Browsing by Author "Ukar, E."
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Item Effects of laser-textured on rake face in turning PCD tools for Ti6Al4V(2021-11-01) Fernández-Lucio, P.; Villarón-Osorno, I.; Pereira Neto, O.; Ukar, E.; López de Lacalle, L.N.; Gil del Val, A.; FABRIC_INTELThe demand inherent to the aeronautical industry in terms of productivity and quality requirements leads to develop new cutting tools. Hence, PCD tools meet the requirements in productivity while machining low machinability aeronautical alloys such as Ti6Al4V. Tool chipbreakers play a considerable role in terms of tool life. However, due to the extreme conditions (temperature and pressure) required to manufacture PCD tools, any complex geometry on tool rake faces is not viable, so chipbreakers are not possible, except for those external to inserts. This work proposes a groove-type laser engraved chipbreaker design and a manufacturing methodology, with experimental validation on turning a Ti6Al4V workpiece. The so-manufactured chipbreakers achieve titanium alloy chip fragmentation, making easy chip removal from the cutting zone. A set of experiments involving various laser parameters to characterize the PCD depth and surface integrity and experimental validation for those chipbreakers designs were carried out in finishing cutting conditions. The optimum parameters for the engraving of PCD were found, obtaining satisfactory breakage of titanium chips. Chip length was always below 17.29 mm.Item Experimental study of laser dissimilar joining for Usibor 2000 and Al-T7075 with Tepex 102(2019) Ukar, E.; Arrizubieta, I.; Andres, M.; Ferros, M.; Liébana, F.; COMPUTER_VISION; COMPOSITE; Tecnalia Research & InnovationDue to the needs of weight reduction in the automobile structures and of time reduction in the Body-In-White (BIW) manufacturing stage, effective and accurate dissimilar joining is demanded to take advantage of metal-polymer structures. Automotive industry is highly interested in the combination of metal alloys and composite materials; however, dissimilar joining of this type of materials without using mechanic or adhesive joining is a challenge. As an alternative to the classical joining techniques, laser technology can be used to join dissimilar materials. In laser direct joining, a laser beam is used to heat the metal and by conduction to heat the polymer up to melting temperature in the interface without reaching degradation temperature. In this work, an experimental procedure is proposed to set the basis of dissimilar joining between metal and composite parts for the automobile industry. To do that, laser texturing on metallic parts was studied and a wide battery of experimental test were performed to obtain the proper joining process parameters for dissimilar joining between Usibor 2000 and Al-T7075 with Tepex 102. Results show that is possible to reach over 17 MPa in lap shear adhesion test which is similar to the performance of typical adhesives used in automotive industry.Item An industrial approach of laser polishing with different laser sources(WILEY-V C H VERLAG GMBH, BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY, 2015) Ukar, E.; Lamikiz, A.; Liébana, F.; Martínez, S.; Tabernero, I.Surface 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 Laser Texturing and Dissimilar Material Joining(2017) Ukar, E.; Liébana, F.; Andrés, M.; Marcos, I.; Lamikiz, A.; COMPOSITE; COMPUTER_VISIONLaser texturing is a process used to remove material selectively. Metallic parts were processed in order to create a surface texture that enables metal-polymer joining. This kind of dissimilar joining is carried out combining a pressure fixture and heating using a direct diode laser source. In order to reach a good result, it is critical to texture the surface with correct parameters to generate surface features that maximizes the contact between materials and heating enough the materials to soften the polymer but without melting and degrading the material, so, a temperature control system is necessary to get best results. In this work, the texturing capabilities of conventional CW laser source were explored and numerical model was developed in order to simulate and control the process temperature in the joining interface.