Multiscale simulations of silicon nanoindentation

Nanoindentation experiments are an excellent probe of micromechanical properties, but their interpretation is complicated by the multiple length scales involved. We report simulations of silicon nanoindentation, based on an extended version of the local quasicontinuum model, capable of handling complex crystal structures, This method embeds an interatomic force law within a finite element framework. We identify which features of the simulation are robust by investigating the effect of different interatomic force laws and different finite element meshes. We find that our simulations qualitatively reproduce the experimental load vs. displacement curves of indented silicon and provide information on the microscopic aspects of the phase trans formations that take place during indentation. This information is linked to the macroscopic electrical resistance, providing a simple physical picture that gives a satisfactory explanation of experimental results. (C) 2001 Acta Materialia Ltd. Published by Elsevier Science Ltd. All rights reserved.