Coplanar different-material multi-station selective laser melting method

Abstract

The invention discloses a coplanar different-material multi-station selective laser melting method, which belongs to the technical field of additive manufacturing, and comprises the following steps of: partitioning a component required to be printed corresponding to powder types required by different components, establishing an independent model according to the different components, and slicing the model; powder is laid on the placing net surfaces above and below the powder preparation platform; powder laid on a first placement net surface and a second placement net surface above and below a powder preparation platform vertically falls on a printing platform at the top of a forming cylinder, and various kinds of powder are combined into a complementary complete pattern on the printing platform; the requirement that powder can be placed on the first placing net face and the second placing net face of the powder preparing platform is met, the adsorbed powder can be conveniently placed on the printing platform subsequently through the switching type negative pressure adsorption mechanism, and two or more kinds of raw material powder are printed on the same plane; and the functional performance of the component can be improved to the greatest extent.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of additive manufacturing technology, in particular to a method for multi-station selective laser melting of same-plane different materials. BACKGROUND

[0002] Selective laser melting forming technology is a 3D printing technology that forms a molten pool by selective irradiation of a high-energy laser beam on metal powder, and then solidifies on the substrate to print parts layer by layer. In this technology, a three-dimensional part model is modeled and sliced to obtain two-dimensional plane information of the part and import the two-dimensional plane information into a computer for additive manufacturing process. The parts formed by this technology have high surface precision and good forming performance, and have broad development prospects.

[0003] The specific processing process of the existing 3D printer is as follows: after processing each layer, the workbench is lowered by a certain distance, a certain amount of powder is sent out by the powder feeder and then flattened by the powder laying mechanism, and then the laser is sintered on the layer of powder. The process of sintering-workbench lowering-powder feeding-powder laying is repeated continuously, and finally the processing is completed.

[0004] The current equipment uses a scraper to lay powder, and usually only one kind of powder can be laid in the same plane. However, when the printed parts need to place different materials in different areas of the same plane, or place different materials in different areas at different heights, the traditional 3D printing process for laying different powders in multiple areas of the same plane is cumbersome, and it is not convenient to print multiple powders separately in the same plane, not convenient to mix two or more raw material powders together for printing, and the efficiency of laying different materials in the same plane is not high. Therefore, it is necessary to design a method for multi-station selective laser melting of same-plane different materials. SUMMARY

[0005] The purpose of the present application is to provide a method for multi-station selective laser melting of same-plane different materials to solve the problems raised in the background art.

[0006] In order to solve the above technical problems, the present application provides the following technical scheme: a method for multi-station selective laser melting of same-plane different materials, comprising the following steps:

[0007] S1. The powder types required by the components to be printed are divided into different parts according to the independent models of different parts, and the models are sliced;

[0008] S2. Prepare a plurality of powder preparation platforms provided with first and second placing net surfaces opposite to each other, lay powder on the first placing net surface of the powder preparation platform and prepare the required shape, and use the switching negative pressure adsorption mechanism inside the powder preparation platform to adsorb the powder laid on the first placing net surface, then use the turnover motor to drive the powder preparation platform to turn over, rotate the second placing net surface of the powder preparation platform to the upper side, lay powder on the second placing net surface of the powder preparation platform and prepare the required shape;

[0009] The switching negative pressure adsorption mechanism only adsorbs the powder laid on the first or second placing net surface when working;

[0010] S3. Move the powder preparation platform to above the forming cylinder, switch the switching negative pressure adsorption mechanism to adsorb the powder laid on the second placing net surface of the powder preparation platform, at this time the powder laid on the first placing net surface of the powder preparation platform falls vertically on the printing platform at the top of the forming cylinder, then use the turnover motor to drive the powder preparation platform to turn over, rotate the second placing net surface of the powder preparation platform to the lower side, then stop the switching negative pressure adsorption mechanism, at this time the powder laid on the second placing net surface of the powder preparation platform falls vertically on the printing platform at the top of the forming cylinder;

[0011] S4. Combine a plurality of powders on the printing platform into a complete pattern complementary to each other, move the forming cylinder to the laser station, and use laser to perform selective laser melting processing on the required powder to be melted until the processing is completed.

[0012] In further embodiments, in step S2, the micro vacuum pump provided on the powder preparation platform in the switching negative pressure adsorption mechanism is connected to the two air suction covers provided above and below the powder preparation platform through the bidirectional electromagnetic reversing valve at the air suction end, and the two air suction covers are communicated with the adsorption cover adjacent to the first placing net surface or the adsorption cover adjacent to the second placing net surface in the powder preparation platform through a plurality of air suction hoses, and the adsorption cover adjacent to the first placing net surface is driven to seal and fit with the first placing net surface or the adsorption cover adjacent to the second placing net surface is driven to seal and fit with the second placing net surface through the sealing and fitting mechanism provided in the powder preparation platform, and the micro vacuum pump works to suck air to realize the negative pressure adsorption of the powder laid on the first or second placing net surface by the adsorption cover.

[0013] In a further embodiment, in step S2, the first electric push cylinder and the second electric push cylinder arranged between the two moving plates for fixing the adsorption cover above and below the inside of the powder preparation platform are used to push the adjacent moving plate connected with the output end of the first electric push cylinder or the second electric push cylinder, so that the moving plate moves towards the first placement net surface or the second placement net surface, and the adsorption cover is sealed and attached to the adjacent first placement net surface or second placement net surface.

[0014] In a further embodiment, in step S2, the first placement net surface and the second placement net surface of the powder preparation platform are used to supply powder, and a scraper, a brush, a roller or other devices are used to spread the powder to the required thickness.

[0015] In a further embodiment, in step S2, the powder in the area not needed is removed using a suction head, leaving the powder area needed.

[0016] In a further embodiment, in step S4, the forming cylinder moves to the laser station through the linear motor and guide rail.

[0017] In a further embodiment, in step S4, there is no limitation on the type of powder spreading in the same plane.

[0018] In a further embodiment, in step S2, a sealing ring is arranged on the side of the adsorption cover facing the first placement net surface or the second placement net surface, and a pressure sensor is arranged on the side of the sealing ring facing the first placement net surface or the second placement net surface. By setting a predetermined pressure threshold, the pressure sensor senses the pressure, and when the pressure threshold is reached, the first electric push cylinder or the second electric push cylinder no longer pushes the adjacent moving plate, ensuring that the adsorption cover is tightly sealed and attached to the adjacent first placement net surface or second placement net surface.

[0019] In a further embodiment, in step S2, a fixing frame is arranged on the outside of the powder preparation platform, the turnover motor is fixed on the fixing frame, the output end of the turnover motor is connected with the powder preparation platform, and a sliding table air cylinder is further arranged on the fixing frame, and the output end of the sliding table air cylinder is connected with the turnover motor through a sliding table seat.

[0020] In a further embodiment, in step S2, a limiting rod is arranged inside the powder preparation platform, and the moving plate is slidably sleeved on the limiting rod, so that the first electric push cylinder or the second electric push cylinder pushes the moving plate to move stably.

[0021] Compared with the prior art, the present application has the beneficial effects that: the present application adjusts and switches through the switching type negative pressure adsorption mechanism, cooperates with the overturning mechanism, realizes that the powder demand can be placed on the first placing net surface and the second placing net surface of the powder preparation platform, at the same time, through the switching type negative pressure adsorption mechanism, the adsorbed powder is conveniently placed on the printing platform, in the whole working process, the most suitable material can be selected according to the functional requirements of different parts, by spreading powder of different materials on the corresponding positions, two or more than two raw material powders can be printed on the same plane according to the needs, the optimization of the local strength, rigidity or other performance of the part can be realized, so that the functional performance of the part can be maximized. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a schematic diagram of the powder preparation platform installation structure of the present application;

[0023] Figure 2 is a schematic diagram of the switching type negative pressure adsorption mechanism structure of the present application;

[0024] Figure 3 is a method flowchart of the present application;

[0025] Figure 4 is a schematic diagram of the powder adsorption effect on the backup platform of the present application, a is a CuSn single material model cross-section path planning, b is a cross-section diagram after the CuSn single material model cross-section selected area powder removal, c is a 316L single material model cross-section path planning, and d is a cross-section diagram after the 316L single material model cross-section selected area powder removal;

[0026] Figure 5 is a schematic diagram of the powder spreading effect on the printing platform of the present application;

[0027] Figure 6 is a schematic diagram of the actual powder spreading effect of powder A on the printing platform of the present application;

[0028] Figure 7 is a final powder spreading effect diagram of powder A after powder B is laid on the printing platform of the present application after powder A is laid on the printing platform;

[0029] The reference signs are: powder preparation platform 1, first placing net surface 2, micro vacuum pump 3, overturning motor 4, fixing frame 5, sliding table air cylinder 6, limiting rod 7, two-way electromagnetic reversing valve 8, air suction cover 9, adsorption cover 10, air suction hose 11, sealing ring 12, moving plate 13, first electric push cylinder 14, second electric push cylinder 15, second placing net surface 16. DETAILED DESCRIPTION

[0030] In the following description, numerous specific details are set forth to provide a more thorough understanding of the present application. However, it will be apparent to one skilled in the art that the present application can be practiced without one or more of these specific details. In other instances, well-known features have not been described in order to avoid obscuring the present application.

[0031] Referring now to the drawings Figures 1-7 The present application provides a technical solution: a method for multi-station selective laser melting of the same plane and different materials, comprising the following steps:

[0032] S1. The component to be printed is divided into different powder types required by different parts, independent models are established according to different parts, and the model is sliced using layering slicing software;

[0033] The inert gas is introduced into the slicing area, the powder transfer area, the forming cylinder and the printing platform area on the top of the forming cylinder, and the whole processing area of the laser melting through the gas supply system, the equipment is washed with gas, the oxygen is prevented from contacting the metal material being processed, the risk of oxidation is reduced, the quality of the printed part is improved, and potential pollutants such as moisture and dust are removed;

[0034] S2. Prepare a plurality of powder preparation platforms 1 provided with first and second placing nets 2 and 16 facing away from each other, wherein the first placing net 2 is arranged on the front surface of the powder preparation platform 1, and the second placing net 16 is arranged on the back surface of the powder preparation platform 1. The first and second placing nets 2 and 16 are arranged facing away from each other. The powder is laid on the surface of the first placing net 2 of the powder preparation platform 1 and prepared into the required shape. The powder is laid into the required thickness using a scraper, a brush, a roller and other devices. The powder in the area not required is removed using a suction head, leaving the powder area required. The powder laid on the surface of the first placing net 2 is negatively adsorbed by the switching negative pressure adsorption mechanism inside the powder preparation platform 1. Then, the powder preparation platform 1 is turned over by the turning motor 4, and the second placing net 16 of the powder preparation platform 1 is rotated to the upper side. The powder is laid on the surface of the second placing net 16 of the powder preparation platform 1 and prepared into the required shape.

[0035] The switching negative pressure adsorption mechanism only negatively adsorbs the powder laid on the surface of the first or second placing net 2 or 16 when it works;

[0036] S3. The powder preparation platform 1 is moved above the forming cylinder, the switching negative pressure suction mechanism is switched to the powder laid on the surface of the second placing net 16 of the powder preparation platform 1 for suction, at this time the powder laid on the first placing net 2 of the powder preparation platform 1 falls vertically on the printing platform at the top of the forming cylinder, then the overturning motor 4 drives the powder preparation platform 1 to overturn, the second placing net 16 of the powder preparation platform 1 is rotated to the lower side, then the switching negative pressure suction mechanism stops working, at this time the powder laid on the surface of the second placing net 16 of the powder preparation platform 1 falls vertically on the printing platform at the top of the forming cylinder;

[0037] S4. Each kind of powder is sucked into the corresponding pattern and falls on the printing platform, the number of repeated times is the same as the number of powder types, finally the multiple powders are combined into a complete pattern which is complementary to each other on the printing platform of the forming cylinder, the forming cylinder is moved to the laser working position, and the laser is used to carry out selective laser melting processing on the powder needed to be melted, until the processing is completed.

[0038] In step S3, when other powders need to be laid on the printing platform, the powder preparation platform 1 on which the above-mentioned powder is laid on the printing platform is moved out of the working position, the powder preparation platform 1 on which the other powder is laid is moved above the forming cylinder, then the powder is vertically laid on the printing platform at the top of the forming cylinder until the powder of the layer is laid.

[0039] In a further embodiment, in step S2, the switching negative pressure suction mechanism includes two air suction covers 9 arranged above and below the powder preparation platform 1, a micro vacuum pump 3 is arranged on the powder preparation platform 1, the air suction end of the micro vacuum pump 3 is connected with the two air suction covers 9 through a two-way electromagnetic reversing valve 8, the powder preparation platform 1 is internally provided with an adsorption cover 10 adjacent to the first placing net 2 and the second placing net 16 above and below, the adsorption cover 10 is communicated with the adjacent air suction cover 9 through a plurality of air suction hoses 11, and the powder preparation platform 1 is further provided with a fitting mechanism for driving the adsorption cover 10 to be sealingly fitted with the adjacent first placing net 2 or second placing net 16.

[0040] Through the above technical solution, the micro vacuum pump 3 is started to perform air suction, the valve at the connection between the two-way electromagnetic reversing valve 8 and the air suction cover 9 adjacent to the first placing net 2 or the second placing net 16 is opened, so that negative pressure is formed in the air suction cover 9, negative pressure is formed in the adsorption cover 10 adjacent to the first placing net 2 or the second placing net 16 through the air suction hose 11, the powder laid on the surface of the first placing net 2 or the second placing net 16 is adsorbed, and the fitting mechanism ensures that the adsorption cover 10 is sealingly fitted with the adjacent first placing net 2 or second placing net 16, so as to ensure stable adsorption.

[0041] In a further embodiment, in step S2, the fitting mechanism includes a moving plate 13 arranged inside the powder preparation platform 1 up and down for fixing the adsorption cover 10, and a first electric push cylinder 14 and a second electric push cylinder 15 are arranged between the moving plates 13.

[0042] Through the above technical solution, through the cooperation of the first electric push cylinder 14 and the second electric push cylinder 15, when the powder on the surface of the first placing net 2 or the second placing net 16 needs to be adsorbed, the first electric push cylinder 14 or the second electric push cylinder 15 pushes the moving plate 13 adjacent to the first placing net 2 or the second placing net 16, so that the corresponding adsorption cover 10 is fitted to the first placing net 2 or the second placing net 16. The air suction hose 11 is a soft tube, and the moving plate 13 is provided with a mounting hole matched with the air suction hose 11. The length of the air suction hose 11 is greater than the moving distance of the moving plate 13 when the adsorption cover 10 is fitted to the first placing net 2 or the second placing net 16. When the moving plate 13 moves, the air suction hose 11 does not affect the subsequent air suction and negative pressure adsorption requirements.

[0043] In a further embodiment, the powder preparation platform 1 is transferred above the forming cylinder, and the forming cylinder can also be transferred below the powder preparation platform 1. The transfer of the forming cylinder or the powder preparation platform 1 is completed through a linear motor and a guide rail. The linear motor drives the forming cylinder or the powder preparation platform 1 to move as a whole on the guide rail.

[0044] In a further embodiment, the forming cylinder is moved to the laser station, and the laser station can also be moved to the forming cylinder. The transfer of the forming cylinder or the laser station can be completed through a linear motor and a guide rail.

[0045] In a further embodiment, in step S2, the shape of the powder sucked by the suction head can be freely designed. For example, the laid powder material can be zoned and planned like a two-dimensional code, and the required heterogeneous material powder is dropped in the specified pattern, i.e., the two-dimensional code "pixel" area range.

[0046] In a further embodiment, in step S4, there is no limitation on the type of powder laid in the same plane. Three, four, or even several hundred different material powders are also applicable, and 1-10000 different materials can be laid, transferred, and fused in the same plane.

[0047] In a further embodiment, in step S2, one side of the adsorption cover 10 facing the first placing net 2 or the second placing net 16 is provided with a sealing ring 12, and the side of the sealing ring 12 facing the first placing net 2 or the second placing net 16 is provided with a pressure sensor.

[0048] Through the technical scheme, the sealing ring 12 is tightly attached to the first placing net surface 2 or the second placing net surface 16 by pushing the adsorption cover 10 to move towards the first placing net surface 2 or the second placing net surface 16, so that the sealing effect is guaranteed, and the adsorption cover 10 stops moving after the pressure threshold is reached by setting the predetermined pressure threshold and the pressure sensor sensing the pressure, so that the sealing ring 12 is tightly attached to the first placing net surface 2 or the second placing net surface 16.

[0049] In a further embodiment, in step S2, the outside of the powder preparation platform 1 is provided with a fixing frame 5, the overturning motor 4 is fixed on the fixing frame 5, the output end of the overturning motor 4 is connected with the powder preparation platform 1, and the fixing frame 5 is further provided with a sliding table cylinder 6, and the output end of the sliding table cylinder 6 is connected with the overturning motor 4 through a sliding table seat.

[0050] Through the technical scheme, the overturning motor 4 drives the powder preparation platform 1 to overturn, and the height of the overturning motor 4 is fine-tuned by the sliding table cylinder 6, so that the height of the powder preparation platform 1 is fine-tuned, and the powder is stably dropped on the printing platform.

[0051] In a further embodiment, in step S2, the inside of the powder preparation platform 1 is provided with a limiting rod 7, and the moving plate 13 is slidingly sleeved on the limiting rod 7.

[0052] Through the technical scheme, the moving plate 13 is limited by the limiting rod 7, so that the moving plate 13 moves stably, and the subsequent sealing ring 12 is further guaranteed to be tightly attached to the placing net surface 2.

[0053] In a further embodiment, in step S7, the design of each layer in the printing direction can be different, and if each layer is regarded as a pattern, each layer in the additive direction can be a pattern independent of each other.

[0054] In order to better understand, the application will be further described below in combination with specific examples, and in the examples, 316L and CuSn alloy powder are selected, but the type of alloy powder is not limited to the alloy components listed in the examples, and the content of the application includes but is not limited to the material matching in the examples.

[0055] Embodiment

[0056] (1) First, supply 316L powder A on the powder preparation platform, and then use a scraper, a brush, a roller and the like to spread the powder into a required thickness.

[0057] (2) Use a suction head to suck powder on the powder preparation platform, remove the powder in the area not required, leave the powder area required, and form a required shape.

[0058] (3) Turn over the powder preparation platform and move it above the forming cylinder, and drop the powder on the printing platform, such as Figure 6The actual powder laying effect of powder A on the additive platform is shown in Figure 2.

[0059] (4) Repeat the above steps to complete the laying of the CuSn alloy powder B.

[0060] (5) Each powder is sucked into the corresponding pattern and falls on the printing platform, as shown in Figure 3. Figure 7 The final powder laying effect on the printing platform is shown in Figure 4. The number of repetitions is the same as the number of powder types. Finally, the multiple powders are combined on the printing platform of the forming cylinder to form a complete pattern that is complementary to each other.

[0061] (6) The forming cylinder moves to the laser station, and the laser is used to perform selective melting processing on the powder to be melted. Then, the above steps are repeated to continue processing the second layer and the third layer until the complete component is printed.

[0062] The specific process parameters of this embodiment can be adjusted according to the different types of powders.

[0063] Working Principle: The components to be printed are divided into zones according to the powder types required for different parts. Independent models are created for each component. Layered slicing software is used to slice the models. Inert gas is introduced into the slicing zone, powder preparation and transfer zone, forming cylinder and the printing platform area on top of the forming cylinder, and the entire laser melting processing area through the gas supply system for equipment purging. Several powder preparation platforms 1 with opposing first placement screen 2 and second placement screen 16 are prepared. Powder is spread on the surface of the first placement screen 2 of the powder preparation platform 1 and the required shape is prepared. Devices such as scrapers, brushes, and rollers are used to spread the powder to the required thickness. The powder in the unwanted areas is removed using a suction head, leaving the required powder areas. The micro vacuum is then activated. The air pump 3 is used for suction. The valve at the connection between the bidirectional electromagnetic reversing valve 8 and the suction hood 9 adjacent to the first placement mesh surface 2 is opened, creating a negative pressure inside the suction hood 9. This negative pressure is then created inside the adsorption hood 10 adjacent to the first placement mesh surface 2 via the suction hose 11, adsorbing the powder spread on the surface of the first placement mesh surface 2. A bonding mechanism ensures a tight seal between the adsorption hood 10 and the first placement mesh surface 2, guaranteeing stable adsorption. Subsequently, the powder preparation platform 1 is rotated by the flipping motor 4, bringing the second placement mesh surface 16 of the powder preparation platform 1 to the top. Powder is then spread on the surface of the second placement mesh surface 16 of the powder preparation platform 1 and shaped as needed. The powder preparation platform 1 is then moved above the forming cylinder or the forming cylinder is moved below the powder preparation platform 1. The bidirectional electromagnetic reversing valve 8 is opened. The valve at the connection between the electromagnetic reversing valve 8 and the suction hood 9 adjacent to the second placement mesh surface 16 creates a negative pressure inside the suction hood 9. This negative pressure, through the suction hose 11, creates a negative pressure inside the adsorption hood 10 adjacent to the second placement mesh surface 16, adsorbing the powder spread on the surface of the second placement mesh surface 16. At this time, the powder spread on the first placement mesh surface 2 of the powder preparation platform 1 loses its adsorption force and falls vertically onto the printing platform at the top of the forming cylinder. Then, the flipping motor 4 drives the powder preparation platform 1 to flip, rotating the second placement mesh surface 16 of the powder preparation platform 1 to the lower position. Subsequently, the micro vacuum pump 3 stops working. At this time, the powder spread on the surface of the second placement mesh surface 16 of the powder preparation platform 1 loses its adsorption force and falls vertically onto the printing platform at the top of the forming cylinder, thus adsorbing each type of powder. The powder is formed into a corresponding pattern and placed on the printing platform. The number of repetitions is the same as the number of powder types. Finally, the various powders are combined on the printing platform of the forming cylinder to form a complete pattern that complements each other. The forming cylinder is moved to the laser station, and the laser is used to selectively melt the powder to be melted. Then, the second layer, third layer, etc. are processed according to the above steps until the processing is completed. In the whole process, the present invention can select the most suitable material according to the functional requirements of different parts. By spreading different materials in the corresponding positions, two or more raw material powders can be printed on the same plane as needed. This can optimize the local strength, rigidity or other properties of the parts and maximize the functional performance of the parts.

[0064] The preferred embodiments of the present application are described in detail above with reference to the accompanying drawings, but the present application is not limited to the specific details in the above-described embodiments, and various equivalent transformations can be made to the technical solutions of the present application within the technical concept of the present application, and these equivalent transformations all belong to the protection scope of the present application.

Claims

1. A method for out-of-plane heterogeneous multi-station selective laser melting, characterized in that, The method comprises the following steps: S1. Partitioning the powder types required by different parts of the component to be printed, establishing independent models according to different parts, and slicing the models; S2. Preparing a plurality of powder preparation platforms (1) provided with opposite first placing nets (2) and second placing nets (16), laying powder on the surface of the first placing nets (2) of the powder preparation platforms (1) and preparing the required shape, using a switching negative pressure adsorption mechanism inside the powder preparation platforms (1) to adsorb the laid powder on the surface of the first placing nets (2), then using a turnover motor (4) to drive the powder preparation platforms (1) to turn over, rotating the second placing nets (16) of the powder preparation platforms (1) to the upper side, laying powder on the surface of the second placing nets (16) of the powder preparation platforms (1) and preparing the required shape; The switching negative pressure adsorption mechanism only adsorbs the laid powder on the surface of the first placing nets (2) or the second placing nets (16) when working; S3. Moving the powder preparation platforms (1) to above the forming cylinder, switching the switching negative pressure adsorption mechanism to adsorb the powder laid on the surface of the second placing nets (16) of the powder preparation platforms (1), at this time the powder laid on the first placing nets (2) of the powder preparation platforms (1) falls vertically on the printing platform at the top of the forming cylinder, then using the turnover motor (4) to drive the powder preparation platforms (1) to turn over, rotating the second placing nets (16) of the powder preparation platforms (1) to the lower side, then stopping the switching negative pressure adsorption mechanism from working, at this time the powder laid on the surface of the second placing nets (16) of the powder preparation platforms (1) falls vertically on the printing platform at the top of the forming cylinder; S4. Combining a plurality of powders into a complete pattern that is complementary to each other on the printing platform, moving the forming cylinder to a laser station, and using a laser to perform selective laser melting processing on the required melted powder until the processing is completed.

2. The method of claim 1, wherein: In the step S2, a micro vacuum pump (3) provided on the powder preparation platform (1) in the switching negative pressure adsorption mechanism is used, the air suction end of the micro vacuum pump (3) is connected with two air suction covers (9) provided above and below the powder preparation platform (1) through a bidirectional electromagnetic reversing valve (8), the two air suction covers (9) are communicated with an adsorption cover (10) adjacent to the first placing net (2) or an adsorption cover (10) adjacent to the second placing net (16) provided inside the powder preparation platform (1) through a plurality of air suction hoses (11), and the adsorption cover (10) adjacent to the first placing net (2) is driven to seal and fit with the first placing net (2) or the adsorption cover (10) adjacent to the second placing net (16) is driven to seal and fit with the second placing net (16) through a sealing mechanism provided inside the powder preparation platform (1), air suction is performed through the working of the micro vacuum pump (3), and the adsorption cover (10) adsorbs the laid powder on the surface of the first placing net (2) or the second placing net (16) through negative pressure.

3. The method of claim 2, wherein: The step S2, the first electric push cylinder (14) and the second electric push cylinder (15) are arranged between the two moving plates (13) for fixing the adsorption cover (10) inside the powder preparation platform (1) up and down, the adjacent moving plate (13) connected with the output end of the first electric push cylinder (14) or the second electric push cylinder (15) is pushed, so that the moving plate (13) moves towards the first placing net surface (2) or the second placing net surface (16), and the adsorption cover (10) is sealed and attached to the adjacent first placing net surface (2) or second placing net surface (16).

4. The method of claim 1, wherein: In the step S2, the first placing net surface (2) and the second placing net surface (16) of the powder preparation platform (1) are used for supplying powder, and a scraper, a powder brush, a roller and the like are used to spread the powder to the required thickness.

5. The method of claim 1, wherein: In the step S2, the powder in the area not needed is removed by using the suction head, and the powder area needed is left.

6. The method of claim 1, wherein: In the step S4, the forming cylinder moves to the laser station and is completed by the linear motor and the guide rail.

7. The method of claim 1, wherein: In the step S4, there is no limitation on the powder type in the same plane.

8. The method of claim 3, wherein: In the step S2, the sealing ring (12) arranged on the side of the adsorption cover (10) facing the first placing net surface (2) or the second placing net surface (16) and the pressure sensor arranged on the side of the sealing ring (12) facing the first placing net surface (2) or the second placing net surface (16) are used, a predetermined pressure threshold is set, the pressure sensor senses the pressure, and after the pressure threshold is reached, the first electric push cylinder (14) or the second electric push cylinder (15) no longer pushes the adjacent moving plate (13), so that the adsorption cover (10) is sealed and attached to the adjacent first placing net surface (2) or second placing net surface (16) tightly.

9. The method of claim 1, wherein: In the step S2, the fixed frame (5) is arranged on the outside of the powder preparation platform (1), the turnover motor (4) is fixed on the fixed frame (5), the output end of the turnover motor (4) is connected with the powder preparation platform (1), and the fixed frame (5) is further provided with a sliding table air cylinder (6), and the output end of the sliding table air cylinder (6) is connected with the turnover motor (4) through a sliding table seat.

10. The method of claim 3, wherein: In the step S2, the limiting rod (7) is arranged in the powder preparation platform (1), the moving plate (13) is slidably sleeved on the limiting rod (7), and the first electric push cylinder (14) or the second electric push cylinder (15) pushes the moving plate (13) to move stably.

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