Multi-material laser additive forming process and laser oscillation forming system

Abstract

The invention provides a multi-material laser additive forming process and a laser oscillation forming system, and belongs to the technical field of laser machining, and the multi-material laser additive forming process comprises the steps that S1, a multi-material L-PBF forming process database is formed by training a plurality of multi-material forming components; s2, a multi-material L-PBF forming process database is called, intelligent segmentation is conducted on a current component, the powder laying process and the laser oscillation forming process of all segmented parts are planned, according to the powder laying process, multi-material powder is laid layer by layer according to preset requirements, and the powder layer thickness is controlled; in the laser oscillation forming process, the multi-material molten pool is stirred through laser oscillation, and laser beams are shaped; and S3, according to the powder laying technology and the laser oscillation forming technology in the step S1, a powder laying device and a laser oscillation forming system are combined, and the multi-material component is formed. Through the powder laying technology and the laser oscillation forming technology, the powder laying device and the laser oscillation forming system are combined, and therefore the quality of formed products is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of laser processing, and relates to a forming process, in particular to a multi-material laser additive forming process and a laser oscillation forming system. Background Art

[0002] The "material-structure-property" integrated multi-material components are an important development trend in the manufacturing industry. In the prior art, traditional techniques such as casting, forging, and machining are used to prepare multi-material components, with complex and cumbersome process flows, long processing cycles, and high costs, making it impossible to fabricate complex multi-material components. The multi-material laser powder bed fusion (L-PBF) technology can fabricate high-precision and complex multi-material components through layer-by-layer fixed-point laying of multi-material powders + selective area laser forming process, with a short processing cycle and high forming quality, and is one of the important development directions in the field of laser additive manufacturing.

[0003] However, in the process of forming heterogeneous cross-sections by existing multi-material L-PBF, the following main disadvantages or deficiencies exist: First, during the L-PBF forming process, there are differences in thermal physical properties between the base materials of multi-material components, such as thermal expansion coefficient, melting point, etc. During L-PBF forming, there are often defects such as poor fusion, pores, and cracks at the interfaces. Second, during the L-PBF forming process, coarse and brittle intermetallic compounds often precipitate at the multi-material interfaces. As the thermal stress during L-PBF forming continuously increases, macroscopic cracking will occur at the multi-material interfaces. Summary of the Invention

[0004] The purpose of the present invention is to address the above problems in the existing technology and propose a multi-material laser additive forming process that can improve the quality of laser printing.

[0005] The purpose of the present invention can be achieved by the following technical solutions: A multi-material laser additive forming process includes: S1: Form a multi-material L-PBF forming process database by training multiple multi-material forming components; S2: Call the multi-material L-PBF forming process database to perform intelligent segmentation on the current component, and plan the powder laying process and laser oscillation forming process for each part after segmentation. Among them, the powder laying process lays multi-material powders layer by layer according to preset requirements, and controls the thickness of the multi-material powder layer; the laser oscillation forming process stirs the multi-material molten pool through laser oscillation and shapes the laser beam; S3: According to the powder laying process and laser oscillation forming process in step S1, and in combination with the powder laying device and the laser oscillation forming system, form a multi-material component.

[0006] In the above multi-material laser additive manufacturing process, for the laser oscillation forming process in step S2, it includes the steps: S21: Divide the forming component model of the current multi-material powder layer into an edge area and a filling area. Among them, when the forming component model of the current multi-material powder layer is set as a polygon, the edge area is located at the outer contour edge of the polygon; when the forming component model of the current multi-material powder layer is set as a pipe, the edge area is located at the inner contour edge of the pipe; S22: Process the edge area of the forming component model through a point light source, and process the filling area of the forming component model through the surface light source formed by laser oscillation, and complete the processing of the forming component model within the current multi-material powder layer.

[0007] In the above multi-material laser additive manufacturing process, step S2 further includes step S23: Use high-power laser high-frequency oscillation to form a uniform surface light source, and perform heat treatment on the current multi-material powder layer to eliminate stress concentration or prevent local stress concentration. Among them, when large-area preheating of the current multi-material powder layer is required, this step S23 is located before step S21; when local high-temperature heat treatment of the laser forming area is required, this step S23 is carried out synchronously with step S22; when heat treatment of the stress concentration prone area of the forming component model is required, this step S23 is located after step S22.

[0008] In the above multi-material laser additive manufacturing process, it further includes step S4: Perform real-time online monitoring on the formed component. If there are defects in the forming component model of the current multi-material powder layer, then perform laser oscillation remelting on the current forming component model.

[0009] In the above multi-material laser additive manufacturing process, step S4 includes the steps: S41: The laser beam performs remelting scanning on the defective target area of the current forming layer in a high-frequency oscillation manner along a preset path, so that the surface of the target area melts and repairs the forming defect; S42: After step S41 is completed, analyze the forming layer again through online monitoring to detect whether the defect is repaired. If it is not repaired, return to step S41. If it has been repaired, continue with step S2.

[0010] In the above multi-material laser additive manufacturing process, it further includes the steps: S5: Optimize and adjust the process online, and feedback the adjusted parameter data to the multi-material L-PBF forming process database to update the parameter data in the multi-material L-PBF forming process database.

[0011] In the above multi-material laser additive manufacturing process, it further includes the steps: S6: After the component is formed, perform quality inspection on the formed component.

[0012] To achieve the laser oscillation effect described in steps S1 - S6, the present invention also provides a laser oscillation forming system adopting the multi - material laser additive manufacturing process described above, which includes a galvanometer assembly and a numerical control machine tool. Among them, by adjusting the movement trajectory of the numerical control machine tool in the X - axis and Y - axis directions, the stirring of the multi - material molten pool by laser oscillation during the multi - material L - PBF forming process is realized; by adjusting the distance of the numerical control machine tool in the Z - axis direction, the dynamic regulation of the laser spot size is realized.

[0013] In the above - mentioned laser oscillation forming system, the laser oscillation forming system includes: A numerical control machine tool, on which there is a first output shaft that can move along the X - axis direction, a second output shaft that can move along the Y - axis direction, and a third output shaft that can move along the Z - axis direction. Among them, the first output shaft, the second output shaft, and the third output shaft form a three - coordinate system in space, and a galvanometer assembly with a laser light source is connected to the third output shaft; A powder bed, located below the galvanometer assembly, and a multi - material powder layer is laid on the powder bed. Among them, the laser light source on the galvanometer assembly realizes the laser printing of the multi - material powder layer along a preset trajectory.

[0014] To achieve the laser oscillation effect described in steps S1 - S6, the present invention also provides a laser oscillation forming system adopting the multi - material laser additive manufacturing process described above, which includes an ultrasonic driver and an expander lens assembly and a galvanometer assembly in the optical path system. Among them, by driving the galvanometer assembly with the ultrasonic driver, the stirring of the multi - material molten pool by laser oscillation during the multi - material L - PBF forming process is realized; by driving the optical path expander lens assembly with the ultrasonic driver, the dynamic regulation of the laser spot size is realized.

[0015] In the above - mentioned laser oscillation forming system, the laser oscillation forming system includes: An expander lens assembly, other devices in the optical path system, and a galvanometer assembly with a laser light source, two ultrasonic drivers, namely a first ultrasonic driver and a second ultrasonic driver, and the first ultrasonic driver is connected to the expander lens assembly, and the second ultrasonic driver is connected to the galvanometer assembly; A powder bed, located below the galvanometer assembly, and a multi - material powder layer is laid on the powder bed. Among them, the laser light source on the galvanometer assembly realizes the laser printing of the multi - material powder layer along a preset trajectory.

[0016] To achieve the laser oscillation effect described in steps S1 - S6, the present invention also provides a laser oscillation forming system using the multi - material laser additive manufacturing process described above. The system includes a beam expander assembly, a galvanometer assembly, and a rotary mirror assembly in the optical path system. Among them, the galvanometer assembly is used to realize the scanning of the laser in the X - axis and Y - axis directions; through the rotary mirror assembly, it realizes the stirring of the multi - material molten pool by laser oscillation during the multi - material L - PBF forming process, and realizes the dynamic regulation of the laser spot size.

[0017] In the above - mentioned laser oscillation forming system, the laser oscillation forming system includes: A beam expander assembly, other devices in the optical path system, a galvanometer assembly, and a rotary mirror assembly provided with a laser light source; A powder bed, located below the rotary mirror assembly, and a multi - material powder layer is laid on the powder bed. Among them, the laser light source on the rotary mirror assembly realizes the laser printing of the multi - material powder layer along a preset trajectory.

[0018] To achieve the laser oscillation effect described in steps S1 - S6, the present invention also provides a laser oscillation forming system using the multi - material laser additive manufacturing process described above. The system includes an optical path system and a spatial light modulator. Among them, through the spatial light modulator, the positioning of the laser and the planning of the scanning path are carried out, realizing the stirring of the multi - material molten pool by laser oscillation during the multi - material L - PBF forming process, and realizing the dynamic regulation of the laser spot size.

[0019] In the above - mentioned laser oscillation forming system, the laser oscillation forming system includes: Other devices in the optical path system and a spatial light modulator provided with a laser light source; A powder bed, located below the spatial light modulator, and a multi - material powder layer is laid on the powder bed. Among them, the laser light source on the spatial light modulator realizes the laser printing of the multi - material powder layer along a preset trajectory.

[0020] Compared with the prior art, the beneficial effects of the present invention are: (1) A material laser additive manufacturing process provided by the present invention, through the powder - laying process and the laser oscillation forming process, and in combination with the powder - laying device and the laser oscillation forming system, thereby improving the quality of the formed product; (2) Using laser oscillation to stir the molten pool at the multi - material interface. On the one hand, it can strengthen the convective stirring effect of the melt, effectively capture the bubbles in the molten pool, accelerate the escape of bubbles, and reduce forming defects such as poor multi - material interface fusion, pores, and cracks. On the other hand, it can effectively change the morphology of the molten pool, regulate the temperature field distribution and flow - field convection of the molten pool, and promote the mixing of the melt and the diffusion of elements, reducing the precipitation of coarse and brittle intermetallic compounds; (3) During the beam shaping process, a conventional small-diameter and high-precision point light source is used to print the edge of the formed component, enabling the formed component to obtain a more uniform and fine structure, improving the strength, wear resistance, and corrosion resistance of the surface of the formed component. By using a surface light source with high-speed laser oscillation scanning, the forming efficiency of the formed component can be improved, a relatively coarse structure can be obtained, and the overall plasticity and toughness of the formed component can be enhanced. (4) By using high-power laser high-frequency oscillation to form a uniform surface light source, the stress concentration phenomenon can be eliminated or local stress concentration can be prevented. (5) Through laser oscillation remelting, the forming defects of the component can be reduced, and the forming ability of structural features such as high variability (such as thin-walled components), unsupported (such as cantilever components), and easy stress concentration (such as sharp-corner components) can be significantly improved. (6) By using high-power laser high-frequency oscillation to form a uniform surface light source and preheating the powder bed and the component during the forming process, the range of processable materials for L-PBF can be effectively expanded, such as brittle materials like refractory alloys and intermetallic compounds. Description of the Drawings

[0021] Figure 1 is a flowchart of a multi-material laser additive manufacturing process of the present invention.

[0022] Figure 2 is a schematic structural diagram of a laser oscillation forming system in Embodiment 1 of the present invention.

[0023] Figure 3 is a schematic structural diagram of a laser oscillation forming system in Embodiment 2 of the present invention.

[0024] Figure 4 is a schematic structural diagram of a laser oscillation forming system in Embodiment 3 of the present invention.

[0025] Figure 5 is a schematic structural diagram of a laser oscillation forming system in Embodiment 4 of the present invention.

[0026] Figure 6 is a working principle diagram of the surface light source in a multi-material laser additive manufacturing process of the present invention.

[0027] Figure 7 is a processing schematic diagram of a formed component model in a polygon shape in a multi-material laser additive manufacturing process of the present invention.

[0028] Figure 8 is a processing schematic diagram of a formed component model in a pipe shape in a multi-material laser additive manufacturing process of the present invention.

[0029] Figure 9 is a schematic structural diagram of layer-by-layer processing in a multi-material laser additive manufacturing process of the present invention.

[0030] In the figure, 10. CNC machine tool; 11. First output shaft; 12. Second output shaft; 13. Third output shaft; 20. Galvo scanner assembly; 30. Powder bed; 40. Beam expander assembly; 50. Other devices in the optical path system; 60. Ultrasonic driver; 61. First ultrasonic driver; 62. Second ultrasonic driver; 70. Rotary mirror assembly; 80. Spatial light modulator; S1. First optical path; S2. Second optical path; S3. Third optical path; A1. Edge region; A2. Filling region; B1. Point light source; B2. Surface light source. Detailed implementation manners

[0031] The following are specific embodiments of the present invention and, in conjunction with the accompanying drawings, further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0032] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0033] As Figures 1 to 9 shown, a multi-material laser additive manufacturing process provided by the present invention includes the steps: S1: By training multiple multi-material forming components, a multi-material L-PBF forming process database is formed; S2: Call the multi-material L-PBF forming process database to perform intelligent segmentation on the current component, and plan the powder spreading process and laser oscillation forming process for each part after segmentation. Among them, the powder spreading process lays multi-material powder layer by layer according to preset requirements, and controls the thickness of the multi-material powder layer; the laser oscillation forming process stirs the multi-material molten pool through laser oscillation and shapes the laser beam; S3: According to the powder spreading process and laser oscillation forming process in step S1, and in combination with the powder spreading device and laser oscillation forming system, a multi-material component is formed.

[0034] A material laser additive manufacturing process provided by the present invention, through the powder spreading process and laser oscillation forming process, and in combination with the powder spreading device and laser oscillation forming system, thereby improving the quality of the formed product.

[0035] It is further pointed out that for the laser oscillation forming system in step S2, generally there are the following four implementation modes.

[0036] Mode 1: Combine the galvanometer assembly 20 with a precision numerical control machine tool 10 or a robotic arm. Among them, by adjusting the movement trajectory of the numerical control machine tool 10 in the X-axis and Y-axis directions, the stirring of the multi-material molten pool by laser oscillation during the multi-material L-PBF forming process is realized, and parameters such as the oscillation path, frequency, and amplitude are adjusted; by adjusting the distance of the numerical control machine tool 10 in the Z-axis direction, the dynamic regulation of the laser spot size is realized.

[0037] Mode 2: Combine the ultrasonic driver 60 with the beam expander assembly 40 and the galvanometer assembly 20 in the optical path system. Among them, by driving the galvanometer assembly 20 with the ultrasonic driver 60, the stirring of the multi-material molten pool by laser oscillation during the multi-material L-PBF forming process is realized, and parameters such as the oscillation path, frequency, and amplitude are adjusted; by driving the beam expander assembly 40 in the optical path with the ultrasonic driver 60, the dynamic regulation of the laser spot size is realized.

[0038] Mode 3: Combine the beam expander assembly 40, the galvanometer assembly 20, and the rotary mirror assembly 70 in the optical path system. Among them, the rapid and precise scanning of the laser in the X-axis and Y-axis directions is realized through the galvanometer assembly 20; through the rotary mirror assembly 70, the stirring of the multi-material molten pool by laser oscillation during the multi-material L-PBF forming process is realized, and parameters such as the oscillation path, frequency, and amplitude are adjusted, and the dynamic regulation of the laser spot size is realized.

[0039] Mode 4: Combine the optical path system with the spatial light modulator 80. Among them, through the spatial light modulator 80, the precise positioning of the laser and the planning of the scanning path are carried out, the stirring of the multi-material molten pool by laser oscillation during the multi-material L-PBF forming process is realized, and parameters such as the oscillation path, frequency, and amplitude are adjusted, and the dynamic regulation of the laser spot size is realized.

[0040] It is further pointed out that for Mode 1, the specific structure is as Figure 1 shown. This laser oscillation forming system includes: A numerical control machine tool 10, on which there is a first output shaft 11 that can move along the X-axis direction, a second output shaft 12 that can move along the Y-axis direction, and a third output shaft 13 that can move along the Z-axis direction. Among them, the first output shaft 11, the second output shaft 12, and the third output shaft 13 form a three-coordinate system in space, and a galvanometer assembly 20 connected with a laser light source is arranged on the third output shaft 13; A powder bed 30, located below the galvanometer assembly 20, and a multi-material powder layer is laid on the powder bed 30. Among them, the laser light source on the galvanometer assembly 20 realizes the laser printing of the multi-material powder layer along a preset trajectory.

[0041] It is further pointed out that for Method 2, the specific structure is as Figure 2 shown. The laser oscillation forming system includes: a beam expander assembly 40, other devices 50 in the optical path system, and a galvanometer assembly 20 provided with a laser light source, and the three form a right triangle layout. Among them, the beam expander assembly 40 and other devices 50 in the optical path system are connected by a first optical path S1, and other devices 50 in the optical path system and the galvanometer assembly 20 are connected by a second optical path S2. The first optical path S1 and the second optical path S2 are respectively two right sides of the right triangle; Two ultrasonic drivers 60, namely a first ultrasonic driver 61 and a second ultrasonic driver 62, and the first ultrasonic driver 61 is connected to the beam expander assembly 40, and the second ultrasonic driver 62 is connected to the galvanometer assembly 20; a powder bed 30, located below the galvanometer assembly 20, and a multi-material powder layer is laid on the powder bed 30. Among them, the laser light source on the galvanometer assembly 20 realizes laser printing of the multi-material powder layer along a preset trajectory.

[0042] It is further pointed out that for Method 3, the specific structure is as Figure 3 shown. The laser oscillation forming system includes: a beam expander assembly 40, other devices 50 in the optical path system, a galvanometer assembly 20, and a rotating mirror assembly 70 provided with a laser light source, and the four form a right triangle layout. Among them, the beam expander assembly 40 and other devices 50 in the optical path system are connected by a first optical path S1, other devices 50 in the optical path system and the galvanometer assembly 20 are connected by a second optical path S2, and the galvanometer assembly 20 and the rotating mirror assembly 70 are connected by a third optical path S3. And the first optical path S1 is located on one right side of the right triangle, and the second optical path S2 and the third optical path S3 are located on the other right side of the right triangle, or the first optical path S1 and the second optical path S2 are located on one right side of the right triangle, and the third optical path S3 is located on the other right side of the right triangle; a powder bed 30, located below the rotating mirror assembly 70, and a multi-material powder layer is laid on the powder bed 30. Among them, the laser light source on the rotating mirror assembly 70 realizes laser printing of the multi-material powder layer along a preset trajectory.

[0043] It is further pointed out that for Method 4, the specific structure is as Figure 4 shown. The laser oscillation forming system includes: other devices 50 in the optical path system and a spatial light modulator 80 provided with a laser light source, and the two are on the same straight line, and other devices 50 in the optical path system and the spatial light modulator 80 are connected by a first optical path S1; The powder bed 30 is located below the spatial light modulator 80, and a multi-material powder layer is laid on the powder bed 30. Among them, the laser light source on the spatial light modulator 80 realizes laser printing of the multi-material powder layer along a preset trajectory.

[0044] It is worth mentioning that, in this embodiment, the galvanometer assembly 20 usually includes one or more high-speed and high-precision mirrors, and these mirrors are mounted on a small motor (i.e., the galvanometer). By controlling the angle of the motor, the direction of the incident laser can be changed quickly and accurately.

[0045] The beam expander assembly 40 is mainly used to change the diameter and divergence angle of the laser beam. It usually consists of a group of lenses, and the size of the laser beam can be enlarged or reduced by adjusting the distance between the lenses. The main function of the beam expander is to improve the quality of the laser beam, reduce the size of the focused spot, and reduce the divergence degree of the laser beam, thereby improving the efficiency and accuracy in the laser processing or transmission process.

[0046] The rotating mirror assembly 70 refers to a mirror that rotates around a certain axis, and it can be used to continuously change the direction of the light beam. This kind of assembly is often used in applications that require the light beam to scan a certain angular range, such as certain types of lidar (LiDAR), barcode scanners, or some special optical experimental devices. By rotating the assembly, the laser beam can cover a wider area, which is suitable for detecting or scanning large-area targets.

[0047] The spatial light modulator 80 is a device that can modulate the amplitude, phase, or polarization state of the incident light in a spatial distribution, and is widely used in many fields such as optical information processing, laser display, holography, wavefront correction, and quantum computing. The core function of the spatial light modulator 80 is to convert an electrical signal into an optical signal with a spatial distribution, so as to achieve precise control of the light beam.

[0048] In this embodiment, laser oscillation is used to stir the multi-material interface molten pool. On the one hand, it can strengthen the convection stirring effect of the melt, effectively capture the bubbles in the molten pool, accelerate the escape of the bubbles, and reduce the forming defects such as poor multi-material interface fusion, holes, and cracks. On the other hand, it can effectively change the morphology of the molten pool, regulate the temperature field distribution and flow field convection of the molten pool, and promote the mixing of the melt and the diffusion of elements, and reduce the precipitation of coarse brittle intermetallic compounds.

[0049] Preferably, when the laser light source realizes laser printing of the multi-material powder layer of the component along a preset trajectory, the formed component model of the current multi-material powder layer can be divided into an edge area A1 and a filling area A2. Among them, the edge area A1 is laser printed by a point light source B1 with a small diameter and high precision, and the filling area A2 is laser reciprocally printed by a surface light source B2 formed by high-speed oscillating scanning.

[0050] In this embodiment, during the beam shaping process, a conventional point light source B1 with a small diameter and high precision is used to print the edge of the forming component, so that the forming component can obtain a more uniform and fine structure, improving the strength, wear resistance and corrosion resistance of the surface of the forming component. The surface light source B2 formed by high-speed laser oscillation scanning can improve the forming efficiency of the forming component, obtain a relatively coarse structure, and improve the overall plasticity and toughness of the forming component.

[0051] It is worth mentioning that, as Figure 5 shown, when the forming component model of the current multi-material powder layer is set in a polygon, first, the forming component model is divided into an edge area A1 and a filling area A2. Among them, the edge area A1 is located at the outer contour edge of the polygon. Then, the edge area A1 is processed by the point light source B1, and the filling area A2 is processed by the surface light source B2 formed by laser oscillation, and finally, the forming component model required for the current multi-material powder layer is formed.

[0052] As Figure 6 shown, when the forming component model of the current multi-material powder layer is set in a pipe, first, the forming component model is also divided into an edge area A1 and a filling area A2. Among them, the edge area A1 is located at the inner contour edge of the pipe. Then, the edge area A1 is processed by the point light source B1, and the filling area A2 is processed by the surface light source B2 formed by laser oscillation, and finally, the forming component model required for the current multi-material powder layer is formed.

[0053] Preferably, when the laser light source realizes laser printing of the multi-material powder layer of the component along the preset trajectory, there will be a phenomenon of stress concentration. To solve the stress concentration problem, generally, the following three methods are adopted.

[0054] Method 1: Before the multi-material powder layer corresponding to the forming component model is formed, high-power laser high-frequency oscillation is used to form a uniform surface light source B2 to preheat the multi-material powder layer over a large area and adjust the stress distribution, so as to prevent the occurrence of stress concentration.

[0055] Method 2: During the formation of the multi-material powder layer corresponding to the forming component model, high-power laser high-frequency oscillation is used to form a uniform surface light source B2 to perform local high-temperature heat treatment on the laser forming area, so as to reduce the thermal stress during the forming process.

[0056] Method 3: After the multi-material powder layer corresponding to the forming component model is formed, high-power laser high-frequency oscillation is used to form a uniform surface light source B2 to perform heat treatment on the stress concentration prone area of the forming component model, so as to prevent local stress concentration.

[0057] Preferably, when the laser light source realizes the laser printing of the multi-material powder layer of the component along the preset trajectory, it further includes step S4 of performing real-time online monitoring on the formed component. The component may have defects such as local spheroidization, warping, and large roughness. At this time, laser oscillation remelting needs to be performed on the component, including step S41: The laser beam performs remelting scanning on the defective target area of the current formed layer along the preset path in a high-frequency oscillation manner, so that the surface of the target area melts and the forming defects are repaired; S42: After step S41 is completed, analyze the formed layer again through online monitoring to detect whether the defects are repaired. If not, return to step S41. If already repaired, continue with step S2.

[0058] In this embodiment, through laser oscillation remelting, the forming defects of the component are reduced, and the forming capabilities of structural features with high variability (such as thin-walled components), no support (such as cantilever components), and easy stress concentration (such as sharp-corner components) are greatly improved.

[0059] Preferably, a multi-material laser additive manufacturing process provided by the present invention further includes the steps: S5: Optimize and adjust the process online, and feedback the adjusted parameter data to the multi-material L-PBF forming process database to update the parameter data in the multi-material L-PBF forming process database; S6: After the component is formed, perform quality inspection on the formed component.

[0060] It should be noted that in the present invention, descriptions such as "first", "second", and "one" are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. Terms such as "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can be the internal connection of two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0061] In addition, the technical solutions between various embodiments of the present invention can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions conflicts with each other or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0062] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Those skilled in the art to which the present invention pertains may make various modifications or supplements to the described specific embodiments or use similar means for substitution, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A multi-material laser additive manufacturing process, characterized in that: Includes steps: S1: Form a multi-material L-PBF forming process database by training multiple multi-material forming components; S2: Call the multi-material L-PBF forming process database, intelligently segment the current component, and plan the powder laying process and laser oscillation forming process of each part after segmentation. The powder laying process lays multi-material powder layer by layer according to preset requirements and controls the thickness of the multi-material powder layer; the laser oscillation forming process stirs the multi-material molten pool and shapes the laser beam through laser oscillation; S3: According to the powder spreading process and laser oscillation forming process in step S1, and in combination with the powder spreading device and the laser oscillation forming system, a multi-material component is formed.

2. The multi-material laser additive manufacturing process according to claim 1, characterized in that: The laser oscillation forming process in step S2 includes the following steps: S21: dividing the forming component model of the current multi-material powder layer into an edge area and a filling area, wherein when the forming component model of the current multi-material powder layer is set as a polygon, the edge area is located at the outer contour edge of the polygon; when the forming component model of the current multi-material powder layer is set as a pipeline, the edge area is located at the inner contour edge of the pipeline; S22: The edge area of ​​the component model is processed by a point light source, and the filling area of ​​the component model is processed by a surface light source formed by laser oscillation, so as to complete the processing of the component model in the current multi-material powder layer.

3. The multi-material laser additive manufacturing process according to claim 2, characterized in that: Step S2 also includes step S23: using high-power laser high-frequency oscillation to form a uniform surface light source, heat treating the current multi-material powder layer to eliminate stress concentration or prevent local stress concentration, wherein when it is necessary to preheat the current multi-material powder layer over a large area, step S23 is located before step S21; when it is necessary to perform local high-temperature heat treatment on the laser forming area, step S23 is performed simultaneously with step S22; when it is necessary to perform heat treatment on the stress concentration-prone area of ​​the formed component model, step S23 is located after step S22.

4. The multi-material laser additive manufacturing process according to claim 1, characterized in that: The method further comprises step S4: real-time online monitoring of the formed component, and if defects occur in the current multi-material powder layer formed component model, laser oscillation remelting is performed on the current formed component model.

5. The multi-material laser additive manufacturing process according to claim 4, characterized in that: Step S4 comprises the steps of: S41: The laser beam remelts and scans the defective target area of ​​the current forming layer along a preset path in a high-frequency oscillation manner, so that the surface of the target area is melted and the forming defects are repaired; S42: After step S41 is completed, the forming layer is analyzed again through online monitoring to detect whether the defect has been repaired. If it has not been repaired, return to step S41; if it has been repaired, continue to step S2.

6. The multi-material laser additive manufacturing process according to claim 1, characterized in that: Also includes the steps: S5: Optimize and adjust the process online, and feed back the adjusted parameter data to the multi-material L-PBF forming process database to update the parameter data in the multi-material L-PBF forming process database.

7. The multi-material laser additive manufacturing process according to claim 1, characterized in that: Also includes the steps: S6: After the component is formed, the formed component is subjected to quality inspection.

8. A laser oscillation forming system, which can be processed by the multi-material laser additive forming process according to any one of claims 1 to 7, characterized in that: It includes a galvanometer assembly and a CNC machine tool, wherein the stirring of the multi-material molten pool by laser oscillation during the multi-material L-PBF forming process is achieved by adjusting the motion trajectory of the CNC machine tool in the X-axis and Y-axis directions; and the dynamic control of the laser spot size is achieved by adjusting the distance of the CNC machine tool in the Z-axis direction.

9. The laser oscillation forming system according to claim 8, characterized in that: Laser oscillation forming system includes: A numerically controlled machine tool, on which a first output shaft movable along an X-axis direction, a second output shaft movable along a Y-axis direction, and a third output shaft movable along a Z-axis direction are provided, wherein the first output shaft, the second output shaft, and the third output shaft form a three-coordinate system in space, and a galvanometer assembly provided with a laser light source is connected to the third output shaft; The powder bed is located below the galvanometer assembly and a multi-material powder layer is laid on the powder bed, wherein the laser light source on the galvanometer assembly realizes laser printing of the multi-material powder layer along a preset trajectory.

10. A laser oscillation forming system, which can be processed by the multi-material laser additive forming process according to any one of claims 1 to 7, characterized in that: It includes an ultrasonic driver and a beam expander assembly and a galvanometer assembly in an optical path system, wherein the galvanometer assembly is driven by the ultrasonic driver to achieve stirring of the multi-material molten pool by laser oscillation during the multi-material L-PBF forming process; and the optical path beam expander assembly is driven by the ultrasonic driver to achieve dynamic control of the laser spot size.

11. The laser oscillation forming system according to claim 10, characterized in that: Laser oscillation forming system includes: A beam expander assembly, other devices in the optical path system, and a galvanometer assembly provided with a laser light source; Two ultrasonic drivers, namely a first ultrasonic driver and a second ultrasonic driver, wherein the first ultrasonic driver is connected to the beam expander assembly, and the second ultrasonic driver is connected to the galvanometer assembly; The powder bed is located below the galvanometer assembly and a multi-material powder layer is laid on the powder bed, wherein the laser light source on the galvanometer assembly realizes laser printing of the multi-material powder layer along a preset trajectory.

12. A laser oscillation forming system, which can be processed by the multi-material laser additive forming process according to any one of claims 1 to 7, characterized in that: It includes a beam expander assembly, a galvanometer assembly and a rotating mirror assembly in the optical path system, wherein the galvanometer assembly is used to realize the scanning of the laser in the X-axis and Y-axis directions; the rotating mirror assembly is used to realize the stirring of the multi-material molten pool by laser oscillation during the multi-material L-PBF forming process, and to realize the dynamic regulation of the laser spot size.

13. The laser oscillation forming system according to claim 12, characterized in that: Laser oscillation forming system includes: Beam expander assembly, other devices in the optical path system, galvanometer assembly and rotating mirror assembly with laser light source; The powder bed is located below the rotating mirror assembly and a multi-material powder layer is laid on the powder bed, wherein the laser light source on the rotating mirror assembly realizes laser printing of the multi-material powder layer along a preset trajectory.

14. A laser oscillation forming system, which can be processed by the multi-material laser additive forming process according to any one of claims 1 to 7, characterized in that: It includes an optical path system and a spatial light modulator, wherein the spatial light modulator is used to position the laser and plan the scanning path, so that the laser oscillation stirs the multi-material molten pool during the multi-material L-PBF forming process and the laser spot size is dynamically controlled.

15. The laser oscillation forming system according to claim 14, characterized in that: Laser oscillation forming system includes: Other devices in the optical path system and a spatial light modulator provided with a laser light source; The powder bed is located below the spatial light modulator and a multi-material powder layer is laid on the powder bed, wherein the laser light source on the spatial light modulator realizes laser printing of the multi-material powder layer along a preset trajectory.

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