0000000000345304

AUTHOR

Olivier Calonne

showing 3 related works from this author

Optical modeling of nickel-base alloys oxidized in pressurized water reactor

2012

International audience; The knowledge of the aging process involved in the primary water of pressurized water reactor entails investigating a mixed growth mechanism in the corrosion of nickel-base alloys. A mixed growth induces an anionic inner oxide and a cationic diffusion parallel to a dissolution-precipitation process forms the outer zone. The in situ monitoring of the oxidation kinetics requires the modeling of the oxide layer stratification with the full knowledge of the optical constants related to each component. Here, we report the dielectric constants of the alloys 600 and 690 measured by spectroscopic ellipsometry and fitted to a Drude-Lorentz model. A robust optical stratificati…

Materials sciencePASSIVE FILMSCORROSION BEHAVIOROxidechemistry.chemical_elementDIFFUSE REFLECTION SPECTROSCOPY02 engineering and technologyDielectric01 natural sciencesFocused ion beamCorrosionchemistry.chemical_compoundTHIN-FILMSX-ray photoelectron spectroscopy0103 physical sciencesMaterials ChemistryXPSThin film010302 applied physicsHIGH-TEMPERATURE WATERMetallurgyMetals and AlloysSurfaces and InterfacesOXIDE-FILMS021001 nanoscience & nanotechnologySTAINLESS-STEELSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsNickelchemistryChemical engineeringTransmission electron microscopyHYDROGENATED WATERGROWTH0210 nano-technology
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Early-stage detection of surface stress corrosion cracking at the subgranular level

2014

The strain field at the interface between an alloy and its oxide layer has been mapped using nanopatterned gauges resistant to the environment of the primary nuclear medium. It was found that oxidation has decreased the alloy ductility, thereby enabling some grain boundary opening to be detectable from 1.8 % strain. It is shown that statistics of extreme rare events of hotspots quantify the occurrence of the local opening of intergranular cracks, and thereby the ageing process.

Materials scienceMechanical EngineeringSurface stressAlloyMetallurgytechnology industry and agricultureMetals and AlloysOxideengineering.materialIntergranular corrosionequipment and suppliesCondensed Matter PhysicsCorrosionCrackingchemistry.chemical_compoundchemistryMechanics of MaterialsengineeringGeneral Materials ScienceGrain boundaryDuctilityScripta Materialia
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Strain mapping near a triple junction in strained Ni-based alloy using EBSD and biaxial nanogauges

2011

A key element for analyzing the crack initiation in strained polycrystalline alloys is the local quantification of the surface strain distribution according to the grain texture. Using electron backscattered diffraction, the local microstructure was determined to both localize a triple junction and deduce the local Schmid factors. Kernel average misorientation (KAM) was also used to map the areas of defect concentration. The maximum principal strain and the in-plane shear strain were quantified using the biaxial nanogauge. Distortions of the array of nanodots used as spot markers were analyzed near the triple junction. The crystallographic orientation and the surface strain were then invest…

Materials sciencePolymers and PlasticsStrain (chemistry)Triple junctionMetals and AlloysElectronic Optical and Magnetic MaterialsCrystallographyCeramics and CompositesShear stressGrain boundaryTexture (crystalline)CrystalliteDeformation (engineering)Composite materialElectron backscatter diffractionActa Materialia
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