linkedintwitter
Annuaire  |  Flux RSS  |  Espace presse  |  Wiki IJL  |  Webmail  |  Videos  |    Photos   Articles scientifiques  Articles scientifiques 

Publications: Articles

Annees:  
Toutes :: 2007, ... , 2010, 2011, 2012, ... , 2014
Auteurs:  
Tous :: A, B, C, D, E, F, G, H, I, J, K, L, M, N, P, R, S, T, V, W, X, Y, Z 
Tous :: da Costa Teixeira, ... , Delfosse, Denand, Denis, ... , Drillett 
Preferences: 
References par page: Mots clefs Voir les resumes
References

Articles:

Appolaire, Benoit, Perevoshchikova, Nataliya, Teixeira, Julien and Denis, Sabine
Solid State Phenomena, 172-174(Part 1):1214-1219
2011
ISSN: 1012-0394

Resume: We have adapted the Quickhull algorithm with the general dimension Beneath-Beyond algorithm [6] for computing the convex hull of the Gibbs energy hypersurface of multicomponent two-phase alloys. We illustrate the salient features of our method with calculations of isothermal ferrite-austenite equilibria in Fe-C-Cr. Finally, successive equilibrium calculations in a Fe-C-Cr-Mo steel over a large temperature range show the benefit of computing the convex hull before performing the conventional Newton-Raphson search.

Equipe: Département SI2M : Microstructures et Contraintes

Dehmas, M., Kovac, J., Aeby-Gautier, E., Appolaire, B., Denand, B. and Da-Costa-Teixeira, J.
Solid State Phenomena, 172-174:396-401
2011

Equipe: Département SI2M : Microstructures et Contraintes

Daoudi, M., Triki, A. and Redjaïmia, A.
Journal of Thermal Analysis and Calorimetry, 104 (2):627-633
2011

Equipe: Département SI2M : Microstructures et Contraintes

Hell, Jean-Christophe, Dehmas, Moukrane, Allain, Sebastien, Prado, Juscelino Mendes, Hazotte, Alain and Chateau, Jean-Philippe
ISIJ International, 51(10):1724-1732
2011
ISSN: 0915-1559

Resume: We elaborated two carbide-free bainitic steels with different microstructures through specific alloy design and austempering process. Microstructural characterizations were performed by means of EBSD analysis and in-situ high energy synchrotron diffraction in order to evaluate the phase fractions and the carbon content in the retained austenite, as well as the microtextures. These microstructural features were correlated to the tensile properties. Both steels exhibited an excellent compromise between high strength (above 1 250 MPa), good ductility (uniform elongation up to 14%) and high fracture strain (reduction of area up to 46%). The volume fraction of MA blocks (blocks of retained austenite partially transformed into fresh martensite during the final cooling at room temperature) was a key relevant parameter that strongly influenced the work-hardening at the expense of the damaging processes at high strain.

Equipe: Département SI2M : Microstructures et Contraintes

Borgese, L., Bontempi, E., Gelfi, M., Depero, L. E., Goudeau, P., Geandier, G. and Thiaudière, D.
Acta Materialia, 59(7):2891-2900
2011
ISSN: 1359-6454

Resume: Amorphous TiO2 thin films were deposited by means of atomic layer deposition on Kapton substrates and then crystallized ex situ by annealing at 300 degrees C to obtain the anatase phase. The morphology, structure and microstructure of films treated for 12, 24, 72 and 90 h were investigated. The local Ti coordination changes were studied by X-ray near-edge structure (XANES). On the basis of X-ray diffraction residual stress calculations, the elastic anisotropy of the films is experimentally determined for the first time (A*(comp) = 0.07, A*(shear) = 0.03). The film macro-strains increased with the time of treatment, while the micro-strains decreased. This effect may be correlated with the incipient anatase-to-rutile transformation as suggested by the changes observed in the XANES pattern of the film treated for 90 h. However, the contribution of the substrate cannot be excluded. (C) 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Equipe: Département SI2M : Microstructures et Contraintes

Di Napoli, P., Appolaire, B., Aeby-Gautier, E. and Bénéteau, A.
Solid State Phenomena, 172-174:1044-1049
2011

Equipe: Département SI2M : Microstructures et Contraintes

Grigorieva, Raisa, Drillett, Pascal, Mataigne, J. -M. and Redjaïmia, A.
Solid State Phenomena, 172-174(Part 1):784-790
2011
ISSN: 1012-0394

Resume: Nowadays more and more hot stamped steel sheets dedicated for the automotive body-in-white structure are pre-coated to prevent the steel surface against iron oxidation and decarburization during the austenitization step. For these applications, the coating is deposited by continuous hot-dipping the steel in an Al-Si bath. The Al-Si coating, at the delivery state, contains Al-grains, Al-Fe-Si ternary phases, Al-Fe binary phases. During the austenitization, the Al-Si coating transforms completely by inter-diffusion and solidification reactions. The mechanisms of Al-Fe-Si phase transformations at high temperature are almost unknown. The phase transformations occurring during austenitization define the final coating microstructure responsible for the in use properties of the product like spot welding, painting adherence or corrosion behavior. It is the aim of this paper to propose a new way of understanding the mechanisms of phase transformation in the Al-Si coating during the austenitization step (between 900 and 930 degrees C) before the transfer into the hot-stamping press.

Equipe: Département SI2M : Microstructures et Contraintes

Settefrati, A., Aeby-Gautier, E., Dehmas, M., Geandier, G., Appolaire, B., Audion, S. and Delfosse, J.
Solid State Phenomena, 172-174(Part 1):760-765
2011
ISSN: 1012-0394

Resume: In the present study we focus on the precipitation processes during heating and ageing of beta-metastable phase in the near beta Ti-5553 alloy. Transformation processes have been studied using continuous high energy X-Ray Diffraction (XRD) and electrical resistivity for two different states of the beta-metastable phase. Microstructures have been observed by electron microscopy. Different transformation sequences are highlighted depending on both heating rate and chemical composition of the beta-metastable phase. At low temperatures and low heating rates, the hexagonal omega(iso) phase is first formed as generally mentioned in the literature. Increasing the temperature, XRD evidences the formation of an orthorhombic phase (alpha"), which evolves toward the hexagonal pseudo compact alpha phase. For higher heating rates or for richer composition in beta-stabilizing elements of the beta-metastable phase, omega phase may not form and alpha" forms directly and again transforms into alpha phase. A direct transformation from beta-metastable to alpha phase is observed for the highest heating rate. The formation of the metastable omega(iso) and alpha" phases clearly influences the final morphology of alpha.

Equipe: Département SI2M : Microstructures et Contraintes

Dehmas, Moukrane, Lacaze, Jacques, Niang, Aliou and Viguier, Bernard
Advances in Materials Science and Engineering, 2011:9
2011
ISSN: 1687-6822

Resume: Inconel 718 is widely used because of its ability to retain strength at up to 650 degrees C for long periods of time through coherent metastable gamma `' Ni(3)Nb precipitation associated with a smaller volume fraction of gamma' Ni(3)Al precipitates. At very long ageing times at service temperature, gamma `' decomposes to the stable Ni(3)Nb delta phase. This latter phase is also present above the gamma `' solvus and is used for grain control during forging of alloy 718. While most works available on delta precipitation have been performed at temperatures below the gamma `' solvus, it appeared of interest to also investigate the case where delta phase precipitates directly fromthe fccmatrix free of gamma `' precipitates. This was studied by X-ray diffraction and transmission electron microscopy (TEM). TEM observations confirmed the presence of rotation-ordered domains in delta plates, and some unexpected contrast could be explained by double diffraction due to overlapping phases.

Equipe: Département SI2M : Microstructures et Contraintes

Mourot, Mickael, Courleux, Alice, Dehmas, Moukrane, Gautier, Elisabeth, Geandier, Guillaume, Dezellus, Olivier, Claude Viala, Jean, Martin, Olivier, Karnatak, Nikhil and Danoix, Frederic
Solid State Phenomena, 172-174:747-752
2011

Equipe: Département SI2M : Microstructures et Contraintes

Cette annee / Total:
10 / 41
Exporter au format:
BibTeX, XML