Browsing by Author "Suárez, Alfredo"
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Item Analysis of the Machining Process of Titanium Ti6Al-4V Parts Manufactured by Wire Arc Additive Manufacturing (WAAM)(2020-02-01) Veiga, Fernando; Gil Del Val, Alain; Suárez, Alfredo; Alonso, Unai; Tecnalia Research & Innovation; FABRIC_INTELIn the current days, the new range of machine tools allows the production of titanium alloy parts for the aeronautical sector through additive technologies. The quality of the materials produced is being studied extensively by the research community. This new manufacturing paradigm also opens important challenges such as the definition and analysis of the optimal strategies for finishing-oriented machining in this type of part. Researchers in both materials and manufacturing processes are making numerous advances in this field. This article discusses the analysis of the production and subsequent machining in the quality of TI6Al4V produced by Wire Arc Additive Manufacturing (WAAM), more specifically Plasma Arc Welding (PAW). The promising results observed make it a viable alternative to traditional manufacturing methods.Item Analysis of the Wall Geometry with Different Strategies for High Deposition Wire Arc Additive Manufacturing of Mild Steel(Multidisciplinary Digital Publishing Institute (MDPI), 2020-07) Aldalur, Eider; Veiga, Fernando; Suárez, Alfredo; Bilbao, Jon; Lamikiz, AitzolAdditive manufacturing has gained relevance in recent decades as an alternative to the manufacture of metal parts. Among the additive technologies, those that are classified as Directed Energy Deposition (DED) are characterized by their high deposition rate, noticeably, Wire Arc Additive Manufacturing (WAAM). However, having the inability to produce parts with acceptable final surface quality and high geometric precision is to be considered an important disadvantage in this process. In this paper, different torch trajectory strategies (oscillatory motion and overlap) in the fabrication of low carbon steel walls will be compared using Gas Metal Arc Welding (GMAW)-based WAAM technology. The comparison is done with a study of the mechanical and microstructural characteristics of the produced walls and finally, addressing the productivity obtained utilizing each strategy. The oscillation strategy shows better results, regarding the utilization rate of deposited material and the flatness of the upper surface, this being advantageous for subsequent machining steps.Item Characterization of Inconel 718® superalloy fabricated by wire Arc Additive Manufacturing: effect on mechanical properties and machinability: effect on mechanical properties and machinability(2021-09) Alonso, Unai; Veiga, Fernando; Suárez, Alfredo; Gil Del Val, Alain; Tecnalia Research & Innovation; FABRIC_INTELWire and Arc Additive Manufacturing has the potential to become an appropriate technique to produce large complex-shaped metallic parts. However, a post-processing machining operation is necessary to reach the final geometry. In this work, Inconel 718 walls were manufactured in a monitored environment and their microstructure and mechanical properties were characterised. Then, slot milling operations were performed to investigate the influence of cutting speed and machining direction. The conclusions drawn from this article can be used as a guide for a correct definition of strategies and milling parameters. It was observed that at higher cutting speeds a better surface quality and lower torques are obtained. Moreover, the main novelty of this work is that is shows the influence of the anisotropy of WAAM-Inconel 718 on its machinability. Milling along the torch's travel direction offers better dimensional tolerance values with lower cutting torques, being more favourable than machining in the building direction.Item Effect of the Heat Input on Wire-Arc Additive Manufacturing of Invar 36 Alloy: Microstructure and Mechanical Properties: Microstructure and Mechanical Properties(2022-04-07) Veiga, Fernando; Suárez, Alfredo; Artaza, Teresa; Aldalur, Eider; Tecnalia Research & Innovation; FABRIC_INTELInvar, also known as FeNi36, is a material of great interest due to its unique properties, which makes it an excellent alterna tive for sectors such as tooling in aeronautics and aerospace. Its manufacture by means of wire arc additive manufacturing (WAAM) technology could extend its use. This paper aims to evaluate the comparison of two of the most widespread WAAM technologies: plasma arc welding (PAW) and gas metal arc welding (GMAW). This comparison is based on the analysis of wall geometry, metallography, and mechanical properties of the material produced by both technologies. The results show a slight increase in toughness and elongation before fracture and worse tensile strength data in the case of PAW, with aver age values of 485 MPa for ultimate tensile strength (UTS), 31% for elongation and 475 MPa, 40% in GMAW and PAW, respectively. All results gathered from the analysis show the possibility of successful manufacturing of Invar by means of WAAM technologies. The novelties presented in this paper allow us to establish relationships between the thermal input of the process itself and the mechanical and metallographic properties of the material produced.Item Effect of the Metal Transfer Mode on the Symmetry of Bead Geometry in WAAM Aluminum(2021-07-10) Veiga, Fernando; Suárez, Alfredo; Aldalur, Eider; Bhujangrao, Trunal; Tecnalia Research & Innovation; FABRIC_INTELThe symmetrical nature in the case of wall fabrication by wire arc additive manufacturing (WAAM) has been observed in the literature, but it has not been studied as a source of knowledge. This paper focuses on the comparative study of three drop transfer methods employing Gas Metal Arc Welding (GMAW) technology, one of the most reported for the manufacture of aluminum alloys. The transfer modes studied are the well-known pulsed GMAW, cold arc, and the newer pulsed AC. The novelty of the last transfer mode is the reversal of the polarity during the preparation phase of the substance for droplet deposition. This study compares the symmetry of zero beads to determine the best parameters and transfer modes for wire arc additive manufacturing of 5 series aluminum. The pulsed transfer modes show values of 0.6 for symmetry ratio, which makes them more interesting strategies than cold arc with a symmetry ratio of 0.5. Furthermore, the methodology proposed in this study can be extrapolated to other materials manufactured with this technology.Item Experimental Investigation of the Influence of Wire Arc Additive Manufacturing on the Machinability of Titanium Parts(2020-01) Alonso, Unai; Veiga, Fernando; Suárez, Alfredo; Artaza, Teresa; Tecnalia Research & Innovation; FABRIC_INTELThe manufacturing of titanium airframe parts involves significant machining and low buy-to-fly ratios. Production costs could be greatly reduced by the combination of an additive manufacturing (AM) process followed by a finishing machining operation. Among the different AM alternatives, wire arc additive manufacturing (WAAM) offers deposition rates of kg/h and could be the key for the production of parts of several meters economically. In this study, the influence of the manufacturing process of Ti6Al4V alloy on both its material properties and machinability is investigated. First, the mechanical properties of a workpiece obtained by WAAM were compared to those in a conventional laminated plate. Then, drilling tests were carried out in both materials. The results showed that WAAM leads to a higher hardness than laminated Ti6Al4V and satisfies the requirements of the standard in terms of mechanical properties. As a consequence, higher cutting forces, shorter chips, and lower burr height were observed for the workpieces produced by AM. Furthermore, a metallographic analysis of the chip cross-sectional area also showed that a serrated chip formation is also present during drilling of Ti6Al4V produced by WAAM. The gathered information can be used to improve the competitiveness of the manufacturing of aircraft structures in terms of production time and cost.Item High-Temperature Mechanical Properties of IN718 Alloy: Comparison of Additive Manufactured and Wrought Samples(Multidisciplinary Digital Publishing Institute (MDPI), 2020-08-09) Bhujangrao, Trunal; Veiga, Fernando; Suárez, Alfredo; Iriondo, Edurne; Mata, Franck GirotWire Arc Additive Manufacturing (WAAM) is one of the most appropriate additive manufacturing techniques for producing large-scale metal components with a high deposition rate and low cost. Recently, the manufacture of nickel-based alloy (IN718) using WAAM technology has received increased attention due to its wide application in industry. However, insufficient information is available on the mechanical properties of WAAM IN718 alloy, for example in high-temperature testing. In this paper, the mechanical properties of IN718 specimens manufactured by the WAAM technique have been investigated by tensile tests and hardness measurements. The specific comparison is also made with the wrought IN718 alloy, while the microstructure was assessed by scanning electron microscopy and X-ray diffraction analysis. Fractographic studies were carried out on the specimens to understand the fracture behaviour. It was shown that the yield strength and hardness of WAAM IN718 alloy is higher than that of the wrought alloy IN718, while the ultimate tensile strength of the WAAM alloys is difficult to assess at lower temperatures. The microstructure analysis shows the presence of precipitates (laves phase) in WAAM IN718 alloy. Finally, the effect of precipitation on the mechanical properties of the WAAM IN718 alloy was discussed in detail.Item Influence of Heat Input on the Formation of Laves Phases and Hot Cracking in Plasma Arc Welding (PAW) Additive Manufacturing of Inconel 718(2020-06) Artaza, Teresa; Bhujangrao, Trunal; Suárez, Alfredo; Veiga, Fernando; Lamikiz, Aitzol; FABRIC_INTEL; Tecnalia Research & InnovationNickel-based alloys have had extensive immersion in the manufacturing world in recent decades, especially in high added value sectors such as the aeronautical sector. Inconel 718 is the most widespread in terms of implantation. Therefore, the interest in adapting the manufacture of this material to additive manufacturing technologies is a significant objective within the scientific community. Among these technologies for the manufacture of parts by material deposition, plasma arc welding (PAW) has advantages derived from its simplicity for automation and integration on the work floor with high deposition ratios. These characteristics make it very economically appetizing. However, given the tendency of this material to form precipitates in its microstructure, its manufacturing by additive methods is very challenging. In this article, three deposition conditions are analyzed in which the energy and deposition ratio used are varied, and two cooling strategies are studied. The interpass cooling strategy (ICS) in which a fixed time is expected between passes and controlled overlay strategy (COS) in which the temperature at which the next welding pass starts is controlled. This COS strategy turns out to be advantageous from the point of view of the manufacturing time, but the deposition conditions must be correctly defined to avoid the formation of Laves phases and hot cracking in the final workpiece.Item Model for the Prediction of Deformations in the Manufacture of Thin-Walled Parts by Wire Arc Additive Manufacturing Technology(2021-04-21) Casuso, Mikel; Veiga, Fernando; Suárez, Alfredo; Bhujangrao, Trunal; Aldalur, Eider; Artaza, Teresa; Amondarain, Jaime; Lamikiz, Aitzol; FABRIC_INTEL; Tecnalia Research & InnovationGas Metal Arc Welding (GMAW) is a manufacturing technology included within the differentWire Arc Additive Manufacturing alternatives. These technologies have been generating great attention among scientists in recent decades. Its main qualities that make it highly productive with a large use of material with relatively inexpensive machine solutions make it a very advantageous technology. This paper covers the application of this technology for the manufacture of thin-walled parts. A finite element model is presented for estimating the deformations in this type of parts. This paper presents a simulation model that predicts temperatures with less than 5% error and deformations of the final part that, although quantitatively has errors of 20%, qualitatively allows to know the deformation modes of the part. Knowing the part areas subject to greater deformation may allow the future adaptation of deposition strategies or redesigns for their adaptation. These models are very useful both at a scientific and industrial level since when we find ourselves with a technology oriented to Near Net Shape (NNS) manufacturing where deformations are critical for obtaining the final part in a quality regime.Item Predicted Torque Model in Low-Frequency-Assisted Boring (LFAB) Operations(2021-06-24) Veiga, Fernando; Gil Del Val, Alain; Penalva, Mari Luz; Pereira, Octavio; Suárez, Alfredo; López de Lacalle Marcaide, Luis Norberto; Tecnalia Research & Innovation; FABRIC_INTELA low-frequency-assisted boring operation is a key cutting process in the aircraft manufacturing sector when drilling deep holes to avoid chip clogging based on chip breakage and, consequently, to reduce the temperature level in the cutting process. This paper proposes a predicted force model based on a commercial control-supported chip breaking function without external vibration devices in the boring operations. The model was fitted by conventional boring measurements and was validated by vibration boring experiments with different ranges of amplitude and frequency. The average prediction error is around 10%. The use of a commercial function makes the model more attractive for the industry because there is no need for intrusive vibration sensors. The low-frequency assisted boring (LFAB) operations foster the chip breakage. Finally, the model is generic and can be used for different cutting materials and conditions. Roughness is improved by 33% when vibration conditions are optimal, considered as a vibration amplitude of half the feed per tooth. This paper presents, as a novelty, the analysis of low-frequency vibration parameters in boring processes and their effect on chip formation and internal hole roughness. This has a practical significance for the definition of a methodology based on the torque model for the selection of conditions on other hole-making processes, cutting parameters and/or materials.Item Study of the Mechanical Behavior of Topologically Optimized Arc Wire Direct Energy Deposition Aerospace Fixtures(2022-02-24) Suárez, Alfredo; Veiga, Fernando; Bhujangrao, Trunal; Aldalur, Eider; FABRIC_INTEL; Tecnalia Research & InnovationThe reliability and performance qualification of additively manufactured metal parts is essential for their successful and safe use in engineering applications. Additive Manufacturing (AM) allows parts to be produced more easily than traditional manufacturing. Arc Wire Direct Energy Deposition (AW-DED) is one of the lesser-known metal additive manufacturing technologies. It has enormous potential for large-scale 3D printing applications in the aerospace industry. However, in the aerospace industry, one of the main challenges today is to reduce the weight of components without compromising their structural functionality. Topology optimization offers design engineers the opportunity to create lightweight and complex structural parts. In arc wire direct energy deposition (AW-DED) processes, processing parameters affect material microstructure features, overall part quality, and integrity, as well as bulk mechanical behavior. To address such challenges, the investigation presented in this paper describes a novel digital design approach combining topology optimization, process simulations, and size optimization of the tool components used in the aerospace industry to address effects caused during manufacturing by using Finite Element Modeling (FEM) simulations. This can lead to reduced costs, development time, material consumption, and product weight. Due to the flexibility mentioned above, parts designed for AM have the same structural load as conventional parts but with reduced mass and better part design. The results of this application are discussed in depth in this paper. This is a new research work with useful results and conclusions in the methodology for the evaluation of mechanical behavior of topologically optimized metal additive manufactured components. For this purpose, aerospace fixtures have been topologically designed by means of AW-DED-process-oriented techniques. Aerospace fixtures are normally used in the aerospace industry to support and hold various components. These new design paradigms make it possible to save on material costs oriented toward more sustainable and flexible manufacturing.Item Study on Arc Welding Processes for High Deposition Rate Additive Manufacturing(2018) Tabernero, Iván; Paskual, Amagoia; Álvarez, Pedro; Suárez, Alfredo; Ivántabernero; FABRIC_INTELAlthough Additive Manufacturing implementation is rapidly growing, industrial sectors are demanding an increase of manufactured part size which most extended processes, such as Selective Laser Melting (SLM) or Laser Metal Deposition (LMD), are not able to offer. In this sense, Wire-Arc Additive Manufacturing (WAAM) offers high deposition rates and quality without size limits, becoming the best alternative for additive manufacturing of medium-large size parts with high mechanical requirements such as structural parts in the aeronautical industry. WAAM technology adds material in form of wire using an arc welding process in order to melt both the wire and the substrate. There are three welding processes that are mainly used in WAAM: Plasma Arc Welding (PAW), Gas Tungsten Arc Welding (GTAW or TIG) and Gas Metal Arc Welding (GMAW or MIG). This paper studies these processes regarding on their capabilities for additive manufacturing and compares the mechanical properties obtained by the different welding technologies applied in WAAM. Obtained results show the applicability of the technology as an alternative of traditional metallic preforms manufacturing processes, such as casting or forging.Item Surface integrity investigations for prediction of fatigue properties after machining of alloy 718(2021-03) Holmberg, Jonas; Wretland, Anders; Hammersberg, Peter; Berglund, Johan; Suárez, Alfredo; Beno, Tomas; FABRIC_INTELFatigue performance is crucial for gas turbine components, and it is greatly affected by the manufacturing processes. Ability to predict the expected fatigue life of a component based on surface integrity has been the objective in this work, enabling new processing methods. Alloy 718 samples were prepared by different machining setups, evaluated in fatigue testing and surface integrity investigations. These results generated two predictive statistical multi-variate regression models. The fatigue correlated well with roughness, residual stresses and deformation. The two models showed great potential, which encourages further exploration to fine-tune the procedure for the particular case.Item Thread Quality Control in High-Speed Tapping Cycles(2020-02) Gil Del Val, Alain; Veiga, Fernando; Suárez, Alfredo; Arizmendi, Mikel; Tecnalia Research & Innovation; FABRIC_INTELThread quality control is becoming a widespread necessity in manufacturing to guarantee the geometry of the resulting screws on the workpiece due to the high industrial costs. Besides, the industrial inspection is manual provoking high rates of manufacturing delays. Therefore, the aim of this paper consists of developing a statistical quality control approach acquiring the data (torque signal) coming from the spindle drive for assessing thread quality using different coatings. The system shows a red light when the tap wear is critical before machining in unacceptable screw threads. Therefore, the application could reduce these high industrial costs because it can work self-governance.Item Validation of the Mechanical Behavior of an Aeronautical Fixing Turret Produced by a Design for Additive Manufacturing (DfAM)(2022-05-27) Veiga, Fernando; Bhujangrao, Trunal; Suárez, Alfredo; Aldalur, Eider; Goenaga, Igor; Gil-Hernandez, Daniel; Tecnalia Research & Innovation; FABRIC_INTEL; MAQUINAS; SMART_MONThe design of parts in such critical sectors as the manufacturing of aeronautical parts is awaiting a paradigm shift due to the introduction of additive manufacturing technologies. The manufacture of parts designed by means of the design-oriented additive manufacturing methodology (DfAM) has acquired great relevance in recent years. One of the major gaps in the application of these technologies is the lack of studies on the mechanical behavior of parts manufactured using this methodology. This paper focuses on the manufacture of a turret for the clamping of parts for the aeronautical industry. The design of the lightened turret by means of geometry optimization, the manufacture of the turret in polylactic acid (PLA) and 5XXX series aluminum alloy by means of Wire Arc Additive Manufacturing (WAAM) technology and the analysis by means of finite element analysis (FEA) with its validation by means of a tensile test are presented. The behavior of the part manufactured with both materials is compared. The conclusion allows to establish which are the limitations of the part manufactured in PLA for its orientation to the final application, whose advantages are its lower weight and cost. This paper is novel as it presents a holistic view that covers the process in an integrated way from the design and manufacture to the behaviour of the component in useItem Wire Arc Additive Manufacturing of Mn4Ni2CrMo Steel: Comparison of Mechanical and Metallographic Properties of PAW and GMAW(Elsevier B.V., 2019) Artaza, Teresa; Suárez, Alfredo; Murua, Maialen; García, J.C.; Tabernero, Iván; Lamikiz, AitzolWire arc additive manufacturing, WAAM, is a popular wire-feed additive manufacturing technology that creates components through the deposition of material layer-by-layer. WAAM has become a promising alternative to conventional machining due to its high deposition rate, environmental friendliness and cost competitiveness. In this research work, a comparison is made between two different WAAM technologies, GMAW (gas metal arc welding) and PAW (plasma arc welding). Comparative between processes is centered in the main variations while manufacturing Mn4Ni2CrMo steel walls concerning geometry and process parameters maintaining the same deposition ratio as well as the mechanical and metallographic properties obtained in the walls with both processes, in which the applied energy is significantly different. This study shows that acceptable mechanical characteristics are obtained in both processes compared to the corresponding forging standard for the tested material, values are 23% higher for UTS and 56% for elongation in vertical direction in the PAW process compared to GMAW (no differences in UTS and elongation results for horizontal direction and in Charpy for both directions) and without significant directional effects of the additive manufacturing technology used.