A thermodynamic approach to assess glass-forming ability of bulk metallic glasses

According to the Gibbs free energy difference between liquid and crystal, a thermodynamic glass-forming ability(GFA) parameter related to characteristic temperatures, onset crystallization temperature(Tx) and liquidus temperature(Tl), was proposed for evaluating the GFA of bulk metallic glasses(BMGs). The new parameter defined as ω=Tl(Tl+Tx)/(Tx(Tl−Tx)) has good correlation with the critical section thickness(Zc) of Ca-Mg-Cu BMGs. Being verified by the glasses data, including oxide glasses, which were used to validate the former GFA parameters, ω is one of the most reliable and applicable GFA parameters among Trg (=Tg/Tl), γ(=Tx/(Tl+Tg)), α (=Tx/Tl), δ (=Tx/(Tl−Tg), and so on. Finally, predicting GFA of Cu-Ag-Zr-Ti and Cu-Zr-Ti-Al BMGs using ω was compared with the experimental results.