Plastic Deformation Mechanism of Ductile Fe50Ni30P13C7 Metallic Glass

Shear band (SB) multiplication is considered as an essential characteristic of the plastic deformation in metallic glasses (MGs). In this work, the evolutionary characteristics of SBs and serrated behavior in ductile Fe50Ni30P13C7 MGs were studied by the finite element method simulation. The study demonstrated that the stress field would redistribute and become inhomogeneous during SB sliding, where the stress perpendicular to the original SB gradually accumulates until reaching the magnitude of yielding strength and triggering new SBs. The results of simulation are in good agreement with the SBs intersection morphologies observed in SEM images and the serration flows on the stress–strain curves. Furthermore, several factors affecting stress field distribution in MGs, such as contact friction, aspect ratio, and boundary confinement, were also analyzed and discussed. The overall results indicate that the ductility of Fe-based MGs could be achieved without any inhomogeneous structure, and scientifically explicate the dependence of SB multiplication on both material properties and loading condition, which can provide us with a deeper understanding on plastic deformation mechanism of MGs.