Dislocation emission at the onset of plasticity during nanoindentation in gold

Esther Carrasco (1) , Oscar Rodríguez de La Fuente (1) , Juan M. Rojo (1)

1 Física de Materiales

Nanoindentations and the subsequent plastic damage in the form of dislocation configurations have been both generated and imaged with Scanning Tunnelling Microscopy (STM) on a reconstructed Au(001) surface, the resulting observations being interpreted in terms of the elastic theory of dislocations in a continuum. The rearranged pileup material around the nanoindentation is described in terms of dislocation emission and glide involving, in particular, multiple cross-slip. ‘Mesas', shallow protrusions stemming from a special dislocation configuration consisting of Shockley partial dislocations encompassing two stacking faults, are shown to glide parallel to the surface under the stress generated by further nanoindentations. The spatial distribution of ‘mesas' around the nanoindentation traces is shown to be controlled by a balance between the interactions between the different ‘mesas' and the stresses arising from the nanoindentation itself.

Mots clés: Physical Sciences

Esther Carrasco, Oscar Rodríguez de La Fuente, Juan M. Rojo. Dislocation emission at the onset of plasticity during nanoindentation in gold. Philosophical Magazine, 2008, 88 (03), pp.281-296. ⟨10.1080/14786430701798951⟩. ⟨hal-00513848⟩