The ductility and toughness improvement in metallic glass through the dual effects of graphene interface

Bulk metallic glasses own unique mechanical properties such as high strength and excellent elastic behavior due to their amorphous atomic structure. Nonetheless, they usually fail catastrophically by shear localization without showing any macroscale plastic deformation under tension and therefore are notoriously brittle. In this study, graphene was proposed as an effective reinforcement to improve the ductility and toughness of metallic glass for possessing a unique combination of strong in-plane strength and weak interbonding with the metal matrix based on molecular dynamics simulations. Both continuous and discontinuous graphene sheets with various configurations and lengths were taken into account. It was found that with proper dispersion of the graphene reinforcements, more than 100% increase in the ductility and more than 150% increase in the toughness can be achieved in the nanocomposites as compared to the monolithic metallic glass of similar size, which was enabled by spreading and delocalizing the plastic shearing deformation in the nanocomposites because of the dual effects of the added graphene.