Highly efficient strategy of compositional design for metallic glasses driven by melting entropy

Abstract

Since the introduction of metallic glasses, optimizing their compositional design has been a challenging yet crucial subject, necessitating pioneering design strategies to overcome the low efficiency problem produced by traditional trial-and-error modes. Starting from the glass formation thermodynamics, we have found that melting entropy is a more fundamental and comprehensive quantity to express the glass formation and mixing thermodynamics. This letter formulates a new composition design strategy for Zr-Cu-Ag alloys using the melting entropies in the binary Zr-Cu and Zr-Ag alloys. By combining the eutectic Zr_38.2Cu_61.8 and the intermetallic Zr₂Ag with low melting-entropies in terms of entropy balance, where individual melting entropy is used to determine the weight coefficient of the level rules, we immediately achieve the composition Zr_47.59Cu_41.41Ag₁₁, showing far higher glass forming ability than the reported Zr₅₀Cu₄₀Ag₁₀ and the Zr_51.22Cu_26.05Ag_22.73 designed based on enthalpy of mixing. The extremely high efficiency features the entropy-controlled design strategy for metallic glasses.