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

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.

2019 ◽  
Vol 269 ◽  
pp. 05002
Author(s):  
Priyantomo Agustinus Ananda

WAAM ( Wire + Arc Additive Manufacturing) is a process of adding material layer by layer in order to build a near net shape components. It shows a further promising future for fabricating large expensive metal components with complex geometry. Engineering Procurement and Construction (EPC) company as one of the industrial section which related with engineering design and products, wide range of material type, and shop based or site based manufacturing process have been dealing with conventional manufacturing and procurement process in order to fulfill its requirement for custom parts and items for the project completion purpose. During the conventional process, there is a risk during the transportation of the products from the manufacturing shop to then site project, this risk is even greater when the delivery time take part as one of the essential part which affect the project schedule. Wire Arc Additive Manufacturing process offering an alternative process to shorten the delivery time and process for a selected material and engineered items, with the consideration of essential variables which can affect the final products of WAAM process, such as : heat input, wire feed speed, travel speed, shielding gas, welding process and robotic system applied. In this paper, the possibilities of WAAM application in EPC company will be assessed, an in depth literature review of the various process which possible to applied, include the loss and benefit compared with conventional method will be presented. The main objective is to identify the current challenge and the prospect of WAAM application in EPC company.


Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2491 ◽  
Author(s):  
Philipp Henckell ◽  
Maximilian Gierth ◽  
Yarop Ali ◽  
Jan Reimann ◽  
Jean Pierre Bergmann

Wire arc additive manufacturing (WAAM) by gas metal arc welding (GMAW) is a suitable option for the production of large volume metal parts. The main challenge is the high and periodic heat input of the arc on the generated layers, which directly affects geometrical features of the layers such as height and width as well as metallurgical properties such as grain size, solidification or material hardness. Therefore, processing with reduced energy input is necessary. This can be implemented with short arc welding regimes and respectively energy reduced welding processes. A highly efficient strategy for further energy reduction is the adjustment of contact tube to work piece distance (CTWD) during the welding process. Based on the current controlled GMAW process an increase of CTWD leads to a reduction of the welding current due to increased resistivity in the extended electrode and constant voltage of the power source. This study shows the results of systematically adjusted CTWD during WAAM of low-alloyed steel. Thereby, an energy reduction of up to 40% could be implemented leading to an adaptation of geometrical and microstructural features of additively manufactured work pieces.


Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 608 ◽  
Author(s):  
Markus Köhler ◽  
Sierk Fiebig ◽  
Jonas Hensel ◽  
Klaus Dilger

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.


Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1009 ◽  
Author(s):  
Marcel Graf ◽  
Andre Hälsig ◽  
Kevin Höfer ◽  
Birgit Awiszus ◽  
Peter Mayr

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.


2021 ◽  
Vol 30 (1) ◽  
pp. 188-198
Author(s):  
Bellamkonda Prasanna Nagasai ◽  
Sudersanan Malarvizhi ◽  
Visvalingam Balasubramanian

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).


2020 ◽  
Vol 326 ◽  
pp. 01003
Author(s):  
Thomas Klein ◽  
Alois Birgmann ◽  
Martin Schnall

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.


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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