Multi-material additive manufacturing method and device

Abstract

The present invention discloses a multi-material additive manufacturing method and device. The multi-material additive manufacturing method includes S1, slicing a three-dimensional model of a sample to be prepared to form a plurality of surface layers stacked in sequence along a first direction; S2, spraying a binder on a set area of ​​the first surface layer, and laying a molding powder on the binder, the molding powder and the binder forming a base structure; S3, curing the base structure to solidify the base structure into a matrix; S4, removing the uncured molding powder; S5, repeating steps S2-S4 to form N matrixes on the first surface layer, the N matrixes are connected or not connected, N≥2, and the molding powders used to form the N matrixes are different; S6, repeating steps S1-S5 to mold the structure on the surface layer layer by layer along the first direction until the sample preparation is completed. The present invention can print different materials on different parts of a surface layer, so that the function of the product will be greatly expanded and the reliability of the product will be improved.

Description

Technical Field

[0001] The present invention relates to a multi-material additive manufacturing method and device, belonging to the technical field of additive manufacturing. Background Art

[0002] Additive manufacturing, one of the most advanced molding methods currently available, includes 3D printing. Invented in the 1990s, it uses digital model files as the basis for constructing objects through layer-by-layer printing of powdered metal or non-metallic materials. It has applications in a wide range of fields, including aviation, aerospace, shipbuilding, automotive, electronics, healthcare, and jewelry. Its distinguishing feature is that it eliminates the need for machining or mold fabrication, allowing parts of any shape to be generated from computer graphics data. Another key feature is its rapid repair capability. When equipment malfunctions during field operations or military training, damaged parts need to be quickly replaced. 3D printers can quickly print the necessary parts, enabling quick repairs and saving time.

[0003] Regarding powder-laying or powder-feeding 3D printing technology, traditional printing technology first lays the powder and then applies a binder on the powder during printing. In this method, since the powder is easily piled up when laying, the surface of the mixed part of the powder and binder becomes uneven. It is necessary to use a scraper or other tool to scrape the mixed part flat and then solidify it. When printing on different parts of the same surface layer, there are already solidified parts. When scraping other parts flat, due to the inconsistent hardness of the solidified part and the higher hardness of the solidified part, in order to protect the solidified part, the scraper cannot abut against the surface of the solidified part. As a result, when scraping the unsolidified part flat, it is easy for the unsolidified part and the solidified part to have unequal heights. This makes the heights of different parts on the same surface layer uneven, which in turn affects subsequent printing, reduces the yield rate of the manufactured product, and affects product quality. Existing printing technology generally does not have the function of printing different materials at any position on the same cross-section, which objectively affects the functional expansion of the product. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the object of the present invention is to provide a multi-material additive manufacturing method and device.

[0005] To achieve the aforementioned object of the invention, the technical solutions adopted by the present invention include:

[0006] The present invention provides a multi-material additive manufacturing method, comprising the following steps:

[0007] S1. Slicing the three-dimensional model of the sample to be prepared to form a plurality of surface layers stacked in sequence along a first direction;

[0008] S2. Spraying a binder on the area set by the first surface layer, and laying a molding powder on the binder, wherein the molding powder and the binder form a base structure;

[0009] S3, curing the base structure using a curing source, so that the base structure is cured and formed into a matrix;

[0010] S4, removing the uncured molding powder;

[0011] S5. Repeat steps S2-S4 to form N matrixes on the first surface layer. The N matrixes are connected or not connected, thereby completing the structural forming on the first surface layer. N is greater than or equal to 2, and the molding powders used to form the N matrixes are different.

[0012] S6. Repeat steps S1-S5 to form multiple structures on the surface layer layer by layer along the first direction until the sample preparation is completed.

[0013] Furthermore, the adhesive includes a thermosetting resin or a quick-drying resin.

[0014] Furthermore, in S3, the curing source includes a heating lamp, and the heating lamp is used to at least cure the base structure of the adhesive including the thermosetting resin.

[0015] Furthermore, the molding powder includes any one of resin film powder, metal powder, and gypsum.

[0016] Furthermore, in the S3, a laser source is also used to perform secondary curing on the base structure of the molding powder including the resin film powder and the metal powder.

[0017] The present invention also provides a multi-material additive manufacturing device for implementing the above-mentioned multi-material additive manufacturing method, including a workbench, a printing mechanism, a powder spreading mechanism, a curing mechanism and a recovery mechanism. The workbench is at least used to fix and support the substrate, the printing mechanism is at least used to apply a binder in a set area, the powder spreading mechanism is at least used to spread molding powder on the binder, the curing mechanism is at least used to cure and shape the base structure, and the recovery mechanism is at least used to remove and recover the uncured molding powder on the workbench.

[0018] Furthermore, the workbench includes a work plate body and a driving mechanism, the work plate body is connected to the driving mechanism, the work plate body is at least used to fix and support the base, and the driving mechanism is at least used to drive the work plate to rotate around a set axis so that the unsolidified molding powder falls from the work plate body by gravity.

[0019] Furthermore, the workbench includes a base plate, which is provided with a first end face and a second end face facing each other, the first end face is fixedly connected to the working plate body, the second end face is at least used to fix and support the base, and the second end face is provided with a fixing groove, and when receiving the base, part of the base is fixed in the fixing groove.

[0020] Furthermore, the fixing groove is a grid-like groove structure.

[0021] Furthermore, the driving mechanism includes a motor and a rotating shaft, one end of the rotating shaft is fixedly connected to the working plate body, and the other end of the rotating shaft is fixedly connected to the output shaft of the motor, and the motor drives the work platform body to rotate around the axis of the rotating shaft.

[0022] Furthermore, the recovery mechanism includes a hopper, which is arranged on the lower side of the working plate body along the first direction, and the hopper is at least used to receive the molding powder dropped from the working plate body.

[0023] Furthermore, the recovery mechanism includes a negative pressure pump and a storage bin, the hopper is provided with a suction port, the suction port is communicated with the storage bin, the negative pressure pump is connected to the suction port, and the negative pressure pump is at least used to suck the molding powder in the hopper into the storage bin through the suction port.

[0024] Furthermore, the hopper is provided with a plurality of suction ports, the recovery mechanism includes a plurality of storage bins, and the plurality of suction ports and the plurality of storage bins are connected one by one.

[0025] Furthermore, the suction port is provided with a valve.

[0026] Furthermore, the powder spreading mechanism includes a first bracket and a powder sprinkler, the first bracket includes a first support plate extending along the second direction, and a first crossbeam movably connected to the first support plate, the first crossbeam extends along a third direction, the second direction and the third direction are arranged to intersect, the powder sprinkler is arranged on the first crossbeam, the first support plate can perform telescopic movement along the first direction to drive the powder sprinkler to move along the first direction, the first crossbeam can move along the second direction on the first support plate, the powder sprinkler includes a connected powder bin and a bulk port, the powder bin is at least used to accommodate the molding powder, the bulk port is arranged opposite to the workbench, and the bulk port covers the workbench along the third direction.

[0027] Furthermore, the powder spreading mechanism includes a conveying pipeline and a pneumatic conveying pump, one end of the conveying pipeline is connected to the storage bin, and the other end is connected to the powder bin, the pneumatic conveying pump is connected to the conveying pipeline, and the pneumatic conveying pump is at least used to convey the molding powder from the storage bin to the powder bin through the conveying pipeline.

[0028] Furthermore, a transition hopper is provided between one end of the conveying pipeline and the powder bin, the transition hopper is provided with an inner cavity and an outlet and an inlet connected to the inner cavity, the inlet is connected to the conveying pipeline, the outlet is connected to the powder bin, and the transition hopper is provided with an exhaust filter port, and the exhaust filter port is connected to the inner cavity.

[0029] Furthermore, the exhaust filter port includes a dust filter cover.

[0030] Furthermore, the dust filter cover is a labyrinth-type metal filter structure.

[0031] Furthermore, the powder spreading mechanism includes a plurality of conveying pipelines, one end of each of the plurality of conveying pipelines is connected to each of the plurality of storage bins, and the other end of each of the plurality of conveying pipelines is connected to the powder bin.

[0032] Furthermore, the printing mechanism includes a second bracket and a printer, the second bracket includes a second support plate extending along the second direction, and a second beam movably connected to the second support plate, the second beam extends along the third direction, the second direction and the third direction are arranged to intersect, the printer is arranged on the second beam, the second support plate can perform telescopic movement along the first direction to drive the printer to move along the first direction, the second beam can move along the second direction on the second support plate, the printer includes a first inner cavity and a printing port that are connected, the first inner cavity is at least used to accommodate the adhesive, and the printing port is arranged opposite to the workbench.

[0033] Furthermore, the second crossbeam is provided with a first track extending along a third direction, and the printer is movably connected to the second crossbeam and can move along the first track.

[0034] Furthermore, the curing mechanism includes a third bracket and a curing part, the third bracket includes a third support plate extending along the second direction, and a third beam movably connected to the third support plate, the third beam extends along the third direction, the second direction and the third direction are arranged to intersect, the curing part is arranged on the third beam, the third support plate can perform telescopic movement along the first direction to drive the curing part to move along the first direction, the third beam can move along the second direction on the third support plate, and the curing part includes at least one curing source, and the curing source is arranged opposite to the workbench.

[0035] Furthermore, the curing source includes a heating lamp and a laser lamp.

[0036] Furthermore, the third crossbeam is provided with a third track extending along the third direction, and the curing component is movably connected to the third crossbeam and can move along the third track.

[0037] Furthermore, the additive manufacturing device also includes a sealed working cover, which at least covers the workbench, the printing mechanism, the powder spreading mechanism, the curing mechanism and the recovery mechanism.

[0038] Compared with the prior art, the advantages of the present invention include:

[0039] 1) The present invention can print different materials on different parts of a surface layer to obtain a denser solid structure and higher mechanical properties, which will greatly expand the function of the product and improve the reliability of the product.

[0040] 2) By spraying the binder on designated locations before applying the molding powder, the present invention eliminates the need for scraping and ensures high consistency across different components on the same surface layer, further improving the quality and yield of printed products. This allows for printing different materials on different components on the same surface layer. Furthermore, spraying the binder first and then applying the molding powder ensures support stability when printing on different surface layers.

[0041] 3) The present invention provides a rotatable workbench to recycle and utilize the molding powder by its own gravity, effectively avoiding the situation where the unprinted molding powder is adulterated, resulting in significant performance degradation, and the performance of the products printed after secondary or multiple reuses is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 2. It is a schematic diagram of a process of printing a substrate in one embodiment of the multi-material additive manufacturing method of the present invention;

[0043] Figure 21 is a schematic structural diagram of an embodiment of a multi-material additive manufacturing device of the present invention;

[0044] Figure 3 yes Figure 2 A schematic diagram of a portion of the structure as viewed from the direction A is shown;

[0045] Figure 4 yes Figure 2 A schematic diagram of the structure of the working table after rotation in the embodiment shown;

[0046] Figure 5 Schematic diagram of the structure of a substrate in an embodiment of a multi-material additive manufacturing device of the present invention.

[0047] Description of reference numerals:

[0048] 110, binder; 120, molding powder; 130, base structure; 140, base; 200, workbench; 210, work plate; 220, rotating shaft; 230, base plate; 231, fixing groove; 310, printer; 320, second bracket; 321, second support plate; 322, second crossbeam; 410, powder sprayer; 411, powder bin; 412, bulk material outlet; 420, first bracket ; 421, first support plate; 422, first crossbeam; 430, conveying pipeline; 440, pneumatic transmission pump; 450, transition hopper; 510, curing part; 520, third bracket; 521, third support plate; 522, third crossbeam; 610, hopper; 620, negative pressure pump; 630, storage bin; 640, suction port; 650, valve; 700, working cover; 710, dust filter cover. DETAILED DESCRIPTION

[0049] In view of the shortcomings of the prior art, the inventors of this case, after long-term research and extensive practice, have proposed the technical solution of the present invention. The following will further explain this technical solution, its implementation process and principles.

[0050] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0051] In addition, in the description of the present invention, it should be understood that the terms "upper", "lower", "inside", "outside", "horizontal", "vertical", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0052] Throughout this specification, references to terms such as "one embodiment," "an embodiment," or "the embodiment" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. Throughout this specification, the illustrative use of these terms does not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0053] See also Figure 2-Figure 4 The present invention also provides a multi-material additive manufacturing device, which is used to implement a multi-material additive manufacturing method, including a workbench 200, a printing mechanism, a powder spreading mechanism, a curing mechanism and a recovery mechanism. The workbench 200 is at least used to fix and support the substrate 140, the printing mechanism is at least used to apply the adhesive 110 in the set area, the powder spreading mechanism is at least used to spread the molding powder 120 on the adhesive 110, the curing mechanism is at least used to cure and shape the base structure 130, and the recovery mechanism is at least used to remove and recover the uncured molding powder 120 on the workbench 200.

[0054] In one embodiment, as Figure 2 As shown, the workbench 200 is placed horizontally, and the upper end surface of the workbench 200 can be used to fix and support the printing substrate 140. The printing mechanism, the powder spreading mechanism, and the curing mechanism are arranged on the upper side of the workbench 200. During use, the printing mechanism first sprays a certain amount of binder 110 on a designated area on the upper end surface of the workbench 200. The printing mechanism stops working, and then the powder spreading mechanism spreads a certain amount of molding powder 120 on the upper end surface of the workbench 200. Part of the laid molding powder 120 contacts and combines with the binder 110 to form a base structure 130. The powder spreading mechanism stops spreading powder, and the curing mechanism starts working to cure the base structure 130 on the workbench 200, so that the base structure is cured and formed. In addition, there is still excess uncured molding powder 120 on the workbench 200, which is then removed and recycled by the recycling mechanism.

[0055] The workbench 200 includes a work plate 210 and a drive mechanism. The work plate 210 is connected to the drive mechanism. The work plate 210 is used to at least secure and support the base 140. The drive mechanism is used to at least drive the work plate to rotate about a predetermined axis, so that uncured molding powder 120 falls from the work plate 210 by gravity. The drive mechanism includes a motor and a rotating shaft 220. One end of the rotating shaft 220 is fixedly connected to the work plate 210, and the other end of the rotating shaft 220 is fixedly connected to the output shaft of the motor. The motor drives the workbench 200 to rotate about the axis of the rotating shaft 220. The recovery mechanism includes a hopper 610, which is arranged on the lower side of the work plate 210 along a first direction. The hopper 610 is used to receive at least the molding powder 120 that falls from the work plate 210.

[0056] In one embodiment, if Figure 2 、 4 As shown, the workbench 200 includes a work plate body 210 and a driving mechanism, wherein the work plate body 210 is a rectangular plate structure, the work plate body 210 is placed horizontally, the upper end surface of the work plate body 210 is used to fix and support the base 140, and the driving mechanism includes a motor and a rotating shaft 220, wherein the rotating shaft 220 is placed in the horizontal direction, and the extension direction of the rotating shaft 220 can be consistent with the width direction of the working plate body 210, one end of the rotating shaft 220 is fixedly connected to the middle position of the lower end of the working plate body 210, and the other end of the rotating shaft 220 is fixedly connected to the output shaft of the motor so that the motor can drive the working plate body 210 to perform a vertical flipping movement. A hopper 610 is also provided on the lower side of the workbench 200, and the opening of the hopper 610 faces upward, and the width of the opening of the hopper 610 is greater than the width of the working plate body 210. When the remaining uncured molding powder 120 needs to be cleared and recycled, the motor can be controlled to drive the working plate 210 to rotate 90° axially around the rotating shaft 220, so that the working plate 210 is in a vertical state, and the formed substrate 140 is fixed on the working plate 210, so that the uncured molding powder 120 falls from the working plate 210 by its own gravity. The hopper 610 located on the lower side of the workbench 200 can receive and store the fallen molding powder 120 to realize the recycling of the uncured molding powder 120. After the uncured molding powder 120 on the working plate 210 is cleared, the motor is controlled to drive the working plate 210 to rotate 90° in the opposite direction so that the working plate 210 is in a horizontal state again, and then the next substrate 140 is prepared on the working plate 210.

[0057] In the above structure, by rotating the working plate 210, the uncured molding powder 120 falls from the working plate 210 by its own gravity, making the cleaning process more convenient and quick. In addition, since the adhesive 110 has been cured and formed, when the working plate 210 is flipped, the adhesive 110 will not drip from the working plate 210, effectively avoiding the problem in the prior art that when the uncured molding powder 120 is removed by a scraper or other structure, the mixture of the adhesive 110 and the molding powder 120 is easily dropped together, resulting in the recycled molding powder 120 being doped and the performance of the molding powder 120 being reduced, further ensuring the performance requirements of the molding powder 120, facilitating the further reuse of the uncured molding powder 120, further saving costs, and effectively avoiding waste of resources.

[0058] In the specific structure for fixing the base 140, the workbench 200 includes a base plate 230, which is provided with a first end face and a second end face facing each other. The first end face is fixedly connected to the working plate body, and the second end face is at least used to fix and support the base 140. The second end face is provided with a fixing groove 231. When receiving the base 140, a part is basically fixed in the fixing groove 231, and the fixing groove 231 is a grid-like groove structure.

[0059] In this embodiment, if Figure 5 As shown, the substrate 230 is a rectangular plate-like structure, wherein the lower end surface of the substrate 230 forms a first end surface, and the upper end surface of the substrate 230 forms a second end surface. During installation, the first end surface of the substrate 230 is fixedly connected to the working plate body 210, that is, the substrate 230 is horizontally installed on the working plate body 210. A fixing groove 231 is provided on the second end surface of the substrate 230. When receiving the base 140, when preparing the first surface layer, part of the adhesive 110 and the molding powder 120 can be mixed and solidified in the fixing groove 231, so that the components on the first surface layer are formed in the fixing groove 231, thereby achieving fixed reception of the base 140. After the product is prepared, the part located in the fixing groove 231 is cut off. In addition, the structure of the fixing groove 231 is a grid-like structure, which further improves the stability of the support and fixation of the base 140.

[0060] Furthermore, the recovery mechanism includes a negative pressure pump 620 and a storage bin 630. The hopper 610 is provided with a suction port 640, which is connected to the storage bin 630. The negative pressure pump 620 is connected to the suction port 640. The negative pressure pump 620 is at least used to draw the molding powder 120 in the hopper 610 into the storage bin 630 through the suction port 640. The hopper 610 is provided with multiple suction ports 640, and the recovery mechanism includes multiple storage bins 630. The multiple suction ports 640 are connected to the multiple storage bins 630 one by one. The suction ports 640 are provided with valves 650.

[0061] In one embodiment, a suction port 640 is provided at the bottom of the hopper 610, and the suction port 640 can be connected to the storage bin 630 through a pipe. A negative pressure pump 620 is provided between the suction port 640 and the storage bin. The negative pressure pump 620 can form a negative pressure environment between the suction port 640 and the storage bin 630, so that after the uncured molding powder 120 falls from the working plate 210 to the hopper 610, it can be quickly sucked from the suction port 640 into the storage bin 630 for storage, thereby greatly improving the recycling efficiency. In addition, since different molding powders 120 need to be used during printing, a plurality of suction ports 640 are provided at the bottom of the hopper 610. In addition, a plurality of storage bins 630 are provided to recycle and store a variety of different molding powders 120. For example, three suction ports 640 are provided at the bottom of the hopper 610, and valves 650 are provided at the three suction ports 640. At the same time, three storage bins 630 are provided, which are respectively connected to the three suction ports 640 through three pipes. One or three negative pressure pumps 620 can be provided so that the three passages all have a negative pressure environment. When recycling the first type of molding powder 120, the valve 650 corresponding to the first suction port 640 is opened, and the valves 650 of the remaining two suction ports 640 are closed, so that the first type of molding powder 120 can only pass through the first suction port 640 and enter the corresponding storage bin 630. According to this recycling method, multiple types of molding powders 120 can be effectively recycled and stored separately to avoid mixing. This also further improves recycling efficiency.

[0062] In the specific structure of the powder spreading mechanism, such as Figure 2 、 3 As shown, the powder spreading mechanism includes a first bracket 420 and a powder sprinkler 410, the first bracket 420 includes a first support plate 421 extending along the second direction, and a first beam 422 movably connected to the first support plate 421, the first beam 422 extends along the third direction, the second direction and the third direction are arranged to intersect, the powder sprinkler 410 is arranged on the first beam 422, the first support plate 421 can perform telescopic movement along the first direction to drive the powder sprinkler 410 to move along the first direction, the first beam 422 can move along the second direction on the first support plate 421, the powder sprinkler 410 includes a connected powder bin 411 and a bulk port 412, the powder bin 411 is at least used to accommodate the molding powder 120, the bulk port 412 is arranged opposite to the workbench 200, and the bulk port 412 covers the workbench 200 along the third direction.

[0063] In one embodiment, the first direction is the vertical direction, the second direction is the width direction of the working plate body 210, and the third direction is the length direction of the working plate body 210. Two first support plates 421 can be provided, and the two first support plates 421 are respectively connected to the symmetrical two sides of the working plate body 210 in the vertical direction. The first crossbeam 422 is provided in the horizontal direction, and its two ends are respectively connected to the two first support plates 421. The powder spreader is provided on the first crossbeam 422, wherein the bulking port 412 of the powder spreader is facing downwardly towards the working plate body 210, and the required molding powder 120 is loaded in the powder bin 411. The molding powder 120 in the powder bin 411 can be spread on the working plate body 210 through the bulking port 412, wherein the first support plate 421 can perform telescopic movement in the vertical direction, thereby driving the powder spreader to move along the first direction to meet the requirement of laying molding powder 120 on different surface layers. In addition, the first crossbeam 422 can also move along the length direction of the working plate body 210 on the first support plate 421 to meet the requirement of laying the molding powder 120 on components at different positions on the same surface layer.

[0064] Furthermore, the powder spreading mechanism includes a conveying pipeline 430 and a pneumatic conveying pump 440. One end of the conveying pipeline 430 is connected to the storage bin 630 and the other end is connected to the powder bin 411. The pneumatic conveying pump 440 is connected to the conveying pipeline 430 and is at least used to transfer the molding powder 120 from the storage bin 630 to the powder bin 411 through the conveying pipeline 430. A transition hopper 450 is provided between one end of the conveying pipeline 430 and the powder bin 411. The transition hopper 450 has an inner cavity and an outlet and an inlet connected to the inner cavity. The inlet is connected to the conveying pipeline 430, and the outlet is connected to the powder bin 411. The powder spreading mechanism includes multiple conveying pipelines 430. One end of each of the conveying pipelines 430 is connected to each of the multiple storage bins 630, and the other end of each of the conveying pipelines 430 is connected to the powder bin 411.

[0065] In one embodiment, the powder bin 411 of the powder spreader is connected to the storage bin 630 through a conveying pipe 430, and a pneumatic conveying pump 440 is also provided between the storage bin 630 and the powder bin 411, so that the molding powder 120 in the storage bin 630 can be transferred to the powder bin 411. The feeding rate is effectively improved. In addition, after the uncured molding powder 120 is recovered to the storage bin 630 through the hopper 610, the powder spreading mechanism can then convey it to the powder spreader for secondary or multiple utilization, thereby forming a circulation loop of the molding powder 120, greatly improving the recycling efficiency of the molding powder 120, greatly saving production costs, and improving material utilization. Furthermore, the powder spreading mechanism can be set in a corresponding number of conveying pipes 430 in the storage bin 630 to convey different types of molding powder 120.

[0066] Furthermore, a transition hopper 450 is provided between one end of the delivery pipeline 430 and the powder silo 411. The transition hopper 450 has an inner cavity, an outlet, and an inlet communicating with the inner cavity. The inlet communicates with the delivery pipeline 430, and the outlet communicates with the powder silo 411. The transition hopper 450 has an exhaust filter port communicating with the inner cavity. The exhaust filter port includes a dust filter cover 710; the dust filter cover 710 is a labyrinthine metal filter structure.

[0067] In this embodiment, one end of the conveying pipeline 430 is connected to the inlet of the transition hopper 450, and the outlet of the transition hopper 450 can be connected to the powder bin 411. When the molding powder is conveyed to the powder bin 411, due to the use of the pneumatic conveying pump 440, the conveyed molding powder 120 is mixed with gas. The provision of the transition hopper 450 can serve as a buffer area. The molding powder 120 conveyed from the conveying pipeline 430 by the pneumatic conveying pump 440 first enters the inner cavity of the transition hopper 450 for buffering. The mixed gas can be discharged from the exhaust filter port of the transition hopper 450, thereby maintaining the pressure inside the transition hopper 450 and ensuring the effect of pneumatic conveying. The exhaust filter port is provided with a dust filter cover 710, which can not only discharge the gas but also prevent the molding powder 120 from being discharged, further preventing the waste of molding materials and protecting the production environment. The dust filter cover 710 can be selected from a labyrinth metal filter structure to further improve the filtering effect of the molding powder 120. In addition, a valve is provided at the outlet of the transition hopper 450, which can control the opening and closing of the outlet. When the molding powder 120 is pneumatically conveyed, the outlet is closed. When it is necessary to replenish the powder bin 411, the powder bin 411 is moved to the bottom of the outlet, the outlet is opened, and the molding powder 120 in the inner cavity is transferred to the powder bin 411 by gravity, thereby completing the replenishment.

[0068] In the specific structure of the printing mechanism, such as Figure 2 、 3 As shown, the printing mechanism includes a second bracket 320 and a printer 310. The second bracket 320 includes a second support plate 321 extending in a second direction and a second crossbeam 322 connected to the second support plate 321. The second crossbeam 322 extends in a third direction, intersecting the second direction and the third direction. The printer 310 is disposed on the second crossbeam 322. The second support plate 321 can telescope in a first direction to drive the printer 310 in the first direction. The second crossbeam 322 can move in the second direction on the second support plate 321. The printer 310 includes a first inner cavity and a print port that are connected to each other. The first inner cavity is used to hold at least the adhesive 110. The print port is located opposite the workbench 200. The second crossbeam 322 is provided with a first track extending in the third direction. The printer 310 is movably connected to the second crossbeam 322 and can move along the first track.

[0069] In one embodiment, two second support plates 321 can be provided, and the two second support plates 321 are respectively connected to two symmetrical sides of the working plate body 210 in the vertical direction. The second crossbeam 322 is provided in the horizontal direction, and its two ends are respectively connected to the two second support plates 321. The printer 310 is provided on the second crossbeam 322, wherein the printing port of the printer 310 faces downwardly toward the working plate body 210, and the required adhesive 110 is loaded in the first inner cavity. The adhesive 110 in the first inner cavity can be sprayed on the working plate body 210 through the printing port, wherein the second support plate 321 can perform telescopic movement in the vertical direction, thereby driving the printer 310 to move along the second direction to meet the requirement of spraying the adhesive 110 on different surface layers. The second crossbeam 322 can move along the length direction of the working plate body 310 on the second support plate 321 to drive the printer 310 to move along the length direction of the working plate body 310. In addition, a first track is provided on the second crossbeam 322. The first track extends along the third direction, so that the printer 310 can move along the width direction of the working plate body 210 to meet the requirements of spraying the adhesive 110 at different positions.

[0070] In the specific structure of the curing mechanism, such as Figure 2 、 3 As shown, the curing mechanism includes a third bracket 520 and a curing member 510. The third bracket 520 includes a third support plate 521 extending along the second direction, and a third crossbeam 522 connected to the third support plate 521. The third crossbeam 522 extends along the third direction, and the second and third directions are arranged to intersect. The curing member 510 is arranged on the third crossbeam 522. The third support plate 521 can perform telescopic movement along the first direction to drive the curing member 510 to move along the first direction. The third crossbeam 522 can move along the second direction on the third support plate 521. The curing member 510 includes at least one curing source, which is arranged opposite to the workbench 200. The curing source includes a heating lamp and a laser lamp. The third crossbeam 522 is provided with a second track extending along the third direction. The curing member 510 is movably connected to the third crossbeam 522 and can move along the second track.

[0071] In one embodiment, two third support plates 521 may be provided, the two third support plates 521 being vertically connected to symmetrical sides of the work plate 210. A third crossbeam 522 is provided horizontally, with its ends connected to the two third support plates 521. The curing unit 510 is provided on the third crossbeam 522, with the curing source of the curing unit 510 facing downwardly toward the work plate 210. The third support plates 521 can telescope vertically, thereby driving the curing unit 510 to move along a first direction to meet the requirement of curing the base structure 130 on different surface layers. The third crossbeam 522 can move along the length of the work plate 310 on the third support plate 521, thereby driving the curing unit 510 to move along the length of the work plate 310. In addition, a second track is provided on the third crossbeam 522, extending along a third direction, allowing the curing unit 510 to move along the width of the work plate 210, thereby curing the base structure 130 at different locations on the work plate 210. The curing source includes a heating lamp and a laser lamp to cure different adhesives 110 and molding materials.

[0072] In addition, the multi-material additive manufacturing device further includes a sealed working cover 700 , which at least encloses the workbench 200 , the printing mechanism, the powder spreading mechanism, the curing mechanism, and the recovery mechanism.

[0073] See also Figure 1 A multi-material additive manufacturing method using the multi-material additive manufacturing device includes the following steps:

[0074] S1. Slice the three-dimensional model of the sample to be prepared to form a plurality of surface layers stacked in sequence along a first direction.

[0075] In this step, a three-dimensional model of the sample to be prepared is first made by using 3D modeling software on a computer, and then the three-dimensional model is sliced ​​in a first direction using the software, wherein the first direction can be selected as the vertical direction. After slicing, the three-dimensional model forms a plurality of surface layer structures stacked in sequence along the first direction, and each surface layer is provided with a part pattern structure corresponding to the sample, and then the sliced ​​structure of the three-dimensional model is sent to the controller of the corresponding 3D printing device.

[0076] S2 . Spray the adhesive 110 on the area set in the first surface layer, and lay the molding powder 120 on the adhesive 110 . The molding powder 120 and the adhesive 110 form a base structure 130 .

[0077] In this step, after the 3D device receives the slice structure information of the three-dimensional model, it begins printing the sample layer by layer. Since the slice structure is stacked vertically, the 3D printing device first prints the first surface layer at the bottom. During the printing process, a certain amount of binder 110 is first sprayed on the corresponding area of ​​the first surface layer. That is, a certain amount of binder 110 is first sprayed at a relative position on the workbench 200. Then, a certain amount of molding powder 120 is laid on the binder 110 in this area. The molding powder 120 and the binder 110 form a base structure 130. The amount of molding powder 120 is determined based on factors such as the quality of the sample to be prepared, the thickness of the surface layer, and the material properties of the molding powder 120. The amount of binder 110 is determined based on factors such as the amount of molding powder 120 and the thickness of the surface layer to ensure that the curing requirements of the molding powder 120 are met. In addition, the type of binder 110 is selected accordingly based on the material of the molding powder 120.

[0078] In one embodiment, the binder 110 includes a thermosetting resin or a quick-drying resin. The molding powder 120 includes any one of resin film powder, metal powder, and gypsum.

[0079] S3 . Curing the base structure 130 through a curing source, so that the base structure 130 is cured and formed into a matrix 140 .

[0080] Since the base structure 130 obtained in step S2 is a liquid structure of a mixed binder 110 and a molding powder 120, it is necessary to perform a curing molding process on the base structure 130 in this step to make it a solid sample part structure on the surface layer. The base structure 130 obtained in step S2 is cured and molded by a curing source so that the base structure 130 is cured and molded into a matrix 140 constituting the sample. The curing source includes a heating lamp, which is at least used to cure the base structure 130 including the binder 110 of a thermosetting resin. In addition, a laser source is also provided, which is at least used to perform secondary curing on the base structure 130 including the molding powder 120 of a resin film powder and a metal powder. During the specific operation, the curing methods differ due to the different types of binder 110 and molding powder 120. When curing the base structure 130, an appropriate curing source is selected based on the types of molding powder 120 and binder 110 contained in the base structure 130. For example, when the binder 110 is a thermosetting resin, a heating lamp can be used as the curing source for the curing and molding operation. The power of the heating lamp is matched to the selected resin, and the curing temperature of different resins also varies. When the binder 110 is a quick-drying resin, the binder 110 has a rapid curing rate, so a heating lamp is not required for further curing. When the molding material is a resin film powder or metal powder, after the initial curing, a laser source is required for secondary curing and molding. Laser heating causes the resin film to melt and form a bond, further enhancing the curing strength. When using metal powder, the heating lamp curing operation only binds the metal powder to the binder 110 and does not metallurgically bond it. The laser heating melts the metal powder, forming a single piece. In addition, by controlling the solidification rate and solidification gradient by controlling the laser power, sequential or simultaneous solidification of the liquid metal is achieved, thereby obtaining a denser solid structure and higher mechanical properties. In a specific application, the present invention directly prints the wear-resistant liner and the casing as a whole by controlling the solidification rate and solidification gradient by controlling the laser power, achieving a metallurgical bond between the casing and the wear-resistant liner, ensuring that the wear-resistant liner does not fall off, and replacing the existing method of first preparing the casing and then inserting the wear-resistant liner into it, so that the function of the product will be greatly expanded and the reliability of the product will be greatly improved.

[0081] S4. Remove the uncured molding powder 120.

[0082] In step S2, in order to meet the molding requirements of the base 140, an excess of molding powder 120 needs to be laid, and the binder 110 adheres a corresponding amount of molding powder 120 so that it can be subsequently solidified and formed into the desired base 140, while the remaining molding powder 120 is scattered around the base structure 130, and the remaining molding powder 120 is not in contact with the binder 110. In the subsequent solidification process, it will not be solidified and formed, and will remain in a powder state. In order not to affect the production of the next base 140, the remaining molding powder 120 needs to be removed. In the method of clearing the molding powder 120, gravity can be used to remove the unsolidified molding powder. Specifically, after the molding powder 120 and the binder 110 are solidified, the workbench 200 supporting the base 140 is rotated, and the unsolidified molding powder 120 is dropped from the workbench 200 by gravity, thereby achieving the removal of the unsolidified molding powder. In addition, a negative pressure system may be provided above the carrier to suck out the uncured molding powder through negative pressure, thereby completing the removal of the uncured molding powder 120 .

[0083] S5. Repeat steps S2 to S4 to form N matrixes 140 on the first surface layer. The N matrixes 140 are connected or not connected, thereby completing the structural molding on the first surface layer. N ≥ 2, and the molding powders 120 used to form the N matrixes 140 are different.

[0084] In this step, the remaining substrates 140 on the first surface layer are prepared according to the process flow of steps S2-S4, wherein the molding materials used for the N substrates 140 on the first surface layer may be different, depending on the requirements of the various parts of the prepared sample.

[0085] S6. Repeat steps S1-S5 to form multiple structures on the surface layer layer by layer along the first direction until the sample preparation is completed.

[0086] After completing the preparation of the required substrate 140 for the first surface layer according to the above steps S2-S5, the 3D printing device moves upward in the vertical direction to the second surface layer, repeats steps S2-S5, and then prepares the required substrate 140 for the second surface layer. Similarly, the required substrate 140 for each surface layer is prepared layer by layer along the first direction until the printing of the entire sample is completed.

[0087] In traditional printing technology, it is necessary to first lay the molding powder 120, and then apply a certain amount of adhesive 110 on the molding powder 120, solidify the part where the molding powder 120 and the adhesive 110 are in contact and mixed, and then remove the unsolidified molding powder 120. In this method, since the molding powder 120 is prone to accumulation when laying the molding powder 120, the surface of the adhesive 110 becomes uneven when the adhesive 110 is applied again, and it is necessary to use a scraper or other tool to flatten the mixed part before solidifying it. However, when printing on different parts of the same surface layer, due to the presence of solidified parts, when scraping other parts, the hardness of the solidified parts and the uncured parts is inconsistent, and the solidified parts have a higher hardness. The surface of the cured parts is not completely flat, and in order to protect the solidified parts, the scraper cannot abut against the surface of the solidified parts. Therefore, when scraping the uncured parts, it is easy to have the problem of unequal heights between the uncured parts and the solidified parts, resulting in uneven heights of different parts on the same surface layer, which in turn affects subsequent printing, reduces the yield rate of the prepared products, and affects product quality.

[0088] In the method provided by the present invention, a certain amount of binder 110 is first applied to the corresponding position, and then molding powder 120 is laid, so that a certain amount of molding powder 120 is contacted and mixed with the binder 110, and then solidified. Since the certain amount of binder 110 can be fused and solidified with the certain amount of molding powder 120, and unsolidified molding powder 120 can be formed on top of the solidified parts, the unsolidified molding powder 120 is then removed without the need for a flattening process, and then the above steps are repeated to achieve printing of different materials on different parts of a surface layer. By the above steps, the high consistency of different parts of the same surface layer can be guaranteed while avoiding the flattening process, further improving the quality of the printed product and improving the yield of the product. In addition, the method of first applying the binder 110 and then laying the molding powder 120 can also effectively avoid the situation in the traditional printing method that, when printing the next surface layer, the unsolidified molding powder 120 of the previous surface layer is also needed to support the molding material laid on this surface layer, thereby ensuring the support stability when printing different surface layers.

[0089] The technical solution of the present invention is further described in detail below in conjunction with several preferred embodiments and the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. The test methods in the following examples where specific conditions are not specified are generally based on conventional conditions.

[0090] Implementation Example 1

[0091] Prepare a sample of multiple non-metallic powders, all of which are non-metallic molding materials. A printing mechanism sprays thermosetting resin on designated areas of the work plate 210. Next, a powder spreading mechanism spreads non-metallic molding powder 120 across the entire workbench 200. The powder spreading mechanism heats and solidifies the powder using a heating lamp. The workbench 200 is rotated, allowing the uncured non-metallic molding powder 120 to flow by gravity into the hopper 610. Thermosetting resin is then sprayed on other areas of the surface layer. Another type of non-metallic molding powder 120 is then spread across the entire workbench 200. This process repeats until the substrate 140 required for this surface layer is printed. After printing this surface layer, the preparation process for this surface layer is repeated to print the second surface layer, ultimately completing the printing process for the entire product.

[0092] Implementation Example 2

[0093] Prepare a sample of multiple metal powders, all of which are metal molding materials. A thermosetting resin is sprayed on a designated area of ​​the work plate 210 by a printing mechanism. Next, the molding powder 120 is spread across the entire workbench 200 by a powder spreading mechanism. A curing mechanism first heats the sample with a heating lamp for initial curing. A laser is then used to heat the thermosetting resin and the metal molding powder 120. The thermosetting resin vaporizes at high temperatures, while the metal molding powder 120 melts and solidifies at high temperatures. The workbench 200 is then rotated to allow the uncured molding powder 120 to flow by gravity into the hopper 610. The thermosetting resin is then sprayed on other areas of the surface layer. Another type of metal molding powder 120 is then spread across the entire workbench 200. This process is repeated until the substrate 140 required for the current surface layer is printed. After printing the current surface layer, the preparation process for the current surface layer is repeated to print the second surface layer, ultimately completing the printing process for the entire product.

[0094] Implementation Example 3

[0095] Printing of various non-metallic powders and metal powders

[0096] A sample of multiple metal powders is prepared, and the molding materials used are all metal materials. A thermosetting resin is sprayed on a designated area of ​​the work plate 210 by a printing mechanism. Next, a non-metallic (or metal) powder with a resin film is laid on the entire workbench 200 by a powder spreading mechanism. The curing mechanism first uses a heating lamp to heat and initially cure it. Then, a laser is used to heat the thermosetting resin and the non-metallic (or metal) molding powder 120 with a resin film. The thermosetting resin vaporizes at high temperature, and after the resin film melts, a glue bond is formed. The workbench 200 is then rotated to allow the uncured non-metallic (or metal) molding powder 120 with a resin film to flow into the hopper 610 by gravity. Then, thermosetting resin is sprayed on other areas of the surface layer, and another type of non-metallic (or metal) molding powder 120 with a resin film is laid on the entire workbench 200. This process is repeated until the substrate 140 required for the current surface layer is printed. After printing the current surface layer, the preparation process of the current surface layer is repeated to print the second surface layer, and finally the printing process of the entire product is completed.

[0097] It should be understood that the above embodiments are merely illustrative of the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent variations or modifications made in accordance with the spirit and substance of the present invention are intended to be encompassed within the scope of protection of the present invention.

Claims

1. A multi-material additive manufacturing method, characterized in that: The following steps are involved: S1. Slicing the three-dimensional model of the sample to be prepared to form a plurality of surface layers stacked in sequence along a first direction; S2. Spraying a binder on the area set by the first surface layer, and laying a molding powder on the binder, so that the binder and the molding powder in contact with the binder are combined to form a base structure, and the base structure is a liquid structure of a mixture of the binder and the molding powder; S3, curing the base structure using a curing source, so that the base structure is cured and formed into a matrix; S4, removing the uncured molding powder by utilizing its own gravity or negative pressure suction; S5. Repeat steps S2-S4 to form N matrixes on the first surface layer. The N matrixes are connected or not connected, thereby completing the structural forming on the first surface layer. N is greater than or equal to 2, and the molding powders used to form the N matrixes are different. S6, repeating steps S1-S5, forming a plurality of structures on the surface layer layer by layer along the first direction until the sample preparation is completed; The binder includes a thermosetting resin; In said S3, the curing source comprises a heating lamp, and said heating lamp is used to cure at least the base structure of the binder comprising a thermosetting resin; The molding powder includes any one of resin film powder, metal powder, and gypsum; In the step S3, when the molding powder is a resin film powder or a metal powder, after the molding powder is primarily cured, it is secondarily cured using a laser source.

2. A multi-material additive manufacturing device for implementing the multi-material additive manufacturing method according to claim 1, characterized in that: include: A workbench, a printing mechanism, a powder spreading mechanism, a curing mechanism and a recycling mechanism, wherein the workbench is at least used to fix and support the substrate, the printing mechanism is at least used to apply a binder in a set area, the powder spreading mechanism is at least used to spread molding powder on the binder, the curing mechanism is at least used to cure and shape the base structure, and the recycling mechanism is at least used to remove and recycle the uncured molding powder on the workbench.

3. The multi-material additive manufacturing device according to claim 2, characterized in that: The workbench includes a work plate and a driving mechanism, the work plate is connected to the driving mechanism, the work plate is at least used to fix and support the base, and the driving mechanism is at least used to drive the work plate to rotate around a set axis so that the unsolidified molding powder falls from the work plate by gravity.

4. The multi-material additive manufacturing device according to claim 3, characterized in that: The workbench includes a base plate, which is provided with a first end face and a second end face facing each other. The first end face is fixedly connected to the working plate body, and the second end face is at least used to fix and support the base. The second end face is provided with a fixing groove, and when the base is supported, part of the base is fixed in the fixing groove.

5. The multi-material additive manufacturing device according to claim 4, characterized in that: The fixing groove is a grid-shaped groove structure.

6. The multi-material additive manufacturing device according to claim 3, characterized in that: The driving mechanism includes a motor and a rotating shaft, one end of the rotating shaft is fixedly connected to the working plate body, and the other end of the rotating shaft is fixedly connected to the output shaft of the motor, and the motor drives the workbench to rotate around the axis of the rotating shaft.

7. The multi-material additive manufacturing device according to claim 3, characterized in that: The recovery mechanism includes a hopper, which is arranged at the lower side of the working plate body along the first direction, and the hopper is at least used to receive the molding powder dropped from the working plate body.

8. The multi-material additive manufacturing device according to claim 7, characterized in that: The recovery mechanism includes a negative pressure pump and a storage bin. The hopper is provided with a suction port, which is communicated with the storage bin. The negative pressure pump is connected to the suction port. The negative pressure pump is at least used to suck the molding powder in the hopper into the storage bin through the suction port.

9. The multi-material additive manufacturing device according to claim 8, characterized in that: The hopper is provided with a plurality of suction ports, and the recovery mechanism includes a plurality of storage bins, and the plurality of suction ports and the plurality of storage bins are connected one by one.

10. The multi-material additive manufacturing device according to claim 8, characterized in that: The material suction port is provided with a valve.

11. The multi-material additive manufacturing device according to claim 8, characterized in that: The powder spreading mechanism includes a first bracket and a powder sprinkler, the first bracket includes a first support plate extending along the second direction, and a first crossbeam movably connected to the first support plate, the first crossbeam extends along the third direction, the second direction and the third direction are arranged to intersect, the powder sprinkler is arranged on the first crossbeam, the first support plate can perform telescopic movement along the first direction to drive the powder sprinkler to move along the first direction, the first crossbeam can move along the second direction on the first support plate, the powder sprinkler includes a connected powder bin and a bulk port, the powder bin is at least used to accommodate the molding powder, the bulk port is arranged opposite to the workbench, and the bulk port covers the workbench along the third direction.

12. The multi-material additive manufacturing device according to claim 11, characterized in that: The powder spreading mechanism includes a conveying pipeline and a pneumatic conveying pump. One end of the conveying pipeline is connected to the storage bin, and the other end is connected to the powder bin. The pneumatic conveying pump is connected to the conveying pipeline. The pneumatic conveying pump is at least used to convey the molding powder from the storage bin to the powder bin through the conveying pipeline.

13. The multi-material additive manufacturing device according to claim 12, characterized in that: A transition hopper is provided between one end of the conveying pipeline and the powder bin. The transition hopper is provided with an inner cavity and an outlet and an inlet connected to the inner cavity. The inlet is connected to the conveying pipeline, and the outlet is connected to the powder bin. The transition hopper is provided with an exhaust filter port, and the exhaust filter port is connected to the inner cavity.

14. The multi-material additive manufacturing device according to claim 13, characterized in that: The exhaust filter port includes a dust filter cover.

15. The multi-material additive manufacturing device according to claim 14, characterized in that: The dust filter cover is a labyrinth-type metal filter structure.

16. The multi-material additive manufacturing device according to claim 12, characterized in that: The powder spreading mechanism includes a plurality of conveying pipelines, one end of each of the conveying pipelines is connected to each of the plurality of storage bins, and the other end of each of the conveying pipelines is connected to the powder bin.

17. The multi-material additive manufacturing device according to claim 2, characterized in that: The printing mechanism includes a second bracket and a printer. The second bracket includes a second support plate extending along a second direction, and a second crossbeam movably connected to the second support plate. The second crossbeam extends along a third direction, and the second direction and the third direction are arranged to intersect. The printer is arranged on the second crossbeam. The second support plate can perform telescopic movement along the first direction to drive the printer to move along the first direction. The second crossbeam can move along the second direction on the second support plate. The printer includes a first inner cavity and a printing port that are connected to each other. The first inner cavity is used to at least accommodate the adhesive. The printing port is arranged opposite to the workbench.

18. The multi-material additive manufacturing device according to claim 17, characterized in that: The second crossbeam is provided with a first track extending along a third direction, and the printer is movably connected to the second crossbeam and can move along the first track.

19. The multi-material additive manufacturing device according to claim 17, characterized in that: The curing mechanism includes a third bracket and a curing component, the third bracket includes a third support plate extending along the second direction, and a third crossbeam movably connected to the third support plate, the third crossbeam extends along the third direction, the second direction and the third direction are arranged to intersect, the curing component is arranged on the third crossbeam, the third support plate can perform telescopic movement along the first direction to drive the curing component to move along the first direction, the third crossbeam can move along the second direction on the third support plate, the curing component includes at least one curing source, and the curing source is arranged opposite to the workbench.

20. The multi-material additive manufacturing device according to claim 19, characterized in that: The curing source includes a heating lamp and a laser lamp.

21. The multi-material additive manufacturing device according to claim 19, characterized in that: The third crossbeam is provided with a third track extending along the third direction, and the curing component is movably connected to the third crossbeam and can move along the third track.

22. The multi-material additive manufacturing device according to claim 2, characterized in that: It also includes a sealed working cover, which at least covers the workbench, the printing mechanism, the powder spreading mechanism, the curing mechanism and the recovery mechanism.

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