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Lomello F.,French Atomic Energy Commission | Lomello F.,CEA Saclay Nuclear Research Center | Yazdi M.A.P.,IRTES LERMPS UTBM | Sanchette F.,University of Technology of Troyes | And 3 more authors.
Surface and Coatings Technology | Year: 2014

Nanolayered TiN-CrN coatings were synthesized by cathodic arc deposition (CAD) on M2 tool steel substrates. The aim of this study was to establish a double-correlation between the influence of the bilayer period and the deposition temperature on the resulting mechanical-tribological properties.The superlattice hardening enhancement was observed in samples deposited at different temperatures - i.e. without additional heating, 300. °C and 400. °C. Nonetheless, the residual compressive stresses are believed to be the responsible for reducing the hardness enhancement when the deposition temperature was increased. For instance, sample deposited without additional heating presented a hardness of 48.5. ±. 1.3. GPa, while by increasing the processing temperature up to 400. °C it was reduced down to 31.2. ±. 4.1. GPa due to the stress relaxation. Indeed, the sample deposited at low temperature which possesses the thinnest bilayer period (13. nm) exhibited better mechanical properties. On the contrary, the role of the interfaces introduced when the period is decreased seems to rule the wear resistance. © 2013 Elsevier B.V. Source


Apreutesei M.,INSA Lyon | Boissy C.,INSA Lyon | Mary N.,INSA Lyon | Arab Pour Yazdi M.,IRTES LERMPS UTBM | And 2 more authors.
Acta Materialia | Year: 2015

Thin film metallic glasses are a new class of promising materials for advanced structural applications. In this work, binary Zr-based thin film metallic glasses (TFMGs) were deposited by the magnetron co-sputtering process from pure metal targets. Two similar enrichments were investigated (44 at.% for the nickel, 43 at.% for the cobalt), in order to determine the effect of the alloying element's nature on the structural, mechanical and electrochemical behaviors. Structure of films was determined by in situ XRD measurements carried out during heating up to 600 °C, while their morphology was characterized by SEM observations. Mechanical properties of amorphous and crystallized films (hardness and Young's modulus) were measured by nanoindentation. Intrinsic electrochemical properties are deduced from polarization curves and electrochemical impedance spectroscopy measurements carried out in Na2SO4 aqueous solution. It is found that the surface morphology of TFMGs was very smooth with a compact and dense microstructure. When heated, glassy films exhibit a high structural stability (up to 440 °C) with crystallization occurring through a multistage process for the Co-containing film. Whatever the coating, Zr affords its beneficial passive-ability, while crystallization process accelerates the global corrosion kinetics. Corrosion mechanisms of the Zr-based TFMGs were discussed in the light of the alloying element (Ni or Co) and the structure of films (amorphous or crystallized). © 2015 Acta Materialia Inc. Source


Arab Pour Yazdi M.,IRTES LERMPS UTBM | Lomello F.,CEA Saclay Nuclear Research Center | Lomello F.,French Atomic Energy Commission | Wang J.,French Atomic Energy Commission | And 9 more authors.
Vacuum | Year: 2014

TiSiN nanocomposites coatings were synthesized for the first time by a hybrid deposition technique where high power impulse (HiPIMS) and pulsed-DC (PDCMS) magnetron co-sputtering were used for Ti and Si deposition respectively in an Ar + N2 atmosphere. For the Ti target, the deposition parameters were fixed, while the current applied to the Si target ranged from 0 to 0.9 A. Thus, the Si content in the films was adjusted from 0 to 8.8 at.% Si to allows tailoring of microstructure and mechanical properties. TiSiN grain sizes decreased from ∼41 to ∼6 nm as the coatings became more siliceous. The hardness increased from 20 ± 0.41 to 41.31 ± 2.93 GPa when the Si concentration rose from 0 to 4.4 at.% Si, but beyond this last value, hardness degrades reaching 36.1 ± 2.21 GPa at 8.8 at.% Si. The wear behaviours evaluated by ball-on-disc tests were correlated with the Hardness/Young's modulus ratio. Moreover, the silicon enhanced the oxidation resistance and the least hardness deterioration was found in the sample with the higher silicon content (8.8 at.% Si) after a thermal annealing in air (2 h/700 °C). © 2014 Elsevier Ltd. All rights reserved. Source


Taguett A.,IRTES LERMPS UTBM | Yazdi M.A.P.,IRTES LERMPS UTBM | Sanchez J.-B.,University of Franche Comte | Monsifrot E.,SARL DEPHIS | And 3 more authors.
Key Engineering Materials | Year: 2014

In this paper, we investigate the feasibility of La1-xAg xCoO3-α nanowires by reactive magnetron sputtering. After a short description of the experimental and hydrocarbon sensing bench devices, a first part will be dedicated to the chemical, microstructural and structural characterization (SEM, XRD,...) of the coatings. As deposited coatings are amorphous and a post heat-treatment under air at 873 K is necessary to crystallise them in the perovskite structure. Finally, the performance as dodecane-sensors of these coatings with amorphous and crystalline structures will be discussed depending on dodecane concentrations and sensitive surface's temperature and will be compared to those of La0.40Sr 0.15Ag0.45CoO3-α nanowires. © (2014) Trans Tech Publications. Source


Coddet P.,IRTES LERMPS UTBM | Liao H.-L.,IRTES LERMPS UTBM | Coddet C.,IRTES LERMPS UTBM
Advances in Manufacturing | Year: 2013

Manufacturing of solid oxide fuel cell (SOFC) components remains nowadays a key point for the industrial development of this technology. Especially, the deposition of the dense electrolyte layer which is sandwiched between the porous anode and the porous cathode is of paramount importance and thus focuses a lot of attention. Therefore, this paper considers and reviews recent developments concerning solid electrolyte layers manufacturing using thermal spray (TS) and physical vapour deposition (PVD) technologies. © 2013 Shanghai University and Springer-Verlag Berlin Heidelberg. Source

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