Micro-pillar testing of amorphous silica

Rémi Lacroix (1) , Vincent Chomienne (1) , G. Kermouche (1) , J. Teisseire (2) , S. Queste (3) , E. Barthel (2)

1 LTDS - Laboratoire de Tribologie et Dynamique des Systèmes
2 SVI - Surface du Verre et Interfaces
3 FEMTO-ST - Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174)

Amorphous silica exhibits a complex mechanical response. The elastic regime is highly non linear while plastic flow does not conserve volume, re- sulting in densification. As a result the quantification of a reliable constitutive equation is a difficult task. We have assessed the potential of micro-pillar compression testing for the investigation of the micromechanical properties of amorphous silica. We have calculated the response of amorphous silica mi- cropillars as predicted by Finite Element Analysis. The results were compared to preliminary micro-compression tests. In the calculations an advanced con- stitutive law including plastic response, densification and strain hardening was used. Special attention was paid to the evaluation of the impact of substrate compliance, pillar misalignment and friction conditions. We find that amor- phous silica is much more amenable than some metals to microcompression experiments due to a comparatively high ratio between yield stress and elastic modulus. The simulations are found to be very consistent with the experimen- tal results. However full agreement cannot be obtained without allowance for the non linear response of amorphous silica in the elastic regime.

Keywords: Pressure dependent elasticity; Micro-pillars; Nanoindentation; Amorphous materials; FEM

Domains: Materials Science [cond-mat.mtrl-sci]

Rémi Lacroix, Vincent Chomienne, G. Kermouche, J. Teisseire, S. Queste, et al.. Micro-pillar testing of amorphous silica. International Journal of Applied Glass Science, 2012, 3 (1), pp.36-43. ⟨10.1111/j.2041-1294.2011.00075.x⟩. ⟨hal-00677258⟩