Browsing by Author "Penalva, Mariluz"
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Item Accuracy and Surface Quality Improvements in the Manufacturing of Ti-6Al-4V Parts Using Hot Single Point Incremental Forming(2019-06) Ortiz, Mikel; Penalva, Mariluz; Iriondo, Edurne; López de Lacalle, Luis Norberto; FABRIC_INTELThe present work focuses on the manufacturing of Ti-6Al-4V parts using hot single point incremental forming (SPIF), a non-conventional forming technology mainly oriented toward the fabrication of prototypes, spare parts, or very low volume series. In the used procedure, the entire sheet is heated and kept at uniform temperature while the tool incrementally forms the part, with the limited accuracy of the obtained parts being the major drawback of the process. Thus, this work proposes two approaches to improve the geometric accuracy of Ti-6Al-4V SPIF parts: (i) correct the tool path by applying an intelligent process model (IPM) that counteracts deviations associated with the springback, and (ii) skip overforming deviations associated with the deflection of the sheet along the perimeter of the part based on a design improvement. For this purpose, a generic asymmetric design that incorporates features of a typical aerospace Ti-6Al-4V part is used. The results point out the potential of both solutions to significantly improve the accuracy of the parts. The application of the IPM model leads to an accuracy improvement up to 49%, whereas a 25.4% improvement can be attributed to the addendum introduction. The geometric accuracy study includes the two finishing operations needed to obtain the part, namely decontamination and trimming.Item Hot Single Point Incremental Forming of Ti-6Al-4V Alloy(Trans Tech Publications Ltd, 2014) Ortiz, Mikel; Penalva, Mariluz; Puerto, Mildred J.; Homola, Petr; Kafka, Václav; FABRIC_INTEL; FACTORYThe lightweight metal alloy Ti-6Al-4V is widely used in the aeronautical industry due to its excellent mechanical properties. However, it is known the difficulty to deform Ti-6Al-4V sheets at room temperature because of its microstructure conditions. The present work focuses on the evaluation of formability of Ti-6Al-4V sheets using hot single point incremental forming (SPIF) process which it seems appropriate to produce small batches of parts due to its flexibility as it allows a significant reduction of costs and lead times. In order to characterize the SPIF of Ti-6Al-4V under hot forming conditions, a set of forming trials evaluation tests was carried out. The obtained results have allowed identifying the key process features and have demonstrated the potential of the proposed approach to hot form of small amounts of Ti-6Al-4V parts.Item Investigation of Thermal-Related Effects in Hot SPIF of Ti–6Al–4V Alloy(2019) Ortiz, Mikel; Penalva, Mariluz; Iriondo, Edurne; López de Lacalle, Luis Norberto; FABRIC_INTELThe present work focuses on a new approach to hot form hard-to-work materials by Single Point Incremental Forming (SPIF) technology using a global heating of the sheet. A set of trials was carried out in order to identify the optimum temperature cycles to minimize geometric distortions associated to each process stage on the fabrication of parts made of Ti–6Al–4V. On the one hand, heating trials allowed defining the optimal procedure to improve the temperature distribution homogeneity along the sheet and consequently to minimize its thermal distortion previous to the forming stage. On the other hand, the influence of both working temperature and the applied cooling on the geometric accuracy was evaluated by means of SPIF trials. For this purpose, a generic asymmetric design with typical aeronautical features was used. These trials pointed out that high forming temperatures allow reducing significantly the material springback whereas a controlled cooling (with an intermediate stress relief treatment) minimizes both the distortion of the part during the cooling and the mechanical stresses accumulated on the clamping system. Furthermore, the work includes a post-forming material evaluation to determinate the influence of the employed processing conditions on microcracks, alpha-case layer, microstructure and hardness.Item Oversizing Thread Diagnosis in Tapping Operation(2021-03-25) Gil Del Val, Alain; Veiga, Fernando; Penalva, Mariluz; Arizmendi, Miguel; Tecnalia Research & Innovation; FABRIC_INTELAutomotive, railway and aerospace sectors require a high level of quality on the thread profiles in their manufacturing systems knowing that the tapping process is a complex manufacturing process and the last operation in a manufacturing cell. Therefore, a multivariate statistical process control chart, for each tap, is presented based on the principal components of the torque signal directly measured from spindle motor drive to diagnosis the thread profile quality. This on-line multivariate control chart has implemented an alarm to avoid defected screw threads (oversized). Therefore, it could work automatically without any operator intervention assessing the thread quality and the safety is guaranteed during the tapping process.Item Three-Dimensional Finite Element Modelling of Sheet Metal Forming for the Manufacture of Pipe Components: Symmetry Considerations: Symmetry Considerations(2022-01-25) Bhujangrao, Trunal; Veiga, Fernando; Penalva, Mariluz; Costas, Adriana; Ruiz, Cristina; Tecnalia Research & Innovation; FABRIC_INTELThe manufacture of parts by metal forming is a widespread technique in sectors such as oil and gas and automotives. It is therefore important to make a research effort to know the correct set of parameters that allow the manufacture of correct parts. This paper presents a process analysis by means of the finite element model. The use case presented in this paper is that of a 3-m diameter pipe component with a thickness of 22 mm. In this type of application, poor selection of process conditions can result in parts that are out of tolerance, both in dimensions and shape. A 3D finite element model is made, and the symmetry of the tube section generated in 2D is analysed. As a novelty, an analysis of the process correction as a function of the symmetrical deformation of the material in this case in the form of a pipe is carried out. The results show a correct fitting of the model and give guidelines for manufacturing.Item Zero Defect Manufacturing Strategies for Reduction of Scrap and Inspection Effort in Multi-stage Production Systems(2018) Eger, Florian; Coupek, Daniel; Caputo, Davide; Colledani, Marcello; Penalva, Mariluz; Ortiz, Jon Ander; Freiberger, Hermann; Kollegger, Gernot; FABRIC_INTELMulti-stage production systems offer a huge potential for defect compensation and defect propagation avoidance on system level, in contrast to current single-stage solutions, in order to reduce scrap and to minimize time-consuming and cost-intensive quality control. Integration of additional sensor systems and sophisticated analysis of the acquired signals enable strategies in the field of downstream compensation, inline rework and enhanced process control without including additional process and inspection stages. The presented strategies are validated in three emerging European industrial sectors (aerospace, railway and medical) yielding a universal solution for zero defect manufacturing in multi-stage production systems.