Dresden 2011 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 10: Computational Materials Modelling III
MM 10.5: Vortrag
Montag, 14. März 2011, 16:45–17:00, IFW B
Plasticity of Cu and Pd nanoparticles in nanoextrusion — •Antti Tolvanen1,2 and Karsten Albe1 — 1Institute of Materials Science, Darmstadt University of Technology, Germany — 2Department of Physics, University of Helsinki, Finland
Recent transmission electron microscopy experiments have shown how nanoparticles can be encapsulated inside carbon onions and electron irradiation induced contraction of these onions can be used to apply pressure of tens of GPa to the encapsulated particle [1]. If an orifice is opened to the carbon onion, this system can be used to study the extrusion of the encapsulated material through this orifice. Therefore studying the extrusion of metallic nanoparticles from such nanocontainers provides information on the plasticity of individual nanograins. In this study, the results of molecular dynamics simulation of the extrusion of Cu and Pd nanoparticles pressurised in spherical force field mimicking the behaviour of contracting carbon onion are presented. We compare the plastic behavior single-crystalline nanoparticles of Cu and Pd with multiply-twinned nanoparticles. The effects of the low and high stacking fault energies of Cu and Pd, correspondingly, and the effect of twins on the dislocation nucleation and propagation is reported for both metals.
[1] L. T. Sun et al, Phys. Rev. Lett. 101, 156101 (2008)