A method of 3D printing of a composite material

Abstract

The application discloses a 3D integral printing method of a composite material, which comprises the following steps: firstly, a test piece model is intercepted from a three-dimensional numerical model of a part to be printed, test printing parameters are obtained through the test piece model, and a test piece is printed based on the test printing parameters; quality detection is performed on the test piece, if the forming quality meets the requirements, the test printing parameters are taken as the printing parameters, otherwise, the test printing parameters are corrected until the forming quality is qualified; then, a three-dimensional model is corrected according to the size parameters of the test piece to obtain a corrected three-dimensional model; finally, the printing of an official piece is performed through the printing parameters and the corrected three-dimensional model; compared with the prior art, the application can determine whether the test printing parameters are reliable through the test piece with the same structure, can observe the deformation of the part in the printing process through the test piece, and can formulate corresponding preventive measures, so that the printing quality and the one-time forming rate of the official piece are improved, and the manufacturing cycle and the production cost of the part can be effectively shortened.

Description

Technical Field

[0001] This application relates to the field of hole-making technology, specifically to a method for 3D integral printing of composite materials. Background Technology

[0002] 3D printing technology has unparalleled advantages over traditional manufacturing technologies. While enabling the integral and precise forming of complex components, it also promotes the liberation and improvement of structural design concepts. It is of great significance for realizing the application of low-cost and highly manufacturable advanced aerospace composite materials and can effectively solve the manufacturing technology problems faced when expanding the application of existing composite materials.

[0003] Complex skin + honeycomb core is a typical complex structure composite part. It is an integrated integral part designed based on 3D printing technology. The part material is polyetheretherketone (PEEK), a high-performance resin material that is currently popular in the aerospace field. This type of part is large in size and is formed by cold deposition 3D printing. During the printing process, there are problems such as crystallization shrinkage and deformation, resulting in poor printing quality. Summary of the Invention

[0004] The main objective of this application is to provide a method for 3D integral printing of composite materials, which aims to solve the problem of poor printing quality in the prior art.

[0005] The present invention achieves the above objectives through the following technical solutions;

[0006] A 3D printing method for composite materials includes the following steps:

[0007] The test piece model is extracted from the three-dimensional digital model of the part to be printed, and the test printing parameters are obtained based on the test piece model;

[0008] Print test pieces according to the test printing parameters, and test the molding quality of the test pieces. If the molding quality is qualified, the test printing parameters are used as the printing parameters; otherwise, modify the test printing parameters until the molding quality of the printed test pieces is qualified.

[0009] The dimensional parameters of the test piece are detected, and the three-dimensional digital model of the part to be printed is corrected according to the dimensional parameters to obtain the corrected three-dimensional digital model of the part to be printed.

[0010] Print the final part according to the printing parameters and the corrected 3D digital model;

[0011] Correct the shape of the final part and perform post-processing.

[0012] Optionally, the test piece model includes a skin and a core, wherein the length ratio of the skin to the core is the same in both the test piece model and the part to be printed; the length ratio of the test piece model to the part to be printed is (0.25-0.35):1.

[0013] Optionally, both ends of the test specimen model are stepped; both ends of the skin are provided with outward flanges.

[0014] Optionally, detecting the dimensional parameters of the test piece, correcting the 3D digital model of the part to be printed based on the dimensional parameters, and obtaining the corrected 3D digital model of the part to be printed includes the following steps:

[0015] Measure the actual length L of the test piece 实际 and the deformation amount Q of the outer flange;

[0016] Based on the actual length L 实际 Calculate the length compensation coefficient of the part to be printed;

[0017] Based on the actual length L 实际 The deformation amount Q of the outer flange is used to design an auxiliary support scheme for the part to be printed.

[0018] The length compensation coefficient and auxiliary support components are imported into the three-dimensional digital model to obtain the corrected three-dimensional digital model.

[0019] Optionally, the expression for the compensation coefficient is K = L 理论 / L 实际 -1, where L 理论 L represents the theoretical dimension of the part. 实际 The actual measured dimensions of the printed test specimen.

[0020] Optionally, based on the actual length L 实际 Designing an auxiliary support scheme for the part to be printed includes the following steps:

[0021] Based on the interval parameter and the actual length L 实际 A number of support ribs are arranged; wherein each of the support ribs is arranged sequentially along the axial direction of the part to be printed;

[0022] The thicknessing parameters are set for the skin according to the process requirements;

[0023] Determine whether the deformation amount Q of the outer flange meets the technical requirements. If it does not meet the requirements, add several reinforcing ribs. Each of the reinforcing ribs is parallel to the axis of the part to be printed.

[0024] Optionally, the shape of the final part is corrected, and post-processing is performed, including the following steps:

[0025] A calibration component is installed on the final part, and the final part is clamped once by the calibration component;

[0026] The workpiece is subjected to a heat treatment at the first heat treatment temperature.

[0027] The final part is clamped a second time using the alignment components;

[0028] The clamped parts are subjected to a second heat treatment at a second heat treatment temperature.

[0029] Remove the final part after the second heat treatment and allow it to cool naturally to room temperature.

[0030] Remove the alignment components, support ribs, and reinforcing ribs, and sand the outer surface of the final part.

[0031] Optionally, the alignment assembly includes a top plate, a bottom plate, and several fixing clips. The top plate is attached to the top surface of the core of the formal part. Each of the supporting ribs is connected to the bottom plate. Along the axial direction of the formal part, each of the fixing clips is arranged sequentially and clamps the top plate and the bottom plate respectively.

[0032] Optionally, the calibration assembly also includes several pressure blocks, each of which is arranged sequentially along the axial direction of the formal part within the cavity section of the part to be printed, and each of the pressure blocks is respectively attached to the inner wall of the formal part.

[0033] Optionally, the first heat treatment temperature is 95℃-100℃ for 5-10 minutes; the second heat treatment temperature is 135℃-145℃ for 3-4 hours.

[0034] Compared with the prior art, this application has the following beneficial effects:

[0035] This application first extracts a test piece model from the 3D digital model of the part to be printed, obtains test printing parameters through the test piece model, and prints the test piece based on the test printing parameters; the test piece is then subjected to quality inspection, and if the molding quality meets the requirements, the test printing parameters are used as the printing parameters; otherwise, the test printing parameters are corrected until the molding quality is qualified; then, the 3D model is corrected according to the dimensional parameters of the test piece to obtain a corrected 3D model, and finally, the final part is printed using the printing parameters and the corrected 3D model;

[0036] Compared with the prior art, the test piece model in this application is derived from the three-dimensional model of the final part. Therefore, its structure is the same as that of the final part. At the same time, the test piece is similar to the part to be printed in appearance. Therefore, after the test piece is printed, it will also undergo deformation similar to that of the final part. By observing the deformation of the test piece, it is possible to quickly determine whether the test printing parameters can be applied to the printing of the final part. It is also convenient for those skilled in the art to correct the test printing parameters according to the deformation of the test piece until the molding quality of the test piece meets the requirements, thereby ensuring the accuracy and reliability of the printing parameters.

[0037] Meanwhile, compared with the final product, the test piece is smaller in size. Under the condition of a certain 3D printing speed, this application can effectively shorten the printing time and thus improve the verification efficiency. Compared with directly printing the final product, this application can also effectively reduce the production cost.

[0038] Secondly, by observing the deformation of the test piece, the three-dimensional model can be modified in a targeted manner, so as to prepare for the deformation in the later stage in the initial design stage, thereby improving the one-time molding rate of the parts and also improving the printing quality.

[0039] Finally, during the 3D model correction process, a support structure will be designed based on the corrected dimensions and structure to form a more reasonable support, which can effectively ensure the manufacturing accuracy of the parts and thus improve the printing quality of the parts. Attached Figure Description

[0040] Figure 1 A flowchart illustrating a 3D printing method for composite materials provided in Embodiment 1 of this application;

[0041] Figure 2 This is a schematic diagram of the structure of the test specimen model;

[0042] Figure 3 To revise the structural schematic diagram of the 3D digital model;

[0043] Figure 4 This is an assembly diagram of the alignment components;

[0044] Figure 5 This is a schematic diagram of the clamping block installation;

[0045] Attached reference numerals: 1-skin, 2-core, 3-outer flange, 4-support rib, 5-reinforcing rib, 6-top plate, 7-bottom plate, 8-fixing clamp, 9-pressure block.

[0046] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0048] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0049] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0050] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0051] Implementation Method 1

[0052] Reference Figure 1 and Figure 4 This embodiment, as an optional embodiment of this application, discloses a 3D printing method for composite materials, including the following steps:

[0053] S1. Extract the test piece model from the three-dimensional digital model of the part to be printed, and obtain the test printing parameters based on the test piece model;

[0054] First, obtain a 3D digital model of the part to be printed, and then cut a section from the 3D digital model. Figure 1 The segment serves as a test specimen model;

[0055] Since the part to be printed includes both skin and core, the resulting 3D model must also include both skin and core.

[0056] Meanwhile, the skin at both ends of the cut test piece model is extended to form outward flanges, which simulate the empty skin at both ends of the part to be printed; the length of the outward flanges is 10-15m.

[0057] The test specimen model is designed with stepped ends to allow for the measurement of more data; the core cut-off point is designed as a plane to improve the accuracy of the measurement data.

[0058] After the cut is completed, calculate the length ratio of the skin to the core, and at the same time calculate the length ratio of the skin to the core in the 3D model. The two ratios must be equal.

[0059] In selecting the specific cut-off area, it is necessary to ensure that the shape of the cut-off area is the same as or similar to the shape of the entire part to be printed. If the shape of some areas in the three-dimensional model is a scaled-down version of the part to be printed, then the above-mentioned areas should be selected as the test piece model.

[0060] Meanwhile, the length ratio of the test specimen model to the part to be printed is (0.25-0.35):1;

[0061] The above settings can ensure that the real structure of the part to be printed is reproduced on a smaller test piece, thereby ensuring the accuracy and reliability of subsequent simulated printing;

[0062] Secondly, by controlling the length of the test piece model, the printing time of the test piece can be effectively adjusted, thereby improving the efficiency of simulation printing and the printing efficiency of the final part.

[0063] After selecting the test specimen model, import the test specimen model into the 3D printing equipment, and automatically generate the test printing parameters through the slicing software that comes with the 3D printing equipment.

[0064] S2. Print the test piece according to the test printing parameters, and check the molding quality of the test piece. If the molding quality is qualified, use the test printing parameters as the printing parameters; otherwise, modify the test printing parameters until the molding quality of the printed test piece is qualified.

[0065] The test piece is obtained by directly 3D printing using the test printing parameters obtained in step S1.

[0066] After the test piece is printed, its molding quality is observed. If its molding quality meets the requirements, the test printing parameters in step S1 are retained and used as printing parameters.

[0067] If the molding quality does not meet the requirements, the test printing parameters are manually adjusted and the test piece is printed again until the molding quality of the test piece meets the requirements.

[0068] S3. Detect the dimensional parameters of the test piece, correct the three-dimensional digital model of the part to be printed according to the dimensional parameters, and obtain the corrected three-dimensional digital model of the part to be printed.

[0069] S31. Measure the actual length L of the test piece. 实际 and the deformation amount Q of the outer flange;

[0070] The actual length L of the test piece was determined using testing tools. 实际 It should be noted that the actual length L 实际 The actual length of both the skin and the core needs to be measured multiple times to ensure accuracy.

[0071] S32, Based on the actual length L 实际 Calculate the length compensation coefficient of the part to be printed;

[0072] The expression for the compensation coefficient is K = L 理论 / L 实际 -1, where L 理论 L represents the theoretical dimension of the part. 实际 The actual measured dimensions of the printed test specimen;

[0073] During the calculation, the length compensation coefficients of the skin and the core are calculated separately. At the same time, each measurement parameter in step S31 needs to be calculated once, and the average value is finally taken as the length compensation coefficient of the part to be printed.

[0074] S33, Based on the actual length L 实际 The deformation amount Q of the outer flange is used to design an auxiliary support scheme for the part to be printed.

[0075] S331, Based on the interval parameters and actual length L 实际 A number of support ribs are arranged; wherein each of the support ribs is arranged sequentially along the axial direction of the part to be printed;

[0076] The spacing parameters are determined according to the actual process requirements. The spacing parameters are 100-150mm. Each support rib is arranged along the axial direction of the part to be printed, and the top of each support rib is in contact with the bottom surface of the part to be printed.

[0077] The thickness of each of the aforementioned support ribs is 2.9-3.1 mm;

[0078] The use of support ribs effectively improves the axial strength of the part to be printed, ensuring that curved, thin-walled areas do not twist or deform during printing. Serrated supports are automatically generated for the remaining areas using slicing software.

[0079] S332. Set the thicknessing parameters for the skin according to the process requirements;

[0080] The thickening parameter is generally 10%-15% of the thickness of the part to be printed. At the same time, the contact area between the support rib and the part to be printed also needs to be thickened to leave enough machining allowance for subsequent cutting and grinding of the support rib.

[0081] S333. Determine whether the deformation amount Q of the outer flange meets the requirements according to the technical requirements. If it does not meet the requirements, add several reinforcing ribs. Each of the reinforcing ribs is parallel to the axis of the part to be printed.

[0082] The deformation Q of the outward flange is detected by measuring tools. If it meets the technical requirements, no reinforcing rib is required. If it exceeds the technical requirements, a reinforcing rib is required.

[0083] The reinforcing ribs are parallel to the axis of the part to be printed.

[0084] S34. Import the length compensation coefficient and auxiliary support components into the three-dimensional digital model to obtain the corrected three-dimensional digital model;

[0085] First, retrieve the 3D model of the part to be printed, and then recalculate the lengths of the skin and core in the 3D digital model based on the length compensation coefficient.

[0086] It should be noted that when importing the length compensation coefficient, it is necessary to scale it up proportionally according to the length ratio between the test piece and the 3D model to ensure the accuracy of the length compensation.

[0087] Then, the designed support ribs are imported into the 3D model according to their corresponding positions;

[0088] If reinforcing ribs are required, they should be installed on the inner walls of the cavity areas at both ends of the part to be printed, with the reinforcing ribs arranged parallel to the axis of the part to be printed.

[0089] S4. Print the final part according to the printing parameters and the corrected 3D digital model;

[0090] The corrected 3D model obtained in step S3 is imported into the 3D printing equipment, and the printing parameters obtained in step S2 are also imported into the 3D printing equipment. The final part is then printed using the 3D printing equipment.

[0091] S5. Correct the shape of the official parts and perform post-processing.

[0092] S51. Install the alignment component on the formal part and clamp the formal part once using the alignment component;

[0093] Install the calibration components immediately after the official document is printed;

[0094] The alignment assembly includes a top plate, a bottom plate, and several fixing clips. During installation, the bottom plate is placed at the bottom, followed by the formal component placed on the bottom plate, with the supporting ribs on the formal component connected to the bottom plate; then the top plate is placed on the top surface of the core of the formal component.

[0095] Each fixing clip is arranged along the axial direction of the formal component. The fixing clip is in the form of a U-shaped or G-shaped structure, with one end face attached to the top plate and the other end face attached to the bottom plate, thereby clamping and fixing the formal component from the upper and lower sides.

[0096] The calibration assembly also includes several pressure blocks, each of which is arranged sequentially in the cavity section of the final part along the axial direction of the part to be printed, and each of the pressure blocks is respectively attached to the inner wall of the final part.

[0097] S52. Perform a heat treatment on the formal part at the first heat treatment temperature;

[0098] The temperature of the heating furnace is set as the first heating temperature, and the first heat treatment temperature is 95℃-100℃, with the specific temperature determined according to the actual working conditions.

[0099] After the furnace temperature stabilizes at the first heating temperature, the final part with the calibration components is placed into the furnace. It should be noted that, in order to better protect the final part, a pad is placed inside the furnace and the final part is placed on the pad.

[0100] Remove the final product after heating for 5-10 minutes;

[0101] S53. The formal part is clamped a second time using the alignment components;

[0102] After removing the original part, adjust the retaining clamp to further increase the clamping force to the maximum value.

[0103] The temperature of the heating furnace is then adjusted to the second heat treatment temperature, which is 135℃-145℃. The specific temperature is determined according to the actual working conditions.

[0104] S54. Perform a second heat treatment on the clamped part at the second heat treatment temperature.

[0105] Once the furnace temperature stabilizes at the second heat treatment temperature, place the final product back into the furnace and heat for 3-4 hours.

[0106] S55. Take out the final part after the second heat treatment and let it cool naturally to room temperature.

[0107] S56. Remove the alignment components, support ribs, and reinforcing ribs, and grind the outer surface of the final part.

[0108] If the parts are clamped in one go, the end face of the final product is very prone to cracking due to deformation. Clamping in stages can improve the protection of the final product and increase the success rate of printing on the first try.

[0109] Compared with the prior art, the test piece model in this application is derived from the three-dimensional model of the final part. Therefore, its structure is the same as that of the final part. At the same time, the test piece is similar to the part to be printed in appearance. Therefore, after the test piece is printed, it will also undergo deformation similar to that of the final part. By observing the deformation of the test piece, it is possible to quickly determine whether the test printing parameters can be applied to the printing of the final part. It is also convenient for those skilled in the art to correct the test printing parameters according to the deformation of the test piece until the molding quality of the test piece meets the requirements, thereby ensuring the accuracy and reliability of the printing parameters.

[0110] Meanwhile, compared with the final product, the test piece is smaller in size. Under the condition of a certain 3D printing speed, this application can effectively shorten the printing time and thus improve the verification efficiency. At the same time, compared with directly printing the final product, this application can also effectively reduce the production cost.

[0111] Secondly, by observing the deformation of the test piece, the length compensation coefficient can be calculated in a targeted manner. The 3D model can be corrected by the length compensation coefficient, so as to prepare for the strain of the later deformation in the initial design stage, thereby improving the one-time molding rate of the part and also improving the printing quality.

[0112] Finally, during the 3D model correction process, a support structure will be designed based on the corrected dimensions and structure to form a more reasonable support, which can effectively ensure the manufacturing accuracy of the parts and thus improve the printing quality of the parts.

[0113] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A 3D printing method for composite materials, characterized in that, Includes the following steps: The test piece model is extracted from the three-dimensional digital model of the part to be printed, and the test printing parameters are obtained based on the test piece model; Print test pieces according to the test printing parameters, and test the molding quality of the test pieces. If the molding quality is qualified, the test printing parameters are used as the printing parameters; otherwise, modify the test printing parameters until the molding quality of the printed test pieces is qualified. The process of detecting the dimensional parameters of the test piece, correcting the 3D digital model of the part to be printed based on the dimensional parameters, and obtaining the corrected 3D digital model of the part to be printed includes the following steps: measuring the actual length L of the test piece. 实际 and the deformation amount Q of the outer flange; based on the actual length L 实际 Calculate the length compensation coefficient of the part to be printed; based on the actual length L 实际 The deformation amount Q of the outer flange is used to design an auxiliary support scheme for the part to be printed: the length compensation coefficient and the auxiliary support component are imported into the three-dimensional digital model to obtain the corrected three-dimensional digital model; Print the final part according to the printing parameters and the corrected 3D digital model; Correct the shape of the final part and perform post-processing; When importing the length compensation coefficient, the model is enlarged proportionally based on the length ratio between the test piece and the 3D model. The expression for the compensation coefficient is K = L. 理论 / L 实际 -1, where L 理论 L represents the theoretical dimension of the part. 实际 The actual measured dimensions of the printed test specimen; The test piece model includes a skin (1) and a core (2). The length ratio of the skin (1) to the core (2) is the same in the test piece model and the part to be printed. The length ratio of the test piece model to the part to be printed is (0.25-0.35):

1. Both ends of the test piece model are stepped. Both ends of the skin (1) are provided with outward flanges (3).

2. The 3D printing method for composite materials according to claim 1, characterized in that, The actual length L 实际 Designing an auxiliary support scheme for the part to be printed includes the following steps: Based on the interval parameter and the actual length L 实际 Arrange a number of support ribs (4); wherein each of the support ribs (4) is arranged sequentially along the axial direction of the part to be printed; The thicknessing parameters are set for the skin according to the process requirements; Determine whether the deformation amount Q of the outer flange meets the requirements according to the technical requirements. If it does not meet the requirements, add several reinforcing ribs (5); wherein each of the reinforcing ribs (5) is parallel to the axis of the part to be printed.

3. The 3D printing method for composite materials according to claim 2, characterized in that, The correction of the formal part's shape and subsequent post-processing includes the following steps: A calibration component is installed on the final part, and the final part is clamped once by the calibration component; The workpiece is subjected to a heat treatment at the first heat treatment temperature. The final part is clamped a second time using the alignment components; The clamped parts are subjected to a second heat treatment at a second heat treatment temperature. Remove the final part after the second heat treatment and allow it to cool naturally to room temperature. Remove the alignment components, support ribs, and reinforcing ribs, and sand the outer surface of the final part.

4. The 3D printing method for composite materials according to claim 3, characterized in that, The alignment component includes a top plate (6), a bottom plate (7), and several fixing clips (8). The top plate (6) is attached to the top surface of the core (2) of the formal part. Each of the supporting ribs (4) is connected to the bottom plate (7). Along the axial direction of the formal part, each of the fixing clips (8) is arranged in sequence and clamps the top plate (6) and the bottom plate (7) respectively.

5. The 3D printing method for composite materials according to claim 4, characterized in that, The alignment component also includes several pressure blocks (9), each of which is arranged sequentially in the cavity section of the formal part along the axial direction of the formal part, and each of which is in contact with the inner wall of the formal part.

6. The 3D printing method for composite materials according to claim 3, characterized in that, The first heat treatment temperature is 95℃-100℃, and the heat treatment time is 5-10 min; the second heat treatment temperature is 135℃-145℃, and the heat treatment time is 3-4 h.

Images