Effects of nanocrystals on evolution behavior of shear transformation zones in Zr85Cu15 metallic glasses

• Nanocrystals would occupy the preferred sites of shear transformation zones (STZs).
• The occupation effect of nanocrystals alters the path of shear bands fundamentally.
• They activate more STZs and increase the ductility in model with 13.5% nanocrystals.

Structural evolution sites induced by shear stress and annealing were investigated via molecular dynamic simulations using a Zr85Cu15 metallic glass (MG) system. The crystalline phase induced by annealing occupies the preferred sites of shear transformation zones (STZs), forcing STZ formation in other parts of the amorphous matrix through deformation. This process fundamentally alters the path of shear bands in nanocrystal MGs. Meanwhile, more STZs are activated in the rest of the parts of the amorphous matrix when the volume fraction of nanocrystals is 13.5%, significantly enhancing the plasticity of nanocrystal-MGs. Our study may provide novel insights regarding the plastic deformation mechanism of nanocrystal MGs at the atomic scale.