Multi-material metal 3D printing forming system and working method thereof

Abstract

The invention relates to the technical field of additive equipment, in particular to a multi-material metal 3D printing forming system and a working method thereof. The multi-material metal 3D printing forming system comprises a closed forming chamber, a machine tool body, a material laying platform, a first moving device, a powder layer transferring device, a region projection device and a plurality of powder laying subsystems. The area projection device is used for processing the powder layer transfer device, so that the powder layer transfer device has the capacity of adsorbing metal powder materials, the multiple powder laying subsystems are used for supplying different metal powder materials, and the metal powder materials are sequentially adsorbed to different preset areas of the powder layer transfer device; according to the metal powder laying device, high-precision laying of metal powder of different materials can be achieved through a one-time carrying process, the powder layer transferring device is used for adsorption, transferring and laying in different areas, the problem of mutual pollution of different powder in the laying process can be effectively avoided, and the labor intensity of workers is lowered. And the cost is effectively reduced.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing equipment technology, and in particular to a multi-material metal 3D printing forming system and its working method. Background Technology

[0002] Metal 3D printing technology is a new manufacturing technology that has developed in recent years. Based on the principle of layer-by-layer manufacturing, it completes the manufacturing of parts by processing and stacking layers one by one. Currently, metal 3D printing technology is mainly divided into powder bed-based metal 3D forming technology and filament-based metal 3D printing forming technology according to the type of materials used. Powder bed-based metal 3D printing forming technology first slices the geometric model of the part to obtain the printing contour data of each layer; then, it drives a powder spreading device to lay metal powder layer by layer in the forming chamber. After the metal powder is laid, the computer drives a laser or inkjet printhead to print the powder according to the contour data of each layer of the part. This process is repeated layer by layer until the desired part is obtained. Multi-material metal 3D printing technology based on powder bed mainly achieves patterned powder spreading of multiple materials in each layer, and then drives a laser to melt the multi-material metal powder to achieve multi-material metal 3D printing. This technology can realize the integrated manufacturing of metal components with different material properties, greatly improving the overall performance of the components and reducing the manufacturing difficulty of complex functional metal components.

[0003] However, the current powder bed-based multi-material metal 3D printing technology suffers from cross-contamination during the powder spreading process, resulting in low powder recycling rate and high manufacturing cost of multi-material metal parts, which hinders the popularization and promotion of multi-material metal 3D printing technology. Summary of the Invention

[0004] This invention provides a multi-material metal 3D printing forming system and its working method to solve the defect of mutual contamination in the multi-material metal powder spreading process in the prior art.

[0005] This invention provides a multi-material metal 3D printing forming system, comprising: A sealed forming chamber, comprising a first zone and a second zone; The main body of the machine tool is located in a sealed forming chamber; A material distribution platform is located in the first area; A first moving device is used to move between above the first region and above the second region; A powder transfer device is disposed on the first moving device and has multiple preset areas for adsorbing different metal powder materials. It is also used to release the metal powder materials adsorbed in the different preset areas onto the spreading platform. A surface projection device is fixed in the second region of the machine tool body and is used to project a preset region corresponding to different metal powder materials on each layer of the printing pattern on the lower surface of the powder transfer device, so that different metal powder materials are adsorbed on the corresponding preset region. Multiple powder-laying subsystems are positioned close to the second region to output different metal powder materials, which are then adsorbed onto the corresponding preset regions by the powder layer transfer device.

[0006] According to the present invention, a multi-material metal 3D printing forming system is provided. The area projection device includes: light source; The powder transfer device includes: A conveying mechanism is provided on the first mobile device; An organic photosensitive layer is disposed on the conveying mechanism. Through the movement of the conveying mechanism, the organic photosensitive layer has multiple preset areas facing the light source for adsorbing different metal powder materials. When the organic photosensitive layer is charged and illuminated by the light source at a preset wavelength, a change in resistance is generated in the preset areas, thereby adsorbing different metal powder materials.

[0007] According to the present invention, a multi-material metal 3D printing forming system includes a conveying mechanism comprising: Conveyor motor; A flexible conveyor belt is connected to the conveyor motor, and the organic photosensitive layer is disposed on the outer side of the flexible conveyor belt.

[0008] According to the multi-material metal 3D printing system provided by the present invention, the powder layer transfer device further includes: The first charging mechanism is located on one side of the organic photosensitive layer and is used to charge a preset area of ​​the organic photosensitive layer to adsorb metal powder material. A discharge mechanism, located on the other side of the organic photosensitive layer, is used to discharge a predetermined area of ​​the organic photosensitive layer to release metal powder material.

[0009] According to the multi-material metal 3D printing system provided by the present invention, the powder layer transfer device further includes: A powder collector, positioned near the organic photosensitive layer, is used to collect residual metal powder material.

[0010] According to the present invention, a multi-material metal 3D printing forming system is provided, wherein each of the powder spreading subsystems comprises: The second moving device is used to convey the metal powder material to the area below the powder transfer device; The hopper contains metal powder material; The second charging mechanism is located near the hopper and is used to charge the metal powder material in the hopper so that the metal powder material is adsorbed onto the lower surface of the powder transfer device by the electrostatic force generated by opposite charges. A rotating roller, located at the outlet of the hopper, is used to convey charged metal powder material to the second moving device.

[0011] According to the multi-material metal 3D printing system provided by the present invention, each of the powder spreading subsystems further includes: A powder conveying mechanism is connected to the hopper.

[0012] A multi-material metal 3D printing forming system provided by the present invention further includes: An inert gas circulation subsystem is connected to the sealed forming chamber.

[0013] A multi-material metal 3D printing forming system provided by the present invention further includes: The laser subsystem, located in the sealed forming chamber, is used to print metal powder material laid on the material spreading platform.

[0014] The present invention also provides a method for operating a multi-material metal 3D printing forming system according to the present invention, comprising: The first moving device drives the powder transfer device to move above the second area; The first preset area for adsorbing metal powder material is projected onto the lower surface of the powder transfer device by the area projection device. When the first preset area of ​​the powder layer transfer device is in an energized state, a first type of metal powder material is supplied to the powder layer transfer device through the corresponding powder spreading subsystem so that the metal powder material is adsorbed in the first preset area. The powder transfer device is switched to the second preset area for adsorbing metal powder material, and the second preset area for adsorbing metal powder material is projected on the lower surface of the powder transfer device by the area projection device. When the second preset area of ​​the powder layer transfer device is in an energized state, a second type of metal powder material is supplied to the powder layer transfer device through the corresponding powder spreading subsystem so that the metal powder material is adsorbed in the second preset area. By analogy, various metal powder materials are adsorbed onto a designated preset area; The first moving device drives the powder layer transfer device to move above the first area; Discharge is applied to each preset area in sequence, and the metal powder material falls onto the material spreading platform due to its own gravity.

[0015] This invention provides a multi-material metal 3D printing system and its working method, comprising: a sealed forming chamber, a machine tool body, a material placement platform, a first moving device, a powder layer transfer device, a surface projection device, and multiple powder placement subsystems. The sealed forming chamber has a first region and a second region; the machine tool body is located within the sealed forming chamber; the material placement platform is located in the first region; the first moving device is used to move between above the first region and above the second region; the powder layer transfer device is located on the first moving device and has multiple preset regions for adsorbing different metal powder materials, and is also used to release the metal powder materials adsorbed in different preset regions onto the material placement platform; the surface projection device is fixed to the second region of the machine tool body and is used to project the preset regions corresponding to different metal powder materials on the lower surface of each printing pattern on the powder layer transfer device, so that different metal powder materials are adsorbed in the corresponding preset regions; multiple powder placement subsystems are arranged close to the second region and are used to output different metal powder materials, which are adsorbed in the corresponding preset regions under the action of the powder layer transfer device. This invention provides a multi-material metal 3D printing forming system. A powder transfer device is processed by a surface projection device to enable it to adsorb metal powder materials. Different metal powder materials are supplied through multiple powder spreading subsystems, and are sequentially adsorbed onto different preset areas of the powder transfer device. A first moving device drives the powder transfer device to a spreading platform for unloading. This invention achieves high-precision spreading of different metal powder materials in a single transport process. By utilizing the powder transfer device for regional adsorption, transfer, and spreading, the cross-contamination problem between different powders during the spreading process can be effectively avoided, thereby effectively reducing costs. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a multi-material metal 3D printing forming system provided in one embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of the structure of a powder layer transfer device provided in one embodiment of the present invention.

[0019] Figure 3 This is a schematic diagram of the structure of the hopper, the second charging mechanism, and the rotating roller provided in one embodiment of the present invention.

[0020] Figure label: 1. Machine tool body; 2. Sealed forming chamber; 3. Laser subsystem; 4. Forming box; 5. Material spreading platform; 6. First moving device; 7. Powder layer transfer device; 7-1. Flexible conveyor belt; 7-2. Conveyor motor; 7-3. Powder collector; 7-1-1. Organic photosensitive layer; 7-1-2. First charging mechanism; 7-1-3. Discharge mechanism; 8. Area projection device; 9. First Y-axis motion system; 10. Second Y-axis motion system; 11. First powder spreading device; 11-1. Hopper; 11-2. Second charging mechanism; 11-3. Rotating roller; 12. Second powder spreading device; 13. Inert gas circulation subsystem; 14. First powder conveying mechanism; 15. Second powder conveying mechanism; 16. Control system. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0022] In the description of this embodiment, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this embodiment and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this embodiment.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this embodiment, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0024] In this embodiment, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," "link," and "fix" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to 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 embodiment based on the specific circumstances.

[0025] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0026] The following is combined Figures 1-3 ( Figure 2 The middle arrow indicates the transmission direction of the flexible conveyor belt 7-1. This describes a multi-material metal 3D printing system according to the present invention. The multi-material metal 3D printing system includes: a sealed forming chamber 2, a machine tool body 1, a material spreading platform 5, a first moving device 6, a powder layer transfer device 7, a surface projection device 8, and multiple powder spreading subsystems.

[0027] The sealed forming chamber 2 has a first region and a second region; the machine tool body 1 is located inside the sealed forming chamber 2; the material spreading platform 5 is located in the first region; the first moving device 6 is used to move between the first region and the second region; the powder layer transfer device 7 is located on the first moving device 6 and has multiple preset areas for adsorbing different metal powder materials, and is also used to release the metal powder materials adsorbed in different preset areas onto the material spreading platform 5; the area projection device 8 is fixed in the second region of the machine tool body 1 and is used to project the preset areas corresponding to different metal powder materials on each layer of the printed pattern on the lower surface of the powder layer transfer device 7, so that different metal powder materials are adsorbed in the corresponding preset areas; multiple powder spreading subsystems are set close to the second region and are used to output different metal powder materials, which are adsorbed in the corresponding preset areas under the action of the powder layer transfer device 7.

[0028] Specifically, the sealed forming chamber 2 is divided into two areas: a first area and a second area. The first area contains a forming box, and a material spreading platform 5 is arranged inside the forming box and has a lifting function; that is, the material spreading platform 5 is a lifting platform. The area projection device 8 and the powder spreading subsystem are both located in the second area. In the second area, the metal powder material can be adsorbed onto the powder layer transfer device 7 through the area projection device 8 and the powder spreading subsystem. A first moving device 6 is arranged between the first area and the second area to realize the movement of the powder layer transfer device 7 between the two areas, and to realize the transfer of the adsorbed metal powder material to the first area and spread it on the material spreading platform 5.

[0029] The machine tool body 1 serves as the main load-bearing structure of the entire system, ensuring the system's stability and reliability during operation. In such cases... Figure 1 In the structure shown, the first moving device 6 is a moving device along the X-axis, which can be a linear reciprocating motion device such as a linear module, lead screw or moving platform to drive the powder layer transfer device 7 to move between the first region and the second region.

[0030] The area projection device 8 is located below the powder layer transfer device 7. It consists of a special wavelength light source and optical lenses, and is used to project the layered patterns corresponding to different materials onto the preset area of ​​the powder layer transfer device 7 for adsorbing metal powder materials. Through the principle of opposite charge adsorption, the metal powder materials are adsorbed onto the corresponding preset areas. By arranging multiple preset areas, different metal powder materials can be adsorbed sequentially by a single powder layer transfer device 7. Then, the first moving device 6 transports the powder layer transfer device 7, which has adsorbed multiple metal powder materials, to the first area. The powder layer transfer device 7 releases the adsorption of the metal powder materials, and the metal powder materials fall onto the laying platform 5 due to their own gravity, and are laid sequentially according to the 3D printing requirements.

[0031] This invention provides a multi-material metal 3D printing system, comprising: a sealed forming chamber 2, a machine tool body 1, a material spreading platform 5, a first moving device 6, a powder layer transfer device 7, a surface projection device 8, and multiple powder spreading subsystems. The sealed forming chamber 2 has a first region and a second region; the machine tool body 1 is disposed within the sealed forming chamber 2; the material spreading platform 5 is disposed in the first region; the first moving device 6 is used to move between above the first region and above the second region; the powder layer transfer device 7 is disposed on the first moving device 6 and has multiple preset regions for adsorbing different metal powder materials, and is also used to release the metal powder materials adsorbed in different preset regions onto the material spreading platform 5; the surface projection device 8 is fixed to the second region of the machine tool body 1 and is used to project the preset regions corresponding to different metal powder materials on the lower surface of each printing pattern on the powder layer transfer device 7, so that different metal powder materials are adsorbed in the corresponding preset regions; the multiple powder spreading subsystems are disposed close to the second region and are used to output different metal powder materials, which are adsorbed in the corresponding preset regions under the action of the powder layer transfer device 7. This invention provides a multi-material metal 3D printing forming system. A surface projection device 8 processes a powder transfer device 7, enabling it to adsorb metal powder materials. Multiple powder-laying subsystems supply different metal powder materials, which are sequentially adsorbed onto different preset areas of the powder transfer device 7. A first moving device 6 moves the powder transfer device 7 to a material-laying platform 5 for unloading. This invention achieves high-precision laying of different metal powder materials in a single transport process. By utilizing the powder transfer device 7 for regional adsorption, transfer, and laying, the cross-contamination problem between different powders during the laying process can be effectively avoided, thereby significantly reducing costs.

[0032] In one embodiment of the present invention, the area projection device 8 includes: a light source and an optical lens; the light source emits light of a special wavelength and irradiates the organic photosensitive layer 7-1-1, causing a change in its resistance; preferably, the light source emits light of a wavelength of 700-850nm.

[0033] In one embodiment of the present invention, the powder transfer device 7 includes a conveying mechanism and an organic photosensitive layer 7-1-1. The conveying mechanism is mounted on the first moving device 6; the organic photosensitive layer 7-1-1 is mounted on the conveying mechanism. Through the movement of the conveying mechanism, the organic photosensitive layer 7-1-1 has multiple preset regions facing the light source for adsorbing different metal powder materials. When the organic photosensitive layer 7-1-1 is charged and illuminated by light of a preset wavelength from the light source, a resistance change occurs in the preset regions, thereby adsorbing different metal powder materials.

[0034] In the above embodiments, the conveying mechanism can move the organic photosensitive layer 7-1-1. This movement causes different areas on the organic photosensitive layer 7-1-1 to face the light source. These different areas (i.e., the different preset areas in this embodiment) provide positions for the adsorption of different metal powder materials. Depending on the type of metal powder material, it is adsorbed into different areas, thus ensuring that multiple metal powder materials can be simultaneously processed through one organic photosensitive layer 7-1-1. In this embodiment, there are two preset areas to accommodate the adsorption of two different metal powder materials. Irradiation by the light source reduces the resistance of the corresponding areas. When charged using a positive charging device, within the same time frame, areas with higher surface resistance of the organic photosensitive layer 7-1-1 acquire a larger positive charge, while areas with lower resistance acquire a smaller positive charge or no charge. The powder-laying subsystem processes the metal powder material, giving it a negative charge. Through the principle of attraction between opposite charges, the metal powder material is adsorbed onto the organic photosensitive layer 7-1-1. The specific processing device and process of the powder-laying subsystem for the metal powder material are detailed in the following embodiments. Similarly, if it is necessary to lay the corresponding type of metal powder material on the laying platform 5, the corresponding area on the organic photosensitive layer 7-1-1 is discharged to release it from the adsorption state of the metal powder material, and the metal powder material falls onto the laying platform 5 by its own gravity.

[0035] In the above embodiments, the illumination by the light source causes a local increase in the surface resistance of the organic photosensitive layer 7-1-1, resulting in that region carrying a larger positive charge, while regions with lower resistance carry a smaller positive charge or no charge. The following principle is provided to explain the above phenomenon: The amount of electrostatic charge is closely related to the properties of an object itself. These properties determine the object's ability to gain or lose electrons during processes such as friction, contact, or induction, as well as the state of charge retention and distribution.

[0036] Resistivity is a key factor determining whether an object can accumulate static electricity. For insulators, charge is difficult to dissipate through internal conduction, and a large amount of static electricity easily accumulates after friction or contact. For conductors, charge can be rapidly conducted through internal free electrons, making it generally difficult to accumulate static electricity. Therefore, in the above embodiment, by increasing the resistance in a local area, the local area exhibits the characteristics of an insulator, causing charge to accumulate within this area, thus accumulating a large amount of positive charge. Conversely, areas with lower resistance exhibit the characteristics of a conductor, where electrons conduct rapidly, making it generally difficult to accumulate static charge, resulting in this area accumulating only a small amount of positive charge or being uncharged.

[0037] In one embodiment of the present invention, the conveying mechanism includes a conveying motor 7-2 and a flexible conveyor belt 7-1. The flexible conveyor belt 7-1 is connected to the conveying motor 7-2, and the conveying motor 7-2 drives the flexible conveyor belt 7-1 to rotate. An organic photosensitive layer 7-1-1 is disposed on the outer side of the flexible conveyor belt 7-1. Specifically, the drive motor drives the flexible conveyor belt 7-1 to move through a drive wheel, and a driven wheel is disposed at the other end, which rotates synchronously with the drive wheel. Preferably, if the organic photosensitive layer 7-1-1 has two preset areas for adsorbing two different metal powder materials respectively, the upper surface and the lower surface of the flexible conveyor belt 7-1 can be designated as different preset areas for adsorbing two different metal powder materials respectively.

[0038] In one embodiment of the present invention, the powder layer transfer device 7 further includes a first charging mechanism 7-1-2 and a discharging mechanism 7-1-3. The first charging mechanism 7-1-2 is disposed on one side of the organic photosensitive layer 7-1-1 and is used to charge a predetermined area of ​​the organic photosensitive layer 7-1-1 to adsorb metal powder material; the discharging mechanism 7-1-3 is disposed on the other side of the organic photosensitive layer 7-1-1 and is used to discharge a predetermined area of ​​the organic photosensitive layer 7-1-1 to release metal powder material. In this embodiment, the organic photosensitive layer 7-1-1 is charged and discharged by the first charging mechanism 7-1-2 and the discharging mechanism 7-1-3, respectively. During the charging process, the corresponding area of ​​the organic photosensitive layer 7-1-1 becomes positively charged, generating a tactical force with the negative charge of the metal powder material, thereby allowing the metal powder material to be adsorbed onto the organic photosensitive layer 7-1-1. When the metal powder material needs to be laid on the laying platform 5, the discharging mechanism 7-1-3 discharges the corresponding area, causing the metal powder material to release from the adsorption state of the organic photosensitive layer 7-1-1 and fall freely onto the laying platform 5 due to its own gravity. It should be understood that the charging properties of the first charging mechanism 7-1-2 are opposite to those of the second charging mechanism 11-2 (described in detail in the following embodiments) to achieve the above-mentioned adsorption state.

[0039] In one embodiment of the present invention, the powder transfer device 7 further includes a powder collector 7-3, which is disposed near the organic photosensitive layer 7-1-1 for collecting residual metal powder material. In this embodiment, by disposing of the powder collector 7-3 downstream of the organic photosensitive layer 7-1-1, the residual metal powder material is collected by the powder collector 7-3 after the metal powder material is de-adsorbed, thereby avoiding material waste.

[0040] In one embodiment of the present invention, each powder spreading subsystem includes: a second moving device, a hopper 11-1, a second charging mechanism 11-2, and a rotating roller 11-3. The second moving device is used to convey the metal powder material to the lower part of the powder layer transfer device 7; the hopper 11-1 contains the metal powder material; the second charging mechanism 11-2 is disposed near the hopper 11-1 and is used to charge the metal powder material in the hopper 11-1 so that the metal powder material is adsorbed onto the lower surface of the powder layer transfer device 7 by means of electrostatic attraction generated by opposite charges; the rotating roller 11-3 is disposed at the outlet of the hopper 11-1 and is used to transfer the charged metal powder material to the second moving device. Specifically, the hopper 11-1 is a container for holding a specified metal powder material. The metal powder material is charged by the second charging mechanism 11-2 using a negative charging plate to give the metal powder material a negative charge. The rotating roller 11-3 is used to transport the negatively charged metal powder material to the second moving device. The second moving device moves along the Y-axis and can be a moving platform that reciprocates along the Y-axis, which is perpendicular to the moving direction of the first moving device 6, and transports the metal powder material to the bottom of the powder layer transfer device 7.

[0041] Taking the setup of two powder-spreading subsystems as an example, in such cases... Figure 1The structure shown includes: a first Y-axis motion system 9, a second Y-axis motion system 10, a first powder spreading device 11, and a second powder spreading device 12; wherein, the first powder spreading device 11 and the second powder spreading device 12 respectively include: a hopper 11-1, a negative charging plate, and a rotating roller 11-3. The first Y-axis motion system 9 is connected to the rotating roller 11-3 of the first powder spreading device 11 and is used to transport the first type of metal powder material to the bottom of the powder layer transfer device 7. The second Y-axis motion system 10 is connected to the rotating roller 11-3 of the second powder spreading device 12 and is used to transport the second type of metal powder material to the bottom of the powder layer transfer device 7. The specific usage process is as follows: First, the first preset area of ​​the organic photosensitive layer 7-1-1 is oriented towards the surface projection device 8 via the flexible conveyor belt 7-1, making the organic photosensitive layer 7-1-1 suitable for adsorbing metal powder material. Then, the first powder spreading device 11 and the first Y-axis motion system 9 are used to move the first type of metal powder material to the lower surface of the organic photosensitive layer 7-1-1, where the first type of metal powder material is adsorbed onto the lower surface of the organic photosensitive layer 7-1-1. Next, the first type of metal powder material is transferred to the upper surface of the organic photosensitive layer 7-1-1 via the flexible conveyor belt 7-1, at which point the second preset area is oriented towards the surface projection device 8, making the organic photosensitive layer 7-1-1 suitable for adsorbing metal powder material. Then, the second powder spreading device 12 and the second Y-axis motion system 10 are used to transfer the second type of metal powder material... The powder material moves to the area below the organic photosensitive layer 7-1-1, and the second type of metal powder material is adsorbed onto the lower surface of the organic photosensitive layer 7-1-1. At this time, the upper and lower surfaces of the organic photosensitive layer 7-1-1 are respectively adsorbed with the first type of metal powder material and the second type of metal powder material. Then, the powder layer transfer device 7 is transferred to the top of the spreading platform 5 using the first moving device 6. According to the printing sequence, the power supply to the designated preset areas is deactivated one by one. Due to its own gravity, the metal powder material falls onto the spreading platform 5 (for example, the second preset area is first discharged through the discharge mechanism 7-1-3, and the second type of metal powder material falls; then, the flexible conveyor belt 7-1 moves, and the first preset area is discharged through the discharge mechanism 7-1-3 again, and the first type of metal powder material falls). Finally, printing is performed using the laser subsystem 3.

[0042] In one embodiment of the invention, each powder spreading subsystem further includes a powder conveying mechanism connected to the hopper 11-1. Specifically, the powder conveying mechanism may be a bucket elevator or a screw conveyor, etc. Figure 1 In the embodiment shown, a first powder conveying mechanism 14 and a second powder conveying mechanism 15 are provided, which are respectively connected to hoppers 11-1 containing different types of metal powder materials.

[0043] In one embodiment of the present invention, the multi-material metal 3D printing forming system further includes: an inert gas circulation subsystem 13, which is connected to the sealed forming chamber 2, and inert gas is introduced into the sealed forming chamber 2 through the inert gas circulation subsystem 13 to reduce the oxygen content in the sealed forming chamber 2 to the process-permitted value.

[0044] In one embodiment of the present invention, the multi-material metal 3D printing system further includes a control system 16 and a laser subsystem 3. The laser subsystem 3 is located in a sealed forming chamber 2 and is used to print metal powder material laid on a material spreading platform 5. The control system 16 is connected to the material spreading platform 5, the first moving device 6, the powder layer transfer device 7, the area projection device 8, the first Y-axis motion system 9, the second Y-axis motion system 10, the first powder spreading device 11, the second powder spreading device 12, the inert gas circulation subsystem 13, and the powder conveying mechanism, and is used to control the working state of the above devices and systems. The control system 16 drives the laser subsystem 3 according to the layer slicing information of the printing model to perform the melting process of the metal material according to the processing path, and completes the printing of the current layer of metal sample.

[0045] The present invention also provides a method for operating the multi-material metal 3D printing forming system according to the above embodiments of the present invention. The method includes the following steps: S1. The powder transfer device 7 is moved to the upper part of the second area by the first moving device 6; S2. The first preset area for adsorbing metal powder material is projected on the lower surface of the powder transfer device 7 by the area projection device 8. S3. When the first preset area of ​​the powder layer transfer device 7 is in an energized state, a first type of metal powder material is supplied to the powder layer transfer device 7 through the first powder spreading subsystem so that the metal powder material is adsorbed in the first preset area. S4. The powder layer transfer device 7 is switched to the second preset area for adsorbing metal powder material, and the second preset area for adsorbing metal powder material is projected on the lower surface of the powder layer transfer device 7 by the area projection device 8. S5. When the second preset area of ​​the powder layer transfer device 7 is in an energized state, a second type of metal powder material is supplied to the powder layer transfer device 7 through the second powder spreading subsystem so that the metal powder material is adsorbed in the second preset area. S6. By analogy, various metal powder materials are adsorbed onto the designated preset area; S7. The powder transfer device 7 is moved above the first area by the first moving device 6; S8. Discharge each preset area in sequence, and the metal powder material falls onto the material spreading platform 5 in sequence due to its own gravity.

[0046] According to the structure in the above embodiments of the present invention, the specific steps of its working method are as follows: Step 1: Before the multi-material metal 3D printing forming system works, a three-dimensional model of the sample to be printed is first created, and then the three-dimensional model is sliced ​​into layers to obtain the laser processing path and multi-material powder laying area information for each layer. Step 2: The control system 16 starts the inert gas circulation subsystem 13 to reduce the oxygen content in the sealed forming chamber 2 to the process-permitted value. Step 3: The control system 16 drives the first powder conveying mechanism 14 and the second powder conveying mechanism 15 to feed the first metal material and the second metal material into the hoppers 11-1 corresponding to the first powder spreading device 11 and the second powder spreading device 12, respectively. Step 4: According to the layer slicing information of the printed model, the control system 16 drives the surface projection device 8 to emit light with a wavelength of 700-850nm to irradiate the laying area of ​​the first material of the organic photosensitive layer 7-1-1 on the bottom flexible conveyor belt 7-1 of the powder layer transfer device 7 according to the current multi-material powder laying area. Under the irradiation of special wavelength light, the regional resistance of the organic photosensitive layer 7-1-1 on the flexible conveyor belt 7-1 decreases. Step 5: The control system 16 drives the first charging mechanism 7-1-2 on the flexible conveyor belt 7-1, so that the area with a larger surface resistance value of the organic photosensitive layer 7-1-1 carries a larger positive charge, and the area with a smaller surface resistance value carries a smaller positive charge or no charge. Step 6: The control system 16 drives the second charging mechanism 11-2 of the first powder spreading device 11 to charge the metal powder in the feeding hopper 11-1 with a negative charge. At the same time, the rotating roller 11-3 of the first powder spreading device 11 starts to rotate at a constant speed, conveying the metal powder in the first powder spreading device 11 to the powder spreading port. Step 7: The control system 16 drives the first Y-axis motion system 9 to move along the Y-axis direction. When the first metal powder carried on it passes under the powder transfer device 7, the charged first metal material encounters the charged area of ​​the organic photosensitive layer 7-1-1 of the flexible conveyor belt 7-1. The metal material is adsorbed onto the surface of the flexible conveyor belt 7-1, and then the first Y-axis motion system 9 resets. Step 8: The control system 16 drives the conveyor motor 7-2 of the powder layer transfer device 7 to start rotating, causing the flexible conveyor belt 7-1 to rotate and transfer a new powder transfer area (i.e., the laying area corresponding to the second material) to the position directly below the powder layer transfer device 7. Step 9: According to the layer slicing information of the printed model, the control system 16 drives the surface projection device 8 to emit special wavelength light to irradiate the second material-corresponding area of ​​the organic photosensitive layer 7-1-1 on the bottom flexible conveyor belt 7-1 of the powder transfer device 7, so that the regional resistance of the organic photosensitive layer 7-1-1 in the new powder transfer area (i.e., the second material-corresponding area) on the flexible conveyor belt 7-1 decreases under the irradiation of special wavelength light. Step 10: The control system 16 drives the first charging mechanism 7-1-2 on the flexible conveyor belt 7-1, so that the area with a larger surface resistance value of the organic photosensitive layer 7-1-1 in the new powder conveying area is charged, while the area with a smaller surface resistance value is not charged. Step 11: The control system 16 drives the second charging mechanism 11-2 of the second powder spreading device 12 to charge the metal powder in the feeding hopper 11-1 to a negative charge. At the same time, the rotating roller 11-3 of the second powder spreading device 12 starts to rotate at a constant speed, conveying the metal powder in the second powder spreading device 12 to the powder spreading port. Step 12: The control system 16 drives the second Y-axis motion system 10 to move along the Y-axis direction. When the second metal powder carried on it passes under the powder transfer device 7, the charged second metal material encounters the charged area of ​​the organic photosensitive layer 7-1-1 in the new powder transfer area of ​​the flexible conveyor belt 7-1. The second metal material is adsorbed onto the surface of the flexible conveyor belt 7-1, and then the second Y-axis motion system 10 is reset. Step 13: Control system 16 controls the material spreading platform 5 inside the forming box 4 to descend and fix the layer thickness; Step 14: The control system 16 drives the powder layer transfer device 7 to move along the X-axis direction with the first moving device 6 to the top of the material spreading platform 5 of the forming box 4, and drives the discharge mechanism 7-1-3 of the powder layer transfer device 7 to make the charge of the powder conveying area on the surface of the flexible conveyor belt 7-1 that has been electrostatically adsorbed with the second metal material zero. The metal material falls onto the material spreading platform 5 under the action of gravity. Then, the control system 16 drives the conveyor motor 7-2 to start rotating, so that the flexible conveyor belt 7-1 rotates and moves the powder conveying area corresponding to the first metal material to the position directly below the powder layer transfer device 7. Then, the control system 16 drives the discharge mechanism 7-1-3 of the powder layer transfer device 7 to make the charge of the powder conveying area on the surface of the flexible conveyor belt 7-1 that has been electrostatically adsorbed with the first metal material zero. The metal material falls onto the material spreading platform 5 under the action of gravity, and finally the laying of the current layer of multi-material powder is completed. Step 15: The control system 16 drives the powder layer transfer device 7 to move back above the surface projection device 8, and at the same time drives the conveyor motor 7-2 of the powder layer transfer device 7 to start rotating one revolution, and drives the powder collector 7-3 to remove the remaining powder material on the flexible conveyor belt 7-1. Step 16: The control system 16 drives the laser subsystem 3 according to the layer slicing information of the printing model to carry out the melting process of the metal material according to the processing path, and completes the printing of the metal sample of the current layer. Step 17: Repeat steps 4 to 16, printing layer by layer, until the multi-material metal part is finally printed and formed.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-material metal 3D printing forming system, characterized in that, include: The sealed forming chamber (2) has a first region and a second region; The main body of the machine tool (1) is located in a closed forming chamber (2); The material spreading platform (5) is located in the first area; A first moving device (6) is used to move between above the first region and above the second region; The powder transfer device (7) is located on the first moving device (6) and has multiple preset areas for adsorbing different metal powder materials. It is also used to release the metal powder materials adsorbed in the different preset areas onto the spreading platform (5). The area projection device (8) is fixed in the second area of ​​the machine tool body (1) and is used to project the preset area corresponding to the different metal powder materials on each layer of the printing pattern on the lower surface of the powder transfer device (7) so that the different metal powder materials are adsorbed on the corresponding preset area. Multiple powder-laying subsystems are positioned close to the second region to output different metal powder materials, which are then adsorbed onto the corresponding preset regions under the action of the powder layer transfer device (7).

2. The multi-material metal 3D printing forming system according to claim 1, characterized in that, The area projection device (8) includes: light source; The powder transfer device (7) includes: A conveying mechanism is provided on the first moving device (6); An organic photosensitive layer (7-1-1) is disposed on the conveying mechanism. Through the movement of the conveying mechanism, the organic photosensitive layer (7-1-1) has multiple preset areas facing the light source for adsorbing different metal powder materials. When the organic photosensitive layer (7-1-1) is charged and illuminated by the light source at a preset wavelength, a change in resistance is generated in the preset areas, thereby adsorbing different metal powder materials.

3. The multi-material metal 3D printing forming system according to claim 2, characterized in that, The transmission mechanism includes: Conveyor motor (7-2); A flexible conveyor belt (7-1) is connected to the conveyor motor (7-2), and the organic photosensitive layer (7-1-1) is disposed on the outside of the flexible conveyor belt (7-1).

4. The multi-material metal 3D printing forming system according to claim 3, characterized in that, The powder transfer device (7) further includes: The first charging mechanism (7-1-2) is located on one side of the organic photosensitive layer (7-1-1) and is used to charge a preset area of ​​the organic photosensitive layer (7-1-1) to adsorb metal powder material. The discharge mechanism (7-1-3) is located on the other side of the organic photosensitive layer (7-1-1) and is used to discharge a preset area of ​​the organic photosensitive layer (7-1-1) to release the metal powder material.

5. The multi-material metal 3D printing forming system according to claim 3, characterized in that, The powder transfer device (7) further includes: A powder collector (7-3) is disposed near the organic photosensitive layer (7-1-1) for collecting residual metal powder material.

6. The multi-material metal 3D printing forming system according to claim 1, characterized in that, Each of the powder spreading subsystems includes: The second moving device is used to transport the metal powder material to the area below the powder transfer device (7); Hopper (11-1) contains metal powder material; The second charging mechanism (11-2) is located close to the hopper (11-1) and is used to charge the metal powder material in the hopper (11-1) so that the metal powder material is adsorbed on the lower surface of the powder transfer device (7) by the electrostatic force generated by opposite charges. A rotating roller (11-3) is located at the outlet of the hopper (11-1) and is used to transfer charged metal powder material to the second moving device.

7. The multi-material metal 3D printing forming system according to claim 6, characterized in that, Each of the powder spreading subsystems further includes: A powder conveying mechanism is connected to the hopper (11-1).

8. The multi-material metal 3D printing forming system according to any one of claims 1 to 7, characterized in that, Also includes: An inert gas circulation subsystem (13) is connected to the sealed forming chamber (2).

9. The multi-material metal 3D printing forming system according to any one of claims 1 to 7, characterized in that, Also includes: The laser subsystem (3) is located in the sealed forming chamber (2) and is used to print metal powder material laid on the material spreading platform (5).

10. A method of operating the multi-material metal 3D printing forming system according to any one of claims 1 to 9, characterized in that, include: The powder transfer device (7) is moved above the second area by the first moving device (6); The first preset area for adsorbing metal powder material is projected onto the lower surface of the powder transfer device (7) by the area projection device (8); When the first preset area of ​​the powder layer transfer device (7) is in an energized state, a first type of metal powder material is supplied to the powder layer transfer device (7) through the corresponding powder spreading subsystem so that the metal powder material is adsorbed in the first preset area; The powder layer transfer device (7) is switched to the second preset area for adsorbing metal powder material, and the second preset area for adsorbing metal powder material is projected on the lower surface of the powder layer transfer device (7) by the area projection device (8). When the second preset area of ​​the powder layer transfer device (7) is in an energized state, a second type of metal powder material is supplied to the powder layer transfer device (7) through the corresponding powder spreading subsystem so that the metal powder material is adsorbed in the second preset area; By analogy, various metal powder materials are adsorbed onto a designated preset area; The powder transfer device (7) is moved above the first area by the first moving device (6); Discharge is applied to each preset area in sequence, and the metal powder material falls onto the material spreading platform (5) in sequence due to its own gravity.

Images