Manufacturing method of pointed-cone-shaped cavity thin-wall structure composite material part

Abstract

The invention discloses a pointed-cone-shaped cavity thin-wall structure composite material part manufacturing method, which is characterized in that the structure of a pointed-cone-shaped part structure model is optimized on the basis of fused deposition forming process characteristics, filling bodies are arranged in a hollow interlayer between an inner wall and an outer wall in a dot matrix manner, then the pointed-cone-shaped part structure model is placed upside down, and the pointed-cone-shaped cavity thin-wall structure composite material part is manufactured. The pointed conical cavity thin-wall structure composite material part is obtained through printing from bottom to top and from outside to inside, so that the overall strength of the part is improved, the requirement for the strength of the part is met, the part is changed into die-free forming from traditional forming depending on a die, and the part is changed into digital forming from manual paving. The manufacturing quality and the qualified rate of parts are improved, the production cost is reduced, and the overall manufacturing period is shortened.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of 3D printing forming, and particularly relates to a manufacturing method of a sharp cone cavity thin-wall structure composite part. BACKGROUND

[0002] Composite materials have the characteristics of high strength, light weight, functional combination, etc., and have been widely used in aircraft fuselages, tail wings, leading edges and other structural or functional components to achieve the effects of component function, performance expansion and improvement, weight reduction, etc. According to different application scenarios, they are mainly divided into two categories: functional composite materials and structural composite materials. Functional composite materials are mainly used to meet the application requirements of diversified functions of aircraft structural components, such as wave-absorbing paint, wave-absorbing honeycomb core, intelligent skin radar cover, etc. Structural composite materials are mainly used to meet the application requirements of lightweight and high-strength structural components of aircraft, and their mechanical properties reach or exceed those of aluminum alloy, mainly represented by wings, skins, supporting frames, various protective covers, etc. The sharp cone cavity thin-wall composite part belongs to a structural composite part, which is formed by using the current mainstream vacuum bag-hot press tank method and relies on a mold. However, it is difficult to form, and the size and surface quality of the formed part are poor, resulting in a low manufacturing qualification rate of the part.

[0003] Therefore, in view of the above technical problems existing in the preparation of the sharp cone cavity thin-wall composite part by using the vacuum bag-hot press tank method in the prior art, the application discloses a manufacturing method of a sharp cone cavity thin-wall structure composite part. SUMMARY

[0004] The application discloses a manufacturing method of a sharp cone cavity thin-wall structure composite part. The sharp cone part structure model is optimized and designed, a filler is arranged in the hollow interlayer point array of the sharp cone part structure model to provide support, and a short-cut carbon fiber composite wire material is used as a raw material to prepare the sharp cone cavity thin-wall structure composite part by using a fused deposition forming method. The preparation efficiency is improved, and the forming qualification rate of the sharp cone cavity thin-wall structure composite part is effectively ensured.

[0005] The application is implemented by the following technical scheme: A manufacturing method of a sharp cone cavity thin-wall structure composite part, comprising the following steps: Step 1, preparing a short-cut carbon fiber composite wire material, wherein the short-cut carbon fiber composite wire material is composed of short carbon fibers as a reinforcing phase and polyether ether ketone as a resin matrix; Step 2, designing a sharp cone part structure model, wherein the sharp cone part structure model comprises an inner wall, an outer wall and a hollow interlayer arranged between the inner wall and the outer wall, and the hollow interlayer is filled with fillers in the inside point array; Step 3, place the spinous process part structure model upside down, and increase the sawtooth support structure on the bottom outside of the spinous process part structure model, generate the final process model; Step 4, according to the process model, adopt the fused deposition forming mode to print the short carbon fiber composite wire material into the spinous process part according to the sequence of printing the outer wall, placing the filler and printing the inner wall; Step 5, remove the support structure outside the spinous process part, polish the outer wall, and then put the spinous process part into the oven for heat treatment.

[0006] In order to better realize the present application, further, the thickness of the inner wall is 1-1.2mm, the thickness of the outer wall is 1-1.2mm, and the filler is a helical icosahedron.

[0007] In order to better realize the present application, further, the helical icosahedron comprises a plurality of helical walls, the thickness of the helical wall is 0.3-0.5mm, and the wall spacing between adjacent helical walls is 3-5mm.

[0008] In order to better realize the present application, further, the diameter of the short carbon fiber composite wire material is less than or equal to 1.75mm.

[0009] In order to better realize the present application, further, in the process of printing the spinous process part, the printing line width is less than or equal to 0.4mm, the printing layer is less than or equal to 0.15mm, and the printing speed is 20-40mm / s.

[0010] In order to better realize the present application, further, the overlap rate between the printing lines is less than or equal to 10%.

[0011] In order to better realize the present application, further, the spacing between adjacent support structures is less than or equal to 2.5mm.

[0012] In order to better realize the present application, further, the temperature of the heat treatment is greater than or equal to 280℃, the holding time after heat treatment is greater than or equal to 120min, and the heating rate during heat treatment is less than or equal to 5℃ / min.

[0013] In order to better realize the present application, further, the short carbon fiber powder and the polyether ether ketone powder are dried, then the short carbon fiber powder and the polyether ether ketone powder are physically mixed and dispersed, then the mixed powder is dried again, and the dried mixed powder is heated and melted by a double screw extrusion device to obtain the short carbon fiber composite wire material.

[0014] Compared with the prior art, the present application has the following advantages and beneficial effects: The application is based on the characteristics of the fused deposition forming process, optimizes the structure of the sharp pyramid part structure model, sets the filling body in the hollow interlayer midpoint array between the inner wall and the outer wall, then places the sharp pyramid part structure model upside down, prints the sharp cone cavity thin-wall structure composite part in the order from bottom to top and from outside to inside, thereby improving the overall strength of the part, meeting the strength requirement of the part, and changing the traditional mold forming of such parts into moldless forming, changing the manual laying into digital forming, improving the manufacturing quality and qualification rate of the part, reducing the production cost, and shortening the overall manufacturing cycle. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 FIG. 1 is a three-dimensional schematic view of a sharp pyramid part structure model; Figure 2 FIG. 2 is a sectional view of the structure of the sharp pyramid part structure model; Figure 3 FIG. 3 is a structural schematic view of a helical icosahedron; Figure 4 FIG. 4 is a structural schematic view of a helical wall; Figure 5 FIG. 5 is a schematic view of a support structure; Figure 6 FIG. 6 is a preparation process schematic view of a chopped carbon fiber composite wire;

[0016] In the figure, 1 is an inner wall, 2 is an outer wall, and 3 is a filling body. DETAILED DESCRIPTION

[0017] Example 1 The sharp cone cavity thin-wall structure composite part manufacturing method of the example comprises the following steps: Step 1, prepare a chopped carbon fiber composite wire, which is composed of short carbon fibers as a reinforcing phase and polyether ether ketone as a resin matrix; Step 2, design a sharp pyramid part structure model, which comprises an inner wall 1, an outer wall 2, and a hollow interlayer between the inner wall 1 and the outer wall 2, and the inside of the hollow interlayer is filled with a filling body 3; Step 3, place the sharp pyramid part structure model upside down, and increase a jagged support structure on the outside of the bottom of the sharp pyramid part structure model to generate a final process model; Step 4, according to the process model, use the fused deposition forming method to print the sharp pyramid part in the order of printing the outer wall 2, placing the filling body 3, and printing the inner wall 1; Step 5, remove the support structure on the outside of the sharp pyramid part, polish the outer wall 2, and then put the sharp pyramid part into an oven for heat treatment.

[0018] Further, the thickness of the inner wall 1 is 1-1.2mm, the thickness of the outer wall 2 is 1-1.2mm, and the filling body 3 is a helical icosahedron.

[0019] Further, the helical icosahedron comprises a plurality of helical walls, the thickness of the helical wall is 0.3-0.5mm, and the wall spacing between adjacent helical walls is 3-5mm.

[0020] Further, the diameter of the chopped carbon fiber composite wire is less than or equal to 1.75mm.

[0021] Further, in the process of printing the shaped sharp keel part, the printing line width is less than or equal to 0.4mm, the printing layer is less than or equal to 0.15mm, and the printing speed is 20-40mm / s.

[0022] Further, the overlap rate between the printing lines is less than or equal to 10%.

[0023] Further, the spacing between adjacent support structures is less than or equal to 2.5mm.

[0024] Further, the temperature of the heat treatment is greater than or equal to 280℃, the holding time after heat treatment is greater than or equal to 120min, and the heating rate during heat treatment is less than or equal to 5℃ / min.

[0025] Further, as shown in Figure 6 The short carbon fiber powder and the polyether ether ketone powder are dried, then the short carbon fiber powder and the polyether ether ketone powder are blended and dispersed in a physical mixing manner, then the mixed powder is dried again, and the dried mixed powder is heated and melted by a double screw extrusion device to obtain a chopped carbon fiber composite wire.

[0026] Example 2: The embodiment discloses a manufacturing method of a sharp cone-shaped cavity thin-wall structure composite part, which is further optimized on the basis of the embodiment 1 and comprises the following steps. Material preparation The process adopted by the scheme is fused deposition forming, which is one of 3D printing processes, and its principle is that a filament-shaped hot melt material is heated and melted in a nozzle, and then extruded out through a micro nozzle of the nozzle. After the hot melt material leaves the nozzle, it is immediately bonded with the previous layer of material. After one layer of material is deposited, the workbench is lowered by one layer of thickness, and the next layer is continuously melted and sprayed for deposition. In this way, the layers are deposited one by one until the desired solid model is accumulated. The diameter of the chopped carbon fiber composite wire is φ1.75mm, so the material needs to be prepared into a wire for fused deposition forming.

[0027] The preparation process of the chopped carbon fiber composite wire mainly includes the following steps: 1. Dry the short carbon fiber powder and polyetheretherketone powder separately; 2. Use physical method to blend and disperse the dried short carbon fiber powder and polyetheretherketone powder in a certain proportion to make them evenly mixed; 3. Dry the blended and dispersed powder again; 4. Use a twin-screw extruder to heat and melt the dried powder and extrude a standard wire with a specification of φ1.75mm, and use a standard material tray for winding.

[0028] Design of the structure model of the pointed cone parts: Based on the overall weight of the parts and the manufacturing cycle, according to the previous process experience, such as Figures 1-4 As shown, the thickness of both the outer wall 2 and the inner wall 1 is preferably 1.2 mm. A hollow interlayer is formed between the inner and outer walls 1 and 2, and a filler 3 is lattice-filled within the hollow interlayer for support. The filler 3 is a helical icosahedron, comprising a plurality of spiral walls. The thickness t of the spiral walls is 0.4 mm, and the spacing d between adjacent spiral walls is 5 mm.

[0029] According to the part configuration and the principle of fused deposition modeling, the present invention chooses to use an inverted placement method for printing, which can greatly reduce the deformation of the parts and ensure the printing quality of the parts; Figure 5 As shown in the figure, serrated support structures are added on both sides of the bottom of the part, and the spacing between adjacent support structures is 2.5 mm to generate a process model.

[0030] Parts manufacturing and post-processing: Import the process model into the slicing software, set the slicing parameters, generate the printing program code, bring the printing program code into the device, and start part printing. The slicing parameters are shown in Table 1: Table 1. Printing and Slicing Parameters After the part is printed, it is removed from the equipment, and the adhesive film and auxiliary support structures are removed. The surface of the part is then polished to improve the surface quality. To further improve the strength of the part, it is subjected to heat treatment at 280°C for 120 minutes at a heating rate of ≤5°C / min. After heat treatment, the mechanical properties are improved by over 30%.

[0031] The rest of this embodiment is the same as that of embodiment 1, so it will not be described again.

[0032] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A method for manufacturing a composite material part with a tapered cavity and thin-walled structure, characterized in that: The following steps are involved: Step 1: preparing a chopped carbon fiber composite filament, wherein the chopped carbon fiber composite filament is composited with short carbon fibers as a reinforcement phase and polyetheretherketone as a resin matrix; Step 2: Designing a conical part structural model, wherein the conical part structural model comprises an inner wall (1), an outer wall (2), and a hollow interlayer arranged between the inner wall (1) and the outer wall (2), wherein the inner lattice of the hollow interlayer is filled with a filling body (3); Step 3: Place the pointed cone part structure model upside down, and add a serrated support structure on the outside of the bottom of the pointed cone part structure model to generate the final process model; Step 4: According to the process model, the short carbon fiber composite wire is subjected to a fused deposition modeling method, and the conical part is printed in the order of printing the outer wall (2), placing the filler (3), and printing the inner wall (1); Step 5: Remove the supporting structure on the outside of the conical part, polish the outer wall (2), and then place the conical part in an oven for heat treatment.

2. The method for manufacturing a composite material part with a tapered cavity and thin-walled structure according to claim 1, characterized in that: The thickness of the inner wall (1) is 1-1.2 mm, the thickness of the outer wall (2) is 1-1.2 mm, and the filling body (3) is a spiral icosahedron.

3. The method for manufacturing a composite material part with a tapered cavity and thin-walled structure according to claim 2, characterized in that: The spiral icosahedron includes a plurality of spiral walls, the thickness of the spiral walls is 0.3-0.5 mm, and the wall spacing between adjacent spiral walls is 3-5 mm.

4. The method for manufacturing a composite material part with a tapered cavity and thin-walled structure according to claim 3, characterized in that: The diameter of the chopped carbon fiber composite filament is less than or equal to 1.75 mm.

5. The method for manufacturing a composite material part with a tapered cavity and thin-walled structure according to claim 4, characterized in that: During the printing process of the conical parts, the printing line width is less than or equal to 0.4mm, the printing layer is less than or equal to 0.15mm, and the printing speed is 20-40mm / s.

6. The method for manufacturing a composite material part with a tapered cavity and thin-walled structure according to claim 5, characterized in that: The overlap between printed lines is less than or equal to 10%.

7. The method for manufacturing a composite material part with a tapered cavity and thin-walled structure according to claim 6, characterized in that: The spacing between adjacent support structures is less than or equal to 2.5 mm.

8. The method for manufacturing a composite material part with a tapered cavity and thin-walled structure according to claim 7, characterized in that: The temperature of the heat treatment is greater than or equal to 280° C., the holding time after the heat treatment is greater than or equal to 120 min, and the heating rate during the heat treatment process is less than or equal to 5° C. / min.

9. The method for manufacturing a composite material part with a tapered cavity and thin-walled structure according to claim 8, characterized in that: The short carbon fiber powder and polyetheretherketone powder are dried, and then the short carbon fiber powder and polyetheretherketone powder are blended and dispersed by physical mixing. The mixed powder is then dried again, and the dried mixed powder is heated and melted using a twin-screw extruder and then extruded to obtain short carbon fiber composite filaments.

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