Physical aging effects on the dynamic relaxation behavior and mechanical properties of Cu₄₆Zr₄₆Al₈ metallic glass

Mechanical relaxation of glassy materials is strongly influenced by their mechanical and physical properties. In the current study, dynamic mechanical relaxation of Cu₄₆Zr₄₆Al₈ metallic glass has been investigated by mechanical spectroscopy and molecular dynamics simulations. Our results show that mechanical properties of metallic glasses are highly dependent on their thermal history. α relaxation in the frequency region of the Cu₄₆Zr₄₆Al₈ metallic glass was described by Havriliak-Negami (HN) model. In the framework of the quasi-point defects theory, the correlated factor χ could be used to characterize the concentration of “defects” of glassy materials. By molecular dynamics simulations of dynamic mechanical tests at different temperatures and frequencies, it is noted that adjusting of defects is inversely correlated to storage modulus at the atomic level. On the other hand, physical aging below the glass transition temperature T_g reduces the concentration of defects and narrows down the width of shear bands, which corresponds to decreasing of the atomic mobility.