Exploring the Role of Thermodynamic Parameters in Determining Zr–Cu–Al–Ag Glass-Forming Composition

A new glass-forming composition (GFC) has been proposed in the Zr–Cu–Al–Ag system using thermodynamic modelling. Enthalpy of chemical mixing (∆H_chem) and mismatch entropy (∆S_σ/k_B) is used along with configurational entropy (∆S_c/R) to optimize the GFC. In the present work, a novel computational calculation method is introduced on behalf of a graphical approach to accurately determine GFCs using the aforementioned thermodynamic parameters. Systematically quaternary Zr–Cu–Al–Ag system is subdivided into ternary systems to determine P_HS (∆H_chem*∆S_σ/k_B) and P_HSS (P_HS*∆S_c/R) parameters. The P_HSS parameter is critically compared with reported Zr–Cu–Al–Ag BMGs. Based on the computational approach a new composition, Zr₄₇Cu₄₀Al₈Ag₅, is determined which is found to closely match with earlier reported metallic glasses. The role of varying Ag concentration from 1 to 8 at. pct has been analysed to understand the stability in GFCs. A thermodynamic analysis is also endeavoured to further explore the role of binary pairs on ∆H_chem, ∆S_σ/k_B, ∆S_c/R, P_HS, and P_HSS in this work.