Multi-material selective laser melting forming follow-up wind field system and method

Abstract

The multi-material selective laser melting forming follow-up type wind field system is installed in an equipment forming chamber and comprises a frame structure, a dust removal unit and a motion control unit. The dust removal unit is connected to the frame structure, and motion control of the dust removal unit is achieved through the motion control unit. The mode of a fixed wind field covering the whole forming chamber is changed, an efficient and controllable wind field is provided for each forming unit for laser scanning through a dust removal unit capable of precisely moving along a guide rail, and the dust removal process has the advantages of being small in working area and capable of being precisely controlled. According to the multi-material selective laser melting and forming precise dust removal device, multi-material selective laser melting and forming precise dust removal with partition covering, unit follow-up and adjustable parameters can be achieved, smoke dust splashing is eliminated from the source, the problems that in the multi-material selective laser melting process, smoke dust splashing occurs, and a powder bed and an entity are polluted by airflow are effectively solved, and the application prospect of multi-material selective laser melting and forming is effectively promoted.

Description

Technical Field

[0001] This invention relates to the field of laser selective melting forming technology, specifically to a multi-material laser selective melting forming follow-up wind field system and method. Background Technology

[0002] Selective laser melting (SLM), a precision metal additive manufacturing technology, has been widely applied in the efficient, short-process manufacturing of complex components in aerospace, automotive electronics, and other fields. In recent years, multi-material SLM has become a cutting-edge research hotspot in additive manufacturing technology due to its ability to achieve gradient or abrupt distributions of material composition and properties within a single component. This offers significant advantages such as functional integration, promotion of innovative design, and advancement of emerging fields. During the SLM forming process, the high-energy laser beam undergoes a complex and intense reaction with the metal powder, generating a large amount of fumes (tiny particles formed by the condensation of metal vapor) and splashes (tiny droplets). If these substances are not handled promptly, they will cause the laser beam to scatter across their surfaces, weakening the energy reaching the powder bed surface. Simultaneously, fumes and splashes falling onto the powder bed surface can easily form metallurgical defects such as incomplete fusion, inclusions, and cracks, affecting the internal quality of the formed product.

[0003] Existing laser selective melting forming equipment generally employs a fixed circulating airflow to remove smoke and splashes within the forming chamber. For example, the patent application titled "Smoke and Dust Treatment Device for Laser Selective Melting Additive Manufacturing Equipment" (publication number CN105413330A) describes a system where, based on the equipment's internal structure, air outlets and suction ports are installed on two opposite side walls within the forming chamber. Each outlet and suction port is connected to a fan. During operation, the fans create a directional circulating airflow within the forming chamber, carrying away smoke and splashes from the powder bed surface. The airflow is then absorbed by a filtration system, thus purifying the forming chamber through this cycle. To ensure effective dust removal across the entire forming area and reduce the harmful effects of turbulent airflow and eddies on smoke and splash removal, the forming process often involves increasing the fan speed at the outlet and suction ports to increase the airflow velocity, thereby achieving a superior dust removal effect within the forming chamber.

[0004] In the field of multi-material laser selective melting forming, the aforementioned fixed circulating airflow has the following problems: First, this technology uses two or more types of metal powders as raw materials. During the laser melting process, the fumes and spatter generated by one material are inevitably transported long distances by airflow to the suction port, falling onto the powder bed of another material or the surface of the formed structure. This introduces unintended impurities, leading to metallurgical defects such as incomplete fusion, inclusions, and cracks within the material during subsequent forming processes. Second, during multi-material laser selective melting forming, strong airflow or eddies can disperse and mix different types of powders (especially low-density aluminum alloy and titanium alloy powders) already laid on the powder bed surface, causing powder bed contamination and severely damaging the performance and reliability of the manufactured parts. Therefore, developing a dust removal technology for the forming chamber that solves the problems of fumes and spatter, and airflow contamination of the powder bed and the formed structure during multi-material laser selective melting forming has high engineering application value. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the present invention aims to provide a multi-material laser selective melting forming follow-up air field system and method, which changes the fixed air field mode covering the entire forming chamber. Through a dust removal unit that can move precisely along the guide rail, an efficient and controllable air field is provided for each forming unit of laser scanning, eliminating dust splashing from the source. At the same time, because the working area of ​​the dust removal process is small and can be precisely controlled, the system achieves precise dust removal for multi-material laser selective melting forming with "partitioned coverage, unit follow-up, and adjustable parameters", completely solving the problem of powder dispersion and mixing in the powder bed.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A multi-material laser selective melting forming follow-up air field system is installed in the forming chamber of the equipment, including a frame structure 1, a dust removal unit 2 and a motion control unit 3; the dust removal unit 2 is connected to the frame structure 1, and the motion of the dust removal unit 2 is precisely controlled by the motion control unit 3.

[0007] The frame structure 1 includes a bracket 11, a guide rail 12, a lead screw 13, a slider A14, and a slider B15. The bracket 11 is fixed to the main frame 4 of the equipment. The guide rail 12 and the lead screw 13 are installed on the bracket 11. The lead screw 13 is located inside the guide rail 12. The slider A14 is installed on the lead screw 13. The slider B15 is installed on the groove on the outside of the guide rail 12. The guide rail 12, the lead screw 13, the slider A14, and the slider B15 are all made of high-hardness and high-wear-resistant metal materials.

[0008] The dust removal unit 2 includes an air outlet 21, an air inlet 22, an air outlet bracket 23, and flexible and retractable pipes 25. The air outlet 21 and the air inlet 22 are arranged opposite to each other and are each installed on the air outlet bracket 23, forming an air outlet assembly and an air inlet assembly, respectively. The air outlet assembly and the air inlet assembly are connected to sliders A14 and B15, respectively. One end of each of the two flexible and retractable pipes 25 is connected to the air outlet 21 and the air inlet 22, respectively, and the other end is connected to the fan of the equipment's circulating filtration system.

[0009] The motion control unit 3 includes a displacement motor 31 and a controller 32. The displacement motor 31 is connected to the lead screw 13. The controller 32 receives instructions from the equipment software system or the PLC master control, and is responsible for controlling the motion state and parameters of the displacement motor 31, and obtaining the position feedback of the dust removal unit 2 in real time, so as to realize the coordinated work of the motion of the dust removal unit 2 and the laser scanning.

[0010] The working method of the above-mentioned multi-material laser selective melting forming follow-up wind field system includes the following steps: Step 1, multi-material powder bed laying: Before forming, the equipment powder laying mechanism 5 on the main frame 4 of the equipment selectively and accurately lays multi-material metal powder on the forming platform 8 according to the three-dimensional model and slice file of the multi-material product, forming a multi-material metal powder bed that meets the requirements of dimensional accuracy and regional distribution. Step 2, Layered and Partitioned Planning: After powder spreading, the equipment software system, based on the cross-sectional shape of the entity to be formed in the current layer, the material type and characteristics of each area, divides the area to be scanned within the forming area of ​​this layer into several strip-shaped rectangular regions along the direction of guide rail 12. The dimension along the direction of guide rail 12 is defined as the segmentation width, and each such strip-shaped rectangular region is defined as a forming unit; Step 3, Forming of the First Forming Unit: The software system drives the lead screw 13 through the motion control unit 3 to move the dust removal unit 2 directly above the first forming unit. According to the material characteristics of this unit, it calls the process database and fine-tunes the lead screw 13 by controlling the displacement motor 31 to adjust the distance between the air outlet 21 and the air inlet 22 to the optimized value (usually greater than the segmentation width of the unit, and ensuring that interference with the laser beam is avoided); Subsequently, the circulating filtration system fan is started to generate a directional and efficient airflow for the dust removal unit, the laser emits light, and the scanning of the entity area within the forming unit begins. During the forming process, the smoke and splashes generated are removed by the dust removal unit 2, which consists of the air outlet 21 and the air intake 22. Step 4: Forming unit switching and forming: After the first forming unit is scanned, the laser stops emitting light and the air field of the dust removal unit is turned off. The controller 32 drives the lead screw 13 to move the dust removal unit 2 to the next adjacent forming unit. The process in step 3 is repeated to complete the forming task of this forming unit. In this way, the scanning task of all forming units in this layer is completed in sequence. The scanning sequence of the forming units should start from any end and always select the next unit adjacent to the current unit. Step 5: Interlayer reset and loop: After all forming units in this layer are scanned, the software system controls the dust removal unit 2 to move to a safe position at the edge of the forming chamber where the powder spreading mechanism 5 of the equipment is not interfering with the powder spreading mechanism of the next layer. Then, the equipment lays the next layer of multi-material powder and repeats steps 2 to 4 until the forming of the entire multi-material metal product is completed.

[0011] In step 2, the segmentation width should be set as large as possible while ensuring the quality of dust splash removal, so as to reduce the number of forming units and improve the overall manufacturing efficiency. For specific multi-material combinations, a segmentation width database needs to be formed through flow field simulation and process experiments for direct use in the forming process.

[0012] The distance between the lower end face of the air outlet 21 and air inlet 22 of the dust removal unit 2 and the surface of the powder bed is defined as the distance between the air outlet and the powder bed. This distance must meet two conditions: first, it must be higher than the highest point of the powder bed to ensure that the dust removal unit 2 does not scrape the already laid powder during movement and adjustment; second, it cannot be too high to avoid affecting the dust removal effect. For specific multi-material combinations, the distance between the air outlet and the powder bed should be combined with flow field simulation and process test to form a process parameter library, which can be called and used during the forming process.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: Since the present invention adopts a local precision wind field system, it can efficiently absorb the smoke and dust and splashes generated in the multi-material laser selective melting and forming process, and avoid the metal powder on the powder bed surface being blown up, effectively solving the problem of cross-contamination of dissimilar metals, promoting the engineering application of multi-material laser selective melting technology, and has profound innovative value. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of a multi-material laser selective melting forming follow-up wind field system.

[0015] Figure 2 This is a schematic diagram of the framework structure of an embodiment.

[0016] Figure 3 This is a schematic diagram of the slider A structure in the embodiment.

[0017] Figure 4 This is a schematic diagram of the slider B structure in the embodiment.

[0018] Figure 5 This is a schematic diagram of the dust removal unit structure in an embodiment.

[0019] Figure 6 This is a schematic diagram of the main frame and motion control unit structure of the embodiment device.

[0020] Figure 7 This is a schematic diagram of the structure of the multi-material powder supply system in the embodiment.

[0021] Figure 8 This is a schematic diagram of a multi-material product forming section forming unit.

[0022] Figure 9 This is a schematic diagram of the forming unit in the embodiment.

[0023] In the diagram, 1. Frame structure; 11. Support; 12. Guide rail; 13. Lead screw; 14. Slider A; 15. Slider B; 2. Dust removal unit; 21. Air outlet; 22. Air inlet; 23. Air outlet support; 24. Bolt; 25. Flexible and retractable pipeline; 3. Motion control unit; 31. Displacement motor; 32. Controller; 4. Main frame of equipment; 5. Multi-material powder spreading system; 51. Powder silo A; 52. Powder silo B; 53. Powder silo support; 54. Multi-material powder spreader; 6. Substrate; 7. Powder collection bin; 8. Forming platform; 9. Forming platform lifting system. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments and accompanying drawings.

[0025] Reference Figure 1A multi-material laser selective melting forming follow-up air field system is installed in the forming chamber of the equipment, including a frame structure 1, a dust removal unit 2 and a motion control unit 3; the dust removal unit 2 is connected to the frame structure 1, and the dust removal unit 2 achieves motion control through the motion control unit 3.

[0026] Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 The frame structure 1, serving as the skeleton and motion foundation, includes a support 11, a guide rail 12, a lead screw 13, a slider A14, and a slider B15. The support 11 is fixed to the main frame 4 of the equipment, providing rigid support for the entire system. The guide rail 12 and the lead screw 13 are mounted on the support 11. The lead screw 13 is located inside the guide rail 12, and the slider A14 is mounted on the lead screw 13. When the lead screw 13 rotates, the slider A14 moves along its length inside the guide rail 12. The slider B15 is mounted on the groove on the outer side of the guide rail 12, and the slider B15 slides freely along the groove. The guide rail 12, the lead screw 13, the slider A14, and the slider B15 are all made of high-hardness, high-wear-resistant metal materials to ensure long-term operational accuracy and stability.

[0027] Reference Figure 2 , Figure 5 The dust removal unit 2 is a direct component that performs the dust removal function. It includes an air outlet 21, an air intake 22, an air outlet bracket 23, bolts 24, and a flexible and retractable pipe 25. The air outlet 21 and the air intake 22 are arranged opposite to each other and are respectively installed on the air outlet bracket 23, forming an air outlet assembly and an air intake assembly. The air outlet assembly and the air intake assembly are connected by the bolts 24 to the sliders A14 and B15. One end of the flexible and retractable pipe 25 is connected to the air outlet 21 and the air intake 22 respectively, and the other end is connected to the fan of the equipment's circulating filtration system.

[0028] Reference Figure 2 , Figure 5 , Figure 6 The motion control unit 3 is used to drive and track the movement of the dust removal unit 2. It includes a displacement motor 31 and a controller 32. The displacement motor 31 is connected to the lead screw 13 and drives the lead screw 13 to rotate precisely, thereby moving the slider A14 meshing with the lead screw 13 and the dust removal unit 2 connected thereto. Since the air outlet 21 and the air inlet 22 are fixed to the slider A14 and the slider B15 respectively, the relative distance between the air outlet 21 and the air inlet 22 is adjusted by precisely controlling the rotation of the displacement motor 31. The controller 32 receives instructions from the equipment software system or the PLC master control and is responsible for controlling the motion state and parameters (position and speed) of the displacement motor 31. It also obtains the position feedback of the dust removal unit 2 in real time, so as to realize the coordinated work of the movement of the dust removal unit 2 and the laser scanning, and avoid interference with the laser scanning.

[0029] Based on the above-mentioned working method of a multi-material laser selective melting forming follow-up air field system, the following steps are included: Step 1, multi-material powder bed laying: Before forming, the powder laying mechanism 5 on the main frame 4 of the equipment selectively and precisely lays multi-material metal powder on the forming platform 8 according to the three-dimensional model and slice file of the multi-material product, forming a multi-material metal powder bed that meets the requirements of dimensional accuracy and regional distribution; refer to Figure 7 The powder spreading mechanism 5 consists of powder hopper A51, powder hopper B52, powder hopper support 53, and multi-material powder spreader 54; the forming platform 8 is connected to the forming platform lifting system 9, and the forming platform 8 is equipped with a substrate 6; the powder collection bucket 7 is connected to the main frame 4 of the equipment; Step 2, layered and zoned planning: After the powder spreading is completed, the equipment software system, based on the cross-sectional shape of the entity to be formed in the current layer, the material type and characteristics of each area, divides the area to be scanned and formed within the forming area of ​​the layer into several strip-shaped rectangular areas along the direction of the guide rail 12. The dimension along the direction of the guide rail 12 is defined as the dividing width, and each such strip-shaped rectangular area is defined as a forming unit; Step 3, the first forming unit is formed: The software system drives the lead screw 1 through the motion control unit 3. 3. Move the dust removal unit 2 directly above the first forming unit. Based on the material characteristics of this unit, call the process database and adjust the distance between the air outlet 21 and the air intake 22 to the optimized value by controlling the displacement motor 31 and fine-tuning the lead screw 13 (usually greater than the segmentation width of the unit, and ensuring to avoid interference with the laser beam). Then, start the circulating filtration system fan to generate a directional and efficient airflow for the dust removal unit. The laser emits light and begins scanning the solid area within the forming unit. Simultaneously, the dust and splashes generated during the forming process are efficiently removed by the dust removal unit 2, which consists of the air outlet 21 and the air intake 22. Step 4: Forming unit switching and forming: After the first forming unit is scanned, the laser stops emitting light, and the airflow of the dust removal unit is turned off. The controller drives the lead screw to move the entire dust removal unit above the next adjacent forming unit. Repeat the process in step 3 to complete the forming task of this forming unit. In this way, the scanning task of all forming units in this layer is completed sequentially. To maximize efficiency, the scanning sequence of the forming units should start from any end and always select the next unit adjacent to the current unit to reduce the unnecessary movement time of the dust removal unit; Step 5, inter-layer reset and cycle: After all forming units in this layer have been scanned, the software system controls the dust removal unit 2 to move to a safe position at the edge of the forming chamber where it does not interfere with the powder spreading mechanism 5 for the next layer of powder spreading. Then, the equipment spreads the next layer of multi-material powder and repeats steps 2 to 4 until the entire multi-material metal product forming is completed.

[0030] In step 2, setting the segmentation width is a key optimization parameter. A smaller segmentation width means that the dust removal unit 2 can act more closely on the laser-powder reaction area, resulting in better dust removal. However, this leads to an increase in the number of forming units, increasing the time for the dust removal unit 2 to move and start / stop, and reducing the overall forming efficiency. Therefore, it is necessary to increase the segmentation width as much as possible while ensuring the quality of dust splash removal, so as to reduce the number of forming units and improve the overall manufacturing efficiency. For specific multi-material combinations, it is necessary to form a segmentation width database through flow field simulation and process experiments for direct use in the forming process.

[0031] The distance between the lower end face of the air outlet 21 and air inlet 22 of the dust removal unit 2 and the surface of the powder bed is defined as the distance between the air outlet and the powder bed. This distance must meet two conditions: first, it must be higher than the highest point of the powder bed to ensure that the dust removal unit 2 does not scrape the already laid powder during movement and adjustment; second, it cannot be too high to avoid affecting the dust removal effect. For specific multi-material combinations, the distance between the air outlet and the powder bed should be combined with flow field simulation, process test and other methods to form a process parameter library, and the parameters can be called and used during the forming process.

[0032] In the equipment preparation stage of this embodiment, the main processes include substrate installation and leveling, powder filling of the multi-material powder hopper, scraper installation, and gas atmosphere replacement in the forming chamber. During the gas atmosphere replacement process, the air outlet 21 and air inlet 22 are first moved to their respective positions on the sidewalls of the forming chamber using the displacement motor 31, at which point the distance between them is greatest. Then, the equipment's circulation filtration system is turned on, and inert gas is used to replace the air in the forming chamber and pipelines until the oxygen content in the forming chamber is less than 100 ppm before forming can begin. Other processes in the equipment preparation stage of this embodiment are the same as those in commonly used laser selective melting forming equipment.

[0033] This embodiment employs a multi-material laser selective melting forming multi-material powder spreader 54 to lay a layer of powder containing multiple materials. The equipment software system, based on the multi-material type information of the current layer to be formed, calls the segmentation width value from the process database, such as... Figure 8 As shown, along the direction of guide rail 12, the forming range is divided into 5 forming units, which are numbered sequentially (#1-#5); secondly, the equipment software system drives the distance between the air outlet 21 and the lowest edge of the air inlet 22 and the powder bed to meet the requirements by calling the distance between the air outlet and the powder bed in the process database.

[0034] This embodiment retrieves the device software system. Figure 8 The division of forming units on the forming plane is achieved by the displacement motor 31 driving the lead screw 13 to move. Figure 4 Dust removal unit 2 moves to Figure 7 Above the forming unit 1 shown, as Figure 9As shown, the forming unit 1 should be located in the center of the rectangular area formed by the air outlet 21 and the air inlet 22. Along the direction of the guide rail 12, the size of this rectangular area is larger than the size of the forming unit to avoid interference between the dust removal unit 2 and the laser beam forming process of the forming unit.

[0035] In this embodiment, after the dust removal unit 2 moves to the dust removal position of the forming unit 1, the equipment drives the circulating filtration system fan to start. The air outlet 21 is connected to the blowing fan through a flexible and retractable pipe 25, and the air intake 22 is connected to the suction fan through another flexible and retractable pipe 25. This generates a uniform and stable dust removal airflow within the forming unit 1. The laser selectively melts and solidifies the solid structure in the forming unit 1 according to parameters such as laser power and scanning speed of the solid material in the forming unit 1. The smoke and dust generated during the forming process of the forming unit 1 are removed in situ, instantly, and efficiently by the dust removal unit 2.

[0036] After the first forming unit in this embodiment completes its forming process, the laser stops emitting light, and the airflow of the equipment's circulating filtration system is shut down. The equipment software then drives the lead screw 13 again, moving the entire dust removal unit 2 above the adjacent forming unit 2, repeating the process from the previous step to complete the forming task of forming unit 2. In this manner, the scanning and forming tasks of forming units 3#-5# in this layer are completed sequentially.

[0037] In this embodiment, the equipment software system drives the displacement motor 31 to rotate the lead screw 13, controlling the dust removal unit 2 to move to a safe position at the edge of the forming chamber that does not interfere with the powder spreading mechanism's next layer of powder spreading work.

[0038] In this embodiment, the equipment lays the next layer of powder and divides the next layer of forming area into forming units in the manner described above. The dust removal unit 2 accurately absorbs the smoke and dust generated during the forming process of each forming unit. The process is carried out layer by layer until the entire product is formed.

Claims

1. A multi-material laser selective melting forming follow-up wind field system, characterized in that: Installed in the forming chamber of the equipment, it includes a frame structure (1), a dust removal unit (2) and a motion control unit (3); the dust removal unit (2) is connected to the frame structure (1), and the dust removal unit (2) achieves precise movement through the motion control unit (3).

2. The system according to claim 1, characterized in that: The frame structure (1) includes a bracket (11), which is fixed on the main frame (4) of the equipment. A guide rail (12) and a lead screw (13) are installed on the bracket (11). The lead screw (13) is located inside the guide rail (12). A slider A (14) is installed on the lead screw (13), and a slider B (15) is installed on the groove outside the guide rail (12).

3. The system according to claim 2, characterized in that: The guide rail (12), lead screw (13), slider A (14) and slider B (15) are all made of metal materials with high hardness and high wear resistance.

4. The system according to claim 1, characterized in that: The dust removal unit (2) includes an air outlet (21) and an air inlet (22). The air outlet (21) and the air inlet (22) are arranged opposite to each other and are installed on the air outlet bracket (23) to form an air outlet assembly and an air inlet assembly respectively. The air outlet assembly and the air inlet assembly are connected by slider A (14) and slider B (15). One end of the two flexible and retractable pipes (25) are connected to the air outlet (21) and the air inlet (22) respectively, and the other end is connected to the fan of the equipment circulation filtration system.

5. The system according to claim 1, characterized in that: The motion control unit (3) includes a displacement motor (31), which is connected to a lead screw (13). The controller (32) receives instructions from the equipment software system or PLC control system, and is responsible for controlling the motion state and parameters of the displacement motor (31). It also obtains the position feedback of the dust removal unit (2) in real time, so as to realize the coordinated operation of the motion of the dust removal unit (2) and laser scanning.

6. A working method for a multi-material laser selective melting forming follow-up wind field system according to any one of claims 1-5, characterized in that, Includes the following steps: Step 1, multi-material powder bed laying: Before forming, the equipment powder laying mechanism (5) on the main frame (4) of the equipment selectively and precisely lays multi-material metal powder on the forming platform (8) according to the three-dimensional model and slice file of the multi-material product, forming a multi-material metal powder bed that meets the requirements of dimensional accuracy and regional distribution. Step 2, Layered and Partitioned Planning: After the powder is spread, the equipment software system divides the area to be scanned within the current layer into several rectangular strips along the guide rail (12) based on the cross-sectional shape of the entity to be formed in the current layer, the material type and characteristics of each area. The dimension along the guide rail (12) is defined as the dividing width, and each such rectangular strip is defined as a forming unit. Step 3, Forming of the First Forming Unit: The software system drives the lead screw (13) through the motion control unit (3) to move the dust removal unit (2) directly above the first forming unit. Based on the material characteristics of the unit, the process database is called, and the displacement motor (31) is driven by the controller (32) to rotate the two lead screws (13) to adjust the distance between the air outlet (21) and the air inlet (22) to an appropriate value. Subsequently, the circulating filtration system fan is started to generate a directional and efficient airflow for the dust removal unit. The laser emits light and begins to scan the entity area within the forming unit. At the same time, the dust generated during the forming process is removed. The dust and splashes are sucked away by the dust removal unit (2) consisting of the air outlet (21) and the air inlet (22); Step 4, forming unit switching and forming: After the first forming unit is scanned, the laser stops emitting light and the dust removal unit air field is turned off; the controller (32) drives the lead screw (13) to move the dust removal unit (2) as a whole to the next adjacent forming unit; repeat the process in step 3 to complete the forming task of this forming unit; in this way, the scanning task of all forming units in this layer is completed in sequence; the scanning sequence of the forming unit should start from any end in the direction of the guide rail and always select the next unit adjacent to the current unit; Step 5, inter-layer reset and cycle: after all forming units in this layer are scanned, the software system controls the dust removal unit (2) to move to the edge of the forming chamber where the powder spreading mechanism (5) of the equipment does not interfere with the next layer of powder spreading, and then the equipment lays the next layer of multi-material powder and repeats steps 2 to 4 until the entire multi-material metal product is formed.

7. The method according to claim 6, characterized in that: In step 2, the segmentation width should be set as large as possible while ensuring the quality of dust splash removal, so as to reduce the number of forming units and improve the overall manufacturing efficiency. For specific multi-material combinations, a segmentation width database needs to be formed through flow field simulation and process experiments for direct use in the forming process.

8. The method according to claim 6, characterized in that: The distance between the lower end face of the air outlet (21) and air inlet (22) of the dust removal unit (2) and the surface of the powder bed is defined as the distance between the air outlet and the powder bed. This distance must meet two conditions: first, it must be higher than the highest point of the powder bed to ensure that the dust removal unit (2) does not scrape the powder that has been laid during the movement and adjustment process; second, the position cannot be too high to avoid affecting the dust removal effect. For specific multi-material combinations, the distance between the air outlet (21), air inlet (22) and the powder bed should be combined with flow field simulation and process test to form a process parameter library, and the parameters can be called and used during the forming process.

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