A multi-material additive manufacturing apparatus and method

Abstract

The application provides a multi-material additive manufacturing device and method, belonging to the technical field of additive manufacturing, comprising: a forming assembly comprising a base, a lifting driving element, a forming table, a translation driving element and a translation table; a powder spreading assembly comprising a powder bin and a baffle; a scanning galvanometer; a powder suction assembly comprising an electrostatic generator, an electrostatic powder suction roller and a vacuum powder suction device.The beneficial effects of the application are that: the electrostatic powder suction roller of the multi-material additive manufacturing device is provided with static electricity by the electrostatic generator, so that the powder on the forming table is adsorbed, the powder does not fall off, and the powder is separated from the powder particles by the vacuum powder suction device and the powder is refilled into the powder bin.Compared with a simple vacuum powder suction device, the powder absorption rate is improved, the pollution between different powders is reduced, and the utilization rate of the powder is greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of additive manufacturing technology, and relates to a multi-material additive manufacturing apparatus and method. Background Technology

[0002] Integrated "material-structure-function" components possess exceptional performance and hold immense promise for applications in aerospace, rail transportation, and other fields. Currently, multi-material components are typically joined using traditional post-processing techniques such as welding, resulting in low strength at the joint area and susceptibility to defects such as cracks, porosity, and inclusions, which negatively impact component performance. Unlike traditional processes, multi-material laser powder bed fusion technology actively controls the physical properties, structure, and function of the constructed component from the microscopic to the macroscopic level based on the layer-by-layer material composition changes. This truly enables the integrated fabrication of multi-material components, achieving higher bonding strength between dissimilar materials.

[0003] Multi-material laser powder bed fusion (LDF) is a novel additive manufacturing technology that overcomes the limitations of traditional additive manufacturing, which can only produce single materials. It allows for the deposition of multiple heterogeneous materials at any location on a component, offering greater design freedom in terms of composition and performance. This makes it an ideal forming technology for the rapid production of multi-material, high-performance parts. However, the mainstream multi-material powder bed fusion technique involves local removal followed by local filling. After filling and forming, the heterogeneous powders in the unmelted areas mix and contaminate each other, making separation difficult, especially for materials of similar density. This complex separation process hinders the recycling and reuse of the powder formed by this technology, significantly increasing production costs. Therefore, there is considerable room for improvement in addressing the challenge of recycling and reusing powder after use in multi-material laser powder bed fusion. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned problems in the prior art by proposing a multi-material additive manufacturing apparatus and method.

[0005] The objective of this invention can be achieved through the following technical solution: a multi-material additive manufacturing apparatus, comprising:

[0006] A forming assembly includes a base, a lifting drive element, a forming stage, a translation drive element, and a translation stage. The lifting drive element is connected to the base and can drive the forming stage to rise and fall. The translation drive element is connected to the base and can drive the translation stage to move.

[0007] A powder spreading assembly includes a powder hopper and a baffle. The powder hopper is disposed on the translation stage. The baffle can seal or expose the opening of the powder hopper. When the translation drive element drives the translation stage to move, the baffle can expose the opening of the powder hopper and be used to release powder.

[0008] A scanning galvanometer is aligned with the forming stage, and the scanning galvanometer is used to emit laser light toward the forming stage in a designated area to melt the powder;

[0009] The powder suction assembly includes an electrostatic generator, an electrostatic powder suction roller, and a vacuum powder suction device. The negative terminal of the electrostatic generator is connected to the forming stage, and the positive terminal of the electrostatic generator is connected to the electrostatic powder suction roller. The electrostatic powder suction roller is rotatably connected to the translation stage. The vacuum powder suction device is located above and aligned with the electrostatic powder suction roller. The electrostatic generator is used to give the unmelted powder on the forming stage a negative charge and to give the electrostatic powder suction roller a positive charge, thereby attracting the negatively charged powder. The vacuum powder suction device is used to remove the powder attracted on the electrostatic powder suction roller.

[0010] In the aforementioned multi-material additive manufacturing apparatus, the powder suction component further includes a flexible scraper. The flexible scraper is disposed on the vacuum powder suction device, and the flexible scraper can contact the electrostatic powder suction roller. The flexible scraper is used to scrape off the powder adsorbed by the rotating electrostatic powder suction roller.

[0011] In the aforementioned multi-material additive manufacturing apparatus, the powder suction component further includes an ion wind generator, which is located in the vacuum powder suction device. The ion wind generator is used to generate ion wind to eliminate the negative charge carried by the powder in the vacuum powder suction device, and the vacuum powder suction device is connected to the powder hopper.

[0012] In the aforementioned multi-material additive manufacturing apparatus, the powder suction assembly further includes a powder particle separator, which is located between the vacuum powder suction device and the powder hopper. The vacuum powder suction device is connected to the powder hopper through the powder particle separator, and the powder particle separator is used to separate powder and gas.

[0013] The aforementioned multi-material additive manufacturing apparatus also includes a powder cleaning component, which includes a compaction scraper connected to the translation stage. The compaction scraper is aligned with the forming stage and used to compact the loose powder on the forming stage and scrape the excess powder onto the base stage.

[0014] In the aforementioned multi-material additive manufacturing apparatus, the powder removal component further includes a vacuum suction tube and a powder suction nozzle. The vacuum suction tube is connected to the translation stage, and the powder suction nozzle is connected to the vacuum suction tube. The powder suction nozzle is aligned with the forming stage, and the vacuum suction tube is used to remove excess powder from the forming stage through the powder suction nozzle.

[0015] In the aforementioned multi-material additive manufacturing apparatus, the width of the powder-absorbing flat nozzle is greater than the width of the compaction scraper, the compaction scraper is disposed in the middle of the powder-absorbing flat nozzle, and powder-absorbing channels are formed between the two sides of the compaction scraper and the powder-absorbing flat nozzle.

[0016] In the aforementioned multi-material additive manufacturing apparatus, the powder spreading assembly further includes a spiral feed rod, which is disposed at the outlet of the powder hopper. The spiral feed rod is rotatably connected to the powder hopper and is used to stir the powder at the outlet of the powder hopper.

[0017] In the aforementioned multi-material additive manufacturing apparatus, the powder spreading assembly further includes an ultrasonic generator connected to the powder hopper, which is used to vibrate the powder in the powder hopper.

[0018] Secondly, a multi-material additive manufacturing method is also provided, and the multi-material additive manufacturing apparatus includes:

[0019] A forming assembly includes a base, a lifting drive element, a forming stage, a translation drive element, and a translation stage. The lifting drive element is connected to the base and can drive the forming stage to rise and fall. The translation drive element is connected to the base and can drive the translation stage to move.

[0020] A powder spreading assembly includes a powder hopper, a baffle, a spiral feeder, and an ultrasonic generator. The powder hopper is disposed on the translation platform. The baffle can seal or expose the opening of the powder hopper. When the translation drive element drives the translation platform to move, the baffle can expose the opening of the powder hopper and be used to release powder. The spiral feeder is disposed at the outlet of the powder hopper. The spiral feeder is rotatably connected to the powder hopper and is used to stir the powder at the outlet of the powder hopper. The ultrasonic generator is connected to the powder hopper and is used to vibrate the powder in the powder hopper.

[0021] A scanning galvanometer is aligned with the forming stage, and the scanning galvanometer is used to emit laser light toward the forming stage in a designated area to melt the powder;

[0022] The powder suction assembly includes an electrostatic generator, an electrostatic powder suction roller, a vacuum powder suction device, a flexible scraper, an ion wind generator, and a powder particle separator. The negative terminal of the electrostatic generator is connected to the forming stage, and the positive terminal of the electrostatic generator is connected to the electrostatic powder suction roller. The electrostatic powder suction roller is rotatably connected to the translation stage. The vacuum powder suction device is located above and aligned with the electrostatic powder suction roller. The electrostatic generator is used to negatively charge the unmelted powder on the forming stage and to positively charge the electrostatic powder suction roller, thereby attracting the negatively charged powder. The vacuum powder suction device is used to remove the powder. The powder adsorbed on the electrostatic powder-attracting roller is removed by a flexible sliding blade disposed in the vacuum powder-attracting device. The flexible scraper can contact the electrostatic powder-attracting roller and is used to scrape off the powder adsorbed on the rotating electrostatic powder-attracting roller. An ion wind generator is located in the vacuum powder-attracting device and is used to generate ion wind to eliminate the negative charge carried by the powder in the vacuum powder-attracting device. A powder particle separator is located between the vacuum powder-attracting device and the powder hopper. The vacuum powder-attracting device is connected to the powder hopper through the powder particle separator and is used to separate powder and gas.

[0023] It also includes a powder cleaning component, which includes a compaction scraper, a vacuum suction tube, and a powder suction nozzle. The compaction scraper is connected to the translation stage and is aligned with the forming stage to compact the loose powder on the forming stage and scrape the excess powder onto the base stage. The vacuum suction tube is connected to the translation stage, and the powder suction nozzle is connected to the vacuum suction tube and is aligned with the forming stage. The vacuum suction tube is used to suck away the excess powder on the forming stage through the powder suction nozzle.

[0024] The steps include:

[0025] S1: The lifting drive element drives the forming table to move downward by the distance of one layer of powder;

[0026] S2: The translation drive element drives the translation stage to the forming stage, the ultrasonic generator generates vibration, the spiral feed rod starts to stir, the baffle opens, the powder hopper containing the first powder starts to drop powder evenly, and at the same time, the compaction scraper follows the movement of the powder hopper to compact the loose first powder and scrape the excess first powder onto the base.

[0027] S3: The translation drive element drives the translation stage to the base, the baffle closes, and the vacuum suction tube sucks away the excess first powder on the forming stage through the powder suction flat nozzle. At this time, there is a layer of compacted and uniform first powder on the forming stage.

[0028] S4: The scanning galvanometer emits a laser beam toward the forming stage in a designated area to melt the first powder;

[0029] S5: The electrostatic generator operates, causing the first powder on the forming platform to become negatively charged and the electrostatic powder-absorbing roller to become positively charged. The electrostatic powder-absorbing roller and the first powder generate electrostatic force, causing the first powder to be firmly adsorbed onto the surface. The electrostatic powder-absorbing roller rotates, and the translation drive element drives the translation platform to move in the opposite direction of powder spreading to the base. The flexible scraper contacts the electrostatic powder-absorbing roller and scrapes off the first powder adsorbed by the rotating electrostatic powder-absorbing roller. The vacuum powder collector sucks away the first powder adsorbed on the electrostatic powder-absorbing roller. The negative charge on the first powder in the vacuum powder collector is eliminated by the ion wind generator. The first powder is sucked into the powder particle separator to separate the first powder and gas. The first powder falls into the powder hopper.

[0030] S6: Repeat steps S2-S5 to spread other powders until the layer is formed.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] 1. The electrostatic powder-attracting roller of this multi-material additive manufacturing device is made to be statically charged by an electrostatic generator to attract powder on the forming table and prevent the powder from falling off. After passing through a vacuum powder suction device and a powder particle separator, the powder is refilled into the powder hopper. Compared with a simple vacuum powder suction device, it improves the powder absorption rate, reduces contamination between different powders, and greatly improves the powder utilization rate.

[0033] 2. An electrostatic generator causes the forming table and the unmelted powder on it to be positively charged, and the electrostatic powder-collecting roller to be negatively charged. The electrostatic powder-collecting roller then attracts the negatively charged powder, and by rotating, the powder is brought close to the vacuum powder collector. The vacuum powder collector then removes the powder attracted by the electrostatic powder-collecting roller, thus achieving powder recovery.

[0034] 3. The flexible scraper can scrape off the powder adsorbed by the rotating electrostatic powder suction roller, thus ensuring that all the powder adsorbed on the electrostatic powder suction roller can be sucked away by the vacuum powder suction device.

[0035] 4. The ion wind generator can generate ion wind to eliminate the negative charge on the powder in the vacuum powder suction device. This allows the powder to be de-charged during the process of being sucked in by the vacuum powder suction device. After the negative charge is eliminated, the powder falls back into the powder hopper and can then be redistributed onto the forming table, greatly improving the utilization rate of the powder.

[0036] 5. When the powder sucked in by the vacuum powder suction device enters the powder particle separator, the powder particle separator separates the powder and gas, thereby limiting all the powder to enter the powder hopper and preventing the powder falling into the powder hopper from being thrown up.

[0037] 6. The compaction scraper is aligned with the forming table and used to compact the loose powder on the forming table and scrape the excess powder onto the base, thereby preventing excess powder residue on the forming table and reducing cross-contamination between powders.

[0038] 7. The vacuum suction tube removes excess powder from the forming table through the powder suction flat nozzle, cleaning up excess powder after spreading and reducing cross-contamination between powders. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the multi-material additive manufacturing apparatus of the present invention.

[0040] Figure 2 This is a schematic diagram of the powder spreading component of the present invention.

[0041] Figure 3 This is a schematic diagram of the powder-absorbing component of the present invention.

[0042] Figure 4 This is a schematic diagram of the structure of the powder cleaning component of the present invention.

[0043] Figure 5 This is a schematic diagram of the internal structure of the powder cleaning component of the present invention.

[0044] Figure 6 This is a schematic diagram illustrating the working principle of the powder-absorbing component of the present invention.

[0045] Figure 7 This is a schematic diagram of the structure of the multiple powder spreading components, the powder suction component with multiple vacuum powder suction devices, and the multiple powder cleaning components of the present invention.

[0046] Figure 8 This is a schematic diagram of the multi-material additive manufacturing method of the present invention.

[0047] In the diagram, 100 is the forming component; 110 is the base; 120 is the lifting drive element; 130 is the forming table; 140 is the translation drive element; 150 is the translation table; 200 is the powder spreading component; 210 is the powder hopper; 220 is the baffle; 230 is the spiral feed rod; 240 is the ultrasonic generator; 300 is the scanning galvanometer; 400 is the powder suction component; 410 is the electrostatic generator; 420 is the electrostatic powder suction roller; 430 is the vacuum powder suction device; 440 is the flexible scraper; 450 is the ion wind generator; 460 is the powder particle separator; 500 is the powder cleaning component; 510 is the compaction scraper; 520 is the vacuum suction tube; and 530 is the powder suction flat nozzle. Detailed Implementation

[0048] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings to further illustrate the technical solutions of the present invention. However, the present invention is not limited to these embodiments.

[0049] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0050] Furthermore, in this invention, descriptions involving terms such as "first," "second," and "a" are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0051] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0052] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0053] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

[0054] like Figures 1-7 As shown, a multi-material additive manufacturing apparatus includes: a forming component 100, a powder spreading component 200, a scanning galvanometer 300, and a powder suction component 400.

[0055] The forming assembly 100 includes a base 110, a lifting drive element 120, a forming stage 130, a translation drive element 140, and a translation stage 150. The lifting drive element 120 is connected to the base 110 and can drive the forming stage 130 to rise and fall. The translation drive element 140 is connected to the base 110 and can drive the translation stage 150 to move.

[0056] The powder spreading assembly 200 includes a powder hopper 210 and a baffle 220. The powder hopper 210 is disposed on the translation stage 150. The baffle 220 can seal or expose the opening of the powder hopper 210. When the translation drive element 140 drives the translation stage 150 to move, the baffle 220 can expose the opening of the powder hopper 210 and be used to release powder.

[0057] The scanning galvanometer 300 is aligned with the forming stage 130, and the scanning galvanometer 300 is used to emit laser light toward the forming stage 130 in a designated area to melt the powder.

[0058] The powder suction assembly 400 includes an electrostatic generator 410, an electrostatic powder suction roller 420, and a vacuum powder suction device 430. The negative terminal of the electrostatic generator 410 is connected to the forming stage 130, and the positive terminal of the electrostatic generator 410 is connected to the electrostatic powder suction roller 420. The electrostatic powder suction roller 420 is rotatably connected to the translation stage 150. The vacuum powder suction device 430 is located above and aligned with the electrostatic powder suction roller 420. The electrostatic generator 410 is used to give the unmelted powder on the forming stage 130 a negative charge and to give the electrostatic powder suction roller 420 a positive charge, thereby attracting the negatively charged powder. The vacuum powder suction device 430 is used to remove the powder attracted on the electrostatic powder suction roller 420.

[0059] In this embodiment, the electrostatic generator 410 causes the forming table 130 and the unmelted powder on it to be positively charged, and the electrostatic powder-collecting roller 420 to be negatively charged. The electrostatic powder-collecting roller 420 then adsorbs the negatively charged powder, and by rotating it, the powder is brought close to the vacuum powder collector 430. The vacuum powder collector 430 then sucks away the powder adsorbed on the electrostatic powder-collecting roller 420, thus achieving powder recovery.

[0060] like Figure 1 , Figure 3 , Figure 7As shown, based on the above embodiment, the powder suction assembly 400 further includes a flexible scraper 440. The flexible scraper is disposed on the vacuum powder suction device 430. The flexible scraper 440 can contact the electrostatic powder suction roller 420. The flexible scraper 440 is used to scrape off the powder adsorbed by the rotating electrostatic powder suction roller 420.

[0061] In this embodiment, the flexible scraper 440 can scrape off the powder adsorbed by the rotating electrostatic powder suction roller 420, thereby ensuring that all the powder adsorbed on the electrostatic powder suction roller 420 can be sucked away by the vacuum powder suction device 430.

[0062] like Figure 1 , Figure 3 , Figure 7 As shown, based on the above embodiment, the powder suction assembly 400 further includes an ion wind generator 450, which is located in the vacuum powder suction device 430. The ion wind generator 450 is used to generate ion wind to eliminate the negative charge carried by the powder in the vacuum powder suction device 430. The vacuum powder suction device 430 is connected to the powder hopper 210.

[0063] In this embodiment, the ion wind generator 450 can generate ion wind to eliminate the negative charge carried by the powder in the vacuum powder suction device 430, so that the negative charge can be eliminated during the process of the powder being sucked in by the vacuum powder suction device 430. After the negative charge is eliminated, the powder falls back into the powder hopper 210, so that it can be redistributed onto the forming table 130, which greatly improves the utilization rate of the powder.

[0064] like Figure 1 , Figure 3 , Figure 7 As shown, based on the above embodiment, the powder suction assembly 400 further includes a powder particle separator 460, which is located between the vacuum powder suction device 430 and the powder hopper 210. The vacuum powder suction device 430 is connected to the powder hopper 210 through the powder particle separator 460, and the powder particle separator 460 is used to separate powder and gas.

[0065] In this embodiment, when the powder sucked in by the vacuum powder suction device 430 enters the powder particle separator 460, the powder particle separator 460 separates the powder and the gas, thereby limiting all the powder to enter the powder hopper 210 and preventing the powder falling into the powder hopper 210 from being thrown up.

[0066] like Figure 1 , Figure 5 , Figure 6As shown, based on the above embodiment, a powder cleaning component 500 is also included. The powder cleaning component 500 includes a compaction scraper 510, which is connected to the translation stage 150. The compaction scraper 510 is aligned with the forming stage 130 and is used to compact the loose powder on the forming stage 130 and scrape the excess powder onto the base stage 110.

[0067] In this embodiment, the compaction scraper 510 is aligned with the forming table 130 and used to compact the loose powder on the forming table 130 and scrape the excess powder onto the base 110, thereby preventing excess powder residue on the forming table 130 and reducing cross-contamination between powders.

[0068] like Figure 1 , Figure 5 , Figure 6 As shown, based on the above embodiment, the powder cleaning component 500 further includes a vacuum suction tube 520 and a powder suction nozzle 530. The vacuum suction tube 520 is connected to the translation stage 150, and the powder suction nozzle 530 is connected to the vacuum suction tube 520. The powder suction nozzle 530 is aligned with the forming stage 130, and the vacuum suction tube 520 is used to suck away excess powder on the forming stage 130 through the powder suction nozzle 530.

[0069] In this embodiment, the vacuum suction tube 520 sucks away excess powder on the forming table 130 through the powder suction nozzle 530, cleaning up the excess powder after spreading and reducing cross-contamination between powders.

[0070] like Figure 1 , Figure 5 , Figure 6 As shown, based on the above embodiment, the width of the powder suction nozzle 530 is greater than the width of the compaction scraper 510. The compaction scraper 510 is disposed in the middle of the powder suction nozzle 530, and powder suction channels (not shown in the figure) are formed between the two sides of the compaction scraper 510 and the powder suction nozzle 530, respectively.

[0071] In this embodiment, powder suction channels are formed between the two sides of the compaction scraper 510 and the powder suction nozzle 530, so that the powder on both sides of the compaction scraper 510 can be cleaned at the same time.

[0072] like Figure 1 , Figure 2 As shown, based on the above embodiment, the powder spreading assembly 200 further includes a spiral feeding rod 230, which is disposed at the outlet of the powder hopper 210. The spiral feeding rod 230 is rotatably connected to the powder hopper 210 and is used to stir the powder at the outlet of the powder hopper 210.

[0073] In this embodiment, the screw feed rod 230 is rotatably connected to the powder hopper 210 and can stir the powder at the outlet of the powder hopper 210 to prevent powder agglomeration.

[0074] like Figure 1 , Figure 2 As shown, based on the above embodiment, the powder spreading assembly 200 further includes an ultrasonic generator 240, which is connected to the powder hopper 210 and is used to vibrate the powder in the powder hopper 210.

[0075] In this embodiment, the ultrasonic generator 240 can vibrate the powder in the powder hopper 210, improve the flowability of the powder in the powder hopper 210, prevent the powder from clumping, improve the uniformity of powder spreading, and improve the forming quality.

[0076] In summary, the electrostatic powder suction roller 420 of this multi-material additive manufacturing apparatus is electrostatically charged by the electrostatic generator 410, which is used to attract powder on the forming table 130 to prevent the powder from falling off. After passing through the vacuum powder suction device 430 and the powder particle separator 460, the powder is refilled into the powder hopper 210. Compared with a simple vacuum powder suction device, it improves the powder absorption rate, reduces contamination between different powders, and greatly improves the powder utilization rate.

[0077] It is worth noting that for powders of different materials, a powder spreading component 200, a powder suction component 400, and a powder cleaning component 500 corresponding to each material powder can be added, and the different materials can be processed by different powder spreading components 200, powder suction components 400, and powder cleaning components 500.

[0078] like Figure 7 As shown, powder spreading components A-F powder spreading components 200 and powder cleaning components A-F powder cleaning components 500 are integrated on the translation stage 150, respectively corresponding to powder suction components A-F powder suction components 400-F powder suction components 400 on the electrostatic powder suction roller 420. When the powder spreading component 200 and powder suction component 400 of one material are working, the flexible scraper 440 on the electrostatic vacuum powder suction unit corresponding to the other materials moves upward and opens. For example, when the powder spreading component A, powder suction component A, and powder cleaning component A are working, the flexible scraper 440 of powder suction components B / C / D / E / F are in an open state, and only the flexible scraper 440 of powder suction component A is in a closed state.

[0079] like Figure 8 As shown, a multi-material additive manufacturing method is illustrated, taking the dual-material printing of powder A and powder B as an example:

[0080] S1: The lifting drive element 120 drives the forming table 130 to move downward by the distance of one layer of powder;

[0081] S2: The translation drive element 140 drives the translation stage 150 to the forming stage 130, the ultrasonic generator 240 generates vibration, the spiral feed rod 230 starts to stir, the baffle 220 opens, the powder hopper 210 containing powder A starts to drop powder evenly, and at the same time, the compaction scraper 510 follows the powder hopper 210 to compact the loose powder A and scrape the excess powder A onto the base 110.

[0082] S3: The translation drive element 140 drives the translation stage 150 to the base 110, the baffle 220 is closed, and the vacuum suction tube 520 sucks away the excess powder A on the forming stage 130 through the powder suction flat nozzle 530. At this time, there is a layer of compacted and uniform powder A on the forming stage 130.

[0083] S4: The scanning galvanometer 300 emits a laser beam toward the forming stage 130 in a designated area to melt the powder A;

[0084] S5: The electrostatic generator 410 operates, causing the powder A on the forming table 130 to become negatively charged and the electrostatic powder-absorbing roller 420 to become positively charged. The electrostatic powder-absorbing roller 420 generates electrostatic force with the powder A, causing the powder A to be firmly adsorbed on the surface. The electrostatic powder-absorbing roller 420 rotates, and the translation drive element 140 drives the translation table 150 to move in the opposite direction of powder spreading to the base 110. The flexible scraper 440 contacts the electrostatic powder-absorbing roller 420 and scrapes off the powder A adsorbed by the rotating electrostatic powder-absorbing roller 420. The vacuum powder suction device 430 sucks away the powder A adsorbed on the electrostatic powder-absorbing roller 420. After the ion wind generator 450 eliminates the negative charge of the powder A in the vacuum powder suction device 430, the powder A is sucked into the powder particle separator 460 to separate the powder A and the gas. The powder A falls into the powder hopper 210.

[0085] S6: The translation drive element 140 drives the translation stage 150 to the forming stage 130, the ultrasonic generator 240 generates vibration, the spiral feed rod 230 starts to stir, the baffle 220 opens, the powder hopper 210 containing powder B starts to drop powder evenly, and at the same time, the compaction scraper 510 follows the powder hopper 210 to compact the loose powder B and scrape the excess powder B onto the base 110.

[0086] S7: The translation drive element 140 drives the translation stage 150 to the base 110, the baffle 220 is closed, and the vacuum suction tube 520 sucks away the excess powder B on the forming stage 130 through the powder suction flat nozzle 530. At this time, there is a layer of compacted and uniform powder B on the forming stage 130.

[0087] S8: The scanning galvanometer 300 emits a laser beam toward the forming stage 130 in a designated area to melt the powder B;

[0088] S9: The electrostatic generator 410 operates, causing the powder B on the forming table 130 to become negatively charged and the electrostatic powder-absorbing roller 420 to become positively charged. The electrostatic powder-absorbing roller 420 generates electrostatic force with the powder B, causing the powder B to be firmly adsorbed on the surface. The electrostatic powder-absorbing roller 420 rotates, and the translation drive element 140 drives the translation table 150 to move in the opposite direction of powder spreading to the base 110. The flexible scraper 440 contacts the electrostatic powder-absorbing roller 420 and scrapes off the powder B adsorbed by the rotating electrostatic powder-absorbing roller 420. The vacuum powder suction device 430 sucks away the powder B adsorbed on the electrostatic powder-absorbing roller 420. After the ion wind generator 450 eliminates the negative charge of the powder B in the vacuum powder suction device 430, the powder B is sucked into the powder particle separator 460 to separate the powder B and gas. The powder B falls into the powder hopper 210.

[0089] S10: Repeat steps S1-S9 until the current layer is formed. The forming platform 130 moves down and begins the powder spreading-powder suction reciprocating motion for the next layer.

Claims

1. A multi-material additive manufacturing apparatus, characterized in that, include: A forming assembly includes a base, a lifting drive element, a forming stage, a translation drive element, and a translation stage. The lifting drive element is connected to the base and can drive the forming stage to rise and fall. The translation drive element is connected to the base and can drive the translation stage to move. A powder spreading assembly includes a powder hopper and a baffle. The powder hopper is disposed on the translation stage. The baffle can seal or expose the opening of the powder hopper. When the translation drive element drives the translation stage to move, the baffle can expose the opening of the powder hopper and be used to release powder. A scanning galvanometer is aligned with the forming stage, and the scanning galvanometer is used to emit laser light toward the forming stage in a designated area to melt the powder; The powder suction assembly includes an electrostatic generator, an electrostatic powder suction roller, and a vacuum powder suction device. The negative terminal of the electrostatic generator is connected to the forming stage, and the positive terminal of the electrostatic generator is connected to the electrostatic powder suction roller. The electrostatic powder suction roller is rotatably connected to the translation stage. The vacuum powder suction device is located above and aligned with the electrostatic powder suction roller. The electrostatic generator is used to give the unmelted powder on the forming stage a negative charge and to give the electrostatic powder suction roller a positive charge, thereby attracting the negatively charged powder. The vacuum powder suction device is used to remove the powder attracted on the electrostatic powder suction roller. It also includes a powder cleaning component, which includes a compaction scraper connected to the translation stage. The compaction scraper is aligned with the forming stage and used to compact the loose powder on the forming stage and scrape the excess powder onto the base stage. The powder cleaning assembly also includes a vacuum suction tube and a powder suction nozzle. The vacuum suction tube is connected to the translation stage, and the powder suction nozzle is connected to the vacuum suction tube. The powder suction nozzle is aligned with the forming stage, and the vacuum suction tube is used to suck away excess powder from the forming stage through the powder suction nozzle. The width of the powder-absorbing flat nozzle is greater than the width of the compaction scraper. The compaction scraper is located in the middle of the powder-absorbing flat nozzle, and powder-absorbing channels are formed between the two sides of the compaction scraper and the powder-absorbing flat nozzle.

2. The multi-material additive manufacturing apparatus as described in claim 1, characterized in that: The powder suction assembly also includes a flexible scraper, which is disposed on the vacuum powder suction device. The flexible scraper can contact the electrostatic powder suction roller and is used to scrape off the powder adsorbed by the rotating electrostatic powder suction roller.

3. The multi-material additive manufacturing apparatus as described in claim 1, characterized in that: The powder suction assembly also includes an ion wind generator, which is located in the vacuum powder suction device. The ion wind generator is used to generate ion wind to eliminate the negative charge carried by the powder in the vacuum powder suction device. The vacuum powder suction device is connected to the powder hopper.

4. The multi-material additive manufacturing apparatus as described in claim 3, characterized in that: The powder suction assembly also includes a powder particle separator, which is located between the vacuum powder suction device and the powder hopper. The vacuum powder suction device is connected to the powder hopper through the powder particle separator, and the powder particle separator is used to separate powder and gas.

5. The multi-material additive manufacturing apparatus as described in claim 1, characterized in that: The powder spreading assembly also includes a spiral feeding rod, which is disposed at the outlet of the powder hopper. The spiral feeding rod is rotatably connected to the powder hopper and is used to stir the powder at the outlet of the powder hopper.

6. The multi-material additive manufacturing apparatus as described in claim 1, characterized in that: The powder spreading assembly also includes an ultrasonic generator connected to the powder hopper, which is used to vibrate the powder in the powder hopper.

7. A multi-material additive manufacturing method, characterized in that, Multi-material additive manufacturing apparatus includes: A forming assembly includes a base, a lifting drive element, a forming stage, a translation drive element, and a translation stage. The lifting drive element is connected to the base and can drive the forming stage to rise and fall. The translation drive element is connected to the base and can drive the translation stage to move. A powder spreading assembly includes a powder hopper, a baffle, a spiral feeder, and an ultrasonic generator. The powder hopper is disposed on the translation platform. The baffle can seal or expose the opening of the powder hopper. When the translation drive element drives the translation platform to move, the baffle can expose the opening of the powder hopper and be used to release powder. The spiral feeder is disposed at the outlet of the powder hopper. The spiral feeder is rotatably connected to the powder hopper and is used to stir the powder at the outlet of the powder hopper. The ultrasonic generator is connected to the powder hopper and is used to vibrate the powder in the powder hopper. A scanning galvanometer is aligned with the forming stage, and the scanning galvanometer is used to emit laser light toward the forming stage in a designated area to melt the powder; The powder suction assembly includes an electrostatic generator, an electrostatic powder suction roller, a vacuum powder suction device, a flexible scraper, an ion wind generator, and a powder particle separator. The negative terminal of the electrostatic generator is connected to the forming stage, and the positive terminal of the electrostatic generator is connected to the electrostatic powder suction roller. The electrostatic powder suction roller is rotatably connected to the translation stage. The vacuum powder suction device is located above and aligned with the electrostatic powder suction roller. The electrostatic generator is used to negatively charge the unmelted powder on the forming stage and to positively charge the electrostatic powder suction roller, thereby attracting the negatively charged powder. The vacuum powder suction device is used to remove the powder. The powder adsorbed on the electrostatic powder-attracting roller is scraped off by a flexible scraper located in the vacuum powder-attracting device. The flexible scraper can contact the electrostatic powder-attracting roller and is used to scrape off the powder adsorbed on the rotating electrostatic powder-attracting roller. An ion wind generator is located in the vacuum powder-attracting device and is used to generate ion wind to eliminate the negative charge carried by the powder in the vacuum powder-attracting device. A powder particle separator is located between the vacuum powder-attracting device and the powder hopper. The vacuum powder-attracting device is connected to the powder hopper through the powder particle separator, which is used to separate powder and gas. It also includes a powder cleaning component, which includes a compaction scraper, a vacuum suction tube, and a powder suction nozzle. The compaction scraper is connected to the translation stage and is aligned with the forming stage to compact the loose powder on the forming stage and scrape the excess powder onto the base stage. The vacuum suction tube is connected to the translation stage, and the powder suction nozzle is connected to the vacuum suction tube and is aligned with the forming stage. The vacuum suction tube is used to suck away the excess powder on the forming stage through the powder suction nozzle. The steps include: S1: The lifting drive element drives the forming table to move downward by the distance of one layer of powder; S2: The translation drive element drives the translation stage to the forming stage, the ultrasonic generator generates vibration, the spiral feed rod starts to stir, the baffle opens, the powder hopper containing the first powder starts to drop powder evenly, and at the same time, the compaction scraper follows the movement of the powder hopper to compact the loose first powder and scrape the excess first powder onto the base. S3: The translation drive element drives the translation stage to the base, the baffle closes, and the vacuum suction tube sucks away the excess first powder on the forming stage through the powder suction flat nozzle. At this time, there is a layer of compacted and uniform first powder on the forming stage. S4: The scanning galvanometer emits a laser beam toward the forming stage in a designated area to melt the first powder; S5: The electrostatic generator operates, causing the first powder on the forming platform to become negatively charged and the electrostatic powder-absorbing roller to become positively charged. The electrostatic powder-absorbing roller and the first powder generate electrostatic force, causing the first powder to be firmly adsorbed onto the surface. The electrostatic powder-absorbing roller rotates, and the translation drive element drives the translation platform to move in the opposite direction of powder spreading to the base. The flexible scraper contacts the electrostatic powder-absorbing roller and scrapes off the first powder adsorbed by the rotating electrostatic powder-absorbing roller. The vacuum powder collector sucks away the first powder adsorbed on the electrostatic powder-absorbing roller. The negative charge on the first powder in the vacuum powder collector is eliminated by the ion wind generator. The first powder is sucked into the powder particle separator to separate the first powder and gas. The first powder falls into the powder hopper. S6: Repeat steps S2-S5 until the layer is formed.

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