阅读说明：本技术 一种消除电弧增材制造构件边缘塌陷的路径修正方法 (Path correction method for eliminating edge collapse of arc additive manufacturing component ) 是由 刘海华 李亮玉 张文浩 高文强 赵淘 陈豪杰 王力斌 王天琪 于 2019-12-03 设计创作，主要内容包括：本发明适用于电弧增材制造技术领域,提供了一种消除电弧增材制造构件边缘塌陷的路径修正方法。本方法包括：根据焊缝尺寸计算边缘层单个焊缝高度下降量,确定增加边缘补偿焊道所需要的层数；将正常填充路径和边缘补偿焊道修正路径组合为一个制造周期,根据构件高度确定制造周期数。经过实验验证,构件的表面平整度得到提高,边缘塌陷完全消除。(The invention is suitable for the technical field of electric arc additive manufacturing, and provides a path correction method for eliminating edge collapse of an electric arc additive manufacturing component. The method comprises the following steps: calculating the height descending amount of a single welding seam of the edge layer according to the size of the welding seam, and determining the number of layers required for increasing the edge compensation welding bead; the normal fill path and the edge compensation bead modification path are combined into one manufacturing cycle, and the number of manufacturing cycles is determined based on the height of the component. Experiments prove that the surface flatness of the component is improved, and the edge collapse is completely eliminated.)

1. A path correction method for eliminating edge collapse of an arc additive manufacturing component is characterized in that: calculating the height descending amount of a single welding seam of the edge layer according to the size of the welding seam, and determining the number of layers required for increasing the edge compensation welding bead; the normal fill path and the edge compensation bead modification path are combined into one manufacturing cycle, and the number of manufacturing cycles is determined based on the height of the component. The specific method comprises the following steps:

there is no material shortage area in the middle of the member, so the middle bead is not considered. Let B (x, y) represent the xth pass of the xth layer, pass B (1, 1) being the first pass deposited on the substrate and pass B (1, n) being the last pass deposited on the substrate. The deposition sequence is from left to right, with B (1, 2) being the lap pass and B (2, 1) being the second layer of the edge pass, with the deposition path and B (1, 1) being on the same axis. When a weld bead B (2, 1) is deposited on the upper side of the weld bead B (1, 1), a material shortage area exists on the axial side of the weld bead B (1, 1), and the material shortage area of the weld bead B (2, 1) is filled by partial material of the weld bead B (2, 1), so that the actual deposition amount of the weld bead B (2, 1) is less than the ideal deposition amount. And calculating the material loss amount of B (2, 1) to obtain the height reduction amount of the single-pass weld joint.

As the height of the member is accumulated, when the height of the edge bead is decreased by an amount close to one bead height, the height difference compensation bead in which the axis 1 of the edge bead and the axis n are in the same position is increased, that is, the edge compensation bead correction path. And combining the normal filling path and the edge compensation bead correction path into one manufacturing period, and determining the required manufacturing period according to the height of the actual component to eliminate the height difference between the layer edge and the main body.

2. The method of claim 1, wherein the method comprises: the method can improve the surface flatness of the arc additive manufacturing component.

3. The method of claim 1, wherein the method comprises: the method can eliminate collapse of the edge of the arc additive manufacturing component.

Technical Field

The invention relates to the technical field of electric arc additive manufacturing, in particular to a path correction method for eliminating edge collapse of an electric arc additive manufacturing component.

Background

The Wire and Arc Additive Manufacturing (WAAM) is a direct manufacturing technique for forming metal parts by melting synchronously fed Wire materials and depositing the same layer by layer on a substrate. Compared with the traditional manufacturing method, the WAAM has the advantages of simple device, wide material use, large forming size, short production period, high material utilization rate, low manufacturing cost and the like. The technology is widely applied to the fields of aerospace, automobile manufacturing, national defense and the like.

The numerical control machining technology or the robot technology is combined with the WAAM technology, so that the production efficiency and the material utilization rate can be improved, and the forming precision and the forming quality of the metal member can be improved. Yu Ming Zhang et al developed a rapid manufacturing system (RP-system) for GMAW in conjunction with the welding process, in which different application modules were adapted to different deposition processes and the precision of component formation was improved by controlling droplet size and transition frequency. Jun Xiong et al developed a set of vision sensing systems for monitoring, controlling and adjusting the working distance between the welding gun and the substrate in real time, and established the corresponding relationship between the geometric shape of the weld joint and the welding process parameters by using the artificial neural network technology, and predicted the optimal welding process parameters of the required weld bead shape. Kwak Y M et al propose a deposited material temperature scanning control method, which eliminates thermal deformation of metal materials and improves the geometric accuracy of the component. Karunakaran K P et al, which combines a cnc milling machine and a welding system into a cnc additive manufacturing system that can be directly used for near-net forming and finishing of complex metal components, developed cnc machining program generation software suitable for the system.

The cross section of the single-layer welding bead is fitted with standard curves such as a parabola, a cosine, an arc and the like by the Skowa et al, and the fitting degree of the cross section of the single-layer welding bead and the parabola is found to be the best. Aiyiti W et al established an adjacent weld bead overlap model, and systematically studied the relationship between the aspect ratio of the weld, the center distance of adjacent weld beads and the overlap ratio, which significantly improved the flatness of the upper surface of a single-layer, multi-pass weld. The Donghong Ding et al establishes a weld joint lapping model, obtains the optimal center distance d of the adjacent weld bead as 0.738w (w is the weld joint width), and the upper surface of the single-layer multi-pass weld joint reaches high flatness under the lapping rate. Katou M et al obtain better structure components and mechanical properties by optimizing forming parameters and selecting different alloy materials to alternately stack and form complex thin-walled parts. Ding D et al propose an MAT path planning method suitable for thin-walled components, which significantly improves the forming quality and geometric accuracy of metal components. Panchaggula J S et al can manufacture complex thin-walled metal components using a multi-degree-of-freedom mechanical device in combination with developed path generation software. The above researches are directed at the overlapping rate of adjacent welding beads and the accurate forming of the thin-wall component, so that the thin-wall component achieves high geometric accuracy and good mechanical performance. Xu F et al propose a cyclically alternating lamination strategy for multilayer multi-channel solid structures, with every two adjacent layers of deposition path rotated by 90 ° or 180 °, experiments show that the lamination strategy can improve the forming quality. Li Y et al propose a path correction strategy for edge layer material shortage of a multilayer multi-pass member that offsets the edge bead by a distance to fill the material shortage area, which improves the forming quality of the metal member.

At present, the research on the surface flatness and the side collapse of a multilayer multi-channel thick-wall component is relatively few, and a path correction method for eliminating the side collapse of an electric arc additive manufacturing component is provided, so that the descending amount of an edge layer is compensated in time, the surface flatness of the component is improved, and the side collapse is eliminated.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides the path correction method for eliminating the side collapse of the electric arc additive manufacturing component, and the method has the advantages of simple device, wide material use, large forming size, short production period, high material utilization rate, low manufacturing cost and the like. Aims to solve the technical problems of low flatness and side collapse of the component.

In order to achieve the purpose, the invention provides the following technical scheme:

a path correction method to eliminate arc additive manufacturing component edge collapse, the method comprising:

calculating the height descending amount of a single welding seam of the edge layer according to the size of the welding seam, and determining the number of layers required for increasing the edge compensation welding bead; the normal fill path and the edge compensation bead modification path are combined into one manufacturing cycle, and the number of manufacturing cycles is determined based on the height of the component. The specific method comprises the following steps:

there is no material shortage area in the middle of the member, so the middle bead is not considered. Let B (x, y) represent the xth pass of the xth layer, pass B (1, 1) being the first pass deposited on the substrate and pass B (1, n) being the last pass deposited on the substrate. The deposition sequence is from left to right, with B (1, 2) being the lap pass and B (2, 1) being the second layer of the edge pass, with the deposition path and B (1, 1) being on the same axis. When a weld bead B (2, 1) is deposited on the upper side of the weld bead B (1, 1), a material shortage area exists on the axial side of the weld bead B (1, 1), and the material shortage area of the weld bead B (2, 1) is filled by partial material of the weld bead B (2, 1), so that the actual deposition amount of the weld bead B (2, 1) is less than the ideal deposition amount. And calculating the material loss amount of B (2, 1) to obtain the height reduction amount of the single-pass weld joint.

As the height of the member is accumulated, the height difference between the positions of the axis 1 and the axis n of the edge bead is increased to compensate for the bead when the height of the edge bead is lowered by an amount close to one bead height. The normal filling path and the edge compensation bead modification path are combined into a manufacturing cycle, the required manufacturing cycle is determined according to the height of the actual component, and the height difference between the layer edge and the main body is eliminated.

Compared with the prior art, the path correction method for eliminating the side collapse of the arc additive manufacturing component has the following characteristics:

1. the surface flatness of the arc additive manufacturing component is improved;

2. collapse of the edges of the arc additive manufacturing component is completely eliminated.

Drawings

In order to more clearly illustrate the technical solutions provided by the embodiments of the present invention, the drawings used in the present invention will be briefly described below, and it is obvious that the drawings in the following description are only some implementation examples of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a mathematical model of path correction

FIG. 2 is a schematic diagram of a path correction method

FIG. 3 is an experimental result, in which (a) is a rectangular parallelepiped member manufactured by a conventional deposition path; (b) a cuboid component cross-section fabricated for a conventional deposition path; (c) is a rectangular parallelepiped member manufactured by the present route correction method; (d) for the cross section of a rectangular parallelepiped member manufactured by the present path correcting method

Detailed Description

The present invention will be further described in detail with reference to the following examples and the accompanying drawings.

The invention discloses a path correction method for eliminating side collapse of an arc additive manufacturing component, which adopts the following technical scheme:

there is no material shortage area in the middle of the member, so the middle bead is not considered. As shown in the path correction mathematical model of fig. 1, assume that the xth pass of the xth layer is represented by B (x, y), pass B (1, 1) is the first pass deposited on the substrate, and pass B (1, n) is the last pass deposited on the substrate. Deposition sequence is from left to right, B (1, 2) is the lap pass, B (2, 1) is the second layer of the edge pass S_ACDThe deposition path and B (1, 1) are on the same axis. There is a material shortage region to the left of the axis of the bead B (1, 1), and when the bead B (2, 1) is deposited over B (1, 1), the material shortage region S of part B (2, 1) to B (1, 1) is present_ACDAnd (4) filling, so that the actual deposition amount of B (2, 1) is less than the ideal deposition amount, and the height of the welding seam is less than h. And calculating the material loss amount of B (2, 1) to obtain the height reduction amount of the single-pass weld joint.

In the model, the cross section of the welding bead is in a quadratic parabola shape, wherein w is the width of the welding seam, h is the height of the welding seam, and the functional expression is as follows:

f(x)＝ax²+c

h＝c

in order to obtain the height drop value of the weld bead B (2, 1), the area S of the material shortage region of the weld bead B (1, 1) must be calculated_ACD. The calculation formula is as follows:

S_ACD＝S_ABCD-S_ABC

the material shortage of the weld bead B (1, 1) is filled up with the partial material of the weld bead B (2, 1), and the height drop value of the weld bead can be quantitatively determined by determining the material shortage of the weld bead B (2, 1). Assuming that the height of the descent is h', the abscissa corresponding to the vertex after the descent is x₀The method for calculating the loss of the B (2, 1) material is as follows:

S_EFGH＝2(S_EFIA-S_GFIA)

when the material shortage area of B (1, 1) and the material loss amount of B (2, 1) are equal, the coordinate value x corresponding to the vertex after the descent can be obtained₀Height of descent h', layer body and layerThe height difference H' between the edges is calculated as follows:

S_ACD＝S_EFGH

calculating the height drop h' of a single welding seam of the edge layer according to the size of the welding seam, and determining the number of layers required for increasing the edge compensation welding bead; the normal fill path and the edge compensation bead modification path are combined into one manufacturing cycle, and the number of manufacturing cycles is determined based on the height of the component.

As shown in the schematic diagram of the path correction method in fig. 2, the first layer is stacked on the substrate, the layer edge forms a material shortage region, the welding bead B (2, 1) fills the material shortage region of the first layer, the welding bead height is decreased by h ', the welding bead B (3, 1) fills the material shortage region of the layer B (2, 1), the height difference is accumulated to be 2 h', and so on, the decrease value of the edge height of the fourth layer is close to the height of one welding bead, the height difference between the axis 1 of the edge welding bead and the axis n at the same position is increased to compensate the welding bead, and the height difference between the layer edge and the main body is eliminated. After the path correction method is adopted, the height of the edge layer is H_cdKeeping the height of the main body layer consistent, and the upper surface of the highest layer is a smooth plane. The correction method can improve the flatness of the surface of the component and eliminate the side surface collapse by only increasing the height difference compensation welding bead without changing the manufacturing parameters.

The path correction method was verified by experiments that produced two cuboid members by the conventional deposition path and the path correction method, respectively. The experimental results are shown in fig. 3, (a) is a rectangular parallelepiped member manufactured by a conventional deposition path, and the flatness of the upper surface is low: (c) the flatness of the upper surface of a rectangular parallelepiped member manufactured by the path correction method is improved. The member obtained by the two methods was cut from the position shown by the red dotted line in fig. 3, and the cross section thereof was observed, as shown in (b) (d), and the ideal cross-sectional profile was marked by the red dotted line. Experimental results show that the surface flatness of the component obtained by the path correction method is improved, and the side collapse is completely eliminated.