A method of preventing collapse of an arc initiation / extinction site in an electric arc additive manufacturing process

Abstract

The application discloses a method for preventing the collapse of arc starting / extinguishing positions in an electric arc additive manufacturing process, which comprises the following steps: 1. optimization of a model: evaluating and locally processing a three-dimensional model of a metal component, and performing a chamfering treatment to determine arc starting / extinguishing positions and quantities of the electric arc additive manufacturing and to perform parameter design; 2. slice processing and electric arc additive manufacturing path planning: performing slice processing and electric arc additive manufacturing path planning on the three-dimensional model of the optimized metal component; and 3. electric arc additive manufacturing: adjusting arc starting / extinguishing process parameters to complete the electric arc additive manufacturing process and obtain the metal component. The application controls and optimizes the arc starting / extinguishing current and time of the electric arc additive manufacturing process in different manufacturing stages, so that the arc starting / extinguishing positions form good fusion, the collapse of the arc starting / extinguishing positions in the electric arc additive manufacturing process is controlled, and the electric arc additive manufacturing metal component with consistent additive manufacturing height and consistent performance is obtained.

Description

Technical Field

[0001] This invention belongs to the field of arc-fused-wire additive manufacturing, and specifically relates to a method for preventing the collapse of the arc initiation / extinguishing parts during the arc-fused-wire additive manufacturing process. Background Technology

[0002] Arc-wire additive manufacturing technology uses an electric arc as the heat source to melt metal wire. Through continuous addition of wire, and under program control, metal parts are gradually formed from lines to surfaces to solids based on a three-dimensional digital model. It boasts advantages such as high deposition efficiency, high wire utilization, short manufacturing cycle, low cost, fewer restrictions on part size, and ease of part repair. Furthermore, it possesses the capability for in-situ composite manufacturing and forming large-size components.

[0003] Currently, arc-wire additive manufacturing technology constructs three-dimensional solid components by layer-by-layer accumulation. Due to the characteristics of arc-wire additive manufacturing, severe deficiencies often occur at the arc initiation / exit points. In practice, it has revealed the following shortcomings, specifically: (1) The arc initiation temperature is low, the amount of wire melted is small, and the additive manufacturing is severely insufficient in both the horizontal and vertical directions; (2) The arc extinguishing temperature is high, the molten pool lacks constraint, the horizontal spread is large, but the vertical additive manufacturing height is severely insufficient; (3) Due to the severe deficiency of the vertical additive manufacturing height at the arc initiation and extinguishing points, normal arc initiation is impossible, resulting in interruption of the additive manufacturing process; (4) Collapse at the arc initiation and extinguishing points will cause incomplete component dimensions or inconsistent performance, or even component additive manufacturing failure. Therefore, providing a method to prevent the collapse of the arc initiation / exit points during arc-wire additive manufacturing will help solve the efficiency problem of arc-wire additive manufacturing of metal components and improve the consistency of the overall performance of the components. Summary of the Invention

[0004] The technical problem this invention aims to solve is to address the shortcomings of the prior art by providing a method for preventing collapse of the arc initiation / extinction region during arc additive manufacturing. This method controls and optimizes the arc initiation / extinction current and time at different manufacturing stages to regulate the collapse of the arc initiation / extinction region during arc additive manufacturing and compensate for over-spreading, resulting in a continuous increase in additive manufacturing height and obtaining arc additive manufactured metal components with consistent performance. This solves the problem of inconsistent additive manufacturing height or inconsistent performance of metal components caused by arc initiation / extinction region collapse.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: a method for preventing the collapse of the arc initiation / extinguishing section during arc additive manufacturing, characterized in that, as the height of the additive manufacturing process continues to increase, the height and fusion condition of the arc initiation / extinguishing section remain consistent with those of other sections. The method specifically includes the following steps:

[0006] Step 1: Optimizing the Model

[0007] Step 101: Evaluate the three-dimensional model of the metal component to determine the metal component's partitioning scheme and arc additive manufacturing direction;

[0008] Step 102: Locally process the arc additive manufacturing parts in the three-dimensional model of the metal component that are not easy to implement, to ensure that they can be manufactured by arc additive manufacturing; the local processing includes hollowing, suspension and uniform wall thickness processing.

[0009] Step 103: Make the various rounded corners of the three-dimensional model of the metal component right-angled or beveled to reduce the difficulty of slicing and arc additive manufacturing.

[0010] Step 104: Determine the location and quantity of arc initiation / extinction points for arc additive manufacturing;

[0011] Step 105: Design arc additive manufacturing parameters for the arc initiation / extinction points determined in Step 104;

[0012] Step 2: Slicing and Arc Additive Manufacturing Path Planning

[0013] Step 201: Based on the metal component partitioning scheme and arc additive manufacturing direction determined in Step 101, slice the three-dimensional model of the optimized metal component in Step 1, and determine the slicing direction as horizontal.

[0014] Step 202: Perform arc additive manufacturing path planning on the 3D model of the metal component after slicing in step 201, so that the number of arc starting / extinguishing points is kept to 1 each, and the arc additive manufacturing path planning can be realized by arc additive manufacturing.

[0015] Step 3: Arc Additive Manufacturing

[0016] Step 301: Perform arc additive manufacturing according to the arc additive manufacturing parameters designed in step 105 and the arc additive manufacturing path planned in step 202, and adjust the arc initiation / extinction process parameters according to the arc additive manufacturing process.

[0017] Step 302: Complete the electric arc additive manufacturing process to obtain a metal component.

[0018] This invention first evaluates the 3D model of the metal component and determines the component's partitioning scheme and arc additive manufacturing direction. Then, based on the characteristics of arc additive manufacturing and the equipment used, including the need for additional printing allowance during model processing due to the need for post-processing of arc additive manufacturing components, the high heat input of arc additive manufacturing easily leading to residual stress or deformation requiring additional treatment, the need for support for printed suspended parts, and the need for increased energy input for printing corners or joints, as well as the feasibility of heating to improve residual stress, the availability of variable machine positions for printing complex structures including unsupported printing, and the equipment characteristics such as coaxial or off-axis wire feeding, the 3D model is further optimized to ensure its suitability for arc additive manufacturing. Finally, the arc initiation / extinction points and number of arc additive manufacturing processes are determined. The invention first measures the quantity and then designs the arc additive manufacturing parameters for the metal component. Next, it slices the optimized 3D model of the metal component and plans the arc additive manufacturing path. Then, it performs arc additive manufacturing according to the designed parameters and path. Based on the arc additive manufacturing process, it adjusts the arc initiation / exit process parameters, including the arc initiation / exit current, arc initiation / exit current time, and arc initiation / exit current gradient time. This controls the molten pool state, temperature, and material accumulation at the arc initiation / exit location, ensuring that the temperature at the arc initiation / exit location remains as consistent as possible and the material accumulation is sufficient. This effectively controls the tendency for the arc initiation / exit location to collapse during arc additive manufacturing, avoiding process interruptions, incomplete filling of the arc initiation / exit location, and inconsistent metal component performance caused by arc collapse. This invention significantly improves the shape and performance consistency of arc additive manufactured metal components by controlling key process parameters at the arc initiation / exit location, and is suitable for continuous additive manufacturing of large-sized or high-height components.

[0019] The method described above for preventing the collapse of the arc initiation / extinguishing part during arc additive manufacturing is characterized in that the metal component in step 101 is made of magnesium alloy or carbon steel.

[0020] The above-mentioned method for preventing the collapse of the arc initiation / extinction point during electric arc additive manufacturing is characterized in that the arc initiation / extinction point in step 104 comes from the arc initiation / extinction position of the closed path, the arc initiation / extinction positions at both ends of the non-closed path, and the arc initiation / extinction position at the intersection of different paths.

[0021] The above-mentioned method for preventing the collapse of the arc initiation / extinction points during arc additive manufacturing is characterized in that, during the arc additive manufacturing process described in step 301, when a significant height difference or collapse occurs at the arc initiation / extinction points, the arc initiation current is adjusted to 120%~180% of the normal arc additive manufacturing current, and the arc extinguishing current is adjusted to 10%~50% of the normal arc additive manufacturing current.

[0022] The arc additive manufacturing process typically includes an arc initiation stage, an arc extinguishing stage, and a normal arc additive manufacturing stage in between. The first and last stages are relatively short, lasting only a few seconds, while the normal arc additive manufacturing stage often lasts from tens of seconds to several hours. Usually, the arc initiation / extinguishing process parameters are adjusted at the beginning of the arc additive manufacturing process, and can be adjusted accordingly based on the different additive manufacturing materials to control the collapse of the arc initiation / extinguishing points. This invention increases the arc initiation current to provide sufficient energy input, ensuring that the material at the arc initiation position can completely melt and achieve good fusion. By reducing the arc extinguishing current, it ensures that the arc extinguishing position does not overheat, preventing melt flow or collapse. This overcomes the phenomenon in conventional arc additive manufacturing where the temperature at the arc extinguishing position is much higher than the temperature at the arc initiation position, leading to poor fusion at the arc initiation position and collapse due to excessively high temperature at the arc extinguishing position.

[0023] The method described above for preventing collapse of the arc initiation / extinction points during arc additive manufacturing is characterized in that, during the arc additive manufacturing process described in step 301, when a significant height difference or collapse occurs at the arc initiation / extinction points, the arc initiation current time is adjusted to 0.1s~5s, and the arc extinguishing current time is adjusted to 0~10s. This invention adjusts the arc initiation / extinction current time to regulate the energy input at the arc initiation and extinction positions, ensuring that the arc initiation / extinction positions do not collapse. The appropriate arc initiation / extinction current time is selected based on the degree of collapse susceptibility; if the collapse is severe, the arc initiation / extinction current time needs to be further extended.

[0024] The method described above for preventing collapse of the arc initiation / extinction points during arc additive manufacturing is characterized in that, during the arc additive manufacturing process described in step 301, when a significant height difference or collapse occurs at the arc initiation / extinction points, the arc initiation current gradient time is adjusted to 0.1s~0.5s, and the arc extinguishing current gradient time is adjusted to 0.1s~3s. This invention adjusts the arc initiation / extinction current gradient time to regulate the energy input at the arc initiation and extinction positions, ensuring that the arc initiation / extinction positions do not collapse.

[0025] In practice, better collapse control is usually achieved by adjusting the arc initiation / extinction current, combined with adjusting the arc initiation / extinction current timing and the arc initiation / extinction current gradient timing.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] 1. In the arc additive manufacturing process of the present invention, by controlling and optimizing the arc additive manufacturing process parameters of arc initiation / extinction current and time in different manufacturing stages, on the one hand, the energy input at the arc initiation position is increased and the energy input at the arc extinguishing position is reduced, thereby increasing the degree of fusion at the arc initiation position and reducing the possibility of collapse at the arc extinguishing position. On the other hand, by increasing the amount of material accumulation at the arc initiation / extinction position, the excessive spreading caused by the lack of constraint around the molten pool at the arc initiation / extinction position is compensated, thereby controlling the collapse of the arc initiation / extinction part during the arc additive manufacturing process. While the additive manufacturing height continues to increase, the collapse of the arc initiation / extinction part is avoided, which may cause inconsistency in the additive manufacturing height or inconsistency in the performance of the metal component, thus obtaining arc additive manufactured metal components with consistent performance.

[0028] 2. The method of the present invention, by adjusting the energy input and time at the arc initiation / exit position, achieves the effect of preventing the collapse of the arc initiation / exit position during the arc additive manufacturing process. It can ensure good fusion at the arc initiation / exit position of the closed path, the arc initiation / exit positions at both ends of the non-closed path, and the arc initiation / exit positions at the intersection of different paths, and maintain a consistent additive manufacturing height, thereby further improving the performance of the metal component.

[0029] 3. In the process of preparing large-scale metal arc additive manufacturing components, the method of the present invention can maintain the consistency of each layer of additive manufacturing by controlling the arc start / extinguishing process parameters, and will not cause the arc start / extinguishing position to collapse, thereby ensuring that large-scale metal components can be continuously additively manufactured for a long time.

[0030] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0031] Figure 1 This is a physical image of the magnesium alloy single-layer wall prepared in Example 1 of the present invention.

[0032] Figure 2 This is a physical image of the magnesium alloy single-layer wall prepared in Example 2 of the present invention.

[0033] Figure 3 This is a cross-sectional schematic diagram of the complex magnesium alloy component prepared in Example 3 of the present invention.

[0034] Figure 4 This is a physical image of the complex magnesium alloy component prepared in Example 3 of the present invention.

[0035] Figure 5 This is a physical image of the carbon steel single-layer wall prepared in Example 4 of the present invention.

[0036] Figure 6 This is a physical image of the complex carbon steel component prepared in Example 5 of the present invention. Detailed Implementation

[0037] Example 1

[0038] This embodiment includes the following steps:

[0039] Step 1: Optimizing the Model

[0040] Step 101: Evaluate the three-dimensional model of the magnesium alloy single wall, determine that the partitioning scheme of the magnesium alloy single wall is planar partitioning, and determine that the arc additive manufacturing direction is vertically upward.

[0041] Because the three-dimensional model of the magnesium alloy single wall is simple in structure, it can be manufactured by electric arc additive manufacturing without the need for local processing or rounding.

[0042] Step 102: Determine that the additive manufacturing path of the magnesium alloy single wall is a straight line, which is a non-closed path, and each layer contains only one additive manufacturing path. Therefore, the arc start / extinguishing point is the arc start / extinguishing position at both ends of the non-closed path. Cross arc start is adopted to avoid continuous arc start at a single point.

[0043] Step 103: Design the arc additive manufacturing parameters for the arc initiation / extinction points determined in Step 102, including the transformation of the arc initiation / extinction positions, the layer height of each layer, and the additive manufacturing height.

[0044] Step 2: Slicing and Arc Additive Manufacturing Path Planning

[0045] Step 201: Based on the partitioning scheme of the magnesium alloy single wall and the direction of electric arc additive manufacturing determined in Step 101, slice the three-dimensional model of the optimized magnesium alloy single wall in Step 1, and determine the slicing direction as horizontal.

[0046] Step 202: Perform electric arc additive manufacturing path planning on the 3D model of the magnesium alloy single wall after slicing in Step 201. All paths are straight lines, and the arc start / extinguishing points are located at both ends.

[0047] Step 3: Arc Additive Manufacturing

[0048] Step 301: Perform arc additive manufacturing according to the arc additive manufacturing parameters designed in Step 103 and the arc additive manufacturing path planned in Step 202. Adjust the arc initiation / extinction process parameters according to the arc additive manufacturing process: In the initial stage, adjust the arc initiation current to 120% of the normal arc additive manufacturing current and the arc extinguishing current to 10% of the normal arc additive manufacturing current; when obvious collapse occurs at the arc extinguishing point, adjust the arc initiation current time to 0.1s and the arc extinguishing current time to 10s; when abnormal molten pool is observed at the arc initiation / extinction point, adjust the arc initiation current gradient time to 0.1s and the arc extinguishing current gradient time to 0.1s.

[0049] Step 302: Complete the electric arc additive manufacturing process to obtain a magnesium alloy single-layer wall.

[0050] Figure 1 Here is a physical image of the magnesium alloy single-layer wall prepared in this embodiment. Figure 1 It can be seen that the heights at both ends of the magnesium alloy single wall are basically the same as those in the middle, and no obvious collapse has occurred.

[0051] Example 2

[0052] This embodiment includes the following steps:

[0053] Step 1: Optimizing the Model

[0054] Step 101: Evaluate the three-dimensional model of the magnesium alloy single wall, determine that the partitioning scheme of the magnesium alloy single wall is planar partitioning, and determine that the arc additive manufacturing direction is vertically upward.

[0055] Because the three-dimensional model of the magnesium alloy single wall is simple in structure, it can be manufactured by electric arc additive manufacturing without the need for local processing or rounding.

[0056] Step 102: Determine that the additive manufacturing path of the magnesium alloy single wall is a straight line, which is a non-closed path, and each layer contains only one additive manufacturing path. Therefore, the arc start / extinguishing point is the arc start / extinguishing position at both ends of the non-closed path. Cross arc start is adopted to avoid continuous arc start at a single point.

[0057] Step 103: Design the arc additive manufacturing parameters for the arc initiation / extinction points determined in Step 102, including the transformation of the arc initiation / extinction positions, the layer height of each layer, and the additive manufacturing height.

[0058] Step 2: Slicing and Arc Additive Manufacturing Path Planning

[0059] Step 201: Based on the partitioning scheme of the magnesium alloy single wall and the direction of electric arc additive manufacturing determined in Step 101, slice the three-dimensional model of the optimized magnesium alloy single wall in Step 1, and determine the slicing direction as horizontal.

[0060] Step 202: Perform electric arc additive manufacturing path planning on the 3D model of the magnesium alloy single wall after slicing in Step 201. All paths are straight lines, and the arc start / extinguishing points are located at both ends.

[0061] Step 3: Arc Additive Manufacturing

[0062] Step 301: Perform arc additive manufacturing according to the arc additive manufacturing parameters designed in Step 103 and the arc additive manufacturing path planned in Step 202. Adjust the arc initiation / exit process parameters according to the arc additive manufacturing process: Due to the long additive manufacturing path length of the magnesium alloy single wall in this embodiment, the arc initiation point temperature is low. When it is observed that the molten droplet does not spread well and the arc initiation point fusion is poor, adjust the arc initiation current to 150% of the normal arc additive manufacturing current and the arc extinguishing current to 20% of the normal arc additive manufacturing current. When the arc extinguishing point collapses significantly, i.e., the end is significantly lower than the middle part, adjust the arc initiation current time to 0.5s and the arc extinguishing current time to 5s. When it is observed that the molten pool at the arc initiation / exit point is abnormal, i.e., the fusion is poor or there is obvious delamination, adjust the arc initiation current gradient time to 0.3s and the arc extinguishing current gradient time to 0.3s.

[0063] Step 302: The arc additive manufacturing process is completed by swinging left and right on the basis of a straight path to obtain a magnesium alloy single wall.

[0064] Figure 2 Here is a physical image of the magnesium alloy single-layer wall prepared in this embodiment. Figure 2 It can be seen that the height of the arc initiation / extinguishing part of the magnesium alloy single wall is consistent with that of other parts, the end is well fused, and no obvious collapse is formed.

[0065] Example 3

[0066] This embodiment includes the following steps:

[0067] Step 1: Optimizing the Model

[0068] Step 101: Evaluate the 3D model of the complex magnesium alloy component and determine the partitioning scheme for the complex magnesium alloy component, such as... Figure 3 As shown, different colored parts represent different structures after dissection, and the direction of arc additive manufacturing is determined to be vertically upward.

[0069] Step 102: Locally process the additive manufacturing parts in the three-dimensional model of the complex magnesium alloy component that are not easy to implement, so as to ensure that they can be manufactured by arc additive manufacturing; the local processing includes: filling the holes in the middle of the vertical thin wall, supporting the thin wall boss, and unifying the wall thickness of the thin wall with inconsistent and small differences.

[0070] Step 103: Make the various rounded corners of the three-dimensional model of the complex magnesium alloy component right-angled or beveled to reduce the difficulty of slicing and arc additive manufacturing.

[0071] Step 104: Determine the arc initiation / extinction points of complex magnesium alloy components, including one closed path arc initiation / extinction point, 12 non-closed path arc initiation / extinction points at both ends, and 16 arc initiation / extinction points at the intersections of different paths.

[0072] Step 105: Design the arc additive manufacturing parameters for the arc initiation / extinction points determined in Step 104, including the changes in arc initiation / extinction positions, layer height of each layer, additive manufacturing height, and additive manufacturing sequence.

[0073] Step 2: Slicing and Arc Additive Manufacturing Path Planning

[0074] Step 201: Based on the metal component partitioning scheme and arc additive manufacturing direction determined in Step 101, slice the three-dimensional model of the optimized magnesium alloy complex component in Step 1, and determine the slicing direction as horizontal.

[0075] Step 202: Perform arc additive manufacturing path planning on the 3D model of the complex magnesium alloy component after slicing in Step 201. The specific path is the centerline path. Each segmented part is formed by a single wall, that is, each layer is formed by a single wall + a single wall, so that the number of arc starting / extinguishing points is kept to 1 each, and the additive manufacturing path planning can be realized by arc additive manufacturing.

[0076] Step 3: Arc Additive Manufacturing

[0077] Step 301: Perform arc additive manufacturing according to the arc additive manufacturing parameters designed in Step 105 and the arc additive manufacturing path planned in Step 202. Adjust the arc initiation / extinction process parameters according to the arc additive manufacturing process: Since the outermost ring of the additive manufacturing path of the complex magnesium alloy component in this embodiment is relatively long and there are many arc initiation positions in the internal structure, when performing arc additive manufacturing on the outermost ring, if poor fusion or gaps are observed at the arc initiation / extinction points of the closed path, or if the cross joints cannot be completely fused or cannot be joined together, immediately adjust the arc initiation current to 180% of the normal arc additive manufacturing current and the arc extinguishing current to 50% of the normal arc additive manufacturing current. Adjust the arc initiation current time to 5s and the arc extinguishing current time to 10s. When poor fusion or gaps are observed at the arc initiation / extinction points of the outermost closed path, or if the cross joints cannot be completely fused or the molten droplets are obviously delaminated, adjust the arc initiation current gradient time to 0.5s and the arc extinguishing current gradient time to 3s.

[0078] Step 302: Complete the electric arc additive manufacturing process to obtain a complex magnesium alloy component.

[0079] Figure 3This is a cross-sectional schematic diagram of the complex magnesium alloy component prepared in this embodiment. Different colors represent different structural parts, including the outermost closed path, straight path, and the intersection of different paths.

[0080] Figure 4 Here is a physical image of the complex magnesium alloy component prepared in this embodiment, from... Figure 4 It can be seen that, due to the adjustment of additive manufacturing parameters at the cross joint, the fusion at the cross joint is good and there is no collapse.

[0081] Example 4

[0082] This embodiment includes the following steps:

[0083] Step 1: Optimizing the Model

[0084] Step 101: Evaluate the three-dimensional model of the carbon steel single wall, determine that the partitioning scheme of the carbon steel single wall is planar partitioning, and determine that the electric arc additive manufacturing direction is vertically upward.

[0085] Because of the simple structure of carbon steel single-wall, no local treatment or rounding is required, it can be manufactured by electric arc additive manufacturing.

[0086] Step 102: Determine that the additive manufacturing path of the carbon steel single wall is a straight line, which is a non-closed path, and each layer contains only one additive manufacturing path. Therefore, the arc start / extinguishing point is the arc start / extinguishing position at both ends of the non-closed path. Cross arc start is adopted to avoid continuous arc start at a single point.

[0087] Step 103: Design the arc additive manufacturing parameters for the arc initiation / extinction points determined in Step 102, including the transformation of the arc initiation / extinction positions, the layer height of each layer, and the additive manufacturing height.

[0088] Step 2: Slicing and Arc Additive Manufacturing Path Planning

[0089] Step 201: Based on the partitioning scheme of the carbon steel single wall and the direction of electric arc additive manufacturing determined in Step 101, slice the three-dimensional model of the carbon steel single wall optimized in Step 1, and determine the slicing direction as horizontal.

[0090] Step 202: Perform electric arc additive manufacturing path planning on the 3D model of the carbon steel single wall after slicing in Step 201. All paths are straight lines, and the arc start / extinguishing points are located at both ends.

[0091] Step 3: Arc Additive Manufacturing

[0092] Step 301: Perform arc additive manufacturing according to the arc additive manufacturing parameters designed in Step 103 and the arc additive manufacturing path planned in Step 202. Adjust the arc initiation / exit process parameters according to the arc additive manufacturing process: Due to the long additive manufacturing path length of the carbon steel single wall in this embodiment, the arc initiation point temperature is low. When it is observed that the molten droplets do not spread well and the arc initiation point fusion is poor, adjust the arc initiation current to 120% of the normal arc additive manufacturing current and the arc extinguishing current to 10% of the normal arc additive manufacturing current. When the arc extinguishing point collapses significantly, i.e., the end is significantly lower than the middle part, adjust the arc initiation current time to 0.1s and the arc extinguishing current time to 2s. When it is observed that the molten pool at the arc initiation / exit point is abnormal, i.e., the fusion is poor or there is obvious delamination, adjust the arc initiation current gradient time to 0.2s and the arc extinguishing current gradient time to 0.1s.

[0093] Step 302: Complete the electric arc additive manufacturing process to obtain a carbon steel single-layer wall.

[0094] Figure 5 This is a physical image of the carbon steel single-layer wall prepared in this embodiment. Figure 5 It can be seen that the heights at both ends of the carbon steel single wall are basically the same as those in the middle, and no obvious collapse has occurred.

[0095] Example 5

[0096] This embodiment includes the following steps:

[0097] Step 1: Optimizing the Model

[0098] Step 101: Evaluate the 3D model of the complex carbon steel component with a partially suspended structure and determine the partitioning scheme of the complex carbon steel component: First, partition the structure that can be vertically upward, that is, make the 3D model as additively manufactured as possible in the vertical direction. Then, rotate the 3D model around the bottom by about 15° and use the section perpendicular to the horizontal plane to partition the part of the 3D model with an excessively large additive angle, that is, the part that is not easy to be additively manufactured in the vertical direction. And determine that the direction of electric arc additive manufacturing is vertically upward.

[0099] Step 102: Locally process the additive manufacturing parts in the three-dimensional model of the complex carbon steel component that are not easy to implement, so as to ensure that they can be manufactured by electric arc additive manufacturing. The local processing includes: beveling the horizontal bottom of the three-dimensional model of the complex carbon steel component, rotating the whole, and filling the part of the bottom surface that forms an angle and is suspended after beveling, so that the cross section is parallel to the horizontal plane, so as to reduce the number of subdivisions and realize the long-term continuous electric arc additive manufacturing process.

[0100] Step 103: Make the various rounded corners of the three-dimensional model of the complex carbon steel component right-angled or beveled to reduce the difficulty of slicing and arc additive manufacturing.

[0101] Step 104: Determine the arc start / extinguishing points of complex carbon steel components, including the arc start / extinguishing positions of the closed path in the lower half and the arc start / extinguishing positions at both ends of the non-closed path in the upper half. Each layer of arc additive manufacturing path contains only one arc start / extinguishing position. The arc start / extinguishing positions of each layer of the closed path are not in the same position, and the arc start / extinguishing positions of each layer of the non-closed path are located at both ends.

[0102] Step 105: Design the arc additive manufacturing parameters for the arc initiation / extinction points determined in Step 104, including the change of arc initiation / extinction positions, the layer height of each layer, and the additive manufacturing height.

[0103] Step 2: Slicing and Arc Additive Manufacturing Path Planning

[0104] Step 201: Based on the partitioning scheme of the complex carbon steel component and the direction of electric arc additive manufacturing determined in Step 101, slice the three-dimensional model of the optimized carbon steel single wall in Step 1, and determine the slicing direction as horizontal.

[0105] Step 202: Perform electric arc additive manufacturing path planning on the 3D model of the carbon steel single wall after slicing in Step 201. Each path has only one start and extinguish point. The lower half is an ellipse with a closed path, and the upper half is a non-closed arc path.

[0106] Step 3: Arc Additive Manufacturing

[0107] Step 301: Perform arc additive manufacturing according to the arc additive manufacturing parameters designed in Step 103 and the arc additive manufacturing path planned in Step 202. Adjust the arc initiation / exit process parameters according to the arc additive manufacturing process: Due to the long additive manufacturing path length of the magnesium alloy single wall in this embodiment, the arc initiation point temperature is low. When it is observed that the molten droplet does not spread well and the arc initiation point fusion is poor, adjust the arc initiation current to 130% of the normal arc additive manufacturing current and the arc extinguishing current to 30% of the normal arc additive manufacturing current. When the arc extinguishing point collapses significantly, i.e., the end is significantly lower than the middle part, adjust the arc initiation current time to 0.8s and the arc extinguishing current time to 2s. When it is observed that the molten pool at the arc initiation / exit point is abnormal, i.e., the fusion is poor or there is obvious delamination, adjust the arc initiation current gradient time to 0.3s and the arc extinguishing current gradient time to 0.2s.

[0108] Step 302: Complete the electric arc additive manufacturing process to obtain a complex carbon steel component.

[0109] Figure 6 Here is a physical image of the complex carbon steel component prepared in this embodiment, from... Figure 6It can be seen that the heights at both ends of this complex carbon steel component are basically close to those in the middle, and no obvious collapse has occurred.

[0110] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Any simple modifications, alterations, and equivalent changes made to the above embodiments based on the inventive essence shall still fall within the protection scope of the present invention.

Claims

1. A method for preventing collapse of the arc initiation / extinguishing section during electric arc additive manufacturing, characterized in that, As the height of additive manufacturing continues to increase, the height and fusion of the arc initiation / extinguishing section remain consistent with other parts. This method specifically includes the following steps: Step 1: Optimizing the Model Step 101: Evaluate the three-dimensional model of the metal component to determine the metal component's partitioning scheme and arc additive manufacturing direction; Step 102: Locally process the arc additive manufacturing parts in the three-dimensional model of the metal component that are not easy to implement, to ensure that they can be manufactured by arc additive manufacturing; the local processing includes hollowing, suspension and uniform wall thickness processing. Step 103: Make the various rounded corners of the three-dimensional model of the metal component right-angled or beveled to reduce the difficulty of slicing and arc additive manufacturing. Step 104: Determine the location and quantity of arc initiation / extinction points for arc additive manufacturing; Step 105: Design arc additive manufacturing parameters for the arc initiation / extinction points determined in Step 104; Step 2: Slicing and Arc Additive Manufacturing Path Planning Step 201: Based on the metal component partitioning scheme and arc additive manufacturing direction determined in Step 101, slice the three-dimensional model of the optimized metal component in Step 1, and determine the slicing direction as horizontal. Step 202: Perform arc additive manufacturing path planning on the 3D model of the metal component after slicing in step 201, so that the number of arc starting / extinguishing points is kept to 1 each, and the arc additive manufacturing path planning can be realized by arc additive manufacturing. Step 3: Arc Additive Manufacturing Step 301: Perform arc additive manufacturing according to the arc additive manufacturing parameters designed in Step 105 and the arc additive manufacturing path planned in Step 202. Adjust the arc initiation / extinction process parameters, including arc initiation / extinction current, arc initiation / extinction current time and arc initiation / extinction current gradual change time, according to the arc additive manufacturing process. During the arc additive manufacturing process, when a significant height difference or collapse occurs at the arc initiation / extinction point, the arc initiation current is adjusted to 120%~180% of the normal arc additive manufacturing current, and the arc extinguishing current is adjusted to 10%~50% of the normal arc additive manufacturing current; the arc initiation current time is adjusted to 0.1s~5s, and the arc extinguishing current time is adjusted to 0~10s; the arc initiation current gradual change time is adjusted to 0.1s~0.5s, and the arc extinguishing current gradual change time is adjusted to 0.1s~3s. Step 302: Complete the electric arc additive manufacturing process to obtain a metal component.

2. The method for preventing collapse of the arc initiation / extinguishing section during arc additive manufacturing according to claim 1, characterized in that, The metal component mentioned in step 101 is made of magnesium alloy or carbon steel.

3. The method for preventing collapse of the arc initiation / extinguishing section during arc additive manufacturing according to claim 1, characterized in that, The arc start / extinguishing points mentioned in step 104 are selected from the arc start / extinguishing positions of closed paths, the arc start / extinguishing positions at both ends of non-closed paths, and the arc start / extinguishing positions at the intersection of different paths.

Images