The Experts below are selected from a list of 258 Experts worldwide ranked by ideXlab platform
Philippe Marcus - One of the best experts on this subject based on the ideXlab platform.
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The fate of the Protective Oxide Film on stainless steel upon early stage growth of a bioFilm
Corrosion Science, 2015Co-Authors: Antoine Seyeux, Sandrine Zanna, Audrey Allion, Philippe MarcusAbstract:Abstract For metals and alloys that are protected against corrosion by a surface Oxide Film (the passive Film), the modification or degradation of this passive Film in presence of bacteria is a key issue in terms of integrity and reliability of structures. The objective of this work was to reveal the nature of the interaction of stainless steel with bacteria, in particular the modifications of the passive Film after bacteria adhesion in the early stage of bioFilm formation. An innovative approach, based on advanced surface analysis, has been developed. The use of Time of Flight Secondary Ions Mass Spectrometry (ToF-SIMS) allowed us to have access to and characterize the bacteria/substrate interface. Here we show that a passive Film remains under the bacteria, but its chemical composition is modified. The passive Film under Escherichia coli bacteria, for a surface coverage by bacteria of ∼20%, is enriched in Cr compared to the passive Film on stainless steel not exposed to the bacteria.
Rex D. Ramsier - One of the best experts on this subject based on the ideXlab platform.
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Non-destructive characterization of Films grown on Zircaloy-2 by annealing in air
Journal of Physics D: Applied Physics, 2002Co-Authors: Jeremiah S. Mcnatt, M. J. Shepard, N. Farkas, J. M. Morgan, Rex D. RamsierAbstract:Zircaloy-2 is often used in engineering applications because of its corrosion resistance; a property attributable to a Protective Oxide Film that grows on its surface. Variable angle infrared (IR) reflection spectroscopy and atomic force microscopy are used to determine the thickness and roughness of such Films grown thermally on Zircaloy-2 surfaces in air. We find cubic growth kinetics in the temperature range 500–600uC with an apparent activation energy of 227 kJ mol −1 . We also demonstrate how an increase in microscopic surface roughness at higher temperatures correlates with a loss of Oxide homogeneity as sampled by the IR method.
R. Molins - One of the best experts on this subject based on the ideXlab platform.
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Study by deflection of the oxygen pressure influence on the phase transformation in alumina thin Films formed by oxidation of Fe3Al
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2007Co-Authors: A.m. Huntz, P.y. Hou, R. MolinsAbstract:Abstract The influence of oxygen pressure on the stability of transition aluminas formed by the oxidation of an Fe 3 Al intermetallic alloy was studied by means of deflection tests, a technique based on the curvature of an asymmetrical sample consisting of a thin and elongated metallic substrate covered on one face by a Protective Oxide Film. Three different atmospheres were chosen: air, argon and Ar–H 2 –H 2 O mixture in order to obtain three different oxygen pressures and different water vapour contents. The deflection results were analysed on the basis of knowledge obtained from kinetics and TEM and SEM microstructural observations.
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Study by deflection of the oxygen pressure influence on the phase transformation in alumina thin Films formed by oxidation of Fe3Al
Materials Science and Engineering: A, 2007Co-Authors: A.m. Huntz, P.y. Hou, R. MolinsAbstract:International audienceThe influence of oxygen pressure on the stability of transition aluminas formed by the oxidation of an Fe3Al intermetallic alloy was studied by means of deflection tests, a technique based on the curvature of an asymmetrical sample consisting of a thin and elongated metallic substrate covered on one face by a Protective Oxide Film. Three different atmospheres were chosen: air, argon and Ar–H2–H2O mixture in order to obtain three different oxygen pressures and different water vapour contents. The deflection results were analysed on the basis of knowledge obtained from kinetics and TEM and SEM microstructural observations
Huseyin Cimenoglu - One of the best experts on this subject based on the ideXlab platform.
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sliding wear characteristics of molybdenum containing stellite 12 coating at elevated temperatures
Tribology International, 2015Co-Authors: Amir Motallebzadeh, Erdem Atar, Huseyin CimenogluAbstract:Abstract The addition of 10 wt% Mo encouraged a eutectic reaction to form Co 6 Mo 6 C complex carbide and Co 3 Mo intermetallic in addition to Cr 23 C 6 while causing solid solution hardening of the Co-rich dendritic matrix in the microstructure of the PTA deposited Stellite 12 coating. The addition of molybdenum not only imposed a higher hardness but also enhanced wear resistance. Under oxidation dominated wear conditions (500 and 700 °C), the addition of molybdenum provided a remarkable increase in wear resistance in comparison to the lower temperatures (RT and 300 °C), due to the development of a Protective Oxide Film on the worn surface.
Ricardo M. Souto - One of the best experts on this subject based on the ideXlab platform.
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Effect of acidic fluoride solution on the corrosion resistance of ZrTi alloys for dental implant application
Corrosion Science, 2014Co-Authors: Daniel Mareci, G. Bolat, Adrian Cailean, J.j. Santana, Javier Izquierdo, Ricardo M. SoutoAbstract:The electrochemical behaviour of Zr5Ti, Zr25Ti, and Zr45Ti, with and without surface modification were monitored in acidic artificial saliva (pH = 3) containing NaF concentrations 0.2, 0.5, and 1 wt.%, simulating the fluoride concentrations in dental rinses. A passive behaviour for thermally oxidized ZrTi alloys was found using EIS, and XPS data show that the Protective Oxide Film contains both TiO2 and ZrO2, though titanium contents in the outer layer bigger than those in the base alloy result from thermal oxidation. High corrosion resistance to acidic fluoridated environments of ZrTi alloys treated using thermal oxidation in air at 500 C.
