Multi-property laser partitioned scanning methods, apparatuses, and devices for additive manufacturing

Abstract

Disclosed are a multi-property laser partition scanning method, device and equipment for additive manufacturing. The method acquires a three-dimensional model of a component to be formed and performs slicing processing to obtain a plurality of layers to be formed; performs regional division on the layers to be formed according to geometric features, dimensional features and / or accuracy requirements of corresponding regions of the layers to be formed to obtain a first laser forming region (R1), a second laser forming region (R2) and a laser splicing region (R3) located between the two regions; determines first and second laser beams (L1 and L2) with different energy distribution characteristics and generates corresponding scanning paths according to forming requirements of different regions; controls the first and second laser beams (L1 and L2) to scan corresponding forming regions respectively and to overlap scan the laser splicing region (R3), so that continuous metallurgical connections are formed between different laser forming regions to realize differential forming of different regions and improve forming efficiency, forming accuracy and forming quality of the additive manufacturing component.

Description

Technical Field

[0001] This application relates to the field of additive manufacturing, and more particularly to a multi-characteristic laser partition scanning method, apparatus and equipment for additive manufacturing. Background Technology

[0002] Additive manufacturing is an advanced manufacturing technology that uses a three-dimensional model to create parts by accumulating materials layer by layer. Among them, additive manufacturing methods that use lasers as an energy source to selectively melt materials can overcome the limitations of traditional processing techniques on structural complexity and are suitable for manufacturing high-performance parts with complex curved surfaces, internal flow channels, thin-walled structures, and lightweight topologies.

[0003] In laser-based additive manufacturing, the laser scanning strategy is a crucial factor affecting the forming efficiency, dimensional accuracy, surface quality, and microstructure of parts. For the same component to be formed, different regions typically have different structural characteristics and performance requirements. For example, large solid areas require high material deposition efficiency and stable melting capabilities, while thin-walled structures, small features, complex contours, and high-precision areas require smaller heat-affected zones and higher boundary control capabilities.

[0004] Existing additive manufacturing processes typically employ a single laser beam to scan the entire area to be formed, and improve the forming effect by adjusting parameters such as laser power, scanning speed, scanning spacing, layer thickness, and scanning path. However, because a single laser beam usually has fixed energy distribution characteristics and spot features, it is difficult to achieve a balance when dealing with areas with different forming requirements. For example, a laser beam with a high degree of energy concentration is beneficial for improving local melting ability and fine structure forming accuracy, but when used for processing large areas, it is easily limited by scanning efficiency and concentrated heat input; while a laser beam with a more uniform energy distribution or a larger coverage area is beneficial for improving forming efficiency in large areas, but when applied to complex boundary or microstructure areas, it is easily affected by melt pool expansion, heat-affected zone, and dimensional control capabilities.

[0005] To address these issues, existing technologies employ laser processing schemes with different beam characteristics, spot sizes, or energy distribution patterns to meet the manufacturing needs of different regions. For example, beams with concentrated energy distribution at the center can be used for fine structure processing, while beams with relatively uniform energy distribution can be used for rapid prototyping of large areas. However, when laser beams with different characteristics act on different regions of the same component, differences in molten pool size, heat input methods, and solidification processes can easily lead to problems such as insufficient fusion, discontinuous microstructure, dimensional deviations, or residual stress concentration at the boundaries between regions.

[0006] Therefore, how to rationally configure laser beams with different characteristics according to the structural features and forming requirements of different regions of the component, and improve the fusion quality at the junction of different laser forming regions, so as to achieve continuous metallurgical transition between different regions, is a technical problem that needs to be solved in the current additive manufacturing field. Summary of the Invention

[0007] The purpose of this invention is to provide a multi-characteristic laser partition scanning method, apparatus and equipment for additive manufacturing. According to the structural characteristics and forming requirements of different regions of the component to be formed, laser beams with different energy distribution characteristics are used to process different regions in a coordinated manner, so as to improve the forming efficiency, dimensional accuracy and surface quality of different regions.

[0008] Furthermore, another objective of this application is to improve the problem of reduced fusion quality at the interface between different laser forming areas by setting up a laser splicing area located between different laser forming areas and using laser beams with different characteristics to perform remelting scanning and melting connection on the laser splicing area.

[0009] Furthermore, another objective of this application is to enable laser beams with different energy distribution characteristics to leverage their advantages in large-area high-efficiency forming and local high-precision forming by synergistically controlling the scanning sequence, scanning area, remelting range and process parameters of different laser beams, thereby achieving a balance between forming efficiency, structural accuracy and connection quality in the additive manufacturing process.

[0010] In a first aspect, embodiments of this application provide a multi-characteristic laser partition scanning method for additive manufacturing, comprising: acquiring a three-dimensional model of a component to be formed, and slicing the three-dimensional model according to preset forming parameters to obtain multiple layers to be formed; dividing the layers to be formed into regions according to the geometric features, dimensional features, and / or accuracy requirements of the regions corresponding to the layers to be formed, to obtain a first laser forming region, a second laser forming region, and a laser splicing region located between the first laser forming region and the second laser forming region; determining a first laser beam and a second laser beam respectively for scanning the first laser forming region and the second laser forming region according to the forming requirements of the first laser forming region and the second laser forming region, and generating scanning paths corresponding to the first laser forming region and the second laser forming region, wherein the first laser beam and the second laser beam have different energy distribution characteristics; controlling the first laser beam to scan the first laser forming region, controlling the second laser beam to scan the second laser forming region, and controlling the first laser beam and the second laser beam to perform remelting scanning on the laser splicing region, so as to form a continuous metallurgical connection between the first laser forming region and the second laser forming region.

[0011] According to a preferred embodiment of the first aspect, the first laser beam is a flat-top beam and the second laser beam is a Gaussian beam.

[0012] According to a preferred embodiment of the first aspect, the first laser forming region is a solid filling region; the second laser forming region includes at least one of a thin-walled region, a complex contour region, an inner cavity region, a fine structure region, and / or a region requiring high precision.

[0013] According to a preferred embodiment of the first aspect, the laser splicing area is determined based on the boundary position between the first laser forming area and the second laser forming area, and a transition area of ​​a preset width is provided along the boundary position.

[0014] According to a preferred embodiment of the first aspect, controlling the first laser beam and the second laser beam to perform remelting scanning on the laser splicing area includes: adjusting the degree of remelting in the laser splicing area by adjusting the overlap rate of the scanning paths of the first laser beam and the second laser beam in the laser splicing area; wherein the overlap rate of the scanning paths is determined based on at least one of the spot size of the first laser beam and the second laser beam, the scanning speed, the laser power, and the thermophysical parameters of the material to be formed.

[0015] According to a preferred embodiment of the first aspect, controlling the first laser beam to scan the first laser forming region, controlling the second laser beam to scan the second laser forming region, and controlling the first and second laser beams to perform remelting scans on the laser splicing region includes: controlling the first and second laser beams to scan according to a preset scanning sequence, wherein the preset scanning sequence includes: first controlling the first laser beam to scan the first laser forming region and the laser splicing region, and then controlling the second laser beam to scan the second laser forming region and the laser splicing region; or, first controlling the second laser beam to scan the second laser forming region and the laser splicing region, and then controlling the first laser beam to scan the first laser forming region and the laser splicing region.

[0016] According to a preferred embodiment of the first aspect, the first laser forming region is formed using a first forming layer thickness, and the second laser forming region is formed using a second forming layer thickness different from the first forming layer thickness; wherein the first forming layer thickness and the second forming layer thickness satisfy a preset multiple relationship.

[0017] According to a preferred embodiment of the first aspect, the method further includes: within a preset forming cycle, controlling the first laser forming region and the second laser forming region to perform multi-layer collaborative forming according to the first forming layer thickness and the second forming layer thickness, so that the first laser forming region and the second laser forming region have the same cumulative forming height after the preset forming cycle ends; controlling the molten pool formed by the first laser beam to overlap with the formed solid region; and simultaneously controlling the molten pool formed by the first laser beam and the molten pool formed by the second laser beam to overlap in the laser splicing area along the horizontal and vertical directions, so that a continuous metallurgical connection is formed between the first laser forming region and the second laser forming region.

[0018] According to a preferred embodiment of the first aspect, the multi-layer collaborative forming includes: controlling the second laser beam to perform layered scanning of the second laser forming region according to the second forming layer thickness, and controlling the first laser beam and the second laser beam to alternately scan the first laser forming region, the second laser forming region and the laser splicing region according to the multiple relationship between the first forming layer thickness and the second forming layer thickness.

[0019] Secondly, embodiments of this application provide a multi-characteristic laser partitioning scanning device for additive manufacturing, comprising: a model processing module, used to acquire a three-dimensional model of a component to be formed, and to slice the three-dimensional model according to preset forming parameters to obtain multiple layers to be formed; a region division module, used to divide the layers to be formed into regions according to the geometric features, dimensional features and / or accuracy requirements of the regions corresponding to the layers to be formed, to obtain a first laser forming region, a second laser forming region and a laser splicing region located between the first laser forming region and the second laser forming region; a path generation module, used to determine a first laser beam and a second laser beam respectively for scanning the first laser forming region and the second laser forming region according to the forming requirements of the first laser forming region and the second laser forming region, and to generate corresponding scanning paths, wherein the first laser beam and the second laser beam have different energy distribution characteristics; and a laser control module, used to control the first laser beam to scan the first laser forming region, control the second laser beam to scan the second laser forming region, and control the first laser beam and the second laser beam to perform remelting scanning on the laser splicing region, so as to form a continuous metallurgical connection between the first laser forming region and the second laser forming region.

[0020] Thirdly, embodiments of this application provide an additive manufacturing apparatus, comprising: a forming cavity for accommodating a material to be formed; a laser scanning system for outputting a first laser beam and a second laser beam having different energy distribution characteristics; and a controller connected to the laser scanning system, the controller being configured to perform the method as described in any of the first aspects.

[0021] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description

[0022] The accompanying drawings, which are incorporated herein and form part of this specification, illustrate one or more embodiments of the present application and, together with the description, serve to explain the principles of the present application and to enable those skilled in the art to make and use the present application.

[0023] Figure 1 A flowchart illustrating the steps of a multi-characteristic laser partition scanning method for additive manufacturing provided in this application embodiment; Figure 2 A process flow diagram of a multi-characteristic laser partition scanning method for additive manufacturing provided in an embodiment of this application; Figure 3 This is a schematic diagram of the region division of the layer to be formed provided in an embodiment of this application; Figure 4 A schematic diagram of the Gaussian-then-flat-top scanning strategy provided in this application embodiment; Figure 5 A schematic diagram of the flat-top followed by Gaussian scanning strategy provided in this application embodiment; Figure 6 The test results of the surface roughness of the sample under different process parameters provided in Example 1 of this application are as follows: (a) to (c) correspond to the surface roughness of the sample under the flat top beam parameters P1 to P3, respectively, and (d) to (f) correspond to the surface roughness of the sample under the Gaussian beam parameters G1 to G3, respectively. Figure 7 The mechanical property test results of the flat-top-Gauss laser-formed specimens under different process parameters provided in Example 1 of this application are shown in (a) and (b) respectively. (a) shows the engineering stress-engineering strain curves of the specimens under different process parameters, and (b) shows the comparison results of tensile strength and engineering strain of the specimens under different process parameters. Figure 8 The forming density of laser splicing regions of different sizes provided in Embodiment 1 of this application is shown in (a) to (g), which are cross-sectional microstructure diagrams obtained under the conditions of remelting width W of 0.2 mm, 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm and 3.0 mm, respectively, and (h) is the density change curve corresponding to different remelting width conditions. Figure 9The surface quality analysis results of laser splicing areas of different sizes provided in Embodiment 1 of this application are shown in (a) to (c), which are scanning electron microscope images of the laser splicing areas under the conditions of remelting width W of 0.5 mm, 1.0 mm and 2.0 mm, respectively, and (d) to (f) are the three-dimensional surface contour test results under the above conditions, respectively. Figure 10 The mechanical property test results of laser splicing regions of different sizes provided in Embodiment 1 of this application are shown, wherein (a) is the stress-strain curve of the sample under different remelting width conditions, and (b) is the tensile strength and engineering strain of the sample under different remelting width conditions. Figure 11 The forming density of the laser splicing region under different remelting width conditions provided in Embodiment 2 of this application, wherein (a) to (g) are metallographic images of the splicing region obtained under the conditions of remelting width W of 0.2 mm, 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm and 3.0 mm respectively; Figure 12 The surface morphology and three-dimensional contour test results of the laser splicing area under different remelting width conditions provided in Embodiment 2 of this application are shown. Among them, (a) to (c) are the scanning electron microscopy morphology of the splicing area under the conditions of remelting width W of 0.5 mm, 1.0 mm and 2.5 mm, respectively, and (d) to (f) are the laser contour scanning results under the corresponding conditions. Figure 13 The mechanical property test results of the laser splicing area under different remelting widths provided in Embodiment 2 of this application are shown in (a) the stress-strain curves of the samples under different remelting widths, and (b) the corresponding tensile strength and engineering strain changes. Figure 14 A schematic diagram of the two-layer Gaussian and double-thickness flat-top splicing process provided in the embodiments of this application; Figure 15 A schematic diagram of the first splicing scheme of a two-layer Gaussian roof and a double-thickness flat roof provided in an embodiment of this application; Figure 16 A schematic diagram of a second splicing scheme for a two-layer Gaussian roof and a double-thickness flat roof provided in an embodiment of this application; Figure 17 A schematic diagram of the additive manufacturing equipment provided in the embodiments of this application; Figure 18 This is a schematic diagram of the module connection of the multi-feature laser partition scanning device provided in the embodiments of this application. Detailed Implementation

[0024] Exemplary embodiments of this application will now be described more fully with reference to the accompanying drawings. However, this application is not limited to the embodiments described below, but can be implemented in many different forms. These embodiments are provided so that those skilled in the art can fully understand the technical solutions, technical principles, and technical effects of this application.

[0025] It should be understood that the terms "first," "second," etc., described in this application are used only to distinguish different technical features or technical objects, and do not indicate any limitation on the order or importance of the technical features.

[0026] In the description of this application, it should be noted that, unless otherwise expressly specified, the terms "connection," "setting," "correspondence," etc., should be interpreted broadly. For example, they can refer to direct or indirect connection, fixed or adjustable setting, structural or functional correspondence.

[0027] Furthermore, the expressions "in some embodiments" and "exemplary" used in this application indicate that the relevant technical solutions can be implemented as one or more embodiments of this application, and do not constitute a limitation on the scope of protection of this application. Those skilled in the art can make equivalent substitutions or combinations of the relevant technical features without departing from the technical concept of this application.

[0028] To facilitate understanding of the technical solution of this application, some of the technical terms involved in this application are explained as follows: Multi-characteristic laser: refers to a process in which at least two laser beams with different energy distribution characteristics are used for collaborative scanning in the same part or the same additive manufacturing task.

[0029] Flat-top beam: refers to a laser beam with relatively uniform energy distribution within its beam cross-section.

[0030] Gaussian beam: refers to a laser beam in which the energy density within the beam's cross-section is approximately Gaussian, with a higher energy density in the central region.

[0031] Laser splicing area: refers to the transition area set at the junction of the first laser forming area and the second laser forming area, used to achieve continuous connection of laser beam forming areas with different energy distribution characteristics.

[0032] Interlayer rotation angle: refers to the rotation angle between adjacent forming layers in the direction of the scanning vector.

[0033] Relative rotation angle: refers to the angle between the scanning vector directions of the first laser beam and the second laser beam within the same forming layer.

[0034] Figure 1A flowchart illustrating the steps of a multi-characteristic laser partition scanning method for additive manufacturing provided in this application embodiment; Figure 2 A process flow diagram of a multi-characteristic laser partition scanning method for additive manufacturing provided in an embodiment of this application. (Refer to...) Figure 1 and Figure 2 This application provides a multi-characteristic laser partition scanning method 100 for additive manufacturing. This method 100 can be applied to the additive manufacturing process based on a laser energy source. It is used to adopt a laser scanning strategy that is adapted to different regions according to the forming requirements of different regions of the component to be formed, so as to improve the connection quality between different forming regions.

[0035] like Figure 2 As shown in the embodiment of this application, a three-dimensional model of the component to be formed is used as the input object. Multiple layers to be formed are obtained by slicing the three-dimensional model. The regional features corresponding to each layer to be formed are analyzed, and partitioning is performed according to the forming requirements of different regions. Among them, at least a first laser forming region R1, a second laser forming region R2, and a laser splicing region R3 located between the first laser forming region R1 and the second laser forming region R2 are formed in the same layer to be formed.

[0036] To meet the forming requirements of different laser forming regions, a first laser beam L1 and a second laser beam L2 are configured to scan the first laser forming region R1 and the second laser forming region R2, respectively, and corresponding scanning paths are generated based on the corresponding laser beams. During the scanning and forming process of each region, the first laser beam L1 and the second laser beam L2 are controlled to perform a remelting scan on the laser splicing region R3, so that a continuous metallurgical connection is formed between the different laser forming regions.

[0037] Specifically, the method 100 provided in this application includes the following steps.

[0038] 101. Obtain the three-dimensional model of the component to be formed, and slice the three-dimensional model according to the preset forming parameters to obtain multiple layers to be formed.

[0039] In this embodiment, the three-dimensional model corresponding to the component to be formed is first obtained. This three-dimensional model can be a three-dimensional digital model created using computer-aided design software, or a digital model obtained through three-dimensional scanning, reverse modeling, or other methods.

[0040] For example, a three-dimensional model may include the outline information, internal structure information and dimensional information of the component to be manufactured, and the above information can characterize the overall geometric structure of the component to be formed.

[0041] After obtaining the three-dimensional model of the component to be formed, the three-dimensional model is sliced ​​according to the preset forming parameters to convert the continuous three-dimensional model into multiple two-dimensional cross-sectional data arranged sequentially along the forming direction, thereby obtaining multiple layers to be formed.

[0042] The preset forming parameters may include, but are not limited to, parameters such as slicing direction, slice thickness, forming direction, and scanning area division rules. Those skilled in the art can set these parameters according to the material properties, structural characteristics, and process capabilities of the additive manufacturing equipment for the component to be formed.

[0043] In some embodiments, a plurality of layers to be formed are arranged sequentially along a preset forming direction, and each layer to be formed is used to characterize the cross-sectional profile information of the component to be formed at a corresponding height position.

[0044] 102. Based on the geometric features, dimensional features and / or precision requirements of the corresponding area of ​​the layer to be formed, the layer to be formed is divided into regions to obtain a first laser forming region R1, a second laser forming region R2 and a laser splicing region R3 located between the first laser forming region R1 and the second laser forming region R2.

[0045] After obtaining multiple layers to be formed, the corresponding area of ​​each layer is analyzed, and the area is divided according to the structural characteristics and forming requirements of different areas.

[0046] Specifically, different locations in the layer to be formed can be identified and divided based on the geometric features, dimensional features, and / or accuracy requirements of the corresponding area of ​​the layer to be formed, so as to determine the areas suitable for different laser scanning strategies.

[0047] For example, for the same layer to be formed, different regions may have different geometries, size ranges or forming accuracy requirements. Therefore, the layer to be formed can be divided into multiple laser forming regions based on the above characteristics.

[0048] In this embodiment, after the area is divided, at least a first laser forming area R1, a second laser forming area R2, and a laser splicing area R3 disposed between the two are formed.

[0049] The first laser forming region R1 and the second laser forming region R2 are used to form using different laser scanning strategies, and the laser splicing region R3 is set at the junction of the first laser forming region R1 and the second laser forming region R2 to achieve continuous connection between the two regions.

[0050] It should be noted that this application does not limit the specific location, shape, or area ratio of the first laser forming region R1 and the second laser forming region R2. Those skilled in the art can adaptively divide the forming layers according to the actual structural characteristics of the component to be formed and the forming requirements of different regions.

[0051] In some embodiments, the first laser forming region R1 can be set as a large solid region in the layer to be formed, the second laser forming region R2 can be set as a detailed feature region, and a laser splicing region R3 is set between the first laser forming region R1 and the second laser forming region R2 to achieve a transition connection between the different laser forming regions. For example, when the component to be formed has different forming requirements for the central region and the peripheral region, the first laser forming region R1 can be set in the middle region of the layer to be formed, the second laser forming region R2 can be set in the edge region of the layer to be formed, and the laser splicing region R3 is formed at the junction of the two.

[0052] In other embodiments, the spatial layout of the first laser forming region R1 and the second laser forming region R2 is not limited to the above-mentioned left-right partitioning or center / edge partitioning forms, but can be set according to the geometry of the component to be formed, local features, and forming requirements of different regions. For example, the first laser forming region R1 and the second laser forming region R2 can form inner and outer contour partitions, that is, corresponding to the inner region and outer contour region of the component, respectively; or they can form different functional partitions according to the forming requirements of different functional regions of the component.

[0053] In some embodiments, the first laser forming region R1 and the second laser forming region R2 can also form an island-shaped partition, a strip partition, or a multi-region staggered partition layout. For example, for a component to be formed with multiple local complex structures or multiple fine feature regions, multiple local regions can be divided into the second laser forming region R2, and corresponding laser splicing regions R3 can be set between different laser forming regions to achieve multi-region collaborative forming.

[0054] In some embodiments, the same layer to be formed may include one or more first laser forming regions R1 and / or one or more second laser forming regions R2, and multiple laser splicing regions R3 may be respectively set at the junction positions between different laser forming regions, thereby meeting the partition forming requirements of complex structural components.

[0055] 103. Based on the forming requirements of the first laser forming region R1 and the second laser forming region R2, determine the first laser beam L1 and the second laser beam L2 respectively for scanning the first laser forming region R1 and the second laser forming region R2, and generate scanning paths corresponding to the first laser forming region R1 and the second laser forming region R2, wherein the first laser beam L1 and the second laser beam L2 have different energy distribution characteristics.

[0056] After the region division is completed, the first laser beam L1 and the second laser beam L2 for scanning different regions are determined according to the forming requirements corresponding to the first laser forming region and the second laser forming region.

[0057] Specifically, in this embodiment, laser beams with different characteristics are used to scan the first laser forming region R1 and the second laser forming region R3, so that different laser beams can be adapted to the forming requirements of their respective regions. The first laser beam and the second laser beam have different energy distribution characteristics. By using laser beams with different energy distribution characteristics to scan different regions, the laser energy input method can be matched with the forming requirements of the regions, thereby improving the forming adaptability of different regions.

[0058] After determining the first laser beam L1 and the second laser beam L2, corresponding scanning paths are generated based on the area range and geometric contour information of the first laser forming region R1 and the second laser forming region R2.

[0059] For example, based on the two-dimensional contour data of the layer to be formed, the region boundary information, and the preset scanning rules, a first scanning path corresponding to the first laser beam L1 and a second scanning path corresponding to the second laser beam L2 can be generated, so that the first laser beam L1 can act on the first laser forming region according to the first scanning path, and the second laser beam L2 can act on the second laser forming region according to the second scanning path.

[0060] 104. Control the first laser beam L1 to scan the first laser forming region R1, control the second laser beam R2 to scan the second laser forming region R2, and control the first laser beam L1 and the second laser beam R2 to perform remelting scan on the laser splicing region R3, so as to form a continuous metallurgical connection between the first laser forming region R1 and the second laser forming region R2.

[0061] After generating the scanning paths corresponding to the first laser beam L1 and the second laser beam L2, the laser scanning system is controlled to perform a partitioned scanning forming process according to the generated scanning paths.

[0062] Specifically, the first laser beam L1 is controlled to scan the first laser forming region R1 according to the corresponding scanning path, causing the material to be formed (i.e., the powder to be scanned) in the first laser forming region R1 to melt and solidify under the action of laser energy, thereby forming the corresponding solid region. At the same time, the second laser beam L2 is controlled to scan the second laser forming region R2 according to the corresponding scanning path, causing the material to be formed in the second laser forming region R2 to complete the melting and forming process.

[0063] Since the first laser forming region R1 and the second laser forming region R2 are formed by the first laser beam L1 and the second laser beam L2 with different energy distribution characteristics, the two regions have different energy input methods and molten pool formation states during the forming process.

[0064] To improve the continuity of connection between different laser forming regions, embodiments of this application further control the first laser beam L1 and the second laser beam L2 to perform remelting scanning on the laser splicing region R3 located between the first laser forming region R1 and the second laser forming region R2.

[0065] Specifically, within the laser splicing area R3, the first laser beam L1 and the second laser beam L2 act on the area respectively, causing the material already formed within the laser splicing area R3 to be subjected to laser energy again, resulting in local remelting. Through this remelting effect, mutual diffusion and fusion between the materials at the interface between the first laser forming area R1 and the second laser forming area R2 can be promoted.

[0066] In some embodiments, the first laser beam L1 and the second laser beam L2 can act on the laser splicing area R3 according to a preset scanning path, so that the molten areas formed by the two laser forming areas are connected in the laser splicing area R3, and a continuous metallurgical bond is formed in the subsequent solidification process.

[0067] Through the above methods, the embodiments of this application can avoid the problem of insufficient connection at the boundary of regions when using different laser beams for regional forming, improve the connection quality between different laser forming regions, and enable the components formed by the synergistic formation of multiple laser characteristics to have a continuous organizational structure.

[0068] This application also provides an implementation method for configuring laser beams with different energy distribution characteristics according to the structural features of different forming regions.

[0069] Figure 3 This is a schematic diagram illustrating the division of the region to be formed in an embodiment of this application. Figure 3As shown, the first laser forming region R1 and the second laser forming region R2 correspond to different forming requirements, and the first laser beam L1 and the second laser beam L2 are matched according to the forming requirements of the corresponding regions. Specifically, the first laser beam L1 can be used to scan the first laser forming region R1, and the second laser beam L2 can be used to scan the second laser forming region R2.

[0070] In some embodiments, the first laser beam L1 can be a flat-top beam, and the second laser beam L2 can be a Gaussian beam.

[0071] It should be understood that, due to the relatively uniform energy input characteristics of a flat-top beam within its spot size, a more stable molten pool can be formed during scanning. When the first laser beam L1 uses a flat-top beam, it can be used to scan areas requiring high material melting efficiency and a large forming area. Because a Gaussian beam has the characteristic of energy concentration in the central region, it can achieve high local energy control during scanning. When the second laser beam L2 uses a Gaussian beam, it can be used to scan areas requiring high boundary control, structural detail control, or dimensional accuracy.

[0072] In some embodiments, the arrangement of the first laser beam L1 and the second laser beam L2 is not limited to the combination of the flat-top beam and the Gaussian beam described above. Those skilled in the art can select the energy distribution characteristics of the laser beams according to the shaping requirements of different regions.

[0073] For example, the first laser beam L1 and the second laser beam L2 can be selected from different beam modes such as Gaussian beam, ring beam, flat-top beam, Bessel beam, vector beam, and saddle beam.

[0074] Different beam modes can have different energy spatial distribution characteristics. For example, a ring beam can change the energy input mode in the edge region of the molten pool, a Bessel beam can increase the local energy penetration depth, and a vector beam can change the energy distribution characteristics in different directions. Therefore, a suitable beam mode can be selected according to the structural characteristics of the region to be formed.

[0075] In some embodiments, the first laser beam L1 and the second laser beam L2 may also have different spot shapes. For example, the spot shapes of the first laser beam L1 and the second laser beam L2 may be circular, elliptical, triangular, rectangular, or other irregular structures. By setting different spot shapes, the energy coverage and molten pool morphology within the laser action area can be changed, improving the forming adaptability of different structural regions.

[0076] In some embodiments, the first laser forming region R1 and the second laser forming region R2 can be divided according to the structural characteristics of different locations of the component to be formed.

[0077] like Figure 3 As shown, the first laser forming region R1 can be a solid filling region, and the second laser forming region R2 can include at least one of a thin-walled region, a complex contour region, an internal cavity region, a fine structure region, and / or a region requiring high precision. Solid filling regions typically have a large continuous forming area and require high material melting efficiency and forming stability. A first laser beam L1 (flat-top beam) with a large effective energy coverage range can be used to scan this region to improve the forming efficiency of the solid region. For thin-walled regions, complex contour regions, internal cavity regions, fine structure regions, or regions requiring high precision, due to their small structural dimensions, obvious boundary features, or high dimensional control requirements, a second laser beam L2 (Gaussian beam) with higher local energy control capability can be used for scanning to reduce the heat-affected zone and improve the forming quality of the local structure.

[0078] In some embodiments, the laser splicing region R3 is determined based on the boundary position between the first laser forming region R1 and the second laser forming region R2, and a transition region of a preset width is provided along the boundary position between the first laser forming region R1 and the second laser forming region R2. The laser splicing region R3 is used to provide a transition connection region between the first laser beam L1 and the second laser beam L2, enabling continuous connection between different laser forming regions formed by the first laser beam L1 and the second laser beam L2 with different energy distribution characteristics.

[0079] Specifically, the laser splicing region R3 can be located at the adjacent boundary between the first laser forming region R1 and the second laser forming region R2, serving as a transition area between the two regions. During subsequent scanning and forming processes, by controlling the first laser beam L1 and the second laser beam L2 to act on the laser splicing region R3, the molten pools formed in the two regions interact spatially, thereby promoting the melting and solidification of materials between different laser forming regions and improving the metallurgical bonding quality at the region boundary.

[0080] In some embodiments, the width of the laser splicing area R3 can be set according to the spot size of the first laser beam L1 and the second laser beam L2, the scanning parameters, the characteristics of the material to be formed, and the area connection requirements. For example, the laser splicing area R3 can extend along the boundary line between the first laser forming area R1 and the second laser forming area R2, and its width direction can intersect the boundary direction between the two areas, for example, be set perpendicular to the boundary direction, so that the first laser beam L1 and the second laser beam L2 can form an effective working range within this area.

[0081] In some embodiments, the width of the laser splicing region R3 can be adjusted according to specific forming requirements. For example, it can be set to a fixed width, or it can be set to a variable width according to the structural characteristics, heat input requirements, and connection quality requirements of different positions of the component to be formed. By reasonably setting the width of the laser splicing region R3, the interaction range between different laser forming regions can be increased, allowing the first laser beam L1 and the second laser beam L2 to form more complete material fusion during the subsequent remelting scan, thereby improving the continuity of the region connection position and the metallurgical bonding quality.

[0082] For example, the remelting width can be set to be greater than 0 and not greater than 3 mm, so as to achieve effective connection between different laser forming areas while reducing the thermal impact expansion problem that may be caused by an excessively wide remelting area.

[0083] This application does not limit the specific shape, width, or spatial location of the laser splicing area R3. In some embodiments, the laser splicing area R3 can be a regular strip-shaped area extending along the boundary between the first laser forming area R1 and the second laser forming area R2; in other embodiments, the laser splicing area R3 can also be adaptively adjusted according to the boundary shape of the two laser forming areas, for example, forming a curved, polygonal, or irregular area that matches the local structural contour, to adapt to the component to be formed with a complex geometry.

[0084] In some embodiments, a remelting scan is performed on the laser splicing region R3 located between the first laser forming region R1 and the second laser forming region R2. Specifically, the laser splicing region R3 serves as a transition region between laser beams with different energy distribution characteristics, and its interior is simultaneously affected by the first laser beam L1 and the second laser beam L2. By controlling the first laser beam L1 and the second laser beam L2 to repeatedly scan the laser splicing region R3, the material at the boundary between the first laser forming region R1 and the second laser forming region R2 can be remelted, promoting the fusion between the molten pools of different regions, thereby improving the metallurgical bonding state between the different regions.

[0085] In some embodiments, the degree of remelting within the laser splicing region R3 can be adjusted by regulating the overlap rate of the scanning paths of the first laser beam L1 and the second laser beam L2 within the laser splicing region R3. The scan path overlap rate characterizes the degree of overlap between adjacent scan paths. Increasing the scan path overlap rate expands the overlap range between the action areas of the first laser beam L1 and the second laser beam L2, thereby increasing the heat input and material fusion degree within the laser splicing region R3. Conversely, decreasing the scan path overlap rate reduces localized heat input and avoids excessively large heat-affected zones caused by repeated melting.

[0086] In some embodiments, the scanning path overlap rate can be determined based on at least one of the spot size of the first laser beam L1 and the second laser beam L2, the scanning speed, the laser power, and the thermophysical parameters of the material to be formed. For example, when the first laser beam L1 and the second laser beam L2 have different spot sizes, the overlap ratio between the scanning paths can be adjusted according to the difference in the effective range of the two laser beams, so that laser beams with different energy distribution characteristics form appropriate molten pool overlaps within the laser splicing region R3.

[0087] In some embodiments, the scanning order of the first laser beam L1 and the second laser beam L2 can be adjusted according to the material state and heat input requirements of different regions. Specifically, as described above, the first laser beam L1 is controlled to scan the first laser forming region R1, the second laser beam L2 is controlled to scan the second laser forming region R2, and the first laser beam L1 and the second laser beam L2 are controlled to perform a remelting scan on the laser splicing region R3. Specifically, the first laser beam L1 and the second laser beam L2 can be controlled to perform the following scans according to a preset scanning order.

[0088] Figure 4 This is a schematic diagram of the Gaussian-first, flat-top scanning strategy provided in an embodiment of this application. (Refer to...) Figure 4 A scanning method of first using a Gaussian beam and then a flat-top beam can be adopted. That is, firstly, the second laser beam L2 is controlled to scan the second laser forming region R2 and the corresponding laser splicing region R3, so that the second laser forming region R2 is formed and the laser splicing region R3 forms an initial fusion region; then, the first laser beam L1 is controlled to scan the first laser forming region R1 and the laser splicing region R3, so that the first laser beam L1 acts on the laser splicing region R3, remelting the existing fusion region, thereby enhancing the metallurgical connection between the first laser forming region R1 and the second laser forming region R2.

[0089] Figure 5 This diagram illustrates the flat-top followed by Gaussian scanning strategy provided in an embodiment of this application. (Refer to...) Figure 5 In another embodiment, a scanning method of first using a flat-top beam and then a Gaussian beam can also be adopted. That is, firstly, the first laser beam L1 is controlled to scan the first laser forming region R1 and the laser splicing region R3, so that the first laser forming region R1 is formed; then, the second laser beam L2 is controlled to scan the second laser forming region R2 and the laser splicing region R3, and the second laser beam L2 acts on the laser splicing region R3 again to improve the connection quality between the two regions.

[0090] Example 1 (Process parameter determination stage) To determine the forming process parameters corresponding to the first laser beam L1 and the second laser beam L2 in the subsequent multi-characteristic laser partitioning scanning process, this embodiment first uses a flat-top beam and a Gaussian beam to conduct single-characteristic spot forming experiments, and analyzes the surface quality and mechanical properties of the samples under different laser power and scanning speed conditions.

[0091] In this embodiment, a flat-top beam is used as the first laser beam L1, and a Gaussian beam is used as the second laser beam L2. Different laser power and scanning speed parameters are set for the flat-top beam and the Gaussian beam to obtain shaped samples under different process conditions. As shown in Table 1 below, this embodiment sets three sets of flat-top beam process parameters and three sets of Gaussian beam process parameters. P1, P2, and P3 correspond to different flat-top beam shaping parameters, and G1, G2, and G3 correspond to different Gaussian beam shaping parameters.

[0092] Table 1: Process parameters for flat-top and Gaussian structures

[0093]

[0094] After preparing samples under different process parameters, the surface morphology and mechanical properties of the obtained samples were tested to evaluate the influence of different laser parameters on the forming quality.

[0095] Figure 6 The test results for the surface roughness of the sample under different process parameters provided in Embodiment 1 of this application are shown, where (a) to (c) correspond to the surface roughness of the sample under flat-top beam parameters P1 to P3, respectively, and (d) to (f) correspond to the surface roughness of the sample under Gaussian beam parameters G1 to G3, respectively. Figure 6 It can be seen that the surface quality obtained by using a flat-top beam and a Gaussian beam differs under different laser power and scanning speed conditions. Different parameter combinations significantly affect the surface undulation and uniformity of the sample. By comparing the surface roughness under different parameter conditions, suitable laser process parameters for subsequent multi-characteristic laser partitioning scanning can be selected.

[0096] Figure 7 The mechanical property test results of the flat-top-Gauss laser-formed specimens under different process parameters provided in Example 1 of this application are shown. (a) shows the engineering stress-engineering strain curves of the specimens under different process parameters, and (b) shows the comparison results of the tensile strength and engineering strain of the specimens under different process parameters. Figure 7It can be seen that different combinations of laser power and scanning speed have a certain impact on the mechanical properties of the samples. As the laser parameters are adjusted, the tensile strength and plastic deformation capacity of the samples change. Among them, under the flat-top beam condition, the sample corresponding to the P3 parameter has a higher scanning speed while maintaining good mechanical properties; under the Gaussian beam condition, the sample corresponding to the G3 parameter exhibits better overall forming performance.

[0097] Taking into account surface quality, forming efficiency and mechanical properties, this embodiment selects P3 as the forming process parameter for the subsequent first laser beam L1 (flat-top beam) and G3 as the forming process parameter for the subsequent second laser beam L2 (Gaussian beam). Based on the above parameters, a multi-characteristic laser partition scanning experiment including the laser splicing area is further carried out.

[0098] (Partition scanning phase) After optimizing the process parameters, a partitioning forming experiment was conducted using the multi-characteristic laser partitioning scanning method provided in the embodiments of this application to verify the impact of coordinated scanning of laser beams with different characteristics and remelting of laser splicing areas on the quality of regional connection.

[0099] This embodiment uses the optimized process parameters obtained in the aforementioned process parameter determination stage for forming. Specifically, the flat-top laser region uses the process parameters corresponding to P3, and the Gaussian laser region uses the process parameters corresponding to G3.

[0100] Specifically, this embodiment adopts Figure 4 The Gaussian-then-flat-top scanning strategy is shown. The layer to be formed is divided into a first laser forming region R1, a second laser forming region R2, and a laser splicing region R3 located between the first laser forming region R1 and the second laser forming region R2.

[0101] In this embodiment: the second laser beam L2 is a Gaussian beam used to scan the second laser forming region R2; the first laser beam L1 is a flat-top beam used to scan the first laser forming region R1; the beam scanning directions of the first laser beam L1 and the second laser beam L2 are consistent, that is, the relative rotation angle between the flat-top beam and the Gaussian beam is set to 0°; and a 67° interlayer rotation is used between adjacent forming layers.

[0102] In the specific forming process, firstly, a powder layer of a preset thickness is laid on the current layer to be formed. Then, the second laser beam L2 is controlled to scan the second laser forming region R2 according to a preset scanning path, and simultaneously acts on the laser splicing region R3, so that the second laser forming region R2 completes the forming of the current layer. After completing the above steps, the first laser beam L1 is switched, and the first laser beam L1 is controlled to scan the first laser forming region R1 according to a preset scanning path, and then scans the laser splicing region R3 again. Because the first laser beam L1 uses a flat-top beam, its energy distribution is more uniform, enabling the formation of a wider molten pool. Therefore, when scanning the laser splicing region R3, the boundary region formed by the preceding Gaussian beam can be remelted, creating a continuous molten connection between the first laser forming region R1 and the second laser forming region R2.

[0103] In this embodiment, the regional connection effect under different remelting width conditions is studied by adjusting the remelting width W of the laser splicing area R3, that is, by adjusting the overlap range of the first laser beam L1 and the second laser beam L2 in the boundary area.

[0104] For example, the remelting width W of the laser splicing region R3 is set to 0.2 mm, 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, and 3.0 mm, respectively. By setting laser splicing regions R3 with different widths, the effects of different degrees of molten pool overlap on the region connection quality, surface quality, and mechanical properties can be studied.

[0105] Figure 8 The forming density of laser-spliced ​​regions of different sizes provided in Embodiment 1 of this application is shown, wherein (a) to (g) correspond to cross-sectional microstructure images obtained under conditions where the remelting width W is 0.2 mm, 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm and 3.0 mm, respectively, and (h) is the density variation curve corresponding to different remelting width conditions. Figure 8 As shown, after adopting the Gaussian-then-flat-top scanning strategy, the laser-jointed region R3 exhibits high density under various remelting width conditions. When the remelting width W is small, for example, 0.2 mm, due to the limited effective interaction area between the first laser beam L1 and the second laser beam L2, a small number of insufficiently fused areas still exist in the joint area, resulting in relatively low overall density. As the remelting width W increases, the effective range of the flat-top beam expands, allowing the molten pool formed to cover a larger joint area and further fuse fully with the already formed area by the Gaussian beam. Therefore, the internal defects of the joint area gradually decrease, and the density gradually increases. When the remelting width increases to above 2.0 mm, the density of the joint area further improves and tends to stabilize. Among them, the joint area achieves the highest density when the remelting width W is 3.0 mm.

[0106] The above results show that by setting an appropriate width for the laser splicing area R3, the connection quality between laser forming areas with different characteristics can be effectively improved.

[0107] Figure 9 The surface quality analysis results of laser-stitched regions of different sizes provided in Embodiment 1 of this application are shown. (a) to (c) are scanning electron microscope (SEM) images of the laser-stitched regions under remelting widths W of 0.5 mm, 1.0 mm, and 2.0 mm, respectively, and (d) to (f) are the three-dimensional surface contour test results under the above conditions. Figure 9 It is known that when remelting is insufficient, the laser splicing area is prone to discontinuous molten pool transition and local unmelted powder residue in its boundary region due to the action of two laser beams with different energy distributions. As the remelting width W increases, the coverage area of ​​the splicing area by the flat-top beam expands, allowing for more complete melting of the powder in the boundary region, while also improving the molten pool transition state between the Gaussian beam region and the flat-top beam region. Therefore, as the remelting width increases, the amount of unmelted powder on the surface of the laser splicing area gradually decreases, and surface continuity improves. Three-dimensional profile test results show that increasing the remelting width can reduce the height fluctuation of the splicing area, resulting in a decreasing trend in surface roughness. Therefore, it can be concluded that by adjusting the remelting width R3 of the laser splicing area, the surface morphology differences generated during the partitioning process of laser beams with different characteristics can be effectively improved.

[0108] Figure 10 The mechanical property test results of laser splicing regions of different sizes provided in Embodiment 1 of this application are shown, wherein (a) is the stress-strain curve of the sample under different remelting width conditions, and (b) is the tensile strength and engineering strain of the sample under different remelting width conditions. Figure 10 As shown, the samples exhibit good mechanical properties under different remelting widths. When the remelting width is small, insufficient overlap of the molten pool within the laser splicing area may lead to inadequate connection in some local areas, resulting in relatively low tensile strength. With increasing remelting width, the overlap between the flat-top laser molten pool and the Gaussian laser-formed area improves, reducing internal defects in the splicing area and enhancing material continuity, thus gradually increasing the tensile strength. When the remelting width is in the range of 0.5–2.0 mm, the overall mechanical properties of the sample are close to those of a single flat-top laser-formed area. Further increasing the remelting width may lead to increased local heat input due to the expanded range of the flat-top laser, causing microstructure coarsening or an expansion of the heat-affected zone, resulting in a certain downward trend in mechanical properties. Among these, the sample achieves superior overall mechanical properties when the remelting width W is 1.0 mm.

[0109] Based on the above results of density, surface quality, and mechanical property tests, it can be concluded that the multi-characteristic laser partitioning scanning strategy of first Gaussian and then flat-top in this embodiment can effectively achieve synergistic forming between laser beams with different energy distributions. By adjusting the remelting width W of the laser splicing region R3, the degree of overlap of the molten pool between the two regions can be further controlled.

[0110] Under the conditions of this embodiment, when the remelting width W is 0.5~2.0mm, the laser splicing area can achieve a balance of high density, low surface roughness and good mechanical properties; among them, the best comprehensive performance is obtained when W is 1.0mm.

[0111] Example 2 (Process parameter determination stage) The single-characteristic laser process parameters used in this embodiment were determined through pre-conducted process parameter optimization experiments. Specifically, single-region forming experiments were conducted for both the flat-top beam and the Gaussian beam. By analyzing the surface quality, internal density, and mechanical properties of the formed samples under different laser power and scanning speed conditions, optimized process parameters suitable for the partitioned scanning process in this embodiment were determined. The flat-top beam used the same optimized process parameters as in Example 1, and the Gaussian beam used the same optimized process parameters as in Example 1. After obtaining the above optimized process parameters, further partitioned scanning forming experiments based on dual-characteristic lasers were conducted to study the influence of different laser scanning sequences on the region connectivity quality.

[0112] (Partition scanning phase) This embodiment uses, as follows: Figure 5 The scanning strategy shown is a flat-top followed by Gaussian scanning strategy. Specifically, in this embodiment, the layer to be formed is divided into a first laser forming region R1, a second laser forming region R2, and a laser splicing region R3 located between the first laser forming region R1 and the second laser forming region R2. The first laser beam L1 uses a flat-top beam; the second laser beam L2 uses a Gaussian beam; the relative rotation angle between the flat-top beam and the Gaussian beam is set to 0°; and a 67° interlayer rotation scanning method is used between adjacent forming layers.

[0113] In this embodiment, the first laser beam L1 is first controlled to scan the first laser forming region R1 and the laser splicing region R3, so that the first laser forming region R1 is formed. Then, the second laser beam L2 is switched and controlled to scan the second laser forming region R2 and the laser splicing region R3, so that the second laser beam L2 remelts the laser splicing region R3. In this way, the heat input compensation of the transition region between the flat-top beam forming region and the Gaussian beam forming region is performed by the post-scanning Gaussian beam, so that the laser splicing region R3 is remelted, thereby improving the metallurgical bonding state between the two beam forming regions with different characteristics.

[0114] In this embodiment, the forming quality of the splicing area under different remelting ranges is analyzed by changing the remelting width W of the laser splicing area R3. The remelting width W of the laser splicing area R3 is set to: 0.2mm, 0.5mm, 1.0mm, 1.5mm, 2.0mm, 2.5mm, and 3.0mm.

[0115] Figure 11 The image shows the forming density of the laser-jointed region under different remelting widths provided in Embodiment 2 of this application. (a) to (g) correspond to metallographic images of the joined region obtained under remelting widths W of 0.2 mm, 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, and 3.0 mm, respectively, and (h) is the density variation curve corresponding to different remelting widths. Figure 11 It can be seen that when adopting the flat-top followed by Gaussian scanning strategy, the laser splicing region maintains a high level of density under various remelting width conditions, indicating that rescanning the splicing region with a subsequent Gaussian beam can effectively improve the connection state between the regions formed by different beams. Furthermore, as the remelting width W of the laser splicing region R3 increases, the number of pores inside the splicing region generally decreases, and the density gradually increases. Specifically, when the remelting width reaches a certain range, the density of the splicing region tends to stabilize, indicating that appropriately increasing the remelting range can expand the molten pool's effective area and improve the fusion degree between the regions formed by the two beams; however, an excessively large remelting width has limited effect on improving density. These results demonstrate that by adjusting the size of the laser splicing region R3, the metallurgical connection quality between regions during the flat-top followed by Gaussian scanning process can be effectively controlled.

[0116] Figure 12 The following are the surface morphology and three-dimensional contour test results of the laser-jointed area under different remelting widths provided in Embodiment 2 of this application. (a) to (c) show the scanning electron microscopy morphology of the joined area under remelting widths W of 0.5 mm, 1.0 mm, and 2.5 mm, respectively, while (d) to (f) show the laser contour scanning results under the corresponding conditions. Figure 12 It can be seen that after remelting with the Gaussian beam, the surface transition area between the original flat-top beam-shaped area and the Gaussian beam-shaped area is significantly improved, and the unmelted powder and surface undulations caused by different beam characteristics within the laser splicing area are reduced. As the remelting width W increases, the area affected by the subsequent Gaussian beam in the laser splicing area expands, the molten pool coverage area increases, and the height difference between the two areas gradually decreases, improving the continuity of the surface contour. Meanwhile, when the remelting width is small, due to insufficient remelting range, some surface fluctuations still exist in the laser splicing area; however, as the remelting width further increases, the surface quality tends to stabilize.

[0117] This demonstrates that by setting a reasonable remelting width W, the surface differences between laser scanning areas with different characteristics can be effectively reduced, thereby improving the overall forming quality of the component.

[0118] Figure 13 The mechanical property test results of the laser-jointed region under different remelting widths provided in Embodiment 2 of this application are shown, where (a) is the stress-strain curve of the sample under different remelting widths, and (b) is the corresponding tensile strength and engineering strain change. Figure 13 It can be seen that the laser-jointed area formed by the strategy of first flat-topping and then Gaussian scanning maintains a high level of overall mechanical properties. As the remelting width W increases, the tensile strength and engineering strain of the joined area show a trend of first increasing and then decreasing. When the remelting width is in the range of 0.5~2.0 mm, the laser-jointed area exhibits good comprehensive mechanical properties. Among them, when the remelting width W is 1.5 mm, the sample shows superior tensile strength and plasticity.

[0119] Further analysis reveals that a small remelting width cannot adequately eliminate the interface differences between different beam-shaped regions, resulting in localized areas of weakness. Conversely, an excessively large remelting width may increase the range of repeated heat input, causing microstructure coarsening or expansion of the heat-affected zone, thereby leading to a decrease in mechanical properties. Therefore, under the conditions of this embodiment, when employing a flat-top followed by Gaussian scanning strategy, appropriately setting the remelting width W of the laser splicing region R3 can effectively balance the quality of regional connection and the overall mechanical properties of the component.

[0120] As can be seen from the above embodiments, under the same single-characteristic laser optimization process parameters, changing the scanning order of the flat-top beam and the Gaussian beam will affect the forming quality of the laser splicing area. This embodiment adopts a strategy of scanning the flat-top beam first and then the Gaussian beam, and then re-melting the splicing area with the subsequent Gaussian beam, which can also achieve effective connection between laser-formed areas with different characteristics.

[0121] As can be seen from Examples 1 and 2, the dual-characteristic laser region collaborative scanning method proposed in this application can improve the metallurgical bonding quality between different beam forming regions by setting a laser splicing region R3 and using laser beams with different characteristics to repeatedly heat the splicing region, thereby achieving coordinated optimization between forming efficiency, dimensional accuracy and component performance.

[0122] In the above embodiments, the first laser forming region R1 and the second laser forming region R2 can be formed by scanning layer by layer with the same forming layer thickness. In some embodiments, different forming layer thicknesses can be used for staggered scanning of different laser forming regions according to the energy input characteristics of the first laser beam L1 and the second laser beam L2, the size of the molten pool, and the characteristics of the region structure.

[0123] Specifically, in the embodiments of this application, the first laser forming region R1 is formed using a first forming layer thickness, and the second laser forming region R2 is formed using a second forming layer thickness. The first forming layer thickness and the second forming layer thickness are different and satisfy a preset multiple relationship.

[0124] By using different layer thicknesses to form different regions, laser beams with different energy distribution characteristics can each leverage their advantages. For example, a laser beam with a larger melt pool width and higher spreading capability can be used to form thicker layers in larger areas to improve forming efficiency; while a laser beam with higher energy density and a smaller effective range can be used to form thinner layers in finer areas to ensure local structural accuracy.

[0125] In some embodiments, the first laser forming region R1 may have a larger first forming layer thickness, and the second laser forming region R2 may have a smaller second forming layer thickness; alternatively, the two regions may be configured in reverse according to their structural characteristics, i.e., the first laser forming region R1 may have a smaller layer thickness, and the second laser forming region R2 may have a larger layer thickness. This application does not limit this.

[0126] The ratio between the thickness of the first forming layer and the thickness of the second forming layer can be set according to the penetration capability of the laser beam, material properties, and structural requirements of the component. For example, the thickness of the first forming layer can be two times, three times, or other preset multiples of the thickness of the second forming layer, so that different areas can achieve the same cumulative forming height after multiple scanning cycles.

[0127] Figure 14 This is a schematic diagram illustrating the two-layer Gaussian composite and double-thickness flat-top splicing process provided in an embodiment of this application. For example, as shown... Figure 14 As shown, when the first laser forming area R1 is formed using double-thickness flat-top laser forming and the second laser forming area R2 is formed using single-thickness Gaussian laser forming, after the second laser forming area R2 completes two thin-layer scans, the first laser forming area R1 completes one thick-layer scan, ensuring that the two areas have the same cumulative height after the same forming cycle. This staggered scanning method reduces the number of scans required in the layer-by-layer scanning process for large areas, improving overall manufacturing efficiency while retaining dimensional control capabilities for fine areas.

[0128] In some embodiments, the method 100 of this application further includes: within a preset forming cycle, controlling the first laser forming region R1 and the second laser forming region R2 to perform multi-layer collaborative forming according to the multiple relationship between the first forming layer thickness and the second forming layer thickness, so that the first laser forming region R1 and the second laser forming region R2 have the same cumulative forming height after the preset forming cycle ends. Specifically, during the staggered scanning process, the second laser beam L2 performs layered scanning of the second laser forming region R2 according to the second forming layer thickness. After each forming of the second forming layer thickness is completed, the first laser beam L1 is controlled to complete the scanning of the first laser forming region R1 according to the corresponding thickness according to the relationship between the first forming layer thickness and the second forming layer thickness.

[0129] In the above process, although different regions are formed using different layer thicknesses, the scanning cycle is matched to ensure that the first laser forming region R1 and the second laser forming region R2 grow synchronously in the height direction, thereby avoiding the problem of inconsistent regional heights due to differences in layer thickness.

[0130] Furthermore, during the synergistic growth process across different regions, it is also necessary to ensure sufficient molten pool overlap within the laser splicing area R3. Specifically, the molten pool formed by the first laser beam L1 can be controlled to overlap with the already formed solid area, enabling the new material to form a metallurgical bond with the underlying solid area. Simultaneously, the molten pools formed by the first laser beam L1 and the second laser beam L2 can be controlled to overlap along both the horizontal and vertical directions within the laser splicing area R3. Through this molten pool overlap method, a continuous molten connection area is formed between the first laser forming area R1 and the second laser forming area R2, reducing incomplete fusion defects caused by differences in layer thickness or laser characteristics, and improving the compactness of the connection points.

[0131] In some embodiments, multi-layer co-forming includes: controlling a second laser beam L2 to perform layered scanning of the second laser-forming region R2 according to the second forming layer thickness; and controlling the first laser beam L1 and the second laser beam L2 to alternately scan the first laser-forming region R1, the second laser-forming region R2, and the laser splicing region R3 according to the multiple relationship between the first forming layer thickness and the second forming layer thickness. Different staggered scanning strategies can be formed according to the forming efficiency and dimensional accuracy requirements of different regions.

[0132] Figure 15 This is a schematic diagram of a first splicing scheme for a two-layer Gaussian beam and a double-thickness flat top provided in an embodiment of this application. As shown in Figure 15, in this embodiment, the second laser forming region R2 is scanned using a Gaussian beam L2, and the first laser forming region R1 is scanned using a flat top beam L1. The specific steps are as follows: First, a powder layer of thickness t is deposited on the forming substrate. A Gaussian beam L2 is controlled to scan the second laser forming region R2, completing the first layer forming of the second laser forming region R2. Then, another powder layer of thickness t is deposited, causing the second laser forming region R2 to accumulate a forming height twice the thickness of the first layer. Next, a flat-top beam L1 is controlled to scan the first laser forming region R1, causing the first laser forming region R1 to complete the melting forming of the corresponding double-thickness powder region in one pass. During the scanning process of the flat-top beam L1, the molten pool formed by the flat-top beam extends to the laser splicing region R3, overlapping or remelting with the edge of the Gaussian beam forming region already formed in the second laser forming region R2. After completing the above steps, the cumulative forming height of both the first laser forming region R1 and the second laser forming region R2 reaches 2t, thus forming a complete double-layer forming cycle.

[0133] In this scheme, due to the large effective range and wide molten pool size of the flat-top beam, the laser splicing area R3 is mainly formed by the flat-top optical molten pool.

[0134] In some embodiments, the melting depth of the flat-top beam L1 can be greater than twice the layer thickness, and further penetrate into the underlying solid region, so that the flat-top beam melt pool can simultaneously fuse with the first and second Gaussian beam forming regions, thereby reducing the risk of buried unfused defects forming inside the splicing region.

[0135] This solution is suitable for laser splicing areas R3 located in the internal area of ​​a component, the load-bearing area, or in locations where high overall connection performance is required.

[0136] Figure 16 This is a schematic diagram illustrating a second splicing scheme for a two-layer Gaussian roof and a double-thickness flat roof, as provided in an embodiment of this application. (See diagram below.) Figure 16 As shown, in this embodiment, the first laser forming region R1 is formed with a flat-top beam L1 for double-layer thickness, and the second laser forming region R2 is formed with a Gaussian beam L2 for two single-layer thickness scans. The specific steps are as follows: First, after the first layer of powder is laid, the Gaussian beam L2 is controlled to scan the second laser forming region R2, completing the first layer forming of the second laser forming region R2. Then, another layer of powder with a thickness of t is laid, resulting in a cumulative powder layer thickness of double that of the first laser forming region R1. Next, the flat-top beam L1 is controlled to scan the first laser forming region R1, completing the double-layer forming of R1 and causing the flat-top laser fused pool to overlap with the edge of the first layer forming region of the Gaussian beam within the laser splicing region R3. Finally, the Gaussian beam L2 is controlled to scan the second laser forming region R2 again, completing the second layer forming of R2, while simultaneously performing local remelting or fine trimming on the upper part of the laser splicing region R3. After completing these steps, the cumulative forming height of both the first laser forming region R1 and the second laser forming region R2 reaches 2t.

[0137] In this scheme, by using a Gaussian beam L2 to scan the upper part of the laser splicing area R3 again, the dimensional consistency and surface quality of the upper surface of the splicing area can be further improved. Therefore, this scheme is suitable for laser splicing areas R3 that are close to the outer contour of components, thin-walled structures, microporous structures, narrow groove structures, or other locations with high dimensional accuracy requirements.

[0138] As can be seen from the above embodiments, this application is not limited to using the same forming layer thickness for scanning the first laser forming region R1 and the second laser forming region R2. In the actual forming process, different forming layer thicknesses can be used for coordinated scanning of different regions based on the energy distribution characteristics of different laser beams, the size of the molten pool, the forming efficiency requirements, and the local structural characteristics of the component. By matching the scanning cycles of different regions, each region can maintain synchronous growth in the height direction. By setting a reasonable laser splicing region R3, sufficient overlap can be achieved between molten pools formed under different layer thicknesses. Using a laser beam with greater melting depth or higher precision control capability to remelt or trim the spliced ​​region can effectively improve the connection state between different regions and reduce incomplete fusion defects caused by differences in layer thickness and laser energy distribution.

[0139] In the above embodiments, by using different laser beams to scan different forming areas in sections, and by reasonably setting the scanning sequence, scanning angle, and interlayer rotation method, the coordinated optimization of forming efficiency, dimensional accuracy, and area connection quality in different areas can be achieved. It should be noted that the scanning sequence in this application is not limited to the Gaussian-then-flat-top scanning or the flat-top-then-Gaussian scanning methods described in the above embodiments.

[0140] For example, in some embodiments, the scanning order of the first laser beam L1 and the second laser beam L2 can be adjusted based on the structural characteristics of the component, the regional thermal accumulation state, and / or the energy input characteristics of different laser beams. For example, a layer-by-layer alternating scanning method, a local area alternating scanning method, a checkerboard alternating scanning method, or a strip alternating scanning method can be used. Alternatively, the scanning order of different regions can be adaptively selected based on the temperature field, thermal stress, or thermal accumulation monitoring results during the forming process to further reduce the thermal accumulation effect.

[0141] In the above embodiments, the relative scanning angle between the first laser beam L1 and the second laser beam L2, and the interlayer rotation angle between adjacent forming layers, can be adjusted according to the component size, structural features, and / or performance requirements, and are not limited to the angles used in the embodiments. In some embodiments, the relative scanning angle between the first laser beam L1 and the second laser beam L2 can be set to 0°, 45°, 67°, 90°, or other preset angles; the interlayer rotation angle between adjacent forming layers can be set to 45°, 60°, 67°, 90°, random angles, or optimized and determined according to the main force direction, heat conduction direction, and / or defect-sensitive areas of the component.

[0142] Furthermore, the first and second laser beams in this application are not limited to specific beam types. As long as they can form two energy beams with different energy distribution characteristics, different molten pool behaviors, or different forming capabilities, they can be applied to the technical solutions of this application. For example, energy beams with different spot morphologies, different energy distribution modes, or different effective ranges can be used for regionalized collaborative forming according to actual needs.

[0143] Figure 17 This is a schematic diagram of additive manufacturing equipment provided in an embodiment of this application. Figure 17 As shown, this application embodiment also provides an additive manufacturing apparatus 200, which can be used to perform the multi-characteristic laser partition scanning method for additive manufacturing in the above embodiments.

[0144] Reference Figure 17 The additive manufacturing equipment 200 includes a forming cavity 201, a laser scanning system 202, and a controller 203. The forming cavity 201 accommodates the material to be formed and provides forming space for the layer-by-layer forming of the component to be formed. A substrate and a powder supply mechanism for laying the material to be formed are disposed within the forming cavity 201 to complete the layer-by-layer manufacturing of the component to be formed according to preset forming parameters. The laser scanning system 202 outputs a first laser beam L1 and a second laser beam L2 with different energy distribution characteristics, and scans the area to be formed according to control commands output by the controller 203. In this embodiment, the laser scanning system 202 includes optical components such as a laser, a beam shaper, and a galvanometer. The beam shaper adjusts the energy distribution of the laser beam output by the laser to form laser beams with different energy distribution characteristics. For example, the beam shaper can adjust the laser beam to have a concentrated energy distribution at the center, or to have a relatively uniform energy distribution, thereby forming the first laser beam L1 and the second laser beam L2, respectively.

[0145] It should be noted that the above-described method of adjusting the energy distribution characteristics of the laser beam using a beam shaper is only one example. In practical applications, the first laser beam L1 and the second laser beam L2 can also be output from different lasers, or laser beams with different energy distribution characteristics can be formed through other optical structures. This application does not impose any specific limitations on this.

[0146] The controller 203 is connected to the laser scanning system 202 and is used to control the laser scanning system 202 to perform scanning operations. The controller 203 may include a processor and a memory. The memory stores a computer program. When the processor executes the computer program, it causes the additive manufacturing equipment 200 to perform the multi-characteristic laser partition scanning method for additive manufacturing as described in any of the above embodiments.

[0147] Specifically, the controller 203 can divide the layer to be formed into regions based on the three-dimensional model of the component to be formed and the preset forming parameters, determine the first laser forming region, the second laser forming region, and the laser splicing region located between the two, and control the laser scanning system 202 to output the first laser beam L1 and the second laser beam L2 to scan the corresponding regions respectively. At the same time, the controller controls the first laser beam L1 and the second laser beam L2 to perform overlapping scanning of the laser splicing region, so that a continuous metallurgical connection is formed between the first laser forming region and the second laser forming region.

[0148] The additive manufacturing equipment 200 provided in this application embodiment can be configured with laser beams of different energy distribution characteristics according to the forming requirements of different regions, and the continuous connection between different laser forming regions can be realized by using the laser splicing area, thereby improving the regional adaptability and overall forming quality in the additive manufacturing process.

[0149] Figure 18 This is a schematic diagram of the module connections of the multi-feature laser partition scanning device provided in an embodiment of this application. (Refer to...) Figure 18 The multi-feature laser partition scanning device 300 provided in this application may include: The model processing module 301 is used to acquire a three-dimensional model of the component to be formed, and to slice the three-dimensional model according to preset forming parameters to obtain multiple layers to be formed.

[0150] The region division module 302 is used to divide the layer to be formed into regions according to the geometric features, size features and / or accuracy requirements of the corresponding region of the layer to be formed, so as to obtain a first laser forming region, a second laser forming region and a laser splicing region located between the first laser forming region and the second laser forming region.

[0151] The path generation module 303 is used to determine a first laser beam and a second laser beam for scanning the first laser forming region and the second laser forming region respectively, based on the forming requirements of the first laser forming region and the second laser forming region, and to generate corresponding scanning paths, wherein the first laser beam and the second laser beam have different energy distribution characteristics.

[0152] The laser control module 304 is used to control the first laser beam to scan the first laser forming area, control the second laser beam to scan the second laser forming area, and control the first laser beam and the second laser beam to perform remelting scan on the laser splicing area so that a continuous metallurgical connection is formed between the first laser forming area and the second laser forming area.

[0153] It should be understood that the device embodiments and method embodiments can correspond to each other, and similar descriptions can be referred to the method embodiments. To avoid repetition, further details are omitted here. Specifically, the device can correspond to the corresponding subject in executing the method of the embodiments of this application, and each unit in the device is for implementing the corresponding process in the method. For the sake of brevity, further details are omitted here.

[0154] It should also be understood that the various units in the apparatus involved in the embodiments of this application are based on logical functional division. In practical applications, the function of one unit can also be implemented by multiple units, or the function of multiple units can be implemented by one unit. Furthermore, these functions can also be implemented with the assistance of one or more other units. For example, some or all of the units in the apparatus may be merged into one or more additional units. As another example, some units(s) in the apparatus can be further divided into multiple functionally smaller units to achieve the same operation without affecting the technical effects of the embodiments of this application. Furthermore, the apparatus may also include other units, and in practical applications, these functions can also be implemented with the assistance of other units, and can be implemented collaboratively by multiple units.

[0155] It should also be understood that the terms "module" or "unit" used in the embodiments of this application refer to a computer program or part of a computer program that has a predetermined function and works with other related parts to achieve a predetermined goal, and can be implemented wholly or partially using software, hardware (such as processing circuitry or memory), or a combination thereof. Similarly, a processor (or multiple processors or memory) can be used to implement one or more modules or units. Furthermore, each module or unit can be part of an overall module or unit that includes the functionality of that module or unit.

[0156] For example, the apparatus and methods of the embodiments of this application can be constructed by running a computer program (including program code) capable of executing the steps involved in the corresponding methods on a general-purpose computing device including processing elements and storage elements such as a central processing unit (CPU), random access memory (RAM), and read-only memory (ROM). The computer program can be recorded on, for example, a computer-readable storage medium and loaded into an electronic device through the computer-readable storage medium, and the computer program is used to implement the corresponding methods of the embodiments of this application. In other words, the units mentioned above can be implemented in hardware, in software instructions, or in a combination of hardware and software. Specifically, the steps of the method embodiments in the embodiments of this application can be completed by integrated logic circuits in the hardware of a processor and / or by software instructions. The steps of the methods disclosed in the embodiments of this application can be directly embodied as being executed by a hardware decoding processor, or by a combination of hardware and software in a decoding processor. Optionally, the software can reside in mature storage media in the art such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, and registers. The software in the memory can be run by the processor to perform the steps described in the method embodiments above.

[0157] Other embodiments of this application will readily conceive of by those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and embodiments are to be considered exemplary only, and this application is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope.

Claims

1. A multi-characteristic laser partition scanning method for additive manufacturing, characterized in that, include: A three-dimensional model of the component to be formed is obtained, and the three-dimensional model is sliced ​​according to preset forming parameters to obtain multiple layers to be formed. Based on the geometric features, dimensional features and / or precision requirements of the corresponding region of the layer to be formed, the layer to be formed is divided into regions to obtain a first laser forming region, a second laser forming region and a laser splicing region located between the first laser forming region and the second laser forming region. Based on the forming requirements of the first laser forming region and the second laser forming region, a first laser beam and a second laser beam are determined for scanning the first laser forming region and the second laser forming region, respectively, and a scanning path corresponding to the first laser forming region and the second laser forming region is generated, wherein the first laser beam and the second laser beam have different energy distribution characteristics. The first laser beam is controlled to scan the first laser forming area, the second laser beam is controlled to scan the second laser forming area, and the first and second laser beams are controlled to perform remelting scans on the laser splicing area so that a continuous metallurgical connection is formed between the first laser forming area and the second laser forming area.

2. The method according to claim 1, characterized in that, The first laser beam is a flat-top beam, and the second laser beam is a Gaussian beam.

3. The method according to claim 2, characterized in that, The first laser-formed area is a solid-filled area; The second laser forming region includes at least one of a thin-walled region, a complex contour region, an inner cavity region, a fine structure region, and / or a region requiring high precision.

4. The method according to claim 1, characterized in that, The laser splicing area is determined based on the boundary position between the first laser forming area and the second laser forming area, and a transition area of ​​a preset width is set along the boundary position.

5. The method according to claim 4, characterized in that, The control of the first and second laser beams to perform remelting scans on the laser splicing area includes: The degree of remelting within the laser splicing area is adjusted by adjusting the overlap rate of the scanning paths of the first and second laser beams. The overlap rate of the scanning path is determined based on at least one of the spot size of the first laser beam and the second laser beam, the scanning speed, the laser power, and the thermophysical parameters of the material to be formed.

6. The method according to claim 1, characterized in that, The step of controlling the first laser beam to scan the first laser forming area, controlling the second laser beam to scan the second laser forming area, and controlling the first and second laser beams to perform remelting scans on the laser splicing area includes: The first and second laser beams are controlled to scan according to a preset scanning sequence, wherein... The preset scanning order includes: First, control the first laser beam to scan the first laser forming area and the laser splicing area, and then control the second laser beam to scan the second laser forming area and the laser splicing area; or, First, control the second laser beam to scan the second laser forming area and the laser splicing area, and then control the first laser beam to scan the first laser forming area and the laser splicing area.

7. The method according to claim 1, characterized in that, The first laser forming area is formed using a first forming layer thickness, and the second laser forming area is formed using a second forming layer thickness different from the first forming layer thickness. The thickness of the first forming layer and the thickness of the second forming layer satisfy a preset multiple relationship.

8. The method according to claim 7, characterized in that, The method further includes: Within a preset forming cycle, the first laser forming region and the second laser forming region are controlled to perform multi-layer collaborative forming according to the first forming layer thickness and the second forming layer thickness, so that the first laser forming region and the second laser forming region have the same cumulative forming height after the preset forming cycle ends. Control the molten pool formed by the first laser beam to overlap with the already formed solid region; Simultaneously, the molten pool formed by the first laser beam and the molten pool formed by the second laser beam are controlled to overlap in the horizontal and vertical directions within the laser splicing area, so as to form a continuous metallurgical connection between the first laser forming area and the second laser forming area.

9. The method according to claim 8, characterized in that, The multi-layer synergistic forming includes: The second laser beam is controlled to perform layered scanning of the second laser forming area according to the second forming layer thickness, and the first laser beam and the second laser beam are controlled to alternately scan the first laser forming area, the second laser forming area and the laser splicing area according to the multiple relationship between the first forming layer thickness and the second forming layer thickness.

10. A multi-characteristic laser partition scanning device for additive manufacturing, characterized in that, include: The model processing module is used to acquire a three-dimensional model of the component to be formed, and to slice the three-dimensional model according to preset forming parameters to obtain multiple layers to be formed. The region division module is used to divide the layer to be formed into regions according to the geometric features, size features and / or accuracy requirements of the corresponding region of the layer to be formed, so as to obtain a first laser forming region, a second laser forming region and a laser splicing region located between the first laser forming region and the second laser forming region. The path generation module is used to determine the first laser beam and the second laser beam for scanning the first laser forming region and the second laser forming region respectively, based on the forming requirements of the first laser forming region and the second laser forming region, and generate the corresponding scanning path, wherein the first laser beam and the second laser beam have different energy distribution characteristics. The laser control module is used to control the first laser beam to scan the first laser forming area, control the second laser beam to scan the second laser forming area, and control the first laser beam and the second laser beam to perform remelting scan on the laser splicing area so as to form a continuous metallurgical connection between the first laser forming area and the second laser forming area.

11. An additive manufacturing apparatus, characterized in that, include: A forming cavity is used to hold the material to be formed. A laser scanning system for outputting a first laser beam and a second laser beam with different energy distribution characteristics; A controller, connected to the laser scanning system, is configured to perform the method as described in any one of claims 1-9.

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