Powder processing device and method and additive manufacturing equipment

Abstract

A powder processing apparatus (10), method and additive manufacturing apparatus (20) are provided. The device (10) comprises: at least one layer of screen (11); the powder feeding unit (12) is arranged in a powder falling path before and / or after the treatment of the at least one layer of screen (11) so as to uniformly convey powder flow; the vibrator (13) is used for controlling the at least one layer of screen (11) and / or the powder feeding unit (12) to vibrate and flow through the powder (P); and the plasma generator (14) is arranged on at least one side of the powder falling path before and / or after the treatment of the at least one layer of screen (11) and / or the powder feeding unit (12) to form a plasma action area (140), and is used for emitting plasma (141) to the passing powder (P) to change the form and the property of the powder (P).

Description

Technical Field

[0001] The present application relates to powder processing, and more particularly to powder processing apparatus, methods and additive manufacturing equipment. Background Art

[0002] Additive Manufacturing (AM), especially powder bed-based AM technology, has become an important means of manufacturing complex metal parts. In the AM process, the processing quality of the powder layer (such as uniformity, purity, fluidity and powder distribution) will have an important impact on the final quality of the part. Ensuring the processing quality of the powder layer on the substrate platform can achieve uniform action of the energy source on the powder bed, and obtain good interlayer bonding and structural integrity. On the contrary, problems such as uneven distribution of powder, poor fluidity or excessive impurity content can easily lead to structural defects, inconsistent performance and surface quality problems of parts. Therefore, the processing quality of the powder layer is one of the core factors to improve the accuracy, stability and part performance of the additive manufacturing process. Summary of the invention

[0003] The present application provides a powder processing device, method and additive manufacturing equipment to optimize the build quality of the powder layer.

[0004] One embodiment provides a powder processing device, comprising: at least one layer of screen; a powder feeding unit, arranged in a powder falling path before and / or after being processed by at least one layer of the screen to uniformly convey the powder flow; a vibrator, used to control the vibration of at least one layer of the screen and / or the powder feeding unit to flow through the powder; and a plasma generator, arranged on at least one side of the powder falling path before and / or after being processed by at least one layer of the screen and / or the powder feeding unit to form a plasma action area, used to emit plasma to the passing powder to change the morphology and properties of the powder.

[0005] Another embodiment provides a device for processing powder, which is used in additive manufacturing equipment, wherein the device includes: at least one layer of screen, arranged above the substrate platform for releasing processed powder to the substrate platform; a powder feeding unit, arranged in the powder falling path before and / or after processing by at least one layer of the screen to evenly convey the powder flow; a vibrator, used to control at least one layer of the screen and / or the powder feeding unit to vibrate the powder flowing through; and a first drive unit, the first drive unit is connected to at least one layer of the screen, and is used to drive the screen to move periodically within a horizontal range to adjust the powder falling path; wherein the periodic motion is movement and / or rotation, and the first drive unit is further used to adjust the frequency and / or speed of the periodic motion in stages so that the powder is evenly deposited on the substrate platform.

[0006] Another embodiment provides an additive manufacturing device including the apparatus described in any one of the aforementioned embodiments.

[0007] Another embodiment provides a control method for the powder processing device described in the first aspect, wherein the method includes: controlling the vibrator to transmit vibration to at least one layer of the screen and / or the powder feeding unit to act on the powder flowing through; and controlling the plasma generator to emit plasma to the passing powder to change the morphology and properties of the powder.

[0008] Another embodiment provides a control method for the powder processing device described in the second aspect, wherein the method includes: controlling the vibrator to transmit vibration to at least one layer of the screen and / or the powder feeding unit to act on the powder flowing through; controlling the first driving unit to drive the screen to move periodically to adjust the powder falling path, and periodically adjusting the frequency and / or speed of the periodic motion so that the powder is evenly deposited on the substrate platform, wherein the periodic motion is movement and / or rotation.

[0009] It should be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate one or more embodiments of the present application and, together with the description, serve to explain the principles of the present application and to enable one of ordinary skill in the relevant art to make and use the present application.

[0011] Figure 1 shows a schematic diagram of the construction of a powder processing device according to an example embodiment;

[0012] Figure 2A and Figure 2B Schematic diagrams of the structure of the slow-down unit according to example embodiments are respectively shown;

[0013] Figure 3 A schematic structural diagram of a powder feeding unit according to an example embodiment is shown;

[0014] Figure 4 A schematic structural diagram of an additive manufacturing device according to an example embodiment is shown;

[0015] Figure 5 The figure shows the comparison of the powder layer morphology formed by conventional gravity powder dropping and screen gravity powder dropping, wherein (a) is the powder layer morphology formed by conventional gravity powder dropping, and (b) is the powder layer morphology formed by screen gravity powder dropping;

[0016] Figure 6The figure shows the schematic diagram of the gaps in the powder layer formed by the gravity powder falling from the screen, wherein (a) is the surface structure of the screen, and (b) is the gaps in the powder layer formed by the gravity powder falling from the screen;

[0017] Figure 7 A schematic diagram of the periodic motion of a screen according to an example embodiment is shown;

[0018] Fig. 8A and Figure 8B Schematic diagrams showing the movement of the screen on the substrate platform according to example embodiments are shown respectively;

[0019] Fig. 9 A schematic diagram showing an arrangement of a powder feeding unit on a substrate platform according to an example embodiment is shown;

[0020] Fig.10 shows a schematic diagram of an arrangement of an injector on a substrate platform according to an example embodiment;

[0021] Fig.11 A schematic structural diagram of a substrate platform according to an example embodiment is shown. DETAILED DESCRIPTION

[0022] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments may be implemented in a variety of forms and should not be construed as being limited to the examples set forth herein; rather, the description of these embodiments is intended to make the present application more comprehensive and complete and to fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, many specific details are provided to provide a deeper understanding of the embodiments of the present application.

[0023] The additive manufacturing referred to in this article refers to powder bed-based additive manufacturing, such as LPBF (Laser Powder Bed Fusion), EBM (Electron Beam Melting), SLM (Selective Laser Melting), SLS (Selective Laser Sintering) and other additive manufacturing types that use powder as the building material.

[0024] The "powder" referred to herein refers to the raw material used to manufacture three-dimensional objects, and in terms of physical structure, refers to powder particles, which can have different shapes, sizes and particle sizes. The "powder" herein is preferably made of metal materials, such as stainless steel, copper, copper alloys, titanium, titanium alloys, aluminum, aluminum alloys, and other metal materials that can be manufactured or used. In addition, in an optional manner, powders of ceramics, plastics, and composite materials can also be used to construct three-dimensional objects.

[0025] In order to better process powder and solve the problems described in the background technology, the present application provides a powder processing device. The specific form and purpose of the device can be selected. For example, the device can be used as an independent device (such as a powder screening device) to perform pretreatment such as screening, sorting and homogenization on the powder before additive manufacturing to improve the quality of the powder and ensure that the quality of the pretreated powder meets the printing requirements. For another example, the device can be used as a powder supply device to be integrated into the production system as part of the additive manufacturing equipment to evenly deposit the powder on the substrate platform to form a powder layer layer by layer.

[0026] <Implementation Method of Using Powder Processing Device as Powder Screening Equipment>

[0027] Figure 1 FIG. 2 shows a schematic diagram of the construction of a powder processing device according to an example embodiment. Figure 1 In the exemplary embodiment, the provided device 10 has a screen 11, a powder feeding unit 12, a vibrator 13 and a plasma generator 14.

[0028] The screen 11 is arranged in the powder falling path, and is used to screen the received powder P. The mesh size of the screen 11 can be selected according to actual needs to screen out oversized or undersized particles and impurities in the powder P, so that only powder particles that meet the requirements enter the subsequent process. In addition, the surface of the screen 11 can be coated (such as polytetrafluoroethylene, silicone resin and fluoride coating) to reduce the adhesion of the powder P.

[0029] The powder delivery unit 12 is arranged in the powder falling path, and is used to deliver the received powder P to a target location, such as a storage container. By controlling the speed and / or direction of the powder delivery unit 12, a stable supply of powder P can be achieved, and material waste or operation interruption caused by too fast or too slow powder supply can be avoided.

[0030] exist Figure 1In the example implementation, the powder delivery unit 12 adopts a sloped trough structure to realize the conveying and control of the powder P. The so-called sloped trough structure can be understood as a trough body with a certain slope, and can also be described as a slope plate with baffles at both ends. The inclined surface of the sloped trough provides a natural gravity flow path, allowing the powder P to flow freely on the surface of the sloped trough. Thanks to the action of gravity and the guidance of the sloped trough, the powder P can flow from one end of the sloped trough to the other end at a relatively uniform speed, and then enter the subsequent screening or modification treatment stage. The inclination angle of the sloped trough determines the uniformity and flow rate of the powder P conveying. In actual use, the inclination angle of the sloped trough can be adjusted according to the physical properties of the powder P (such as particle size, shape, fluidity) and the processing requirements of the equipment. Generally speaking, the angle adjustment range of the sloped trough can be set between -45° and 45°. Within this range, the powder feeding unit 12 can ensure that the powder P is transported at an appropriate speed: if the angle is too small, it is easy to cause the powder P to accumulate and the flow rate to be insufficient, while if the angle is too large, it is easy to cause excessive falling of the powder P or the flow rate to be too fast and out of control, that is, the powder rushing phenomenon. Optionally, the side of the slope that contacts the powder P can be set to a curved surface structure. In addition, in order to further optimize the function of the slope, the baffles at both ends of the slope can play a role in limiting the overflow of powder, ensuring that the flow path of the powder P is stable and controllable.

[0031] In addition to the slope trough structure, the powder delivery unit 12 can also adopt other forms of conveying structures according to actual needs. These alternative forms include but are not limited to screw conveyors, belt conveyors, funnel structures and hourglass structures. For example, the screw conveyor uses a rotating screw to push the powder P in a closed or semi-closed trough to achieve precise conveying control, and is also suitable for conveying powder materials with strong adhesion or irregular particle shapes; the belt conveyor moves the powder P smoothly through a continuously moving conveyor belt, which is suitable for large-scale and uniform powder P conveying needs, and its smooth conveying path can effectively avoid the stratification and segregation problems of the powder P. The core of the funnel structure is gravity conveying, and the flow is completed by the natural fall of the powder P. The size of the discharge port of the funnel can be adjusted to accurately control the powder P flow rate, which is particularly suitable for use in preliminary screening or metering and conveying links. The hourglass structure adjusts the flow rate of the powder P through a narrow channel between the openings at both ends. Its characteristics are that it can achieve a long, stable and slow powder release, and is suitable for precision machining processes that require strict control of the powder flow rate.

[0032] The plasma generator 14 is arranged in the powder falling path to form a plasma action area 140, which is used to emit plasma 141 to the passing powder P to change its morphology and properties. In a specific implementation, the plasma generator 14 can be arranged in a variety of ways. For example, the first way is to respectively arrange the plasma generators 14 on both sides of the powder falling path, so that the two plasma generators 14 emit plasma 141 to the plasma action area 140 from opposite directions, so that the plasma 141 uniformly covers the entire surface of the powder particles. The second way is to arrange the plasma generator 14 only on one side of the powder falling path, and emit plasma 141 from a single direction. The third way is to arrange the plasma generator 14 around the powder falling path to form a plasma action area 140 that emits plasma 141 in multiple directions. It should be understood that the first way is suitable for processing powders P with larger particle sizes or complex morphologies. Due to its uniform energy distribution, the surface roughness, oxide film thickness and surface activity of the powder P can be greatly improved. The second way is suitable for powders P with smaller particle sizes and regular morphologies. Since the powder P is affected by gravity and plasma 141 during the powder falling process, the powder particles will flip during the movement, thereby achieving a more uniform treatment of the surface of the powder P. The third method can ensure that the powder particles are fully affected by the plasma 141 regardless of their movement to achieve the best treatment effect. In this way, the surface morphology of the powder P can be improved and the uniformity of its internal structure can be improved, such as reducing the porosity or improving the arrangement of microscopic grains.

[0033] The vibrator 13 can be driven by motor vibration, pneumatic vibration, ultrasonic vibration or a combination thereof. On the one hand, the vibrator 13 can be configured to be connected to the screen 11 to provide a periodic vibration force to the screen 11, so that the powder P is broken up and evenly distributed on the screen 11, while preventing the powder particles from accumulating on the surface of the screen 11 or clogging the sieve holes. Under the action of the vibration force, the powder particles are constantly moving, enhancing their contact with the aperture of the screen 11, especially the particles with a particle size close to the aperture of the screen 11, which can pass through the screen 11 more easily through the vibration, thereby improving the screening efficiency. On the other hand, the vibrator 13 can be configured to be connected to the powder feeding unit 12 to improve the fluidity of the powder P during the conveying process, and avoid the problem of poor conveying caused by adhesion or electrostatic effects between the powder particles. Under the action of the vibration force, the powder particles can maintain continuous and stable conveying, and the vibration force can break up the agglomerated particles that may exist in the powder P, so that the powder feeding is more uniform.

[0034] The number and location of the screen 11, vibrator 13 and plasma generator 14 can be freely selected. Figure 1In the exemplary embodiment, the screen 11 and the plasma generator 14 are both arranged at the upper and lower ends of the powder feeding unit 12, namely the screens 11A and 11B, and the plasma generators 14A and 14B. The screen 11A is arranged above the powder feeding unit 12 (at the entrance) to perform preliminary screening of the powder P entering the powder feeding unit 12 and remove large particles and impurities in the powder P. The screen 11B is arranged below the powder feeding unit 12 (at the exit) to perform secondary screening of the powder P output from the powder feeding unit 12 to further optimize the particle size and purity of the powder P. In coordination therewith, the upper plasma generator 14A is arranged above the screen 11A to perform plasma treatment on the powder P before entering the screen 11A, and further optimize its fluidity or reactivity by changing the morphology or chemical properties of the surface of the powder P. The plasma generator 14B is arranged below the screen 11B, and is used to process the screened powder P again, and further improve the performance of the powder P, such as improving its fluidity, increasing its surface energy, or removing residual impurities. As a match, the vibrator 13 is provided with three vibrators, namely, vibrators 13A, 13B, and 13C, wherein the vibrator 13A is provided to be connected to the screen 11A, the vibrator 13B is provided to be connected to the screen 11B, and the vibrator 13C is provided to be connected to the powder feeding unit 12.

[0035] In other example embodiments, in order to meet more simplified or specific powder processing requirements, the screen 11 and the plasma generator 14 can be set only at one end of the powder feeding unit 12, for example, the screen 11A is set above the powder feeding unit 12 and the screen 11B is cancelled, or the screen 11B is set below the powder feeding unit 12 and the screen 11A is cancelled, for example, the plasma generator 14A is set above the screen 11A and the plasma generator 14B is cancelled, or the plasma generator 14B is set below the screen 11B and the plasma generator 14A is cancelled. In addition, in order to improve the screening accuracy, the screens 11 at the upper and lower ends of the powder feeding unit 12 can be set to a multi-layer structure, for example, the upper screen 11A and / or the lower screen 11B can adopt a multi-layer screen design with a gradually reduced aperture. Through the stacked screening of the multi-layer screen, powder particles of different particle sizes can be separated step by step, thereby achieving a finer particle distribution, such as screening out larger particles, intermediate particles and fine powder at the same time.

[0036] In order to increase the residence time of the powder P in the plasma action region 140 , the device 10 is further provided with a slow-fall unit so that the powder particles can fully receive the action of the plasma 141 in the plasma action region 140 .

[0037] Figure 2A FIG. 1 shows a schematic diagram of a structure of a slow-down unit according to an exemplary embodiment. Figure 2AIn the exemplary embodiment, the slow-fall unit 15 is in the form of a baffle 15A, which is arranged on one side of the plasma generator 14 along the falling path of the powder P. The baffle 15A adopts a multi-stage inclined structure, and each stage of the baffle is arranged at a certain angle to the horizontal plane to effectively disperse the falling powder flow, forcing the powder particles to make multiple contacts and rebounds on each stage of the baffle 15A, thereby slowing down its falling speed. In this way, the residence time of the powder P in the plasma action area 140 is significantly extended, increasing the processing opportunities of the particles in the plasma 141. In addition, the structural form of the baffle 15A can be a solid structure with no gaps on the surface to better carry the powder P and guide its movement path, which is suitable for powder types with poor fluidity or larger particles. Optionally, the baffle 15A can also adopt a screen structure, through the selective permeability of the screen holes, allowing smaller particles of powder to pass through the screen, while larger particles continue to stay and slide on the surface of the baffle 15A, to achieve a preliminary particle size classification function. The baffle 15A of the screen structure not only plays a role in slowing down the falling, but also can perform preliminary screening treatment on the powder P.

[0038] Figure 2B Another schematic diagram of the structure of the slow-down unit according to an example embodiment is shown. Figure 2B In the example embodiment, the slow-fall unit 15 is configured as an airflow conveyor 15B. The airflow conveyor 15B actively intervenes in the powder flow through the airflow 150, and has the characteristics of high efficiency and controllability. The airflow conveyor 15B is composed of an airflow supply device and a nozzle for spraying the airflow 150, and is arranged on one or more sides of the plasma generator 14. Its working principle is to spray the airflow 150 through the nozzle to form an upward airflow 151 in the opposite direction of the falling direction of the powder P in the plasma action area 140. The function of this upward airflow 151 is to generate resistance and disturbance to the powder flow through aerodynamics, reduce the falling speed of the powder P and change its motion trajectory, so that the powder P is more evenly distributed in the plasma action area 140. In addition, the arrangement position and number of the airflow conveyor 15B can be adjusted according to actual needs. For example, in a scenario where a large area is required to be covered, a plurality of airflow conveyors 15B can be set, distributed at different positions of the powder falling path, to form a continuous upward airflow area. For scenes requiring local control, the airflow conveyor 15B can be centrally arranged at key locations, and the movement of the powder P can be precisely controlled by adjusting the angle, airflow speed and direction of the nozzle. In addition, the nozzle setting can also be optimized for different powder characteristics, such as selecting a nozzle with adjustable airflow width and intensity to accommodate powders P of different particle sizes and shapes.

[0039] In some embodiments, in order to further optimize the distribution and retention effect of the powder P in the plasma action region 140, Figure 2A The baffle 15A and Figure 2B The airflow conveyor 15B in the plasma action area 140 is provided with two slow-falling units 15. When the baffle 15A and the airflow conveyor 15B are used in combination, the baffle 15A preliminarily disperses and decelerates the powder P before it enters the plasma action area 140. The baffle 15A, through its multi-stage inclined arrangement, allows the powder particles to slide and rebound step by step, effectively disperses the flow density of the powder P, reduces the overall falling speed of the powder flow, and increases the uniformity of the powder particles. After the baffle 15A preliminarily decelerates the powder flow, the airflow conveyor 15B takes over to complete the fine control of the powder P. The airflow conveyor 15B forms an ascending airflow 151 in the opposite direction of the falling direction of the powder P in the plasma action area 140 by injecting the airflow 150 to further slow down the falling speed of the powder P, so that the powder P remains suspended or slowly passes through the plasma 141, thereby extending the residence time of the powder P in the plasma action area 140. In addition, the disturbance of the airflow 150 can further break up the agglomeration of the powder particles, so that each particle can be evenly affected by the plasma 141 .

[0040] Figure 3 FIG. 2 shows a schematic diagram of the structure of a powder feeding unit according to an example embodiment. Figure 3 In the example implementation, the powder delivery unit 12 is configured as a slope groove, and a plurality of powder blocking plates 121 (or one in other examples) are provided in the slope groove, and a powder delivery space for restricting the height of the powder flow is formed between the powder blocking plate 121 and the bottom plate 122 of the slope groove, that is, there is a gap between the powder blocking plate 121 and the bottom plate 122. Specifically, the powder blocking plate 121 is vertically installed in the slope groove, and the direction of its plate surface is perpendicular to the plane where the bottom plate 122 of the slope groove is located, so that the powder flow path is clearly divided, so that the flow range of the powder is limited, and the powder is prevented from flowing or rushing in the slope groove. The vertically arranged powder blocking plate 121 can play a role in slowing down the flow speed of the powder, so that the powder is advanced layer by layer in the slope groove. Optionally, the powder blocking plate 121 can also be installed in the slope groove in an inclined manner. In this case, the powder is not only affected by gravity during the flow process, but also lateral dispersion is produced due to contact with the powder blocking plate 121, thereby achieving a more uniform powder conveying effect. In addition, the bottom plate 122 of the slope groove can be partially or completely processed into a wavy surface to further constrain the flow path of the powder, increase the residence time of the powder particles in the slope groove, and make its flow more uniform; and the wavy surface provides a larger contact area, making the distribution of the powder in the slope groove more uniform, reducing the possibility of concentrated flow or accumulation; in addition, the wavy structure can also play a certain vibration buffering role, reducing the interference of external vibration on the stability of powder flow.

[0041] In some embodiments, the provided device 10 also has a control system, which is at least configured to control the operating state of the vibrator 13 to transmit the vibration to the screen 11 and / or the powder feeding unit 12 to optimize the flow performance and screening efficiency of the powder P. By adjusting the frequency and amplitude of the vibration, the control system can make the powder P evenly distributed on the screen 11 while avoiding the loss of powder caused by accumulation or excessive vibration. In addition, for the vibrator 13 connected to the powder feeding unit 12, the control system can adjust the vibration intensity according to the actual demand of the powder flow to maintain the stable flow of the powder P in the conveying path. At the same time, the control system can also control the operating state of the plasma generator 14 in real time. By regulating the emission parameters (such as power, frequency and emission direction) of the plasma 141, the control system can make the plasma 141 act on the powder P flowing through in the best way, which can not only effectively change the morphology and surface characteristics of the powder P, but also have a positive effect on the charge state, fluidity and particle size distribution of the powder P. For example, in an application scenario where the powder particles need to be surface modified or the fluidity is enhanced, the control system can automatically adjust the intensity and duration of the action of the plasma 141 to achieve the desired powder performance. In addition, the control system can also be combined with a sensor module to achieve closed-loop feedback control. By deploying multiple sensors around the screen 11, the powder feeding unit 12 and the plasma generator 14, the system can monitor the flow state, particle characteristics and processing effect of the powder P in real time. According to the data fed back by the sensors, the control system can automatically adjust the operating parameters of the vibrator 13 and the plasma generator 14 to dynamically optimize the entire powder processing process.

[0042] <Implementation Method of Using Powder Processing Device as Powder Supply Equipment>

[0043] This embodiment describes the situation where the device is used as a powder supply device. It should be understood that this embodiment is a variation of the previous device used as a screening device. The two embodiments are highly compatible in structure and function, and can be combined and converted with each other according to actual needs. For example, this embodiment can select any structure or function from the embodiment of the screening device to constitute a part of this embodiment to achieve the specific setting of the powder supply device. The following is a detailed description of the embodiment of the device used as a powder supply device. Since the device is used as a part of an additive manufacturing device, the additive manufacturing device covering the device is generally introduced.

[0044] Figure 4 FIG. 1 shows a schematic diagram of the structure of an additive manufacturing device according to an example embodiment. Figure 4In an exemplary embodiment, an additive manufacturing device 20 for additively manufacturing (3D printing) a three-dimensional object 223 is provided. The additive manufacturing device 20 has a forming chamber 21. The forming chamber 21 is used to accommodate the printing process and is composed of sealed wall panels to prevent the external environment from interfering with the printing process and provide a controlled environment. The forming chamber 21 usually needs to be filled with an inert gas, such as Ar (argon), to reduce oxidation and adverse reactions of the material. A processing plane 211 for processing powder P is formed at the bottom of the forming chamber 21. The additive manufacturing device 20 has a forming cylinder 22. The forming cylinder 22 is used to accommodate the three-dimensional object 223 formed during the printing process. The structure formed during the printing process will gradually accumulate in the forming cylinder 22, and the forming cylinder 22 is moved up and down in the vertical direction by a lifting device 221 arranged at the bottom thereof. After each layer of printing is completed, the lifting device 221 moves the forming cylinder 22 downward by a small distance, and a new layer of powder P is applied to the top of the forming cylinder 22 by a powder supply device to form a flat powder layer PL / powder bed PB. It should be understood that the powder layer PL is formed by a certain amount of powder P, and the powder bed PB is formed by at least one layer of powder layer PL. The substrate platform 220 is detachably mounted in the forming cylinder 22, and is used to carry the bottom surface of the printed object and provide stable support. It can move up and down along the inner wall of the forming cylinder 22 under the drive of the lifting device 221 to promote the layer-by-layer addition of powder P so as to build the required three-dimensional object 223 in the forming cylinder 22. The additive manufacturing device 20 has an optical path system 23. The optical path system 23 mainly includes optical components such as an energy beam emitter (such as a laser) and a galvanometer, which are used to control the irradiation position and angle of the energy beam 230 (such as a laser) so that its focused light spot is irradiated onto the powder layer PL formed above the substrate platform 220 to achieve sintering / melting of the powder P. The additive manufacturing device 20 has a control system. The control system is connected to the components of the additive manufacturing device 20 in communication to control the execution of the entire 3D printing process.

[0045] Figure 4 The example additive manufacturing apparatus 20 has a device 10. The device 10 is provided with a screen 11, a powder feeding unit 12, a vibrator 13 and a plasma generator 14. The powder feeding unit 12, the plasma generator 14 and the screen 11 are sequentially arranged along the powder falling path, and the powder P is sequentially processed by the powder feeding unit 12, the plasma action area 140 formed by the plasma generator 14 and the screen 11, and then released on the substrate platform 220 to form a powder layer PL.

[0046] The screen 11 is arranged above and close to the substrate platform 220, and is used to perform the final treatment on the powder P, so that the powder released onto the substrate platform 220 forms a powder layer PL with a uniform particle size distribution. The powder feeding unit 12 is located above the screen 11, and the powder P first enters the powder feeding unit 12. Through the treatment of the powder feeding unit 12 (such as a slope trough structure or a spiral conveying device, etc.), the powder P is evenly transported to the next treatment area, and the powder passing through the screen 11 is enabled to be stably laid on the substrate platform 220. The plasma generator 14 is arranged between the powder feeding unit 12 and the screen 11 to form a plasma action area 140. The plasma generator 14 modifies the morphology and properties of the powder P by emitting plasma 141 to the powder P, thereby improving the fluidity and melting performance of the powder P. In addition, plasma treatment can also remove impurity particles in the powder P and improve the purity of the material. In order to further optimize the treatment effect of the powder P, the vibrator 13 is integrated into the device 10. The vibrator 13 can be as follows Figure 4 As shown, it is only connected to the powder feeding unit 12, but it can also be connected to the screen 11 at the same time or as an alternative in other examples to transmit vibration of appropriate frequency to the powder feeding unit 12 and / or the screen 11, thereby effectively preventing the accumulation or adhesion of the powder P during the processing. The vibration setting can maintain the continuity of the flow of the powder P and make the powder P pass quickly through the screen 11, thereby improving the processing efficiency of the powder P.

[0047] It should be understood that the number and location of the screen 11, vibrator 13 and plasma generator 14 in this embodiment are not limited to Figure 4 Draw the constraints of the layout, which can be freely arranged and combined as described above.

[0048] In some embodiments, the device 10 has a first drive unit 16A and a second drive unit 16B, the first drive unit 16A is configured to be connected to the screen 11, and the second drive unit 16B is configured to be connected to the powder feeding unit 12 and the plasma generator 14. The first drive unit 16A and the second drive unit 16B are set to drive the screen 11, the powder feeding unit 12 and the plasma generator 14 to move above the substrate platform 220 to deposit the powder P layer by layer on the substrate platform 220, and after completing the deposition of each layer, drive the screen 11, the powder feeding unit 12 and the plasma generator 14 to leave the area above the substrate platform 220.

[0049] The first drive unit 16A is mainly used to drive the motion control of the screen 11. As the last component in the device 10 to process the powder P, the position and movement path of the screen 11 determine the uniformity of the distribution of the powder P on the substrate platform 220. Driven by the first drive unit 16A, the screen 11 can move along a preset trajectory above the substrate platform 220, so that the processed powder P is evenly covered on the processing plane 211 of the substrate platform 220, thereby forming a powder layer PL with a uniform thickness. The first drive unit 16A can take a variety of forms, such as a servo motor, a stepper motor, a linear drive or a pneumatic drive device. In addition, the drive unit 16A is also connected to the control system to adjust the moving speed and position of the screen 11 through a preset program or real-time feedback, so as to achieve high-quality powder distribution when printing complex geometric shapes.

[0050] The second drive unit 16B is configured to be connected to the powder feeding unit 12 and the plasma generator 14 at the same time, and is used to control the overall movement of the two components. The powder feeding unit 12 is used to transport the powder P to the plasma action area 14 of the plasma generator 14, and the plasma generator 14 modifies the powder by emitting plasma 141. Driven by the second drive unit 16B, the two components can coordinate movement to achieve the processing and transportation of powder P at different positions. The movement mode of the second drive unit 16B can be linear motion, curved motion or compound trajectory motion to adapt to different deposition requirements on the substrate platform 220. Through linkage with the control system, the second drive unit 16B can adjust the movement path and stop position according to the different requirements of the printing model to achieve the continuity of the powder processing and deposition process.

[0051] Specifically, during the manufacturing process of each printing layer, the powder feeding unit 12 uniformly transports the powder P to the plasma action area 140 through the second driving unit 16B, and modifies the powder P through the action of the plasma generator 14. Then, the powder P flows through the screen 11, and forms a uniform powder layer PL above the substrate platform 220 under the control of the first driving unit 16A. After each layer of powder P is deposited, the first driving unit 16A and the second driving unit 16B will quickly move the screen 11, the powder feeding unit 12 and the plasma generator 14 out of the area above the substrate platform 220 according to the preset program, making room for the optical path system 23 to perform the energy beam 230 scanning operation.

[0052] In some embodiments, the width of the screen 11 in the horizontal direction can be set to match the width of the substrate platform 220, or even slightly exceed the width of the substrate platform 220, so as to promote the powder P processing process to cover the entire processing area of ​​the substrate platform 220, and avoid the phenomenon of uneven powder distribution due to insufficient width of the screen 11. By optimizing the width of the screen 11, the powder flow can completely cover the surface of the substrate platform 220 when passing through the screen 11. Of course, it can also be set to be smaller than the width of the substrate platform 220, so that the powder can be moved along the substrate platform 220 under the drive of the first driving unit 16A.

[0053] In some embodiments, in order to further optimize the deposition effect of the powder P and improve the flatness of the powder layer PL, the device 10 may further include a powder flattening component 17. The powder flattening component 17 is configured to smooth the powder P deposited on the substrate platform 220, thereby eliminating particle accumulation and uneven thickness during the deposition process, so that the surface of the powder layer PL is uniform and the thickness is consistent.

[0054] The form of the flat powder component 17 can be selected according to different needs. For example, in some implementations, it can be selected as a scraper or roller that moves in the horizontal direction. The smooth edge of the scraper can evenly push or scrape off the excess powder P during the movement, and at the same time compact and flatten the powder layer PL. The speed and pressure of the scraper movement can be adjusted according to the characteristics of the powder particles and the target powder layer thickness. The roller flattens the powder layer PL by rotating, and its surface can be set to a smooth hard material, or it can be covered with a flexible material layer to adapt to the characteristics of different powders P. The advantage of the roller is that it can apply pressure to the powder P in a softer way, reduce damage to the particles, and improve the density of the powder layer PL. It should be understood that when the flat powder component 17 is a scraper or a roller, the powder falling width of the device 10 on the substrate platform 220 may not be limited by the width of the substrate platform 220. That is to say, even if the initial deposition distribution width of the powder P is insufficient and no powder feeding is performed, the flat powder component 17 can redistribute excess powder P to the uncovered area by horizontal movement, so that the surface of the substrate platform 220 is completely covered with powder P, thereby greatly improving the tolerance of the powder deposition process and reducing the dependence on the initial distribution accuracy of the powder feeding unit 12.

[0055] In some implementations, the powder flattening component 17 can also be configured as a pressing plate that moves in the vertical direction, and the powder layer PL is compacted and flattened by vertical pressure. During operation, the pressing plate adjusts its pressing depth and pressure through a control system to achieve the effect of uniformly applying pressure. Compared with a scraper and a roller, the advantage of a pressing plate is that it can provide a greater vertical compaction force, making the powder layer PL denser. Of course, it can also be configured to be used in combination with a scraper or a roller.

[0056] Figure 5 The figure shows the comparison of the powder layer morphology formed by conventional gravity powdering and screen gravity powdering, where (a) is the powder layer morphology formed by conventional gravity powdering, and (b) is the powder layer morphology formed by screen gravity powdering.

[0057] exist Figure 5 In (a), conventional gravity powder dropping relies on the way that powder P naturally falls under the action of gravity and is deposited on the substrate platform. However, this simple powder dropping method has a significant problem, that is, powder P is easily affected by air flow, particle morphology and landing point distribution during the falling process, resulting in unstable morphology of the powder layer PL. Specifically, larger powder particles will deposit faster at the bottom of the powder layer PL due to the higher gravitational acceleration, while smaller particles will be diffusely distributed near the landing point. This phenomenon usually causes the powder layer PL to form a "narrow at the top and wide at the bottom" cone-shaped stacking morphology, which is manifested as an uneven surface and uneven particle distribution, affecting the subsequent printing quality. The powder layer PL with large surface undulations will make it difficult to accurately position the focus of the energy beam in the target area, causing incomplete melting or overburning of the material, and even causing printing failure in severe cases. In addition, this narrow at the top and wide at the bottom cone-shaped stacking morphology is also prone to cause the stratification effect of powder particles, causing fluctuations in the mechanical properties and density of each layer, thereby affecting the overall performance of the printed object.

[0058] Different from conventional gravity powder dropping, Figure 5 (b) The screen gravity powder falling greatly improves the uniformity of powder deposition by setting a screen 11 in the powder falling path, which is specifically manifested in that the screen 11 disperses the falling powder P with its evenly distributed mesh structure, forcing the originally concentrated falling powder particles to be divided into a more delicate particle flow. In this process, the spacing and aperture of the mesh of the screen 11 play a screening role in the flow rate and distribution of the powder. Larger particles take a relatively long time to pass through the mesh, while smaller particles pass through at a faster speed, thereby improving the uniformity of the particle distribution of the powder. In addition, through the screen 11, the powder P will encounter a certain resistance when passing through the mesh, reducing the falling speed of the particles. This speed control can effectively reduce the phenomenon of powder aggregation and stacking due to inertia, making the deposition of powder particles on the substrate platform softer and more uniform. In addition, the screen 11 can also optimize the flow direction of the powder and correct the particle deviation caused by gravity or air disturbance. The multi-directional particle flow formed by the mesh arrangement can promote the powder flow to be evenly distributed on the substrate platform, avoiding the situation where too much or too little powder is accumulated in a certain area. Through the above-mentioned action of the screen 11, Figure 5 The powder layer PL shown in (b) presents an ideal flat shape, which can improve the accuracy of the subsequent printing process, make the focusing of the energy beam on the flat powder layer PL more stable, and make the density / strength of each layer of the printed structure more consistent.

[0059] Figure 6 The schematic diagram of the powder layer gap formed by the gravity powder falling from the screen is shown, where (a) is the surface structure of the screen, and (b) is the powder layer gap formed by the gravity powder falling from the screen. It should be understood that under the action of the screen 11, the powder P falls to the substrate platform 220 through the grid 110 on its surface to form a powder layer PL. However, due to the geometric characteristics of the grid 110, a part of the powder particles are blocked during the falling process and cannot be evenly distributed on the entire substrate platform surface. This local blocking causes the powder layer PL to form spaced gaps in the horizontal direction, such as Figure 6 (b) The gaps P1 to P n The presence of voids will lead to uneven distribution of PL density in the powder layer, affecting the subsequent printing quality, so effective measures need to be taken to optimize it.

[0060] Figure 7 A schematic diagram of the periodic motion of a screen according to an example embodiment is shown. Figure 7 In the exemplary embodiment of the present invention, the first driving unit 16A is configured to drive the screen 11 to periodically move in a horizontal range under the control of the control system to adjust the powder falling path, thereby changing the gaps P1 to P n Make up.

[0061] In one implementation, the first driving unit 16A may be a driving component configured to drive the screen 11 to move in a horizontal direction, such movement including both large-scale movement along the substrate platform to deliver powder and remove the substrate platform, and small-scale periodic movement to fill the gaps P1 to P2. n .

[0062] In one implementation, the first driving unit 16A may be composed of a moving device and a vibrator. The moving device is configured to drive the screen 11 to move over a large range above the substrate platform to deliver powder and remove the substrate platform, and the vibrator is configured to drive the screen 11 to vibrate periodically in a small range, especially to drive the screen 11 to vibrate slightly in the horizontal direction to redistribute the powder P in the blocked area to the gaps P1 to P2. n area, making the density of the powder layer PL more uniform.

[0063] In one implementation, the first drive unit 16A can also achieve periodic rotational motion through the first drive unit 16A. The rotation of the screen 11 can change the motion trajectory of the powder particles and enhance the interaction between the particles, thereby further optimizing the density of the powder layer PL. The frequency and amplitude of the rotational motion can be adjusted according to the characteristics of the powder particles to meet different deposition requirements. For example, in the case of large particles, the rotation frequency can be reduced to ensure stable deposition of the particles; for fine particle powders, the frequency can be increased to accelerate the deposition process. Through this multi-level regulation, the screen 11 can dynamically adapt to different process parameters and achieve efficient distribution of powder P.

[0064] Through the precise control of the first drive unit 16A, the movement of the screen 11 can achieve phased frequency and / or speed adjustment, thereby significantly improving the uniform deposition effect of the powder P on the substrate platform 220. The movement mode of the screen 11 is not static, but is dynamically optimized based on the different requirements of the deposition stage. In the initial stage of powder deposition, the main task of the screen 11 is to solve the problem of large-area gaps that may exist in the powder layer PL. Therefore, the first drive unit 16A sets a lower movement frequency and / or a smaller movement range in the initial stage, so that the screen 11 can regulate the powder P more carefully, so as to effectively fill the larger gaps and ensure that the deposited powder layer PL has basic continuity. The optimization focus of this stage is to reduce the concentrated accumulation of powder particles through the slow movement and uniform vibration of the screen 11, and prevent the local bulge or excessive sparseness of the initial powder layer PL. As the powder deposition process progresses, the first drive unit 16A gradually increases the movement frequency and amplitude of the screen 11 and enters the refinement stage. In the refinement stage, the fast movement and wider coverage of the screen 11 can improve the distribution of powder particles, make the surface of the powder layer PL smoother, and improve the uniformity of density distribution. Through adjustment, the screen 11 can not only evenly spread the powder P on the substrate platform, but also effectively eliminate the tiny gaps caused by the difference in powder particle size or stacking inertia.

[0065] In some embodiments, in order to meet the needs of various materials and realize additive manufacturing of complex structures, multiple powder feeding units 12 are arranged along the horizontal direction corresponding to the surface of the substrate platform 220, and each powder feeding unit is configured to convey powders of different materials, so that the equipment can use multiple powder materials for multi-material printing in a single manufacturing process.

[0066] Fig. 8A FIG. 2 shows a schematic diagram of the movement of the screen on the substrate platform according to an example embodiment. Fig. 8AIn the example implementation, the screen interval is set to two layers, namely screen 11A and screen 11B. Among them, screen 11B is arranged above the substrate platform 220, becoming the powder screening layer closest to the deposition area, and screen 11A is located above screen 11B, forming a primary powder screening layer. In order to ensure that the two layers of screens can move independently, this implementation configures the first drive unit 16A1 to be connected to screen 11A, and configures the first drive unit 16A2 to be connected to screen 11B. Screens 11A and 11B are configured to be able to move in a staggered manner, that is, the grids of the two layers of screens are intertwined to achieve a complex powder P distribution effect.

[0067] Specifically, under the action of the first drive units 16A1 and 16A2, the screens 11A and 11B can move relative to each other in different directions and / or frequencies and / or amplitudes. For example, when the screen 11A is driven to move to the left by the first drive unit 16A1, the screen 11B is driven to move to the right by its corresponding first drive unit 16A2, forming a synchronous but relative misaligned motion mode; when the screen 11A moves to the right in the opposite direction, the screen 11B moves to the left accordingly. Through this relative dynamic synergy, multiple disturbances of the powder flow when passing through the two layers of screen mesh are achieved, thereby further refining the distribution effect of the powder P. For example, the screen 11A is driven by the first drive unit 16A1 to periodically rise and fall in the vertical direction, while the screen 11B is driven by the first drive unit 16A2 to swing left and right in the horizontal direction. Through the staggered motion, when the powder P passes through the two layers of screens, the flow path will be constantly disturbed by the relative movement of the two layers of meshes, so that the powder distribution is no longer a simple uniform spread, but can form a deposition effect with a specific shape or pattern.

[0068] The staggered movement can not only improve the deposition uniformity of the powder on the substrate platform 220, but also prevent the problem of powder flow being blocked between the meshes of the screen. As the meshes of the screens 11A and 11B move alternately, the powder P will constantly change direction and flow path when passing through the screen, thus preventing the powder from staying in a certain position for a long time and causing particle accumulation or adhesion.

[0069] In addition, the meshes of the screens 11A and 11B can also be set to have different aperture sizes. Specifically, the mesh of the upper screen 11A can be set to a larger aperture for preliminary screening of powders to remove large particles and impurities; the lower screen 11B uses a smaller aperture to finely screen the powder that has passed the initial screening, so that the powder finally deposited on the substrate platform 220 has a highly consistent particle size distribution. The double-layer screening mechanism not only improves the quality of powder deposition, but also enables the classification and use of powders of different particle sizes, providing the possibility for multi-material additive manufacturing.

[0070] In addition, the staggered motion of the two layers of screens can further control the local characteristics of the deposition. For example, by adjusting the trajectory and speed of the screen movement, a deposition layer with different density distribution can be formed on the substrate platform 220, which is of great significance for the manufacture of functional gradient materials. By programming the coordinated motion of the screens 11A and 11B, more complex geometric shapes or pattern deposition can also be achieved.

[0071] Figure 8B A schematic diagram showing movement of a screen on a substrate platform according to an example embodiment is shown. Figure 8B An example implementation of Fig. 8A A variation based on the example, in which a baffle plate 112 is provided between the screen 11A and the screen 11B, and a first drive unit 16A3 is configured to be connected to the baffle plate 112 to drive it to move in the horizontal direction, so as to block a portion of the mesh of the screen 11B. The position and movement of the baffle plate 112 can be freely adjusted to meet different deposition requirements. For example, when the first drive unit 16A3 drives the baffle plate 112 to move to the left, it can block the left part of the mesh of the screen 11B, so that the powder is deposited on the substrate platform 220 only through the unblocked mesh on the right; when the baffle plate 112 moves to the right, it blocks the right part of the mesh on the contrary, allowing the powder to pass through the mesh on the left, so that a deposition area with a specific shape or distribution pattern can be formed on the substrate platform 220.

[0072] Furthermore, the shielding plate 112 can also be dynamically adjusted to form a complex deposition pattern in coordination with the staggered movement of the screens 11A and 11B. Assuming that the screen 11A is moving to the left and the screen 11B is moving to the right, the shielding plate 112 can remain in a fixed position to form a clear powder deposition boundary; or, the shielding plate 112 can also move synchronously at a specific speed to further enrich the local characteristics of the deposition layer. For example, in some complex printing tasks, the movement trajectory of the shielding plate 112 can be controlled by programming to form a gradual, periodic or asymmetric powder deposition pattern during the printing process.

[0073] The first drive unit 16A3 can be configured to adjust the movement amplitude and speed of the shielding plate 112 so that it can be seamlessly matched with the movement of the screen. For example, when depositing a high-precision pattern, the first drive unit 16A3 needs to accurately move the shielding plate 112 in small steps; while when depositing a large area of ​​uniform powder layer, it can be moved quickly or completely out of the shielding range to provide the maximum mesh throughput.

[0074] Fig. 9FIG. 2 shows a schematic diagram of the arrangement of the powder delivery unit on the substrate platform according to an example embodiment. The powder delivery unit is divided into powder delivery units 12A, 12B and 12C, which are arranged above the substrate platform 220 in an intermittent arrangement. The powder delivery unit 12A is configured to deliver the first material P a The powder feeding unit 12B is configured to feed the second material P b The powder feeding unit 12C is configured to feed the third material P c In order to make different materials (P a , P b , P c ) can be deposited evenly and stably on the substrate platform 220, and an independent plasma generator (respectively 14A, 14B and 14C) is correspondingly arranged below each powder feeding unit 12. The function of the plasma generators 14A, 14B and 14C is to improve the fluidity and deposition behavior of the powder particles through plasma treatment, thereby improving the adhesion effect and deposition quality of the powder on the substrate platform. In addition, a screen 11 is also arranged below the plasma generators 14A, 14B and 14C, and its main function is to adjust the particle size distribution of the falling powder and form a uniform powder layer through the filtering effect of the grid. The layered structure can make the deposition processes of multiple materials both independent and coordinated with each other. For example, the screen 11 can prevent large particles of powder from being directly deposited on the substrate platform 220, avoiding the influence on the subsequent printing accuracy. At the same time, through the periodic movement of the screen 11, the distribution of powders of different materials can be further homogenized, so that the overall shape of each layer of powder is smoother. Through the arrangement of multiple powder feeding units, combined with the synergistic effect of the plasma generators 14A, 14B and 14C and the screen 11, the additive manufacturing device can efficiently complete multi-material printing.

[0075] Fig.10 FIG. 2 shows a schematic diagram of an arrangement of an injector on a substrate platform according to an example embodiment. Fig.10 In the exemplary embodiment, the device further has an injector 18 disposed below the screen 11, the injector 18 having a powder inlet 18A for receiving the falling powder and a nozzle 18B for injecting the received powder onto the substrate platform 220. The injector 18 can achieve secondary dispersion and accelerated injection of the powder falling from the screen 11 to further improve the uniformity of powder deposition.

[0076] Specifically, the injector 18 has a powder inlet 18A for receiving the powder falling from the screen 11, and a nozzle 18B for injecting the received powder onto the substrate platform 220. The position of the powder inlet 18A is precisely aligned with respect to one or more meshes of the screen 11, so that the powder P falling from the screen 11 can enter the injector 18, avoiding the loss of the powder P. In addition, the nozzle 18B will also directly inject the powder P onto the surface of the substrate platform 220 at a specific injection angle and speed.

[0077] In some embodiments, the injector 18 may be one or more. Fig. 9 As shown in FIG. 2 , these injectors 18 are arranged in an array above the substrate platform 220. The array arrangement can cover a larger deposition area, and can also meet the powder deposition requirements of different areas by adjusting the spacing between the injectors 18. This function is achieved by the third drive unit 16C connected to each injector 18. The third drive unit 16C can adopt an automatic guide rail structure, and each injector 18 is independently installed on the guide rail. By adjusting the position of the guide rail by the control system, the spacing between any adjacent injectors 18 can be adjusted.

[0078] Optionally, the device further includes a pressure regulating unit 19 connected to the injector 18. The pressure regulating unit 19 is used to adjust the injection pressure of the injector 18 in real time so that the powder flow rate and flow rate output by the nozzle 18B can be dynamically adjusted according to specific deposition conditions. For example, when a thinner powder layer is required, the pressure regulating unit 19 can reduce the injection pressure to promote a smooth and uniform flow of powder; and when rapid deposition or large-area powder spreading is required, the pressure regulating unit 19 can increase the injection pressure, thereby improving production efficiency.

[0079] In addition, the injector 18 can be configured to move synchronously with the screen 11, for example, by coordinated control of the first drive unit. The synchronous movement of the screen 11 and the injector 18 can cooperate with each other during the powder deposition process in different areas, avoiding uneven density or gap problems in the powder layer due to changes in the deposition area. For example, during the movement, the mesh of the screen 11 preliminarily sorts the powder, and the injector 18 evenly distributes the powder through secondary injection, and finally forms a powder layer PL with high flatness and uniformity on the substrate platform 220.

[0080] In some embodiments, the provided device 10 can also be configured to consist of a screen 11, a powder feeding unit 12, a vibrator 13 and a first drive unit 16A. The screen 11 is arranged above the substrate platform 220 to release the processed powder to the substrate platform 220. The powder feeding unit 12 is arranged in the powder falling path before and / or after being processed by the screen 11 to uniformly convey the powder flow. The vibrator 13 is configured to control the screen 11 and / or the powder feeding unit 12 to vibrate the powder flowing through. The first drive unit 16A is connected to the screen 11, and is used to drive the screen 11 to periodically move within a horizontal range to adjust the powder falling path; wherein the periodic motion is movement and / or rotation, and the first drive unit 16A is further used to periodically adjust the frequency and / or speed of the periodic motion so that the powder is uniformly deposited on the substrate platform 220.

[0081] Fig.11 A substrate platform 220 designed for experimental or test printing purposes is schematically shown, which is used to support in-situ characterization analysis during the printing process, especially real-time monitoring of the internal structure and phase of the molten pool through X-ray diffraction imaging. For this reason, the construction of the substrate platform 220 takes into account the absorption and scattering effects of X-rays when penetrating the material. In order to minimize these effects, the substrate platform 220 is configured to be close to a two-dimensional feature, and its width is designed to be very narrow, such as about 2 mm, to greatly reduce the energy loss of X-rays when passing through the substrate platform 220, and to make the penetration depth and signal clarity of X-rays into the molten pool, so that diffraction imaging can accurately capture the phase evolution inside the molten pool. For example, by capturing the morphological changes of the molten pool under different laser powers, scanning speeds and powder properties in real time, researchers can deeply understand the solidification behavior, grain growth direction and defect formation mechanism of the material.

[0082] The device provided in this application can be used in Fig.11 In the exemplary substrate platform 220, for example, the screen 11, the powder feeding unit 12, the vibrator 13 and the plasma generator 14 of the device 10 are arranged on the substrate platform 220. The powder feeding unit 12, the plasma generator 14 and the screen 11 are arranged in sequence along the powder falling path, and the powder P is processed by the powder feeding unit 12, the plasma action area 140 formed by the plasma generator 14 and the screen 11 in sequence, and then released on the substrate platform 220 to form a powder layer PL.

[0083] To cooperate Fig.11According to the requirements of the experimental substrate platform 220 shown, the above-mentioned components of the device 10 are reduced in size to match, for example, the width of the screen 11 is set to about 2 mm. The powder feeding unit 12 can adopt a funnel or hourglass structure. The funnel-type powder feeding unit 12 transports the powder P to the substrate platform 220 by gravity, while maintaining the stability of the powder flow, which is suitable for relatively small-scale experimental printing scenarios. The hourglass structure further optimizes the powder flow control, and the uniform release of the powder can be achieved by adjusting the size and shape of the hourglass caliber. In order to achieve both uniform and stable powder deposition on the substrate platform 220 during the experimental printing process, it lays the foundation for the formation of a high-quality molten pool. In addition, in order to be closely integrated with the X-ray diffraction imaging technology, other components of the device (such as the screen 11 and the injector 18) are also optimized to adapt to the requirements of the experimental substrate platform 220. For example, the screen 11 preliminarily screens the powder through its mesh so that the powder particles deposited on the substrate platform 220 have a uniform particle size distribution. The injector 18 evenly distributes the powder on the surface of the substrate platform 220 through a specific injection pressure to avoid abnormal morphology of the molten pool caused by uneven powder.

[0084] In some embodiments, the present application also provides a control method for the device described above, which can be configured to perform any of the following steps:

[0085] The vibrator is controlled to transmit vibration to at least one layer of the screen and / or the powder feeding unit to act on the powder flowing through.

[0086] The plasma generator is controlled to emit plasma to the passing powder to change the morphology and properties of the powder.

[0087] The first driving unit is controlled to drive the screen to move periodically in a horizontal range to adjust the powder falling path, and the frequency and / or speed of the periodic motion is adjusted in stages to make the powder evenly deposited on the substrate platform, wherein the periodic motion is movement and / or rotation.

[0088] It should be understood that the control process of the above method in the present application can be implemented in whole or in part through software, hardware, firmware or any other combination.

[0089] Further examples are described below to facilitate understanding of the present application.

[0090] Aspect 1: A powder processing device is provided, comprising: at least one layer of screen; a powder feeding unit, arranged in a powder falling path before and / or after being processed by at least one layer of the screen to uniformly convey the powder flow; a vibrator, used to control the vibration of at least one layer of the screen and / or the powder feeding unit to flow through the powder; and a plasma generator, arranged on at least one side of the powder falling path before and / or after being processed by at least one layer of the screen and / or the powder feeding unit to form a plasma action area, used to emit plasma to the passing powder to change the morphology and properties of the powder.

[0091] Aspect 2: The device according to Aspect 1, wherein at least one layer of the screen is arranged above the substrate platform of the additive manufacturing equipment to release the processed powder to the substrate platform, and the plasma generator is arranged in the powder falling path between the powder feeding unit and at least one layer of the screen.

[0092] Aspect 3: The device according to aspect 2, wherein at least one layer of the screen covers the substrate platform in a horizontal direction.

[0093] Aspect 4: The device according to Aspect 2 comprises a first driving unit connected to at least one layer of the screen, wherein the first driving unit is used to drive the screen to move periodically to adjust the powder falling path.

[0094] Aspect 5: The device according to Aspect 4, wherein the periodic motion is movement and / or rotation, and the first driving unit is further used to adjust the frequency and / or speed of the periodic motion in stages so that the powder is evenly deposited on the substrate platform.

[0095] Aspect 6: The device according to Aspect 4, wherein the screen is arranged to be connected to the first driving unit respectively and spaced in sequence in at least two layers above the substrate platform, and the first driving unit is further used to drive at least two layers of the screen to move relatively in different directions and / or frequencies and / or amplitudes.

[0096] Aspect 7: The device according to Aspect 1 or Aspect 2 includes a slow-fall unit, which is arranged on one side of the plasma generator along the powder falling path to increase the residence time of the powder in the plasma action area.

[0097] Aspect 8: The device according to Aspect 7, wherein the slow-fall unit includes a baffle and / or an air flow conveyor to disperse the powder flow and slow down its falling speed, wherein the baffle is arranged along the powder falling path in a multi-level inclined manner; and the direction of the air flow conveyed by the air flow conveyor is opposite to the powder falling direction.

[0098] Aspect 9: The device according to any one of aspects 1 to 6, wherein the powder feeding unit is configured to have any one of a screw conveying device, a belt conveying device, a funnel, an hourglass, and a slope trough.

[0099] Aspect 10: The device according to Aspect 9, wherein when the powder feeding unit is set as the slope groove, the device further includes at least one powder blocking plate, which is arranged in the slope groove and forms a powder feeding space between the powder blocking plate and the slope groove for restricting the height of the powder flow.

[0100] Aspect 11: The device according to Aspect 2 further includes a second driving unit, which is used to drive the powder feeding unit and the plasma generator to move above the substrate platform to deposit the powder layer by layer on the substrate platform.

[0101] Aspect 12: The device according to Aspect 2 comprises a flat powder component, which is arranged above the substrate platform and is used to smooth the powder deposited on the substrate platform to form a uniform powder layer.

[0102] Aspect 13: According to the device described in Aspect 2, a plurality of the powder feeding units are arranged along a horizontal direction corresponding to the surface of the substrate platform, and each of the powder feeding units is used to transport powders of different materials.

[0103] Aspect 14: The device according to Aspect 2 further includes one or more injectors arranged below at least one layer of the screen, the injector having a powder inlet for receiving falling powder and a nozzle for injecting the received powder above the substrate platform, wherein when there are multiple injectors, their powder inlets are arranged relative to at least one mesh hole of the screen to form an array arrangement above the substrate platform.

[0104] Aspect 15: The device according to Aspect 14 further includes a pressure regulating unit connected to one or more of the injectors, for adjusting the injection pressure of the injectors; wherein when there are multiple injectors, the device further includes a third driving unit respectively connected to the multiple injectors, for adjusting the spacing between any adjacent injectors.

[0105] Aspect 16: A device for processing powder is provided for use in additive manufacturing equipment, wherein the device includes: at least one layer of screen, arranged above a substrate platform for releasing processed powder to the substrate platform; a powder feeding unit, arranged in a powder falling path before and / or after processing by at least one layer of the screen to uniformly convey the powder flow; a vibrator, used to control at least one layer of the screen and / or the powder feeding unit to vibrate the powder flowing through; and a first drive unit, the first drive unit being connected to at least one layer of the screen, and being used to drive the screen to periodically move to adjust the powder falling path; wherein the periodic motion is movement and / or rotation, and the first drive unit is further used to periodically adjust the frequency and / or speed of the periodic motion so that the powder is uniformly deposited on the substrate platform.

[0106] Aspect 17: The device according to Aspect 16 further includes a plasma generator, which is arranged on at least one side of the powder falling path before and / or after being processed by at least one layer of the screen and / or the powder feeding unit to form a plasma action area, and is used to emit plasma to the passing powder to change the morphology and properties of the powder.

[0107] Aspect 18: Provides an additive manufacturing device, comprising the device described in any one of Aspects 1 to 17.

[0108] Aspect 19: A control method for a powder processing device is provided, wherein the device includes: at least one layer of screen; a vibrator, a powder feeding unit, which are arranged in the powder falling path before and / or after being processed by at least one layer of the screen; and a plasma generator, which is arranged on at least one side of the powder falling path before and / or after being processed by at least one layer of the screen and / or the powder feeding unit to form a plasma action area; wherein the method includes: controlling the vibrator to transmit vibration to at least one layer of the screen and / or the powder feeding unit to act on the powder flowing through; and controlling the plasma generator to emit plasma to the passing powder to change the morphology and properties of the powder.

[0109] Aspect 20: A control method for a powder processing device is provided, wherein the device is used in additive manufacturing equipment and includes: at least one layer of screen, arranged above a substrate platform; a vibrator; a powder feeding unit, arranged in a powder falling path before and / or after processing by at least one layer of the screen; and a first drive unit, connected to at least one layer of the screen; wherein the method includes: controlling the vibrator to transmit vibration to at least one layer of the screen and / or the powder feeding unit to act on the powder flowing through; controlling the first drive unit to drive the screen to move periodically to adjust the powder falling path, and periodically adjusting the frequency and / or speed of the periodic motion so that the powder is evenly deposited on the substrate platform, wherein the periodic motion is movement and / or rotation.

[0110] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the contents disclosed herein. The present application is intended to cover any variations, uses or adaptations of the present application, which follow the general principles of the present application and include common knowledge or customary technical means in the art that are not disclosed in the present application. The specification and embodiments are to be regarded as exemplary only, and the present application is not limited to the precise structures described above and shown in the drawings, and various modifications and changes may be made without departing from the scope thereof.

Claims

1. A powder processing device, comprising: At least one layer of screen; A powder delivery unit is arranged in the powder falling path before and / or after being processed by at least one layer of the screen to evenly deliver the powder flow; A vibrator, used to control at least one layer of the screen and / or the powder feeding unit to vibrate and flow through the powder; and The plasma generator is arranged on at least one side of the powder falling path before and / or after being processed by at least one layer of the screen and / or the powder feeding unit to form a plasma action area, and is used to emit plasma to the passing powder to change the shape and properties of the powder.

2. The device according to claim 1, wherein at least one layer of the screen is arranged above the substrate platform of the additive manufacturing equipment to release the processed powder to the substrate platform, and the plasma generator is arranged in the powder falling path between the powder feeding unit and at least one layer of the screen. The apparatus according to claim 2 , wherein at least one layer of the mesh covers the substrate platform in a horizontal direction.

4. The device according to claim 2, further comprising a first driving unit connected to at least one layer of the screen, wherein the first driving unit is used to drive the screen to move periodically to adjust a powder falling path.

5. The device according to claim 4, wherein the periodic motion is movement and / or rotation, and the first driving unit is further used to adjust the frequency and / or speed of the periodic motion in stages so that the powder is evenly deposited on the substrate platform.

6. The device according to claim 4, wherein the screen is arranged to be connected to the first driving unit respectively and spaced in sequence in at least two layers above the substrate platform, and the first driving unit is further used to drive at least two layers of the screen to move relatively in different directions and / or frequencies and / or amplitudes.

7. The device according to claim 1 or 2, further comprising a slow-fall unit, which is arranged on one side of the plasma generator along the powder falling path and is used to increase the residence time of the powder in the plasma action area.

8. The device according to claim 7, wherein the slow-fall unit comprises a baffle and / or an air flow conveyor to disperse the powder flow and slow down its falling speed, wherein: The baffles are arranged along the powder falling path in a multi-stage inclined manner; The airflow direction conveyed by the airflow conveyor is opposite to the powder falling direction.

9. The device according to any one of claims 1 to 6, wherein the powder feeding unit is configured to have any one of a screw conveying device, a belt conveying device, a funnel, an hourglass and a slope trough.

10. The device according to claim 9, wherein when the powder feeding unit is configured as the slope groove, the device further comprises at least one powder blocking plate, wherein the powder blocking plate is disposed in the slope groove and forms a powder feeding space for restricting the height of the powder flow between the powder blocking plate and the slope groove. 11 . The device according to claim 2 , further comprising a second driving unit, the second driving unit being used to drive the powder feeding unit and the plasma generator to move above the substrate platform to deposit powder layer by layer on the substrate platform. 12 . The device according to claim 2 , further comprising a powder flattening component, which is disposed above the substrate platform and is used to smooth the powder deposited on the substrate platform to form a uniform powder layer.

13. The device according to claim 2, wherein a plurality of the powder feeding units are arranged along a horizontal direction corresponding to the surface of the substrate platform, and each of the powder feeding units is used to transport powders of different materials.

14. The apparatus according to claim 2, further comprising one or more injectors disposed below at least one layer of the screen, the injectors having a powder inlet for receiving falling powder and a nozzle for injecting the received powder onto the substrate platform. When there are multiple injectors, the powder inlets thereof are arranged relative to at least one mesh of the screen to form an array arrangement above the substrate platform.

15. The device according to claim 14 further comprises a pressure regulating unit connected to one or more of the injectors, for adjusting the injection pressure of the injectors; wherein when there are multiple injectors, the device further comprises a third driving unit respectively connected to the multiple injectors, for adjusting the spacing between any adjacent injectors.

16. An apparatus for processing powder for use in an additive manufacturing apparatus, wherein the apparatus comprises: at least one screen disposed above the substrate platform for releasing the processed powder to the substrate platform; A powder delivery unit is arranged in the powder falling path before and / or after being processed by at least one layer of the screen to evenly deliver the powder flow; A vibrator, used to control at least one layer of the screen and / or the powder feeding unit to vibrate and flow through the powder; and A first driving unit, the first driving unit is connected to at least one layer of the screen, and is used to drive the screen to move periodically to adjust a powder falling path; The periodic motion is movement and / or rotation, and the first driving unit is further used to adjust the frequency and / or speed of the periodic motion in stages so that the powder is evenly deposited on the substrate platform.

17. The device according to claim 16 further comprises a plasma generator, which is arranged on at least one side of the powder falling path before and / or after being processed by at least one layer of the screen and / or the powder feeding unit to form a plasma action area, and is used to emit plasma to the passing powder to change the morphology and properties of the powder.

18. An additive manufacturing device, comprising the device according to any one of claims 1 to 17.

19. A control method for a powder processing device, wherein the device comprises: At least one layer of screen; Vibrator, A powder feeding unit is arranged in the powder falling path before and / or after being processed by at least one layer of the screen; and A plasma generator is arranged on at least one side of the powder falling path before and / or after being processed by at least one layer of the screen and / or the powder feeding unit to form a plasma action area; The method comprises: Controlling the vibrator to transmit vibration to at least one layer of the screen and / or the powder feeding unit to act on the powder flowing through; and The plasma generator is controlled to emit plasma toward the passing powder to change the morphology and properties of the powder.

20. A control method for a powder processing device, wherein the device is used in an additive manufacturing device and comprises: At least one layer of screen is arranged above the substrate platform; Vibrator; A powder feeding unit is arranged in the powder falling path before and / or after being processed by at least one layer of the screen; and A first driving unit connected to at least one layer of the screen; The method comprises: Controlling the vibrator to transmit vibration to at least one layer of the screen and / or the powder feeding unit to act on the powder flowing through; The first driving unit is controlled to drive the screen to move periodically to adjust the powder falling path, and the frequency and / or speed of the periodic motion is adjusted in stages to make the powder evenly deposited on the substrate platform, wherein the periodic motion is movement and / or rotation.

Images