Browsing by Author "Ramiro, Pedro"
Now showing 1 - 7 of 7
Results Per Page
Sort Options
Item Analysis of the Machining Process of Inconel 718 Parts Manufactured by Laser Metal Deposition(2019-07-01) Ostra, Txomin; Alonso, Unai; Veiga, Fernando; Ortiz, Mikel; Ramiro, Pedro; Alberdi, Amaia; FABRIC_INTEL; Tecnalia Research & InnovationLaser metal deposition (LMD) is an additive manufacturing process that allows the manufacturing of near-net-shape products. This could mean significant savings in terms of materials and costs in the manufacturing of high-performance components for the aeronautical industry. In this work, an analysis of how the LMD processing of alloy 718 affects the final machining has been carried out. For this purpose, a comparative study has been done by means of the monitoring of the end milling process of a part manufactured by LMD and a rough-milled part from forged material. Differences between process outputs such as chip morphology and cutting forces were studied. Material characteristics such as microstructure, hardness and mechanical properties were also analyzed.Item Characteristics of Fe-, Ni- and Co-based Powder Coatings Fabricated by Laser Metal Deposition without Preheating the base Material(2018) Ramiro, Pedro; Alberdi, Amaia; Ortiz, Mikel; Lamikiz, Aitzol; Ukar, Eneko; FABRIC_INTELThe objective of this work was to select the best material from Fe-, Ni- and Co-based alloy powder for coating, by Laser Metal Deposition (LMD) the filets of a hardened 42CrMoS4 extrusion screw without preheating process. Even though most of the articles recommended preheating the base material as a condition for a crack free coating, the time wasted in the process decrease the productivity and distortions can be also generated in the part. In this work, a comparison of the main characteristics of the coatings done on preheated and non-preheated base material has been made. The relationships between the relevant LMD parameters (feed rate, laser power, and powder feeding rate) and the main geometrical characteristics of a single clad (height, width, dilution, deposition rate, efficiency, etc.) were examined. In addition, different characteristics of overlapped clads in a preheated, non-preheated and a hardened base material have been also analyzed. All the study was made in the Ibarmia ZVH 45/1600 Add+Process hybrid machine with a high power Yb-Fiber laser (3 kW) and discrete coaxial LMD head. Coatings with thickness from 1.2 to 0.76 were created without cracks and other defects except in the case of Ni-based coating. The microstructural features of these coatings were studied using optical and scanning electron microscopy. The mechanical properties were determined using microhardness measurements and a pin on disk tribometer.Item Characteristics of Fe-based powder coatings fabricated by laser metal deposition with annular and four stream nozzles(2018) Ramiro, Pedro; Ortiz, Mikel; Alberdi, Amaia; Lamikiz, Aitzol; FABRIC_INTELThe present work focuses on performing a comparative study in the field of Laser Metal Deposition (LMD) analyzing the obtained clads in terms of geometry and quality when vertically using a discrete coaxial nozzle or an annular one. A Fe-based alloy powder (Eutroloy 16606A.04) was used for the study, a heat treatable alloy, with high wear-resistant to abrasion and fatigue stress, typically employed for coating applications. The possibility of controlling the coating process with a non-coaxial thermographic camera has also been evaluated.Item Effect of Heat Treatment on the Microstructure and Hardness of Ni-Based Alloy 718 in a Variable Thickness Geometry Deposited by Powder Fed Directed Energy Deposition(2022-05-31) Ramiro, Pedro; Galarraga, Haize; Pérez-Checa, Anabel; Ortiz, Mikel; Alberdi, Amaia; Bhujangrao, Trunal; Morales, Elena; Ukar, Eneko; Tecnalia Research & Innovation; FABRIC_INTEL; CIRMETAL; Caracterización y Validación. Materiales; Caracterización y Validación. MecánicosFeature addition to existing parts is a trending application for Directed Energy Deposition (DED) and can be used to add complex geometry features to basic forged geometries with the aim to reduce and simplify the number of processing steps as machining and assembling. However, the mechanical properties of as-deposited Inconel 718 fabricated by Powder-fed Directed Energy Deposition (Powder-fed DED) are far lower than the relevant specifications, making it necessary to apply different heat treatment with the purpose of improving deposited material performance. In addition, the effects of heat treatments in both variable thickness deposited geometry and forge substrate have not been studied. In this study, the effect of heat treatment within the Aerospace Materials Specifications (AMS) for cast and wrought Inconel 718 on the microstructure and hardness of both the Ni-Based Alloy 718 deposited geometry and substrate are analyzed in different parts of the geometry. The microstructure of all samples (as-deposited and heat-treated) is analyzed by Scanning Electron Microscope (SEM) and Energy Dispersive Spectrometer (EDS), confirming the formation of aluminum oxides and titanium nitrides and carbonitrides in the deposited structure.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 Geometrical model and strategy in single and multilayer structures deposited by powder-fed Directed Energy Deposition(2020) Ramiro, Pedro; Ortiz, Mikel; Alberdi, Amaia; Lamikiz, Aitzol; FABRIC_INTELThis work presents a geometrical model of coatings fabricated by powder-fed Directed Energy Deposition (DED) and defines guidelines and manufacturing strategies for multilayered structures based on the geometrical model results. This model obtains as output both the overlapped clad geometry and the dilution area of the coating at different input parameters and defines the strategy of multi-layer structures. The results of this work validate the model that comes in handy: a) To understand the influence of each parameter and the single clad geometry when fabricating coatings and structures; b) To select the parameters depending on the requirements of the coating like effective thickness and dilution; c) To detect lack of fusion with the substrate due to an excessive overlap percentage; d) To select the deposition strategy and the tool path for additive manufacturing; e) To select the subsequent machining strategy based on the predicted geometry of the model.Item Strategy Development for the Manufacturing of Multilayered Structures of Variable Thickness of Ni-Based Alloy 718 by Powder-Fed Directed Energy Deposition(Multidisciplinary Digital Publishing Institute (MDPI), 2020-09-24) Ramiro, Pedro; Ortiz, Mikel; Alberdi, Amaia; Lamikiz, AitzolIn this study, a manufacturing strategy, and guidelines for inclined and multi-layered structures of variable thickness are presented, which are based on the results of an own-developed geometrical model that obtains both the coating thickness and dilution. This model is developed for the powder-fed directed energy deposition process (DED) and it only uses the DED single-track cladding characteristics (height, width, area, and dilution depth), the overlap percentage, and the laser head tilting-angle as inputs. As outputs, it calculates both the cladding geometry and the dilution area of the coating. This model for the Ni-based alloy 718 was improved, based on previous studies of the single clad working both vertically and at an inclined angle, adding the equations of the single clad characteristics with respect to the main process parameters. The strategy proposed in this paper for multilayered cladding consisted of both adding an extra clad at the edges of the layer and using a variable value of the overlap percentage between clads for geometric adaptations. With this strategy, the material deposition is more accurate than otherwise, and it shows stable growth. Manufacturing a multilayered wall of wider thicknesses at higher heights was utilized to validate the strategy.