| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 794105 | Journal of the Mechanics and Physics of Solids | 2006 | 19 Pages |
The indentation hardness–depth relation established by Nix and Gao [1998. Indentation size effects in crystalline materials: a law for strain gradient plasticity. J. Mech. Phys. Solids 46, 411–425] agrees well with the micro-indentation but not nano-indentation hardness data. We establish an analytic model for nano-indentation hardness based on the maximum allowable density of geometrically necessary dislocations. The model gives a simple relation between indentation hardness and depth, which degenerates to Nix and Gao [1998. Indentation size effects in crystalline materials: a law for strain gradient plasticity. J. Mech. Phys. Solids 46, 411–425] for micro-indentation. The model agrees well with both micro- and nano-indentation hardness data of MgO and iridium.
