Dresden 2017 – wissenschaftliches Programm
MM 61: Topical session: Dynamics, relaxation and deformation in deeply supercooled metallic liquids and glasses V - dynamical response
MM 61.3: Vortrag
Donnerstag, 23. März 2017, 12:30–12:45, IFW A
The Effect of Glass Structure, Stress State and Strain Rate on Shear and Densification - A Nanomechanical Study on a Sodium-Boro-Silicate Glass — •Christoffer Zehnder1, Niklas Peltzer1, Doris Möncke2, James Gibson1, and Sandra Korte-Kerzel1 — 1RWTH Aachen University, Germany — 2Alfred University, New York, USA
It is well known that the mechanical properties of glasses are closely related to their atomic structure. The exact structure-property-relationship, however, is only poorly understood even for fundamental mechanisms like shear and densification. Nanomechanical test methods like micropillar compression and nano-impact indentation can help fill this gap. In this study a sodium-boro-silicate glass is quenched from different temperatures to induce changes in the atomic structure. Micropillar compression was used to investigate the effect of uniaxial stresses and nanoindentation with different tip geometries enabled testing under different amounts of hydrostatic pressure. Finally, impact nanoindentation was utilised to observe the effect of high strain rates on the deformation of glass. It is shown that by changing the glass structure or the stress state one can influence the occurrence of shear and densification. Testing with different strain rates also revealed a strong strain rate dependence of the deformation mechanism. These findings are analysed against the background of the glass structure. The experimental techniques and analyses presented could easily be applied also to metallic glasses in order to investigate the effects of rate and stress state on their plastic deformation.