General Conclusions and Outlook

Abstract

Within this thesis, we introduced a novel approach called artificial microstructures to determine microstructure–property relationships in complex materials. The biggest advantage of this technique over other conventional methods is the systematic data analysis and quantification of results, where we determine the effect of each feature on mechanical properties through completely independent feature variation. We utilized this approach to address two important problems in metallic glasses (MGs). The first problem was to understand the behavior of MGs in hexagonal cellular structures. Here, we found that the deformation can be controlled and manipulated by changing the relative density. As a consequence, three major deformation regions are discovered: collective buckling showing nonlinear elasticity, localized failure exhibiting a brittle-like deformation, and global sudden failure with negligible plasticity. The ideal density for optimal mechanical properties was determined to be ~ 25.0 %, which is within the local failure deformation regime. Enhancement in mechanical properties in MG cellular structures was achieved by stress optimization through corner-fillets, which doubled the strength at the expense of 0.2 % density increase. Besides, energy absorption of MG cellular structures exceeds cellular structures of most other materials due to the utilization of a size effect.