Journal Article

PreJuSER-10980

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Plastic deformation mechanism in complex solids

Heggen, M.FZJ* ; Houben, L.FZJ* ; Feuerbacher, M.FZJ*

2010
Nature Publishing Group Basingstoke

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Please use a persistent id in citations: doi:10.1038/nmat2713

Abstract: In simple crystalline materials, plastic deformation mostly takes place by the movement of dislocations. Although the underlying mechanisms in these materials are well explored, in complex metallic alloys--crystalline solids containing up to thousands of atoms per unit cell--the defects and deformation mechanisms remain essentially unknown. Owing to the large lattice parameters of these materials, extended dislocation concepts are required. We investigated a typical complex metallic alloy with 156 atoms per unit cell using atomic-resolution aberration-corrected transmission electron microscopy. We found a highly complex deformation mechanism, based on the movement of a dislocation core mediating strain and separate escort defects. On deformation, the escort defects move along with the dislocation core and locally transform the material structure for the latter. This mechanism implies the coordinated movement of hundreds of atoms per elementary glide step, and nevertheless can be described by simple rearrangement of basic structural subunits.

Keyword(s): J

Note: We thank C. Thomas and M. Schmidt for producing the materials and J. Barthel for carrying out the HAADF-STEM image simulation. This work was supported by the 6th Framework EU Network of Excellence 'Complex Metallic Alloys' (Contract No. NMP3-CT-2005-500140) and the Deutsche Forschungsgemeinschaft, (PAK 36).

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Contributing Institute(s):

1. Mikrostrukturforschung (IFF-8)

Research Program(s):

1. Grundlagen für zukünftige Informationstechnologien (P42)

Appears in the scientific report 2010

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