Solid metal additive manufacturing system and method

Abstract

The invention belongs to the technical field of additive manufacturing, and particularly relates to a solid metal additive manufacturing system and method.The solid metal additive manufacturing system is characterized in that a first laser, a powder spray gun and a second laser are arranged on a motion platform, and the motion platform is used for controlling the first laser, the powder spray gun and the second laser to move above a base material according to a preset path; preparing a coating on the surface of the base material; the motion platform controls the first laser device, the powder spray gun and the second laser device to move above the base material according to a preset path, and in the coating preparation process, a first laser beam spot of the first laser device on the base material is located in front of a powder beam contact point of a powder beam sprayed by the powder spray gun on the base material; a second laser beam spot of the second laser device on the base material is located behind the powder beam contact point, and the first laser beam spot intersects with the powder beam contact point. According to the method, the compactness and binding force of the metal coating can be improved, and therefore the manufacturing requirement of the high-performance metal coating is met.

Description

Technical Field

[0001] The present invention belongs to the technical field of additive manufacturing, and particularly relates to a solid-state metal additive manufacturing system and method. Background Art

[0002] Additive Manufacturing (AM) refers to a technology for manufacturing objects by layer-by-layer stacking of materials. Different from traditional subtractive manufacturing (such as milling, turning, etc.), additive manufacturing gradually constructs the shape of materials through a controlled process, enabling more complex geometric shapes and higher design freedoms. In the industrial field, additive manufacturing has been widely applied in aerospace, automotive, tool manufacturing and other fields, becoming an important means to improve production efficiency and reduce costs.

[0003] Existing solid-state metal additive manufacturing equipment still has some deficiencies. For example, during the coating deposition process, the bonding strength between coatings needs to be improved, and the porosity is difficult to effectively reduce, which affects the mechanical properties and quality of the final product. In addition, the powder feeding method of traditional equipment is relatively single, unable to meet diverse experimental and manufacturing requirements, and restricting its application flexibility in different scenarios. Summary of the Invention

[0004] To solve the problems in the prior art, the purpose of the present invention is to provide a solid-state metal additive manufacturing system and method, which can improve the densification and bonding force of metal coatings, thereby meeting the manufacturing requirements of high-performance metal coatings.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions: A solid-state metal additive manufacturing system includes a motion platform, on which a first laser, a powder spray gun and a second laser are provided. The motion platform is used to control the first laser, the powder spray gun and the second laser to move above the substrate along a preset path to prepare a coating on the substrate surface; during the process that the motion platform controls the first laser, the powder spray gun and the second laser to move above the substrate along a preset path to prepare the coating, the spot of the first laser beam on the substrate is located in front of the contact point of the powder beam sprayed by the powder spray gun on the substrate, and the spot of the second laser beam on the substrate is located behind the contact point of the powder beam, wherein the spot of the first laser beam intersects with the contact point of the powder beam.

[0006] Preferably, the radius of the spot of the first laser beam is not less than the radius of the contact point of the powder beam.

[0007] Preferably, the radius of the spot of the first laser beam is 1.5 - 2 times the radius of the contact point of the powder beam; the center distance between the spot of the first laser beam and the contact point of the powder beam is not greater than the difference between the radius of the spot of the first laser beam and the radius of the contact point of the powder beam and is greater than zero.

[0008] Preferably, the radius of the second laser beam spot is not less than the radius of the powder beam contact point.

[0009] Preferably, the radius of the second laser beam spot is 1.0 - 1.5 times the radius of the powder beam contact point; the center distance between the second laser beam spot and the powder beam contact point is 1 - 2 times the sum of the radius of the second laser beam spot and the radius of the powder beam contact point.

[0010] Preferably, the powder inlet of the powder spray gun is connected with a powder conveying pipeline. An active powder feeder and a passive powder feeder are arranged in parallel on the powder conveying pipeline. The powder conveying pipeline is provided with a switching device for switching between the active powder feeder and the passive powder feeder to feed powder. The carrier gas inlet of the active powder feeder is connected with an air flow rate control system.

[0011] Preferably, the solid - state metal additive manufacturing system of the present invention further includes a cooling system, and the cooling system includes a cooling plate for placing the substrate.

[0012] The present invention also provides a solid - state metal additive manufacturing method, which is carried out by using the solid - state metal additive manufacturing system as described above in the present invention. The method includes: Start the first laser, the powder spray gun and the second laser, and control the first laser, the powder spray gun and the second laser to scan on the surface of the substrate along a preset path through the motion platform, so as to prepare a coating with a preset shape on the surface of the substrate; Control the first laser, the powder spray gun and the second laser to scan on the surface of the substrate along a preset path through the motion platform. During the process of preparing the coating on the surface of the substrate: The first laser beam emitted by the first laser irradiates the surface of the substrate. The first laser beam spot pre - heats the substrate. At the same time, the first laser beam emitted by the first laser contacts the powder beam sprayed by the powder spray gun, heats and activates the metal powder in the powder beam. The heated and activated metal powder is sprayed onto the part of the substrate pre - heated by the first laser beam spot, forming a coating on the surface of the substrate. As the motion platform moves, the second laser beam emitted by the second laser irradiates the surface of the formed coating, post - processes the coating, melts the surface of the coating, densifies the coating, and further reduces the porosity of the coating.

[0013] Preferably, when controlling the first laser, the powder spray gun and the second laser to scan on the surface of the substrate along a preset path through the motion platform during the process of preparing the coating on the surface of the substrate, the walking paths of the first laser, the powder spray gun and the second laser are the same.

[0014] Preferably, the power of the first laser is 100 - 800 watts, and the wavelength is 700 - 1400 nanometers; the power of the second laser is 300 - 1000 watts, and the wavelength is 1000 - 1100 nanometers; the carrier gas pressure of the powder spray gun is 0.5 - 2 MPa, and the flow rate is 30 - 150 liters per minute; the distance between the nozzle of the powder spray gun and the surface of the substrate is 5 - 15 millimeters, the moving speed of the powder spray gun is 10 - 30 millimeters per minute, the angle between the axis of the nozzle and the surface of the substrate is 85° - 90°, the radius of the powder beam is 4 - 8 millimeters, and the powder feeding rate is 10 - 30 grams per minute.

[0015] The present invention has the following beneficial effects: In the solid-state metal additive manufacturing system of the present invention, through the special limitation of the positions of the first laser, the powder spray gun, and the second laser, during the additive manufacturing process, the first laser can preheat the area of the substrate surface where the coating is to be prepared. The preheated substrate surface can help the metal powder particles undergo plastic deformation when they impact, thereby enhancing the bonding force between the powder and the substrate. Moreover, the first laser beam emitted by the first laser can contact (i.e., be coupled with) the powder beam sprayed by the powder spray gun to activate the metal powder in the powder beam, which can enhance the fluidity and adhesion of the metal powder during the spraying process. The second laser beam emitted by the second laser will directly irradiate the surface of the sprayed area, and the energy of the laser emitted by the second laser heats and fine-tunes the already deposited powder coating. This heating process not only optimizes the microstructure of the coating but also promotes the melting and bonding of the powder particles, ensuring that the bonding between the coatings is tighter, reducing internal voids or microcracks, and enhancing the overall strength and durability of the coating. In summary, the present invention can improve the density and bonding force of the metal coating, thereby meeting the manufacturing requirements of high-performance metal coatings. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 It is the overall structural schematic diagram of the solid-state metal additive manufacturing system in the embodiment of the present invention; Figure 2 It is the partial schematic diagram of the coupling part between the first laser and the powder spray gun in the embodiment of the present invention; Figure 3 It is the position design schematic diagram of the first laser beam spot, the powder beam contact point, and the second laser beam spot in the embodiment of the present invention; Figure 4Process flow chart of the solid-state metal additive manufacturing method in the embodiments of the present invention; Fig. 5(a) is a photograph of the coating prepared by the solid-state metal additive manufacturing method in the embodiments of the present invention; Fig. 5(b) is a photograph of the cold-spray coating prepared on the substrate surface by the traditional cold spraying technology.

[0018] In the figure: 1 is the first laser; 1-1 is the first laser beam; 2 is the second laser; 2-1 is the second laser beam; 3 is the powder spray gun; 4 is the powder nozzle; 5 is the three-axis motion platform; 6 is the active powder feeder; 7 is the passive powder feeder; 8 is the air flow control system; 9 is the robotic arm console; 10 is the temperature sensor; 11 is the post-processed coating; 12 is the non-post-processed coating; 13 is the powder beam; 14 is the first laser beam spot; 15 is the second laser beam spot; 16 is the substrate; 17 is the powder delivery pipeline; 18 is the powder beam contact point. Specific embodiments

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, rather than all, of the embodiments of the present invention. Usually, the components described and shown in the accompanying drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0020] The present invention provides a solid-state metal additive manufacturing system and method. The present invention adopts the solid-state metal additive manufacturing technology, which can not only enhance the adhesion of the metal coating through the coupling of the laser and the powder beam during the spraying process, but also further improve the quality of the coating through subsequent laser treatment, making the combination between the coating and the substrate closer, and significantly reducing the porosity. The present invention can improve the density and bonding force of the metal coating, thereby meeting the manufacturing requirements of high-performance metal coatings, enhancing the quality and bonding property of the metal coating, and being widely applied to fields such as the repair, additive manufacturing, and surface modification of metal parts.

[0021] See Figures 1 - 3, in this embodiment, the solid-state metal additive manufacturing system includes a moving platform, on which a first laser 1, a powder spray gun 3 and a second laser 2 are provided. The moving platform is used to control the first laser 1, the powder spray gun 3 and the second laser 2 to move above the substrate 16 along a preset path to prepare a coating on the surface of the substrate 16. During the process that the moving platform controls the first laser 1, the powder spray gun 3 and the second laser 2 to move above the substrate 16 along a preset path to prepare the coating, the first laser beam spot 14 of the first laser 1 on the substrate 16 is located in front of the powder beam contact point 18 of the powder beam 13 sprayed by the powder spray gun 3 on the substrate 16, and the second laser beam spot 15 of the second laser 2 on the substrate 16 is located behind the powder beam contact point 18, and the first laser beam spot 14 intersects with the powder beam contact point 18.

[0022] A method for solid-state metal additive manufacturing using the solid-state metal additive manufacturing system of the above embodiment of the present invention includes the following process: start the first laser 1, the powder spray gun 3 and the second laser 2, and control the first laser 1, the powder spray gun 3 and the second laser 2 to scan on the surface of the substrate 16 along a preset path by the moving platform to prepare a preset coating on the surface of the substrate 16; During the process of controlling the first laser 1, the powder spray gun 3 and the second laser 2 to scan on the surface of the substrate 16 along a preset path by the moving platform to prepare a coating on the surface of the substrate 16: The first laser beam 1-1 emitted by the first laser 1 irradiates the surface of the substrate 16, and the first laser beam spot 14 preheats the substrate 16. At the same time, the first laser beam 1-1 emitted by the first laser 1 contacts the powder beam 13 sprayed by the powder spray gun 3, heats and activates the metal powder in the powder beam 13. The heated and activated metal powder is sprayed onto the part of the substrate 16 preheated by the first laser beam spot 14 to form a coating on the surface of the substrate 16. As the moving platform moves, the second laser beam 2-1 emitted by the second laser 2 irradiates the surface of the formed coating to perform post-treatment on the coating, melting the surface of the coating, densifying the coating, and further reducing the porosity of the coating.

[0023] As a preferred embodiment of the present invention, in this embodiment, the radius of the first laser beam spot 14 is not less than the radius of the powder beam contact point 18. To ensure that the first laser 1 can fully preheat the area of the surface of the substrate 16 to be sprayed with the coating, and at the same time can also ensure the full activation and softening of the metal powder in the powder beam 13. Further, to ensure better effects, in this embodiment, the radius of the first laser beam spot 14 is 1.5-2 times the radius of the powder beam contact point 18; the center distance between the first laser beam spot 14 and the powder beam contact point 18 is not greater than the difference between the radius of the first laser beam spot 14 and the radius of the powder beam contact point 18 and is greater than zero. For specific requirements, see Figure 3 and Table 1: Table 1

[0024] In addition, the radius of the second laser beam spot 15 is not less than the radius of the powder beam contact point 18, so as to ensure that the second laser beam spot 15 can fully process the formed coating. Further, in order to ensure better effects, in this embodiment, the radius of the second laser beam spot 15 is 1.0 - 1.5 times the radius of the powder beam contact point 18; the center distance between the second laser beam spot 15 and the powder beam contact point 18 is 1 - 2 times the sum of the radius of the second laser beam spot 15 and the radius of the powder beam contact point 18. For specific requirements, see Figure 3 and Table 2: Table 2

[0025] In the above solution of the present invention, the motion platform is used to control the first laser 1, the powder spray gun 3 and the second laser 2 to scan on the surface of the substrate 16 according to a preset path. During the process of preparing the coating on the surface of the substrate 16, the traveling paths of the first laser 1, the powder spray gun 3 and the second laser 2 are the same. The power of the first laser 1 is 100 - 800 watts, and the wavelength is 700 - 1400 nanometers; the power of the second laser 2 is 300 - 1000 watts, and the wavelength is 1000 - 1100 nanometers; the carrier gas pressure of the powder spray gun 3 is 0.5 - 2 MPa, and the flow rate is 30 - 150 liters per minute; the distance between the nozzle 4 of the powder spray gun 3 and the surface of the substrate 16 is 5 - 15 millimeters, the moving speed of the powder spray gun 3 is 10 - 30 millimeters per minute, the included angle between the axis of the nozzle 4 and the surface of the substrate 16 is 85° - 90°, the radius of the powder beam 13 is 4 - 8 millimeters, and the powder feeding rate is 10 - 30 grams per minute.

[0026] As a preferred implementation of the present invention, in this embodiment, the powder inlet of the powder spray gun 3 is connected with a powder conveying pipeline 17. An active powder feeder 6 and a passive powder feeder 7 are arranged in parallel on the powder conveying pipeline 17. The powder conveying pipeline 17 is provided with a switching device for switching between the powder feeding of the active powder feeder 6 and the powder feeding of the passive powder feeder 7. The carrier gas inlet of the active powder feeder 6 is connected with an air flow rate control system 8. Among them, the active powder feeder 6 is used to control the conveying amount of metal powder by electric or pneumatic means, and is suitable for high-precision additive manufacturing processes; the passive powder feeder 7 feeds the metal powder into the spray gun 3 through the action of air flow, and is suitable for additive manufacturing processes with large areas and low precision requirements. The switching device can flexibly switch the usage of the active powder feeder 6 and the passive powder feeder 7 according to actual needs, with high flexibility.

[0027] As a preferred embodiment of the present invention, in this embodiment, the solid-state metal additive manufacturing system of the present invention further includes a cooling system. The cooling system includes a cooling plate for placing the substrate 16 to cool the substrate 16 and ensure the preparation conditions of the coating.

[0028] Example 1 The solid-state metal additive manufacturing system in this embodiment adopts laser-assisted cold spraying technology, including: a first laser 1 for activating metal powder to enhance the adhesion and uniformity of the metal powder during the spraying process; a powder spray gun 3, the powder nozzle 4 of the powder spray gun can spray a metal powder beam onto the surface of the substrate; a powder delivery pipeline 17 connected to the powder spray gun 3 for transporting metal powder; an air flow rate control system 8 connected to the powder feeder for controlling the conveying speeds of the metal powder and the air flow by the powder feeder; a first laser 1 for activating metal powder to enhance the fluidity and adhesion of the metal powder during the spraying process, so that the metal powder during the spraying process can adhere to the surface of the substrate more evenly; a second laser 2 for post-processing the sprayed coating, improving the surface structure and internal structure of the coating through laser post-processing, enhancing the density of the coating and the bonding force between coatings, and reducing the porosity of the coating; a laser-gun coupling device connecting the first laser 1, the powder spray gun 3 and the second laser 2 to ensure that the laser of the first laser 1 irradiates the metal powder beam sprayed by the powder spray gun 3 to heat and activate the metal powder; a powder feeder for selecting the powder feeding method according to different experimental and manufacturing requirements, including an active powder feeder 6 and a passive powder feeder 7: the active powder feeder 6 is connected to the powder spray gun 3 through the powder delivery pipeline 17 for controlling the conveying amount of the metal powder by electric or pneumatic means, and is suitable for high-precision additive manufacturing processes; the passive powder feeder 7 is connected to the powder spray gun 3 through the powder delivery pipeline 17, and feeds the metal powder into the spray gun 3 by the action of air flow. The passive powder feeder has the characteristics of simplicity and low cost, and is suitable for additive manufacturing processes with large areas and low precision requirements; the powder feeding path can be connected to the active powder feeder or the passive powder feeder through a switching device for selection according to different experimental manufacturing requirements. A temperature sensor 10 for real-time monitoring of the temperatures of the coating and the substrate 16 to adjust the laser power and irradiation time; a control system for adjusting the working parameters of each component to achieve the best additive manufacturing effect; a three-axis or multi-axis motion platform for controlling the relative motion of the substrate 16 and the powder spray gun 3 to achieve precise motion control during the spraying process; a cooling system for cooling the equipment and the substrate 16. Among them, the power and spot size of the first laser 1 are adjustable for additive manufacturing requirements of different metal materials. The first laser 1 is coupled with the powder beam 13 of the powder spray gun 3. By irradiating the metal powder with laser, the metal powder is heated and activated, enhancing the fluidity and adhesion of the metal powder during the spraying process, and making it adhere to the surface of the substrate more evenly during the spraying process. The laser power and irradiation time of the second laser 2 are adjustable and can be precisely controlled according to the thickness and material characteristics of the coating. It also includes a laser beam guiding device for guiding the laser beams of the first laser 1 and the second laser 2.

[0029] See Figure 4 , the use process of the solid-state metal additive manufacturing system and equipment in this embodiment is as follows: In the preparation stage, first, select dry metal powders with appropriate particle sizes according to manufacturing requirements and load them into the active powder feeder 6 and the passive powder feeder 7 respectively (if two powder feeders are needed). Pretreat the substrate 16 to ensure that the surface of the substrate 16 is clean and flat, which is conducive to the adhesion and bonding of metal powders.

[0030] Install the substrate 16 on the workbench of the manufacturing equipment and set the initial position and motion parameters of the substrate 16 (such as rotation speed, translation speed, etc., if the substrate needs to move) through the control system.

[0031] Adjust the position of the spray gun 3 so that it maintains an appropriate distance and angle from the surface of the substrate 16. Usually, the axis of the spray gun 13 is perpendicular or nearly perpendicular to the surface of the substrate 16, and the distance is set according to specific process requirements, generally between 5 - 15 millimeters.

[0032] According to the manufacturing process requirements, set the initial parameters of the first laser 1 and the second laser 2, such as laser power. For the first laser 1, for example, set its power to 100 - 800 watts and the wavelength to 700 - 1400 nanometers (taking a near-infrared laser as an example); for the second laser 2, set its power to 300 - 1000 watts and the wavelength to 1000 - 1100 nanometers (taking a fiber laser as an example). At the same time, set the pressure of the high-pressure gas to 0.5 - 2 MPa and the flow rate to 30 - 150 liters per minute.

[0033] In the powder delivery and laser collaborative working stage (coating deposition), start the high-pressure gas delivery path. The high-pressure gas enters from the contraction section of the spray gun 3, accelerates through the throat, and then enters the expansion section of the spray gun. At this time, switch the powder delivery path to be connected to the active powder feeder 6 through the control system. The active powder feeder 6 delivers metal powders to the expansion section of the spray gun according to the preset powder delivery amount and powder delivery speed. During the coating deposition process, the first laser 1 and the second laser 2 work together to ensure the high-quality deposition of the coating and excellent adhesion. First, the laser beam of the first laser 1 irradiates the surface of the substrate 16 for preheating, and the temperature is controlled between 100 - 300 °C, which helps the metal powder particles to undergo plastic deformation when they impact, thereby enhancing the bonding force between the powder and the substrate. At the same time, the second laser 2 plays an auxiliary role in this process. The laser beam of the second laser 2 directly irradiates the surface of the spraying area, and the energy of the laser heats and fine-tunes the already deposited powder coating. This heating process not only optimizes the microstructure of the coating but also promotes the melting and bonding of the powder particles, ensuring that the coatings are more tightly bonded and reducing internal voids or microcracks. The role of the second laser 2 is to synchronously process the already deposited coating, optimize the microstructure between the coatings, and improve the overall strength and durability of the coating.

[0034] During the laser post - processing stage (to improve the coating quality), when the coating reaches the predetermined thickness and the powder deposition stops, the second laser 2 continues to operate, increasing the power to further post - process the deposited coating. In this stage, the laser beam causes the metal particles inside the coating to further fuse, filling the micro - pores, enhancing the density of the coating, and strengthening the bonding force between the coatings. This process helps to eliminate the micro - cracks or pores in the coating, improving the mechanical properties and long - term stability of the coating. The laser power is generally controlled between 500 - 1500 watts in this stage, and the specific power and time are adjusted according to the thickness of the coating and the characteristics of the material.

[0035] Completion stage: After the laser post - processing is completed, the operation of the first laser 1 and the second laser 2 is stopped. The high - pressure gas supply is closed, causing the spray gun to stop working. The manufactured component is removed from the workbench and subjected to subsequent post - processing operations, such as machining (removing excess parts, grinding, etc.), heat treatment (improving the overall performance, etc.), to obtain a solid - state metal additive - manufactured component that finally meets the usage requirements.

[0036] The solid - state metal additive - manufacturing system and equipment of the present invention give full play to the functions of each component through the designed workflow, achieving high - quality and high - efficiency solid - state metal additive manufacturing, and can meet the manufacturing requirements of metal components with various complex shapes and performance requirements.

[0037] Example 2 In this example, the parameter information of the first laser beam spot, the powder beam contact point, and the second laser beam spot is shown in Tables 3 and 4: Table 3

[0038] Table 3

[0039] The power of the first laser 1 is 400 watts, and the wavelength is 915 nanometers; the power of the second laser 2 is 800 watts, and the wavelength is 1064 nanometers; the carrier gas pressure of the powder spray gun 3 is 0.8 MPa, and the flow rate is 80 liters per minute; the distance between the nozzle 4 of the powder spray gun 3 and the surface of the substrate 16 is 10 millimeters, the moving speed of the powder spray gun 3 is 15 millimeters per minute, the angle between the axis of the nozzle 4 and the surface of the substrate 16 is 90°, and the powder feeding rate is 20 grams per minute.

[0040] A laser-assisted cold spraying system that couples a first laser 1 with the powder beam 13 of a spray gun 3 is used to spray 7075 aluminum alloy powder on the surface of a pure aluminum plate substrate. By adjusting the power and spot size of the first laser 1, the sprayed metal powder can be uniformly heated, improving the density and adhesion of the coating. Subsequently, a second laser 2 is used for post-treatment of the sprayed coating. The laser irradiates the surface of the coating, further enhancing the density and bonding strength of the coating.

[0041] The coating obtained in this embodiment is shown in Figure 5(a). The coating prepared by the traditional method (the traditional method refers to forming a coating by accelerating solid powder with high-pressure gas to impact the substrate, with the same spraying parameters of the powder spray gun and directly spraying without a laser) is shown in Figure 5(b). After testing, the porosity of the coating is reduced from the original 10% (see Figure 5(b)) to 3% (see Figure 5(a)), and the bonding strength between the coating and the substrate is significantly enhanced.

[0042] The solid-state metal additive manufacturing system and equipment of the present invention adopt laser-assisted cold spraying technology. The first laser activates the metal powder to improve the adhesion and uniformity of the coating. At the same time, the second laser is used for post-treatment of the coating to improve the bonding force between the coating and the substrate and significantly reduce the porosity of the coating. This design effectively solves the problems of poor coating bonding and high porosity in the existing cold spraying technology, improving the quality and efficiency of metal additive manufacturing. In addition, by equipping with an active powder feeder and a passive powder feeder, the present invention can adapt to different experimental requirements and has high flexibility and applicability.

[0043] Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0044] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: the specific implementation manners of the present invention can still be modified or equivalently replaced, and any modification or equivalent replacement without departing from the spirit and scope of the present invention shall be covered by the scope of the present invention.

Claims

1. A solid-state metal additive manufacturing system, characterized in that, It includes a moving platform, on which a first laser (1), a powder spray gun (3) and a second laser (2) are provided. The moving platform is used to control the first laser (1), the powder spray gun (3) and the second laser (2) to move above a substrate (16) along a preset path to prepare a coating on the surface of the substrate (16). During the process that the moving platform controls the first laser (1), the powder spray gun (3) and the second laser (2) to move above the substrate (16) along the preset path and prepare the coating, the first laser beam spot (14) of the first laser (1) on the substrate (16) is located in front of the powder beam contact point (18) of the powder beam (13) sprayed by the powder spray gun (3) on the substrate (16), and the second laser beam spot (15) of the second laser (2) on the substrate (16) is located behind the powder beam contact point (18), wherein the first laser beam spot (14) intersects with the powder beam contact point (18).

2. The solid metal additive manufacturing system according to claim 1, wherein The radius of the first laser beam spot (14) is not less than the radius of the powder beam contact point (18).

3. A solid metal additive manufacturing system according to claim 1, characterized in that, The radius of the first laser beam spot (14) is 1.5 - 2 times the radius of the powder beam contact point (18); the center distance between the first laser beam spot (14) and the powder beam contact point (18) is not greater than the difference between the radius of the first laser beam spot (14) and the radius of the powder beam contact point (18) and is greater than zero.

4. A solid metal additive manufacturing system according to claim 1, characterized in that The radius of the second laser beam spot (15) is not less than the radius of the powder beam contact point (18).

5. A solid-state metal additive manufacturing system according to claim 1, wherein, The radius of the second laser beam spot (15) is 1.0 - 1.5 times the radius of the powder beam contact point (18); the center distance between the second laser beam spot (15) and the powder beam contact point (18) is 1 - 2 times the sum of the radius of the second laser beam spot (15) and the radius of the powder beam contact point (18).

6. The solid-state metal additive manufacturing system according to claim 1, characterized in that The powder inlet of the powder spray gun (3) is connected with a powder conveying pipeline (17). An active powder feeder (6) and a passive powder feeder (7) are arranged in parallel on the powder conveying pipeline (17). The powder conveying pipeline (17) is provided with a switching device for switching between the active powder feeder (6) for powder feeding or the passive powder feeder (7) for powder feeding. The carrier gas inlet of the active powder feeder (6) is connected with an air flow rate control system (8).

7. A solid metal additive manufacturing system according to claim 1, characterized in that, It further includes a cooling system, and the cooling system includes a cooling plate for placing the substrate (16).

8. A solid-state metal additive manufacturing method, characterized in that, This method is carried out by using the solid - state metal additive manufacturing system according to any one of claims 1 - 7. The method includes: Starting the first laser (1), the powder spray gun (3) and the second laser (2), and controlling the first laser (1), the powder spray gun (3) and the second laser (2) to scan on the surface of the substrate (16) along a preset path through the moving platform to prepare a coating with a preset shape on the surface of the substrate (16); Controlling the first laser (1), the powder spray gun (3) and the second laser (2) to scan on the surface of the substrate (16) along a preset path through the moving platform. During the process of preparing the coating on the surface of the substrate (16): The first laser beam (1-1) emitted by the first laser (1) irradiates the surface of the substrate (16). The first laser beam spot (14) preheats the substrate (16). At the same time, the first laser beam (1-1) emitted by the first laser (1) contacts the powder beam (13) sprayed by the powder spray gun (3), heats and activates the metal powder in the powder beam (13). The heated and activated metal powder is sprayed onto the part of the substrate (16) preheated by the first laser beam spot (14), and a coating is formed on the surface of the substrate (16). As the moving platform moves, the second laser beam (2-1) emitted by the second laser (2) irradiates the surface of the formed coating, and post-treats the coating to melt the surface of the coating, densify the coating, and further reduce the porosity of the coating.

9. A solid-state metal additive manufacturing method according to claim 8, characterized in that The first laser (1), the powder spray gun (3) and the second laser (2) are controlled by the moving platform to scan along a preset path on the surface of the substrate (16). During the process of preparing the coating on the surface of the substrate (16), the traveling paths of the first laser (1), the powder spray gun (3) and the second laser (2) are the same.

10. A solid-state metal additive manufacturing method according to claim 8, characterized in that, The power of the first laser (1) is 100 - 800 watts, and the wavelength is 700 - 1400 nanometers; the power of the second laser (2) is 300 - 1000 watts, and the wavelength is 1000 - 1100 nanometers; the carrier gas pressure of the powder spray gun (3) is 0.5 - 2 MPa, and the flow rate is 30 - 150 liters per minute; the distance between the nozzle (4) of the powder spray gun (3) and the surface of the substrate (16) is 5 - 15 millimeters, the moving speed of the powder spray gun (3) is 10 - 30 millimeters per minute, the angle between the axis of the nozzle (4) and the surface of the substrate (16) is 85° - 90°, the radius of the powder beam (13) is 4 - 8 millimeters, and the powder feeding rate is 10 - 30 grams per minute.

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