A method for arc additive suitable for closing members

Abstract

The application is a method for arc additive of closed components. The method comprises the following steps: step (1) determining the overlapping length d of cladding; step (2) determining the additive path: determining the number of accumulation layers, taking 2m layers as one path cycle, wherein m<=5, the component is added with N path cycles, N=P / 2m; the first m layers in each path cycle are added in the clockwise or counterclockwise direction, the last m layers are added in the direction opposite to that of the first m layers, and the arc starting and extinguishing positions of each layer in the m layers in each path cycle are uniformly distributed along the closed path; and step (3) adding the component. The application solves the problems of poor forming quality of additive closed components, additive defects and the like, and greatly improves the additive efficiency of the component and the utilization rate of the wire.

Description

Technical Field

[0001] This invention belongs to the field of additive manufacturing, and specifically relates to a method for arc additive manufacturing of enclosed components. Background Technology

[0002] Arc additive manufacturing is a directional energy deposition method based on wire. Using an electric arc as a heat source, it continuously melts metal wire and deposits it layer by layer along a designed path to form a shape. It offers advantages such as large forming size, low manufacturing cost, simple equipment, high material utilization, and high deposition efficiency, making it a primary manufacturing method for high-quality, rapid forming of large metal components. Parts obtained through arc additive manufacturing can meet performance requirements after simple machining, demonstrating significant technological advantages in production efficiency and the production of complex components. It is suitable for the fabrication of components made of metal materials such as steel, aluminum, magnesium, and titanium.

[0003] Because the arc initiation and extinguishing positions in arc additive manufacturing are constantly being adjusted in terms of process parameters, defects such as poor forming and incomplete fusion are prone to occur. In non-closed components produced by arc additive manufacturing, the arc initiation and extinguishing positions are often designed as redundant structures to be removed during machining after additive manufacturing. However, in closed structures produced by arc additive manufacturing, the arc initiation and extinguishing positions are an indispensable part of the overall component and cannot be removed by machining after additive manufacturing. Therefore, their forming accuracy has a significant impact on the quality of the additively formed component.

[0004] When arc additive manufacturing is used for a closed frame, the single-layer additive path is a closed route. After starting from the starting arc point and moving around the specified path for one circle, it returns to the vicinity of the starting arc point to extinguish the arc. The forming accuracy of the joint after melting and cladding at the starting and extinguishing arc points is extremely difficult to control and becomes the weak link of the entire component. The overlapping length d of the melting and cladding at the starting and extinguishing arc points of the deposited layer is the key parameter for controlling the height consistency of a single-pass deposited layer. When the heights are inconsistent, the macroscopic forming of the multi-pass deposited layers obtained by additive manufacturing is poor, and the component will bulge to a certain height at the starting and extinguishing arc points, resulting in that both the macroscopic forming and mechanical properties of the component cannot meet the requirements. Aiming at the poor macroscopic forming of the closed component, currently, the main method is to perform additive forming of the component by layer-by-layer stacking + grinding the overlapping positions of the starting and extinguishing arcs with a grinding wheel, so that the overall height of the deposited layer is basically the same. If no subsequent subtractive treatment is carried out, additive defects such as stress concentration and lack of fusion often appear at the overlapping positions of the starting and extinguishing arcs of the component. Even with the layer-by-layer stacking of the deposited layer, the overlapping positions of the starting and extinguishing arcs are too high, resulting in that the welding torch nozzle cannot start the arc normally at this position. Although this method can effectively improve the macroscopic forming of the component, the starting and extinguishing arc points of different layers are set at the same position, and additive defects such as local residual stress cannot be eliminated after grinding, resulting in low mechanical properties at the joint position and unable to improve the overall mechanical properties of the component; in addition, this method also greatly reduces the additive efficiency and wire utilization rate of the component and cannot meet the high-efficiency and high-quality additive manufacturing of the closed component. How to achieve high-quality additive manufacturing at the starting and extinguishing arc positions of the closed component through process control methods has become one of the main factors restricting its practical application. Summary of the Invention

[0005] The purpose of the present invention is to provide a method suitable for arc additive manufacturing of closed components.

[0006] The technical solution for achieving the purpose of the present invention is as follows: A method suitable for arc additive manufacturing of closed components includes the following steps:

[0007] Step (1): Determine the initial value range of the melting and cladding overlapping length d: According to the material and shape of the closed component, determine the wire type and additive process parameters. Using the determined wire and additive process parameters, additively manufacture two deposited layers successively along a straight line, and make the extinguishing arc point of the second deposited layer melt and clad the starting arc point of the first deposited layer to determine the initial value range of the melting and cladding overlapping length d, that is, 0 < d < min{h / tanα, h / tanβ}, where h is the single-layer height; α and β are the wetting angles of the starting arc point and the extinguishing arc point with the substrate respectively;

[0008] Step (2): Determine the melting and cladding overlapping length d: According to the initial value range of the melting and cladding overlapping length d in step (1), conduct experiments to determine the melting and cladding overlapping length d;

[0009] Step (3): Determine the additive path: Based on the required height H of the additive closed component and the height kh of the single cladding layer after single-pass deposition, determine the number of deposited layers P = H / kh, where k is the remelting coefficient; take 2m layers as one path cycle, where m≤5, the component additive process has N path cycles, N = P / 2m; the first m layers in each path cycle are added in a clockwise or counterclockwise direction, and the additive direction of the last m layers is opposite to that of the first m layers, and the arc start and extinguishing positions of each layer in each path cycle are evenly distributed along the closed path;

[0010] Step (4): Component Addition: Addition is carried out according to the additive path determined in step (3) and the overlap length d determined in step (2). After each layer of additive is completed, the temperature of the arc starting point of the layer is detected by a temperature measuring device. After cooling to 150℃~200℃, the welding torch is raised by one layer height and moved to the arc starting position of the next layer for additive until the specified size of the component is reached.

[0011] Furthermore, in step (2), the cladding overlap length d is determined as follows:

[0012] Step (201): Select different values ​​within the initial range of the cladding overlap length d determined in step (1) to conduct multiple sets of single-layer double-pass deposition additive manufacturing experiments;

[0013] Step (202): Use a 3D scanner to scan the surface morphology of the deposition layer obtained in step (201), and select the value that is equal to or closest to the height error of a single deposition layer as the final cladding overlap length.

[0014] Furthermore, in step (2), the cladding overlap length d is determined as follows:

[0015] Step (211): Select different cladding overlap lengths d within the initial range of the cladding overlap length d determined in step (1), and perform reciprocating additive manufacturing at the same position of the joint, with a straight wall of 8-12 additive layers;

[0016] Step (212): For the straight wall obtained by additive manufacturing in step (211), select a point every 5 mm from one end of the top surface of the straight wall to the other end, measure its vertical height with the substrate in sequence and connect them, draw a line graph, observe the height difference between the joint position and the other positions, and select d with a difference ≤ 5% for subsequent component additive manufacturing.

[0017] Furthermore, the remelting coefficient k is set to 0.7-0.9. The remelting coefficient k is calculated as follows: k = (2L-L1) / L, where L is the height of a single layer and L1 is the height of the deposited layer after the two layers of deposited material are fused together.

[0018] Furthermore, when determining the additive path in step (3), if the closed component has a uniform cross section, the path period of 2m during the additive process does not need to be changed, ensuring that the horizontal distance between adjacent joints is not less than 20mm.

[0019] Furthermore, when determining the additive path in step (3), if the closed component has a variable cross section, the path period changes accordingly during the additive process, and ensures that within m periods, the deposition layer with the shortest cross section perimeter can satisfy the requirement of at least two uniformly distributed joints; and the horizontal distance between adjacent joints cannot be less than 20 mm.

[0020] Furthermore, the electric arc additive heat source can be a molten electrode heat source or a non-molten electrode heat source.

[0021] Furthermore, the height h of the sedimentary layer is 2-4 mm.

[0022] A sealing component is prepared using the method described above.

[0023] One application of the above method is for additive manufacturing of alloys such as steel, aluminum, copper, titanium, and magnesium.

[0024] Compared with the prior art, the significant advantages of this invention are:

[0025] This invention utilizes the additive manufacturing of closed frames by adjusting the length of the arc initiation and extinguishing joints in the deposition layer, thereby reducing the height of the joint positions and ensuring a consistent overall height of the components. Compared to the previous method of layer-by-layer stacking and joint grinding, this significantly improves the additive manufacturing efficiency and wire utilization rate. Furthermore, since there is a height difference between the arc initiation and extinguishing points and the stable area of ​​the deposition layer, minor protrusions inevitably occur at the joints. The reciprocating stacking path used in the experiment helps to ensure the consistency of the overall height of the components.

[0026] This invention utilizes additive manufacturing with dispersed joints at the component's location. On one hand, this allows the deposited layer joints and deposited layers to alternate vertically, reducing the frequency of micro-protrusions at the joints. This, coupled with repeated deposition, further improves the overall height of the component, resulting in a more uniform height. On the other hand, the dispersed distribution of joints overcomes the problem of poor mechanical properties at joint locations, which is a common issue in traditional additive manufacturing. This contributes to improved overall mechanical properties of the component.

[0027] This invention enables high-quality forming of various alloy frame components and has wide application value. Attached Figure Description

[0028] Figure 1 This is a schematic diagram illustrating the principle of determining the overlap length of the cladding in this invention.

[0029] Figure 2 This is the macroscopic morphology of the cladding overlap length test determined in Examples 1 and 2.

[0030] Figure 3 Schematic diagram for scanning the surface topography of a single-pass deposition layer using a three-dimensional scanner; where (a) is the three-dimensional scanning schematic diagram, and (b) is the broken-line schematic diagram.

[0031] Figure 4 It is the straight-wall macroscopic morphology and the broken-line graph of the straight-wall height in the joint tests of Examples 1 and 2; where (a) is the straight-wall macroscopic morphology, and (b) is the broken-line graph of the straight-wall height.

[0032] Figure 5 It is the additive manufacturing path schematic diagram of the filleted box-shaped component in Example 1.

[0033] Figure 6 It is the macroscopic morphology of the filleted box-shaped component in Example 1.

[0034] Figure 7 It is the additive manufacturing path schematic diagram of the cylindrical component in Example 2.

[0035] Figure 8 It is the macroscopic morphology of the cylindrical component in Example 2.

[0036] Figure 9 It is the macroscopic morphology of the cylindrical component with an unoptimized additive manufacturing path. Specific implementation manners

[0037] The present invention will be further described in detail below with reference to the accompanying drawings.

[0038] A method applicable to arc additive manufacturing of a closed component includes the following steps:

[0039] Step 1: Determine the initial value range of the cladding overlap length d: As Figure 1 shown, according to the material and shape of the closed component, determine the wire type and additive manufacturing process parameters. Using the determined wire and additive manufacturing process parameters, additively manufacture two deposition layers successively along a straight line, and make the arc extinguishing point of the second deposition layer melt and cover the arc starting point of the first deposition layer, and determine the initial value range of the cladding overlap length d, that is, 0 < d < min{h / tanα, h / tanβ}, where h is the single-pass layer height; α and β are the wetting angles of the arc starting point and the arc extinguishing point with the substrate respectively;

[0040] Step 2: Determine the cladding overlap length d: According to the initial value range of the cladding overlap length d in step (1), conduct tests to determine the cladding overlap length d;

[0041] Select different values within the initial value range of the determined cladding overlap length d for multiple groups of single-layer double-pass deposition additive manufacturing tests; use a three-dimensional scanner to scan the surface topography of the obtained deposition layer, and select the value with a height error equal to or closest to that of the single-pass deposition layer as the final cladding overlap length.

[0042] Alternatively, within the initial range of the determined cladding overlap length d, different cladding overlap lengths d can be selected, and the joint can be reciprocated in the same position for a straight wall with 8-12 layers of additive material. For the straight wall obtained by the above additive material, select a point every 5 mm from one end of the top surface of the straight wall to the other end, measure its vertical height from the substrate in sequence and connect it, draw a line graph, observe the height difference between the joint position and the other positions, and select d with a difference ≤5% for subsequent component additive material.

[0043] Step 3: Determine the additive manufacturing path: Based on the required additive component height H and the single-layer height kh after single-pass deposition, determine the required number of deposition layers P = H / kh, where k is the remelting coefficient; use 2m layers as one path cycle. Where m ≤ 5, the component additive manufacturing takes N path cycles, N = P / 2m; if the component size varies significantly (e.g., cones, frustums, etc.), the component is divided into zones according to its size, and the path cycle changes accordingly during the additive manufacturing process, ensuring that within m cycles, the deposition layer with the shortest cross-sectional perimeter satisfies at least two evenly distributed joints. Furthermore, the horizontal distance between adjacent joints cannot be less than 20mm.

[0044] Step 4: Component Addition: Add material according to the additive path determined in step (3) and the overlap length d determined in step (2). After each layer of additive material is completed, a temperature measuring device is used to detect the arc starting point temperature of that layer. After cooling to 150℃~200℃, the welding torch is raised by one layer height and moved to the arc starting position of the next layer to add material until the specified size of the component is reached.

[0045] This invention, through rational planning of the additive manufacturing path, not only effectively improves the forming accuracy of components compared to the previous method, but also avoids unnecessary subtractive manufacturing processes caused by protrusions at component joints. This improves wire utilization and reduces manufacturing costs. A 2m layer is selected as a cycle, with the joint positions of the first m and the last m layers being the same. The first m layers are all prepared clockwise (or counterclockwise), and the last m layers are all prepared counterclockwise (or clockwise). This is mainly because, according to this path planning, each joint of a clockwise deposited layer has a corresponding counterclockwise additive manufacturing layer joint. This can, to a certain extent, compensate for the slight dimensional differences between the joints at the arc initiation and arc extinguishing ends, allowing the additive manufacturing process to proceed smoothly and further improving the flatness of the component.

[0046] Distributing the joints across each layer of the component is also a key aspect of this invention. Since joints often contain defects, their performance is weaker than that of the deposited layers in other locations. Traditional additive manufacturing often concentrates joints in a single vertical position, leading to a "barrel effect" where deformation or even breakage occurs first at the joints, rendering the component unusable. To address this, this invention distributes joints dispersedly, alternating between joints and deposited layers. This helps to lengthen the shortest stave in the "barrel effect," thereby improving the component's "water storage" capacity. In other words, it improves the mechanical properties of the component that are locally reduced due to concentrated joints, mitigating the poor mechanical properties caused by excessively concentrated joints before optimization.

[0047] Example 1

[0048] An AZ91 magnesium alloy frame component with rounded corners was additively formed using this method. The component is 65mm high, with a corner radius of 20mm, an outer side length of 155mm, an inner side length of 140mm, and a frame thickness of 15mm. The component is powered by an EWM PC300 additive power supply (with a built-in water-cooling system) and uses a MOTOMAN YRC1000 six-axis Yaskawa robot as the motion mechanism. A push-pull wire welding torch is fixed to the end of the robot's sixth axis. Arc additive manufacturing parameters are: peak current 170A, wire feed speed 8m / min, travel speed 24cm / min, oscillation amplitude 5mm, and oscillation frequency 1.4Hz. During the additive manufacturing process, the layer height h of the deposited layer is approximately 3 mm. After cooling to 150°C between layers, the next layer is added. The protective gas used in the deposition process is pure Ar gas. The filler filament is AZ91 magnesium alloy with a diameter of 1.2 mm. The substrate is AZ91 magnesium alloy with dimensions of 450×250×8 mm. The heat source for arc additive manufacturing is a molten electrode inert gas protected power supply. The specific steps are as follows:

[0049] Step 1: Determine the initial range of the overlap length d: By controlling the MOTOMAN YRC1000 six-axis Yaskawa robot, adjust the welding torch height to ensure that the distance from the welding torch nozzle to the substrate is 13mm, with a welding wire extension of 12mm and a distance from the welding wire tip to the substrate of 1mm. Determine the arc starting point on the substrate. Use an arc additive manufacturing heat source to deposit a 50mm long deposition layer on the substrate. Along the deposition layer direction, add a second 50mm long deposition layer 48mm in front of the arc starting point, covering the first deposition layer. d is obtained from h / tanα = 3.3mm and h / tanβ = 10.2mm. <min{h / tanα;h / tanβ}=3.3mm。

[0050] Step 2: Determine the cladding overlap length d: Based on the initial value range of the cladding overlap length d in step (1), conduct experiments to determine the cladding overlap length d;

[0051] like Figure 2As shown, different values ​​were selected within the initial range of the cladding overlap length d determined above to conduct multiple sets of single-layer double-channel deposition additive manufacturing experiments. Figure 3 The method of scanning the surface morphology of the obtained deposition layer using a 3D scanner is presented, and the value that is equal to or closest to the height error of a single deposition layer is selected as the final cladding overlap length.

[0052] Furthermore, within the initial range of the determined cladding overlap length d, different cladding overlap lengths d were selected, and cladding lengths of d = 1, 2, and 3 mm were tested successively. For example... Figure 4 As shown, the joint undergoes reciprocating additive manufacturing at the same location, resulting in a 10-layer straight wall. It can be observed that when the cladding length d = 1 mm, the surface forming of the reciprocating additive manufacturing is superior to that of unidirectional additive manufacturing, with no significant undulations at the joint, thus improving the forming accuracy of the component. For the straight wall obtained by the above additive manufacturing, points are selected every 5 mm from one end of the top surface of the straight wall to the other end, and their vertical heights relative to the substrate are measured and connected. A line graph is plotted to observe the height difference between the joint location and other locations. When the cladding length d = 2 mm, the overall height of the straight wall tends to be uniform. Therefore, the cladding length d for the additively manufactured rounded frame joint is determined to be 2 mm.

[0053] Step 3: Determine the additive manufacturing path: such as Figure 5 As shown, based on the required additive component height H = 65mm and the single-layer height kh = 0.9 * 3 = 2.7mm after single-pass deposition, the required number of deposition layers is determined as P = H / kh ≈ 65 / (0.9 * 3) = 24 layers, where k is the remelting coefficient; 2m layers are considered as one path cycle. Where m = 4, the component additive manufacturing takes N path cycles, N = P / 2m = 24 / 8 = 3; during additive manufacturing, the first m layers are added in a clockwise direction, and the last m layers are added in the opposite direction, ensuring that the arc initiation and extinguishing positions of each layer in the m cycles (4 layers) are evenly distributed along the closed path.

[0054] Step 4: Component Additive Manufacturing: such as Figure 6 As shown, the additive manufacturing process is carried out according to the additive manufacturing path determined in step (3) and the overlap length d=2 determined in step (2). After each layer of additive manufacturing is completed, the temperature of the arc starting point of the layer is detected by a temperature measuring device. After cooling to 150°C, the welding torch is raised by one layer height and moved to the arc starting position of the next layer for additive manufacturing until the specified size of the component is reached.

[0055] Example 2

[0056] The required additive manufacturing process involved path planning and fabrication, resulting in the creation of an AZ91 magnesium alloy cylindrical component. The component is 65mm high, with an outer diameter of 150mm and an inner diameter of 135mm, meaning the cylinder thickness is 15mm. The component was manufactured using an EWM PC300 additive power supply (with a built-in water-cooling system) and a MOTOMAN YRC1000 six-axis Yaskawa robot as the motion mechanism. A push-pull wire bonding torch was fixed to the end of the robot's sixth axis. Arc additive manufacturing parameters: peak current 170A, wire feed speed 8m / min, travel speed 24cm / min, oscillation amplitude 5mm, oscillation frequency 1.4Hz. During the additive manufacturing process, the layer height h of the deposited layer is approximately 3mm. The next layer is added after cooling to 150℃ between layers. The protective gas used in the deposition process is pure Ar gas. The filler wire is AZ91 magnesium alloy with a diameter of 1.2mm. The substrate is AZ91 magnesium alloy with dimensions of 450×250×8mm. The heat source for arc additive manufacturing is a molten electrode inert gas protective power supply. The specific steps are as follows:

[0057] Step 1: Determine the initial range of the cladding overlap length d: By controlling the MOTOMAN YRC1000 six-axis Yaskawa robot, adjust the welding torch height to ensure that the distance from the welding torch nozzle to the substrate is 13mm, with a welding wire extension of 12mm and a distance from the welding wire end to the substrate of 1mm. Since the cladding length d = 2mm has already been obtained in Example 1, no further testing is needed, and we can proceed directly to Step 3;

[0058] Step 3: Determine the additive manufacturing path: such as Figure 7 As shown, based on the required additive component height H = 65mm and the single-layer height kh = 0.9 * 3 = 2.7mm after single-pass deposition, the required number of deposition layers is determined as P = H / kh ≈ 65 / (0.9 * 3) = 24 layers, where k is the remelting coefficient; 2m layers are considered as one path cycle. Where m = 4, the component additive manufacturing takes N path cycles, N = P / 2m = 24 / 8 = 3; during additive manufacturing, the first m layers are added in a clockwise direction, and the last m layers are added in the opposite direction, ensuring that the arc initiation and extinguishing positions of each layer in the m cycles (4 layers) are evenly distributed along the closed path.

[0059] Step 4: Component Additive Manufacturing: such as Figure 8 As shown, the additive manufacturing process is carried out according to the additive manufacturing path determined in step (3) and the overlap length d=2 determined in step (2). After each layer of additive manufacturing is completed, the temperature of the arc starting point of the layer is detected by a temperature measuring device. After cooling to 150°C, the welding torch is raised by one layer height and moved to the arc starting position of the next layer for additive manufacturing until the specified size of the component is reached.

[0060] The macroscopic morphology of the cylindrical component with an unoptimized additive manufacturing path is as follows: Figure 9 As shown in the figure, a high bulge appears at the joint, indicating poor forming; the optimized cylinder forming yields excellent results, with significantly improved forming accuracy. Figure 6 and Figure 8 It can be seen that the additively formed frame and cylindrical component with rounded corners using this invention has excellent forming quality and there is no height difference between the joint position and the overall component. In addition, compared with the original (joint position is concentrated in one place) component joint ultimate tensile strength increased from 147MPa to 252MPa, which greatly improved the overall mechanical properties of the component.

[0061] By rationally planning the additive manufacturing path and distributing the joints, poor forming caused by protrusions or depressions at the joints of the components during additive manufacturing can be effectively avoided, and the overall mechanical properties of the components can be optimized. This overcomes the problems of poor forming morphology, unnecessary waste of wire, and poor mechanical properties caused by a large number of defects when joints are concentrated during the additive manufacturing of various alloy components. High-quality forming and more uniform mechanical properties of the components are achieved.

Claims

1. A method for arc additive manufacturing of enclosed components, characterized in that, It includes the following steps: Step (1): Determine the initial value range of the cladding overlap length d: Determine the wire type and additive manufacturing process parameters according to the material and shape of the closed component. Use the determined wire and additive manufacturing process parameters to additively manufacture two deposition layers successively along a straight line, and make the arc extinguishing point of the second deposition layer melt and cover the arc starting point of the first deposition layer, so as to determine the initial value range of the cladding overlap length d, that is, 0 < d < min{h / tanα, h / tanβ}, where h is the height of a single layer; α and β are the wetting angles of the arc starting point and the arc extinguishing point with the substrate respectively; Step (2): Determine the cladding overlap length d: According to the initial value range of the cladding overlap length d in step (1), conduct tests to determine the cladding overlap length d; Step (3): Determine the additive path: Based on the required height H of the additively sealed component and the single-pass layer height h after single-pass deposition, determine the number of deposition layers P=H / k h, where k This is the remelting coefficient; Take 2m layers as a path cycle, where m ≤ 5, and the component is additively manufactured for N path cycles, N = P / 2m; in the first m layers of each path cycle, the additive manufacturing is carried out in the clockwise or counterclockwise direction, and the additive manufacturing direction of the latter m layers is opposite to that of the first m layers, and the arc starting and extinguishing positions of each layer in the m layers of each path cycle are evenly distributed along the closed path; Step (4): Component additive manufacturing: Carry out additive manufacturing according to the additive manufacturing path determined in step (3) and the cladding overlap length d determined in step (2). After each layer of additive manufacturing is completed, use a temperature measuring device to detect the temperature of the arc starting point of this layer. After cooling to 150°C - 200°C, the welding torch is lifted by one layer height and moved to the arc starting position of the next layer for additive manufacturing until the specified size of the component is reached.

2. The method according to claim 1, characterized in that, Specifically, determining the cladding overlap length d in step (2) is as follows: Step (201): Select different values within the initial value range of the cladding overlap length d determined in step (1) to conduct multiple groups of single-layer double-pass deposition additive manufacturing tests; Step (202): Use a three-dimensional scanner to scan the surface topography of the deposition layer obtained in step (201), and select the value whose height error is equal to or closest to that of the single-pass deposition layer as the final cladding overlap length.

3. The method according to claim 1, characterized in that, Specifically, determining the cladding overlap length d in step (2) is as follows: Step (211): Select different cladding overlap lengths d within the initial value range of the cladding overlap length d determined in step (1), and the joint is additively manufactured reciprocally at the same position, and the number of additive manufacturing layers is a straight wall of 8 - 12 layers; Step (212): For the straight wall obtained by additive manufacturing in step (211), select a point every 5 mm from one end to the other end of the top surface of the straight wall, measure its vertical height from the substrate in turn and connect them to draw a broken line graph, observe the height difference between the joint position and the other positions, and select d with a difference ≤ 5% for subsequent component additive manufacturing.

4. The method according to claim 1, characterized in that, remelting coefficient k The remelting coefficient has a value of 0.7-0.

9. k The calculation method is as follows: k = (2L-L1) / L, where L is the height of a single layer and L1 is the height of the sedimentary layer after the two sedimentary layers are clad.

5. The method according to claim 4, characterized in that, When determining the additive manufacturing path in step (3), if the closed component has an equal cross-section, the path cycle 2m does not need to be changed during the additive manufacturing process, and it is ensured that the horizontal distance between adjacent joints is not less than 20 mm.

6. The method according to claim 4, characterized in that, When determining the additive manufacturing path in step (3), if the closed component has a variable cross-section, the path cycle changes accordingly during the additive manufacturing process, and it is ensured that within m cycles, the deposition layer with the shortest cross-sectional perimeter in one layer can satisfy at least 2 joints evenly distributed; and the horizontal distance between adjacent joints is not less than 20 mm.

7. The method for arc additive manufacturing according to claim 1, characterized in that, The arc additive manufacturing heat source is a consumable electrode heat source or a non-consumable electrode heat source.

8. The method for arc additive manufacturing according to claim 1, characterized in that, The height h of a single sedimentary layer is 2-4 mm.

9. A closing component, characterized in that, Prepared using the method described in any one of claims 1-8.

10. Use of the method according to any one of claims 1-8, characterized in that, Additive manufacturing for steel, aluminum, copper, titanium or magnesium alloys.

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