scholarly journals Effect of Substrate Alloy Type on the Microstructure of the Substrate and Deposited Material Interface in Aluminium Wire Arc Additive Manufacturing

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 916
Author(s):  
Eloise Eimer ◽  
Stewart Williams ◽  
Jialuo Ding ◽  
Supriyo Ganguly ◽  
Bechir Chehab

Wire + Arc Additive Manufacture is an Additive Manufacturing process that requires a substrate to initiate the deposition process. In order to reduce material waste, build and lead time, and improve process efficiency, it is desirable to include this substrate in the final part design. This approach is a valid option only if the interface between the substrate and the deposited metal properties conform to the design specifications. The effect of substrate type on the interface microstructure in an aluminium part was investigated. Microstructure and micro-hardness measurements show the effect of substrate alloy and temper on the interface between the substrate and deposited material. Microcracks in the as-deposited condition were only found in one substrate. The deposited material hardness is always lower than the substrate hardness. However, this difference can be minimised by heat treatment and even eliminated when the substrate and wire are made of the same alloy.

2021 ◽  
Author(s):  
Chunyang Xia ◽  
Zengxi Pan ◽  
Yuxing Li ◽  
Huijun Li

Abstract Wire-arc additive manufacturing (WAAM) technology has been widely recognized as a promising alternative for fabricating large-scale components, due to its advantages of high deposition rate and high material utilization rate. However, some anomalies may occur during the deposition process, such as humping, spattering, and robot suspend. this study proposed to apply Deep Learning in the visual monitoring to diagnose different anomalies during WAAM process. The melt pool images of different anomalies were collected for training and validation by a visual monitoring system. The classification performance of several representative CNN architectures, including ResNet, EfficientNet, VGG-16 and GoogLeNet, were investigated and compared. The classification accuracy of 97.62%, 97.45%, 97.15% and 97.25% was achieved by each model. The results proved that the CNN models are effective in classifying different types of melt pool images of WAAM. Our study is applicable beyond WAAM and should benefit other additive manufacturing or arc welding techniques.


Author(s):  
Gourav K Sharma ◽  
Piyush Pant ◽  
Prashant K Jain ◽  
Pavan K Kankar ◽  
Puneet Tandon

Induction Heating (IH) method is gaining traction in the field of Additive Manufacturing (AM) as it is a low cost, clean, safe, and precise energy source. Wire as a feedstock material is highly efficient as compared to the powder form in terms of material utilization and economic viability. Thus, the combination of IH and wire feedstock delivery to additive manufacture a part has been explored on an in-house developed novel AM setup. The processing of aluminum wire (Al-5356) in semi-solid form from the extruder, heated using IH method has been performed. The approach adopted in this paper is to perform an in situ infrared imaging to analyze the evolution of thermal field during the extruder heating and metal deposition process. An effective thermal cartography has been undertaken to acquire temperature history of filament, extruder, and deposition process. The temperature profile plot is utilized to understand the temperature distribution and average temperature in the heating, extrusion, and layering process during layer fabrication. The presented work facilitates a priori anticipation to utilize IH as a potential energy source for the metal AM systems.


2021 ◽  
Author(s):  
Rameez Israr ◽  
Johannes Buhl ◽  
Markus Bambach

Abstract Wire-Arc Additive Manufacturing (WAAM) provides an alternative for the production of various metal products needed in small to medium batch sizes due to its high deposition rates. However, the cyclic heat input in WAAM may cause local overheating. To avoid adverse effects on the performance of the part, interlayer dwelling and active cooling are used, but these measures increase the process time. Alternatively, the temperature during the WAAM process could be controlled by optimizing the welding power. The present work aims at introducing and implementing a novel temperature management approach by adjusting the weld-bead cross-section along with the welding power to reduce the heat accumulation in the WAAM process. The temperature evolution during welding of weld beads of different cross-sections is investigated and a database of the relation between optimal welding power for beads of various sizes and different pre-heating temperatures was established. The numerical results are validated experimentally with a block-shaped geometry. The results show that by the proposed method, the test shape made was welded with lower energy consumption and process time as compared to conventional constant-power WAAM. The proposed approach efficiently manages the thermal input and reduces the need for pausing the process. Hence, the defects related to heat accumulation might be reduced, and the process efficiency increased.


Author(s):  
Rameez Israr ◽  
Johannes Buhl ◽  
Markus Bambach

AbstractWire-arc additive manufacturing (WAAM) provides an alternative for the production of various metal products needed in medium to large batch sizes due to its high deposition rates. However, the cyclic heat input in WAAM may cause local overheating. To avoid adverse effects on the performance of the part, interlayer dwelling and active cooling are used, but these measures increase the process time. Alternatively, the temperature during the WAAM process could be controlled by optimizing the welding power. The present work aims at introducing and implementing a novel temperature management approach by adjusting the weld-bead cross-section along with the welding power to reduce the heat accumulation in the WAAM process. The temperature evolution during welding of weld beads of different cross-sections is investigated and a database of the relation between optimal welding power for beads of various sizes and different pre-heating temperatures was established. The numerical results are validated experimentally with a block-shaped geometry. The results show that by the proposed method, the test shape made was welded with lower energy consumption and process time as compared to conventional constant-power WAAM. The proposed approach efficiently manages the thermal input and reduces the need for pausing the process. Hence, the defects related to heat accumulation might be reduced, and the process efficiency increased.


Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1415
Author(s):  
Dan Liu ◽  
Boyoung Lee ◽  
Aleksandr Babkin ◽  
Yunlong Chang

Additive manufacturing technology is a special processing technology that has developed rapidly in the past 30 years. The materials used are divided into powder and wire. Additive manufacturing technology using wire as the material has the advantages of high deposition rate, uniform composition, and high density. It has received increasingly more attention, especially for the high efficiency and rapid prototyping of large-size and complex-shaped components. Wire arc additive manufacturing has its unique advantages. The concept, connotation, and development history of arc additive manufacturing technology in foreign countries are reviewed, and the current research status of arc-based metal additive manufacturing technology is reviewed from the principles, development history, process, and practical application of arc additive manufacturing technology. It focuses on the forming system, forming material, residual stress and pores, and other defect controls of the technology, as well as the current methods of mechanical properties and process quality improvement, and the development prospects of arc additive manufacturing technology are prospected. The results show that the related research work of wire arc additive manufacturing technology is still mainly focused on the experimental research stage and has yet not gone deep into the exploration of the forming mechanism. The research work in this field should be more in-depth and systematic from the physical process of forming the molten pool system from the perspectives of stability, the organization evolution law, and performance optimization. We strive to carry out wire arc additive forming technology and theoretical research to promote the application of this technology in modern manufacturing.


2021 ◽  
Vol 11 (10) ◽  
pp. 4694
Author(s):  
Christian Wacker ◽  
Markus Köhler ◽  
Martin David ◽  
Franziska Aschersleben ◽  
Felix Gabriel ◽  
...  

Wire arc additive manufacturing (WAAM) is a direct energy deposition (DED) process with high deposition rates, but deformation and distortion can occur due to the high energy input and resulting strains. Despite great efforts, the prediction of distortion and resulting geometry in additive manufacturing processes using WAAM remains challenging. In this work, an artificial neural network (ANN) is established to predict welding distortion and geometric accuracy for multilayer WAAM structures. For demonstration purposes, the ANN creation process is presented on a smaller scale for multilayer beads on plate welds on a thin substrate sheet. Multiple concepts for the creation of ANNs and the handling of outliers are developed, implemented, and compared. Good results have been achieved by applying an enhanced ANN using deformation and geometry from the previously deposited layer. With further adaptions to this method, a prediction of additive welded structures, geometries, and shapes in defined segments is conceivable, which would enable a multitude of applications for ANNs in the WAAM-Process, especially for applications closer to industrial use cases. It would be feasible to use them as preparatory measures for multi-segmented structures as well as an application during the welding process to continuously adapt parameters for a higher resulting component quality.


Author(s):  
Yashwant Koli ◽  
N Yuvaraj ◽  
Aravindan Sivanandam ◽  
Vipin

Nowadays, rapid prototyping is an emerging trend that is followed by industries and auto sector on a large scale which produces intricate geometrical shapes for industrial applications. The wire arc additive manufacturing (WAAM) technique produces large scale industrial products which having intricate geometrical shapes, which is fabricated by layer by layer metal deposition. In this paper, the CMT technique is used to fabricate single-walled WAAM samples. CMT has a high deposition rate, lower thermal heat input and high cladding efficiency characteristics. Humping is a common defect encountered in the WAAM method which not only deteriorates the bead geometry/weld aesthetics but also limits the positional capability in the process. Humping defect also plays a vital role in the reduction of hardness and tensile strength of the fabricated WAAM sample. The humping defect can be controlled by using low heat input parameters which ultimately improves the mechanical properties of WAAM samples. Two types of path planning directions namely uni-directional and bi-directional are adopted in this paper. Results show that the optimum WAAM sample can be achieved by adopting a bi-directional strategy and operating with lower heat input process parameters. This avoids both material wastage and humping defect of the fabricated samples.


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