scholarly journals In situ alloying of aluminium-based alloys by (multi-)wire-arc additive manufacturing

2020 ◽  
Vol 326 ◽  
pp. 01003
Author(s):  
Thomas Klein ◽  
Alois Birgmann ◽  
Martin Schnall
Keyword(s):  
Additive Manufacturing ◽  
Large Scale ◽  
Welding Process ◽  
Chemical Compositions ◽  
Present Contribution ◽  
Cold Metal Transfer ◽  
Chemical Homogeneity ◽  
Welding Equipment ◽  
Wire Arc Additive Manufacturing

Wire-arc additive manufacturing (WAAM) has received considerable attention in the past years due to advantages in terms of deposition rate, design freedom, buy-to-fly ratio and economic factors. This process can generally be conducted using conventional or near-conventional welding equipment to fabricate intricate but relatively large-scale structures. The present contribution explores options to utilize this novel process not only for manufacturing of particular aluminium structures, but to create the actual alloy composition during processing. Thereby, the possibilities of dual-wire techniques based on cold metal transfer (CMT) to create alloys in the welding process in situ is investigated. For this purpose, a modified CMT twin welding system is used with standard wires differing significantly in their alloying content. The characterization of the chemical compositions at different specimen positions suggests good chemical homogeneity after initial process optimization steps. The microstructural homogeneity is analysed by means of optical light microscopy and scanning electron microscopy. Quantified phase fractions underpin non-equilibrium solidification conditions, when compared to theoretical equilibrium predictions. The assessment of the performed analyses suggests that dual-wire processes are powerful in terms of enhancing achievable depositions rates as well as enabling in situ alloying. This approach might be expandable to multi-wire-based techniques.

scholarly journals Plasma Multiwire Technology with Alternating Wire Feed for Tailor-Made Material Properties in Wire and Arc Additive Manufacturing

Metals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 745 ◽  
Author(s):  
Uwe Reisgen ◽  
Rahul Sharma ◽  
Lukas Oster
Keyword(s):  
Additive Manufacturing ◽  
Chemical Composition ◽  
Material Properties ◽  
Large Scale ◽  
Welding Process ◽  
Chemical Compositions ◽  
The Wire ◽  
Graded Structures ◽  
Wire Feed

Wire and arc additive manufacturing (WAAM) is one of the most promising technologies for large-scale 3D printing of metal parts. Besides the high deposition rates, one of the advantages of WAAM is the possibility of using in situ alloying to modify the chemical composition and therefore the material properties of the fabricated workpiece. This can be achieved by feeding multiple wires of different chemical compositions into the molten pool of the welding process and generating a new alloy during the manufacturing process itself. At present, the chemical composition is changed stepwise by keeping the wire feed speeds per layer constant. This article describes the possibilities of generating chemically graded structures by constantly alternating the wire feed speeds of a multiwire WAAM process. This enables the chemical composition to be smoothly changed during the printing process, and generating structures with highly complex material properties. Several material combinations for different possible applications were successfully tested. Furthermore, grading strategies to avoid negative influences of low-ductility intermetallic phases were examined. The results show that low-ductility phases may even have a beneficial influence on the fracture behavior if they are combined with ductile phases. Moreover, prospective possible applications are discussed.

Control of humping phenomenon and analyzing mechanical properties of Al–Si wire-arc additive manufacturing fabricated samples using cold metal transfer process

2021 ◽  
pp. 095440622199840
Author(s):  
Yashwant Koli ◽  
N Yuvaraj ◽  
Aravindan Sivanandam ◽  
Vipin
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Heat Input ◽  
Large Scale ◽  
High Deposition Rate ◽  
Bead Geometry ◽  
Layer By Layer ◽  
Cold Metal Transfer ◽  
Geometrical Shapes ◽  
Wire Arc Additive Manufacturing

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.

scholarly journals Wire Arc Additive Manufacturing (WAAM) of Aluminum Alloy AlMg5Mn with Energy-Reduced Gas Metal Arc Welding (GMAW)

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2671 ◽  
Author(s):  
Maximilian Gierth ◽  
Philipp Henckell ◽  
Yarop Ali ◽  
Jonas Scholl ◽  
Jean Pierre Bergmann
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Arc Welding ◽  
Energy Input ◽  
Large Scale ◽  
Unit Length ◽  
Gas Metal Arc Welding ◽  
Cold Metal Transfer ◽  
Metal Arc Welding ◽  
Wire Arc Additive Manufacturing

Large-scale aluminum parts are used in aerospace and automotive industries, due to excellent strength, light weight, and the good corrosion resistance of the material. Additive manufacturing processes enable both cost and time savings in the context of component manufacturing. Thereby, wire arc additive manufacturing (WAAM) is particularly suitable for the production of large volume parts due to deposition rates in the range of kilograms per hour. Challenges during the manufacturing process of aluminum alloys, such as porosity or poor mechanical properties, can be overcome by using arc technologies with adaptable energy input. In this study, WAAM of AlMg5Mn alloy was systematically investigated by using the gas metal arc welding (GMAW) process. Herein, correlations between the energy input and the resulting temperature–time-regimes show the effect on resulting microstructure, weld seam irregularities and the mechanical properties of additively manufactured aluminum parts. Therefore, multilayer walls were built layer wise using the cold metal transfer (CMT) process including conventional CMT, CMT advanced and CMT pulse advanced arc modes. These processing strategies were analyzed by means of energy input, whereby the geometrical features of the layers could be controlled as well as the porosity to area portion to below 1% in the WAAM parts. Furthermore, the investigations show the that mechanical properties like tensile strength and material hardness can be adapted throughout the energy input per unit length significantly.

scholarly journals Context awareness in process monitoring of additive manufacturing using a digital twin

2022 ◽  
Author(s):  
Raven T. Reisch ◽  
Tobias Hauser ◽  
Benjamin Lutz ◽  
Alexandros Tsakpinis ◽  
Dominik Winter ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Process Monitoring ◽  
Context Awareness ◽  
Large Scale ◽  
Spatial Context ◽  
Context Aware ◽  
Cold Metal Transfer ◽  
Digital Twin ◽  
Local Anomaly ◽  
Wire Arc Additive Manufacturing

AbstractWire Arc Additive Manufacturing allows the cost-effective manufacturing of customized, large-scale metal parts. As the post-process quality assurance of large parts is costly and time-consuming, process monitoring is inevitable. In the present study, a context-aware monitoring solution was investigated by integrating machine, temporal, and spatial context in the data analysis. By analyzing the voltage patterns of each cycle in the oscillating cold metal transfer process with a deep neural network, temporal context was included. Spatial context awareness was enabled by building a digital twin of the manufactured part using an Octree as spatial indexing data structure. By means of the spatial context awareness, two quality metrics—the defect expansion and the local anomaly density—were introduced. The defect expansion was tracked in-process by assigning detected defects to the same defect cluster in case of spatial correlation. The local anomaly density was derived by defining a spherical region of interest which enabled the detection of aggregations of anomalies. By means of the context aware monitoring system, defects were detected in-process with a higher sensitivity as common defect detectors for welding applications, showing less false-positives and false-negatives. A quantitative evaluation of defect expansion and densities of various defect types such as pore nests was enabled.

scholarly journals In Situ Production of Titanium Aluminides during Wire Arc Additive Manufacturing with Hot-Wire Assisted GMAW Process

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 578 ◽  
Author(s):  
Philipp Henckell ◽  
Yarop Ali ◽  
Andreas Metz ◽  
Jean Pierre Bergmann ◽  
Jan Reimann
Keyword(s):  
Additive Manufacturing ◽  
Titanium Aluminides ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Alloy Formation ◽  
Layer By Layer ◽  
Feeding Rates ◽  
Hot Wire ◽  
Wire Arc Additive Manufacturing

As part of a feasibility study, an alternative production process for titanium aluminides was investigated. This process is based on in situ alloying by means of a multi-wire technique in the layer-wise additive manufacturing process. Thereby, gas metal arc welding (GMAW) was combined with additional hot-wire feeding. By using two separate wires made of titanium and aluminum, it is possible to implement the alloy formation of titanium aluminides directly in the weld bead of the welding process. In this study, wall structures were built layer-by-layer with alloy compositions between 10 at% and 55 at% aluminum by changing the feeding rates. During this investigation, the macroscopic characteristics, microstructural formation, and the change of the microhardness values were analyzed. A close examination of the influence of welding speed and post-process heat treatment on the Ti–47Al alloy was performed; this being particularly relevant due to its economically wide spread applications.

scholarly journals Comparison of Mechanical Properties of Ni-Al-Bronze Alloy Fabricated through Wire Arc Additive Manufacturing with Ni-Al-Bronze Alloy Fabricated through Casting

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1164
Author(s):  
Jisun Kim ◽  
Jaewoong Kim ◽  
Changmin Pyo
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Welding Process ◽  
Wear Test ◽  
Hardness Test ◽  
Longitudinal Direction ◽  
Bronze Alloy ◽  
Cold Metal Transfer ◽  
Wire Arc Additive Manufacturing ◽  
Welding Direction

This study compared the mechanical properties of the NAB (Ni-Al-bronze) material fabricated using wire arc additive manufacturing (WAAM) technology with those of the cast NAB. Using a CMT (cold metal transfer) welding process, this study analyzed the bead shape for six welding conditions, determined an appropriate bead shape, and fabricated a square bulk NAB material using the bead shape. For a mechanical properties comparison, the study obtained two test specimens per welding direction from the fabricated bulk NAB material, and compared those with the cast NAB materials. In the tensile test, the deposited NAB material showed significantly better results than the cast NAB; furthermore, the deposited NAB material showed better performance than the cast NAB material in the Vickers hardness test, impact test and wear test. In addition, the deposited NAB showed anisotropy depending on the welding direction, and showed high tensile strength, hardness and shock absorption in the longitudinal direction of the welding line.

scholarly journals Wire and Arc Additive Manufacturing of Aluminum Components

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 608 ◽  
Author(s):  
Markus Köhler ◽  
Sierk Fiebig ◽  
Jonas Hensel ◽  
Klaus Dilger
Keyword(s):  
Additive Manufacturing ◽  
Process Development ◽  
Complex Geometry ◽  
Welding Process ◽  
Surface Finishing ◽  
Process Conditions ◽  
Efficient Production ◽  
Layer By Layer ◽  
Cold Metal Transfer ◽  
Wire Arc Additive Manufacturing

An increasing demand for flexibility and product integration, combined with reduced product development cycles, leads to continuous development of new manufacturing technologies such as additive manufacturing. Wire and arc additive manufacturing (WAAM) provides promising technology for the near net-shape production of large structures with complex geometry, using cost efficient production resources such as arc welding technology and wire materials. Compared to powder-based additive manufacturing processes, WAAM offers high deposition rates as well as enhanced material utilization. Because of the layer-by-layer built up approach, process conditions such as energy input, arc characteristics, and material composition result in a different processability during the additive manufacturing process. This experimental study aims to describe the effects of the welding process on buildup accuracy and material properties during wire arc additive manufacturing of aluminum structures. Following a process development using pulse cold metal transfer (CMT-P), linear wall samples were manufactured with variations of the filler metal. The samples were analyzed in terms of surface finishing, hardness, and residual stress. Furthermore, mechanical properties were determined in different building directions.

scholarly journals Thermo-Mechanical Modelling of Wire-Arc Additive Manufacturing (WAAM) of Semi-Finished Products

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1009 ◽  
Author(s):  
Marcel Graf ◽  
Andre Hälsig ◽  
Kevin Höfer ◽  
Birgit Awiszus ◽  
Peter Mayr
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Additive Manufacturing ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Temperature Fields ◽  
Filler Materials ◽  
Cold Metal Transfer ◽  
Cold Metal ◽  
Wire Arc Additive Manufacturing

Additive manufacturing processes have been investigated for some years, and are commonly used industrially in the field of plastics for small- and medium-sized series. The use of metallic deposition material has been intensively studied on the laboratory scale, but the numerical prediction is not yet state of the art. This paper examines numerical approaches for predicting temperature fields, distortions, and mechanical properties using the Finite Element (FE) software MSC Marc. For process mapping, the filler materials G4Si1 (1.5130) for steel, and AZ31 for magnesium, were first characterized in terms of thermo-physical and thermo-mechanical properties with process-relevant cast microstructure. These material parameters are necessary for a detailed thermo-mechanical coupled Finite Element Method (FEM). The focus of the investigations was on the numerical analysis of the influence of the wire feed (2.5–5.0 m/min) and the weld path orientation (unidirectional or continuous) on the temperature evolution for multi-layered walls of miscellaneous materials. For the calibration of the numerical model, the real welding experiments were carried out using the gas-metal arc-welding process—cold metal transfer (CMT) technology. A uniform wall geometry can be produced with a continuous welding path, because a more homogeneous temperature distribution results.

scholarly journals Mechanical properties of wire arc additive manufactured carbon steel cylindrical component made by gas metal arc welding process

2021 ◽  
Vol 30 (1) ◽  
pp. 188-198
Author(s):  
Bellamkonda Prasanna Nagasai ◽  
Sudersanan Malarvizhi ◽  
Visvalingam Balasubramanian
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Carbon Steel ◽  
Large Scale ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Vertical Direction ◽  
Low Carbon ◽  
Cylindrical Component ◽  
Wire Arc Additive Manufacturing

Abstract Wire arc additive manufacturing (WAAM), a welding-based additive manufacturing (AM) method, is a hot topic of research since it allows for the cost-effective fabrication of large-scale metal components at relatively high deposition rates. In the present study, the cylindrical component of low carbon steel (ER70S-6) was built by WAAM technique, using a GMAW torch that was translated by an automated three-axis motion system using a rotation table. The mechanical properties of the component were evaluated by extracting tensile, impact toughness and hardness specimens from the two regions of the building up (vertical) direction. It is found that the tensile properties of the built material exhibited anisotropic characteristics. The yield strength and ultimate tensile strength varied from 333 to 350 MPa and from 429 to 446 MPa, respectively, (less than 5 % variation).

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