3D versus 2D finite element simulation of the effect of surface roughness on nanoindentation of hard coatings

摘要

Indentation with a spherical indenter tip into CrN coatings with an arithmetic surface roughness (Ra) ranging between 2.6 and 11.1 nm modelled with the finite element method. Results are compared for a 2D axisymmetric model (published earlier) and a true 3D model for three different coatings within that roughness range. Both models predict a significant underestimation of the evaluated Young's modulus due to the effect of surface roughness. They give comparable results for Ra <3 nm, but differ considerably for higher roughness values. The axisymmetric setup of the 2D model leads to increased scatter of the load-displacement data and higher stiffness on average compared to the 3D model and therefore a 3D simulation seems preferable. (C) 2009 Elsevier B.V. All rights reserved.