Device and method for regulating and controlling in-situ performance of composite material in three-dimensional photocuring

Abstract

The invention provides a device and a method for regulating and controlling the in-situ performance of a composite material in three-dimensional photocuring. Real-time regulation and control on the microstructure orientation of the composite material can be realized in the photocuring 3D printing process. The existing photocuring additive manufacturing technology is improved, a set of microscopic particle orientation control system is integrated in the photocuring forming process, and the system is mainly composed of a scraper which can rotate by 360 degrees in a plane and can move in any direction. The microscopic particles are forced to be arranged in the moving direction of the scraper through shear stress formed by the scraper on the liquid resin in the moving process, and the purpose of controlling the orientation of the microscopic particles is achieved. According to the method, the performance of the composite material is regulated and controlled layer by layer in the photocuring process, so that personalized customization of structure and function integration of a printed product is achieved, and the method is based on a mature photocuring additive manufacturing technology, can be matched with an existing photocuring machine and has good compatibility.

Description

Technical Field

[0001] The invention belongs to the technical field of printers, and in particular relates to a device and method for in-situ performance control of composite materials in stereolithography. Background Art

[0002] Composite materials are widely used in high-tech fields such as industrial manufacturing, electronic equipment, and medical devices. They are usually composed of a base material and one or more filler materials. They have become a hot topic in smart material research because they combine the excellent properties of multiple materials and can respond quickly or adjust functions under external stimuli. The performance of composite materials directly depends on the internal microstructure, including microscopic parameters such as particle orientation, distribution, and interface bonding strength. At present, a variety of manufacturing processes have been developed, including mold casting, hot pressing sintering, lamination, and injection molding. However, most of these traditional processes rely on fixed mold molding or heated pressing, which can only achieve simple structures and it is difficult to effectively control the microstructure, and cannot meet the current high-performance, high-complexity composite material structure and functional requirements.

[0003] As an emerging manufacturing method, stereolithography additive manufacturing technology has brought new possibilities for the preparation of composite materials. Its basic principle is to use photosensitive resin to undergo polymerization reaction under the irradiation of a specific light source and quickly solidify and shape it. By precisely controlling the scanning path and exposure time of the light source, the light source solidifies the resin along the shape of the material cross section, and the three-dimensional structure of the set object is completed after stacking layer by layer. The photosensitive resin is used as a matrix and mixed with the filling material for a photocuring process to achieve photocuring additive manufacturing of composite materials. This method can achieve nanometer-level resolution through high focusing and precise control of the light source, ensuring high precision and detail fidelity in the molding process, thereby meeting the design requirements of composite materials for tiny structures and complex geometric shapes. Although this solution is simple and easy to implement and is applicable to almost any photocuring machine, there is currently no relevant technology that can regulate the microstructure of the composite material during the photocuring process to achieve the purpose of optimizing and regulating device performance. Summary of the invention

[0004] The purpose of the present invention is to provide a device and method for in-situ performance control of composite materials in stereolithography, improve the existing photocuring additive manufacturing technology, focus on adjusting the orientation of composite material particles through the synergistic effect of an external electric field or multi-physical field during the photocuring process, thereby guiding the directional arrangement of particles in the matrix during the layer-by-layer manufacturing process, and avoiding the sedimentation and aggregation of particles in the material, so as to achieve in-situ adjustment of the microstructure of the composite material. This solves the technical problem that the microstructure of the composite material cannot be controlled during the photocuring process in the prior art.

[0005] In order to solve the above technical problems, the specific technical solutions of the device and method for in-situ performance control of composite materials in stereolithography proposed by the present invention are as follows:

[0006] A device for in-situ performance control of composite materials in stereolithography, the device comprising a three-dimensional linear motion platform, a rotatable scraper, and a resin tank; the three-dimensional linear motion platform is fixed above the resin tank;

[0007] The three-dimensional linear motion platform is composed of a first linear motion rod, a second linear motion rod, a third linear motion rod and a fourth linear motion rod;

[0008] The first linear motion rod and the second linear motion rod are fixed on two opposite sides of the resin tank, and the lengths of the first linear motion rod and the second linear motion rod are equal to the side lengths of the resin tank where the first linear motion rod and the second linear motion rod are located, and the first linear motion rod and the second linear motion rod are parallel to each other;

[0009] The two ends of the third linear motion rod are respectively fixed to the motion blocks of the first linear motion rod and the second linear motion rod, and the third linear motion rod can move linearly along the linear motion slide bars of the first linear motion rod and the second linear motion rod through the motion blocks; the third linear motion rod is perpendicular to the first linear motion rod and the second linear motion rod, and the length of the third linear motion rod is equal to the length of the side of the resin tank perpendicular to the first linear motion rod and the second linear motion rod;

[0010] One end of the fourth linear motion rod is fixed on the motion block of the third linear motion rod, so that the length direction of the fourth linear motion rod is perpendicular to the plane formed by the first linear motion rod, the second linear motion rod and the third linear motion rod.

[0011] Furthermore, the rotatable scraper includes a scraper, a rotatable shaft and a servo motor; the scraper is fixed to one end of the rotatable shaft, and the other end of the rotatable shaft is connected to the servo motor.

[0012] Furthermore, the servo motor is fixed on the moving block of the fourth linear motion rod, the scraper, the rotatable shaft and the servo motor are kept in a straight line and parallel to the fourth linear motion rod, and the rotatable scraper moves linearly along the linear motion slide rod of the fourth linear motion rod.

[0013] Furthermore, the overall length of the rotatable scraper is such that when the moving block of the fourth linear motion rod moves to the lowermost position of the fourth linear motion rod, the bottom of the scraper just contacts the bottom of the resin tank.

[0014] The present invention also provides a method for in-situ performance control of composite materials in stereolithography, which is applied to an in-situ performance control device for composite materials in stereolithography. The method comprises the following steps:

[0015] Step S1: weighing particles and resin to prepare a composite resin, and pouring the prepared composite resin into a resin tank;

[0016] Step S2: setting printing parameters;

[0017] Step S3: The printer is ready to print a new layer of composite resin. The printing platform rises to a specified height. After the composite resin is leveled, the three-dimensional motion platform moves the scraper to the printing area and lowers the scraper to a set height.

[0018] Step S4: According to the set particle orientation, the scraper automatically adjusts the angle through the rotation of the servo motor and completely sweeps the designated area so that the particle orientation in the area reaches the preset orientation;

[0019] Step S5: the scraper exits the printing area, and the printing platform descends to a height of one layer;

[0020] Step S6: The laser starts working, scanning the cross-sectional profile of the object, and the printing of this layer is completed;

[0021] Repeat steps S3 to S6 to complete the in-situ performance control of the composite material during the photocuring additive manufacturing process.

[0022] Furthermore, step S1 includes the following steps:

[0023] Step S11: weighing particles and resin, with a mass ratio of particles / (particles+resin) of 0 to 35%, placing the weighed particles and resin into a container, and using a mechanical stirring device to fully stir the particles and resin at a speed of 3000 r / min for at least 20 minutes to obtain a stirred composite resin;

[0024] Step S12: placing the stirred composite resin in a vacuum chamber and leaving it to stand for at least 30 minutes to eliminate bubbles therein, thereby obtaining a composite resin;

[0025] Step S13: slowly pouring the composite resin into the resin tank.

[0026] Further, step S2 includes the following steps:

[0027] Step S21: according to the different mass ratios of particles and resin in the composite resin, the power of the laser is set. The single-point laser power range is 100-250Mw. For a scanning light-curing printer, the scanning speed also needs to be set. The speed range is 1mm-100mm / s.

[0028] Step S22: according to the performance requirements of the printed product, the orientation of each layer of particles is set, the orientation range is 0-360°, and the movement speed range of the scraper when adjusting the orientation of the particles is: 1-100 mm / s.

[0029] Furthermore, the height set in step S3 means that the scraper is immersed in the composite resin, and the distance between the bottom of the scraper and the resin tank should be smaller than the long axis of the particle.

[0030] Compared with the prior art, the present invention has the following beneficial technical effects:

[0031] (1) The present invention has no impact on the original light-curing workflow and can be adapted to any light-curing equipment. It only requires replacing the resin tank with a scraper device and resetting the printing parameters. It has the advantages of strong adaptability and low cost.

[0032] (2) Compared with traditional microstructure control methods (such as heat treatment), the method provided by the present invention is simpler and more efficient, and can control the microstructure of any shape, realize the integrated design and manufacturing of structure and function, and greatly improve the performance and functional performance of composite materials.

[0033] (3) The method of the present invention not only ensures the design freedom of the material in the macroscopic structure, but also can maintain the high-performance output and input of the material when manufacturing complex and precise geometric structures, which is beneficial to the integrated design and manufacturing needs of the structure and function of intelligent devices.

[0034] (4) The present invention realizes layer-by-layer regulation of the performance of composite materials during the photocuring process, thereby achieving personalized customization of the integrated structure and function of the printed product. Moreover, the present invention is based on mature photocuring additive manufacturing technology, so it can be adapted to existing photocuring machines and has good compatibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0036] Figure 1 It is a schematic diagram of the structure of the device for in-situ performance regulation of composite materials in stereolithography of the present invention.

[0037] Figure 2 It is a schematic diagram of the structure of the three-dimensional linear motion platform of the present invention.

[0038] Figure 3 It is a schematic diagram of the rotatable scraper structure of the present invention.

[0039] Figure 4 It is a schematic diagram of the execution results of the method for in-situ performance regulation of composite materials in stereolithography of the present invention.

[0040] Markings in the figure: 1-three-dimensional linear motion platform; 2-rotatable scraper; 3-resin tank; 4-printing platform; 11-first linear motion rod; 12-second linear motion rod; 13-third linear motion rod; 14-fourth linear motion rod; 21-scraper; 22-rotatable shaft; 23-servo motor. DETAILED DESCRIPTION

[0041] 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.

[0042] The stereolithography of the printer will have a short stay when each layer is formed. The rational use of the stay time to introduce external control factors will not affect the original printing process. Based on this principle, the present invention proposes a device for in-situ performance control of composite materials in stereolithography, which can adjust the particle orientation layer by layer during the stereolithography process.

[0043] like Figure 1 As shown, the device includes a three-dimensional linear motion platform 1, a rotatable scraper 2, and a resin tank 3; the three-dimensional linear motion platform 1 is fixed above the resin tank 3.

[0044] like Figure 2 As shown, the three-dimensional linear motion platform 1 is composed of a first linear motion rod 11, a second linear motion rod 12, a third linear motion rod 13 and a fourth linear motion rod 14. The first linear motion rod 11, the second linear motion rod 12, the third linear motion rod 13 and the fourth linear motion rod 14 have the same structure, and their structures are now described as linear motion rods, which include a linear motion bottom rod, an end, a linear motion slide bar and a motion block; an end is respectively arranged at the two end edges of the linear motion bottom rod, a linear motion slide bar is arranged above the linear motion bottom rod, and the two ends of the linear motion slide bar are connected to the two ends, and the motion block is arranged on the linear motion slide bar, and can move linearly along the linear motion slide bar on the linear motion slide bar.

[0045] The first linear motion rod 11 and the second linear motion rod 12 are fixed on two opposite sides of the resin tank 3, and the lengths of the first linear motion rod 11 and the second linear motion rod 12 are equal to the side lengths of the resin tank 3 where they are located, and the first linear motion rod 11 and the second linear motion rod 12 are parallel to each other. The two ends of the third linear motion rod 13 are respectively fixed on the moving blocks of the first linear motion rod 11 and the second linear motion rod 12, and the moving blocks enable the third linear motion rod 13 to move linearly along the linear motion slide bars of the first linear motion rod 11 and the second linear motion rod 12. The third linear motion rod 13 is perpendicular to the first linear motion rod 11 and the second linear motion rod 12, and the length of the third linear motion rod 13 is equal to the side length of the side of the resin tank 3 perpendicular to the first linear motion rod 11 and the second linear motion rod 12. One end of the fourth linear motion rod 14 is fixed on the moving block of the third linear motion rod 13, so that the length direction of the fourth linear motion rod 14 is perpendicular to the plane formed by the first linear motion rod 11, the second linear motion rod 12, and the third linear motion rod 13. The length of the fourth linear motion rod 14 is determined according to the specific light-curing printer, and is smaller than the vertical distance between the printing platform 4 and the bottom of the resin tank 3 after the printing platform 4 rises.

[0046] like Figure 3 As shown, the rotatable scraper 2 includes a scraper 21, a rotatable shaft 22 and a servo motor 23; the scraper 21 is fixed to one end of the rotatable shaft 22, and the other end of the rotatable shaft 22 is connected to the servo motor 23. The rotatable shaft 22 is driven to rotate by the connected servo motor 23. The servo motor 23 is fixed to the moving block of the fourth linear motion rod 14, and the scraper 21, the rotatable shaft 22 and the servo motor 23 are kept in a straight line and parallel to the fourth linear motion rod 14. The rotatable scraper 2 can move linearly (up and down) along the linear motion slide bar of the fourth linear motion rod 14, and the overall length of the rotatable scraper 2 is when the moving block of the fourth linear motion rod 14 moves to the lowermost position of the fourth linear motion rod 14, and the bottom of the scraper 21 just contacts the bottom of the resin tank 3.

[0047] The three-dimensional linear motion platform 1 can control the scraper to move in any direction within the two-dimensional plane of the printing area. The scraper can rotate 360 ​​degrees through the connected servo motor. The three-dimensional linear motion platform 1 is fixed on the resin tank of the pull-up light-curing printer. When working, keep the scraper immersed in the composite resin, and the distance between the bottom of the scraper and the resin tank should be less than the long axis of the particles (long strips). The superposition of the scraper's direction and the movement of the scraper in the two-dimensional plane can induce the directional flow of the resin in the area where the scraper passes, thereby generating shear force to make the particles in the resin arrange along the direction of the scraper's movement, so as to achieve the purpose of controlling the orientation of microscopic particles. After that, the laser scans the area where the adjustment is completed, and the particles can be adjusted layer by layer in situ.

[0048] Based on the above-mentioned device for in-situ performance control of composite materials in stereolithography, the present invention proposes a method for in-situ performance control of composite materials in stereolithography, the method comprising the following steps:

[0049] Step S1: weighing particles and resin to prepare composite resin.

[0050] Step S11: Weigh the particles and resin, the mass ratio of particles / (particles+resin) is 0-35%, put the weighed particles and resin into a container, and use a mechanical stirring device to fully stir the particles and resin at a speed of 3000r / min for at least 20 minutes to obtain a stirred composite resin. The specific stirring time can be adjusted according to the particle size. If the particles are at the micron scale, the particles need to be chemically modified to enhance their stability in the resin.

[0051] Step S12: Place the stirred composite resin in a vacuum chamber and let it stand for at least 30 minutes to eliminate bubbles therein, thereby obtaining a composite resin. The specific length of standing is adjusted according to different combinations of particles and resins. The resin particle mixture after stirring and standing should be a composite resin with uniform particle distribution and no bubbles.

[0052] Step S13: slowly pouring the composite resin into the resin tank.

[0053] Step S2: Setting printing parameters

[0054] Step S21: According to the different mass ratios of particles and resin in the composite resin, the power of the laser is set. The single-point laser power range is 100-250mW. For a scanning light-curing printer, the scanning speed also needs to be set. The speed range is 1mm-100mm / s. The basic principle is that the higher the particle content, the smaller the particles, the higher the laser power, and the slower the speed. Conversely, the lower the particle content, the larger the particles, the smaller the laser power, and the faster the speed.

[0055] Step S22: according to the performance requirements of the printed product, the orientation of each layer of particles is set, the orientation range is 0-360°, and the movement speed range of the scraper when adjusting the orientation of the particles is: 1-100mm / s, based on the fact that after the scraper moves, only the orientation of the particles in the scraped area follows the direction of the scraper movement, and does not affect the orientation of the particles in other areas.

[0056] The setting of specific parameters should refer to the microstructural characterization of the printed product. If the printed product is too large or solidification occurs in the non-printing area, the laser power needs to be reduced or the scanning speed needs to be increased. If the product cannot be formed or there are printing defects, the laser power needs to be increased or the scanning speed needs to be reduced.

[0057] Step S3: Figure 4As shown in a, the printer is ready to print a new layer of composite resin. The printing platform rises to a specified height. After the composite resin is leveled, the three-dimensional motion platform moves the scraper to the printing area and lowers the scraper to a set height. The set height means that the scraper is immersed in the composite resin, and the distance between the bottom of the scraper and the resin tank should be less than the long axis of the particle (long strip).

[0058] Step S4: Figure 4 As shown in b, according to the set particle orientation, the scraper automatically adjusts the angle through the rotation of the servo motor and completely sweeps the specified area so that the particle orientation in the area reaches the preset orientation.

[0059] Step S5: Figure 4 As shown in c in FIG. 1 , the scraper exits the printing area and the printing platform descends to a height of one layer.

[0060] Step S6: The laser starts working and scans the cross-sectional profile of the object, and the printing of this layer is completed.

[0061] By repeatedly performing steps S3 to S6, the in-situ performance regulation of the composite material during the photocuring additive manufacturing process can be completed.

[0062] For different resin matrices and filling materials, a series of key parameters need to be precisely controlled during the stereolithography additive manufacturing process to ensure the efficiency and accuracy of molding. Experimental optimization includes photocuring parameters such as laser power, exposure time, and scanning speed to ensure that the resin achieves the best curing effect under different material conditions. The movement speed and height of the scraper are also key control factors, especially in the case of highly filled materials, the scraper parameters directly affect the uniformity of the particles. Determining these parameter combinations through systematic experiments can effectively improve the molding efficiency and accuracy of different resins and filling materials during the photocuring process, providing reliable support for the precision manufacturing of composite materials.

[0063] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A device for in-situ performance control of composite materials in stereolithography, characterized in that: The device comprises a three-dimensional linear motion platform (1), a rotatable scraper (2), and a resin tank (3); the three-dimensional linear motion platform (1) is fixed above the resin tank (3); The three-dimensional linear motion platform (1) is composed of a first linear motion rod (11), a second linear motion rod (12), a third linear motion rod (13) and a fourth linear motion rod (14); The first linear motion rod (11) and the second linear motion rod (12) are fixed on two opposite sides of the resin tank (3), and the lengths of the first linear motion rod (11) and the second linear motion rod (12) are equal to the side lengths of the resin tank (3) where the first linear motion rod (11) and the second linear motion rod (12) are located, and the first linear motion rod (11) and the second linear motion rod (12) are parallel to each other; The two ends of the third linear motion rod (13) are respectively fixed on the motion blocks of the first linear motion rod (11) and the second linear motion rod (12), and the third linear motion rod (13) can move linearly along the linear motion slide bars of the first linear motion rod (11) and the second linear motion rod (12) through the motion blocks; the third linear motion rod (13) is perpendicular to the first linear motion rod (11) and the second linear motion rod (12), and the length of the third linear motion rod (13) is equal to the length of the side of the resin tank (3) perpendicular to the first linear motion rod (11) and the second linear motion rod (12); One end of the fourth linear motion rod (14) is fixed on the motion block of the third linear motion rod (13), so that the length direction of the fourth linear motion rod (14) is perpendicular to the plane formed by the first linear motion rod (11), the second linear motion rod (12) and the third linear motion rod (13).

2. The device for in-situ performance control of composite materials in stereolithography according to claim 1, characterized in that: The rotatable scraper (2) comprises a scraper (21), a rotatable shaft (22) and a servo motor (23); the scraper (21) is fixed to one end of the rotatable shaft (22), and the other end of the rotatable shaft (22) is connected to the servo motor (23).

3. The device for in-situ performance control of composite materials in stereolithography according to claim 2, characterized in that: The servo motor (23) is fixed on the moving block of the fourth linear motion rod (14); the scraper (21), the rotatable shaft (22) and the servo motor (23) are kept in a straight line and parallel to the fourth linear motion rod (14); the rotatable scraper (2) moves linearly along the linear motion slide rod of the fourth linear motion rod (14).

4. The device for in-situ performance control of composite materials in stereolithography according to claim 3, characterized in that: The overall length of the rotatable scraper (2) is such that when the moving block of the fourth linear motion rod (14) moves to the lowest end position of the fourth linear motion rod (14), the bottom of the scraper (21) just contacts the bottom of the resin tank (3).

5. A method for in-situ performance control of composite materials in stereolithography, characterized in that: The device for in-situ performance control of composite materials in stereolithography as claimed in any one of claims 1 to 4 comprises the following steps: Step S1: weighing particles and resin to prepare a composite resin, and pouring the prepared composite resin into a resin tank; Step S2: setting printing parameters; Step S3: The printer is ready to print a new layer of composite resin. The printing platform rises to a specified height. After the composite resin is leveled, the three-dimensional motion platform moves the scraper to the printing area and lowers the scraper to a set height. Step S4: According to the set particle orientation, the scraper automatically adjusts the angle through the rotation of the servo motor and completely sweeps the designated area so that the particle orientation in the area reaches the preset orientation; Step S5: the scraper exits the printing area, and the printing platform descends to a height of one layer; Step S6: The laser starts working, scanning the cross-sectional profile of the object, and the printing of this layer is completed; Repeat steps S3 to S6 to complete the in-situ performance control of the composite material during the photocuring additive manufacturing process.

6. The method for in-situ performance control of composite materials in stereolithography according to claim 5, characterized in that: Step S1 includes the following steps: Step S11: weighing particles and resin, with a mass ratio of particles / (particles+resin) of 0 to 35%, placing the weighed particles and resin into a container, and using a mechanical stirring device to fully stir the particles and resin at a speed of 3000 r / min for at least 20 minutes to obtain a stirred composite resin; Step S12: placing the stirred composite resin in a vacuum chamber and leaving it to stand for at least 30 minutes to eliminate bubbles therein, thereby obtaining a composite resin; Step S13: slowly pouring the composite resin into the resin tank.

7. The method for in-situ performance control of composite materials in stereolithography according to claim 5, characterized in that: Step S2 includes the following steps: Step S21: according to the different mass ratios of particles and resin in the composite resin, the power of the laser is set. The single-point laser power range is 100-250Mw. For a scanning light-curing printer, the scanning speed also needs to be set. The speed range is 1mm-100mm / s. Step S22: according to the performance requirements of the printed product, the orientation of each layer of particles is set, the orientation range is 0-360°, and the movement speed range of the scraper when adjusting the orientation of the particles is: 1-100 mm / s.

8. The method for in-situ performance control of composite materials in stereolithography according to claim 5, characterized in that: The height set in step S3 means that the scraper is immersed in the composite resin, and the distance between the bottom of the scraper and the resin tank should be smaller than the long axis of the particle.

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