Determination of Plastic Properties of Polycrystalline Metallic Materials by Nanoindentation – Experiments and Finite Element Simulations

Bjoern Backes (1) , Karsten Durst (1) , Mathias Goeken (1)

1 Materials Science & Engineering, Institute I

Nanoindentation experiments at low indentation depths are strongly influenced by micromechanical effects like the indentation size effect, the pile-up or sink-in behaviour and the crystal orientation of the investigated material. For an evaluation of load-displacement data and a reconstruction of stress-strain curves from nanoindentations, these micromechanical effects need to be considered. The influence of size effects on the experiments were estimated by comparing the results of finite element simulation and experiments, using uniaxial stress-strain data of the indented material as input for the simulations. The experiments were performed on conventional und ultrafine-grained copper and brass and the influence of the indentation size effect and the pile-up formation is discussed in terms of microstructure. Applying a pile-up correction on Berkovich and cube-corner indentation data, a piecewise reconstruction of stress-strain curves from load-displacement data is possible with Tabor's concept of representative strain. A good approximation of the slope of the stress-strain curve from the indentation experiments is found for all materials down to an indentation depth of 800 nm.

Mots clés: Physical Sciences

Bjoern Backes, Karsten Durst, Mathias Goeken. Determination of Plastic Properties of Polycrystalline Metallic Materials by Nanoindentation – Experiments and Finite Element Simulations. Philosophical Magazine, 2006, 86 (33-35), pp.5541-5551. ⟨10.1080/14786430600735468⟩. ⟨hal-00513702⟩