Tissue property regulation and control method and device for additive manufacturing alloy component

Abstract

According to the structure performance regulation and control method and device for the additive manufacturing alloy component, according to the performance requirements of the to-be-manufactured alloy component at different positions, the performance areas of the fusion layer used for forming the alloy component are divided, and the target grain characteristics needed by all the performance areas are determined; dividing each performance region into a grid shape formed by a plurality of sub-regions according to the characteristics of the target crystal grains, and setting each performance region to have different sub-region sizes, and according to a preset scanning path, controlling a high-energy beam to sequentially fill and scan the corresponding positions of the sub-regions on the powder layer one by one so as to form a fusion layer with different crystal grain characteristics in the performance regions. Therefore, grain characteristics matched with required performance can be achieved in different areas of the alloy component, and target grain characteristics such as a polycrystalline structure, a polycrystalline layered structure and an oriented columnar crystal can be formed only by adjusting the sizes of the sub-areas under the condition that scanning parameters are not changed.

Description

Technical Field

[0001] The present disclosure relates to the field of additive manufacturing, and more particularly to a multi-model driven powder bed additive manufacturing method and apparatus. Background Art

[0002] Powder bed-based additive manufacturing, such as LPBF (Laser Powder Bed Fusion), uses a laser beam to melt and solidify powder materials layer by layer to achieve high-precision and complex geometric parts manufacturing. This technology has unique advantages in manufacturing alloy components, such as reducing material waste, shortening production cycles, and achieving lightweight design.

[0003] In the additive manufacturing process, the grain characteristics of the material have an important influence on the mechanical properties of the final product. For example, the size and morphology of the grains will affect the material's strength, ductility, fatigue resistance, and oxidation resistance. Therefore, different components have different requirements for grain characteristics according to their use environment and mechanical requirements.

[0004] For example, nickel-based superalloys are often used in key components in aero engines and turbines, such as turbine disks and turbine blades, due to their excellent high-temperature performance. These components are subjected to complex loads during service, so the mechanical properties of the materials are extremely high. Turbine disks need to withstand multiaxial stresses, requiring equiaxed grain structures to ensure isotropic performance; while turbine blades are mainly subjected to uniaxial stresses, often requiring oriented grains such as single crystals or columnar crystals to meet the high-temperature strength requirements in a specific direction. At present, there have been public reports on the grain control of LPBF manufacturing nickel-based superalloys at home and abroad. The method of adjusting process parameters is adopted to produce a molten pool with a high depth / width ratio at a higher energy density by adjusting the laser power, scanning speed, and scanning spacing to promote an equiaxed grain structure; the heat treatment method is adopted to form an isotropic grain structure in the alloy through recrystallization; the interlayer selective scanning strategy is adopted to reduce the crystal texture in nickel-based superalloys; the method of alloy composition design is adopted to add rare earth elements to the alloy to obtain a grain structure with a high equiaxed crystal ratio.

[0005] However, most of the existing technologies rely on complex process parameter adjustments or post-processing processes to achieve the regulation of grain characteristics. These methods usually involve precise regulation of multiple variables, such as laser power, scanning speed, scanning spacing, etc., to form a specific molten pool morphology and cooling rate, thereby affecting the growth and arrangement of grains. In addition, additional heat treatment may be required after manufacturing to recrystallize or optimize the microstructure of the material. These operations are often cumbersome, increasing the complexity of the process, and the effect may also be limited by the mutual influence of various process parameters. It is difficult to achieve uniform and precise grain control in different areas, resulting in inconsistent performance of the final product or difficulty in meeting the expected standards. Summary of the invention

[0006] The present disclosure proposes a method and device for controlling the microstructure and properties of alloy components in additive manufacturing, which can achieve grain characteristics matching the required performance in different regions of the alloy component. The formation of different grain characteristics can be achieved by adjusting the sub-region size, especially without changing the scanning parameters, only by adjusting the sub-region size.

[0007] A first aspect of the present disclosure provides a method for controlling the microstructure and properties of alloy components in additive manufacturing, wherein the additive manufacturing utilizes a high-energy beam to selectively melt powder layers applied layer by layer to manufacture the alloy components, and the method comprises: dividing one or more fusion layers used to form the alloy components into performance regions according to the performance requirements of the alloy components at different positions to be manufactured, and determining the target grain characteristics required for each performance region; dividing each performance region into a grid shape consisting of a plurality of sub-regions according to the target grain characteristics and setting each performance region to have a different sub-region size; and controlling the high-energy beam to sequentially fill and scan the corresponding positions of each sub-region on the powder layer according to a preset scanning path to form the one or more fusion layers having different grain characteristics in each performance region.

[0008] According to a preferred implementation of the first aspect, the filling scan of each sub-region by the high-energy beam is set to have the same scanning parameters.

[0009] According to a preferred embodiment of the first aspect, the scanning parameters include one or more of scanning power, scanning rate, layer thickness, scanning spacing, scanning trajectory and inter-layer rotation degree.

[0010] According to a preferred embodiment of the first aspect, the target grain characteristics include at least two of single crystal structure, polycrystalline structure, polycrystalline layered structure, oriented columnar crystal and equiaxed crystal.

[0011] According to a preferred embodiment of the first aspect, when the target grain characteristics are polycrystalline structure, polycrystalline layered structure and oriented columnar crystal, the sub-region size of the performance region corresponding to the polycrystalline structure is smaller than the sub-region size of the performance region corresponding to the polycrystalline layered structure, and the sub-region size of the performance region corresponding to the polycrystalline layered structure is smaller than the sub-region size of the performance region corresponding to the oriented columnar crystal.

[0012] According to a preferred embodiment of the first aspect, the width of the sub-region of the polycrystalline structure corresponding to the performance region is 200 to 400 μm.

[0013] According to a preferred embodiment of the first aspect, the method further includes: adjusting the size of the sub-region so that the molten pool generated during the scanning process merges along the scanning spacing direction to form a molten pool similar in size and shape to the sub-region to refine the grains and weaken the texture.

[0014] According to a preferred embodiment of the first aspect, the method further comprises: dividing at least one performance region into a plurality of performance gradient regions and setting each performance gradient region to have a gradually changing sub-region size.

[0015] According to a preferred embodiment of the first aspect, the division of the multiple performance gradient regions includes: dividing the at least one performance region in a cross section to achieve a gradient distribution of grain characteristics between the same levels, and / or, superimposing and dividing the at least one performance region layer by layer in a longitudinal direction corresponding to multiple fusion layers to achieve a gradient distribution of grain characteristics between different levels.

[0016] According to a preferred embodiment of the first aspect, when forming the performance region of the oriented columnar crystal, the method further comprises: adjusting the incident angle of the high-energy beam so that the growth direction of the oriented columnar crystal is consistent with the solidification direction of the molten pool.

[0017] A second aspect of the present disclosure provides an alloy component obtained by the method described in any one of the first aspects.

[0018] A third aspect of the present disclosure provides a device for controlling the microstructure and properties of alloy components manufactured by additive manufacturing, wherein the additive manufacturing utilizes a high-energy beam to selectively melt powder layers applied layer by layer to manufacture the alloy components, and the device comprises: a performance region division module, configured to divide one or more fusion layers used to form the alloy component into performance regions according to the performance requirements of the alloy component at different positions to be manufactured; a target grain feature determination module, configured to determine the target grain features required for each performance region according to the performance requirements; a sub-region division module, configured to divide each performance region into a grid shape consisting of a plurality of sub-regions according to the target grain features and to set each performance region to have a different sub-region size; and a scanning control module, configured to control the high-energy beam to sequentially fill and scan the corresponding positions of each sub-region on the powder layer according to a preset scanning path to form the one or more fusion layers with different grain features in each performance region. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate one or more embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure and to enable one of ordinary skill in the relevant art to make and use the present disclosure.

[0020] Figure 1 A schematic diagram of sub-region division of an alloy component according to an embodiment of the present disclosure is shown;

[0021] Figure 2A schematic diagram of different sub-region width scanning strategies according to an embodiment of the present disclosure is shown;

[0022] Figure 3 The cross-sectional grain characteristic morphology of the nickel-based high-temperature alloy sample obtained according to Comparative Example 1 is shown;

[0023] Figure 4 The morphology of the molten pool of the nickel-based high-temperature alloy sample obtained according to Example 1 is shown;

[0024] Figure 5 The morphology diagram of the cross-section grain characteristics of the nickel-based high-temperature alloy sample obtained according to Example 1 is shown;

[0025] Figure 6 The morphology diagram of the cross-section grain characteristics of the nickel-based high-temperature alloy sample obtained according to Example 1.1 is shown;

[0026] Figure 7 The morphology diagrams of the cross-sectional grain characteristics of the nickel-based high-temperature alloy samples obtained according to Comparative Example 2 (above) and Example 2 (below) are shown;

[0027] Figure 8 The morphology diagrams of the cross-sectional grain characteristics of the nickel-based high-temperature alloy samples obtained according to Comparative Example 3 (above) and Example 3 (below) are shown;

[0028] Fig. 9 The tensile properties curves of the nickel-based high-temperature alloy samples obtained according to Comparative Example 2 and Example 2 at room temperature are shown;

[0029] Fig.10 A schematic diagram of a structure and performance control device for additively manufacturing alloy components according to the present disclosure is shown;

[0030] Fig.11 A schematic diagram of a framework of an electronic device according to the present disclosure is shown. DETAILED DESCRIPTION

[0031] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments may be implemented in a variety of forms and should not be construed as being limited to the examples set forth herein; rather, the description of these embodiments is intended to make the present disclosure more comprehensive and complete and to fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, many specific details are provided to provide a deeper understanding of the embodiments of the present disclosure.

[0032] The term "additive manufacturing" as used in this disclosure refers to 3D printing technology that manufactures three-dimensional objects by adding powder materials layer by layer and melting the powder materials using a high-energy beam (such as a laser or electron beam). This technology uses a digital model generated by computer-aided design (CAD) software to precisely control the melting and solidification process of powder materials, thereby building complex three-dimensional objects layer by layer. In practical applications, these three-dimensional objects can be functional parts, structural parts, tools, or any other form of physical objects, and their design and manufacture can be customized according to the specific needs of their final use.

[0033] The "alloy component" referred to in the present disclosure is a metal or metal matrix composite component manufactured by additive manufacturing technology for various engineering and industrial applications. The alloy component can be made of a single type of alloy powder or a mixture of multiple alloy powders to form a component with specific mechanical properties and chemical properties.

[0034] The "fused layer" referred to in the present disclosure is a cross-sectional layer of metal or alloy formed by melting and solidifying powder material layer by layer. Each fused layer represents a cross section of the component and is the basis of the final geometry and internal structure of the component. As the high-energy beam scans and melts the powder material layer by layer, these fused layers gradually accumulate and eventually form a complete three-dimensional object.

[0035] The present disclosure provides a method for regulating the microstructure and properties of an alloy component during the additive manufacturing process, and the method is also an additive manufacturing method for an alloy component. The method mainly includes two stages: a process configuration stage and a forming construction stage.

[0036] In the process configuration stage, firstly, the one or more fusion layers used to form the alloy component are divided into performance areas according to the performance requirements of the alloy component to be manufactured at different positions. Then, for each performance area, the target grain characteristics required are determined. Based on these target grain characteristics, each performance area is further divided into a grid consisting of multiple sub-areas, and different sub-area sizes are set for each performance area. In the forming construction stage, the high-energy beam is controlled according to the preset scanning path to fill and scan the corresponding positions of each sub-area on the powder layer one by one to form the one or more fusion layers with different grain characteristics in each performance area, and the powder is spread and scanned layer by layer to obtain other fusion layers, and finally the required alloy component is formed.

[0037] In order to make the final manufactured alloy components meet their functional requirements in practical applications, it is first necessary to analyze the performance required by the components at different positions, including a comprehensive understanding of the working environment of the components, the mechanical loads, thermal loads, corrosion resistance and other specific requirements. For example, for turbine disks used in aircraft engines, which operate in high temperature and high pressure environments, the outer edge needs to have high heat resistance and creep resistance, while the inner edge requires higher toughness and fatigue resistance. Based on the performance requirements of these different positions, the performance areas of the components at different positions can be reasonably divided, and the target grain characteristics required for each performance area can be further determined.

[0038] Figure 1 A schematic diagram of the sub-region division of an alloy component according to an embodiment of the present disclosure is shown, which is crucial for microstructure control in the additive manufacturing process. After determining the performance requirements of the alloy component 11 at different positions, the three-dimensional model thereof is first sliced ​​to obtain the layered fusion layers 11A-11E. It should be noted that these fusion layers are only examples and do not reflect all the layers involved in the actual manufacturing process.

[0039] After obtaining these fusion layers, all or part of the layers covered by the fusion layers 11A-11E are divided into performance regions according to the performance demand distribution of the alloy component 11. Taking the fusion layer 11A as an example, the division result of the fusion layer 11A is: Figure 1 The first performance region 12A, the second performance region 12B and the third performance region 13B are shown, and it is determined that the first performance region 12A corresponds to the first target grain characteristic, the second performance region 12B corresponds to the second target grain characteristic, and the third performance region 12C corresponds to the third target grain characteristic.

[0040] After determining these performance regions and their corresponding target grain characteristics, each performance region is further divided into a grid structure consisting of multiple sub-regions. For example, each performance region of the fusion layer 11A is divided into multiple sub-regions, that is, the first performance region 12A is divided into sub-regions 12A1-12A n The second performance area 12B is divided into sub-areas 12B1-12B n The third performance area 12C is divided into sub-areas 12C1-12C nAt the same time, different sub-region sizes are set for each performance region, for example, the grid width of the first performance region 12A is set to W1, the grid width of the second performance region 12B is set to W2, and the grid width of the third performance region 12C is set to W3. The sizes of these sub-regions can be set according to the required grain characteristics, so that in the additive manufacturing process, the microstructure control in different performance regions can be achieved through filling scanning of the high-energy beam.

[0041] Figure 2 FIG. 2 shows a schematic diagram of different sub-area width scanning strategies according to an embodiment of the present disclosure. Figure 2 In the example of FIG. 1 , the sub-region width of the first performance region 12A is set to 200 μm, the sub-region width of the second performance region 12B is set to 500 μm, and the sub-region width of the third performance region 12C is set to 1400 μm.

[0042] In the forming and construction phase, the high-energy beam is controlled to scan and fill the corresponding positions of 12A-12C on the powder layer one by one according to the preset scanning path to form a fusion layer of 12A-12C with different grain characteristics. The scanning order of these areas is not fixed and depends on the specific path design. The high-energy beam can scan sub-area 12A first, or 12B or 12C first, as long as all sub-areas can be evenly filled in the end. This scanning order can optimize the forming efficiency and material utilization without affecting the final grain characteristics, ensuring that areas with different grain characteristics are formed in the same layer, thereby meeting the performance requirements of alloy components at different positions.

[0043] In the description of "the high-energy beam is controlled to fill and scan the positions of 12A-12C corresponding to the powder layer one by one according to the preset scanning path", it is necessary to understand that the setting of the preset scanning path is not limited to any specific regular pattern. Although in the traditional laser powder bed fusion (LPBF) process, the scanning path is usually carried out in a certain order, such as a linear arrangement from left to right or from top to bottom, in practical applications, especially in order to optimize the microstructure performance and reduce residual stress, the scanning path can adopt a random scanning order, so that the high-energy beam scans these sub-areas in an irregular order during the process of filling and scanning the positions on the powder layer one by one, thereby reducing heat concentration and improving the quality of the final formed part. In addition, the random scanning order can also break the periodic texture structure that may be formed in the component, making the grain structure of the material more refined and uniform.

[0044] The target grain characteristics of the present disclosure cover a variety of grain structure types to meet the requirements of different performance areas, such as at least two of single crystal structure, polycrystalline structure, polycrystalline layered structure, oriented columnar crystal and equiaxed crystal. By combining the above multiple grain characteristics, the present disclosure can achieve targeted microstructure forming in different performance areas, thereby manufacturing alloy components with complex performance requirements.

[0045] Specifically, the single crystal structure is a structure with almost no grain boundaries inside, with excellent high temperature performance and creep resistance, and is suitable for areas that require high temperature strength and fatigue resistance. The polycrystalline structure is composed of multiple randomly oriented grains, each of which has a regular atomic arrangement inside, but there is a certain dislocation at the grain boundary. The existence of the polycrystalline structure enables the material to absorb energy through the slip of the grain boundary and the deformation within the grain when it is under load. It has a good balance of strength and toughness and is suitable for areas that need to balance between load-bearing capacity and impact resistance. The polycrystalline layered structure is a layered grain arrangement formed on the basis of the polycrystalline structure, which can achieve a gradual change in performance between different layers, thereby providing excellent crack propagation resistance inside the material, and is suitable for key parts that require crack propagation resistance. Directed columnar crystals are columnar crystal structures with excellent creep resistance formed by grains growing in a specific direction. They are usually used in areas that require high creep resistance, such as parts that need to withstand high temperature loads for a long time. Equiaxed crystals are composed of isotropic grains. This grain structure has consistent performance in all directions and is suitable for areas that require uniform mechanical properties.

[0046] The shape of the sub-regions divided by the present disclosure (i.e., the shape of the grid) can be selected according to the performance requirements of the alloy component, including but not limited to squares, rectangles, and other possible polygonal or curved boundary shapes. Preferably, it is a square, because the square sub-region is simpler in scanning path planning and energy distribution control, and can maintain the uniformity of temperature and energy input inside each sub-region, and better achieve uniform grain growth and consistent microstructure. In addition, the size of the sub-region (such as the size of the square sub-region is expressed as the sub-region width) can also be adjusted according to specific performance requirements, such as selecting or adjusting according to the required grain characteristics, heat conduction path, uniformity of energy input, and geometric accuracy of the final component.

[0047] In some embodiments, the filling and scanning process of the high-energy beam adopted in the present disclosure for each sub-region is set to have the same scanning parameters. The scanning parameters include but are not limited to various parameters such as scanning power (e.g., laser power), scanning rate, layer thickness, scanning pitch, scanning trajectory (e.g., serpentine trajectory scanning), and interlayer rotation degree (e.g., 90° interlayer rotation). These parameters remain unchanged throughout the scanning process so that the energy input and heat conduction applied by the high-energy beam to each sub-region are consistent. Adjusting the scanning parameters is a conventional method to achieve different grain characteristics in the fusion layer. The present disclosure provides a new process method, that is, under the same scanning parameters, different grain characteristics can be obtained only by adjusting the size of the sub-region. This simplifies the manufacturing process and improves the manufacturing efficiency, providing a more efficient implementation method for manufacturing complex alloy components with various grain characteristics.

[0048] In some embodiments, when the target grain characteristics are polycrystalline structure, polycrystalline layered structure, and directional columnar crystal, the sub-region size of the performance region corresponding to the polycrystalline structure is smaller than the sub-region size of the performance region corresponding to the polycrystalline layered structure, and the sub-region size of the performance region corresponding to the polycrystalline layered structure is smaller than the sub-region size of the performance region corresponding to the directional columnar crystal. For example, when the target grain characteristic of the first performance region 12A is polycrystalline structure, the target grain characteristic of the second performance region 12B is polycrystalline layered structure, and the target grain characteristic of the third performance region 12C is directional columnar crystal, the width of the sub-region 12A1-12A n is set to be smaller than the width of the sub-region 12B1-12B n and the width of the sub-region 12B1-12B n is set to be smaller than the width of the sub-region 12C1-12C n , that is, W1 < W2 < W3. Among them, in order to ensure that polycrystalline structure can be formed, W1 is set to be 200 to 400 μm.

[0049] The implementation and effect verification of the present invention will be further described below based on detailed embodiments.

[0050] To verify the influence of sub-region division on the microstructure and properties of nickel-based superalloys, the following comparative examples and examples both select nickel-based superalloy specimens as the implementation objects for additive manufacturing. By weight percentage, the powder purity ≥ 99.9%. The composition table of the powder raw materials used is as follows (excluding inevitable impurities):

[0051]

[0052] Comparative Example 1

[0053] The obtained powder raw material was placed in a laser powder bed fusion (LPBF) device, and the laser power was set to 250 W, the scanning rate was 600 mm / s, the scanning spacing was 100 μm, the layer thickness was 40 μm, and the serpentine trajectory was used for scanning, and the interlayer rotation was 90°. Under this process condition, the component model was not divided into sub-regions, and additive manufacturing was directly performed to finally obtain a nickel-based high-temperature alloy sample.

[0054] Example 1

[0055] The obtained powder raw material was placed in the LPBF equipment, and the laser power was set to 250 W, the scanning rate was set to 600 mm / s, the scanning spacing was set to 100 μm, the layer thickness was set to 40 μm, and the serpentine trajectory was used for scanning, and the interlayer rotation was 90°. At the same time, sub-regions (square grids) of different widths were divided in the three regions of the sample model, and the sub-region widths were set to 200 μm, 500 μm and 1400 μm respectively. After the settings were completed, the printing was started to obtain the nickel-based high-temperature alloy sample.

[0056] Example 1.1

[0057] Example 1.1 uses the same process parameters as Example 1, except that Example 1.1 simultaneously divides multiple areas of the sample model into sub-areas (square grids) of different widths, and the sub-area widths are set to 200 μm, 500 μm, 600 μm, 1000 μm and 1400 μm, respectively.

[0058] Comparative Example 2

[0059] The obtained powder raw material was placed in the LPBF equipment, and the laser power was set to 160 W, the scanning rate was 1310 mm / s, the scanning spacing was 76 μm, the layer thickness was 40 μm, the serpentine trajectory was used for scanning, and the layer rotation was 90°. Under this process condition, the component model was not divided into sub-areas, and additive manufacturing was directly performed to finally obtain a nickel-based high-temperature alloy sample.

[0060] Example 2

[0061] The obtained powder raw material was placed in the LPBF equipment, and the laser power was set to 160 W, the scanning rate was 1310 mm / s, the scanning spacing was 76 μm, the layer thickness was 40 μm, the serpentine trajectory was used for scanning, and the interlayer rotation was 90°. The sub-regions (square grids) of different widths were divided in the three regions of the sample model, and the sub-region widths were set to 200 μm, 500 μm and 1400 μm respectively. After the settings were completed, the printing was started to obtain the nickel-based high-temperature alloy sample.

[0062] Comparative Example 3 The obtained powder raw material was placed in the LPBF equipment, and the laser power was set to 255 W, the scanning rate was 960 mm / s, the scanning spacing was 60 μm, the layer thickness was 40 μm, the serpentine trajectory was used for scanning, and the layer rotation was 90°. Under this process condition, the component model was not divided into sub-areas, and additive manufacturing was directly performed to finally obtain a nickel-based high-temperature alloy sample.

[0063] Example 3

[0064] The obtained powder raw material was placed in the LPBF equipment, and the laser power was set to 255 W, the scanning rate was 960 mm / s, the scanning spacing was 60 μm, the layer thickness was 40 μm, the serpentine trajectory was used for scanning, and the interlayer rotation was 90°. The sub-regions (square grids) of different widths were divided in the three regions of the sample model, and the sub-region widths were set to 200 μm, 500 μm and 1400 μm respectively. After the settings were completed, the printing was started to obtain the nickel-based high-temperature alloy sample.

[0065] Figure 3 The characteristic morphology of the cross-section grains of the nickel-based high-temperature alloy sample obtained according to Comparative Example 1 is shown. In this morphology, it can be observed that the growth direction of the grains is relatively consistent. This is mainly because under the conventional scanning strategy, the molten pool always moves along the speed direction of the laser scanning, resulting in the stability of the heat flow direction. Due to the stability of the heat flow direction, the growth of the grains is also relatively consistent, showing a relatively uniform epitaxial growth pattern. The interface between the grains is relatively obvious, and the overall structure appears orderly, but there is also a lack of fine grain generation. This phenomenon shows that the heat flow field under the conventional scanning strategy changes little, and the convection intensity is weak, so it will not significantly induce the diversification of grain morphology.

[0066] Figure 4 The morphology of the molten pool of the nickel-based high-temperature alloy sample obtained according to Example 1 is shown. In this embodiment, a scanning strategy of sub-region division is adopted, and the sub-region width is set to 200 μm. Under this condition, when the laser completes a scan in a sub-region, the molten pool has not yet completely solidified and the adjacent scan begins, resulting in the merging of two adjacent molten pools to form a large molten pool with a width of about 200 μm. Figure 4 The molten pool morphology in the figure shows that the molten pool is always in dynamic change from its formation to final solidification, and the change of heat flow direction is relatively complex. Compared with conventional scanning, the application of sub-area division strategy makes the growth of grains inside the large molten pool no longer share a single preferred growth direction, thereby increasing the diversity of grain structure.

[0067] Figure 5The morphology of the cross-sectional grain characteristics of the nickel-based high-temperature alloy sample obtained according to Example 1 is shown. In this morphology, the influence of the complex thermal flow field caused by the sub-region division strategy on the grain growth direction can be observed. Specifically, Figure 5 The grain growth directions shown in the figure are not consistent, and there are obvious differences in grain orientation at the edge and center of the molten pool. This phenomenon is consistent with the Walton and Chalmers competitive growth selection model. At the edge of the large molten pool, due to the arc shape of the molten pool boundary, the deviation <001> The grains in the direction will grow preferentially, while in the center of the molten pool, the grains can grow along <001> The epitaxial growth proceeds in the same direction, eventually forming a polycrystalline layered structure.

[0068] Figure 6 The morphology of the cross-sectional grain characteristics of the nickel-based high-temperature alloy sample obtained according to Example 1.1 is shown. In this embodiment, the sub-region width is increased to 500 μm, and the width of the molten pool is also increased accordingly. Under this condition, the central heat flow direction of the large molten pool tends to be consistent, and the grains can grow epitaxially along the construction direction, and the crystal orientation is <001> However, at the edge of the large molten pool, due to the arc shape of the molten pool boundary, the growth direction of the grains will deviate, resulting in differences in the grain orientations at the center and the edge, thus forming a polycrystalline layered structure. It is worth noting that as the width of the sub-region further increases to 1400 μm, the characteristics of the molten pool gradually disappear, and the grains begin to show a clear oriented columnar crystal structure, such as Figure 5 shown.

[0069] Figure 7 The morphology of the cross-sectional grain characteristics of the nickel-based high-temperature alloy sample obtained according to Comparative Example 2 (above) and Example 2 (below) is shown. In Comparative Example 2, a conventional scanning strategy is adopted, so the epitaxial growth of the grains is more obvious, and the preferred growth direction of the grains is more consistent. In Example 2, due to the application of the sub-region division strategy, the convection phenomenon inside the molten pool is intensified, resulting in the generation of a large number of fine grains. This phenomenon shows that under a complex thermal flow field, the convection movement in the melt significantly affects the morphology of the grains, thereby enhancing the fine grain characteristics of the material.

[0070] Figure 8 The morphology of the cross-sectional grain features of the nickel-based high-temperature alloy specimens obtained according to Comparative Example 3 (above) and Example 3 (below) is shown. In Comparative Example 3, due to the application of the conventional scanning strategy, the growth of the grains is restricted and the epitaxial growth of the grains is blocked. However, in Example 3, the complex thermal flow field and enhanced melt convection caused by the sub-region division scanning strategy lead to the generation of heterogeneous nucleation and a large number of fine grains, especially near the edge of the molten pool, where the number of fine grains increases significantly. Figure 8The significant influence of different scanning strategies on the characteristic morphology of grains is clearly shown, proving the advantages of the sub-region division strategy in controlling grain growth direction and grain refinement.

[0071] Fig. 9 The tensile properties curves of the nickel-based high-temperature alloy samples obtained according to Comparative Example 2 and Example 2 at room temperature are shown. The yield strength of the sample in Comparative Example 2 is 885 MPa, the tensile strength is 1191 MPa, and the elongation is 35%, which shows that under the conventional scanning strategy, the sample has a higher ductility but a lower yield strength. After adopting the scanning strategy of Example 2, the yield strength of the sample is significantly increased to 993 MPa, the tensile strength is slightly increased to 1193 MPa, and the elongation is significantly reduced to 12%. This change in performance can be attributed to the fine grain structure introduced by the scanning strategy in Example 2, which improves the strength of the material but sacrifices ductility at the same time. Specifically, the fine grain structure usually increases the strength of the material by increasing the number of grain boundaries to hinder dislocation movement, but also reduces the plastic deformation ability of the material, which explains the decrease in elongation. By comparing the performance of the two samples, it can be seen that the scanning strategy of Example 2 effectively optimizes the mechanical properties of the sample, especially improves the yield strength, which is of great significance to improving the bearing capacity of nickel-based high-temperature alloys in practical applications.

[0072] It can be seen that according to the disclosed method for controlling microstructure and properties, by adjusting the width of the sub-region, the microstructure of the nickel-based high-temperature alloy can be effectively controlled without changing other scanning parameters. Specifically, by controlling the width of the sub-region, a variety of different crystal structures can be formed under the same process conditions, which significantly improves the applicability of the high-temperature alloy in different application scenarios.

[0073] In some embodiments of the present disclosure, the method for regulating microstructure and properties further involves adjusting the size of the sub-region so that the molten pool generated during the scanning process merges along the scanning spacing direction to form a molten pool similar in size and shape to the sub-region, so as to refine the grains and weaken the texture.

[0074] Specifically, for example, by controlling the size of the sub-regions, the morphology and behavior of the molten pool during the scanning process can be affected, so that the molten pool merges along the scanning spacing direction. This merging effect is achieved by reasonably designing the size and shape of the sub-regions, so that the molten pool matches the preset sub-regions in size and shape. This merging of molten pools can facilitate the refinement of grains and the weakening of textures. When the molten pools merge during the scanning process, since the size of the molten pools is similar to that of the sub-regions, this matching relationship will promote the uniform cooling and solidification process in the molten pool, thereby generating finer grains. Fine grain structures usually significantly improve the mechanical properties of materials, such as improving the strength and toughness of materials. In addition, the uniform cooling environment formed by the merging of the molten pools also helps to weaken the texture effect of the material and reduce the influence of anisotropy on the mechanical properties, so that the optimization control of the material microstructure can be achieved by adjusting the size of the sub-regions without changing other parameters such as the scanning speed and laser power.

[0075] In some embodiments of the present disclosure, the tissue-property regulation method further optimizes the microstructure and mechanical properties of the material, for example, by dividing the performance region to form a plurality of performance gradient regions, so that the sub-region sizes within the regions have gradually changing characteristics, thereby achieving a gradual grain structure and performance performance in different parts of the material.

[0076] Specifically, the division method of the performance gradient area can be adjusted in two dimensions. First, within the cross section, at least one performance area can be divided to achieve a gradient distribution of grain characteristics between the same levels. In this case, as the size of the sub-area gradually changes, the molten pool morphology and cooling rate in different sub-areas also change accordingly, thereby generating a microstructure with different grain characteristics. This gradient distribution can achieve a gradual change in mechanical properties within the same level and optimize the local performance of the material at different parts. Secondly, in the longitudinal direction, the gradient distribution of grain characteristics between different levels can be achieved by superimposing and dividing multiple fusion layers layer by layer. In this case, the sub-area size of each layer can be gradually changed from bottom to top, thereby forming a gradual microstructure between different fusion layers. This longitudinal gradient distribution can effectively adjust the mechanical properties of the material in the thickness direction, so that it has targeted optimized structural characteristics at different levels, such as showing different strengths and toughness in parts subjected to different stresses.

[0077] By combining these two gradient area division methods, the present disclosure can achieve highly customized grain characteristics and performance of materials, thereby providing an effective technical means for manufacturing complex, multi-performance high-temperature alloy parts. It can not only improve the overall performance of the material, but also optimize its fatigue resistance, creep resistance and high temperature resistance in specific areas.

[0078] In some embodiments of the present disclosure, in order to optimize the formation effect of oriented columnar crystals, the microstructure and performance control method can also adjust the incident angle of the high-energy beam so that the growth direction of the oriented columnar crystals is consistent with the solidification direction of the molten pool.

[0079] Specifically, in the process of melt manufacturing using, for example, laser, the morphology and solidification process of the molten pool have a direct impact on the direction of crystal growth. In order to form oriented columnar crystals, it is generally required that the growth direction of the crystal is consistent with the cooling direction (i.e., solidification direction) of the molten pool. However, in actual processing, due to the limitations of equipment settings or process parameters, the incident angle of the high-energy beam may deviate from the solidification direction of the molten pool, resulting in a shift in the crystal growth direction, affecting the final columnar crystal orientation and uniformity. In order to solve this problem, the present disclosure can control the incident angle of the high-energy beam to match the solidification direction of the molten pool, for example, according to the shape of the molten pool and the expected growth direction of the columnar crystal, adjust the inclination angle of the high-energy beam relative to the workpiece surface to ensure that the heat input of the laser is more evenly distributed in the molten pool, thereby promoting the gradual cooling of the molten pool along a predetermined direction, and guiding the crystal to grow along this direction to form an ideal oriented columnar crystal. This will not only be conducive to the formation of oriented columnar crystals with excellent mechanical properties, but also can reduce the number of grain boundaries and reduce the defect density in the material, thereby improving the strength, ductility and high temperature resistance of the material.

[0080] It should be understood that the various processes and steps described above can be implemented by configuring the functional modules of the tissue performance control device (i.e., the additive manufacturing device). Although the specific content of the method has been described in detail, in order to more clearly understand the core part of the tissue performance control device involved in the present disclosure, the following is combined with Fig.10 A brief introduction to its main components is given. Fig.10 A schematic diagram of the framework of a microstructure and performance control device for additively manufacturing alloy components according to the present disclosure is shown.

[0081] In some embodiments, the tissue performance regulating device 20 involved in the present disclosure includes a performance region division module 21 , a target grain feature determination module 22 , a sub-region division module 23 and a scanning control module 24 .

[0082] The performance region division module 21 is configured to divide one or more fusion layers used to form the alloy component into performance regions according to the performance requirements of the alloy component at different positions to be manufactured.

[0083] The target grain characteristic determination module 22 is configured to determine the target grain characteristics required for each performance region according to the performance requirements.

[0084] The sub-region division module 23 is configured to divide each performance region into a grid shape consisting of a plurality of sub-regions according to the target grain characteristics and to set each performance region to have a different sub-region size.

[0085] The scanning control module 24 is configured to control the high-energy beam to sequentially fill and scan the positions of each sub-region corresponding to the powder layer according to a preset scanning path to form the one or more fused layers with different grain characteristics in each performance region.

[0086] It should be noted that although several modules for constituting the tissue performance control device 20 are mentioned in the above detailed description, such division is not mandatory. In fact, according to the embodiment of the present disclosure, the features and functions of two or more modules described above can be embodied in one module. Conversely, the features and functions of one module described above can be further divided into multiple modules for embodiment.

[0087] Fig.11 A schematic diagram of a framework of an electronic device according to the present disclosure is shown. In some embodiments, the electronic device 30 includes a processor 31 and a memory 32 (wherein the number of the processor 31 and the memory 32 can be one or more). The memory 32 is coupled to the processor 31 and is used to store instructions executed by the processor 31, which, when executed by the processor 31, enables the electronic device 30 to execute any of the tissue performance control methods described in the foregoing.

[0088] Specifically, the processor 31 communicates with the memory 32, and the memory 32 may include a read-only memory and a random access memory, providing instructions and data to the processor 31. In addition, a part of the memory 32 may also include a non-volatile random access memory (NVRAM). In the memory 32, operation instructions, executable modules, data structures or their subsets, or even their extended sets are stored. These operation instructions cover various operations and are used to implement various operations. The organizational performance control method described in the embodiment of the present disclosure can be applied to the processor 31, or implemented by the processor 31. The processor 31 can be any applicable computer processor, such as a central processing unit (CPU), a graphics processing unit (GPU), a programmable logic device (FPGA), etc. In the embodiment of the present disclosure, the processor 31 is responsible for executing each step of the organizational performance control method.

[0089] In some embodiments, the present disclosure further provides a computer-readable storage medium storing a computer program, which, when executed by the processor 31, implements the tissue performance regulation method described in any of the foregoing items. Specifically, a computer-readable storage medium refers to a medium that can be read by a computer system, such as a hard disk, a solid-state hard disk, an optical disk, a flash drive, etc. In some embodiments of the present disclosure, a computer-readable storage medium stores a set of computer programs, which are executed by the processor 31 to implement the various steps and functions described in the tissue performance regulation method. These computer programs may include operating systems, embedded software, applications, etc., for controlling and managing the process of the method. By reading and executing programs stored on a computer-readable storage medium, a computer system can effectively implement the tissue performance regulation method of the present disclosure.

[0090] In some embodiments, the present disclosure further provides a computer program product, which includes computer executable instructions. When the computer executable instructions are executed by a processor, the computer implements the method for regulating tissue performance described in any of the above items. A computer program product is a product that stores computer executable instructions, and its purpose is to implement the various steps and functions described in the method for regulating tissue performance when executed by the processor 31 of a computer system. The computer executable instructions may include an operating system, an application, an embedded software, etc., to control and manage the process of the method. By using this computer program product, a user can execute the method for regulating tissue performance of the present disclosure on a computer system.

[0091] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing what is disclosed herein. The present disclosure is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary technical means in the art that are not disclosed in the present disclosure. The specification and embodiments are to be considered merely as exemplary, and the present disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes may be made without departing from the scope thereof.

Claims

1. A method for controlling the microstructure and properties of an alloy component in additive manufacturing, wherein the alloy component is manufactured by selectively melting powder layers applied layer by layer using a high-energy beam, wherein: The method comprises: According to the performance requirements of the alloy component to be manufactured at different positions, one or more fusion layers used to form the alloy component are divided into performance regions and target grain characteristics required for each performance region are determined; Dividing each performance region into a grid shape consisting of a plurality of sub-regions according to the target grain characteristics and setting each performance region to have a different sub-region size; and According to a preset scanning path, the high-energy beam is controlled to sequentially scan the positions of each sub-region corresponding to the powder layer to fill and scan one by one to form the one or more fused layers with different grain characteristics in each performance region. 2 . The method according to claim 1 , wherein the filling scan of each sub-area by the high-energy beam is set to have the same scanning parameters.

3. The method according to claim 2, wherein the scanning parameters include one or more of scanning power, scanning rate, layer thickness, scanning spacing, scanning trajectory and inter-layer rotation degree. 4 . The method according to claim 1 , wherein the target grain characteristics include at least two of single crystal structure, polycrystalline structure, polycrystalline layered structure, oriented columnar crystal and equiaxed crystal.

5. The method according to claim 4, wherein when the target grain characteristics are polycrystalline structure, polycrystalline layered structure and oriented columnar crystal, the sub-region size of the performance region corresponding to the polycrystalline structure is smaller than the sub-region size of the performance region corresponding to the polycrystalline layered structure, and the sub-region size of the performance region corresponding to the polycrystalline layered structure is smaller than the sub-region size of the performance region corresponding to the oriented columnar crystal. 6 . The method according to claim 4 , wherein the width of the sub-region of the polycrystalline structure corresponding to the performance region is 200 to 400 μm.

7. The method according to claim 1, wherein the method further comprises: The size of the sub-region is adjusted so that the molten pools generated during the scanning process are merged along the scanning pitch direction to form a molten pool similar in size and shape to the sub-region, so as to refine the grains and weaken the texture.

8. The method according to claim 1, wherein the method further comprises: At least one performance region is divided into a plurality of performance gradient regions and each performance gradient region is set to have a gradually changing sub-region size.

9. The method according to claim 8, wherein the division of the plurality of performance gradient regions comprises: The at least one performance region is divided in the cross section to achieve a gradient distribution of grain characteristics between the same levels, and / or, the at least one performance region is divided and stacked layer by layer in the longitudinal direction corresponding to the plurality of fusion layers to achieve a gradient distribution of grain characteristics between different levels.

10. The method according to claim 4, wherein when forming the performance region of the oriented columnar crystals, the method further comprises: The incident angle of the high-energy beam is adjusted so that the growth direction of the oriented columnar crystals is consistent with the solidification direction of the molten pool.

11. An alloy member obtained by the method according to any one of claims 1 to 10.

12. A device for controlling the microstructure and properties of an alloy component in additive manufacturing, wherein the alloy component is manufactured by selectively melting powder layers applied layer by layer using a high energy beam, wherein: The device comprises: A performance region division module is configured to divide one or more fusion layers used to form the alloy component into performance regions according to performance requirements of the alloy component at different positions to be manufactured; a target grain feature determination module, configured to determine target grain features required for each performance region according to the performance requirements; a sub-region division module configured to divide each performance region into a grid shape consisting of a plurality of sub-regions according to the target grain characteristics and to set each performance region to have a different sub-region size; and The scanning control module is configured to control the high-energy beam to sequentially fill and scan the positions of each sub-region corresponding to the powder layer according to a preset scanning path to form the one or more fusion layers with different grain characteristics in each performance region.

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