Analysis of nanoindentation in copper single crystals and related size effect based on experiments, crystal plasticity and dislocation dynamics

by Hyung-Jun Chang ((Mines ParisTech, Centre des matériaux))

Friday 9 Oct 2009, 11:00 → 12:00 Europe/Zurich

TE Auditorium (CERN)

This work deals with experiments and simulations of nanoindentation in copper single crystals. Indentation experiments are performed with different orientations of the indentation axis and both the load-displacement curve and the surface imprint observed by atomic force microscopy are analysed and compared. Simulations are then performed using crystal plasticity finite element modelling. ABAQUS user subroutines are specially developed in order to account for the physics of dislocation activity in the twelve glide systems of copper crystals. 3D simulations are then performed and comparisons with the experiments give access to key parameters of the constitutive equations. A multiscale approach based on discrete dislocation dynamics is used to reproduce (111) indentations of copper single crystals. Molecular dynamics simulations give details of dislocation nucleation beneath the indenter. Dislocation dynamics simulations are then performed and the indentation size effect is addressed. Finally, the indentation size effect is reproduced using a simplified strain gradient theory implanted in the finite element modelling.

Keywords: Nanoindentation, Crystal plasticity, Finite element method (FEM), Dislocation dynamics (DD), Molecular dynamics (MD), Indentation size effect, Multi-scale simulation, ABAQUS, TRIDIS, CASTEM

Paper Chang_long_abstract.pdf

Slides Chang_Slides_Seminar.pdf Chang_Slides_Seminar.ppt