Plastic flow and failure in metallic glass/nanocrystal composites

The exploitation of metallic glasses' high strength in structural applications is limited by their lack of any hardening subsequent to yield. This lack of hardening leads to plastic localization as evidenced by the spontaneous formation of shear bands. One proposed method of forestalling such instabilities is to introduce nanocrystal inclusions to disrupt shear band nucleation and propagation. We have undertaken a series of molecular dynamics simulations of glasses with different morphologies of nanocrystallites. We report the resulting plastic response, and we use various simulations of these types to test the applicability of the shear transformation zone (STZ) constitutive relation for modeling such complex nano-composite materials.