Documents disponibles écrits par cet auteur

Microband evolution during large plastic strains of stable {1 1 0}〈1 1 2〉 Al and Al–Mn crystals / A. Albou in Acta materialia, Vol. 58 N° 8 (Mai 2010) 

Public ISBD [article]  in Acta materialia > Vol. 58 N° 8 (Mai 2010) . - pp. 3022–3034 Titre : Microband evolution during large plastic strains of stable {1 1 0}〈1 1 2〉 Al and Al–Mn crystals Type de document : texte imprimé Auteurs : A. Albou, Auteur ; J.H. Driver, Auteur ; C. Maurice, Auteur Année de publication : 2011 Article en page(s) : pp. 3022–3034 Note générale : Métallurgie Langues : Anglais (eng) Mots-clés : Microstructure  Microbands  Disorientation  EBSD  Aluminium Résumé : The deformation microstructures of Al and Al–Mn {1 1 0}〈1 1 2〉 single crystals have been characterized after room temperature channel-die compression up to true strains of 2.1. The evolution of local misorientations and microband structures were quantified by high-resolution electron backscatter diffraction in a field emission gun scanning electron microscope and their alignments compared with the traces of active slip planes and macroscopic shear stress planes. During plane-strain compression these “Brass” oriented crystals remain stable in terms of the final, average, orientation, with a small orientation spread. However, the microband alignment varies with strain and also with solute content. There is a general tendency for the microbands to be both crystallographic and non-crystallographic at low strains, then crystallographic, and finally mixed again at high strains (with some lamellar banding). DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645410000480 [article] Microband evolution during large plastic strains of stable {1 1 0}〈1 1 2〉 Al and Al–Mn crystals [texte imprimé] / A. Albou, Auteur ; J.H. Driver, Auteur ; C. Maurice, Auteur . - 2011 . - pp. 3022–3034. Métallurgie Langues : Anglais (eng) in Acta materialia > Vol. 58 N° 8 (Mai 2010) . - pp. 3022–3034 Mots-clés : Microstructure  Microbands  Disorientation  EBSD  Aluminium Résumé : The deformation microstructures of Al and Al–Mn {1 1 0}〈1 1 2〉 single crystals have been characterized after room temperature channel-die compression up to true strains of 2.1. The evolution of local misorientations and microband structures were quantified by high-resolution electron backscatter diffraction in a field emission gun scanning electron microscope and their alignments compared with the traces of active slip planes and macroscopic shear stress planes. During plane-strain compression these “Brass” oriented crystals remain stable in terms of the final, average, orientation, with a small orientation spread. However, the microband alignment varies with strain and also with solute content. There is a general tendency for the microbands to be both crystallographic and non-crystallographic at low strains, then crystallographic, and finally mixed again at high strains (with some lamellar banding). DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645410000480

Microstructure and microtexture evolution during strain path changes of an initially stable Cu single crystal / H. Paul in Acta materialia, Vol. 58 N° 8 (Mai 2010) 

Public ISBD [article]  in Acta materialia > Vol. 58 N° 8 (Mai 2010) . - pp. 2799–2813 Titre : Microstructure and microtexture evolution during strain path changes of an initially stable Cu single crystal Type de document : texte imprimé Auteurs : H. Paul, Auteur ; C. Maurice, Auteur ; J.H. Driver, Auteur Année de publication : 2011 Article en page(s) : pp. 2799–2813 Note générale : Métallurgie Langues : Anglais (eng) Mots-clés : Shear  bands  Changing  strain  path  Orientation  mapping  Texture  Copper Résumé : The microstructure and microtexture evolution in a deformed Goss oriented crystal were characterized after a sample rotation and consequent change in strain path, over a range of scales by optical microscopy, high resolution scanning electron microscopy equipped with field emission gun and electron packscattered diffraction facilities and transmission electron microscopy orientation mapping. High purity copper single crystals with initial Goss{1 1 0}〈0 0 1〉 orientation were channel-die compressed 59% to develop a homogeneous structure composed of two sets of symmetrical primary microbands. New samples with ND rotated orientations of Goss{1 1 0}〈0 0 1〉, brass{1 1 0}〈1 1 2〉, M{1 1 0}〈1 1 1〉 and H{1 1 0}〈0 0 1〉, were then cut out and further compressed in channel-die by a few per cent. The change in flow stress could be correlated with the change in dislocation substructure and microtexture, particularly along shear bands initiated by the strain path change. In the H{1 1 0}〈0 1 1〉 and M{1 1 0}〈1 1 1〉 orientations, the flow stress increased by Taylor factor hardening then decreased by intense macroscopic shear band (MSB) formation. In the softer brass orientation and in the absence of Taylor factor hardening, more diffuse MSB formation occurred. The local rotations in the band were used to deduce the possible local slip systems initiated during the strain path change. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645410000030 [article] Microstructure and microtexture evolution during strain path changes of an initially stable Cu single crystal [texte imprimé] / H. Paul, Auteur ; C. Maurice, Auteur ; J.H. Driver, Auteur . - 2011 . - pp. 2799–2813. Métallurgie Langues : Anglais (eng) in Acta materialia > Vol. 58 N° 8 (Mai 2010) . - pp. 2799–2813 Mots-clés : Shear  bands  Changing  strain  path  Orientation  mapping  Texture  Copper Résumé : The microstructure and microtexture evolution in a deformed Goss oriented crystal were characterized after a sample rotation and consequent change in strain path, over a range of scales by optical microscopy, high resolution scanning electron microscopy equipped with field emission gun and electron packscattered diffraction facilities and transmission electron microscopy orientation mapping. High purity copper single crystals with initial Goss{1 1 0}〈0 0 1〉 orientation were channel-die compressed 59% to develop a homogeneous structure composed of two sets of symmetrical primary microbands. New samples with ND rotated orientations of Goss{1 1 0}〈0 0 1〉, brass{1 1 0}〈1 1 2〉, M{1 1 0}〈1 1 1〉 and H{1 1 0}〈0 0 1〉, were then cut out and further compressed in channel-die by a few per cent. The change in flow stress could be correlated with the change in dislocation substructure and microtexture, particularly along shear bands initiated by the strain path change. In the H{1 1 0}〈0 1 1〉 and M{1 1 0}〈1 1 1〉 orientations, the flow stress increased by Taylor factor hardening then decreased by intense macroscopic shear band (MSB) formation. In the softer brass orientation and in the absence of Taylor factor hardening, more diffuse MSB formation occurred. The local rotations in the band were used to deduce the possible local slip systems initiated during the strain path change. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645410000030

Microtexture tracking in hot-deformed polycrystalline aluminium / R. Quey in Acta materialia, Vol. 58 N° 6 (Avril 2010) 

Public ISBD [article]  in Acta materialia > Vol. 58 N° 6 (Avril 2010) . - pp. 2271–2281 Titre : Microtexture tracking in hot-deformed polycrystalline aluminium : Comparison with simulations Type de document : texte imprimé Auteurs : R. Quey, Auteur ; D. Piot, Auteur ; J.H. Driver, Auteur Année de publication : 2011 Article en page(s) : pp. 2271–2281 Note générale : Métallurgie Langues : Anglais (eng) Mots-clés : Microstructure  Plastic  deformation  Modelling  Electron  backscattering  diffraction  (EBSD)  Aluminium  alloys Résumé : The average rotations of 157 individual grains measured in an Al–0.1%Mn polycrystal deformed in hot plane-strain compression to a strain of 1.2 have been compared to the predictions from several crystal plasticity models. The Taylor model successfully predicts the distributions of the rotation angles, but overestimates the rate of evolution of the rotation axes, which explains the overestimation of the final texture. The model also provides a first-order agreement for the rotation axes and the final components of the individual grains. The discrepancies are related to the influence of grain interaction. The main mechanisms of texture development at the level of the individual grains are identified through an analysis of their orientation trajectories. The introduction of local grain interactions, which produce a rotation variability at constant orientation, is shown to weaken texture development. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645409008568 [article] Microtexture tracking in hot-deformed polycrystalline aluminium : Comparison with simulations [texte imprimé] / R. Quey, Auteur ; D. Piot, Auteur ; J.H. Driver, Auteur . - 2011 . - pp. 2271–2281. Métallurgie Langues : Anglais (eng) in Acta materialia > Vol. 58 N° 6 (Avril 2010) . - pp. 2271–2281 Mots-clés : Microstructure  Plastic  deformation  Modelling  Electron  backscattering  diffraction  (EBSD)  Aluminium  alloys Résumé : The average rotations of 157 individual grains measured in an Al–0.1%Mn polycrystal deformed in hot plane-strain compression to a strain of 1.2 have been compared to the predictions from several crystal plasticity models. The Taylor model successfully predicts the distributions of the rotation angles, but overestimates the rate of evolution of the rotation axes, which explains the overestimation of the final texture. The model also provides a first-order agreement for the rotation axes and the final components of the individual grains. The discrepancies are related to the influence of grain interaction. The main mechanisms of texture development at the level of the individual grains are identified through an analysis of their orientation trajectories. The introduction of local grain interactions, which produce a rotation variability at constant orientation, is shown to weaken texture development. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645409008568

Microtexture tracking in hot-deformed polycrystalline aluminium / R. Quey in Acta materialia, Vol. 58 N° 5 (Mars 2010) 

Public ISBD [article]  in Acta materialia > Vol. 58 N° 5 (Mars 2010) . - pp. 1629–1642 Titre : Microtexture tracking in hot-deformed polycrystalline aluminium : Experimental results Type de document : texte imprimé Auteurs : R. Quey, Auteur ; D. Piot, Auteur ; J.H. Driver, Auteur Année de publication : 2011 Article en page(s) : pp. 1629–1642 Note générale : Métallurgie Langues : Anglais (eng) Mots-clés : Microstructure  Plastic  deformation  Deformation  structure  Electron  backscattering  diffraction  (EBSD)  Aluminium  alloys Résumé : A split sample of Al–0.1%Mn has been deformed by a series of compression tests in a channel-die at 400 °C to a final strain of 1.6. The orientations of 176 grains in a View the MathML source internal surface were followed by high-resolution electron backscatter diffraction at four different strains to compare with crystal plasticity models. Typically 3000 orientations per grain were used to quantify the average lattice rotations of each grain together with their orientation spreads (termed microtexture tracking). The average orientations tend towards the standard β-fibre plane-strain compression texture components, albeit with some variations. The in-grain orientation spreads develop strongly at first, then tend to saturate at high strains. Finally, the influence of grain environment on lattice rotation is examined by means of the rotation “variability at constant orientation”. On average and at the beginning of the deformation, two grains of the same initial orientation, but different neighbours, would rotate by angles that vary by 25% and axes separated by 37°; their orientations at ε=1.2 would vary by 12°. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645409007824 [article] Microtexture tracking in hot-deformed polycrystalline aluminium : Experimental results [texte imprimé] / R. Quey, Auteur ; D. Piot, Auteur ; J.H. Driver, Auteur . - 2011 . - pp. 1629–1642. Métallurgie Langues : Anglais (eng) in Acta materialia > Vol. 58 N° 5 (Mars 2010) . - pp. 1629–1642 Mots-clés : Microstructure  Plastic  deformation  Deformation  structure  Electron  backscattering  diffraction  (EBSD)  Aluminium  alloys Résumé : A split sample of Al–0.1%Mn has been deformed by a series of compression tests in a channel-die at 400 °C to a final strain of 1.6. The orientations of 176 grains in a View the MathML source internal surface were followed by high-resolution electron backscatter diffraction at four different strains to compare with crystal plasticity models. Typically 3000 orientations per grain were used to quantify the average lattice rotations of each grain together with their orientation spreads (termed microtexture tracking). The average orientations tend towards the standard β-fibre plane-strain compression texture components, albeit with some variations. The in-grain orientation spreads develop strongly at first, then tend to saturate at high strains. Finally, the influence of grain environment on lattice rotation is examined by means of the rotation “variability at constant orientation”. On average and at the beginning of the deformation, two grains of the same initial orientation, but different neighbours, would rotate by angles that vary by 25% and axes separated by 37°; their orientations at ε=1.2 would vary by 12°. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645409007824