Multiscale Simulation of Wedge Nanoindentation Based on the Repulsive Force-field Approach

摘要

A new method is proposed to perform the multiscale simulation of nanoindentation with wedge indenter. We designed a potential field to model the wedge indenter based on the repulsive force-field approach which was used to model round indenters. A smooth curve representing the indenter tip is used to avoid the singularity of an ideal wedge indenter. Simulation with our approach correctly shows essential features of wedge nanoindentation. The load responses during retraction is confirmed by elastic model based on the Oliver-Pharr approach. Significant indentation size effect that the contact hardness decreases with the increase of contact depth is compared with existing models. The atomic configurations of the film shows that perfect dislocations nucleate under the indenter with Burges vectors perpendicular to the indentation direction. The strain distribution under the indenter shows that the length of plastic zone in the indentation direction is much larger than the contact width.