A method of processing a corner in an electric arc filament additive manufacturing

Abstract

This invention discloses a method for processing corners in arc wire additive manufacturing, belonging to the field of arc wire additive manufacturing technology. In this invention, a right angle A1 is selected on the center path of a square weld bead. The first right angle point after A1 is A3, the second right angle point is A6, and the third right angle point is A9. Starting from A1, A2 is taken in the A1A3 path; starting from A3, A4 and A5 are taken in the A3A6 path; starting from A6, A7 and A8 are taken in the A6A9 path; and A9 is taken in the A9A1 path. 10 The distances from A2 and A4 to A3 on the weld center path are: A2A3=A4A3=; The distances from A5 and A7 to A6 on the weld center path are: A5A6=A7A6=; The distances from A8 and A4 to A6 on the weld center path are: A5A6=A7A6=; 10 The distance from A8 to A9 is: A8A9=A 10 A9 = ; r is the weld radius, therefore, the printed weld path in arc wire additive manufacturing is A1→A2→A4→A5→A7→A8→A 10 →A1. In this invention, the printing path at the corner of the arc-fuse additive manufacturing process is optimized by calculating the weld radius, which effectively prevents the accumulation of printing material at the weld corner, reduces material waste, and makes the weld printing smooth at the corner.

Description

Technical Field

[0001] This invention belongs to the field of arc fuse additive manufacturing technology, and specifically relates to a method for processing corners in arc fuse additive manufacturing. Background Technology

[0002] Wafer Additive Manufacturing (WAAM) is an advanced manufacturing technology that uses an electric arc as a heat source and metal welding wire as raw material. Through program-controlled welding torch movement, layers are melted and deposited onto a substrate to directly produce metal parts with near-final shapes. Additive manufacturing employs a layer-by-layer deposition model to produce the required parts, resulting in short production cycles, high material utilization, low production costs, and good material properties. It has broad application prospects in aerospace, biomedicine, automotive, and shipbuilding industries.

[0003] As research into this technology continues to deepen, the trajectory planning of 3D model cross-sections by software is becoming increasingly important. Printing path planning has a significant impact on forming speed and forming quality. Through reasonable path planning, heat accumulation effects and material buildup can be reduced, thereby improving the forming quality and forming speed of components.

[0004] When the printing path needs to change direction, corners are created. However, traditional path planning often results in material buildup at these corners, forming a large, round bead. This is because the welding torch has two strokes at the corner, increasing the dwell time at the same position and causing material accumulation. During subsequent printing, the arc is attracted to the protruding area, leading to an imbalance in heat distribution before and after the corner. This uneven heat distribution continues to worsen during subsequent forming processes, ultimately increasing the risk of the welding torch colliding due to excessively high nodal peak values. To address this issue, this application provides a chamfering method for different weld bead diameters in arc wire additive manufacturing. This method effectively prevents material buildup at corners during arc wire additive manufacturing. Summary of the Invention

[0005] To address or partially address the problems existing in related technologies, this invention proposes a method for processing corners in arc-fused wire additive manufacturing.

[0006] This invention provides a method for processing corners in arc-fused wire additive manufacturing, comprising the following steps: (1) Set n points along the deposition loop from the starting point of the arc, and label them in order as A1, A2, ..., A n n is a positive integer less than 10. Using arc-fused-wire additive manufacturing, the welding torch is positioned between A1 and A2. n A square weld bead is formed by deposition between points, with A1 as the starting point and A1 as the ending point. 10 The arc is extinguished at point A1, eventually returning to point A1, A2, ..., A n Set on the center path of the square weld bead; (2) There are four right-angle points on the center path of the weld bead. Select the first right-angle point after starting from the arc starting point A1 as point A3, the second right-angle point as point A6, and the third right-angle point as point A9; starting from point A1, select one point between A1 and A3 as point A2; starting from A3, select two points between A3 and A6 as A4 and A5; starting from point A6, select two points between A6 and A9 as points A7 and A8; select one point between A9 and A1 as point A9. 10 point; (3) According to the requirements of the arc wire additive manufacturing process, the wire feeding speed and welding speed are set to S1m / min and S2mm / s respectively. The radius of the resulting square weld bead is r mm. Then the distances from points A2 and A4 on the center path of the weld bead to A3 are: A2A3=A4A3= The distances from points A5 and A7 on the weld center path to point A6 are both: A5A6 = A7A6 = Points A8 and A on the center path of the weld bead 10 The distance from point A8 to A9 is: A8A9=A 10 A9= ; (4) Therefore, the printed weld path of arc wire additive manufacturing is A1→A2→A4→A5→A7→A8→A 10 →A1.

[0007] In the method for processing corners in the arc-fuse additive manufacturing of the present invention, there are no restrictions on the materials used in the arc-fuse additive manufacturing; as long as an arc-fuse can be used, this method is applicable.

[0008] The technical solution provided by this invention has the following beneficial effects: This invention optimizes the printing path at corners in arc-wire additive manufacturing by calculating the weld bead radius. This overcomes the problem of traditional printing methods where material accumulation at corners creates a weld bead higher than on straight paths, leading to further material buildup due to heat accumulation as the subsequent printing path passes through, thus affecting the forming quality. Therefore, the corner treatment method in arc-wire additive manufacturing described in this invention effectively prevents material accumulation at weld bead corners, reduces material waste, and ensures smooth weld bead printing at corners. Furthermore, since this invention calculates the printing path at corners using the weld bead radius, for different weld bead radii, only the weld bead diameter needs to be measured to determine the optimal corner printing path. Attached Figure Description

[0009] Figure 1 The actual weld pattern obtained by printing using the traditional path.

[0010] Figure 2This is a distribution diagram of each point in the weld bead planning path in Example 1.

[0011] Figure 3 It is a square formed by the path at the corner and the boundary of the weld.

[0012] Figure 4 This is the weld path after passing points e and f in Comparative Example 1.

[0013] Figure 5 This is the weld path after the weld edge passes through points a and c in Example 1.

[0014] Figure 6 This is the actual weld bead obtained by printing the processed path in Example 1. Detailed Implementation

[0015] Example 1 A method for treating corners in arc-fuse additive manufacturing includes the following steps: (1) Set 10 points along the deposition loop from the starting point of the arc, and label them in order as A1, A2, A3, A4, A5, A6, A7, A8, A9, A 10 The arc-wire additive manufacturing process is used to enable the welding torch to operate in the range of A1~A 10 A square weld bead is formed by deposition between points, with A1 as the starting point and A1 as the ending point. 10 The arc is extinguished at point A1, eventually returning to point A1, A2, ..., A 10 It is set on the center path of the square weld bead.

[0016] (2) such as Figure 2 As shown, there are four right-angle points on the center path of the weld bead. The first right-angle point after starting from the arc starting point A1 is selected as point A3, the second as point A6, and the third as point A9. Starting from point A1, one point between A1 and A3 is selected as point A2. Starting from A3, two points between A3 and A6 are selected as A4 and A5. Starting from point A6, two points between A6 and A9 are selected as points A7 and A8. Finally, one point between A9 and A1 is selected as point A1. 10 point.

[0017] (3) Taking point A3 as an example, the center path and boundary of the square weld bead are idealized as straight lines. Since the weld bead has a width, the weld bead boundary includes the inner weld bead boundary and the outer weld bead boundary. Taking point A3 as an example, a square is formed by the weld bead boundary of weld bead A3A1 and the weld bead boundary of weld bead A6A3, as follows: Figure 3 As shown. The inner weld bead boundary is a square inner weld bead boundary, the outer weld bead boundary is a square outer weld bead boundary, and the weld bead center path is a square weld bead path.

[0018] (4) The treatment of the corner in arc wire additive manufacturing is related to the diameter of the weld bead. The wire feed speed and welding speed are two process parameters that directly affect the weld bead diameter. In this embodiment, the material used is 5356 aluminum alloy, and the process parameters of wire feed speed of 3.8m / min and welding speed of 2.5 mm / s are selected to obtain a weld bead with a diameter of 5 mm.

[0019] (5) The weld path does not stop at the corner and the process parameters do not change, but due to the width of the weld, at the corner, such as Figure 3 The actual amount of material deposited in the area Sabcd shown is twice that deposited along the straight line: when the welding torch prints to point A3, the square S abcd The area has been filled with printing material, but due to path constraints, it needs to move from point A3 to the next point. At this point, the material is still cladding, and the actual deposited material is in square S. abcd Deposition occurred twice, resulting in twice the theoretical deposition amount. Reducing the amount of deposited material in the Sabcd area will solve the problem of excessive material deposition at the corners.

[0020] The Sabcd square is located at the corner and is a square with sides of length 2r x 2r (2r being the weld width). The center of the Sabcd square is point O, which is point A3. The straight line represents the amount of deposition material needed to print within the same area using a straight path, i.e., the theoretical deposition amount.

[0021] (6) When the outer edge path of the weld bead at the corner passes through points a and c, S abc = S abcd At this point, the amount of deposited material at the corner is exactly equal to the amount deposited along the straight line. For example... Figure 5 As shown, the weld path at this point is points m and n. The distances from point o (point A3) to point m (point A2) and from point o to point n (point A4) are: Therefore, the weld path is diagonally changed 3.5 mm from the corner intersection to prevent excessive material buildup at the corner.

[0022] (7) The path and calculation were checked for reasonableness by using a distance of 3.5 mm from the intersection point o at both ends of the path. The same method as at A3 was used at A6 and A9 (i.e., step (6)). The results are as follows. Figure 6 As shown, the weld beads printed by this processing method are... Figure 1 Compared to the traditional path without corner handling, this path is smooth at the three corners, preventing material buildup and solder beads. Therefore, the line connecting points m and n is the optimal path A2A4, so the final printed path is A1→A2→A4→A5→A7→A8→A 10 →A1.

[0023] Comparative Example 1 A method for treating corners in arc-fuse additive manufacturing includes the following steps: (1) Set 10 points along the deposition loop from the starting point of the arc, and label them in order as A1, A2, A3, A4, A5, A6, A7, A8, A9, A 10 The arc-wire additive manufacturing process is used to enable the welding torch to operate in the range of A1~A 10 A square weld bead is formed by deposition between points, with A1 as the starting point and A1 as the ending point. 10 The arc is extinguished at point A1, eventually returning to point A1, A2, ..., A 10 It is set on the center path of the square weld bead.

[0024] (2) such as Figure 2 As shown, there are four right-angle points on the center path of the weld bead. The first right-angle point after starting from the arc starting point A1 is selected as point A3, the second as point A6, and the third as point A9. Starting from point A1, one point between A1 and A3 is selected as point A2. Starting from A3, two points between A3 and A6 are selected as A4 and A5. Starting from point A6, two points between A6 and A9 are selected as points A7 and A8. Finally, one point between A9 and A1 is selected as point A1. 10 point.

[0025] (3) Taking point A3 as an example, the center path and boundary of the square weld bead are idealized as straight lines. Since the weld bead has a width, the weld bead boundary includes the inner weld bead boundary and the outer weld bead boundary. Taking point A3 as an example, a square is formed by the weld bead boundary of weld bead A3A1 and the weld bead boundary of weld bead A6A3, as follows: Figure 3 As shown. The inner weld bead boundary is a square inner weld bead boundary, the outer weld bead boundary is a square outer weld bead boundary, and the weld bead center path is a square weld bead path.

[0026] (4) The treatment of the corner in arc wire additive manufacturing is related to the diameter of the weld bead. The wire feed speed and welding speed are two process parameters that directly affect the weld bead diameter. In this embodiment, the process parameters of wire feed speed of 3.8 m / min and welding speed of 2.5 mm / s are selected to obtain a weld bead with a diameter of 5 mm.

[0027] (5) The weld path does not stop at the corner and the process parameters do not change, but due to the width of the weld, at the corner, such as Figure 3 The actual amount of deposited material in the area Sabcd shown is twice that deposited along the straight line. Reducing the amount of deposited material in the Sabcd area to less than half can solve the problem of excessive material deposition at the corners.

[0028] (6) For example Figure 4As shown, the area of ​​square abcd is Sabcd = 25mm. The intersection of the extension of the actual inner boundary of weld A3A1 and the center path of the weld is set as point f, and the intersection of the extension of the actual inner boundary of weld A6A3 and the center path of the weld is set as point e. Let the intersection of the two weld paths A3A1 and A3A6 at the corner be point o, i.e., A3. Let the weld now change from the original path (A1→A3→A6) to a path passing through points e and f (A1→e→f→A5). Let the outer boundary of the weld be line segment gh, which is equal to the line segment parallel to ef and 2.5mm away. Now, calculate the proportion of the area of ​​pentagon abcgh to the area of ​​square abcd. Divide pentagon abcgh into four areas for calculation: square aeoh, square ebfo, square fcgo, and triangle gho. All three squares are equal, with a weld radius r × r = 6.25mm. The area of ​​triangle gho is S gho = (2.5 × 2.5) ÷ 2 = 3.12. The area S of pentagon abcgh. abcgh =6.25×3+3.12=21.88mm, >0.5. Therefore, the EF path cannot reduce material buildup at corners.

[0029] (7) At A6 and A9, the same method as at A3 (i.e. step (6)) is used, and material will also accumulate at the corner.

[0030] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for treating corners in arc-fused wire additive manufacturing, characterized in that: Includes the following steps: (1) Set n points along the deposition loop from the starting point of the arc, and label them in order as A1, A2, ..., A n With n=10, an arc-wire additive manufacturing process is used to make the welding torch operate between A1 and A2. n A square weld bead is formed by deposition between points, with A1 as the starting point and A1 as the ending point. 10 The arc is extinguished at point A1, eventually returning to point A2, ..., A1. n Set on the center path of the square weld bead; (2) There are four right-angle points on the center path of the weld bead. Select the first right-angle point after starting from the arc starting point A1 as point A3, the second right-angle point as point A6, and the third right-angle point as point A9; starting from point A1, select one point between A1 and A3 as point A2; starting from A3, select two points between A3 and A6 as A4 and A5; starting from point A6, select two points between A6 and A9 as points A7 and A8; select one point between A9 and A1 as point A9. 10 point; (3) According to the requirements of the arc wire additive manufacturing process, the wire feeding speed and welding speed are set to S1 m / min and S2 mm / s respectively. The radius of the resulting square weld bead is r mm. Then the distances from points A2 and A4 on the center path of the weld bead to A3 are: A2A3=A4A3= The distances from points A5 and A7 on the weld center path to point A6 are both: A5A6 = A7A6 = Points A8 and A on the center path of the weld bead 10 The distance from point A8 to A9 is: A8A9=A 10 A9= ; (4) Therefore, the printed weld path of arc wire additive manufacturing is A1→A2→A4→A5→A7→A8→A 10 →A1.

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