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DOI 10.1007/s00170-022-08966-y
A machine learning approach for the prediction of melting efficiency in wire arc additive manufacturing
2022-05
Barrionuevo, German O.
;
Sequeira-Almeida, Pedro M.
;
Rios Contesse, Sergio Eduardo
;
Ramos-Grez, Jorge A.
;
Williams, Stewart W.
Wire arc additive manufacturing (WAAM) appears as one of the most promising technologies due to its capacity to process all types of materials used in welding, its high production rate, and capacity to process large geometries of particular interest in the aeronautical industry. Since this technology is still under investigation, it is important to determine the efficiency of the process; in this sense, the melting efficiency stands out not only as a parameter of interest in energy terms but also as a measure of the stability of the process. For calculating melting efficiency, it is necessary to use tailored colorimeters or apply models requiring specific dimensions that involve destructive testing. For this reason, in the development of this work, the melting efficiency is evaluated through machine learning algorithms. Processing parameters such as wire diameter, wire feed speed, travel speed, and net power are used to determine melting efficiency. In addition, a simplified analytical model was developed to compare the results. The average melting efficiency analytically calculated was 44.56 +/- 5.48%, while the predicted value reaches a comparable value of 44.32 +/- 4.79% obtained with the Gaussian process regressor, which shows the highest accuracy. Moreover, the known relationship with travel speed was verified.
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DOI 10.1007/s00170-022-08966-y
A machine learning approach for the prediction of melting efficiency in wire arc additive manufacturing
2022-05
Barrionuevo, German O.
;
Sequeira-Almeida, Pedro M.
;
Rios Contesse, Sergio Eduardo
;
Ramos-Grez, Jorge A.
;
Williams, Stewart W.
Wire arc additive manufacturing (WAAM) appears as one of the most promising technologies due to its capacity to process all types of materials used in welding, its high production rate, and capacity to process large geometries of particular interest in the aeronautical industry. Since this technology is still under investigation, it is important to determine the efficiency of the process; in this sense, the melting efficiency stands out not only as a parameter of interest in energy terms but also as a measure of the stability of the process. For calculating melting efficiency, it is necessary to use tailored colorimeters or apply models requiring specific dimensions that involve destructive testing. For this reason, in the development of this work, the melting efficiency is evaluated through machine learning algorithms. Processing parameters such as wire diameter, wire feed speed, travel speed, and net power are used to determine melting efficiency. In addition, a simplified analytical model was developed to compare the results. The average melting efficiency analytically calculated was 44.56 +/- 5.48%, while the predicted value reaches a comparable value of 44.32 +/- 4.79% obtained with the Gaussian process regressor, which shows the highest accuracy. Moreover, the known relationship with travel speed was verified.
Scopus© Citations 41 3
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DOI 10.3390/su12219227
The Analysis Performance of a Grid-Connected 8.2 kWp Photovoltaic System in the Patagonia Region
2020-11
Vidal Gutierrez, Humberto Ricardo
;
Rivera, Marco
;
Wheeler, Patrick
;
Vicencio, Nicolas
Solar PV structures for locations at high latitudes in the Northern and Southern Hemispheres are increasingly in the spotlight. The work reported in this paper analyses the behaviour of a grid-connected 8.2 kWp photovoltaic system to either feed on-site electrical loads (a public institution, Corporacion Nacional Forestal (CONAF), located 5.5 km south of Punta Arenas, lat. 53 degrees S) or to feed into the electrical grid when the photovoltaic system generation is higher than the on-site load demand. The system simulation uses the PVSyst software with Meteonorm derived and measured climate information sets (ambient temperature, solar irradiation and wind speed). The agreement between the simulated and measured energy yield is analysed including the evaluation of the optimal generation energy of the PV array, the energy that is fed into the network, the performance ratio, and the normalised energy generation per installed kWp. The PV system considered in this work generates 7005.3 kWh/year, out of which only 6778 kWh/year are injected into the grid. The measured annual performance ratio is around 89%. The normalised productions of the inverter output or final system yield, i.e., useful energy, is 3.6 kWh/kWp/day. The measured annual average capacity factor obtained from this study is 15.1%. These performance parameters will encourage greater use of photovoltaic technology in the Chilean Patagonia region.
Scopus© Citations 26 1
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DOI 10.1016/j.jmatprotec.2018.08.043
Metal transfer modes in plasma Wire plus Arc additive manufacture
2019-02
Rios Contesse, Sergio Eduardo
;
Colegrove, Paul A.
;
Williams, Stewart W.
The stability of Plasma transferred arc Wire + Arc Additive Manufacture is critically dependent on the transfer mode of the wire into the melt pool which can either be in permanent contact (TM1), intermittent (TM2) or fleeting (TM3) and it's governed by the position of the wire. Analysis of the voltage waveforms in conjunction with video imaging was used to understand the preferred mode for process control and how these transfer modes are affected by convex and concave melt pools shapes. The study indicated that stable transfer can be more easily achieved with the convex weld pool, because it minimises the extent of the undesirable TM3 where droplet transfer occurs in an erratic fashion. Furthermore, even though the operational range of TM2 is limited, a control algorithm could be more easily developed for this transfer mode. Finally, video imaging showed how the melt pool oscillation interacts with droplet detachment under some operational conditions.
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DOI 10.1016/j.jmatprotec.2018.08.043
Metal transfer modes in plasma Wire plus Arc additive manufacture
2019-02
Rios Contesse, Sergio Eduardo
;
Colegrove, Paul A.
;
Williams, Stewart W.
The stability of Plasma transferred arc Wire + Arc Additive Manufacture is critically dependent on the transfer mode of the wire into the melt pool which can either be in permanent contact (TM1), intermittent (TM2) or fleeting (TM3) and it's governed by the position of the wire. Analysis of the voltage waveforms in conjunction with video imaging was used to understand the preferred mode for process control and how these transfer modes are affected by convex and concave melt pools shapes. The study indicated that stable transfer can be more easily achieved with the convex weld pool, because it minimises the extent of the undesirable TM3 where droplet transfer occurs in an erratic fashion. Furthermore, even though the operational range of TM2 is limited, a control algorithm could be more easily developed for this transfer mode. Finally, video imaging showed how the melt pool oscillation interacts with droplet detachment under some operational conditions.
Scopus© Citations 66 1
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DOI 10.1590/0104-9224/si24.03
Additive Techniques to Refurbish Ni Based Components
2019
Cardozo, Eloisa Pereira
;
Pardal, Gonçalo Rodrigues
;
Rios Contesse, Sergio Eduardo
;
Ganguly, Supriyo
;
D’Oliveira, Ana Sofia C. M.
Abstract The attractiveness of additive techniques to refurbish worn components requires the availability of data from different process. This study correlates two additive techniques, Plasma Transferred Arc (PTA – AM) and Direct Laser Deposition (DLD), using IN 625 wire. Specific features of each technique are discussed regarding their potential use to recover geometry and properties of worn components. Multilayers were processed with each technique on a section of a blade and the interaction between materials together with the effect of post deposition heat treatment were characterized. Results show that there are differences in the final microstructure and in the interaction with the part being refurbished imposed by the additive technique used. Competitive changes can be made by changing the feedstock. PTA-AM using powder material exhibits a microstructure that approaches that obtained in DLD using wire.
Scopus© Citations 7 3
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DOI 10.1007/s00170-018-2340-z
Assessment of the effect of different forms of Inconel 625 alloy feedstock in Plasma Transferred Arc (PTA) additive manufacturing
2018-09
Cardozo, Eloisa Pereira
;
Rios Contesse, Sergio Eduardo
;
Ganguly, Supriyo
;
D'Oliveira, Ana Sofia C. M.
Additive manufacturing (AM) is an emerging fabrication technology, which can offer a faster, versatile, flexible, easily customizable, and a cheaper production path, when compared to conventional manufacturing. There are different additive manufacturing techniques differentiated by the way of material is made available and melted in each layer. The Plasma Transferred Arc (PTA) is a promising AM technique became of its superior energy efficiency compared to laser-related processes. PTA allows to process materials both in powder and wire forms. Recent evidences suggested that the characteristics of the feedstock will impact the final microstructure and consequently the mechanical properties of the deposit. This work carried out a detailed analysis on effects of the feedstock form using PTA to build multilayers with wire and powder IN625 alloy. It considered the specific features of each feedstock for the processing and explored the relationship with the characteristics of the deposited multilayers. Powder plus arc and wire plus arc multilayers were analyzed using confocal microscopy, scanning electron microscopy, X-ray diffraction, and micro-hardness profile. It is shown that the microstructure and mechanical properties of a multilayer component are influenced on choice of the feedstock, mainly because of the differing parameters that will be required in their processing.
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DOI 10.1007/s00170-018-2340-z
Assessment of the effect of different forms of Inconel 625 alloy feedstock in Plasma Transferred Arc (PTA) additive manufacturing
2018-09
Cardozo, Eloisa Pereira
;
Rios Contesse, Sergio Eduardo
;
Ganguly, Supriyo
;
D'Oliveira, Ana Sofia C. M.
Additive manufacturing (AM) is an emerging fabrication technology, which can offer a faster, versatile, flexible, easily customizable, and a cheaper production path, when compared to conventional manufacturing. There are different additive manufacturing techniques differentiated by the way of material is made available and melted in each layer. The Plasma Transferred Arc (PTA) is a promising AM technique became of its superior energy efficiency compared to laser-related processes. PTA allows to process materials both in powder and wire forms. Recent evidences suggested that the characteristics of the feedstock will impact the final microstructure and consequently the mechanical properties of the deposit. This work carried out a detailed analysis on effects of the feedstock form using PTA to build multilayers with wire and powder IN625 alloy. It considered the specific features of each feedstock for the processing and explored the relationship with the characteristics of the deposited multilayers. Powder plus arc and wire plus arc multilayers were analyzed using confocal microscopy, scanning electron microscopy, X-ray diffraction, and micro-hardness profile. It is shown that the microstructure and mechanical properties of a multilayer component are influenced on choice of the feedstock, mainly because of the differing parameters that will be required in their processing.
Scopus© Citations 22 1
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DOI 10.1109/icmimt52186.2021.9476168
Comparative Evaluation of Machine Learning Regressors for the Layer Geometry Prediction in Wire arc Additive manufacturing
2021-5-13
Barrionuevo, German Omar
;
Rios Contesse, Sergio Eduardo
;
Williams, Stewart W.
;
Andres Ramos-Grez, Jorge
In this paper, a set of the most employed machine learning (ML) algorithms were trained and tested to assess which ones present the highest accuracy in predicting the layer geometry of the Ti-6Al-4V processed by plasma transfer arc deposition. Wire and arc additive manufacturing brings about the possibility of manufacturing large and robust components based on metal wires. One of the critical aspects to take into account during the manufacturing process is the layer geometry. Bead geometry depends on several processing parameters, e.g., arc voltage, welding current, travel speed, wire feed speed, and gas flow rate. The algorithms that better adjusted the prediction were multilayer perceptron with five hidden layers, linear support vector regression, and boosting regressors, which combine multiple models to reduce overfitting risk.
Scopus© Citations 20 1
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DOI 10.1016/j.addma.2018.04.003
Analytical process model for wire plus arc additive manufacturing
2018-5
Rios Contesse, Sergio Eduardo
;
Colegrove, Paul A.
;
Martina, Filomeno
;
Williams, Stewart W.
An analytical process model for predicting the layer height and wall width from the process parameters was developed for wire + arc additive manufacture of Ti-6Al-4V, which includes inter-pass temperature and material properties. Capillarity theory predicted that cylindrical deposits were produced where the wall width was less than 12 mm (radius < 6 mm) due to the large value of the surface tension. Power was predicted with an accuracy of +/- 20% for a wide range of conditions for pulsed TIG and plasma deposition. Interesting differences in the power requirements were observed where a surface depression was produced with the plasma process due to differences in melting efficiency and/or convection effects. Finally, it was estimated the impact of controlling the workpiece temperature on the accuracy of the deposit geometry.
Scopus© Citations 106 3

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