M. Auger - Academia.edu (original) (raw)

Papers by M. Auger

Philosophical Magazine, 2017

[ES] En este trabajo se han estudiado láminas de TiN crecidas sobre cuchillas de acero inoxidable... more [ES] En este trabajo se han estudiado láminas de TiN crecidas sobre cuchillas de acero inoxidable empleadas en el corte de fibra de vidrio, para mejorar sus propiedades mecánicas y aumentar el tiempo de vida de la herramienta, reduciendo de este modo las paradas de producción. La técnica de depósito utilizada ha sido la de sputtering magnetrón reactivo. La composición química de las capas de TiN ha sido determinada mediante medidas de Espectroscopía Auger, RBS (Rutherford Backscattering Spectroscopy) y XANES (X-Ray Spectroscopy Near the Absorption Edge) y se ha relacionado con la composición de la mezcla gaseosa presente en la cámara de reacción. La estructura cristalina se ha determinado mediante Difracción de Rayos X, y mediante la técnica de SEM (Scanning Electron Microscopy) se ha observado la morfología de las capas. La dureza del recubrimiento se ha calculado a partir de medidas de nanoindentación, obteniéndose un valor de 21.54±1.04 GPa, típico en la literatura para el TiN. L...

Journal of Nuclear Materials, 2014

ABSTRACT An oxide dispersion strengthened (ODS) alloy with nominal composition Fe-14Cr-2W-0.3Ti-0... more ABSTRACT An oxide dispersion strengthened (ODS) alloy with nominal composition Fe-14Cr-2W-0.3Ti-0.24Y (wt.%) was produced by mechanical alloying using elemental powders, and subsequent hot isostatic pressing. The microstructure of the material and characteristics of the oxide particle dispersion were investigated by electron microscopy. The effect of heat treatments on the microhardness and tensile properties at room temperature was also studied. The results show that a fine dispersion of Y-O-rich nanoparticles is achieved, together with larger (Cr, Ti)-rich precipitates. The absence of Ti is apparent in the majority of these nanoparticles, in contrast with reported results for ODS Ti-modified steels processed with Y2O3 addition.

Bol. Soc. Esp. Ceram. Vidr., 2006

Materials Science and Technology, 2011

Reduced activation ferritic/martensitic and ferritic steels strengthened by a dispersion of oxide... more Reduced activation ferritic/martensitic and ferritic steels strengthened by a dispersion of oxide nanoparticles have been considered viable structural materials for fusion applications above 550uC. However, the microstructural stability and mechanical behaviour of these steels subjected to the aggressive operating conditions of these reactors are not well known. An accelerated development of these materials is crucial if they are going to be used in future power reactors. Then, it is indispensable to understand their atomic scale evolution under high temperature and irradiation conditions. The present paper reviews how the combination of transmission electron microscopy and atom probe tomography has been successfully applied for the characterisation of these steels at the near atomic scale, to reveal the nanoparticle structure, grain boundary chemistry and void distribution.

Boletín de la Sociedad Española de Cerámica y Vidrio, 2004

En este trabajo se han estudiado láminas de TiN crecidas sobre cuchillas de acero inoxidable empl... more En este trabajo se han estudiado láminas de TiN crecidas sobre cuchillas de acero inoxidable empleadas en el corte de fibra de vidrio, para mejorar sus propiedades mecánicas y aumentar el tiempo de vida de la herramienta, reduciendo de este modo las paradas de producción. La técnica de depósito utilizada ha sido la de sputtering magnetrón reactivo. La composición química de las capas de TiN ha sido determinada mediante medidas de Espectroscopía Auger, RBS (Rutherford Backscattering Spectroscopy) y XANES (X-Ray Spectroscopy Near the Absorption Edge) y se ha relacionado con la composición de la mezcla gaseosa presente en la cámara de reacción. La estructura cristalina se ha determinado mediante Difracción de Rayos X, y mediante la técnica de SEM (Scanning Electron Microscopy) se ha observado la morfología de las capas. La dureza del recubrimiento se ha calculado a partir de medidas de nanoindentación, obteniéndose un valor de 21.54±1.04 GPa, típico en la literatura para el TiN. Los resultados de la prueba en fábrica de las cuchillas recubiertas muestran un aumento en su tiempo de vida de hasta un 67%. Palabras clave: Sputtering magnetrón reactivo, TiN, propiedades mecánicas, dureza TiN deposition on cutting tools for industrial use TiN coatings on stainless steel blades for glass fibre cutting have been investigated in this work. The aim was to improve their mechanical properties and increase the tool time life, decreasing in this way the production stops. Reactive magnetron sputtering has been the deposition technique. TiN films chemical composition has been determined by AES (Auger Electron Spectroscopy), RBS (Rutherford Backscattering Spectroscopy) and XANES (X-Ray Spectroscopy Near the Absorption Edge), and it has been correlated to the gas mixture composition in the vacuum chamber. Crystalline structure has been determined by X-Ray Diffraction, and the films morphology has been observed by SEM (Scanning Electron Microscopy). The hardness coating has been extracted from nanoindentation measurements, giving a 21.54±1.04 GPa hardness value, typical for TiN in the literature. Factory proofs for coated cutting blades show a 67% lifetime increase.

Vacuum, 2007

ZrN coatings have been grown in an rf sputtering deposition chamber, using different ratios of Ar... more ZrN coatings have been grown in an rf sputtering deposition chamber, using different ratios of Ar/N 2 (5/1, 5/5, 1/5) in the reactive gas flow. After deposition, the coatings were thermally treated in a 500 1C oxygen atmosphere, in order to test the thermal stability of the layers or the oxynitride formation. The chemical composition, surface roughness and structural, mechanical and tribological properties of the as-deposited and annealed samples have been measured by energy dispersive spectroscopy (EDS), atomic force microscopy (AFM), X-ray diffractometry, nanoindentation and pin-on-disk techniques, respectively. Deposition parameters determine the growth rate, crystalline structure and surface roughness, which affect the mechanical and tribological behaviour of the samples. The best mechanical and tribological performance and highest growth rate was found for the sample grown under 5 sccm Ar+1 sccm N 2 gas flow. The as-deposited layers have a low wear, showing an increase in hardness after annealing making them suitable as protective layers.

Thin Solid Films, 2003

TiNyAlN bilayers and multilayers were deposited on (100) silicon substrates using reactive magnet... more TiNyAlN bilayers and multilayers were deposited on (100) silicon substrates using reactive magnetron sputtering technique. These combined coatings are known to possess high hardness and wear resistance, hence, their structural and mechanical properties were investigated. X-Ray diffraction, transmission electron microscopy, atomic force microscopy, spectroscopic ellipsometry and nanoindenter measurements were applied to characterise the films. The bilayer hardness increases with the individual layer thickness ratio approaching unity and further enhancement was obtained in the multilayers. The enhanced hardness seems to be related to a dislocation blocking effect at the interfaces which is promoted by the hexagonal (002) and cubic (111) textures found in AlN and TiN layers, respectively.

Thin Solid Films, 2006

Development of new methods in the formation of hollow structures, in particular, nanotubes and na... more Development of new methods in the formation of hollow structures, in particular, nanotubes and nanocages are currently generating a great interest as a consequence of the growing relevance of these nanostructures on many technological fields, ranging from optoelectronics to biotechnology. In this work, we report the formation of titanium nitride (TiN) nanotubes and nanohills via reactive sputtering magnetron processes. Anodic

Surface and Interface Analysis, 2005

ABSTRACT In this paper, we have studied, using X-ray photoelectron spectroscopy (XPS), the chemic... more ABSTRACT In this paper, we have studied, using X-ray photoelectron spectroscopy (XPS), the chemical stability of TiN, TiAlN and AlN layers produced by magnetron sputtering on Si wafer substrates, against humid, SO2-polluted atmospheres. The results have indicated that the TiN layers suffer almost no degradation after seven days of exposure to the aggressive environment. The degradation of the TiAlN layers is small, and this is evidenced by the appearance of signals corresponding to NO bonds in the N 1s spectra, after seven days of exposure to the corrosive atmosphere and the increase in the Ti 2p spectra of the contribution corresponding to TiO2. In contrast, the degradation experienced by the AlN layers is quite large. The spectra reveal dramatic changes after just one day of exposure to the aggressive conditions. This is related to the preferential growth of the AlN layers, which gives rise to an open, columnar structure. Copyright © 2005 John Wiley & Sons, Ltd.

Surface and Interface Analysis, 2006

ABSTRACT We have studied the corrosion behaviour of AlN and TiAlN coatings deposited by magnetron... more ABSTRACT We have studied the corrosion behaviour of AlN and TiAlN coatings deposited by magnetron sputtering on pure iron substrates. The samples have been subjected to two different corrosion tests: (i) a Prohesion test and (ii) an accelerated corrosion test in constantly humid SO2-polluted atmospheres. The transformations induced in the coatings by the aggressive environments have been followed by X-ray photoelectron spectroscopy (XPS). The results indicate that under the corrosion conditions of the Prohesion test, the TiAlN coatings confer on the substrate a more efficient protection than the AlN coatings. Under the conditions of the accelerated corrosion tests in SO2-polluted atmospheres, the behaviour of both coatings is very similar in the initial stages since in both cases the corrosion of the underlying iron occurs just after 1 day of exposure to the aggressive conditions. However, it seems that once the corrosion has started it progresses faster under the AlN coating than under the TiAlN coating. The XPS results also show that the TiAlN coating is more chemically inert than the AlN coating, which suffers chemical transformations under the influence of the two different aggressive conditions considered. The better performance of the TiAlN coating is attributed to its denser microstructure since these AlN coatings have been observed to grow in a more open columnar structure. Copyright © 2006 John Wiley & Sons, Ltd.

Surface and Coatings Technology, 2002

... Mechanical properties have been extracted from nano-indentation measurements, giving hardness... more ... Mechanical properties have been extracted from nano-indentation measurements, giving hardness values for TiN/AlN bilayer in the ... the shutter during pre-sputtering target cleaning and then move it towards the titanium target, staying ... 200) and (400) orientation peaks associated ...

Surface and Coatings Technology, 2004

Aluminium nitride (AlN) films have been deposited on (100) oriented silicon substrates by dc reac... more Aluminium nitride (AlN) films have been deposited on (100) oriented silicon substrates by dc reactive magnetron sputtering for different deposition times (10FtF200 min) at a constant growth rate of 5 nmymin. The films have been characterized by tapping mode atomic force microscopy (AFM) and X-ray diffraction (XRD) techniques in order to study the correlation between the film growth and structural properties. The film growth has been characterized through the analysis of the temporal evolution of surface roughness, s, obtained from the AFM data. The XRD measurements have shown the presence of a polycrystalline hexagonal phase for all film thicknesses. For t-40 min, the films are composed of (002) textured regions embedded in a less ordered matrix. In this regime, the steep change of s with the deposition time as sAt is consistent with an unstable growth mode. In contrast, for 40FtF200 min, a homogeneous structure with hexagonal (002) texture is mainly present, and the film roughening considerably decreases to sAt due to growth stabilization. Hence, the XRD and AFM data have revealed the 0.37 existence of two growth regimes, and indicate that there is a strong link between the film structure and crystallinity and the film growth mode.

Journal of Nuclear Materials, 2009

W and W alloys containing 0.5 wt% Y 2 O 3 , x wt% Ti and (x wt% Ti + 0.5 wt% Y 2 O 3) have been p... more W and W alloys containing 0.5 wt% Y 2 O 3 , x wt% Ti and (x wt% Ti + 0.5 wt% Y 2 O 3) have been prepared, x 2 or 4. Elemental powders were blended or ball milled, canned, degassed and finally consolidated by a two stage HIP process under a pressure of 195 MPa. It is found that Ti addition favours the densification attaining a fully dense material. XRD, SEM and EDX analyses of the material with Ti addition reveal the formation of a microstructure consisting of tungsten particles embedded in a W Ti matrix. The microhardness of these materials increased noticeably with the titanium content.