Intrinsic correlation between elastic modulus and atomic bond stiffness in metallic glasses

•Atomic bonds are regarded as the components in MGs instead of atoms.•A new rule of mixture was used to explain the inheritance of elastic modulus.•Bonds between different elements have remarkable contribution to the elastic modulus.

ZrxCu100−x (x=15–70) metallic glass (MG) models were constructed by molecular dynamics simulations to explore the intrinsic correlation between elastic modulus and atomic bond stiffness in MGs. The elastic modulus and atomic mole fraction of MGs approximately behave parabolically, and their maxima location shifts to lower Zr mole fraction. This phenomenon is due to the variation of their atomic bond percentages, which suggests that elastic modulus reflects the inherent stiffness of atomic bonds. The “rule of mixture”, which uses atomic bonds as the components, is more applicable than that in which atoms are used as the components to explain the inheritance of elastic modulus.