Dresden 2014 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 20: Topical Session: Nanomechanics of nanostructured materials and systems IV - Tribology/Composites

MM 20.1: Topical Talk

Tuesday, April 1, 2014, 10:15–10:45, IFW A

Nanometer-scale plasticity of (amorphous) metallic surfaces — •Arnaud Caron, Johannes Maurer, and Roland Bennewitz — INM Leibniz-Institute for New Materials, Camnpus D2.2, 66123 Saarbrücken, Germany

The sub-micrometer-scale plastic deformation of Pt(111) and Pt57.5Cu14.7Ni5.3P22.5 metallic glass is discrete in nature and can be rationalized by the respective mechanisms for plastic deformation: burst-like activation and sliding of dislocation for crystalline metals and localized shear banding for metallic glasses. The discrete character of plastic deformation is conserved at the nm-scale for Pt(111). In contrast we observe a homogeneous flow in the case of Pt57.5Cu14.7Ni5.3P22.5 metallic glass at the nm-scale. On the one hand, the nm-scale plastic deformation of Pt(111) is mediated by the homogeneous nucleation and gliding of single dislocations. On the other hand, the nm-scale plastic deformation of Pt57.5Cu14.7Ni5.3P22.5 metallic glass involves the collaborative flow of structural unit, such as in the flow of viscous liquids and can be referred to as a structural collapse. Likewise, the nm-scale wear behaviour of Pt(111) occurs by dislocation-mediated homogeneous plastic deformation. In contrast, the wear of Pt57.5Cu14.7Ni5.3P22.5 metallic glass occurs through localized plastic deformation in shear bands that merge together in a single shear zone above a critical load and corresponds to the shear softening of metallic glasses.