Manage local deformation by patterning structural heterogeneity : controlling toughness in honeycomb patterned metallic glass composites

Abstract

Shear band dominated strong strain localization is known for causing brittleness in metallic glasses. By pre-patterning glassy regions with different mechanical properties in the geometry of a honeycomb lattice, we show that the brittleness can be alleviated or even eradicated. The underlying mechanisms in this new design of composite with structural heterogeneity relate to the new microstructure parameters such as the width and the mechanical properties of the patterned regions. The optimal toughness can be achieved through redistributing the heterogeneous structural components such that the local shear is distributed heterogeneously during deformation. This finding points to a new design principle for toughening metallic glass composites that have been synthesized by far in ad hoc fashion by dispersing inclusions randomly.