Multi-scale Discrete Dislocation Plasticity Analysis: Application to Nano-indentation
S.M.A. Khan and L.E. Levine
National Institute of Standards and Technology, US
nanoindentation, multiscale modeling, dislocation dynamics, mechanical properties
With the growing utilization of nano-scale components in various technologies like MEMS, NEMS, thin films, medical diagnostics etc, nano-indentation testing is finding new expanding applications towards quantitative determination of mechanical properties at the nano-scale. In addition, it represents a ‘non-destructive’ testing technique for macro applications since mechanical properties of bulk material can be extracted from nano-indentation testing using appropriate models. Thus accurate models of the nano-indentation process are crucial at various length scales.
In the present study, we develop and incorporate the model for nano-indentation testing into a 3D Multiscale Discrete Dislocation Plasticity (MDDP) model. MDDP couples two length scales: discrete dislocation dynamics and finite element. The study also validates the model and investigates the effect of various numerical parameters and discusses the appropriate model boundary conditions. The second part of the study closely analyzes the dislocation structure evolution during nano-indentation. Since dislocation dynamics tracks the evolving dislocation microstructure, this model provides a tool which incorporates the effect of dislocation microstructure directly into larger length scales.
This study is a part of a larger research project aimed at developing the methodology for extracting quantitative mechanical properties from nano-indentation testing using a combined experiment-modeling (atomistic-to-continuum) approach.
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Nanotech 2006 Conference Program Abstract