Activation volume and the role of solute atoms in Al-Mg-Si alloy processed by equal channel angular extrusion

Autor: Amel Soula, Jean Philippe Couzinié, Hanen Heni, Julie Bourgon, Yannick Champion, Nabil Njah
Přispěvatelé: Faculté des Sciences de Sfax, Université de Sfax - University of Sfax, Institut de Chimie et des Matériaux Paris-Est (ICMPE), Institut de Chimie du CNRS (INC)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Science et Ingénierie des Matériaux et Procédés (SIMaP), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Journal of Alloys and Compounds
Journal of Alloys and Compounds, Elsevier, 2021, 899, pp.163334. ⟨10.1016/j.jallcom.2021.163334⟩
ISSN: 0925-8388
DOI: 10.1016/j.jallcom.2021.163334⟩
Popis: International audience; Grain refinement to the sub-micron scale was found to enhance both strength and plasticity. In this size range, the micro-mechanisms of deformation are not yet sufficiently specified. In the present work, strain rate sensitivity was investigated in an Al-Mg-Si alloy processed by equal-channel angular extrusion. The microstructure was controlled by conventional transmission electron microscopy and orientation imaging-ASTAR. In the as-quenched state, deformation produces grains below 100 nm in size. The activation volume V was reduced to 70b 3. Based on published theoretical models, we have shown that in such alloy, pure grain boundary sliding cannot be revealed in the low-stress range, due to the intervention of solute atoms. Beyond, the stressdependence of V consists with an inverse Cottrell-Stokes behavior. This trend was confirmed by TEM which revealed dislocation activity and grain boundary emission. Ageing at 150 °C increases the contribution of GBS whereas the residual activation volume continues to be leveled.
Databáze: OpenAIRE
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