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Microstructure evolution of 6061 O Al alloy during ultrasonic consolidation / E. Mariani in Acta materialia, Vol. 58 N° 7 (Avril 2010) 

Public ISBD [article]  in Acta materialia > Vol. 58 N° 7 (Avril 2010) . - 2492–2503 Titre : Microstructure evolution of 6061 O Al alloy during ultrasonic consolidation : An insight from electron backscatter diffraction Type de document : texte imprimé Auteurs : E. Mariani, Auteur ; E. Ghassemieh, Auteur Année de publication : 2011 Article en page(s) : 2492–2503 Note générale : Métallurgie Langues : Anglais (eng) Mots-clés : Electron  backscatter  diffraction  (EBSD)  Ultrasonic  consolidation  (UC)  Recrystallized  microstructure  Continuous  dynamic  recrystallization  (CDRX)  Aluminium  alloys Résumé : 6061 O Al alloy foils were welded to form monolithic and SiC fibre-embedded samples using the ultrasonic consolidation (UC) process. Contact pressures of 135, 155 and 175 MPa were investigated at 20 kHz frequency, 50% of the oscillation amplitude, 34.5 mm s−1 sonotrode velocity and 20 °C. Deformed microstructures were analysed using electron backscatter diffraction (EBSD). At all contact pressures deformation occurs by non-steady state dislocation glide. Dynamic recovery is active in the upper and lower foils. Friction at the welding interface, instantaneous internal temperatures (0.5–0.8 of the melting temperature, Tm), contact pressure and fast strain rates result in transient microstructures and grain size reduction by continuous dynamic recrystallization (CDRX) within the bonding zone. Bonding occurs by local grain boundary migration, which allows diffusion and atom interlocking across the contact between two clean surfaces. Textures weaken with increasing contact pressure due to increased strain hardening and different grain rotation rates. High contact pressures enhance dynamic recovery and CDRX. Deformation around the fibre is intense within 50 μm and extends to 450 μm from it. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645409008830 [article] Microstructure evolution of 6061 O Al alloy during ultrasonic consolidation : An insight from electron backscatter diffraction [texte imprimé] / E. Mariani, Auteur ; E. Ghassemieh, Auteur . - 2011 . - 2492–2503. Métallurgie Langues : Anglais (eng) in Acta materialia > Vol. 58 N° 7 (Avril 2010) . - 2492–2503 Mots-clés : Electron  backscatter  diffraction  (EBSD)  Ultrasonic  consolidation  (UC)  Recrystallized  microstructure  Continuous  dynamic  recrystallization  (CDRX)  Aluminium  alloys Résumé : 6061 O Al alloy foils were welded to form monolithic and SiC fibre-embedded samples using the ultrasonic consolidation (UC) process. Contact pressures of 135, 155 and 175 MPa were investigated at 20 kHz frequency, 50% of the oscillation amplitude, 34.5 mm s−1 sonotrode velocity and 20 °C. Deformed microstructures were analysed using electron backscatter diffraction (EBSD). At all contact pressures deformation occurs by non-steady state dislocation glide. Dynamic recovery is active in the upper and lower foils. Friction at the welding interface, instantaneous internal temperatures (0.5–0.8 of the melting temperature, Tm), contact pressure and fast strain rates result in transient microstructures and grain size reduction by continuous dynamic recrystallization (CDRX) within the bonding zone. Bonding occurs by local grain boundary migration, which allows diffusion and atom interlocking across the contact between two clean surfaces. Textures weaken with increasing contact pressure due to increased strain hardening and different grain rotation rates. High contact pressures enhance dynamic recovery and CDRX. Deformation around the fibre is intense within 50 μm and extends to 450 μm from it. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645409008830