Electric arc fuse wire additive manufacturing method and system based on array type and layer height compensation strategy

Abstract

The invention discloses an arc fuse additive manufacturing method and system based on an array type and a layer height compensation strategy, and the method comprises the steps: carrying out the part array of a to-be-machined part, and obtaining an array model; performing array type path planning on the array model to obtain an additive manufacturing path and a processing pause layer number; then, processing code conversion is conducted on the additive manufacturing path, and additive layer-by-layer processing is started; in the machining process, every time N layers are machined, forming height measurement is conducted on the machined area, the machined height is obtained, the machined height is input into a process compensation strategy to adjust machining parameters, and the N layers continue to be machined till part machining is completed; according to the method, multiple parts are alternately and synchronously machined in the material adding process, the problems of high heat accumulation of the arc fuse layer and poor forming precision are systematically solved, the printing efficiency is guaranteed, and the printing quality is not affected.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of arc wire additive manufacturing, and particularly relates to an arc wire additive manufacturing method and system based on an array type and layer height compensation strategy. BACKGROUND

[0002] Wire Arc Additive Manufacturing (WAAM) is a 3D printing technology that melts metal wire through welding arc heat, which has the advantages of high forming efficiency, low processing cost and suitability for manufacturing large-size parts compared with other 3D printing technologies, and has been widely used in the fields of aerospace, shipbuilding and heavy machinery. However, there are problems of low forming precision and poor layer height consistency in the process of arc wire additive manufacturing. The main reasons for these problems include two aspects: first, in the process of layer-by-layer stacking of materials, continuous high heat input leads to temperature accumulation between layers; second, as the height of the part increases, the heat dissipation mode of the deposited layer changes from mainly dissipated by the substrate to mainly dissipated by the air, and the heat dissipation capacity decreases significantly.

[0003] The common interlayer temperature control strategy is to control the starting temperature of the next layer printing by prolonging the interlayer waiting time. Although this method effectively solves the problem of temperature accumulation between layers, it greatly reduces the part processing efficiency and is not suitable for industrial mass production of parts. In addition, there is also a control strategy of accelerating cooling through cooling medium to reduce the interlayer waiting time, for example, the document "Influence of Interlayer Forced Cooling on Temperature Field and Flow Field of Arc Wire Additive Manufacturing of Titanium Alloy [J]." (Zhang Yunshu et al., Northwestern Engineering Technology Journal, 2024, 23(3): 199-205, 213.) explores the influence of interlayer forced cooling on the molten pool. However, this method also has some problems. If the cooling rate is too fast, it may lead to a decrease in part performance, or even cause quenching cracks; if the cooling rate is too slow, the processing efficiency of the part still cannot meet the requirements of mass production; and this method introduces a new variable into the arc wire additive manufacturing process, further increasing the complexity of the arc wire additive manufacturing process control.

[0004] On the other hand, the current approach to addressing the problem of poor layer height consistency during the printing process is to adjust the welding gun height using closed-loop control. For example, the paper "Increasing stability in robotic GTA-based additive manufacturing through optical measurement and feedback control[J]" (Robotics and Computer-Integrated Manufacturing, 2019, 59:385-393) regulates wire feed speed based on the distance between the tungsten needle and the build layer to compensate for build height errors, thereby maintaining stability in GTA additive manufacturing. However, this control method still has limitations, such as response lag and insufficient control accuracy. Furthermore, when printing multiple parts simultaneously, it cannot guarantee consistent layer height for each part.

[0005] Therefore, a new solution is urgently needed to address the problem of interlayer accumulation in the arc fuse process, which can ensure printing efficiency without affecting printing quality. Summary of the Invention

[0006] To overcome the shortcomings of the above-mentioned prior art, the present invention aims to provide an arc fuse additive manufacturing method and system based on an array-based and layer height compensation strategy. Based on the array-based arc fuse additive manufacturing strategy, an array path planning method is developed to achieve alternating and synchronous processing of multiple parts, which not only solves the problem of temperature accumulation between arc fuse layers but also ensures processing efficiency. Through the use of processed area point cloud measurement technology and layer height compensation process control strategy, the problem of layer height consistency of array parts is specifically solved. The coordinated control of the two strategies systematically solves the problems of high heat accumulation and poor forming accuracy in arc fuse layers, ensuring printing efficiency without affecting printing quality.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] An arc fuse additive manufacturing method based on an array-type and layer height compensation strategy comprises the following steps:

[0009] First, the parts to be processed are arrayed to obtain an array model; then, array path planning is performed on the array model to obtain the additive manufacturing path and the number of processing pause layers N; then, the additive manufacturing path is converted into processing code, and additive layer-by-layer processing begins; during the processing process, after processing N layers, the forming height of the processed area is measured to obtain the processed height, and the processed height is input into the process compensation strategy to adjust the processing parameters, and processing of N layers is continued until the part is completed.

[0010] The array type path planning is: for the array model, if the array number is greater than the set value, the interlayer waiting time is set to zero; if the array number does not reach the set requirement, the interlayer waiting time t is calculated; then, other parameters are initialized and the array model is sliced to obtain the total number of additive layers and the additive area of each layer, and other parameters include layer height, layer width, welding current, wire feeding speed and welding speed; after completion, path planning is started: first, path planning is performed for the i-th layer, then all parts in the current layer are planned, if all layer path planning is not completed, the layer number i=i+1 operation is performed, and the i-th layer path planning is performed again, until all layer planning is completed; finally, the machining pause layer number is input to obtain the additive manufacturing path and the machining pause layer number N.

[0011] The planning of all parts in the current layer is: after the path planning operation for the i-th layer, the path planning of the current part in the current layer is performed, if all part planning in the current layer is not completed, the next part is determined by the chessboard jumping algorithm, and the path planning of the current part is repeatedly executed until all part planning in the current layer is completed.

[0012] The chessboard jumping algorithm is to select the diagonal adjacent parts of the current part, if the diagonal adjacent parts have been processed, select the part which is not adjacent to the part and is closest to the part, so as to ensure the uniformity of array part heat output and avoid the mutual interference of array part heat input caused by too close array distance.

[0013] The forming height measurement is: for the processed area, point cloud camera shooting is performed, then point cloud data acquisition and point cloud data processing are performed to obtain the forming area Z coordinate and the substrate area Z coordinate, and the difference between the two Z coordinates is obtained to obtain the processed height.

[0014] The process compensation strategy is: for the processed height, if the actual processed height is greater than the design height, the welding current is increased, if the actual processed height is less than the design height, the welding current is reduced, and finally the obtained processing parameters are output.

[0015] The increase and decrease values of welding current each time are determined by experimental data, and the welding current is set to have an upper limit and a lower limit to ensure the stability and safety of the welding process.

[0016] An arc wire additive manufacturing system based on array type and layer height compensation strategy, which realizes the arc wire additive manufacturing method based on array type and layer height compensation strategy.

[0017] Compared with the prior art, the beneficial effects of the present application are:

[0018] (1) The present application is based on an array-based additive manufacturing strategy, and an array-based path planning method is developed, which alternately prints multiple parts in each layer of the additive process, solving the problem of interlayer temperature heat accumulation in the electric arc wire manufacturing process, and greatly improving the additive manufacturing processing efficiency.

[0019] (2) The forming height measurement and layer height process compensation strategy proposed in the present application compensates for the additive layer height error by adjusting the processing parameters, effectively solving the problems of poor electric arc wire layer height consistency and low forming precision.

[0020] (3) The array strategy and layer height compensation strategy proposed in the present application are interrelated, the interlayer heat accumulation problem solved by the array strategy is the biggest influencing factor of layer height instability, and the layer height compensation strategy further ensures the layer height consistency of each array part in each layer, both of which systematically improve the processing precision of electric arc wire additive manufacturing. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The present application is based on an array-based additive manufacturing strategy, and an array-based path planning method is developed, which alternately prints multiple parts in each layer of the additive process, solving the problem of interlayer temperature heat accumulation in the electric arc wire manufacturing process, and greatly improving the additive manufacturing processing efficiency.

[0022] Figure 2 The present application is based on an array-based additive manufacturing strategy, and an array-based path planning method is developed, which alternately prints multiple parts in each layer of the additive process, solving the problem of interlayer temperature heat accumulation in the electric arc wire manufacturing process, and greatly improving the additive manufacturing processing efficiency.

[0023] Figure 3 The present application is based on an array-based additive manufacturing strategy, and an array-based path planning method is developed, which alternately prints multiple parts in each layer of the additive process, solving the problem of interlayer temperature heat accumulation in the electric arc wire manufacturing process, and greatly improving the additive manufacturing processing efficiency.

[0024] Figure 4 The present application is based on an array-based additive manufacturing strategy, and an array-based path planning method is developed, which alternately prints multiple parts in each layer of the additive process, solving the problem of interlayer temperature heat accumulation in the electric arc wire manufacturing process, and greatly improving the additive manufacturing processing efficiency.

[0025] Figure 5 The present application is based on an array-based additive manufacturing strategy, and an array-based path planning method is developed, which alternately prints multiple parts in each layer of the additive process, solving the problem of interlayer temperature heat accumulation in the electric arc wire manufacturing process, and greatly improving the additive manufacturing processing efficiency.

[0026] Figure 6 The present application is based on an array-based additive manufacturing strategy, and an array-based path planning method is developed, which alternately prints multiple parts in each layer of the additive process, solving the problem of interlayer temperature heat accumulation in the electric arc wire manufacturing process, and greatly improving the additive manufacturing processing efficiency.

[0027] Figure 7 The present application is based on an array-based additive manufacturing strategy, and an array-based path planning method is developed, which alternately prints multiple parts in each layer of the additive process, solving the problem of interlayer temperature heat accumulation in the electric arc wire manufacturing process, and greatly improving the additive manufacturing processing efficiency. DETAILED DESCRIPTION

[0028] The present application is described below in conjunction with the embodiments and drawings, which are only used to explain the present application and not to limit the scope of the present application.

[0029] Referring to Figure 1 , an electric arc wire additive manufacturing method based on array and layer height compensation strategy, comprising the following steps:

[0030] First, the parts to be processed are arrayed to obtain an array model; then, array path planning is performed on the array model to obtain the additive manufacturing path and the number of processing pause layers N; then, the additive manufacturing path is converted into processing code to obtain G code that can directly control the processing equipment, and then additive processing of the array model is started layer by layer; during the processing process, every time N layers are processed, if the processing of the array model is not completed, the forming height of the processed area is measured to obtain the processed height after processing N layers, and then the processed height is input into the process compensation strategy to obtain new processing parameters, and then N layers are processed again until all layers of the array model are processed and the part processing is completed.

[0031] Reference Figure 2 , the array path planning is as follows: for the array model, if the number of arrays is greater than the set value, it proves that the number of arrays is sufficient, and the inter-layer waiting time is set to zero. If the number of arrays does not meet the set requirements, the inter-layer waiting time t is calculated; then, other parameters are initialized, including layer height, layer width, welding current, wire feeding speed, and welding speed. After the parameters are set, the array model is sliced ​​to obtain the total number of additive layers and the additive area of ​​each layer. After the above operations are completed, the array path planning is started: first, path planning is performed for the i-th layer and i=1 is started. Then, path planning is performed for the additive areas of all parts in the current layer one by one, and all parts in the current layer are planned. If the path planning of all layers is not completed, the operation of the to-be-planned layer i=i+1 is performed, and then the path planning of the i-th layer is performed until all layer planning is completed; finally, the number of processing pause layers is input to obtain the additive manufacturing path and the number of processing pause layers N.

[0032] Reference Figure 3 、 Figure 6, the planning of all parts of the current layer is: array clamps 1-1 are used to fix array parts 1-2 to 1-10; after the path planning operation for the i-th layer, the part 1-2 is selected as the first current part by default, the first layer selection method is manual input selection through a prompt box, the array position parameters of the first current part of the subsequent layers are the same as those of the first current part of the first time, after the selection of the current part is completed, the path planning of the current part is performed, the path planning method is the same as that of the traditional path planning algorithm, after the planning of the current part is completed, it is judged whether all parts of the current layer are planned, if not, the next part is determined through the chessboard jumping algorithm, the next part 1-6 in this embodiment, the chessboard jumping algorithm is to select the part adjacent to the diagonal of the current part, if the parts adjacent to the diagonal have been processed, the part closest to the current part is selected, for example, when the part 1-8 is processed, the part 1-4 is selected as the next part, the purpose of this algorithm is to ensure the uniformity of the array part heat output and to avoid the interference of the array part heat input caused by the close distance between the array parts; after the selection of the next part is completed, the next part is taken as the current part, and the path planning of the current part is repeatedly performed until the planning of all parts of the current layer is completed.

[0033] Referring to Figure 4 , the forming height measurement is: for the processed area, after the processing is stopped, the point cloud camera is used for shooting, then the point cloud data is acquired and processed, the point cloud data processing mainly includes point cloud denoising, point cloud classification and point cloud smoothing operations, the purpose is to extract and distinguish the part forming area point cloud data and the substrate area point cloud data, to obtain the forming area Z coordinate and the substrate area Z coordinate, and finally to make the difference between the two Z coordinates, and the absolute value of the difference is the processed height.

[0034] Referring to Figure 5 , Figure 7 , the process compensation strategy is: for the processed height, for example, as shown by the part 1-2, the actual processed height 2-1 of the current layer and the design height 2-2 of the part are compared, the design height 2-2 is the height that should be formed in theory after the part is processed in the slicing algorithm, if the actual processed height 2-1 is greater than the design height 2-2, the welding current is increased, if the actual processed height 2-1 is less than the design height 2-2, the welding current is reduced, in this embodiment, the actual processed height 2-1 is less than the design height 2-2, so the welding current should be reduced; the increase and decrease values of the welding current each time are determined by experimental data, and the welding current is set to have an upper limit and a lower limit to ensure the stability and safety of the welding process, finally the obtained processing parameters are output as the processing parameters of the subsequent N layers.

[0035] An electric arc wire additive manufacturing system based on array and layer height compensation strategy, which realizes the electric arc wire additive manufacturing method based on array and layer height compensation strategy.

[0036] The above description is only the preferred embodiment of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An arc fuse additive manufacturing method based on array type and layer height compensation strategy, characterized in that: The following steps are involved: First, the parts to be processed are arrayed to obtain an array model; then, array path planning is performed on the array model to obtain the additive manufacturing path and the number of processing pause layers N; then, the additive manufacturing path is converted into processing code, and additive layer-by-layer processing begins; during the processing process, after processing N layers, the forming height of the processed area is measured to obtain the processed height, and the processed height is input into the process compensation strategy to adjust the processing parameters, and processing of N layers is continued until the part is completed.

2. The manufacturing method according to claim 1, characterized in that The array path planning is as follows: for the array model, if the number of arrays is greater than the set value, the inter-layer waiting time is set to zero; if the number of arrays does not meet the set requirements, the inter-layer waiting time t is calculated; then, other parameters are initialized and the array model is sliced ​​to obtain the total number of additive layers and the additive area of ​​each layer. Other parameters include layer height, layer width, welding current, wire feeding speed and welding speed; after completion, path planning begins: first, path planning is performed for the i-th layer, and then all parts of the current layer are planned. If the path planning for all layers is not completed, the layer number i=i+1 operation is performed, and then the i-th layer path planning is performed until all layer planning is completed; finally, the number of processing pause layers is input to obtain the additive manufacturing path and the number of processing pause layers N.

3. The manufacturing method according to claim 2, characterized in that The planning of all parts in the current layer is as follows: after performing the path planning operation on the i-th layer, path planning is performed on the current part in the current layer. If the planning of all parts in the current layer is not completed, the next part is determined by the chessboard jumping algorithm, and the path planning of the current part is repeated until the planning of all parts in the current layer is completed.

4. The manufacturing method according to claim 3, characterized in that The chessboard jumping algorithm is to select the parts diagonally adjacent to the current part. If the diagonally adjacent parts have been processed, the part that is not adjacent to the part and is closest to it is selected to ensure the uniformity of the heat output of the array parts and avoid mutual interference in the heat input of the array parts caused by the array distance being too close.

5. The manufacturing method according to claim 1, characterized in that The forming height measurement is as follows: a point cloud camera is used to shoot the processed area, and then point cloud data is acquired and processed to obtain the Z coordinate of the forming area and the Z coordinate of the substrate area. The two Z coordinates are subtracted to obtain the processed height.

6. The manufacturing method according to claim 1, characterized in that The process compensation strategy is: for the processed height, if the actual processed height is greater than the designed height, the welding current is increased; if the actual processed height is less than the designed height, the welding current is reduced, and finally the obtained processing parameters are output.

7. The manufacturing method according to claim 6, characterized in that The increase and decrease values ​​of each welding current are determined by experimental data, and upper and lower limits are set for the welding current to ensure the stability and safety of the welding process.

8. An arc fuse additive manufacturing system based on an array and layer height compensation strategy, characterized by: A method for additively manufacturing arc fuses based on an array-type and layer height compensation strategy as described in any one of claims 1-7 is implemented.

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