Browsing by Keyword "Roughness"
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Item Effects of Machining Parameters on the Quality in Machining of Aluminium Alloys Thin Plates(2019-09) Del Sol, Irene; Rivero, Asuncion; Gamez, Antonio J.; SGNowadays, the industry looks for sustainable processes to ensure a more environmentally friendly production. For that reason, more and more aeronautical companies are replacing chemical milling in the manufacture of skin panels and thin plates components. This is a challenging operation that requires meeting tight dimensional tolerances and differs from a rigid body machining due to the low stiffness of the part. In order to fill the gap of literature research on this field, this work proposes an experimental study of the effect of the depth of cut, the feed rate and the cutting speed on the quality characteristics of the machined parts and on the cutting forces produced during the process. Whereas surface roughness values meet the specifications for all the machining conditions, an appropriate cutting parameters selection is likely to lead to a reduction of the final thickness deviation by up to 40% and the average cutting forces by up to a 20%, which consequently eases the clamping system and reduces machine consumption. Finally, an experimental model to control the process quality based on monitoring the machine power consumption is proposed.Item An industrial approach of laser polishing with different laser sources: Industrielle Methode zum Laserpolieren mit verschiedenen Laserstrahlquellen(2015-07-01) Ukar, E.; Lamikiz, A.; Liébana, F.; Martínez, S.; Tabernero, I.; COMPOSITESurface finishing of dies and molds is one of the most interesting applications of laser polishing process. Because of the variety of materials used in die and mold manufacturing, as well as the different surface topographies, in each case, it is necessary to use appropriate process parameters. The presented work focuses on the study of laser polishing process on three commonly used materials in the manufacture of dies and molds, such as tool steels AISI D2 and AISI P20, ductile cast iron GGG70L and LaserForm ST-100, a specific material developed for plastic injection mold making. Experimental studies were carried out determining the influence of the energy density on the roughness reduction rate. A key point that has a direct impact on the resulting surface roughness is the initial surface finishing of the material before laser polishing. In order to determine the degree of influence, experimental studies were conducted on two steels, AISI H13 and AISI P20, which are typically used in mold making industry. The experimental tests showed that a random distribution of peaks and valleys allows more homogenous material melting and gives as result a smoother surface after laser polishing.Item Mejora de la calidad superficial de piezas conformadas incrementalmente mediante la aplicación del bruñido hidrostático(2018-11) Gil-Vildósola, Ariadna; Rodriguez-Ezquerro, Adrián; Penalva-Oscoz, Mariluz; Ortiz-Edesa, Mikel; López-De-Lacalle-Marcaide, Luis Norberto; Iriondo-Plaza, Edurne; FABRIC_INTELThe research work presented aims to validate the operation of the hydrostatic ball burnishing as a strategy to improve the surface quality of an aeronautical component of Inconel 718, previously shaped by Asymetric Incremetal Sheet Forming (AISF). The combination of both processes, burnishing on AISF, has a very high level of innovation and is a pioneer in its application on an industrial component made of this high performance nickel-chromium alloy. The surface quality of the incrementally shaped component has been studied to subsequently apply a burnishing by means of the hydrostatic ball. The results obtained confirm the feasibility of the proposed strategy, with a reduction in roughness up to 30%, depending on the area treated.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 Tool-path effect on the geometric deviations in the machining of UNS A92024 aeronautic skins(2017) Del Sol, I.; Rivero, A.; Salguero, J.; Fernández-Vidal, S.R.; Marcos, M.; SGTraditionally, aeronautics skins are being machined by chemical milling, a high-pollutant process. An efficient alternative to this technology is conventional machining. However, to ensure the parts machined with this process keeps the industrial quality controls, the effect of tool-path might be characterized, specially analyzing final thickness and roughness. In this paper, five different tool-paths have been applied under the same machining parameters in the dry milling of Al-Cu UNS A92024 thin plates. Machining time, final thickness and roughness have been evaluated. Most roughness and thickness results are under the industrial quality limits stablished for this type of parts.