Special nanostructures in Al-Mg alloys subjected to high pressure torsion
Liu, Manping; Roven, Hans Jørgen; Liu, XT; Murashkin, Maxim; Valiev, Ruslan Z.; Ungar, Tamas; Balogh, Lavente
Journal article, Peer reviewed
Accepted version
Date
2010Metadata
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- Institutt for materialteknologi [2549]
- Publikasjoner fra CRIStin - NTNU [38289]
Original version
Transactions of Nonferrous Metals Society of China. 2010, 20 (11), 2051-2056. 10.1016/S1003-6326(09)60416-7Abstract
Deformation twins and stacking faults were observed in nanostructure Al-Mg alloys subjected to high pressure torsion. These observations are surprising because deformation twinnings have never been observed in their coarse-grained counterparts under normal conditions. Experimental evidences are introduced on non-equilibrium grain boundaries, deformation twinnings and partial dislocation emissions from grain boundaries. Some of these features can be explained by the results reported from molecular-dynamics simulations of pure FCC metals. Special emphasis is laid on the recent observations of high density hexagonal and rhombic shaped nanostructures with an average size of 3 nm in the Al-Mg alloys processed by high pressure torsion. A possible formation process of these nanostructures is proposed based on molecular-dynamics simulations.