Shear banding in amorphous metals originates from the activation and percolation of flow units.To uncover the self-assembly dynamics of flow units in metallic glasses,a rectangular sample with two flow units embedded ...Shear banding in amorphous metals originates from the activation and percolation of flow units.To uncover the self-assembly dynamics of flow units in metallic glasses,a rectangular sample with two flow units embedded in the matrix undergoing simple shearing was analyzed using finite element simulations.The vortex evolution behavior,including activation,growth,and collapse during the self-assembly of flow units,was revealed.It was found that the formation of a mature vortex indicates the onset of yielding,and the collapse of the vortex represents the percolation of flow units or shear localization.The effects of initial free volume distribution and the distance between flow units on vortex behavior were also studied.Increasing the initial free volume concentration within flow units or the matrix leads to a gentler vortex evolution process and better homogeneous plasticity.The shape of vortex tends to be"flatter"with the increase in flow units'spacing,and the optimal spacing was found to maximize the strength of the material.展开更多
基金supported by the NSFC(Nos.11972346 and 11790292)the NSFCBasic ScienceCenter Program for“Multi-scale Problems in Nonlinear Mechanics”(No.11988102).
文摘Shear banding in amorphous metals originates from the activation and percolation of flow units.To uncover the self-assembly dynamics of flow units in metallic glasses,a rectangular sample with two flow units embedded in the matrix undergoing simple shearing was analyzed using finite element simulations.The vortex evolution behavior,including activation,growth,and collapse during the self-assembly of flow units,was revealed.It was found that the formation of a mature vortex indicates the onset of yielding,and the collapse of the vortex represents the percolation of flow units or shear localization.The effects of initial free volume distribution and the distance between flow units on vortex behavior were also studied.Increasing the initial free volume concentration within flow units or the matrix leads to a gentler vortex evolution process and better homogeneous plasticity.The shape of vortex tends to be"flatter"with the increase in flow units'spacing,and the optimal spacing was found to maximize the strength of the material.
