Browsing by Keyword "Magnetron sputtering"
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Item Chemical and microstructural characterization of (Y or Zr)-doped CrAlN coatings(2012-10-25) Rojas, T. C.; El Mrabet, S.; Domínguez-Meister, S.; Brizuela, M.; García-Luis, A.; Sánchez-López, J. C.; INGENIERÍA DE SUPERFICIES; TECNOLOGÍAS DE HIDRÓGENOMagnetron sputtered chromium aluminium nitride films are excellent candidates for advanced machining and protection for high temperature applications. In this work CrAlN-based coatings including Y or Zr as dopants (2at.%) are deposited by d.c. reactive magnetron sputtering on silicon substrates using metallic targets and Ar/N 2 mixtures. The hardness properties are found in the range of 22-33GPa with H/E ratios close to 0.1. The influence of the dopant element in terms of oxidation resistance after heating in air at 1000°C is studied by means of X-ray diffraction (XRD), cross-sectional scanning electron microscopy (X-SEM) and energy dispersive X-ray analysis (EDX). The microstructure and chemical bonding are investigated using a transmission electron microscope (TEM) and electron energy-loss spectroscopy (EELS) respectively. The improvement in oxidation resistance as compared to pure CrN coating is manifested in the formation of a Al-rich outer layer that protects the underneath coating from oxygen diffusion. The best performance obtained with the CrAlYN film is investigated by in situ annealing of this sample inside the TEM in order to gain knowledge about the structural and chemical transformations induced during heating.Item Magnetron sputtering of Cr(Al)N coatings: Mechanical and tribological study: Mechanical and tribological study(2005-10-01) Brizuela, Marta; García-Luis, A.; Braceras, I.; Onate, J.I.; Sánchez-López, J.C.; Martínez-Martínez, D.; López-Cortés, C.; Fernández, A.; López-Cartes, C.; INGENIERÍA DE SUPERFICIES; TECNOLOGÍAS DE HIDRÓGENO; Tecnalia Research & InnovationCrN coatings produced by magnetron sputtering are routinely deposited on tools and components for machining and forming applications. This paper reports on the effect of additions of aluminium (<15 at.%) on the mechanical and tribological properties of CrN coatings. Aluminium has been incorporated into CrN by co-sputtering of chromium and aluminium in a mixture of argon and nitrogen. Mechanical properties have been evaluated by ultramicroindentation techniques and scratch testing, while tribological tests have been carried out against ball bearing steel and titanium alloy balls by the pin-on-disc method. The thermal stability and oxidation resistance of the coatings have also been examined. A significant increase in hardness, reaching values up to 35 GPa, has been achieved for the CrAlN coatings when compared to CrN coatings. The improvement in tribological properties has also been remarkable, with a decrease in friction coefficient against bearing steel and also a non-adhesive wear mechanism against titanium alloy balls. In addition, the CrAlN coatings exhibited higher thermal stability than pure CrN coatings.Item Mechanical properties of nanocrystalline Ti–B–(N) coatings produced by DC magnetron sputtering(2005-10-01) García-Luis, A.; Brizuela, Marta; Onate, J.I.; Sánchez-López, J.C.; Martínez-Martínez, D.; López-Cartes, C.; Fernández, A.; TECNOLOGÍAS DE HIDRÓGENO; INGENIERÍA DE SUPERFICIES; Tecnalia Research & InnovationTi–B–(N) coatings have been deposited by DC magnetron sputtering using TiB2 targets in Ar/N2 gas mixtures. The influence of bias voltage and nitrogen flow on the mechanical and tribological properties of these coatings has been studied. Mechanical properties have been evaluated by ultra-microindentation techniques and scratch testing; tribology tests have been performed in a pin-on-disc apparatus with controlled humidity conditions. Microstructural characterization by X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM) demonstrates the nanocrystalline structure of Ti–B–(N) coatings and allows the interpretation of their mechanical behaviour. Hardness values up to 58 GPa have been achieved, depending on deposition conditions. Increasing the bias voltage on the substrates improves the hardness of coatings, while the addition of nitrogen significantly decreases these values. Coating adhesion obtained on highspeed steel is very good in most cases, reaching values higher than 60 N of critical load. Tribotests performed on these coatings against a Steel contact (wear conditions: 0.98 N load, 10 cm/s, 50% RH, 10 mm bearing steel ball diameter) have yielded very low wear rates but friction coefficients in the range of 0.6–1.0.Item Mikrobioak eta gainazalak: arazoa eta konponbidea?(2022-07) Braceras, Iñigo; Imaz, Naroa; INGENIERÍA DE SUPERFICIESCOVID-19a dela medio, eguneroko albiste bihurtu zaizkigu gaixotasun infekziosoak. Dena den, gaixotasun horiekiko kezka aurretikoa da, mikrobioak antibiotikoekiko erresistentzia garatzen ari baitira etengabe. Hori dela eta, etorkizunerako beste estrategia batzuk ikertzen ari dira. Horien artean, jakinekoa da gainazalek garrantzi handia dutela hainbat mikrobioren hedapenean . Beraz, mikrobioei aurre egiteko gainazal aproposak bagenitu inguru desberdinetarako, arazoa mugatzeko bidean geundeke. Helburu horrekin, Tecnaliak eta Cidetec Surface Engineeringek arlo horretan teknologia ezberdinak ikertzen eta ahalbide berriak garatzen dihardute.Item Monolithic All-Solid-State High-Voltage Li-Metal Thin-Film Rechargeable Battery(2022-10-24) Madinabeitia, Iñaki; Rikarte, Jokin; Etxebarria, Ane; Baraldi, Giorgio; Fernández-Carretero, Francisco José; Garbayo, Iñigo; Cid, Rosalía; García-Luis, Alberto; Muñoz-Márquez, Miguel Ángel; Tecnalia Research & Innovation; TECNOLOGÍAS DE HIDRÓGENOThe substitution of an organic liquid electrolyte with lithium-conducting solid materials is a promising approach to overcome the limitations associated with conventional lithium-ion batteries. These constraints include a reduced electrochemical stability window, high toxicity, flammability, and the formation of lithium dendrites. In this way, all-solid-state batteries present themselves as ideal candidates for improving energy density, environmental friendliness, and safety. In particular, all-solid-state configurations allow the introduction of compact, lightweight, high-energy-density batteries, suitable for low-power applications, known as thin-film batteries. Moreover, solid electrolytes typically offer wide electrochemical stability windows, enabling the integration of high-voltage cathodes and permitting the fabrication of higher-energy-density batteries. A high-voltage, all-solid-state lithium-ion thin-film battery composed of LiNi0.5Mn1.5O4 cathode, a LiPON solid electrolyte, and a lithium metal anode has been deposited layer by layer on low-cost stainless-steel current collector substrates. The structural and electrochemical properties of each electroactive component of the battery had been analyzed separately prior to the full cell implementation. In addition to a study of the internal solid–solid interface, comparing them was done with two similar cells assembled using conventional lithium foil, one with thin-film solid electrolyte and another one with thin-film solid electrolyte plus a droplet of LP30 liquid electrolyte. The thin-film all-solid state cell developed in this work delivered 80.5 mAh g–1 in the first cycle at C/20 and after a C-rate test of 25 cycles at C/10, C/5, C/2, and 1C and stabilized its capacity at around 70 mAh g–1 for another 12 cycles prior to the start of its degradation. This cell reached gravimetric and volumetric energy densities of 333 Wh kg–1 and 1,212 Wh l–1, respectively. Overall, this cell showed a better performance than its counterparts assembled with Li foil, highlighting the importance of the battery interface control.Item Role of y in the oxidation resistance of CrAlYN coatings(2015-10-30) Domínguez-Meister, S.; El Mrabet, S.; Escobar-Galindo, R.; Mariscal, A.; Jiménez De Haro, M. C.; Justo, A.; Brizuela, M.; Rojas, T. C.; Sánchez-López, J. C.; INGENIERÍA DE SUPERFICIESCrAlYN coatings with different aluminum (4-12 at.%) and yttrium (2-5 at.%) contents are deposited by d.c. reactive magnetron sputtering on silicon and M2 steel substrates using metallic targets and Ar/N 2 mixtures. The influence of the nanostructure and chemical elemental distribution on the oxidation resistance after heating in air at 1000 °C is studied by means of cross-sectional scanning electron microscopy (X-SEM), energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD) and glow discharge optical emission spectroscopy (GD-OES). The sequential exposure to the metallic targets during the synthesis leads to a multilayer structure where concentration of metallic elements (Cr, Al and Y) is changing periodically. A good oxidation resistance is observed when Al- and Y-rich regions are separated by well-defined CrN layers, maintaining crystalline coherence along the columnar structure. This protective behavior is independent of the type of substrate and corresponds to the formation of a thin mixed (Al, Cr)-oxide scale that protects the film underneath. The GD-OES and XRD analysis have demonstrated that Y acts as a reactive element, blocking the Fe and C atoms diffusion from the steel and favoring higher Al/Cr ratio in the passivation layer after heating. The coating with Y content around 4 at.% exhibited the best performance with a thinner oxide scale, a delay in the CrN decomposition and transformation to Cr 2 N, and a more effective Fe and C blocking.Item Tribological behaviour at high temperature of hard CrAlN coatings doped with y or Zr(2014-01-01) Sánchez-López, J. C.; Contreras, A.; Domínguez-Meister, S.; García-Luis, A.; Brizuela, M.; TECNOLOGÍAS DE HIDRÓGENO; INGENIERÍA DE SUPERFICIESThe tribological properties of CrAlN, CrAlYN and CrAlZrN coatings deposited by direct current reactive magnetron sputtering are studied by means of pin-on-disc experiments at room temperature, 300, 500 and 650 C using alumina balls as counterparts. The influence of the metallic composition (Al, Y and Zr) on the friction, wear properties and oxidation resistance is studied by means of scanning electron microscopy, energy dispersive X-ray analysis and Raman analysis of the contact region after the friction tests. The results obtained allow us to classify the tribological behaviour of the CrAl(Y,Zr)N coatings into three groups according to the nature of the dopant and aluminium content. The sliding wear mechanism is characterized by the formation of an overcoat rich in chromium and aluminium oxides whose particular composition is determined by the initial chemical characteristics of the coating and the testing temperature. The fraction of Cr2O3 becomes more significant as the Al content decreases and the temperature increases. The addition of Y, and particularly Zr, favours the preferential formation of Cr2O 3 versus CrO2 leading to a reduction of friction and wear of the counterpart. Conversely, the tribological behaviour of pure CrAlN coatings is characterized by higher friction but lower film wear rates as a result of higher hardness and major presence of aluminium oxides on the coating surface.