Large-layer-thickness selective laser melting forming method for metal blade

Abstract

The invention relates to the technical field of metal additive manufacturing, in particular to a large-layer-thickness selective laser melting forming method for a metal blade, which comprises the following steps of: dividing the blade into a main body area and an outline area when laser is adopted to scan and print the blade layer by layer; layering scanning printing is conducted on the blade, layering scanning printing is conducted on the main body area firstly, and layering scanning printing is conducted on the outline area after printing of the main body area is completed; wherein the thickness of each layer for scanning and printing the main body area and the contour area is not less than 100 microns, the laser power for scanning and printing the contour area is lower than the laser power for scanning and printing the main body area, and the scanning speed for scanning and printing the contour area is lower than the scanning speed for scanning and printing the main body area; therefore, the forming effect of the blade body and the contour area is further guaranteed, and the overall forming quality of the blade is improved.

Description

Technical Field

[0001] This invention relates to the field of metal additive manufacturing technology, and in particular to a method for selective laser melting forming of large-layer thickness metal blades. Background Technology

[0002] Selective Laser Melting (SLM) is a technique that uses a laser beam to directly melt metal powder layer by layer into metal parts. SLM technology can form metal parts with precise dimensions and complex structures, and is widely used to replace traditional casting processes in the manufacture of parts with thin walls and internal cavities, such as blades.

[0003] Currently, when using SLM technology to form metal blades, a conventional layer thickness of 30μm-50μm is typically chosen. This results in a low surface roughness and high structural density in the formed metal parts. However, conventional layer thicknesses do not offer advantages in processing efficiency and cost compared to traditional casting processes. Therefore, to control costs, layer thicknesses of 100μm or more are used. However, the heat accumulation and stress distribution in the blade contour area differ from those in the main body area during layer-by-layer scanning printing. Using the same process parameters as the main blade area may lead to forming defects such as warping in the blade contour. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the problem of various defects appearing in the blade contour area when using large-layer-thickness selective laser melting forming for metal blades in the prior art, and to provide a large-layer-thickness selective laser melting forming method for metal blades.

[0005] The present invention solves the above-mentioned technical problems through the following technical solution:

[0006] This invention provides a method for selective laser melting and forming of large-layer-thickness metal blades, comprising the following steps:

[0007] When printing blades using laser layer-by-layer scanning, the blades are divided into a main body area and a contour area;

[0008] The blades are scanned and printed in layers. First, the main body area is printed, and then the outline area is printed after the main body area is printed.

[0009] In this process, the thickness of each layer in the scanning and printing of the main body area and the contour area is not less than 100 μm, and the laser power for scanning and printing the contour area is lower than the laser power for scanning and printing the main body area, and the scanning speed for scanning and printing the contour area is lower than the scanning speed for scanning and printing the main body area.

[0010] In summary, the selective laser melting forming method for large-layer thickness metal blades provided by this invention divides the blade into a main body region and a contour region, using different process parameters for different regions. This allows for the generation of suitable melt pool depths and widths for different regions of the blade, thereby ensuring forming quality. Furthermore, scanning and printing the main body region first, followed by scanning and printing the contour region, results in a more uniform heat distribution in the main body region, reducing heat accumulation at the blade edges and preventing edge warping. Additionally, the laser power used for scanning and printing the contour region is lower than that used for scanning and printing the main body region, thus reducing heat input to the contour region and preventing overheating and deformation of the blade edges. Simultaneously, the scanning speed for scanning and printing the contour region is lower than that for scanning and printing the main body region, thereby improving the melt pool stability in the contour region and enhancing the flatness of the blade edges. Thus, this method further ensures the forming effect of the blade body and contour region, improving the overall forming quality of the blade.

[0011] Preferably, the laser power used for scanning and printing the contour area and the laser power used for scanning and printing the main body area are both no greater than 500W. This further ensures that neither the main body nor the contour area of ​​the blade will have keyholes or incomplete fusion defects.

[0012] Preferably, the step of performing layered scanning printing on the blades, and first printing the main body area, and then printing the outline area after the main body area has been printed, specifically includes:

[0013] The laser power used to scan the main area is 400 W - 480 W, the scanning speed is 750 mm / s - 950 mm / s, the scanning channel spacing is 0.1 mm - 0.13 mm, and the laser exclusion angle is (40°-60°) to (300°-320°).

[0014] Preferably, printing the outline region specifically includes:

[0015] The laser power used to scan the contour area is 300 W - 350 W, and the scanning speed is 450 mm / s - 500 mm / s.

[0016] Preferably, layered scanning and printing of the outline area specifically includes:

[0017] Multiple contours are set on the blade along the direction from the outer side of the blade to the inner side of the blade, wherein the offset distance between the multiple contours is 0.05 mm - 0.1 mm;

[0018] Perform each contour scan sequentially from the outer side of the blade towards the inner side.

[0019] This configuration allows the width and depth of the multiple molten pools to completely cover the unfused defects near the edge of the blade, enabling the laser to be repeated multiple times until these protrusions are completely melted, thereby eliminating the unfused defects.

[0020] Preferably, dividing the blades into sections specifically includes:

[0021] Set the spacing between the outline area and the main body area to 0-0.02mm.

[0022] By setting a certain distance between the contour area and the main body area, a buffer zone can be formed between the contour area and the main body area, so that the two areas have a certain independent shrinkage space, which helps to reduce the overall residual stress and reduce the problem of warping deformation at the blade edge.

[0023] Preferably, the process further includes, prior to performing layered scanning printing on the blades:

[0024] 316L stainless steel powder was selected as the blade forming material.

[0025] The powder is placed in a vacuum drying oven for drying to remove moisture from the powder;

[0026] The powder has a particle size of 15μm-53μm.

[0027] Using 316L stainless steel powder as the blade forming material ensures high-precision forming of the metal blades, guaranteeing high density and good surface quality. Furthermore, by drying the powder, the porosity of the blades can be significantly reduced, resulting in near-fully dense metal blades.

[0028] Preferably, before performing layered scanning printing on the main body area, the method further includes:

[0029] Preheat the substrate;

[0030] A support structure is printed on the substrate so that scanning printing of the main body area can begin from the support structure.

[0031] Preheating the substrate helps reduce the lateral and longitudinal temperature gradients at the junction of the blade or support structure and the substrate during the cooling process, thereby effectively reducing the blade's susceptibility to cracking. By incorporating a support structure, the blade can be fixed to the substrate to resist the tendency of the blade to warp during contraction. Furthermore, the support structure itself can absorb and disperse some residual stress, further preventing stress concentration on the blade structure and thus avoiding blade deformation.

[0032] Preferably, after the layered scanning printing of the blade is completed, the process further includes: stress-relieving annealing of the formed blade.

[0033] By performing stress-relief annealing on the formed blades, residual stress inside the blade structure can be effectively eliminated, thereby greatly improving the dimensional stability of the formed parts.

[0034] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention. Attached Figure Description

[0035] Figure 1 This is a schematic flowchart of a method for selective laser melting and forming of large-layer-thickness metal blades provided in an embodiment of the present invention.

[0036] Figure 2 This is a schematic diagram of the blade structure and support structure provided in an embodiment of the present invention.

[0037] Figure 3 This is a schematic diagram of the blade partitioning provided in an embodiment of the present invention.

[0038] Explanation of reference numerals in the attached figures:

[0039] 1. Leaf blade; 11. Outline area; 12. Main body area;

[0040] 2. Supporting structure. Detailed Implementation

[0041] The present invention will be further illustrated by way of embodiments below, but the present invention is not limited to the scope of the embodiments described herein.

[0042] For the low-pressure cylinder of a steam turbine, the last-stage blades are the core component, playing a crucial role in the final conversion of steam energy into mechanical energy. Traditionally, steam turbine blades are manufactured through casting. However, this method requires molds, which not only limits the possible machining options but also generally results in lower-quality parts.

[0043] Selective Laser Melting (SLM) is a technology that uses a laser beam to directly melt metal powder layer by layer to form metal parts. SLM technology can form metal parts with precise dimensions and complex structures, such as 316L stainless steel parts. It is widely used to replace traditional casting processes in manufacturing parts with thin walls and internal cavity structures, such as the turbine blades mentioned above.

[0044] Currently, when using SLM technology to form metal blades, a conventional layer thickness of 30μm-50μm is typically chosen. This results in a low surface roughness and high structural density in the formed metal parts. However, conventional layer thicknesses do not offer advantages in processing efficiency and cost compared to traditional casting processes. Therefore, to control costs and improve forming efficiency, layer thicknesses of 100μm or more are used. However, the heat accumulation and stress distribution in the blade contour area differ from those in the main body area during layer-by-layer scanning printing. Using the same process parameters as the main blade area may lead to forming defects such as warping in the blade contour area.

[0045] To address the above issues, this invention provides a method for selective laser melting forming of metal blades with large layer thickness. By employing specific process parameters, the method ensures forming efficiency at various locations on the blade and improves the forming quality of the blade when using selective laser melting forming of large layer thickness.

[0046] The above describes the core ideas of the embodiments of the present invention. The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0047] like Figure 1 As shown, this embodiment of the invention provides a method for selective laser melting and forming of large-layer-thickness metal blades, which includes the following steps:

[0048] Step 104: When printing the blade using laser layer-by-layer scanning, the blade is divided into a main body area and a contour area;

[0049] Step 105: The blades are scanned and printed in layers. First, the main body area is printed, and then the outline area is printed after the main body area is printed.

[0050] In this process, the thickness of each layer for scanning and printing the main body area and the outline area is not less than 100μm. Furthermore, the laser power for scanning and printing the outline area is lower than that for scanning and printing the main body area, and the scanning speed for scanning and printing the outline area is lower than that for scanning and printing the main body area.

[0051] Specifically, the blade is divided into sections to form a main body area and a contour area. This allows for the application of different process parameters to different areas during subsequent printing and scanning. This results in appropriate melt pool depths and widths for different regions of the blade, ensuring the closure of edge gaps and eliminating unfused defects. Each layer printed in both the main body and contour areas is at least 100 μm thick, ensuring efficient laser melting using large layer thicknesses.

[0052] The width of the contour area is determined by the laser power and scanning speed during scanning and printing. In other words, the width of the molten pool during scanning and printing is determined by the laser power and scanning speed, thereby determining the width of the contour area.

[0053] Based on this, the laser power used for scanning and printing the contour area is lower than that used for scanning and printing the main body area, in order to reduce the heat input to the contour area and avoid overheating and deformation of the blade edges. Furthermore, the scanning speed for scanning and printing the contour area is lower than that for scanning and printing the main body area, in order to improve the stability of the molten pool in the contour area, thereby improving the flatness of the blade edges.

[0054] In summary, the selective laser melting forming method for large-layer thickness metal blades provided by this invention divides the blade into a main body region and a contour region, using different process parameters for different regions. This allows for the generation of suitable melt pool depths and widths for different regions of the blade, thereby ensuring forming quality. Furthermore, scanning and printing the main body region first, followed by scanning and printing the contour region, results in a more uniform heat distribution in the main body region, reducing heat accumulation at the blade edges and preventing edge warping. Additionally, the laser power used for scanning and printing the contour region is lower than that used for scanning and printing the main body region, reducing heat input to the contour region and preventing overheating and deformation of the blade edges. Simultaneously, the scanning speed for scanning and printing the contour region is lower than that for scanning and printing the main body region, thereby improving the melt pool stability in the contour region and enhancing the flatness of the blade edges. Thus, this method further ensures the forming effect of the blade body and contour region, improving the overall forming quality of the blade.

[0055] In some specific implementations, the laser power used for scanning and printing the contour area and the laser power used for scanning and printing the main body area can both be no more than 500W. This can further ensure that neither the main body nor the contour part of the blade will have keyholes or incomplete fusion defects.

[0056] like Figure 1 As shown, in some embodiments, the process further includes: [further details to be added] before performing layered scanning printing on the blades.

[0057] Step 101: Select 316L stainless steel powder as the blade forming material, and place the powder in a vacuum drying oven for drying treatment to remove moisture from the powder.

[0058] The powder has a particle size of 15μm-53μm.

[0059] 316L stainless steel is a typical low-carbon austenitic stainless steel containing a high proportion of chromium (Cr) and nickel (Ni). It possesses excellent strength, ductility, and corrosion resistance, and is widely used in aerospace, medical devices, and chemical equipment. This invention uses 316L stainless steel powder as the blade forming material, ensuring high-precision forming of the metal blades and guaranteeing high density and good surface quality.

[0060] Furthermore, since laser melting involves using a high-energy laser beam to instantly melt powder, if the powder contains moisture, the water will rapidly evaporate and expand, forming high-pressure steam bubbles in the molten pool. These bubbles cannot escape before the molten pool solidifies rapidly and become trapped inside the blade, forming porosity defects. Therefore, by drying the powder, the porosity of the blade can be significantly reduced, thereby producing near-fully dense metal blades.

[0061] In practice, the drying time can be set to 4 hours and the drying temperature to 120℃ to ensure sufficient drying effect. Of course, in other embodiments, the drying time and temperature can be adjusted adaptively according to the actual situation.

[0062] In some embodiments, when the blade is divided into sections to form a contour region and a main body region, the spacing between the contour region and the main body region can be set to 0-0.02 mm.

[0063] The distance between the contour area and the main body area refers to the horizontal distance between the contour scanning path and the main body scanning path. The existence of this distance can avoid the generation of large internal stress at the junction of the contour and the main body due to different shrinkage rates when the contour area and the main body area use different processing parameters. In other words, the distance between the contour area and the main body area can form a buffer zone, so that the two areas have a certain independent shrinkage space, thereby helping to reduce the overall residual stress and reduce the problem of warping deformation at the blade edge.

[0064] When using selective laser melting with a large layer thickness (greater than 100 μm), the laser energy density needs to be increased compared to the conventional 50 μm layer thickness. However, excessively high laser energy density can cause severe disturbances in the molten pool, leading to collapse of the keyhole and the cavity at the keyhole tip. Furthermore, the high laser energy density also generates a large number of molten droplet splashes. These splashes collide and form agglomerates, falling near the edge of the blade. As a result, when scanning the next powder layer, surface protrusions form near the edge of the blade. The laser cannot completely melt these protrusions during contour scanning, resulting in incomplete fusion defects.

[0065] Therefore, in this embodiment of the invention, when performing layered scanning printing on the contour area, the blade can be further configured with multiple contours along the direction from the outer side of the blade to the inner side of the blade, and the offset distance between the multiple contours is 0.05mm-0.1mm. Then, each contour is scanned sequentially along the direction from the outer side of the blade to the inner side of the blade.

[0066] In this way, the width and depth of the multiple molten pools can completely cover the unfused defects near the edge of the blade, allowing the laser to be repeated multiple times until these protrusions are completely melted, thereby eliminating the unfused defects.

[0067] In practice, multiple contour scans are performed sequentially from the outer side of the blade towards the inner side. This further reduces blade boundary expansion caused by thermal deformation and improves the dimensional accuracy of the blade. For example, 2-4 contour scans can be set to achieve better forming results.

[0068] In this embodiment, the distance of the contour scanning offset is set to 0.05 mm - 0.1 mm to better match the processing parameters used on the contour area, thereby obtaining a blade structure with better forming effect.

[0069] like Figure 1 and Figure 2 As shown, in some embodiments, the process further includes: before performing layered scanning printing on the main area.

[0070] Step 102: Preheat the substrate;

[0071] Step 103: Set a support structure on the substrate so that scanning and printing of the main body area can start from the support structure.

[0072] Preheating the substrate helps reduce the lateral and longitudinal temperature gradients at the junction of the blade 1 or support structure 2 and the substrate during the cooling process, thereby effectively reducing the susceptibility of the blade 1 to cracking. For example, the substrate can be preheated to 40-80°C.

[0073] Based on this, since the bottom of blade 1 is a curved surface, a support structure 2 needs to be set at the bottom of blade 1, i.e., on the substrate, to prevent the first layer of molten metal from sinking due to the lack of solid support, thus facilitating the laser melting and forming of blade 1. Furthermore, because laser melting and forming causes the metal powder to melt and cool and solidify at a uniform rate, this rapid heating-cooling process generates enormous thermal stress. Stainless steel itself has a high coefficient of thermal expansion, and the constraint it experiences during solidification and shrinkage will generate significant residual stress.

[0074] If the blade 1 is scanned and printed directly on the substrate, the shrinkage tendency of the blade will be firmly constrained by the lower temperature substrate when it cools and shrinks, resulting in huge tensile stress at the bottom of the blade 1, which will cause the blade to lift up from the edge or the suspended part.

[0075] By providing the support structure 2, the blade 1 can be fixed to the substrate to resist the deformation tendency of the blade 1 due to contraction and warping. Furthermore, the support structure 2 itself can absorb and disperse some of the residual stress, thereby further preventing stress concentration on the blade 1 structure and thus avoiding deformation of the blade 1.

[0076] In practice, the support structure can adopt a mesh structure. This allows it to withstand a certain degree of deformation, thereby more effectively absorbing and dispersing some of the residual stress to ensure the quality of blade forming.

[0077] In some embodiments, after the layered scanning printing of the blade is completed, the process further includes: stress-relieving annealing of the formed blade.

[0078] Because laser melting of metal materials is a rapid heating and cooling process, the metal material expands when heated and contracts when cooled, which generates huge residual stress inside the structure. This may cause changes in the shape and size of the structure after the stress is released, or even cracking.

[0079] By performing stress-relief annealing on the formed blades, residual stress inside the blade structure can be effectively eliminated, thereby greatly improving the dimensional stability of the formed parts.

[0080] The above description details the method for selective laser melting and forming of large-layer-thickness metal blades provided by embodiments of the present invention. The following examples further illustrate the above-described setup steps and parameter acquisition steps through specific embodiments.

[0081] Example 1

[0082] 316L stainless steel powder was selected as the raw material, with a particle size of 15μm-53μm. The powder was placed in a vacuum drying oven for drying to remove adsorbed moisture. The drying time was set to 4 hours, and the drying temperature was set to 120℃. A support structure was set on the substrate so that the powder material in the main area and the contour area could be scanned and printed with a layer thickness of 100μm.

[0083] Before printing, preheat the substrate to 40℃-80℃, and then use the following method: Figure 3 The main area and outline area shown are divided into sections, and the leaf printing scan begins.

[0084] Furthermore, when printing the blade using laser layer-by-layer scanning, the main body area is scanned first. The laser melting parameters for the main body area are set as follows: laser power of 400 W - 450 W, scanning speed of 900 mm / s - 950 mm / s, and track spacing of 0.1 mm - 0.13 mm. This setting ensures that the laser energy density is moderate, thereby guaranteeing that there are no keyholes or incomplete fusion defects inside the blade.

[0085] Then, the contour area is scanned and printed. The laser power in the contour area is lower than that in the main body area to reduce heat input and prevent overheating and deformation of the blade edges. Furthermore, the scanning speed is slower than that in the main body area to improve the stability of the molten pool, thereby improving the smoothness of the blade edges.

[0086] For example, the laser melting parameters for the contour area are set as follows: laser power of 300 W - 350 W, scanning speed of 450 mm / s - 500 mm / s, and distance between the contour and the body of 0 mm - 0.02 mm.

[0087] When the blade is not divided into sections, but the entire blade is directly laser-melted and formed using the parameters set for the main body area as described above, the edges of the metal blade will adhere to the surrounding powder due to poor heat dissipation and high temperature, resulting in slag, and gaps will remain between the slag.

[0088] In this embodiment, the contour area is laser-melted separately, and the above-mentioned processing parameters are used. The final contour area has a molten pool width of 252μm and a molten pool depth of 138μm. In this way, the molten pools of two adjacent contour layers can form a good overlap, and the contour and the body can be well adapted, making the blade edge flat. The contour molten pool can also basically close the gaps generated by the blade edge, thus achieving a better forming effect.

[0089] Furthermore, the laser removal angle for laser melting of the main area is set to 60°-300°. This allows the dust generated during laser scanning to be more easily carried away by the inert gas and will not fall onto the blade edge. At the same time, it ensures that there is no dust interference in the laser scanning path and avoids laser energy attenuation.

[0090] When scanning and printing the contour, set the number of contour scans to 2-3 times, and the contour scan offset distance to 0.05-0.1mm. In this way, the molten pools of two adjacent contours will partially overlap. The width and depth of the multiple molten pools can completely cover the unfused defects at the blade edge, allowing the laser to be repeated multiple times until these protrusions are completely melted, thereby eliminating the unfused defects.

[0091] In practice, the scanning proceeds sequentially from the outer edge of the blade towards the inner edge.

[0092] The metal blades produced using the above processing parameters in this embodiment have a density of 99.4%. The printing time for a single blade is 13 hours, thus ensuring both good forming quality and processing efficiency.

[0093] Example 2

[0094] 316L stainless steel powder was selected as the raw material, with a particle size of 15μm-53μm. The powder was placed in a vacuum drying oven for drying to remove adsorbed moisture. The drying time was set to 4 hours, and the drying temperature was set to 120℃. A support structure was set on the substrate so that the powder material in the main area and the contour area could be scanned and printed with a layer thickness of 200μm.

[0095] Before printing, preheat the substrate to 40℃-80℃, and then use the following method: Figure 3 The main area and outline area shown are divided into sections, and the leaf printing scan begins.

[0096] Furthermore, the main body area is scanned first, and the laser melting parameters of the main body area are set as follows: laser power of 450 W - 480 W, scanning speed of 750 mm / s - 800 mm / s, track spacing of 0.1 mm - 0.13 mm, and laser exclusion angle of 40° - 320°.

[0097] If the blade is not divided into sections, and instead the parameters set for the main body area are used to directly laser melt and form the entire blade, surface undulations and incomplete fusion defects occur at the edges of the metal blade. This is because when the layer thickness increases to 200 μm, the molten pool is prone to instability, and the spreading and solidification of the metal powder are difficult to control well, resulting in wavy undulations on the surface. At the same time, the instability of the molten pool also causes poor overlap of the molten pools of adjacent powder layers, resulting in incomplete fusion defects.

[0098] Therefore, in this embodiment, the contour area is scanned and printed separately, and the laser power in the contour area is lower than that in the main body area to reduce heat input and avoid overheating and deformation of the blade edges. Furthermore, the scanning speed is slower than that in the main body area to improve the stability of the molten pool, thereby improving the smoothness of the blade edges.

[0099] For example, the laser melting parameters for the contour area are set as follows: laser power of 300 W - 350 W, scanning speed of 450 mm / s - 500 mm / s, and distance between the contour and the body of 0 mm - 0.02 mm.

[0100] Furthermore, when scanning and printing the outline, the number of outline scans is set to 2-4 times in the order from the outside of the blade to the inside, and the distance between the outline and the main body is set to 0-0.02mm, and the outline scan offset distance is set to 0.05-0.1mm.

[0101] The metal blades produced using the above processing parameters in this embodiment have a density of 99.1%. The printing time for a single blade is 6 hours, thus ensuring both good forming quality and processing efficiency.

[0102] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A method for selective laser melting and forming of large-layer thickness metal blades, characterized in that, Includes the following steps: When printing blades using laser layer-by-layer scanning, the blades are divided into a main body area and a contour area; The blades are scanned and printed in layers. First, the main body area is printed, and then the outline area is printed after the main body area is printed. In this process, the thickness of each layer in the scanning and printing of the main body area and the contour area is not less than 100 μm, and the laser power for scanning and printing the contour area is lower than the laser power for scanning and printing the main body area, and the scanning speed for scanning and printing the contour area is lower than the scanning speed for scanning and printing the main body area.

2. The method for selective laser melting and forming of large-layer thickness metal blades as described in claim 1, characterized in that, The laser power used for scanning and printing the contour area, and the laser power used for scanning and printing the main body area, are both no greater than 500W.

3. The method for selective laser melting and forming of large-layer thickness metal blades as described in claim 2, characterized in that, The process of performing layered scanning printing on the blades, specifically including printing the main body area first and then printing the outline area after the main body area is printed, includes: The laser power used to scan the main area is 400 W - 480 W, the scanning speed is 750 mm / s - 950 mm / s, the scanning channel spacing is 0.1 mm - 0.13 mm, and the laser exclusion angle is (40°-60°) to (300°-320°).

4. The method for selective laser melting and forming of large-layer thickness metal blades as described in claim 2, characterized in that, Printing the outline region specifically includes: The laser power used to scan the contour area is 300 W - 350 W, and the scanning speed is 450 mm / s - 500 mm / s.

5. The method for selective laser melting and forming of large-layer thickness metal blades as described in claim 1, characterized in that, Layered scanning and printing of the outline area specifically includes: Multiple contours are set on the blade along the direction from the outer side of the blade to the inner side of the blade, wherein the offset distance between the multiple contours is 0.05 mm - 0.1 mm; Perform each contour scan sequentially from the outer side of the blade towards the inner side.

6. The method for selective laser melting and forming of large-layer thickness metal blades as described in claim 5, characterized in that, The specific steps of dividing the blades into zones include: Set the spacing between the outline area and the main body area to 0-0.02mm.

7. The method for selective laser melting and forming of large-layer thickness metal blades as described in any one of claims 1-6, characterized in that, The process of performing layered scanning printing on the blades also includes: 316L stainless steel powder was selected as the blade forming material. The powder is placed in a vacuum drying oven for drying to remove moisture from the powder; The powder has a particle size of 15μm-53μm.

8. The method for selective laser melting and forming of large-layer thickness metal blades as described in any one of claims 1-6, characterized in that, Before performing layered scanning and printing on the main body area, the following steps are also included: Preheat the substrate; A support structure is printed on the substrate so that scanning printing of the main body area can begin from the support structure.

9. The method for selective laser melting and forming of large-layer thickness metal blades as described in any one of claims 1-6, characterized in that, After the layered scanning printing of the blade is completed, the process also includes stress-relieving annealing of the formed blade.

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