Additive manufacturing system

Abstract

The utility model provides an additive manufacturing system. The additive manufacturing system comprises a powder supply device used for supplying powder materials; a molding device configured to accommodate the powder material from the powder supply device and provide a space for printing the powder material into a workpiece; the apparatus includes a forming device configured to form a powder material, an energy source configured to selectively apply an energy beam to the powder material in the forming device so as to print the powder material, and an electric field force applying device configured to apply an electric field force to the powder material in the forming device in a predetermined direction. According to the additive manufacturing system, the electric field force applying device can be used for selectively applying the electric field force to the powder material, so that the controlled vector force is provided, and the industrial applicability of the additive manufacturing system is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of additive manufacturing, in particular to an additive manufacturing system for performing additive manufacturing by melting and stacking materials layer by layer. Background Art

[0002] Additive layer manufacturing (ALM) technology is a technology that first uses a computer to design a product and then prints it out with a printer. In computer design, the product to be formed is modeled, and then the workpiece model of the product is stored in the computer for subsequent printing. During the printing process, an energy source (for example, a laser beam, electron beam, plasma or ion beam) is used to accumulate and print (i.e., melt and accumulate) the material layer by layer until the final 3D product is formed. Additive manufacturing is also commonly referred to as 3D printing. Additive manufacturing is particularly suitable for the manufacture of metal parts with complex shapes or special structures in the aerospace industry.

[0003] In the additive manufacturing process, materials are deposited layer by layer, and subsequent material layers need to be deposited on previously formed material layers. When the workpiece to be printed has an overhanging structure that is inclined relative to the horizontal direction, if the inclination angle is greater than the critical angle (usually 45°), it can be self-supported by the formed powder material to form the desired overhanging structure. On the other hand, if the inclination angle of the overhanging structure to be printed is less than the critical angle of the material, the solid powder material in the lower layer cannot provide sufficient support for the heated and molten powder droplets, causing the processed workpiece to collapse or deform easily, which seriously affects the quality of the processed workpiece.

[0004] In order to solve the above problems, existing additive manufacturing technology usually prints the supporting structure while printing the above-mentioned overhanging structure, and the supporting structure provides support for the overhanging structure. However, printing such a supporting structure consumes a lot of resources, such as raw materials, printing time and energy. In addition, after printing, post-processing is required to remove the supporting structure, which will lead to poor surface quality between the supporting structure and the workpiece, reduced printing efficiency, and long post-processing time.

[0005] Furthermore, existing additive manufacturing systems utilize gravity to cause subsequently printed layers of material to be deposited on top of previously printed layers of material, but in reduced gravity environments (e.g., in microgravity or zero gravity environments), existing additive manufacturing systems do not function properly. Utility Model Content

[0006] One object of the present disclosure is to reduce the application limitations of an additive manufacturing system and improve the industrial applicability of the additive manufacturing system.

[0007] Another object of the present disclosure is to provide an additive manufacturing system that can reduce processing costs, reduce processing time, and improve processing quality.

[0008] Yet another object of the present disclosure is to provide an additive manufacturing system that can be used in a reduced gravity environment.

[0009] According to one aspect of the present disclosure, an additive manufacturing system is provided. The additive manufacturing system includes: a powder supply device, the powder supply device is used to supply powder material; a molding device, the molding device is configured to accommodate the powder material from the powder supply device and provide a space for printing the powder material into a workpiece; an energy source, the energy source is configured to selectively apply an energy beam to the powder material in the molding device for printing; and an electric field force applying device, the electric field force applying device is configured to apply an electric field force to the powder material in the molding device along a predetermined direction.

[0010] According to one aspect of the present disclosure, the electric field force applying device includes an electric field generating device and a power source, wherein the power source is connected to the forming device to charge the powder material in the forming device, and the electric field generating device includes a first electrode plate and a second electrode plate opposite to each other and with opposite polarities to generate an electric field between the first electrode plate and the second electrode plate.

[0011] According to one aspect of the present disclosure, the first electrode plate and the second electrode plate extend in a vertical direction and are spaced apart from each other in a horizontal direction, so that the electric field force applying device applies an electric field force in a horizontal direction to the powder material.

[0012] According to one aspect of the present disclosure, the forming device is arranged between the first electrode plate and the second electrode plate, and the heights of the first electrode plate and the second electrode plate in the vertical direction are greater than the height of the forming device in the vertical direction.

[0013] According to one aspect of the present disclosure, the first electrode plate and the second electrode plate extend in a horizontal direction and are spaced apart from each other in a vertical direction, so that the electric field force applying device applies an electric field force in a vertical direction to the powder material.

[0014] According to one aspect of the present disclosure, the forming device is arranged between the first electrode plate and the second electrode plate, and the lengths of the first electrode plate and the second electrode plate in the horizontal direction are greater than the length of the forming device in the horizontal direction.

[0015] According to one aspect of the present disclosure, the electric field generating device also includes a third electrode plate and a fourth electrode plate opposite to each other and with opposite polarities, the third electrode plate and the fourth electrode plate extend in the horizontal direction and are spaced apart from each other in the vertical direction, so that the electric field force applying device also applies an electric field force in the vertical direction to the powder material.

[0016] According to one aspect of the present disclosure, the molding device includes a base plate for supporting a powder material contained in the molding device and the base plate is movable in a vertical direction, and the power source is connected to the base plate.

[0017] According to the additive manufacturing system of the present application, an electric field force applying device can be used to selectively apply electric field force to the powder material to provide a controlled vector force, so that the additive manufacturing system can be suitable for various usage environments and / or process workpieces of various complex structures, thereby improving the industrial applicability of the additive manufacturing system.

[0018] Other advantages and features of the present invention will become apparent from the following non-limiting detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The features and advantages of one or more embodiments of the present invention will become more easily understood through the following description with reference to the accompanying drawings, in which:

[0020] Figure 1 is a cross-sectional schematic diagram of an additive manufacturing system according to a first embodiment of the present application;

[0021] Figure 2a It is a schematic diagram of the end face of a workpiece printed according to an existing additive manufacturing system; Figure 2b is a schematic diagram of an end face of a workpiece printed by an additive manufacturing system according to the first embodiment of the present application;

[0022] Figure 3a-3c is a force analysis diagram of powder particles for different areas to be formed in the additive manufacturing system according to the first embodiment of the present application;

[0023] Figure 4 is a schematic cross-sectional view of an additive manufacturing system according to a second embodiment of the present application;

[0024] Figure 5 is a schematic cross-sectional view of an additive manufacturing system according to a third embodiment of the present application; and

[0025] Figure 6a and Figure 6b is a flow chart of an additive manufacturing method according to an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0026] The utility model is described in detail below with reference to the accompanying drawings and with the aid of embodiments. The following detailed description of the utility model is only for illustrative purposes and is by no means a limitation of the utility model and its application or use. In all the drawings, corresponding reference numerals represent corresponding parts.

[0027] Embodiments are provided herein so that the present disclosure will be thorough and will fully convey the scope to those skilled in the art. Many specific details such as examples of specific components, devices and methods are set forth to provide a thorough understanding of the embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be adopted, and the embodiments can be implemented in many different forms and should not be construed as limiting the scope of the present disclosure. In some embodiments, known methods, known device structures and known technologies are no longer described in detail.

[0028] Although the terms first, second, third, etc. can be used in this article to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another element, component, region, layer or section. Unless the context clearly indicates, terms such as "first", "second" and other numerical terms do not mean order or sequence when used in this article. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the embodiment.

[0029] The directional words mentioned in this article, such as "up, down, left, right", refer to the directions observed on the drawings for the purpose of description, and do not limit the present invention, unless otherwise clearly stated in this article.

[0030] The following will refer to Figure 1 To describe the additive manufacturing system 10 according to the first embodiment of the present application. It should be understood that Figure 1 The additive manufacturing system 10 schematically shown in FIG. 1 is for illustrative purposes only and is not intended to limit the specific structure of the additive manufacturing system according to the present application.

[0031] See also Figure 1 The additive manufacturing system 10 may include a powder supply device 100 , a molding device 200 , an energy source 300 , an electric field force applying device 400 , and a controller 500 .

[0032] The powder supply device 100 may be configured to supply powder material to the molding device 200. For example, the powder material may include metal powder. Figure 1As shown, the powder supply device 100 may include a powder storage device 110 for storing powder material and a conveying device 120 for conveying the powder material from the powder storage device 110 to the forming device 200. The powder storage device 110 may include a piston rod 112 configured to move up and down. The conveying device 120 may include a conveying roller that can move in a horizontal direction.

[0033] When powder material needs to be supplied, first, the piston rod 112 of the powder storage device 110 moves along the Figure 1 The conveying device 120 moves upward in the direction indicated by the arrow A in the figure so that the powder material protrudes to the outside of the upper edge of the powder storage device 110. Then, the conveying device 120 is moved from one end ( Figure 1 The left end of the molding device 200 is moved in the direction indicated by arrow B to the other end ( Figure 1 The conveying device 120 is connected to the molding device 200 from the other end ( Figure 1 The right end in the middle) returns in the direction opposite to the arrow B to the end ( Figure 1 ), so that the powder material is evenly spread on the top of the molding device 200.

[0034] It should be understood that the configuration of the powder supply device 100 should not be limited to Figure 1 The specific examples shown in the figure can be changed as long as the functions described in the text can be achieved. For example, the powder supply device can also include a powder supply funnel arranged above the molding device 200 to evenly spray the powder material into the molding device.

[0035] After the delivered powder material reaches a predetermined thickness, the energy source 300 can selectively apply an energy beam to the powder material in the molding device 200 according to the workpiece model to melt the powder material and then solidify to print a layer to form the workpiece. Figure 1 In the example of FIG. 3 , the energy source 300 may include a laser 310 for emitting a laser beam and a light shaping device 320 for shaping the laser beam. The laser beam shaped by the light shaping device 320 has the desired light characteristics, spot size or shape, etc. However, it should be understood that the energy source should not be limited to Figure 1 The specific examples shown in the drawings can be changed as long as the functions described in this article can be achieved. For example, the energy source can also generate an energy source for electron beams, plasma or ion beams.

[0036] The molding device 200 is configured to receive the powder material from the powder supply device 100 and provide a space for printing the powder material into a workpiece. The molding device 200 may include a base plate 210 configured to support the powder material received in the molding device 200 and to be able to move up and down in a vertical direction. After a layer of the workpiece is printed and formed, the base plate 210 may be moved along the vertical direction. Figure 1 The powder material is then dropped in the vertical direction indicated by the arrow C in the figure, for example, by a height corresponding to the thickness of the next layer of the workpiece to be printed. Then, the powder feeding device 100 again delivers the powder material to the top of the molding device 200, and thereafter the above molding process is repeated to print the next layer of the molded workpiece. As the workpiece is molded layer by layer, the piston rod 112 of the powder feeding device 100 moves upward in the direction of the arrow A, the base plate 210 of the molding device 200 moves downward in the direction of the arrow C, and the workpiece is manufactured layer by layer in the upward direction indicated by the arrow D.

[0037] The electric field force applying device 400 may be configured to apply an electric field force (also referred to as Coulomb force) to the powder material in the molding cavity 200 along a predetermined direction. The electric field force applying device 400 may include a power source 410 and an electric field generating device 420. The power source 410 may be connected to the molding device 200 to charge the powder material in the molding cavity. Figure 1 The power source 410 is exemplarily shown to make the powder particles in the molding device 200 positively charged. Preferably, the power source 410 can be connected to the substrate 210 of the molding device 200 to always provide a sufficient charge conduction area during the process of the substrate 210 moving up and down. The electric field generating device 420 may include a first electrode plate 422 and a second electrode plate 424 that are opposite to each other and have opposite polarities to generate an electric field between the first electrode plate 422 and the second electrode plate 424. For example, as Figure 1 As shown, the first electrode plate 422 and the second electrode plate 424 may have positive polarity and negative polarity respectively by being connected to an external power source respectively.

[0038] like Figure 1 As exemplarily shown in FIG. 4 , the first electrode plate 422 and the second electrode plate 424 may extend in the vertical direction and be spaced apart from each other in the horizontal direction, so that a horizontal electric field force F1 may be applied to the powder material. Figure 1 As shown, the molding device 200 can be arranged between the first electrode plate 422 and the second electrode plate 424, and the height of the first electrode plate 422 and the second electrode plate 424 in the vertical direction is greater than the height of the molding device 200 in the vertical direction, so that the powder material in the entire molding device 200 is subjected to uniform electric field force.

[0039] In the existing additive manufacturing process, if the forming angle between the forming direction and the vertical direction of the workpiece to be processed is less than 135 degrees (that is, the inclination angle between the forming direction and the horizontal direction is less than 45 degrees), the solid powder material in the lower layer cannot provide sufficient support for the heated and molten powder droplets, which causes the processed workpiece to sag or deform easily, thus seriously affecting the quality of the processed workpiece. Therefore, the 45-degree angle principle is well known in additive manufacturing technology. Once the inclination angle is less than 45 degrees, it is necessary to add a support structure to the workpiece during the additive manufacturing process, otherwise the workpiece will be deformed or even unable to be printed normally.

[0040] Figure 2a It is a schematic diagram of the end face of a workpiece printed according to an existing additive manufacturing system; Figure 2b is a schematic diagram of the end face of a workpiece printed by the additive manufacturing system according to the first embodiment of the present application. Figure 2a As shown, the workpiece may include a first forming area A, a second forming area B and a third forming area C. The inclination angle Z between the second forming area B and the third forming area C and the horizontal direction is less than 45 degrees. When printing these areas, it is necessary to simultaneously print a support structure S to support the powder material. Otherwise, the powder material in the overhanging part will sink under the action of gravity during the printing process, causing quality defects. However, the presence of the support structure will reduce the surface quality of the workpiece, and removing the support structure requires a complex post-processing process. In addition, printing such a support structure will also cause consumption of raw materials, printing time and energy. Therefore, the support structure is considered to be a technical problem that is difficult to overcome in additive manufacturing.

[0041] In comparison, reference Figure 2b , using the additive manufacturing system according to the first embodiment of the present application, the second forming area B and the third forming area C can be printed without using a support structure, and the electric field force can be applied to the powder material by the electric field force applying device 400 to provide a controlled vector force, so that the second forming area B and the third forming area C can be printed and manufactured without support. Specifically, the electric field force applying device 400 can apply a horizontal electric field force to the powder particles, so that the powder particles are subjected to the combined force of the horizontal electric field force and gravity, and the angle between the direction of the combined force on the powder particles and the forming direction is greater than a preset angle threshold.

[0042] Preferably, the additive manufacturing system 10 may further include a controller 500, which may be connected to the electric field force applying device 400, and may also communicate with the electric field force applying device 400 wirelessly. The controller 500 may be configured to determine the forming direction of the to-be-formed region of the workpiece based on the model of the workpiece and control the electric field force applying device 400 according to the forming direction. Figure 1As shown, the workpiece may include a first area to be formed P, a second area to be formed Q and a third area to be formed R. Figure 1 as well as Figure 3a-3c , the first area to be formed P has a first forming direction along the arrow p, and the controller 500 can determine the first forming angle α between the first forming direction and the gravity direction to be 180 degrees based on the workpiece model. The second area to be formed Q has a second forming direction along the arrow q, and the controller 500 can determine the second forming angle β between the second forming direction and the gravity direction to be 130 degrees based on the workpiece model. The third area to be formed R has a third forming direction along the arrow r, and the controller 500 can determine the third forming angle δ between the third forming direction and the gravity direction to be 130 degrees based on the workpiece model.

[0043] Further, the controller 500 may be configured to set the area to be processed as a sagging area and activate the electric field force applying device 400 when the forming angle is less than a preset angle threshold. The preset angle threshold may be, for example, 135 degrees. Of course, the angle threshold may vary within a certain range according to factors such as the type of powder material.

[0044] Specifically, the controller 500 determines that the first forming angle α is greater than the angle threshold of 135 degrees, and the electric field force applying device is not enabled to process the first area to be formed P. The controller determines that the second forming angle β and the third forming angle δ are less than the angle threshold of 135 degrees. Therefore, the second area to be formed Q and the third area to be formed R are set as sagging areas and the electric field force applying device is enabled to process the second area to be formed Q and the third area to be formed R.

[0045] Therefore, when processing the second to-be-formed area Q and the second to-be-formed area R, the electric field force applying device 400 is used. At this time, the power source 410 charges the powder material in the molding cavity 200 through the substrate 210; and the electric field applying device 420 applies a horizontal electric field force to the charged powder material. As a result, the powder material is subjected to the combined force of the horizontal electric field force F1 and the vertical downward gravity G.

[0046] Furthermore, the controller 500 may control the horizontal electric force applied by the electric field force applying device 400 so that the angle between the direction of the resultant force acting on the powder material and the forming direction is greater than a preset angle threshold, such as 135 degrees.

[0047] Figure 3bIt is exemplarily shown that the second forming direction indicated by arrow q can be tilted to the left. At this time, the first electrode plate 422 on the left side can be made positive and the second electrode plate 424 on the right side can be made negative, so as to apply a horizontal rightward electric field force F1 to the powder material, and the horizontal rightward electric field force F1 causes the direction of the resultant force F2 on the powder material to deflect to the right by an angle Ω relative to the gravity direction, and the field strength of the electric field force applying device 400 is adjusted so that the sum of the second forming angle β and the deflection angle Ω is greater than 135 degrees. FIG3 also exemplarily shows that the third forming direction indicated by the arrow r can be tilted to the right. Therefore, when processing the third area to be formed R, the polarity of the two electrode plates can be changed, so that the first electrode plate 422 on the left has a negative polarity and the second electrode plate 424 on the right has a positive polarity, thereby applying a horizontal leftward electric field force F1' to the powder material. The horizontal leftward electric field force F1' causes the direction of the resultant force F2' on the powder material to deflect to the left by an angle Ω' relative to the gravity direction. The field strength of the electric field force applying device 400 is adjusted so that the sum of the third forming angle δ and the deflection angle Ω' is greater than 135 degrees. In this way, even when printing the sagging area where a support structure must be used in the prior art, the heated and molten powder droplets can be stably supported on the solid powder particles of the lower layer, supported by the powder material itself without the need for an additional support structure, thereby enabling additive manufacturing of more complex workpieces, and significantly reducing manufacturing costs, improving manufacturing efficiency and workpiece quality.

[0048] According to the first embodiment of the present application, the additive manufacturing system can print and manufacture workpieces with overhanging structures without support, and can even print and manufacture overhanging structures with an inclination angle close to 0°. This unsupported additive manufacturing technology can overcome the limitations of the 45-degree rule, improve the design freedom of metal additive manufacturing, allow designers to build processing models more freely, print and manufacture workpieces with more complex structures, improve the industrial applicability of the additive manufacturing system, and this unsupported additive manufacturing technology can also shorten processing time, reduce processing costs, and improve the forming quality of workpieces.

[0049] Despite Figure 1 The electric field force applying device 400 is exemplarily shown to include a first electrode plate 422 and a second electrode plate 424 extending in the vertical direction, but it should be understood that the electric field force applying device 400 should not be limited to Figure 1 The specific example shown in , but can be changed, as long as it can make the angle between the direction of the resultant force on the powder material and the forming direction greater than the angle threshold, for example, the first electrode plate 422 and the second electrode plate 424 can also be inclined at a certain angle relative to the vertical direction. Preferably, the following is adopted Figure 1The electric field force applying device 400 shown can manufacture a suspension structure with a larger angle range, and can even manufacture a suspension structure with an inclination angle close to 0°.

[0050] In addition, although the above description exemplarily describes that the electric field force applying device is controlled by the controller 500, it should be understood that the present disclosure is not limited to this. The controller 500 may be omitted and the switch of the electric field force applying device may be manually operated. For example, the required maximum electric field force may be calculated in advance and the operator may manually turn on the switch according to whether the printed workpiece is in a sagging area so that the electric field force applying device applies the electric field force for processing the workpiece.

[0051] In addition, preferably, the controller 500 can also be configured to use the electric field force applying device 400 to apply a layer-by-layer increasing electric field force to the powder material during a predetermined time period, and the predetermined time period can correspond to multiple layers before continuously printing the first layer of the second area Q to be formed and the time required to print the first layer.

[0052] Reference Figure 1 , according to the model of the workpiece, the second area to be formed Q is set as a sagging area and the first area to be formed P needs to be printed before printing the second area to be formed Q. Exemplarily, during the printing of the 9 layers before the first layer of the second area to be formed Q (i.e., the first to the ninth last layer of the first area to be formed P) and the first layer of the second area to be formed Q, an electric field that increases layer by layer is applied to the powder material by the electric field force applying device 400. Specifically, as shown in Table 1 below (the first area to be formed P and the second area to be formed Q are referred to as P and Q, respectively, in Table 1), the electric field strength applied when printing the ninth last layer of the first area to be formed P is 5N / C, at which time the direction of the combined force of the horizontal electric field force and gravity on the powder particles is deflected by 1 degree relative to the vertical direction; the electric field strength applied when printing the eighth last layer of the first area to be formed P is 10N / C, at which time the direction of the combined force of the horizontal electric field force and gravity on the powder particles is deflected by 2 degrees relative to the vertical direction; By analogy, when printing the last layer of the first area to be formed P, the electric field strength applied is 45N / C, at which time the direction of the combined force of the horizontal electric field force and gravity on the powder particles is deflected 9 degrees relative to the vertical direction; when printing the first layer of the second area to be formed Q, the electric field strength applied is 50N / C, at which time the direction of the combined force of the horizontal electric field force and gravity on the powder particles is deflected 10 degrees relative to the vertical direction, and during the printing of other layers of the second area to be formed Q, the field strength is maintained to apply a uniform electric field force to the powder material. Therefore, during the printing of the entire second forming area Q, the angle between the combined force direction of the powder material and the forming direction increases from the original 130 degrees by 10 degrees and remains at 140 degrees, which is greater than the threshold angle of 135 degrees.

[0053] Table 1: Electric field forces used for different layers

[0054]

[0055]

[0056] In this way, by gradually applying an electric field force that increases layer by layer, it is possible to prevent the powder material from undergoing significant horizontal movement when it is suddenly subjected to a sharply increased electric field force, thereby improving the forming quality of the additively manufactured workpiece.

[0057] Preferably, the additive manufacturing system 10 may further include a thickness detector 600, and the controller 500 may be connected to the thickness detector and the energy source or communicate with the thickness detector and the energy source wirelessly. Exemplarily, the thickness detector 600 may include a time of flight (TOF) camera, and the deposition thickness of the powder material at different positions may be obtained by the TOF camera. The thickness detector 600 is configured to detect the deposition thickness of multiple spaced-apart positions of the powder material used to form the workpiece in the forming device 200, and the controller 500 may adjust the energy size of the energy beam according to the detected deposition thickness. For example, when printing the first layer of the second area to be formed Q, multiple positions of the powder material used to form the first layer in the forming device 200 may be detected to obtain the deposition thickness of the powder material at different positions of the first layer. The controller 500 may cause the energy source to emit a larger energy beam to the thicker area and a smaller energy beam to the thinner area according to the size of the deposition thickness.

[0058] In this way, even if the powder material undergoes some displacement under the action of the horizontal electric field force so that the deposition thickness of the same layer is uneven, such uneven deposition layer can be accommodated by applying an adjustable energy beam.

[0059] According to the following Figure 4 , the additive manufacturing system according to the second embodiment of the present application is described in detail. The structure of the additive manufacturing system 10A of the second embodiment of the present application is substantially the same as that of the additive manufacturing system 10 of the first embodiment of the present application, and the only difference is that the arrangement of the electric field applying device is different.

[0060] like Figure 4As shown, the electric field generating device 420A of the additive manufacturing system 10A may include a first electrode plate 422A and a second electrode plate 424A that are opposite to each other and have opposite polarities, and the first electrode plate 422A and the second electrode plate 424A extend in the horizontal direction and are spaced apart from each other in the vertical direction, so that an electric field force F3 in the vertical direction can be applied to the powder material. Preferably, the molding device 200 may be arranged between the first electrode plate 422A and the second electrode plate 424A, and the length of the first electrode plate 422A and the second electrode plate 424A in the horizontal direction is greater than the length of the molding device 200 in the horizontal direction, so that the entire molding device 200 is subjected to a uniform electric field force.

[0061] In an environment with reduced gravity, the electric field force applying device 400A of the additive manufacturing system 10A charges the powder material using the power supply 410. The electric field generating device 420A applies a vertical downward electric field force F3 to the charged powder material, and under the action of the electric field force, the subsequently formed material layer is deposited on the previously formed material layer, thereby constructing the desired workpiece layer by layer.

[0062] The additive manufacturing system according to the second embodiment of the present application can overcome the problem that the existing additive manufacturing system cannot work in an environment with reduced gravity, broaden the application scenarios of the additive manufacturing system, and improve the industrial applicability of the additive manufacturing system.

[0063] According to the following Figure 5 , the additive manufacturing system according to the third embodiment of the present application is described in detail. The structure of the additive manufacturing system 10B of the third embodiment of the present application is substantially the same as that of the additive manufacturing system 10 of the first embodiment of the present application, and the only difference is that the arrangement of the electric field applying device is different.

[0064] like Figure 5 As shown, the electric field generating device 420B of the additive manufacturing system 10B may include two groups of electrode plates. The first group of electrode plates includes a first electrode plate 422B and a second electrode plate 424B that are opposite to each other and have opposite polarities. The first electrode plate 422B and the second electrode plate 424B extend in the vertical direction and are spaced apart from each other in the horizontal direction, so that a horizontal electric field force can be applied to the powder material. The second group of electrode plates includes a third electrode plate 426B and a fourth electrode plate 428B that are opposite to each other and have opposite polarities. The third electrode plate 426B and the fourth electrode plate 428B extend in the horizontal direction and are spaced apart from each other in the vertical direction, so that a vertical electric field force can be applied to the powder material.

[0065] The additive manufacturing system 10B according to the third embodiment of the present application can have the functions of both the additive manufacturing system 10 according to the first embodiment of the present application and the additive manufacturing system 10A according to the second embodiment of the present application. That is to say, the additive manufacturing system 10B can select different usage modes according to the usage conditions, so that it can print and manufacture workpieces with overhanging structures without support, and can even print and manufacture overhanging structures with an inclination angle close to 0°, and can also realize additive manufacturing in an environment with reduced gravity, which further improves the industrial applicability of the additive manufacturing system.

[0066] Next, we will refer to Figure 6a and Figure 6b An additive manufacturing method according to an embodiment of the present disclosure is described.

[0067] See also Figure 6a The additive manufacturing method may include the following steps: using a powder supply device 100 to supply powder material to a molding device 200 (step S10); using an electric field force applying device to apply an electric field force to the powder material (step S20); and using an energy beam to print the powder material (step S30).

[0068] In a preferred embodiment, step S20 may include: calculating a forming angle between a forming direction and a vertical direction of a to-be-formed area of ​​the workpiece based on a model of the workpiece (step S21); comparing the forming angle with a preset angle threshold (step S22); setting the to-be-formed area having a forming angle less than or equal to the angle threshold as a drooping area (step S23); applying an electric field force to the powder material when printing the drooping area, and controlling the electric field force so that the angle between the direction of the resultant force of gravity and the electric field force acting on the powder material and the forming direction is greater than the angle threshold (step S25).

[0069] Preferably, step S20 may further include step S24: during the continuous printing of the plurality of layers before the first layer of the sagging area and during the first layer, applying an electric field force that increases layer by layer to the powder material, wherein the maximum value of the electric field force is the first electric field force. Furthermore, during the printing of the sagging area, the first electric field force may be uniformly applied to the powder material.

[0070] Preferably, step S20 may further include step S30': detecting the deposition thickness of a plurality of positions of the powder material for the workpiece spaced apart in a horizontal direction, and adjusting the energy of the energy beam according to the deposition thickness.

[0071] In another embodiment, see Figure 6bThe additive manufacturing method may include the following steps: using the powder supply device 100 to supply powder material to the molding device 200 (step S10); using the electric field force applying device to apply a vertical downward electric field force to the powder material (step S20A); and using an energy beam to print the powder material (step S30).

[0072] It should be understood that the additive manufacturing method according to the present disclosure should not be limited to the specific examples described herein or shown in the drawings, but can be changed. For example, steps can be added, steps can be omitted, the order of each step can be changed, etc. according to actual needs.

[0073] Example 1

[0074] The diameter is 20-80μm (average diameter is 50μm) and the density is 4.51g / cm 3 The titanium alloy TC4 is used as powder material to manufacture the second to-be-formed region Q of the workpiece in the additive manufacturing system according to the first embodiment of the present application. The mass of the heavier TC4 powder particles with a diameter of 80 μm is m=1.21*10 -6 kg, assuming g is 9.8N / kg and the deflection angle Ω is 10 degrees, then the electric field force F1 = m*g*tanΩ = 2.09*10 -6 N. The strength of the applied uniform electric field is E1 = 50 N / C, so the charge of each powder particle should be 4.17*10 -8 C. Assuming that the total volume of the powder material contained in the molding device is 40cm*40cm*20cm, the charge of each powder particle is 4.17*10 -8 C, the total amount of electricity required to charge the powder material should be about 21,000C (about 1.3kWh).

[0075] Example 2

[0076] The diameter is 20-80μm (average diameter is 50μm) and the density is 4.51g / cm 3 The titanium alloy TC4 is used as powder material to manufacture workpieces in the additive manufacturing system according to the second embodiment of the present application. In an environment with reduced gravity, the powder material can be normally stacked layer by layer when subjected to about 1 / 10 of the gravity. Therefore, the electric field force required for the powder material is F2 = 10% * m * g. Then in a uniform electric field with a field strength of E2 = 50N / C, for a TC4 powder particle with a diameter of 80μm, the charge should be Q = 2.4*10 -8 C. Assuming that the total volume of the powder material contained in the molding device is 40cm*40cm*20cm, the charge of each particle is 2.4*10 -8C, the total amount of electricity required to charge the powder material should be about 11,600C (about 0.7kWh).

[0077] It can be seen from the above embodiments that, through the additive manufacturing system and method according to the present application, the additive manufacturing system and method can be adapted to various usage environments and / or process workpieces of various complex structures with very little power consumption and processing cost, thereby improving the industrial applicability of the additive manufacturing system and method.

[0078] Although the present invention has been described with reference to the embodiments, it should be understood that the present invention is not limited to the specific embodiments / examples described and shown in detail herein, and that those skilled in the art may make various changes to the embodiments without departing from the scope defined by the claims.

Claims

1. An additive manufacturing system, characterized in that: include: A powder supply device (100), the powder supply device being used to supply powder material; A molding device (200), the molding device being configured to receive the powder material from the powder supply device and to provide a space for printing the powder material into a workpiece; An energy source (300) configured to selectively apply an energy beam to the powder material in the molding device so as to print the powder material; as well as An electric field force applying device (400, 400A, 400B) is configured to apply an electric field force to the powder material in the forming device along a predetermined direction.

2. The additive manufacturing system according to claim 1, characterized in that: The electric field force applying device (400, 400A, 400B) comprises a power source (410) and an electric field generating device (420, 420A, 420B), wherein the power source (410) is connected to the forming device (200) to charge the powder material in the forming device, and the electric field generating device (420, 420A, 420B) comprises a first electrode plate (422, 422A, 422B) and a second electrode plate (424, 424A, 424B) which are opposite to each other and have opposite polarities to generate an electric field between the first electrode plate and the second electrode plate.

3. The additive manufacturing system according to claim 2, characterized in that: The first electrode plate (422) and the second electrode plate (424) extend in the vertical direction and are spaced apart from each other in the horizontal direction, so that the electric field force applying device applies an electric field force (F1) in the horizontal direction to the powder material.

4. The additive manufacturing system according to claim 3, characterized in that The forming device (200) is arranged between the first electrode plate (422) and the second electrode plate (424), and the heights of the first electrode plate and the second electrode plate in the vertical direction are greater than the height of the forming device in the vertical direction.

5. The additive manufacturing system according to claim 2, characterized in that: The first electrode plate (422A) and the second electrode plate (424A) extend in the horizontal direction and are spaced apart from each other in the vertical direction, so that the electric field force applying device applies an electric field force (F3) in the vertical direction to the powder material.

6. The additive manufacturing system according to claim 5, characterized in that: The forming device (200) is arranged between the first electrode plate (422A) and the second electrode plate (424A), and the length of the first electrode plate (422A) and the second electrode plate (424A) in the horizontal direction is greater than the length of the forming device in the horizontal direction.

7. The additive manufacturing system according to claim 3, characterized in that: The electric field generating device (420B) also includes a third electrode plate (426B) and a fourth electrode plate (428B) that are opposite to each other and have opposite polarities, and the third electrode plate and the fourth electrode plate extend in the horizontal direction and are spaced apart from each other in the vertical direction, so that the electric field force applying device also applies an electric field force in the vertical direction to the powder material.

8. The additive manufacturing system according to any one of claims 2 to 7, characterized in that: The molding device (200) comprises a base plate (210) for supporting a powder material contained in the molding device and the base plate is movable in a vertical direction, and the power source (410) is connected to the base plate (210).

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