Browsing by Author "Artaza, Teresa"
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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 Effects of the Nozzle Tip Clogging and the Scanning Direction on the Deposition Process During Laser Metal Deposition of Alloy 718 Using a Four-Stream Discrete Nozzle(2019) Artaza, Teresa; Ramiro, Pedro; Ortiz, Mikel; Alberdi, Amaia; Lamikiz, Aitzol; FABRIC_INTELDepending on the configuration of the LMD system, the nozzle tilting is necessary to be able to manufacture parts with complex geometry. In these cases, the use of discrete coaxial nozzles is recommended. With this type of nozzle, the powder can clog the internal tips of the nozzle streams due to an inappropriate shape, size distribution, humidity or temperature conditions of the powder particles during the deposition process. This undesired effect can be an opportunity depending on the combination of the activated powder tips for coating complex surfaces when the geometry of the substrate acts as a barrier for the powder stream. This work presents for first time the effect of the scanning direction and the stream clogging on the deposition process in terms of powder efficiency, Material Deposition Rate (MDR) and clad geometry and dimensions, when Alloy 718 is deposited by LMD using a four-stream discrete coaxial nozzle.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 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 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.