The correlation between weakest configurations and yield strength of Zr-based metallic glasses

A direct relationship between the yield strength and the atomic ratio of solvent (Zr) atoms in the Zr-Cu-Al-Ni metallic glasses system is firstly uncovered. It is found that either shear modulus or yield strength decreases almost nearly with the increase in atomic ratio of Zr. The origin of this relationship is ascribed to the preferential straining of the weakest configurations, which consist of the solvent-solvent bonds and the free volume concentrated in them. It is suggested that a higher atomic ratio of Zr corresponds to a larger amount of weakest configurations, which will facilitate the activation and the accumulation of the shear transformations and finally results in the lower yield strength. This finding may provide an effective strategy for designing high-strength metallic glasses by modifying the chemical composition.