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Abstract In metallic glasses (MGs), shear bands are easy to appear at low temperatures and high stress levels, which lead to the structural damage and greatly limit the structural reliability of MGs. In this paper, the formation and evolution of shear bands and their mechanical properties of three kinds of Cu64Zr36 MG plates (without notch, one notch on one side and two notches on both sides) during tensile test are studied by molecular dynamics (MD) simulations. The results show that the non-notched MG sample spontaneously appears local shear transformation zones (STZs) and shear localization during tensile test. As tensile continues, a shear band forms along approximately 45° with the loading axis in the MG sample. The formation of shear band is related to the distribution and localization of STZs. Strain localization of notched samples occurs earlier than that of the non-notched one, that is, the shear band forms at lower tensile strain, and the tensile strength is also correspondingly lower. Under the same conditions, the tensile strength of sample with one notch on one side is almost the same as that of the sample with two notches on both sides. However, the degree of strain localization of the sample with two notches on both sides is slightly lower, largely because the STZs occur at the both side edges of two notches, leading to the unconcentrated distribution and localization, which is also the main reason for the formations of the main shear band and the secondary shear band. The results provide important information for further understanding the formation and evolution of shear bands in MGs from an atomistic perspective.
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Received: 29 November 2019
Published: 12 June 2020
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2020, Vol. 41 
