;

[0032] Figure 3 This is a schematic diagram of a four-point bending test in Experimental Example 1 of the present invention;

[0033] Figure 4 1 and 2 are the bending moment diagram and shear force diagram in Experimental Example 1 of the present invention. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] See also Figure 1 , a method for manufacturing a carbon fiber reinforced plastic dovetail structure, comprising the following steps:

[0036] S1, using prepreg to produce 0° and 90° T300 carbon fiber unidirectional prepreg fabrics respectively;

[0037] S101, selecting T300 carbon fiber precursor and cutting it, and performing surface electroplating on the cut carbon fiber precursor;

[0038] Among them, an ultrasonic cleaner is used to clean the carbon fiber precursor to remove surface impurities, a sandblaster is used to roughen the carbon fiber precursor, and an acid solution is used to remove surface oxides from the carbon fiber precursor and open the micropores on the carbon fiber surface. Under the action of the electric field, metal ions migrate from the anode to the cathode and deposit on the carbon fiber surface to form a coating. After reaching the preset coating thickness, the electroplating power supply is turned off and the carbon fiber precursor is taken out.

[0039] The carbon fiber precursor is cleaned with clean water to remove the electroplating solution residue on the surface, and the cleaned carbon fiber precursor is dried to remove the moisture on the surface.

[0040] S102, using epoxy resin, heating the resin to 70-80° C., and preparing prepregs with different resin contents.

[0041] Among them, the epoxy resin and the curing agent are mixed in a ratio of 100:20, stirred evenly, the mixed resin is put into the heater, the power of the heater is adjusted to 1000-1500W, the resin temperature is stabilized at 70-80°C, and the heated resin is evenly coated on the carbon fiber precursor. After the coating is completed, the carbon fiber precursor is placed in a curing furnace and cured at 70-80°C for a certain period of time to form a solid resin layer.

[0042] S103, coating the resin evenly on the carbon fiber precursor by a resin coating device, controlling the coating amount of the resin, and during the coating process, controlling the coating speed and the resin temperature;

[0043] The flow rate of the metering pump is 126g / m per minute. 2 The production line speed is 5m / min, and the flow rate of the metering pump should be set to 630g / min (126g / m 2×5m / min).

[0044] The speed of the coating device is 5m / min;

[0045] Use a thermostatic heater to keep the resin at 30℃±2℃. Monitor the resin temperature through a temperature sensor, and use a temperature control system to automatically adjust the power of the heater to maintain the resin temperature within the set range.

[0046] S104, sending the resin-coated carbon fiber precursor into a curing furnace for curing;

[0047] Among them, the tensile strength of the resin after curing is ≥300MPa, the bending strength is ≥500MPa, and the compressive strength is ≥400MPa.

[0048] The curing temperature is 120°C and the curing time is 12h.

[0049] S105, rolling up the cured prepreg into a roll and cutting it, and the cut prepreg is 0° and 90° T300 carbon fiber unidirectional prepreg.

[0050] S2. Place the prepreg into a hot press in a plying order of [0° / 90°]25, set the temperature to 120°C, and maintain the pressure at 0.1 MPa for 12 hours to produce a carbon fiber plate;

[0051] [0° / 90°]25 means the layers are laid alternately at angles of 0° and 90°, with a total of 25 layers.

[0052] Among them, the temperature of the hot press is preheated to 120°C, and the cut carbon fiber cloth is stacked on the heating plate of the hot press in the order of [0° / 90°]25. After the carbon fiber cloth is stacked, the pressure of the hot press is adjusted to 0.1MPa so that the pressure is evenly applied to the entire carbon fiber cloth layer. The lid of the hot press is closed and heating is started. The temperature is maintained at 120°C and the pressure is maintained at 0.1MPa for 12 hours. After 12 hours, the hot press is closed, the lid is opened, and the cured carbon fiber board is taken out. At this time, the carbon fiber cloth layer has formed a whole. The carbon fiber board is placed in a ventilated place to cool naturally to room temperature, and the carbon fiber board is taken out after it is completely cooled.

[0053] S3, using a three-axis CNC machine tool to cut it to obtain a male tenon and a female tenon;

[0054] Among them, the model of the three-axis CNC machine tool is CNC-850.

[0055] S4, inserting the male tenon into the female tenon groove to obtain the CFRP dovetail structure;

[0056] S5. Perform surface treatment on the CFRP dovetail structure.

[0057] S501, using dimethylformamide as a solvent and preparing it, DMF: water is 70:30, and the prepared DMF solution is placed in a cleaning tank;

[0058] S502, placing the CFRP dovetail structure into a DMF solution for treatment, and during the cleaning process, shaking the cleaning tank to allow the surface of the CFRP dovetail structure to fully contact with the solvent;

[0059] S503, after the cleaning is completed, the CFRP dovetail structure is cleaned with clean water to remove the DMF residue on the surface, and then the CFRP dovetail structure is placed in a drying oven and dried at a temperature of 70-80°C to make sure that there is no moisture residue on the surface of the CFRP dovetail structure. Figure 2 shown.

[0060] Embodiment 2

[0061] A method for manufacturing a carbon fiber reinforced plastic dovetail structure comprises the following steps:

[0062] S1, using prepreg to produce 0° and 90° T300 carbon fiber unidirectional prepreg fabrics respectively;

[0063] S101, selecting T300 carbon fiber precursor and cutting it, and chemically treating the cut carbon fiber precursor;

[0064] Specifically, a sodium hydroxide solution with a concentration of 20% is prepared, that is, 200 grams of sodium hydroxide is added to every 1000 milliliters of water, and the carbon fiber precursor is placed in the sodium hydroxide solution for a treatment time of 30-60 minutes to remove the surface oxide layer.

[0065] A 10% sulfuric acid solution is prepared, that is, 100 grams of sulfuric acid is added to every 1000 milliliters of water, and the oxidized carbon fiber precursor is placed in the sulfuric acid solution. The treatment time is usually 15-30 minutes to remove the oxide layer and surface impurities again.

[0066] Use clean water to thoroughly clean the carbon fiber precursor to remove chemical reagent residues, put the cleaned carbon fiber precursor into a drying oven, and dry it at a temperature of 70-80°C to ensure that there is no moisture residue on the surface of the carbon fiber precursor.

[0067] Experimental Example 1: A four-point bending test was performed on the fabricated CFRP dovetail specimen using an Instron 5982 material testing machine. Figure 3 shown.

[0068] Step 1: Set the test parameters

[0069] Material and size of the pressure head: Select 45 steel to make the pressure head with a radius of 3mm.

[0070] Support span: Set the support span to 160mm.

[0071] Pressure head descent rate: Set the pressure head descent rate to 2mm / min.

[0072] Step 2: Perform a four-point bending test

[0073] Specimen placement: The specimen is placed between two indenters so that it is subjected to pure bending only.

[0074] Symmetrical placement of the pressure heads: Based on the relationship LA / 2, the two pressure heads are placed symmetrically.

[0075] Test start: Start the testing machine and perform a four-point bending test according to the set parameters.

[0076] Step 4: Strain Measurement Using DIC

[0077] To create the speckle pattern: paint the specimen with white paint and spray it with black speckles.

[0078] Set up the industrial camera: Use the FLIR GS3-PGE60SM-C industrial camera, set it to automatic shooting, and the shooting rate is 1 frame / second.

[0079] Data collection: During the entire test process, the strain of the specimen is collected through an industrial camera. Figure 4 Bending moment diagram and shear force diagram.

[0080] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0081] In the drawings of the embodiments disclosed in the present invention, only the structures related to the embodiments disclosed in the present invention are involved, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present invention can be combined with each other.

[0082] Parts not involved in the present invention are the same as the prior art or can be implemented by the prior art. Although the embodiments of the present invention have been shown and described, it is understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for manufacturing a carbon fiber reinforced plastic dovetail structure, characterized in that: The following steps are involved: S1, using prepreg to produce 0° and 90° T300 carbon fiber unidirectional prepreg fabrics respectively; S2. Place the prepreg into a hot press in a plying order of [0° / 90°]25, set the temperature to 120°C, and maintain the pressure at 0.1 MPa for 12 hours to produce a carbon fiber plate; S3, using a three-axis CNC machine tool to cut it to obtain a male tenon and a female tenon; S4, inserting the male tenon into the female tenon groove to obtain the CFRP dovetail structure; S5. Perform surface treatment on the CFRP dovetail structure.

2. The method for manufacturing a carbon fiber reinforced plastic dovetail structure according to claim 1, characterized in that: In step S1, the specific steps of making carbon fiber reinforced plastic are: S101, selecting T300 carbon fiber precursor and cutting it, and performing surface electroplating or chemical treatment on the cut carbon fiber precursor; S102, using epoxy resin, heating the resin to 70-80° C., and preparing prepregs with different resin contents; S103, uniformly coating the resin on the carbon fiber precursor by a resin coating device; S104, sending the resin-coated carbon fiber precursor into a curing furnace for curing; S105, rolling up the cured prepreg into a roll and cutting it, and the cut prepreg is 0° and 90° T300 carbon fiber unidirectional prepreg.

3. The method for manufacturing a carbon fiber reinforced plastic dovetail structure according to claim 1, characterized in that: In step S2, [0° / 90°]25 is alternately stacked at angles of 0° and 90°, with a total of 25 layers stacked.

4. The method for manufacturing a carbon fiber reinforced plastic dovetail structure according to claim 1, characterized in that: In step S5, the specific manufacturing steps of surface treatment of the CFRP dovetail structure are: S501, using dimethylformamide as a solvent and preparing it, DMF: water is 70:30, and the prepared DMF solution is placed in a cleaning tank; S502, placing the CFRP dovetail structure into a DMF solution for treatment, and during the cleaning process, shaking the cleaning tank to allow the surface of the CFRP dovetail structure to fully contact with the solvent; S503, after the cleaning is completed, the CFRP dovetail structure is cleaned with clean water to remove the DMF residue on the surface, and then the CFRP dovetail structure is placed in a drying oven and dried at a temperature of 70-80° C. to make sure that there is no moisture residue on the surface of the CFRP dovetail structure.

5. The method for manufacturing a carbon fiber reinforced plastic dovetail structure according to claim 4, characterized in that: The CFRP dovetail structure is placed in the DMF solution for a treatment time of 10-60 minutes.

6. The method for manufacturing a carbon fiber reinforced plastic dovetail structure according to claim 2, characterized in that: In step S104, the curing temperature is 120°C and the curing time is 12 hours.

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