This work clarifies the origin of anomalous surface deformation reflected by peculiar surface patterns around indentation impressions on various crystallographic planes of sapphire. The three-dimensional finite element simulation (3D-FEM) of nanoindentation in Al2O3 crystal allowed the authors to localize the regions in which various kinds of twinning and slip are most prone to be activated. The work provides a novel approach to the “hardness anisotropy”, which was modeled so far using a modified uniaxial-stress approximation of this essentially 3D, non-isotropic contact problem. The calculated results enabled the authors to unravel the asymmetric surface deformation detected on prismatic planes by the high-resolution microscopy, which cannot be explained using simple crystallographic considerations.
|Journal||JSME International Journal, Series 1: Solid Mechanics, Strength of Materials|
|Publication status||Published - 2003|
|MoE publication type||A1 Journal article-refereed|
- FEM simulation
- anisotropic contact problem
Nowak, R., Manninen, T., Li, C., Heiskanen, K., Hannula, S-P., Lindroos, V., Soga, T., & Yoshida, F. (2003). Anomalous surface deformation of sapphire clarified by 3D-FEM simulation of the nanoindentation. JSME International Journal, Series 1: Solid Mechanics, Strength of Materials, 46(3), 265-271. https://doi.org/10.1299/jsmea.46.265