Process Development for a Robotized Laser Wire Additive Manufacturing

Author(s):  
Meysam Akbari ◽  
Yaoyu Ding ◽  
Radovan Kovacevic

Additive manufacturing has attracted the attention of industries such as aerospace and automotive as well as the medical technology sectors in recent years. Among all metal-based additive techniques, laser metal wire deposition offers some advantages like shorter processing time, more efficient material usage, and a larger buildup envelop. It has been found that robotized laser/wire additive manufacturing (RLWAM) is a demanding process. A plethora of process parameters must be controlled compared to other laser-based metal deposition processes. The influence of main process parameters such as laser power, stepover increment, wire feed speed, travel speed and z-increment was investigated in this study to find the optimal values. Droplet formation, wire dripping, irregular deposition in the first layer, and deviation of the wire tip were also found to be the main obstacles throughout the process and practical solutions were proposed to deal with these issues. In this study, an 8-axis robot (6-axis arm robot with a 2-axis positioner) and a 4 kW fiber laser along with a wire feeder were integrated to print the different geometrical shapes in 3D. In order to verify the geometrical accuracy of the as-built part, the buildup was scanned using a portable 3D laser scanner. The 3D representation, the Standard Tessellation Language (STL) format obtained from the buildup, was compared with the original CAD model. The results show that RLWAM can be successfully applied in printing even complicated geometries.

2021 ◽  
Vol 1016 ◽  
pp. 24-29
Author(s):  
Achraf Ayed ◽  
Guénolé Bras ◽  
Henri Bernard ◽  
Pierre Michaud ◽  
Yannick Balcaen ◽  
...  

Additive manufacturing (AM) using wire as an input material is currently in full swing, with very strong growth prospects thanks to the possibility of creating large parts, with high deposition rates, but also a low investment cost compared to the powder bed fusion machines. A versatile 3D printing device using a Direct Energy Deposition Wire-Laser (DED-W Laser) with Precitec Coaxprinter station to melt a metallic filler wire is developed to build titanium parts by optimizing the process parameters. The geometrical and metallurgical of produced parts are analyzed. In the literature, several authors agree to define wire feed speed, travel speed, and laser beam power as first-order process parameters governing laser-wire deposition. This study shows the relative importance of these parameters taking separately as well as the importance of their sequencing at the start of the process. Titanium deposit are obtained with powers never explored in bibliography (up to 5 kW), and wire feed speed up to 5 m.min-1 with a complete process repeatability.


2021 ◽  
Vol 1016 ◽  
pp. 250-255
Author(s):  
Achraf Ayed ◽  
Guénolé Bras ◽  
Henri Bernard ◽  
Pierre Michaud ◽  
Yannick Balcaen ◽  
...  

In additive manufacturing, technologies based on the fusion of a metallic wire using an electric arc represent an interesting alternative to current manufacturing processes, particularly for large metal parts, thanks to higher deposition rates and lower process costs than powder or wire-laser technologies. A versatile 3D printing device using a DED-W Arc (Direct Energy Deposition by wire-arc) station to melt a metallic filler wire is developed to build titanium parts by optimizing the process parameters and control the geometrical, metallurgical and the mechanical properties of produced parts. In this study, the impact of two different CMT synergic lines on the energetic and geometric behavior of Ti-6Al-4V single deposits is highlighted. These are related to first order parameters: wire feed speed (WFS) and travel speed (TS). The results show difference on energy, geometric of deposits and different deposition regime between these two law with identical process parameters. The second part of this study focuses on the transition from single deposits to walls and blocks. By first choosing the best set of process parameters to make the construction of thin walls (composed of stacked layers), and then the research the optimal horizontal step of deposition (overlapping) for thicker constructions, results obtained made it possible to validate transition from single deposits (1D) to thick walls (3D) without any weld pool collapse or lack of fusion.


2020 ◽  
Vol 321 ◽  
pp. 03002
Author(s):  
A. Ayed ◽  
G. Bras ◽  
H. Bernard ◽  
P. Michaud ◽  
Y. Balcaen ◽  
...  

Arc-wire or laser-wire additive manufacturing seems promising because it allows large parts to be produced with significant deposition rates (ten times higher than powder bed additive manufacturing), for a lower investment cost. These additive manufacturing techniques are also very interesting for the construction or the repair of parts. A versatile 3D printing device using a Wire Arc Additive Manufacturing (WAAM) station or laser device Wire Laser Additive Manufacturing (WLAM) for melting a filler wire is developed to repair and build large titanium parts. The final objectives of the study are to optimize the process parameters to control the dimensional stability, the metallurgical and mechanical properties of the produced parts. In this paper, an experimental study is carried out to determine the first order process parameter ranges (synergic law, laser power, wire feed speed, travel speed) appropriate for these two techniques, for repair or construction parts on Ti-6 Al-4V.


2019 ◽  
Vol 3 (2) ◽  
pp. 32 ◽  
Author(s):  
Yuri Yehorov ◽  
Leandro João da Silva ◽  
Américo Scotti

The purpose of the study was to propose a strategy to assess the potential reduction of the production cost during wire+arc additive manufacturing (WAAM) based on the combination of wire feed speed (related to deposition rate) and travel speed (related to deposition time). A series of experiments, using a multilayer-non-oscillated single pass wall made of an Al-Mg alloy, was conducted. The quality of the wall was assessed through the lateral surface waviness and top layer undulation. The concepts of Surface Waviness and Buy-to-Apply indices were introduced. Initially, the range of travel speed (TS) that provided layers with acceptable quality was determined for a given wire feed speed (WFS), corresponding to a constant current. Then, the effect of the increase of production capacity of the process (though current raising, yet maintaining the ratio WFS/TS constant) on the wall quality for a given condition within the TS range was assessed. The results showed that the useful range of TS prevents too rough a waving surface below the lower limit and top surface undulation over the higher limit. However, inside the range, there is little quality variation for the case under study. Finally, simulations of deposition time were developed to demonstrate the weight of the TS on the final deposition time and wall quality as a function of a target wall width. This respective weight showed the existence of a complex and unpredictable, yet determined, power of a combination of TS, target wall geometry, and dead time between subsequent layers. It was verified to be possible to find optimized TS as a function of different target geometries.


Author(s):  
Valentine Cazaubon ◽  
Audrey Abi Akle ◽  
Xavier Fischer

AbstractAdditive Manufacturing has proven to be an economically and industrially attractive process in building or repairing parts. However, the major issue of this new process is to guarantee a mechanical behavior identical to the subtractive manufacturing methodologies. The work, presented in this paper, is centered on the Laser Wire Metal Deposition (LMD-w) method with the metallic alloy TA6V. Its working principle is to fuse a coaxial wire on a substrate with a laser as a heat source. To better understand the interaction between the input parameters (Laser Power, Wire Feed Speed and Tool Speed) and the clad geometry output variables (Height, Width and Contact Angle) and the substrate displacement, we have realized an experimentation. We printed 9 clads according Taguchi’s experimental design. Pearson correlation coefficient and Fisher test performed on the experimental measures showed as main result: Tool Speed is the parameter with the most significant influence on the output variables.


2018 ◽  
Vol 24 (2) ◽  
pp. 342-350 ◽  
Author(s):  
Haibin Geng ◽  
Jinglong Li ◽  
Jiangtao Xiong ◽  
Xin Lin ◽  
Dan Huang ◽  
...  

Purpose As known, the wire and arc additive manufacture technique can achieve stable process control, which is represented with periodic surface waviness, when using empirical methods or feedback control system. But it is usually a tedious work to further reduce it using trial and error method. The purpose of this paper is to unveil the formation mechanism of surface waviness and develop a method to diminish it. Design/methodology/approach Two forming mechanisms, wetting and spreading and remelting, are unveiled by cross-section observation. A discriminant is established to differentiate which mechanism is valid to dominate the forming process under the given process parameters. Findings Finally, a theoretical method is developed to optimize surface waviness, even forming a smooth surface by establishing a matching relation between heat input (line energy) and materials input (the ratio of wire feed speed to travel speed). Originality/value Formation mechanisms are revealed by observing cross-section morphology. A discriminant is established to differentiate which mechanism is valid to dominate the forming process under the given process parameters. A mathematical model is developed to optimize surface waviness, even forming a smooth surface through establishing a matching relation between heat input (line energy) and materials input (the ratio of wire feed speed to travel speed).


2017 ◽  
Vol 9 (7) ◽  
pp. 168781401771498
Author(s):  
Khasempong Songsorn ◽  
Keartisak Sriprateep ◽  
Sampan Rittidech

In this article, an optimization technique using the Taguchi method with multiple performance characteristics for the percent zinc coating balances edge joints of galvanized steel sheets for metal inert gas pulse brazing process was proposed. The orthogonal array, multi-response signal-to-noise ratio, and analysis of variance were employed to study the performance characteristics. Five metal inert gas pulse brazing process parameters, namely, wire feed speed, arc voltages, travel speed, peak currents, and pulse frequency, were optimized with considerations of multiple performance characteristics including percent zinc coating balances edge joints. Experimental results were provided to confirm the effectiveness of this approach. The optimum metal inert gas pulse brazing technique conditions were wire feed speed of 3.25 m/min, arc voltages of 18 V, travel speed of 0.8 m/min, peak currents of 425 A, and pulse frequency of 35 Hz. Confirmation tests of the optimal levels with the initial cutting parameters are carried out in order to illustrate the effectiveness of this method in metal inert gas pulse brazing technique for galvanized steel sheets.


2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Wei Liang ◽  
Qiongying Lv ◽  
Lin Guan ◽  
Zhigang Xing

The paper studies the complicated problem in the spinning process of the shell with longitudinal and latitudinal inner ribs. The finite element software ABAQUS is used to establish the finite element model of the cylindrical shell with the longitudinal and latitudinal inner ribs. The numerical simulation of the spinning process is carried out. The stress distribution and strain distribution of the inner and outer surfaces during the spin-forming process are determined, and the orthogonal test method is used to determine the optimization process test parameters. The influence of the main process parameters on the wall thickness difference of the inner rib shell is obtained by the range analysis: wall thickness reduction rate > rotary wheel feed speed > rotor working angle (arranging according to their influences). And then the corresponding process parameters recommended by the spinning test are given. The measurement problem of inner ribs is solved by building of the robot shape measurement system which helps detect the three-dimensional shape of the inner ribs, and the precision of the spun sample was detected by the point cloud deviation comparison.


2019 ◽  
Vol 26 (3) ◽  
pp. 499-508
Author(s):  
Yun Zhao ◽  
Fang Li ◽  
Shujun Chen ◽  
Zhenyang Lu

Purpose The purpose of this paper is to develop a build strategy for inclined thin-walled parts by exploiting the inherent overhanging capability of the cold metal transfer (CMT) process, which release wire-arc additive manufacturing from tedious programming work and restriction of producible size of parts. Design/methodology/approach Inclined thin-walled parts were fabricated with vertically placed welding torch free from any auxiliary equipment. The inclined features were defined and analyzed based on the geometrical model of inclined parts. A statistical prediction model was developed to describe the dependence of inclined geometrical features on process variables. Based on these models, a build strategy was proposed to plan tool path and output process parameters. After that, the flow work was illustrated by fabricating a vase part. Findings The formation mechanism and regulation of inclined geometrical features were revealed by conducting experimental trials. The inclined angle can be significantly increased along with the travel speed and offset distance, whereas the wall width is mainly dependent on the ratio of wire feed speed to travel speed. In contrast to other welding process, CMT has a stronger overhanging capability, which provides the possibility to fabricate parts with large overhanging features directly with high forming accuracy. Originality/value This paper describes a novel build strategy for inclined thin-walled parts free from any auxiliary equipment. With the proposed strategy, a complex structural component can be deposited directly in the rectangular coordinates additive manufacturing system, indicating infinite possibilities on the producible size of the parts. Moreover, equipment requirements and tedious program work can also be significantly reduced.


Author(s):  
Song Zhang ◽  
Xuedao Shu ◽  
Chang Xu ◽  
Jitai Wang ◽  
Zixuan Li

Abstract The paper describes wall thickness non-uniformity of hollow axles by three-roll skew rolling and the proposed improved measure. According to the characteristics of the three-roll skew rolling process, a simulation model of hollow axles by three-roll skew rolling was established. In order to study the influence of different process parameters on wall thickness uniformity, five main process parameters (feed angle, rolling angle, length of forming zone, axial feed speed, temperature) were selected and imported into the simulation model for simulation analysis. The results show that the optimum process parameters are feed angle 7°, rolling angle 30°, length of forming zone 5mm, axial feed speed 20–30 mm/s and temperature 1050°C with the same conditions, and the maximum deviation of the wall thickness is 0.7mm. The uneven wall thickness of the axle body is caused by the metal reflow, which can be solved by compensating for the radial feed of the roller or by secondary machining. Reasonable selection of process parameters can significantly improve wall thickness uniformity of hollow axles by three-roll skew rolling.


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