阅读说明：本技术 圆环结构件丝弧增材制造形貌控制方法 (Method for controlling shape of circular ring structural member during wire arc additive manufacturing ) 是由 王鑫 刘飞 谭峰 李海青 王淑娴 任文举 冯松 于 2021-01-29 设计创作，主要内容包括：本发明请求保护一种圆环结构件丝弧增材制造形貌控制方法,属于丝弧増材与3D成形领域；针对圆环结构件的成形,提出逐层错位的成形的方式,并采取分阶段划分控制起始端恒流提速、尾端恒速降流的分级衰减电弧控制方法：从第一层到第五层的过渡成形中,采用逐层降低10％左右能量密度的方法降低层间热累积效应,第六层后的稳定成形过程中,在起始端速度比稳定阶段高60％左右,尾端能量衰减30％左右。本发明提出一种圆环结构件丝弧增材制造成形控制的新思路,降低了启弧次数,极大的降低了逐层沉积过程中热累积引起的金属熔体沉积高度不稳定,有效解决了圆环结构件成形时Z轴运动点上金属瘤堆积与路径规划的控制等难题。(The invention discloses a method for controlling the wire arc additive manufacturing appearance of a circular ring structural member, belonging to the field of wire arc additive and 3D forming; aiming at the forming of the circular ring structural member, a layer-by-layer staggered forming mode is provided, and a graded attenuation electric arc control method for controlling constant current acceleration at a starting end and constant current reduction at a tail end by grading is adopted: in the transition forming from the first layer to the fifth layer, the interlayer heat accumulation effect is reduced by adopting a method of reducing the energy density by about 10 percent layer by layer, in the stable forming process after the sixth layer, the speed at the starting end is about 60 percent higher than that in the stable stage, and the energy at the tail end is attenuated by about 30 percent. The invention provides a new idea for controlling the wire arc additive manufacturing and forming of the circular ring structural member, which reduces the arc starting times, greatly reduces the unstable deposition height of the metal melt caused by heat accumulation in the layer-by-layer deposition process, and effectively solves the problems of the control of the metal nodule accumulation and the path planning on the Z-axis movement point during the forming of the circular ring structural member.)

1. A wire arc additive manufacturing appearance control method for a circular ring structural part and a multilayer closed thin-wall part structural part is used for manufacturing a circular ring structural part and a multilayer closed thin-wall part structural part and is formed by a 3D printing system of an electric arc additive manufacturing system, and is characterized by comprising the following steps of:

the method comprises the following steps: designing a circular structural member, wherein the circular structural member comprises the diameter, the total height, the expected layer height and the expected layer width of a designed part, and slicing three-dimensional data of the circular structural member to obtain the information of the number and the perimeter of a circle;

step two: the ring structural member consists of m layers, the forming length of each layer is L, and the length of each layer of transition section which is staggered layer by layer is set as S;

step three: in the transition forming from the first layer to the fifth layer, the interlayer heat accumulation effect is reduced by adopting a method of reducing the energy density layer by layer, and the current is reduced;

step four: in the stable forming process after the sixth layer, the forming current adopted for the starting end is unchanged, and the current in the stable stage is set at a fixed value;

step five: the forming speed of the tail end is unchanged, and the energy density of the electric arc is gradually reduced to 30% of the energy density in the stable forming stage at a position 8-15 mm away from the tail end;

step six: when the forming path of each layer is finished, arc quenching is not needed after the forming of each layer is finished through three-dimensional motion forming;

step seven: and in the movement of Z-axis descending and the transition section length S, reducing the wire feeding speed simultaneously until the forming control of the mth layer is completed, and realizing the control of the forming height in the path length and the height of the path intersection point by TIG electric arc additive manufacturing of the ring structural member until the processing of the sample piece is completed.

2. The method for controlling the wire arc additive manufacturing morphology of the circular ring structural member according to claim 1, wherein the step one is to design the diameter, the total height, the desired layer height and the desired layer width of the part, and specifically comprises the following steps: the diameter of the designed part is 70mm, the height is 50mm, and the height of each expected layer is h_d1.85mm, the desired layer width is designed to be 8 mm.

3. The method as claimed in claim 1, wherein in the third step of transition from the first layer to the fifth layer, the current is adjusted from 220A to 140A layer by layer, so that the energy density of each layer is reduced by about 10%, and the interlayer heat accumulation effect is finally reduced.

4. The method for controlling the wire arc additive manufacturing morphology of the circular ring structural member according to claim 1, wherein in the stable forming process after the fourth and sixth layers, the forming current is adopted for the starting end to be constant, the fixed value of the current in the stable stage is 130A, and the forming speed is about 60% higher than that in the stable stage within 8-15 mm of the starting end.

5. The method for controlling the additive manufacturing profile of the wire arc of the circular ring structural member according to claim 1, wherein in the movement of the Z-axis descending and the transition section length S, the wire feeding speed is required to be reduced simultaneously, specifically, 50% of the normal value.

6. The method for controlling the wire arc additive manufacturing morphology of the ring structural member according to any one of claims 1 to 5, wherein a test platform is a self-built TIG wire-feeding electric arc additive manufacturing device, a power supply system of the test platform is Fornes MW3000, a wire feeder is an argon arc welding automatic wire feeder WF-007A, a wire is a 7A09 aluminum alloy welding wire with the diameter of 1.2mm, a welding gun is fixed on a three-dimensional workbench and sends a motion instruction by an upper computer, a substrate is made of 7A09 aluminum alloy, the size of the substrate is 300mm x 200mm x 10mm, and technological parameters for testing are as follows: the current is 130A-220A, the forming speed is 1 mm/s-6 mm/s, the protective gas is 99.9999 percent pure argon, and the gas flow is 10L/min.

Technical Field

The invention belongs to the technical field of TIG electric arc additive manufacturing, and particularly relates to a wire arc additive manufacturing forming control method for a circular ring structural member.

Background

The TIG electric arc additive manufacturing technology is a novel metal rapid forming technology, has the characteristics of high forming efficiency, controllable heat input and low equipment cost, and is suitable for personalized manufacture of complex workpieces.

The ring structure is a typical structural member, and is characterized in that the ratio of the surface contour dimension to the thickness is large, and the ring structure has the advantages of light weight, compact structure, strong bearing capacity and the like, and at present, the following two main difficulties exist during the TIG electric arc additive manufacturing of the ring structural member: (1) the topography of the multi-layer heat accumulation sink layer fluctuates. With the increase of the forming layer number, the heat dissipation condition is gradually transited from three-dimension to two-dimension, the heat transfer channel is reduced, so that the multilayer heat accumulation effect is gradually obvious, the transition flow of the molten metal in the forming process is caused, the molten metal presents irregular fluctuation, and the expected shape is not reached. (2) The metal tumor accumulation on the Z-axis movement point causes the appearance of the point to be convex, the wire feeding is difficult, and the end part of the tungsten electrode is easy to contact with a molten pool and cannot be continuously formed. The above problems will bring great challenges to the manufacturing of the ring structural member, and therefore, research on the TIG arc additive manufacturing and forming control of the ring structural member is necessary.

At present, the research on the forming precision control of the circular ring structural part is less, and a learner provides accurate arc blowout and arc starting when a Z axis descends, but the arc starting at the same point for multiple times damages the formed size structure. There have also been proposals to increase the amount of wire feed and then mill the accumulated metal nodules, but this approach not only reduces manufacturing efficiency but also wastes material. Therefore, a simple, practical and effective control method is needed to be developed, so that the forming stability and quality of the TIG arc additive manufacturing of the ring structural member are further improved.

Disclosure of Invention

The invention aims to solve the problems of forming appearance fluctuation, metal tumor accumulation and the like in the TIG electric arc additive manufacturing process of the ring structural member in the prior art. A method for controlling the shape of a circular structural member during wire arc additive manufacturing is provided. The technical scheme of the invention is as follows:

a wire arc additive manufacturing appearance control method for a circular ring structural part and a multilayer closed thin-wall part structural part is used for manufacturing a circular ring structural part and a multilayer closed thin-wall part structural part and is formed through a 3D printing system of an electric arc additive manufacturing system, and comprises the following steps:

the method comprises the following steps: designing a circular structural member, wherein the circular structural member comprises the diameter, the total height, the expected layer height and the expected layer width of a designed part, and slicing three-dimensional data of the circular structural member to obtain the information of the number and the perimeter of a circle;

step two: the ring structural member consists of m layers, the forming length of each layer is L, and the length of each layer of transition section which is staggered layer by layer is set as S;

step three: in the transition forming from the first layer to the fifth layer, the interlayer heat accumulation effect is reduced by adopting a method of reducing the energy density layer by layer, and the current is reduced;

step four: in the stable forming process after the sixth layer, the forming current adopted for the starting end is unchanged, and the current in the stable stage is set at a fixed value;

step five: the forming speed of the tail end is unchanged, and the energy density of the electric arc is gradually reduced to 30% of the energy density in the stable forming stage at a position 8-15 mm away from the tail end;

step six: when the forming path of each layer is finished, arc quenching is not needed after the forming of each layer is finished through three-dimensional motion forming;

step seven: and in the movement of Z-axis descending and the transition section length S, reducing the wire feeding speed simultaneously until the forming control of the mth layer is completed, and realizing the control of the forming height in the path length and the height of the path intersection point by TIG electric arc additive manufacturing of the ring structural member until the processing of the sample piece is completed.

Further, the step one is to design the diameter, the total height, the height of each layer and the width of each layer of the part, and specifically includes: the diameter of the designed part is 70mm, the height is 50mm, and the height of each expected layer is h_d1.85mm, the desired layer width is designed to be 8 mm.

Further, in the third step of transition formation from the first layer to the fifth layer, the current is adjusted from 220A to 140A layer by layer, so that the energy density of each layer is reduced by about 10%, and finally the interlayer heat accumulation effect is reduced.

In the stable forming process after the fourth and sixth layers, the forming current is constant at the starting end, the fixed value of the current in the stable stage is 130A, and the forming speed is about 60% higher than that in the stable stage within 8-15 mm of the starting end.

Furthermore, in the seventh step, in the movement of the Z-axis descending and the transition section length S, the wire feeding speed needs to be reduced at the same time, specifically, 50% of the normal value.

Further, TIG that test platform was built by oneself send an electric arc vibration material disk equipment, its electrical power generating system is fornices MW3000, send a machine for argon arc welding automatic wire feeder WF-007A, the silk material is the 7A09 aluminum alloy welding wire that the diameter is 1.2mm, welder fixes on three-dimensional workstation, send the motion instruction by the host computer, the base plate material is 7A09 aluminum alloy, the size is 300mm 200mm 10mm, the technological parameter of experimental usefulness is: the current is 130A-220A, the forming speed is 1 mm/s-6 mm/s, the protective gas is 99.9999 percent pure argon, and the gas flow is 10L/min.

The invention has the following advantages and beneficial effects:

(1) compared with the traditional method, the method provided by the invention has the advantages that the operability is strong, and the problem of unstable deposition height of the metal melt caused by heat accumulation in the layer-by-layer deposition process is simply and effectively solved.

(2) The provided layer-by-layer staggered forming mode automatically reduces the wire feeding amount in the descending of the Z axis and the movement of the transition section, and effectively solves the problems of the accumulation of metal tumors on the path point of the Z axis, the control of path planning and the like when the circular ring structural member is formed.

(3) The arc extinguishing and the motion pause are not needed in the whole forming process, so that the forming time is shortened, the cost is reduced, the forming quality is improved, and the TIG arc additive manufacturing of the ring structural member is realized.

Drawings

FIG. 1 is a schematic view of a preferred embodiment of the invention providing a layer-by-layer malposition forming of a circular ring structure;

FIG. 2 is a flow chart of a method for controlling a wire arc additive manufacturing profile of a circular structural member according to a preferred embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described in detail and clearly with reference to the accompanying drawings. The described embodiments are only some of the embodiments of the present invention.

The technical scheme for solving the technical problems is as follows:

the TIG that concrete test platform was built by oneself send an electric arc vibration material disk equipment among this embodiment, its electrical power generating system is Fornes MW3000, send a machine for argon arc welding automatic wire feeder WF-007A, the silk material is the 7A09 aluminum alloy welding wire that the diameter is 1.2mm, welder fixes on three-dimensional workstation, send the motion instruction by the host computer, the base plate material is 7A09 aluminum alloy, the size is 300mm 200mm 10mm, the technological parameter of experimental usefulness is: the current is 130A-220A, the forming speed is 1 mm/s-6 mm/s, the protective gas is 99.9999 percent pure argon, and the gas flow is 10L/min.

A method for controlling TIG arc additive manufacturing and forming of a ring structural member comprises the following steps of:

the method comprises the following steps: the embodiment designs a circular ring structural member based on fig. 1, the diameter of a design part is 70mm, the height of the design part is 50mm, and the height of each layer is h_dThe desired layer width was designed to be 8mm at 1.85mm, per layer period.

Step two: slicing the annular three-dimensional data to obtain the information of the number of layers and the perimeter of a circle;

step three: the ring structural member consists of m layers, the forming length of each layer is L, and the length of each layer of transition section which is staggered layer by layer is set as S;

step four: in the transition formation from the first layer to the fifth layer, the current is adjusted from 220A to 140A layer by layer, so that the energy density of each layer is reduced by about 10 percent, and the interlayer heat accumulation effect is finally reduced;

step five: in the stable forming process after the sixth layer, the forming current adopted for the starting end is unchanged, and the forming speed is about 60 percent higher than that in the stable stage within 8-15 mm of the starting end;

step six: the tail end is shaped at a constant speed, and the energy density of the electric arc is gradually reduced to 30% of the energy density in the stable shaping stage at a position 8-15 mm away from the tail end;

step seven: when the forming path of each layer is finished, arc quenching is not needed after the forming of each layer is finished through three-dimensional motion forming;

step eight: in the movement of Z-axis descending and transition section length S, wire feeding speed needs to be reduced at the same time, and the normal value is 50%; and (4) until the forming control of the mth layer is completed, controlling the forming height and the path cross point height in the path length by TIG electric arc additive manufacturing of the ring structural member until the processing of the sample piece is completed.

Compared with the prior art, the method distributes single-point descending of the circular ring structure to different nodes of each layer, reduces the arc starting and extinguishing times, shortens the forming time, reduces the production cost, completes the forming process in a full-automatic mode, reduces the energy density by adjusting the forming current, the forming speed and the layered adjusting current in a segmented mode, and does not need manual intervention. Compared with the prior art, the method for controlling the wire arc additive manufacturing morphology of the circular ring structural part has the advantages that the manufactured circular ring structural part has higher size precision and surface smoothness, and a more efficient direct forming method and a basic theory are provided for path planning of circular ring structural parts.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The above examples are to be construed as merely illustrative and not limitative of the remainder of the disclosure. After reading the description of the invention, the skilled person can make various changes or modifications to the invention, and these equivalent changes and modifications also fall into the scope of the invention defined by the claims.